Stormwater Management, 2006 Water Quality Report to Congress

Construction Site Erosion, Dunn County.
DNR Photo.

In 2004 and 2005, Wisconsin's storm water management efforts focused on implementing EPA's Phase II requirements via the Wisconsin Pollutant Discharge Elimination System (WPDES).

When rain falls and snow melts, water running across construction sites, yards, parking lots, driveways, streets and roof tops picks up soil, fertilizer, oil, pet waste and other pollutants and carries them into storm sewers that typically empty into lakes or rivers without treatment. Milwaukee, Shorewood and Superior are the only Wisconsin municipalities that have some of their storm water directed to a wastewater treatment plant through a combined sewer system.

Revised chapter NR 216, Wis. Adm. Code, became effective in August 2004. The state rule is consistent with federal rules that took effect March 10, 2003. It extends to smaller municipalities and to more than 2,000 smaller construction sites annually the same kinds of requirements Wisconsin's bigger cities and construction sites have faced for a decade. The law is primarily implemented through general permits and it requires construction site landowners and municipal separate storm sewer system operators to apply for permit coverage through submittal of a "notice of intent" or NOI to DNR. The general permits specify the site-specific plans and programs that must be developed and implemented to reduce the discharge of stormwater pollution.

Construction Site Erosion Control

Since 2003 federal law has required that landowners of construction sites with one acre or more of land disturbance obtain construction site storm water permit coverage to address erosion control and storm water management.

The Department received over 1600 "notice of intent"(NOI) applications in year 2006 and has over 4000 construction sites covered under the construction site general permit. This general permit will expire and is expected to be reissued in 2007. Construction Standards

Landowners with projects disturbing one or more acres of land are required to get permit coverage under the new state rule. Previously, the threshold was five acres of land disturbance. The storm water construction site permit requires that a site-specific erosion control and storm water management plan be developed which details practices that must be followed to minimize soil from moving off the construction site, and to incorporate designs that once construction is done, allow rain or snowmelt to soak in on the site or be managed to settle or filter pollutants out of the runoff. Sediment from construction sites can destroy habitat by covering the stream bottom, and pollutants attached to the sediment can decrease the diversity of fish and other aquatic species.

Because the technology of erosion control is continuously improving, Wisconsin has developed a series of technical standards for construction site erosion control and post-construction storm water management and made them available ad hoc on the Internet. The series of standards replaces the outdated Construction Site Best Management Practice Handbook and will be updated on a more regular basis as needed.

Industrial Permits

About 5200 industrial facilities are regulated under one of 5 industrial general permits. Two of the industrial general permits (scrap and also auto parts recycling) are expired but they were public noticed and should be reissued in 2007.

In addition to tier 1 (heavy industry)and tier 2 (lighter industry) general permits that cover groups of industrial facilities by standard industrial classification, there are three additional industry-specific storm water general permits in Wisconsin: auto dismantling, scrap recycling and non-metallic mining.

Industrial Permits by Type

The auto dismantling and scrap recycling permittees are offered the choice to join a "Cooperative Compliance Program" (CCP), developed to establish industry-wide approaches to reducing or eliminating storm water contamination. The CCPs provide group training, foster information sharing, and promote best management practices. In December 2005, there were eight CCPs serving 344 facilities.

The tier 3 industrial storm water general permit was discontinued and replaced by the "No Exposure Certification." Tier 3 permittees were notified of the need to either apply for coverage under the tier 2 general permit (lighter industry) or certify there is no discharge of contaminated storm water. They are required to recertify every five years.

Municipal Permits

Wisconsin has been regulating "Municipal Separate Storm Sewer System" (MS4) discharges under individual permits since 1994. Currently, there are 62 "MS4s"regulated under individual permits in Wisconsin. Madison, Milwaukee and an additional 60 municipalities are currently covered; another 10 or so are expected to receive individual MS4 permit coverage.

Starting in starting in 2003, the federal government extended the requirements for MS4 coverage to many other smaller municipalities. To meet the federal requirements, an additional 150 municipalities - those that are part of an "urbanized area" or having a population of 10,000 and density of 1000 people per square mile - are expected to be covered under the MS4 general permit. In the permit application, municipalities must summarize the programs and practices they will implement to comply with the MS4 general permit. The Department expects to issue its MS4 general permit fall 2006, and this permit will be used to regulate an additional 140+ MS4s.

Municipal stormwater permits are an integral part of implementing Wisconsin's comprehensive runoff management standards adopted in ch. NR 151, Wis. Adm. Code, in 2002 to reduce polluted runoff and storm water from entering lakes, streams, groundwater and wetlands. The developed urban area standard requires permitted MS4s to reduce the discharge of total suspended solids by 40 percent as compared to no storm water management controls.

Research on urban streams in Wisconsin has shown high concentrations of suspended solids, bacteria, heavy metals, oil and grease and polyaromatic hydrocarbons (PAHs) in the discharges from municipal storm water sewers, which empty directly into lakes and streams with no treatment.

The additional municipalities regulated under general permit (signed in January 2006) will be responsible for public education, involvement and outreach, detecting and eliminating illegal discharges to the sewer system, developing construction site erosion control and post-construction storm water management ordinances, practicing pollution prevention in their municipal operations, annual reporting, mapping areas contributing runoff to their storm water sewer systems, and locating outfalls where the storm water enters lakes and streams.

Last Revised: Wednesday August 02 2006