The City of Cedar Rapids is investigating the problem of excess water entering the sanitary sewer system, also known as inflow and infiltration (I&I). The information gathered during this pilot study will be used to develop a plan to reduce inflow and infiltration and the associated basement backups and sewer overflows throughout the 660+ miles of sanitary sewers in Cedar Rapids.
Inflow and Infiltration
Cedar Rapids has a problem with too much water entering the sanitary sewer system through inflow and infiltration. Inflow occurs when stormwater enters the sewer system through direct connections like sump pumps, foundation drains, storm sewer connections and openings in manhole lids. Infiltration occurs when groundwater enters the sewer system through defective joints or cracks in the sewer pipes. Inflow and infiltration can quickly overwhelm the capacity of the sanitary sewer system during extreme rain events, causing basement backups and sewer overflows. The excess flow also strains the capacity of our Water Pollution Control Facility.
The goal of this study is to gain an understanding of the prevalence and nature of inflow and infiltration problems in a specified area to use as a basis for developing a city-wide plan to reduce the problem.
The study will employ a number of different methods.
Crews consisting of representatives from the City of Cedar Rapids and HDR Inc. Engineering will visit homes in sections of the study area starting Oct. 24. With your permission, inspectors will access your basement and determine if you have a sump pump connected to the sanitary sewer. If your sump pump is connected to the sanitary sewer, a contractor hired by the City will disconnect the illegal connection at NO COST to you. Residents will receive a notice on their door to let them know when crews would be in the area.
Crews will perform smoke testing to identify defects in the sewer system. This work will take place in late Oct. through Nov. 2017. During this test, crews will fill the sewer with a non-toxic, odorless smoke. If your drain traps are full of water and you do not have any defects in your plumbing, smoke should not enter your property during this test. You will receive a notice on your door when smoke testing will be in your area. This notice will include instructions on how to prepare for the test. Weather permitting, smoke testing will last approximately 3 days.
The information gathered during this pilot study will be used to develop a plan to reduce inflow and infiltration and the associated basement backups and sewer overflows throughout the 660+ miles of sanitary sewers in Cedar Rapids.
For More Information about the Pilot Study:
Cedar Rapids Project Engineer