Inflow and Infiltration Testing: What You Need to Know
Whether in the news or in your own backyard, the issue of residential flooding never seems to go away.
In many cases, the root of the problem lays with inflow and infiltration(I/I) which is defined as the way in which groundwater and stormwater (clean water sources) enter into a sanitary sewer system. Clean water connections incorrectly tied to a sanitary system, broken pipes, clogs and other such circumstances may cause the sewer to surcharge, resulting in the flooding of sewage into basements, public streams and other natural resources.
So, how do we sort out the problem and work towards a solution?
Solving Residential Flooding
As with many things, it begins with testing.
Smoke Testing
One option is smoke testing. Smoke testing is done by setting up smoke machines in pre-determined locations. Smoke is pumped into nearby manholes and observations are made to see where the smoke escapes.
If the smoke is placed in a storm sewer line and is visible from the sanitary sewer line, it can be assumed that clean water is infiltrating into the sanitary sewer system. This not only causes strain on the sanitary system, but adds to the overall cost of water treatment as clean water is now traveling to a wastewater plant. Smoke testing can be used for areas with hundreds or thousands of houses.
Dye Testing
Once compromised sanitary lines have been observed and recorded, further testing can be done.
Dye testing is an option that is frequently used if professionals need to enter a residence or to further investigate problems occurring on private properties.
Dye can also be used for external testing to show the flow of the water. Dye is put into roof drains or yard drains and observations are made to see where the dye travels. If dye flow is visible in the sanitary sewer, there is likely an incorrect connection to the sanitary sewer. If the dye only appears in the stormwater system, all is in working order.
CCTV Testing
Beyond smoke and dye testing, technology can be used to determine what lies beneath. Closed-circuit television cameras (CCTV) can be dropped down to navigate the pipes and connections to gather more information and pinpoint exact locations of any issues.
If and when an issue is detected, the next step is to determine who is responsible for the cost of repairs. It may be the county, the city, the township, or numerous other parties who must research funding options and prepare a work order to lay out an order of repair.
Plan Ahead for Inflow and Infiltration Issues with Expert Support from EDG
Correction of an inflow and infiltration issue is not cheap, but you want to have all the information on the front end to try to avoid surprises throughout the process. Learn more about how the team at EDG can be of assistance to your community with our water & wastewater services or contact us for more information.