Sanitary and storm pipes start to deteriorate as soon as they're put in place. The cost of rehabilitation often falls on the homeowner's shoulders. Photo: C&K Industrial Services
Private property dyed water testing: Because of inconsistencies in smoke testing, dyed water testing is becoming the preferred I/I source detection method. Dyed water testing also can help qualify and quantify the leaks found and, though more expensive, is a better evaluation tool.
The equipment needed for dyed water testing includes dye, hoses, and closed-circuit TV equipment. The camera should be placed in the sanitary sewer and pulled up to each service connection. Water and dye is placed into each downspout, and if there is a deficiency, the attendant in the TV truck will soon see the dyed water and can record when the water was observed and its color.
Some field crews have developed a variation of this test using a manifold to distribute water to all downspouts simultaneously. Once the crew has determined that a leak exists, dye is added to each downspout individually and the leak can be isolated. This method has been used successfully to find leaks that occur during intense rainfall events. All houses in an area should be tested for possible deficiencies.
At the conclusion of the dyed water testing of all houses in an area, the results are reported and used to initiate the rehabilitation program.
• Stormwater piping replacementRehabilitation
In approaching the rehabilitation of private property piping, it is important to provide a remedy that will sever the connection between surface water runoff and sanitary laterals. This may entail simple rerouting of deficient stormwater lateral pipes.
Identifying the source of the problem involves intense testing and at times internal inspection of the lateral. Remedies may include grouting, lining, complete replacement, or installation of “pop-up” rain emitters. Low-cost spot repairs can be made when problems are isolated to a small area where debris or root intrusion has caused blockage. Evaluating which remedy to use should be done on a case by case basis. Rehabilitation of private property I/I sources may include:
• Lining or grouting of sewer laterals
• Installing “pop-up” rain emitters.
Residents must be kept informed of the findings and progress throughout the rehabilitation. The costs of private property rehabilitation are generally borne by the resident, however some communities are experimenting with partial or complete funding of private property deficiencies in order to speed up the rehabilitation process.
The municipality should maintain lists of approved contractors and provide oversight of the rehabilitation work. The most important aspect of the “fix” in rehabilitation of laterals is first to understand what is “broke.”
— Ed Kelly is wastewater systems manager of C&K Industrial Services, Independence, Ohio.