Illicit Discharge Detection & Elimination

An illicit discharge is defined as any release into the drainage system (MS4) of contaminated water, or any non-stormwater discharge that contributes pollutants to receiving waters.

Public Works conducts inspections of stormwater outfalls throughout town as part of ongoing compliance with our Phase II permit. A town by-law (Article V, Section 26) provides enforcement and fining procedures for illicit discharges found within the town’s MS4. Any discharge deemed a threat to public safety, public health, or the environment is in violation of this by-law and thus subject to a removal order and/or fines by the Conservation Commission, Board of Health, or Inspectional Services.

Examples of illicit discharges:
  • Sanitary wastewater from crushed or collapsed pipes or surcharges
  • Direct septic connections into the storm drain system
  • Overflow from septic tanks, car wash wastewater
  • Laundry wastewater
  • Improper disposal of automobile and household products
  • Bagged pet waste
  • Leaves and other debris dumped into open drainage and stream channels
Exceptions (not considered illicit discharges):
  • Water line flushing
  • Landscape irrigation
  • Diverted stream flows
  • Rising or out-breaking groundwater
  • Uncontaminated pumped groundwater (includes clean sump pump discharges)
  • Potable water source discharges
  • Foundation drains
  • Dechlorinated swimming pool discharges
  • Stormwater runoff from streets and sidewalks

For more information regarding the Phase II Stormwater Management Program, contact or phone 508-532-6010.