Stormwater and Collection Systems

Collection System
LRWWU's collection system is designed to protect the health, safety, and environment of the greater Lowell community, which includes Lowell, Dracut, Chelmsford, Tewksbury, and Tyngsborough. Without this collection system, flooding and waterborne illnesses would be difficult, if not impossible, to prevent.

The collection system is the network of pipes, manholes, catch basins, pump stations and diversion stations that collect sewage and stormwater runoff and convey these flows to state-approved discharge points, or outfalls. The collection system was first designed in the 1700's, and is comprised of combined sewers (the oldest type), sanitary sewers, and separate storm sewers. The collection system is operated and maintained by the LRWWU Maintenance Division.

The system includes:

  • 220 miles of gravity sewers
  • 12 sewer pumping stations
  • 10 miles of large-diameter interceptors (48-120 inch diameter)
  • 9 diversion stations for wet-weather-flow control

CMOM Reports

2022 CMOM Annual Report

Stormwater Management (MS4 / MSGP)

Management of stormwater has become an increasingly important initiative over the past decade. There has been a recent emphasis on regulating the quality of stormwater discharges to surface water bodies.

The primary initiatives related to stormwater are identifying outfalls, eliminating illicit discharges, mapping the city's drainage system, and educating the public and municipal employees about stormwater issues. Stormwater is regulated by two permits:

  • Municipal Separate Storm Sewer System (MS4) - this program is aimed at regulating stormwater discharges to local waterways in urban areas. 
  • Multi-Sector General Permit (MSGP) - this program regulates stormwater discharges to local waterways from certain industries, including wastewater treatment facilities.

MS4 Annual Reports

2022 MS4 Annual Report