NPDES Update: Documented improvements

July 2007 » Feature Articles
The San Antonio Water System has made great strides implementing NPDES requirements, and showing how increased stormwater management activities are impacting the San Antonio River positively.
Philip Handley, R.E.M.

Initiatives prompted by NPDES Phase II yield positive results for the San Antonio River.

A community’s successful implementation of stormwater regulations involves more than compliance with requirements. Establishing metrics to show results of associated initiatives proves validity of such programs. Such feedback makes developers, construction professionals, civil engineers, water quality professionals, and other citizens feel engaged and empowered to support the requirements. And with data to show effects, support comes not just because they have to, but because they are saving time and money in avoiding fines and Stop Work Orders, and most importantly, improving their area’s water quality.

The San Antonio River south of downtown.

The San Antonio Water System (SAWS) has made great strides in using technology, data management, education, water quality modeling, and more to implement the requirements of the National Pollution Discharge Elimination System (NPDES) Phase II, and to show how increased stormwater management activities are impacting the San Antonio River positively.

A growing community
Since 1691 when the Spanish and Native Americans began settlements along the San Antonio River, this waterway has been a vital lifeline in the development of what is today San Antonio, Texas. San Antonio is the seventh largest city in the United States, with a population of approximately 1.3 million and a geographic area of 504 square miles. It is also the third fastest-growing city in the United States; the population has increased by more than 70,000 people since 2000.

The SAWS Storm Water Management Program works to protect the water quality of the San Antonio River and its surface water tributaries in San Antonio. In addition, the program provides protection to the city’s primary source of drinking water, the Edwards Aquifer, which is an underground karsts aquifer that is recharged by surface water runoff during rain events.

SAWS is the city’s stormwater regulatory agency for the local Storm Water Management Program and manager of the Texas Pollutant Discharge Elimination System (TPDES) Construction and Industry permits issued by the Texas Commission on Environmental Quality (TCEQ). San Antonio is a NPDES Phase I city, with three co-permit partners: the San Antonio Water System, the City of San Antonio, and the Texas Department of Transportation-San Antonio.

The TCEQ assumed delegation of the construction program from the U.S. Environmental Protection Agency (EPA) as part of the NPDES Phase II program in 2002. The TCEQ TPDES General Construction Permit TXR150000 went into effect on March 5, 2003. The biggest change to result from this permit was coverage for 1- to 5-acre construction sites. Historically, SAWS receives an average of more than 500 Notice of Intent applications annually from the local construction community. Phase II, on average, has generated a 16-percent increase in permitted sites annually for evaluation by the SAWS program.

To meet the demands of the TPDES Construction permit, additional Phase II requirements, and a robust local development community, SAWS has developed a multi-faceted approach to the stormwater management program. For the most part, these tasks are performed by the Construction Compliance Section of SAWS, a staff of six stormwater quality specialists and one supervisor.

One change in approach was the transition to the use and leveraging of technology. In 2004, SAWS Construction Compliance staff performed 2,741 site evaluations using the traditional paper system of site evaluation documentation and mail outs to construction operators. In 2006, SAWS moved to a complete wireless, electronic database application system and increased field/site presence by performing 5,114 site evaluations. An electronic database allows for increased exposure of regulatory staff in the field and provides site operators with immediate results of site evaluations, affording site operators an opportunity to make more efficient, timely correction of non-compliance items identified during the evaluation process.

SAWS staff conducting site inspections have ready-access to technology in their trucks so that they can provide reports to site operators immediately following evaluations.

Importantly, the improved data management allows SAWS staff to monitor trends of poor compliance by operators, allowing for timely communication between SAWS and site operators to restore compliant behavior quickly. Good, frequent communication translates to improved compliance, which reduces time spent by SAWS staff in preparing documentation for elevated enforcement.

In 2005, SAWS developed a TPDES Inspector Training Workshop. This workshop is designed to meet the "qualified person" requirement of the TPDES permit. After evaluating site operator trends following implementation of Phase II stormwater regulations, SAWS staff discovered that many site operator inspectors were not conducting site inspections properly and were not familiar with regulatory expectations of a site inspection.

Therefore, a six-hour workshop was developed that includes presentations on stormwater pollution prevention plan site management, expectations of a regulatory site visit, and an interactive inspection. SAWS staff uses a DVD virtual site inspection and provides attendees with a mock residential site plan and an inspection form. Participants are guided through a series of video clips of various best management practices from the DVD to evaluate and document the site inspection. At the end of the DVD virtual inspection, SAWS staff reviews the evaluation with the attendees. The class concludes with a walking field trip to see standard and innovative erosion and sedimentation control technologies installed in a field environment.

To date, 411 stormwater field inspectors/operators have attended the workshop, and all have been given both pre- and post-workshop evaluations to determine knowledge gained in the training session. The pre-workshop evaluation average score is 59. The post-workshop evaluation average score is 83. What’s more, SAWS has noted the knowledge gained by the site operators when in the field, seeing improved inspection documentation and increasing compliance.

In fact, in 2005 there were 3,187 site evaluations performed, and 20 percent of those sites received Field Correction Notices (notices of violations) and 6 percent were issued Stop Work Orders. In 2006, there were 5,114 site evaluations performed but only 5 percent of those sites received Field Correction Notices and less than 1 percent of the sites were issued Stop Work Orders. This is a significant improvement—in just a short timeframe—that is directly linked to the training workshop.

Monitoring and modeling
SAWS monitors all streams and tributaries to the San Antonio River each year, performing analytical sampling and lab analysis for water quality, and maintaining a complex water quality model to monitor and evaluate trends in pollutant loading. Each year, SAWS staff works in the dry summer months to evaluate approximately 500 field screen points (stormwater discharge points) into creeks, tributaries, and the San Antonio River. Most discharge points are found dry. Field screen points that have flow are field-tested for a variety of constituents such as metals, surfactants, and other pollutants. If specific concentrations of pollutants are found, an investigation begins and ultimately the source of the pollutant is located. Once the pollutant source is located and evaluated, the pollutant source operator is notified and the pollutant discharge is ceased.

SAWS also monitors six permanent, automated sampling stations strategically located along the river and its primary tributaries. During rain events these stations collect representative samples that are sent for laboratory analysis of various pollutant constituents. This data is then included in the water quality/pollutant model and evaluated for pollutant-loading quantities and trends. Remarkably, historical modeling data indicates that pollutant loading in the river and tributaries has remained consistent or has experienced a lower loading trend even though the area has experience steady population and development growth since 2000.

The SAWS also communicates with the San Antonio River Authority, a local agency charged by the state of Texas to monitor the entire watershed from San Antonio to the Gulf of Mexico and to review the biological health of the river, which hasn’t always been good. In a 2002 San Antonio Express-News article, San Antonio River Authority (SARA) Biologist Ernest Moran said, "When I came to the river authority 20 years ago, the San Antonio River was basically a dead zone from I.H. loop 410 to Kennedy, Texas."

Today, things have clearly changed. In the same article, Mike Gonzalez of SARA said, "We now have documentation of nine pollution-intolerant species of fish in the river."

On a national scale, rating a river’s health is measured by the Index of Biological Integrity (IBI). This rating runs from zero to 60, based on the diversity of organisms. The San Antonio River IBI was 48 (high quality) in 2001. By 2003, the IBI of the river improved to 54 (between high quality and exceptional). From 2001 to 2006, the San Antonio River has maintained an IBI score of 50 or above, which indicates good habitat for aquatic life and good water quality condition of the river.

The combination of leveraging technology and improvement of data management, education, water quality sampling, and development growth/pollutant load trend modeling has allowed the SAWS stormwater management program to implement Phase II stormwater regulations effectively and successfully. The metrics and measures established and monitored by the SAWS program are documenting the successes of regulation, enforcement, education efforts, cooperative partnerships with the construction and development community, and cooperative communications with other regional water quality agencies.

And this success has far-reaching impacts, namely improved water quality has eliminated the need for more costly practices to treat drinking water drawn from the Edwards Aquifer for San Antonio regional residents. These savings alone far exceed the costs of operating the Storm Water Management Program. In addition, downstream users of surface water flowing from the upper San Antonio River benefit from quality water leaving the San Antonio metropolitan area. But perhaps most excitingly, aquatic habitat is reaping the benefit of the continued improvement of water quality in the San Antonio River. What a great message to share with the development and construction community to keep them motivated.

Philip Handley, R.E.M., is a construction compliance supervisor with the San Antonio Water System, San Antonio, Texas. He can be reached at 210-233-3564 or via e-mail at

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