What this service solves
Inflow and infiltration is clear water — from rain, groundwater, sump pumps, downspouts, foundation drains, bad joints, cracks, or improper connections — that gets into the sanitary sewer system where it does not belong. Too much clear water overloads the sewer system, so some cities require an INI inspection of the private sewer service before a home or building can change hands.
The Metropolitan Council identifies private sources of I/I such as defective sewer service lines and improperly connected sump pumps, downspouts, and foundation drains. That is why private-property sewer lines matter, even though the larger sewer system is shared by cities, townships, and regional infrastructure.
The inspection uses a sewer camera to document the condition of the private sewer service and identify possible sources of inflow and infiltration. Requirements vary by city, including when the inspection is triggered, what paperwork is needed, what counts as passing, and whether repairs are required before transfer. The right first step is confirming what your specific city requires.
We inspect the line, record the video, document what we find, and explain what a passing result, cleaning need, or required repair may mean for the property.
Why cities care about I/I
I/I is not just a paperwork issue. Clear water entering the sanitary sewer can increase flow during storms, add stress to sewer pipes and treatment facilities, and contribute to sewer-overflow risk. That is why some communities require private sewer inspections when a property is sold or transferred.
For more background, see the Metropolitan Council resource on reducing inflow and infiltration.
INI inspections, homebuyers, and sellers
If you are buying or selling a home in a city that requires an INI inspection, it can overlap with a homebuyer sewer camera inspection. A drain-cleaning company can inspect the line, record the video, explain what the footage shows, and help determine whether cleaning or repair is needed.
This can help avoid paying once for a general camera scope and then again for a drain company to inspect the same line before cleaning, diagnosing, or documenting the issue.
Signs you should call
- Your city requires an inspection before selling
- A point-of-sale or transfer inspection is triggered
- You have clear-water backups during heavy rain
- A sump pump or downspout may be tied into the sewer
- You need documentation for a property transfer
How the service call works
- Confirm what your specific city requires
- Access the cleanout and camera the sewer service
- Document inflow and infiltration sources
- Provide a report for the property transfer
- Explain repair options if the line does not pass
INI inspections and property transfer requirements
Some Twin Cities metro communities require an inflow and infiltration inspection, commonly called an INI inspection, before a property can transfer. These inspections look for clear water entering the sanitary sewer system through defects, illegal connections, or failing private sewer components.
For a buyer or seller, the practical issue is timing. If an INI inspection is required, it should be handled early enough to avoid delaying closing. A sewer camera inspection can also reveal defects that may need repair before transfer.
Related: homebuyer sewer camera inspection, camera inspection, and trenchless pipe repair.