The City of Ames is commencing the process of a comprehensive evaluation of the sanitary sewer system in order to identify and eliminate sources of unnecesary infiltration and inflow (I/I). The ability of the sewer system to convey wastewater well into the future is dependent on the removal of the current large amount of I/I in the system that occurs during rain events. In order to convey flows from new development as the City grows, the City must work to reduce to the overall I/I in the system. It was recommended in the Sanitary Sewer System Study completed in 2008 to develop a full Sanitary Sewer System Evaluation (SSSE).
This evaluation is a comprehensive and systematic program for identifying the defects that could contribute I/I in a sanitary sewer system, prioritizing those defects, and establishing rehabilitation costs so that repairs can then be included in the Capital Improvements Plan (CIP). The SSSE program typically consists of the following tasks: data collection, sewer televising, smoke testing, manhole inspection, and sump pump inspection. Not only would the SSSE identify and correct sources of I/I, it would also identify areas of aging infrastructure in need of repair to prevent unexpected failures and emergency repairs. Staff has begun Phase 1 for the highest priority areas revealed during the 2008 and 2010 floods. Additionally, this evaluation will analyze the benefit/cost of the current Footing Drain Grant Program and make a recommendation of how much longer this program may be beneficial to the community.
The City of Ames has over 200 miles of sanitary sewer main, 4,000 manholes, 7 siphons and 4 lift stations.
The City has hired Veenstra & Kimm, Inc of West Des Moines Iowa to lead the study team.