STORMWATER ASSESSMENT OF NUTRIENT LOADING AND E. COLI CONTAMINATION OF TOWN CREEK, JACKSON, MISSISSIPPI

A stormwater assessment of aqueous nutrient loading at one site, and the determination of E. Coli contamination from two sites on Town Creek was conducted from April through August 2010. In addition to nitrate and phosphate concentrations, total dissolved and suspended solids were measured. There has been renewed interest in Town Creek since a recent plan to create a river walk in the downtown area using Town Creek was announced. Aesthetic degradation of the Town Creek channel is readily observable through the presence of floating and submerged anthropogenic debris. Jackson, Mississippi has a population of over 184,000 residents in the 174 km² city limit. Land use within the 34 km² Town Creek watershed ranges from residential to light industrial. An automated stormwater sampler recovered 4L instantaneous and composite samples during eight storm events. Storm runoff phosphate and nitrate concentrations averaged 0.68 mg/L and 181.20 mg/L respectively. The total dissolved solids averaged 1128 mg/L and total suspended solids averaged 365 mg/l in the same samples. The TDS and TSS storm runoff averages were over 4 and 12 times the low flow average (n=94) values for Town Creek taken over the previous year. The average storm runoff values for nitrate were over 200 times the low flow average; no reportable difference was noted for phosphate concentrations. E. Coli concentrations taken from two sites during baseline flow conditions averaged over 3,500 colonies per 100 ml; storm runoff values for those same sites averaged over 146,000 E. Coli colonies per 100 ml. The high observed nitrate and E. Coli concentrations may be attributed to sewage system overflow during storm events.