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Source Water ProtectionCase Studies
Leah G Walker, P.E.Senior Sanitary Engineer
California Department of Health ServicesDrinking Water Technical Programs Branch
2
California Examples
• Protection– Sebastopol– Anaheim– Lake Berryessa
• Assessment and Protection– Yosemite Valley
5
Sebastopol - Background
• Population 7,800• Regional “urban” center for surrounding rural area• Water System:
– 5 wells = 483 MG/year
– Well 5 off-line due to PCE
– Well 4 has shown 1,2-DCA and MTBE
– Well 7 – new well
• Hydrogeologic setting– Unconfined, porous media aquifer
– High transmissivity, steep gw gradient from west
6
Sebastopol - Vulnerability
• Sources are most vulnerable to PCAs associated with detected contaminants:– Dry Cleaners (PCE)– Known Contaminant Plumes (PCE and 1,2-DCA)– LUFTs (1,2-DCA and MTBE)– Gas Stations (1,2-DCA and MTBE)
• And …
7
Sebastopol - Vulnerability
• And to those PCAs not associated with detected contaminants from the top of the vulnerability ranking:– Chemical storage– Metal plating/finishing– Plastics/synthetics producers– Septic systems on parcels < 1 acre– Sewer Lines
8
Sebastopol – After the Assessment
• No formal plan or ordinance adopted, but– Invited a public committee; held some meetings
– More vigorously pursuing cleanup of contamination
– Prioritizing sewer line repairs in Zone A
– Eliminated use of pesticides on city-owned property
– Evaluating all proposed development in City for possible GW impacts
– Evaluating land use proposals outside city limits, but in zones, for possible impacts
– Considers allowing hookup to city sewer if septic system fails in Zone A
10
Lake Berryessa - Background
• Lake developed and operated by US Bureau of Reclamation for flood control and water supply
• Water supply users– Solano County Water Agency
(360,000 population in 5 communities)
– 9 small resorts and subdivisions
• Meeting initiated by DHS and EPA as demonstration project
11
Lake Berryessa - Background• Meeting Participants:
– US Bureau of Reclamation– Solano County Water Agency– Resort owners– Napa County Public Works – DHS– EPA– RWQCB– Fish & Game– Napa County Environmental Health
Key participants
12
Lake Berryessa - Results
• Key participants: – Regular meetings (now run by SCWA)– Contaminant Management Plan– Coordinated WQ Monitoring Plan– Communication on spills, accidents– Coordinated review of development proposals– Hazardous waste collection day– Marina operator workshop– Signs, brochures (boaters, campers, day users,
home owners)
13
City of Anaheim/
Orange County Water District
Purpose:• “Establish Public/
Private/ Community partnership to protect public health through a proactive process to prevent groundwater contamination”
14
Anaheim - Background
• Began in 1993 – Pre-DWSAP• Local Groundwater Protection Pilot Program• Population = 290,000• 29 wells providing more than 2/3 of water supply• 6 GW basins recharged by OCWD through an
elaborate system• 8 wells out of service:
– 4 Nitrates– 2 Benzene– 2 Chlorinated hydrocarbons
15
Anaheim – Project Objectives
• Establish Technical Advisory Committee (TAC)
• Select Pilot Project Area• Delineate Capture Zones• Identify Potential Pollution Sources• Manage Potential Pollution Sources• Prepare a Contingency Plan• Implement Public and Industry
Public Education and Participation Program
16
Anaheim – TAC
• City of Anaheim• Orange County Water District• Orange County Environmental Health• Orange County Environmental Management• DHS• Regional Water Quality Control Board• Dept. of Toxics Substances Control• EPA Region IX
17
Anaheim - Delineation
• Done by OCWD
• Used QuickFlow groundwater model
• Defined capture zones for wells in project area
18
Anaheim – PCA Checklist
• Did not have DWSAP checklists
• Identified chlorinated solvents as primary contaminant of concern
• Collected data from a variety of sources– Amount of data was overwhelming
• Developed a list of 1,000 businesses
• Narrowed list to those associated with chlorinated solvents in protection areas
19
Anaheim – Field Inspections• Inspected facilities from list• Used a checklist to verify:
– Type of activity– Regulatory status – Presence of Class V UIC wells
• underground injection wells • shallow disposal wells
– Materials handled or stored – Underground storage tanks– Presence, storage, and disposal of hazardous
materials
20
Anaheim – Vulnerability Analysis
• Using information from databases and field inspections, did a risk assessment to rank the facilities
• Considered:– Presence in zone– Presence of Class V well – Presence and quantity of chlorinated solvents– Presence and status of UST– Presence and compliance of hazardous materials– Presence and compliance of hazardous waste– Industrial discharge compliance
21
Anaheim – Well Identification Project
• Goals:– Verify the existence, location, and condition of “unknown
status” wells within project area
– Determine if wells were potential source of groundwater pollution
– Use retired senior volunteers
• Results:– Enough volunteers (20) to do project throughout city
– 251 wells researched, 49 found, 17 possible findings, 10 additional wells found
– 245 volunteer hours
22
Anaheim – Managing Pollution Sources
• Verify status of existing UST, industrial, and VOC cleanups in capture zones
• Prioritize inspections of facilities by risk assessment
• Provide compliance and technical assistance to businesses
• Identify if enforcement action necessary• Develop public education and participation
programs
23
Anaheim – Education and Participation
• Industry– Business newsletters– Fact sheets– Technical libraries– Workshops– Groundwater Star program– Well construction and closure guidelines– Technical assistance
25
Anaheim – Education and Participation
• Community– Bus shelter posters– Groundwater protection educational posters– Environmental First Aid Kit– Water Quality research project at high school– Water works summer reading program– Groundwater guardian program– Used oil recycling program– Speakers Bureau– Community events
26
Orange County Water District – Current Activities
• Children’s Drinking Water Festival– 7,000 students, teachers, volunteers, presenters– 2-day event
• Sponsor of the Blue Planet Foundation
• Interactive water exhibit at Discovery Museum of Orange County
28
Yosemite Valley
Purpose:
• Another test of DWSAP procedures and demonstration of a federal/state partnership for SWP
29
Yosemite Valley - Background
• Yosemite National Park – Total = 1,169 sq. miles– Undeveloped wilderness = 1,100 sq. miles– 4 million visitors/year– 1,500 – 3,000 employees of NPS and YCS
• Water Systems– 21 public water systems– 4 community systems, 17 non-community
30
Yosemite Valley - Background
• Yosemite Valley Water System– Permanent Population = 2,500– Visitors = 3.2 million/year– Service connections = 235
• 3 Wells– Confined aquifer of glacial porous media – Artesian conditions for most of year until late
summer, early fall
31
Yosemite Valley – Working Group
• National Park Service
• DHS
• EPA Region IX
• Concessionaire*
• Public Meeting– Counties – Other interested parties
32
Yosemite - Delineation
Zone B5Zone B5Zone A
Buffer ZoneBuffer Zone
Zone B10Zone B10
Buffer ZoneBuffer Zone
Zone B10Zone B10
33
Yosemite Valley – Assessment Tasks
• PCA Inventory– Done w/ field review and maps by DHS, NPS
and EPA
• PBEConfined aquifer + Artesian = High
• Vulnerability– No contaminants detected– Historic gas stations– Known contaminant plumes
34
Yosemite Valley - Protection
• Evaluation of current practices– NPS and YCS are already implementing most
SWP activities we could recommend, due to other programs or planning
• Recommended public education– Get these messages across:
“Yosemite Valley water is Naturally Protected From the Ground Up”
“Fill up on Valley water before heading to back country”