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Articles in support of small community water and wastewater operators.

Featured Video: Sewer Dye Testing

Featured Video: Sewer Dye Testing

A municipal sanitary sewer system is designed to collect and transport wastewater from homes, offices, businesses, restaurants and other sources to a municipal wastewater treatment plant for treatment and safe discharge into the environment. If other sources of water are allowed to enter the sewer system, the collection system and wastewater treatment plant can become over loaded allowing untreated water to be discharged. This is defined as sanitary sewer overflows, or SSO’s. One of the biggest sources of excess water is infiltration of storm water and groundwater into the sanitary sewers. A method to detect this infiltration is through dye testing.

Dye testing is a simple procedure where storm drains, yard drains, and the outside of the foundation walls of the house, or other areas are flooded with water to simulate a period of heavy rainfall. The colored water is pumped through the ground and storm water system and appears in the sanitary sewer collection system where leaks occur. This test is simple and complements smoke testing that may have been done previously.

The dye testing procedure can be accomplished in the following steps.

  1. Isolating a section of the storm water network to test by plugging pipes at specific locations. 
  2. Then, bright-dyed water is pumped into the storm water network until it reaches capacity. 
  3. Remote CCTV cameras are deployed into the sanitary sewer system, where any points of storm water ingress are highlighted clearly by the dyed water.

Once the testing is completed, the locations of these sources of infiltration makes the process of repairing these leaks far more straightforward facilitating effective piping and system repairs which keep infiltration to a minimum.

A video showing how dye testing can be carried out is shown below: