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Vermillion River Watershed JPO: Technical Reports

Vermillion River Water Fecal Coliform Bacteria Study - 2004

The Vermillion River was officially listed as impaired for swimming in 1998 when it was added to the Federal 303(d) list of impaired waters due to high bacteria levels. A Total Maximum Daily Load (TMDL) Study for fecal coliform bacteria in the Vermillion watershed officially began in 1999 with guidance and support from the PCA and project management by the Dakota County Soil and Water Conservation District (SWCD). However, the scope of the Vermillion River TMDL changed after the Regional TMDL Study for Fecal Coliform Bacteria in the Lower Mississippi River Basin in Minnesota was developed by the PCA and accepted by the EPA. Since the Vermillion River watershed is included in the Regional TMDL, the Vermillion River TMDL effort was changed from a formal TMDL to a technical supporting document to the Regional TMDL. Water monitoring through the Vermillion study found bacteria levels above the standard of 200 organisms/100 ml throughout the watershed from the headwaters to just below the falls in Hastings. Since landuse in the watershed varies from dense urban centers to rural agricultural areas, there is a wide variety of potential bacteria sources including failing individual sewage treatment systems, manure running off fields and feedlots, urban runoff, wildlife, and wastewater treatment plants.

It was recommened by MPCA staff that it was most appropriate to estimate and express source loads in relative categorical terms (low, moderate, high) for the Vermillion River TMDL Study. Therefore all available data including landuse/landcover data, impirical bacteria data, and anecdotal information was reviewed by a large group of stakeholders who assigned relative loadings from different fecal coliform sources. The entire watershed was divided into nine subwatersheds and relative loads were assigned to each (Table 1.1).

Table 1.1 Relative Load in Subwatersheds and Overall Ranking of Sources
Livestock in Water Low High Low NA Mod. Low Low Mod. Low 1.3
Feedlots Mod. High Low NA Mod. NA Low Mod. Mod. 1.4
ISTS Mod. Mod. Low Low High Mod. High Mod. - High High 2.2
Manure Application Mod. High Mod. Low Low Mod. Mod. Mod. Mod. 1.9
WWTP Mod. NA NA NA Low NA Low Low - Mod. NA 0.6
Urban Low Mod. Mod. High Low Mod. Low Low Low 1.5
Wildlife Low Low Low Low Low Low Low Low Low 1.0

1 Overall ranking was calculated by taking the average of the scores where NA (not applicable) = 0, low = 1 point, moderate = 2 points, and high = 3 points.

Overall, individual sewage treatment systems (ISTS) were found to be the highest contributor to the fecal contamination in the river. Manure applied to fields, urban runoff, and feedlot runoff contributed the next highest amounts of bacteria, respectively.

Local stakeholder involvement and public outreach was a large component of this study. Efforts to educate stakeholders on the impairment, the study, and the TMDL process were varied and included updating citizens, interested parties, and the Vermillion River Watershed Joint Powers Organization (JPO) on a regular basis. Currently, the JPO is in the middle of developing a comprehensive watershed management plan. Recommendations on implementation strategies are being considered by the JPO for inclusion in the watershed management plan.

Full Study (39 pages, 1.19mb)
Appendices (23 pages, 704kb)
Figures (5 pages, 2.24mb) Page Size: 11 x 17"