Corona City Council
July 1, 2026

4.E. Geology and Soils December 2015
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regular basis until the primary settlement has stabilized and before those areas are released for construction.

As recommended in the Geotechnical Report, and required by Mitigation Measure GEO-1, the site’s loose, compressible residual soil, non-engineered onsite fill, colluvium, alluvium, landslide debris, older alluvium and weathered bedrock would be removed from fill areas prior to placement of fill and from shallow cut areas, where exposed at finish grades. Fills associated with "recreational" grading, construction of unpaved access roads, mining operations and existing trench backfill would be removed prior to fill placement. Other fills, including roadway fills and trench backfill, are not mapped due to their localized extent and minor thickness. Removals would extend below the undocumented fill until competent materials are encountered.

The Geotechnical Report recommends that all alluvial and colluvial soils below proposed fill areas and in cut areas shall be removed to expose competent bedrock or terrace deposits. All alluvium deposits exposed at existing or cut grades would be entirely removed prior to fill placement. Anticipated average removal depths for alluvium/colluvium areas are expected to vary to an estimated maximum thickness of 35 feet. All landslide debris that could adversely affect the proposed development would be removed to expose the underlying competent bedrock.28 The seismic refraction survey revealed that excavation difficulty is expected to increase with depth and, in order to attain design grades, very heavy ripping would be anticipated in the Silverado and Ladd formations underlying the site. Therefore, it is likely that excavating during grading would also encounter ledges and zones of extremely hard rock that may require blasting.

Guidelines to determine the depth of removals are provided in the Geotechnical Report; however, the exact extent of the removals would be determined in the field during grading, when observation and evaluation of the greater detail afforded by those exposures can be performed by the Geotechnical engineer and/or Engineering Geologist.29 The minimum backcut ratio would be 1:1 (horizontal to vertical). The bottoms of all removal areas would be observed, mapped and approved by the Engineering Geologist prior to fill placement. It is recommended that the bottoms of removals be surveyed and documented by the Project Civil Engineer.30 With the incorporation of recommendations of the Geotechnical Report regarding temporary shoring and temporary excavations, as required by Mitigation Measure GEO-2, the project site is considered suitable for the proposed excavation and fill activities and impacts related to the stability of cut and fill slope would be less than significant.

Ascending and descending natural slopes exist within the site that range in height up to approximately 200 feet with slope ratios from 2:1 to locally 1.2:1. Stability analyses of the highest ascending slope of 160 feet above Lot 4 indicates a factor-of-safety in excess of the code minimums (described in Appendix II of the 28 Ginter & Associates, Inc., April 25, 2014, page 43. 29 Slope stability analyses were performed for the proposed highest cut slope (Section 1-1’), highest fill slope (Section 2-2’), buttressed slope (Section 3-3’), highest ascending natural slope (Section 4-4’), highest descending natural slope (Section 5-5’). Temporary backcut conditions for buttressed slopes as shown on Section 3-3’ was also analyzed. Shear strength parameters established and used in 2006 analyses by previous consultant Pacific Soils Engineering, Inc. were utilized. The slopes were analyzed by calculating the factors of safety for circular-type failures using the Modified Bishop’s Method and block-type failure surfaces using Modified Janbu Method. GSTABL7 was utilized to evaluate slope stability factors of safety under static and pseudo-static conditions. For pseudo- static analyses, a horizontal seismic coefficient of 0.15g was utilized for the critical failure surfaces on each cross-section. 30 Ginter & Associates, Inc., April 25, 2014, page 41.

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Geotechnical Report). Therefore, no geologic hazards associated with natural slopes on the project site would occur as a result of project implementation.
(4) Expansive Soils
Threshold 4: Be located on expansive soil, as defined in Table 18 1 B of the Uniform Building Code (1994), creating substantial risks to life or property?
Impact 4.E-4 On-site soils are anticipated to have low to medium expansion potential. Any soils with high or critical expansion potential would be replaced with compacted fill with low or medium expansion potential as required by Mitigation Measure GEO-4. Design of foundations to meet medium soils expansion potential, as required by Mitigation Measure GEO-10, would reduce risks to life or property to a less than significant level.

Expansive soils are characterized by the ability to undergo significant volume change (shrink and swell) as a result of variation in soil moisture content.

Based on the laboratory tests performed during the investigation of the site by PSE, it is anticipated that the majority of onsite soils would classify as "very low" to "medium" in expansion potential according to Table 18-I-B of the 1997 UBC31. However, portions of the Silverado Formation could produce materials ranging from very high to critical in expansion potential. If warranted, over excavation to depth and replacement with compacted fill, as recommended in the Geotechnical Report and required by Mitigation Measure GEO-4, would reduce the effects of any highly expansive soils encountered at grade.32 The compacted engineered fill at the project site is anticipated to be low to medium soil expansion potential.

Preliminary geotechnical criteria for design of building foundations, including conventional footing and post- tensioned foundation options, according to medium soil expansion are presented in the Geotechnical Report.33 With adherence to the recommendations of the Geotechnical Report for foundation design, as required by Mitigation Measure GEO-10, impacts related to risks to life or property resulting from expansive soils would be reduced to a less than significant level. (5) Septic Tanks and Alternative Wastewater Disposal Systems Threshold 5: Have soils incapable of adequately supporting the use of septic tanks or alternative waste water disposal systems where sewers are not available for the disposal of waste water? Impact 4.E-5 The project would be served by the City’s wastewater system. Infrastructure (i.e., pipes) would be installed to accommodate the proposed expansion. No significant impact would occur with regard to soils supporting septic tanks or alternative wastewater disposal systems. 31 Ginter & Associates, Inc., April 25, 2014, page 38. 32 Ginter & Associates, Inc., April 25, 2014, page 47. 33 Ginter & Associates, Inc., April 25, 2014, pages 51 and 52.

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The project site would be served by the City’s wastewater system. Thus, no septic systems or alternative wastewater systems would be installed. Therefore, no significant impact with regard to soils supporting septic tanks or alternative wastewater disposal systems would occur. Please see Section 4.N, Utilities and Service Systems, of this Draft EIR for a detailed analysis regarding wastewater. (6) Consistency With Regulatory Framework
Threshold 6: Conflict with an applicable plan, policy or regulation adopted for the purpose of avoiding or mitigating physical impacts associated with geology and soils? Impact 4.E-6 The proposed project would comply with all requirements related to seismic and geologic hazard safety standards. The project would not conflict with an applicable plan, policy or regulations adopted for the purpose of avoiding or mitigating physical impacts associated with geology and soils and impacts would be less than significant with implementation of Mitigation Measures GEO-1 through GEO-23.

Table 4.E-1, General Plan Consistency Analysis, provides an analysis of the project relative to applicable goals and policies in the Environmental Hazards and Public Safety Element of the General Plan. As shown in Table

4.E-1, the project would be consistent with the policies and would not conflict with portions of the policies that are directed at the City. The proposed project would comply with all applicable state and local building standards with regard to seismic and geologic hazard safety standards. The project would not be located within a designated Alquist-Priolo Special Study Zone. As indicated in the Geotechnical Report, no known active or potentially active faults exist within the project site. However, because the age of last movement along a fault exposed in Trench T-12, in the northwest corner of the site is presently unknown due to lack of dateable overlying sediments, a provisional habitable structures setback zone for the fault has been recommended until additional investigation may be undertaken. The Geotechnical Report considers this a conservative interpretation because the fault has no surface expression and its length is limited based on the un-faulted strata observed in the north-central part of the site south of Mabey Canyon. Prior investigators also concluded that the Alquist-Priolo trace of the Main Street Fault is clearly overlain by un-faulted upper Pleistocene sediments near Mabey Canyon and is thus, not active in the northwest part of the site south of Mabey Canyon, which precludes the need for habitable structures setbacks in that area.34 In addition, the project would incorporate the recommendations in the site-specific Geotechnical Report, as required by Mitigation Measures GEO-1 through GEO-23. Therefore, the project would not conflict with an applicable plan, policy or regulation adopted for the purpose of avoiding or mitigating physical impacts associated with geology and soils and impacts would be less than significant.

3. CUMULATIVE IMPACTS
For geology and soils, the study area considered for the cumulative impact includes (1) the area that could be affected by proposed project and (2) the areas affected by other projects whose activities could directly or indirectly affect the geology and soils of the project site. Geologic and soil impacts are generally site-specific and there is little, if any, cumulative relationship between development projects. Adherence to all relevant 34 Pacific Soils Engineering, Inc. (2005) cited in Ginter & Associates, April 25, 2014, page 36.

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Table 4.E-1
General Plan Consistency Analysis
Goals and Policies Consistency
Environmental Hazards and Public Safety – Seismic, Geologic, and Erosion Hazards Goal 11.1 – Substantially reduce the
known level of risk to loss of life, personal
injury, public and private property
damage, economic and social dislocation,
and disruption of vital community
services that would result from
earthquake damage or other geologic
disturbance.

Consistent. The proposed project would comply with all applicable state and local building standards. A geotechnical/soils report prepared for the proposed project would be reviewed and approved by the City Engineer, along with other approvals for the project. The project would comply with all recommendations stated therein to reduce substantially the risk of loss of life, personal injury, public and private property damage, economic and social dislocation, or disruption of vital community services that would result from earthquake damage or other geologic disturbances. . Policy 11.1.1 – Require new development and re-development to be
undertaken in a manner that is in
compliance with current seismic and
geologic hazard safety standards, as
follows:

Regulate land uses in areas known to
have, or have potential to have,
significant seismic and/or other
geologic hazards.

Require detailed scientific analyses of
natural hazards to the satisfaction of
the City Engineer as a condition of
development approval within the City
of Corona.

Consistent. As indicated above, the proposed project would comply with all applicable state and local building standards with regard to seismic and geologic hazard safety standards. The project would not be located within a designated Alquist-Priolo Special Study Zone and, as indicated in the Geotechnical Report, no known active or potentially active faults exist within the project site. However, because the age of last movement along a fault exposed in Trench T-12, in the northwest corner of the site is presently unknown due to lack of dateable overlying sediments, a provisional habitable structures setback zone for the fault until has been recommended until additional investigation may be undertaken. The Geotechnical Report considers this a conservative interpretation because the fault has no surface expression and its length is limited based on the unfaulted strata observed in the north-central part of the site south of Mabey Canyon. Prior investigators also concluded that the Alquist-Priolo trace of the Main Street Fault is clearly overlain by un-faulted upper Pleistocene sediments near Mabey Canyon and is thus, not active in the northwest part of the site south of Mabey Canyon, which precludes the need for habitable structures setbacks in that area.35 In addition, the project would incorporate the recommendations in the site-specific Geotechnical Report.

Therefore, the project would not conflict with an applicable plan, policy or regulations adopted for the purpose of avoiding or mitigating physical impacts associated with geology and soils and impacts would be less than significant. Source: City of Corona General Plan, ICF International, and PCR Services Corporation. 35 Pacific Soils Engineering, Inc. (2005) cited in Ginter & Associates, April 25, 2014, page 36. plans, codes, and regulations with respect to project design and construction would reduce project-specific and cumulative geologic impacts to a less-than significant level. Therefore, since geologic hazards are site- specific, the project, in combination with other past, present, and reasonably foreseeable future projects, would not create a potentially significant cumulative impact on geological resources.

Impacts from erosion and loss of topsoil from site development and operation can be cumulative in effect within a watershed. The Santa Ana Watershed, which encompasses the City of Corona and the sphere of

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influence, forms the geographic context of cumulative erosion impacts. Development throughout the watershed would be subject to State and local runoff and erosion prevention requirements, including the applicable provisions of the general construction permit, BMPs, and Phases I and II of NPDES, as well as implementation of fugitive dust control measures of SCAQMD Rule 403. These measures would be implemented as conditions of approval of project development and subject to continuing enforcement. As a result, it is anticipated that cumulative impacts on the Santa Ana Watershed due to runoff and erosion from cumulative development activity would be less than significant.

4. MITIGATION MEASURES
In order to ensure that impacts related to geology, soils, and seismicity are reduced to less than significant, the following mitigation measures are proposed:

Mitigation Measure GEO-1: Site Preparation and Removals. All grading shall be accomplished under the observation and testing of the Project Geotechnical Engineer and Engineering Geologist in accordance with the recommendations contained in the Project Geotechnical Report, contained in Appendix F of this Draft EIR), the current codes practiced by the City of Corona and the Earthwork Specifications contained in Appendix IV of the Project Geotechnical Report. Loose, compressible residual soil, non-engineered onsite fill, colluvium, alluvium, landslide debris, older alluvium and weathered bedrock shall be removed from fill areas prior to placement of fill and shall be removed from shallow cut areas, where exposed at finish grades. Guidelines to determine the depth of removals are presented below; however, the exact extent of the removals must be determined in the field during grading, when observation and evaluation of the greater detail afforded by those exposures can be performed by the Geotechnical engineer and/or Engineering Geologist.

The minimum backcut ratio shall be 1:1 (horizontal to vertical). The bottoms of all removal areas shall be observed, mapped and approved by the Engineering Geologist prior to fill placement. It is recommended that the bottoms of removals be surveyed and documented by the Project Civil Engineer.

Groundwater, if encountered during grading, shall be evaluated by the Geotechnical Engineer and/or Engineering Geologist. In general, groundwater is not anticipated to adversely affect grading although saturated soils and free water may be encountered along canyons and within alluvium removals. If groundwater is excessive, remedial measures such as horizontal drains or under drains may need to be installed. Further, settlement monuments and plates (see Plate VI of the Geotechnical Report) shall be installed during and after completion of grading to monitor settlement monuments and plates shall be used to determine when the majority of the primary settlement has been completed to allow for the release of affected lots for construction.

Stripping: Vegetation, debris and other deleterious materials are unsuitable as structural fill material and shall be disposed of offsite prior to commencing removals and placement of compacted fills. The thick, natural vegetative growth onsite is significant and will require consideration for removal. An onsite mulching operation

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may be considered. The mulched materials could then be used in future landscape areas.

Soil and Weathered Bedrock (unmapped): Loose, compressible onsite soils and underlying weathered bedrock shall be removed to expose the underlying competent bedrock materials prior to placement of compacted fill and when exposed in shallow cut area. An average removal depth of 5 feet is anticipated for removal of topsoil and weathered bedrock. In general, onsite soils and weathered bedrock are suitable to be re-used as structural fill when properly moisture-conditioned.

Undocumented Artificial Fill (locally mapped as AFu): Fills associated with "recreational" grading, construction of unpaved access roads, mining operations and existing trench backfill shall be removed prior to fill placement. Generally, these artificial fills range from a depth of 3 to 20 feet. Local areas of undocumented fill associated with previous geotechnical investigations are not plotted on the map.

Other fills, including roadway fills and trench backfill, are not mapped due to their localized extent and minor thickness. Removals shall extend below the undocumented fill until competent materials are encountered.

Alluvium/Colluvium (map symbol Qal): All alluvium deposits exposed at existing or cut grades shall be entirely removed prior to fill placement. These deposits range in thickness from approximately 5 feet to 35 feet. Ginter and Associates recommends that all alluvial and colluvial soils below proposed fill areas and in cut areas be removed to expose competent bedrock or terrace deposits. Anticipated average removal depths for alluvium/colluvium areas are expected to vary to an estimated maximum thickness of 35 feet.

Groundwater was not encountered during PSE's subsurface investigation within the alluvium onsite. However, access was limited and certain alluvial areas could not be investigated such as within Krooner Canyon. If "saturated" alluvium is encountered that possesses a degree of saturation of 85% of more and is consistent with depth to bedrock, consideration may be given to leaving the saturated alluvium in-place, provided that settlement time-delay consequences are acceptable to the owner. If saturated alluvium is encountered and is going to remain in-place, an additional liquefaction investigation may be required and dynamic settlement recommendations for those areas will likely change.

Older Alluvium (Qoa): All older alluvium shall be removed to expose the underlying competent bedrock. Generally, these deposits range in depth from 10 to about 20 feet.

Landslide Debris (Qls): All landslide debris that could adversely affect the proposed development shall be removed to expose the underlying competent bedrock.

Generally, these deposits range in depth from 10 to about 29 feet, but may range up to around 35 feet in depth.

Removals Along Grading Limits: Removals of unsuitable soils shall be required prior to fill placement along the grading limit. A 1:1 projection, from toe of slope or grading limit, outward to competent materials shall be established, when possible.

Where removals are not possible due to grading limits, property line or easement restrictions, removals shall be initiated at the grading boundary (property line easement, grading limit or outside the improvement) at a 1:1 ratio inward to competent materials. Where this reduced removal criterion is implemented, special maintenance zones may be necessary. Affected areas shall be established, minimally, as a 1:1 projection from suitable removal bottom to finish ground surface. This

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condition is mainly expected in the slope areas. Where the projection intersects the face of the slope, the potential for distortion of the slope in response to post-grading settlements exists and provisions for future maintenance of such slopes shall be provided.

Mitigation Measure GEO-2: Slope Stability and Remediation Cut Slopes: The majority of cut slopes have been designed at a slope ratio of 2:1. The Engineering Geologist shall observe cut slopes and cut slope stabilization backcuts during grading. Modifications to the recommendations presented herein will likely be required based upon conditions exposed by grading.

Williams Formation (KW): Cut slopes within the Williams Formation may expose adverse bedding that shall require remediation. The cut slope superjacent to Lots 278 and 279 is anticipated to require replacement with a buttress fill. Probable buttresses are anticipated for the cut slope above Lots 261 through 267 and the cut slope below the WQMP Basin and Lots 247 through 255, as depicted on Figure 1 and Figure 2 (pocket) of the Geotechnical Report. Ladd Formation: Cut slopes within the Ladd Formation may expose adverse bedding that shall require remediation. The majority of the cut slopes should expose bedding dipping into the slope or at an angle steeper than the proposed cut slopes (greater than 60 degrees). Cut slopes within the Ladd Formation that expose bedding dipping into the slope or at an angle steeper than the proposed cut slopes are expected to be grossly stable; however, the final determination shall be made based on exposed conditions during grading. Cut slopes within the Ladd Formation may expose conglomerate resulting in poorly cemented sands, cobbles and boulders at finish grade, producing a rough uneven surface. These cut slopes shall be evaluated in the field by the Project Engineering Geologist or Geotechnical Engineer. Replacement of those slopes with compacted stabilization fills may be required. Future exploration and in-grading observation could reveal more favorable geology in these specific areas.

Alluvium/Colluvium: Cut slopes exposing alluvial/colluvial soils (Qal) shall require replacement with a drained stabilization fill. Typically, such corrective grading would be constructed with a minimum key width corresponding to one-half the full height of the superjacent slope, but not less than 15 feet. Minimum key depths at the toe shall be 2 feet. All stabilization fills shall be provided with a backdrain and outlet system as detailed in Appendix IV of the Geotechnical Report. Silverado Formation: Cut slopes within the Silverado Formation are expected to be grossly stable; however the final determination shall be made based on exposed conditions during grading. Cut slopes within the Silverado Formation may expose poorly cemented sands, cobbles and boulders at finish grade, which would produce a rough uneven surface. These cut slopes shall be evaluated in the field by the Project Engineering Geologist or Geotechnical Engineer. Replacement of those slopes with compacted stabilization fills may be required.

Fill Slopes: The majority of fill slopes on the project are designed at a maximum slope ratio of 2:1. The highest fill slope is approximately 160 feet in height and located subjacent to Lot 68. Based on the results of the calculations, the 2:1 fill slopes 160 feet and less in height, when properly constructed with onsite materials, are expected to be grossly stable, as designed. Keys shall be constructed at the toe of all fill slopes where unsuitable soil removals do not accomplish a minimum key width of one-half

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the slope height plus bench widths or twenty (20) feet, whichever is greater.

Minimum key depths at the toe shall be 2 feet. Due to grading limit restrictions, removals of unsuitable soils beyond the proposed toe may be limited; therefore, additional slope maintenance shall be expected in the areas where a 1:1 projection into approved materials cannot be achieved.

Mitigation Measure GEO-3: Subsurface Drainage. Canyon subdrains are proposed as depicted on Figures 1 through 7 of the Geotechnical Report and shall consist of 6-inch and 8-inch diameter pipes and shall be constructed in accordance with the details shown in Appendix IV of the Geotechnical Report. Final determination of drain locations shall be made in the field. Outletting of subdrain systems shall require coordination with the Project Civil Engineer in determining suitable facilities to accept to drain water.

Mitigation Measure GEO-4: Overexcavation. Where a transition of cut and fill occurs across a finished lot, it shall be necessary to overexcavate the bedrock portions and replace it with compacted fill. The depth of bedrock overecavation shall be equal to 1/3 the maximum fill depth (after removals) on the fill side of the transition. Anticipated transition lots are shown on figures 1-7 of the geotechnical report. Cut pads shall be overexcavated a minimum of 5 feet to provide a uniform foundation material. Some highly expansive soils of the Silverado formation may be encountered at grade in some areas. Consideration shall be given to increasing the overexcavation depth to mitigate for highly expansive soils, if warranted. Difficult excavation with a backhoe can be expected in some street areas. Ginter & associates recommends street overexcavation and replacement with compacted fill to facilitate utility emplacement in these street areas and driveways.

Depths of overexcavation shall extend one (1) foot below the deepest utility line.

Mitigation Measure GEO-5: Fill Materials. Excavated on-site soils may be used as compacted fill.

The fill materials to be used as compacted engineered fill shall be free of organics, debris, deleterious materials, and rocks over 6 inches maximum dimension, and must be approved by the project geotechnical engineer or project geologist prior to use. Import soils, if required, shall be evaluated by the project geotechnical engineer for suitability prior to delivery. Import soils shall be free of trash, debris or other objectionable materials. All import fill shall have engineering characteristics similar to the on-site soils.

Mitigation Measure GEO-6: Fill Placement, Moisture Conditioning, and Compaction. After approval of the over-excavation and prior to placement of any compacted engineered fill materials, the exposed removal bottoms shall be scarified to a minimum depth of six (6) inches. The area shall then be moisture conditioned approximately 1 to 2 percentage points above the optimum moisture content, and compacted to a minimum of 90 (or 93) percent of the applicable maximum density. The planned development will involve deep fills in the canyon areas and side-hill fill slopes. In order to reduce the amount of fill settlement, the fill shall be compacted to the minimum relative compaction shown below:

Fill Depth
(Feet)
Minimum Relative Compaction (ASTM: D1557)
(%)
0 – 50 90
Below 50 93

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Fill slopes shall also be constructed at the minimum relative compactions shown above, with the exception of the outer 3 feet of the slope face which can be placed at 90% relative compaction. Deep fill areas requiring 93% relative compaction are delineated in Plate VI of the Geotechnical Report. Generation of oversized rock (over 8 inches in maximum dimension) from excavations in the bedrocks is anticipated. Oversize rock shall be placed in single file windrows not exceeding three feet in height and six (6) feet in width with a minimum equipment width (15 feet) separating each windrow or a rock blanket fill not exceeding two (2) to three (3) feet in height. Large erratic rocks shall be buried individually. Granular fill shall be thoroughly flooded in the rock voids and covered with a minimum two feet compacted fill blanket. Successive windrows shall be staggered and none shall be placed within 10 feet of finished grade or closer than 15 feet to compacted fill slope surfaces. Typical rock placement construction detail is provided in Appendix IV of the Geotechnical Report.

Placement of rock windrows shall be performed under the observation and recommendations of the Project Geotechnical Engineer.

Fill materials shall be spread in thin lifts, moisture conditioned to about 1 to 2 percentage points over optimum moisture content and compacted to a minimum of 90 (or 93) percent of the laboratory maximum dry density as determined in accordance with ASTM Test Method D-1557. Each lift shall be treated in a like manner until the desired finished grades are achieved. The grading contractor shall have suitable and sufficient compaction equipment in operation to achieve the required compaction. When necessary, earthmoving equipment may be utilized for compaction or temporarily halted in order to permit adequate compaction of fills.

Mitigation Measure GEO-7: Slope Construction

1. Care shall be taken during grading to prevent spillage of loose materials over slopes to remain natural. Should loose soil be spilled onto natural slopes by the grading contractor, removal of the loose fill shall be required.

2. Fill shall be properly benched into firm bedrock or compacted fill as directed by the Project Engineering Geologist and/or Geotechnical Engineer during grading. Typical benching shall include 4-foot verticals exposing approved, competent material (see Appendix D – Typical Benching Detail of the Geotechnical Report).

3. In order to minimize surficial slumps on compacted fill slopes, the following grading procedures shall be used:
a) Where possible, fill slopes shall be constructed by overfilling a minimum of three (3) horizontal feet and then trimming back to expose the dense inner core of the slope surface. Compacted fill slopes shall be back-rolled during construction at intervals not exceeding four (4) vertical feet. Care shall be taken to construct the slope in a workmanlike manner so that it is positioned at its designed orientation and slope ratio. Achieving a uniform slope surface by subsequent thin wedge filling must be avoided. Any add-on correction to a fill slope shall be done by overfilling the affected area in horizontal, compacted lifts which must be benched into the existing fill prism. The overfilled slope may then be trimmed to the design gradient.

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b) Where fill slopes are planned above natural slopes and cannot be overfilled and trimmed back, the slopes shall be rolled for the entire height of the slope with a sheepsfoot roller and then finished with a grid roller. If the desired compaction is not obtained in this manner, a vibratory sheepsfoot roller may be required. To be most effective, this equipment shall be anchored and manipulated from a side- boom tractor. In lieu of a grid roller, the slope may be track rolled with a John Deere 450, Caterpillar D-8 dozer or equivalent. To obtain the required compaction and appearance of the slope face, the soil moisture shall be maintained at above optimum from the time of mass filling to the completion of grid rolling. c) The grading contractor shall take proper care to avoid spillage of loose material down the face of the slopes during grading and during drainage terrace and down- drain construction. Fine grading operations for benches and down-drains shall not deposit loose trimmed soils on the finished slope surfaces. Loose soil materials shall require removal.
d) Seeding and planting of slopes shall proceed as rapidly as possible to achieve a well-established and deep-rooted vegetal cover requiring minimal watering. The type of vegetation and watering schedule shall be established by a landscape architect familiar with hillside maintenance.

Mitigation Measure GEO-8: Earthwork Observations and Testing a) The site preparation, over-excavation, and earthwork shall be performed under the observation and testing by a representative of the Project Geotechnical Engineer or Project Geologist.
b) The fill shall be tested at the time of placement to verify that the required compaction is achieved. c) The fill compaction shall be determined in the field by the Sand Cone Method (ASTM: D 1556) or Nuclear Gauge Method (ASTM: D 2216), or other test method approved by the Project Geotechnical Engineer.
d) During grading, an adequate number of field density tests shall be performed using approved test procedures in order to determine compliance of earthwork to the project requirements. The frequency of field density testing shall be in accordance with the recommendations of the Project Geotechnical Engineer. e) Quality control testing performed to determine the acceptability of the fill compaction shall be based on the laboratory maximum dry density and optimum moisture content determined in accordance with ASTM: D 1557 test procedure. f) Any surface or subsurface obstructions, or questionable materials encountered during grading shall be brought immediately to the attention of the Project Geotechnical Engineer. Deeper excavations may be required, should unsuitable soils be encountered locally, as determined by the Project Geotechnical Engineer and/or Project Geologist.

Mitigation Measure GEO-9: Deep Fill Settlement Monitoring. In deep fill areas, settlement monuments shall be installed and periodically surveyed by the project civil engineer to evaluate the magnitude and progress of settlements. Ginter & associates proposes positioning settlement monuments at strategic locations in the deeper fill areas as shown on figure vi of the geotechnical report. These shall be monitored on a regular basis until the primary settlement has stabilized before those areas released for construction.

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Mitigation Measure GEO-10: Foundation Design. The compacted engineered fill at the project site is anticipated to be low to medium soil expansion potential. Presented below are preliminary geotechnical criteria for design of building foundations, based on medium soil expansion potential for the on-site soils:

Option 1 - Conventional Footing:

Allowable Bearing Pressure (1) = 1,500 pounds per square foot (psf) Minimum Footing Depth (2) = 24 inches
Minimum Footing Width = Continuous: 12 inches
Isolated: 24 inches
Passive Soil Pressure (3) = 250 psf/ft.

Friction Coefficient = 0.30 (ultimate)
Minimum Footing Reinforcement = Four No. 4 bars, 2 each at top and bottom Garage Door Grade Beam = 18 inches deep, Four No. 4 bars, Two each at top and bottom, tied into foundation elements.
(1) The above value may be increased 250 psf for each additional foot exceeding the minimum embedment depth and/or width, subject to a maximum of 2,500 psf. Allowable bearing pressures may be increased by one-third for short term loading due to wind or seismic forces.
(2) Footing depth is from lowest adjacent finished soil grade. Footings shall be deepened, as necessary, to provide setback distance from adjacent slope in conformance with CBC criteria.
(3) Value applies to level soil condition, and is subject to a maximum of 2000 psf.

Option 2 – Post-Tensioned Foundation:

If post-tensioned slab/footing system is selected for the subject project, the design may be based on the geotechnical criteria shown below for medium soil expansion potential.

These are based on the guidelines presented in the PTI, Third Edition design manual.

Thornthwaite Moisture Index = -20
Equilibrium Suction = 3.6
Edge Lift Moisture Variation Distance, em = 5.1 feet
Edge Lift, ym = 1.1 inches
Center Lift Moisture Variation Distance, em = 9.0 feet
Center Lift, ym = 0.47inches
Minimum Footing Depth (Exterior) = 18 inches below adjacent grade The above foundation criteria are based on medium soil expansion consideration only.

Foundation design shall consider anticipated post-construction settlements, as appropriate. Foundation design details such as slab thickness, concrete strength, reinforcements, etc. shall be established by the Project Structural Engineer considering medium soil expansion and settlement potential provided below.

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Mitigation Measure GEO-11: Foundation Settlement. Total static and differential post- construction settlements for footings designed and constructed in accordance with the criteria given below and supporting loads not exceeding the typical loadings for residential construction (column and wall loads on the order of 30 kips and 3 kips/lineal foot, respectively) are not anticipated to exceed the values shown below. The settlement estimates shall be confirmed based on review of the foundation plans. Structures shall be designed for the following post-construction settlements: - Total settlement = 1 inch - Differential settlement = ¾-inch (*) (*) Between similarly loaded column footings and for continuous footings and slabs over a distance of approximately 30 feet.

General Remarks:
(i) Footing depths shall not be allowed to be affected adversely, such as through erosion softening, digging, landscaping, etc.
(ii) Where foundations encroach closer than five (5) feet horizontally from the flow line of drainage swales, the footing shall be deepened sufficiently to maintain the required embedment depth below the adjacent flow line.
(iii) Foundation details such as concrete strength, reinforcements, etc. shall be established by the Project Structural Engineer, considering the loading and medium soil expansion potential. The footing and slab reinforcements recommended in the Geotechnical Report are minimum requirements. More restrictive criteria based on structural design considerations or Code requirements shall govern. (iv) Foundation excavations shall be observed and approved by the Project Geotechnical Engineer prior to the placement of reinforcement or concrete. Forming of footing excavations may be required. Excavations shall be free of slough and debris and thoroughly moisture conditioned prior to placing concrete. (v) Excavated material from footing and utility trenches shall not be placed in slab-ongrade areas unless properly compacted and tested.

Mitigation Measure GEO-12: Slab-On-Grade.

Recommended Minimum Criteria For Slab-On-Grade Are Shown Below:

Concrete Floor Slabs: Concrete floor slabs shall be 5 inches thick (minimum) and shall be reinforced with No. 3 bars at 18 inches on center, each way at mid height. No. 3 bars at 18 inches on center shall be provided connecting floor slabs to footings. In order to minimize migration of moisture up the concrete slab from soil subgrade and damage to floor coverings, a moisture barrier/water vapor retarder is recommended beneath floor slabs as discussed hereinafter. Moisture/Water Vapor Retarder for Concrete Slab-on-Grade: In order to reduce the potential for moisture/water vapor migration up through the slab and possibly affecting floor covering, a moisture/vapor retarder is recommended under concrete floor slab-onPage 2285 of 3613

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grade. The moisture barrier shall be properly installed, lapped and sealed in accordance with the manufacturer’s specifications. Punctures and rips shall be repaired prior to placement of sand. At a minimum, this moisture/water vapor retarder shall consist of 10- millimeter thick polyethylene (“Visqueen”), lapped and sealed, and placed mid-height within a 4-inch coarse sand layer. This moisture/water vapor retarder shall be installed in accordance with manufacturer’s specifications. The following recommendations are based on the tentative guidelines by the American Concrete Institute (ACI, April 2001) to reduce the potential moisture/water vapor intrusion in concrete slab-on-grade. Based on Ginter & Associates’ review of available literature, it appears that the ACI procedure would be more effective to help reduce potential moisture/water vapor migration up through concrete slab-on-grade.

Recommendations based on the ACI guidelines are presented below:

The moisture/water vapor retarder shall consist of high strength polyethylene membrane and shall meet or exceed the ASTM: E-1745-97 Class C material requirements for water vapor permeance, tensile strength and puncture resistance.

The vapor retarder shall consist of “Moistop Plus” (Fortifiber Building Products Systems) or “Vapor Block” VB 15 (Americover, Inc.), or approved equal. The vapor retarder shall be underlain by a capillary break comprised of minimum 4 inches thick pea gravel layer. The gravel layer shall be placed and compacted on approved soil sub-grade.

The membrane shall be placed on approved gravel layer and properly lapped and sealed. Membranes intersecting utility pipes, sewer lines, ducts or drains shall be properly wrapped around the penetrations and sealed. All punctures and rips in the membrane shall be repaired prior to placement of concrete, following manufacturer’s recommendations. The vapor retarder shall be installed in general accordance with the procedures outlined in ASTM: E-1643, and in conformance with the installation procedures recommended by the manufacturer.

To minimize slab curling, a low slump concrete (low shrinkage mix design) shall be used for the slab construction, as determined by the Project Structural Engineer.

The moisture/water vapor protection for concrete slab-on-grade shall be selected based on cost and construction considerations, and considering potential future problems resulting from improper and uncontrolled landscape irrigation practices. Regardless of the moisture/water vapor retarder option selected, it should be emphasized that proper control of irrigation and landscape water adjacent to the structure is of paramount importance.

Mitigation Measure GEO-13: Driveways. Driveway concrete slabs shall be 5 inches thick (minimum) with no. 3 bars at 18 inches on center, each way at mid-height. The slab may be placed directly on properly prepared sub-grade. No moisture barrier is required under driveway slabs.

Mitigation Measure GEO-14: Exterior Flatwork. Exterior concrete flatwork (e.g. Sidewalks, walkways) shall be 4 inches thick (minimum), with no. 3 bars at 24 inches on center, each way at mid-height and placed on properly prepared sub-grade. Hardscape areas within two feet of the descending slopes shall include a thickened edge deepened to provide a

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minimum five (5) feet horizontal setback between the bottom outside face of the thickened edge and slope face.

Mitigation Measure GEO-15: Sub-Grade Pre-Saturation. Prior to concrete placement, the soil sub-grade shall be thoroughly wetted to about 12 inches in depth at a moisture condition of about 2 to 3 percentage points above the optimum moisture content.

Mitigation Measure GEO-16: General. Interior floor slabs and exterior concrete flatwork, including driveway, shall be properly designed for the construction and service loading conditions, potential settlements and soil expansion. The structural details, such as slab thickness, concrete strength, reinforcing criteria, joint spacing, etc. Shall be established by the project structural engineer. The recommended minimum reinforcements for concrete slabs provided above are intended for preliminary design only. More restrictive criteria as dictated by structural design or regulatory requirements shall govern. Mitigation Measure GEO-17: Retaining Walls Foundations: Retaining wall foundations may be supported on either compacted engineered fill or competent bedrock. If a bedrock/fill transition is encountered, the bedrock portion shall be over-excavated minimum 2 feet and replaced with approved compacted fill. Alternatively, a cold joint shall be constructed in both the footing and the wall. Footings may be designed in accordance with the foundation design criteria presented in the Geotechnical Report when embedded at least two feet below lowest adjacent grade. Footings located on or at top of slopes shall be deepened, as necessary, to provide minimum lateral setback between footing and slope faces in accordance with CBC requirements.

Lateral Earth Pressures: The earth pressures acting on retaining walls depend primarily on allowable wall movement, type of backfill materials, backfill slopes, wall inclination, surcharges, and any hydrostatic pressure. The following lateral earth pressures are recommended for vertical walls with no hydrostatic pressure and no surcharge loading:

Wall Condition Backfill Type
Lateral Earth Pressure (Equivalent Fluid
Pressure) (pcf)
Level 2:1 (H:V)
Active (Cantilever) Sandy Soils 40 65
The surcharge effect of anticipated loads on the wall backfill (i.e. traffic, construction equipment, footings, etc.) shall be included in the wall design. If the wall is free to deflect, 33 percent of the maximum surcharge load located within a distance equal to the height of wall shall be used in the design.

Backfill: Retaining wall backfill shall consist of predominantly granular non- expansive soils. The backfill shall extend within a 45-degree plane from the wall footing. Retaining wall backfill shall be mechanically compacted to minimum 90 percent of the applicable laboratory maximum density and performed under the observation and testing of the Project Geotechnical Engineer. No jetting, ponding, or flooding shall be permitted. No backfill shall be placed against concrete until minimum design strengths are attained.

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Backfill Drainage: The wall design shall include waterproofing and weep holes or sub-drains or back-drains, as appropriate, for relieving possible hydrostatic pressures. If on-site soils are utilized for wall backfill, the design shall include a prefabricated drainage blanket (such as Miradrain 2000, or equivalent). At a minimum, sub-drains shall consist of 4-inch diameter, perforated Schedule 40, PVC pipe or equivalent, embedded in approximately 3 cubic feet per lineal foot of ¾-inch (maximum) rock, or approved alternate. This permeable material shall be enveloped in Geofabric consisting of Mirafi 140 or equivalent. The pipe and trench bottom shall be sloped at a gradient of 2+ percent to a suitable discharge outlet. Sub-drains placed behind retaining walls shall be approved by the Project Geotechnical Engineer prior to backfill placement.

Mitigation Measure GEO-18: Soil Corrosion. The previous geotechnical consultants, pacific soils engineering, inc., performed preliminary testing and indicated that the site soils are corrosive to metals. Therefore, representative finished grade samples shall be tested for corrosion suites (sulfate, chloride, ph and resistivity) upon completion of grading. It may be necessary to retain a corrosion engineer for consultation.

Mitigation Measure GEO-19: Utility Trench Backfill
Bedding material shall consist of on-site sandy or imported materials exhibiting a San Equivalent (S.E.) value of 30 or greater.

The on-site soils are considered suitable for trench backfill, provided they are free of organic materials and oversize rocks.

Backfill of all exterior and interior trenches shall be placed in thin lifts not exceeding 4 inches and mechanically compacted to achieve a relative compaction of not less than 90% based on ASTM: D1157. Care shall be taken not to damage utility lines.

Utility trenches shall not be located within the influence of footings. This is defined as a zone located below the footing and a line sloping at an inclination of 1:1 (horizontal to vertical) outward from the outside edge of footings. If utility lines are located within the zone of footings, the backfill shall be compacted to a minimum 95 percent relative compaction or slurry backfilled (minimum 1-1/2 sack cemented sand mix.

To reduce potential water migration into building sub-grade through the granular bedding/shading layer and/trench backfill, utility trenches shall be backfilled with the onsite finer grained materials or sand-cement slurry for minimum 3 feet length at their entry points.

Trenches in fill soils and alluvial deposits greater than 4 feet in depth shall be shored or sloped back as required by the local regulatory agency, the state of California Division of Industrial Safety Construction Safety Orders, and Federal OSHA requirements.

Mitigation Measure GEO-20: Asphalt Concrete Pavement. Preliminary asphalt concrete pavement sections for the planned streets in the development were developed utilizing the Caltrans method of design and the structural section design guide for California cities and counties. The following recommended pavement sections were computed assuming an “r” value of 30 for site soils compacted as sub-grade material, and assumed traffic indices. The actual “r” value will depend on the soil conditions exposed at the planned street sub-grade elevations. During rough grading, “r” value testing shall be performed on the pavement sub-grade soils to confirm the pavement design basis. Further analysis

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and evaluation are necessary if the design traffic index and the sub-grade “r” value are different from those used in Ginter & Associates’ analyses.

Traffic Index
Recommended Minimum Pavement Section
Asphalt
Concrete
(inches)
Aggregate
Base
(inches)
Total
(inches)

5.0 6.0

7.0 8.0

3.0 4.0

4.0 5.0

6.0 8.0

10.0 12.0

9.0 12.0

14.0 16.0
Aggregate base shall consist of crushed aggregate base (CAB) or crushed miscellaneous base (CMB) and shall comply with the specifications outlined in the “Standard Specifications for Public Works Construction”, (“Green Book”). The base material shall be compacted to minimum 95 percent of the maximum laboratory density, determined in accordance with ASTM: D-1557. The soil sub-grade shall be compacted to minimum 90 percent relative compaction. The subgrade soils shall exhibit a firm and unyielding surface, in addition to the recommended minimum compaction. Final compaction and testing of pavement sub-grade shall be performed just prior to placement of aggregate base.

Mitigation Measure GEO-21: Site Drainage. All roof and surface drainage shall be directed away from structures and their appurtenances and slopes to approved drainage facilities.

Ponding of water shall be avoided. For graded soil areas, a minimum gradient of 2 percent away from structures shall be maintained. The drainage patterns designed by the project civil engineer shall be established at the time of fine grading and maintained throughout the life of the structure or, if altered, shall be replaced with a properly designed area drain system. Irrigation activities at the site shall be monitored and controlled to prevent overwatering. Planter areas adjacent to structures shall be avoided.

If utilized, such planters shall include measures to contain irrigation water and prevent moisture migration into walls and under foundations and slabs-on-grade. Mitigation Measure GEO-22: Slope Planting, Irrigation And Maintenance. General guidelines for slope planting, irrigation and maintenance are shown below:
a) Slope planting shall consist of appropriate drought resistant vegetation as recommended by the Landscape Architect. Landscaping of slopes shall be completed as soon as possible and properly maintained.
b) The property owner is responsible for proper irrigation and for maintenance and repair of installed irrigation systems. Leaks shall be repaired immediately.

Sprinklers shall be adjusted to provide maximum coverage with a minimum of water usage and overlap. Over-watering with consequent excessive runoff and ground saturation shall be avoided.
c) If automatic sprinkler systems are installed, their use shall be adjusted to account for natural rainfall conditions.

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d) All interceptor ditches, drainage terraces, down-drains, and any other drainage devices that have been installed shall be maintained and cleaned. e) If rodent activity is present, the property owner shall undertake a program for the elimination of burrowing animals. This shall be an ongoing program in order to promote slope stability.
f) Water shall not be allowed to flow over the constructed or natural slopes. This may require the construction of berms or ditches along the top of slopes, if such devices are not in place.

Mitigation Measure GEO-23: Additional Investigation. Additional geologic and geotechnical investigation may be necessary during the 40-scale grading plan review phase to obtain supplemental information relative to the site geologic conditions and engineering properties of on-site materials and to confirm the preliminary recommendations provided herein.

5. LEVEL OF SIGNIFICANCE AFTER MITIGATION
With compliance with applicable requirements regarding geology and soils, impacts associated with geology and soils would be less than significant.

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4.0 ENVIRONMENTAL IMPACT ANALYSIS
F. GREENHOUSE GAS EMISSIONS

INTRODUCTION
This section of the EIR addresses the project’s potential effect on global climate change (GCC) due to generation of greenhouse gas (GHG) emissions. Relevant regulations and existing conditions are described as well as the potential for the project to result in GCC-related impacts due to generation of GHG emissions that would exceed applicable thresholds of significance, either directly or indirectly, or conflict with an applicable plan, policy or regulation adopted for the purpose of reducing the GHG emissions. Data used to prepare this section was obtained from the Air Quality and Greenhouse Gas Report, Skyline Heights Project (herein referred to as the Air Quality and Greenhouse Gas Report) prepared by Michael Brandman Associates, dated May 2014 which is included in Appendix C of this Draft EIR.

1. ENVIRONMENTAL SETTING
a. Existing Conditions
The main contribution of GHG emissions in California between the years 2000 through 2009 was the transportation sector. The second highest sector was industrial, which includes sources from refineries, general fuel use, oil and gas extraction, cement plants, and cogeneration heat output. California GHG emissions in 2009 totaled approximately 453 million metric tons (MMT) of carbon dioxide equivalent (CO2e).1
In California, climate change may result in consequences such as the following:2 A reduction in the quality and supply of water from the Sierra snowpack. If heat-trapping emissions continue unabated, more precipitation will fall as rain instead of snow, and the snow that does fall will melt earlier, reducing the Sierra Nevada spring snowpack by as much as 70 to 90 percent. This can lead to challenges in securing adequate water supplies. It can also lead to a potential reduction in hydropower.

Increased risk of large wildfires. If rain increases as temperatures rise, wildfires in the grasslands and chaparral ecosystems of southern California are estimated to increase by approximately 30 percent toward the end of the 21st century because more winter rain will stimulate the growth of more plant “fuel” available to burn in the fall. In contrast, a hotter, drier climate could promote up to 1 GHG emissions other than carbon dioxide are commonly converted into carbon dioxide equivalents, which take into account the differing global warming potential (GWP) of different gases. For example, the Intergovernmental Panel on Climate Change finds that nitrous oxide has a GWP of 310 and methane has a GWP of 21. Thus, the emission of 1 ton of nitrous oxide and 1 ton of methane is represented as the emission of 310 tons of CO2e and 21 tons of CO2e, respectively. This allows for the summation of different GHG emissions into a single total. 2
California Climate Change Center. 2006. Our Changing Climate, Assessing the Risks to California: A Summary Report from the California Climate Change Center, CEC-500-2006-077, July 2006, http://www.scc.ca.gov/webmaster/ftp/pdf/climate_change/ assessing_risks.pdf. Accessed May 2012.

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90 percent more northern California fires by the end of the century by drying out and increasing the flammability of forest vegetation.

Reductions in the quality and quantity of certain agricultural products. The crops and products likely to be adversely affected include wine grapes, fruit, nuts, and milk.

Exacerbation of air quality problems. If temperatures rise to the medium warming range, there could be 75 to 85 percent more days with weather conducive to ozone formation in Los Angeles and the San Joaquin Valley, relative to today’s conditions. This is more than twice the increase expected if rising temperatures remain in the lower warming range. This increase in air quality problems could result in an increase in asthma and other health-related problems.

A rise in sea levels resulting in the displacement of coastal businesses and residences. During the past century, sea levels along California’s coast have risen about seven inches. If emissions continue unabated and temperatures rise into the higher anticipated warming range, sea level is expected to rise an additional 22 to 35 inches by the end of the century. Elevations of this magnitude would inundate coastal areas with salt water, accelerate coastal erosion, threaten vital levees and inland water systems, and disrupt wetlands and natural habitats.

An increase temperature and extreme weather events. Climate change is expected to lead to increases in the frequency, intensity, and duration of extreme heat events and heat waves in California. More heat waves can exacerbate chronic disease or heat-related illness.

A decrease in the health and productivity of California’s forests. Climate change can cause an increase in wildfires, an enhanced insect population, and establishment of non-native species.

These changes in California’s climate and ecosystems are occurring at a time when California’s population is expected to increase from 34 million to 59 million (by 2040).3 As such, the number of people potentially affected by climate change, as well as the amount of anthropogenic GHG emissions expected under a “business as usual” (BAU) scenario, is expected to increase. Changes similar to those noted above for California would also occur in other parts of the world, with regional variations in the resources affected and vulnerability to adverse effects. GHG emissions in California are attributable to human activities, such as those associated with industry/manufacturing, utilities, transportation, and the residential and agricultural sectors, as well as natural processes.4
b. Regulatory Framework
(1) Federal
The U.S. Environmental Protection Agency (USEPA) is responsible for implementing federal policy to address GHGs. The federal government administers a wide array of public-private partnerships to reduce the GHG intensity generated in the United States. These programs focus on energy efficiency, renewable energy, methane and other non-CO2 gases, agricultural practices, and implementation of technologies to achieve GHG reductions. The USEPA implements numerous voluntary programs that contribute to the reduction of GHG emissions. These programs (e.g., the Energy Star labeling system for energy-efficient products) play a 3 California Energy Commission, Inventory of California Greenhouse Gas Emissions and Sinks: 1990 to 2004, (2006). Available:
http://www.energy.ca.gov/2006publications/CEC-600-2006-013/CEC-600-2006-013-SF.PDF. 4 Ibid.

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significant role in encouraging voluntary reductions from large corporations, consumers, industrial and commercial buildings, and many major industrial sectors.

In Massachusetts v. Environmental Protection Agency (Docket No. 05–1120), the United States Supreme Court held in April of 2007 that the USEPA has statutory authority under the federal Clean Air Act to regulate GHGs.

The Court did not hold that the USEPA was required to regulate GHG emissions; however, it indicated that the agency must decide whether GHGs cause or contribute to air pollution that is reasonably anticipated to endanger public health or welfare.

On May 19, 2009, the President announced a national policy for fuel efficiency and emissions standards in the United States auto industry. The adopted federal standard applies to passenger cars and light-duty trucks for model years 2012 through 2016. The rule surpasses the prior Corporate Average Fuel Economy standards and requires an average fuel economy standard of 35.5 miles per gallon (mpg) and 250 grams of CO2 per mile by model year 2016, based on USEPA calculation methods. These standards were formally adopted on April 1, 2010. In August 2012, standards were adopted for model year 2017 through 2025 passenger cars and light-duty trucks. By 2025, vehicles are required to achieve 54.5 mpg (if GHG reductions are achieved exclusively through fuel economy improvements) and 163 grams of CO2 per mile. According to the USEPA, a model year 2025 vehicle would emit one-half of the GHG emissions from a model year 2010 vehicle.5 On December 7, 2009, the USEPA Administrator signed two distinct findings regarding GHGs under Section 202(a) of the federal Clean Air Act. The USEPA adopted a Final Endangerment Finding for the six defined GHGs (CO2, CH4, N2O, HFCs, PFCs, and SF6) on December 7, 2009. The Endangerment Finding is required before USEPA can regulate GHG emissions under Section 202(a)(1) of the Clean Air Act consistently with the United States Supreme Court decision. The USEPA also adopted a Cause or Contribute Finding in which the USEPA Administrator found that GHG emissions from new motor vehicle and motor vehicle engines are contributing to air pollution, which is endangering public health and welfare. These findings do not themselves impose any requirements on industry or other entities. However, these actions were a prerequisite for implementing GHG emissions standards for vehicles.

On July 20, 2011, the USEPA published its final rule deferring GHG permitting requirements for carbon dioxide emission from biomass-fired and other biogenic sources until July 21, 2014. In September 2011, the USEPA released an “Accounting Framework for Biogenic CO2 Emissions from Stationary Sources,” which analyzes accounting methodologies and suggests an implementation for biogenic carbon dioxide emitted from stationary sources. Environmental groups successfully challenged the permitting deferral in Center for Biological Diversity v. EPA, 722 F.3d 401 (DC Cir. 2013). The court did not rule on whether the USEPA has authority under the federal Clean Air Act to permanently exempt biogenic carbon dioxide sources from permitting.

On April 13, 2012, the USEPA published a proposed rule to establish, for the first time, a new source performance standard for GHG emissions. Under the proposed rule, new fossil fuel-fired electric generating units larger than 25 MW would be required to limit emissions to 1,000 pounds CO2 per megawatt-hour 5 United States Environmental Protection Agency, “EPA and NHTSA Set Standards to Reduce Greenhouse Gases and Improve Fuel Economy for Model Years 2017-2025 Cars and Light Trucks,” http://www.epa.gov/oms/climate/documents/420f12051.pdf. 2012.

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(MWh) on an average annual basis, subject to certain exceptions. On January 8, 2014, the USEPA withdrew that proposed rule6 and replaced it with a new proposed rule that shares much in common with the previous proposal.7 However, there also are a number of differences, including the universe of sources covered by the rule, the emissions standards for subcategories of sources, a determination of the best system of emission reduction for coal-fired electric generating units, and a new alternative compliance option, among others.

On April 17, 2012, the USEPA issued emission rules for oil production and natural gas production and processing operations.
(2) State
With the passage of several pieces of legislation, including state senate and assembly bills and executive orders, California launched an innovative and pro-active approach to dealing with GHG emissions and climate change at the state level.
(a) Assembly Bill 1493
In response to the transportation sector accounting for a large portion of California’s CO2 emissions, Assembly Bill (AB) 1493, enacted on July 22, 2002, required CARB to set GHG emission standards for passenger vehicles, light duty trucks, and other vehicles whose primary use is non-commercial personal transportation manufactured in and after 2009. In setting these standards, CARB must consider cost effectiveness, technological feasibility, economic impacts, and provide maximum flexibility to manufacturers.

The State of California in 2004 submitted a request for a waiver from federal clean air regulations, which ordinarily preempts state regulation of motor vehicle emission standards, to allow the state to require reduced tailpipe emissions of CO2. In late 2007, the USEPA denied California’s waiver request. In early 2008, the state brought suit against USEPA related to this denial. In January 2009, the President directed the USEPA to assess whether its denial of the waiver was appropriate under the federal Clean Air Act. In June 2009, the USEPA granted California the waiver.

However, as discussed previously, the USEPA have adopted federal standards for model year 2012 through 2016 light-duty vehicles. In light of the USEPA standards, California - and states adopting California emissions standards - have agreed to defer to the proposed national standard through model year 2016. The 2016 endpoint of the federal and state standards is similar, although the federal standard ramps up slightly more slowly than required under the state standard. The state standards (called the Pavley standards) require additional reductions in CO2 emissions beyond model year 2016 (referred to as Pavley Phase II standards). As noted above, the USEPA have adopted GHG emission standards for model year 2017 through 2025 vehicles. These standards are slightly different from the Pavley Phase II standards, but the State of California has agreed not to contest these standards, in part due to the fact that while the national standard would achieve slightly less reductions in California, it would achieve greater reductions nationally and is 6 79 Fed. Reg. 1352 (Jan. 8, 2014). 7
79 Fed. Reg. 1430 (Jan. 8, 2014).

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stringent enough to meet state GHG emission reduction goals.8 On November 15, 2012, CARB approved an amendment that allows manufacturers to comply with the 2017-2025 national standards to meet state law. (b) Executive Order S-3-05
The goal of this executive order is to reduce California’s GHG emissions to: 1) 2000 levels by 2010, 2) 1990 levels by 2020, and 3) 80 percent below the 1990 levels by 2050. In 2006, this goal was further reinforced with the passage of AB 32.
(c) Assembly Bill 32
The Global Warming Solutions Act of 2006 sets the same overall GHG emissions reduction goals outlined in Executive Order S-3-05 while further mandating that CARB create a plan that includes market mechanisms and implement rules to achieve “real, quantifiable, cost-effective reductions of greenhouse gases.” Executive Order S-20-06 further directs state agencies to begin implementing AB 32, including the recommendations made by the state’s Climate Action Team.

The CARB Board approved the 1990 greenhouse gas emissions level of 427 million metric tons of carbon dioxide equivalent (MMTCO2e) on December 6, 2007 (California Air Resources Board 2007). Therefore, emissions generated in California in 2020 are required to be equal to or less than 427 MMTCO2e. Emissions in 2020 in a BAU scenario were estimated in 2008 to be 596 MMTCO2e, which do not account for reductions from AB 32 regulations (California Air Resources Board 2008c). However, CARB updated the year 2020 business as usual (BAU) scenario in 2012 based on new and revised data. The updated forecast accounts for the effects of the recent economic recession, as well as new estimates for future fuel and energy demand, as well as other factors. The 2020 BAU forecast taking into account the effects of the recent economic recession is 545 MMTCO2e. Therefore, a 21.7 percent reduction from the year 2020 BAU forecast is required to achieve AB 32 reduction goal for year 2020.
(d) Executive Order S-01-07
Executive Order S-1-07, the Low Carbon Fuel Standard (issued on January 18, 2007), requires a reduction of at least 10 percent in the carbon intensity of California’s transportation fuels by 2020. Regulatory proceedings and implementation of the Low Carbon Fuel Standard have been directed to CARB. The Low Carbon Fuel Standard has been identified by CARB as a discrete early action item in the adopted Climate Change Scoping Plan. CARB expects the Low Carbon Fuel Standard to achieve the minimum 10-percent reduction goal; however, many of the early action items outlined in the Climate Change Scoping Plan work in tandem with one another. To avoid the potential for double-counting emission reductions associated with AB 1493 (see previous discussion), the Climate Change Scoping Plan has modified the aggregate reduction expected from the Low Carbon Fuel Standard to 9.1 percent. CARB released a draft version of the Low Carbon Fuel Standard in October 2008. The final regulation was approved by the Office of Administrative Law and filed with the Secretary of State on January 12, 2010; the Low Carbon Fuel Standard became effective on the same day.
8 California Air Resources Board, “Advanced Clean Cars Summary,” http://www.arb.ca.gov/msprog/clean_cars/acc%20summaryfinal.pdf. Accessed April 2014.

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(e) Senate Bill 97
Senate Bill (SB) 97 required the Governor's Office of Planning and Research (OPR) to develop amendments to the California Environmental Quality Act (CEQA) Guidelines for addressing GHG emissions. The amendments became effective on March 18, 2010.
(f) Renewable Energy Standard/Renewable Portfolio Standard (2002/2006/2011) SB 1078 (2002) and SB 107 (2006) created the Renewable Energy Standard (RES) program, which required electric companies to increase their procurement of eligible renewable energy resources by at least 1 percent of their retail sales annually, until reaching 20 percent by 2010. SB 2X 1 (2011) required a Renewable Portfolio Standard (RPS, functionally the same thing as the RES) of 33 percent by 2020. (3) Regional
After AB 32 was passed, the SCAQMD formed a Climate Change Committee along with a Greenhouse Gases CEQA Significance Thresholds Working Group and the SoCal Climate Solutions Exchange Technical Advisory Group. On September 5, 2008, the SCAQMD Board approved the SCAQMD Climate Change Policy, which outlines actions the SCAQMD will take to assist businesses and local governments in implementing climate change measures, decrease the agency’s carbon emissions, and provide information to the public regarding climate change. On December 5, 2008, the Board approved interim CEQA GHG significance thresholds for stationary source projects where it is the lead agency. The threshold is a tiered approach to determine a project’s significance, with 10,000 metric tons of CO2e as a screening numerical threshold for stationary source projects. In order to provide guidance to local lead agencies on determining the significance of GHG emissions identified in CEQA documents, the GHG CEQA Significance Threshold Working Group drafted thresholds with the intent of capturing 90 percent of development projects.9 Under Tiers 1 and 2, projects that are exempt from CEQA or consistent with an approved local GHG reduction plan can be found to be less than significant. Under Tier 3, a project’s GHG emissions are compared to the draft screening thresholds. At present, the SCAQMD has not formally adopted thresholds for use by other lead agencies, but recommends that industrial projects utilize the 10,000 MTCO2e screening level that has been adopted for SCAQMD projects. The GHG CEQA Significance Threshold Working Group has drafted a significance indicator of 3,000 MTCO2e for mixed-use or all land use projects, but it has not been formally adopted. Under Tier 4, a project’s GHG emissions are compared to a performance standard, such as achieving a percentage reduction in GHG emissions from a base case scenario (i.e., BAU scenario) or achieving a project-level efficiency target of 4.8 MTCO2e per service population.
(4) Local
The City of Corona General Plan includes policies related to GHG emissions. The following policies are applicable to the proposed project:

Goal 1.5 – Distinct neighborhoods and districts that contribute to the identity, character, and image of Corona as a vital, livable, diverse, innovative, and environmentally sustainable community. 9 South Coast Air Quality Management District, Board Meeting, December 5, 2008, Agenda No. 31, Interim GHG Significance Threshold Proposal – Key Issues/Comments Attachment D.

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Policy 1.5.14 – Require that developers demonstrate water conservation in the landscape design of their proposed projects, such as the use of drought tolerant species.

Policy 1.5.17 – Require that new residential, commercial, office, and industrial development be designed to minimize consumption of and sustain scarce environmental resources through such methods as the following, as applicable to the type and scale of development:

Site design—concentration and intermixing of development to minimize vehicular trips and promote walking, building orientation in consideration of solar access and heat gain and loss, and other. Landscaping—drought-tolerant species, use of recycled water for irrigation, and other purposes. Capture of rainwater and re-use on site. Building design and construction materials—energy-and water efficient fixtures, recycled building materials, insulation and wall thickness, permeable paving surfaces, and comparable techniques. Goal 10.2 – Ensure sustainable use of finite energy and water resources for the long-term use of residents and visitors of Corona. Policy 10.2.5 – Require the use of reclaimed water in common areas and landscape treatments for all proposed developments.

Goal 10.21 – Reduce air quality degradation through energy conservation.

Policy 10.21.1 – Reduce the amount of energy consumed by commercial and residential uses, as recommended by the Southern California Air Quality Management District.

Policy 10.21.2 – Continue to require the use and installation of energy conservation features in all new construction projects and wherever feasible, retrofitting in existing and re-development projects.

The City of Corona adopted a Climate Action Plan (CAP) in 2012. The purpose of the CAP is to provide guidance on how to analyze GHG emissions and determine the significance of the emissions during the CEQA review of proposed development projects within the City of Corona.10 To address the state’s requirement to reduce GHG emissions, the City of Corona prepared its CAP with the goal of reducing GHG emissions within the City by 15 percent below existing (2008) levels by 2020. The City's target is consistent with the AB 32 target and ensures that Corona will be providing GHG reductions locally that will complement state and international efforts to stabilize climate change. Because the City's CAP addresses GHG emissions reductions, is in concert with AB 32 and international efforts to address GCC, and includes specific local requirements that will substantially lessen the cumulative problem, compliance with the plan fulfills the description of mitigation found in the State CEQA Guidelines. 10 City of Corona, Climate Action Plan, (2012).

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According to SCAQMD’s interim guidance document for addressing GHG emissions, carbon dioxide (CO2) is the most important component of GHGs because it constitutes the majority of total GHG emissions and is very long lasting in the atmosphere. For this reason, estimated CO2 emissions are used as the benchmark for analysis.

2. ENVIRONMENTAL IMPACTS
a. Methodology
The evaluation of potential impacts related to the emission of GHGs is based on the comparison of the project to the thresholds stated below and applicable regulatory requirements. The analysis is based on the information contained in the Air Quality and Greenhouse Gas Report prepared by Michael Brandman Associates, dated May 2014, which is included as Appendix C of this Draft EIR. Mass daily GHG emissions from construction and operation of the project were estimated using the CalEEMod (version 2013.2.2) emissions model, an emissions estimation/evaluation model developed in collaboration with air quality management districts of California. For construction activities, the CalEEMod model separates the construction process into multiple phases to account for various construction scenarios, including structure demolition, site clearing, and asphalt paving and the application of architectural coatings.

Assumptions regarding construction phasing and equipment use were based on information received from the project Applicant and the construction contractor. A complete list of the construction equipment by phase, construction phase duration assumptions, and changes to modeling default values used in this analysis is included in the CalEEMod printout sheets, which are provided in Attachment A of the Air Quality and Greenhouse Gas Report prepared by Michael Brandman Associates, dated May 2014 (refer to Appendix C of this Draft EIR). With regards to operational GHG emissions, the CalEEMod model was used to calculate GHG emissions from mobile and area sources, such as on-site consumer products, architectural coatings, landscaping equipment, etc., that would occur during long-term project operations. In calculating mobile- source emissions, the CalEEMod default trip assumptions and trip generation rates from the traffic report (refer to Appendix C in this EIR) were applied to arrive at the total vehicle miles traveled (VMT) associated with operational project elements.
b. Thresholds of Significance
(1) CEQA Appendix G (Greenhouse Gas Emissions)
Appendix G of the CEQA Guidelines provides thresholds of significance to determine whether a project would have a significant environmental impact regarding GHG emissions. The Appendix G thresholds identified below are included for evaluation in this Draft EIR.

Would the Project:

Threshold 1: Generate GHG emissions, either directly or indirectly, that may have a significant impact on the environment (refer to Impact Statement 4.F-1); or
Threshold 2: Conflict with an applicable plan, policy or regulation adopted for the purpose of reducing the emissions of GHG (refer to Impact Statement 4.F-2).

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(2) Greenhouse Gas Emissions
The City of Corona allows project to utilize either the SCAQMD’s draft thresholds or the City’s adopted Greenhouse Gasses Thresholds Points Worksheet. The City of Corona comments on the project, dated December 19, 2012, Community Development Department comment 1PL-006 (2) demonstrates that the use of the SCAQMD’s draft threshold is considered equivalent to the use of the City’s Greenhouse Gasses Thresholds Points Worksheet. To determine whether the project is significant, this project uses the SCAQMD draft local agency tiered threshold. The threshold is as follows:

Tier 1: The project is not exempt under CEQA; go to Tier 2.

Tier 2: There is no GHG reduction plan applicable to the project; go to Tier 3.

Tier 3: Project GHG emissions compared with the threshold: 3,500 MTCO2e per year.

Tier 4, option 1: Reduce greenhouse gas emissions from BAU consistent with AB 32 (e.g., by 21.7 percent). The California 2020 emissions target is 427 MMTCO2e and the 2020 baseline (without any AB 32 related regulations) is 545 MMTCO2e (CARB’s projected statewide 2020 GHG emissions taking into account the economic recession). Therefore, a 21.7 percent reduction is required to reduce emissions to the target level.

Tier 4, option 2: 4.8 MTCO2e/SP/year.
c. Project Design Features
The project would implement project design features that would reduce the potential for GHG emissions due to project construction and operations. The project design features would include, but are not limited to compliance with the California Green Building Standards, as discussed below.

California Green Building Standards. On January 12, 2010, the State Building Standards Commission unanimously adopted updates to the California Green Building Standards Code, which went into effect on January 1, 2011. The Code is a comprehensive and uniform regulatory code for all residential, commercial and school buildings.

The California Green Building Standards Code does not prevent a local jurisdiction from adopting a more stringent code as state law provides methods for local enhancements. The Code recognizes that many jurisdictions have developed existing construction and demolition ordinances, and defers to them as the ruling guidance provided they provide a minimum 50-percent diversion requirement. The code also provides exemptions for areas not served by construction and demolition recycling infrastructure. State building code provides the minimum standard which buildings need to meet in order to be certified for occupancy. Enforcement is generally through the local building official.

The 2013 California Green Building Standards Code includes the following mandatory requirements for residential developments:

Division 4.1 - Planning and Design (Site Development)

4.106.2 Storm Water Drainage and Retention During Construction

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Projects which disturb less than one acre of soil and are not part of a larger common plan of development shall manage storm water drainage during construction.

4.106.3 Grading and Paving
Construction plans shall indicate how the site grading or drainage system will manage all surface water flows to keep water from entering buildings, with the exception of additions and alterations not altering the drainage path.

Division 4.2 - Energy Efficiency

4.201.1 Scope
Standards for residential buildings do not require compliance with levels of minimum energy efficiency beyond those required by the 2013 California Energy Code.

Division 4.3 - Water Efficiency and Conservation (Indoor Water Use)

4.303.1 Water Conserving Plumbing Fixtures and Fittings Plumbing fixtures and fittings shall comply with the following:

4.303.1.3.2 Multiple Showerheads: combined flow rate of all showerheads and/or other shower be in operation at a time

4.303
60 psi
default to 1.8 gpm

4.303.2 Standards for Plumbing Fixtures and Fittings
Plumbing fixtures and fittings shall be installed in accordance with the California Plumbing Code.

Division 4.3 - Water Efficiency and Conservation (Outdoor Water Use)

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4.304.1 Irrigation Controllers
Automatic irrigation system controllers for landscaping provided by the builder and installed at the time of final inspection shall comply with the following:
1 - Controllers shall be weather- or soil moisture-based controllers that automatically adjust irrigation in response to changes in plant watering needs as weather or soil conditions change. 2 - Weather-based controllers without integral rain sensors or communication systems that account for rainfall shall have a separate wired or wireless rain sensor which connects or communicates with the controller(s).

Division 4.4 - Material Conservation & Resource Efficiency (Enhanced Durability & Reduced Maintenance)

4.406.1 Rodent Proofing
Annular spaces around pipes, electric cables, conduits, or other openings in sole/bottom plates at exterior walls shall be closed with cement mortar, concrete masonry or a similar method acceptable to the enforcing agency to prevent passage of rodents.

Division 4.4 - Material Conservation & Resource Efficiency (Construction Waste Reduction, Disposal & Recycling)

4.408.1 Construction Waste Reduction of at least 50%
Recycle and/or salvage for reuse a minimum of 50% of the nonhazardous construction and demolition waste in accordance with either Section 4.408.2, 4.408.3 or 4.408.4; OR meet a more stringent local construction and demolition waste management ordinance. Documentation is required per Section 4.408.5.

Exceptions:
1 - Excavated soil and land-clearing debris.
2 - Alternate waste reduction methods developed by working with local enforcing agencies if diversion or recycle facilities capable of compliance with this item do not exist or are not located reasonably close to the jobsite.
3 - The enforcing agency may make exceptions to the requirements of this section when isolated jobsites are located in areas beyond the haul boundaries of the diversion facility.

4.408.2 Construction Waste Management Plan
Submit a construction waste management plan meeting Items 1 through 5 in Section 4.408.2. Plans shall be updated as necessary and shall be available for examination during construction.

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4.408.3 Waste Management Company
Utilize a waste management company, approved by the enforcing agency, which can provide verifiable documentation that diverted construction and demolition waste materials meet the requirements in Section

4.408.1.

4.408.4 Waste Stream Reduction Alternative
Generate a total combined weight of construction and demolition waste disposed in landfills that is equal to or less than 4 pounds per square-foot of the building area.

Division 4.4 - Material Conservation & Resource Efficiency (Building Maintenance & Operation)

4.410.1 Operation and Maintenance Manual
At the time of final inspection, a manual, compact disc, web-based reference or other media acceptable to the enforcing agency which covers 10 specific subject areas shall be placed in the building.

Division 4.5 - Environmental Quality (Fireplaces)

4.503.1 General
Any installed gas fireplace shall be a direct-vent sealed-combustion type. Any installed woodstove or pellet stove shall comply with U.S. EPA Phase II emission limits where applicable. Woodstoves, pellet stoves and fireplaces shall also comply with all applicable local ordinances.

Division 4.5 - Environmental Quality (Pollutant Control)

4.504.1 Covering of Duct Openings and Protection of Mechanical Equipment During Construction At the time of rough installation, during storage on the construction site and until final startup of the heating, cooling and ventilating equipment, all duct and other related air intake and distribution component openings shall be covered. Tape, plastic, sheet metal or other methods acceptable to the enforcing agency to reduce the amount of water, dust and debris entering the system may be used.

4.504.2.1 Adhesives, Sealants and Caulks
Adhesives, sealants and caulks used on the project shall meet the requirements of the following standards unless more stringent local or regional air pollution or air quality management district rules apply:
1 - Adhesives, adhesive bonding primers, adhesive primers, sealants, sealant primers, and caulks shall comply with local or regional air pollution control or air quality management district rules where applicable, or SCAQMD Rule 1168 VOC limits, as shown in Tables 4.504.1 or 4.504.2, as applicable.

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Such products shall also comply with Rule 1168 prohibition on the use of certain toxic compounds (chloroform, ethylene dichloride, methylene chloride, perchloroethylene and trichloroethylene), except for aerosol products as specified in Subsection 2 below. 2 - Aerosol adhesives, and smaller unit sizes of adhesives, and sealant or caulking compounds (in units of product, less packaging, which do not weigh more than 1 pound and do not consist of more than 16 fluid ounces) shall comply with statewide VOC standards and other requirements, including prohibitions on use of certain toxic compounds, of the California Code of Regulations, Title 17, commencing with Section 94507.

4.504.2.2 Paints and Coatings
Architectural paints and coatings shall comply with VOC limits in Table 1 of the Air Resources Board Architectural Suggested Control Measure, as shown in Table 4.504.3, unless more stringent local limits apply.

The VOC content limit for coatings that do not meet the definitions for the specialty coatings categories listed in Table 4.504.3 shall be determined by classifying the coating as Flat, Nonflat, or Nonflat-High Gloss coating, based on its gloss, as defined in subsections 4.21, 4.36, and 4.37, of the 2007 California Air Resources Board, Suggested Control Measure, and the corresponding Flat, Nonflat, or Nonflat-High Gloss VOC limit in Table

4.504.3 shall apply.

4.504.2.3 Aerosol Paints and Coatings
Aerosol paints and coatings shall meet the Product-Weighted MIR Limits for ROC in Section 94522(a)(3) and other requirements, including prohibitions on use of certain toxic compounds and ozone depleting substances, in Section 94522(c)(2) and (d)(2) of the California Code of Regulations, Title 17, commencing with Section 94520; and in areas under the jurisdiction of the Bay Area Air Quality Management District shall additionally comply with the percent VOC by weight of product limits of Regulation 8, Rule 49.

4.504.3 Carpet Systems
All carpet installed in the building interior shall meet the testing and product requirements of one of the following:
1 - Carpet and Rug Institute's Green Label Plus Program 2 - California Department of Public Health, "Standard Method for the Testing and Evaluation of Volatile Organic Chemical Emissions from Indoor Sources Using Environmental Chambers," Version 1.1, February 2010 (also known as Specification 01350.)
3 - NSF/ANSI 140 at the Gold level
4 - Scientific Certifications Systems Indoor Advantage™ Gold

4.504.3.1 Carpet Cushion

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All carpet cushion installed in the building interior shall meet the requirements of the Carpet and Rug Institute's Green Label Program.

4.504.3.2 Carpet Adhesive
All carpet adhesives shall meet the requirements of Table 4.504.1.

4.504.4 Resilient Flooring Systems
Where resilient flooring is installed, at least 80% of floor area receiving resilient flooring shall comply with one or more of the following:
1 - VOC emission limits defined in the Collaborative for High Performance Schools (CHPS) High Performance Products Database.
2 - Products compliant with CHPS criteria certified under the Greenguard Children & Schools program. 3 - Certification under the Resilient Floor Covering Institute (RFCI) FloorScore program. 4 - Meet the California Department of Public Health, “Standard Method for the Testing and Evaluation of Volatile Organic Chemical Emissions from Indoor Sources Using Environmental Chambers,” Version

1.1, February 2010 (also known as Specification 01350.)

4.504.5 Composite Wood Products
Hardwood plywood, particleboard and medium density fiberboard composite wood products used on the interior or exterior of the building shall meet the requirements for formaldehyde as specified in the Air Resources Board's Air Toxics Control Measure for Composite Wood (17 CCR 93120 et. seq.), on or before the dates specified in those sections as shown in Table 4.504.5. Documentation is required per Section 4.504.5.1.

Definition of Composite Wood Products: Composite wood products include hardwood plywood, particleboard, and medium density fiberboard. "Composite wood products" do not include hardboard, structural plywood, structural panels, structural composite lumber, oriented strand board, glued laminated timber, prefabricated wood I-joists, or finger-jointed lumber, all as specified in CCR, Title 17, Section 93120.1(a).

Division 4.5 - Environmental Quality (Interior Moisture Control)

4.505.2 Concrete Slab Foundations
Concrete slab foundations or concrete slab-on-ground floors required to have a vapor retarder by the California Building Code, Chapter 19, or the California Residential Code, Chapter 5, respectively, shall also comply with this section.

4.505.2.1 Capillary Break

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A capillary break shall be installed in compliance with at least one of the following: 1 - A 4-inch (101.6 mm) thick base of 1/2-inch (12.7 mm) or larger clean aggregate shall be provided with a vapor retarder in direct contact with concrete and a concrete mix design which will address bleeding, shrinkage and curling shall be used. For additional information, see American Concrete Institute, ACI 302.2R-06. 2 - Other equivalent methods approved by the enforcing agency. 3 - A slab design specified by a licensed design professional.

4.505.3 Moisture Content of Building Materials
Building materials with visible signs of water damage shall not be installed. Wall and floor framing shall not be enclosed when the framing members exceed 19% moisture content. Moisture content shall be verified in compliance with the following: 1 - Moisture content shall be determined with either a probe-type or a contact-type moisture meter. Equivalent moisture verification methods may be approved by the enforcing agency and shall satisfy requirements in Section 101.8. 2 - Moisture readings shall be taken at a point 2 feet (610 mm) to 4 feet (1219 mm) from the grade-stamped end of each piece to be verified. 3 - At least three random moisture readings shall be performed on wall and floor framing with documentation acceptable to the enforcing agency provided at the time of approval to enclose the wall and floor framing. Insulation products which are visibly wet or have a high moisture content shall be replaced or allowed to dry prior to enclosure in wall or floor cavities. Manufacturers’ drying recommendations shall be followed for wet-applied insulation products prior to enclosure.

Division 4.5 - Environmental Quality (Indoor Air Quality & Exhaust)

4.506.1 Bathroom Exhaust Fans
Each bathroom shall be mechanically ventilated and shall comply with the following: 1 - Fans shall be ENERGY STAR compliant and be ducted to terminate outside the building. 2 - Unless functioning as a component of a whole house ventilation system, fans must be controlled by a humidity control. a) Humidity controls shall be capable of manual or automatic adjustment between a relative humidity range of less than 50% to a maximum of 80%. b) A humidity control may be a separate component to the exhaust fan and is not required to be integral or built-in. Note: For CALGreen a "bathroom" is a room which contains a bathtub, shower, or tub/shower combination. Fans are required in each bathroom.

Division 4.5 - Environmental Quality (Environmental Comfort)

4.507.2 Heating and Air Conditioning System Design
Heating and air conditioning systems shall be sized, designed, and equipment selected using the following methods: 1 - The heat loss and heat gain is established according to ANSI/ACCA 2 Manual J - 2004 (Residential Load Calculation), ASHRAE handbooks or other equivalent design software or methods. 2 - Duct systems are sized according to ANSI/ACCA 1 Manual D - 2009 (Residential Duct Systems), ASHRAE handbooks or other equivalent design software or methods. 3 - Select heating and cooling equipment according to ANSI/ACCA 3 Manual S - 2004 (Residential Equipment Selection) or other equivalent design software or methods.

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Exception: Use of alternate design temperatures necessary to ensure the system functions are acceptable CHAPTER 7 - Installer & Special Inspector Qualifications (Qualifications, Verifications) 702.1 Installer Training
HVAC system installers shall be trained and certified in the proper installation of HVAC systems and equipment by a recognized training or certification program. Examples of acceptable HVAC training and certification programs include but are not limited to the following:
1 - State certified apprenticeship programs.
2 - Public utility training programs.
3 - Training programs sponsored by trade, labor or statewide energy consulting or verification organizations.
4 - Programs sponsored by manufacturing organizations.
5 - Other programs acceptable to the enforcing agency.
702.2 Special Inspection
Special inspectors must be qualified and able to demonstrate competence to the enforcing agency in the discipline in which they are inspecting.
703.1 Documentation
Documentation of compliance shall include, but is not limited to, construction documents, plans, specifications, builder or installer certification, inspection reports, or other methods acceptable to the local enforcing agency. Other specific documentation or special inspections necessary to verify compliance are specified in appropriate sections of CALGreen.
d. Analysis of Project Impacts
(1) GHG Emissions
Threshold Would the project generate GHG emissions, either directly or indirectly, that may have a significant impact on the environment?
Impact 4.F-1 Based on a threshold of significance determined by the City of Corona to be functionally equivalent to those in its CAP, project implementation would generate GHG emissions such that a less than significant impact on the environment would occur.

Construction of the project would generate GHG emissions through the use of on-site heavy-duty construction equipment and the addition of off-site vehicle trips generated by construction workers as well as haul/delivery trucks that travel to and from the project site. Mobile-source emissions would result from

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the use of construction equipment such as graders, scrapers, bulldozers, wheeled loaders, cranes, etc.

Operation of the project is expected to result in emissions of GHG emissions related to vehicular trips (i.e., mobile-source emissions) and energy consumption from building illumination, heating and cooling, as well as water conveyance and treatment and solid waste disposal.

As directed in the Corona CAP CEQA thresholds and screening tables, project analysis can be conducted either through emissions calculations or by using the screening table provided in the CAP.11 For the project, CAP conformity is demonstrated via GHG emissions calculations. For new residential development, the amount of emissions required to be reduced under AB 32, which is equivalent to the reductions required by the City’s CAP, would be 21.7 percent when compared with BAU conditions and taking into account CARB’s revised BAU estimates for the State, inclusive of the economic recession.12 The project’s construction-related GHG emissions are provided in Table 4.F-1, Construction Greenhouse Gas Emissions. Although GHGs are generated during construction and are accordingly considered one-time emissions, it is important to consider them when assessing all of the long-term GHG emissions associated with a project. The draft SCAQMD significance thresholds recommend that construction-related GHG emissions be amortized over a project’s 30-year lifetime in order to include these emissions as part of a project’s annualized lifetime total emissions, so that GHG reduction measures will address construction GHG emissions as part of the operational GHG reduction strategies. In accordance with this guidance, the estimated project’s construction GHG emissions have been amortized over a 30-year period and are included in the annualized operational GHG emissions.

The project’s operational GHG emissions are shown in Table 4.F-2, Project-Operational Greenhouse Gas Emissions. Project activities such as vehicles traveling to and from the Project Site, use of energy resources, water/wastewater conveyance, etc., waste disposal and, as described above, amortized construction activity would generate GHG emissions. At the same time, the project would incorporate project design features beyond regulatory requirements that would reduce the potential amount of GHG emissions (refer to subsection 2.(c), Project Design Features). The estimated total annual project-related GHG emissions shown in Table 4.F-2 are based on the anticipated level of GHG emissions with implementation of these project design features. The total annual project emissions also include the estimated GHG emissions sequestered from the planting of new trees. The project will occur located on an undeveloped 271 acre plot, of which only 127 acres will be covered by the residential units. Based on carbon sequestration values calculated by the Intergovernmental Panel on Climate Change (IPCC),13 the 126 acres of preserved grassland and 17 acres of forest land containing 6,100 new trees, is estimated to increase the carbon sink capacity of the project site compared to pre-development levels.

The emissions shown in Table 4.F-2 also include emissions from a comparable BAU project. The BAU scenario emissions estimates include energy and water consumption in accordance with the minimum 11 City of Corona, Climate Action Plan, (2012). 12 The 2.38 metric tons per 1,000 for commercial space number was calculated by taking the factor of 23,203 MTCO2e of emissions to be reduced through new Commercial and Industrial Projects in the City and dividing that by 9,747,000 square feet of new commercial and industrial buildings anticipated within Corona to accommodate anticipated job growth, for a total of 2.38 MTCO2e per 1,000 square feet of building area. Generation factors were taken from the City of Corona CAP (2012). 13 Intergovernmental Panel on Climate Change, Good Practice Guidance for Land Use, Land-Use Change and Forestry, Appendix 3a.4, (2003).

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regulatory requirements during the time period consistent with CARB’s revised BAU estimates for the State.

The BAU project does not account for energy and water efficiency measures that would exceed the regulatory requirements that existing at the time CARB projected the State’s BAU GHG emissions, and does not account for reductions in mobile source GHG emissions from the availability of alternative transportation options and improved tailpipe emissions standards. As shown, the project would constitute an equivalent or larger reduction from BAU than has been determined by CARB to be necessary to meet the goals of AB 32 – that is, a reduction of at least 21.7 percent fewer GHG emissions than a comparable BAU development.

Therefore, the Project would result in a less than significant impact with regard to GHG emissions. (2) Consistency with Applicable GHG Plans, Policies and Regulations Threshold Would the project conflict with an applicable plan, policy or regulation adopted for the purpose of reducing the emissions of GHGs?
Impact 4.F-2 The project would not conflict with an applicable plan, policy or regulation adopted for the purpose of reducing the emissions of GHGs. Therefore, the project would result in a less than significant impact.

As stated previously the City of Corona has an adopted CAP. The City of Corona CAP is a planning and implementation tool to reduce the City’s GHG emissions to levels that are less-than or equal-to 1990’s levels by 2020. The CAP provides an analysis of the GHG emission sources that are attributed to the City; strategies for meeting regional, State, and Federal reduction targets; and methods for monitoring the City’s progress towards reaching those goals. As stated in Impact 4.F-1, the City has determined that the use of the SCAQMD’s draft quantitative thresholds is equivalent to the City’s “Greenhouse Gases Thresholds Points Table 4.F-1
Construction Greenhouse Gas Emissions
Phase
Annual Emissions (MTCO2e) a Onsite Offsite Total
Site Preparation (2015) 225.21 10.46 235.67
Grading (2015) 509.51 16.24 525.75
Paving (2016) 79.30 5.25 84.55
Building Construction (2017) 312.93 198.01 510.94
Building Construction (2018) 310.57 192.78 503.35
Building Construction (2019) 307.09 187.06 494.15
Building Construction (2020) 303.70 181.40 485.09
Building Construction (2021) 76.51 45.24 121.75
Architectural Coatings (2021) 9.59 6.17 15.76
Total 2,997.02
Amortized over Project Lifetime (30 years) 99.23
a MTCO2e = metric tons of carbon dioxide equivalents (includes carbon dioxide, methane, and/or nitrous oxide).

Source: Michael Brandman Associates, Air Quality and Greenhouse Gas Report, Skyline Heights Project, May 2014

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Worksheet.” As shown in Table 4.F-2, the project would result in GHG emissions that would be below the threshold of 21.7 percent reduction compared to a BAU project. Therefore, the project would be consistent with the GHG reductions required in the City’s CAP and impacts would be less than significant. Table 4.F-3, General Plan Consistency Analysis, provides an analysis of the project’s consistency with the applicable goals and policies contained in Chapter 5, Environmental Resources, of the City’s General Plan relative to GHGs. As discussed in Table 4.F-3, the project would be consistent with the applicable General Plan goals and policies. As such, impacts related to consistency with applicable plans and regulations would be considered less than significant.

3. CUMULATIVE IMPACTS
GHGs and climate change are exclusively cumulative impacts. There are no non-cumulative GHG emissions impacts from a climate change perspective. As such, GHGs and climate change are cumulatively considerable, even though the contribution may be individually limited. SCAQMD methodology and thresholds are, thus, cumulative in nature. Therefore, the project area for cumulative impacts related to GHGs and climate change is the State of California.

As discussed earlier under Regulatory Setting and demonstrated in Table 4.F-1, the project would be consistent with California’s goal to reduce GHG emissions statewide. The project’s emissions, without considering cumulative global emissions, would not be enough to cause climate change. The project would Table 4.F-2
Project Operational Greenhouse Gas Emissions
Source
GHG Emissions (MTCO2e per year) Percent Reduction from
BAU Project BAU
Area 64.83 64.76 0.01 %
Energy 1,169.63 952.29 18.6 %
Mobile 4,994.84 3,535.40 29.2 %
Waste 155.18 155.18 0.0 %
Water 132.60 98.16 26.0 %
Subtotal – Operation 6,517.07 4,805.78 26.3 %
Subtotal – Construction
(Amortized over 30 years)

99.23 99.23 0.0 %
Carbon Sequestration from
Newly Planted Trees
-215.94 -215.94 0.0 %
Net Total 6,400.36 4,689.07 26.7 %
Emission Reduction Goal: 21.7 %
Does project achieve the reduction goal? Yes
MTCO2e = metric tons of carbon dioxide equivalents
Source: Michael Brandman Associates, Air Quality and Greenhouse Gas Report, Skyline Heights Project, May 2014

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Table 4.F-3
General Plan Consistency Analysis
Goals and Policies Consistency
Environmental Resources - Air Quality
Goal 1.5 – Distinct neighborhoods and
districts that contribute to the identity,
character, and image of Corona as a vital,
livable, diverse, innovative, and
environmentally sustainable community. Consistent. A full analysis of construction and operational impacts related to GHG emissions was prepared for the proposed project, as provided in the Air Quality and Greenhouse Gas Report, Skyline Heights Project, prepared by Michael Brandman Associates, dated May 2014 (provided in Appendix C).

As indicated in the analysis of GHG emissions, the project would not conflict with applicable GHG reduction plans and would result in less than significant impacts.

Policy 1.5.14 – Require that developers
demonstrate water conservation in the
landscape design of their proposed
projects, such as the use of drought
tolerant species. Consistent. As discussed in Section 2.0, Project Description, plantings on commonly-owned (i.e., under Homeowners’ Association [HOA] ownership) and private slopes would be chosen from the “Defensible Space Landscaping Plant Palette for Fuel Modification in Riverside County” guidelines and all trees and shrubs would be California Department of Water Resources “Water Use Classifications of Landscape Species” (WUCOLS) low water use.

Policy 1.5.17 – Require that new
residential, commercial, office, and
industrial development be designed to
minimize consumption of and sustain
scarce environmental resources through
such methods as the following, as
applicable to the type and scale of
development.

Site design—concentration and
intermixing of development to
minimize vehicular trips and
promote walking, building
orientation in consideration of solar
access and heat gain and loss, and
other
Landscaping—drought-tolerant
species, use of recycled water for
irrigation, and other purposes
Capture of rainwater and re-use on
site
Building design and construction
materials—energy and water
efficient fixtures, recycled building
materials, insulation and wall
thickness, permeable paving
surfaces, and comparable techniques
Consistent. The project would minimize vehicle trips and promote walking by containing pedestrian routes and pathways, common open space and other amenities. The project would provide connectivity to Skyline Drive and associated trails allowing for pedestrian and bicycle access. The project would also provide connectivity to the Foothill Parkway west extension, which would serve to reduce traffic congestions on east-west thoroughfares in the City. The project would incorporate energy efficiency and water efficiency measures that would at a minimum meet the California Green Building Standards. The project would reduce energy related to water use by installing water-conserving fixtures that would achieve at least a 20-percent reduction in indoor water use and moisture-sensing or other equivalent “smart” irrigation systems for larger landscaped areas.

Common open space recreation areas would be planted with WUCOLS low- water plants minimizing the demand for irrigation water.

Goal 10.2 – Ensure sustainable use of
finite energy and water resources for the
long-term use of residents and visitors of
Corona.

Consistent. The project would incorporate energy efficiency and water efficiency measures that would at a minimum meet the California Green Building Standards for building energy use and indoor and outdoor water use. The project would reduce energy related to water use by installing water-conserving fixtures that would achieve at least a 20-percent reduction in indoor water use and moisture-sensing or other equivalent “smart” irrigation systems for larger landscaped areas. Common open space recreation areas would be planted with WUCOLS low-water plants.

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Goals and Policies Consistency
As indicated in the analysis of GHG emissions, the project would not conflict with applicable GHG reduction plans and would result in less than significant impacts.

Policy 10.2.5 – Require the use of
reclaimed water in common areas and
landscape treatments for all proposed
developments. Consistent. The project would incorporate appropriate systems to deliver reclaimed water to meet the project’s non-potable needs. As discussed in the Preliminary Reclaimed Water Report, prepared by KWC Engineers, dated January 16, 2014, computer modeling results verifies that adequate service pressures, at the meter locations, can be provided to the project during the demand scenarios considered.

Goal 10.21 – Reduce air quality
degradation through energy
conservation.

Consistent. See discussion under Goal 10.2 above.

Policy 10.21.1 – Reduce the amount of
energy consumed by commercial and
residential uses, as recommended by the
Southern California Air Quality
Management District. Consistent. See discussion under Goal 10.2 above.

Policy 10.21.2 – Continue to require the
use and installation of energy
conservation features in all new
construction projects and wherever
feasible, retrofitting in existing and re- development projects.

Consistent. See discussion under Goal 10.2 above.

Source: City of Corona General Plan; PCR Services Corporation, 2014 be consistent with the state’s goal of reducing GHG emissions to 1990 levels by 2020. As such, the project’s contribution to climate change/worldwide GHG emissions would be less than significant.

4. MITIGATION MEASURES
Based on the analysis above, the project would result in a less than significant impact and mitigation is not required.

5. LEVEL OF SIGNIFICANCE AFTER MITIGATION
Impacts related to GHG would be less than significant.

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City of Corona Skyline Heights Project
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4.0 ENVIRONMENTAL IMPACT ANALYSIS
G. HAZARDS AND HAZARDOUS MATERIALS

INTRODUCTION
This section analyzes potential impacts associated with hazards and hazardous materials that could occur with implementation of the Project. Relevant regulations and existing conditions are described as well as the potential for the Project to: create a significant hazard to the public or the environment related to hazardous materials; impair implementation of an adopted emergency response plan; or, expose people or structures to wildland fire hazards. This section is based on a Phase I Environmental Site Assessment (ESA) for the site prepared by Hillman Consulting (2013) and a Fuel Modification Report prepared by BMLA Landscape Architecture (2014). These reports are provided in Appendix G of this EIR. 1. ENVIRONMENTAL SETTING a. Existing Conditions
(1) Hazardous Materials/Records Review
Currently, the site is mostly vacant characterized by steep topography, generally increasing in elevation from the northeast to the southwest. The site is in an almost natural state with dense chaparral punctuated by sporadic stands of scrub oak covering most slopes. Several canyons and ravines that are located on the site convey natural drainage across the site. One single-family home is located within the larger annexation area surrounding the site, which is located to the north of the project site. Access to the single-family residence is provided via Green River Road. Miscellaneous vacated buildings, used in conjunction with a former horse stable enterprise, are located adjacent to and east of the existing residence.

Historically, the property has been primarily undeveloped since at least the early 1900s. The northwest portion of the site was used as a landing strip from approximately the 1950s until at least the 1990s. The abandoned landing strip, including a concrete pad that may have been used for a hanger, is located on the southern side of Mabey Canyon, south of Mabey Canyon Road and to the west of the Mabey Canyon Debris Basin. Some evidence of spills or releases was observed in the area of the abandoned landing strip during the site reconnaissance conducted as part of the Phase I ESA. In addition, running approximately parallel to the north of the landing strip between the landing strip and Mabey Canyon Road is a drainage culvert.

Multiple cars were observed to have been laid on their sides to construct the western portion of the southern berm. The vehicles appeared to be from the 1940s to 1960s. Some isolated areas of nuisance dumping were also observed during the site reconnaissance. More specifically, construction debris, including pieces of concrete; car parts; and trash were observed in several locations on the site. Currently, there are no utilities provided to the site. There is no evidence of wells or septic systems on the site.

As part of the ESA, environmental agency databases that log known hazardous site conditions were reviewed to ascertain whether the site or any adjacent properties were listed on such Federal, State, or local databases.

These databases list properties by location and provide historic information regarding past use and presence of hazardous conditions. The site was not identified on any of the regulatory databases searched and no

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adjoining properties were identified on the databases. In addition, the site and adjoining properties were not identified on the Registered Storage Tank or on the Leaking Underground Storage Tank Databases. No Brownfield listings were identified within a ½-mile radius of the site.

Radon, which is a naturally occurring, colorless, odorless gas that is a byproduct of the decay of radioactive materials potentially present in bedrock and soil, can be a concern at a site since it can enter the lowest level of a building through floor cracks, structural joints or plumbing conduits. Based on U.S. Environmental Protection Agency (USEPA) data, the site is located in an area with a low potential for radon concentrations that exceed USEPA action guidelines. In addition, the County of Riverside is classified as Zone 3, or low risk area for radon.

In terms of other hazardous materials that can occur on a site, as there are no buildings on the site and the one single-family home with adjacent miscellaneous vacated buildings previously used for horse stables are located within the larger annexation area surrounding the site which are not to be removed, a screening of asbestos-containing materials, lead-based paint, and mold were not undertaken as part of the ESA. Based on the ESA, no evidence of recognized environmental conditions was identified in connection with the site. The site and surrounding properties are not listed in any of the record searches in the ESA. (2) Areas of Fire Hazard/Wildfire
The site is adjacent to the Cleveland National Forest with residential development to the north and east and forest lands to the south. The site contains steep slopes and narrow canyons and is vegetated with chaparral with areas of buckwheat, grasses, chemise and ceanothus.

The City of Corona has conducted an analysis of fire hazards in the City and has determined that no areas within the City limits would be within a very high fire hazard severity zone (VHFHSZ) classification.1 However, the site is located outside the City limits but within the City’s Sphere of Influence (SOI). Therefore, the site is within the State Responsibility Area (SRA). Based on the State Fire Hazard Severity Zones in SRAs for the County of Riverside, the project site is designated SRA VHFHSZ. As indicated in the General Plan Update Technical Background Report, the wildland/urban interfaces create extremely dangerous and complex fire situations. Development of lands within the SOI areas would increase the urban-wildland interface and associated wildland fire risk.

As indicated in the Fuel Modification Report, which is provided in Appendix G of this EIR, the site is located in an inland valley transitional environment, in which the summers are hot and the winters are mild.

Because of down slope air mass drainage, the site is not affected by freezing and the hot days are tempered by coastal effects of gentle breezes moving west to east through the Santa Ana canyon at the end of each day. Like most of the Inland Empire the effects of the Santa Ana winds have a strong impact on the site, especially throughout the fall months. The Santa Ana winds are strong off-shore winds driven by the heat of the desert creating a high pressure that can drive the wind gusts to 60 miles per hour and greater. The wind direction is generally out of the northeast. The site is also affected by the southwesterly breezes, which carrycoastal moisture down the slopes of the site, and which provide additional moisture to support the chaparral habitat for which the Cleveland National Forest is known.
1 City of Corona General Plan Update Technical Background Report, EIP Associates, March 2004.

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Though the Santa Ana winds are not limited to the fall months, the winds are especially impactful and create an identified fire season. Based on the Fuel Modification Report, the property has not been subject to a wild fire in several decades and has a high potential for large amounts of fuel loading in the understories of the large shrub masses. Due to the site’s proximity to wildland area, the geography of the area, and the density and type of vegetation, which can have very high oil content that can create fire danger, the site has a high potential for wildland fire danger.

An analysis of the provision of fire protection services is contained in Section 4.I, Public Services, of this EIR.

As indicated in Section 4.I, the City of Corona Fire Department (CFD), Riverside County Fire Department, and the California Department of Forestry all provide service to areas outside the City limits but within the SOI, depending on the location of a fire.
b. Regulatory Framework
This section provides a discussion of federal, state, and local regulations that address hazardous materials as well as wildland fires.
(1) Federal
(a) Federal Resource Conservation and Recovery Act (RCRA) According to the U.S. Environmental Protection Agency (US EPA), a “hazardous” waste is defined as one “which because of its quantity, concentrations, or physiochemical or infectious properties, may either increase mortality or produce irreversible or incapacitating illness, or pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, or disposed of, or otherwise managed” (U.S. Public Health and Welfare Code Section 25140-25145.4). Special handling and management are required for materials and wastes that exhibit hazardous properties. Treatment, storage, transport, and disposal of these materials are highly regulated at both the Federal and State levels.

Compliance with Federal and State hazardous materials laws and regulations minimizes the potential risks to the public presented by these potential hazards.

The Federal hazardous waste laws are generally contained in the Resource Conservation and Recovery Act (RCRA) (Title 40 of the Code of Regulations at parts 239 through 282). These laws provide the “cradle to grave” regulation of hazardous wastes. Businesses, institutions, and other entities that generate hazardous waste are required to identify and track their hazardous waste from the point of generation until it is recycled, reused, or disposed of. The primary responsibility for implementing RCRA is assigned to the US EPA, although individual states are encouraged to seek authorization to implement some or all RCRA provisions.
(2) State
(a) California Department of Toxic Substances Control (DTSC) The responsibility for implementation of RCRA was given to the DTSC in August 1992. The DTSC is also responsible for implementing and enforcing California’s own hazardous waste laws, which are known collectively as the Hazardous Waste Control Law. Although similar to RCRA, the California Hazardous Waste Control Law and its associated regulations define hazardous waste more broadly and so regulate a larger

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number of chemicals. Hazardous wastes regulated by California but not by US EPA are called “non-RCRA hazardous wastes.”
(b) Unified Hazardous Waste and Hazardous Materials Management Regulatory Program Title 27 of the California Code of Regulations, otherwise known as the Unified Hazardous Waste and Hazardous Materials Management Regulatory Program (“Unified Program”), was created in 1993 by Senate Bill 1082 to consolidate, coordinate, and make consistent the administrative requirements, permits, inspections, and enforcement activities for environmental and emergency management programs. The Unified Program is implemented at the local government level by Certified Unified Program Agencies (CUPAs). The Unified Program consolidates, coordinates, and makes consistent the following hazardous materials and hazardous waste programs (Program Elements):

Hazardous Waste Generation (including on-site treatment under Tiered Permitting); Aboveground Petroleum Storage Tanks (APST) (only the Spill Prevention Control and Countermeasure Plan [SPCC]);
Underground Storage Tanks (USTs);
Hazardous Material Release Response Plans and Inventories; California Accidental Release Prevention Program (CalARP); and Uniform Fire Code Hazardous Material Management Plans and Inventories. (c) California Health and Safety Code
The Code regulates health and safety including hazardous waste and materials, household waste, vectors, emergency preparedness, fire hazards, radiation, and water protection. (d) Hazardous Building Components
Structural building components sometimes contain hazardous materials such as asbestos, polychlorinated biphenyls (PCBs), lead, and mercury. These materials are subject to various regulatory protocols. However, there are no structures located on the site and therefore, these regulations would not be applicable. The one single-family home with adjacent miscellaneous vacated buildings previously used for horse stables are located within the larger annexation area surrounding the site which are not to be removed. (e) California Fire Plan
The California Fire Plan is the State’s plan for reducing the risk of wildfire through a cooperative effort between the State Board of Forestry and Fire Protection and the California Department of Forestry and Fire Protection (CAL FIRE). By placing the emphasis on prevention, the Fire Plan looks to reduce firefighting costs and property losses; to increase firefighter safety; and to contribute to ecosystem health. The Fire Plan sets up the structure of County-level plans. However, the Fire Plan is structured so that individual fire departments can establish plans and policies for land within their respective jurisdictions.

Sections 51175-51189 of the California Government Code (GC) define responsibilities for CAL FIRE and for local agencies. Sections 51178 and 51181 define the CAL FIRE Director’s responsibility to identify VHFHSZs; transmit this information to local agencies; and periodically review the recommendations relative to

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identification of VHFHSZs. In part, Sections 51178.5 and 51179 define the local agency’s responsibility to make the recommendation available for public review and to designate, by ordinance, VHFHSZs in its jurisdiction. Section 51176 identifies that land is classified in the State “in accordance with whether a VHFHSZ is present so that public officials are able to identify measures that will retard the rate of spread, and reduce the potential intensity, of uncontrolled fires that threaten to destroy resources, life, or property, and to require that those measures be taken.” Sections 51175-51189 direct CAL FIRE to map areas of VHFHSZ within Local Responsibility Areas (LRAs) and SRAs. Wildland fire protection in California is the responsibility of either the state, local government, or the federal government. LRAs include the incorporated cities, cultivated agricultural lands, and portions of the desert with service typically provided by municipal fire departments, fire protection districts, counties, and by CAL FIRE under contract to the local government. SRAs include areas of the state in which the financial responsibility of preventing and suppressing fires has been determined to be primarily the responsibility of the State.

Mapping of the VHFHSZs is based on relevant factors such as fuels, terrain, and weather. VHFHSZ maps were initially developed in the mid-1990s, but are now being updated based on improved science, mapping techniques, and data. Mapping was prepared by CAL FIRE’s Fire and Resource Assessment Program using data and models that describe development patterns, potential fuels over a 30-50 year horizon, expected fire behavior, and expected burn probabilities to quantify the likelihood and nature of vegetation fire exposure to new construction. Based on the State “Fire Hazard Severity Zones in SRA” for the County of Riverside, the project site is designated SRA VHFHSZ. When development is located within a VHFHSZ, annual vegetation clearing, building design/materials restrictions, and other building mandates are required to protect properties from wildfire.
(f) California Fire Code (CFC) 2010, California Code of Regulations, Title 24, Part 9 The City of Corona has adopted the 2013 CFC. The purpose of the CFC is to establish the minimum requirements consistent with nationally recognized good practices to safeguard the public health, safety and general welfare from the hazards of fire, explosion or dangerous conditions in new and existing buildings, structures and premises, and to provide safety and assistance to fire fighters and emergency responders during emergency operations.
(i) CFC Chapter 49, Fire Code, Requirements for Wildland-Urban Interface Fire Areas The purpose of Chapter 49, Requirements for Wildland-Urban Interface Fire Areas, of the CFC is to provide minimum standards to increase the ability of a building to resist the intrusion of flame or burning embers being projected by a vegetation fire and contributes to a systematic reduction in conflagration losses through the use of performance and prescriptive requirements.
(g) California Building Code Chapter 7A, Materials and Construction Methods for Exterior Wildfire Exposure
The purpose of Chapter 7A, Materials and Construction Methods for Exterior Wildfire Exposure, of the California Building Code (CBC) is to establish minimum standards for the protection of life and property by increasing the ability of a building located in any Fire Hazard Severity Zone (FHSZ) within SRAs or any Wildland-Urban Interface Fire Areas to resist the intrusion of flame or burning embers projected by a vegetation fire and contributes to a systematic reduction in conflagration losses. Chapter 7A applies to

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building materials, systems and or assemblies used in the exterior design and construction of new buildings within a Wildland-Urban Interface Fire Area.
(h) Local
(i) City of Corona General Plan, Environment Hazards and Public Safety Chapter 4, Infrastructure and Public Services, of the City of Corona’s General Plan addresses the provision of public utilities and services, including the provision of fire protection services. Chapter 4 contains goals and policies regarding fire protection services. An analysis of project consistency with the applicable goals and policies of the City’s Infrastructure and Public Services Element regarding fire services is provided in the Analysis of Project Impacts subsection, below (see Threshold 7).

Chapter 6, Environment Hazards and Public Safety, of the City of Corona’s General Plan contains the City’s Public Health and Safety Element. The chapter of the General Plan addresses environmental hazards including: seismic, geologic, erosion; flooding; hazardous materials; noise control; and emergency/disaster preparedness. An analysis of project consistency with the applicable goals and policies of the City’s Public Health and Safety Element regarding hazards and hazardous materials is provided in the Analysis of Project Impacts subsection, below (see Threshold 7).
(ii) City of Corona Municipal Code, Title 3 Revenue and Finance, Chapter 3.36, Fire Facilities Fee It is the purpose and intent of this chapter to implement the City’s General Plan to attempt to assure that fire facilities which satisfy City standards are available concurrent with the need caused by new development within the City. Due to the location of certain development within the urban/wildland interface area by the Cleveland National Forest, such development will create a fire hazard impacts not found in other parts of the City. The City has established a fire facilities fee to fund the provision of fire provision services to property located within this urban/wildland interface.

2. ENVIRONMENTAL IMPACTS
a. Methodology
The analysis focuses on the hazardous materials and potential hazards associated with wildland fires that could occur as a result of the residential subdivision. An ESA was conducted on the site to assess the environmental condition of a property to determine the presence or likely presence of hazardous substances that could result in an existing, previously existing, or potential release of a hazardous substance on the site.

The methodology for preparation of the ESA include review of USGS map; review of historical records; review of previous Phase I ESA; a search of environmental regulatory databases; and visual reconnaissance.

The ESA was conducted using generally accepted Phase I ESA industry standards in accordance with the ASTM Standard Practice E 1527-05 for Phase I ESAs. Information from the assessment was used to determine whether any portion of the 270.9-acre site is on a list of hazardous materials sites or would create a significant hazard to the public or the environment. In determining the level of significance, the analysis assumes that construction and operation of the proposed project would be in compliance with relevant federal, state, and local laws and regulations pertaining to the use, storage, and disposal of hazardous materials.

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The Fuel Modification Report provides information regarding existing site conditions and provides a plan that would be reviewed by the CFD. The Fuel Modification Plan is summarized below under the Project Design Features subsection.
b. Thresholds of Significance
Appendix G of the CEQA Guidelines (the Initial Study Environmental Checklist form) and the City’s Initial Study Checklist include questions relating to hazards and hazardous materials that are utilized as the thresholds of significance in this section (Thresholds 1-8). Accordingly, the proposed project may create a significant environmental impact if it would result in one or more of the following:

Threshold 1: Create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials (refer to Impact Statement 4.G-1); Threshold 2: Create a significant hazard to the public or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment (refer to Impact Statement 4.G-1);
Threshold 3: Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school (refer to Impact Statement 4.G-2);
Threshold 4: Be located on a site which is included on a list of hazardous materials sites compiled pursuant to Government Code section 65962.5 and, as a result, would it create a significant hazard to the public or the environment (refer to Impact Statement 4.G-3); Threshold 5: For a project located within 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 result in a safety hazard for people residing or working in the project area (refer to Impact Statement

4.G-4);
Threshold 6: For a project within the vicinity of a private airstrip, would the project result in a safety hazard for people residing or working in the project area (refer to Impact Statement 4.G-4); Threshold 7: Conflict with an applicable plan, policy or regulation adopted for the purpose of avoiding or mitigating any physical impacts associated with hazards or hazardous materials (i.e., impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan) (refer to Impact Statement 4.G-5); or Threshold 8: Expose people or structures to a significant risk of loss, injury or death involving wildland fires, including where wildlands are adjacent to urbanized areas or where residences are intermixed with wildlands (refer to Impact Statement 4.G-6).

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c. Project Design Features
The Project would include the implementation of a Fuel Modification Plan, which would be approved by the CFD. Figure 4.G-1A, Conceptual Fuel Modification Plan – Northerly Half of Skyline Heights, and Figure 4.G1B, Conceptual Fuel Modification Plan – Southerly Half of Skyline Heights, illustrate the zones that would be established on the site in order to provide protection from fire hazards. The residential lots would be maintained, irrigated defensible space and would conform to the defensible space principles set forth by the City’s Health and Safety Codes and Building Code. No encroachment of flammable improvements from the private lots into the fuel modification zones would be allowed. All planting would comply with the City’s adopted acceptable plant list and irrigated to maintain moisture content. The defensible space zone would be a minimum of 30 feet between the property line and the structure.

All structures and/or residences built within the proposed development would include, but not be limited to, the following:

All residences would be sprinklered;
All structures would comply with applicable City Building Codes, International Wildland-Urban Interface Codes, and California Fi re and Building Codes; Roof overhangs or eaves on lots adjacent to Fuel Modification Zone I would be enclosed with 1-hour rated or non-combustible materials per City Building Code and skylights would not be allowed on structure roofs in these areas;
Structures such as patios, decks, arbors and fences would be constructed of non-combustible materials;
Any chimney, flue or stovepipe would have an approved spark arrestor;2and All structures that are located within 200 feet of wildland areas would have one-hour constructed eaves around the entire perimeter of the structure.

The common open space areas within the site would be located in the Maintained, Irrigated Landscape Improvement Zones as shown in Figures 4.G-1A and 4.G-1B. These areas would consist of manufactured slopes, planted recreational spaces and flood and water quality basins. The areas would contain 15-foot wide access maintenance paths and service access roads where required for basin maintenance. Any constructed features, such as walls, fences, and pilasters within these areas would be constructed of nonflammable material. The plant material would conform to the Plant Palette for Defensible Space Guideline provided by the City’s Fire Department. Spaces would be irrigated in accordance with the City’s standards.

These areas would be maintained by the Homeowner’s Association (HOA).

Fuel Modification Zone 1 (see Figures 4.G-1A and 4.G-1B above) would be a minimum of 30 feet wide measured horizontally from the residential property line. Native vegetation would be removed in these areas and would be replaced with plants from the Plant Palette for Defensible Space Guideline provided by the CFD. The areas would be overhead irrigated to provide moisture content in the plantings. Any 2 An approved spark arrestor is defined as a device constructed of non-flammable materials, 12 gauge minimum thickness, or other approved material found satisfactory by the Corona Fire Department, and having 1/2” perforations for arresting carbon or sparks and installed to be visible for the purposes of inspection and maintenance.

Conceptual Fuel Modi FIGURE ca on Plan – Northerly Por on of Skyline Heights Skyline Heights Project 4.G-1A Source: bmla Landscape Architecture, 2014. 0 600 Feet N

Conceptual Fuel Modi FIGURE ca on Plan – Southerly Por on of Skyline Heights Skyline Heights Project 4.G-1B Source: bmla Landscape Architecture, 2014. 0 600 Feet N

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maintenance pathways or service roads contained in Fuel Modification Zone 1 would be fenced and gated and kept weed free. The Fuel Modification Zone 1 would be maintained by the HOA.

Fuel Modification Zone 2 (see Figures 4.G-1A and 4.G-1B above) would be a minimum of 70 feet wide beginning at the outer limits of Zone 1. Native vegetation would be thinned by 50 percent to remove the fuel loading and dead vegetation from this zone. The area would be maintained in accordance with the City’s weed abatement policies. The Fuel Modification Zone 2 would be maintained by the HOA.

The fuel modification treatments that include trimming of native vegetation must be complete prior to delivery of combustible material to the site in order to provide protection during construction of the subdivision.
d. Analysis of Project Impacts
Threshold 1: Create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials?
Threshold 2: Create a significant hazard to the public or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment?
Impact 4.G-1 Project implementation would result in the development of the currently largely undeveloped site with 292 residences, roads, landscaping, and detention basins, which would result in an increase in the use, storage, transport, and disposal of hazardous materials. During construction, hazardous materials, such as gasoline and oil would be used. During occupancy of the residences household hazardous materials, such as pesticides, cleaners, paints, and pool supplies would be used and stored on site. Compliance with applicable regulations would reduce potential significant impacts regarding hazardous materials to a less than significant level.
(1) Construction
Based on the ESA and as discussed above, the site is not included on the list of hazardous materials sites (Cortese List) compiled pursuant to Government Code Section 65962.5. The site is vacant and therefore, no buildings that could contain hazardous materials such as asbestos or lead would be demolished. The singlefamily home with adjacent miscellaneous vacated buildings previously used for horse stables are located within the larger annexation area surrounding the site which are not to be removed. During construction, hazardous materials, such as gasoline and oil would be used. However, compliance with applicable regulations would reduce potential significant impacts regarding hazardous materials to a less than significant level.
(2) Operation
The Project includes the development of 292 residences and would not involve the routine transport, use, or disposal of significant amounts of hazardous materials. The proposed residential uses would result in the use of ordinary household or general commercial cleaners, solvents, painting supplies, pesticides for

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landscaping and pool maintenance, and other substances utilized for cleaning and maintenance of residential development. These types of chemicals are not considered acutely hazardous, and would be used in limited quantities. All potentially hazardous materials would be contained, stored, and used in accordance with manufacturers’ instructions and handled in compliance with applicable federal, state, and local health and safety standards and regulations. Any associated risk transport, use, or disposal of hazardous materials would be adequately reduced to a less than significant level through compliance with these standards and regulations.

Threshold 3: Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school? Impact 4.G-2 The site is located further than one-quarter mile from an existing or proposed school. The project would result in the development of 292 single-family residences. While some hazardous materials are used in homes, the quantities are generally small. Therefore, the project would not result in the handling or emissions of hazardous materials, substances, or waste within one- quarter mole of an existing or proposed school and no significant impact would occur.

The site is not located within one-quarter mile of an existing or proposed school. The site is located approximately 1.5 miles from the nearest school. In addition, the 292 proposed residences that would be located on the site would not emit hazardous emissions. While the residences would use small amounts of hazardous materials as discussed above under Impact Statement 4.G-1, the quantities would be small. As the residences would not emit hazardous emissions or result in the handling of hazardous or acutely hazardous materials, substances or waste aside from what is routinely used in residences within one-quarter mile of an existing or proposed school, no significant impact would occur.

Threshold 4: Be located on a site which is included on a list of hazardous materials sites compiled pursuant to Government Code section 65962.5 and, as a result, would it create a significant hazard to the public or the environment?
Impact 4.G-3 Based on the Phase I ESA, the site is not located on a list of hazardous materials sites compiled pursuant to Government Code section 65962.5. As the project would not create a significant hazard to the public or the environment, no significant impact would occur.

As discussed above under Environmental Setting, a Phase I ESA was performed on the parcels that comprise the site. The ESA provides information within a one-mile radius. Based on the ESA, the project site is not on a list of Hazardous Waste and Substances (Cortese) List compiled pursuant to Government Code section 65962.5. Therefore, the project would not create a significant hazard to the public or the environment and no significant impact would occur.

Threshold 5: For a project located within 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 result in a safety hazard for people residing or working in the project area?

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Threshold 6: For a project within the vicinity of a private airstrip, would the project result in a safety hazard for people residing or working in the project area? Impact 4.G-4 The site is located approximately three miles south of the Corona Municipal Airport and no private airstrips are located within the vicinity of the site. Therefore, the project would not result in a safety hazard for people living in the subdivision as a result of a public airport or private airstrip.

The Corona Municipal Airport is located in the northwest portion of the City at 1900 Aviation Drive, approximately three miles north of the site. The airport is recreational (i.e., it is not used by commercial aircraft) and is located on approximately 100 acres of land owned by the U.S. Army Corps of Engineers and leased by the City of Corona. The airport has a 600-plane capacity and currently serves 350 to 400 general aviation aircraft. The airport is operated by the City’s Maintenance Services Department.

The Corona Municipal Airport Comprehensive Land Use Plan was adopted by the Riverside County Airport Land Use Commission in 1993. The Airport Comprehensive Land Use Plan contains policies to maintain flight paths and minimize impacts to residents and employees of the area for this general aviation facility.

The site is not located within the Airport Comprehensive Land Use Plan area. In addition, no private airstrips are located within the vicinity of the site. Therefore, the project would not result in an aircraft safety hazard for people living in the project area.

Threshold 7: Conflict with an applicable plan, policy or regulation adopted for the purpose of avoiding or mitigating any physical impacts associated with hazards or hazardous materials (i.e., impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan)?
Impact 4.G-5 The project would not conflict with an applicable plan, policy or regulation associated with hazards or hazardous materials. The residential subdivision would not physically interfere with an adopted emergency response plan. The project would be consistent with the applicable General Plan policy. Thus, no significant impacts would occur.

As indicated previously, the project would result in the development of 292 residences. As such, the use, storage, transport, and disposal of hazardous materials would be limited. As such, the project would not conflict with an applicable plan, policy or regulation associated with hazards or hazardous materials or physically interfere with an adopted emergency response plan.

With regard to emergency response plans, the City of Corona Emergency Operations Plan addresses the planned response to emergency situations associated with natural or human caused disasters and technological incidents. The Plan includes a matrix of functions and responsibilities for each department, by potential disaster. However, residential uses do not typically result in accidents associated with hazardous materials. In the event of a natural disaster, the City would respond as appropriate.

As shown in Table 4.G-1, General Plan Consistency Analysis, Goal 11.3 addresses the health, safety, and welfare of residents and visitors through good land use planning and adherence to applicable regulations

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Table 4.G-1
General Plan Consistency Analysis
Goals and Policies Consistency
Infrastructure and Public Services – Police and Fire
Goal 9.6 – Address fire prevention measures on open
space land to reduce the risk of wildland fires.

Consistent. The project would implement a fuel
modification plan designed specifically to help suppress a wildland fire in different ways. With implementation
of the project design features and prescribed mitigation measures relating to fire prevention, any significant risk of loss, injury or death involving wildland fires, would be minimized to the maximum extent feasible. Because the
site is not maintained as a fuel modification area and
consists of uncontrolled wildland vegetation, existing
single-family residences to the north, northeast, and east of the site would gain increased protection from the
spread of fire. As such, the proposed project would
reduce the threat of wildland fires to people and
structures in the project vicinity and thus, reduce the demand for fire services needed in the event of a
wildland fire. In addition, in the event of a wildland fire in the project vicinity, the CFD has automatic aid
agreements with all fire agencies in State.

Policy 9.6.1 – Implement brush clearing and other fire
prevention programs on Open Space lands, thereby
reducing the possibility for the encroachment of
wildland fires onto inhabited areas (in consideration of maintenance programs for important plant and animal
habitats).

Policy 9.6.2 – Remove chaparral and other highly
flammable vegetation and replace it with slow-burning
and fire-resistant species in natural areas that are
proximate to urbanized areas.

Environmental Hazards and Public Safety – Hazardous Materials Goal 11.3 – Ensure that the health, safety and general
welfare of residents and visitors of the City of Corona including the overall health of the natural environment is provided through good land use planning and strict
adherence and enforcement of the City of Corona
Hazardous Material Area Plan, Uniform Fire Code,
Certified Unified Program Agency, and other pertinent
sources and documents.

Consistent. A Phase 1 ESA was prepared for the site.

Based on the ESA, no evidence of recognized
environmental conditions was identified in connection
with the site. The site and surrounding properties are
not listed in any of the record searches in the ESA. The project would result in 292 residences on the site.

Compliance with applicable regulations regarding the
storage and disposal of household hazardous wastes
would reduce potential impacts to a less than significant level.

Source: PCR Services Corporation, 2014.

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regarding hazardous materials. The site is located in the City’s SOI and the project would result in the annexation into the City and development of the site. Thus, development is anticipated on the site and has been considered in the City’s planning efforts. In addition, compliance with applicable regulations regarding the storage and disposal of household hazardous wastes would reduce potential impacts to a less than significant level. Thus, the project would be consistent with the City’s General Plan goal and policies relating to hazards and hazardous materials. Therefore, no significant impact with regard to emergency response plans would occur.

Threshold 8: Expose people or structures to a significant risk of loss, injury or death involving wildland fires, including where wildlands are adjacent to urbanized areas or where residences are intermixed with wildlands?
Impact 4.G-6 With the implementation of the fuel modification plan the project would not expose people or structures to a significant risk of loss, injury or death involving wildland fires. Thus, no significant impact would occur with regard to wildland fires with implementation of applicable project design features and mitigation measures.

As discussed above, the site is located within a VHFHSZ within a SRA.3 Due to the location of the site within the urban/wildland interface area by the Cleveland National Forest and the development of the proposed residential subdivision, the project would locate people within the wildland/urban interface area, which could pose a safety threat to the public and firefighters. Approval and implementation of a Fuel Modification Plan would be required for the project as indicated in correspondence from the CFD.4 The proposed Fuel Modification Plan is described in Section 2.c, Project Design Features, above, and would be reviewed and approved by the CFD prior to implementation. In addition, compliance with the CBC Chapter 7A (Materials and Construction Methods for Exterior Wildfire Exposure), would be required to be clearly shown on the building plans submitted for review and approval by the CFD. The creation of the different zones as shown in the Fuel Modification Plan and the use of non-flammable materials in compliance with code requirements would serve to reduce the potential fire hazard.

The project would not conflict with General Plan policies regarding wildland fires. As shown in Table 4.G-1, consistent with Policy 9.6.2, the project would result in the replacement of highly flammable vegetation with plants on the City’s approved list of fire-resistant species as indicated in the proposed Fuel Modification Plan.

In addition, maintenance of the zones would be completed by the HOA, which would ensure continued maintenance over time.

The site is not currently maintained as a fuel modification area and consists of uncontrolled wild land vegetation. The implementation of the Fuel Modification Plan would provide some protection to the existing single-family residences to the north, northeast, and east of the site. As such, the proposed project could reduce the threat of wildland fires to people and structures in the project vicinity and thus, could reduce the demand for fire services needed in the event of a wildland fire. In the event of a wildland fire in the project vicinity, the CFD has automatic aid agreements with all fire agencies in State. 3 Fire Hazard Severity Zones in SRA, Western Riverside County, adopted by CAL FIRE on November 7, 2007. 4 Cindi Schmitz, Corona Fire Department, Email correspondence, dated February 27, 2014.

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With implementation of the project design feature (i.e., Fuel Modification Plan), as required by Mitigation Measure PS-1 below, compliance with all applicable regulations regarding fire access, fire flows, and number of hydrants, and the prescribed mitigation measures relating to fire prevention contained in Section 4.I, Public Services, of this EIR, any significant risk of loss, injury or death involving wildland fires, would be reduced to a less than significant level.

3. CUMULATIVE IMPACTS
The health and safety hazards posed by most hazardous materials are typically local in nature. They generally do not combine in any cumulative sense with the hazards of other projects. Possible exceptions, however, include potential toxic air contaminant emissions, transportation of hazardous materials, and waste disposal. The need to respond to hazardous materials emergencies could also increase as a result of cumulative development. However, as indicated above, the residential development of the site would result in limited use of hazardous materials. Such use would include materials that are typically used in residences.

As such, the project would not result in a significant impact with regard to hazardous materials. Therefore, the project would not contribute to a cumulatively significant impact.

With regards to cumulative impacts regarding adopted emergency response and evacuation plans, all related projects would be evaluated on a project-by-project basis to determine consistency with applicable plans.

For example, all related projects would be required to provide the minimum number of required emergency access roads per applicable regulatory requirements and any related traffic improvements would be reviewed by the CFD for approval of emergency access as required by the City. The project would not conflict with any adopted emergency response and evacuation plans and as such, would not contribute impacts that are cumulatively considerable regarding impairing implementation of or physically interfering with an adopted emergency response plan or emergency evacuation plan.

With regards to cumulative impacts associated with wildland fires, the project site and vicinity is located in an area highly prone to wildfires. Similar to the Project, any related project adjacent to an area susceptible to wildland fire hazards would be required to implement a Fuel Modification Plan. Mitigation of potential wildland fire hazards is regulated by federal, state, and local requirements, and would be addressed on an individual basis. There would be a beneficial effect from the project in reducing the potential for exposure to wildland fires on existing residential uses in the local project vicinity. Therefore, with implementation of requirements, including a Fuel Modification Plan, the proposed project would not result in cumulatively considerable impacts relative to wildfire hazards.

In summary, the project would not contribute to cumulatively significant impacts with regard to hazardous materials, emergency response plans or hazards. Therefore, no mitigation measures to address cumulative impacts would be necessary.

4. MITIGATION MEASURES
Based on the analysis above, the project would result in a no significant or less than significant impacts with regard to hazards and hazardous materials. However, to ensure that impacts remain below the threshold, the following mitigation measures provided in Section 4.I, Public Services, of this Draft EIR with regard to fire protection services are also recommended to address wildland fire hazards:

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Mitigation Measure PS-1: Prior to issuance of building permits, the project Applicant shall obtain CFD review and approval of the site plan, fuel modification plan, and project design features including, but not limited to roadway design to meet or exceed minimum fire and emergency access requirements including ingress/egress; driveway and fire lane width; turning radii inside and outside; grades/elevations; adequate on-site space to park CFD apparatus; fire hydrant sizing, spacing and locations; fire protection systems including automatic fire sprinkler systems and fire alarms installed in each residence; availability of adequate firefighting water flow; and approved building materials. The project Applicant shall implement the fuel modification plan and other CFD-required fire life safety features prior to issuance of a certificate of occupancy.

Mitigation Measure PS-2: Prior to the issuance of building permits, the project Applicant shall pay the required service and development fees pursuant to the “Fire Facilities Fund” as amended in Chapter 3.36 of the CMC to the City of Corona for the public improvements and facilities associated with the CFD.

5. LEVEL OF SIGNIFICANCE AFTER MITIGATION
With compliance with applicable requirements regarding hazards and hazardous materials and with the implementation of the above mitigation measures, impacts associated with hazards and hazardous materials would be remain below the threshold.

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4.0 ENVIRONMENTAL IMPACT ANALYSIS
H. HYDROLOGY AND WATER QUALITY

INTRODUCTION
This section of the EIR evaluates the potential impacts to hydrology and water quality conditions in the City of Corona from implementation of the proposed project. The analysis in this section is based, in part, upon a Preliminary Drainage Report (Hydrology Study) and Water Quality Management Plan (WQMP), which were both prepared by KWC Engineers in January 2014 as well as the Infiltration Opportunities, Constraints and Recommendations for Water Quality Treatment Purposes prepared by Ginter & Associates, Inc. in May 2013. These documents are included in Appendix H of this EIR.

1. ENVIRONMENTAL SETTING
a. Existing Conditions
(1) Existing Water Quality Conditions
(a) Santa Ana Region
The project site is located within Region 8 (Santa Ana Region) of the California Regional Water Quality Control Board (RWQCB). The Santa Ana River and its principal tributaries begin in the San Bernardino Mountains, the eastern San Gabriel Mountains, and the Santa Ana Mountains. The Santa Ana Region’s boundaries are illustrated in Figure 4.H-1, Santa Ana Region Watershed Map. The project site falls within the Santa Ana River Watershed, with the primary water quality concerns being wastewater reclamation (Total Dissolved Solids [TDS] and nitrogen issues), groundwater recharge, water level management, and invasive plant eradication. Table 4.H-1, Receiving Waters for Urban Runoff from the Project Site, identifies receiving waters that would receive urban stormwater runoff from the project site, the listed water quality impairments, and beneficial uses associated with these water bodies (also see further discussion below regarding beneficial uses). According to the Santa Ana Water Quality Control Plan, water quality in the project area is continuously altered by a number of factors including, but not limited to, consumptive use, importation of water high in dissolved solids, runoff from urban and agricultural areas, and the recycling of water within the basin. In general, water quality in the Santa Ana Region becomes progressively poorer as water moves along hydraulic flow paths. The highest quality water is typically associated with tributaries flowing from surrounding mountains and groundwater recharged by these streams. As indicated above in Table 4.H-1, each of the receiving waters has multiple designated beneficial uses. These designations provide a description of how the water is used and what beneficial purposes it serves. The following provides a description of each of these water uses for the two affected receiving water bodies.1 Agricultural Supply (AGR) – Waters used for farming, horticulture, or ranching, including, but not limited to, irrigation, stock watering, and support of vegetation. 1
State Water Resources Control Board. “Water Quality Control Plan for the Santa Ana River Basin (Region 8).” Updated July 2014.

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Groundwater Recharge (GWR) – Waters used for natural or artificial recharge of groundwater for purposes of future extraction, maintenance of water quality, or halting of saltwater intrusion into freshwater aquifers.

Rare, Threatened, or Endangered (RARE) – Waters support the habitats necessary for the survival and successful maintenance of plant or animal species designated under state or federal law as rare, threatened, or endangered.

Water Contact Recreation (REC1) – Waters used for recreational activities involving body contact with water where ingestion of water is reasonably possible. Uses include, but are not limited to, swimming, water-skiing, whitewater activities, fishing, and use of natural hot springs.

Non-contact Water Recreation (REC2) – Waters used for recreational activities involving proximity to water, but not normally involving body contact with water where ingestion of water is reasonably possible. Uses include, but are not limited to, picnicking, sunbathing, hiking, camping, boating, hunting, sightseeing, and aesthetic enjoyment.

Warm Freshwater Habitat (WARM) – Waters that support warm water ecosystems including, but not limited to, preservation and enhancement of aquatic habitats, vegetation, fish, and wildlife, including invertebrates.

Wildlife Habitat (WILD) – Water that support wildlife habitats including, but not limited to, the preservation and enhancement of vegetation and prey species used by wildlife, such as waterfowl. (2) Existing Surface Hydrology and Drainage Conditions
The project site is located within the Foothill area of the City’s West Sphere of Influence (SOI) within the Santa Ana River Watershed, which encompasses approximately 153.2 square miles across three counties (San Bernardino County, Riverside County, and Orange County). Flows within this watershed start in the San Bernardino Valley, crossing Riverside and Orange Counties before emptying into the Pacific Ocean.

The project site consists of sparsely vegetated and otherwise undeveloped land with the exception of dirt roads. The site is characterized by steep topography, generally increasing in elevation from the northeast to Table 4.H-1
Receiving Waters for Urban Runoff from the Project Site Receiving Waters 303(d) List Impairments Designated Beneficial Uses Proximity to RARE Beneficial
Use
Temescal Creek, Reach 1 pH REC1, REC2, WARM, WILD -- Santa Ana River, Reach 3 Bacteria and Viruses
(Pathogens), Copper (wet
season) and Lead
AGR, GWR, REC1, REC2,
WARM, WILD, RARE -- Notes: pH = percent hydrogen (acidity/alkalinity); AGR = Agricultural Supply; GWR = Ground Water Recharge; REC1 = Water Contact Recreation; REC2 = Non-contact Water Recreation; WARM = Warm Water Freshwater Habitat; WILD = Wildlife Habitat; RARE = Rare, threatened, or endangered species.

Source: KWC Engineers, 2014 and PCR Services Corporation, 2014.

Santa Ana River Watershed Map FIGURE
Skyline Heights Project 4.H-1
Source: Riverside County Flood Control and Water Conserva on District, 2009.

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the southwest. There are several canyons and ravines on the site that convey natural drainage across the site. The site generally drains from southwest to northeast, in a natural canyon flow condition, with the flowline of the streams having an average slope of about 10 to 20 percent. Figure 4.H-2, Existing Site Hydrology, illustrates the current drainage patterns within and surrounding the project site. There are four major watersheds on and adjacent to the site: Areas A, B, C, and D. Area A is approximately 15.4 acres in size and is located north of Mabey Canyon and is situated entirely on the site.

The northerly and westerly portion of Area A drains north and west. Area B is approximately 48.2 acres in size and is located south of Mabey Canyon and is situated entirely on the site. Currently, the natural canyon flows into an engineered open space west of Cape Drive, into a concrete trapezoidal channel that flows towards Border Avenue. Area C, which is approximately 311.6 acres in size, is located south of Area B and extends in a westerly direction off the site. The un-named blueline stream, which is located in Area C, flows into the Oak Street Debris Basin via an engineered concrete trapezoidal channel. Area D, which is approximately 44.5 acres, is located on the southern portion of the site and extends beyond the site boundary. The natural canyon drains into a storm drain located in Trudy Way which outlets into the Oak Street Debris Basin. The total site drainage area comprises approximately 419.7 acres and under existing conditions generates 977.0 cubic feet per second (cfs) in the 100-year event and 594.9 cfs in the 10-year event.

There are two USGS designated blueline streams onsite. Mabey Canyon flows into an existing basin prior to discharging towards Lincoln Avenue. The other un-named stream flows into Kroonen Channel and the Oak Street Debris Basin prior to discharging into the Oak Creek Channel.

Since the site is undeveloped there are no major drainage improvements on-site or upstream of the site. The City of Corona Drainage Master Plan does not identify the drainage facilities for the area surrounding the Skyline Heights project site area. Under existing conditions, stormwater runoff is conveyed via natural channel flow through the site and discharges into storm drains in Border Avenue, Lincoln Avenue and the Oak Street Channel before discharging into Temescal Creek – Reach 1, which is located approximately three miles north of the site.
(3) Groundwater Resources
Water resources in the City and throughout Riverside County are sustained by substantial groundwater basins, which are used as reservoirs to store water during wet years. These underground reservoirs are tapped throughout the year according to the demand for water. Groundwater conditions in these basins are influenced by natural hydrologic conditions such as percolation of precipitation, groundwater seepage, and ephemeral stream flow within the watershed areas.

As discussed in the 2008 Groundwater Management Plan (GWMP, included as Appendix D to the City’s 2010 Urban Water Management Plan [UWMP]), the City’s service area overlays the Temescal, Bedford, and Coldwater sub-basins, though only the Temescal sub-basin underlies a portion of the site. The Temescal subbasin is a DWR-defined sub-basin of the Upper Santa Ana Valley Groundwater Basin, bounded on the north by the Chino sub-basin and the south by the Elsinore Groundwater Basin. The GWMP mentions that the Bedford and Coldwater sub-basins were historically considered a part of the Elsinore Groundwater Basin, but are not DWR-defined sub-basins. Figure 4.H-3, Groundwater Basins, illustrates the extents of the Temescal sub-basin and the approximate locations of the Bedford and Coldwater sub-basins.

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The City’s groundwater supplies are pumped from the Temescal, Bedford, and Coldwater sub-basins. The City has 25 groundwater wells consisting of 20 wells in the Temescal sub-basin, seven of which feed the Temescal Desalter, and five wells in the Coldwater sub-basin, two of which are inactive. In the past decade the City has strived to increase the production of local water relative to imported water. In 2000, water from the all of the basins composed 33 percent of total production. Since 2006, this percentage has varied between 53 and 62 percent.

The three sub-basins from which the City extracts groundwater are not adjudicated, as defined by DWR.

Therefore, there are no defined legal pumping rights for the City. While there is no formal legal adjudication of the basins, a memorandum of agreement concerning water production from the Coldwater sub-basin went into effect December 1, 2008. The agreement arose because a groundwater well (Trilogy Well), constructed by Elsinore Valley Municipal Water District (EVMWD) was not located in accordance with terms of a previous legal agreement established in 1963.

The new agreement ensures that the City and the EVMWD will be allowed to pump sufficient water from the Coldwater sub-basin to meet their respective requirements and to maximize the sustainable use of the Coldwater sub-basin as a water supply. According to the agreement, an operating committee will annually determine the amount of groundwater that can be safely extracted from the Coldwater sub-basin. (a) Bedford Sub-basin
The Bedford sub-basin is located south of the Temescal sub-basin in Temescal Canyon between the Santa Ana Mountains and the El Sobrante Hills (see Figure 4.H-3). The basin covers an area of approximately ten square miles with an alluvial depth ranging from 30 to 200 feet. Groundwater within the basin tends to flow northwest into the Temescal sub-basin. The City has abandoned one potable well in the Bedford sub-basin, Well No. 4, and has two non-potable wells that can be used to supplement reclaimed water from the water reclamation facility (WRF). Between 2007 and 2009, an average of just under 300 acre-feet per year (AFY) was supplied by the non-potable wells. The City currently does not use the non-potable wells for a continuous source of supply, but they can supplement the reclaimed water system when necessary. With additional treatment, the City may use the wells as a potable supply source in the future.

Other extractors from the basin have been EVMWD and Foothill Properties. EVMWD extracted 616 AF from four wells in 1993, and Foothill Properties extracted 887 AF from three wells in 1993. According to the 2008 GWMP, the City may plan to re-drill this source for future use. (b) Coldwater Sub-basin
The City acquired the rights to the surface flows of Coldwater Canyon in 1964 when it purchased the assets of the Corona City Water Company (CCWC). To meet DPH requirements, the surface flow is spread in percolation ponds and extracted by the City’s three Glen Ivy area wells in the Coldwater sub-basin.

The Coldwater sub-basin is located southwest of the Bedford sub-basin and the Temescal Wash (see Figure 4.H-3). The basin encompasses an area of approximately 2.6 square miles and lies within the structural graben between the Santa Ana Mountains to the west and the El Sobrante Hills to the east. The Coldwater sub-basin is bound by the North Glen Ivy Fault to the northeast. The North Glen Ivy Fault behaves as an effective barrier to groundwater flow and prevents migration of groundwater from the Coldwater

Exis ng Site Hydrology FIGURE
Skyline Heights Project 4.H-2
Source: KWC Engineers, 2014. 0 800 Feet N

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Groundwater Basins FIGURE
Skyline Heights Project 4.H-3
Source: City of Corona, 2013. N
0 3 Miles

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sub-basin into the Temescal Wash. Groundwater levels throughout the basin typically respond rapidly to precipitation and recharge because of the high permeability and limited groundwater storage within this basin.

The City and EVMWD are the two major extractors of groundwater from the Coldwater sub-basin. The City currently operates three wells in the Coldwater sub-basin. Future production from the Coldwater sub-basin is projected to remain static through the year 2030.
(c) Temescal Basin
The Temescal sub-basin encompasses an area of approximately 26 square miles bound by the Santa Ana River, La Sierra Hills, El Sobrante Hills and the Santa Ana Mountains. Typical depths for the City’s wells in the Temescal sub-basin range from 180 to 480 feet. Groundwater quality of these wells typically does not meet the EPA and DPH maximum contaminant levels (MCLs) for nitrate (45 mg/L). The shallow basin groundwater typically has levels of nitrates ranging from 4.0 to 110 mg/L, some of which require treatment and/or blending to meet regulatory requirements.
(d) Groundwater Levels and Historical Trends
The groundwater sub-basins underlying the City have undergone significant changes since groundwater development began in the early 1900s. Since that time, the groundwater sub-basins have supported a variety of uses including extensive agricultural irrigation (especially citrus), industrial demand from mining and citrus packaging, and increasing urban use. Early agricultural activities in the sub-basins were supplemented by diversions of surface water imported into the basin. Agricultural reliance on groundwater increased through the 1940s and 1950s, peaking in the early 1960s but continuing into the 1970s.

Increasing urban use has replaced most of that early agricultural demand. Groundwater pumping has varied over time and by sub-basin. In the late 1940s, the total amount of groundwater pumping in the sub-basins was about 20,000 AFY. That amount increased to between 25,000 AFY and 32,000 AFY from the late 1950s to the mid-1970s. Total groundwater pumping decreased to below 20,000 AFY in the 1980s and early 1990s due to a decrease in agricultural irrigation, but has increased to about 25,000 AFY in recent years due to municipal pumping for urban uses. Most of the pumping occurred in the Temescal sub-basin.

Production in the Coldwater sub-basin has been less than 25 percent in recent years. Bedford sub-basin production is relatively minor and currently is only used to supplement the reclaimed water system when necessary. Total production exceeded 15,000 AFY in the Temescal sub-basin from 1951 to 1978 in support of agriculture irrigation with peak production occurring from 1959 through 1964. Production declined to below 10,000 AFY by 1979 and averaged about 9,419 AFY over the next 17 years (1979-1996). During this time, agricultural pumping had significantly declined, but municipal pumping had not yet increased. Since 2002, pumping has exceeded 20,000 AFY for the first time since the 1960s peak irrigation totals.

Total production in the Coldwater sub-basin typically ranges from less than 3,000 AFY to more than 10,000 AFY. Since 1980, production has averaged 7,018 AFY. Production from Bedford sub-basin is significantly less than in Temescal or Coldwater sub-basins. Since 1947, Bedford sub-basin production has ranged from 373 AFY to 4,658 AFY and has declined slightly over time with decreasing agriculture land use. The City has not supplied its potable water system from the Bedford sub-basin since 2000. The City has two non-potable

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wells which supplement the reclaimed water system from the Bedford sub-basin, but currently does not rely upon these for continuous use.
(e) Sources of Recharge and Discharge
The Temescal sub-basin receives runoff and recharge from almost 14,000 acres of uplands in the adjacent Santa Ana Mountains. Watersheds contributing runoff from the east are almost as large, but contribute less runoff because of lower elevations and corresponding precipitation.

Temescal Wash is lined through most of the Corona city limits. The only unlined portion of the wash in the Temescal sub-basin is the 1.5-mile area where the wash emerges from Temescal Canyon. This area is characterized by high groundwater, likely the result of infiltration of stream flow and relatively fine-grained surficial deposits. Other than limited infiltration in this narrow section of the sub-basin, Temescal Wash does not contribute significant natural recharge to the Temescal sub-basin. However, the City operates three water reclamation facilities (WRFs), two of which provide percolation to groundwater in the Temescal subbasin via wastewater discharge ponds.

Volume typically ranges between 4,000 and 10,000 AFY. Watersheds contributing runoff to the Coldwater sub-basin and Bedford sub-basin cover 9,525 acres and 11,858 acres, respectively, more than three times the area of the sub-basin. Although the watershed contributing runoff to the Bedford sub-basin is more than 2,000 acres larger than the Coldwater watershed, the Coldwater sub-basin receives more runoff due to the higher watershed elevations.
(4) Floodplains
The National Flood Insurance Act (1968) established the National Flood Insurance Program, which is based on the minimal requirements for flood plain management and is designed to minimize flood damage within Special Flood Hazard Areas. The Federal Emergency Management Agency (FEMA) is the agency that administrates the National Flood Insurance Program. Special Flood Hazard Areas (SFHAs) are defined as areas that have a one-percent chance of flooding within a given year, also referred to as the 100-year flood.

Flood Insurance Rate Maps (FIRMs) were developed to identify areas of flood hazards within a community.

According to the FIRM catalog, the FIRM produced by FEMA that cover the project area are Map Nos. 06065C1351G and 06065C1353G.2 As illustrated on the FIRM, the project site is located outside the FIRM study limits and currently within an unmapped Zone X area. b. Regulatory Framework
(1) Federal
(a) Clean Water Act
In 1972, President Nixon signed the Federal Water Pollution Control Act (now known as the Clean Water Act) into law (33 U.S.C. § 1251 et seq.) for purposes of restoring and maintaining the chemical, physical, and biological integrity of the nations’ waters by preventing point and nonpoint pollution sources. More specifically, the Act introduced the National Pollutant Discharge Elimination System (NPDES) permits for the 2 Both maps were revised on August 28, 2008.

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discharge of pollutants to “Waters of the U.S.”3from any point source.4In 1987, the Clean Water Act was amended to require that the U.S. Environmental Protection Agency (USEPA) establish regulations for permitting municipal and industrial storm water discharges under the NPDES permit program. Final regulations regarding storm water discharges were issued on November 16, 1990, and require that municipal separate storm sewer system (MS4) discharges and industrial (including construction) storm water discharges to surface waters be regulated by an NPDES permit.

The Clean Water Act requires states to adopt water quality standards for receiving water bodies and to have those standards approved by the USEPA. Water quality standards consist of designated beneficial uses for a particular receiving water body (e.g., wildlife habitat, agricultural supply, fishing), along with the water quality criteria necessary to support those uses. Water quality criteria are prescribed concentrations or levels of constituents (such as lead, suspended sediment, and fecal coliform bacteria) or narrative statements that represent the quality of water that support a particular use. Because the State of California was unable to develop these standards for priority toxic pollutants, the USEPA promulgated the California Toxics Rule in 1992 (40 Code of Federal Regulations [CFR] 131.38), which fills this gap. As a separate Rule, the California Toxics Rule is discussed further below under State regulations.

When water quality issues compromise the designated beneficial uses of a particular receiving water body, Section 303(d) of the Clean Water Act requires the identification and listing of that water body as “impaired”.

Once a water body has been deemed impaired, a Total Maximum Daily Load (TMDL) must be developed for the impairing pollutant(s). A TMDL is an estimate of the total load of pollutants from point, non-point, and natural sources that a water body may receive without exceeding applicable water quality standards (plus a “margin of safety”). Once established, the TMDL allocates the loads among the water body’s current and future pollutant sources.

Section 404 of the Clean Water Act is a program administered by the U.S. Army Corps of Engineers (USACE) that regulates the discharge of dredged and fill material into “Waters of the U.S.”, including wetlands.

Activities that affect “Waters of the U.S.” that are regulated under this program include fills for development (including physical alterations to drainages to accommodate storm drainage, stabilization, and flood-control improvements); water resource projects (such as dams and levees); infrastructure development (such as highways and airports); and conversion of wetlands to uplands for farming and forestry. The USEPA and the USACE have issued Section 404(b)(1) Guidelines (40 CFR 230) that regulate dredge and fill activities, including water quality aspects of such activities.

Section 401 of the Clean Water Act requires that any person applying for a federal permit or license that may result in a discharge of pollutants into “Waters of the U.S.” must obtain a State water quality certification ensuring that the activity complies with all applicable water quality standards, limitations, and restrictions.

Section 404 permits and authorizations are subject to a Section 401 certification by the local Regional Water Quality Control Board (RWQCB).
3 “Waters of the U.S.” include all waters that have, are, or may be used in interstate or foreign commerce (including sightseeing or hunting), including all waters subject to the ebb and flow of the tide and all interstate waters including interstate wetlands (33 CFR 328.3). 4
Point sources are discrete water conveyances such as pipes or man-made ditches.

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(b) Federal Antidegradation Policy
The federal Antidegradation Policy was released in 1968 and was included in the USEPA’s first Water Quality Standards Regulation. The Antidegradation Policy represents a three-tiered approach to maintaining and protecting water quality. First, all existing beneficial uses and levels of water quality necessary to protect those uses must be preserved and protected from degradation. Second, water quality must be protected in areas where the quality cannot support the propagation of fish, shellfish, and wildlife and recreation (“fishable/swimmable”). Third, the policy provides special protection of waters for which the ordinary water quality criteria are not sufficient. These waters are called “Outstanding National Resources Waters” and have been designated as unique or ecologically sensitive.

If an activity is going to be allowed to degrade or lower water quality (in situations where existing water quality is higher than that needed to maintain established beneficial uses), the Antidegradation Policy requires that proposed projects meet the criteria below:

The activity is necessary to accommodate important economic or social development in the area.

Water quality is adequate to protect and fully maintain existing beneficial uses. (c) National Flood Insurance Act
The National Flood Insurance Act of 1968 (42 U.S.C. 4001, et. Seq.) established the National Flood Insurance Program, which is based on the minimal requirements for floodplain management and is designed to minimize flood damage within Special Flood Hazard Areas. FEMA is the agency that administers the National Flood Insurance Program. Special Flood Hazard Areas (SFHA) are defined as areas that have a one-percent chance of flooding within a given year, also referred to as the 100-year flood. Flood Insurance Rate Maps were developed to identify areas of flood hazards within a community. (2) State
(a) Porter-Cologne Water Quality Act
California’s Porter-Cologne Water Quality Control Act of 1970 (Water Code § 13000 et seq.) (Porter-Cologne Act) grants the State Water Resource Control Board (SWRCB) and the nine regional boards (RWQCBs) power to protect surface water and groundwater quality and is the primary vehicle for implementing California’s responsibilities under the federal Clean Water Act. The Porter-Cologne Act grants the SWRCB and the RWQCBs authority and responsibility to adopt plans and policies, to regulate discharges of waste to surface and groundwater, to regulate waste disposal sites, and to require cleanup of discharges of hazardous materials and other pollutants. The Porter-Cologne Act also establishes reporting requirements for unintended discharges of any hazardous substance, sewage, or oil or petroleum product.

Each RWQCB must formulate and adopt a Water Quality Control Plan (Basin Plan) for its region. The Basin Plan must conform to the policies set forth in the Porter-Cologne Act and established by the SWRCB in its State Water Policy. The Basin Plan establishes beneficial uses for surface and groundwater in the region, and sets forth narrative and numeric water quality standards to protect those beneficial uses. The Porter- Cologne Act also states that an RWQCB may include water discharge prohibitions applicable to particular conditions, areas, or types of waste within its regional plan. For this project, the applicable RWQCB is the Santa Ana Board (Region 8).

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(b) California Toxics Rule
The California Toxics Rule (40 CFR 131.38) is a USEPA-issued federal regulation that provides water quality criteria for potentially toxic constituents in California surface waters with designated uses related to human health or aquatic life. The rule fills a gap in California water quality standards that was created in 1994 when a State court overturned the State’s water quality control plans containing water quality criteria for priority toxic pollutants. These federal criteria are legally applicable in the State of California for inland surface waters, enclosed bays, and estuaries for all purposes and programs under the Clean Water Act.

The California Toxics Rule establishes two types of aquatic life criteria: (1) acute criteria represent the highest concentration of a pollutant to which aquatic life can be exposed for a short period of time5 without harmful effects and (2) chronic criteria equal the highest concentration to which aquatic life can be exposed for an extended period of time (four days) without deleterious effects. Due to the intermittent nature of storm water runoff (especially in southern California), the acute criteria are considered to be more applicable to storm water conditions than chronic criteria. (c) State Antidegradation Policy
State Water Board Resolution No. 68-16 (“Statement of Policy with Respect to Maintaining the High Quality of Waters of the State”, also known as the “Anti-degradation Policy”) restricts degradation of surface water and groundwater. In particular, Resolution 68-16 protects water bodies where existing quality is higher than necessary for the protection of beneficial uses. Under Resolution 68-16, whenever the existing quality of water is better than the quality established in policies, such existing high quality will be maintained until it has been demonstrated to the state that any change would be consistent with maximum benefit to the people of the State, will not unreasonably affect present and anticipated beneficial use of such water and will not result in water quality that is less than that prescribed in the policies. Any activity that produces or may produce a waste or increased volume or concentration of waste and which discharges or proposes to discharge to existing high quality waters will be required to meet waste discharge requirements that would result in the best practicable treatment or control of the discharge necessary to assure that (a) a pollution or nuisance will not occur and (b) the highest water quality consistent with the maximum benefit to the people of the State will be maintained.
(d) National Pollutant Discharge Elimination System Permit The NPDES permit program is administered in the State of California by the RWQCBs, and was first established under the authority of the Clean Water Act to control water pollution by regulating point and non-point sources that discharge pollutants into “Waters of the U.S.”. If discharges from industrial, municipal, and other facilities go directly to surface waters, those project applicants must obtain permits. An individual NPDES permit is specifically tailored to a facility. A general NPDES permit covers multiple facilities within a specific activity category such as construction activities. A general permit applies the same or similar conditions to all dischargers covered under the general permit. 5 The rule does not specify timeframe for “acute”. Standard practice would likely imply that any condition that is permanent or semipermanent is chronic—all else would be short-term.

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(i) General Construction Permit
The SWRCB has issued a statewide general NPDES Permit and Waste Discharge Requirements (WDRs) for storm water discharges from construction sites. Under this General Construction Permit, discharges of storm water from construction sites with a disturbed area of one or more acres are required to either obtain individual NPDES permits for storm water discharges or be covered by the General Construction Permit.

Each applicant under the General Construction Permit must file a Notice of Intent (NOI) with the RWQCB and ensure that a Storm Water Pollution Prevention Plan (SWPPP) is prepared prior to grading. Terms of the SWPPP must be implemented during construction. The primary objective of the SWPPP is to identify Best Management Practices (BMPs) to reduce or eliminate pollutants in storm water discharges and authorized non-storm water discharges from the site during construction.

In 1999, the SWRCB issued and subsequently amended the General Construction Storm Water Permit (Water Quality Order 99-08-DWQ), which governs discharges from construction sites that disturb one acre or more of surface area. Again, on September 2, 2009, the SWRCB adopted a General Construction Permit that (Water Quality Order 2009-0009-DWQ) substantially altered the approach taken to regulate construction discharges through (1) requiring the determination of risk levels posed by a project’s construction discharges to water quality and (2) establishing numerical water quality thresholds that trigger permit violations. These permit regulations took effect on July 1, 2010, but were challenged. Subsequent to the legal challenge, the SWRCB adopted an order 2010 and then another updated permit on July 17, 2012 (WQO-2012-0006-DWQ/NPDES CAS000002).
(ii) Municipal Storm Water Permitting (MS4 Permit)
The State’s Municipal Storm Water Permitting Program regulates storm water discharges from MS4s. MS4 Permits were issued in two phases. Phase I was initiated in 1990, under which the RWQCBs adopted NPDES storm water permits for medium (serving between 100,000 and 250,000 people) and large (serving more than 250,000 people) municipalities. As part of Phase II, the SWRCB adopted a General Permit for small MS4s (serving less than 100,000 people) and non-traditional small MS4s including governmental facilities such as military bases, public campuses, and prison and hospital complexes (WQ Order No. 2003-0005- DWQ).
(e) Groundwater Management
The Groundwater Management Act (Water Code §§ 10750-10755.4) was first introduced in 1992 as Assembly Bill 3030. It has since been amended by SB 1938 in 2002 and AB 359 in 2011. Generally, the Groundwater Management Act provides a systematic procedure for local agencies to develop Groundwater Management Plans (GMPs). The 2011 amendments to the Act require public agencies to prepare and implement GWPs that focus on identifying groundwater recharge areas.

In September 2014, Governor Brown signed a three-bill legislative package (AB 1739, SB 1168, and SB 1319) into law, collectively referred to as the Sustainable Groundwater Management Act (SGMA). The SGMA provides a framework for sustainable management of ground water supplies by local authorities, with a limited role for state intervention if necessary to protect the groundwater resource. The SGMA requires the formation of local groundwater sustainability agencies (GSAs) that must assess conditions in their local water basins and adopt locally-based management plans. Once identified, the GSAs have the authority to require registration of groundwater wells, measure and manage extractions, require reports and assess fees,

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request revisions of basin boundaries, including establishing new sub-basins. GSAs responsible for high- and medium-priority basins must adopt groundwater sustainability plans within five to seven years, depending on whether the basin is in critical overdraft. Agencies may adopt a single plan covering an entire basin or combine a number of plans created by multiple agencies. Preparation of groundwater sustainability plans is exempt from CEQA. Plans must include a physical description of the basin, including groundwater levels, groundwater quality, subsidence, information on groundwater-surface water interaction, data on historical and projected water demands and supplies, monitoring and management provisions, and a description of how the plan will affect other plans, including city and county general plans. Plans will be evaluated every five years.

The Department of Water Resources (DWR) also has duties under the SGMA, including: designating basins as high, medium, low or very low priority (January 1, 2015); adopting regulations for boundary adjustments (January 1, 2016); adopting regulations for evaluating the adequacy of GSPs and GSA coordination agreements (June 1, 2016); publishing a report estimating water available for groundwater replenishment (December 31, 2016); and publishing groundwater sustainability BMPs (January 1, 2017). The project site is located in the Upper Santa Ana Valley Groundwater Basin. This groundwater basin has been designated as a medium priority basin by the DWR.6 The GSA for the Upper Santa Ana Valley Groundwater Basin is the Western Municipal Water District (WMWD).
(3) Regional
(a) Basin Plan
As indicated above, the project site is located within the Santa Ana RWQCB’s jurisdiction. The Water Quality Control Plan for the Santa Ana River Basin (Santa Ana River Basin Plan) designates beneficial uses and water quality objectives for water bodies in the region. Narrative water quality criteria contained in the Basin Plan cover a range of both organic and inorganic constituents for both surface and groundwater; the Santa Ana River Basin Plan prohibits the degradation of water quality in a manner that would adversely impact a water body’s designated beneficial uses. The Basin Plan incorporates applicable portions of a number of national and statewide water quality plans and policies, including the California Water Code and the Clean Water Act.

For certain designated surface water bodies and groundwater management zones, specific numeric water quality objectives have been established for a range of constituents. These water quality criteria apply within receiving waters and do not apply directly to runoff. Within the project area, there are no water bodies (or groundwater management zones) for which numeric objectives have been established. However, there are water quality objectives that apply by the tributary rule. The Santa Ana RWQCB defines a beneficial use for surface waters in the region as “one of the various ways that water can be used for the benefit of people and/or wildlife.” Beneficial uses, along with specific water quality criteria, comprise water quality standards for surface (navigable) waters as defined by Section 303 of the federal Clean Water Act (33 United States Code [USC] §1313). Under the Porter-Cologne Water Quality Control Act (California Water Code §§13050 et seq.), these concepts are separately considered as beneficial uses and water quality objectives. Beneficial uses and water quality objectives are to be established for all “Waters of the State”, both surface and subsurface groundwater. 6 California Department of Water Resources Website, CASGEM Groundwater Basin Prioritization, Casgem Basin Summary, Upper Santa Ana Valley, dated May 30, 2014, http://www.water.ca.gov/groundwater/casgem/pdfs/basin_prioritization/SRO%20206.pdf, accessed June 2015.

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There are 23 beneficial uses defined statewide; of these, 19 are recognized within the Santa Ana Region. One additional beneficial use—Limited Warm Freshwater Habitat—is unique to the Santa Ana Region, bringing the total number of beneficial uses recognized in the Santa Ana Region to 20. The 20 beneficial uses include the following: MUN: municipal and domestic supply; AGR: agricultural supply; IND: industrial service supply; PROC: industrial process supply; GWR: Groundwater Recharge; NAV: navigation; POW: hydropower generation; REC1: water contact recreation; REC2: noncontact water recreation; COMM: commercial and sport fishing; WARM: warm freshwater habitat; LWARM: limited warm freshwater habitat; COLD: cold freshwater habitat; BIOL: biological significance; WILD: wildlife habitat; RARE: rare, threatened, or endangered species; SPWN: spawning, reproduction, and development; MAR: marine habitat; SHEL: shellfish harvesting; EST: estuarine habitat. The beneficial uses identified for Temescal Creek (Reach 1) and the Santa Ana River (Reach 3) are listed in the Existing Conditions section above. (b) General Waste Discharge Requirements for Discharges to Surface Waters Which Pose an Insignificant (de minimus) Threat to Water Quality (Dewatering Permit) The Santa Ana RWQCB issued Order No. R8-2003-0061 and Amendments to NPDES Permit No. CAG998001 (Dewatering Permit) to regulate the discharge of dewatering wastes from construction, subterranean seepage, and other similar types of discharges considered to have “de minimus” impacts on water quality within the jurisdictions covered by the permit. This permit was updated in March 2009 (by Order No. R8- 2009-0003, NPDES NP. CAG998001) and applies to projects located within the jurisdiction of the Santa Ana RWQCB, including the City of Corona. To obtain coverage under this permit, an applicant must submit a Notice of Intent (NOI) and data establishing the chemical characteristics of the dewatering discharge. A standard monitoring and reporting program is included as part of the permit. For dewatering activities that are not covered by the General Permit, Waste Discharge Requirements, and an individual NPDES permit must be obtained from the applicable RWQCB.
(c) Riverside County Water Quality Management Plan (WQMP) Guidance Document This document is intended to provide guidelines for project-specific post-construction BMPs and for regional and sub-regional source control BMPs and structural BMPs to address management of urban runoff quantity and quality to protect receiving waters. The document identifies the BMPs, including design criteria for treatment control BMPs that may be applicable when considering any map or permit for which discretionary approval is sought. New development and significant redevelopment projects submitted since December 31, 2004, are required to submit a project-specific WQMP prior to the first discretionary project approval or permit. Project applicants may be required to submit a preliminary project-specific WQMP for discretionary project approval (such as land use entitlement). Project applicants are required to submit for review and approval a final project-specific WQMP that is in substantial conformance with the preliminary project- specific WQMP prior to the issuance of any building or grading permit. The new MS4 permit adopted on January 29, 2010 and amended on June 7, 2013, identifies new requirements for approval of WQMPs by local agencies.
(4) Local
(a) City of Corona Groundwater Management Plan
The City of Corona developed a Groundwater Management Plan in 2008 (GWMP) to support the management of a reliable and sustainable groundwater resource for the City. The GWMP follows the guidelines set forth by AB 3030, the California Department of Water Resources Groundwater Management

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Act, which provides a systematic procedure for an existing local agency to develop a groundwater management plan. The GWMP allows the City of Corona to address issues of groundwater recharge and storage in order to effectively manage the local sub-basins and the City’s water supply. The GWMP area covers three groundwater sub-basins within the City’s water service area and sphere of influence. These three sub-basins, including the Temescal, Coldwater, and Bedford sub-basins, are located in western Riverside County in the Santa Ana River Watershed. Collectively, the analysis of these basins is used to describe the “state of the basins” with respect to groundwater use, water levels, quality, and storage. The GWMP identified the following objectives for the management and operations of the relevant basins:

Operate the groundwater basin in a sustainable manner for beneficial uses; Increase the reliability of water supply for basin users; Prevent substantial water level declines in Channel Aquifer; Protect groundwater quality in unconfined aquifers;
Maintain required outflow at Prado Dam; and
Monitor groundwater levels, quality, and storage.
(b) City of Corona General Plan
The City of Corona General Plan contains policies relevant to hydrology, drainage, groundwater resources, and surface water quality. Specifically, the relevant policies of the Infrastructure and Utilities Element and the Environmental Resources Element of the General Plan address impacts of development on the City’s storm drain system, surface water quality, flooding hazards, and City water supply sources including groundwater basins. The proposed project’s consistency with the applicable policies of the General Plan is discussed below under Consistency with Regulatory Framework. (c) City of Corona Municipal Code
The City of Corona Municipal Code (CMC) contains various requirements relative to stormwater management, including minimizing flooding, construction of and connection to City storm drains, and control pollutants in storm water runoff from development sites. The relevant regulations contained in the CMC are discussed individually below.
(i) Floodplain Management
Title 18, Floodplain Management, of the CMC is intended to protect people and property within the City from flooding and flood-related hazards. The purpose of CMC Title 18 is to promote the public health, safety and general welfare and to minimize public and private losses due to flood conditions in specific areas by provisions designed to:

1. Protect human life and health;

2. Minimize the expenditure of public funds for costly flood control projects;

3. Minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;

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4. Minimize prolonged business interruptions;

5. Minimize damage to public facilities and utilities such as water and gas mains; electric, telephone and sewer lines; streets and bridges located in areas of special flood hazard;

6. Help maintain a stable tax base by providing for the use and development of areas of special flood hazard so as to minimize future flood blight areas;

7. Ensure that potential buyers are notified that property is in an area of special flood hazard; and

8. Assure that those who occupy the areas of special flood hazard assume responsibility for their actions.
(ii) Storm Drains
Chapter 13.16, Storm Drains, of the CMC addresses the construction of and connection to the City’s storm drain system. Chapter 13.16 regulates diversions of stormwater flows from existing storm drains, prohibits off-site flow of irrigation runoff or other wastewater, and dictates the size and location of catch basins. (iii) Storm Water Management and Discharge Controls
Chapter 13.27, Storm Water Management and Discharge Controls, of the CMC regulates stormwater quality and discharges to the storm drain system. The purpose of Chapter 13.27 is to protect the future health, safety and general welfare of the City’s citizens by:

1. Reducing pollutants in storm water discharges to the maximum extent practicable;

2. Regulating illicit connections and discharges to the storm drain system; and

3. Regulating non-storm water discharges to the storm drain system.

The enforcement of Chapter 13.27 is intended to protect and enhance the water quality of City watercourses, water bodies, groundwater and wetlands in a manner consistent with the Federal Clean Water Act (33 USC 1342 et seq.).

2. ENVIRONMENTAL IMPACTS
a. Methodology
A Hydrology Study was prepared by KWC Engineers for the project. The purpose of the study was to hydrologically model the project site’s on-site and off-site tributary watersheds and to determine the existing and proposed peak runoffs and volumes in order to analyze stormwater measures. The hydrologic analysis was prepared using the Rational Method as specified in the Riverside County Hydrology Manual.

The Hydrology Study also approximates the peak storage required to mitigate any increased runoff due to development for the most critical storm and duration event using the Unit Hydrograph Method in accordance with the Riverside County Rational Method. The Hydrology Study also contains a Debris Basin Analysis for the undeveloped tributary watershed areas upstream of the site. The analysis was conducted using the U.S. Army Corps of Engineers Los Angeles District Method for Prediction of Debris Yield

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Water quality impacts were assessed by considering the types of pollutants and/or effects on water quality likely to be associated with construction and operation of the project, project design features to treat contaminants, and expected contaminant flows with project implementation. Project consistency with relevant regulatory permits/requirements, including BMPs and applicable plans, was evaluated to demonstrate how compliance would ensure that the project would not significantly degrade existing water quality.

Flooding impacts were addressed in consideration of applicable safety policies of the City’s General Plan Safety Element and the design requirements within the City’s Municipal Code. A determination was made as to whether such policies, procedures, and regulatory requirements would adequately address potential flooding hazards on the site.

Groundwater impacts were evaluated by estimating the domestic water demands of the proposed project, a portion of which is provided by local groundwater basins, relative to the safe yield of affected aquifers. b. Thresholds of Significance
Appendix G of the CEQA Guidelines provides a checklist of questions to assist in determining whether a proposed project would have a significant impact related to various environmental issues including hydrology and water quality. Based on the following issue areas identified in Appendix G of the CEQA Guidelines, a significant impact to hydrology and water quality would occur if the project would result:

Threshold 1: Violate any water quality standards or waste discharge requirements (refer to Impact Statement 4.H-1 below);
Threshold 2: Substantially deplete groundwater supplies or interfere substantially with groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of the local groundwater table level (e.g., the production rate of pre-existing nearby wells would drop to a level which would not support existing land uses or planned uses for which permits have been granted) (refer to Impact Statement 4.H-2 below);
Threshold 3: Substantially alter the existing drainage pattern of the site or area, including through alteration of the course of a stream or river, in a manner which would result in substantial erosion or siltation on- or off-site (refer to Impact Statement 4.H-1 below); Threshold 4: Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, or substantially increase the rate or amount of surface runoff in a manner that would result in flooding on- or off-site (refer to Impact Statement 4.H-3 below);
Threshold 5: Create or contribute runoff water which would exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff (refer to Impact Statement 4.H-3 below);
Threshold 6: Otherwise substantially degrade water quality (refer to Impact Statement 4.H-1 below);

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Threshold 7: Place housing within a 100-year flood plain as mapped on federal Flood Hazard Boundary or Flood Insurance Rate Maps or other flood hazard delineation maps (refer to Impact Statement 4.H-4 below);
Threshold 8: Place within a 100-year flood plain structures which would impede or redirect flood flows (refer to Impact Statement 4.H-4 below);
Threshold 9: Expose people or structures to a significant risk of loss, injury or death involving flooding, including flooding as a result of the failure of a levee or dam (refer to Impact Statement 4.H-4 below);
Threshold 10: Inundation by seiche, tsunami, or mudflow (refer to Impact Statement 4.H-4 below); or Threshold 11: Comply with any applicable plan, policy, or regulation of an agency with jurisdiction over the project (including, but not limited to the general plan and municipal code) adopted for the purpose of avoiding or mitigating a physical impact associated with hydrology and water quality (refer to Impact Statement 4.H-5 below).
c. Project Design Features
A Water Quality Management Plan (WQMP) has been prepared for the proposed project in compliance with the requirements of the County and City NPDES Stormwater Program requirements for stormwater management. The following Project Design Features (PDFs), which include various Best Management Practices (BMPs), would be incorporated into the project:

PDF HYD-1 The project will consist of 292 single family residential lots with a minimum lot size of 7,200 square feet on 270.9 acres and the proposed development pattern will preserve approximately 96 acres of this area as natural open space areas in which no grading would occur and thus the existing vegetation and drainage patterns will be protected.

PDF HYD-2 Approximately 21.38 acres of the site will be acquired by the RCTC/City of Corona for the construction of the Westerly Extension of Foothill Parkway and Mabey Canyon Debris Basin.

Drainage and water quality for these areas will be coordinated with the development plans for the project.

PDF HYD-3 The Applicant will seek coverage under the Statewide General Construction Activity NPDES Permit. In accordance with the requirements of the permit, the Applicant will implement a Storm Water Pollution Prevention Plan (SWPPP), which will specify BMPs and erosion control measures to be used during construction that will address both runoff conditions and potential pollution. BMPs could include, but not be limited to, such measures as water bars, silt fences, staked straw bales, wind erosion control, stabilized construction entrances and exits, and street sweeping and vacuuming.

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PDF HYD-4 The project will install a system of flow-by basins, detention basins, and storm drain piping so that off-site flows will by-pass the site and will not be co-mingled with development runoff which will be treated at the designated BMP treatment areas.

PDF HYD-5 The site is divided into five tributary areas, or Drainage Management Areas (DMAs), which are designated as Basins A, B, C, D, and E. The Applicant will install biotreatment BMPs (i.e., extended detention basins) within each DMA as approved by the City Department of Public Works.

PDF HYD-6 The onsite storm drain system will be owned by the City of Corona and maintained by the Public Works Department, except for the WQMP basins and pipes leading to and from the WQMP basins, which will be maintained by the Homeowners’ Association. An Operation and Maintenance Plan and Documentation of Finance, Maintenance and Recording Mechanisms (O&M) will be provided with the Final WQMP and will agreed to by the Applicant and the City of Corona to ensure perpetual maintenance of the BMPs.

PDF HYD-7 Project landscaping will comply with applicable landscaping requirements specified in Chapter 13.26, Water Conservation Plan of the CMC. The proposed landscape design will consist of moderately drought-tolerant sustainable plantings and trees and the irrigation system will utilize weather-based, water-conserving irrigation technology and management.

Reclaimed water will be used for non-potable water demands. d. Analysis of Project Impacts
(1) Water Quality
Threshold 1: Would the project violate any water quality standards or waste discharge requirements? Threshold 3: Substantially alter the existing drainage pattern of the site or area, including through alteration of the course of a stream or river, in a manner which would result in substantial erosion or siltation on- or off-site?
Threshold 6: Would the project otherwise substantially degrade water quality? Impact 4.H-1 Construction and operation of the project would comply with all applicable regulatory requirements regarding water quality. Compliance with applicable regulatory requirements and implementation of the project design features, including BMPs as part of the project’s WQMP, would ensure that construction and operational water quality impacts would be less than significant.
(a) Construction
(i) Water Contaminants
Construction activities would include the use of heavy equipment and construction-related chemicals, such as fuels, oils, grease, solvents and paints that would be stored in limited quantities on-site. In the absence of

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proper controls, these construction activities could result in accidental spills or disposal of potentially harmful materials used during construction that could wash into and pollute surface waters or groundwater.

However, the project would be subject to existing regulations associated with the protection of water quality.

The applicable WDRs, the NPDES Construction General Permit for construction activities, and SWPPP (with associated BMPs) are considered protective of water quality during construction and would, therefore, prevent a substantial violation of water quality standards and minimize the potential for contributing additional sources of polluted runoff during construction of the project. These existing regulations, programs, and policies would ensure that the potential for discharge of polluted stormwater from construction sites to affect beneficial uses of receiving waters and water quality standards, where applicable, would not be substantial. Compliance with regulatory requirements would ensure that construction of the project would not result in the exceedance of water quality standards during construction, including TMDL limits applicable to Temescal Creek and Santa Ana River. Therefore, construction-related impacts would be less than significant.
(ii) Erosion and Sedimentation
During construction, the project site would be subject to ground-disturbing activities (e.g., excavation and grading, foundation and infrastructure construction, the installation of utilities). These activities would expose soils for a limited time, allowing for possible erosion and sediments to enter into runoff.

Although project development has the potential to result in the erosion of soils, this potential would be reduced through standard erosion controls imposed during site preparation and grading activities. For instance, the project would be subject to existing regulations associated with the protection of water quality.

Specifically, construction activities would be carried out in accordance with the requirements of the General Construction NPDES Permit. In accordance with the requirements of the permit, the Project would implement a SWPPP, which as indicated in PDF HYD-3 would specify BMPs and erosion control measures to be used during construction that would address both runoff conditions and potential pollution. BMPs could include, but not be limited to, the use of or implementation of water bars, silt fences, staked straw bales, wind erosion control, stabilized construction entrances and exits, and street sweeping and vacuuming. Lastly, the project would implement standard erosion control construction practices as required by the City to reduce the potential for erosion during construction. With the implementation of standard erosion control measures, impacts with respect to erosion and sedimentation would be less than significant. (b) Operation
(i) Pollutant Discharges
Stormwater discharge is generated by rainfall that runs off the land and impervious surfaces such as paved streets, driveways, patios, and rooftops. Stormwater discharge may include pollutants of concern, which are those that are expected to be generated by the project and that could impact stormwater. During operation of the project, pollutants of concern within runoff may include, but are not limited to, bacterial indicators, metals, nutrients, pesticides, toxic organic compounds, sediments, trash and debris, and oil and grease.

These pollutants of concern are typical in hillside development and residential subdivisions. The project priority Pollutants of Concern are bacterial indicators and metals as these are the listed water quality impairments for the Temescal Creek and Santa Ana River.

December 2015 4.H. Hydrology and Water Quality
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PCR Services Corporation/SCH No. 2014021003 4.H-25
This runoff can flow directly into storm drains and continue through pipes until it is released, untreated, into Temescal Creek and the Santa Ana River. Untreated stormwater runoff degrades water quality in surface waters and groundwater and can affect drinking water, human health, and plant and animal habitats. The project’s design features, including operational BMPs, listed under the Project Design Features section above would be implemented in a manner consistent with applicable Municipal NPDES Permit and City WQMP requirements to ensure less than significant water quality impacts. The Preliminary WQMP has been prepared for the project in accordance with City of Corona WQMP requirements, which includes both source control and treatment control BMPs, as well as site design BMPs.

Based on the City’s WQMP requirements, retention BMPs must be designed to retain, on-site, (infiltrate, harvest and use, or evapotranspire) storm water runoff up to 85 percent average annual capture efficiency.

According to the Model WQMP, if it is not feasible to meet LID performance criteria through retention and/or biotreatment provided on-site or at a sub-regional/regional scale, then treatment control BMPs shall be provided on-site or off-site prior to discharge to waters of the US. Sizing of treatment control BMP(s) shall be based on either the unmet volume after claiming applicable water quality credits, if appropriate. The City of Corona may conduct verifications to assure that implementation and appropriate maintenance of structural and non-structural BMPs prescribed within the project WQMP is taking place at the project site.

The HOA would retain operations, inspections and maintenance records of these BMPs and they would be made available to the City upon request. All records would be maintained for at least five (5) years after the recorded inspection date for the lifetime of the project. (ii) Hydrologic Conditions of Concern
In addition to the direct introduction of pollutants to stormwater flows, impacts to water quality can also result from changes to the hydrologic regime including: (1) increased runoff volume and velocity; (2) reduced infiltration; (3) increased flow frequency, duration, and peaks; (4) faster time to reach peak flow; or (5) other water quality degradation. Under certain circumstances, changes could also result in the reduction in the amount of available sediment for transport (i.e., storm flows could fill this sediment-carrying capacity by eroding the downstream channel). These changes have the potential to permanently impact downstream channels and habitat integrity. A change to the hydrologic regime of a development project site would be considered a hydrologic condition of concern (HCOC) if the change would have a significant impact on downstream erosion compared to the pre-development condition or have significant impacts on stream habitat, alone or as part of a cumulative impact from development in the watershed. A project-specific WQMP must address the issue of HCOCs unless one of the following exceptions apply to the project:

HCOC Exemption 1: The Priority Development Project disturbs less than one acre. The Co- Permittee has the discretion to require a Project-Specific WQMP to address HCOCs on projects less than one acre on a case by case basis. The disturbed area calculation should include all disturbances associated with larger common plans of development.

HCOC Exemption 2: The volume and time of concentration of storm water runoff for the post- development condition is not significantly different from the pre-development condition for a 2-year return frequency storm (a difference of 5% or less is considered insignificant) using one of the following methods to calculate:
o Riverside County Hydrology Manual

4.H. Hydrology and Water Quality December 2015
City of Corona Skyline Heights Project
PCR Services Corporation/SCH No. 2014021003 4.H-26
o Technical Release 55 (TR-55): Urban Hydrology for Small Watersheds (NRCS 1986), or derivatives thereof, such as the Santa Barbara Urban Hydrograph Method o Other methods acceptable to the Co-Permittee
HCOC Exemption 3: All downstream conveyance channels to an adequate sump (for example, Prado Dam, Lake Elsinore, Canyon Lake, Santa Ana River, or other lake, reservoir or naturally erosion resistant feature) that will receive runoff from the project are engineered and regularly maintained to ensure design flow capacity; no sensitive stream habitat areas will be adversely affected; or are not identified on the Co-Permittees Hydromodification Sensitivity Maps.

The runoff from the proposed project site (WQMP Areas A, B, C, and E) would discharge directly to the City/County maintained MS4 Storm Drain System and the Mabey Canyon Debris Basin, which drains to the Santa Ana River Reach 3. These facilities have been identified by Riverside County Flood Control and Water Conservation District to be within a watershed not susceptible to HCOC according to the HCOC Applicability Map. As such, a portion of the proposed project would meet HCOC Exemption 3 above, and therefore, an analysis of HCOCs is not required for WQMP Areas A, B, C, and E.

However, the runoff from proposed WQMP drainage areas D1, D2, and D3 would not fall into HCOC Exemption 3 criteria, and therefore the project is required to mitigate the HCOC. As such, the project would include the installation of a series of privately maintained Detention Basins within the site to mitigate the HCOC requirements as well as the increase in runoff that would occur from the development of the site. The Hydrology Study indicates that for WQMP Area D1, D2, and D3, the on-site Detention Basin located upstream of the discharge point would mitigate the HCOC runoff and velocity for this drainage area. (iii) Conclusion
Compliance with applicable regulatory requirements, as well as implementation of the project design features and BMPs identified in the WQMP, would ensure that operation of the project would not adversely affect the receiving waters of Temescal Creek or the Santa Ana River, result in the violation of water quality standards, and minimize the potential for contributing sources of polluted runoff. Based on the above, water quality impacts would be less than significant.
(2) Groundwater Resources
Threshold 2: Would the project substantially deplete groundwater supplies or interfere substantially with groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of the local groundwater table level (e.g., the production rate of pre-existing nearby wells would drop to a level which would not support existing land uses or planned uses for which permits have been granted)?
Impact 4.H-2 The project would not substantially deplete groundwater supplies or interfere substantially with groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of the local groundwater table level. As such, impacts to groundwater resources would be less than significant.

December 2015 4.H. Hydrology and Water Quality
City of Corona Skyline Heights Project
PCR Services Corporation/SCH No. 2014021003 4.H-27
The project would result in the development of 292 single-family residences on the approximately 270.9- acre site within an undeveloped hillside area to the south/southwest of the Foothill Parkway Westerly Extension. Approximately 21.38 acres of the eastern portion of the site would be used as right-of-way for the construction of the Foothill Parkway Westerly Extension. Approximately 96 acres of the 270.9-acre project site would not be graded and thus would remain as natural open space. The proposed project would not involve any groundwater extraction or other activities that could result in direct withdrawal or depletion of groundwater supplies. As noted above, a portion of the City’s water supply is provided by groundwater from local aquifers, and as such the project would increase demands on the City’s groundwater basins. However, as discussed in Section 4.N, Utilities and Service Systems, of this Draft EIR, buildout of the project would not result in any adverse impacts to the City’s water supplies, including groundwater resources. The City is able to meet the water demands of the proposed project in normal, single dry, and multiple dry years through 2035. As the proposed project would not adversely affect groundwater resources and water demand would not exceed water supplies, impacts to groundwater resources would be less than significant. (3) Hydrology and Drainage
Threshold 4: Would the project substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, or substantially increase the rate or amount or surface runoff in a manner which would result in flooding on or off- site? Threshold 5: Would the project create or contribute runoff water which would exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff?
Impact 4.H-3 The project would be designed to maintain existing drainage patterns of the site and area. Post development runoff would be consistent with applicable regulatory requirements and the post- project site would not result in significant hydrology impacts downstream such that flooding or erosion would occur on- or off-site. Furthermore, the project would not create or contribute runoff water which would exceed the capacity of existing or planned stormwater drainage.

Overall, impacts regarding changes in drainage patterns and stormwater flows would be less than significant with mitigation. The project would result in an increase in runoff as a result of the development of an undeveloped hillside area. The project would add approximately 40 acres of impervious area in the form of streets, rooftops, driveways, and sidewalks. Runoff from rooftops would be designed to drain into pervious landscape areas within each residential lot prior to discharge onto streets or connection to the proposed on-site storm drain systems. The amount of impervious surfaces would represent about 15 percent of the site or about four percent of the total tributary area. Approximately 96 acres of the 270.9-acre project site would not be graded and would be set aside as natural open space. However, because the development of the site would introduce a greater percentage of impervious surfaces, the post-development flow volumes that would be generated on site would be higher than the pre-development flows without an adequate drainage system and a well-planned post-construction WQMP which would include addressing any hydrologic conditions of concern that could result from the proposed project.

4.H. Hydrology and Water Quality December 2015
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PCR Services Corporation/SCH No. 2014021003 4.H-28
As indicated above and as evaluated in the Hydrology Study, the project site is divided into four tributary areas, or Drainage Management Areas (DMAs), as shown in Figure 4.H-4, Proposed Site Hydrology, which are designated as Basins A, B, C, and D. Table 4.H-2, Comparison of Existing and Proposed Peak Flows, provides a comparison between the existing condition and proposed condition Rational Method 10 and 100 Year Hydrology results. Under existing conditions, as discussed above, the site has a total drainage area of approximately 419.7 acres and a total flow rate of 976.98 cfs in the 100-year event and 594.92 cfs in the 10- year event. As can be seen in Table 4.H-2, the proposed condition would generate approximately 996.8 cfs in the 100-year event and 614.2 in the 10-year event, which would be an increase of about 19.86 cfs in the 100- year event and 19.25 cfs in the 10-year event. While there would be an increase in the proposed condition, the proposed discharge from the site would be within three percent of the existing discharge. The difference in peak flow would be mitigated in the proposed detention basins. Area A would include the entire northern portion of the site; however, only a portion of Area A in the existing condition drains towards Mabey Canyon, which is the proposed outlet. Under the proposed condition a flow increase of 24.54 cfs in the 100-year event and 15.63 cfs in the 10-year event would result. The Hydrology Study indicates that the flow increase is inconsequential to the flow in Mabey Canyon and detention for Area A would not be required.7 The project would result in the installation of an on-site storm drain system that would be owned by the City of Corona and maintained by the City of Corona Public Works Department, except for the WQMP basins and pipes leading to and from the WQMP basins, which would be maintained by the HOA. The Hydrology Study provides preliminary estimated sizes and locations for the storm drain facilities, which would be refined in the design review and final engineering process. The system would be designed in accordance with City standards. Mainline pipe sizes would be based on the 100-year storm event. Catch basins and storm drain laterals would be placed at locations to keep the 10-year flow below the top of the curb and the 100-year flow below the right-of-way. The on-site street capacities would be sufficient to provide the level of protection required by Riverside County. Since the storm drain mainline pipes would be sized for the 100- year storm event, the street would contain local flows until catch basins intercept the 100-year flow. 7 Preliminary Drainage Report, KWC Engineers, January 21, 2013, page 7.

Table 4.H-2
Comparison of Existing and Proposed Peak Flows
Area
Existing
Q10 (cfs)
Proposed
Q10 (cfs)
Difference Q10
(Prop-Exist)
Existing
Q100 (cfs)
Proposed
Q100 (cfs)
Difference Q100
(Prop-Exist)
A 15.71 31.34 15.63 25.22 49.76 24.54
B 74.19 111.99 37.80 125.48 180.87 55.39
C 412.19 368.21 -43.98 675.81 600.73 -75.08
D 80.81 102.63 21.82 131.32 165.48 34.16
Total 594.92 614.17 19.25 976.98 996.84 19.86
Source: KWC Engineers, Preliminary Drainage Report, January 2014

Proposed Site Hydrology FIGURE
Skyline Heights Project 4.H-4
Source: KWC Engineers, 2014. 0 750 Feet N

4.H. Hydrology and Water Quality December 2015
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PCR Services Corporation/SCH No. 2014021003 4.H-30
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December 2015 4.H. Hydrology and Water Quality
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PCR Services Corporation/SCH No. 2014021003 4.H-31
The project proposes a detention basin for each drainage area. A combination WQMP and detention basin is proposed for drainage area A. However, for drainage areas A, B, C, and D separate WQMP and detention basins are proposed. More specifically, as illustrated in Figure 4.H-5, Preliminary WQMP Site Plan, the WQMP establishes five DMAs, which are designated as Basins A, B, C, D1, D2, D3, and E. Each DMA tributary area for the proposed project would drain into an extended detention basin, the locations of which are illustrated in Figure 4.H-5. Area A, which would have 45 lots, would drain towards the Mabey Canyon detention basin. Two extended detention basins would be located in the southern portion of Area A. Area B, a larger area would drain through a water quality basin and detention basin prior to entering a storm drain proposed as part of the Foothill Extension project which would outlet into the same canyon as in the existing conditions (into an engineered open space west of Cape Drive, into a concrete trapezoidal channel flowing towards Border Avenue). Area C, a smaller area would drain into an extension of the concrete channel constructed as part of the Foothill Parkway project. Upstream natural canyons would flow into debris basins and on-site flows would be conveyed via a storm drain pipe system into a water quality basin prior to discharging into the canyon downstream of the project grading limits. Storm drain pipes are proposed within the project site, per the project WQMP, to collect on-site development runoff which would be treated at strategically located WQMP basins within the project site.

As shown in Figure 4.H-6, Proposed Storm Drain Facilities, the proposed project would outlet at four (4) locations. Outlet Structure No. 1 and No. 2 would be located in the northern portion of the development, north of Mabey Canyon. Outlet Structure No. 3 would be located just west of the Foothill Parkway Extension and Outlet Structure No. 4 would be located in Area C of the subdivision. Area C would outlet into an existing canyon bottom; however, the remaining areas would connect directly to existing storm drains or future storm drain pipes that would be constructed as part of the Foothill Parkway Westerly Extension project. For Area C, a concrete impact basin energy dissipator and rip-rap pad would be designed as part of the final engineering for the project in accordance with City standards. The outlet velocity would be at or below the existing condition or to a non-erosive velocity. A mitigation measure, Mitigation Measure HYD-1, is recommended to ensure the implementation of the requirement.

In addition, four flow-by basins would be installed on the site on the westernmost portion of the subdivision in the central and southern portion of the site. In addition, the Hydrology Study includes a debris basin analysis, which determines the debris yield for the undeveloped tributary watershed areas upstream of the proposed project. Based on the debris bulking analysis, each on-site debris basin has been sized to accommodate the anticipated flows within each respective tributary area. Thus, the system of flow-by basins, detention basins, and storm drain piping would ensure that off-site flows would by-pass the site and would not be co-mingled with development runoff which needs to be treated at the proposed designated BMP treatment areas.

As such, despite the increase in runoff that would result from the development of the site, with the proposed drainage system the pre- and post-developed conditions would be met at the outlet of the project. The post- project site would not result in significant hydrology impacts such that flooding would occur on- or off-site.

In addition, the project would not create or contribute runoff water which would exceed the capacity of existing or planned stormwater drainage. As such, impacts regarding changes in drainage patterns and stormwater flows would be less than significant with implementation of applicable mitigation.

4.H. Hydrology and Water Quality December 2015
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PCR Services Corporation/SCH No. 2014021003 4.H-32
(4) Flood Hazards
Threshold 7: Place housing within a 100-year flood plain as mapped on federal Flood Hazard Boundary or Flood Insurance Rate Maps or other flood hazard delineation maps? Threshold 8: Place within a 100-year flood plain structures which would impede or redirect flood flows? Threshold 9: Expose people or structures to a significant risk of loss, injury or death involving flooding, including flooding as a result of the failure of a levee or dam? Threshold 10:Inundation by seiche, tsunami, or mudflow? Impact 4.H-4 Implementation of the project would not expose people and structures to flood hazards since residential pad elevation would be approximately 25 feet higher than the streambed flowline. In addition, the site is not located within an area subject to inundation from a levee or dam failure.

Given the site location impacts from seiches, mudflows, or tsunamis would not occur. Therefore, impacts related to flooding are considered less than significant.

As indicated above, the project site is located outside the FIRM study limits and currently within an unmapped Zone X area. The Project would require a Conditional Letter of Map Revision (CLOMR) through FEMA. Prior to the issuance of the Certificate of Occupancy, the Applicant shall secure FEMA’s approval for the Letter of Map Revision (LOMR) which may impact the Mabey Canyon channel. The proposed Foothill Parkway Westerly Extension project proposes to expand regional storm water facilities, including the Mabey Canyon Debris Basin, prior to the construction of the proposed Skyline Heights project. The Skyline Heights project would include grading of the area along the northerly channel bank of Mabey Canyon streambed to create residential lots adjacent to the channel. The lowest proposed residential pad elevation would be approximately 25 feet higher than the streambed flowline. Given the existing width and configuration of the Mabey Canyon drainage channel, and the elevation of the proposed residential pads throughout the site, the potential for flooding in the development would not be likely to occur.

As shown in Figure 5.2-1 of the City’s General Plan Technical Background Report, the project site is not located within an area subject to inundation from failure of a levee or dam. Therefore, no adverse impacts related to flooding as a result of the failure of a levee or dam would occur. Lastly, the project site is located approximately 24 miles inland from the ocean and no other large bodies of water exist in proximity to the project site. Thus, there would be no potential for flooding from seiche effects or tsunamis, or potential mudflow hazards, associated with a seismic event. No impacts would occur in this regard. (5) Consistency with Regulatory Framework
Threshold 11: Would the project conflict with any applicable plan, policy, or regulation of an agency with jurisdiction over the project (including, but not limited to the general plan and municipal code) adopted for the purpose of avoiding or mitigating a physical impact associated with hydrology and water quality?
Impact 4.H-5 Implementation of the proposed project would not conflict with any applicable plan, policy, or regulation of an agency with jurisdiction over the project (including, but not limited to the General Plan and Municipal Code) with regard to hydrology, drainage, flooding, and water quality. Therefore, the project would result in a less than significant impact.

Preliminary WQMP Site Plan FIGURE
Skyline Heights Project 4.H-5
Source: KWC Engineers, 2014. 0 120 Feet N

Proposed Storm Drain Facili es FIGURE
Skyline Heights Project 4.H-6
Source: KWC Engineers, 2014. 0 700 Feet N
N.A.P

December 2015 4.H. Hydrology and Water Quality
City of Corona Skyline Heights Project
PCR Services Corporation/SCH No. 2014021003 4.H-35
(a) Corona General Plan
As discussed above, the project would comply with all applicable federal, state, and local laws and regulations related to hydrology, drainage, flooding, and water quality. The City of Corona General Plan contains goals and policies related to hydrology, drainage, flooding, and water quality. As shown in Table 4.H-3, General Plan Consistency Analysis, the project would be consistent with the applicable goals and policies of the City’s General Plan, and therefore impacts in this regard would be less than significant. (b) Corona Municipal Code
The project site, as discussed above, is not located within the boundaries of a designated 100-year flood plain. However, to the extent required by the City, the proposed project would comply with Title 18, Floodplain Management, of the CMC, which is intended to protect people and property within the City from flooding and flood-related hazards. Additionally, the proposed project would involve the construction of new storm drains on-site in order to ensure the project-related stormwater flows do not exceed the capacity of storm drains serving the area (see discussion above). As such, the proposed project would comply with Chapter 13.16, Storm Drains, of the CMC, which addresses the construction of and connection to the City’s storm drain system and also regulates diversions of stormwater flows from existing storm drains, prohibits off-site flow of irrigation runoff or other wastewater, and dictates the size and location of catch basins. As required by Chapter 13.27, Storm Water Management and Discharge Controls, of the CMC, the proposed project would implement the project-specific WQMP in order to minimize adverse impacts to water quality.

Overall, the proposed project would not conflict with the applicable requirements of the CMC, and as such impacts in this regard would be less than significant.

3. CUMULATIVE IMPACTS
Cumulatively, development within the watershed would result in an increase in impervious surfaces in addition to changes in land use and associated pollutant runoff characteristics. Increased impervious surfaces are likely to alter existing hydrology and increase potential pollutant loads. However, all development and future development in the City and throughout the Santa Ana RWQCB must comply with all requirements of and obtain NPDES permits as applicable. Although continued growth is anticipated to occur in the City and surrounding areas, new development and significant redevelopment would have to minimize their individual impacts to water quality and pollutant transport through implementation of BMPs. Because these requirements would be imposed on all other developments, it is anticipated that each development would be required to mitigate its own specific impact on water quality and drainage. Therefore, if all other developments are required to mitigate for impacts to water quality, a less than significant cumulative impact to water quality would occur.

While cumulative development in the City and region would increase the demand for water, groundwater recharge policies and practices implemented by the City and other local agencies would ensure groundwater supplies are maintained at appropriate levels. Other regulatory mechanisms such as the water management plan conservation policies (such as education and outreach to residents and business owners) further ensure that groundwater levels are maintained at the appropriate levels. As such, impacts related to groundwater recharge would be less than significant.

4.H. Hydrology and Water Quality December 2015
City of Corona Skyline Heights Project PCR Services Corporation/SCH No. 2014021003 4.H-36 Table 4.H-3
General Plan Consistency Analysis
Goals and Policies Consistency
Infrastructure and Public Services – Storm Drainage
Policy 7.6.6 – Require new development to prepare
hydrologic studies to assess storm runoff impacts on
the local and sub-regional storm drainage systems,
and, if warranted, require new development to
provide adequate drainage facilities and to mitigate
increases in stormwater flows and/or cumulative
increases in regional flows. Developers of proposed
projects are to submit a final drainage plan for the
City Engineer's review and approval.

Consistent. Per City requirement, a preliminary Hydrology Study and a preliminary WQMP were prepared for the project. The City engineer will review and comment on the WQMP until an approval is granted for the project. The studies indicate the types of features to be employed and the resulting flows to be generated off-site. Using a system of flow-by basins, detention basins, and storm drain piping, off-site flows would by-pass the site and would not be co-mingled with development runoff which would be treated at the proposed designated BMP treatment areas. In addition, while the project would increase stormwater flows, the pre- and post-development conditions would be met at the outlet of the project. The project would be consistent with this policy.

Goal 7.7 – Ensure that urban runoff from existing
and new development does not degrade the quality
of the City’s surface waters, groundwater system,
and other sensitive environmental areas.

Consistent. The proposed project would be designed to avoid water quality impacts in accordance with the requirements within the WQMP and SWPPP for project construction and operation. See Policies 7.6.6 and 7.7.7.

Policy 7.7.1 – Ensure that new development does
not degrade surface waters or the groundwater
system.

Consistent. The proposed project would be designed to avoid water quality impacts in accordance with the requirements within the WQMP and SWPPP for project construction and operation. See Policies 7.6.6 and 7.7.7.

Policy 7.7.2 – Reduce pollutant loading through
passive treatment systems such as vegetated filter
strips, grass swales, and infiltration/sedimentation
areas in suitable open space areas, overland flow
channels and landscaping adjacent to parking lots
and streets.

Consistent. The project would incorporate sustainable design principles, including water-wise planting and irrigation; water quality and stormwater best management practices, extended detention basins, and on-site biotreatment. The project would also include approximately 96 acres of ungraded natural open space within the 270.9-acre project site. Therefore, the project would reduce pollutant loading through passive treatment systems appropriate to the site and the nature of the development. The project would be consistent with this policy.

Policy 7.7.3 – In new developments, minimize
impervious areas that are directly connected to
piped or channelized drainage systems.

Consistent. The proposed project would be designed to avoid water quality impacts in accordance with the requirements in the SWPPP and WQMP for project construction and operation. See Policies 7.6.6 and 7.7.7.

Policy 7.7.5 – Require that development projects
consider the appropriateness of the channelization
of storm water runoff to facilitate its possible
capture and re-use for on-site irrigation and other
purposes.

Consistent. The proposed project would be designed to avoid water quality impacts in accordance with the requirements within the WQMP and SWPPP for project construction and operation. See Policies 7.6.6 and 7.7.7. The project would use reclaimed water for non- portable water demand and would install moderately drought-tolerant sustainable plantings and trees and the irrigation system would utilize weather-based, water-conserving irrigation technology and management. Therefore, the project would be consistent with the intent of this

December 2015 4.H. Hydrology and Water Quality
Table 4.H-3 (Continued)
General Plan Consistency Analysis
City of Corona Skyline Heights Project PCR Services Corporation/SCH No. 2014021003 4.H-37 Goals and Policies Consistency
policy.

Policy 7.7.7 – Require developers to obtain a
National Pollutant Discharge Elimination System
(NPDES) permit from the State Water Resources
Control Board (SWRCB) prior to moving
construction equipment onto a development site.

The NPDES permit shall be retained at the
construction site throughout the construction
period, and a copy shall be filed with the City
Engineer.

Consistent. Construction activity resulting in a land disturbance of one acre or more, or less than one acre when part of a larger common plan of development or sale, must obtain the General Permit for Discharges of Stormwater Associated with Construction Activity. The permit requires the development and implementation of a SWPPP. The SWPPP must list the BMPs the discharger will use to protect stormwater runoff and information regarding the placement of those BMPs. Additionally, the SWPPP must contain a visual monitoring program; a chemical monitoring program for "non-visible" pollutants to be implemented if the BMPs fail; and a sediment monitoring plan if the site discharges directly to a water body on the 303(d) list for sediment. The proposed project would comply with all SWRCB and City requirements per the City’s NPDES permit. The project would be consistent with this policy.

Policy 7.7.8 – During construction projects, ensure
compliance with all the terms and conditions
outlined as part of the NPDES permit, including the
implementation of the latest BMPs and a
determination of need for any additional Water
Quality Management Plans to reduce pollutants and
urban runoff flows to the maximum extent practical.

Consistent. See Policy 7.7.7.

Policy 7.7.9 – Require that new developments
employ the most efficient drainage technology to
control drainage and minimize damage to
environmentally sensitive areas.

Consistent. See Policies 7.6.6 and 7.7.7.

Environmental Resources - Hydrological Resources
Policy 10.1.2 – Conduct construction activities to
minimize adverse impacts on water resources
through the use of Best Management Practices, as
established and updated from time to time, by the
City of Corona.

Consistent. The proposed project would comply with all applicable state and local requirements to reduce flooding impacts. Furthermore, the parcel map for the project, which would be reviewed and approved by the City engineer, would comply with all recommendations stated therein to reduce impacts related to flooding hazards. The project would be designed to connect to the City’s storm drain system and direct water safely off and through the project site. The project would be consistent with this policy.

4.H. Hydrology and Water Quality December 2015
Table 4.H-3 (Continued)
General Plan Consistency Analysis
City of Corona Skyline Heights Project PCR Services Corporation/SCH No. 2014021003 4.H-38 Goals and Policies Consistency
Policy 10.1.3 – In the event that previously unknown soil or groundwater contamination is encountered during construction, suspend
construction and implement appropriate health and
safety procedures. Where site contamination is
identified, implement an appropriate remediation
strategy that is approved by the City and DTSC.

Consistent. A Phase 1 Environmental Site Assessment (ESA) was prepared for the proposed project (see Appendix H and Section 4.G, Hazards and Hazardous Materials, of this EIR). As part of the ESA, environmental agency databases that log known hazardous site conditions were reviewed to ascertain whether the site or any adjacent properties were listed on such federal, state, or local databases. The site was not identified on any of the regulatory databases searched and no adjoining properties were identified on the databases. In addition, the site and adjoining properties were not identified on the Registered Storage Tank or on the Leaking Underground Storage Tank Databases. No Brownfield listings were identified within a one-half mile radius of the site. The project would be required to comply with all recommendations for hazardous substances removal if encountered on-site. Thus, the project would be consistent with this policy.

Policy 10.1.4 – Prohibit the discharge of toxins,
debris, refuse, and other pollution into
watercourses, other drainages and groundwater
basins.

Consistent. The project would result in the development of 292 single-family residences. A HOA would be formed and would be responsible for the maintenance of the WQMP basins and pipes leading to and from the WQMP basins. In addition, educational materials would be provided to residents regarding the detention basins and stormwater pollution prevention information regarding the use and disposal of hazardous materials associated with residential uses, such as pesticides, household cleaning supplies, paints, etc. Landscaping would be designed to minimize irrigation, to promote surface infiltration where appropriate, and to minimize the use of fertilizers and pesticides. Project landscaping must comply with the applicable landscaping requirements specified in Chapter 13.26, Water Conservation Plan of the CMC. Therefore, no significant impacts regarding water quality would occur and the project would be consistent with this policy.

Policy 10.2.4 – Require the use of water and energy
conservation features and materials in the design and
construction of all public buildings, projects, and site development while encouraging their use citywide.

Consistent. The project would install water- and energy-efficient appliances to reduce water demand and energy output. In addition, project landscaping must comply with the applicable landscaping requirements specified in Chapter 13.26, Water Conservation Plan of the CMC. The proposed landscape design would incorporate water conservation measures including water- conserving planting, efficient irrigation systems, and water-conserving fixtures. Therefore, the project would comply with this policy.

Policy 10.2.5 – Require the use of reclaimed water in
common areas and landscape treatments for all
proposed development.

Consistent. As discussed in Section 4.N, Utilities and Service Systems, of this EIR, a new 12- inch Zone 3 reclaimed water line is proposed as part of the City’s Foothill Parkway Westerly Extension Improvements and would be located in Foothill Parkway from Chase Drive to Serfas Club Drive and in Chase Drive from Foothill Parkway to Skyline Drive. This reclaimed water line is assumed to be in place prior to implementation of the proposed project. Therefore, reclaimed water would be available to the site. Reclaimed water service would be utilized at

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Table 4.H-3 (Continued)
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the project site for irrigation purposes. Therefore, the project would comply with this policy.

Policy 10.3.2 – Incorporate natural drainage systems
into developments where appropriate and feasible.

Consistent. The project site is currently undeveloped and in its natural state. Natural drainage courses currently exist on the project site. The proposed project would, however, incorporate a storm drain system, including biotreatment (i.e., extended detention basins) in order to capture and treat on-site stormwater flows. The pre- and post-developed conditions would be met at the outlet of the project. Therefore, the project would be consistent with this policy.

Policy 10.3.3 – Retain storm water at or near the site
of generation for percolation into the groundwater to
conserve it for future uses and to mitigate adjacent
flooding.

Consistent. Refer to Policy 10.3.2. The proposed project would incorporate biotreatment features on the project site in order to retain stormwater flows and minimize flooding potential both on- and off-site.

Environmental Hazards and Public Safety – Flooding Hazards Goal 11.2 – Reduce the potential risk of flood
hazards to community property and human life.

Consistent. The proposed project would be partially located within the 500-year floodplain.

The proposed project would comply with all applicable state and local requirements to reduce flooding impacts. In addition, the lowest proposed residential pad elevation would be approximately 25 feet higher than the streambed flowline. The project would be designed to connect to the City’s storm drain system and direct water safely off and through the project site. Therefore, the project would be consistent with this goal.

Policy 11.2.2 – Require that all new development
incorporate sufficient measures to mitigate flood
hazards including the design of onsite drainage
systems linking with Citywide storm drainage,
gradation of the site so that runoff does not impact
adjacent properties or structures on the site, and
elevation of the structures above any flooding
elevation.

Consistent. See Goal 11.2.

Policy 11.2.8 – Require that all new stormwater
drainage facilities be constructed and managed in
accordance with City and Riverside County design
specifications.

Consistent. All proposed stormwater facilities on the site would be constructed and managed in accordance with all applicable City and County design requirements. A Final Hydrology and Hydraulics Report would be conducted to determine the proposed hydraulic grade lines throughout the storm drain system and final detention basin sizing. The Final Hydrology and Hydraulics Report would be reviewed and approved by the City Department of Public Works to ensure compliance with applicable requirements. Therefore, the project would be consistent with this policy.

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Policy 11.2.11 – Require stormwater detention
basins, where appropriate, to reduce the potential
risk of flood hazards. The location, design, and
operational practices of the detention basins shall be
in conformity with applicable Federal, State, County,
and City environmental codes and regulations.

Consistent. Refer to Policy 10.3.3 and Policy 11.2.8 above.

Source: PCR Services Corporation, 2014.

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4. MITIGATION MEASURES
The project would comply with applicable regulations that would reduce potential impacts related to hydrology and water quality to less than significant. However, the following mitigation measure is recommended to ensure compliance:

Mitigation Measure HYD-1: For Drainage Management Area C, the final engineering for the drainage of Area C shall include a concrete impact basin energy dissipater and rip-rap pad and shall be designed in accordance with City standards. The outlet velocity shall be at or below the existing condition or to a non-erosive velocity. The plans shall be submitted to the City for review and approval.

5. LEVEL OF SIGNIFICANCE AFTER MITIGATION
With the implementation of project design features and the recommended mitigation measure, impacts related to hydrology and water quality would be less than significant.

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4. ENVIRONMENTAL IMPACT ANALYSIS
I. LAND USE AND PLANNING

INTRODUCTION
This section of the EIR describes the existing environmental and regulatory setting for land use and planning, analyzes potential impacts on land use and planning that would result from implementation of the proposed project, and identifies the significance of those impacts. The analysis is also based on the following applicable plans and policies: The Southern California Association of Governments’ 2008 Regional Comprehensive Plan, Regional Transportation Plan/Sustainable Communities Strategy, and Compass Blueprint Growth Vision; the City of Corona’s General Plan (adopted March 17, 2004, with latest updates in 2008), and applicable Municipal Code sections.

Land use and planning compatibility issues concern the physical compatibility of the land uses of the proposed project with adjacent or surrounding land uses as well as a proposed project’s consistency with the plans and policies of the agencies that have regulatory jurisdiction over the project. This analysis describes existing land uses that could be affected by the proposed project and the proposed project’s compliance with relevant land use plans, policies, and ordinances of the City of Corona as well as regional planning agencies. The land use analysis addresses issues pertaining to the potential for the creation of physical incompatibilities between the proposed project and adjacent land uses or activities and determines whether any identified incompatibilities would result in physical impacts on the environment.

1. ENVIRONMENTAL SETTING
The City of Corona is located approximately 45 miles southeast of Los Angeles in western Riverside County.

The City limits encompass 39.2 square miles.1 The City of Corona contains a broad diversity of uses including housing, schools, parks, libraries, religious facilities, civic, retail, industrial, offices, and open space.

The majority of the City (67 percent) is developed for housing, public, parks and open space uses and approximately 17 percent of the City is undeveloped.2
a. Existing Conditions
(1) Project Site
The project site is located within unincorporated Riverside County in the City of Corona Sphere of Influence (SOI). As shown in Figure 2-1, Regional and Vicinity Map, in Chapter 2 of this EIR, the site is located approximately three miles south of State Route 71 (SR-71, Chino Valley Freeway) and SR-91 (Riverside Freeway) and approximately four miles west of Interstate 15 (I-15, Temecula Valley Freeway) along the southwestern boundary of the City of Corona. The 270.9-acre project site is located adjacent to, and southwest of, the proposed Foothill Parkway Westerly Extension. As shown in Figure 2-5, West Sphere of 1 Source: City of Corona website; available: http://discovercorona.com/About-Corona.aspx 2 Source: City of Corona General Plan, adopted March 17, 2004, page 19.

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Influence County of Riverside Zoning, in Chapter 2 of this EIR, the most of the SOI is zoned Rural Residential (0.2 – 0.5 dwelling units per acre) under the County of Riverside Zoning Code. A smaller section to the south of the current Trudy Way terminus is zoned A-1-10 (Light Agriculture). (2) Surrounding Uses
Figure 2-2, Aerial Photo of the Project Site and Surrounding Uses, in Chapter 2 illustrates the location of the 270.9-acre project site, the annexation area, and surrounding development. As shown in Figure 2-2, the project site is generally bounded on the north and east by single-family residences and on the south and west by the Cleveland National Forest and large privately owned parcels. No commercial land uses are located within the immediately surrounding area.

The nearest development (Tract Map 31955) is located adjacent to and southeast of the project site, south of the Foothill Parkway, with access provided by Trudy Way, Rawley Street, Elker Road, and Corbett Street.

Tract 31955 consists of an approximately 154-lot, residential subdivision within the R1-7.2 zone, which corresponds to low-density single-family and a 7,200-square-foot minimum lot area. The edges of the subdivision are zoned R1-AD/HD, which corresponds to agricultural/hillside uses in a residential zone. The purpose for the latter zone is to maintain common open spaces on the periphery of the residential development.

The area to the south of Tract 31955 is zoned R1-9.6 (single-family residential, with a 9,600-square-foot minimum lot size) and OS (open space). It is currently undeveloped. This area is accessed by, and to the south of, Skyline Drive.

Existing single-family neighborhoods are also located to the northeast of the project site and Foothill Parkway Westerly Extension. These neighborhoods are generally zoned low-density residential (R1-7.2, R1- 8.4, and R1-9.6). Large, undeveloped parcels within the OS zone are interspersed among the residential areas. All of the adjacent developed areas are located within the City of Corona.

The Cleveland National Forest is located to the west of the annexation area and project site. The National Forest is accessed via Skyline Drive, a graded forest service access road to the south of the project site. This road provides recreational hiking and mountain biking opportunities to residents on a local and regional level.
b. Regulatory Framework
The following discussion identifies and describes the regulatory plans, policies, and ordinances that would be applicable to development at the site of the proposed project. Specific provisions of those documents that pertain to the project and address land use and planning issues are listed in the Impact Analysis section below and evaluated for consistency with the Project Design Features (also described below). (1) State Cortese-Knox-Hertzberg Local Government Reorganization Act of 2000 Annexation is the means by which an existing city extends its corporate boundaries. The Cortese-Knox Local Government Reorganization Act (Government Code §56000, et seq.) is the framework within which

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proposed city annexations, incorporations, consolidations, and special district formations are considered.

This law establishes a Local Agency Formation Commission (LAFCO) in each county, empowering it to review, approve or deny proposals for boundary changes and incorporations for cities, counties, and special districts.

In 2000, the Legislature passed AB 2838 (Chapter 761, Statutes of 2000) making the broadest and most significant set of sweeping changes to local government reorganization law since the creation of LAFCOs. In addition to renaming the act the Cortese-Knox-Hertzberg Local Government Reorganization Act of 2000 (CKH Act), AB 2838 affirmed and strengthened the role of LAFCOs in helping shape the future physical and economic growth and development of the State, including, once again, the role of LAFCOs in annexation proceedings.

AB 2838 (Hertzberg, 2000), recognizes and affirms the important role that LAFCOs play in California in serving as an arm of the State, not only in the oversight of local government boundaries, but in evaluating and guiding the efficient, cost-effective, and reliable delivery of municipal services to California’s citizenry.

AB 2838 expanded the powers and duties of LAFCOs, in its decision-making role in government organization changes, and its examination and guidance of municipal service location and extension timing. This law establishes a LAFCO in each county, empowering it to review, approve, or deny proposals for boundary changes and incorporations/formations for cities, counties, and special districts. In granting these powers, the state has occupied the field of annexation law to the exclusion of local legislation. Therefore, a city or county cannot take actions that frustrate or conflict with state annexation procedures. For this reason, a city cannot adopt a local ordinance that would allow city voters to pass sole judgment on proposed annexation proceedings.

LAFCOs are composed of elected officials from the county and local cities, and a member of the general public. As of 2011, 29 of the 58 LAFCOs also have special district representation. In addition, some LAFCOs have special membership pursuant to the CKH Act. Each LAFCO operates independently of the state.

However, it is expected to act within a set of state-mandated parameters encouraging "planned, well- ordered, efficient urban development patterns," the preservation of open-space lands, and the discouragement of urban sprawl. The Legislature has taken care to guide the actions of the LAFCOs by providing statewide policies and priorities for the consideration of annexations (Gov. Code § 56844), and by establishing criteria for the delineation of spheres of influence (Gov. Code § 56425).

State Law does not mandate that annexations conform to local general plans beyond requiring that the LAFCO consider "consistency with the city or county general and specific plans" (Section 56841(g)).

Nonetheless, the statutes contain numerous references that attempt to link local land use and open-space policies to the annexation process (Sections 56300, 56375, 56377, 56425, and 56841). Accordingly, the Commission is expected to attempt to harmonize local planning policies with the intent of the State legislation. Where there is a clear conflict, such as incompatibility between city and county general plans, the State law would prevail.

The factors that the LAFCO must consider in reviewing annexation proposals include, but are not limited to, the following (Gov. Code § 56841):

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1. Population, population density, land area and use, per capita assessed valuation, topography, natural boundaries, drainage basins, proximity to populated areas, and the likelihood of significant growth during the next ten years.

2. Need for organized community services, present cost and adequacy of government services and controls, probable future needs, probable effect of the annexation and of alternative courses of action on the cost and adequacy of services and controls in the area and vicinity.

3. The effect of the proposed annexation and of alternative actions on adjacent areas, on mutual social and economic interests and on the local government structure of the county.

4. Conformity of the proposal and its effects with LAFCO policies on providing planned, orderly, efficient patterns of urban development and with state policies and priorities in conversion of open- space lands to other uses.

5. Effect of the proposal on maintaining the physical and economic integrity of lands in an agricultural preserve in open-space use.

6. Clarity of the boundaries of the territory, the nonconformance of proposed boundaries with lines of assessment or ownership, the creation of islands or corridors of unincorporated territory and other similar matters affecting the proposed boundaries.

7. Consistency with appropriate city or county general and specific plans.

8. The sphere of influence of any agency which may be applicable to the proposal being reviewed.

9. The comments of any affected agency.

Under Government Code Section 56375(a), a LAFCO is required to approve a city's request to annex land adjacent to its borders when the commission finds that either of the following circumstances exist:

1. The land is substantially surrounded by the city or the Pacific Ocean, is substantially developed or developing, is not prime agricultural land, is designated for urban growth on the city's general plan, and is not within the sphere of influence of another city.

2. The land is located within an urban service area designated by the LAFCO, is not prime agricultural land, and is designated for urban growth on the city's general plan.

Both of these conditions require review of the annexing city's general plan by the LAFCO. A general plan which reflects the proposed annexation improves the chances that the annexation will be approved. (2) Regional
(a) Southern California Association of Governments
SCAG is the designated regional planning agency for six counties: Los Angeles, Orange, San Bernardino, Riverside, Ventura and Imperial. Within these counties are 16 subregions or Council of Governments (COG).

The project site is within the Western Riverside COG, which includes 17 cities and the County of Riverside.

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SCAG is a joint powers agency with responsibilities pertaining to regional issues. SCAG’s mandated responsibilities include developing plans and policies with respect to the region’s population growth, transportation programs, air quality, housing, and economic development. (i) 2008 Regional Comprehensive Plan
As part of its planning obligations, SCAG prepared the 2008 Regional Comprehensive Plan (RCP). The 2008 RCP was accepted by SCAG for use as an advisory document that may be voluntarily used by local jurisdictions when developing local plans and addressing local issues of regional significance. The RCP addresses issues related to future growth and provides a means for assessing the potential impact of individual development projects within a regional context. Local Governments are asked to consider the RCP’s recommendations in the preparation of General Plan updates, municipal code amendments, design guidelines, incentive programs and other actions. The applicable goals of the RCP relevant to land use and an analysis of the project’s consistency with these goals and policies are provided below under the subheading Analysis of Project Impacts.

The RCP is also closely linked to, and serves as a basis for the preparation of, SCAG’s Regional Transportation Plan and the Compass Blueprint Growth Vision (2 % strategy) program. (ii) Regional Transportation Plan/Sustainable Communities Strategy In April 2012, SCAG’s Regional Council adopted the 2012 - 2035 Regional Transportation Plan – Sustainable Communities Strategy (RTP/SCS). The RTP/SCS presents the transportation vision for the region through the year 2035 and provides a long-term investment framework for addressing the region’s transportation and related challenges. Also, the RTP/SCS contains baseline socioeconomic projections that are used as the basis for SCAG’s transportation planning and the provision of services by other regional agencies. The RTP/SCS includes goals and policies that pertain to economic development, mobility, accessibility, travel safety, productivity of the transportation system, protection of the environment and health through improved air quality, energy efficiency, and land use and growth patterns that complement the state and region’s transportation investments, and security of the regional transportation system. The applicable goals and policies of the RTP/SCS relevant to the project and an analysis of the project’s consistency with these goals and policies are provided below under the subheading Analysis of Project Impacts.

On June 6, 2013, SCAG’s Regional Council approved Amendment One to the RTP/SCS and Amendment 13-04 to the 2013 Federal Transportation Improvement Program (FTIP). On September 11, 2014, SCAG’s Regional Council approved Amendment Two to the RTP/SCS. The draft amendments were developed as a response to changes to projects in the RTP/SCS and 2013 FTIP. A total of 43 projects were modified or added in these amendments, with a majority of the changes being minor in nature, including changes to completion years, as well as minor modifications to project scopes, costs, and funding. (iii) Compass Blueprint Growth Vision
SCAG also engages in the Compass Growth Vision effort that addresses the regional development pattern so as to accommodate future development and provide land patterns that improve mobility, reduce vehicle miles traveled, and support the goals and polices established in the RTP. The Growth Vision is driven by four key principles: mobility – getting where we want to go; livability - creating positive communities; prosperity - long-term health for the region; and sustainability - preserving natural surroundings.