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Indicator of the Month: June 2001 - Vermillion River - Restoring an Impaired River

In 1998, the section of the Vermillion River, from Empire Township to Hastings, was placed on a list of impaired waters. Water quality data indicated that the river's use for swimming was impaired due to high levels of fecal coliform bacteria. Based on the water quality data available in 1998, the MPCA identified the impaired section of the Vermillion River as needing a Total Maximum Daily Loading (TMDL) for fecal coliform.

For the Vermillion River TMDL process, the Dakota County Soil and Water Conservation District (SWCD) stepped up as the local partner. Beginning the TMDL process required the Dakota County SWCD, with the help of local volunteers, to collect more water quality data for the impaired stretch of the Vermillion River. Data was also collected from major tributaries to the Vermillion River.

Looking at Figure 1, the map identifies the sample sites used by the Dakota County SWCD. The color of the site locations indicates the extent of fecal coliform pollution, relative to the MPCA's standard. A GREEN SITE indicates the geometric mean of the fecal coliform measurements is less than 50% of the MPCA's standard. A YELLOW SITE indicates the geometric mean of the fecal coliform measurements is between 50% and 100% of the MPCA's standard. An ORANGE SITE indicates the geometric mean of the fecal coliform measurements is between 100% and 200% of the MPCA's standard. A RED SITE indicates the geometric mean of the fecal coliform measurements is more than 200% of the MPCA's standard.

Moving downstream (west to east), the main stem of the Vermillion River has increasing levels of fecal coliforms. The only YELLOW SITES on the main stem are at the far western part of the mapped river segment. ORANGE and RED SITES dominate the central and eastern portions of the river. Most of the smaller tributaries to the Vermillion River also show levels near or above the MPCA's fecal coliform standard. Only one monitoring site on the map, on a north-western tributary, showed levels less than 50% of the fecal coliform standard. Figure 1 does not show the locations of two other GREEN SITES; near Red Wing, and where the Vermillion River meets the Mississippi River.

Future phases of work by the Dakota County SWCD will combine land use information with the fecal coliform monitoring data. Then the Dakota County SWCD will seek to reduce the amount of fecal contamination reaching the water, by focusing on the predominant source of fecal pollution in particular parts of the river or tributaries.

Figure 1: Vermillion River - Fecal Coliform Monitoring Sites

Vermillion River - Fecal Coliform Data -
Courtesy of Dakota County Soil and Water Conservation District

Data used to construct the Vermillion River Map: Sample sites are presented in a West to East Progression. Where samples are very close in the West to East progression, the sites are presented in a North to South order.

Figure 2 compares fecal coliform monitoring data taken during storm events and between storm events. The storm event numbers all exceed the MPCA standard (represented by the red line) by large amounts. Fecal contamination during storm events may be due to agricultural land uses, including feedlots, pastures and land-applied manure. Non-storm event measurements are also at or above the MPCA fecal coliform standard. Fecal contamination during non-storm events may come from waste-water treatment plants, leaking sewer pipes, failing septic systems, livestock in streams and rivers, pet waste or wildlife. An important goal of the Vermillion River TMDL effort is to identify the important sources of fecal contamination to the river and apply appropriate pollutant reduction practices to those sources.

Figure 2: Fecal Coliform Storm Events vs Non-storm Events

What is Fecal Coliform? Fecal coliform is a family of bacteria present in the feces of all animals (humans included). The family of bacteria known as fecal coliforms are not harmful to humans, but do indicate the presence of fecal contamination in the water. Many other types of bacteria found in animal feces are harmful to humans.

The MPCA's standard for fecal coliforms is to protect against skin contact with the numerous types of bacteria present in waters with fecal contamination. The Minnesota Department of Health's standard for fecal coliform is to protect against the ingestion of bacteria present in waters with fecal contamination.

What is a Total Maximum Daily Loading (TMDL)? The concept of a TMDL comes from the federal Clean Water Act, passed by the U.S. Congress in 1972. A TMDL is based on the idea that there is a maximum level of a pollutant that a water body can receive and still have adequate water quality. To develop a TMDL, all sources of the pollutant causing the impairment must be considered. Point sources, such as factories and municipal waste water plants, as well as non-point sources, such as agricultural land uses and residential land uses, must be considered together. The end result of the TMDL process is a maximum level of pollutant the water may receive daily, as well as an allocation of the allowable amount of pollutant that may be released to the water body by each source of the pollutant.

Development of a TMDL involves the following work:

The U.S. Environmental Protection Agency (USEPA) provides federal funding to the MPCA to conduct TMDL work on impaired waters. Then the MPCA provides funding to local partners to conduct the TMDL work and develop the final TMDL. The final TMDL must be approved by the USEPA.

To learn more about Total Maximum Daily Loadings, visit: http://www.pca.state.mn.us/water/tmdl.html

To learn more about the Dakota County Soil and Water Conservation, visit: http://www.dakotaswcd.org

Or contact Laura Jester at:
Dakota Co. Soil and Water Conservation District
4100 220th St. W. Suite 102
Farmington MN 55024
651-480-7784 phone
651-480-7775 fax
laura.jester@co.dakota.mn.us