On April 1, 2010, the Kentucky Division of Water (KDOW) issued the Small Municipal Separate Storm Sewer Systems (MS4) Permit authorizing storm water and certain non-storm water discharges to the city’s MS4. This affects cities with populations under 100,000 (according to the 1990 Census Bureau) such as Louisville and Lexington.
The City of Radcliff submitted to the KDOW a Notice of Intent (NOI) requesting coverage under this permit and a Storm Water Management Program (SWMP) that outlined the city’s proposed Minimum Control Measures (MCM) as follows:
- Public Education and Outreach.
- Public Involvement and Participation.
- Illicit Discharge Detection and Elimination.
- Construction Site Runoff Control.
- Post-Construction Storm Water Management.
- Pollution Prevention and Good Housekeeping.
Each of these MCMs lists specific Best Management Practices developed to reduce storm water pollutants discharged to the city’s MS4.The KDOW accepted the city’s NOI and SWMP, and has authorized the city to discharge stormwater associated with the Small MS4 under the terms and conditions set forth in the permit.
What is an MS4?
- 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)
A small MS4 is any MS4 not already covered by the Phase I program as a medium or large MS4. The Phase II Rule automatically covers on a nationwide basis all small MS4s located in “urbanized areas” (UAs) as defined by the Bureau of the Census (unless waived by the NPDES permitting authority), and on a case-by-case basis those small MS4s located outside of UAs that the NPDES permitting authority designates.
Why have cities implemented these programs?
Storm water quality management programs are a response to regulations from the Environmental Protection Agency (EPA) connected to the federal Clean Water Act. These regulations require cities to obtain a permit under the National Pollutant Discharge Elimination System, or in the case of Kentucky, the Kentucky’s Pollutant Discharge Elimination System, and to create a comprehensive program to seek out and eliminate, to the maximum extent practical, pollutants carried by storm water.
In 1972, Congress amended the Federal Water Pollution Control Act (commonly referred to as the Clean Water Act (CWA)) which prohibited the discharge of any pollutant to waters of the United States from a “point source” unless the discharge is authorized by a National Pollutant Discharge Elimination System permit. A “point source” is a single identifiable localized source of pollution such as an industry, business or a sewer system.
In 1987, the CWA was amended and established a $400 million program for States to develop and implement, on a watershed basis, nonpoint source management, because water quality studies showed sparse sources of water pollution were also significant causes of pollution. They called these sparse sources of pollutants a “nonpoint source.” A “nonpoint source” pollution is water pollution that is difficult to trace to a specific discharge point because it comes from many sources. Examples of common nonpoint source pollutants include fertilizers, pesticides, sediments, oils, salts, trace metals, and litter. Nonpoint sources come from locations such as farms, yards, roofs, construction sites, automobiles and streets.
In 1990, EPA promulgated rules establishing Phase I of the National Pollutant Discharge Elimination System (NPDES) stormwater program. The Phase I program for MS4s requires operators of “medium” and “large” MS4s, that is, those that generally serve populations of 100,000 or greater, to implement a stormwater management program as a means to control polluted discharges from these MS4s.
Phase II rules for small municipalities and construction activity were finalized in December 1999 to small municipalities with residential populations under 100,000 (according to the 1990 Census Bureau). Phase II requires permit coverage for all small MS4s located within urbanized areas, where an urbanized area is defined by the U.S. Census Bureau as “a land area comprising one or more places — central place(s) — and the adjacent densely settled surrounding area — urban fringe — that together have a residential population of at least 50,000 and an overall population density of at least 1,000 people per square mile.”
For more information about the City of Radcliff Storm Water Management Plan, please contact the Engineering Department at 270-351-4714.