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Bacteria Pollution in Scott County

Bacteria lives in our water in many forms, the same way it lives in our bodies. Most species of bacteria are useful; they are necessary to provide food for larger organisms and maintain the foundation for many biochemical cycles like decomposition, nitrogen fixation, and digestion.

However, harmful bacteria—known as pathogens—can find their way into our waterbodies. Just like they can find their way into our bodies and make us sick, harmful bacteria can make our lakes, rivers, and streams sick too. Scott County has seen an increase in the number of waterbodies being added to the Federal Impaired Waters List for harmful bacteria. Big Possum Creek, Brewery Creek, Credit River, County Ditch 10, Eagle Creek, Minnesota River, Porter Creek, Raven Stream, Roberts Creek, Sand Creek, the Vermillion River, and West Raven Stream are all currently listed on the Minnesota Pollution Control Agency’s list of impaired waters. Some waterbodies have been listed for a bacteria impairment since 2002.

Where does the bacteria come from?

Studies have been done on these impaired systems—specifically in the Vermillion Watershed, where the problem is most notable and consistent. Bacteria can come from a variety of different places, including animal waste (domestic pets, agricultural operations), overloaded waste treatment systems, human sewage from failing on-site sewage systems (septic systems), and leaky sewer pipes. When these sources go unchecked, harmful bacteria can end up in waterbodies through rainfall, erosion, and improper soil filtration. The importance of taking care of bacteria sources

Bacteria from human waste is kept in check using soil treatment septic systems and regular maintenance. When working properly, septic systems run all the water leaving your house from one main drainage pipe into a septic tank(s). The water settles in the tank, allowing solids to separate to the bottom, and liquids float to the top. The liquid then exits the tank and goes into a soil treatment system before eventually filtering down into the groundwater.

The Vermillion River Watershed Joint Powers Organization (JPO) completed DNA testing on E. coli bacteria samples taken from the Vermillion River and found human DNA as the source of the E. coli bacteria. When maintained

and running properly, septic systems should effectively remove most pollutants including harmful bacteria like E. Coli and viruses. Maintaining your septic system is the cheapest and easiest way to keep our surface and groundwater healthy. Always hire a state-licensed septic tank pumper to maintain your septic tank(s).

It is against the law to pump raw sewage from your septic tank(s) to the ground or any nearby surface water. Properly maintaining your septic system will help ensure that harmful bacteria is filtered out of the water before re-entering our surface and ground water.

What can you do to help?

Conducting regular maintenance on your septic system is the best way to ensure the water you’re using in your home isn’t contributing to unintentional water pollution. If there is no information on file at the County, your system might be very old. Some ways to tell if your system is failing is the presence of pooled water or marshy areas around your property, slow drainage or weak flush, overgrown or dead vegetation, green outer area around the septic tank, or drains that constantly back up.

Regular maintenance on your system and having a properly designed and constructed drainfield will help keep your septic system running longer and help protect your local water quality. Septic system maintenance companies can help provide repairs and answer general questions you might have about your septic system.

Replacing your septic system might be necessary in certain cases. The Vermillion River Watershed has grants to help in the replacement of septic system posing an imminent health threat (leaks out onto the ground, backs up into the home, etc.). Contact Mary VonEschen at for more information and eligibility. If you have any general questions about septic systems or want to know what kind of system you have, please contact the Environmental Services Office at 952-496-8177.

Limiting your water usage is another great way to help minimize your impact on surface and groundwaters. Taking shorter showers, turning the faucet off when brushing your teeth, and fixing any leaking faucets or toilets can really help cut back on water usage.

Together, we can work to help improve our local waterbodies, and be a little more conscious of our impact on the waters we see flowing past us every day.


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