Smith Creek TMDL Plan

Water Quality Problems in Smith Creek


In 1996 Smith Creek was added to Virginia’s impaired waters list when water quality monitoring showed:

  • Smith Creek was violating the State’s water quality standard for bacteria, which is based on the concentration of E. coli bacteria in the water (the E.coli bacteria count should not exceed a geometric mean of 126 cfu per 100 mL of water for two or more samples taken over a 30-day period, and it should not exceed 235 cfu per 100 mL at any time).
  • Smith Creek was violating the general standard for aquatic life use. This standard states that all state waters should support “the propagation and growth of a balanced indigenous population of aquatic life…” Based on biological monitoring conducted by the Virginia Department of Environmental Quality, it was concluded that Smith Creek was not meeting this designation. The primary stressor on the aquatic community was identified as sediment.

In accordance with the federal Clean Water Act, in 2004 the state developed a Smith Creek Total Maximum Daily Load (TMDL) which specified the maximum bacteria and sediment loads that the stream can handle and still meet the water quality standard for bacteria while also supporting a healthy and diverse aquatic population.

In May 2009, a TMDL Implementation Plan and TMDL Public Document were developed to describe measures to reduce bacteria and sediment loads and to restore the stream to its original healthy state. These measures include both agricultural and urban “best management practices” supported by state and federal agencies and the application of improved technology such as waste water treatment systems.