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Stormwater pollution prevention the work of many entities

By Angie Hong

A sweep of updates to federal laws in 1972, commonly known as the Clean Water Act, set into motion decades’ worth of work since to nurse our nation’s polluted waterways back to good health and protect those that are still pristine from harm. The first step was to regulate industries dumping chemicals and other contaminants directly into lakes and rivers. Within 20 years, however, it became obvious that regulating these “point sources” alone would not be good enough.

In 1996, the U.S. Environmental Protection Agency conducted a National Water Quality Inventory and came to the conclusion that stormwater runoff from cities was a leading source of water pollution. Not only do urbanized areas have more impervious surfaces like rooftops, parking lots and roads where rainwater cannot soak in, but also, they have stormwater infrastructure specially designed to quickly take rain and melting snow off roads to prevent localized flooding. In most communities built before the late 1970s, storm pipes carry water from streets directly to nearby wetlands, lakes, streams and rivers. In Minneapolis and St. Paul, for example, most storm pipes connect to the Mississippi River. In south Washington County, most storm pipes connect to the Mississippi River, though many outlet into natural wetlands or manmade stormwater ponds first. This stormwater carries with it a toxic combination of pesticides, fertilizers, oils, metals, pathogens, salt, sediment, litter and organic debris. Additionally, the water itself can be a problem during heavy rains and spring melt when the increased volume erodes ditches and streams, sending sediment downstream.

As a result of the water quality inventory, the Municipal Separate Storm Sewer System (MS4) general permit came into being. The program regulates cities and other entities that manage storm sewer systems and is administered in our state by the Minnesota Pollution Control Agency.

Most MS4s are cities, but watershed districts, counties, and townships can also be designated as MS4s, and some large campuses are regulated as well — places like universities, hospitals and prison complexes that operate their own private roads and drainage systems. Minneapolis and St. Paul, the two biggest cities in Minnesota, were the first to receive stormwater permits during the first phase of the program in 2000. Many smaller cities were added to the list during the second phase in 2005, and several more are added each year as the Twin Cities and other metro areas in Minnesota continue to grow. Currently, cities with more than 10,000 people that have storm sewer systems are automatically required to have a MS4 permit, but many smaller communities are regulated as well, either because they are within the larger Twin Cities metro area, or because their stormwater discharges to an “outstanding resources value water” such as the St. Croix River. In Washington County, MS4 entities include bigger cities like Woodbury, Oakdale and Cottage Grove, as well as small cities like Newport and St. Paul Park, and even two mostly rural communities — Grant and West Lakeland townships.

MS4 entities are required to develop stormwater pollution prevention programs, educate the public about stormwater pollution, and engage citizens in solving local water pollution problems. The permit also requires MS4s to identify and stop illegal dumping (called illicit discharges), take steps to reduce runoff from construction and development, and practice “good housekeeping” to avoid polluting waterways during routine road and park maintenance. There are also separate permit programs to regulate industrial sites and construction sites.

In Washington County, MS4 entities collaborate with one another, as well as the county and watershed management organizations, to improve the efficiency and effectiveness of their stormwater pollution prevention efforts. One example is the East Metro Water Resource Education Program, created in 2006, which supports 22 local government partners and is hosted by the Washington Conservation District.


Angie Hong is an educator for East Metro Water. Contact her at 651-330-8220 ext. 35, or by email at [email protected].

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Very informative material

I was really impressed with this class. I loved the visual/video learning aspect mixed in with the academic learning material as part of the training as well. Coming from a QA Inspector in Arizona.

Rating: 5.0 / 5.0

Jason M.
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