TEXAS: SAN ANTONIO
San Antonio Protects Edwards Aquifer
Background
San Antonio, the seventh largest city in the United States, covers approximately 515
square miles of Bexar County in south central Texas. Throughout its colorful history, the
city's culture and traditions are influenced by Native Americans, Old Mexico, Germans,
the Wild West, African-Americans and the Deep South. Over one million people call San
Antonio home, and nearly seven million tourists visit the city each year.
The San Antonio Water System (SAWS) presently serves approximately 1.2 million
customers, via 91 wells that draw from the Edwards Aquifer, 16 Trinity aquifer wells, and
for the first time SAWS is currently receiving approximately 6 million gallons per day of
surface water. These new non-Edwards water sources make up approximately 8.5% of
the water supplied to our customers. Additionally, SAWS completed construction of an
Aquifer Storage and Recover (ASR) project for the Edwards aquifer region, this
technology is expected to reduce summer peak demands on the aquifer by pumping the
Edwards aquifer water stored in the ASR project rather than directly from the Edwards
aquifer.
The Edwards Aquifer consists of extensively faulted and fractured carbonate limestone
that lies within the Balcones fault zone. The size, storage capacity, flow characteristics,
water producing capabilities, and efficient recharging ability of this geologic feature make
it one of the most impressive aquifers in the nation. The small hydraulic gradients and
the large discharge volume at the springs and many high yielding wells indicate the
immense transmissivity of the Edwards Aquifer. In 1975, it was the first aquifer in the
U.S. to receive a sole source designation by the Environmental Protection Agency.
The Edwards Aquifer extends approximately 180 miles from the Brackettville area in the
western region of San Antonio, to Kyle in the eastern region of the municipality. Urban
development, both residential and commercial, is rapidly increasing in the aquifer's
recharge zone. With this increased development comes an increased possibility of
contamination from spills, leakage from hazardous materials, and urban runoff. Other
potential contamination sources of the Edwards Aquifer include abandoned or mineral
exploration wells, runoff from highways and railroads, underground or above ground
chemical storage tanks, municipal landfills, industrial and hazardous waste disposal, and
agricultural chemicals such as fertilizers and pesticides.
Priority Contamination Threat
Priority contamination threats include commercial and residential spills, hazardous
materials, and urban runoff,
Local Involvement and Developing the Protection Plan
Public education and outreach are the main avenues for local involvement in SAWS's
source water protection program. These programs focus on water conservation,
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stormwater runoff, water quality, reuse, aquifer studies, recycling and wellhead
protection. Audiences include school groups, homeowner associations, community
organizations, and government agencies. Specific programs include Adopt-A-Creek,
Texas Watch Monitoring, and Storm Drain Stenciling. SAWS regularly conducts training
workshops for the professional trades to address local, state and federal regulations
associated with construction and industrial activities. SAWS also provides technical
assistance for San Antonio's rural residents who rely on private wells for their household
water supply, and provides information on proper well construction, proper well setting,
backflow prevention, and plugging abandoned wells. SAWS's Groundwater Protection
Division also helps well owners by answering inquiries on where water samples are
accepted for testing, and suggesting basic wellhead protection practices.
Management Measures
SAWS's Wellhead Protection Program was initiated by the Texas Natural Resource
Conservation Commission. In addition to completing a study of the region's geology,
ground water, and land use, SAWS has delineated a one-quarter mile radius of each
public supply water well, and inventoried potential sources of ground water degradation.
Public education and outreach are also important components of SAWS's program, as
described above.
Additional strengths of the SAWS source water protection program are its Abandoned
Well Program, Sensitive Land Acquisition Program, land use reviews and assessments,
and various contaminant source inspection programs. These programs and other
planned initiatives are described below.
SAWS Abandoned Well Program
SAWS is very active in identifying and closing abandoned wells because they are direct
conduits for contaminants to enter the Edwards Aquifer. SAWS defines abandoned wells
as any well which exists in a deteriorated condition, has not been used for a minimum of
six consecutive months and which is not connected to an active electrical or other power
source. SAWS identifies abandoned wells through the inspection of platted or replatted
properties, or through property inspections when SAWS receives an application for
water service. SAWS issues permits for approximately 70 well closures each year.
When an abandoned well is located, the plat is denied and the engineering firm and/or
developer is notified. SAWS will release the plat if (1) the well is immediately plugged in
accordance with SAWS Groundwater Protection Division's plugging procedures, or (2) a
bond/cashiers check is provided in an amount equal to an accompanying bid to have the
well plugged by a licensed water well driller or pump installer. The bond or cashier's
check is held for a maximum of six months.
If a well is located on an individual's property that has applied for water service, the
customer may plug the well or apply for a variance. If the variance is granted the
customer must install a backflow prevention device on their incoming service line. This
device prevents the possibility of a cross connection between the well water and SAWS
water. The San Antonio Water System recently received an EPA 319 Grant
(administered by the Texas Natural Resource Conservation Commission) to fund the
plugging of abandoned wells for well owners that cannot afford the cost of doing so.
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Sensitive Land Acquisition Program
In 1997, SAWS initiated this program to protect and preserve the quantity and quality of
water entering into the aquifer recharge zone by acquiring lands that are predisposed to
contamination due to their geologic sensitivity. Through conservation easements and fee
simple acquisition (outright purchase) of these lands, detrimental land uses within the
recharge zone are reduced. SAWS has developed standardized criteria for evaluating
the suitability of properties to be acquired through this program. Criteria include:
maximum thickness of Edwards limestone on property, presence of streams and/or
rivers, presence of faulting, presence of major features, availability, and affordability of
the parcel. To date, SAWS has acquired and or established conservation easements on
20,519.68 acres.
Land Use Reviews and Assessments
SAWS's Aquifer Protection and Evaluation section helps protect the aquifer recharge
area through the review and assessment of various land uses (zoning changes, site
development plans, building permits, Water Pollution Abatement Plans), and reporting
their findings to the appropriate authority (Zoning Commission, City Council, Planning
Commission, Texas Commission on Environmental Quality).
SA WS Inspection Programs
\ndustrial Inspections: Industries in San Antonio are required to file for an TCEQ
stormwater discharge permit dependent on the type of operations they conduct
(classified by SIC). SAWS Industrial Compliance Specialists inspect those industries
required to maintain Industrial Storm Water Discharge permits. Through this program,
SAWS assist industry managers to achieve and maintain permit compliance, conduct
routine and emergency site inspections, review pollution prevention plans, provide
alternatives for current disposal methods as necessary, and offer general stormwater
assistance.
Construction Inspections
In this program, SAWS specialists review Stormwater Pollution Prevention Plans
(SWP3) to ensure that projects are being administered within the parameters set by
federal law. Specialists check sites for "good housekeeping" and function as a liaison
between the community and developers. The city code provisions covering Clearing and
Grading requirements are intended to improve the conditions in the site-clearing phase
of construction.
Illicit Connection Monitoring Program
Through this program, SAWS inspects San Antonio's (and part of Bexar County's)
Municipal Separate Storm Sewer System (MS4) to identify unlawful connections. Illicit
connections into the storm drain system are either terminated or redirected into the
sanitary sewer system as soon as they are identified so that the discharge may be
treated. Other discharges include leaking sanitary lines crossing the storm drain system
and/or leaking water mains.
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Instream Monitoring
Through this program, SAWS monitors the storm water runoff quality of San Antonio's
streams and waterways with a system of monitoring stations located in strategic
locations. The program involves quarterly analysis of Biochemical Oxygen Demand
(BOD), Chemical Oxygen Demand (COD), total and dissolved phosphorous, copper,
Total Suspended Solids (TSS), dissolved solids, Total nitrogen total ammonia plus
organic nitrogen lead, cadmium and zinc for all sample sites. The parameters are used
in conjunction with a statistical model to calculate pollutant loading based upon land use,
watershed delineation and locally-adjusted pollutant load equations to include the
complete storm-water dataset information.
Sampling Dry and Wet Weather Field Screen Points
SAWS evaluates approximately 500 field points for biological, physical, and chemical
characteristics throughout the year. These sample locations use field kits to identify
discharges as allowable or not. Further investigation is done in conjunction with the Illicit
connection program to identify and eliminate discharges if needed.
Contingency Planning
SAWS's contingency plan focuses on both short term and long plans in the event of
emergency situations evolving from industrial incidents, train derailments, motor vehicle
accidents, aircraft crashes and the illegal dumping of hazardous materials. The
contingency plan is made available to water system employees and community officials,
and is operated under the jurisdiction of the Fire Department's Hazardous Material
Response Team. SAWS on-call staff respond to spills for testing, expert consultation on
the drainage system, and protection of the environment, as well as cleanup options. In
addition, SAWS has placed signs within the source water protection area that advertise
emergency phone numbers to call in the event of a contamination emergency. Another
component of SAWS's contingency plan is the implementation of annual Water
Emergency Training (WET) exercises. During these exercises, participants are
presented a hypothetical emergency scenario and must organize a task force and
address the problem.
SAWS South Bexar County Well Mitigation Program
The South Bexar County Well Mitigation Program was approved by the SAWS Board of
Trustees in order to address potential water level declines in privately-owned water wells
in the vicinity of the SAWS Twin Oaks Aquifer Storage and Recovery (ASR) Plant. The
ASR Plant allows for water pumped from the Edwards Aquifer to be placed into long-
term subsurface storage in the Carrizo Aquifer until it is needed to satisfy supply
demands during extended dry periods. Although the primary focus of the Mitigation
Program is to address water level fluctuations related to operation of the ASR, a side
benefit has been the elimination of potential sources of contamination to the Carrizo
Aquifer. During the mitigation process, well that are do not meet current regulatory
standards are brought into compliance by such actions as installing a concrete slab at
the wellhead, elevating the casing above ground surface, and installing a functioning
sanitary on the wellhead. These extra measures not only protect the private well
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owners, but also the SAWS customers that benefit from the operation of the Twin Oaks
ASR Plant.
Measuring Program Effectiveness
SAWS's success in source water protection can be measured by the fact that the
organization is continuing to improve its numerous programs and create new ones that
will ensure high-quality water for San Antonio. In 1999, SAWS's source water protection
program received the Environmental Excellence Award from the Environmental
Protection Agency (Region 6). In 2002 SAWS Pretreatment program received the
National Second Place Clean Water Act Award from EPA. In 2003 SAWS Municipal
Storm Water Program received the National Second Place Clean Water Act Award from
EPA and in 2005 SAWS received a National Environmental Achievement Award from
the I EGA for its Storm Water Management Program.
Initiatives
SAWS is currently expanding the scope of its source water protection program to include
projects such as:
• Incorporating and reviewing the State assessment that was completed in 2005;
• Develop hydrologic maps for the Edward aquifer recharge zone in Bexar County,
Texas.
• Develop source water protection projects for the Carrizo and Trinity aquifers;
• Improve the contingency plan that will utilize new technology; and
• Pursue the passage of city ordinances to further the protection of recharge zones
for San Antonio's water supplies.
For further information, contact:
Jim O'Connor
Source Water Protection Specialist
San Antonio Water System
(210)233-3547
ioconnor(S)saws.org
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