Reducing Inflow & Infiltration

Inflow & Infiltration (I&I) is a cost to everyone!

I&I is clear water—stormwater and groundwater—that enters the wastewater collection system. When rain or stormwater end up in wastewater pipes, it can:

•    overload the system and can cause costly sewer backups into homes and buildings; 

•    cause sewer overflows into creeks and rivers; and 

•    take up capacity at the treatment plant resulting in higher treatment costs

Inflow is water entering the sewer system through improper connections. Typical sources include roof drains/downspouts, sump pumps and yard or foundation drains illegally connected to the sewer. 

Infiltration occurs when groundwater seeps into sewer pipes through cracks, leaky pipe joints and/or deteriorated manholes. 

How residents can prevent I&I:

•    Make sure roof drains, yard/foundation drains or sump pump discharges are not connected to the wastewater pipes

•    Inspect your sewer cleanout and make sure the cap is on tight and the pipe is not damaged

•    Don’t plant trees or shrubs over or near where your wastewater pipe is buried

•    If your private sewer line is broken or cracked, have it repaired or replaced by a licensed contractor

Working together, we can reduce I&I and protect our homes and our environment!


Inflow & Infiltration