Inflow & Infiltration: What Every Homeowner Needs to Know
Inflow and Infiltration (I&I) is groundwater and stormwater entering the sanitary sewer system through cracks, broken joints, and improper connections. It causes backups, overflows, and costly repairs. Many Twin Cities cities require homeowners to fix I&I issues.
What Is Inflow & Infiltration?
Inflow
Inflow is stormwater that enters the sanitary sewer system through improper connections. Common sources include sump pumps discharged into floor drains, downspouts connected to the sewer line, and foundation drains tied into the sanitary system. During heavy rain, these connections send large volumes of water into a system designed only for wastewater.
Infiltration
Infiltration is groundwater that seeps into the sewer system through cracks, joint separations, and deteriorated pipe walls. As pipes age, the surrounding groundwater finds its way inside through every gap and defect. This is a constant source of excess water that worsens during wet seasons and high water table periods.
Why It Matters
When excess water enters the sanitary sewer, it overwhelms the system's capacity. This leads to sewage backups into homes, sanitary sewer overflows into streets and waterways, and significantly increased treatment costs for municipalities. Many Twin Cities cities now have active I&I programs that require homeowners to identify and repair sources of inflow and infiltration. Failing to comply can result in fines or mandated repairs on a set timeline.
Signs You Have an I&I Problem
If you notice any of the following, your sewer line may be allowing groundwater or stormwater into the sanitary system.
- Sewer backups during or after heavy rain events
- Sewer odors in your home or yard after storms
- A notification from your city about I&I compliance requirements
- Unexplained wet spots or saturated areas in your yard
- Gurgling drains during rainstorms or snowmelt
If you are experiencing any of these symptoms, a camera inspection can confirm whether your sewer line has cracks, joint failures, or improper connections contributing to I&I. Call 612-961-6460 to schedule an inspection.
Find Your City's I&I Program
Many Twin Cities municipalities have active Inflow & Infiltration programs. Find your city below to learn about requirements and available resources.
Arden Hills
View I&I ProgramChanhassen
View I&I ProgramEagan
View I&I ProgramExcelsior
View I&I ProgramGolden Valley
View I&I ProgramLauderdale
View I&I ProgramMounds View
View I&I ProgramOrono
View I&I ProgramRoseville
View I&I ProgramSt. Anthony Village
View I&I ProgramTonka Bay
View I&I ProgramHow We Fix I&I Problems
From diagnosis to city compliance, we handle the entire I&I repair process using trenchless technology that requires no digging.
Step 1: Camera Inspection
We run an HD sewer camera through your entire line to identify every crack, joint separation, root intrusion point, and improper connection that allows water into the system. You receive a full video recording and written report detailing all defects found.
Step 2: Identify All Sources
We map every I&I source in your system, including inflow connections like sump pumps and downspouts, and infiltration points like cracked pipes and failed joints. This ensures the repair addresses every entry point, not just the obvious ones.
Step 3: Trenchless CIPP Lining
We install a seamless, jointless CIPP (Cured-In-Place Pipe) liner inside your existing sewer pipe. The liner seals every crack, gap, and joint from the inside, permanently eliminating all infiltration entry points without any excavation of your yard or driveway.
Step 4: Compliance Documentation
After the repair, we run a final camera inspection and provide complete before-and-after documentation, including video footage and a written report. Everything is formatted for submission to your city's I&I compliance program so you can close out any outstanding requirements.
I&I FAQ
What happens if I ignore my city's I&I notice?
Most municipalities set a compliance deadline. If you do not address the I&I issues within the required timeframe, your city may issue fines, place a lien on your property, or mandate repairs at your expense. It is always better to address I&I proactively so you can choose your contractor and timeline rather than being forced into an emergency repair.
How much does I&I repair cost?
The cost depends on the length of pipe, severity of the damage, and number of entry points that need to be sealed. Our trenchless CIPP lining is typically more affordable than traditional dig-and-replace methods because there is no excavation, no yard restoration, and the work is completed in a single day. Contact us at 612-961-6460 for a free estimate.
Does CIPP lining actually stop infiltration?
Yes. CIPP lining creates a continuous, seamless pipe within your existing pipe. Because the liner has no joints, seams, or gaps, there are no entry points for groundwater. The before-and-after camera inspection clearly shows the difference, and this documentation satisfies municipal I&I compliance requirements.
Will my city pay for I&I repairs?
Some municipalities offer grants, loans, or cost-sharing programs to help homeowners pay for I&I repairs. Availability varies by city. Visit our Grants & Funding Programs page to see what programs may be available in your area, or call us and we will check for you.
Grants & Funding May Be Available
Many Twin Cities cities offer grants, loans, and assessment programs that can help cover the cost of I&I repairs. We track every available program and help you apply.