By Scott Stanley - City of Mequon
When water from rainfall or melting snow flows across the
landscape, it washes soil particles, bacteria, pesticides, fertilizer, pet
waste, oil, and other toxic materials into our lakes, streams, and groundwater.
This is called "nonpoint source pollution" or "polluted runoff." Nonpoint source
pollution comes from a diverse number of activities in our daily lives including
fertilizing lawns and farm fields, driving and maintaining our cars,
constructing buildings and roads, plowing our fields for crops, and maintaining
our roads in the winter. Urban and rural nonpoint pollution is the leading cause
of water quality problems in Wisconsin, degrading or threatening an estimated 40
percent of the streams, 90 percent of the inland lakes, many of the Great Lakes
harbors and coastal waters, many wetland areas, and substantial groundwater
resources in Wisconsin.* Polluted runoff contributes to habitat destruction,
fish kills, reduction in drinking water quality, harbor and stream siltation,
and a decline in recreational use of lakes.
Municipal Stormwater Management
Runoff from municipal areas contains a mixture of pollutants
from parking lots, streets, rooftops, lawns, and other areas. These areas
contribute heavy metals, pesticides, sediment, nutrients, bacteria, and
oxygen-demanding organic waste. Although municipal storm sewer systems are
efficient at controlling water volume to avoid flooding, they also transport
polluted runoff directly into nearby lakes, rivers, and streams without the
benefit of wastewater treatment or filtration by soil or vegetation.
To meet the requirements of the federal Clean Water Act, the
Wisconsin DNR developed the Wisconsin Pollutant Discharge Elimination System (WPDES)
Stormwater Discharge Permit Program that is regulated under the authority of
Chapter NR 216 of the Wisconsin Administrative Code. As part of the EPA National
Discharge Elimination System, the WPDES Stormwater Discharge
Permit Program regulates discharge of stormwater in Wisconsin from construction
sites, industrial facilities, and selected municipalities.
Who needs a stormwater permit?
WPDES Stormwater Permits are required for discharges from the
following three areas:
selected industrial facilities
construction sites that disturb a certain amount of acreage
selected municipalities, i.e. Mequon
Per Wisconsin Administrative Code NR 216, four types of
municipalities must obtain a Municipal Stormwater Permit:
Municipalities with Population of 100,000 or More
Municipalities with a Separate Storm Sewer System serving a
population of 100,000 people or more must obtain a WPDES Municipal Stormwater
Municipalities in the Great Lakes Areas of Concern
There are five Great Lakes Areas of Concern in Wisconsin. These
are areas on the Lake Superior and Lake Michigan coasts that have persistent
runoff-related water quality problems including Green Bay, Allouez, Ashwaubenon,
DePere, Marinette, Sheboygan, and Superior. See the EPA Great Lakes Areas of
Concern Website for more details (www.epa.gov/grtlakes/aoc/).
Municipalities in a Priority Watershed with a Population of 50,000 or More
In certain Priority Watersheds, stormwater runoff is a primary
source of pollutants. Thus, controlling nonpoint pollution is especially
important in these areas to help improve water quality. Within the state's
Priority Lake and Watershed Projects, Eau Claire, Racine, West Allis, and
Waukesha have populations over 50,000.
Significant Contributors of Contaminated Stormwater
The Department retains the authority to designate a municipality
as a significant source of pollutants. Such a municipality would then be
required to obtain a Municipal Stormwater Permit.
The following municipalities each have a current municipal storm
water permit as of May 1, 2001. About 80 additional municipalities are in
various stages of the municipal storm water permit process (e.g. designation,
pre-application, permit drafting, etc.).