Welcome to The LWSC Engineering Department

The Engineering Department provides technical support related to water, sewer, and drain for residents of Lynn, contractors, and other City departments, as well as coordination with local, state, and national agencies. As part of its work, the Engineering Department maintains detailed plans of Lynn’s water and sewer infrastructure.

Engineering Department

List Our Department Information
  Chief Engineer Anthony Marino
List Contact The Engineering Department
(781) 596-2400 | Ext. 404
  Business Hours

Tuesday - Thursday

8 AM to 8 PM
8 AM to 4 PM
8 AM to Noon

The Engineering Department Oversees

  • Industrial Pre-treatment Program which ensures, through monitoring and inspections that industries pre-treat waste streams to eliminate non-conventional pollutants from upsetting the biological process at the Waste water Treatment Facility
  • Backflow prevention programs which keeps drinking water from being contaminated by other water, such as that in air conditioning equipment or fire suppression systems
  • Review calculations prior to construction of projects such as new housing developments to ensure that residents will have adequate sewerage and drainage service
  • Review of private water and sewer permits for proper engineering and materials
  • Administration of all laboratory contracts performed for the Wastewater Treatment Facility
  • Assisting contractors in obtaining information on the water and sewer systems
  • Provide contractors with permits to repair or install new water, sewer, or drain connections
  • Providing design and construction inspectional services to insure federal mandated work is performed as specified
  • Design technical specifications for complex water, sewerage and drainage projects


Combined sewer systems are sewers that are designed to collect rainwater runoff, domestic sewage, and industrial wastewater in the same pipe. Combined sewer systems are quite common in older cities such as Lynn. Most of the time, Lynn’s combined sewer systems transport all of their wastewater to the Lynn Wastewater Treatment Plant, where it is treated and then discharged to Broad Sound. During periods of heavy rainfall or snowmelt, however, the wastewater volume in the combined sewer system can exceed the capacity of the sewer system or treatment plant. For this reason, combined sewer systems are designed to overflow occasionally and discharge excess wastewater directly to nearby streams, rivers, or other water bodies. Without overflow structures, this mix would back up into homes, businesses, and public streets.

These overflows, called combined sewer overflows (CSOs), contain not only stormwater but also untreated human and industrial waste, toxic materials, and debris. Flows from CSO’s can compromise a water body's uses and lead to water quality violations in the receiving waters.

It is strongly recommended that you avoid contact with receiving waters during and shortly after heavy rains. The Lynn Sewer Collection System contains 5 CSO’s which are shown on Figure 3.1 and described below:

The Summer Street Overflow (CSO 003) is located at the intersection of Summer Street and the Strawberry Brook Culvert, adjacent to the GE Field. This overflow relieves the Western Interceptor and discharges to the Saugus River via the Little River.

The Market Street Overflow (CSO 004) is located in Market Street between Munroe and Broad Streets and relieves the Washington Street Submain and the Eastern Interceptor into Lynn Harbor adjacent to Heritage State Park.

The Broad Street Overflow (CSO 005) is located in Broad Street between Market and Union Streets and relieves the Union Street Submain and the Eastern Interceptor into Lynn Harbor adjacent to Heritage State Park.

The Sanderson Avenue Overflow (CSO 006) is located in Sanderson Avenue at Burrill Avenue and relieves the Eastern Interceptor.

The Groveland Street Overflow (CSO 006A) is located in Groveland Street and relieves the Eastern Avenue Submain.

Both of these structures discharge to the Stacey Brook Stormwater Conduit, ultimately discharging to King’s Beach at the Lynn/Swampscott boundary.
New Item LWSC Overflow Event Logs (PDF)
  2015-2016 | Coming Soon
  2016-2017 | Coming Soon
  2017-2018 | Coming Soon
  2019-2020 | Coming Soon

Website Resources
Websites To learn more about CSO’s:
  Mass State CSO Resource
  EPA CSO Resource
  To learn more about Flooding and Sewage Back-Ups:
  Mass State Flooding and Back-Up Resource

Cross Connection Control Guide

A cross-connection is defined as any actual connection or arrangement between any pipe conveying potable water from a public water system and any non-potable water supply, piping arrangement or equipment including, but not limited to waste pipe, sewer, drain, or other unapproved sources, or any direct or indirect connection between a  plumbing fixture or device whereby contaminated water or fluids, gasses or substances may enter and flow back into the potable water piping system or the distribution system of a public water system.

This guide discusses the importance of controlling cross-connections and preventing backflow occurrences from unprotected cross-connections in the water system.

1. Key Cross-Connection Terms and Definitions

Backflow - The flow of water or other liquids, mixtures, or substances into the distributing pipes of a potable water supply from any source or sources other than its intended source. Back-siphonage is one type of backflow.
Back pressure - Backflow that occurs when the pressure in an unprotected downstream piping system exceeds the pressure in the supply piping.
Back-siphonage - Resulting from negative pressures in the distributing pipes of a potable water supply.

2. Where Can Cross-Connections Occur?

Cross-connections can occur at many points throughout a distribution system and a community's plumbing infrastructure. Cross-connections can be identified by looking for physical interconnections (or arrangements) between a customer's plumbing and the water system. Some specific examples of backflow incidents that can occur are:

  • Lawn chemicals back flowing (back-siphoning) through a garden hose into indoor plumbing and potentially into the distribution system.
  • Back-siphonage of "blue water" from a toilet into a building's water supply.
  • Carbonated water from a restaurant's soda dispenser entering a water system due to backpressure.
  • Back-siphonage of stagnant water in fire suppression systems into the distribution system.
  • Back-siphonage of chemicals from industrial buildings into distribution system mains.
  • Backflow of boiler corrosion control chemicals into an office building's water supply.

3. Cross-Connection Control and Backflow Prevention Programs
Why is it Important to Have a Cross-Connection Control and Backflow Prevention Program?
Controlling cross-connections and preventing backflow is critical to ensuring the safety of your drinking water because:

  • Cross-connections are ever-present dangers that exist in most water systems and can result in serious chemical or microbiological contamination events in drinking water systems.
  • Cross-connections should be protected in order to prevent backflow, which can be hard to detect.
  • In any distribution system, potential cross-connections and therefore sources of contamination can be numerous, varied, and unpredictable.
  • Having these programs in place can help you avoid the costs of responding to a contamination incident.

4. Lynn Water and Sewer’s Cross-Connection Control Program
The Commission is responsible for inspecting all industrial, commercial, and institutional premises served and to determine whether cross connections exist and whether all cross connections are either properly protected by an appropriate control device or eliminated.

On new installations, the Commission will provide on-site evaluation and/or inspection of plans in order to determine the type of backflow preventer, if any, that will be required.  This plan review takes place with the submission of a Design Data Sheet (under the Forms and Documents tab). Installation of the device shall not be performed until an approval letter has been issued by the Commission. 

Forms and Documents Available For Download
These documents are also available throughout the website with each appropriate section or Department.

New Item Acrobat Documents For Download (PDF)
  Drainlayers Bond Form  
  Drainlayer Application  
  Hydrant Meter Rental  
  Fire Hydrant Flow Testing  
  General Service Application  
  Domestic Meter Schematic  
  Cross Connection Design Data Sheet  
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