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,
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.
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).
SAWS Inspection Programs
Industrial 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.
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
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 IECA 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 joconnor@saws.org
