A GUIDE TO UNDERSTANDING THE MS4 PROGRAM
WHAT IS MS4?
MS4 stands for Municipal Separate Storm Sewer System. When it rains, stormwater is carried to the nearest waterway through conveyance systems such as underground pipes, open channels, ditches, swales, or a combination of these. MS4 refers to the pipes, channels and methods used to convey stormwater in your Municipality.
WHY IS IT IMPORTANT?
Your MS4 is important because it is the path or journey of all precipitation from the atmosphere to its eventual discharge into our rivers, streams, or waterways. Along this journey, stormwater may become polluted before it reaches the river, stream or waterway. The Department of Environmental Protection (DEP) created the MS4 program to help ensure our stormwater is free of pollutants before it reaches our waterways.
HOW CAN THE DEPARTMENT OF ENVIRONMENTAL PROTECTION (DEP) BE SO INVASIVE? THEY REGULATE EVERYTHING!
Federal regulations passed under the Clean Water Act require municipalities to obtain permits and to develop and implement a Stormwater Management Program (SWMP). The Clean Water Act allows the government, specifically, the DEP to regulate all MS4s.
ARE YOU SURE WE NEED A PERMIT?
Within a municipality, small MS4s are designated as "regulated" primarily on the basis of whether or not they are located within an "urbanized area" as determined by the 1990 and 2000 censuses. Your Municipal Engineer has already verified that your municipality, or parts of your municipality, are located within an "urbanized area" and thus, are regulated by the DEP. Your Municipal Engineer can provide you with a map based upon the 2000 census that displays the urbanized (regulated) areas within your municipality. In summary, a permit is needed for any MS4 located within an urbanized area. MS4s located outside of an urbanized area are NOT regulated and do NOT require a permit.
WHAT TYPE OF PERMIT DO WE NEED?
General Permit PAG-13 provides a streamlined process to meet the federal requirements. In some cases, a municipality is not eligible for General permit coverage because it discharges to a "Special Protection" watershed. In this case, an Individual NPDES MS4 Permit is needed. (Your Municipal Engineer has already determined that your municipality is eligible for coverage under the General permit.)
WHAT ARE THE REQUIREMENTS OF THE PERMIT?
The municipality must develop, implement, and enforce a Stormwater Management Program to reduce the discharge of pollutants from its regulated MS4s to the Maximum Extent Practicable to meet water quality standards and satisfy the appropriate water quality requirements of the federal Clean Water Act and the Pennsylvania Clean Streams Law. The program must be approved by DEP and contain Best Management Practices (BMPs) and measurable goals for each of the six Minimum Control Measures (MCMs) described below.
The federal regulations establish six Minimum Control Measures (MCMs) that must be implemented by the municipality. These six MCMs in the federal regulations are:
1. Public Education and Outreach
2. Public Participation and Involvement
3. Illicit Discharge Detection and Elimination
4. Construction Site Runoff Control
5. Post-Construction Stormwater Management in New Development and Redevelopment, and
6. Pollution Prevention and Good Housekeeping for Municipal Operations and Maintenance
Also, the municipality must enact and implement either one of the MS4 Stormwater Management Ordinances; a Model Ordinance from an applicable Act 167 Stormwater Management Plan approved by DEP in 2005 or later; or an ordinance(s) that satisfies an MS4 Stormwater Management Ordinance Checklist.
WHAT IS THE PERMIT TIMEFRAME? HOW LONG DO WE HAVE TO DO THIS FOR?
You must meet the requirements of the permit as long as the federal Clean Water Act / PA Clean Streams Law are in place. In other words, forever! The permit term is for a maximum of five years, followed by subsequent permits for similar timeframes. (When your first permit expires after 5 years, you must apply for another one. Another permit will be issued and you must continue to comply with the regulations for another 5 years until that permit expires. Then you will apply for another permit, etc.).
WHAT IS A TMDL?
TMDL stands for Total Maximum Daily Load. Some waterways (streams, creeks, rivers) are under an approved TMDL requirement. The DEP has determined that certain waterways can only "handle" or "accept" a daily maximum pollutant loading. There are several potential pollutants that this maximum loading is applied to. For example, acid mine drainage and metals are common pollutants. The DEP has come up with a total measurable quantity of these pollutants that may be discharged to the waterway each day. IF your municipality’s MS4 discharges to a waterway that has an approved TMDL, then you must prepare and submit a TMDL plan that outlines how you will reduce these pollutants from being discharged into the waterway.
OH NO, WE DISCHARGE TO A WATERWAY WITH A TMDL, WHAT DO WE DO?
Your municipality must work with your Municipal Engineer to develop your TMDL Plan. The plan may include TMDL control measures such as disconnecting impervious areas, planting trees, constructing or upgrading recharge / infiltration facilities, retrofitting stormwater basins, restoring stream banks, establishing or re-establishing stream buffers, and installing green infrastructure.
WE’VE HAD A PERMIT FOR QUITE SOME TIME, WHAT HAVE WE ALREADY DONE?
Your Municipality has already enacted the required Stormwater Management Ordinance. Also, your Municipality has developed a map that displays the locations of all of their MS4 outfalls, and the waterways in which they discharge to. These outfalls have been inspected and written inspection reports are available at the Municipal Building. The Municipality continues to update the map if new outfalls are created.
WHAT IS YOUR MUNICIPALITY, ALONG WITH YOUR MUNICIPAL ENGINEER, WORKING ON NOW?
The six MCMs!!!
We must prepare your written municipal Public Education and Outreach Plan, as well as your written Public Participation and Involvement Plan. This information sheet is designed to satisfy some of the requirements of these plans.
We are also working on your written Operation and Maintenance Plan. This plan details how your Public Works Department will continue to operate and maintain your MS4 system, as well as all Municipal Owned facilities such as the Municipal Building and Public Works Yards or Garages.
Lastly, we are working on developing your written Illicit Discharge Detection and Elimination Plan. This plan details how the Municipality will continue to inspect their MS4 outfalls, and will develop a procedure for the elimination of any potential illicit discharges discovered during inspection.
After these plans are finalized, your Municipal Engineer will prepare your Municipal Progress Report and submit the report, along with the above plans, to the DEP.
SENATE ENGINEERING COMPANY
U-PARC, 420 William Pitt Way
Pittsburgh, PA 15238