East Palo Alto Water Security Feasability Study

403 Pages·2012·12.19 MB·English

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Gloria Way Water Well Production Alternatives
Analysis and Water Security Feasibility Study

City of East Palo Alto, California

City of East Palo Alto  
Gloria Way Water Well Production Alternatives       Todd Engineers 
Analysis and Water Security Feasibility Study      November 2012
TABLE OF CONTENTS

EXECUTIVE SUMMARY ........................................................................................................................ 1 
1.  INTRODUCTION ............................................................................................................................. 5 
1.1  Background and Setting ........................................................................................................... 6 
1.1.1  City Water Supply and Demand ........................................................................................6  
1.1.2  City Groundwater Resources ............................................................................................7  
1.2  Phase I Project Approach and Scope ......................................................................................7  
2.  HYDROGEOLOGIC SITE CONCEPTUAL MODEL .......................................................................9  
2.1  Data Sources ............................................................................................................................9  
2.2  Study Area ..............................................................................................................................1 0 
2.3  Geology and Aquifer Zones ....................................................................................................1 1 
2.4  Aquifer Hydraulic Properties ...................................................................................................1 3 
2.5  Groundwater Levels and Flow ................................................................................................1 4 
2.6  Wells and Production ............................................................................................................. 15 
2.7  San Francisquito Subbasin Water Balance ............................................................................1 8 
2.8  Groundwater Quality .............................................................................................................. 20 
2.8.1  TDS ................................................................................................................................. 20 
2.8.2  Chloride and Saline Water Intrusion ...............................................................................2 1 
2.8.3  Iron and Manganese .......................................................................................................2 2 
2.8.4  Contamination Sites ........................................................................................................2 3 
3.  GLORIA WAY WELL PERFORMANCE AND TREATMENT EVALUATION .............................. 24 
3.1  Gloria Way Well Construction and Operational History ..........................................................2 4 
3.2  Well Performance Testing ...................................................................................................... 25 
3.3  Water Quality Sampling ..........................................................................................................2 5 
3.3.1  Sampling Procedures ......................................................................................................2 6 
3.3.2  Analytical Results ............................................................................................................ 26 
3.3.3  Quality Control Sampling and Analysis ...........................................................................2 8 
3.3.4  Geochemical Data Interpretation ....................................................................................3 0 
3.4  Gloria Way Well Mechanical Condition and Serviceability .....................................................3 1 
3.5  Predicted Hydraulic Performance and Potential for Saltwater Intrusion or Subsidence ......... 31 
3.5.1  Preliminary Groundwater Model and Predicted Drawdown ............................................ 32 
3.5.2  Potential for Saltwater Intrusion ......................................................................................3 3 
3.5.3  Potential for Land Subsidence ........................................................................................3 4 
3.6  Treatment and Blending Evaluation .......................................................................................3 6 
3.6.1  SFPUC Water Quality .....................................................................................................3 6 
3.6.2  Blending .......................................................................................................................... 37 
3.6.3  Wellhead Treatment ........................................................................................................3 7 
3.7  Regulatory Permitting Requirements .....................................................................................3 8 
3.8  Phasing Options and Schedule for Construction ....................................................................3 9 

City of East Palo Alto  
Gloria Way Water Well Production Alternatives       Todd Engineers 
Analysis and Water Security Feasibility Study      November 2012 
i
3.9  Environmental Review Requirements ....................................................................................4 0 
4.  OTHER POTENTIAL CITY GROUNDWATER SUPPLY SOURCES ...........................................4 2 
4.1  Potential City Well Sites ......................................................................................................... 42 
4.1.1  Existing Wells in East Palo Alto ......................................................................................4 2 
4.1.2  Potential New Well Sites .................................................................................................4 2 
4.2  Site Screening Analysis ..........................................................................................................4 3 
4.3  Potential for Saltwater Intrusion or Subsidence .....................................................................4 6 
4.4  Permitting and Environmental Review Requirements ............................................................4 7 
4.5  Preliminary Treatment Alternatives and System Design and Capital and Operating Budget . 47 
4.6  Lifecycle Water Cost Comparisons for Gloria Way and New Well Sites ................................ 48 
5.  OVERVIEW OF NEED FOR EMERGENCY STORAGE...............................................................4 9 
5.1  Storage Sizing ........................................................................................................................ 49 
5.2  Operational Considerations .................................................................................................... 50 
5.3  Storage Locations .................................................................................................................. 51 
5.4  Storage Tank Material ............................................................................................................ 52 
5.5  Cost Estimate ......................................................................................................................... 52 
6.  OVERVIEW OF GOVERNANCE, GROUNDWATER MANAGEMENT, AND FUNDING ............. 53 
6.1  Groundwater Management .....................................................................................................5 3 
6.1.1  Agreements and Ordinances ..........................................................................................5 3 
6.1.2  Adjudication .....................................................................................................................5 4 
6.1.3  Local Management under Authority Granted by State Statute ........................................5 4 
6.1.4  Groundwater Management Plans ...................................................................................5 4 
6.1.5  California Statewide Groundwater Elevation Monitoring Program (CASGEM) ............... 55 
6.1.6  Local Groundwater Basin Development and Management .............................................5 7 
6.2  Governance ............................................................................................................................ 59 
6.2.1  San Bruno ....................................................................................................................... 59 
6.2.2  Palo Alto .......................................................................................................................... 60 
6.2.3  East Palo Alto ..................................................................................................................6 1 
6.3  Funding .................................................................................................................................. 61 
6.3.1  State and Federal Loans and Grants ..............................................................................6 2 
6.3.2  Conventional Bond Financing .........................................................................................6 3 
6.3.3  Self-Financing ................................................................................................................. 64 
6.3.4  Impacts on Rate Payers ..................................................................................................6 4 
7.  RECOMMENDATIONS ................................................................................................................. 66 
7.1  Groundwater Management .....................................................................................................6 6 
7.2  Groundwater Monitoring ......................................................................................................... 66 
7.3  Predictive Modeling of Saline Water Intrusion and Subsidence ............................................ 66 
7.4  Gloria Way Well ..................................................................................................................... 67 
7.5  Other Potential City Groundwater Supply Sources ................................................................6 7 
7.6  Storage Sites ......................................................................................................................... 68 
7.7  Governance and Funding ......................................................................................................6 8 

City of East Palo Alto  
Gloria Way Water Well Production Alternatives       Todd Engineers 
Analysis and Water Security Feasibility Study      November 2012 
ii
7.8  Estimated Costs of Recommendations ..................................................................................6 9 
8.  REFERENCES .............................................................................................................................. 70 

City of East Palo Alto  
Gloria Way Water Well Production Alternatives       Todd Engineers 
Analysis and Water Security Feasibility Study      November 2012 
iii
List of Tables
Table 1 Historical Water Use from the WSMP 
Table 2 Historical Water Use from the UWMP 
Table 3 Projected Water Demand from the WSMP 
Table 4 Projected Water Demand from the UWMP 
Table 5 Future City Supply and Demand Estimates from the UWMP
Table 6 Aquifer Hydraulic Properties from Pumping Tests
Table 7 Estimated Annual Groundwater Pumping San Francisquito Groundwater Subbasin
Table 8 Estimated Annual Groundwater Recharge San Francisquito Groundwater Subbasin
Table 9 Estimated Annual Groundwater Discharge San Francisquito Groundwater Subbasin
Table 10 Historical Water Quality Sampling Results for Gloria Way Well
Table 11 Laboratories Conducting Water Quality Analyses, May 2012 Gloria Way Well Sampling
Table 12 General Physical and Minerals, May 2012 Gloria Way Well Sampling
Table 13 Inorganics, May 2012 Gloria Way Well Sampling
Table 14 Anions, May 2012 Gloria Way Well Sampling
Table 15 Chlorinated Acids, May 2012 Gloria Way Well Sampling
Table 16 Chlorinated Pesticides and PCBs, May 2012 Gloria Way Well Sampling
Table 17 Volatile Organic Compounds, May 2012 Gloria Way Well Sampling
Table 18 Semivolatile Organic Compounds, May 2012 Gloria Way Well Sampling
Table 19 Additional Analytes, May 2012 Gloria Way Well Sampling
Table 20 Cation-Anion Ratios and Percent Error Calculations, May 2012 Gloria Way Well Sampling
Table 21 Piper and Schoeller Diagram Calculations, May 2012 Gloria Way Well Sampling
Table 22 Brine Differentiation Plot Calculations, May 2012 Gloria Way Well Sampling
Table 23 Land Subsidence Monitoring Methods
Table 24 Gloria Way Well Treatment System Construction and Annual Operating Costs
Table 25 Potential New Well Sites Screening
Table 26 Construction and Annual Operating Costs for New 500 GPM Well System
Table 27 Lifecycle Water Cost Comparisons for Gloria Way and New Well Sites
Table 28 Storage Sizing Alternatives
Table 29 Diurnal Demand
Table 30 Cost for Various Tank Options
Table 31 City of San Bruno Customers by Classification
Table 32 San Bruno Water Enterprise Expenses FY 2012-13
Table 33 San Bruno Water Enterprise Staffing FY 2012-13
Table 34 City of Palo Alto Customers by Classification
Table 35 City of Palo Alto Water Fund Expenses
Table 36 Palo Alto Water Enterprise Staffing FY 2012-13
Table 37 City of East Palo Alto Customers by Classification
Table 38 City of East Palo Alto Expenses
Table 39 East Palo Alto Staff Provided by American Water Enterprises
Table 40 Financing Option Borrowing Term

City of East Palo Alto  
Gloria Way Water Well Production Alternatives       Todd Engineers 
Analysis and Water Security Feasibility Study      November 2012 
iv
List of Figures
Figure 1 Study Area and Surrounding Hydrogeologic Features
Figure 2 Elevation of Top of Bedrock
Figure 3 Hydrogeologic Cross Section Locations
Figure 4 Regional Hydrogeologic Cross Section A-A’
Figure 5 Local Hydrogeologic Cross Section B-B’
Figure 6 Local Hydrogeologic Cross Section C-C’
Figure 7 Local Hydrogeologic Cross Section D-D’
Figure 8 Aquifer Hydraulic Parameters
Figure 9 Historic Groundwater Levels in the Hale Well
Figure 10 Generalized Groundwater Elevation Contours
Figure 11 Known Production Well Locations
Figure 12 Regional TDS Concentrations
Figure 13 Groundwater Quality Trends with Depth
Figure 14 Locations of Ravenswood Wells
Figure 15 Regional Chloride Concentrations
Figure 16 Regional Iron Concentrations
Figure 17 Regional Manganese Concentrations
Figure 18 Contamination Sites
Figure 19 As-built Schematic of Gloria Way Well
Figure 20 Water Levels over Time during 2003 Gloria Way Well Pumping Test
Figure 21 Gloria Way 2012 Pumping Rates
Figure 22 Piper Diagram for Gloria Way Well and Other Water Sources
Figure 23 Water Source Diagram for Gloria Way Well and Other Water Sources
Figure 24 Brine Differentiation Plot for Gloria Way Well and Other Water Sources
Figure 25 MODFLOW Model Area and Simulated Steady-State Groundwater Elevations
Figure 26 Predicted Drawdown after One Year, Gloria Way Well Pumping at 100 GPM
Figure 27 Predicted Drawdown after Five Years, Gloria Way Well Pumping at 100 GPM
Figure 28 Predicted Drawdown after One Year, Gloria Way Well Pumping at 200 GPM
Figure 29 Predicted Drawdown after Five Years, Gloria Way Well Pumping at 200 GPM
Figure 30 Predicted Drawdown after One Year, Gloria Way Well Pumping at 300 GPM
Figure 31 Predicted Drawdown after Five Years, Gloria Way Well Pumping at 300 GPM
Figure 32 Schematic Flow Diagram for Gloria Way Well
Figure 33 Gloria Way Well Site Plan
Figure 34 Potential New Well Sites
Figure 35 Predicted Drawdown after One Year, Pad D Well Pumping at 300 GPM
Figure 36 Predicted Drawdown after Five Years, Pad D Well Pumping at 300 GPM
Figure 37 Predicted Drawdown after One Year, Pad D Well Pumping at 500 GPM
Figure 38 Predicted Drawdown after Five Years, Pad D Well Pumping at 500 GPM
Figure 39 Site Plan for 500 GPM Well
Figure 40 Plan View of 1 MG Water Storage Tank
Figure 41 Plan View of 2 MG Water Storage Tank
Figure 42 Plan View of 5 MG Water Storage Tank

City of East Palo Alto  
Gloria Way Water Well Production Alternatives       Todd Engineers 
Analysis and Water Security Feasibility Study      November 2012 
v
List of Appendices
A Quality Assurance Project Plan
B Regional Well Construction Information
C Regional Groundwater Quality Data
D Regional Environmental Contamination Sites
E Gloria Way Well Water Well Drillers Report and 2004 Inspection and Testing Report
F Analytical Laboratory Reports for May 2012 Gloria Way Well Sample
G Permit Requirements for Active Status and New Production Well Systems
H Water Rate Information for Cities of Palo Alto and San Bruno
I California Department of Public Health Safe Drinking Water State Revolving Fund Information

City of East Palo Alto  
Gloria Way Water Well Production Alternatives       Todd Engineers 
Analysis and Water Security Feasibility Study      November 2012 
vi
EXECUTIVE SUMMARY 
The City of East Palo Alto has a current water supply guarantee of 2,199 acre‐feet (AF) annually from the San 
Francisco Public Utilities Commission (SFPUC).  The City’s 2010 Urban Water Management Plan (UWMP) shows 
a current demand of 2,200 AF rising to 2,658 AF in 2015 and 3,400 AF by 2035. Comparison of these values 
indicates that the City does not have adequate water supplies to support further growth and economic 
development. Moreover, additional guaranteed water is not available from the SFPUC. Potential  methods of 
increasing supply or reducing demand identified in the UWMP are: 
• Water conservation by customers 
• Utilization of recycled water for irrigation 
• Transfers 
• Desalination  
• Purchase of additional water rights from other jurisdictions, utilities, and private parties  
• Development of local groundwater resources. 
With regard to future water conservation, East Palo Alto has two important characteristics: a relatively low per 
capita water demand and limited outdoor irrigation. East Palo Alto already has the lowest per capita water 
consumption (58 gallons per day) among the 27 Bay Area Water Supply and Conservation Agency (BAWSCA) 
municipalities.  Accordingly, the potential is limited for reducing water demand relative to available supply.  In 
addition, there is limited opportunity for the use of recycled water.  Parks and school property are typical large 
uses and these are limited in East Palo Alto. Nonetheless, the UWMP provides an overview of potential 
recycled water opportunities and potential methods to encourage recycled water use. Similarly, the UWMP 
outlines transfer and exchange opportunities, which are focused mostly on water shortage conditions. 
Desalination also is addressed in the UWMP as a potential future opportunity as other San Francisco Bay area 
agencies explore the feasibility of regional desalination.  
At this time, the most practical method of increasing supply is development of local groundwater resources. 
Sand and gravel aquifer zones, inter‐bedded with less permeable clay layers, are present beneath the City and 
wells are capable of producing several hundred gallons per minute or more.  The City has an existing well, 
Gloria Way, that is operable but not in use because of high levels of iron and manganese in the groundwater.  
In addition, groundwater is available throughout the City, although comprehensive information regarding the 
available quantities and quality is not completely currently available.  It is noted that the Palo Park Mutual 
Water Company, which lies within the City, has been supplying approximately 1,000 customers with 
groundwater from their well field since 1920. 
Test pumping of the Gloria Way Well has indicated that it can provide a sustained yield of approximately 300 
gallons per minute (gpm).  Because of the elevated iron and manganese, a treatment facility would be 
required; the existing site has adequate space to accommodate such a facility.  The approximate cost for the 
design and construction of an iron/manganese removal facility is $2,000,000. 
The City’s proximity to San Francisco Bay presents a risk of saline water intrusion and groundwater quality 
degradation if groundwater pumping results in excessive drawdown that reverses the natural groundwater 
flow direction toward the Bay.  Land subsidence also may occur as a result of excessive drawdown.  However, 
City of East Palo Alto  
Gloria Way Water Well Production Alternatives       Todd Engineers 
Analysis and Water Security Feasibility Study      November 2012 
    1
preliminary groundwater flow simulations indicate that drawdown and associated risks can be minimized by 
reducing the well pumping rate or cycling operation. Development of a groundwater management plan and 
implementation of a groundwater level and quality monitoring program in and around the City are key steps in 
ensuring that groundwater production is sustainable without significant adverse impacts. 
Other potential well sites in addition to Gloria Way have been identified and evaluated.  The preferred site for 
a second well, referred to as Pad D, is located near the intersection of Bayshore Road and Clarke Street in the 
Ravenswood 101 Shopping Center.  Preliminary hydrogeologic evaluation indicates that a sustained pumping 
rate of 500 gpm is possible at Pad D, but this needs to be confirmed by drilling a test well and performing a 
pumping test.  In addition, groundwater from this test well would be sampled and analyzed to evaluate water 
quality and determine if an iron and manganese treatment facility is required.  Development of a groundwater 
supply at Pad D (including an initial test well investigation, full‐scale production well, and 500‐gpm iron and 
manganese facility) would cost approximately $3,400,000. Project construction costs would be funded through 
a combination of grants, loans, and City reserves. The mix of funding options has not been determined at this 
time. 
In addition to construction costs, there will be future new operation costs. These new operational costs for the 
Gloria Way Well are estimated to be approximately $200,000 annually.  This assumes continuous well 
operation at a rate of 300 gpm.   
Overall project development requires further hydrogeologic and engineering evaluations as well as an 
environmental review. A groundwater management plan and monitoring program also need to be developed 
to ensure long‐term sustainability of the groundwater supply, and to qualify for available funding. 
Recommendations for next steps and implementation of the project are listed below: 
• Groundwater management and protection is strongly recommended to ensure that the 
continued highest beneficial use of the finite groundwater resources is available to meet the 
City’s demands. 
• Monitoring of groundwater levels and water quality conditions should be initiated to help 
manage the resource and provide early warning so that land subsidence and saline water 
intrusion from the Bay are minimized. 
• A Groundwater Monitoring Plan and a Groundwater Management Plan (GWMP) should be 
developed for the City to comply with State Law (AB3030, SB1938, SBx7‐6,), and be eligible for 
State Water Funds, as well as provide guidance on development and implementation of 
groundwater monitoring and management activities to protect and develop the resource to 
ensure the continued highest beneficial use.  
• The groundwater management plan and monitoring program should encompass the 
groundwater subbasin and include coordination with willing neighbor agencies and outreach 
to stakeholders.  
• Further predictive analysis of the effects of pumping by the City and other groundwater 
subbasin users should be performed to better define potential long term impacts under 

City of East Palo Alto  
Gloria Way Water Well Production Alternatives       Todd Engineers 
Analysis and Water Security Feasibility Study      November 2012 
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