The MS4 permit lands on the desk of the person who already wears four hats. In most Montgomery County townships there is no in-house engineer and no stormwater department. There is a manager, a secretary, a public works crew of a handful of people, and a consultant the township calls when the work gets technical. The federal stormwater permit does not care about the size of the office. The annual report is due September 30 every year, and it asks the township to show, measure by measure, what it did.
The good news is that the permit is more manageable than its paperwork suggests. Strip away the acronyms and an MS4 permit is a promise to do six ordinary things and keep records that you did them. This is a working walk through those six, written for the small township that has to satisfy the permit without a full-time engineer on staff.
What MS4 actually is
MS4 stands for Municipal Separate Storm Sewer System. If your township owns storm sewers, inlets, pipes, and ditches that carry rainwater to a stream without first running it through a treatment plant, and you sit in an urbanized area as the census defines it, you almost certainly hold an MS4 permit. Most Montgomery County townships do. The permit is a National Pollutant Discharge Elimination System (NPDES) permit, and the great majority of townships hold it through Pennsylvania’s general permit, PAG-13, rather than an individual one.
The permit requires the township to run a Stormwater Management Program built from six minimum control measures. The legal standard is to reduce pollutants “to the maximum extent practicable.” That phrase does real work. It means the state expects steady, documented effort scaled to what a township can reasonably do, not a perfect stream. A part-time office that keeps good records and hits its deadlines is meeting the standard.
The six measures, in plain terms
One: Public education and outreach. Tell residents how their actions reach the creek. Grass clippings in the gutter, the car washed in the driveway, the dog waste left on the trail, the fertilizer spread before a storm. This is the cheapest measure to satisfy. A few articles a year in the newsletter and on the website, a storm drain marking day with a scout troop, a flyer at the counter. Keep copies and dates. The record is the compliance.
Two: Public involvement and participation. Give residents a way to take part and follow the open-meeting rules while you do it. A stream cleanup, a volunteer day, a public comment window on the stormwater plan. Photos, sign-in sheets, and meeting minutes are the proof.
Three: Illicit discharge detection and elimination. An illicit discharge is anything in the storm system that is not clean rainwater: a sewer cross-connection, a shop dumping wash water into an inlet, gray water piped to a ditch. The township needs a map of its storm system, an ordinance that bans illicit discharges, and a routine for finding and fixing them. The map is the piece small townships put off, and it is the piece an inspector asks for first. If yours is incomplete, that is the project to fund this year.
Four: Construction site stormwater runoff control. Building sites shed mud. For sites disturbing an acre or more, the township needs an ordinance requiring erosion and sediment controls and a way to review and inspect them. In practice much of this rides on the county conservation district, but the township still owns the ordinance and the local enforcement. Know where the line sits between what the district handles and what falls to you.
Five: Post-construction stormwater management. Once a development is built, its basins and infiltration beds have to keep working for the life of the site. The township needs standards for new development and a way to confirm the facilities get maintained after the developer is gone. This is where the model ordinance matters. Existing permittees were required to adopt DEP’s 2022 model stormwater ordinance by September 30, 2022. If your township adopted it, confirm it is on the books. If a gap turns up, that is a solicitor conversation, not an engineering one.
Six: Pollution prevention and good housekeeping. This one is about the township’s own operations. How you store road salt, how you sweep streets, how you clean out inlets and catch basins, how the public works yard handles fuel and waste. Write simple standard procedures, train the crew once a year, and log the inlet cleanings and sweeping. Good housekeeping is the measure a township controls completely, and it is the easiest place to show steady progress.
Where a township’s authority stops
Draw the line honestly for your board. The township controls its own ordinances, its own record keeping, its own housekeeping, and its own map. It does not control the weather, the volume of development the market brings, or the pace at which the state rewrites the rules. When the board wants to “solve stormwater,” point the energy at the six measures the permit actually grades, not at the flooding that a single dry-weather fix will not cure.
The reissuance now underway is the clearest example. DEP’s 2018 PAG-13 permit expired on March 15, 2023 and has run on administrative extension since. The reissued permit is coming, and it changes the technical work: the old Pollutant Reduction Plans give way to Volume Management Plans, and DEP will require a Maximum Extent Practicable calculator to size how much stormwater volume a township must manage. Townships will file a new Notice of Intent to stay covered, and the filing deadline has been reported as September 30, 2026, though DEP owns the final date. This is the part where a small township leans on its consultant and its conservation district. The strategy is the township’s job. The volume math is not.
Where to go next
Three places are worth a bookmark. DEP’s Minimum Control Measures page lays out what each of the six requires in the state’s own words, which is the language your annual report has to answer. Montgomery County’s MS4 program offers county-level support and coordination that a small township should use rather than reinvent. And PSATS keeps a working MS4 stormwater resource with practical ideas from other townships, plus active advocacy: PSATS has pressed DEP to revise the draft permit and credit the reduction work townships already completed. For how the reissuance fits the broader state picture MCATO tracks, see the association’s recent updates.
There is a funding side to all of this, and it deserves its own article. Once the volume plans and capital projects arrive, many townships turn to a dedicated stormwater fee to pay for them. That is the follow-on conversation, and it is coming to more Montgomery County boards.
The bottom line
You do not need an engineer on payroll to hold an MS4 permit. You need to know the six measures, keep the records that prove you did them, and hit September 30 every year. Treat the permit as six ordinary jobs with good paperwork, lean on the county and your consultant for the technical math, and the compliance stops feeling like a threat and starts looking like a checklist you already half finished.