Why is I/I a problem?
The excess clear water from I/I problems uses sanitary sewer capacity needed for wastewater. The result is sewer backups and increased costs for needlessly putting clear water through the wastewater treatment process.


The Metropolitan Council, which provides regional wastewater collection and treatment for the metropolitan area, requires communities with excess I/I to invest in local reduction remedies such as disconnecting sump pumps and foundation drains from sanitary sewers and repairing leaky sanitary sewer pipes. To urge compliance, the Metropolitan Council incorporated surcharges for communities with excess I/I. In 2015, the City of West St. Paul was faced with the choice of either paying a $2,709,950 surcharge (every time West St. Paul has excessive rainfall, it would be open to additional surcharges), alternatively West St. Paul was given the option to invest in an I/I compliance program that would eliminate the 2014 surcharge and prevent future surcharges.

Show All Answers

1. What is Inflow and Infiltration (I/I or I&I)
2. Why is I/I a problem?
3. Who is subject to an I/I Inspection?
4. What do I need to do for the inspection?
5. How do I know if I'm compliant?
6. How long is an I/I Compliance Certificate good for?