Baseline Assessment of Nutrient Loading and Sediment Geochemistry of Town Creek, Jackson, Mississippi

An assessment of aqueous nutrient loading, organic and inorganic sediment geochemistry from five sites on Town Creek provides baseline chemical data for the urban watershed. Jackson, Mississippi has a population of over 184,000 residents in the 174 km² city limit. Seven of the ten larger creeks that flow through the city originate within the city limits and are tributaries of the Pearl River. Land use within the 34 km² Town Creek watershed ranges from residential to light industrial. Bi-monthly aqueous samples were not taken within 48 hours of a storm event to reduce the influence of contaminants in stormwater runoff. Nitrate and sulfate concentrations increase from the headwater to the mouth along the 8.7 km section sampled with concentrations averaging 0.06 and 16.70 mg/l respectively. Soluble reactive phosphorus averages 2.67 mg/l and has been detected at values as high as 3.19 mg/l. The greatest soluble reactive phosphorus concentrations occur in the sampling site immediately downstream of the Sonny Guy Municipal Golf Course. Total dissolved solids average 257 mg/l; total suspended solids are negligible. The concentrations of 16 EPA priority pollutants were evaluated using EPA 8270C protocol. Polycyclic aromatic hydrocarbons (PAH) present in sediment fines were typical of pyrogenic compounds found in urban stream sediment. Only sample sites within 2 km of the mouth contained detectable PAHs.