Staff reports sewer master plan modeling complete; I&I study finds infiltration near Lehi station

Public works staff updated the council on the sewer master plan and ongoing inflow and infiltration (I&I) work.

Modeling and I&I findings: Staff said the current-conditions hydraulic modeling is complete and showed no immediate capacity issues under existing flows; build-out condition modeling will begin next. As part of an I&I field study, crews inspected manholes at night and observed water entering at joints on two lower manholes just south of the Lehi station. Staff said the water was running down the inside of the manholes rather than a forceful spray, and they expect a written report in the coming weeks.

Why it matters: Identifying manholes that admit groundwater or surface water into the sewer system helps prioritize repairs and reduce excess flow treated by the wastewater system. Staff noted groundwater levels and seasonal conditions affect infiltration and that repairs or rehabilitation will be scheduled after the study report.

Public comment and maintenance requests: During public comment a resident raised a separate issue about a deep crater adjacent to a sewer manhole in a cul-de-sac that is damaging vehicle rims and tires; staff said they would contact maintenance to patch the roadway and address the hazard. Council members acknowledged several other localized pavement and sewer patches were pending maintenance work.

Ending: Staff expects the I&I report within a few weeks and will return with recommendations for repairs or rehabilitation where infiltration was observed.