Inflow & Infiltration (I & I) Program

What is the Inflow & Infiltration (I & I) Program?

A city-wide program to prevent sanitary sewer overflows and sewer back-ups by eliminating storm water and groundwater from entering the sanitary sewer system.

What is inflow?

Inflow is storm water that enters the sanitary sewer system through the following:

  • Footing drains
  • Cistern roof collection systems
  • Sump pumps
  • Downspouts
  • Yard drains

What is infiltration?

Infiltration occurs when ground water seeps into sewer pipes through cracks, leaky joints or deteriorated manholes.

The City Code specifically states that inflow and infiltration is illegal.

What are the basic steps in the City of Newton’s Inflow and Infiltration (I & I) Program?

  1. A property owner calls the City to schedule an inspection.
  2. City staff will perform initial inspections outside of the house/building and in the basement.
  3. If there are illegal connections, the property owner obtains quotes and plans to have them removed.
  4. The property owner submits the quotes and plans to the City for approval.
  5. After approval, the property owner hires a contractor to have corrective work completed. 
  6. City inspector makes a final inspection of completed improvements.
  7. City mails the property owner a Notice of Compliance and a Reimbursement Application.
  8. The property owner pays contractor for completed work, returns a signed Reimbursement Application and any required supporting documentation to the City.
  9. City mails reimbursement check to the property owner.

For more information on Newton's Citywide Inflow and Infiltration Program, view: