Water Master Plan and Rate Study
MAY 2025
Prepared for:
SIGNAL HILL PUBLIC WORKS
2175 Cherry Avenue
Signal Hill, California 90755
Contact: Thomas Bekele
Prepared by:
605 Third Street
Encinitas, California 92024
Contact: Greg Ripperger
Printed on 30% post-consumer recycled material.
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Table of Contents
SECTION PAGE NO.
Acronyms and Abbreviations ............................................................................................................................................. v 1 Introduction .......................................................................................................................................................... 1
1.1 Background and Master Plan Objectives .............................................................................................. 1
1.2 Service Area Overview ............................................................................................................................ 2 2 Study Area, Land Use and Population ................................................................................................................ 5
2.1 Existing Land Use ................................................................................................................................... 5
2.2 Recent Developments and Completed CIP ........................................................................................... 6
2.3 Population ............................................................................................................................................... 7
2.4 Water Demand ........................................................................................................................................ 8
2.4.1 Historical Water Consumption ................................................................................................. 8
2.4.2 Unaccounted-for Water ............................................................................................................ 9
2.4.3 Future Demands .................................................................................................................... 10
2.4.4 Peaking Factors ..................................................................................................................... 12
2.4.5 Historical Water Production .................................................................................................. 13
2.4.6 Historical Rainfall ................................................................................................................... 14 3 Water Supply ..................................................................................................................................................... 17
3.1 Overview ............................................................................................................................................... 17
3.2 Groundwater Supply ............................................................................................................................ 18
3.2.1 Groundwater Entitlement ...................................................................................................... 18
3.2.2 Groundwater Quality .............................................................................................................. 19
3.2.3 Groundwater Capacity ........................................................................................................... 19
3.3 Imported Water Supply ....................................................................................................................... 21
3.4 Groundwater vs. Imported Water Supply ........................................................................................... 21
3.5 Emergency Connections...................................................................................................................... 22 4 System Facilities ............................................................................................................................................... 23
4.1 Pressure Zones .................................................................................................................................... 23
4.2 Wells ..................................................................................................................................................... 24
4.3 Existing Storage Reservoirs ................................................................................................................ 25
4.4 Pump Stations ..................................................................................................................................... 26
4.5 Imported Water Connection ................................................................................................................ 30
4.6 Pressure Reducing Stations................................................................................................................ 30
4.7 Pipelines ............................................................................................................................................... 31
4.8 Water Treatment.................................................................................................................................. 32 5 Condition Assessment ...................................................................................................................................... 34
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5.1 General, Distribution System .............................................................................................................. 34
5.2 Wells ..................................................................................................................................................... 34
5.3 Hilltop Reservoir and Pump Station ................................................................................................... 36
5.4 Temple Reservoir and Pump Station.................................................................................................. 38
5.5 Gundry Reservoir and Pump Station .................................................................................................. 39
5.6 SCADA .................................................................................................................................................. 41
5.7 Condition Assessment Summary ........................................................................................................ 43 6 System Evaluation Criteria ............................................................................................................................... 44
6.1 System Pressures ................................................................................................................................ 44
6.2 Pipeline Criteria ................................................................................................................................... 44
6.3 Fire Flow Criteria .................................................................................................................................. 45
6.4 Storage Capacity Criteria .................................................................................................................... 45
6.5 Pump Station Capacity Criteria ........................................................................................................... 46 7 System Analysis ................................................................................................................................................. 48
7.1 Hydraulic Model ................................................................................................................................... 48
7.1.1 Existing Model ........................................................................................................................ 48
7.1.2 Model Updates ....................................................................................................................... 48
7.1.3 Model Calibration ................................................................................................................... 48
7.2 Pipeline Analysis .................................................................................................................................. 49
7.3 Fire Flow Analysis ................................................................................................................................ 51
7.4 Supply Analysis .................................................................................................................................... 52
7.5 Storage Analysis .................................................................................................................................. 53
7.6 Pump Station Analysis ......................................................................................................................... 56 8 Capital Improvement Plans (CIP) ..................................................................................................................... 58
8.1 Project Prioritization ............................................................................................................................ 58
8.2 List of Projects ..................................................................................................................................... 58
8.3 Project Descriptions ............................................................................................................................ 62
8.4 CIP Annual Breakdown ........................................................................................................................ 78 TABLES
Table 2-1. Historical and Projected City Population and Housing Characteristics ........................................................ 7 Table 2-2. Historical Water Consumption ........................................................................................................................ 8 Table 2-3. Production vs. Consumption (Acre-Feet) ..................................................................................................... 10 Table 2-4. Projected Water Demands, Total ADD ......................................................................................................... 11 Table 2-5. Demands by Zone ......................................................................................................................................... 11 Table 2-6. Peaking Factors ............................................................................................................................................ 13 Table 2-7. Total Monthly Water Production (Acre-Feet) ................................................................................................ 14 Table 2-8. Historical Rainfall at Signal Hill Rain Gauge Station (inch) ........................................................................ 15
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Table 3-1. Existing City Well Capacities ......................................................................................................................... 20 Table 3-2. Groundwater Production vs. Imported Water Purchases ........................................................................... 21 Table 3-3. MWD Projected Water Cost .......................................................................................................................... 22 Table 4-1. Potable Water Storage Reservoirs ............................................................................................................... 25 Table 4-2. Potable Water Booster Pump Stations ........................................................................................................ 26 Table 4-3. Existing Pressure Reducing Stations ........................................................................................................... 31 Table 4-4. Pipe Length Breakdown by Material/Age .................................................................................................... 31 Table 5-1. Wells Site Visit ............................................................................................................................................... 34 Table 5-2. Wells Recommendations .............................................................................................................................. 36 Table 5-3. Hilltop Reservoir Site Visit ............................................................................................................................ 36 Table 5-4. Hilltop Reservoir Site Recommendations .................................................................................................... 37 Table 5-5. Temple Reservoir Site Visit ........................................................................................................................... 38 Table 5-6. Temple Reservoir Site Recommendations .................................................................................................. 39 Table 5-7. Gundry Reservoir Site Visit ........................................................................................................................... 40 Table 5-8. Gundry Reservoir Site Recommendations .................................................................................................. 41 Table 5-9. SCADA Site Visit ............................................................................................................................................ 42 Table 5-10. SCADA Recommendations ......................................................................................................................... 43 Table 5-11. Condition Assessment Recommendations ............................................................................................... 43 Table 6-1. Potable Water Pressure Criteria ................................................................................................................... 44 Table 6-2. Potable Water Pipeline Criteria .................................................................................................................... 45 Table 6-3. Fire Flow Criteria ........................................................................................................................................... 45 Table 7-1. Model Calibration .......................................................................................................................................... 49 Table 7-2. Existing Supply Sources ................................................................................................................................ 53 Table 7-3. Supply Analysis – GW Only ........................................................................................................................... 53 Table 7-4. Supply Analysis – Emergency ....................................................................................................................... 53 Table 7-5. Storage Analysis Results – Existing Scenario ............................................................................................. 55 Table 7-6. Storage Analysis Results – 2045 Scenario ................................................................................................. 55 Table 7-7. Pump Station Analysis Results – Existing Scenario .................................................................................... 56 Table 7-8. Pump Station Analysis Results – 2045 Scenario ....................................................................................... 56 Table 8-1. Source of Projects ......................................................................................................................................... 58 Table 8-2. Capital Improvement Plans .......................................................................................................................... 80
FIGURES
Figure 1 1. Regional Map .................................................................................................................................................. 3 Figure 2-1. Existing Land Use. .......................................................................................................................................... 6 Figure 2-2. Annual Water Consumption (Acre-Feet) ........................................................................................................ 9 Figure 2-3. Monthly Water Production vs. Consumption (Acre-Feet) ........................................................................... 10 Figure 2-4. Daily Peaking Factor, 2023......................................................................................................................... 12
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Figure 2-5. Hourly Peaking Factor, Weekdays in August 2023 ................................................................................... 13 Figure 2-6. Monthly Water Production (Acre-Feet) ....................................................................................................... 14 Figure 2-7. Historical Rainfall at Signal Hill (inch) ........................................................................................................ 15 Figure 3-1. Existing Supply Locations ............................................................................................................................ 17 Figure 4-1. Existing Pressure Zones .............................................................................................................................. 23 Figure 4-2. Existing Wells ............................................................................................................................................... 25 Figure 4 3. Signal Hill Potable Water System Schematic ............................................................................................. 28 Figure 7-1. 2045 Peak Hour Demand (PHD) System Analysis .................................................................................... 50 Figure 7-2. 2045 Peak Hour Demand (PHD) Pressure Deficiencies ........................................................................... 51 Figure 7 3. 2045 Fire Flow under MDD Condition ........................................................................................................ 52 Figure 8-1. CIP Locations ............................................................................................................................................... 60 Figure 8-2. CIP Locations – North of City ...................................................................................................................... 61 Figure 8-3. Projected Water CIP Costs by Year. ............................................................................................................ 78 15851 v
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Acronyms and Abbreviations
Acronym/Abbreviation Definition
DDW Division of Drinking Water
HGL Hydraulic Grade Line
MCC Motor Control Center
O&M Operations and Maintenance
PLC Programmable Logic Controller
PRS Pressure Reducing Station
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1 Introduction
1.1 Background and Master Plan Objectives
The City of Signal Hill, California, is a dynamic and vibrant community within the greater Los Angeles area, renowned for its rich history, diverse population, and distinctive topographical features. To ensure the sustainability and resilience of its water resources while accommodating its growing population, the City undertook a comprehensive review of its water system and rates. This review aims to guide the City's water management strategies over the next two decades.
In 2024, the City engaged Dudek, in collaboration with Raftelis Financial Consultants, Inc., to develop a Water Master Plan and conduct Rate Study Services. The primary objective of this Water Master Plan is to establish a strategic framework for the effective management, distribution, and conservation of water resources within Signal Hill. This plan seeks to evaluate the current water supply and demand, identify potential future needs, and outline the necessary infrastructure improvements and policy initiatives required to secure a reliable and sustainable water supply for all residents and businesses.
The Water Master Plan will serve as a comprehensive guiding document, ensuring that the City's water management practices comply with state and federal regulations, including those pertaining to water quality and conservation.
By doing so, the plan aims to safeguard the health and well-being of the community while promoting environmental stewardship.
Signal Hill's water supply is derived from a combination of local groundwater sources and imported water from regional suppliers. The city's unique geographical features and location significantly influence its hydrology, impacting both water availability and quality. The existing water system comprises a network of wells, storage tanks, and distribution pipelines designed to meet the demands of a diverse and expanding population.
The Master Plan will address several key objectives, including:
1. Assessment of Current Water Supply and Demand: Conducting a thorough analysis of the existing water supply sources and current demand patterns to identify any gaps or inefficiencies.
2. Future Water Needs: Projecting future water demand based on anticipated population growth, economic development, and climate change impacts.
3. Infrastructure Improvements: Identifying and prioritizing necessary upgrades and expansions to the water infrastructure to enhance capacity, reliability, and resilience.
4. Regulatory Compliance: Ensuring that all water management practices align with state and federal regulations, including those related to water quality standards and conservation mandates.
By addressing these objectives, the City of Signal Hill aims to create a robust and forward-looking water management strategy that will support the community's needs for decades to come. This proactive approach will help the City maintain a sustainable and resilient water supply, fostering continued growth and prosperity.
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1.2 Service Area Overview
The City of Signal Hill, located in Los Angeles County, California, encompasses an area of approximately 2.2 square miles. It is strategically situated between the San Diego (I-405) Freeway and the Pacific Coast Highway, and is entirely surrounded by the City of Long Beach. The city's topography is distinguished by a prominent hill, which rises to an elevation of 360 feet above mean sea level, making it the highest point in the vicinity. This hill historically served as a critical landmark for coastal navigation and surveying in the late 1800s, which ultimately inspired the city's name. The location of the City is shown in Figure In the 1920s, the discovery of oil in the area that would become Signal Hill led to a boom in oil rig construction and operations. Over time, the landscape transitioned from being dominated by oil rigs to a diverse mix of commercial, industrial, and residential developments. As the city's population expanded, single-family residences were established on the hill and at higher elevations. Concurrently, commercial developments, modern office buildings, and industrial parks were constructed, resulting in a balanced land use distribution: approximately 38% residential, 36% industrial, 20% commercial, 4% public/institutional, and 2% open space.
The residential population of Signal Hill experienced significant growth, nearly doubling from 1980 to 2000. Post2000, the city's growth rate moderated, with the population recorded at 11,218 in 2013 and approximately 11,848 by 2020, according to the US Census Bureau.
The Signal Hill Water Department is responsible for operating a comprehensive water system that serves the entire city. This system is divided into four primary pressure zones to ensure efficient water distribution across all public and private parcels within the service area. The city's primary water supply is sourced from groundwater production wells operated by the city. Two of these wells are located in the North Long Beach area, while a third is situated within Signal Hill itself.
Water storage is facilitated by three reservoirs, and water delivery to higher pressure zones is managed through three booster pump stations. Additionally, the city maintains multiple connections to the Metropolitan Water District's regional water transmission system, allowing for the importation of supplemental water as needed. The distribution network comprises approximately 50 miles of distribution and transmission pipelines, nearly 3,200 domestic service connections, and a groundwater treatment facility.
This robust infrastructure ensures that the City of Signal Hill can reliably meet the water needs of its residents, businesses, and institutions, supporting the continued growth and development of the community.
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Figure 1 1. Regional Map
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2 Study Area, Land Use and Population
2.1 Existing Land Use
A comprehensive review of the land use information for the City of Signal Hill was conducted utilizing the 2021- 2029 Housing Element, dated October 13, 2022. This review provides a detailed overview of the current land use distribution within the city. The land use within Signal Hill is categorized as follows: 38 percent residential, 36 percent industrial, 20 percent commercial, 4 percent public/institutional, and 2 percent open space, as illustrated in Figure 2-1.
The residential areas, which constitute 38 percent of the city's land use, include a mix of single-family homes, multifamily units, and residential complexes. These areas are primarily located on the hill and at higher elevations, offering scenic views and a suburban living environment. The industrial sector, accounting for 36 percent of the land use, comprises various manufacturing facilities, warehouses, and industrial parks. This sector plays a crucial role in the city's economy, providing employment opportunities and supporting local businesses.
Commercial land use, making up 20 percent of the city's area, includes retail centers, office buildings, and serviceoriented businesses. These commercial zones are strategically located to serve the needs of the residential population and attract visitors from neighboring areas. The public/institutional category, which represents 4 percent of the land use, encompasses government buildings, schools, and community facilities that provide essential services to the residents.
Open space, although only 2 percent of the land use, includes parks, recreational areas, and natural landscapes that contribute to the city's environmental quality and residents' well-being. These open spaces offer opportunities for outdoor activities, community events, and conservation efforts.
Since the adoption of the 2018 Water Master Plan (WMP), land use changes within the City of Signal Hill have been minimal. This stability in land use distribution reflects the city's commitment to maintaining a balanced and sustainable development approach. The minimal changes also indicate that the existing infrastructure and resources continue to meet the needs of the community effectively.
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Figure 2-1. Existing Land Use.
2.2 Recent Developments and Completed CIP
Since the adoption of the 2018 Water Master Plan (WMP), the City of Signal Hill has undertaken and completed one significant Capital Improvement Project (CIP). This project involved the replacement of an aging 12-inch cast iron water main located on 33rd Street, extending from Walnut Avenue to California Avenue. The old cast iron pipe, which had been in service for many years, was replaced with a new 12-inch Class 150 ductile iron pipe.
The decision to replace the cast iron water main was driven by the need to enhance the reliability and efficiency of the city's water distribution system. Cast iron pipes, while durable, are prone to corrosion and can develop leaks over time, leading to potential water loss and service disruptions. By upgrading to ductile iron pipe, the City has significantly improved the durability and longevity of the water main, ensuring a more robust and resilient infrastructure.
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Ductile iron pipes offer several advantages over traditional cast iron pipes, including superior strength, flexibility, and resistance to corrosion. These attributes make ductile iron an ideal material for modern water distribution systems, capable of withstanding the demands of a growing urban environment. The new 12-inch Class 150 ductile iron pipe installed on 33rd Street is designed to handle higher water pressures and provide a more reliable supply to the surrounding areas.
2.3 Population
The City of Signal Hill has undergone significant demographic and housing changes over the past few decades.
Table 2-1 provides a detailed overview of the historical population and housing characteristics from 1980 to 2020.
This data highlights the growth in population, the increase in total and occupied dwelling units, and the trends in vacancy rates and population density.
Looking ahead, the City of Signal Hill anticipates continued growth and development over the next decade. However, it is speculated that the population increase will be minimal, according to the City’s 2020 Urban Water Management Plan (UWMP, Table 3-5, Population – Current and Projected), due to the city being nearly built out. The following table provides projections for population and housing characteristics for the years 2025 and 2030.
Table 2-1. Historical and Projected City Population and Housing Characteristics
Historical Population/Housing Projected
19801 19901 20001 20101 20151 2020 2025 2030
Population 5,734 8,371 9,247 10,471 11,896 11,8482 11,8794 12,0454 Total Dwelling
Units
2,780 3,670 3,797 4,389 4,678 4,6323 4,8905 5,1493
Occupied
Dwelling Units
ND 3,375 3,621 4,157 4,444 4,401 4,646 4,892
Vacant Dwelling
Units
ND 295 176 232 234 2313 244 257
Percent Vacant ND 8.0% 4.6% 5.3% 5.0% 5.0% 5.0%1 5.0%1
Population
Density
(Population/Occ
upied Dwelling
Units)
ND 2.48 2.55 2.52 2.68 2.69 2.56 2.46
Data Source:
1 2018 Water Master Plan;
2 US Census;
3 2021-2029 Housing Element;
4 2020 Urban Water Management Plan;
5 Linear Interpolation.
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2.4 Water Demand
2.4.1 Historical Water Consumption
Historical water consumption data, as presented in Table 2-2 and Figure 2-2, indicates a decline in annual water consumption over the past three years compared to earlier years since 2010. This trend is mirrored in the per capita water consumption figures. The correlation between these metrics suggests that the City's population has remained relatively stable since 2010. Notably, there was an increase in water consumption during the fiscal year 2017- 2018, likely due to the lifting of water conservation restrictions.
The City monitors both water consumption and population within its service area. Consequently, per capita water consumption is a key metric for projecting future water demand. This methodology involves comparing the total water consumption across the City's service area, encompassing all land use categories, with the City's population.
It operates on the assumption that water demand from commercial and industrial land uses remains relatively constant. Given that future growth in the City is expected to be predominantly residential, this approach provides a reasonably accurate estimate of future water demands.
Table 2-2. Historical Water Consumption
Year Historic Water Consumption (afy) Per Capita Water Consumption (gpcd) 2010-11 1883 153
2011-12 1958 158
2012-13 2229 178
2013-14 2207 174
2014-15 1980 154
2015-16 1776 138
2016-17 1752 134
2017-18 2179 167
2018-19
2019-20
2020-21 1766 136
2021-22 1735 136
2022-23 1495 119
Average (AF) 1905 150
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Figure 2-2. Annual Water Consumption (Acre-Feet)
2.4.2 Unaccounted-for Water
The discrepancy between water production and consumption, known as unaccounted-for water, arises from factors such as water loss and unmetered consumption. Water losses typically occur due to system leakages, while unmetered consumption results from activities such as hydrant testing and flushing, fire hydrant usage, street sweeping and cleaning operations, the installation and testing of new water mains and facilities, and meter inaccuracies.
Meter errors can significantly contribute to unaccounted-for water. Flow meters operating outside their optimal range often record lower flow rates, and their accuracy diminishes over time due to wear and tear. The City's computerized billing system can detect abnormal meter readings, and these meters are routinely tested. On average, the City replaces each flow meter every ten years.
The total amount of unaccounted-for water is calculated by comparing groundwater and imported water supplies with metered water consumption, as illustrated in Table 2-3. Over the past three years, the average unaccountedfor water has been approximately 11% of total production, which is close to the American Water Works Association's (AWWA) benchmark of 10%. To account for unaccounted-for water, the average annual total production for FY20- 23, which is 1,877 acre-feet per year (AFY) or 1,166 gallons per minute (gpm), was used to estimate the system's average annual demand.
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Table 2-3. Production vs. Consumption (Acre-Feet)
Average AFY FY20-21 FY21-22 FY22-23
3-yr Average
(AFY)
3-yr Average
(gpm)
Production 1,948 2,016 1,666 1,877 1,166
Consumption 1,766 1,735 1,495 1,665 1,034
Consumption / Production (%) 91% 86% 90% 89% 89%
Figure 2-3. Monthly Water Production vs. Consumption (Acre-Feet)
2.4.3 Future Demands
2.4.3.1 Projected Average-Day Demand
Total water usage in the City has generally decreased over the past three years. Due to current and planned water conservation measures and programs implemented by the City, it is estimated that water usage will remain stable over the next 20 years. According to billing records from the past three years (FY 2020-2023), per capita water use (gallons per day) dipped slightly in FY 2022-2023 but remained relatively constant in the previous two years.
Consequently, a conservative estimate of 158 gallons per day per capita was used to project demands for 2030, 2035, 2040, and 2045, as shown in Table 2-4.
The existing City population figures in recent years were sourced from the US Census. The projected populations for 2030, 2035, and 2040 were directly referenced from the 2020 Urban Water Management Plan (UWMP, Table 3-5, Population – Current and Projected). The projected population for 2045 assumes a growth of 200 persons between 2040 and 2045, using the same method applied in the 2020 UWMP to project the 2040 population.
Existing demand and demand projections for 2030, 2035, 2040, and 2045 for each pressure zone are presented in Table 2-5. Based on the spatial join between the City’s billing records and the water meter GIS layer, 76% of the total system demand is allocated to Zone 1, with 14% in Zone 2 and 10% in Zone 3/3A. 0 50
100
150
200
250 Acre-feet
Average Production
Average Consumption
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Table 2-4. Projected Water Demands, Total ADD
Existing Demands Projected Demands
Year FY 20-21 FY 21-22 FY 22-23 2030 2035 2040 2045
City Population 11,559 11,381 11,249 12,045 12,212 12,412 12,612 Population Growth % — -1.5% -1.2% — 1.4% 1.6% 1.6%
Water Production (gpd)
Per Capita
151 158 132 158 158 158 158
Water Demand (AFY) 1,948 2,016 1,666 2,128 2,157 2,193 2,228 Water Demand (gpm) 1,210 1,252 1,035 1,322 1,340 1,362 1,384
2.4.3.2 Projected Maximum-Day and Peak-Hour Demand
By applying the Maximum Day Demand (MDD) / Average Day Demand (ADD) and Peak Hour Demand (PHD) / ADD peaking factors to the projected ADD of the City’s water distribution system for the years 2030, 2035, 2040, and 2045, we can estimate the corresponding MDD and PHD values. These calculations provide a detailed forecast of the system's capacity requirements, ensuring that the infrastructure can meet future demand peaks. The resulting estimated MDD and PHD values are presented in Table 2-5.
Table 2-5. Demands by Zone
Zone 1 Zone 2 Zone 3 Total
Existing
ADD 890 161 114 1,166
MDD 1,513 275 194 1,982
PHD 2,875 522 369 3,766
2030
ADD 1,009 183 130 1,322
MDD 1,716 311 220 2,247
PHD 3,260 591 418 4,270
2035
ADD 1,018 174 147 1,340
MDD 1,739 316 223 2,278
PHD 3,305 599 424 4,328
2040
ADD 1,035 177 150 1,362
MDD 1,768 321 227 2,315
PHD 3,359 609 431 4,399
2045
ADD 1,052 180 152 1,384
MDD 1,796 326 231 2,353
PHD 3,413 619 438 4,470
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2.4.4 Peaking Factors
2.4.4.1 Maximum-Day Demands (MDD)
The maximum-day demand (MDD) represents the highest single-day water demand within a given year. This is determined by applying a maximum-day demand factor to the annual average day demand (ADD). To identify the day with the highest demand of the year, Dudek conducted a comprehensive water balance analysis of the City’s entire system, utilizing SCADA data to monitor storage level changes and flows at key locations.
As a result, the daily demand for 2023 is illustrated in Figure 2.4. The data shows an increase in daily demand during the summer months, peaking on August 30th, 2023, at 1,797 gallons per minute (gpm). Consequently, the MDD/ADD factor was calculated to be 1.67, based on an ADD of 1,074 gpm for FY 2022-2023, derived from production data. For the purposes of this master plan, the MDD/ADD peaking factor has been conservatively rounded up to 1.7.
It is important to note that Metropolitan Water District (MWD) flow data was unavailable from January to June.
Therefore, the daily demand shown in Figure 2.4 for those months is lower than in autumn and winter. However, since the primary objective of this analysis is to determine the maximum daily demand, which historically occurs in July and August, this lack of data does not affect the overall result.
Figure 2-4. Daily Peaking Factor, 2023
* MWD flow data unavailable from January to June. Actual demand in those months is higher than shown.
2.4.4.2 Peak Hour Demands (PHD)
Peak-hour demand (PHD) refers to the highest single-hour water demand within a given year, which may or may not coincide with the maximum-day demand (MDD). The PHD is determined by applying a peak-hour demand factor to the average-day demand (ADD) for that year.
Dudek conducted an hourly water balance analysis for all days in August 2023, the month with the highest demand in 2023, using SCADA data. The analysis revealed that weekdays between August 1 and August 21 generally
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exhibited a morning peak around 8 a.m., as illustrated in Figure 2-5. The highest peak occurred on August 21, 2023, with a PHD/MDD factor of 1.88 at 8 a.m. For the purposes of this master plan, a peak-hour demand factor of 1.9 was utilized. The peaking factors are summarized in Table 2-6.
Figure 2-5. Hourly Peaking Factor, Weekdays in August 2023 Table 2-6. Peaking Factors
Peaking Factor (Value x ADD)
Average (ADD) 1.0
Max Day (MDD) 1.7
Peak Hour (PHD) 3.23
2.4.5 Historical Water Production
On June 10, 2022, the City's Water Conservation Program was elevated to Level 2, following a mandate by the State Water Resources Control Board. This escalation in conservation efforts led to a noticeable reduction in water usage during the fiscal year 2022-2023, compared to the previous two years. The implementation of Level 2 restrictions included measures such as limiting outdoor watering, encouraging the use of water-efficient appliances, and promoting public awareness campaigns about water conservation.
As a result of these measures, the total water production in the City, which encompasses both groundwater production and imported water purchases, experienced a significant decline. This data is comprehensively detailed in Table 2-7 and visually represented in
.
These figures illustrate the impact of the conservation program on the City's overall water usage, highlighting the effectiveness of the implemented measures in reducing water consumption. 0 50 Monthly Production (AF) Production FY20-21
Production FY21-22
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Table 2-7. Total Monthly Water Production (Acre-Feet)
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Total
(AF)
Ratio to
3-yr
Average
FY20-21 137 128 144 158 174 171 185 189 181 173 160 150 1,948 104% FY21-22 154 142 157 161 175 169 178 194 190 181 165 151 2,016 107% FY22-23 119 118 119* 120* 138 141 159 175 163 158 130 126 1,666 89% Average (AF) 136 129 140 146 163 160 174 186 178 170 151 142 1,877 100% Note:
* Data edited to fix reading error.
Figure 2-6. Monthly Water Production (Acre-Feet)
2.4.6 Historical Rainfall
Monitoring annual rainfall conditions is crucial, as rainfall significantly influences water demand, particularly for irrigation purposes, and contributes to the recharge of the underlying groundwater aquifer during wet years.
Understanding these patterns helps in planning and managing the City's water resources effectively.
Table 2-8 presents historical rainfall data recorded at the City of Signal Hill Rain Gauge Station. This data reveals that annual rainfall has fluctuated considerably since 2000, with an average of 9.80 inches per year. These variations in rainfall are essential for predicting water availability and demand, as well as for developing strategies to ensure a sustainable water supply.
During years of higher rainfall, the increased water availability can reduce the need for supplemental irrigation, thereby lowering overall water demand. Conversely, in years of lower rainfall, the demand for irrigation water typically rises, placing additional pressure on the City's water resources. Additionally, wet years contribute to the natural recharge of the groundwater aquifer, enhancing the long-term sustainability of the water supply. 0 50
100
150
200
250 Monthly Production (AF) Production FY20-21
Production FY21-22
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By closely tracking and analyzing rainfall patterns, the City can better anticipate changes in water demand and make informed decisions regarding water conservation measures and resource management. This proactive approach ensures that the City remains resilient in the face of varying climatic conditions and continues to meet the water needs of its residents.
Table 2-8. Historical Rainfall at Signal Hill Rain Gauge Station (inch) Year
00-
01 01-
02 02-
03 03-
04 04-
05 05-
06 06-
07 07-
08 08-
09 09-
10 10-
11 11-
12 Avg.
Annual
Total
13.6 3.4 12.3 5 22.4 6.6 2.7 9.1 8.1 12.9 18 7.4
11.2 Year
12-
13 13-
14 14-
15 15-
16 16-
17 17-
18 18-
19 19-
20 20-
21 21-
22 22-
23 23-
24 Annual
Total
6.1 4.5 8.1 6.5 20.0 3.7 16.4 13.3 4.7 6.81 19.4 23.5
Figure 2-7. Historical Rainfall at Signal Hill (inch)
13.6 3.4
12.3 5
22.4 6.6
2.7 9.1 8.1
12.9 18
7.4 6.1
4.5 8.08
6.48 19.98
3.65 16.42
13.27 4.65
6.81 19.41
20.87 0
5 10
15 20
25 Annual Total Rainfall (in)
Fiscal Year
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INTENTIONALLY LEFT BLANK
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3 Water Supply
3.1 Overview
The City of Signal Hill's primary water supply comes from local groundwater wells that draw from the Central Basin aquifer. This aquifer is an adjudicated basin managed by the Water Replenishment District of Southern California.
Currently, the City operates three wells: Well #7, Well #9, and Well #10. In 2024, Well #10 replaced the older Well #8.
Wells #7 and #10 are located outside the City of Signal Hill's service area. These wells extract water from the Central Basin aquifer and pump it into a transmission pipeline that conveys the water to the Gundry Reservoir site. The Gundry Reservoir serves as a central "forebay," receiving water from these wells for centralized treatment and disinfection before it is distributed to the City's service area. Well #9, on the other hand, is situated within the City.
The groundwater pumped from this well undergoes treatment before being introduced into the distribution system.
This ensures that the water meets all safety and quality standards before reaching consumers.
In addition to its groundwater sources, the City of Signal Hill supplements its water supply with imported water purchased through the Central Basin Municipal Water District (CBMWD), which is a member agency of the Metropolitan Water District (MWD). This imported water helps to ensure a reliable and sufficient water supply, especially during periods of high demand or drought.
Error! Reference source not found. 3-1 illustrates the locations of Wells #7, #9, and #10, as well as the MWD connection.
Figure 3-1. Existing Supply Locations
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3.2 Groundwater Supply
The City of Signal Hill sources its groundwater from the Central Basin aquifer. Over the years, the City has operated four groundwater production wells within this basin. Well #6, constructed in 1969, was operational until 1988 when a rupture in the well casing rendered it unusable, leading to its decommissioning and eventual demolition in September 2000.
Well #7, constructed in 1978, and Well #8, constructed in 1980, are both located within the City of Long Beach, approximately 4.5 miles north of the Signal Hill service area. Currently, Well #7 remains in service, while Well #8 is offline.
Well #9 was constructed in 2008, but due to groundwater quality issues, it was not immediately put into service.
Various treatment options were explored, and in 2016 and 2017, the well was prepared for operation with the construction of a treatment facility on-site. This well and its treatment facility are now operational, contributing to the City's water supply.
As of this master plan update, Well #10 has been constructed to replace Well #8 but has not been on service yet.
Upon Well #10 is online, the combined capacity of Wells #6, #9, and #10 will be sufficient to meet the majority of the City's water demand.
3.2.1 Groundwater Entitlement
The City of Signal Hill is entitled to 2,022 acre-feet per year (AFY) from the Central Basin aquifer, as adjudicated by the Los Angeles Superior Court. This judgment established the Central Basin Watermaster (Watermaster) as the regulatory agency responsible for managing the basin. Water rights have been adjudicated according to the court's judgment and succession from Atchison, Topeka & Santa Fe Railroad Company, Coast Water Company, and Perk/Lewis Foods. The Central Basin aquifer is currently managed by the Water Replenishment District of Southern California.
Under the judgment, the Watermaster annually determines the operating safe yield of the basin. The quantity of groundwater each producer can pump is calculated by applying a pumper’s share percentage to the basin's operating safe yield each year. The City of Signal Hill has prescriptive pumping rights to 2,022 AF of groundwater in the Central Basin, based on a percentage of the aquifer's total safe yield. The Department of Water Resources has confirmed that the judgment permits the City to over-extract up to 20 percent of its allowed pumping allocation, in addition to any carryover provisions.
According to the latest annual report from the Central Basin, in FY 2022-2023, Signal Hill had an allowed pumping allocation of 2,022 AFY, with a net carryover of 1,920.9 AFY from FY 2021-2022, resulting in a total right of 3,942.9 AFY. Over the past three years, the City's water right balance has remained constant, and Signal Hill has not leased its water rights to other agencies. The annual groundwater extractions in Signal Hill have been decreasing, with recorded extractions of 1,595.74 AF, 991.04 AF, and 722.6 AF in the past three years, respectively.
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3.2.2 Groundwater Quality
Enacted in 1974, the Safe Drinking Water Act (SDWA) regulates potable drinking water standards at the federal level. Under the SDWA, the U.S. Environmental Protection Agency (EPA) establishes standards for drinking water quality and oversees the states, localities, and water suppliers who implement these standards.
In California, the State Department of Public Health (CDPH) sets potable water quality standards through Title 22 of the California Code of Regulations. These regulations include primary and secondary maximum contaminant levels (MCLs). Primary MCLs are established for various organic and inorganic chemicals, trihalomethanes, and radioactivity, all of which are critical to public health. Secondary MCLs are set for chemicals or characteristics that affect the taste, odor, or appearance of drinking water. State MCLs are typically aligned with federal MCLs, but in some cases, they are more stringent.
The City of Signal Hill maintains a water quality monitoring program that complies with CDPH requirements. Monthly water quality monitoring reports for the calendar year 2023, provided to Dudek, indicate that the City's water supply consistently meets or exceeds all state and federal potable water quality standards and requirements. The local groundwater generally requires minimal treatment due to its high quality.
The City of Signal Hill disinfects its groundwater using chloramination, which facilitates easier blending with imported water that is also chloraminated. Historically, the City used chlorination as its disinfection method.
However, the transition to chloramination was made to minimize complications when blending with chloraminated imported water from the Metropolitan Water District (MWD). This transition ensures consistent disinfection throughout the system, especially during periods when local groundwater is supplemented with imported water.
The City operates a filtration plant at the Gundry Reservoir site, where water from Wells #7 and #10 is chloraminated and then filtered through a greensand filter system to treat for iron, manganese, and arsenic. It is important to note that the Gundry treatment facility does not treat perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), which have specific MCLs required by the water control resource board.
Chloramination is also conducted at the Gundry Reservoir, Temple Reservoir, and Well #9 sites.
A 20-inch transmission pipeline conveys groundwater from the wellheads to the Gundry Reservoir. The water is chloraminated before entering the Gundry Reservoir and then chloraminated again before being conveyed via a booster pump station to the Temple Reservoir. The Temple Reservoir provides gravity storage for Zone 1, pressurizes Zone 2 through a booster pump station, and serves as a forebay for water pumped to the Hilltop Reservoir. Chloramination at the Temple Reservoir ensures that chlorine residuals are maintained throughout the system, which is particularly critical during periods of low demand.
3.2.3 Groundwater Capacity
The City of Signal Hill operates three wells: Well Nos. 7, 9, and 10. Wells #7 and #10 are located outside the City of Signal Hill service area and extract water from the Central Basin aquifer. This water is then conveyed via a transmission pipeline to the City's service area. For each acre-foot of water pumped from the Central Basin aquifer, the City pays a replenishment assessment to the Water Replenishment District (WRD).
Well #9 is situated within the City of Signal Hill and has a production capacity of 1,200 gallons per minute (gpm).
However, once Well #10 becomes operational, the production capacity of Well #9 will be reduced to 650 gpm to optimize the overall system performance.
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Figure 3-1 illustrates the locations of Wells #7, #9, and #10, providing a clear visual representation of the City's groundwater extraction infrastructure.
Well 7
Well #7, constructed in 1978, is located at 6476 Orange Avenue, south of 65th Street in the City of Long Beach.
According to the well log, Well #7 was drilled to a depth of 1,032 feet, with an estimated maximum production rate of 1,830 gallons per minute (GPM) at the time of construction. However, production data for Well #7 over the past three years indicates a decreasing trend, with annual average production rates of 585 GPM, 403 GPM, and 281 GPM for fiscal years 2020-2023.
An evaluation of Well #7 was conducted by Richard Slade and Associates, with a summary memorandum distributed in May 2010. The evaluation noted that the installation of a new stainless steel casing liner in 2005 had extended the well's operational life. However, it was also observed that over time, the annulus could become clogged with biological growths, making successive well rehabilitation efforts increasingly less effective. Additionally, Well #7 is currently experiencing sanding issues, and it is recommended that the well be replaced within the next few years.
Well 9
Well #9, located in the City of Signal Hill’s Public Works Yard at 2175 28th Street, was drilled in 2008. Initially, it was not placed into operation due to issues with groundwater color. However, a treatment facility was constructed in 2016/2017 and became operational in 2018, allowing Well #9 to be utilized. Currently, Well #9 operates at a pumping rate of 650 to 700 gallons per minute (GPM).
Despite its operational status, the average annual production of Well #9 has shown a decreasing trend over the past three years, with production rates of 650 acre-feet per year (AFY), 340 AFY, and 270 AFY, respectively.
According to the City’s monthly production data, Well #9 has not been in operation since October 2022.
Well #9 has a full design capacity of 1,200 GPM to meet future demand. However, to achieve this capacity, the well would need to be redrilled, repacked, and redeveloped.
Well 10
Well #10 is located at 6065 Cherry Avenue and has a design capacity of 1,200 gallons per minute (GPM). This well is intended to replace the old Well #8, which is in close proximity. However, the Well #10 site is currently experiencing issues with vandalism due to the lack of fencing, which needs to be addressed to ensure the security and integrity of the site.
Table 3-1 provides a summary of the existing well capacities for the City of Signal Hill.
Table 3-1. Existing City Well Capacities
Well
Year
Drilled
Depth
(ft)
Groundwater
Basin
Rated
Capacity
(gpm)
Current
Production1
(gpm) Status
#6 1969 844 Central N/A 0 Demolished
#7 1978 1,032 Central 1,000 423 Active
#8 1980 1,020 Central 500 0 Offline
#9 2008 Central 650 261 Active
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Table 3-1. Existing City Well Capacities
Well
Year
Drilled
Depth
(ft)
Groundwater
Basin
Rated
Capacity
(gpm)
Current
Production1
(gpm) Status
#10 2024 Central 1,200 Permitting in
Process
Total
(GPM)
3,350
Note:
1 FY 2020-2023 three-year average per City’s monthly production data.
3.3 Imported Water Supply
The City of Signal Hill has the capability to import water through the Metropolitan Water District (MWD) Connection Central Basin-19 (CB-19), which can provide up to 3,300 gallons per minute (GPM) of imported water. This connection is located on Bixby Road near Gaviota Street. A 12-inch flow control valve, situated near the intersection of Walnut Avenue and 33rd Street (Walnut PRS), allows for the diversion of water flow directly to the Gundry Reservoir, which is located a few blocks away from the turnout.
The imported water supplies Zone 1 of the City’s distribution system through the Walnut Pressure Reducing and Flow Control Facility, supplementing the supply from the wells when additional water is needed. Figure 3-1 illustrates the location of the MWD (CB-19) connection. Downstream of CB-19, there are two additional pressure reducing stations (PRS) that enable the MWD line to directly feed the Hilltop Reservoir and Zone 3, as detailed in Table 4-3.
3.4 Groundwater vs. Imported Water Supply
The majority of the City of Signal Hill's water system demands can be met by the available local groundwater supply.
Typically, the City has utilized imported water to meet peak season demands, particularly during the four to five month dry-weather period when system demand exceeds the maximum groundwater supply. The existing MWD turnout CB-19 has a capacity of 3,300 gallons per minute (GPM). As of 2024, the combined supply capacity of the City’s operating wells (Nos. 7, 9, and 10) is 2,850 GPM. Currently, imported water serves as the only backup supply source if any of the wells experience significant downtime for maintenance or failure.
Table 3-2 compares the quantity of groundwater produced with the amount of imported water purchased over a three-year period beginning with fiscal year 2020-2021. The percentage of imported water has been rising over the past three years. Additionally, the cost of imported water is increasing, as shown in Table 3-3, which details the historical rates for Tier 1 full-service treated volumetric cost ($/AF).
With the construction of the new Well No. 10, the City is expected to rely less on imported water. For evaluations of supply options under different operating conditions, please refer to Section 7.4.
Table 3-2. Groundwater Production vs. Imported Water Purchases Supply (AFY) FY 2020-2021 FY 2021-2022 FY 2022-2023
Total Groundwater 1,596 991 723
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Table 3-2. Groundwater Production vs. Imported Water Purchases Supply (AFY) FY 2020-2021 FY 2021-2022 FY 2022-2023
Imported Water 352 1,025 944
Total 1,948 2,016 1,666
% Imported Water 18% 51% 57%
Table 3-3. MWD Projected Water Cost
Year Cost ($/AF) Year Cost ($/AF)
2016 942 2021 1,104
2017 979 2022 1,143
2018 1,015 2023 1,209
2019 1,050 2024 1,256
2020 1,078
Ref: MWD Rate Structure Administrative Procedures Handbook Groundwater Storage Plan
The City of Signal Hill, in collaboration with the Cities of Cerritos, Downey, Lakewood, and Long Beach, developed a new groundwater storage plan, which received approval from the Los Angeles Superior Court on December 18, 2013. This plan was designed to ensure the sustainability of the water supply in Southeast Los Angeles County.
Unlike the previous agreement from 1965, this new agreement permits the storage of groundwater, allowing participating cities to store water in the underground water table and extract it when necessary.
This arrangement provides the flexibility for participating cities to purchase water at lower costs during wet years and store it for use during dry years when water purchase costs are higher. Under the new agreement, the City of Signal Hill has the right to pump 2,022 acre-feet (AF) of water per year. Additionally, the City has the capability to store an extra 50 percent of its water right allotment and carry over any unused water up to 60 percent of its water rights in any given year.
3.5 Emergency Connections
The City of Signal Hill has historically maintained an emergency mutual-aid water connection with the City of Long Beach. In emergency situations, the City of Long Beach can supply Signal Hill with a capacity of 750-800 gallons per minute (GPM). This connection, located on Willow Street, links a 20-inch Long Beach main to a 12-inch Signal Hill main through an 8-inch intertie and does not have a meter, resulting in no charge for the water consumed.
Available records indicate that this interconnection was last utilized in August 1983. Historical data shows that the pressure on the Signal Hill side of the connection is slightly higher than on the Long Beach side. It is recommended that this interconnection be exercised regularly and that a meter be installed to ensure proper operation.
In 2017, an additional emergency connection was established with the City of Lakewood at the 3800 block of Cherry Avenue (City of Long Beach). This vault/interconnection was connected to Signal Hill’s new 6-inch pipeline ending at the sidewalk. On May 24, 2022, Signal Hill’s City Council approved an amendment to the water interconnection agreement, allowing the City of Lakewood to provide treated potable water to Signal Hill at a 15% discounted rate compared to the regular rate with the Metropolitan Water District of Southern California. 15851 23
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4 System Facilities
4.1 Pressure Zones
Signal Hill’s potable water system is divided into three primary pressure zones: Zone 1, Zone 2, and Zone 3, along with a sub-zone referred to as Zone 3A. This division is necessary due to the significant variations in topography within the City. The sub-zone, Zone 3A, was established after it was determined that the area could not maintain normal operating pressure when served directly from either Zone 2 or Zone 3. To address this issue, the City created Zone 3A, which receives water through an existing pressure reducing station connected to the Zone 3 system.
Ground elevations within the City of Signal Hill service area range from 20 feet to 358 feet above mean sea level.
The highest elevations are found in the central region of the City, while the lower elevations are located along the City’s boundary. Consequently, the Zone 1 service area primarily encompasses the perimeter of the City, where the pressure is higher. Zones 2 and 3 are situated in the central area, generally south of Willow Street and east of Walnut Avenue.
These pressure zones are designed to ensure that all areas within the City receive adequate water pressure, despite the varying elevations. The graphical representation of these pressure zones is provided in Figure 4-1, which illustrates the distribution and boundaries of each zone.
Figure 4-1. Existing Pressure Zones
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4.2 Wells
The City of Signal Hill operates three groundwater production wells to meet its water supply needs.
Well No. 7, with a capacity of 1,000 gallons per minute (GPM), is located on Orange Avenue in Long Beach, approximately 5 miles north of Signal Hill’s service area. This well plays a crucial role in supplying water to the City, despite being situated outside the immediate service area.
Well No. 9, with a capacity of 650 GPM, is located within the City’s service area, as depicted in Figure 4-1. This well is strategically positioned to directly discharge into the distribution system of Zone 1, ensuring a reliable water supply to the central and lower elevation areas of the City.
Well No. 10, with a capacity of 1,200 GPM, was recently drilled to replace the demolished Well No. 8. It is located near the same site on Cherry Avenue in Long Beach, as shown in Figure 4-2. This new well enhances the City's water production capacity and ensures a stable supply for future demands.
Both Well No. 7 and Well No. 10 pump water into the Gundry Reservoir, which is located at the northern boundary of Signal Hill’s service area. The Gundry Reservoir acts as a central collection and treatment point, where water from these wells is treated and disinfected before being distributed throughout the City. This setup ensures that the water quality meets all regulatory standards and is safe for consumption.
Well No. 9, on the other hand, discharges directly into the distribution system of Zone 1. This direct discharge helps maintain adequate water pressure and supply in the central areas of the City, which are at higher elevations compared to the perimeter zones.
The strategic placement and operation of these wells, along with the Gundry Reservoir, form a robust and efficient water supply system for the City of Signal Hill, ensuring that residents have access to a reliable and high-quality water supply.
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Figure 4-2. Existing Wells
4.3 Existing Storage Reservoirs
The City of Signal Hill operates three reservoirs that provide essential water storage for the system, with a total storage capacity of 7.3 million gallons (MG). The majority of this storage is at the forebay level, within the 4.7 MG capacity Gundry Reservoir. Additionally, the Temple Reservoir stores 1.4 MG within Zone 1, and the Hilltop Reservoir provides 1.2 MG of storage for Zone 2. A summary of the existing storage capacities for the City of Signal Hill is provided in Table 4-1.
Table 4-1. Potable Water Storage Reservoirs
Name Zone
Elevation
(ft)
Maximum Level
(ft) HWL (ft) Dimension Vol (MG)
Gundry Reservoir Gundry 50 20 70 200' Diameter 4.7
Temple Reservoir I 228 25 253 68' x 120'
rectangular base
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Table 4-1. Potable Water Storage Reservoirs
Name Zone
Elevation
(ft)
Maximum Level
(ft) HWL (ft) Dimension Vol (MG)
Hilltop Reservoir II 311 22 332 97.5' Diameter 1.2
Total: 7.3
Gundry Reservoir is a partially buried circular concrete tank with a metal roof, offering a storage capacity of 4.7 MG.
This reservoir is a critical facility for the City, as it receives water from Wells No. 7 and No. 8, which is then conveyed to Zone 1 and the higher-pressure zones. The interior of Gundry Reservoir was recoated in 2006 to maintain its integrity. Groundwater treatment facilities located at the same site as the reservoir and pump station are discussed further in Section 4.8.
Temple Reservoir serves Zone 1 by gravity, with a high water level of 253 feet. It has a storage capacity of 1.4 MG and was constructed as a rectangular concrete structure with a bottom elevation of 229.75 feet, measuring 68 feet in width and 120 feet in length. The Temple Reservoir not only stores water for Zone 1 gravity service but also provides fire storage for Zones 2 and 3. This is facilitated by two dedicated sets of fire pumps at the Temple Pump Station, which are equipped to deliver water to these higher-pressure zones.
Hilltop Reservoir is a 1.2 MG circular pre-stressed concrete tank that serves Zone 2 by gravity and enables storage for water to be pumped to Zone 3. Located near the intersection of Skyline Drive and Dawson Avenue, the reservoir was constructed with a bottom elevation of 313 feet, a high water level of 33 feet, and a diameter of 100 feet.
During its construction, the tank was fully buried to allow for the development of a park above it, optimizing land use and providing additional community benefits.
4.4 Pump Stations
Signal Hill operates four booster pump stations that transfer water from lower to higher pressure zones. The Gundry Pump Station (5,000 GPM) serves as the main water supply for Signal Hill, pumping water from the Gundry Reservoir to the Temple Reservoir. From the Temple Reservoir, the Temple Pump Station has two sets of pumps: the first set provides a capacity of 1,500 GPM to the Hilltop Reservoir (Zone II), while the second set offers a capacity of 3,100 GPM to Zone III, including a 2,500 GPM fire pump and a 600 GPM backup for Zone III domestic demand. The Hilltop Pump Station is the primary supply for Zone III under normal operations, moving water from the Hilltop Reservoir (Zone II) to Zone III and subsequently to Zone 3A through a pressure reducing station (PRS).
Table 4-2 provides detailed information on the existing booster pump stations and their capacities.
Table 4-2. Potable Water Booster Pump Stations
Pump Station Supply Zone
Discharge
Zone #Pumps
Total Capacity
(GPM)
Firm Capacity
(GPM)
Backup
Generator
Gundry PS Gundry
Reservoir
I 4 5,000 3,750 Y
Temple PS I II 3 1,500 1,000 Y
Temple PS I III 3 3,100 600 Y
Hilltop PS II III 2 600 300 N
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The Gundry Pump Station currently operates with four electric-driven pumps, as shown in Table 4-3. Typically, two pumps are used in a lead/lag configuration, with the lead pump operating regularly and the second pump used as needed or when boosting water to the Temple Reservoir. The other two pumps serve as standby units. Historically, the lead pump operates for approximately 17 hours per day during the summer months, with reduced operating hours in the winter. To extend the service life of each pump, they are rotated into service to maintain approximately equal hours of operation.
The Temple Zone 2 Pump Station delivers water from the Temple Reservoir to the Zone 2 Hilltop Reservoir, which has a high water level of 332 feet, and directly into the Zone 2 distribution system. The Temple Zone 3 Pump Station provides domestic and fire flow from the Temple Reservoir directly into the Zone 3 distribution system, with a high water level of 490 feet. The portion of the Temple Pump Station dedicated to pumping to the Zone 2 Hilltop Reservoir has sufficient capacity to meet Zone 2 demands and a portion of Zone 3's maximum-day demand within a 16-hour period.
The Hilltop Pump Station, located at the same site as the Hilltop Reservoir, pumps water to serve Zone 3.
Another important consideration for the City of Signal Hill's pump system is its efficiency and impact on annual energy use. According to pump efficiency tests conducted by Southern California Edison (SCE) leading up to the 2005 Water Master Plan, the pumps were operating at relatively low efficiencies (60 to 65 percent), and the motors were exceeding their service factors at rated pumping capacities. In 2012, the City replaced the electric motors at Well No. 7 and the Gundry Pump Station to improve efficiency.
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Figure 4 3. Signal Hill Potable Water System Schematic
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4.5 Imported Water Connection
The City of Signal Hill has the capability to receive imported water through a service connection from the Metropolitan Water District (MWD) system. This service connection, known as turnout CENB-19, is located on the second lower feeder, specifically on Bixby Road near Gaviota Street. The connection is rated to handle a maximum capacity of 7.5 cubic feet per second (CFS), ensuring a substantial supply of imported water when needed.
The imported water is introduced into the lower zone of the City's water distribution system through the Walnut Pressure Reducing and Flow Control Facility (Walnut PRS), which is situated near the intersection of Walnut Avenue and 33rd Street. This facility plays a crucial role in managing the flow and pressure of the imported water, ensuring it is suitable for distribution within the City's system.
The hydraulic grade line of the MWD water typically ranges from 500 feet to 540 feet in elevation. To integrate this high-pressure water into the City's distribution system, which operates at lower pressures, the City employs several pressure reducing stations (PRS). These stations are designed to take the higher pressure water from the MWD system and reduce the hydraulic grade to a range of 236 feet to 258 feet before transmitting it to the Zone 1 system. This reduction in pressure is essential to prevent damage to the infrastructure and to ensure the safe and efficient distribution of water throughout the City.
The strategic placement and operation of these facilities allow the City of Signal Hill to effectively manage its water supply, ensuring that both local groundwater and imported water are utilized efficiently to meet the needs of its residents. The ability to import water provides an additional layer of reliability and flexibility, particularly during periods of high demand or when local water sources are insufficient.
4.6 Pressure Reducing Stations
The City of Signal Hill's water distribution system includes four pressure reducing stations (PRS), as detailed in Table 4-3. These stations play a crucial role in managing the pressure of imported water from the Metropolitan Water District (MWD) to ensure it is compatible with the City's distribution system.
The imported water from MWD is introduced into Zone 1 through the Walnut PRS, which operates at approximately a 100-foot hydraulic grade line (HGL). This station reduces the high pressure of the imported water to a level suitable for the lower zone of the City's system.
Additionally, the MWD High Pressure Line can directly feed into the Hilltop Reservoir through the Skyline PRS, which operates at around a 330-foot HGL. This setup allows for efficient water transfer to higher elevation areas within the City.
There is also another PRS that enables direct MWD supply into Zone III, operating at approximately a 490-foot HGL.
This station ensures that the high-pressure water from MWD is adequately reduced before being distributed to the higher pressure zones, maintaining system integrity and operational efficiency.
These pressure reducing stations are essential components of the City's water infrastructure, allowing for the seamless integration of imported water into the local distribution system. By effectively managing water pressure, these stations help maintain a reliable and consistent water supply for all areas within the City.
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Table 4-3. Existing Pressure Reducing Stations
PRS Location Supply
Zone
Discharge Zone
Walnut PRS Walnut Ave / E 33rd St MWD I
Skyline PRS Skyline Dr / Ocean
View Dr MWD
II (Hilltop
Reservoir)
III
Zone 3A PRS Temple Ave / E 21st St III 3A
4.7 Pipelines
The City of Signal Hill owns and maintains approximately 50 miles of distribution and transmission pipelines. A summary of the pipeline lengths by material and age is provided in Table 4-4. Notably, 56% of these pipelines consist of aging cast iron or asbestos cement, which were installed before 1980. These older pipelines are in need of either relining or replacement to ensure the reliability and safety of the water distribution system.
Relining the pipelines is a cost-effective option that involves applying a new lining to the interior of the existing pipes. While this method reduces capital costs, it does not address external corrosion, which can continue to compromise the integrity of the pipelines over time. Therefore, in some cases, complete replacement of the cast iron and asbestos cement pipelines may be necessary to fully mitigate the risks associated with aging infrastructure.
Project #14 in Table 8-1 includes the estimated costs for replacing the cast iron and asbestos cement pipelines.
This project is part of the City's ongoing efforts to upgrade and modernize its water distribution system, ensuring a reliable and high-quality water supply for its residents.
Table 4-4. Pipe Length Breakdown by Material/Age
Installation
Year
Material
AC CI DI STL CML & C WSP Unknown Total (ft)
1960s 9,822 46 1,306 11,174
1970s 49,079 648 681 3,801 9 54,218
1980s 34,930 12,925 112 47,967
1990s 50 28,060 789 28,899
2005 1,993 1,993
2012 358 358
Unknown 16,918 76,918 30,780 4,278 14 128,908
Total 110,799 77,611 74,796 9,385 804 121 273,516
% 41% 28% 27% 3% 0% 0% 100%
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4.8 Water Treatment
The City of Signal Hill chloraminates its water supply and operates a filtration plant at the Gundry Reservoir site to remove arsenic, iron and manganese from source water received from Well Nos. 7 and 10.
Since the 2005 Water Master Plan, steps have been taken to convert the City’s disinfection methods from chlorination to chloramination in an effort to increase the compatibility of the local groundwater supply with MWD water. An ancillary benefit of converting to chloramination is the potential reduction in the formation of total trihalomethanes (TTHMs). Available water quality reports show that TTHM levels are well below the MCL and not a typical concern in the water system. Future treatment options depend on preferences for future water supply and whether or not additional water treatment is required for each given option.
At the Gundry Reservoir site the City operates two filtration pressure vessels. The filtration system includes a sodium hypochlorite feed system to oxidize iron, manganese and arsenic.
The design criteria of the filtration system are:
Total Design Flow = 3,000 GPM
Design Flow per Vessel = 1,500 GPM
Iron – treated to less than 10 ppm
Manganese – treated to less than 10 ppb
Arsenic – treated to less than 5 ppb
A liquid sodium hypochlorite and ammonia solution is used to chloraminate water supplied from Well Nos. 7 and 8 at the Gundry Reservoir site. On-site sodium hypochlorite generation capable of producing 150 pounds of chlorine a day was installed at Gundry Reservoir site. The equipment includes an electrolytic cell, control panel, transformer, brine injection pump, brine tank and water softener. A chlorine residual of 1.0mg/l was established as the target chlorine level leaving the Gundry Reservoir site and entering the distribution system.
A liquid sodium hypochlorite and ammonia solution is used to chloraminate water at Temple Reservoir. On-site sodium hypochlorite generation capable of producing 37 pounds of chlorine a day was installed at Temple Reservoir site. The hypochlorite generation system enables the City to maintain chlorine residual through Zone 2 and 3.
The same solution is also used at Well 9 treatment facility to chloraminate well water prior to distribution from the site.
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5 Condition Assessment
In February 2024, Dudek conducted site visits and condition assessments at the City’s major water facilities. Prior to this, the Division of Drinking Water (DDW) carried out a sanitary survey on May 17 and June 12, 2023, and subsequently prepared a report dated November 30, 2023. This Sanitary Survey report identified a list of projects that DDW requested the City to address. The following sections provide a description of observations and recommendations at each site. Detailed site features are included in Appendix A.
5.1 General, Distribution System
The DDW provided a list of recommendations regarding operations and maintenance, specifically focusing on water quality monitoring, record keeping, and the potential need for additional staff. They advised prioritizing the replacement of asbestos cement piping in the City’s distribution system to mitigate the risk of asbestos contamination. Currently, 41% of the City’s 5-mile distribution pipeline network consists of asbestos cement materials installed before the 1980s.
5.2 Wells
Dudek conducted site visits to the three groundwater wells, Well 7, Well 9, and Well 10. The observations from these visits are detailed in Table 5-1, and the recommendations are summarized in Table 5-2.
Table 5-1. Wells Site Visit
Well #7:
The Well #7 site features a gated entrance and a
building that houses the wellhead and electrical
equipment. The existing electrical utility service
entrance section and switchboard, which appear to
be original equipment from 1978, have exceeded
the industry standard useful life of 30 years. The
current site Programmable Logic Controller (PLC) is
a Modicon 984 Micro series, which is no longer
commercially available. In the event of a PLC
failure, replacement parts would be unavailable,
rendering the site inoperable remotely. Well #7
currently has a cast iron casing from 2008 that
need to be replaced with stainless steel casing.
It is recommended to conduct regular testing and
maintenance of the switchboard and to keep spare
breakers on hand until the switchboard and well
motor controller can be replaced. Additionally, it is
advised to replace the PLC within the next year.
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Table 5-1. Wells Site Visit
Well #9:
Constructed in 2008, Well #9 features equipment
that appears to be in excellent condition.
Well #10:
Constructed to replace Well #8 at the same site,
Well #10 has not yet been placed into service as of
2024. The site features a gated entrance and a
building that houses the electrical equipment,
while the wellhead and generator are located
outside the building. The generator has already
experienced vandalism, and the well’s emergency
ON/OFF switch, mounted next to the wellhead, is
also at risk.
It is recommended to enhance site security by
constructing a new building or installing a chainlink cage around the generator and wellhead.
Alternatively, adding an intrusion detection alarm,
increasing the wall height, or installing barbed wire
on the site fence could further deter unauthorized
access.
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Table 5-2. Wells Recommendations
Well # Recommended Improvement Description Type of Issue/ Risk Well #7 Replace electrical equipment and PLC End of Useful Life Well #10 Improve site security Security Risk
5.3 Hilltop Reservoir and Pump Station
Installed in 1998, the Hilltop reservoir and pump station are located in a public park atop a small hill. The reservoir serves Pressure Zone II by gravity and Pressure Zone III through the Hilltop pump station. The 1.2-million-gallon (MG) concrete reservoir is entirely below grade with landscaping on top.
The Hilltop pumps are housed in a below-grade concrete vault. There are two pumps that deliver water to Pressure Zone III, both of which are in good operating condition. Power and control for the pumps are provided by electrical panels mounted at grade near the pump station vault. While there is no permanent backup generator on site, a plug-in receptacle is available to connect a portable generator, ensuring the pump station can operate in the absence of utility power. The observations from the site visit are detailed in Table 5-3, and the recommendations are summarized in Table 5-4.
Table 5-3. Hilltop Reservoir Site Visit
Mechanical:
Dudek was unable to enter the vault during our
inspection, limiting the assessment to a visual
inspection from the access hatch. The pumps and
pump station within the vault appear to be in good
operating condition, and the City has reported no
issues with them.
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Table 5-3. Hilltop Reservoir Site Visit
Structural:
DDW's visual inspection indicated that the stored
water in the reservoir appears stagnant. The
reservoir has six air vents that are less than six
inches above grade, making them susceptible to
contamination by dirt and pesticides.
It is recommended to add a mixer to the reservoir.
Additionally, City staff should adjust operations and
maintenance practices to prevent potential
contamination of the air vents.
Electrical:
The existing utility meter section and Motor Control
Center (MCC), installed in 1998, are approaching the
industry standard life expectancy of 30 years for
electrical equipment. All electrical equipment shows
consistent signs of water entry and rust damage,
particularly at the meter section. The current site
Programmable Logic Controller (PLC) is a Modicon
984 Micro series, which is no longer commercially
available. In the event of a PLC failure, replacement
parts would be unavailable, rendering the site
inoperable remotely.
Immediate repair of the rust hole in the side of the
MCC meter section and elimination of irrigation
water intrusion are recommended. Additionally, it is
advised to replace the PLC within the next year with
a newer series, such as the M340 or M580.
Table 5-4. Hilltop Reservoir Site Recommendations
Asset Discipline Recommended Improvement Description Type of Issue/ Risk Structural Add a mixer to reservoir Safety Risk
Electrical Repair rust hole in MCC meter section, eliminate irrigation water intrusion,
Security Risk
Electrical Replace MCC End of Useful Life
Electrical Replace PLC End of Useful Life
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5.4 Temple Reservoir and Pump Station
Installed in 1998, the Temple Reservoir and pump station are located in a residential area. The reservoir is entirely buried with a shallow earth fill on top, overlooked by several multi-story residential buildings. The lot size is approximately 145 feet by 250 feet. The Temple Reservoir supplies water to Pressure Zone I via gravity flow, and the Temple pump station has two separate sets of pumps to serve Pressure Zones II and III, respectively.
There is no onsite water treatment equipment. At the time of this master plan update, the Temple Reservoir disinfection improvement project is currently in progress. The project involves replacing and upgrading the existing disinfection station, including installing mixers and a submersible pump within the reservoir, as well as incorporating analyzers, control panels, and two 250-gallon double-walled tanks for storing sodium hypochlorite and ammonium sulfate. The City of Signal Hill has posted a Notice of Exemption for this project, indicating that it is moving forward under the guidelines of the California Environmental Quality Act (CEQA).
The observations from the site visit are detailed in Table 5-5, and the recommendations are summarized in Table 5-6.
Table 5-5. Temple Reservoir Site Visit
Mechanical:
The Temple pump station is housed within an atgrade building situated in a fully enclosed area lower than the reservoir. It contains three 25-
horsepower (hp) pumps that deliver water to Zone
II, two 50-hp pumps that deliver water to Zone III,
and one 300-hp fire pump that also serves Zone
III. All pumps are Peerless vertical turbines and are
in good condition.
Structural:
A surge tank is located in an area lower than the
reservoir and appears to be in good condition. The
DDW recommended removing the soil cover from
the reservoir roof to prevent the presence of
burrowing animals in the soil mass. The City
believed that the roof slab was not structurally
capable of supporting earth-moving equipment
and therefore obtained bids for manual earth
removal, which resulted in costs as high as
$500,000. Dudek recommended reviewing the
reservoir design drawings and potentially
evaluating the structural strength of the reservoir
to support soil cover removal using small front-end
loaders and trucks.
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Table 5-5. Temple Reservoir Site Visit
Electrical:
A backup generator is located inside the pump
building, and both the electrical equipment and
generators appear to be in good condition. The
Motor Control Center (MCC) is a current generation
Allen-Bradley model and is in very good condition,
with no need for replacement for another 10 to
15 years.
However, the existing site Programmable Logic
Controller (PLC) is a Modicon 984 Micro series,
which is no longer commercially available. In the
event of a PLC failure, replacement parts would be
unavailable, rendering the site inoperable
remotely. It is recommended to replace the PLC
within the next year with a newer series, such as
the M340 or M580.
Table 5-6. Temple Reservoir Site Recommendations
Asset Discipline Recommended Improvement Description Type of Issue/ Risk Structural Remove soil cover from reservoir roof Safety Risk Electrical Replace PLC End of Useful Life
5.5 Gundry Reservoir and Pump Station
The Gundry Reservoir and Pump Station are situated in a public park surrounded by a residential area. The reservoir site measures approximately 250 feet in width and 300 feet in length, while the entire park spans roughly 300 feet by 600 feet, also housing the abandoned Well #1 and Well #2. The reservoir and pump station were originally installed in December 1929 or the early 1930s and underwent rehabilitation in 1985. The Gundry Reservoir and Pump Station serve as the primary water supply for the entire Signal Hill water system. They receive water from Well #7 and Well #10, supplying Pressure Zone I by pumping to the Temple Reservoir through the Gundry Reservoir, and to upper zones by further pumping from the Temple Reservoir.
The concrete water reservoir is partially buried, with approximately 70% below grade, and has a total storage capacity of 4.7 million gallons (MG). An above-grade 50-foot by 60-foot concrete sand settling structure provides quiescent flow conditions to allow sand to settle out from the well water influent supply. Backup generators are located outdoors, and a 15-foot by 34-foot building adjacent to the sand settling structure houses disinfection
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equipment for water treatment. Next to the Gundry Reservoir, there are horizontally mounted pressure filter tanks designed to remove iron and manganese.
The observations from the site visit are detailed in Table 5-7, and the recommendations are summarized in Table 5-8.
Table 5-7. Gundry Reservoir Site Visit
Mechanical:
An above-grade L-shaped pump building houses
four 125-horsepower (hp) pumps that deliver
water from the Gundry Reservoir to the Temple
Reservoir.
Structural:
The reservoir roof, consisting of thin metal
panels supported by metal columns inside the
reservoir, is deteriorated. The overflow drain,
which discharges to the ground surface, is also
corroded. The roof of the sand settling structure,
made of the same material as the reservoir roof,
is partially collapsed and unsafe for operations
and maintenance access.
Aside from the roofs, the facilities on site appear
worn but remain functional. Water accumulation
was noted on the floor adjacent to the reservoir,
and algae growth was observed near the
overflow outdoor vault, likely due to leakage.
It is recommended to prioritize the replacement
of the reservoir roof and the sand settling
structure roof, as per the DDW 2023 sanitary
survey. The City of Signal Hill is currently
planning to evaluate the cost and feasibility of
these roof replacements. Additionally, City staff
were advised to investigate whether the source
of the leakage is from a nearby park irrigated
with reclaimed water.
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Table 5-7. Gundry Reservoir Site Visit
Electrical:
The generator, at 23 years old, remains in good
condition. However, the switchboard, estimated
to be 60 years old based on record drawings and
consultation with Square D, has surpassed the
industry standard useful life of 30 years for
electrical equipment. This switchboard is
unserviceable as replacement parts are no
longer available. Without regular servicing or
maintenance, there is a high likelihood of a
breaker failing to trip or failing to reset after
a trip.
The existing site Programmable Logic Controller
(PLC) is a Modicon 984 Micro series, which is no
longer commercially available. In the event of a
PLC failure, replacement parts would be
unavailable, rendering the site
inoperable remotely.
It is recommended to replace the switchboard
with a new Specialist Electrical Solutions (SES)
switchboard and Motor Control Center (MCC)
within the next five years. The new switchboard
and MCC will require a larger footprint than the
existing equipment. Additionally, it is advised to
replace the PLC within the next year with a newer
series, such as the M340 or M580.
Table 5-8. Gundry Reservoir Site Recommendations
Asset Discipline Recommended Improvement Description Type of Issue/ Risk Structural Replace reservoir roof Safety Risk
Structural Replace sand settling structure roof Safety Risk Electrical Replace PLC End of Useful Life
Electrical Replace switchboard End of Useful Life
5.6 SCADA
Dudek conducted a site visit to the City’s SCADA headquarters and engaged in discussions with the City’s operators.
The observations and discussions from the site visit are detailed in Table 5-9, and the recommendations are summarized in Table 5-10.
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Table 5-9. SCADA Site Visit
The City is aware of its outdated SCADA system
and has already engaged Ardurra to manage the
SCADA improvement program. The existing
PLC/SCADA telemetry system transmits data via
copper-wired phone lines, which cannot guarantee
functionality during rainy weather. The City
previously conducted a preliminary radio survey to
assess the feasibility of using radio signals to
transmit data between the City’s headquarters and
each water facility site. This survey identified
topographical obstructions that need to be
addressed to use radio signals, and the City is
aware of several potential solutions to this
challenge.
The City also contacted Verizon (Frontier
Communications) regarding the availability of fiberoptic communications from each water facility site to City headquarters. It was determined that
certain sites have access to fiber-optic lines while
others do not. The City would need to cover the
construction costs to extend Frontier fiber optics to
the remaining sites. Consequently, a hybrid
radio/fiber optic telemetry system may be
considered a favorable option. One possible
solution is leasing space on the City of Long Beach
radio tower, which is within line of sight of all
Signal Hill sites. All sites could report to the radio
tower, which would then transmit data to the
SCADA system at City headquarters.
Communication between the Long Beach tower
and the City yard could be via radio or leased fiber
optic lines.
The SCADA server, along with all SCADA computers
and monitors except those at Well 9, are obsolete.
They run on Windows 8.1, which is no longer
supported by Microsoft, posing a security risk. The
SCADA software is 12 years old and needs
updating.
It is recommended to replace the existing SCADA
server, all SCADA computers, and monitors (except
those at Well 9) with new equipment. The SCADA
software should be replaced with Wonderware,
which includes a historical database and reports
for easy access. Additionally, it is advised to
replace the existing telemetry system with one that
operates using spread-spectrum Ethernet
communication radios and/or fiber optic lines.
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Table 5-10. SCADA Recommendations
Asset Discipline Recommended Improvement Description Type of Issue/ Risk SCADA SCADA server, all SCADA computers and monitors
except that at Well 9
End of Useful Life
SCADA Replace SCADA software End of Useful Life
SCADA Replace telemetry system with radio/fiber-optic Operational Failure
5.7 Condition Assessment Summary
Table 5-11. Condition Assessment Recommendations
Asset Discipline Recommended Improvement Description Type of Issue/ Risk Well #7 Replace electrical equipment and PLC End of Useful Life Well #10 Improve site security Security Risk
Hilltop Reservoir Add a mixer to reservoir Safety Risk
Hilltop Reservoir Repair rust hole in MCC meter section, eliminate irrigation water intrusion,
Security Risk
Hilltop Reservoir Replace MCC End of Useful Life
Hilltop Reservoir Replace PLC End of Useful Life
Temple Reservoir Remove soil cover from reservoir roof Safety Risk Temple Reservoir Replace PLC End of Useful Life
Gundry Reservoir Replace reservoir roof Safety Risk
Gundry Reservoir Replace sand settling structure roof Safety Risk Gundry Reservoir Replace PLC End of Useful Life
Gundry Reservoir Replace switchboard End of Useful Life SCADA SCADA server, all SCADA computers and monitors
except that at Well 9
End of Useful Life
SCADA Replace SCADA software End of Useful Life
SCADA Replace telemetry system with radio/fiber-optic Operational Failure
[PROJECT NUMBER] 44 [MONTH YEAR]
6 System Evaluation Criteria
The potable water design criteria outlined in this section were utilized to evaluate the existing water system under various modeled scenarios. These criteria serve as benchmarks to ensure the system's performance, reliability, and safety. They were derived from industry standards and best practices, as well as guidelines from other nearby water agencies in Southern California, such as the Western Municipal Water District.
To ensure the criteria were tailored to the specific needs and conditions of Signal Hill, they were thoroughly discussed with City staff. This collaborative process ensured that the criteria were both relevant and practical for the City's water system. After careful consideration and review, the criteria were formally agreed upon in April 2024.
These design criteria encompass a range of parameters, including water pressure, flow rates, storage capacities, and system redundancy. By applying these criteria, the City can accurately assess the current state of the water system, identify potential areas for improvement, and plan for future upgrades and expansions.
6.1 System Pressures
The potable water system pressure criteria, detailed in Table 6-1, serve as essential benchmarks for evaluating and maintaining the performance of Signal Hill's water distribution system. These criteria were carefully reviewed and confirmed by Signal Hill staff in April 2024, ensuring they are tailored to the specific needs and conditions of the City's water infrastructure.
By adhering to these pressure criteria, the City can ensure that all areas within the service zone receive consistent and reliable water pressure, which is crucial for both residential and commercial users. Adequate water pressure is also vital for the effective operation of fire hydrants and other emergency response systems.
Table 6-1. Potable Water Pressure Criteria
Criteria Recommended value
Minimum service pressure 40 psi
Maximum service pressure 150 psi
Maximum daily pressure fluctuation 20 psi
6.2 Pipeline Criteria
The potable water system pipeline criteria, detailed in Table 6-2, provide essential guidelines for the design, maintenance, and operation of Signal Hill's water distribution network. These criteria were also reviewed and confirmed by Signal Hill staff in April 2024.
The pipeline criteria include maximum velocity in transmission mains (>=12-inch) and in service lines. According to the 2022 California Plumbing Code, the use of asbestos-cement in potable water system is prohibited. By adhering to these criteria, the City can ensure that the pipelines are capable of handling the required water flow and pressure, while also being durable and resistant to corrosion and other forms of degradation.
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Table 6-2. Potable Water Pipeline Criteria
Criteria Recommended value
Maximum velocity
(in transmission pipeline under replenishment conditions) 7 fps
Maximum velocity
(in any water pipeline during PHD or MDD plus emergency fire flow conditions)
Aim for 7 fps, may temporarily
reach up to 10 fps
Minimum transmission pipeline diameter size 12-inch
6.3 Fire Flow Criteria
The fire flow criteria for the City of Signal Hill are established to ensure adequate water supply for firefighting purposes. These criteria are based on guidelines from the California Fire Code, discussions with Signal Hill staff, and guidelines from the Los Angeles County Fire Department.
A residual pressure of at least 20 psi must be maintained when running the fire flow as listed in Table 6-3. These criteria are based on general land use designations and are intended for general planning purposes. They may not reflect the actual fire flow requirements for specific development approval.
Other than flow rates and residual pressures, the water distribution system should be designed with redundancy to ensure continuous water supply during fire emergencies, which is reflected in the storage requirements in Section
6.4. Regular coordination with the Signal Hill Fire Department is essential to review and update fire flow requirements. Joint training exercises and emergency response drills should be conducted to ensure preparedness.
Table 6-3. Fire Flow Criteria
Structure Flow (gpm) Duration (hours)
Single Family Residential 1,250 2
Multi-Family Residential 2,500 2
Commercial (including schools) 3,500 3
Industrial 3,500 3
Note: Fire Flows to be supplied at a minimum residual pressure of 20 psi
6.4 Storage Capacity Criteria
Potable water storage facilities are required to meet the peak hour demand (PHD), maximum day demand (MDD), fire flow and other emergency conditions. The following criteria and were confirmed by Signal Hill staff in April 2024:
Equalizing Storage
Any peak demands (i.e. peak hour) greater than MDD must be supplied from storage. Equalizing storage provides the storage to meet these short-term peak demands. Twenty-five percent (25%) of the estimated MDD is used as the criteria needed to meet daily demand fluctuations within each pressure zone.
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Fire Flow Storage
Fire flow requirements for each pressure zone must be met through storage. Fire flow requirements for each pressure zone are based on the land use in each pressure zone with the highest fire flow requirement per Table 6-3. This resulted in 0.15 MG fire flow storage required for Zone I (mostly low density residential); 0.3 MG for Zone II (Hilltop area, multi-family residential); and 0.63 MG for Zone III (Commercial and Industrial).
Emergency Storage
Emergency storage capacity is needed to sustain the water needs during periods of total or partial shutdown of the water supply facilities. 200% of the estimated ADD is used to calculate emergency storage by pressure zone.
6.5 Pump Station Capacity Criteria
The criteria for potable water system pump stations in the City of Signal Hill were discussed with city staff in April 2024. These criteria are essential to ensure that the water distribution system operates efficiently and reliably under various demand conditions.
Pump stations must have the firm capacity to meet the dependent Maximum Day Demand (MDD) for each pressure zone. Firm capacity is defined as the pump station's pumping capacity with the largest pump out of service. The dependent MDD includes the demand from the pressure zone itself as well as any additional demand that must be transmitted through the zone to reach other intended zones.
Regular assessments of pump station capacity should be conducted to identify any potential deficiencies or areas for improvement. Close coordination with system operators is essential to ensure that pump stations are operated efficiently and that any issues are promptly addressed. Real-time monitoring and control systems should be implemented to optimize pump station performance and respond to changing demand conditions. Regular inspections and maintenance are required to meet these standards and to prevent any potential failures or disruptions in service.
By adhering to these pump station capacity criteria, the City of Signal Hill can ensure that its water distribution system is capable of meeting current and future demands, providing reliable service to all residents and businesses.
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7 System Analysis
7.1 Hydraulic Model
7.1.1 Existing Model
Dudek inherited an existing potable water hydraulic model of Signal Hill’s system in Innovyze InfoWater. While the existing model included all major facilities and proper network connectivity, it lacked an assigned coordinate system, resulting in misalignment with the City’s streets.
7.1.2 Model Updates
Dudek assigned the correct coordinate system to the existing model, resolving the map display issue. Additionally, Dudek reviewed the City’s latest water main GIS data and confirmed that the pipe sizes in the GIS matched those in the existing model.
Using the City’s water meter shapefile, the demand of each user was spatially allocated to the closest junction in the model. Based on the three-year production data from Fiscal Year 2020 to 2023, the annual average demand for the entire system was estimated to be approximately 1,166 gallons per minute (gpm), or 1.68 million gallons per day (MGD). Of this total demand, 94% was successfully assigned to model junctions, while the remaining 6% (due to the lack of account numbers in the water meter shapefile) was evenly distributed across all junctions in the system. This average annual demand (ADD) was saved in the demand set “Existing_ADD” in the updated model.
Dudek also reviewed the operational setpoints at the pump stations in the model and adjusted the controls to maintain the average tank levels in their corresponding zones.
7.1.3 Model Calibration
Dudek conducted a fire flow calibration using recent fire hydrant field test data with the updated model. The test on Gardena Avenue measured a static pressure of 84 psi. With a ground elevation of 168 feet, this indicated a static head of 362 feet, which conflicted with the hydraulic grade line (HGL) of the nearby Hilltop Reservoir, typically running between 310 and 330 feet of head. Consequently, this fire flow test was considered a reading error and was not included in the calibration. The other four tests were replicated in the model without the need to adjust any C factors. All model simulations were performed in a steady state, with storage tanks half full.
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Table 7-1. Model Calibration Fire Flow Test Location Test Date Zone Flow Rate (gpm) Measured Static Pressure (psi) Measured Residual Pressure (psi) Modeled Static Pressure (psi) Modeled Residual Pressure (psi) Static Pressure % diff. Residual Pressure % diff. 2998
Cherry
Ave
1/2/2024 I 1,126 68 64 71 66 4% 3%
1951
Cherry
Ave
4/8/2022 I 1,384 100 94 100 95 0% 1%
720 E
Canton St
July 2024 I 650 95 80 94 84 -1% 5%
2027 E
19th St
July 2024 I 1,300 110 105 104 100 -5% -5%
2600
Gardena
Ave
July 2024 II 993 84 79 66 n/a -21% n/a
7.2 Pipeline Analysis
The model was evaluated under Average Day Demand (ADD), Maximum Day Demand (MDD), and Peak Hour Demand (PHD) for both Existing and projected 2045 conditions. The results indicate compliance with the City's evaluation criteria outlined in Section 6.2, Pipeline Criteria, across all simulated scenarios. High velocity and pressure were confined to the MWD import line, while low pressures below 40 psi were restricted to transmission mains near storage tanks.
Figure 7-1 and Figure 7- 7-2 illustrate the system pressure and pipeline velocities for the 2045 PHD scenario.
System pressures exceed the 40-psi criterion, except for transmission mains near the Temple and Hilltop reservoirs, which lack direct service laterals. At these locations, pipeline pressures are influenced by the water levels in nearby storage tanks. Pressures below 40 psi in these areas do not adversely affect customer water pressure and do not necessitate improvement projects.
System velocities remain below 7 fps, except in the MWD import line, highlighted in red in Figure 7-1 and Figure 7-
2. This suggests that during peak hours in 2045, the City will rely heavily on water supply from MWD, given the current capacities of local groundwater wells. The City plans to reduce dependence on MWD import water in the future, aiming to use local groundwater for 70% of the system supply under normal conditions.
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Figure 7-1. 2045 Peak Hour Demand (PHD) System Analysis
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Figure 7-2. 2045 Peak Hour Demand (PHD) Pressure Deficiencies
7.3 Fire Flow Analysis
Fire flow simulations were conducted under Maximum Day Demand (MDD) conditions, with fire flow requirements specified in Table 6-3 of Section 6.3, Fire Flow Criteria, for each land use category. Given that the City is nearly fully developed, the difference in domestic demand between the current and projected 2045 scenarios is minimal compared to the fire flow demand. Consequently, the results for the existing and 2045 conditions are very similar.
A total of eight fire flow deficient hydrants were identified, marked as red points in Figure 7-3, with the available fire flow at these hydrants labeled accordingly. Most of these hydrants are located in Commercial/Industrial areas where a fire flow of 3,500 gpm is required. These deficiencies are primarily due to dead-end 4-inch or 6-inch pipelines that need to be upsized. The recommended pipeline upgrades and associated costs are summarized as Project #16 in Table 8-.
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Figure 7 3. 2045 Fire Flow under MDD Condition
7.4 Supply Analysis
The supply sources were evaluated to determine their effectiveness in meeting all water system operating conditions. Typically, supply sources are sized to meet maximum-day demand, as detailed in Table 7-2, which lists the capacity of each available supply source.
The City has expressed a preference for prioritizing groundwater supply over imported water. As shown in Table 7-3, if the largest groundwater source, Well 10, is out of service, Wells 7 and 9 together provide 1,650 gpm, which is 332 gpm short of the system's total maximum-day demand of 1,982 gpm. This indicates that the City currently lacks sufficient groundwater capacity to meet existing system demand, a deficiency that will be exacerbated in the ultimate build-out scenario.
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Table 7-4 presents another emergency operating condition where a backup generator is the only available power source. In this scenario, only Wells 9 and 10 are operational, as other supply sources lack backup generators.
Calculations show that this emergency supply can meet 93% of the existing MDD and 79% of the projected 2045 MDD.
To enhance the resiliency of the City's water supply, it is recommended to expand the capacity of existing groundwater wells. This could involve drilling a new well or rehabilitating Well 9 to increase total groundwater capacity under emergency conditions. Alternatively, installing a backup generator at Well 7 would make it a more reliable water source. These potential improvement projects are listed as Projects #4, #5, and #6 in Table 8-.
Table 7-2. Existing Supply Sources
Supply Zone Supplied Capacity (gpm) Backup Generator
Well 7 Gundry Reservoir 1,000 N
Well 9 Zone I 650 Y
Well 10 Gundry Reservoir 1,200 Y
MWD Zone I 3,300 N
Table 7-3. Supply Analysis – GW Only
Timeframe
Demand
(gpm)
GW Supply w/ Largest
Source Off (gpm)
Surplus/
Deficit (gpm) Meet Demand %
Existing MDD 1,982 1,650 -332 83%
2045 MDD 2,353 1,650 -703 70%
Table 7-4. Supply Analysis – Emergency
Timeframe
Demand
(gpm)
Emergency Supply
(gpm)
Surplus/
Deficit (gpm) Meet Demand %
Existing MDD 1,982 1,850 -132 93%
2045 MDD 2,353 1,850 -503 79%
7.5 Storage Analysis
The City's water storage must comply with the requirements outlined in Section 6.4, Storage Capacity Criteria. To assess the system's storage needs, the Maximum Day Demand (MDD) was analyzed for each pressure zone. Each zone's required storage includes equalization storage, emergency storage, and fire storage, as detailed in the criteria chapter.
Equalization storage: also known as operational storage, equalization storage allows the City to manage water demands amid seasonal and daily fluctuations. An operational storage requirement of 25% MDD was used for the City of Signal Hill's water system. Table 7-5 and Table 7-6 provide the operational storage required based on current demand and projected 2045 demand. Since Zone III lacks separate storage, the Temple and Hilltop Reservoirs supply storage to Zone III through the Temple Pump Station (PS) and Hilltop
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PS. The available storage is determined by the firm capacity at these pump stations, assumed to be a 24- hour firm pumping volume, referred to as "24-hour Pumping Credit" in Table 7-5 and Table 7-6. Similar pumping credits were applied to Zones I and II. The tables indicate that the existing reservoirs have sufficient capacity to provide 25% MDD operational storage for both current and 2045 scenarios. Emergency Storage: Southern California water agencies must consider emergency operations and their water systems' ability to store and supply water under emergency conditions. Due to the high seismic potential in Los Angeles County and throughout Southern California, emergency conditions must account for the impact of a major earthquake. Signal Hill is located in Seismic Zone 4, the highest seismic zone rating (with Seismic Zone 1 having the lowest potential). Emergency storage was assumed to be 100% of MDD. The emergency storage requirement in Zone I exceeds the existing storage capacity in both current and 2045 scenarios, but additional storage can be provided from Wells 7 and 10 (pumping credit). Fire Storage: The fire storage requirement was based on the most conservative criteria in Table 6-3, set at 3,500 gpm for 3 hours.
The existing storage alone cannot meet the total storage requirement, except for Zone II under current conditions, where 1.2 MG barely meets the 1.12 MG requirement. Overall, the existing storage tanks can meet the equalization and fire storage requirements for each zone. While the existing storage tanks fall short of meeting the emergency storage requirement, the pumping capacity from lower zones results in a surplus in all zones for both current and 2045 scenarios. Since Zone I is the City's largest pressure zone, it is recommended to expand Zone I's only in-zone storage, Temple Reservoir, to meet the storage requirement under current conditions without relying on Gundry Pump Station. This recommendation is included as Project #19 in Table 8-.
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Table 7-5. Storage Analysis Results – Existing Scenario Pressure
Zone
Existing
Storage
Existing
MDD
Equalization
25% MDD
Emergency
100% MDD
Fire Storage
Total
Required
24-hr
Pumping
Credit Surplus
Fire
Flow Duration Total
(MG) (MGD) (MG) (MG) (gpm) (hour) (MGD) (MG) (MG) (MG)
Gundry 4.71 0 0 0 0 0 0 0 0 0
I 1.4 2.18 0.54 2.18 3,500 3 0.63 3.35 4.72 2.75
II 1.2 0.40 0.10 0.40 3,500 3 0.63 1.12 1.44 1.52
III 0.0 0.28 0.07 0.28 3,500 3 0.63 0.98 4.90 3.92
Total 7.3 2.85 0.71 2.85
1.89 3.35 5.40 3.45
1 The Gundry Reservoir provides available storage for upper zones through booster pump stations. 2 Unlike other zones pumping credit, which was governed by pump capacity, Zone I’s pumping credit was governed by Gundry Reservoir existing storage availability.
Table 7-6. Storage Analysis Results – 2045 Scenario
Pressure
Zone
Existing
Storage
2045
MDD
Equalization
25% MDD
Emergency
100% MDD
Fire Storage
Total
Required
24-hr
Pumping
Fire Flow Duration Total Credit Surplus
(MG) (MGD) (MG) (MG) (gpm) (hour) (MGD) (MG) (MG) (MG)
Gundry 4.71 0 0 0 0 0 0 0 0 0
I 1.4 2.59 0.65 2.59 3,500 3 0.63 3.87 4.72 2.93
II 1.2 0.47 0.12 0.47 3,500 3 0.63 1.22 1.44 1.42
III 0.0 0.33 0.08 0.33 3,500 3 0.63 1.05 4.90 3.85
Total 2.6 3.39 0.85 3.39
1.89 6.13 11.74 8.21
1 The Gundry Reservoir provides available storage for upper zones through booster pump stations. 2 Unlike other zones pumping credit, which was governed by pump capacity, Zone I’s pumping credit was governed by Gundry Reservoir existing storage availability.
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7.6 Pump Station Analysis
The City's water pump station capacities must comply with the requirements outlined in Section 6.5, Pump Station Capacity Criteria. To assess the system's pumping requirements, the Maximum Day Demand (MDD) was analyzed for each pressure zone. The Dependent Demand for each zone was calculated, which includes the demand for the zone itself and all upper zones supplied by this zone through a pump station. For instance, the demand for Zones II and III is served from Zone I, so the capacity of the pump station in Zone I (Gundry Pump Station) must meet the demand for all three zones. The firm pumping capacity was then reviewed using the dependent demand to determine if it was sufficient for each zone.
Table 7-7 and Table 7-8 indicate that all zones have a pumping surplus in both current scenarios, so no improvement projects are needed to expand the pump station capacities to meet system needs.
Table 7-7. Pump Station Analysis Results – Existing Scenario Pressure
Zone
Pump
Station
serving this
zone
Ex.
Dependent
MDD
Ex.
Dependent
MDD
Total
Capacity
Firm
Capacity Surplus
(MGD) (gpm) (gpm) (gpm) (gpm)
I Gundry PS 2.97 2,064 5,000 3,750 1,686
II Temple PS 0.72 500 1,500 1,000 500
III Temple PS &
Hilltop PS
0.33 230 3,700 900 670
Total 2,856
Table 7-8. Pump Station Analysis Results – 2045 Scenario Pressure
Zone
Pump
Station
serving this
zone
2045
Dependent
MDD
2045
Dependent
MDD
Total
Capacity
Firm
Capacity Surplus
(MGD) (gpm) (gpm) (gpm) (gpm)
I Gundry PS 3.43 2,382 5,000 3,750 1,368
II Temple PS 0.83 577 1,500 1,000 423
III Temple PS &
Hilltop PS
0.38 265 3,700 900 635
Total 2,426
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[PROJECT NUMBER] 58 [MONTH YEAR]
8 Capital Improvement Plans (CIP)
This chapter outlines the proposed Capital Improvement Program (CIP) for the City, based on the findings of this Master Plan update. The CIP addresses the future capacity needs of the water distribution system over the next ten years, categorized into high, medium, and low priorities.
8.1 Project Prioritization
On September 24, 2024, Dudek and the City conducted a CIP workshop to discuss project priorities and associated costs. By the time of the workshop, the City had already allocated funding for FY 2024-25. Projects were prioritized based on asset condition, risk of failure, and funding availability. High-priority projects primarily address regulatory compliance and have the most significant impact on customers. Lower-priority projects were identified due to limited immediate impact, funding constraints, or technical feasibility. Prioritizing projects ensures the greatest value to the community by balancing immediate needs with long-term benefits.
Replacing the Gundry Reservoir roof is a top priority for the City, as it is the main water supply for the entire system, and roof failure would severely impact the quality and safety of the City’s drinking water. Funding has been allocated for this project in FY 2024-25.
Rehabilitation of Well 7 and Well 9 to restore their full capacity is also a top priority, as supply analysis indicates the City lacks sufficient water supply to meet emergency requirements.
8.2 List of Projects
Following a comprehensive review of facilities and consultations with City staff during workshops, a prioritized list of capital improvements for the City of Signal Hill water system has been compiled and is presented in Table 8.1.
The projects are ranked from highest to lowest priority, with each entry detailing the rationale for its recommendation. For instance, Section 7.4 of this report identified that the City does not meet supply requirements under emergency conditions, leading to the recommendation of CIP Projects #4-6. The locations of these CIP projects are presented in Figure 8- and Figure 8-2.
Table 8-1. Source of Projects
Rec # Priority Project Name Project Description Source
1 High Gundry Reservoir Roof
Replacement and
Coating
Replace the roof of Gundry
Reservoir and apply new
coating
Condition Assessment and
Sanitary Survey, Section 5.5
2 High Electrical upgrades at
Hilltop PS
Replace MCC, PLC and repair
rust hole
Condition Assessment and
Sanitary Survey, Section 5.3
3 High SCADA upgrades Replace the existing SCADA
server, computers, and monitor
Condition Assessment and
Sanitary Survey, Section 5.4
4 High Well 9 - Rehab Add bowls to increase Well 9
capacity
Supply Analysis, Section 7.4
5 High Rehab of Well 7 Redrill, repack, and redevelop
Well 7 to increase capacity
Supply Analysis, Section 7.4
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Table 8-1. Source of Projects
Rec # Priority Project Name Project Description Source
6 High New well installation Drill a new well, possibly north of Freeway 91
Supply Analysis, Section 7.4
7 Medium Automated Meter
Reading (AMR)
Upgrade 3,500 meter to AMR Operations Workshop
8 Medium Temple reservoir soil
removal / upgrades
Remove the soil on top of the
buried Temple Reservoir
Condition Assessment,
Section 5.4
9 Medium Gundry pump station
rehabilitation
Replace motor and pump,
electrical system, switchboard,
etc.
Condition Assessment,
Section 5.5
10 Medium Disinfection
improvements at Gundry
Install mixers and a
submersible pump within the
reservoir; incorporate analyzers,
control panels, and tanks for
storing sodium hypochlorite and
ammonium sulfate
Operations Workshop
11 Medium Lakewood water line bypass Build bypass pipeline to avoid double treating Lakewood
emergency supply at Gundry
Operations Workshop
12 Medium Well 9 Treatment Bypass Build pipeline to allow Well 7 and Well 10 supply to be
rerouted to Well 9 treatment
facilities during emergency
Operations Workshop
13 Medium Valve replacement Replace defective valves and implement valve exercising
program
Pipeline age breakdown,
Section 4.7
14 Medium Cast iron /asbestos
cement pipeline
replacement
Replace all CI and AC pipelines
installed in the 1960s and
1970s.
Pipeline age breakdown,
Section 4.7
15 Medium Site security for Well 10 Chain link fence or detection alarm to discourage vandalism
at Well 10 site
Condition Assessment and
Sanitary Survey, Section
5.20 16 Medium Upsize pipelines on
hydrants
Upsize pipelines on hydrants
that do not meet fire flow
requirements
Fire Flow Analysis, Section
7.3 17 Low Gundry Reservoir
Treatment Enhancement
Treatment for PFOA and PFOS Groundwater Quality,
Section 3.2.2
18 Low Rehab MWD connection
to Hilltop
Operations Workshop
19 Low Temple reservoir
expansion
Increase capacity of Temple
reservoir by adding a 1.2 MG to
the existing 1.4 MG at the same
site
Storage analysis, Section 0
20 Low Hilltop Disinfection
Station
liquid sodium hypochlorite and
ammonia solution, similar to
that at Gundry Reservoir and
Temple Reservoir
Groundwater Quality,
Section 3.2.2
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Figure 8-1. CIP Locations
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Figure 8-2. CIP Locations – North of City
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8.3 Project Descriptions
This section includes project cut sheets for the high and medium priority projects that are budgeted for the next 5 years.
CIP-1: Gundry Reservoir Roof Replacement and Coating
Project Location: 3315 Gundry Avenue, Signal Hill, CA 90755 Project Description: The Gundry Reservoir roof needs to be replaced to ensure the structural integrity of the facility.
This project involves removing the existing roof, addressing any structural deficiencies, and applying a new protective coating. The new roof will enhance the reservoir's durability and extend its lifespan.
Project Justification: The current roof of the Gundry Reservoir has deteriorated over time, compromising its structural integrity and potentially affecting water quality. The exterior roof sheets are corroded at around ten locations, and holes are present in some roof sheets. Additionally, the steel roof decking and support framework are corroded. Replacing and coating the roof is essential to maintain the reservoir's functionality and safety.
Cost Estimates: $3,300,000
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CIP-2: Electrical Upgrades at Hilltop Pump Station
Project Location: 2351 Dawson Avenue, Signal Hill, CA 90755 Project Description: This project involves comprehensive electrical upgrades at the Hilltop Pump Station to enhance operational efficiency and safety. The upgrades will include replacing Motor Control Center (MCC), repairing the rust hole in the MCC meter section eliminating irrigation water intrusion, installing new wiring, and upgrading Programmable Logic Controller (PLC) to a new series. These improvements will ensure reliable and efficient operation of the pump station.
Project Justification: The existing electrical systems at the Hilltop Pump Station are outdated and prone to failures, which can disrupt water supply services. Upgrading the electrical infrastructure is essential to ensure the pump station operates safely and efficiently. Modernizing the electrical systems will also reduce maintenance costs and improve energy efficiency.
Cost Estimates: $100,000
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CIP-3: SCADA Upgrades
Project Location: 2175 E. 28th St, Signal Hill, CA 90755 Project Description: This project involves upgrading the Supervisory Control and Data Acquisition (SCADA) system to enhance the reliability and security of the City's water facilities. The upgrades will include replacing the existing SCADA server, computers, and monitors (except those at Well 9), and updating the SCADA software to Wonderware.
Additionally, the project will replace the outdated telemetry system with a hybrid radio/fiber optic telemetry system to ensure consistent data transmission.
Project Justification: The City is aware of its outdated SCADA system and has engaged Ardurra to manage the SCADA improvement program. The existing PLC/SCADA telemetry system transmits data via old copper-wired phone lines, which do not function properly during rainy weather. A preliminary radio survey identified topographical obstructions that need to be addressed for radio signals to be feasible. The City also explored the availability of fiber-optic communications, determining that some sites have access while others do not. Consequently, a hybrid radio/fiber optic telemetry system is considered a favorable option. The SCADA server, along with all SCADA computers and monitors (except those at Well 9), are obsolete and run on Windows 8.1, posing a security risk. The SCADA software is 12 years old and needs updating. Upgrading the SCADA system is essential to ensure reliable and secure operation of the City's water facilities.
Cost Estimates: $500,000
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CIP-4: Well #9 Rehab
Project Location: 2175 E. 28th St, Signal Hill, CA 90755 Project Description: This project involves the rehabilitation of Well #9 to increase its capacity and ensure a reliable groundwater supply. The well currently has a capacity of 650 GPM but has a full design capacity of 1,200 GPM to meet future demand. The pumps and motors are relatively new, eliminating the need for their replacement at this time. To achieve its full capacity, the process may include pre-cleaning the well, chemical treatment, airlifting, backwashing, repacking the gravel and/.or removing fine particles to improve flow.
Project Justification: The City would like to increase its groundwater supply. Having a robust emergency water supply is crucial for the City to ensure the safety and well-being of its residents during unforeseen events. Well #9 has the potential to significantly increase its output to meet future demand, but this requires comprehensive rehabilitation.
Enhancing the well's capacity is essential to provide a reliable backup water source, ensuring the City can respond effectively to emergencies and maintain a stable water supply.
Cost Estimates: $300,000
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CIP-5: Well #7 Rehab/Replacement
Project Location: 6476 Orange Avenue, Signal Hill, CA 90755 Project Description: This project involves the rehabilitation of Well #7 to increase its capacity and ensure a reliable groundwater supply. The well currently has a capacity of 1,000 GPM but has a full design capacity of 1,830 GPM to meet future demand. Further study is necessary to determine the cause of the decline in capacity. Thehe well may need to be redrilled, repacked, or redeveloped. Well #7 currently has a cast iron casing installed in 2008, which might have corroded, causing the well to produce a significant amount of sand. The cast iron casing needs to be replaced with a stainless-steel casing. Compared to Well #9, it may be more economically feasible to replace Well #7 rather than rehabilitate it.
Project Justification: The City would like to increase its groundwater supply. Having a robust emergency water supply is crucial for the City to ensure the safety and well-being of its residents during unforeseen events. Well #7 has the potential to significantly increase its output to meet future demand, but this requires comprehensive rehabilitation.
Enhancing the well's capacity is essential to provide a reliable backup water source, ensuring the City can respond effectively to emergencies and maintain a stable water supply.
Cost Estimates: $1,500,000
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CIP-6: New Well Installation
Project Location: To be determined by site study
Project Description: The City is considering the development of a new well on the north side of Freeway 91. To move forward, a comprehensive assessment and planning process is required, including a site selection study to ensure regulatory compliance. An engineering consultant will be engaged to conduct the site study and identify suitable locations for the new well. Once a location is identified, a new well will need to be drilled and equipped. Water quality will also need to be assessed to determine if additional treatment will be required. Finally, the new well will need to be inspected and permitted by the Department of Drinking Water.
Project Justification: The City would like to increase its groundwater supply. Having a robust emergency water supply is crucial for the City to ensure the safety and well-being of its residents during unforeseen events. A new well has the potential to substantially enhance the City's groundwater capacity, thereby decreasing its dependence on imported water to ensure the City can respond effectively to emergencies and maintain a stable water supply.
Cost Estimates: $5,250,000
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CIP-7: Automated Meter Reading (AMR)
Project Location: Throughout the City
Project Description: This project involves the installation of Automated Meter Reading (AMR) systems across the City.
The City manages approximately 3,500 meters that are currently manually read and need to be upgraded. The AMR system will enable remote reading of water meters, improving accuracy and efficiency in water usage monitoring.
Project Justification: Implementing AMR technology is essential for enhancing the City's water management capabilities. The current manual meter reading process is time-consuming and prone to errors. By transitioning to an automated system, the City can ensure more accurate billing, reduce operational costs, and improve customer service. Additionally, AMR systems provide real-time data, helping to identify leaks and reduce water waste.
Cost Estimates: $800,000, can potentially use grant funding
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CIP-8: Temple Reservoir Soil Removal/Upgrades
Project Location: 2200 Temple Avenue, Signal Hill, CA 90755 Project Description: This project involves the removal of the soil cover from the roof of the Temple Reservoir to prevent the presence of burrowing animals in the soil mass. The reservoir is entirely buried with a shallow earth fill on top. The project will include evaluating the structural strength of the reservoir to support soil cover removal using small front-end loaders and trucks.
Project Justification: The Division of Drinking Water (DDW) recommended removing the soil cover from the reservoir roof to prevent burrowing animals from compromising the reservoir's integrity. The City initially believed that the roof slab was not structurally capable of supporting earth-moving equipment and obtained bids for manual earth removal, which resulted in costs as high as $500,000. Dudek recommends reviewing the reservoir design drawings and evaluating the structural strength of the reservoir to support soil cover removal using small front-end loaders and trucks. This approach aims to reduce costs and ensure the reservoir's structural integrity while addressing the DDW's recommendations.
Cost Estimates: $300,000
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CIP-9: Gundry Pump Station Rehabilitation
Project Location: 3315 Gundry Avenue, Signal Hill, CA 90755 Project Description: The Gundry Pump Station Rehabilitation project involves replacing the outdated switchboard and Programmable Logic Controller (PLC) to ensure the continued reliable operation of the pump station. The existing switchboard, estimated to be 60 years old, has surpassed its useful life and is unserviceable due to the unavailability of replacement parts. The current PLC, a Modicon 984 Micro series, is also obsolete and cannot be replaced if it fails. The project includes installing a new Specialist Electrical Solutions (SES) switchboard and Motor Control Center (MCC) within the next five years, and replacing the PLC with a newer series, such as the M340 or M580, within the next year.
Project Justification: The Gundry Pump Station is critical as it carries the main water supply to the entire water system of Signal Hill, making its reliable operation especially important. The switchboard at the Gundry Pump Station is significantly beyond its industry-standard useful life of 30 years, posing a high risk of operational failure.
Without regular servicing or maintenance, there is a high likelihood of a breaker failing to trip or reset, which could lead to severe operational disruptions. Similarly, the existing PLC is no longer commercially available, and a failure would render the site inoperable remotely. Replacing these critical components is essential to maintain the reliability and safety of the pump station, ensuring uninterrupted water supply and system functionality.
Cost Estimates: $942,986
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CIP-10: Disinfection Improvement at Gundry
Project Location: 3315 Gundry Avenue, Signal Hill, CA 90755 Project Description: This project involves upgrading the disinfection system at Gundry Reservoir to enhance water quality and safety. The improvements will include installing mixers and a submersible pump within the reservoir, as well as incorporating analyzers, control panels, and tanks for storing sodium hypochlorite and ammonium sulfate.
These upgrades will ensure effective and reliable disinfection of the water supply.
Project Justification: The City of Signal Hill plans to implement a disinfection project at Gundry Reservoir, similar to the ongoing project at Temple Reservoir. Upgrading the disinfection system is essential to maintain high water quality standards and ensure the safety of the water supply. The current system needs enhancements to provide consistent and effective disinfection, reducing the risk of contamination and improving overall water quality for the community.
Cost Estimates: $300,000
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CIP-11: Lakewood Water Line By-pass
Project Location: 3315 Gundry Avenue, Signal Hill, CA 90755 Project Description: The Lakewood Water Line By-pass project involves constructing a bypass pipeline to connect the emergency water supply from Lakewood directly to the Gundry Reservoir in Signal Hill. This bypass will allow the already treated water from Lakewood to flow directly into the reservoir, eliminating the need for additional treatment at the Gundry facility. The project aims to optimize the water supply process and enhance energy efficiency.
Project Justification: The current system routes the treated water from Lakewood through the Gundry Reservoir's treatment facility, resulting in unnecessary double treatment. By implementing the bypass, the City of Signal Hill will save energy and reduce operational costs associated with the redundant treatment process. This project is essential for improving the efficiency and sustainability of the city's water supply infrastructure.
Cost Estimates: $520,000
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CIP-12: Well 9 Treatment Bypass
Project Location: From Walnut Avenue to Well 9, Signal Hill, CA Project Description: The Well 9 Treatment Bypass project involves installing 2,400 linear feet of 8-inch to 16 inch pipeline to connect Well 7 and Well 10 to Well 9. This bypass will enable the water from Well 7 and Well 10 to be treated at Well 9 in the event that the Gundry water treatment plant is out of service. The project aims to ensure a continuous and reliable water treatment process for the city.
Project Justification: Currently, the Gundry water treatment plant treats water from Well 7 and Well 10, while Well 9 treats its own water independently. In the event of a service disruption at the Gundry plant, there is no alternative treatment route for Well 7 and Well 10 water. By implementing this bypass, the city will enhance its water treatment resilience and ensure uninterrupted water supply and treatment capabilities.
Cost Estimates: $2,800,000
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CIP-13: Valve Replacement
Project Location: Various locations throughout the City of Signal Hill, CA Project Description: The Valve Replacement project involves replacing 50% of the city's total 1600 valves, focusing on those that are 40-50 years old and potentially defective. Most of these valves are 8-inch or 12-inch. Many of these valves have not been exercised for a long time, leading to operational issues. The city is also implementing a new valve exercising program to identify and address defective valves, ensuring the reliability and efficiency of the water distribution system.
Project Justification: Replacing aging and defective valves is crucial for maintaining the integrity and functionality of the city's water distribution system. Many of the existing valves are 40-50 years old and have not been exercised regularly, leading to potential failures and operational inefficiencies. The new valve exercising program will help identify defective valves, and replacing them will enhance system reliability, reduce maintenance costs, and ensure a consistent water supply.
Cost Estimates: $5,900,000 total; approximately $500,000 per year
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CIP-14: Cast Iron/Asbestos Cement Pipeline Replacement
Project Location: Various locations throughout the City of Signal Hill, CA Project Description: The Cast Iron/Asbestos Cement Pipeline Replacement project aims to replace approximately 3% of the city's cast iron and asbestos cement pipelines annually, equating to roughly 4750 linear feet per year.
These pipelines, installed prior to 1980, are prone to leaks and can negatively impact water chemistry. The project involves systematically replacing these aging pipelines to improve water quality and system reliability.
Project Justification: Cast iron pipes are a major cause of water leaks and can adversely affect water chemistry.
Additionally, asbestos cement (AC) pipes pose significant health risks due to the potential release of asbestos fibers into the water supply as they deteriorate. The United States Environmental Protection Agency (EPA) identifies AC pipes as a significant source of asbestos exposure in water systems. Replacing these pipelines is a state mandate and essential for safeguarding public health and ensuring a reliable water supply.
Cost Estimates: $3,065,040 per year
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CIP-15: Site Security for Well 10
Project Location: Well 10, Signal Hill, CA
Project Description: The Site Security for Well 10 project aims to enhance the security of the well site, which features a gated entrance and a building housing electrical equipment. The wellhead and generator, located outside the building, have been vulnerable to vandalism. The project includes constructing a new building or installing a chainlink cage around the generator and wellhead. Additional security measures such as an intrusion detection alarm, increased wall height, or barbed wire on the site fence may also be implemented to deter unauthorized access.
Project Justification: The generator at Well 10 has already experienced vandalism, and the well’s emergency ON/OFF switch is at risk. Enhancing site security is essential to protect critical infrastructure and ensure the uninterrupted operation of the well. Implementing these security measures will safeguard the equipment from vandalism and unauthorized access, thereby maintaining the reliability and safety of the water supply system.
Cost Estimates: $200,000
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CIP-16: Upsize Pipelines on Hydrants
Project Location: Various locations throughout Signal Hill, CA, as shown in graphic below Project Description: The project involves upsizing pipelines to hydrants to ensure adequate water supply during fire emergencies. Specific upgrades include:
Upsize 250 feet of 6" to 8" on E 28th St
Upsize 580 feet of 6" to 10" on N Gaviota Ave
Upsize 540 feet of 6" to 10" on Rose Ave
Upsize 630 feet of 8" to 10" on Gundy Ave north of E Burnett St Upsize 650 feet of 6" to 8" on Gundy Ave south of E Hill St Upsize 500 feet of 6" and 800 feet of 8" to 12" on Pacific Coast Highway, east of Opispo Ave Add a loop between 6" and 10" at Alamitos Ave & E 20th St Project Justification: Hydrants in the city that are currently on unlooped pipelines do not provide as much fire flow capacity as looped pipelines. Upsizing these pipelines will ensure that hydrants have sufficient fire flow, enhancing public safety.
Cost Estimates: $2,387,582
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8.4 CIP Annual Breakdown
Table 8-2 provides the estimated costs for each of the CIP projects and outlines their allocation by year, based on priority and funding availability. The total annual costs are illustrated in Figure 8-3 Figure 8-3. Projected Water CIP Costs by Year.
$0
$1
$2
$3
$4
$5
$6
$7 CIP Costs ($M)
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INTENTIONALLY LEFT BLANK
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Table 8-2. Capital Improvement Plans
Rec # Priority Project name Total Cost FY24-25 FY25-26 FY26-27 FY27-28 FY28-29 FY29-30 FY30-31 FY31-32 FY32-33 FY33-34 10 Years+ 1 High Gundry reservoir roof
replacement and
coating
$3,300,000 $2,576,726 $723,274
2 High Electrical upgrades at
Hilltop PS
$100,000 $100,000
3 High SCADA upgrades $500,000 $70,000 $430,000
4 High Well 9 - Rehab $300,000 $150,000 $150,000
5 High Rehab of Well 7 $1,500,000 $750,000 $750,000
6 High New well installation $5,250,000 $262,500 $2,625,000 $2,362,500 7 Medium Automated Meter
Reading (AMR)
$800,000 $400,000 $400,000
8 Medium Temple reservoir soil
removal / upgrades
$300,000 $300,000
9 Medium Gundry pump station
rehabilitation
$942,986 $942,986
10 Medium Disinfection
improvements at
Gundry
$300,000 $300,000
11 Medium Lakewood water line
by-pass
$520,000 $520,000
12 Medium Well 9 Treatment
Bypass
$2,800,000 $924,000 $1,876,000
13 Medium Valve replacement $5,900,000 $350,000 $500,000 $500,000 $500,000 $500,000 $500,000 $500,000 $500,000 $500,000 $500,000 $1,050,000 14 Medium Cast iron /asbestos
cement pipeline
replacement
$3,065,040 $762,000 $3,065,040 $3,065,040 $3,065,040 $3,065,040 $3,065,040 $3,065,040 $3,065,040 $3,065,040 $3,065,040 $30,650,400 15 Medium Site security for Well
10 $20,000 $20,000
16 Medium Upsize pipelines on
hydrants that do not
meet fire flow
requirements
$2,387,582 $2,387,582
17 Low Gundry Reservoir
Treatment
Enhancement
$9,000,000 $9,000,000
18 Low Rehab MWD
connection to Hilltop
$850,000 $850,000
19 Low Temple reservoir
expansion
$8,000,000 $8,000,000
20 Low Hilltop Disinfection
Station
$650,000 $650,000
Total $46,485,608 $4,308,726 $4,895,040 $4,997,540 $4,785,040 $6,190,040 $5,927,540 $5,432,026 $5,441,040 $5,952,622 $5,065,040 $48,700,400
WATER MASTER PLAN AND RATE STUDY
15851 81
MAY 2025
INTENTIONALLY LEFT BLANK