REDUCE INFLOW AND INFILTRATION (I/I)

Working together, we can protect our health, our homes, and our environment

I/I costs everyone

I/I is clear water — stormwater and groundwater — that enters the wastewater system. It overloads the system and can cause costly sewer backups into homes and buildings. I/I can also cause sewer overflows into rivers and lakes.

Protect your home and community

Up to 80% of I/I comes from private sources, including defective sewer service lines and improperly connected sump pumps, downspouts, and foundation drains. Excessive I/I increases the need to build larger and more expensive sewer pipes and treatment facilities.

You can reduce inflow and infiltration

Local governments in the Twin Cities metro area and the Metropolitan Council have been working for decades to address sources of I/I in city and regional sewer infrastructure. Fixing sources of I/I on private property is just as important.

Property owners can:

  • Inspect and repair damaged sewer service lines.
  • Replace older clay pipes that are beyond their service life.
  • Make sure sump pumps and building drains are not connected to the sanitary sewer system.

Cities and townships can:

  • Educate property owners about I/I.
  • Implement sump pump inspection programs.
  • Consider point of sale inspection programs and other measures.

These efforts will prevent sewage overflows into homes and waterways, reduce costs, and allow cities and townships to invest in other priorities.

More information

Send questions or comments to i.i@metc.state.mn.us