Rockport NPDES Phase II Stormwater Management Program

Rockport Harbor
Rockport Harbor

What is Stormwater?

Stormwater runoff water from rain, hail  and melting snow.  It finds its way into the Town's drainage system, including catch basins and drainage swales, and eventually drains to a body of water such as a wetland, pond, stream or the ocean.  Many of Rockport's stormwater outfalls drain directly into the ocean.  

What is NPDES?

The Environmental Protection Agency (EPA) has mandated that certain communities must file for a permit under the Phase II National Pollutant Discharge Elimination System (NPDES) program.  This mandate by the EPA is authorized under the Clean Water Act.  The goal of this program is to eliminate point source pollution discharging into our waterways.  Under the NPDES program Rockport's drainage system is considered a Municipal Separate Storm Sewer System (MS4).  In 1990 Phase I required medium and large cities to obtain a permit to cover their stormwater discharges.  Phase II began in 1999 and requires regulated small MS4s in urbanized areas, as well as small MS4s that are outside the urbanized area that are designated by the permitting authority, to obtain permit coverage for their stormwater discharges.  Each regulated MS4 is required to develop and implement a stormwater management program to reduce the contamination of stormwater runoff and prohibit illicit discharges. The permit requires that Rockport create a Stormwater Management Plan.  This plan must include the following components:

  • Public education and outreach
  • Public involvment and participation
  • Illicit discharge detection and elimination
  • Construction site stormwater runoff control
  • Post construction stormwater runoff control
  • Good housekeeping in our daily municipal operations.

What is an illicit discharge?

An illicit discharge is essentially any discharge into a stormwater draiange system that is not composed entirely of stormwater.  There are exceptions to this including water from firefighting activities and discharges from facilities already covered by a NPDES permit, such as treated sanitary sewer flows from a wastewater treatment plant.  It is a common misconception that stormwater drainage flows to a wastewater treatment plant.  However this is not the case.  Stormwater drainage flows, generally through pipes, and eventually outfalls to a wetland, river, stream, lake, pond or directly to the ocean. Most stormwater flows receive minimal treatment, if any.  Treatment for stormwater can include various methods of attempting to remove sediment materials and in some cases oils from water before it reaches a discharge.  Illicit discharges can include cross-connections between sanitary sewer systems or private septic systems and the stormwater system, known or unknown, as well as anything that is dumped on the road or directly into a catch basin that includes materials other than stormwater.  A main component of the Town's Stormwater Management Plan is Illicit Discharge Detection and Elimination (IDDE).  The goal of an IDDE program is not necessarily punishment, but elimination of the illicit discharge.  Many illicit discharges exist without the knowledge of the responsible party, and the Town can work with that party to eliminate the discharge.  Sometimes as illicit discharge isn't due to one party but to multiple individuals repeatedly and hopefully unkowingly doing something they shouldn't do.  An example of this would include improper disposal of pet waste.  Often a person walking their dog either doesn't clean up after it, or properly bags their dog's waste, but then drops it in a catch basin rather than waiting to find a trash barrel.  Now the stormwater system is contaminated not only with the dog waste, but also with a plastic bag.  Many catch basins are therefore marked in some way to warn people not to dump anything in them.  In Rockport this is generally done in one of two ways.  Newer catch basin grates may have "No Dumping" stamped in the cast iron grate.  Catch basins without the newer style grate often are painted nearby with a stencil that reads "Dump No Waste - Drains to Ocean".

Municipal Good Housekeeping

Some of the most basic types of municipal good housekeeping conducted in Rockport in relation to stormwater include street sweeping and catch basin cleaning.  Over the course of the winter, sand is used on roads to improve driving conditions during storms.  By summer, much of this sand has found its way into the catch basins.  The DPW Highway Division sweeps the streets to pick up as much of this sand as possible before it reaches the catch basins.  Later, catch basins are cleaned preiodically to remove built-up sediments.  This allows the catch basin sump to properly remove future sediments from stormwater flows.  Sediments and winter sand removed from the drainage system therefore does not get discharged at the stormwater outfall.

What can I do?

  • Clear debris such as trash, leaves and grass clippings away from catch basins and drainage ditches.
  • When possible use biodegradable products when cleaning outside, and if possible, wash your car on the grass instead of the driveway and use low-phosphate deterents.
  • Do not dump household waste such as paint, cleaning products, motor oils, antifreeze, pet waste, or other hazardous material into catch basins and drainage ditches.
  • Dispose of hazardous materials properly.  For more info on this call the DPW office at 978-546-3525.
  • Minimize the use of fertilizers near catch basins and drainage ditches.
  • Dispose of pet waste in the trash.
  • Do not drain chemically treated swimming pools onto the street or into catch basins or drainage ditches.  Pool water should be held until chlorine levels have reached acceptably low levels.
  • Do not dump anything into a catch basin.