Lower Arkansas Basin TMDLs

• TMDLs for the Lower Arkansas Basin
• Implementation Priority
• Schedule for Submitting TMDLs
• Approval Letters

The Section 303(d) list submitted to and approved by EPA in 1998, identifies 129 river segments and 24 lakes in the Lower Arkansas River Basin as water quality impaired. Among the streams, the greatest number of impairments were caused by excessive levels of fecal coliform bacteria. Among the lakes, eutrophic conditions indicative of excessive algae production was the predominant cause of impairment.

Other pollutants limiting the use of the Lower Arkansas River Basin streams include selenium, dissolved oxygen depletion, chloride, chlordane, fluoride, sulfate, ammonia, nutrient oxygen demand, sediment, and pH. Additional lake impairments were caused by chloride, sulfate, selenium, dissolved oxygen depletion, pH, siltation, and excessive aquatic plants. Each parameter causing impairment requires a TMDL.

Many of the stream segments, configured in a watershed setting, will have a TMDL applied to them as a whole. Fifty watershed and 29 lake TMDLs will be developed. The submission of high priority TMDLs was made on June 29, 2000; some were approved on August 9, 2000, and the remainder were approved on September 11, 2000. The medium and low priority lake TMDLs were submitted on September 8, 2000 and approved on November 13, 2000. The medium and low priority stream TMDLs were submitted on April 18, 2001 and approved on July 27, 2001. The chloride TMDLs will be submitted by March 2004.