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Sewer Division

Public Works

The Sewer Division oversees the City's sewer and storm water infrastructure, including pipelines, catch basins, pumps and generators that move the City's waste and storm water to the appropriate channels. 

Diagram of sanitary sewer line

The Division's work can be categorized as:


The Division maintains over 240 miles of sewer and storm water pipelines including:

  • 115 miles of separated sanitary sewer mains, which transport water carrying human and domestic wastes to the Massachusetts Water Resources Authority (MWRA) collection system for processing at the wastewater treatment facility at Deer Island.
  • 78 miles of separated storm water mains, which transport storm water to either Alewife Brook or the Charles River.
  • 43 miles of combined sewer mains, which carry a combination of storm water and waste water to a treatment facility. Combined sewers have regulators called combined sewer overflows (CSO) which allow combined sewers to be relieved during times of unusually high flow. Combined sewer overflows are intended to protect private property from flooding or backups into buildings.


The Sewer Division inspects and clears obstructed sewer lines, cleans catch basins, repairs broken lines, works to control sewer odors, and inspects and approves private connections to the public system. 

Prevention and Inspection:

The Sewer Division also provides preventive sewer maintenance program includes cleaning approximately 2,000 catch basins annually, routine inspection and flushing of 75 problem pipe lines, and working with food establishments to limit the adverse effects of grease on sewer lines. While these activities serve to reduce emergency sewer backups and flooding and to protect water quality, the Division also plays a key role in the response to storm events that produce street flooding.


The division also assists with the development and management of critical projects such as the city's storm water plan, inflow and infiltration studies, combined sewer overflow monitoring, storm water quality sampling, and the administration of the Fats, Oils, and Grease program (FOG). Sewer Division engineers also oversee the design and construction of sewer separation projects

Homeowner Responsibilities: 

While the City maintains the main lines, it is the homeowner's responsibility to maintain the sewer laterals that carry sewer and storm water to the main line. If there is a sewage backup in your home:

  • Call a plumber or a drain cleaning contractor to clear the pipe from the building to the City sewer main
  • If the plumber is unable to clear the pipe, call the Sewer Division at 617-349-4861, M-F 7AM-3PM or the off-hours division at 617-349-4860 any other time. 

In order to prevent sewer problems in living areas that are below grade, homeowners are required to install a backwater valve to protect property from sewer backup. For information about backwater valves, please see our "Protect Your Home from Sewer Backups" brochure. 

To help prevent sewage blockage and backups, avoid flushing items like diapers, flushable wipes, tissues, paper towels, sanitary napkins, cotton balls, cotton swaps, etc. Additionally, don't pour grease and fats down your drain. These items can accumulate, causing major backups into the city lines. Leaves, dirt, sticks, rocks, trash, etc should not be allowed to go into manholes and catch basins as these materials cause blockage and damage to lines. To learn more the impact these items have on the City's sewer system click here

How often are catch basins cleaned?

The sewer division cleans catch basins every week day (weather and other conditions permitting), a section of the city at a time.  Using this cycle, our goal is to clean each catch basin annually.

Who do I call if I see someone dumping something into a catchbasin?

Call the Public Works' Operation Center at 617.349.4800 and leave the nearest address or intersection of the catchbasin and any identifying information of what has been dumped. You may also report using Commonwealth Connect at www.cambridgema.gov/311

Why is there a strong sewer odor in my area?

Sewer odors at catch basins can be caused by rotting leaves, low flow in an adjacent combined sewer and inappropriate dumping of dog feces, oil, paint or other pollutants. Residents can help alleviate these odors by never dumping anything into a catch basin. Catch basins are installed to collect rainwater only. Please call the Operations Center at 617.349.4800 or the Sewer Division at 617.349.4861 and leave your name, phone number and nearest address or street intersection where you smell the sewer odor.

Who do I call if sewage is backed up in my basement or bathroom?

Call a plumber or drain cleaner to clean the pipe from the building to the City sewer main.  If the plumber is unable to clear the pipe, call the Sewer Division at 617-349-4861,  Monday- Friday 7:00 am to 3:00 pm or the Off-hours Division at 617-349-4860 any other time. Please provide your name and phone number and the name and phone number of the plumber or drain cleaner.  Call a plumber or drain cleaner if the water is obviously sewage.

Page was last modified on 6/26/2024 3:59 PM
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