The 2017 and 2018 bacterial analysis of Plum Creek between Warner Lake and Franklin Road have been summarized by the Minnesota Pollution Control Agency (MPCA) and the results look promising. Several years of bacterial stream testing along with the application of Best Management Practices (BMP’s) in the watershed seem to be paying off. 

 

 Plum Creek is a small stream located mostly in Lynden Township. The stretch of the stream between Warner Lake and the Mississippi River was listed by the MPCA in 2012 as impaired for bacteria in the “recreation use” category.

 

The bacteria identified and measured was E. coli, a type of fecal coliform bacterium that lives in the digestive system of warm-blooded animals. While E. coli by itself is seldom disease-causing or pathogenic in surface water, it is used by MPCA as an indicator organism for other types of pathogenic organisms that could originate from human, livestock and poultry in the watershed.    

 

 To solve the problem and get the stream de-listed, the Plum Creek Neighborhood Network (PCNN), was organized and led by Jerry Finch, a former Lynden Township Supervisor, who enlisted help from the Lynden Township Board, Stearns County Soil and Water Conservation District (SWCD), MPCA, the University of Minnesota and St. John’s University.

 

Intensive stream sampling was done from 2014 to 2018 to better understand the nature of the bacteria contamination and determine its potential source(s).

 

Soil and streambed sediment appear to be the major source, but fecal waste from humans and wildlife could not be ruled out. The SWCD worked with local landowners, the Minnesota Dept. of Transportation and the Stearns County Highway Department to apply erosion control practices along the stream. The Stearns County Environmental Services Department also reported that a septic system upgrade was performed in 2018 at a residence adjacent to the stream. 

 

Carol Sinden, environmental research scientist, MPCA, and Dr. Mike Sadowsky, director of the BioTechnology Institute, University of Minnesota, summarized the stream sampling data from 2017 and 2018 in a meeting on March 28 at the SWCD office in Waite Park. 

 

Sinden told the group the preliminary analysis showed the mean value of the bacteria counts for June, July, and August during this period were all below the State’s impairment threshold of 126 organisms per 100ml for this indicator bacterium. She said this newest data appears to show a decreasing trend in E. coli counts which is especially significant because it coincides with the water quality practices applied. However, she stated that more sampling needs to be done in 2019, on a reduced scale, to give the MPCA enough data to reassess Plum Creek. 

 

If the 2019 testing results continue to show average counts below the threshold, the stream could be officially delisted by the US Environmental Protection Agency in 2022. 

 

Dr. Sadowsky tested stream samples in 2016 for human, bird, cow, and swine DNA markers. Markers for human and bird were present but not cow or swine. The bird markers are believed to be from wildlife since there are no poultry operations in this section of the watershed. 

 

In 2018 Dr. Sadowsky focused on human DNA markers. He said human markers continue to be present, but the numbers are not consistent enough to draw any conclusions. The MPCA does not use DNA marker data for bacterial impairment determinations, but it could help watershed planners determine the potential source of the E. coli. 

 

For more information contact Greg Berg at the Stearns County SWCD at 320-251-7800, ext. 3.