By Brett Rosenberg
September 29, 2003

The Waco (TX) metropolitan area, including McLennan County, is home to over 213,000 people and 41,000 dairy cows. The high proportion of dairy cows to residents presents a unique challenge for regional cooperation to ensure high quality water supply without harming the economic vitality of the cattle industry. Waco Mayor Linda Ethridge and Commissioner Kathleen Hartnett White of the Texas Commission on Environmental Quality (TCEQ) presented regional strategies to achieve environmental goals related to animal wastes and non-point sources of pollution at the Conference of Mayors 2003 Urban Water Summit.

Lake Waco, the city's primary water supply, is a precious asset for an otherwise arid region. The Bosque River flows into the lake and introduces agricultural and storm water runoff from the area dairy farms. Consequently, Lake Waco receives large quantities of pathogens posing health risks to area residents, and nitrogen and phosphorus loads that encourage rapid algae growth. When the algae dies, a chemical substance know as geosmin coats water filters and creates odor and taste problems. The decomposition also depletes oxygen levels.

Waco implemented several strategies to alleviate the phosphorous pollution from dairy farms. The initial strategy was to apprise citizens of the challenges facing the Lake and open lines of communication to educate them about the problem. Waco also raised the Lake level by seven feet at a cost of $36 million to provide additional storage capacity and improve habitats. Over $70 million was spent on numerous improvements to water treatment and storage infrastructure. However, these efforts, the construction of a wetlands area and a state'subsidized composting program did not hasten progress in meeting water quality standards.

It soon became apparent that solving the animal waste related water quality problem was beyond local authority. With the help of White and several members of the Texas Congressional delegation, Ethridge was able to form a coalition with the U.S. Department of Agriculture, the Texas Farm Bureau and other stakeholders to address the issue

White explained that Waco's water quality was the shared responsibility between state and local governments. While TCEQ was initially slow to act, Waco's immediate needs and efforts hastened state action. Several encouraging outcomes ensued including progress on the Total Maximum Daily Loads (TMDL) for phosphorous and pathogens; a $7 million EPA grant for composting projects; incentives for CAFO self audits; and a state law identifying sole source impairment zones, such as Lake Waco.

White was asked whether TCEQ has the regulatory and technological means to ensure a margin of safety in managing animal waste lagoons to meet the current 25-year/24-hour storm event standard. She responded that the regulatory approach includes enforcing the standard by addressing the lagoons' contents coupled with managing land applications in a rational manner to reduce runoff. Ethridge noted that a margin of safety in lagoon design and operation is key to protecting Waco's water supply and indicated that updating the standard to reflect a 10-day/24-hour storm event would be more protective.

Given the difficulties of ensuring a clean, healthy water supply while working to minimize economic harm to an industry vital to the region, Waco and its collaborators have shown remarkable progress in addressing such complex issues. Their efforts, as White expressed, indicate that regional watershed approaches to water quality management are a vital means of realizing environmental goals.