MS4 STORMWATER MONITORING PROGRAM AND YEAR 1 RESULTS FOR THE SPRINGFIELD, MISSOURI METROPOLITAN REGION

Municipalities within Greene and Christian Counties in Missouri have implemented stormwater discharge monitoring programs as either Phase 1 with a medium municipal separate storm sewer system (MS4) or Phase II as an urbanized area (UA) to address water quality requirements specific to watersheds within larger municipal political areas. The goal of each monitoring program is to characterize storm water quality from urban source points to local streams. Municipalities are required to contribute to the NPDES stormwater program to reduce adverse impacts from stormwater discharges especially related to water quality and aquatic habitat by previously unregulated sources. In addition, the data derived from these monitoring programs have the ability to facilitate the establishment of Total Maximum Daily Loads (TMDLs) within each County. The pollutants of concern specified by the NPDES permit are aimed to address specific TMDL concerns: total phosphorus, total nitrogen, total suspended solids, chloride, specific conductivity, and pH. Thirty-one sampling sites within two counties were chosen for monitoring based on accessibility for sampling, suitability for the project, network location, and urban land distribution. One base flow and four first flush samples were collected from each site. For analysis, water quality data was grouped by subwatershed to determine what sites were exceeding established limits. In addition, water quality variability is evaluated over different spatial scales to determine what affects combined inputs have on downstream receiving water bodies.