Sanitary Sewer Inflow and Infiltration (I/I) Reduction Study
City of Folsom, California

West Yost is currently managing and implementing an inflow and infiltration (I/I) investigation and sanitary sewer evaluation program for approximately 100 miles of the City of Folsom’s gravity sewer mains to help the City meet its regulatory mandate. West Yost is coordinating field work efforts, documenting and analyzing the findings, and making recommendations for I/I reduction methods and improvements.

Our I/I analysis includes:

  • Quantifying the I/I rates contributed by each defect to estimate the amount of I/I removal that can occur by repairing the defect,
  • Estimating the cost of improvements to analyze the cost effectiveness of I/I removal, and
  • Developing a plan for public and private inflow source disconnection which will allow the City to target its limited funds where they are most effective

In addition to a short-term rehabilitation/replacement plan, West Yost is developing a long-term I/I management plan that addresses improvements to privately-owned upper laterals and the rehabilitation of the publically-owned sewer system.