Local I/I Community Financial Assistance

MWRA's I/I Local Financial Assistance Program provides $860 million in grants and interest-free loans to MWRA sewer communities to perform local infiltration and inflow "I/I" reduction and sewer rehabilitation. Funds are approved for distribution through Fiscal Year 2030.

In September 2022, on recommendation of the MWRA Advisory Board, the MWRA Board of Directors approved a $100 million addition to the community Infiltration/Inflow Local Financial Assistance Program for FY19-23. 

Guidelines  Application

Map and Contact Information

Program enhancements include:

  • Addition of $100 million Phase 14 funds to be distributed as 75% grants and 25% interest-free loans with loan repayment over 10 years.  Phase 14 funds will be allocated to each community in the fiscal year that the community’s Phase 12 funds are allocated.  For communities that have already been allocated Phase 12 funds, Phase 14 funds will be available as of September 30, 2022;
  • Communities will be allowed to by-pass the Phase 13 ‘stop-gap’ funding stage (100% interest-free loans) and move directly from Phase 12 grant/loan funding into Phase 14 grant/loan funding;
  • Phase 12, 13 and 14 funds will be allocated to a community in the fiscal year following distribution of 50% or more of that community’s Phase 11 funds;
  • Phase 10 and 11 funds will become available to a community in the fiscal year following the distribution of 50% or more of that community’s Phase 9 funds;
  • Continuation of the 90-day notification to MWRA for community applications exceeding $2 million; and,
  • Continuation of the annual spring survey to project a community's three-year MWRA I/I financial assistance spending plan.

Eligible projects are detailed in the Program Guidelines and include:

  • Pipeline Replacement
  • Public and Private Inflow Source Removal
  • I/I Reduction Planning
  • Sewer Rehabilitation Construction
  • Engineering Design
  • Engineering Services During Construction

Background On Infiltration And Inflow

Wastewater discharged by member sewer communities to MWRA is influenced by seasonal and wet-weather conditions related to infiltration and inflow (I/I).  I/I is extraneous water that enters all wastewater collection systems through a variety of sources.  I/I, as well as stormwater from combined sewers, reduce sewer system capacity that would otherwise be available to transport sanitary flow.

Typical Sewer System Rehabilitation Projects

Internal television inspection of sewers is performed to identify sewer defects and I/I. The photos below show a technician remotely operating a TV inspection camera inside a sewer pipe. In the second photo, groundwater infiltration into the sewer pipe is viewed through the video from the TV inspection camera.

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man looking at a TV
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water flowing through a crack

Smoke testing of sewers is performed to identify direct and indirect stormwater connections to a separate sewer system. Smoke is blown into the sewer system filling the pipes. Smoke escapes through direct or indirect connections which can identify catch basins or area drains improperly connected to a separate sewer system. The photos below show catch basins connected to the sewer system identified through smoke testing.

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smoke blowing out of a sewer grate
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identification board next to a sewer system

Sewers and sewer manholes that are in poor physical condition are often replaced using open-cut construction. The three photos below show sewer and manhole replacement in an area near a salt marsh with high groundwater.

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men in construction jackets digging a hole
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construction worker waiting in a hole
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construction worker pulling a pipe through the ground

Sewer rehabilitation using a cured-in-place pipe liner is one of many “trenchless” technologies for extending the service life of sewers and eliminating groundwater infiltration. The photos below show installation of cured-in-place pipe and a finished lined pipe.

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two construction workers using machinery
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cured-in-place
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men unloading sewer building equipment out of a van
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inside of a pipe

Sewer manholes located in wetland areas, low areas subject to flooding, or salt marshes are more susceptible to physical defects that may allow inflow to enter the sewer system. Winter freeze-thaw cycles can be damaging to sewer manhole structures. The use of geographic information system (GIS) mapping can be particularly effective in identifying sewer structures located in low lying areas. These structures can then be prioritized for periodic inspection. The three photos below show a defective sewer manhole in a wetland area before and after rehabilitation.

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manhole cover in a wetland, surrounded by reeds and water
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water flowing into a hole in the ground
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a repaired manhole in a wetland

The photos below show a rehabilitated sewer manhole in a salt marsh and the interior of a manhole following the lining process.

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manhole sticking out of a marsh
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interior of a manhole

Basement sump pumps and roof downspouts directly connected to the sewer (via house or building plumbing) can be significant sources of inflow. These direct connections are not allowed in areas served by separate sanitary sewers. They can be identified through community house-to-house inspection surveys. The first two photos below are typical examples of basement sump pumps connected to house plumbing. The third photo is an example of a roof downspout routed into the building basement where it connects to the house plumbing.

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a sump pump in a house basement
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pipes going into the ground in a house
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a roof downspout going into the building basement