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The County of Rock was authorized by the Department of Natural Resources on November 13, 2006 to discharge stormwater from the County owned Municipal Separate Storm Sewer Systems (MS4) in the Urbanized Area of Rock County under a Wisconsin Pollutant Discharge Elimination System (WPDES) general permit.  Polluted stormwater runoff is commonly transported through MS4s, from which it is often discharged untreated into local waterbodies.  An MS4 is a conveyance or system of conveyances that is:

• Owned by a state, city, town, village, or other public entity that discharges to waters of the U.S.
• Designed or used to collect or convey stormwater (including storm drains, pipes, ditches, etc.);
• Not a combined sewer; and
• Not part of a Publicly Owned Treatment Works (sewage treatment plant).

For the County, this consists of conveyance systems (ditches or curb and gutter) associated with County Highways within the Urbanized Area, as determined by population density based on the 2000 census. 

View County Highways that fall into this category.

The EPA created maps indicating the current boundaries of the Urbanized Areas of Janesville and Beloit in November 2002.

Each regulated MS4 operator is required to develop and implement a stormwater management program to reduce the contamination of stormwater runoff and prohibit illicit discharges.  This program is intended, at minimum, to be implemented in the County’s permitted area, i.e. the areas of land under the jurisdiction of the County that drain into a MS4.  Areas excluded from permit coverage, and thus from this plan, are agricultural facilities and practices, industrial or land disturbing construction activities that require separate WPDES permit coverage and storm water discharges that do not enter the County’s MS4.  The County's WPDES MS4 general permit outlines certain minimum programs and documentation that must be developed to maintain compliance with the permit conditions of approval.  The minimum program elements are:

• Public Education and Outreach
• Public Involvement and Participation
• Illicit Discharge Detection and Elimination
• Construction Site Pollution Control
• Post-Construction Storm Water Management
• Pollution Prevention

Information regarding these six programs may be found below and on the EPA Website.

Summary of Six Minimum Program Elements

Public Education and Outreach

An informed and knowledgeable community is crucial to the success of a storm water management program.  Without a public knowledge of local water quality problems caused by urban runoff, it is difficult to obtain public support for local storm water quality programs. This support ranges from individuals changing their daily actions to community backing for this overall storm water management plan. As with all of the aspects of this plan, the goal of this program is to reduce the degradation of local water bodies and improve chemical, physical and biological quality of waters of the state. In order to achieve this water quality benefit, the Public Education program is targeted to encourage changes in public behavior by improving the understanding of the reasons why storm water quality programs exist.  The long-term goal is to achieve greater compliance with all of the programs included in this plan as the public becomes aware of the personal responsibilities expected of them and others in the community, including the individual actions they can take to protect or improve the quality of area waters. 

Public Involvement and Participation

The public can provide valuable input and assistance to the County’s municipal storm water management program. Since it is the activities of the public within urban landscapes that produce diffuse pollution, and the public that funds municipalities, it is imperative that the public be given opportunities to play an active role in both the development and implementation of the program. An active and involved community is crucial to the success of a storm water management program because it allows for: Broader public support, since citizens who participate in the development and decision making process are partially responsible for the program and are more likely to take an active role in its implementation; A broader base of expertise and economic benefits, since the community can be a valuable, free, intellectual resource; and a conduit to other programs, as citizens involved in the storm water program development process provide important cross-connections and relationships with other community and government programs.

The Land Conservation Department will be the responsible department for accepting, documenting and following up on information, questions, or concerns submitted by the public in relation to erosion control and storm water management.  Contact the Department at anytime if you have an interest in being involved in future activities related to the municipal storm water management program or any of the following programs: 

• Rock River Basin Citizen Monitoring Program
• County Clean Sweep Program

Illicit Discharge and Elimination

An illicit discharge is defined by the permit as any discharge to an MS4 that is not composed entirely of storm water except discharges authorized by a WPDES permit or other discharge not requiring a WPDES permit such as landscape irrigation, individual residential car washing, fire fighting and similar discharges. Illicit discharges can result in untreated discharges that contribute high levels of pollutants, including heavy metals, toxics, oil and grease, solvents, nutrients, viruses, and bacteria, to receiving waterbodies. Pollutant levels from these illicit discharges have been shown in EPA studies to be high enough to significantly degrade receiving water quality and threaten aquatic life, wildlife, and human health.

      Regulatory Requirements

As of January 2009, the County is in the process of creating an Illicit Discharge Ordinance (Chapter 33 of the Rock County Code of Ordinances) to prevent and eliminate illicit discharges and connections to the MS4 within the permitted area.  This draft ordinance contains provisions for the prohibition of discharge, spilling or dumping of non-storm water substance or materials into the waters of the state or the MS4.  The draft ordinance identifies non-storm water discharges that are not considered illicit and establishes inspection and enforcement authority to the County Conservationist or his/her designated representative.

Currently, the draft ordinance enumerates the following as non-stormwater discharges that are not considered illicit discharges: water line flushing or other potable water sources, landscape irrigation or lawn watering, diverted stream flows, rising ground water, ground water infiltration, uncontaminated pumped ground water, foundation or footing drains (not including active groundwater dewatering systems), crawl space pumps, air conditioning condensation, springs, individual residential car washing, natural riparian habitat or wetland flows, swimming pools (if dechlorinated - typically less than one PPM chlorine), fire fighting activities, and any other water source not containing Pollutants

In addition to the Illicit Discharge Ordinance, in the coming years, the County will be completing or implementing an Initial Field Screening of the MS4, On-going Field Screening Procedures, and Illicit Discharge Response Procedures in compliance with the terms of the WPDES MS4 Permit.

Construction Site Pollution Control

Polluted storm water runoff from construction sites often flows to MS4s and ultimately is discharged into local rivers and streams. Sediment is usually the main pollutant of concern. Sediment runoff rates from construction sites are typically 10 to 20 times greater than those of agricultural lands, and 1,000 to 2,000 times greater than those of forest lands. During a short period of time, construction sites can contribute more sediment to streams than can be deposited naturally during several decades. The resulting siltation, and the contribution of other pollutants from construction sites, can cause physical, chemical, and biological harm to our nation’s waters. For example, excess sediment can quickly fill rivers and lakes, requiring dredging and destroying aquatic habitats. Additional pollutants are also often present in storm water runoff from construction sites and may result in degradation of receiving water. Nutrients (nitrogen and phosphorous) are of specific concern and can cause significant impairment. In addition, solid and sanitary wastes, pesticides, oil and grease, concrete truck washout, construction chemicals, construction debris and metals may be discharged and cause an impact on receiving waters.

Rock County adopted a Construction Site Erosion Control Ordinance in March 2004 (Chapter 27 of the Rock County Code of Ordinances) based on the NR 152 Model Ordinance.  The Ordinance references the DNR's technical standards and specifications and maintains the performance standards found in NR 151 and the plan requirements contained in NR 216.  The Erosion Control Ordinance currently has jurisdiction in the unincorporated portions of Rock County, except Beloit Township (which has their own ordinance), and in areas annexed by a city or village that does not have an erosion control ordinance that meets or exceeds the standards of the DNR and Rock County (as per 59.693(10) Wis. Stats.)

The Land Conservation Department has been tasked by the Rock County Board of Supervisors with administering the Construction Site Erosion Control Ordinance.  Contact Andrew Baker if you have any questions about the program.

Post-Construction Storm Water Management

Post-construction storm water management in areas undergoing new development or redevelopment is necessary because runoff from these areas has been shown to significantly affect receiving water bodies. Many studies indicate that prior planning and design for the minimization of pollutants in post-construction storm water discharges is the most cost-effective approach to storm water quality management.  There are generally two forms of substantial impacts from post-construction runoff. The first is caused by an increase in the type and quantity of pollutants in storm water runoff. As runoff flows over areas altered by development, it picks up harmful sediment and chemicals such as oil and grease, pesticides, heavy metals, and nutrients (e.g., nitrogen and phosphorus). These pollutants often become suspended in runoff and are
carried to receiving waters, such as lakes, ponds, and streams. Once deposited, these pollutants can enter the food chain through small aquatic life, eventually entering the tissues of fish and humans. The second kind of post-construction runoff impact occurs by increasing the quantity of water delivered to the water body during storms. Increased impervious surfaces interrupt the natural cycle of gradual percolation of water through vegetation and soil. Instead, water is collected from surfaces such as asphalt and concrete and routed to drainage systems where large volumes of runoff quickly flow to the nearest receiving water. The effects of this process include stream bank scouring and downstream flooding, which often lead to a loss of aquatic life and damage to property.

Rock County adopted a Post-Construction Storm Water Management Ordinance in March 2004 (Chapter 28 of the Rock County Code of Ordinances) based on the NR 152 Model Ordinance.  The Ordinance references the DNR's technical standards and specifications and maintains or exceeds the performance standards found in NR 151 and the plan requirements contained in NR 216.  Long-term maintenance provisions are established by the ordinance and an agreement is recorded at the Register of Deeds for each project as a covenant running with the land.  The Storm Water Ordinance currently has jurisdiction in the unincorporated portions of Rock County, except Beloit Township (which has their own ordinance), and in areas annexed by a city or village that does not have a storm water ordinance that meets or exceeds the standards of the DNR and Rock County (as per 59.693(10) Wis. Stats.) 

The Land Conservation Department has been tasked by the Rock County Board of Supervisors with administering the Storm Water Management Ordinance.  Contact Andrew Baker if you have any questions about the program.