St. Helena City Council
May 1, 2023

3.9 – HYDROLOGY AND WATER QUALITY
Hunter Subdivision Project EIR 10839
September 2021 3.9-37
• Runoff control devices (e.g., drainage swales, gravel bag barriers/chevrons, velocity check dams) and slope protection.
• Drainage system inlet protection
• Wind erosion (dust) controls
• Tracking controls
• Prevention of fluid leaks (inspections and drip pans) from vehicles • Dewatering operations best practices
• Materials pollution management
• Proper waste management
• Regular inspections and maintenance of BMPs
The standard requirements contained in a SWPPP are sufficient to address a project’s potential to violate water quality standards or waste discharge requirements. Implementation of SWRCB and San Francisco Bay RWQCB requirements (CWA NPDES Program and Porter–Cologne Water Quality Control Act WDRs) are enforced through the City’s Stormwater and Runoff Pollution Control Ordinance (Chapter 13.32). In addition to stormwater runoff, construction activities can generate fugitive dust, which if not properly controlled, can be deposited in nearby waters. Note that this potential impact is addressed in Section 3.3, Air Quality; actions to mitigate adverse effects on air quality would likewise mitigate potential adverse effects on water quality from atmospheric deposition.

The construction-related impact of the Proposed Project on water quality would be less than significant, because compliance with existing permitting requirements and conditions of approval are sufficient to avoid water quality degradation, meet water quality standards and Basin Plan objectives, and prevent adverse effects on beneficial uses.

Operation
Implementation of the Proposed Project would include the development of impervious surfaces, including roadways and driveways, and structures (dwellings) which would impede water infiltration and contribute to increased water runoff rates. These increased water runoff rates could gather potential pollutants such as heavy metals, nutrients from lawn fertilization, oil/grease and fuels from areas where vehicles are parked, and other household trash and debris. Stormwater runoff would have the potential to pollute nearby surface waters if storm drain infrastructure and buffers would not be used.

Agenda Item #5.4.

3.9 – HYDROLOGY AND WATER QUALITY
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September 2021 3.9-38
Constituents found in urban runoff vary as a result of differences in rainfall intensity and occurrence, geographic features, the land use of a site, as well as vehicle traffic and percent of impervious surface. In the Napa Valley, there is a natural weather pattern of a long dry period generally from May to October. During this seasonal dry period, pollutants contributed by vehicle exhaust, vehicle and tire wear, crankcase drippings, spills, and atmospheric fallout accumulate on roadways, driveways, and parking lots within the urban watershed. Precipitation during the early portion of the wet season (which typically spans from November to April) washes these pollutants into the stormwater runoff, which can result in elevated pollutant concentrations in the initial wet weather runoff (first flush).

The Proposed Project would be subject to the most recent standards and performance criteria contained in the Small MS4 Permit (described in Section 3.9.3, Regulatory Setting). The City is subject to this permit because it makes discharges to the Napa River from its municipal storm drain system. The Small MS4 Permit requires development and redevelopment projects to adhere to the Small MS4 Permit and follow published guidance for compliance. These include the following:
• Site Design Measures: Site design measures requires early assessment and evaluation of how site conditions, such as soils, vegetation, and flow paths will influence the placement of buildings and paved surfaces. The evaluation is used to meet the goals of capturing and treating runoff and maximizing opportunities to mimic natural hydrology.

Options for site design measures include preserving trees, buffering natural water features, and using green roofs or porous pavement.
• Source Control Measures: Source control measures seek to avoid introduction of water quality pollution/degradation altogether. Source control strategies include things like covering refuse/trash areas, properly managing outdoor storage of equipment/materials, minimizing use of pesticides and fertilizers in landscaping, using sumps or special area drains to send non-stormwater discharges to the sewer, ensuring regular grounds maintenance, etc.
• Treatment Control Measures: Treatment control measures retain, treat and/or infiltrate the site runoff produced under normal circumstances, controlling both the quality and quantity of stormwater released to the City’s conveyance system or directly to receiving waters. In most situations, this means implementing structural BMPs (e.g., infiltration, bioretention and/or rainfall harvest and re-use) to treat the volume and rate of runoff produced by 85th percentile storm (i.e., design capture volume). • Operation and Maintenance Requirement: The Small MS4 Permit requires that maintenance agreements stay in place with each property (executed and then recorded with the County Clerk Recorder) to ensure permanent treatment control measures Agenda Item #5.4.

3.9 – HYDROLOGY AND WATER QUALITY
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September 2021 3.9-39
developed on site are properly maintained and/or repaired in accordance with the stormwater quality control plan.

Overall, the Small MS4 Permit requires new development and redevelopment to adopt a lowimpact development strategy, which minimizes hydromodification6 impacts known to have
adverse impacts on receiving waters. The City implements the Small MS4 Permit by requiring developers seeking approval of tentative subdivision maps to comply with MS4 Permit standards and the guidance and criteria in the Bay Area Stormwater Management Agencies Post Construction Manual. Although specific design features have yet to be finalized for the Proposed Project, all of the items above must be included in a Stormwater Control Plan to be submitted to the City as a condition of Proposed Project approval, as described in in the Regulatory Setting section above. The Stormwater Control Plan, to be developed and submitted by the Proposed Project applicant for final Proposed Project approval, must illustrate how the Proposed Project is implementing low-impact development principles and providing for longterm BMP maintenance.

The Proposed Project’s grading plan includes all the elements necessary to demonstrate it can successfully comply with MS4 Permit requirements. Based on the findings in Appendix H, the City’s detention basin is adequately sized to hold the increase in runoff that would be generated by the Proposed Project (further discussed in Impact 3.9-3). It is expected that the detention basin would be used and/or modified, as necessary, to comply with the water quality design capture volume required under the MS4 Permit, the details of which must be included in the Proposed Project’s Stormwater Control Plan. Furthermore, water quality features such as downspouts to landscaped swales; vegetated swales; hydrodynamic oil, water and solid separators; private street sweeping; labeled storm drains (“drains to river”) and homeowner educational materials on stormwater pollution prevention are listed on the grading plan as BMPs to be implemented to prevent storm runoff of poor quality from entering the Napa River or seeping into the underlying groundwater table.

Impacts associated with Proposed Project construction and operation on water quality would be less than significant, because existing permitting requirements and conditions of approval (i.e., MS4 Permit and the City’s Stormwater and Runoff Pollution Control Ordinance) are sufficient to avoid water quality degradation, meet water quality standards and Basin Plan objectives, and prevent adverse effects on beneficial uses. 6 Hydromodification is a primary contributor to problems related to excessive sediment and altered steam flow dynamics (e.g., flow volumes and velocities), primarily due to impervious surfaces, mass grading, and/or poor road designs (both urban and rural/unpaved).

Agenda Item #5.4.

3.9 – HYDROLOGY AND WATER QUALITY
Hunter Subdivision Project EIR 10839
September 2021 3.9-40
Mitigation Measures
None required.

3.9-2: Would the Proposed Project decrease groundwater supplies or interfere substantially with groundwater recharge such that the Project may impede sustainable groundwater management of the basin? This impact would be less than significant.

As discussed in detail under the environmental setting (Groundwater Resources), the County works with local jurisdictions including the City to sustainably manage the Napa Valley Groundwater Subbasin in compliance with SGMA. In its most recent assessment of conditions, the County, through its technical consultant, has determined that the Subbasin is not exhibiting significant and unreasonable impacts with regard to the applicable sustainability indicators defined by SGMA, including lowering of groundwater levels, depletion of groundwater in storage, degradation of groundwater quality, and depletions of interconnected surface waters (LSCE 2021). In its most recent annual report, the Subbasin was found to continue to exhibit stable groundwater levels, even despite a very dry 2020 water year, as it has historically, and has continued to be operated within the sustainable yield of the Subbasin (of between 17,000 and 20,000 AFY) (LSCE 2021). The long term (1988–2020) annual change in storage for the Subbasin is a decrease of 8,945 AF, following the very dry conditions of 2020, but still within the ranges that are generally experienced over the long term (LSCE 2021). Annual storage changes have commonly fluctuated between positive and negative values dating back to 1988; however, the median change is a positive increase of 1,784 AF, indicating that groundwater demands are not resulting in depletion of the aquifer (LCSE 2021).

Potential Proposed-Project-related impacts on groundwater depends on the component of its total water demand that would come from on-site or off-site groundwater wells. Based on the Proposed Project applicant’s Water Neutral Report (Appendix J) the Proposed Project is expected to require 37.04 AFY to supply its total water demand (including both domestic and landscape irrigation, see also Section 3.13, Utilities, Table 3.13-10). Out of this total, it is estimated that up to 17.16 AFY (5,592,210 million gallons) would be supplied by the on-site groundwater well (shown in Figure 3.9-3) to provide for irrigation of all public and private landscaping (including lawns and planter strips between the proposed streets and sidewalks) as well as an existing vineyard in the panhandle portion of the site that is slated to remain. The Proposed Project’s landscape irrigation demand was determined by RHA and Spatial Design Group (see Appendix J) using the City’s Model Water Efficient Landscape Ordinance. The analysis uses an annual reference evapotranspiration (ETo) of 44.1 inches established for the City. Actual landscape water use associated with the Proposed Project may be lower but cannot exceed this amount under the City’s model landscape ordinance. The remainder of the Agenda Item #5.4.

3.9 – HYDROLOGY AND WATER QUALITY
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September 2021 3.9-41
Proposed Project’s water demand (i.e., 19.88 AFY) would be served by the City’s municipal/potable water supply.

Therefore, the groundwater demand associated with the Proposed Project would come from a combination of the onsite well (located on Parcel B – see Figure 2-4 in Chapter 2, Project Description) and the City’s Stonebridge Complex wells (shown in Figure 3.9-3). As discussed in detail in Section 3.13 (Utilities and Service Systems), the City’s municipal water supply system relies on groundwater for, on average, up to 20% of its total supplies (with the remainder coming from a variety of surface water sources). The City relies on its groundwater well to serve as a buffer during drought years, when less surface water is available. It has stated that up to 30% of the City’s demand may be served by groundwater, if necessary, in below normal, dry, and critically dry years. Therefore, it is assumed that between 18% and 30% of the Proposed Project’s domestic water demand could come from the City’s Stonebridge Complex wells. This amounts to 3.98 AFY of Proposed Project demand from the City’s groundwater wells during average years, and up to 5.96 AFY during critically dry years.

The distinction between City water and the on-site well water is important, because the Proposed Project would be required to implement the City’s water neutrality policy (incorporated by reference in Chapter 13.12 [Water Use Efficiency and New Development] of the City’s Municipal Code), in which the Proposed Project must offset the full amount of its City water demand through any combination of on-site water conservation measures, or payment of a fee to be used for implementation of conservation measures for the City’s existing housing stock (such as toilet retrofits or other City approved conservation measures). Because the City’s municipal connections are served by the same combination of water supply sources, including groundwater, this offset would translate to eliminating the Proposed Project’s impact on the City’s municipal groundwater wells. Table 3.9-4 shows the Proposed Project’s demand for City groundwater. Because there may be a delayed effect due to the timing to complete the Proposed Project’s agreed upon offset measures, this impact analysis assumes a (highly unlikely) scenario that the Proposed Project would result in an increase in demand of 3.98 AFY from the City’s groundwater well in an average year.

The Stonebridge Complex wells have produced on average about 350 AFY since 2006, ranging from a low of 182 acre-feet in 2012 to a high of 526 acre-feet in 2013 (LSCE 2016, 2020). The wells have a combined capacity of approximately 595 gallons per minute, which is equivalent to 960 AFY assuming constant pumping. The average municipal groundwater demand of the Proposed Project (3.98 AFY) represents just 1.1% of the groundwater typically pumped from the municipal supply wells. In addition, according to the groundwater basin assessment report, groundwater pumping is a relatively small outflow component compared to surface water stormflows and groundwater baseflow discharged to the Napa River (LSCE 2016). Therefore, the basin groundwater budget is dominated much more by precipitation than it is by Agenda Item #5.4.

3.9 – HYDROLOGY AND WATER QUALITY
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groundwater pumping and the proposed groundwater pumping by the project would be expected to have a negligible effect on flows in the Napa River (LSCE 2016).

Table 3.9-4
Project Demand from City Groundwater Wells During Average and Critically Dry Years Year Percent City Demand Served by Groundwater Proposed Project Demand for City Groundwater1 Average 18% 3.09 AFY
Critically Dry 30% 5.15 AFY
Source: Appendix J.

Note
:
1 Calculated by multiplying the percent (as a fraction) of City groundwater demand per year type by the Proposed Project’s total estimated water demand of 19.88 AFY.

Furthermore, the City’s average groundwater use represents less than 37% of the wells’ combined capacity. Groundwater levels from a dual completion monitoring well located about 600 feet away (SGMA indicator well 222s[/3d]-swgw5, shown in Figure 3.9-3) have been measured on a continuous basis since December 2014. Despite the City’s pumping pattern during this time frame (which includes during drought years), along with the agricultural and domestic pumping that occurs in the vicinity, the groundwater level trend in the monitoring well is stable (LCSE 2021). Marked declines of the groundwater table to a level of up to approximately 30 feet bgs are observed in the summer and fall, but the groundwater table returns to its previous level of approximately 22 bgs by early spring (LSCE 2021).

As discussed in detail in the environmental setting (Groundwater Resources), the dual completion monitoring well is one of the Subbasin’s representative monitoring sites established for measuring whether sustainability goals are being met. The minimum threshold that would indicate a significant and unreasonable lowering of groundwater levels, reduction in groundwater storage, and/or streamflow depletion for the indicator well is 32 feet bgs (equates to 185 feet above mean sea level (amsl)) for the shallow screened well and 53 bgs (164 feet amsl) for the deeper screened well (LSCE 2016). In fall 2019 (when groundwater levels are typically at their lowest), the measured groundwater levels at the indicator well were 29 feet bgs (188 feet amsl) and 46 bgs (171 feet amsl) for the shallow screen and deep screen, respectively (DWR 2020). By Spring 2020, the shallow well had risen to 20.4 feet bgs or 196.6 amsl and the deeper well to approximately 36 feet bgs or 181 amsl (LSCE 2021). Despite heavy pumping to sustain the area’s municipal and agricultural water demands, these levels remain above minimum thresholds set to indicate significant and unreasonable impacts with regard to groundwater sustainability under SGMA. Given the aforementioned factors, a 0.9% increase in the City’s groundwater demand associated with the Proposed Project would not have a measurable impact on the groundwater levels in the vicinity of the Stonebridge Complex wells.

Agenda Item #5.4.

3.9 – HYDROLOGY AND WATER QUALITY
Hunter Subdivision Project EIR 10839
September 2021 3.9-43
This would likewise be the case for the Proposed Project’s demand of 17.16 AFY from the onsite well. This water demand comes out to an average pumping rate of 10.6 gpm compared to the well yields of vicinity wells that range from 39 to 147 gpm. The on-site well, proposed to be located on Parcel B of the proposed subdivision, would easily be capable of supplying this amount based on the well’s yield (as reported by the Project applicant) of 350 gpm. Although the well is currently inoperable and would need to be repaired so it is operational, this is also consistent with regional well yields. The recent well capacity and sustainability assessment performed on the agricultural well on the Project site confirmed an ability of the existing well to meet the proposed average pumping rate of 10.6 gpm (Appendix L). In the 24-hour pump test, a pumping rate of 40 gpm was employed and only one foot of drawdown was measured in the well which stayed consistent throughout the pumping period (Appendix L). The immediate recovery of this relatively small drawdown upon cessation of pumping was further evidence of high aquifer transmissivity (i.e., an ability of a water bearing unit to transmit water flow) and relatively abundant groundwater.

As shown in Table 3.9-2, there are a number of municipal and irrigation wells in the vicinity of the Project site, and average well yields far exceed the anticipated demand for the Proposed Project (note minimum well yields listed are for domestic wells constructed for low yield). The aquifer in general is known to be a productive alluvial aquifer, and therefore, there would be sufficient yield available to supply the Project’s well water landscape irrigation demand as also demonstrated by the findings of the site specific well pump test conducted on the existing agricultural well on the Project site. The proposed rate of pumping is relatively low and the resulting radius of influence would be highly localized, and greatly overshadowed by the radius of influence associated with the much higher producing agricultural and municipal supply wells in the surrounding vicinity. The existing surrounding levels of groundwater pumping has not produced undesirable results under SGMA (LSCE 2021) and both regional and local groundwater levels have remained stable; therefore, the potential impact of using the on-site well as proposed would be less than significant.

A review of the existing well indicates that the well is screened from 80 feet bgs to a total depth of 410 feet bgs with a 20-foot seal at the surface. Therefore, the well would draw from the deeper volcanic aquifer, below the Napa Valley alluvium which is considered hydraulicly connected to the Napa River (Appendix L). Therefore, the proposed pumping from this well is not likely to have any direct effect on surface flow in the Napa River. In addition, as stated above, the Subbasin as a whole is being managed sustainably, with a long-term median increase in groundwater storage of 1,784 AFY, therefore the localized impacts on groundwater levels and effects on flows in the Napa River would be minimal, thus the Proposed Project’s overall impacts on groundwater resources would be less than significant.

Agenda Item #5.4.

3.9 – HYDROLOGY AND WATER QUALITY
Hunter Subdivision Project EIR 10839
September 2021 3.9-44
Mitigation Measures
None required.

3.9-3: Would the Proposed Project substantially alter the existing drainage pattern of the site or area through the addition of impervious surfaces resulting in erosion or siltation on- or off-site; increasing the rate or amount of surface runoff resulting in flooding on- or off-site; contributing runoff water which would exceed the capacity of existing or planned stormwater drainage systems or provide polluted runoff; or impede or redirect flood flows? This impact would be less than significant.

Alterations to drainage patterns would be limited to increases in the rate and volume of storm water runoff associated with impervious surfaces. According to Appendix H, the Proposed Project would result in the addition of 10.91 acres of impervious surface, which is equivalent to an impervious surface coverage of 58%. Increases in the rate and volume of storm water runoff can be associated with exceedance of local storm drain capacity, increases in on- or off-site flooding, and/or hydromodification impacts to receiving waters, which include increase bank erosion or contribution of site-related pollutants. Because the Proposed Project would not alter the course of a stream or river and is not located within the SFHA of the Napa River, it would not impede or redirect flood flows.

In addition, the Project site would be subject to flooding only in a highly unlikely, catastrophic scenario. Because the Proposed Project consists of residences (as opposed to industry or businesses that store appreciable quantities of hazardous materials and/or wastes), the risk of releasing pollutants during such flooding would be low. The residences could have small quantities of household hazardous wastes, and such wastes could be released in a catastrophic flood scenario. However, in the context of such flooding, the release of such waste would not result in measurable increases in pollutant loads carried by the river during such a flood event, and would be dwarfed by the effects caused within the entire watershed.

Potential impacts associated with increases in the rate and/or volume of runoff produced by the Proposed Project are addressed below.

Substantial Erosion or Siltation On- or Off-Site
The off-site City detention basin has been designed with adequate capacity to capture and treat increases in the rate and volume of stormwater runoff associated with development in this area of the City, including development of the Project site with impervious surfaces. Per an agreement with the City and the Comprehensive Flood Protection Project’s Interior Drainage Analysis Final Report for the Miller Property/Hunter Property/Hunt Avenue, it was determined that development of the Flood Protection Project’s detention basin would account for future Agenda Item #5.4.

3.9 – HYDROLOGY AND WATER QUALITY
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development of the Hunter property (Project site) up to 70% impervious surface area (Appendix H). The Proposed Project is estimated to be developed at approximately 58% impervious surface; therefore, allowing the Project site’s increased runoff to be contained within the City’s detention basin without the need to expand the basin or further development of facilities.

As discussed under Impact 3.9-1, the Proposed Project would be subject to the most recent standards and performance criteria contained in the Small MS4 Permit because it would be required to prepare and submit for City approval a Stormwater Control Plan that complies with the Bay Area Stormwater Management Agencies Post Construction Manual. It is expected that the City’s detention basin would be used and/or modified as necessary to comply with the water quality design capture volume required under the MS4 Permit, the details of which must be included in the Proposed Project’s Stormwater Control Plan. Furthermore, water quality features such as downspouts to landscaped swales; vegetated swales; hydrodynamic oil, water and solid separators; private street sweeping; labeled storm drains (“drains to river”) and homeowner educational materials on stormwater pollution prevention are listed on the grading plan as BMPs to be implemented to prevent storm runoff of poor quality from entering the Napa River or seeping into the underlying groundwater table.

The operation-related impact of the Proposed Project on water quality would be less than significant, because compliance with existing permitting requirements and conditions of approval (i.e., MS4 Permit and the City’s Stormwater and Runoff Pollution Control Ordinance) are sufficient to avoid water quality degradation (including erosion and siltation).

Increases in On- or Off-Site Flooding
As previously discussed, the City-owned off-site detention basin has been designed to store the increase in storm water runoff generated from the Project site during a 100-year storm event.

During major flood events, the levee culvert gate is closed, routing stormwater into the detention basin. This avoids contributing to flows within the Napa River. As water fills the basin, the pump station is activated and water is pumped from the basin into the Napa River. However, by the time that occurs, the detention basin would have already captured the increase in flows associated with impervious surfaces on the Project site. For this reason, the impact of the Proposed Project to both on- or off-site flooding would be less than significant.

Stormwater Drainage System Capacity
The Proposed Project would construct storm drains or as required, improve existing storm drains to ensure adequate capacity is available to carry runoff produced by a 10-year storm event. Based on the Proposed Project’s utility plan, on-site storm flows from single-family residences would be conveyed to the off-site detention basin via underground storm drain lines varying in diameter from 15 to 30 inches. Storm runoff from the Project site east of the proposed Agenda Item #5.4.

3.9 – HYDROLOGY AND WATER QUALITY
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September 2021 3.9-46
Starr Avenue extension (multifamily housing) would be collected by 15-inch storm drains and connected to the City’s existing 36-inch storm drain and would drain into the adjacent detention basin. Title 16 of the City’s Municipal Code requires a new stormwater drainage system be designed by a registered civil engineer for ultimate development of the watershed, and to convey runoff generated by the 10-year flood. Per Title 16, the stormwater drainage system must also be designed to provide for the protection of abutting and off-site properties, and offsite storm drain improvements may be required to satisfy this requirement. Street curbs would be designed to adequately collect and convey the runoff produced by a 100-year storm. As indicated above, the existing off-site detention basin was designed to accommodate runoff from the Project site of up to 70% impervious surface area.

Because compliance with the City’s Municipal Code and improvement standards associated with approval of tentative subdivision maps, and because the off-site detention basin was designed with adequate capacity, the Proposed Project would have a less-than-significant impact related to exceedance of stormwater system capacity.

Mitigation Measures
None required.

3.9-4: Would the Proposed Project conflict with or obstruct implementation of a water quality control plan or sustainable groundwater management plan? This impact would be less than significant.

As discussed under Impact 3.9-1, the Proposed Project would comply with applicable regulations and permits designed to comply with the Water Quality Control Plan for the San Francisco Bay Region. The SWPPP and Stormwater Control Plan to be developed and implemented in compliance with the City’s Municipal Code would be effective at meeting water quality objectives of the Basin Plan. As discussed under Impact 3.8-2, the County is currently achieving sustainable groundwater management under an alternative GSP submittal (Basin Analysis Report). For the reasons discussed therein, the groundwater demand of the Proposed Project would not have an appreciable impact on meeting minimum thresholds established for the Napa Valley Subbasin under SGMA. Therefore, the impact of the Proposed Project on water quality and groundwater management plans would be less than significant.

Mitigation Measures
None required.

Agenda Item #5.4.

3.9 – HYDROLOGY AND WATER QUALITY
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September 2021 3.9-47

3.9.5 Cumulative Impacts
The cumulative context for the analysis of potential water quality impacts related to surface water is the Upper St. Helena Reach subwatershed (shown in Figure 3.9-1). This is because stormwater discharges originating from this area could combine with those of the Proposed Project to result in an increase in non-point source pollution discharging into the Napa River upstream of Sulphur Creek. Such increases could result from a combination of construction activities, greater use intensity, increased coverage of impervious surfaces and/or increased use of routine household cleaners and landscape chemicals. New development and/or redevelopment projects in these locations have the potential to generate impacts related to the violation of water quality standards, Basin Plan water quality objectives, and/or TMDLs established for the Napa River.

For groundwater resources, the cumulative context is the Napa Valley Groundwater Subbasin (Subbasin) (shown in Figure 3.9-3). Development of past, present and reasonably foreseeable projects within this area that results in an increase in groundwater demand could result in impacts related to depletion of the underlying aquifer, regional lowering of the groundwater table level, or depletions of interconnected surface waters.

As the Proposed Project does not have impacts with regard to flooding (since the potential impact is eliminated through use of the off-site detention basin), it would not contribute to any cumulative flooding impacts in the subwatershed.

3.9.5: Would the Proposed Project cumulatively degrade surface or groundwater quality? The Project’s contribution would not be considerable.

State and regional regulations described in Section 3.9.3 (Regulatory Setting) would reduce the rate of runoff and filter out pollutants in the same or similar manner as described in Impact 3.9-1. Construction activities are required to comply with the SWRCB statewide NPDES stormwater permit program, the Porter-Cologne Act’s requirements for site-specific waste discharge, as well as local agency public works construction standards. In addition, the City’s 1993 General Plan policies, 2019 General Plan policies, and existing City regulations would ensure protection of water quality, improve stormwater management, and reduce stormwater pollution. Increased impervious surface area as a result of the Proposed Project and other development projects in the watershed would be mitigated through application of the Small MS4 Permit, which requires the capture and treatment of stormwater runoff for the 85th percentile storm event. Areas within the cumulative context that are outside the jurisdictional boundary of the City would implement similar measures because Napa County requires development and redevelopment projects to implement the same standards discussed under Impact 3.9-1 (i.e., SWPPP and MS4 Permit standards).

Agenda Item #5.4.

3.9 – HYDROLOGY AND WATER QUALITY
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Based on development of past, present and reasonably foreseeable projects in the Upper St. Helena Reach subwatershed this is an existing potentially significant cumulative impact.

Due to the residential nature of the Proposed Project and compliance with mandatory existing state and local requirements to ensure protection of water quality in the subwatershed the Proposed Project’s contribution to this potentially significant cumulative impact is less than considerable resulting in a less-than-significant cumulative impact.

Mitigation Measures
None required.

3.9-6: Would the Proposed Project cumulatively decrease groundwater supplies or interfere substantially with groundwater recharge such that sustainable groundwater management of the basin would be impeded? The Project’s contribution would not be considerable.

As discussed under Impact 3.9-2, Napa County monitors the groundwater basin and has established minimum thresholds and measurable objectives for the Subbasin, which includes a representative monitoring site near the Pope Street Bridge crossing of the Napa River. The Basin Analysis Report prepared for the Subbasin, indicates that groundwater conditions in the Subbasin are currently meeting sustainability goals established per SGMA and the Subbasin has operated within its sustainable yield over a period of more than 20 years. The Report includes projects and management actions to ensure sustainability targets are met through the planning and implementation horizon of the City’s 2019 General Plan (2040 and beyond) (LSCE 2016). The City’s 2019 General Plan EIR notes that from 2011 through 2015, groundwater drawn from the Subbasin accounted for about 18% of the City’s total water supply (City of St.

Helena 2018). In addition, due to stable groundwater levels observed during recent drought conditions (from 2012 through 2015) it indicates recent rates of groundwater pumping have not exceeded the sustainable yield of the subbasin (City of St. Helena 2018). As noted above under Impact 3.9-2, the Proposed Project’s increase in water demand that would be supplied by groundwater wells would amount to a 0.9% increase which would not have a measurable impact on the groundwater levels in the vicinity of the Stonebridge Complex wells.

Future development in the City is required to comply with existing regulations that would ensure overall infiltration into the aquifer would remain robust, including requiring low-impact development projects be included to capture and infiltrate stormwater runoff, consistent with Bay Area Stormwater Management Agencies Association Manual, City Municipal Code, and required compliance with the NPDES permit, MS4 requirements, and/or General Waste Discharge Requirements. The 2019 General Plan includes policies PF1.E and PF1.F that require tracking new private wells to protect groundwater production. The 2019 General Plan Agenda Item #5.4.

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does not identify a significant cumulative groundwater impact. However, the Napa County General Plan Update EIR (SCH #2005102088), notes increased demand on groundwater supplies associated with increased development in the County (including cities) could lead to groundwater decline and overdraft contributing to a significant cumulative impact on groundwater resources (Napa County 2007).

The City has implemented actions to ensure the groundwater Subbasin continues to operate within its sustainable yield. The City’s 2011 Water Neutral Policy for Development requires all new development to be water-neutral, through a combination of on-site water conservation measures, off-site retrofitting and use of well water, as allowed. Future development in the City is not expected to result in an increase in total water demand because new development is required to offset new demand with water conservation retrofits of existing facilities, or in-lieu payments to the City to carry out any retrofit projects. In addition, as addressed under Impact

3.9-2, the on-site agricultural well is expected to yield 350 gpm (as reported by the Project applicant) and demonstrated an ability to pump at a rate of 40 gpm over a 24-hour period with negligible drawdown, which is far more capacity than the 10.6 gpm the Proposed Project would require for on-site irrigation. Based on the findings of the well capacity and sustainability test, this rate of pumping would have a highly localized radius of influence, if any, , and would be greatly overshadowed by the radius of influence associated with the agricultural and municipal supply wells in the surrounding vicinity. Therefore, given Napa County’s active management of the Subbasin under SGMA, available information, and the City’s implementation of a water neutral development policy, the Proposed Project’s contribution to a cumulative impact with regard to groundwater is not considerable resulting in a less-than-significant contribution.

Mitigation Measures
None required.

3.9.6 References
City of St. Helena. 1993. City of St. Helena General Plan. http://www.ci.st-helena.ca.us/ planning/page/1993-general-plan.

City of St. Helena. 2003. City of St. Helena Comprehensive Flood Protection Project Revised Draft Environmental Impact Report. Prepared by CDM in association with MBK, MOG, and Swanson Hydrology and Geomorphology. August 2003. State Clearinghouse No. 2002012078.

City of St. Helena. 2004. City of St. Helena Comprehensive Flood Protection Project Final Environmental Impact Report. Prepared by CDM in association with MBK, MOG, and Swanson Hydrology and Geomorphology. January 2004. State Clearinghouse No. 2002012078.

Agenda Item #5.4.

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City of St. Helena 2008. Final Plan to Minimize Impacts to Adjacent Landowners- City of St.

Helena Flood Protection and Flood Corridor Restoration Project. Accessed April 23, 2019. https://water.ca.gov/LegacyFiles/floodmgmt/fpo/sgb/ fpcp/prop84/comp_sol/2008_selections/alist_projects/st_helena/Final_StHelena_Plan_to _minimize_impacts.pdf.

City of St. Helena. 2012. City of St. Helena Flood Project, Office of Director of Public Works January 26, 2012 Presentation. Presented to Watershed Information Center & Conservancy of Napa County. Accessed April 23, 2019.
https://www.napawatersheds.org/managed_files/Document/8622/WICC-Presentation26JAN2012.pdf.

City of St. Helena. 2018. St. Helena General Plan Update 2040, Draft Environmental Impact Report. SCH# 2010042001. October 23, 2018.

City of St. Helena. 2019. City of St. Helena General Plan Update 2040. June 2019.

CVRWQCB (Central Valley RWQCB). 2016. 303(d) Impaired Water Bodies List. https://www.waterboards.ca.gov/rwqcb5/water_issues/tmdl/ impaired_waters_list/#intrpt2018.

DWR (Department of Water Resources). 1992. Well Completion Report No. 482209. Township & Range Section 08N05W30 Certified by Doshier & Gregson. Signed August 10, 1992.

DWR. 2019a. Sustainable Groundwater Management Act 2018 Basin Prioritization. https://water.ca.gov/-/media/DWR-Website/Web-Pages/Programs/GroundwaterManagement/Basin-Prioritization/Files/2018-Sustainable-Groundwater-ManagementAct-Basin-Prioritization.pdf?la=en&hash=B9F946563AA3E6B338674951A7FF B0D80B037530.

DWR. 2019b. Well Completion Report Map Application and Data Download. T08SR06W25, T08SR06W36, T08SR05W30, and T08SR05W31. Accessed April 5, 2019. https://dwr.maps.arcgis.com/apps/webappviewer/index.html?id=181078580a214c0986e 2da28f8623b37.

DWR. 2021. SGMA Data Viewer. Accessed September 18, 2020 and confirmed on June 16, 2021. https://sgma.water.ca.gov/
webgis/?appid=SGMADataViewer.

Agenda Item #5.4.

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FEMA (Federal Emergency Management Agency). 2012. Flood Insurance Rate Map. Napa County, California and Unincorporated Areas. FIRM Panel No 06055C0264E. Accessed at FEMA Map Service Center. Letter of Map Revision (LOMR) 12-09-0871P, Effective 11/5/2012. https://msc.fema.gov/portal/home.

LSCE (Luhdorff and Scalmanini Consulting Engineers). 2016. Napa Valley Groundwater Sustainability – A Basin Analysis Report for the Napa Valley Subbasin. Alternative Groundwater Sustainability Plan (GSP) Submitted to DWR. Prepared for Napa County.

December 16, 2016.

LSCE. 2021. Napa County Groundwater Sustainability – Annual Report for Water Year 2020.

Prepared for Napa County. April 2021.

Max H. Yuan, Project Engineer, P.E., Engineering Management Branch, FEMA, Letter to The Honorable Del Britton, Mayor, City of St. Helena, November 30, 2007.

Mead & Hunt, MBK Engineers, and Kleinfleder, 2006. City of St. Helena Comprehensive Flood Protection Project Application for a Conditional Letter of Map Revision to the FIRMs for Napa County, California: Community No. 0602050275A City of St. Helena, California:

Community No. 06020800050.

Napa County. 1998. Department of Public Works, Flood and Water Resources. Measure A:

Napa Flood Protection and Watershed Improvement Expenditure Plan. Accessed April 23, 2019. https://www.countyofnapa.org/DocumentCenter/View/2553/Measure-APDF?bidId=.

Napa County. 2007. Napa County General Plan Update Draft Environmental Impact Report.

SCH# 2005102088. February 16, 2007.

Napa County. 2013. Napa County Operational Area Hazard Mitigation Plan. 2013 Update.

Executive Office, Emergency Services Division. https://www.countyofnapa.org/ DocumentCenter/View/779/Napa-Operational-Area-Hazard-Mitigation-Plan-2013- PDF?bidId=. 2013.

Napa County. 2019. Department of Public Works, Flood and Water Resources. The History of Floods. Accessed April 23, 2019. https://www.countyofnapa.org/ 1094/The-History-of-Floods.

Napa County FCWCD (Flood Control and Water Conservation District). 2019. Water Level Record for the Napa River near St. Helena, California (11456000). Napa Valley Regional Rainfall and Stream Monitoring System. https://napa.onerain.com/home.php.

Agenda Item #5.4.

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Napa Valley Registrar. 2019. https://napavalleyregister.com/news/local/flood-defenses-holdnapa-valley-in-good-shape-after-storm/article_093203c1-3806-55df-843a6cb7347ef28c.html.

O’Conner, Matthew. 2021. Well Capacity and Sustainability Assessment, Proposed Hunter Subdivision. September 9, 2021.

San Francisco Bay RWQCB (Regional Water Quality Control Board). 2017. San Francisco Bay Bain (Region 2) Water Quality Control Plan. Adopted in1995, amended through May 7, 2017. Accessed April 16, 2019. Website: www.waterboards.ca.gov/ sanfranciscobay/basin_planning.shtml.

SWRCB (State Water Resources Control Board). 2019. Final 2014/2016 California Integrated Report (Clean Water Act Section 303(d) List/305(b) Report). Accessed April 16, 2019. https://www.waterboards.ca.gov/water_issues/programs/tmdl/integrated2014_2016.shtm.

US Climate Data. 2019. Napa, California Monthly Averages. US Climate Data version 2.3 Webpage. Accessed April 10, 2019. https://www.usclimatedata.com/climate/napa/ california/united-states/usca2061.

USGS (U.S. Geological Survey). 2006. Storms and Flooding in California in December 2005 and January 2006 – A Preliminary Assessment. USGS Open File Report 2006–1182. 2006. https://pubs.usgs.gov/of/2006/1182/pdf/ofr2006-1182.pdf.

Western Regional Climate Center. 2016. Saint Helena, California (047643) Coop Station Monthly Climate Summary. Accessed May 2, 2019. https://wrcc.dri.edu/cgibin/cliMAIN.pl?ca7643.

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3.10 LAND USE

3.10.1 Introduction
This section describes existing and planned land uses within and adjacent to the proposed Hunter Subdivision Project (Proposed Project) site within the City of St. Helena (City), identifies land use designations, and zoning, and analyzes consistency of the Proposed Project with the City’s 1993 General Plan goals and policies and the City’s Municipal Code, Title 17 Zoning.

The City has since adopted an update to the 1993 General Plan; the 2019 General Plan (known as the “General Plan Update 2040,” a General Plan with a planning horizon of 2040) was adopted in May 2019. However, since the Proposed Project application was submitted in September 2010 and deemed complete by the City in 2011, this Environmental Impact Report (EIR) uses the 1993 General Plan as the applicable general plan for the purposes of evaluating consistency of the Proposed Project with the City’s General Plan policies in effect when the application was deemed complete by the City. Nonetheless, this EIR also evaluates consistency with the City’s adopted 2019 General Plan for informational and consistency purposes.

California Environmental Quality Act (CEQA) Guidelines Section 15125(d) provides that the environmental setting of an EIR must discuss “any inconsistencies between the proposed project and applicable general plans and regional plans.” Potential inconsistencies between the Proposed Project and the City’s 1993 General Plan, and the Zoning Ordinance are discussed in this section in addition to a review of the City’s 2019 General Plan. Technical sections included in this Draft EIR also evaluate and analyze any potential physical/environmental effects and potential incompatibilities with the 1993 General Plan that may be considered in the determination of physical environmental impacts.

Comments received in response to the Notice of Preparation related to land use included concerns about consistency with the underlying land use designation and zoning, and potential conflicts with the City’s 1993 General Plan. All of these issues are addressed in this section. A copy of the Notice of Preparation and comments received is included in Appendix A.

Information for this section was primarily obtained from the City of St. Helena 1993 General Plan (City of St. Helena 1993), City of St. Helena 2019 General Plan (City of St. Helena 2019), City of St. Helena Municipal Code, and other miscellaneous Proposed Project information.

3.10.2 Environmental Setting
The following provides an overview of the existing land use designation, zoning and land uses on the Project site as well as the surrounding land use designations and zoning.

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Existing Site
The Project site (Assessor’s Parcel Number is 009-030-057) is located in the northeast portion of the City, at the eastern terminus of Adams Street and the west/north1terminus of Starr Avenue, three blocks east of downtown and State Route 29, and generally south/west of the Napa River. The Project site has historically been used for agriculture and contained an orchard that was removed in the 1960s. In the early 1970s a small vineyard was planted on approximately 7-acres of the Project site. In the mid-2000s the site was altered by the addition of fill material primarily associated with the construction of the St. Helena Comprehensive Flood Protection Project (Flood Protection Project) along the Napa River, located to the north and northeast of the Project site.

The Project site is presently undeveloped with the exception of a small vineyard under active cultivation located in the southwestern portion of the site, near the terminus of both Adams Street and Starr Avenue. The site is generally level and does not contain any streams or waterways. Trees are located along the edge of the southern/southeastern boundary of the site, including parallel to the Vineyard Valley Mobile Home Park. Based on the Proposed Project’s grading plan, the elevation across the Proposed Project’s development footprint ranges from approximately 230 feet above mean sea level on its southern edge to approximately 212 feet above mean sea level on its northern edge. The portion of the site planned for the extension of Adams Street ranges from 243 feet to 230 feet above mean sea level. An existing well is located near the southeastern edge of the Project site.

Surrounding Land Uses
Adjacent land uses include single-family and multi-family residential development to the south and southeast, including the Vineyard Valley Mobile Home Park, Hunt’s Grove Apartments, and single-family residences along Starr Avenue (see Figure 2-3 in Chapter 2, Project Description).

Office uses are located immediately adjacent to the site’s westernmost edge at the terminus of Adams Street. Single-family residences along Monte Vista Avenue and Hunt Avenue back up to the site. Undeveloped land currently under cultivation or fallow is located to the north and northwest. A single-family residence along with an accessory dwelling unit and barn is currently under construction just north/west of the site. A gravel maintenance road/public trail borders the site along the north/northwest and a city storm water detention basin borders the site to the south/southeast. A drainage ditch is located along the southwestern edge of the property. Starr Avenue and Adams Street essentially stub into the Project site. 1 The site is oriented on an axis that runs generally on a diagonal from southwest to northeast. Directions in relation to the site are therefore in many cases not directly “north” or “’west” are shown as a combination of directions.

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The open space areas located north and east of the site are part of the City’s Flood Protection Project. The Napa River is located approximately 540 feet north and northeast of the Project site.

Land uses surrounding the Project site are currently designated High Density Residential (HDR) and Medium Density Residential (MDR) adjacent to the south and southeast; Open Space to the north and along the western Proposed Project boundary, and Agriculture farther west in the City’s 2019 General Plan. In the 1993 General Plan, the Open Space parcel to the north and west of the Project site was designated as MDR rather than Open Space.

City of St. Helena 1975 General Plan Land Use Designation The project site was designated for high density residential development in the 1975 St. Helena General Plan. Densities envisioned in the 1975 General Plan were 4-6 units per acre for single family homes and up to 16 units per acre for multi-family dwellings.

That land use policy was revised with the adoption of the updated 1993 General Plan (discussed below).

City of St. Helena 1993 General Plan Land Use Designations The Project site is designated as MDR in the City’s 1993 General Plan. According to the 1993 General Plan, “[t]he MDR designation provides for single-family detached and attached homes, secondary residential units, public and semi-public uses, and similar and compatible uses.

Residential densities shall be in the range of 5.1 to 12.0 dwelling units per gross acre (du/acre).

The MDR designation is the predominant residential designation, occurring throughout large areas of the City. The wide distribution of this designation is intended to maintain a development pattern in newly developing areas that is consistent with historic development patterns” (City of St. Helena 1993).

City of St. Helena 2019 General Plan (“General Plan Update 2040”) As previously mentioned, the City adopted the 2019 General Plan, known as the “General Plan Update 2040,” in May 2019. However, since the Proposed Project application was submitted in September 2010 and deemed complete by the City in 2011, this EIR uses the 1993 General Plan as the applicable general plan for the purposes of evaluating the Proposed Project. For informational purposes, the City’s 2019 General Plan designates the Project site for MDR, the same as the 1993 General Plan (City of St. Helena 2019, Figure 2.1). However, the allowable density is up to 16.0 dwelling units per acre.

Agenda Item #5.4.

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Existing Zoning
The City of St. Helena’s Zoning Code (Title 17) specifies building setback, building height, building density, and site coverage to ensure that the public’s health, welfare, and safety would be protected and that development occurs in a planned, logical fashion. The Project site is currently zoned Medium Density Residential (MR), which allows a residential density of between

5.1 to 16.0 dwelling units per acre. The MR district is consistent with the MDR General Plan designation. The MR district provides for single-family detached homes, accessory dwelling units, limited agricultural uses and compatible uses, as well as attached duplex and triplex units, condominiums, and townhouses, and similar uses with a use permit.

The City’s General Plan Housing Element Update 2015–2023 was revised and last updated in May 2015. The City’s 2015-2023 Housing Element identifies the site as vacant and underutilized (City of St. Helena 2015b, p.133, Table 43).

3.10.3 Regulatory Setting
There are no federal or state land use requirements applicable to the Proposed Project.

Regional Regulations
Plan Bay Area 2040
Plan Bay Area 2040 (Plan), adopted in 2017, is a state-mandated, integrated long-range transportation and land use plan. The region adopted its previous plan — Plan Bay Area — in July 2013. As the Bay Area’s first regional transportation plan to include a Sustainable Communities Strategy (SCS) as required by Senate Bill (SB) 375, the original Plan Bay Area (2013) charted a course for reducing per-capita greenhouse gas emissions through the promotion of more compact, mixed-use residential and commercial neighborhoods near transit.

In the Bay Area, the Metropolitan Transportation Commission and the Association of Bay Area Governments (ABAG) are jointly responsible for developing and adopting a SCS that integrates transportation, land use and housing to meet greenhouse gas reduction targets set by the California Air Resources Board. Plan Bay Area 2040 projects household and employment growth in the Bay Area over the next 24 years, provides a roadmap for accommodating expected growth, and connects it all to a transportation investment strategy that strives to move the Bay Area toward key regional goals for the environment, economy and social equity.

SB 375 was adopted with the goal of reducing greenhouse gas emissions from cars and light trucks. SB 375 will make it easier for communities to build housing and provide transportation choices. The SCS is a plan to meet the region’s greenhouse gas emissions reduction target, while taking into account regional housing needs, transportation demands, and protection of Agenda Item #5.4.

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resource and farm lands based on the best forecast of likely land use patterns provided in coordination with ABAG’s partner agencies.

Local Regulations
City of St. Helena 1993 General Plan
As noted in the General Plan, “growth continues to be one of, if not the primary issue facing St.

Helena according to input from the community. Since the early 1970s when the City experienced a dramatic increase in growth pressures, the community has strongly supported a policy of deliberate slow growth in order to protect the fragile charm and beauty of the City, to ensure that natural resources such as water supply and prime agricultural land are not lost or overused, and to ensure that adequate public services such as schools and sewers can be provided. In addition to regulating the rate of growth, the City will also control where growth can occur by establishing an Urban Service Area.” To address the desire to manage growth the City developed an Urban Service Area, which discourages urban sprawl by containing urban development within the designated Urban Service Area. The Urban Service Area is surrounded by agriculturally designated land and includes 663 acres designated for residential uses to accommodate projected growth, while maintaining a rational and compact development pattern at buildout (City of St. Helena 1993). The Project site is within the Urban Limit Line, which runs along the westerly edge of the Project site, separating it from the agricultural lands to the west and north.

The following goals and policies from the 1993 General Plan applicable to the Proposed Project are listed below. A consistency analysis for all the policies listed below is included in the impact section.

Growth Management
Policy 2.6.1: New development should be required to occur in a logical and orderly manner within well-defined boundaries, and be consistent with the ability to provide urban services.

Policy 2.6.2: Urban development shall be allowed to occur only within the Urban Service Area during the time frame of the General Plan.

Policy 2.6.3: Urban services such as sewer, water, and storm drainage will only be extended to development within the Urban Service Area. Exceptions will be permitted when undue hardship can be demonstrated, and proposed improvements are not found to be growth inducing.

Agenda Item #5.4.

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Policy 2.6.4: Permit infill development and higher densities within currently developed areas wherever possible to minimize and postpone the need for expansion of the Urban Service Area.

Implementing Policy 2.6.6: Limit the amount of land designated for urban uses to those areas that can reasonably be predicted to be developed over the life of the plan. Areas not projected for urban development within the life of the plan shall be designated for agricultural or other non-urban uses.

Residential Growth Management
Policy 2.6.9: Limit the approval of new residential development to a maximum rate of 17 dwelling units per year.

Policy 2.6.10: Maintain a cap on residential development of 2,850 total dwelling units citywide by the year 2010. The total number of dwelling units shall not be construed as a goal, but shall be an absolute maximum allowable number.

Residential
Policy 2.6.14: Encourage a mix of housing types and price ranges to allow choice for current and future generations of St. Helenans.

Policy 2.6.15: Encourage new residential development in all density ranges that is consistent with scale and character' of the older residential districts of the City, particularly the neighborhoods west of Main Street
Policy 2.6.16: Encourage the development of higher density housing in areas near the center of town and close to recreation and services.

Policy 2.6.17: Minimize situations where new residential development will block public view of surrounding vineyards
Policy 2.6.18: Minimize large lot development (one dwelling unit per acre or less), except where this scale of development would not threaten retention of vineyards, inefficiently utilize land, or physically separate the community from the surrounding vineyards Policy 2.6.19: Permit higher density housing in single family neighborhoods as long as the development character of the single family area is maintained (i.e., lot widths, orientation to street, building heights, etc.).

Agenda Item #5.4.

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Policy 2.6.20: Encourage the subdivision and development of larger parcels (3 acres or more) as "planned unit developments" to ensure a more comprehensive and creative approach to planning the development as a single unit.

The “planned unit development” approach provides developers with greater design flexibility while ensuring the City adequate design review. The intent is to create developments that complement existing community character. The City will favor planned unit developments that provide generous amounts of open space, covered parking, the separation of pedestrian and vehicle traffic, and on larger tracts, a variety of housing types: single-family detached, duplex, and multi-family dwellings, in one and two-story structures.

Policy 2.6.21: Require new residential projects to be designed to facilitate non automobile modes of travel (i.e., walking, biking, transit, etc.).

St. Helena 2019 General Plan (“General Plan Update 2040”) The City recently adopted an update to its 1993 General Plan in May 2019. Although the updated general plan policies will not be considered for this Proposed Project as discussed previously, the relevant policies are provided solely for information given the City has an updated general plan and are not evaluated for consistency with the Proposed Project. The Appellate Court has ruled in Chaparral Greens v. City of Chula Vista that “applicable” plan within the meaning of CEQA Guidelines, Section 15125(d) is a plan that has already been adopted and thus legally applies to the project; draft plans need not be evaluated.

In the 2019 General Plan one of the primary goals of the City is to contain development and preserve agricultural lands in and adjacent to the City, similar to the goal of the 1993 General Plan. In lieu of defining an Urban Services Area, the 2019 General Plan updates the City’s Urban Limit Line and designates Urban Reserve Areas. The Urban Limit Line denotes the limit of where urban development is permitted within the incorporated area of the City. The intent is to discourage urban sprawl by containing urban development within designated areas. There are a handful of areas designated Urban Reserve Areas, which can be considered for development after land within the Urban Limit Line are developed and if additional land is needed. Notably, the 2019 General Plan retains the medium density residential designation for the site and does not change the Urban Limit Line relative to the Project site.

The relevant goals and policies of the 2019 General Plan Land Use and Growth Management Element are listed below. As can be seen below, many policies are similar to or the same as the policies contained in the 1993 General Plan.

Agenda Item #5.4.

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Manage Growth and Maintain Community Character.

St. Helena is committed to preserving its existing community character, maintaining agricultural lands, managing growth and the impacts of tourism, and ensuring that adequate infrastructure and facilities are provided.

Promote High-Quality and Sustainable Development.

St. Helena is dedicated to a high standard of quality, economic viability and ecological sustainability with respect to the design, planning, and construction of new and renovated public and private facilities.

Growth Management
Policy LU1.1: Require new development to occur within well-defined boundaries and be consistent with the ability to provide urban services. New development should mitigate infrastructure impacts by using sustainable, best management practices in green building and stormwater management and paying its share of development impact fees, while minimizing impacts on sewer, water, energy, and natural resources.

Policy LU1.2: Allow urban development to occur only within the Urban Limit Line.

Consider an exception for on-site employee housing on Agricultural lands. Urban services, such as sewer, water, and storm drainage, will only be extended to development within the Urban Limit Line.

Policy LU1.3: Support agricultural and low-intensity uses beyond the Urban Limit Line.

Policy LU1.4: In order to minimize and postpone the need for expansion of the Urban Limit Line, encourage infill development within currently developed areas.

Policy LU1.5: Require new development to provide adequate infrastructure and urban services, including compliance with the policies and implementing actions affecting new development as set forth in the Public Facilities and Services Element.

Policy LU1.7: Continue to limit the approval of market rate residential development to the maximum allowed under the Growth Management System. Regulated affordable units and second units are exempt from this limitation.

Implementing Action LU1.A: Continue to allow the construction of second units – also known as accessory dwelling units – and consider allowing the division of single-family homes into two or more units under appropriate circumstances, in order to increase Agenda Item #5.4.

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residential density and housing availability without requiring an extension of the Urban Limit Line.

Residential Neighborhoods
Policy LU2.1: Promote a mix of housing types and price ranges that are consistent with the Housing Element RHNA categories of housing affordability.

Policy LU2.2: Encourage new residential development that is consistent in design, size, color, and floor area ratio (FAR) with the older residences in the neighborhood.

Policy LU2.3: Protect residential neighborhood views of surrounding vineyards and mountains.

Policy LU2.4: Encourage the subdivision and/or development of larger parcels as Planned Unit Developments to ensure a more comprehensive and creative approach to planning the development as a single unit. This does not prohibit use of Planned Unit Developments on parcels less than three acres.

Policy LU2.5: Encourage the development of higher density housing in areas near the center of the city and close to recreation and services, such as transit, retail, and public facilities.

Policy LU2.6: Allow residential density at the higher end of the permitted range for single family development within Medium and High Density Residential Land Use designations as long as the development character of the single family area is maintained, including lot widths, orientation to street, building heights, onsite parking, traffic, and noise, among other considerations.

Policy LU2.7: Ensure safe, walkable, and bikeable residential neighborhoods and vibrant, livable streets.

City of St. Helena Housing Element Update 2015–2023 Goals, Policies, and 8-Year Action Plan
The purpose of the Housing Element is to establish a comprehensive plan to address housing needs in the City over the eight-year planning period between January 31, 2015 and January 31, 2023. Every jurisdiction in the state is required to submit a Housing Element to ensure the housing needs of all residents are being met. The Housing Element establishes the community goals, and policies surrounding the development, rehabilitation, and preservation of housing units to meet the needs of City residents (present and future). The City’s Housing Element was adopted in May 2015.

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Applicable goals and supporting policies from the Housing Element are as follows:
• Goal 1 - A Diversity of Housing to Meet Local Needs: Facilitate development of a variety of housing types to meet the full range of housing needs in our community, with particular emphasis on housing for our local workforce, people with special housing needs, and people with extremely low, very low, low and moderate incomes. • Policy HE1.3: Encourage the development of affordable housing and remove development constraints as feasible.
• Goal 2 - Efficient Land Use and High Quality Neighborhoods: Make efficient use of land within the Urban Limit Line to protect agricultural lands, promoting compact, welldesigned developments that ‘fit in’ with existing neighborhoods and contribute to the overall livability of our community. Encourage a balance of housing types throughout the entire community.
• Policy HE2.1: Encourage higher density development where appropriate. • Policy HE2.2: Ensure that higher density housing opportunity sites are not lost to lower density uses.
• Policy HE2.4: Promote second unit production.
• Policy HE2.6: Promote a balance of types of housing throughout the whole community.

St. Helena Municipal Code –Title 17 Zoning
The City of St. Helena Municipal Code, Title 17 Zoning is designed to protect and promote the public health, safety, and general welfare of the citizens of St. Helena and provides the purpose, permitted and conditional uses, and any special district provisions for the City’s various zoning districts.

Excerpts from applicable sections from the Title 17 of the City’s Municipal Code are included below.

Chapter 17.40 Medium Density Residential District
Section 17.40.010 Purpose
The MR district is established for consistency with the medium density residential general plan designation. The district provides for single-family detached homes, accessory dwelling units, limited agricultural uses and compatible uses. Residential densities shall not be less than 5.1 dwelling units per acre nor more than 16 dwelling units per acre (Ord. 07-5 § 2 (part): Ord. 05-4 § 1 (part): prior code § 27.50).

Agenda Item #5.4.

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Section 17.40.030 Conditional Uses
The following uses require approval of a use permit as regulated by Chapter 17.168:

A. New construction of one single-family dwelling on parcels where the minimum density is two units or greater, pursuant to Section 17.40.060;
B. New attached duplex or triplex units or conversion of an existing single-family dwelling to duplex or triplex, compatible with the design and architecture of the neighborhood and consistent with the density and floor area ratio of the district; Chapter 17.116 Accessory Building, Structures, Dwelling and Uses Section 17.116.030 Accessory Dwelling Units
The purpose of this section is to allow and regulate accessory dwelling units (ADUs) and junior accessory dwelling units (JADUs) in compliance with California Government Code Sections 65852.2 and 65852.22, which allows development of ADUs within land zoned for single-family residential. The City also allows ADUs on land zoned for multifamily dwelling residential use. This section establishes the parameters for development including size, height, setbacks, parking requirements, fees and use of ADUs.

Chapter 17.146 Housing Trust Fund, Housing Impact Fee, and Inclusionary/In-lieu Fee Requirements Section 17.146.050 Residential Development Project—Inclusionary/in-lieu Fee Requirements A. Inclusionary Requirement. At least twenty percent (20%) of all new dwelling units in a residential development project shall be affordable units, which shall be constructed and completed not later than the related market rate units. For fractions of affordable units, including fractions resulting from construction of less than five dwelling units, the developer may elect, at his or her option, to construct the next higher whole number of affordable units, perform an alternative equivalent action which has received the approval of the city council pursuant to subsection B, or pay the housing in-lieu fee specified in subsection E for such fraction.

B. Alternative Equivalent Proposal.

1. A developer of any residential project may propose to meet the requirements of subsection A with an alternative equivalent action, subject to the review and approval of the city council. Proposals for alternative equivalent actions may include, but are not limited to, dedication of vacant land, the construction of affordable units on another site, or acquisition and enforcement of required rental/sales price restrictions on existing standard dwelling units consistent with this section. Any proposal shall Agenda Item #5.4.

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show how the alternative action will further affordable housing opportunities in the city to an equal or greater extent than compliance with the express requirements of subsection A or payment of the appropriate in-lieu housing fee.

2. Alternative equivalent action proposals for single-family and multifamily residential developments shall be considered on a case-by-case basis by the city council, and may be approved at the city council’s sole discretion, if the city council determines that such alternative will further affordable housing opportunities in the city to an equal or greater extent than compliance with the express requirements of subsection A.

C. In-Lieu Housing Fee. A developer of four or fewer residential dwelling units which are the whole of a residential development project may meet the requirements of subsection A through payment of an in-lieu fee.

A developer of any other residential project may propose to meet the requirements of subsection A through payment of an in-lieu fee by showing good cause that it is not feasible to construct the required units. A written request shall be submitted with the developer’s application for a discretionary approval or building permit, whichever comes first. The request shall include: a statement identifying all overriding conditions that prevent the developer from meeting the requirement to construct the affordable units; sufficient independent data, including appropriate financial information, to support the developer’s claim that it is not feasible to construct the required affordable units; and a detailed analysis of why the concessions and incentives identified in subsection F cannot mitigate the conditions that are preventing the developer from constructing the affordable units. The housing director shall review all such requests and prepare a recommendation for the city council. Such requests shall be considered on a case-bycase basis by the city council, and may be approved if the council determines that there are overriding conditions which prevent the developer of a multifamily residential project from meeting the requirement to construct affordable units, and that payment of the inlieu fee will further affordable housing opportunities to an equal or greater extent.

I. Basic Requirements for Owner-Occupied and Rental Affordable Units. Affordable units shall be comparable in number of bedrooms, exterior appearance and overall quality of construction to market rate units in the same residential project. Subject to the approval of the planning commission, square footage of affordable units and interior features in affordable units need not be the same as or equivalent to those in market rate units in the same residential project, so long as they are of good quality and are consistent with contemporary standards for new housing. Affordable units shall be dispersed throughout the residential project, or, subject to the approval of the planning commission, may be clustered within the residential project when this furthers affordable housing opportunities.

Agenda Item #5.4.

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Chapter 17.152 Residential Growth Management System
The City’s Residential Growth Management System is no longer enforceable because the state passed Senate Bill 330 (see Government Code Section 66300), otherwise known as the Housing Crisis Act of 2019. Government Code Section 66300 includes language that prevents cities from “establishing or implementing any provision that . . . [a]cts as a cap on the number of housing units that can be approved or constructed either annually or for some other period” (Section 66300(b)(1)(D)(ii) [emphasis added]). Therefore, the City can no longer implement a restriction on the number of residential units that can be constructed and this ordinance is no longer enforceable.

3.10.4 Impacts
Methods of Analysis
Section 15125(d) of the CEQA Guidelines, requires than an EIR shall discuss any inconsistencies with applicable general plans, specific plans, and regional plans as part of the environmental setting. Applicable land use plans considered in this analysis include the City’s 1993 General Plan, 2015–2023 Housing Element, Zoning Ordinance (Title 17), and ABAG’s Metropolitan Transportation Plan/SCS.

The consistency analysis with the 1993 General Plan focuses on potentially significant environmental impacts that would result from a conflict with a policy adopted for the purpose of avoiding or mitigating an environmental effect. Under state law, a development project cannot be approved if it is inconsistent with the General Plan. Ultimately, it is within the City’s decision makers’ purview to decide if the Proposed Project is consistent with the General Plan. Because policies in a general plan reflect a range of competing interests, the City’s decision makers are allowed to weigh and balance the plan’s policies when applying them, and have broad discretion to construe its policies in light of the plan’s purposes. As previously discussed, a policy consistency analysis with the 2019 General Plan is not included. Even so, generally, the policies in the 2019 General Plan are very similar to the policies contained in the 1993 General Plan. For informational purposes and a brief overview of policies that differ from the 1993 General Plan will be provided.

The Proposed Project’s consistency with applicable ordinances are discussed in this section and in other technical sections of this Draft EIR. This section also considers any inconsistencies with ABAG’s Metropolitan Transportation Plan/SCS, a regional land use and transportation plan.

The analyses of consistency with other planning documents (e.g., regional air quality plans) are provided in the applicable technical sections in Chapter 3 of this Draft EIR.

Agenda Item #5.4.

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Thresholds of Significance
Consistent with Appendix G of the CEQA Guidelines, a significant impact would occur if development of the Proposed Project would do any of the following:
• Physically divide an established community.
• Cause a significant environmental impact due to a conflict with any land use plan, policy or regulation adopted for the purpose of avoiding or mitigating an environmental effect.

Threshold Criteria not Applicable to the Proposed Project Due to the location and characteristics of the Proposed Project, certain significance criteria are not applicable and therefore, are not considered potential impacts. These criteria are addressed briefly below and are not discussed further in this document.

Physically Divide Established Community
The Project site is undeveloped and generally surrounded by development on the south, southeast and southwest with undeveloped land generally located to the northwest and northeast. The Proposed Project is a Tentative Subdivision Map to develop the site with a residential subdivision consistent with the existing neighborhoods generally located to the southwest and southeast of the site. Due to the Proposed Project’s location, development of the Proposed Project would not physically divide an established community because there is no development northwest or northeast of the site. The Proposed Project would, instead, provide a continuation of the existing neighborhood with development of a new residential area.

Development of the Project site would not divide an established community (first threshold criteria); therefore, this issue is not further addressed below.

Impacts and Mitigation Measures

3.10-1: Would the Proposed Project conflict with the City’s 1993 General Plan policies or other regulations adopted for the purpose of avoiding or mitigating an environmental effect? This impact would be less than significant.

City of St. Helena 1993 General Plan
The Proposed Project includes approval of a Tentative Subdivision Map to develop a vacant site with residential uses consistent with the underlying land use designation and zoning that would provide a diversity of housing choices, including single family residences, ADUs, and attached multifamily units. Currently the site is designated as MDR in the City’s 1993 General Plan and Agenda Item #5.4.

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the Proposed Project is not requesting a General Plan Amendment to redesignate the existing land use designation.

General Plan Guiding policies 2.6.1 through 2.6.4 support infill development within the City’s Urban Service Area and growth in existing urbanized areas where City services are in place to support new development. Policy 2.6.4 encourages infill development and higher densities to minimize the need to expand the City’s Urban Services Area. Implementing policy 2.6.6 limits land designed for urban uses to areas that can reasonably be predicted to be developed. Areas not slated for urban development shall be designated for non-urban uses. The Project site is located within the City’s Urban Limit Line and Urban Services Area within a few blocks of downtown St. Helena adjacent to existing residential uses and infrastructure where City services are available. The site has been designated and zoned for residential development for over 25 years and has access to City services.

Policies 2.6.9 and 2.6.10 and the City’s Residential Growth Management System (Municipal Code Chapter 17.152) limit the City’s approval of residential units and imposes a cap on the total number of residential units to 2,850 Citywide by 2010. These policies were included in the General Plan to slow growth in order to ensure that the diverse housing needs of the community are met, development of new housing occurs in designated areas, and to ensure adequate public facilities and services are available to support new residential development. Due to passage of SB 330 otherwise known as the Housing Crisis Act of 2019, the City’s Residential Growth Management System that limits residential development is no longer enforceable so consistency with these policies would not apply to this Proposed Project.

Policies 2.6.14 through 2.6.21 are focused on residential development and encourage a mix of housing types, densities and price ranges consistent with the scale and character of existing neighborhoods; encourage higher density in single family neighborhoods keeping the same development character; minimize large lot development and encourage “planned unit developments” to complement existing community character; minimize blocking views of surrounding vineyards; and encourage new residential projects to facilitate alternative transportation modes. The Proposed Project applicant is only requesting approval of a Tentative Subdivision Map at this time. Therefore, no design details are included as part of this Proposed Project. The Proposed Project applicant would require additional subsequent approvals from the City including design review, site development plan and a use permit (to construct attached multifamily units in the MDR district) in order to engage in any construction of new residences.

The Tentative Subdivision Map includes 51 single-family lots and a 3.4-acre parcel to include 25 attached multifamily units, reflecting a mix of housing types. In addition, 11 of the 51 single-family lots would include an ADU. Therefore, the Proposed Project’s proposed density would be 5.1 Agenda Item #5.4.

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dwelling units/acre, assuming a total of 87 units. (Section 17.116.030 of the Zoning Ordinance does allow ADUs to exceed maximum density provided there is only one ADU per parcel).

The Proposed Project provides sidewalks on all interior roads to encourage walking and bike access throughout the Project site. The existing vineyard on the Project site occupies approximately 6.8 acres and would be removed with the exception of a small portion of the vineyard (approximately 1 acre) that would remain located in the southwestern “panhandle” portion of the site. Currently there are no views of other existing vineyards in the existing agricultural lands to the north, northeast and northwest that could be blocked by residential development (see also Section 3.1 for a discussion of visual impacts and related policies).

The Proposed Project would not conflict with the City’s 1993 General Plan policies related to environmental protection and would not result in a significant environmental effect related to land use plan consistency. The impact is less than significant. 2019 General Plan (“General Plan Update 2040”)
As noted previously, the Proposed Project is not required to demonstrate consistency with the City’s adopted 2019 General Plan Update because it was not adopted when the Proposed Project application was filed and deemed complete in 2011. In general, the 2019 General Plan goals and policies are very similar to the goals and policies included in the 1993 General Plan. The notable differences include that the 2019 General Plan eliminates the Urban Service Area and updates the Urban Limit Line, and designates Urban Reserve Areas (which can only be considered for development if there is no developable land within the Urban Limit Line). The 2019 General Plan Update also supports agricultural and low-intensity uses beyond the Urban Limit Line (Policy LU1.3), and allows an exception for on-site employee housing to be developed on agricultural lands outside of the Urban Limit Line (Policy LU1.2). Overall, the intent of the policies to discourage urban sprawl by containing urban development within the Urban Limit Line and designated areas is consistent with the policy direction provided in the 1993 General Plan. The Proposed Project is consistent with the intent of the 2019 General Plan land use policies to discourage sprawl and to develop areas within the Urban Limit Line.

Housing Element Update 2015-2023 Goals, Policies, and Eight-Year Action Plan The City’s Housing Element includes goals and policies that address the need for the City to provide a diversity of housing and to use land efficiently in creating livable neighborhoods. The Proposed Project includes a mix of single-family residences and ADUs as well as 25 multifamily affordable units, designated for Very Low-income (5 units) and the Moderate-income category (20 units). The inclusion of a mix of housing units meets the intent of Goal 1 and policies HE1.3, HE2.4, and HE2.6 which encourages the development of a variety of housing in the City, including affordable units and second, or accessory units.

Agenda Item #5.4.

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The Project site is located within the City’s Urban Limit Line and as discussed above, has been designated for residential development for over 25 years, since 1993. The Project site is included in the vacant land inventory in the Housing Element. The site is located adjacent to residential development to the south, southwest and east and is adjacent to the limit of the City’s Urban Limit Line. To ensure the protection of agricultural lands to the north, northeast/northwest, the City has zoned the Project site for MDR which allows a higher density.

This encourages more compact development in order to limit encroaching into lands farther away from existing infrastructure and services. Given its location adjacent to existing development, the Project site is served by existing infrastructure including roads, water, sewer, and storm drain and is within a short walk of downtown St. Helena and the City Library. These factors contribute to meeting the intent of policies HE2.1 and HE2.2, which encourage higher density housing to protect agricultural lands and to encourage a balance of housing types (Goal 2). Overall, the Proposed Project is consistent with the City’s Housing Element and the impact is less than significant.

City of St. Helena Zoning Ordinance
A zoning designation applied to the Project site must be consistent with the General Plan and the anticipated uses of the site. The proposed land uses and density of the Proposed Project is consistent with the 1993 General Plan (and 2019 General Plan) MDR land use designation and MR zoning.

Chapter 17.152 of the Zoning Ordinance implements the City’s Residential Growth Management System, intended to regulate residential growth of the City to approximately 2% per year. As stated previously this imposes a cap on the total number of residential units to 2,850 Citywide by 2010 (included as Implementing Policy 2.6.11 of the 1993 General Plan). However, the City’s Residential Growth Management System is no longer enforceable due to the passage of SB 330 (see Gov't Code Section 66300) otherwise known as the Housing Crisis Act of 2019. This act prevents cities from establishing or implementing any provision that imposes a limit on the number of housing units that can be approved or constructed annually or for some other period.

Therefore, as the City can no longer implement a restriction on the number of residential units that can be constructed, the Proposed Project does not have to be consistent with this chapter of the Zoning Ordinance.

The Tentative Subdivision Map includes a 3.4-acre lot (Lot 52) designated for 25 multifamily affordable housing units and also proposes to develop 11 ADUs consistent with Section

17.116.030 of the Zoning Ordinance. The City would enter into an Affordable Housing Agreement in conjunction with the approval of the Tentative Subdivision Map. The Tentative Subdivision Map and the Proposed Project’s Affordable Housing Agreement must be consistent with the City’s Housing Trust Fund, Housing Impact Fee, and Inclusionary/In-lieu Fee Agenda Item #5.4.

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Requirements (Chapter 17.146). Under Section 17.146.050(g)(2), if “the developer is required to build four or more units of affordable housing, the number of affordable units which are required to be constructed in very low, low or moderate units shall be determined by the ratio of units needed in each of those categories in order to satisfy the City’s fair share housing goals.” Per the City’s Regional Housing Needs Allocation, the Proposed Project’s multifamily rental units should be rented to 25% very low-income households, 17% low income households, and 21% moderate income households. The Proposed Project is proposing moderate and very lowincome restricted units, with no units designated for low income single-family houses as required by the City’s inclusionary housing requirements. Additionally, Section 17.146.050(I) states that affordable units should be comparable in number of bedrooms with an exterior appearance consistent with a project’s market rate housing and be dispersed throughout a project site. As proposed, the ADUs would not have a comparable number of bedrooms to the market rate units, and the 25 multifamily affordable housing units would be located on a single

3.4-acre parcel (Lot 52) with 11 ADUs scattered throughout the other 51 single-family lots.

Because these units are not comparable to the proposed single-family units in number of bedrooms and are not dispersed throughout the site the Proposed Project would be required either develop an alternative equivalent proposal or pay an in-lieu fee, both of which require approval by the City Council.

As indicated previously, the Proposed Project applicant is only requesting approval of a Tentative Subdivision Map at this time. The map is consistent with the development standards of the MR zoning district. Note that only the lot configuration of the proposed subdivision can be assessed at this time; individual structures must comply with the MR development standards, including setbacks, height and lot coverage, at the time those applications are submitted. In addition, as noted in Chapter 2, Project Description, the Proposed Project would also be subject to the City’s design review process. Future construction of the attached multifamily units would require approval of a conditional use permit.

If the Proposed Project is approved, additional discretionary and ministerial approvals would be required including design review and a conditional use permit for the multifamily housing. This would require the Proposed Project applicant to demonstrate compliance with specifics of the Zoning Ordinance as well as the City’s Municipal Code. Because the approvals the applicant is requesting at this time are consistent with the City’s Zoning Ordinance the impact is less than significant.

Plan Bay Area 2040
The Plan Bay Area 2040 is the Regional Transportation Plan and SCS for the nine-county San Francisco Bay Area, which includes Napa County. The Plan assumes development of the Project site with residential uses, consistent with the City’s 1993 (and 2040 General Plan) land use designation, and due to its location near downtown, it is consistent with the goal of SB 375 to reduce greenhouse gas emissions from cars and light trucks by developing new uses near Agenda Item #5.4.

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existing infrastructure and alternative transportation choices. The Proposed Project as proposed is consistent with the Plan Bay Area 2040 and the impact is less than significant.

Mitigation Measures
None required.

3.10.5 Cumulative Impacts
The land use analysis in an EIR does not typically include a discussion of cumulative impacts because the consistency analysis for applicable land use goals and policies is not an additive effect.

3.10.6 References
Association of Bay Area Governments. 2017. Plan Bay Area 2040 Draft Environmental Impact Report. April 2017.

City of St. Helena. 1993. City of St. Helena 1993 General Plan. September 28, 1993.

City of St. Helena. 2019. City of St. Helena General Plan Update 2040. May 2019.

Agenda Item #5.4.

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INTENTIONALLY LEFT BLANK
Agenda Item #5.4.

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3.11 NOISE AND VIBRATION

3.11.1 Introduction
This section presents potential noise and vibration impacts of the proposed Hunter Subdivision Project (Proposed Project), which includes the environmental setting and existing ambient noise conditions, regulatory framework, potential short-term and long-term noise and vibration impacts, and proposed measures to mitigate any identified significant impacts.

A total of four comments were received that raised concerns regarding noise and vibration in response to the Notice of Preparation. Two of the comments stated that noise associated with the Proposed Project was a concern; one comment indicated that construction noise needed to be evaluated; the final comment pointed out the presence of a senior residential development in the vicinity of the Project site, and as such it was important to maintain peace and quiet in the area. Concerns regarding noise are addressed in this section. A copy of the Notice of Preparation and comments received is included in Appendix A.

Information contained in this section is based on the proposed tentative map, the Federal Highway Administration (FHWA) Roadway Construction Noise Model and the FHWA Traffic Noise Model (TNM 2.5) used to estimate Proposed Project noise emissions, the California Department of Transportation’s Technical Noise Supplement to the Traffic Noise Analysis Protocol (Caltrans 2013), and Federal Transit Authority (FTA) Transit Noise And Vibration Impact Assessment (FTA 2006). The analysis is based on noise and vibration modeling, which can be found in Appendix I. Other sources consulted are listed in Section 3.11.6, References.

3.11.2 Environmental Setting
Vibrations, traveling as waves through air from a source, exert a force perceived by the human ear as sound. Sound pressure level (referred to as sound level) is measured on a logarithmic scale in decibels (dB) that represent the fluctuation of air pressure above and below atmospheric pressure. Frequency, or pitch, is a physical characteristic of sound and is expressed in units of cycles per second or hertz. The normal frequency range of hearing for most people extends from about 20 to 20,000 hertz. The human ear is more sensitive to middle and high frequencies, especially when the noise levels are quieter. As noise levels get louder, the human ear starts to hear the frequency spectrum more evenly. To accommodate for this phenomenon, a weighting system to evaluate how loud a noise level is to a human was developed. The frequency weighting called “A” weighting is typically used for quieter noise levels which de-emphasizes the low frequency components of the sound in a manner similar to the response of a human ear. This A-weighted sound level is called the “noise level” and is referenced in units of dBA.

Agenda Item #5.4.

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Since sound is measured on a logarithmic scale, a doubling of sound energy results in a 3 dBA increase in the noise level. Changes in a community noise level of less than 3 dBA are not typically noticed by the human ear. Changes from 3 to 5 dBA may be noticed by some individuals who are extremely sensitive to changes in noise. A 5 dBA increase is readily noticeable (EPA 1973). The human ear perceives a 10 dBA increase in sound level as a doubling of the sound level (i.e., 65 dBA sounds twice as loud as 55 dBA to a human ear).

An individual’s noise exposure occurs over a period of time; however, noise level is a measure of noise at a given instant in time. Community noise sources vary continuously, being the product of many noise sources at various distances, all of which constitute a relatively stable background or ambient noise environment. The background, or ambient, noise level gradually changes throughout a typical day, corresponding to distant noise sources, such as traffic volume, as well as changes in atmospheric conditions.

Noise levels are generally higher during the daytime and early evening when traffic (including airplanes), commercial, and industrial activity is the greatest. However, noise sources experienced during nighttime hours when background levels are generally lower can be potentially more conspicuous and irritating to the receiver. To evaluate noise in a way that considers periodic fluctuations experienced throughout the day and night, a concept termed “community noise equivalent level” (CNEL) was developed, wherein noise measurements are weighted, added, and averaged over a 24-hour period to reflect magnitude, duration, frequency, and time of occurrence. A complete definition of CNEL and other terminology used to describe noise is provided in Table 3.11-1.

Exterior Noise Distance Attenuation
Noise sources are classified in two forms: (1) point sources, such as stationary equipment or a group of construction vehicles and equipment working within a spatially limited area at a given time, and (2) line sources, such as a roadway with a large number of pass-by sources (motor vehicles). Sound generated by a point source typically diminishes (attenuates) at a rate of 6.0 dBA for each doubling of distance from the source to the receptor at acoustically “hard” sites and at a rate of 7.5 dBA for each doubling of distance from source to receptor at acoustically “soft” sites. Sound generated by a line source (i.e., a roadway) typically attenuates at a rate of 3 dBA and 4.5 dBA per doubling distance, for hard and soft sites, respectively. Sound levels can also be attenuated by man-made or natural barriers. For the purpose of the sound attenuation discussion, a “hard” or reflective site does not provide any excess ground-effect attenuation and is characteristic of asphalt or concrete ground surfaces, as well as very hard-packed soils. An acoustically “soft” or absorptive site is characteristic of unpaved loose soil or vegetated ground.

Agenda Item #5.4.

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Table 3.11-1
Definitions of Acoustical Terminology
Term Definition
Decibel (dB) A unit describing the amplitude of sound, equal to 20 times the logarithm to the base 10 of the ratio of two like quantities
Sound Pressure Level (SPL) 10 times the logarithm to the base 10 of the ratio between the square of the sound to the square of the reference sound pressure of 20 µPascals. Sound pressure level is the quantity that is directly measured by a sound level meter and expressed in dB.

Frequency (Hz) The number of complete pressure fluctuations per second above and below atmospheric pressure. Normal human hearing is between 20 hertz and 20,000 hertz.

A-Weighted Sound Level (dBA) SPL in decibels as measured on a sound level meter using the A-weighting filter network. The A-weighting filter de- emphasizes low and high frequency components of frequency components of sound in a manner similar to the frequency response of the human ear and correlates well with subjective response to sound. All sound levels in this report are A-weighted.

Noise Unwanted sound.

Equivalent Sound Level (Leq) The average A-weighted sound level during the measurement period. For this CEQA evaluation, Leq refers to a one-hour period unless otherwise stated.

Lmax, Lmin The maximum and minimum A-weighted sound level during the measurement period.

L01, L10, L50, L90 The A-weighted sound levels that are exceeded l%, l0%, 50%, and 90% of the time during the measurement period.

Day/Night Noise Level (Ldn) The average A-weighted noise level during a 24-hour day, obtained after addition of 10 decibels to levels measured during the night between l0 pm and 7 am.

Community Noise Equivalent Level
(CNEL)
The average A-weighted sound level during a 24-hour day, obtained after addition of S decibels in the evening from 7 p.m. to l0 p.m. and after addition of l0 decibels to sound levels during the night between l0 p.m. and 7 a.m.

Ambient Noise Level The composite of noise from all sources near and far. The normal or existing level of environmental noise at a given location.

Impulsive Noise Noise loud enough to disrupt normal activities and usually lasting less than one second.

Source: St. Helena General Plan 1993.

Fundamentals of Vibration
Vibration is an oscillatory motion that can be described in terms of displacement, velocity, or acceleration. The response of humans to vibration is very complex. However, it is generally accepted that human response is best approximated by the vibration velocity level associated with the vibration occurrence.

Heavy equipment operation, including stationary equipment that produces substantial oscillation or construction equipment that causes percussive action against the ground surface, may be perceived by building occupants as perceptible vibration. It is also common for ground-borne vibration to cause windows, pictures on walls, or items on shelves to rattle. Although the Agenda Item #5.4.

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perceived vibration from such equipment operation can be intrusive to building occupants, the vibration is seldom of sufficient magnitude to cause even minor cosmetic damage to buildings.

When evaluating human response, ground-borne vibration is usually expressed in terms of root mean square (RMS) vibration velocity. RMS is defined as the average of the squared amplitude of the vibration signal. As for sound, it is common to express vibration amplitudes in terms of decibels defined as:

𝐿𝑣 = 20 log (
𝑣𝑟𝑚𝑠
𝑣𝑟𝑒𝑓 )
Where vrms is the RMS vibration velocity amplitude in inches/second and vref is the decibel reference of 1x10-6 inches/second.

To avoid confusion with sound decibels, the abbreviation VdB is used for vibration decibels. The vibration threshold of perception for most people is around 65 VdB (which is equivalent to

0.0018 inches per second RMS). Vibration levels in the 70 to 75 VdB range are often noticeable, but generally deemed acceptable, and levels in excess of 80 VdB are often considered unacceptable (FTA 2006).

Vibration impacts to buildings are generally discussed in terms of peak particle velocity (PPV) that describes particle movement over time (in terms of physical displacement of mass, expressed as inches per second). Groundborne vibration generated by construction projects is usually highest during pile driving, rock blasting, soil compacting, jack hammering, and demolition-related activities. Next to pile driving and soil compacting, grading activity has the greatest potential for vibration impacts if large bulldozers, large trucks, or other heavy equipment are used. A conservative maximum vibration level standard is 0.2 inches per second PPV for the prevention of structural damage to typical residential buildings (Caltrans 2013).

Existing Noise Conditions
Project Site Noise Levels
The Project site is currently vacant land with a small vineyard area. The area surrounding the Project site is a mix of agricultural, residential, commercial offices, and open space. Residential properties are located adjacent to the south, southeast, and east of the Proposed Project, as well as approximately 500 feet to the west; the closest existing residences (including mobile homes) are located at distances from 20 feet to 65 feet from the property boundaries. A new single-family residence is currently under construction just west of the Project site. Commercial offices are located at the terminus of Adams Street (approximately 650 feet to the south) and a Agenda Item #5.4.

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preschool is located along Adams Street to the south of the offices (approximately 950 feet to the south of the Proposed Project boundary).

The ambient or existing noise environment is described on the basis of 24-hour measurements completed in the vicinity of the Project site. Existing noise levels were measured at the Project site boundaries in order to establish baseline noise conditions against which to compare Proposed Project operational noise levels, as shown in Figure 3.11-1, Noise Measurement Locations. A total of three 24-hour noise measurements were performed, one apiece on the southern, western, and northern property boundaries. Sound-level measurements were performed using SoftdB Piccolo 3 Models (ANSI Type II). American National Standards Institute (ANSI) Type II sound-level meters have sufficient accuracy to be used for environmental noise evaluation. The sound-level meters were calibrated before and after the 24-hours measurements using a Larson Davis Model CAL150 calibrator.

Table 3.11-2 summarizes the dates and start/stop times for each 24-hour measurement, as well as the calculated 24-hour weighted average noise level (CNEL). See Appendix I for data tables for each of the 24-hour measurement periods and the calculation of CNEL from the recorded hourly average values.

Table 3.11-2
Existing Ambient Noise Measurement Results
Location Dates Start Time Stop Time CNEL (dBA)
Southeast Property Boundary 10/16/2018
to
10/17/2018
11 AM 11 AM
48 Western Property Boundary 50
Northeast Property Boundary 52
Source: Dudek 2018.

Existing noise levels on site, and immediately adjacent to neighboring residential land uses, are well within the City’s exterior noise exposure limit of 60 dBA CNEL for residential land uses (Refer to Section 3.11.3 – Local).

3.11.3 Regulatory Setting
Federal
Federal Highway Administration Standards
Code of Federal Regulations (CFR) Title 23, Part 772 sets procedures for the abatement of highway traffic noise and construction noise. Title 23 is implemented by the Federal Department of Transportation FHWA. The purpose of this regulation is to provide procedures for noise studies and noise abatement measures to help protect the public health and welfare, to supply Agenda Item #5.4.

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noise abatement criteria, and to establish requirements for information to be given to local officials for use in the planning and design of highways. All highway projects which are developed in conformance with this regulation shall be deemed to be in conformance with the Department of Transportation FHWA Noise Standards. Title 23 establishes a 67 dBA Leq(h) standard applicable to federal highway projects for evaluating impacts to land uses including residences, recreational uses, hotels, hospitals, and libraries (23 CFR Chapter 1, Part 772, Section 772.19).

Federal Transit Administration and Federal Railroad Administration Standards Although the FTA standards are intended for federally funded mass transit projects, the impact assessment procedures and criteria included in the FTA’s Transit Noise and Vibration Impact Assessment Manual (FTA 2006) are routinely used for projects proposed by local jurisdictions.

The FTA and Federal Railroad Administration have published guidelines for assessing the impacts of ground-borne vibration associated with rail projects, which have been applied by other jurisdictions to other types of projects. The FTA measure of the threshold of architectural damage for conventional sensitive structures is 0.2 inches per second perturbation projection vector (PPV).

State
California Noise Control Act of 1973
Sections 46000 through 46080 of the California Health and Safety Code, known as the California Noise Control Act of 1973, declares that excessive noise is a serious hazard to the public health and welfare and that exposure to certain levels of noise can result in physiological, psychological, and economic damage. It also identifies a continuous and increasing bombardment of noise in the urban, suburban, and rural areas. The California Noise Control Act declares that the State of California has a responsibility to protect the health and welfare of its citizens by the control, prevention, and abatement of noise. It is the policy of the state to provide an environment for all Californians free from noise that jeopardizes their health or welfare.

California Noise Insulation Standards (CCR Title 24)
In 1974, the California Commission on Housing and Community Development adopted noise insulation standards for hotels, motels, dormitories, and multi-family residential buildings (CCR Title 24, Part 2). Title 24 establishes standards for interior room noise (attributable to outside noise sources). The regulations also specify that acoustical studies must be prepared whenever a multi-family residential building or structure is proposed to be located in an area with CNEL (or Ldn) of 60 dBA or greater. Such acoustical analysis must demonstrate that the residence has been designed to limit intruding noise to an interior CNEL (or Ldn) of at least 45 dBA (California’s Title 24 Noise Standards, Chap. 2-35).

Agenda Item #5.4.

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CHILES AVE

PASEO GRAND DR

STARR AVE

HUNT AVE

HOLLIS LN

ADAMS ST

LAGUNA SECA

MONTE VISTA AVE

GROVE CT

SAN JUAN CT

DEL RIO CT

FULTON LN

MEADOWCREEK CIR
LT1
LT2
LT3
Noise Measurement Locations
Hunter Subdivision Project
SOURCE: Digital Globe 2017, Napa County 2015
0 160 320Feet
Project Boundary
LT - Long Term Noise
Measurement Location
FIGURE 3.11-1
Agenda Item #5.4.

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Agenda Item #5.4.

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Local
City of St. Helena 1993 General Plan
The Public Health and Safety Element of the City of St. Helena 1993 General Plan (City of St.

Helena 1993) provides guiding and implementing policies regarding noise management, including the following:

Policy 8.3.1: Maintain a city-wide noise environment that balances various City objectives while minimizing the impact of highway, railroad, and industrial noise on the public, while recognizing the agricultural basis of the community.

Policy 8.3.2: Discourage noise-sensitive land uses from locating in areas with inappropriate or high noise levels based on the land use compatibility guidelines, interior noise level criteria, and the noise contour maps.

Policy 8.3.3: Require new residential developments to implement noise mitigation measures when built in close proximity to noise sources such as Highway 29, the railroad tracks, and the Harold Smith & Sons gravel quarry. These developments should consider the resulting exterior as well as interior noise environment.

Implementing Policy 8.3.5: Continue to consider the environmental impact of transportation-related noise and other noise sources in the review and approval of subdivision plans and requests for changes in the zoning ordinance.

Implementing Policy 8.3.6: Adopt the Title 24 interior noise level standard of 45 dBA, Ldn in all habitable rooms for all dwelling units. Adopt a maximum allowable noise level standard of 60 dBA Ldn for residential exterior activity areas such as patios, back yards or recreational areas.

Implementing Policy 8.3.11: Require construction operations to use noise suppression devices and techniques and limit noisy construction activities to the least noise sensitive times (8 am to 5 pm, Monday through Friday).

The Public Health and Safety Element also prescribes recommended maximum exterior noise exposure levels for each land use, as presented in Table 3.11-3.

Agenda Item #5.4.

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Table 3.11-3
Noise/Land Use Compatibility Guidelines
Land Use Category
Completely
Compatible a
Tentatively
Compatible b
Normally
Incompatible c
Completely
Incompatible d
Residential < 55 55 to 60 60 to 75 75 >
Commercial/Office < 65 65 to 75 75 to 80 80 >
Industrial/Agriculture < 70 70 to 80 80 to 85 85 >
School/Library/Hospital < 65 65 to 70 70 to 80 80 >
Playground, Park < 67 67 to 70 70 to 75 75 >
Notes:
a Completely Compatible: the noise exposure is such that both the indoor and outdoor environments are pleasant, as long as noise sources do not cause the ambient noise to increase more than 5 dBA, and in the absence of intrusive and intermittent noise. b Tentatively Compatible: the noise exposure is great enough to be of concern, but common building construction practices will make the living indoor environment acceptable, even for sleeping quarters, and the outdoor environment will be reasonably pleasant for recreation and play.
c Normally Incompatible: the noise exposure is so severe that unusual and costly building construction is necessary to ensure some tranquility inside one's home, and barriers must be erected between the site and prominent noise sources to make the outdoor environment tolerable.
d Completely Incompatible: the noise exposure at the site is so severe that construction costs to make the indoor living environment acceptable would be prohibitive and the outdoor environment would still be intolerable.

Source: 1993 St. Helena General Plan.

City of St. Helena 2019 General Plan (“General Plan Update 2040”) The Public Health and Safety Element of the City of St. Helena 2019 General Plan (City of St.

Helena 2019) provides guiding and implementing policies regarding noise management, including the following:

Policy PS2.1: Preserve the current low levels of noise in St. Helena to maintain the City’s rural atmosphere.

Policy PS2.2: Maintain a citywide environment that balances various City objectives while minimizing the impact of highway, railroad, and industrial noise. The City should manage both indoor and outdoor noise levels to protect health and safety. A combination of noise standards and existing noise levels should be used to determine impacts and mitigation measures.

Policy PS2.3: Minimize potential noise impact conflicts between land uses by regulating incompatible land uses. Encourage noise-generating uses to reduce their impacts while promoting land use patterns that avoid conflicts. Employ compatibility guidelines, interior noise level criteria, the City’s noise standards, and noise contour maps to determine the compatibility of land uses.

Agenda Item #5.4.

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Policy PS2.4: Require a reduction and/or control of the use of machinery, mechanical systems and other noise-making equipment and sources in and near residential areas where the noise impacts would be considered intrusive to adjacent residential property, unless consistent with the right-to-farm.

Policy PS2.5: An increase in average noise levels of 5 dBA or greater is considered to be significant and to constitute a noise impact by the noise source in question for the purpose of environmental analyses.

The Public Health and Safety Element also prescribes the same recommended maximum exterior noise exposure levels for each land use, as previously presented in Table 3.11-3.

St. Helena Municipal Code
The St. Helena Municipal Code, Chapter 8.24 of Title 8, the Health and Safety Code, specifies unnecessary noise which can be heard outside of any building by attaching any noiseproducing attachment to any vehicle; or blowing or ringing any horn, whistle or bell; by operating a loudspeaker, public address system or sound amplification system; or by making any other loud or unusual noise which disturbs the peace of any other person would violate the ordinance unless permitted by the Chief of Police. Similarly, noise generated by commercial activities between the hours of 10.00 p.m. and 7:00 a.m. that can be heard at the property line of any parcel is prohibited, unless permitted by the Chief of Police.

Construction activities are limited to the hours between 8:00 a.m. and 5:00 p.m. Monday through Saturday. Construction is not allowed on Sundays and holidays (federal and local) if noise can be heard at the property line of any parcel of real property within the city limits.

Delivery of materials/equipment and cleaning and servicing of machines/ equipment are limited to between 7:00 a.m. and 6:00 p.m.

3.11.4 Impacts and Mitigation Measures
Methods of Analysis
The analysis of existing and future noise environments is based on observations, noise level measurements, and computer modeling (model output data is included in Appendix I). Existing noise levels were monitored at selected on-site and off-site locations using ANSI Type II sound level meters for general environmental noise measurement instrumentation. Traffic noise modeling involved the calculation of existing and future traffic noise levels along roadway sections where the Proposed Project would contribute additional vehicle trips, as provided in the Proposed Project’s traffic report (Appendix K), using the FHWA model. Vibration from transportation sources was not Agenda Item #5.4.

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evaluated in detail because it is not common for vibration from motor vehicles traveling on paved roads to cause disturbance or substantial annoyance in these areas.

Construction Noise and Vibration
Construction noise levels were determined using the FHWA’s Roadway Construction Noise Model.

For construction noise, this analysis assumed that compliance with conditions specified in the City’s Noise Ordinance. Specifically, limiting construction to the hours of 8 a.m. to 5 p.m., Monday through Saturday, and prohibit construction activities on Sunday and holidays. For construction vibration, this analysis uses the FTA thresholds for structural damage (vibration-peak-particle velocities greater than 0.2 inches per second) and FTA’s threshold for human annoyance within residences (80 VdB at residences where people normally sleep, for infrequent events).

For the purposes of noise modeling, it was conservatively assumed that construction of the Proposed Project would occur over a period of approximately 6 years. Construction scenario assumptions, including phasing, equipment mix, and vehicle trips, were based on information provided by the Proposed Project applicant and CalEEMod-generated default values. Complete detailed construction assumptions are included in Appendix I. Implementation of the Proposed Project would include construction of 87 residential units including 51 single-family residences, 11 accessory dwelling units, and 25 multi-family units.

As described in Chapter 2, Project Description, the Proposed Project would grade an approximately 17-acre site. Some soil export would be required to balance the site. Soil balance would occur within each subset area and hauling would not be required between subset areas.

Balancing activities are anticipated to be performed through the use of off-road construction equipment (e.g., excavators, graders, dozers, and scrapers). The construction equipment mix used for estimating the construction noise emissions of the Proposed Project is shown in Table

3.11-4. Notably, because detailed specific information regarding the construction equipment fleet is unknown at the time of analysis, the analysis is based on the default construction equipment fleet provided by CalEEMod.

Table 3.11-4
Construction Equipment List by Phase
Construction Phase Equipment Quantity
Site Preparation Rubber Tired Dozers 3
Tractors/Loaders/Backhoes 4
Grading Excavators 2
Graders 1
Rubber Tired Dozers 1
Scrapers 2
Agenda Item #5.4.

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Table 3.11-4
Construction Equipment List by Phase
Construction Phase Equipment Quantity
Tractors/Loaders/Backhoes 2
Paving Pavers 2
Paving Equipment 2
Rollers 2
Building Construction Cranes 1
Forklifts 3
Generator Sets 1
Tractors/Loaders/Backhoes 3
Welders 1
Architectural Coating Air Compressors 1
Source: See Appendix I for details.

Thresholds of Significance
Consistent with Appendix G of the California Environmental Quality Act (CEQA) Guidelines, a significant impact would occur if development of the Proposed Project would do any of the following:
• Generation of a substantial temporary or permanent increase in ambient noise levels in the vicinity of the project in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies. • Generation of excessive groundborne vibration or groundborne noise levels. • For a project located within the vicinity of a private airstrip or an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels.

Noise Significance Criteria Applicable to the Proposed Project Based on the City’s 1993 General Plan Public Safety Element and Municipal Code (Chapter

8.24), as well as standards adopted by other agencies that are customarily applied to the assessment of short-term noise generation, the Proposed Project would have a significant impact on noise if it would result in:
• Construction, between the hours 8:00 a.m. and 5:00 p.m. Monday through Saturday, construction noise levels greater than 90 dBA Leq at any vicinity residence (FTA 2006).

Also, any noise generating construction activities occurring between 5:00 p.m. and 8 a.m. weekdays and Saturdays, or any time on Sundays or holidays (St. Helena 1993).

Agenda Item #5.4.

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• Construction, the exposure of existing structures in the Proposed Project vicinity to vibration levels exceeding 0.2 inches per second PPV, or exposure of residents to vibration levels of 80 VdB in residences where people normally sleep, for infrequent events (FTA 2006).
• Proposed Project operation, generation of noise in excess of 60 dBA Ldn at the property line for any existing residential properties in the Proposed Project vicinity (St. Helena 1993). • Proposed Project operation, an increase of 3 dBA CNEL or more in existing roadway traffic noise levels, as a result of the addition of Proposed Project generated traffic on vicinity roadways (Caltrans 2013).

Threshold Criteria not Applicable to the Proposed Project Due to the location and characteristics of the Proposed Project, certain significance criteria are not applicable and therefore, are not considered potential impacts. These criteria are addressed briefly below and are not discussed further in this document.

Airports/Airport Land Use Plan
The Project site is not located within two miles of an airport, the closest airport is Angwin-Parrett Field airport approximately 4.5 miles north-northeast of the Project site. Therefore, future residents would not be exposed to elevated noise levels from aircraft operation and airport noise issues (last significance threshold listed above) are not addressed further in the analysis.

Impacts and Mitigation Measures

3.11-1: Would the Proposed Project result in a temporary (short-term) increase in construction noise levels that would cause a substantial increase in ambient noise levels and exceed City standards? This impact would be potentially significant.

Construction of the Proposed Project would generate noise that could expose nearby receptors (residences) to elevated noise levels that may disrupt communication and routine activities. The magnitude of the impact would depend on the type of construction activity, equipment, duration of the construction phase, distance between the noise source and receiver, and intervening structures. Noise from construction equipment generally exhibits point source acoustical characteristics. A point source sound is attenuated (or reduced) at a rate of 6 dB per doubling of distance from the source for “hard site” conditions and at 7.5 dB per doubling of distance for “soft site” conditions. These rules apply to the propagation of sound waves with no obstacles between source and receivers, such as topography (ridges or berms) or structures. The range of maximum noise levels for various types of construction equipment is provided in Table 3.11- Agenda Item #5.4.

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5. Typical operating cycles may involve two minutes of full power, followed by 3 or 4 minutes at lower levels.

Table 3.11-5
Construction Equipment Noise Emission Levels
Equipment Typical Sound Level (dB) - 50 feet from Source Air Compressor 81
Backhoe 80
Compactor 82
Concrete Mixer 85
Crane, Mobile 83
Dozer 85
Generator 81
Grader 85
Loader 85
Paver 89
Pneumatic Tool 85
Pump 76
Roller 74
Saw 76
Scraper 89
Truck 88
Source: FTA 2006.

Whereas Table 3.11-5 shows the noise level of individual pieces of equipment, the noise levels shown in Table 3.11-6 take into account operation of multiple pieces of construction equipment simultaneously, and lists the typical overall noise levels that would be expected for each phase of construction. These noise levels are based on surveys conducted by the United States Environmental Protection Agency in 1971. In the time since 1971, regulations have been enforced to improve noise generated by certain types of construction equipment to meet worker noise exposure standards. Also, because of stringent air quality emissions standards, newer, cleaner, and quieter heavy equipment is used on most construction projects in California. Thus, construction phase noise levels indicated in Table 11.3-6 represent “worst-case” conditions. As the table shows, the highest noise levels are expected to occur during the grading/excavation and building construction phases of construction.

Agenda Item #5.4.

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Table 3.11-6
Outdoor Construction Noise Levels by Phase
Construction Phase
Adjacent Residence at
20 Feet (dBA Leq)
Adjacent Mobile Home
Park at
65 Feet (dBA Leq)
Acoustic Center at
97 Feet (dBA Leq)
Site Preparation 92 82 79
Grading/Excavation 95 85 81
Building Construction 94 84 80
Paving 89 79 75
Finishing 82 71 68
Notes: dBA = A-weighted decibel; Leq = energy equivalent sound level.

Source: Roadway Construction Noise Model, see Appendix I.

As shown in Table 3.11-6, construction-related noise levels could reach up to 95 dBA Leq at residential property lines to the east of the Project site. The City exempts construction activity noise from standard exterior noise exposure limits, if conducted during specific limited daytime hours. The City’s Health and Safety Code (Chapter 8.24 of Title 8, the Health and Safety Code) requires noise generating construction activities (including demolition, excavation, and building construction), be restricted to the hours between 8:00 a.m. and 5:00 p.m., Monday through Saturday, and prohibited on Sunday and holidays (City of St. Helena Chapter 8.24). This ensures that sensitive receptors are not disturbed by early morning or late night activities.

However, the City’s 1993 General Plan includes Implementing Policy 8.3.11, which states “Require construction operations to use noise suppression devices and techniques and limit noisy construction activities to the least noise sensitive times (8 a.m. to 5 p.m., Monday through Friday).” Due to the proximity of residences to the Project site and the potential for construction noise to be an annoyance, as well as the closest adjacent offsite residence potentially being exposed to levels exceeding 90 dBA Leq for the first three construction phases and thus greater than the FTA guidance threshold, the impact is considered potentially significant.

Mitigation Measures
Mitigation Measure NOI-1 would substantially lessen construction noise upon adjacent residences by requiring administrative controls, engineering controls, and/or installation of sound abatement. Installation of an effectively placed storage container or a temporary plywood or blanket barrier on a portion of the site boundary that blocks line-of-sight between the source(s) of noise emission and the receptor of concern (e.g., residence) would be expected to provide a minimum of 3-5 dBA of noise reduction. By way of examples, doubling the distance of an operating generator from a receptor would be expected to yield a 6 dB reduction in noise.

Proper engine mufflers installed on construction equipment helps ensure that source sound emission levels are further reduced. Implementation of Mitigation Measure NOI-1 would help minimize construction noise impacts to less than significant.

Agenda Item #5.4.

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NOI-1: The Project applicant or its contractors shall implement the following for onsite noise control and sound abatement means that, in aggregate, would yield sufficient construction noise reduction during the site preparation, grading/excavation and building construction phases of the Project to ensure compliance with the FTA-based guidance standard of 90 dBA hourly Leq at or beyond the property lines of the nearest residences, as noted.

Administrative Controls – At all times during site preparation and construction:
• Comply with Chapter 8.24 of the Municipal Code with respect to allowable construction periods,
• Minimize idling time of onsite equipment, and
• Either locate onsite stationary construction equipment (such as generators or air compressors) as far from adjacent residential property boundaries as is feasible, or place this equipment inside an approved noise-attenuating casing (e.g., sound-attenuated air intakes and heat vents, exhaust mufflers, etc.), or place this equipment indoors.

Engineering Controls – All mobile and stationary construction equipment employing an internal combustion engine shall be equipped with suitable exhaust and intake silencers which are in good working order; and Install Sound Abatement – During site preparation and construction which involves the operation of more than two pieces of heavy equipment (dozer, backhoe, front-end loader, crane, tractor, etc.) for at least one hour and when operating within 25 feet of the exterior of a residence (either offsite or onsite), do the following:
• Erect a temporary barrier (i.e., plywood sheet) or install sound blankets (or comparable temporary solid barriers) on the Project’s construction fencing, or
• Locate sound path intervening containers or trailers onsite to block direct line-of-sight between residences and the operating heavy equipment.

3.11-2: Would the Proposed Project expose existing residential areas to excessive vibration due to project construction? This impact would be less than significant.

During site clearing, grading and construction activities for the Proposed Project groundborne vibration would be produced by heavy-duty construction equipment. The most important Agenda Item #5.4.

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equipment relative to generation of vibration, and the vibration levels produced by such equipment, is illustrated in Table 3.11-7.

Table 3.11-7
Vibration Velocities for Typical Construction Equipment Equipment
PPV at 25 Feet
(Inches Per Second)
Approximate Ground Vibration Level
25 feet (VdB)
Large Bulldozer 0.089 87
Loaded Trucks 0.076 86
Drill Rig / Auger 0.089 58
Jackhammer 0.035 87
Small Bulldozer 0.003 79
Source: FTA 2006.

As shown in Table 3.11-7, use of heavy equipment (e.g., large bulldozer) generates vibration levels of 0.089 inches per second PPV at a distance of 25 feet. The City’s 1993 General Plan Public Safety Element and Municipal Code (Chapter 8.24) requires limiting the exposure of existing residences to vibration levels exceeding 0.2 inches per second PPV, or exposure of residents to vibration levels of 80 VdB in residences where people normally sleep. The nearest residences to the Project site would be approximately 50 feet from ground disturbance from structural foundations and could experience vibration levels of 0.04 inches per second PPV.

Vibration levels at these receptors would not exceed the FTA building damage threshold of 0.2 inches per second PPV. A large bulldozer has a vibration level of 87 VdB measured at 25 feet, at the nearest residences (50 feet) this level would be attenuated to approximately 78 VdB, which is less than the FTA’s threshold of 80 VdB. Vibration between 70 and 80 VdB could be noticeable but is generally not considered annoying or destructive. As such, construction-related vibration associated with the Proposed Project would result in a less-than-significant impact.

Mitigation Measures
None required.

3.11-3: Would the Proposed Project generate a substantial temporary or permanent operational increase in noise that would exceed City standards? The impact would be less than significant.

Stationary Sources
Operational noise sources for residential areas typically include heating, ventilation, and air conditioning (HVAC) equipment and landscape maintenance activities. Landscape maintenance activities involve short-term noise generation events that do not typically have the potential to Agenda Item #5.4.

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increase the ambient noise levels when referring to the 24-hour Ldn metric (which is referenced in the City’s Public Safety Element policies). These activities would also not be dissimilar in intensity or character from landscape maintenance activities occurring at the adjacent existing residential properties. Typical HVAC units for residences have sound levels not greater than 67 dBA Leq at 1 meter (Lennox 2017). At 20 feet (the closest residences to the Proposed Project boundary), these levels would be reduced to approximately 51 dBA Leq. Even if the HVAC equipment were to run continuously over a 24-hour period, the resulting noise level at the closest residence would be 57 dBA. Thus, operational noise levels from the proposed residences would be expected to remain below 60 dBA Ldn at existing adjacent residences, resulting in a less-than-significant impact.

Mobile Sources
The primary noise-related affect the Proposed Project could have in areas off-site is an increase in traffic, which is the main source of noise in most urban areas. Proposed-Project-related traffic noise levels were examined along roadways where the Proposed Project would principally contribute vehicle trips. Trip volume calculations, including traffic volumes along Main Street, Adams Street, Railroad Avenue, Library Lane, Starr Avenue, Hunt Avenue, Paseo Grande Drive and Silverado Trail are included in Appendix I.

Acoustical calculations using standard noise modeling equations adapted from the FHWA noise prediction model were performed for the following traffic scenarios: Existing (conditions), Existing Plus Project, Cumulative, and Cumulative Plus Project.

The modeling calculations take into account the posted vehicle speed, average daily traffic volumes for each scenario, and the estimated vehicle mix (i.e., automobiles, medium and heavy trucks). The model assumed “pavement” propagation conditions, or a hard site surface. Noise levels are indicated at 50 feet from the centerline of the road, consistent with the methodology used for the St. Helena 2019 General Plan Update Draft Environmental Impact Report (St.

Helena 2018). Noise levels at greater distances from the roadway centerline would be lower due to attenuation provided by increased distance from the noise source. Generally, noise from heavily traveled roadways would experience a decrease of approximately 3 dB for every doubling of distance from the roadway. The noise model does not take into account the soundattenuating effect of intervening structures, barriers, vegetation, or topography. Therefore, the noise levels predicted by the model are conservative with respect to potential exterior exposure levels at noise-sensitive uses located along these roadways.

Future increases in traffic noise levels, with and without the Proposed Project, are provided in Table 3.11-8.

Agenda Item #5.4.

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Table 3.11-8
Proposed-Project-Related Traffic Noise Levels
Roadway Segment
Existing
dBA CNEL
Exist +
Project
dBA CNEL
Cumulative
dBA CNEL
Cumulative +
Project
dBA CNEL
Maximum
Increase (dB)
Main Street
North/West of Adams

65.2 65.3 65.6 65.6 0.1
Main Street
South/East of Adams

65.0 65.1 65.7 65.8 0.1
Adams Street
North of Railroad

63.8 63.8 64.1 64.1 < 0.1
Railroad Avenue
Adams to Hunt

64.2 64.4 64.4 64.6 0.2
Library Lane
East of Adams

49.1 49.4 49.2 49.5 0.3
Starr Avenue
Hunt to Pope

59.7 60.0 61.3 61.5 0.3
Hunt Avenue
North of Railroad

59.6 59.8 61.2 61.4 0.2
Paseo Grande Drive
East of Hunt

62.3 62.5 63.3 63.4 0.3
Silverado Trail
South of Mountain

70.6 70.7 71.5 71.6 0.1
Source: Appendix I.

Proposed-Project-related traffic noise increases along roadways where the Proposed Project would contribute trips would in all cases be less than 1 dBA, as shown in Table 3.11-8. Such increases would therefore be well below the 3 dB perceptible increase threshold. The Proposed Project would also increase the roadway noise level by less than 3 dB in the cumulative scenario. As with project-specific increases, traffic noise levels would increase less than 3 dB CNEL on all roadways, when comparing existing noise levels to those from cumulative plus the Proposed Project. Therefore, the Proposed Project would have a less-than-significant impact due to an increase in off-site roadway traffic noise levels.

Mitigation Measures
None required.

3.11.5 Cumulative Impacts
The cumulative context for traffic noise is the traffic volume increases resulting from the Proposed Project along with buildout of the 1993 General Plan, and the anticipated increase in traffic volumes along local roadways. The traffic analysis assumed a cumulative context of Agenda Item #5.4.

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transportation impacts resulting from the Proposed Project along with buildout of the 2019 General Plan.

Non-transportation noise sources (e.g., those associated with Proposed Project operation, which for residential properties include HVAC equipment and landscape maintenance activities) and construction noise impacts are typically project-specific and highly localized (i.e., these do not generally affect the community noise level at distances beyond several hundred feet). These noise sources do not significantly contribute to cumulative noise impacts at distant locations and are not evaluated on a cumulative level.

Construction activities associated with proposed or future development within the area would contribute to cumulative noise levels, but in a geographically limited and temporary manner. As other development occurs in the area, noise from different types of uses (e.g., traffic, aircraft, fixed noise sources) would continue to combine, albeit on a localized basis, to cause increases in overall background noise conditions within the area. As a result, such sources do not significantly contribute to cumulative noise impacts at distant locations and are not evaluated on a cumulative level.

3.11-4:Would the proposed project, in addition to cumulative development in the City, increase noise that exceeds the City’s noise standards? The Project’s contribution would not be considerable.

The analysis of off-site Proposed-Project-related traffic noise levels included an evaluation of traffic volumes and resulting roadway traffic noise levels from buildout of the City. The evaluation concluded that roadway traffic levels would not reach significant levels when compared against existing roadway traffic noise levels. Therefore, the Proposed Project’s contribution to existing cumulative noise would not be considerable resulting in a less-thansignificant cumulative impact.

Mitigation Measures
None required.

3.11.6 References
Caltrans. 1987. California Vehicle Noise Emission Levels. Report No. FHWA/CA/TL-87/03.

January 1987. http://www.dot.ca.gov/hq/env/noise/pub/CA%20Vehicle%20Noise%20 Emission%20Levels.pdf.

Agenda Item #5.4.

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Caltrans (California Department of Transportation). 2013. Technical Noise Supplement – A Technical Supplement to the Traffic Noise Analysis Protocol. California Department of Transportation; Environmental Program; Environmental Engineering; Noise, Air Quality, and Hazardous Waste Management Office. October 2013. http://www.dot.ca.gov/hq/ env/noise/pub/Technical%20Noise%20Supplement.pdf.

Carrier. 2018. Product Data for 25HPB6 (5-ton capacity) Residential Heat Pump. Catalog No:
25HPB6-02PD. April 2018.

City of St. Helena. 1993. City of St. Helena General Plan, Public Health & Safety Element.

City of St. Helena. 1993. Municipal Code Chapter 8.24.

City of St. Helena. 2018. St. Helena General Plan Update 2040, Draft Environmental Impact Report. SCH# 2010042001. October 23, 2018.

City of St. Helena. 2019. City of St. Helena General Plan Update 2040. May 2019.

FHWA (Federal Highway Administration). 2004. FHWA Traffic Noise Model Version 2.5.

FHWA. 2008. Roadway Construction Noise Model (RCNM), Software Version 1.1. U.S.

Department of Transportation, Research and Innovative Technology Administration, John A. Volpe National Transportation Systems Center, Environmental Measurement and Modeling Division. Washington, D.C.

FTA (Federal Transit Administration). 2006. Transit Noise & Vibration Impact Assessment.

Federal Transit Administration, Office of Planning and Environment. May 2006.

Agenda Item #5.4.

3.12 – PUBLIC SERVICES AND RECREATION
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3.12 PUBLIC SERVICES AND RECREATION

3.12.1 Introduction
This section describes the existing public services (fire and police protection, schools, and libraries) and recreational resources in the City of St. Helena (City) and discusses applicable federal, state, and regional regulations pertaining to the provision of public services and recreational facilities to support implementation of the proposed Hunter Subdivision Project (Proposed Project). This section evaluates the potential effects of increased demand for public services and recreational facilities associated with development of the Proposed Project.

Comments received in response to the Notice of Preparation included concerns regarding overcrowding of local schools, heightened demand for police and fire services, impacts to the City’s volunteer fire department, increase in costs for City services that could be passed onto local residents, increase in use of parks, and impacts to the maintenance road/pedestrian trail along the north/northwest boundary of the Project site. All of these concerns are addressed in this section. A copy of the Notice of Preparation and comments received is included in Appendix A.

Sources referenced to prepare this section includes information provided in Chapter 2, Project Description and from the individual service providers. Other sources consulted are listed in Section 3.12.6, References.

3.12.2 Environmental Setting
This section describes the existing conditions in the Project area and identifies the public services and recreational resources and facilities that could be affected by the Proposed Project.

Fire Protection
The Project site would receive fire protection services from the St. Helena Fire Department (SHFD). The SHFD provides fire protection services for the City, including fire suppression and prevention, education, emergency medical and rescue services, and response to hazardous materials incidents. The SHFD has one station located at 1480 Main Street, approximately 0.2 miles southwest of the Project site. This station is equipped with three fire engines, one water tender, two brush engines and one combination engine and ladder truck (Capponi pers. comm. 2018, updated by A. Vidler 2021). The SHFD also has a satellite fire station located at 1025 Dowdell Lane, approximately 0.85 miles southwest of the Project site.

The SHFD is served by three full-time staff members and 24 paid-call staff, including two fire chiefs, two fire marshals, one administrative assistant/fire inspector, and two full-time firefighters (Capponi pers. comm. 2018; City of St. Helena 2018a; updated by A. Vidler 2021). All Agenda Item #5.4.

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firefighters are trained to the First Responder level and eight are certified Emergency Medical Technicians (Capponi pers. comm. 2018, updated by A. Vidler 2021). The SHFD is equipped with two Type 1 engines, one Type 3 engine, two Type 6 brush vehicles, one command vehicle, two utility vehicles, one water tender, one Type 1 truck, and one medium-duty complement rescue trailer (City of St. Helena 2018b, updated by A. Vidler 2021).

When a call is received the SHFD is dispatched along with the ambulance company. The SHFD strives to maintain a maximum fire response time of 8 minutes or less from dispatch to time of arrival within the city limits (City of St. Helena 2018b). On receiving a call, the department responds to each call with all available paid-call firefighters. On average, 10 firefighters are dispatched in response to a call. The response time to the Project site under current conditions is approximately 3 minutes during the 70-hour coverage period, which occurs between 7 a.m. to 5 p.m. Monday through Sunday, and 5–6 minutes during all other times (Capponi pers. comm. 2018, 2019; updated by A. Vidler 2021). In 2020, the SHFD responded to 855 calls for service, the majority of which were emergency medical calls (City of St. Helena 2018a, updated by A.

Vidler 2021). The department responded to approximately 69% of all calls in less than seven minutes during 2017 (City of St. Helena 2018b).

The SHFD is a member of the Napa County mutual aid automatic aid agreement, which requires all fire departments in the County to respond to a call for service as requested or required. Napa County Station 26, located in the City, and Napa County Station 12, located in the City of Yountville, provide automatic aid to all residential and commercial structure fires in the City (City of St. Helena 2018b).

The SHFD routinely reviews development applications and provides conditions of approval to address requirements for fire sprinklers, emergency access, and other fire-related concerns (City of St. Helena 2018b).

Police Protection
Police services for the Project site would be provided by the St. Helena Police Department (SHPD), located at 1480 Main Street approximately 0.2 miles from the site. The SHPD serves the City with 13 sworn police officers, 5 full-time dispatchers, one community service officer, and six police volunteers. Equipment maintained by the SHPD includes four patrol cars, one K9 unit, one Community Service Officer vehicle, one administrative vehicle, one training vehicle, and one dual purpose motorcycle. The SHPD provides 24-hour security patrol for the entire City, with one sergeant and two officers assigned to each patrol watch for the day and night shifts.

The department currently has a police officer to resident ratio of 10 officers per 7,000 residents, or 1 officer to 700 residents. The department’s on-duty average is 2 officers per 7,000 residents, or one officer per 3,500 residents (Hartley pers. comm. 2021). The department strives to maintain a staffing ratio of approximately two sworn police staff for every 1,000 residents (City of Agenda Item #5.4.

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St. Helena 2018b). The SHPD also strives to maintain an average non-emergency call response time of less than 8 minutes and average emergency response time of 5-minutes or less. The SHPD has an average response time goal for all Priority One calls of three minutes or less. The department had an average response time for Priority One calls of 2 minutes and 20 seconds in 2020. The response time to the Project site under current conditions is less than 3 minutes from the SHPD headquarters. However, according to the department, response times may vary depending on the location of the on-duty patrol unit (Hartley pers. comm. 2021).

In addition to calls within the City, the SHPD participates in separate mutual aid agreements with California Highway Patrol, the Calistoga Police Department, and the County of Napa.

Schools
The Project site is located within the St. Helena Unified School District (SHUSD). The SHUSD had an enrollment of approximately 1,192 students from kindergarten through twelfth grade during the 2017-2018 school year (City of St. Helena 2018b). SHUSD operates one primary school, one elementary school, one middle school, and one high school. Students from two nearby elementary districts also attend the district’s schools (City of St. Helena 2018c). The total capacity for all schools within the SHUSD is 1,776 (California Department of Education Data Reporting Office 2018).

The SHUSD Facility Master Plan (2010) was reviewed to determine projected SHUSD enrollment. With a general trend in declining enrollment in recent years, the district expects adequate capacity in the near term, and generally into the future (City of St. Helena 2018b).

Student capacity in the 2016–2017 school year enrollment, and projected 2017–2018, 2018– 2019, and 2019–2020 enrollment for SHUSD schools is shown in Table 3.12-1.

Table 3.12-1
SHUSD Enrollment and Capacity Data
School
Grades
Served
Total
Capacity
2016-2017
Enrollment
Projected
2017-2018
Enrollment
Projected
2018-2019
Enrollment
Projected
2019-2020
Enrollment
St. Helena Primary
School
K-2nd Grade 284 238 250 252 255
St. Helena Elementary
School
3rd-5th Grade 379 230 239 242 238
Robert Louis
Stevenson Middle
School
6th-8th Grade 387 261 278 265 264
St. Helena High
School
9th-12th Grade 726 469 438 441 439
Total 1,776 1,199 1,205 1,200 1,196
Source: California Department of Education Data Reporting Office 2018, SHUSD 2010.

Agenda Item #5.4.

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Libraries
The City operates one public library, the George and Elsie Wood Public Library, located approximately 0.1 miles northwest of the Project site at 1492 Library Lane. The library currently contains over 75,000 books, DVDs, books on CD, CDs, newspapers, magazines, microfilm and other media (City of St. Helena 2018d). The library also includes the Napa Valley Wine Library, which encompasses approximately 3,500 titles and over 6,000 items. Furthermore, the Robert Louis Stevenson Museum is also located within the library (City of St. Helena 2018d).

The City’s library has 6 full-time employees staffing the library 6 days a week, and 7 part-time employees. The library opens at 10:00 a.m. on Monday through Thursday and closes at 6:00 p.m. on Monday, 7:00 p.m. on Tuesday and Wednesday, and 9:00 p.m. on Thursday. The library is open from 2:00 p.m. until 6:00 p.m. on Friday and Saturday and is closed on Sunday.

The library currently serves approximately 42 people per hour on average. No formal plans have been made for development of new library facilities (Kreiden, pers. comm. 2018).

Recreation
The City’s Parks and Recreation Department oversees the development and operation of parks and recreational facilities within the City. There are eleven active parks and four trails within the City limits, which include a variety of recreational facilities, including tennis courts, softball fields, bocce courts, playgrounds, fitness courses, and picnic facilities. In addition, the Parks and Recreation Department provides a variety of recreational programs, including youth and adult sports programs, community classes and events, youth and teen programs, after-school and educational programs, summer camps, and special events. Maintenance of City recreational facilities is provided by the Parks Division of the Public Works Department (City of St. Helena 1993, 2018e). Table 3.12-2, below, lists the City’s active parks, park acreage, and amenities/facilities available in each park.

Table 3.12-2
City of St. Helena Recreational Facilities
Recreational Facility Type Acreage Amenities
Baldwin Park
(1591 Spring St.)
Mini 0.76 Grassy Area, Pathway, Picnic Tables
Crane Park
(360 Crane Avenue)
Community 11.27 Baseball field, Bocce Ball Courts (lighted), Horseshoe Pits, Picnic Area, Picnic Tables, Playground Equipment, Restrooms, Tennis Courts (lighted), Volleyball Court (lighted)
Jacob Meily Park
(Pope St.)
Neighborhood 5.42 Parking, Paved Walking Trail, Picnic Area, Picnic Tables, Restrooms, Grass Area
Lewis Station
(1100 Church St.)
Mini 0.13 Picnic Tables, Restrooms
Agenda Item #5.4.

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Table 3.12-2
City of St. Helena Recreational Facilities
Recreational Facility Type Acreage Amenities
Lyman Park
(1498 Main Street)
Mini 0.89 Grass Area, Historic Gazebo, Playground Equipment Mary Fryer Park
(1300 Mitchell Dr.)
Mini 0.84 Picnic Tables, Playground Equipment
Mennen Park
(1600 Voorhees
Circle)
Mini 0.17 Grass Area, Pathway
St. Helena Skate Park
(360 Crane Avenue)
Mini 0.41 Skate Park
Stephen C. McCullagh
Park (1758 Crinella
Drive)
Mini 0.14 Sandbox, Climbing Rock and Rope Structures, Benches, Play Area Stone Bridge Park
(Pope St.)
Mini 0.75 Grass Area
Wappo Park
(201 Pope St.)
Neighborhood 6.65 Dog Park, Pathway, Picnic Tables
Total 27.43
Source: City of St. Helena 2018b.

The closest parks to the Project site include Lyman Park, Jacob Meily Park, and Lewis Station, all located approximately 0.3 miles from the site. Lyman Park is an approximately 0.9-acre park that contains a picnic area, turf areas, a children’s play area and a historic gazebo (City of St.

Helena 2018f).
• Jacob Meily Park is an approximately five-acre neighborhood park that includes a turf area, picnic tables, a playground, and a paved walking trail along Sulphur Creek (City of St. Helena 2018g).
• Lewis Station is a pocket-park, measuring 0.13 acres, which contains two picnic tables and benches (City of St. Helena 2018h).
• Stone Bridge Park and Wappo Park are both located approximately 0.4 miles south of the Project site. Stone Bridge Park consists of approximately 0.75 acres of turf/grass and benches, and Wappo Park is a newly constructed neighborhood park that contains passive recreation facilities such as a loop trail, two picnic areas, and a dog park (City of St. Helena 2018i,j).

Additionally, an approximately 0.6 miles pedestrian path/trail is located parallel to the gravel maintenance road located adjacent to the northern boundary of the Project site. The maintenance road is not a City recreation trail but is used informally as a trail by local residents.

An open space parcel owned by the City is located adjacent to the project site to the north/east.

Agenda Item #5.4.

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3.12.3 Regulatory Setting
Federal Regulations
There are no federal regulations regarding the provision of local services or recreational facilities.

State Regulations
The following state regulations pertaining to public services and recreational facilities would apply to the Proposed Project. There are no state regulations pertaining to law enforcement services.

Fire Protection
Uniform Fire Code
The Uniform Fire Code contains regulations relating to construction, maintenance, and use of buildings. Topics addressed in the code include fire department access, fire hydrants, automatic storage and use, provisions intended to protect and assist fire responders, industrial processes, and many other general and specialized fire-safety requirements for new and existing buildings and the surrounding premises. The code contains specialized technical regulations related to fire and life safety.

Building, Fire and Residential Code
The State Fire Marshal’s Building, Fire and Residential Code went into effect on January 1, 2011. The 2010 California Building Standards Code includes the requirement that all new oneand two-family dwellings and townhouses include residential fire sprinklers for all residences constructed after January 1, 2011. Fire sprinkler systems are also required in office buildings and multi-family dwellings (i.e. apartments).

California Health and Safety Code
State fire regulations are set forth in Sections 13000 et seq. of the California Health and Safety Code, include regulations for building standards (as also set forth in the California Building Code), and fire protection and notification systems, fire protection devices such as extinguishers and smoke alarms, high-rise building and childcare facility standards, and fire suppression training.

California Occupational Safety and Health Administration In accordance with California Code of Regulations, Title 8, Sections 1270, Fire Prevention, and 6773, Fire Protection and Fire Equipment, the California Occupational Safety and Health Administration has established minimum standards for fire suppression and emergency medical Agenda Item #5.4.

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services. The standards include guidelines on the handling of highly combustible materials, fire hosing sizing requirements, restrictions on the use of compressed air, access roads, and the testing, maintenance, and use of all firefighting and emergency medical equipment.

California Department of Forestry and Fire Protection
The California Department of Forestry and Fire Protection (CAL FIRE) offers fire protection services for State Responsibility Areas and local jurisdictions with contracts with CAL FIRE.

State Responsibility Areas are located along the western and eastern boundaries of the City within the unincorporated area of Napa County (CALFIRE 2007). CAL FIRE also aids local fire departments by providing wildfire abatement services for their jurisdictions through mutual and automatic aid agreements. CAL FIRE also endorses state-legislated fire safety standards, supports fuel management efforts, and implements fire-safety inspections to further its objectives. CAL FIRE is responsible by law for responding to uncontrolled fire that has the capability for destruction of life, property, or natural resources.

Parks and Recreation
Quimby Act
California Government Code Section 66477, Subdivision Map Act, referred to as the Quimby Act, permits local jurisdictions to require the dedication of land and/or the payment of in-lieu fees solely for park and recreation purposes. The required dedication and/or fee are based upon the residential density, parkland cost, and other factors. Land dedication and fees collected pursuant to the Quimby Act may be used for acquisition, improvement, and expansion of park, playground, and recreational facilities or the development of public schools.

Schools
California Education Code
The California Code of Regulations (CCR), Title 5, Education Code governs all aspects of education within the state. The California Education Code authorizes the California Department of Education to develop site selection standards for school districts which require districts to select a site that conforms to certain net acreage requirements established in the California Department of Education’s 2000 School Site Analysis and Development guidebook. The guide includes the assumption that the land purchased for school sites will be in a ratio of approximately 2:1 between the developed grounds and the building area. If the “availability of land is scarce and real estate prices are exorbitant,” the site size may be reduced. California Department of Education policy states that if a school site is less than the recommended acreage required, the district shall Agenda Item #5.4.

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demonstrate how the students will be provided an adequate educational program, including physical education, as described in the district’s adopted course of study.

Senate Bill 50
Senate Bill (SB) 50 (Chapter 407, Statutes of 1998), known as the Leroy F. Greene School Facilities Act of 1998, created the School Facility Program where eligible school districts may obtain state bond funds. The new state program was funded with bond revenue from Proposition 1A, a $9.2 billion state bond initiative approved by voters in November of 1998. State funding requires matching local funds that generally come from developer fees. The passage of SB 50 eliminated the ability of cities and counties to require full mitigation of school impacts and replaced it with the ability for school districts to assess fees directly to offset the costs associated with increasing school capacity as a result of new development. SB 50 amended Government Code Section 5699(a) to state that payment of SB 50 fees would be the exclusive method of considering and mitigating impacts on school facilities that may result from a project.

Local Regulations
The following local/regional regulations pertaining to public services and recreation would apply to the Proposed Project.

City of St. Helena 1993 General Plan
The Public Health and Safety Element, Public Facilities and Services Element, and Parks and Recreation Element of the City of St. Helena 1993 General Plan provide guiding and implementing policies regarding public services and recreation facilities, including the following.

The General Plan does not contain any policies that address law enforcement.

Public Health and Safety Element - Implementing Policies Policy 8.5.6: Require all new development to meet the minimum fire flow rates specified by the City’s Fire Code.

Policy 8.5.7: Ensure that all streets and roads are adequate in terms of width, turning radius, and grade to facilitate access by City firefighting apparatus, and to provide alternative emergency ingress and egress.

Public Facilities and Services Element – Guiding Policies Policy 9.6.3: Support and cooperate with the St. Helena Unified School District in its efforts to ensure adequate financing for new school facilities. To this end, the City shall cooperate with the School District in the collection of school facility development fees Agenda Item #5.4.

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from new residential and non-residential development, and will work with the District to identify, establish, and implement additional measures that may be necessary to adequately finance school facilities in the city.

Parks and Recreation Element – Guiding and Implementing Policies Policy 10.3.5: Encourage developers to provide open space and recreational facilities as part of new residential developments. The City may consider density bonuses for the inclusion of significant public recreational facilities in new development.

Policy 10.3.6: Assess park development fees on all new commercial, industrial, and residential development sufficient to fund City-wide park improvements.

Implementing Policy 10.3.9: Adopt 5 acres of developed parkland per 1,000 residents as the goal for citywide park acquisition and development.

City of St. Helena 2019 General Plan (“General Plan Update 2040”) The Public Health and Safety Element, Public Facilities and Services Element, and Parks and Recreation Element of the City of St. Helena 2019 General Plan provide the following policies regarding public services and recreation facilities, including the following:

Public Health and Safety Element
Policy PS4.6: Ensure that all streets and roads are adequate in terms of width, turning radius, and grade in order to facilitate access by City firefighting apparatus, and to provide alternative emergency routes of ingress and egress.

Policy PS4.D: Require all new development to meet the minimum fire flow rates specified by the City’s Fire Code.

Public Facilities and Services Element
Policy PF5.4: Require that the approval of residential, commercial, or industrial development be contingent upon the mitigation of the impact of such development on the St. Helena Unified School District’s ability to serve school-age children.

Policy PF5.7: Set a goal of a maximum fire department response time of 8 minutes within the St. Helena city limits.

Policy PF5.8: Set a staffing ratio of 2 police officers per 1,000 population and for priority one calls, an average police department response time of 3 minutes or less.

Agenda Item #5.4.

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Parks and Recreation Element
Policy PR1.1: Retain the park standard from the 1993 General Plan of 5.0 acres of parkland per 1,000 residents, while striving for the nationally recommended standard of

10.5 acres per 1,000 residents.

Policy PR1.4: Require park land dedications or civic improvement fees on all new residential, commercial, and industrial developments to meet the standard of 5.0 acres of parks per 1,000 residents.

St. Helena Municipal Code
Chapter 3.32, Development Impact Fees, of the City’s Municipal Code, specifies that, in order for the City to implement the goals and objectives of the City’s General Plan and to mitigate impacts from new development within the City, the City requires development impact fees to finance public improvement projects related to civic improvement projects, public safety, sewer projects, water projects, traffic mitigation, parks and storm drainage. Development fees for public safety, civic improvement projects, and parks are provided below.

Public Safety Impact Fee
Chapter 3.32, Section 3.32.050 addresses public safety impact fees. Public safety impact fees are used to fund the acquisition, construction, and reconstruction of facilities and equipment and other capital purposes needed for the City’s fire and police departments. The impact fee is one dollar four cents ($1.04) per square foot for all new development projects.

Civic Improvement Fee
Civic improvement fees (Section 3.32.060) are used to fund the acquisition, construction, and reconstruction of City hall, the St. Helena library, community facilities, and equipment and other capital purposes needed for civic services. The impact fee is one dollar ninety-five cents ($1.95) per square foot for all new residential development projects.

Park and Recreation Impact Fee
Park and recreational impact fees (Section 3.32.065) are used to fund the acquisition, construction, and reconstruction of playgrounds, community facilities, recreation facilities and equipment and other capital purposes needed for park and recreation services. The impact fee is twelve dollars eighteen cents ($12.18) per square foot for all new medium and higher density (multi-family) residential development.

Agenda Item #5.4.

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Fire Protection Systems
Chapter 15.36 Section 15.36.060 of the City’s Municipal Code adopts the requirements of the California Fire Code, with amendments. Requirements for fire protection systems for new development within the city is included. The Ordinance requires that approved automatic sprinkler systems be installed in new buildings and structures, including accessory buildings intended for use as a dwelling unit. Furthermore, the Ordinance gives the Fire Code Official authority to require construction documents and calculations for all fire protection systems and to require permits be issued for the installation, rehabilitation or modification of any fire protection system. Construction documents for fire protection systems shall be submitted for review and approval prior to the issuance of a building permit.

3.12.4 Impacts
Methods of Analysis
The impact analysis evaluates the ability of the SHPD, SHFD, SHUSD, St. Helena Parks and Recreation Department, and the George and Elsie Wood Public Library to serve the Proposed Project through a qualitative review of Proposed Project characteristics, such as location, size, and current demand. The analysis also addresses whether the Proposed Project would require the need to add more staff or construct additional facilities to accommodate an increase in demand.

In order to assess whether the Proposed Project would have impacts related to the provision of public services and recreational facilities, the analysis below incorporates estimates for population growth generated by the Project. In order to determine demand for public services and recreation facilities, the number of proposed residential units was multiplied by the current demand factors contained in the City’s Development Impact Fee Study Report (City of St.

Helena 2013).

The Proposed Project would construct 51 single-family residences, 25 attached residential units, and 11 accessory dwelling units (ADU) within the 16.9-acre Project site.

The City uses a persons per household factor of 2.45 people per unit for medium/higher density residential land uses for purposes of calculating public safety, civic improvement, and park and recreation facilities demands (City of St. Helena 2013). Using this factor, the Proposed Project would conservatively generate 213 residents, including the ADUs. It is unlikely the 11 ADU’s would accommodate more than one or two people; therefore, the population estimate of 213 is a conservative assumption for the purposes of evaluating Project impacts.

Table 3.12-3 considers the increase in demand for primary, elementary, middle and high schools generated by the Proposed Project. Student generation rates were derived from the Agenda Item #5.4.

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SHUSD Facility Master Plan, which outlines expected growth in demand for school facilities associated with projected development and plans how to fund and respond to such growth.

Table 3.12-3
Projected Proposed Project Student Generation
Grades Residential Units
Student Generation Rate
(per total number of units) Students Generated
K-2 87 0.058 5
3-5 87 0.080 7
6-8 87 0.088 8
9-12 87 0.088 8
Total 28
Note: For a conservative assumption a total of 87 residential units (including the 11 ADUs) is assumed. The likelihood of all 11 ADUs including school-age children is very low.

Source: SHUSD 2010.

Thresholds of Significance
Consistent with Appendix G of the California Environmental Quality Act Guidelines, a significant impact would occur if the Proposed Project would do any of the following:
• Result in substantial adverse physical impacts associated with the provision of new or physically altered governmental facilities, need for new or physically altered governmental facilities, the construction of which could cause significant environmental impacts, in order to maintain acceptable service ratios, response times or other performance objectives for any of the public services:
o Fire protection.
o Police protection.
o Schools.
o Other public facilities.
• Increase the use of existing neighborhood parks or other recreational services such that a substantial physical deterioration of the facility would occur or require the construction or expansion of facilities that could have a physical adverse effect on the environment.

While important to the quality of life in the Project area, impacts to schools from increased development do not necessarily result in physical environmental impacts. In Goleta Union School District v. Regents of the University of California (2d Dist. 1995) (37 Cal. App. 4th 1025, 1032, 1995), the Court of Appeal found that “[c]lassroom overcrowding, per se, does not constitute a significant effect on the environment.” A General Plan may have policies relating to Agenda Item #5.4.

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public service levels in general or schools in particular. If a development project overwhelms the school district’s capacity and quality of service, it could be inconsistent with the General Plan.

Neither the City of St. Helena 1993 General Plan nor the 2019 General Plan have a specific policy related to school service levels. The Proposed Project applicant would pay the required school impact fees to the SHUSD.

Impacts and Mitigation Measures

3.12-1: Would the Proposed Project increase demand for public services requiring the need to construct new facilities, or expand existing facilities, the construction of which could cause significant environmental impacts? This impact would be less than significant.

Fire Protection
The Project site is currently undeveloped and requires minimal service from the SHFD.

Development of the site with residential uses would result in increased demand for City fire protection services and facilities. Development of the site with residential uses is consistent with existing surrounding development that includes residential and office uses located to the south and southeast of the Project site and is consistent with the underlying land use designation and zoning. The Project site would be served by the City’s fire department located at 1480 Main Street, approximately 0.2 miles from the Project site. As described above, the Proposed Project is expected to increase the City’s population by approximately 213 residents. This population increase is within the projected population for proposed growth in the City’s 1993 General Plan which assumed a residential density of up to 12.0 dwelling units per acre, 1 which would allow a
maximum of 203 dwelling units and up to 497 residents, was assumed. Nevertheless, the Proposed Project would increase demand for fire protection services.

By increasing the population, development of the Project site would increase the demand for fire protection and emergency services, including additional staffing and vehicles, but would not necessitate the construction of a new facility or expansion of an existing facility. The SHFD measures adequate service by response time and not by the number or ratio of firefighters per population.

Fire protection services are funded through various City tax revenues. Development of the Proposed Project would generate revenue to finance the expansion of additional operational services. Furthermore, the Proposed Project applicant would pay required impact fees pursuant to the City’s Public Safety Impact Fee, which funds the acquisition, construction, and 1 The MR zoning permits a maximum density of 16.0 dwelling units per acre. This would permit a maximum of 270 residential units and 661 residents.

Agenda Item #5.4.

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reconstruction of facilities and equipment and other capital purposes needed for the City’s fire department. These fees are based on a proportionate share of the cost of new development for facilities and equipment serving the City. Therefore, because the City’s existing facilities and equipment are planned to serve future development, public safety impact fees are largely intended to recoup a project’s proportionate share of the depreciated replacement cost of existing facilities and equipment.

The Proposed Project would comply with Chapter 15.36 of the City’s Municipal Code and the 2010 State Building Code, which requires installation of approved automatic sprinkler systems in all single-family and multi-family buildings. Furthermore, the Proposed Project would be consistent with 1993 General Plan Policy 8.5.6 and 2019 General Plan Policy PS4.D, which require new development to meet the minimum fire flow rates specified by the City’s Fire Code, and 1993 General Plan Policy 8.5.7 and 2019 General Plan Policy PS4.6, which require all streets and roads to be adequate in terms of width, turning radius, and grade to facilitate access by City firefighting apparatus, and to provide alternative emergency ingress and egress. The site plan would be subject to plan review by the SHFD to ensure proper access for fire and emergency response is provided and required fire suppression features are included. The Proposed Project includes two access points as well as a separate Emergency Vehicle Access.

The increased demand for fire protection services associated with the Proposed Project would be offset by payment of required taxes and fees that would help fund ongoing service and new facilities; therefore, the Proposed Project would have a less-than-significant impact on the provision of fire protection services and would not require the construction of new, or expansion of existing fire facilities.

Police Protection
The Project site is undeveloped and requires minimal law enforcement services from the SHPD at present. Police services for the Project site would be provided from the SHPD’s station located at 1480 Main Street, approximately 0.2 miles from the site. The 1993 General Plan does not include any policies that address law enforcement, but the 2019 General Plan does include Policy PF5.8 to set a staffing ratio of 2 police officers per 1,000 residents and to have an average police department response time of 3 minutes or less for priority one calls. The SHPD currently has a police officer to resident ratio of approximately 2.0 sworn officers per 3,500 residents. The Proposed Project would increase demand for law enforcement services by conservatively adding approximately 213 residents to the City’s population, requiring one officer.

The addition of one officer would not require the construction of new, or the expansion of existing, police facilities because adequate space is available in the SHPD Facility. This would be consistent with the staffing ratio required by Policy PF5.8 and would also improve police department response times due to the larger officer-to-resident ratio.

Agenda Item #5.4.

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The City’s law enforcement operational services are funded through various City tax revenues.

Development of the Proposed Project would generate property tax and sales tax revenue to finance hiring new officers and the expansion of additional services when needed. In addition, the Proposed Project applicant would pay required impact fees pursuant to the City’s Public Safety Impact Fee, which funds the acquisition, construction, and reconstruction of facilities and equipment and other capital purposes needed for the City’s police department. The increased demand for police protection services associated with the Proposed Project would be offset by payment of required taxes and fees that would help fund ongoing service and new facilities; therefore, the Proposed Project would have a less-than-significant impact on the provision of police protection services and would not require the construction of new, or expansion of existing police facilities.

Schools
The SHUSD Facility Master Plan, adopted in July 2010, identifies future plans for new school facilities in the district in order to plan for the anticipated increase in demand for school facilities expected from 2010 through 2020. The projections for future enrollment and student generation are based on historical school enrollment data and trends of enrollment per grade level, district specific birth data, student migration, and land use trends and policies governing residential development (SHUSD 2010). The predicted enrollment is then compared with existing school capacities to determine the need for additional school facilities.

As shown in Table 3.12-3, the Proposed Project would conservatively generate a total of 28 students, based on the assumption that 87 (this includes 11 ADUs) residential units would be constructed and that historical enrollment trends remain relevant. Of these students, five elementary school students would attend St. Helena Primary School (K–2), seven students would attend St. Helena Elementary School (3–5), eight students would attend Robert Louis Stevenson Middle School (6–8), and eight students would attend St. Helena High School (9– 12). This is a conservative estimate because it is unlikely that all 11 ADUs would include families with school-age children. As shown in Table 3.12-1, St. Helena Primary School has an estimated remaining capacity of 29 students, St. Helena Elementary School has an estimated remaining capacity of 141 students, Robert Louis Stevenson Middle School has an estimated remaining capacity of 123 students, and St. Helena High School has an estimated remaining capacity of 287 students, when accounting for the projected 2019–2020 enrollment. Therefore, the addition of school-age students generated by the Proposed Project would not exceed the capacity of schools within the SHUSD, and existing schools are estimated to have more than sufficient capacity for projected enrollment through 2025. Under SB 50, payment of required school impact fees is deemed complete and full mitigation for impacts to school facilities. The impact would be considered less than significant.

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Other Public Facilities
As discussed previously, the Proposed Project would conservatively add 213 residents to the City’s population. This would increase demand for existing public facilities within the City, including the George and Elsie Wood Public Library and City Hall. Payment of the City’s civic improvement fee, as required by the City’s Municipal Code Chapter 3.32, would ensure that the Proposed Project would offset impacts related to other public facilities, including the library, community facilities, and equipment and other capital purposes needed for civic services. These impact fees were calculated to ensure new development would pay their proportionate share of the cost of existing and future capital assets required to serve the City. This would ensure that the Proposed Project would have a less-than-significant impact on other public facilities.

Mitigation Measures
None required.

3.12-2: Would the Proposed Project increase the use of existing neighborhood parks or other recreational services such that a substantial physical deterioration of the facility would occur, or require the construction or expansion of facilities that could have a physical adverse effect on the environment? This impact would be less than significant.

The Proposed Project proposes to construct 87 residential units (including 11 ADUs). Using the average persons per household of 2.45, as stated in the City’s Development Impact Fee Study Report (City of St. Helena 2013), the Proposed Project would conservatively generate 213 residents. As described in Section 3.12.3, the City’s General Plan requires 5 acres of developed parkland per 1,000 residents. This standard ensures that recreational services are provided equally to all residents and that the quality of existing facilities can be maintained. The Proposed Project does not provide any on-site parks or recreational facilities. The City currently contains 27.43 acres of total parkland and has a population of 6,196 (City of St. Helena 2018d, U.S. Census Bureau 2018). On the basis of the 2018 population of 6,196 residents and park acreage of 27.43, the City’s parkland to resident ratio is 4.43 acres per 1,000 residents. Assuming the addition of 213 new residents to the City, the City would have a ratio of 4.28 acres of parkland per 1,000 residents. This falls short of the City’s parkland goal of 5 acres of parkland per 1,000 residents, which included as Implementing Policy 10.3.9 in the 1993 General Plan and Policy PR1.1 in the 2019 General Plan.

Policy PR1.1 also states a goal to reach the nationally recommended standard of 10.5 acres of parkland per 1,000 residents, although this is not a requirement.

Parks within the vicinity of the Proposed Project include Lyman Park, Jacob Meily Park, and Lewis Station, which are all located approximately 0.3 miles from the Project site. These parks have adequate facilities, including picnic and turf areas, children’s playgrounds, and a walking Agenda Item #5.4.

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trail, to support Proposed Project residents. The maintenance road adjacent to the northern boundary of the Project site is not a part of the Proposed Project, nor is it a City trail. There is an existing City trail located in the northside of the maintenance road. A small portion of the maintenance road would be paved to accommodate construction of the Adams Street extension, but sidewalks would be provided along the extension of Adams Street to provide a safe connection to the remainder of the maintenance road and the pedestrian trail, which would remain unaltered by the Proposed Project.

Park and recreational impact fees are imposed upon all residential development within the City.

These impact fees are used to cover the cost of land acquisition and park improvements and are based on added population per unit, then converted into a cost per square foot for each type of residential development. The Proposed Project applicant would pay the required park fees to be used by the City to purchase land to construct new parks or upgrade existing recreation facilities. This would ensure that increased use of existing neighborhood parks due to the Proposed Project residents would not cause substantial physical deterioration and would account for construction and expansion of facilities to accommodate the increase in population associated with the Proposed Project.

Payment of the City’s park and recreational impact fees as stipulated in the City’s Municipal Code Chapter 3.32, consistent with the Quimby Act, would ensure that the Proposed Project would have a less-than-significant impact related to recreational facilities.

Mitigation Measures
None required.

3.12.5 Cumulative Impacts
This cumulative impact analysis does not rely on any list of specific pending, reasonably foreseeable development proposals in the general vicinity of the Proposed Project. The cumulative context includes projected buildout under the City’s 1993 General Plan and other approved projects in the City. While the Proposed Project is required to be evaluated under the 1993 General Plan, any changes relative to the 2019 General Plan are also evaluated for informational purposes.

The geographic scope for the cumulative analysis for the provision of fire and police protection services, parks and recreation and other public services is the City limits which corresponds to the various provider district boundaries. The geographic scope for schools would be the SHUSD district boundary.

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3.12-3: Would the Proposed Project contribute to a cumulative increase in demand for public services, schools, and recreation facilities? The Project’s contribution would not be considerable.

Development of the Proposed Project would contribute to a cumulative increase in demand for public services and parks and recreational facilities. New fire and police personnel and facilities as well new schools and parks and recreation facilities may be required for 1993 General Plan buildout conditions. This could result in the need for new or physically altered governmental facilities in order to maintain acceptable service ratios, response times, or other performance objectives. However, future development within the City would be required to comply with policies set forth in the City’s 1993 General Plan and pay applicable development impact fees as specified in Chapter 3.32, Development Impact Fees, of the City’s Municipal Code.

The City recently updated its General Plan in 2019, and the Draft Environmental Impact Report prepared for the 2019 General Plan notes that the SHFD and the SHPD does not anticipate the need to increase staffing levels or construct any new facilities in order to provide service for future population growth. The projected addition of residents and employees by 2040 (including development of the Project site) would likely increase the demand for emergency fire and police response and preventive services; however, the increase is modest and not expected to create a need for new or expanded fire or police protection facilities and impacts were determined to be less than significant. Therefore, the Proposed Project’s contribution would not be considerable.

The 2019 General Plan notes that the projected addition of residents and employees by 2040 (including development of the Project site) would likely increase the need for more parks and recreation facilities; however, the impact was determined to be less than significant. As discussed above, the Proposed Project would comply with all applicable City goals and policies and pay applicable fees. The Proposed Project’s incremental contribution to the cumulative increase in demand is considered less than significant. Thus, the Proposed Project would not have a considerable contribution to a significant cumulative impact and the Proposed Project’s contribution is less than significant resulting in a less-than-significant cumulative impact.

Mitigation Measures
None required.

3.12.6 References
California Department of Education Data Reporting Office. 2018. 2016-2017 SHUSD Enrollment by Grade. Accessed October 29, 2018. https://data1.cde.ca.gov/dataquest/ dqcensus/EnrGrdLevels.aspx?cds=2866290&agglevel=district&year=2016-17.

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CALFIRE (California Department of Forestry and Fire Prevention). Fire Hazards Severity Zones in SRA: Napa County. November 7, 2007.

Capponi, J. 2018. “RE: St. Helena Fire Response Data.” Email from J. Capponi (St. Helena Fire Department Fire Marshal) to S. Iyer (Dudek). October 23, 2018.

Capponi, J. 2019. “RE: St. Helena Fire Response Data.” Email from J. Capponi (St. Helena Fire Department Fire Marshal) to S. Iyer (Dudek). January 17, 2019.

City of St. Helena. 1993. City of St. Helena 1993 General Plan. September 28, 1993.

City of St. Helena. 2013. Development Impact Fee Impact Report. October 3, 2013.

City of St. Helena. 2018a. Fire Department. Accessed October 29, 2018. http://www.ci.sthelena.ca.us/fire.

City of St. Helena. 2018b. St. Helena General Plan Update 2040 Draft Environmental Impact Report SCH# 2010042001. October 23, 2018.

City of St. Helena. 2018c. Schools. Accessed October 29, 2018. http://www.ci.sthelena.ca.us/community/page/our-schools.

City of St. Helena. 2018d. Library. Accessed October 29, 2018. http://www.ci.sthelena.ca.us/library.

City of St. Helena. 2018e. Parks. Accessed January 16, 2019. https://www.cityofsthelena.org/parksites.

City of St. Helena. 2018f. Lyman Park. Accessed October 29, 2018. http://www.ci.sthelena.ca.us/parksrec/page/lyman-park.

City of St. Helena. 2018g. Jacob Meily Park. Accessed October 29, 2018. http://www.ci.sthelena.ca.us/parksrec/page/jacob-meily-park.

City of St. Helena. 2018h. Lewis Station. Accessed October 29, 2018. http://www.ci.sthelena.ca.us/parksrec/page/lewis-station.

City of St. Helena. 2018i. Stone Bridge Park. Accessed October 29, 2018. http://www.ci.sthelena.ca.us/parksrec/page/stone-bridge-park.

City of St. Helena. 2018j. Wappo Park. Accessed October 29, 2018. http://www.ci.sthelena.ca.us/parksrec/page/wappo-park.

Agenda Item #5.4.

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City of St. Helena. 2019. City of St. Helena General Plan Update 2040. June 2019.

Foley, T. 2018. “RE: St. Helena Police Response Data.” Email from T. Foley (St. Helena Chief of Police) to S. Iyer (Dudek). October 29, 2018.

Hartley, C. 2021. Email from C. Hartley (St. Helena Police Department) to E. Norris. May 18, 2021.

Kreiden, C. 2018. “RE: Library Data.” Email from C. Kreiden (St. Helena Public Library Director) to S. Iyer (Dudek). October 17, 2018.

SHUSD (St. Helena Unified School District). 2010. Facility Master Plan for St. Helena Unified School District. July 7, 2010.

U.S. Census Bureau. 2018. Annual Estimates of the Resident Population: April 1, 2010 to July 1, 2017. May 2018.

Vidler, A. 2021. Email from A. Vidler (St. Helena Police Department) to E. Norris. May 17, 2021.

Agenda Item #5.4.

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3.13 UTILITIES AND SERVICE SYSTEMS

3.13.1 Introduction
This section describes the utilities and service systems that would serve the proposed Hunter Subdivision Project (Proposed Project), specifically water supply, wastewater conveyance and treatment, storm drainage infrastructure, and solid waste disposal and identifies feasible mitigation measures to address impacts.

Comments received in response to the Notice of Preparation included concerns regarding increased water consumption, stormwater drainage capacity, existing sewer infrastructure, water conservation measures, cumulative impacts to water resources, and impacts of on-site groundwater pumping to City of St. Helena (City) groundwater supply wells. Please see Section

3.9, Hydrology and Water Quality for more information pertaining to capacity of the City’s stormwater infrastructure and water quality impacts associated with stormwater discharge. The remaining issues are addressed in this section. A copy of the Notice of Preparation and comments received is included in Appendix A.

This section incorporates information from the following sources: Preliminary Water Calculations Technical Memorandum, included in Appendix J; City of St. Helena Storm Drainage Master Plan (City of St. Helena 2000); City of St. Helena Sewer System Management Plan (City of St. Helena 2014); and City of St. Helena Water Supply Plan (City of St. Helena 2010). Other documentation used in this analysis includes the City of St. Helena 1993 General Plan, City of St. Helena 2019 General Plan1, and the City of St. Helena 2019 General Plan Draft Environmental Impact Report (EIR). Other sources consulted are listed in Section 3.13.6, References.

3.13.2 Environmental Setting
This section describes the existing conditions in the Project area and also identifies the public utilities and services that could be affected by future development of the Project site with residential uses.

Existing Site
The Project site is predominantly undeveloped, with the exception of approximately 40% of the site, which is under cultivation with a vineyard. There is an existing agricultural well in the southeastern end of the Project site (proposed to be located in Parcel B of the subdivision) that has been used historically to supply irrigation water to the site but is currently inoperable. This well is proposed to remain in a production capacity to supply irrigation water to meet the outdoor 1 The 2019 General Plan is also known as the “General Plan Update 2040,” but is referred to here by its adoption date.

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landscaping demands of the Proposed Project, reducing the water demands on the existing City water supplies and delivery system.

The Project site gradually slopes to the east, with existing elevations ranging from approximately 243 feet above mean sea level in the western portion of the site, to approximately 214 feet above mean sea level in the eastern portion of the site. An existing 10-foot-wide public water line easement containing an active 12-inch water line bisects the north/northeast portion of the site.

The easement is proposed to be abandoned as part of the Project and the water line relocated.

The Project site is currently undeveloped and not served by City utilities.

Water
This section describes the existing and past water supplies and water demands within the City of St. Helena. Projected water demand for the City is also discussed. The baseline to establish the “existing conditions” is based on when the Notice of Preparation was released for the Project, which was in March 2018 (CEQA Guidelines Section 15125(a)). The existing conditions constitute the “baseline condition” against which project-related impacts are compared. Since 2018, the City’s water supply conditions have changed due to a variety of factors; therefore, updated information regarding water supply and availability of water to serve the City is also provided.

City of St. Helena Water Supply
The Project site is located within the City’s water service area and is requesting to receive potable water service from the City to meet the Proposed Project’s estimated potable water demands associated with development of residential uses. The Project site is currently undeveloped with the exception of a small vineyard in the “panhandle” portion of the site with a larger vineyard located in the southwestern portion of the site. It is assumed these vineyards have previously been irrigated by the on-site well, which constitutes the only water use on site at present. However, since the well is currently inoperable it is not clear if the vineyard is receiving irrigation.

The City receives potable water from three sources: Bell Canyon Reservoir, the Stonebridge Well Complex, and contract water from the City of Napa. Additionally, the City uses the City-owned Lower Reservoir and a groundwater well located near the Napa River as sources of non-potable water (City of St. Helena 2018). Recycled water is not currently a source of water supply in the City. The following details each of the anticipated sources of water for the Proposed Project. Table 3.13-1 provides the contribution of groundwater and surface water to the City’s historical water supplies and has been updated through 2020.

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Table 3.13-1
City of St. Helena Potable Water Deliveries by Source
Year Bell Canyon Reservoir City of Napa Contract Stonebridge Wells Total Supply (acre-feet)
2013 927 555 400 1,882
2014 865 607 374 1,847
2015 739 523 308 1,570
2016 643 581 241 1,465
2017 736 588 270 1,594
2018 840 623 327 1,790
2019 836 612 240 1,688
2020 702 625 302 1,629
Average 1,637
Source: City of St. Helena, 2021.

Bell Canyon Reservoir
The City holds water rights permits issued by the State Water Resources Control Board (SWRCB) for storage and diversion of water at the Bell Canyon Reservoir. These rights are detailed in permits 9157 and 14810 issued in 1952 and 1965 respectively (City of St. Helena 2010). As detailed in the City’s 2019 General Plan EIR, the City has requested that the SWRCB allow the permits to become a licensed water right (City of St. Helena 2018). These water rights permits have not yet been converted to licenses.

Bell Creek, as impounded in Bell Canyon Reservoir, has served as the City’s major water supply source for over 50 years. Bell Canyon Reservoir encompasses approximately 3,647 acres and has a storage capacity of 2,400 acre-feet. Average historical yield from the reservoir is approximately 1,800 acre-feet per year, and sustainable yield ranges from approximately 500 acre-feet in critically dry years to approximately 1,100 acre-feet in wet years (City of St. Helena 2018).

In total, the City is authorized to divert and store 3,800 acre-feet from Bell Canyon Reservoir each year, and directly divert 1 cubic foot per second between November 15 and April 15 (150 days) of each year. Of the City’s total authorized amount, 2,000 acre-feet can only be diverted and stored between November 15 and April 15 of each year (City of St. Helena 2010). Table 3.13-2 provides quarterly storage data for the Bell Canyon Reservoir for 2018 through March 2020.

Table 3.13-2
Bell Canyon Reservoir Storage
Date1 Storage (acre-feet)
March 2020 1,670.888
January 2020 1,716.734
September 2019 1,708.644
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Table 3.13-2
Bell Canyon Reservoir Storage
Date1 Storage (acre-feet)
June 2019 2,155.966
March 2019 2,383.69
January 2019 1,514.139
December 2018 1,453.859
September 2018 1,708.644
June 2018 2,155.966
March 2018 1,388.627
January 2018 1,328.850
Sources: City of St. Helena 2018, 2019a, 2019b, and 2020.

Note:
1 Data as recorded on the 1st of each month.

In recent years, the annual yield from Bell Canyon Reservoir has declined significantly due to required water releases into the Napa River to support fish habitat and also from drought conditions. Because of this, water from the City of Napa has become an increasingly large portion of the total water supply (City of St. Helena 2018).

City of Napa Contract
The City of Napa’s surface water supplies are obtained from three water sources: State Water Project (SWP) water delivered via the North Bay Aqueduct, Lake Hennessey, and Lake Milliken. On November 8, 2011, the City approved a revised agreement with the City of Napa detailing the availability of treated water supplies from the City of Napa. Under the modified agreement, the City will receive a guaranteed delivery of 600 acre-feet annually from the City of Napa and deliveries are no longer subject to conditions of the City of Napa’s water supplies, like the shortage provision that is tied to shortages imposed by the State Water Project on Napa County’s state contract – even in drought conditions (City of St. Helena 2011). The City is obligated to pay for 600 acre-feet whether or not the City actually uses the 600 acre-feet. Additionally, the City may request up to 200 acre-feet of additional water supply and the City of Napa will deliver the requested quantity of water if it possesses enough water supply to fulfill the request. The City of Napa has the right to supply this additional water from its own existing supplies or to transport the water on behalf of the City for water purchased by the City from another supplier (City of St. Helena 2011). The initial term of this contract expires on December 31, 2035. As shown in Table 3.13-3, the City of Napa’s water supply is expected to be about 31,778 acre-feet during normal years, 17,468 acre-feet during multiple-dry year periods, and about 10,267 acre-feet during single-dry years, according to the 2015 Urban Water Management Plan which is currently being updated (City of Napa 2017). As of 2021 due to the drought conditions water supplies from the City of Napa have been reduced (pers. comm. Wanger 2021).

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Table 3.13-3
City of Napa Water Supply
Source Normal-Year Multiple-Dry Years Single-Dry Year
Supply (acre-feet)
Lake Hennessey 17,500 10,417 5,000
Milliken Reservoir 700 700 400
State Water Project 13,578 6,351 4,867
Total 31,778 17,468 10,267
Source: City of Napa 2017.

Lake Hennessey and Milliken Reservoir are two surface water reservoirs located along tributaries of the Napa River. SWP water is supplied through the North Bay Aqueduct as per an agreement with the Napa County Flood Control and Water Conservation District (NCFCWCD), the SWP contract administrator for several municipalities in Napa County. The City of Napa’s three existing water sources and the normal (average) year quantities available through 2035 are discussed below.

Lake Hennessey
Lake Hennessey, a reservoir located 13 miles north of the City of Napa with an approximate storage capacity of 31,000 acre-feet, is the primary local water source for the City of Napa system. The City of Napa obtains water rights to divert and store up to 30,500 acre-feet per year through a permit with the SWRCB Division of Water Rights. Lake Hennessey has an annual average inflow of 19,962 acre-feet, which is much lower than its storage capacity (City of Napa 2017). Water from Lake Hennessy is treated at the Hennessey Water Treatment Plant in Napa County. Table 3.13-4, below, provides information about Lake Hennessey’s tributary watershed area, average annual inflow, total storage capacity, normal-year yield, multiple-dry years yield, and critical single-dry year yield. In addition, current storage volume as of June 2021 is also provided.

Table 3.13-4
Lake Hennessey Statistics
Tributary Watershed Area 35,000 acres
Average Annual Inflow 19,692 acre-feet (AF)
Total Storage Capacity (Maximum Yield) 31,000 AF
Normal-Year Yield 17,500 AF
Multiple-Dry Years Yield 10,417 AF
Single-Dry Year Yield 5,000 AF
Current (6/23/21) Storage Volume 19,776 AF
Source: City of Napa 2017 and City of Napa 2021.

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Milliken Reservoir
Milliken Reservoir, located approximately five miles northeast of the City of Napa, serves as a seasonal water supply source during the summer months. The City of Napa has a license with the SWRCB that authorizes it to divert and store up to 2,350 acre-feet of water per year for beneficial use. The reservoir has an approximate storage capacity of 1,390 acre-feet and an annual average inflow of 3,656 acrefeet (City of Napa 2017). Water from Milliken Reservoir is treated at the Milliken Water Treatment Plant in Napa County. Table 3.13-5, below, provides information including Milliken Reservoir’s normal-year yield, multiple-dry years yield, and critical single-dry year yield. In addition, current storage volume as of January 2021 (most recent data available) is also provided.

Table 3.13-5
Milliken Reservoir Statistics
Tributary Watershed Area 6,000 acres
Average Annual Inflow 3,656 acre-feet (AF)
Total Storage Capacity (Maximum Yield) 1,390 AF
Normal-Year Yield 700 AF
Multiple-Dry Years Yield 700 AF
Single-Dry Year Yield 400 AF
Current (1/28/2021) Storage Volume 1,131 AF
Source: City of Napa 2017 and City of Napa 2021a.

State Water Project
Starting in 1966, the City has sub-contracted with NCFCWCD for imported surface water from the SWP. The SWP diverts water from the Sacramento-San Joaquin Delta at the Barker Slough Pumping Plant east of the City of Vacaville. This water is then conveyed approximately 21 miles through the North Bay Aqueduct to Cordelia Forebay to serve contractors in Napa and Solano counties. The water is treated at the Edward I. Barwick Jamieson Canyon Water Treatment Plant, in the City of Napa. The majority of this water supply is for SWP entitlements for the City of Napa and the City of Calistoga. This water is also supplied to the City of American Canyon. The City of Napa was originally granted gradually increasing annual allotments, known as “Table A” entitlements, of SWP water in its original 1966 agreement with NCFCWCD. These allotments reached a maximum of 12,500 acre-feet by 1990. However, the agreement was modified in 1982 to reduce the City’s short-term entitlement but increase its final overall entitlement to 18,800 acrefeet by 2021. In 2009, the contract was amended to accelerate the entitlement schedule, and the City of Napa was granted its full 2021 entitlement of 18,800 beginning in 2010. Additionally, in 2000, the City of Napa obtained an additional 1,000 acre-feet per year of SWP water in a transfer agreement between NCFCWCD and the Kern County Water Agency. In 2006, the City of Napa purchased the City of St. Helena’s 1,000 acre-feet Kern County Water Agency entitlement.

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Furthermore, in 2009, the City signed a water transfer agreement with the Town of Yountville, obtaining Yountville’s total SWP Table A entitlement of 1,100 acre-feet per year, along with its North Bay Aqueduct conveyance capacity. Therefore, combined, the City of Napa has a total entitlement to 21,900 acre-feet of water per year. However, actual deliveries are determined by the Department of Water Resources depending on each year’s hydrologic conditions. The full entitlement amount would typically only be available during very wet years. The Department of Water Resources estimates that 62% of SWP contractors’ entitlements would be available for deliver in a normal year, 29% would be available during a multi-dry year period, and 11% would be available during a single-dry year (City of Napa 2017). The current SWP contract is due to expire in 2035 with an extension to 2085 anticipated. Table 3.13-6 lists SWP estimated delivery amounts during normal, multiple-dry, and critical single-dry years.

Table 3.13-6
SWP Reliability Assumptions
Water Year Type
Projected SWP Delivery
(percent of Table A
entitlement)
Advanced Table A
entitlement (acre-feet)
Total SWP Deliveries (acrefeet)
Normal Year 62% - 13,578
Multiple-Dry Years 5% 3,772 6,351
Single-Dry Year 29% - 4,867
Source: City of Napa 2017.

Note:
1 100% Table A entitlement is 21,900 acre-feet
Groundwater
The groundwater basin applicable to the Project site is the Napa-Sonoma Valley Basin, which is further divided into the Napa Valley Subbasin, which contains about 209,619 acre-feet of water on average. This large basin is further divided into the St. Helena Subarea, which lies under the City (Napa County 2018). Groundwater levels within the northern portion of the St. Helena Subarea remain relatively stable but exhibit greater seasonal declines of about 20 feet elsewhere in the subarea; however, lower groundwater levels have been observed in 2020 due to a relatively dry year as discussed in Section 3.9 Hydrology and Water Quality (Napa County 2017 and DWR 2021). The City owns and operates two active groundwater wells, collectively known as the Stonebridge Well Complex, located 410 and 670 feet below the surface that have a combined capacity of approximately 595 gallons per minute. These wells have the potential to provide 960 acre-feet of potable water per year if both could be operated continuously. The wells derive their water source from the Sonoma Volcanic aquifer. Being the most flexible source in the system, groundwater functions as a buffer to balance system flows based on availability of water in Bell Canyon and flow rates being delivered by the City of Napa. The City currently restricts the use of groundwater from these wells with the goal of limiting extraction to 450 AF per year for long term Agenda Item #5.4.

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sustainability. There is an existing well on the Project site that is presently not in operation (see Section 3.9, Hydrology and Water Quality for more information on groundwater resources).

City of St. Helena Safe Yield Water Supply
The City’s total water supply is dependent on annual rainfall. Therefore, the City uses various sources to ensure sustainable yields. Safe yield thresholds developed by the City’s Safe Yield Committee (no longer active) are summarized in Table 3.13-7, below.

Table 3.13-7
City of St. Helena Safe Yields
Source
Normal Water Year (Annual
Safe Yield) (acre-feet)
Dry Year (Phase 2 Water
Emergency) (acre-feet)
Critical Year (Phase 3 Water
Emergency) (acre-feet)
Bell Canyon Reservoir 1,000 600 500
Stonebridge Well Complex1 350 514 471
City of Napa 600 600 600
Total 1,950 1,714 1,571
Source: City of St. Helena 2018.
1 In an agreement with the environmental advocacy group Water Audit California, the City is monitoring water levels with a goal of limiting extraction to 450 AF per year on average (Napa Valley Register, 2021) Due to the ongoing drought the City Council declared a Phase II water emergency on October 27, 2020, which went into effect on November 1, 2020. The amount of water allocated to commercial and residential uses is limited under this water emergency. Residential users are limited to 65 gallons per person per day. Single-family residences will receive an additional 2,500 gallons per month from April through October for landscape irrigation. No new water connections are allowed to be permitted during a Phase II water emergency. The director of public works is providing reports to the City Council and will recommend lifting the water emergency once adequate water supplies are available. A project may proceed through entitlement process during a water emergency, however if a building permit is issued and the City is in a water emergency, no water connection would be provided until the termination of the water emergency.

Water Treatment and Distribution
Water treatment services are provided by the City of St. Helena Water Treatment Division. Water from the Bell Canyon Reservoir is treated by three licensed water treatment operators at the Louis Stralla Water Treatment Plant (WTP), located on Crystal Springs Road in the northeastern part of the City (City of St. Helena 2015a, 2019a). The Louis Stralla WTP has a capacity of 4.3 million gallons per day (MGD). However, there are flow limitations in the inlet piping which restricts use of the plant to less than its capacity (City of St. Helena 2016). The Louis Stralla WTP typically treats

3.5 MGD due to these flow limitations (City of St. Helena 2018). The two groundwater wells that the City uses as a water source include a filtration facility, comprised of filtration tanks, chlorination Agenda Item #5.4.

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facilities, and a backwash return system (City of St. Helena 2016). Water from the City of Napa is received at the City of St. Helena’s Rutherford Pump Station (City of St. Helena 2018).

Water distribution within the City is managed by the Utilities Division of the City’s Public Work’s Department. The Utilities Division reads water meters and conducts fire hydrant maintenance and water leak repairs and provides customer service (City of St. Helena 2019a). The City’s treated water is distributed through six storage tanks, four pump stations, pumps, and a network of distribution pipelines (City of St. Helena 2016). In 2015, the City provided water service to approximately 2,312 connections (City of St. Helena 2018).

Projected Water Demand and Supply
The City of St. Helena’s 2010 Water Supply Plan (Water Supply Plan2) includes an analysis of current and future water demands within the City. The water use habits of existing customers, land use plans providing data for expected growth, and laws and regulations that affect future water use were used to calculate future water demands. Water conservation measures were not considered in future demand calculations.

The Water Supply Plan includes projected water demands for two potential 1993 General Plan buildout scenarios, the Likely Buildout Scenario and the Full Buildout Scenario. Under the Likely Buildout Scenario, the City has the potential to construct 379 more residential dwelling units until buildout of the 1993 General Plan is reached in 2030. Under this scenario, the projected number of dwelling units was limited by the City’s Growth Ordinance and not by the 1993 General Plan Land Use. However, due to a recent change in state law (Senate Bill [SB] 330) the City is no longer limiting residential development. In addition, this scenario accounts for the construction of over 277,000 square feet of commercial, retail, and institutional floor space. Under the Full Buildout Scenario, the City has the potential to construct 891 more residential dwelling units until buildout is reached in 2030. This scenario also includes adding slightly more than 338,000 square feet of commercial, retail, and institutional floor space during the term of the 1993 General Plan (City of St. Helena 2010). As noted throughout this EIR, the City adopted the 2019 General Plan in May 2019. However, since the Proposed Project application was submitted in September 2010 and deemed complete by the City in 2011, this EIR uses the 1993 General Plan as the applicable general plan for the purposes of evaluating the Proposed Project. Nonetheless, this EIR will also evaluate the City’s adopted 2019 General Plan for informational and consistency purposes. Under the City’s 2019 General Plan, it was also assumed that the allowed number of new residential units would be limited to 9 units per year, or a total of 72 units over the eight-year term of the Housing Element (2015 to 2023). As stated previously, the City is no longer allowed to limit residential development due to the passage of SB 330. The 2019 General Plan EIR determined there would 2 The 2010 Water Supply Plan is the most recent document available; however, an Integrated Utility Master Plan is in the process of being prepared at the time of preparation of this document.

Agenda Item #5.4.

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be no expected increase in water demand since new developers would be required to comply with the City’s Water Neutral Policy for Development (see Section 3.9, Hydrology and Water Quality) and offset all new water demands with water conservation retrofits or in-lieu payments for the City to undertake such retrofits (City of St. Helena 2018).

Table 3.13-8 shows details for projected water supplies and demand in the City under the 2010 Water Supply Plan Likely Buildout Scenario and the Full Buildout Scenario.

Table 3.13-8
City of St. Helena Projected Water Supply and Demand
Buildout Scenario
Wet Year (40%
exceedance)
No WSE
Normal Year
(60%
exceedance) No
WSE
Below Normal
Year (82%
exceedance)
Phase II WSE
Dry Year (90%
exceedance)
Phase IV WSE
Critical Dry Year
(100%
exceedence)
Phase V WSE
Annual Water Demand (acre-feet)/year
Likely
Buildout
Scenario
Demand 2,350 2,350 2,115 1,674 1,321
Supply 2,375 2,250 2,286 1,714 1,286
Surplus
(Deficit)
25 (100) 171 40 (35)
Full
Buildout
Scenario
Demand 2,600 2,600 2,340 1,966 1,499
Supply 2,375 2,250 2,286 1,714 1,286
Surplus
(Deficit)
(225) (350) (54) (252) (213)
Source: City of St. Helena 2010.

Note: WSE = Water Shortage Emergency
As shown in Table 3.13-8, water supplies under both the Likely Buildout Scenario and the Full Buildout Scenario would not be sufficient to meet demands during all scenarios. The 2010 Water Supply Plan estimates that the City would likely face water supply shortages after 2020, but before 2030 under current operations (City of St. Helena 2010). Therefore, the City must consider what combination of water conservation measures, acquiring additional surface water from the City of Napa, and groundwater use can be used to meet future demands. The 2010 Water Supply Plan estimated that 495 acre-feet of metered potable water demand could be saved if water conservation measures were implemented. Recommended water conservation actions included (City of St. Helena 2010):
• Hiring a Water Conservation Coordinator
• Modifying and adopting a water rate structure that will ensure adequate program funding while encouraging water conservation by accounting for reduced water consumption in the base water rate and increasing high tier rates
Agenda Item #5.4.

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• Increasing groundwater production reliability and winter pumping capacity In 2010, the City’s Safe Yield Committee was commissioned to analyze the reliability of the City’s water supplies into the future. The Safe Yield Committee found that the long-term safe yield of the City’s water supply is 1,950 acre-feet per year, which consists of 600 acre-feet from the City of Napa contract, a conservative 900 acre-feet from Bell Canyon reservoir, and an average use of 450 acre-feet from groundwater. As shown in Table 3.13-1, recent water usage (or deliveries as the table identifies) in the City is well below the 1,950 acre-feet target, with water usage ranging from 1,882 (2013) to 1,465 acre-feet (2016) over the last eight years. To reduce future water demand within the City, the City established a water-neutral policy, requiring future development to completely offset its water use. Future water demands estimated in the City’s Water Supply Plan do not consider water conservation measures. Considering the current downward water usage trend due to water conservation measures and that future demands are required to offset their projected use, future water demand is not expected to exceed the existing policy limit of 1,950 acre-feet annual use set by the Safe Yield Committee (City of St. Helena 2011).

Wastewater
The City’s Public Works Department provides wastewater collection and treatment services to the city. Wastewater in the city is collected and distributed through an over 22-mile system of 4-inch to 24-inch pipes and trunk lines and treated at the City’s wastewater treatment plant (WWTP) (City of St. Helena 2014). The City currently provides sewer service to approximately 1,726 connections, of which approximately 75% are residential (City of St. Helena 2018). The WWTP, located at 1 Chaix/Thomann Lane in the southeastern portion of the city, currently has a permitted dry weather treatment capacity of 0.5 MGD. The WWTP has a permitted wet flow capacity of 2.8 MGD and treats 0.36 MGD of average wet weather flow. In 2020, approximately 0.384 MGD of wastewater was treated in the City on average. The plant provides secondary treatment for domestic and commercial wastewater from the City through a series of five ponds. Plant treatment processes include Type I and Type 2 Advanced Integrated Pond Systems, a comminuter (solids grinder), chlorine disinfection, and dechlorination. During dry weather conditions, the WWTP disposes effluent by spray irrigation onto a 90-acre grass field, and during wet weather, when irrigation fields are saturated, treated effluent is discharged into the Napa River in accordance with National Pollutant Discharge Elimination System (NPDES) permit No. CA0038016 (SFB RWQCB 2016). In 2020, the WWTP discharged approximately 54 million gallons of reclaimed water for irrigation and 13 million gallons into the Napa River (pers. comm. Erin Sanders, City of St. Helena 2021).

In 2016, the City received a cease and desist order from the California Regional Water Quality Control Board (RWQCB), San Francisco Bay Region. The cease and desist order was received because the WWTP did not have the ability to implement advanced secondary treatment of waters discharged into the Napa River, a requirement imposed by the NPDES permit reissued to the Agenda Item #5.4.

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WWTP in 2016. As the plant is currently designed only to provide secondary treatment, in order to meet the RWQCB’s requirements, the plant would be required to undergo modifications to achieve advanced secondary treatment. The RWQCB establishes a time schedule of no more than five years for the WWTP to undergo the necessary improvements. At this time, the City has produced a Final Feasibility Study that evaluates options to come into compliance with the reissued NPDES permit (SFB RWQCB 2016). The study details two alternatives, Alternative 1, which involves converting the WWTP’s Pond 4 to constructed wetlands that would provide additional treatment through a series of physical, chemical, and biological mechanisms, and Alternative 2, which involves implementation of trickling filters for secondary treatment. Alternative 2 was ultimately recommended for further examination and detailed design in a Facility Master Plan (City of St.

Helena 2016). The City has recently completed plans for modifying and upgrading the WWTP to a Title 22 Tertiary Treatment Plant identified as Alternative 2, and work on upgrading the plant is anticipated to begin sometime in Summer 2021 to be completed by late summer 2022. The City is also pursuing a recycled water distribution system for landscape irrigation. It is not known if the City has funding to implement this project.

The 2015 Facilities Evaluation for the WWTP concluded that the total WWTP capacity was sufficient when operated under design conditions. The average dry weather flow treated in 2014 was 0.36 MGD, the average annual flow treated in 2014 was 0.47 MGD, and the highest daily flow treated was 1.03 MGD during wet weather. The 2015 Facilities Evaluation indicated that as the service area population was growing only slightly and per capita wastewater flows are declining due to conservation measure, the existing WWTP capacity is sufficient in the short-term. The report projected that the 2030 average dry weather flows into the WWTP would be approximately

0.50 MGD. However, the report indicated that the capacity should be increased to 0.65 MGD by 2030 to account for uncertainty (City of St. Helena 2016). As of 2020, the average dry weather flow treated was 0.36 MGD, the average annual flow treated was 0.38 MGD, and the highest daily flow treated was 1.05 MGD during wet weather (pers. comm. Sanders. 2021).

Stormwater Drainage
The direction of stormwater flow in the city is generally from the mountain ranges to the west to the Napa River at the City’s eastern boundary. This drainage is largely collected by creeks that flow into the Napa River, including York Creek and Sulphur Creek. The City’s stormwater drainage system, which consists of a variety of inlet structures and collection systems, discharges into these creeks or directly into the Napa River. Drainage is collected through a system of gravity flow pipes, ditches, channels, and creeks. The City’s storm drainage pipes range from 4 to 60 inches in diameter (City of St. Helena 2000). The City’s Public Works Department maintains drain inlets and drain manholes. Several of the storm drainage facilities are located within sidewalks or other public rights-of-way.

Agenda Item #5.4.

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At present, stormwater moves as sheet flow across the Project site. The Project site does not contain any existing storm drain infrastructure. Section 3.9, Hydrology and Water Quality evaluates capacity of the City’s stormwater infrastructure and water quality impacts associated with stormwater discharge.

Solid Waste
Upper Valley Disposal & Recycling (UVD) provides solid waste services to residents and businesses within the city. UVD provides weekly residential and commercial refuse and recycling pickup and disposal throughout upper Napa County. UVD also offers a Business Food Compost Program for commercial food collection (UVD 2019). In addition, UVD provides a variety of waste reduction programs, including municipal solid waste, nonhazardous materials, mixed recycling and yard waste recycling. A single-stream recycling program accommodates a wide array of wastes including plastic, glass, steel, tin, aluminum, and most types of paper and cardboard. The agency also conducts public education to teach residents and businesses about composting and its recycling and electronic waste disposal programs (City of St. Helena 2010). As of 2016, approximately 69% of collected waste was diverted from landfills by UVD (City of St. Helena 2018).

Solid waste generated within the city is disposed of at the Clover Flat Landfill, an approximately 79-acre Class III landfill site located at 4380 Silverado Trail Road, north of the city (CalRecycle 2019). The Clover Flat Landfill has a maximum permitted throughput of 600 tons per day and total permitted site capacity of 4.9 million cubic yards. The landfill receives approximately 150-175 tons per day of solid waste on average and has an estimated remaining capacity of 2.62 million cubic yards. The facility has an estimated closure date of 2047 (CalRecycle 2018). The landfill accepts nonhazardous solid waste and inert waste; hazardous wastes, liquid wastes, sewage sludge, or infectious wastes are not accepted at this facility. The landfill accepts food waste for composting and transfer, along with mixed loads of construction and demolition materials for recycling (CFL Inc. 2018).

3.13.3 Regulatory Setting
Federal Regulations
The following federal regulations pertaining to utilities and service systems would apply to the Proposed Project.

Agenda Item #5.4.

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Water
Federal Water Pollution Control Act
The Federal Water Pollution Control Act (33 USC 1251 et seq.), otherwise known as the Clean Water Act (CWA), sets forth national goals that waters shall be “fishable, swimmable” waters (CWA Section 101 (a)(2)). To enforce the goals of the CWA, the U.S. Environmental Protection Agency (EPA) established the NPDES program. NPDES is a national program for regulating and administering permits for discharges to receiving waters, including non-point sources. Under Section 1251 (b) of the CWA, Congress and the U.S. EPA must recognize and preserve the primary responsibilities and rights of states concerning the reduction of pollution in water resources.

Numerous agencies have responsibilities for administration and enforcement of the CWA. At the federal level this includes the U.S. EPA, the U.S. Army Corps of Engineers, the Bureau of Reclamation, and the major federal land management agencies such as the U.S. Forest Service and the Bureau of Land Management. At the state level, with the exception of tribal lands, the California EPA and its sub-agencies, including the SWRCB, have been delegated primary responsibility for administering and enforcing the CWA in California.

Safe Drinking Water Act
The Safe Drinking Water Act of 1974 gave the U.S. EPA the authority to set standards for contaminants in drinking water supplies. The U.S. EPA was required to establish primary regulations for the control of contaminants that affected public health and secondary regulations for compounds that affect the taste, odor, and aesthetics of drinking water. Title 22 of the California Administrative Code establishes Department of Public Health and SWRQCB implementing authority and stipulates state drinking water quality and monitoring standards.

Wastewater
National Pollution Discharge Elimination System Permit
Discharge of treated wastewater to surface water(s) of the United States, including wetlands, requires a NPDES permit. In California, the RWQCBs administer the issuance of these federal permits. Obtaining an NPDES permit requires preparation of detailed information, including characterization of wastewater sources, treatment processes, and effluent quality. Whether or not a permit may be issued, the conditions of a permit are subject to many factors such as basin plan water quality objectives, impaired water body status of the receiving water, historical flow rates of the receiving water, effluent quality and flow, the air quality State Implementation Plan, the California Toxics Rule, and established total maximum daily loading rates for various pollutants.

These factors are highly specific to the potential discharge point. Obtaining an NPDES permit is Agenda Item #5.4.

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generally considered difficult in inland areas and may not be possible in sensitive areas. The City is within the jurisdiction of the San Francisco RWQCB and has a current NPDES permit No.

CA0038016 (SFB RWQCB 2016).

Federal and State Clean Water Act
The Porter–Cologne Water Quality Control Act gives the ultimate authority over California water rights and water quality policy to the SWRCB. The Porter–Cologne Act also established nine RWQCBs to ensure that water quality on local/regional levels is maintained. The Project site is under the jurisdiction of the Central Valley RWQCB.

Stormwater
Clean Water Act
The Clean Water Act (CWA), as amended by the Water Quality Act of 1987, is the major federal legislation governing water quality (33 USC 1251 et seq.). The objective of the CWA is “to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.” The CWA establishes basic guidelines for regulating discharges of both point and non-point sources3 of pollutants into the waters of the United States. The CWA requires that states adopt water quality standards to protect public health, enhance the quality of water resources, and ensure implementation of the CWA. See Section 3.9, Hydrology and Water Quality, for more information.

Federal Antidegradation Policy
The federal antidegradation policy (40 CFR Section 131.12) of the federal CWA is designed to protect water quality and water resources. The policy requires states to develop statewide antidegradation policies and identify methods for implementing them. State antidegradation policies and implementation measures must include the following provisions: (1) existing instream uses and the water quality necessary to protect those uses shall be maintained and protected; (2) where existing water quality is better than necessary to support fishing and swimming conditions, that quality shall be maintained and protected unless the state finds that allowing lower water quality is necessary for important local economic or social development; and (3) where high-quality waters constitute an outstanding national resource, such as waters of national and state parks, wildlife refuges, and waters of exceptional recreational or ecological significance, that water quality shall be maintained and protected. State permitting actions must be consistent with the federal 3 Point source discharges are those emanating from a pipe or discrete location/process, such as an industrial process or wastewater discharge. Non-point source pollutants are those that originate from numerous diffuse sources and land uses, and which can accumulate in stormwater runoff or in groundwater.

Agenda Item #5.4.

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Antidegradation Policy. See Section 3.9, Hydrology and Water Quality, for a detailed discussion of federal stormwater regulations.

Solid Waste
Resource Conservation and Recovery Act, Subtitle D
Code of Federal Regulations, Volume 40, Part 258 (Resource Conservation and Recovery Act, Subtitle D) states criteria for the location, operation, design, monitoring, and closure of municipal solid waste landfills. The code requires states to conduct their own permitting program for landfills that follow this criteria.

State
Water
Porter–Cologne Water Quality Control Act
The Porter–Cologne Water Quality Control Act (Porter–Cologne) gives the ultimate authority over California water rights and water quality policy to the California SWRCB. Porter–Cologne also established nine RWQCBs to ensure that water quality on local/regional levels is maintained. The city is under the jurisdiction of the San Francisco RWQCB.

Urban Water Management Planning Act
In 1983, the California Legislature enacted the Urban Water Management Planning Act (Water Code Sections 10610–10656). The act requires that every urban water supplier that provides water to 3,000 or more customers, or that provides over 3,000 acre-feet per year shall prepare and adopt an Urban Water Management Plan. The City does not meet the population requirements for preparation of an Urban Water Management Plan.

Drinking Water Quality
It is the responsibility of the SWRCB and the Department of Public Health to implement the Federal Safe Drinking Water Act, as well as California statutes and regulations related to drinking water. The SWRCB inspects and provides regulatory oversights to public water systems within California, to ensure their compliance. The San Francisco RWQCB protects the beneficial uses, including municipal drinking water supply, of state waters in the San Francisco Bay area.

In accordance with Title 22 of the California Code of Regulations, public water system operators regularly monitor their drinking water sources for microbiological, chemical, radiological, and aesthetic contaminants to ensure that they do not exceed the primary maximum contaminant Agenda Item #5.4.

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levels. The amount of contaminants in drinking water needs to be disclosed to the public annually, by the water supplier, in a consumer confidence report. It is the responsibility of the water supplier to produce and distribute the report and the responsibility of the U.S. EPA to prepare annual summary reports of water system compliance.

Senate Bill X7-7
On November 10, 2009, Governor Arnold Schwarzenegger signed SB X7-7, which requires each urban water supplier to select one of four methods for achieving water conservation targets for 2020. This bill establishes a statewide goal of achieving a 20% reduction in urban per capita water use by 2020 for urban retail water suppliers. The City and its customers have been and continue to implement conservation measures that are moving the City toward desired statewide reductions.

On-going statewide, regional, and City efforts, combined with natural attrition and replacement of water fixtures and appliances with more water efficient units will continue to decrease future water demand for future customers.

California Green Building Standards Code
In January 2010, the California Building Standards Commission adopted the statewide mandatory Green Building Standards Code (CalGreen) that requires the installation of water-efficient indoor infrastructure for all new projects beginning after January 1, 2011. CalGreen was incorporated as Part 11 into Title 24 of the California Code of Regulations (CCR). CalGreen applies to the planning, design, operation, construction, use, and occupancy of every newly constructed building or structure. All development projects must satisfy the indoor water use infrastructure standards necessary to meet CalGreen.

CalGreen requires residential and nonresidential water efficiency and conservation measures for new buildings and structures that will reduce the overall potable water use inside the building by 20%. The 20% water savings can be achieved in one of the following ways: (1) installation of plumbing fixtures and fittings that meet the 20% reduced flow rate specified in CalGreen, or (2) by demonstrating a 20% reduction in water use from the building “water use baseline.” California Model Water Efficient Landscape Ordinance and County Ordinance In 2006, the California Legislature enacted, and the Governor signed, the Water Conservation in Landscaping Act, which required the Department of Water Resources to update the Model Water Efficient Landscape Ordinance (MWELO). On September 10, 2009, the Office of Administrative Law approved the updated MWELO, which required that a retail water supplier and county adopt the provisions of the MWELO by January 1, 2010, or enact its own provisions equal to or more restrictive than the MWELO provisions. The County of Napa adopted the MWELO as its ordinance so all water use calculations have been following the MWELO steps. The City also has a Agenda Item #5.4.

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landscaping ordinance, which issues landscaping approval after reviewing project-specific landscaping plans. The City ordinance follows the MWELO calculation methods.

California Water Code Section 525
California Water Code Section 525 requires water purveyors to install meters on all new service connections after January 1, 1992. As a result, homes constructed after January 1, 1992 all have water meters installed. California Water Code Section 527 requires water purveyors to charge for water based upon the actual volume of water delivered if a meter has been installed.

Wastewater
General Waste Discharge Requirements for Sanitary Sewer Systems The General Waste Discharge Requirements (WDRs) for Sanitary Sewer Systems were adopted by the SWRCB in May 2006. These WDRs require local jurisdictions to develop a Sewer System Management Plan (SSMP) that addresses the necessary operation and emergency response plans to reduce sanitary sewer overflows. The WDRs require that the local jurisdiction approve the SSMP.

Stormwater
General NPDES Permits and WDRs
To enable efficient permitting under both the CWA and the Porter–Cologne Act, the SWRCB and the RWQCBs run permit programs that group similar types of activities that have similar threats to water quality. These “general permit” programs include the Phase II Small Municipal Separate Storm Sewer System (MS4)4 Permit, the construction general permit, and other general permits for low-threat discharges. The Construction Stormwater Program and the Small MS4 Permit are administered by the SWRCB, while other general WDRs are administered by the Central Valley RWQCB. Point source discharges or other activities that threaten water quality that are not covered under a general permit must seek individual NPDES permits and/or WDRs, depending on the type, location and destination of the discharge. For these types of discharges, the initial step in the process is to submit a “Report of Waste Discharge” to the San Francisco RWQCB, who then determines the appropriate permitting pathway. See Section 3.9, Hydrology and Water Quality, for more information.
4 A small MS4 is defined as a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains) that serve populations of fewer than 100,000 persons.

Agenda Item #5.4.

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California Sustainable Groundwater Act
The Sustainable Groundwater Management Act is a package of three bills (Assembly Bill [AB] 1739, SB 1168, and SB 1319) that provides local agencies with a framework for managing groundwater basins in a sustainable manner. The Sustainable Groundwater Management Act establishes minimum standards for sustainable groundwater management, roles and responsibilities for local agencies that manage groundwater resources, as well as priorities and timelines to achieve sustainable groundwater management within 20 years of adoption of a Groundwater Sustainability Plan. Central to the Sustainable Groundwater Management Act is the identification of critically overdrafted basins and the prioritization of groundwater basins, the establishment of Groundwater Sustainability Agencies, and the preparation and implementation of Groundwater Sustainability Plans for medium priority, high priority, and critically over drafted basins. Groundwater Sustainability Agencies must be formed by June 30, 2017; and Groundwater Sustainability Plans must consider all beneficial uses and users of groundwater in the basin, as well as include measurable objectives and interim milestones that ensure basin sustainability. A basin may be managed by a single Groundwater Sustainability Plan or multiple coordinated Groundwater Sustainability Plans. See Section 3.9, Hydrology and Water Quality, for more information.

Solid Waste
California Integrated Waste Management Act—AB 939
To minimize the amount of solid waste that must be disposed of by transformation (i.e., recycling) and land disposal, the State Legislature passed the California Integrated Waste Management Act of 1989 (AB 939), effective January 1990. According to AB 939, all cities and counties are required to divert 25% of all solid waste from landfill facilities by January 1, 1995, and 50% by January 1, 2000.

Solid waste plans are required to explain how each city’s AB 939 plan will be integrated within the respective county plan. They must promote (in order of priority) source reduction, recycling and composting, and environmentally safe transformation and land disposal. Cities and counties that do not meet this mandate are subject to $10,000–per-day fines. The City of St. Helena participates in the Upper Valley Waste Management Agency to achieve compliance with AB 939.

Mandatory Commercial Recycling – AB 341
AB 341 was adopted as part of the AB 32 Scoping Plan by the Air Resources Board pursuant to the California Global Warming Solutions Act on January 17, 2012. The regulation requires businesses that generate 4 cubic yards or more of commercial solid waste per week and multifamily residential dwellings of five units or more to arrange for recycling services. The measure focuses on increasing commercial waste diversion to reduce greenhouse gas emissions.

Agenda Item #5.4.

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Mandatory Commercial Organics Recycling – AB 1826
AB 1826 was enacted in October 2014 in order to divert commercial organic waste from landfills.

The measure requires businesses and multifamily residential dwellings of five or more units to recycle organic waste on and after April 1, 2016 depending on how much solid waste they generate per week. The law includes phasing of requirements over time to ensure that the minimum threshold of organic waste generation by businesses decreases gradually.

Local
City of St. Helena 1993 General Plan
The Public Facilities and Services Element of the St. Helena 1993 General Plan provides guiding policies regarding utilities and service systems, including the following:

Policy 9.2.1: Approval of new development shall be contingent upon the ability of the City to provide water without exceeding the safe annual yield of its water supply system.

Policy 9.2.3: Adopt and implement water conservation measures as a means of extending the capabilities of the City’s water supply.

Policy 9.3.1: Provide adequate sewage treatment capacity at the City treatment plant to meet the needs of population growth permitted under the City's Growth Management System.

Policy 9.3.3: Require extension of City sewer to areas with limited sewerage capacity prior to approval of future growth in these areas.

Policy 9.4.1: New development should provide adequate drainage improvements to handle generated storm runoff from the site to the nearest major watershed. The watersheds include York Creek, Sulphur Creek and the Napa River.

Policy 9.4.2: If a City storm drain is available, the developer should participate in the funding to the extent it benefits the development.

Policy 9.4.3: Extension of existing downstream drains which have adequate capacity should be completed at the developer’s expense with future reimbursement for oversizing costs at the time of connection by others.

City of St. Helena 2019 General Plan (“General Plan Update 2040”) The Public Facilities and Services Element of the St. Helena 2019 General Plan provides guiding policies regarding utilities and service systems, including the following:

Agenda Item #5.4.

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Policy PF1.1: Require that the approval of new development be contingent upon the ability of the City to provide water without exceeding the safe annual yield of its water supply system.

Policy PF1.2: Adopt and implement equitable water conservation measures for both residential and non-residential users so that the City can supply water within the safe yield of its water system.

Policy PF2.1: Ensure adequate sewage treatment capacity at the City treatment plant to meet the needs of population growth, taking into account the City’s Growth Management System, the Regional Housing Needs Allocation, and the needs of non-residential users.

Policy PF3.1: Ensure that new developments provide adequate drainage improvements and detention to mitigate flooding from increased stormwater runoff attributable to the development.

City of St. Helena Municipal Code
St. Helena Water Conservation and Emergency Shortage Ordinances The City has ordinances addressing water supply availability and water shortage contingencies including Chapter 13.12, Water Use and Efficiency of the Municipal Code requiring new developments to “completely offset its water requirement” by identifying residential or nonresidential properties eligible for retrofitting with water efficient hardware and verifying that the required number of retrofits have been completed prior to the issuance of a certificate of occupancy. Section 13.04.220 of the Municipal Code also addresses water shortage emergency conditions.

Water Use and Efficiency and New Development Municipal Code Section 13.12.030 Chapter 13.12 of the Municipal Code Section 13.12.030 requires new development projects within the City to be water-neutral from the City-delivered water system. Prior to construction, any project is required to offset its water demand by providing for the implementation of conservation measures for existing households. The City’s Municipal Code requires that this be demonstrated through a quantitative water analysis of the Proposed Project and can be achieved through any combination of on-site water conservation measures and/or off-site retrofitting and/or using well water. The quantitative water analysis must include a calculation of the baseline existing water demand, the proposed water demand, a comparison of the two and the proposed retrofits to achieve a zero water use increase from the proposed development. Specifically, new development shall completely offset its water requirement by installing city-approved ultra-low flush (ULF) toilets and associated water efficient hardware in a sufficient number of existing homes or nonresidential properties. Therefore, under this section, residential projects are required to complete toilet retrofits Agenda Item #5.4.

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or other City approved conservation measures to offset water use. This effectively locks City water demand at its current levels with the only minor climate related fluctuations. If the city council determines that retrofitting of existing residential or nonresidential buildings is impractical or constitutes an unusual hardship on an applicant, it may authorize the payment to the city of an inlieu retrofit fee. The in-lieu fee shall be the equivalent of the cost of retrofitting a sufficient number of existing homes with the ULF toilets and other required water-saving devices. The City will administer a rebate program to retrofit existing homes using the fees collected or may use the fees for another water use efficiency purpose as approved by the city council. The Proposed Project applicant completed a Water Neutral Report included in Appendix J.

Developer Impact Fees Municipal Code Section 3.32.020
Pursuant to Chapter 3.32 of the Municipal Code Section 3.32.020, the City collects development impact fees on new development or conversions within the city to pay for public improvements related to civic improvement projects, public safety, sewer projects, water projects, traffic mitigation, and storm drainage.

Municipal Code Chapter 13.32
Chapter 13.32, Stormwater and Runoff Pollution Control of the City’s Municipal Code contains the City's Stormwater and Runoff Pollution Control Ordinance. This ordinance empowers the City’s Public Works Department to enforce stormwater pollution regulations, including:
• Prohibiting illicit discharges to the stormwater conveyance system; • Establishing minimum requirements for stormwater management, including source control requirements, to prevent and reduce pollution;
• Establishing requirements for development project site design to reduce stormwater pollution and erosion;
• Establishing requirements for the management of stormwater flows from development projects, both to prevent erosion and to protect and enhance existing water-dependent habitats; and
• Establishing standards for the use of off-site facilities for stormwater management to supplement on-site practices at new development sites.

Title 16, Subdivisions, includes Chapter 16.32, Design Standards and Improvements, including Section 16.32.070, Drainage, which requires stormwater runoff from subdivisions to be collected and conveyed by an approved storm drainage system. The storm drainage system shall be designed by a registered civil engineer for ultimate development of the watershed and shall be capable of collecting and conveying runoff generated by the 10-year flood. The system shall Agenda Item #5.4.

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provide for the protection of abutting and off-site properties that may be adversely affected by any increase in runoff attributed to the development; off-site storm drain improvements may be required to satisfy this requirement. In addition, retention ponds, drainage swales and/or check dams may be required to reduce off-site peak storm flow generated by projects to the historic flow.

City of St. Helena Sewer System Management Plan
The City’s SSMP was developed originally in 2006 to comply with requirements of a 2005 Order from the San Francisco RWQCB. Since then, the SSMP has been revised several times to comply with Provision D.13 of State Water Board Water Quality Order (WQO) 2006-0003 Sanitary Sewer System WDRs and the associated Monitoring Reporting Program. The SSMP was last updated in May 2016, and includes the City’s sewer system management goals, operation and maintenance program, design and performance provisions, overflow emergency response plan, fat, oils, and grease control program, system evaluation and capacity assurance plan, and monitoring, measurement and program modifications.

City of St. Helena Storm Drainage Master Plan
The City’s Storm Drainage Master Plan (Plan) was prepared in September 2000 to analyze the existing storm drain system within the city and to develop a long-term plan for improving the City’s drainage facilities. The plan evaluates the capacity of the storm drain system to support existing development and identifies necessary improvements for future development. Preliminary cost estimates for recommended storm drainage improvements are also included to assist the City in establishing a capital improvements financing program and to confirm development impact fees.

The City is in the process of completing a comprehensive update to the Plan and anticipates adoption sometime in Summer or Fall 2021.

Basin Analysis Report for the Napa Valley Groundwater Subbasin Napa County submitted the Final Alternative Groundwater Sustainability Plan/Basin Analysis Report to the California Department of Water Resources on December 16, 2016, to meet the requirements of the 2014 Sustainable Groundwater Management Act. The report provides an analysis of the Napa Valley Subbasin, including the St. Helena Subarea, and includes groundwater management considerations and data.

City of St. Helena Source Reduction and Recycling Element The City adopted a Source Reduction and Recycling Element to meet the requirements outlined in AB 939. The Source Reduction and Recycling Element sets forth goals that direct the City toward the solid waste diversion requirement and reduce the City’s solid waste impact. The City of St. Helena participates in the Upper Valley Waste Management Agency to achieve compliance with AB 939.

Agenda Item #5.4.

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3.13.4 Impacts
Methods of Analysis
The impact analysis considers the Proposed Project’s effect on the demand for water supply, wastewater infrastructure and treatment, adequacy of stormwater infrastructure, and capacity of the landfill provider to attain solid waste reduction goals and compares this to the thresholds of significance listed below. The analysis considers whether existing utilities and service systems have adequate capacity and infrastructure to serve the demand generated by the Proposed Project and whether the Proposed Project would necessitate modifications to existing facilities or construction of new facilities to accommodate the increase in demand. Proposed Project demands for water, wastewater and solid waste are quantified below.

Water
Residential water demand factors are broken into two categories: single-family and multifamily.

The dwelling unit demands for the 51 single-family units reflect detached homes located on an average lot of 8,330 square-feet, with individual landscaping, hardscapes, pools, and other anticipated outdoor features. Typically, single-family residences have a higher number of people per house than multi-family housing units and a larger landscaped area on a per person basis. The 25 multifamily units share common landscaped areas and have minimal or no individual landscape demand. Multifamily residences typically have a lower average number of people per unit than a single-family unit. These factors result in lower dwelling unit water demand for multi-family residential units. The Proposed Project also includes 11 accessory dwelling units (ADUs) that are treated as multifamily units for the purposes of quantifying demand. The residential unit demand factors described below reflect two distinct uses: indoor use and outdoor use.

A Water Neutral Report (Appendix J) was prepared for the Proposed Project to demonstrate compliance with the City’s Water Neutral Policy. The water analysis calculates the estimated water demand of Proposed Project operation and potential water off-set measures. Indoor water usage factors used in the analysis are based on water usage from water fixtures and appliances in relation to the number of occupants as defined by the City’s Water Neutral Policy. See Appendix J for a breakdown of water demand factors used to calculate total Proposed Project water demands. Note that the ADUs are not identified separately in the preliminary water calculation. However, the water demand for single family residences assumes eight persons per home, based on the City’s demand factor of four bedrooms and two persons per bedroom. This assumes a higher persons per household for the purposes of calculating water demand, as compared to the City’s persons per household of 2.45 to determine a project’s population (City of St. Helena 2015b). Given the size of the ADUs, one to two persons would be a typical occupancy. Therefore, the residential indoor water demand calculations could accommodate an above-average size household and an occupied ADU.

Agenda Item #5.4.

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Residential lots with ADUs would not have additional outdoor water demand (and may have less outdoor water demand, as the area occupied by the ADU might otherwise be landscaped).

The Proposed Project’s water demand is provided below in Table 3.13-9. The Proposed Project is estimated to have a total water demand of 37.04 acre-feet per year at completion, including 17.16 acre-feet for outdoor landscaping. The impact analysis for available water supply is based on a comparison of these water demand numbers to the listed thresholds of significance. Table 3.13-10 provides a more detailed breakdown of the indoor water demand Table 3.13-9
Proposed Project Water Demands (acre-feet per year)
Water Sources Indoor Water Demand1
Outdoor Water
Demand Total Demand
Municipal Water 19.88 0 19.88
On-Site Groundwater Well 0 17.16 17.16
Total Water Demand (acre-feet) 19.88 17.16 37.04
Source: Appendix J.

Note:
1 Existing water meters in the City do not separately track indoor and outdoor residential water use.

Table 3.13-10
Proposed Project Breakdown of Water Demand
Fixture
Flow Rate
gal/min or
gal/flush
Flow Duration
(min., flush, load)
Daily Uses
per
Occupant
Number of
Occupants1
Gallons per
Day
Acre-feet Per
Year
Showerheads 2 8 1 508 8,128 9.10
Sink Faucets 1.5 0.25 3 508 572 0.64
Kitchen Faucet 1.5 4 1 508 3,048 3.41
Toilet 1.3 1 3 508 1,981 2.22
Clothes Washer 19.7 1 0.37 508 3,703 4.15
Dish Washer 6.3 1 0.1 508 320 0.36
Total Water Demand 17,752 19.88
Source: Appendix J.

Note:
1 For the purposes of determining the Proposed Project’s water demand, the City’s demand factor is based on the number of bedrooms and persons per bedroom, which differs from the City’s persons per household (PPH) to determine the number of residents a residential project would generate, which is 2.45 PPH.

Wastewater
Projected wastewater generation for the Proposed Project is based on indoor water demand calculations included in the Water Neutral Report (Appendix J) prepared for the Proposed Project.

The impact analysis for available wastewater capacity is based on a comparison of this wastewater generation calculation to the listed thresholds of significance. As shown in Table 3.13-10, the Agenda Item #5.4.

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Proposed Project would result in an indoor water use of approximately 19.88 acre-feet per year during operation. This translates to a wastewater generation rate of 19.88 acre-feet per year, or

0.018 MGD (Appendix J).

Solid Waste
The impact analysis for solid waste was based on a comparison of projected solid waste demand to the listed thresholds of significance. Table 3.13-11 displays the projected solid waste demand associated with Proposed Project operation. The solid waste generation rates used for Proposed Project operation are based on default generation rates used by CalEEMod, which uses CalRecycle data. The solid waste generation rates used for Proposed Project construction are based on U.S. EPA’s 2003 report Estimating 2003 Building-Related Construction and Demolition Materials Amounts. To determine the approximate amount of construction debris the square footage of development was conservatively estimated to be 733,000 square feet, with 584,000 square feet for single-family lots and ADUs and 149,000 square feet for attached housing. Using the solid waste generation rate of 0.0022 tons per square feet, the Proposed Project is estimated to produce 1,445.4 tons of construction debris (U.S. EPA 2003).

To determine the amount of solid waste generated during Proposed Project operation, generation rates provided by CalRecyle were used and include the following:

Single Family Residential = 0.0033 tons/day/dwelling unit Multifamily Residential = 0.0013 tons/day/dwelling unit The projected amount of solid waste generated by Proposed Project operation is 0.2251 tons per day of residential solid waste or 82 tons per year, shown in Table 3.13-11. The City encourages contractors to use recycling and/or reuse (diversion) measures to reduce the amount of construction waste and other materials sent to landfills.

Table 3.13-11
Proposed Project Projected Waste Generation
Land Use Number of Units Generation Rate
Waste Disposed
(tons per day)
Single Family 51 0.0033 0.1683
ADU 11 0.0013 0.0143
Multifamily/Attached 25 0.0013 0.0325
Total 0.2251
Source: CalRecycle 2018.

Agenda Item #5.4.

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Thresholds of Significance
Consistent with Appendix G of the California Environmental Quality Act Guidelines, considerations for whether a significant impact may occur include whether the Proposed Project would:
• Require or result in the relocation or construction of new or expanded water, wastewater treatment, or stormwater drainage, electric power, natural gas, or telecommunications facilities, the construction or relocation of which could cause significant environmental effects. • Have sufficient water supplies available to serve the project and reasonably foreseeable future development during normal, dry, and multiple dry years. • Result in a determination by the wastewater treatment provider, which serves or may serve the project that it has adequate capacity to serve the project’s projected demand in addition to the provider’s existing commitments.
• Generate solid waste in excess of State or local standards, or in excess of the capacity of local infrastructure, or otherwise impair the attainment of solid waste reduction goals. • Comply with federal, state, and local management and reduction statutes and regulations related to solid waste.

Impacts and Mitigation Measures

3.13-1:Would the Proposed Project require or result in the relocation or construction of new or expanded water, wastewater treatment, or stormwater drainage, electric power, natural gas, or telecommunications facilities? This impact is less than significant.

The Proposed Project would require new water, sewer, storm drain, electric power, natural gas, and telecommunications infrastructure on site to serve the proposed residential development designed in compliance with City specifications. The Project site is currently not served by City utilities. The Proposed Project’s on-site water, sewer, and storm drain lines are proposed to be located within the street/driveway rights-of-way within the Project site. The City’s water and wastewater treatment and conveyance facilities, stormwater drainage facilities, and electric power, natural gas, and telecommunication facilities are expected to have the capacity to accommodate the demands of the Proposed Project, as discussed below.

Water Treatment
An existing 10-foot wide public water line easement containing an active 12-inch water line bisects the north/northeast portion of the Project site. This easement is proposed to be abandoned as part of the Project and the water line relocated.

Agenda Item #5.4.

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The Proposed Project is proposing a looped 8-inch water main within Streets A and B that would connect to the existing water main at two locations. A new 8-inch water main is also proposed within the extension of Adams Street to connect to the existing water main at the southwest end of the Project site. An existing well is located near the southeastern end of the Project site that is proposed to be maintained in place (in proposed Lot 19) and used to provide non-potable irrigation of exterior public landscaping areas. The Proposed Project would be designed not to exceed 0.4 acre-feet/year/dwelling unit of water based on the installation of increasingly efficient and lowerwater-using fixtures and appliances and irrigation systems.

The Proposed Project’s demand for treated water would be supported by the City’s existing water treatment and delivery infrastructure, as well as necessary improvements. As shown in Table 3.13- 9, the Proposed Project is expected to generate a water demand of approximately 37.04 acre-feet per year at build out. As described in the Setting section above, the Louis Stralla WTP, which treats water that is sourced from the Bell Canyon Reservoir, typically treats 3.5 MGD (3,920 acrefeet per year) and has a capacity of 4.3 MGD (4,817 acre-feet per year) (City of St. Helena 2018).

The Proposed Project’s water demand would represent a minimal percentage of the treatment capacity of the Louis Stralla WTP. In addition, the Proposed Project would be served by water from the City of Napa and the City’s groundwater wells, which have treatment facilities of their own. As noted in the setting section, under a contract with the City of Napa the City receives 600 acre-feet annually and may request up to 200 acre-feet of additional water supply if the City of Napa has water supplies available. Furthermore, the City’s groundwater would only account for a minimal amount of water use on the Project site, as the City currently limits the use of groundwater from the City’s wells in an agreement with the Water Audit.

Therefore, water treatment facilities would be able to adequately serve the potable water demand of the Proposed Project and the Proposed Project would not exceed the capacity of these facilities.

The Proposed Project would be served by a variety of available water supply sources, and the Proposed Project’s landscape irrigation demand would be offset through water conservation measures and use of the on-site well (see Appendix J). Pursuant to Municipal Code Section

3.32.020, the City collects development impact fees on new development to pay for public improvements related to water projects. The Proposed Project applicant would pay these fees, which would help offset any increased demands on the City’s water system. Therefore, the Proposed Project would not require or result in the relocation or construction of new or expanded water facilities, the construction or relocation of which could cause significant environmental effects. This impact would be less than significant.

Wastewater Treatment
Wastewater flows from the western portion of the Proposed Project are proposed to drain into an existing public manhole at the corner of Starr and Hunt Avenue via new 8-inch sewer pipes. The area Agenda Item #5.4.

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east of Starr Avenue, lower in elevation, is proposed to drain east through the Project site via new 8- inch sewer pipes, through Lot 21 within a public easement and into an existing public manhole on the adjacent parcel in the Vineyard Valley Mobile Home Park. The Proposed Project would install 8-inch sewer lines within all roadways to service the proposed residences. All sewer mains are sized to accommodate Proposed Project flows, per City standards, and designed at slopes to provide required self-cleaning velocities. Sewer laterals would be installed per City specifications.

The Proposed Project would increase the amount of wastewater requiring treatment at the City’s WWTP. The Proposed Project is expected to generate approximately 0.018 MGD of wastewater during operation. The Proposed Project would not exceed the City’s current permitted dry weather capacity of 0.5 MGD when combined with the average flow of 0.384 that is treated at the WWTP.

Furthermore, pursuant to Municipal Code Section 3.32.020, the City collects development impact fees on new development to pay for public improvements related to sewer projects. The Proposed Project applicant would pay these fees, which would help offset any increased demands on the City’s sewer system. Therefore, the Proposed Project would not result in or require the relocation or construction of wastewater treatment facilities, the construction or relocation of which could cause significant environmental effects. Impacts would be less than significant.

Stormwater Drainage
The Proposed Project would connect to the City’s stormwater drainage system. The Project site drains to an existing City-owned detention basin that was constructed as part of the City’s Flood Protection Project. New storm drain lines would be installed in Streets A, B, and C, and Adams Street. The southwesterly portion of the site is proposed to drain via gutter flow and proposed storm drain pipes and discharge into the existing Starr Avenue storm drain at several different locations. The remainder of the Proposed Project is proposed to drain to the northeast via gutter flow and storm drain pipes and discharge into the City’s existing detention basin. The City requires that all storm drain pipes be sized to accommodate a 10-year storm within the pipe and 100-year storm within the street section.

The Proposed Project would result in an increase in stormwater runoff by converting predominantly undeveloped land to roadways, driveways, and residences, thereby increasing impervious coverage on the Project site. The Proposed Project would result in the addition of 10.91 acres of impervious surface, which is equivalent to an impervious surface coverage of 58%. The Proposed Project would be required to comply with the Bay Area Stormwater Management Agencies Association (BASMAA) requirements designed to prohibit non-stormwater discharges to storm drains and require use of Best Management Practices (BMPs) to minimize the amount of pollutants in runoff in accordance with the City’s Phase II Stormwater NPDES Permit for small MS4s. The NPDES Permit includes a provision (Provision E.12) that mandates municipalities to require specified features and facilities (i.e., vegetated swales, LID features) to control pollutant sources, Agenda Item #5.4.

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control runoff volumes, rates, and durations, and to treat runoff before discharge from the site be included in development plans as conditions of issuing approvals and permits (BASMAA 2019).

The Project is also designed to construct storm drains or as required, improve existing storm drains so that they have adequate capacity to carry the runoff produced by a 10-year storm. Onsite storm flows from the single-family residential portion would be conveyed to the City’s detention basin via underground storm drain lines varying in diameter from 15 to 30 inches. Storm runoff from the Project area east of the proposed Starr Avenue extension would be collected by 15-inch storm drains connected to the City’s existing 36-inch storm drain. Stormwater flows would then be directed to the City’s detention basin. Title 16 of the City’s Municipal Code requires a new stormwater drainage system be designed by a registered civil engineer for ultimate development of the watershed, and to convey runoff generated by a 10-year flood event. Per Title 16, the stormwater drainage system must also be designed to provide for the protection of abutting and off-site properties, and off-site storm drain improvements may be required to satisfy this requirement. Street curbs would be designed to adequately collect and convey the runoff produced by a 100-year storm event. As indicated above, the City’s detention basin was designed to accommodate stormwater runoff assuming 70% of the Project site would be developed with impervious surfaces (i.e., roads, sidewalks, homes).

Pursuant to Municipal Code Section 3.32.020, the City collects development impact fees on new development to pay for public improvements related to stormwater drainage projects. The Proposed Project applicant would pay these fees, which would help offset any increased demands on the City’s stormwater drainage system. Therefore, the Proposed Project would not require or result in the relocation or construction of new or expanded stormwater drainage facilities; this impact would be less than significant.

Electric Power, Natural Gas, or Telecommunications Facilities The Proposed Project would be served by Marin Clean Energy for electricity service and Pacific Gas & Electric Company for natural gas service. Telecommunications services are offered by various service providers within the City. The Project site is located in a developed area of the City, surrounded by commercial, office and residential uses to the west and south. Electric power, natural gas, and telecommunications services all exist adjacent to the Project site and the Proposed Project would tie into these services. The Proposed Project would not require the construction of new or relocation of electric power, natural gas, or telecommunications facilities. On-site electrical, natural gas and telecommunications connections would all be installed subsurface, no overhead facilities would be provided. Therefore, impacts would be less than significant.

Mitigation Measures
None required.

Agenda Item #5.4.

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3.13-2: Would sufficient water supplies be available to serve the Proposed Project and reasonably foreseeable future development during normal, dry, and multiple dry years? This impact would be less than significant.

On March 22, 2011, the City Council adopted the definition of “Safe Yield” as proposed by the Safe Water Yield Committee.5 The Safe Yield Committee found that the long-term safe yield of the City’s water supply is 1,950 acre-feet per year, which consists of 600 acre-feet from the City of Napa contract, a conservative 900 acre-feet from Bell Canyon reservoir, and an average use of 450 acre-feet from groundwater. As shown in Table 3.13-1, recent water usage in the City is well below the 1,950 acre-feet target, with water usage ranging from ranging from 1,882 (2013) to 1,465 acrefeet (2016) and averaging 1,637 acre-feet over the last eight years. To reduce future water demand within the City, the City established a water-neutral policy, requiring future development to completely offset its post-construction water use. As discussed in the setting section, the City is currently under a Phase II water emergency that limits the amount of water for all commercial and residential uses and does not allow approval of new water connections. At this time, it is uncertain when the restrictions will be lifted. The analysis assumes adequate water supplies would be available, but it is under the purview of the City Council to make that determination. The 1993 General Plan Policy 9.2.1 requires approval of new development be contingent upon the ability of the City to provide water without exceeding the safe annual yield of its water supply system.

All new development in the state is required to comply with CalGreen that requires the installation of water-efficient indoor infrastructure to conserve water. In addition to CalGreen, all landscape irrigation is required to comply with the water requirements set forth in the MWELO, which the City has codified in the Municipal Code. Lastly, water meters would be installed for each single-family and multifamily unit.

The Proposed Project’s estimated indoor water demand is 19.88 acre-feet per year at completion during normal water years (see Table 3.13-10). The Proposed Project’s landscape irrigation demand would account for 17.16 acre-feet per year. Assuming the Proposed Project’s entire water demand of 37.04 acre-feet per year, adding it to the highest water demand in recent years of 1,882 results in 1,919 acre-feet, below the Safe Yield of 1,950. In addition, the Proposed Project must comply with the City’s water neutrality policy. In order to comply with this policy, a Water Neutral Report (Appendix J) was prepared for the Proposed Project, which estimates proposed water demand and quantifies water off-set mitigations. The report shows that the 37.04 acre-feet per year of water that would be used during Proposed Project operation would be completely offset through a combination of using the on-site water well for irrigation needs and implementation of water conserving measures, which are detailed in Appendix J. To comply with the City’s water neutrality policy, the Proposed Project applicant is required to off-set the Proposed Project’s water 5 The March 2011 report is the most current version available.

Agenda Item #5.4.

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demand as a condition of approval. To comply with this requirement the Proposed Project applicant would be required to provide in-lieu funds consistent with Municipal Code Section

13.12.030, which permits payment of in-lieu fees equivalent to the cost of retrofitting a sufficient number of existing homes with ULF toilets, funding water meter replacements (smart meter upgrade), old pipeline replacement, and other City-approved projects. The City would use the inlieu fees to retrofit existing homes or for another water use efficiency purpose as approved by the City Council.

The existing on-site agricultural well is proposed to be used to provide non-potable supplies to the separately plumbed landscape irrigation systems throughout the Project site to irrigate public and private landscaping. Historically, this well has been used to serve the irrigation needs of the vineyard located on the property but is currently inoperable. The Proposed Project’s landscape water demand is estimated at 17.16 acre-feet per year, which is within the capacity of the on-site well (groundwater impacts are further discussed in Section 3.9 Hydrology). In addition, the Proposed Project would be required to comply with the MWEL Ordinance.

The City has been well below the Safe Yield of 1,950 acre-feet per year in recent years with adequate water supplies through the use of the three different water supply sources. The City has adequate water to serve the demands of the Proposed Project. In addition, as a condition of approval, the Proposed Project applicant would pay the required fees to offset the Proposed Project’s water demand in addition to implementing mandated water conserving measures.

Therefore, sufficient water supplies are available to serve the Proposed Project and the impact would be less than significant.

Mitigation Measures
None required.

3.13-3: Would adequate wastewater treatment capacity be available to serve the Proposed Project’s increase in demand in addition to the provider’s existing commitments? This impact would be less than significant.

The City’s WWTP would provide wastewater treatment service to the Project site. The City’s WWTP operates under a NPDES permit and is permitted to discharge up to 0.5 MGD during dry weather and up to 2.8 MGD during wet weather of treated effluent (City of St. Helena 2016). The Proposed Project is expected to generate an average of 0.018 MGD of wastewater. As the WWTP currently treats an average flow of 0.384 MGD, the additional 0.018 MGD combined with the current average flow of 0.384 MGD would not exceed the plant’s permitted allowable average dry weather flow effluent limit of 0.5 MGD, as specified under its NPDES permit (City of St. Helena 2016). The 2015 Facilities Evaluation for the WWTP concluded that the total WWTP capacity was sufficient when operated under design conditions. The 2015 Facilities Evaluation indicated that as Agenda Item #5.4.

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the service area population was growing only slightly and per capita wastewater flows are declining due to conservation measures, the existing WWTP capacity is sufficient in the short-term. The report projected that the 2030 average dry weather flows into the WWTP would be approximately

0.50 MGD. However, the report indicated that the capacity should be increased to 0.65 MGD by 2030 to account for uncertainty (City of St. Helena 2016). The San Francisco RWQCB specifies that water treatment facilities must follow conditions under their NPDES permit. The City has been notified by the RWQCB that treatment plant upgrades and an amended permit are required as part of a cease and desist order. The capacity issues of the plant are a function of nutrient load (intensity of effluent) and dry weather flow (amount of effluent). The RWQCB has not requested that there be a moratorium on new connections to the treatment plant.

Wastewater generated by the Proposed Project is not expected to be comprised of any new or substantially different chemical constituents than those that are typically present in these types of residential projects and are not expected to be of concern regarding permitted effluent limitations for chemical parameters. Because adequate capacity is available at the WWTP to serve the Proposed Project, this is considered a less-than-significant impact.

Mitigation Measures
None required.

3.13-4: Would the proposed project generate solid waste in excess of State or local standards, or in excess of the capacity of local infrastructure, or otherwise impair the attainment of solid waste reduction goals? This impact would be less than significant.

Construction
The Proposed Project would increase solid waste generation in the City during construction. Using the solid waste generation rate of 0.0022 tons per square feet, it is estimated that during Proposed Project construction approximately 1,612.6 tons of solid waste would require disposal. The City encourages recycling of construction debris to the extent feasible. In addition, the 2016 CALGreen Tier 1 mandatory measures require preparation of a Construction Waste Management Plan that documents the diversion of materials as required by CALGreen and at least 65% of nonhazardous construction waste would be required to be recycled or salvaged. Assuming a 6-year buildout, the amount of construction-related solid waste would be approximately 201.6 tons per year (0.55 tons per day) at maximum. The Clover Flat Landfill has a maximum permitted throughput of 600 tons per day. As the landfill receives approximately 150–175 tons per day of solid waste on average, this allows for a remaining capacity of approximately 425 tons of solid waste per day. Therefore, the Proposed Project’s construction waste, conservatively assuming none would be diverted or recycled, would contribute less than 0.1% of the landfill’s remaining permitted capacity per day. As this is a minimal contribution, the Clover Flat Landfill would have adequate landfill capacity for the Agenda Item #5.4.