Water Quality & Pollutants

The City of Manhattan samples water from the Kansas River and Wildcat Creek following significant rain events. The samples collected are then tested and the results sent to the Kansas Department of Health and Environment as part of the City's requirements as a National Pollutant Discharge Elimination System (NPDES) Phase II permit holder.

At times, the samples can indicate elevated levels of pollutants. But local residents can take steps to reduce pollution in the waterways we use for swimming, fishing and boating. See our homeowner information for the steps you can take to reduce stormwater pollution.


The following are common pollutants found in stormwater and for which the City of Manhattan tests its stormwater quality.


Natural ammonia is formed when manure, plants and animals break down. From urban sources, this process might originate from domestic animals (e.g. dogs, cats), wildlife (e.g. raccoons, opossums), animals in zoos, and bacteria. Other sources may include sanitary sewer line breaks or inadequately treated sewage.


Atrazine is used extensively for the control of weeds in agricultural crops, especially in crops such as corn, sorghum, wheat and soybeans. It is one of the most heavily used pesticides in North America. It has high mobility, which allows it to be contained in stormwater runoff from major storm events that occur within a few weeks of application.

Oxygen-demanding substances

Adequate dissolved oxygen is necessary for good water quality. However, if oxygen is used up more quickly than it can dissolve into the water from the atmosphere, the decreased oxygen levels can kill fish and other aquatic organisms.
  • PREVENT IT! Do not dump anything directly down the storm drain

E. coli

E. coli (Escherichia coli) is a type of fecal coliform bacteria commonly found in the intestines of animals and humans. The presence of E. coli in water is a strong indication of sanitary sewage contamination or animal waste. Sewage may contain many types of disease-causing organisms.

High pH

Streams generally have pH values ranging between 6 and 9 on a scale of 1 to 14. If pH values are high, the water chemistry changes and endangers aquatic life.


A wide range of human activities contribute to nutrient pollution in our waterways. While nitrogen and phosphorus are important to the growth of algae and aquatic plants, too much cause algal blooms and harm the air and water. Fertilizers, pet waste, and certain soaps and detergents contain nitrogen and phosphorus that can contribute to pollution if not properly disposed.
  • PREVENT IT! Use a commercial car wash or wash your car over your lawn instead of your driveway to naturally filter pollutants from runoff

Petroleum Products

Used oils and lubricants are petroleum-based pollutants frequently found in urban areas. These products cannot be dissolved in water and are capable of quickly migrating long distances. Americans improperly dispose of millions of gallons of used motor oil annually, and small leaks and spills are frequent contributors to the sheen that can be observed on contaminated surface waters.


Sediment is a common pollutant to most local streams and water bodies, partially due to serving as a storage area for other pollutants. Sources of sediment are from streambank erosion, construction sites, street runoff and other sources. Sediment in streams lowers the oxygen level and clarity of the water, making habitable conditions for aquatic life more difficult or impossible. Sedimentation takes up storage areas for flood control and can be a hindrance to flow for waterways.