Excess water in the sewerage system from rainfall, stormwater, groundwater or seawater can reduce the capacity of sewerage networks and wastewater treatment plants to contain and treat sewage. This is why the EPA requires wastewater managers to develop plans to manage excess water. These plans are known as Inflow and Infiltration (I&I) Management Plans.
The EPA has created guidelines to help develop effective I&I Management Plans.
Inflow and Infiltration Management Plan Guidelines (790Kb)