Rescue canines are in the spotlight these days with Major a German Shepherd rescue dog, being the first dog from an animal shelter to reside in the White House. Another rescue dog farther south in Arkansas, Vessel, was discovered in a shelter as having the skills needed to be trained as a Special Service Dog. At the same time, the CED of Central Arkansas Water [CAW] attended a water seminar in Oxford and learned about a UK water utility using canines to sniff out leaks from the potable water system. A CAW employee put him in touch with a local shelter trainer and Vessel was selected as a Leak Detector Trainee, and then sent to training at On the Nose Leak Detection School outside Little Rock. Now Vessel is a full-time member of the CAW leak detection team.
CAW uses Utilis, a satellite imaging company, to pre-locate leaks in the water distribution system Utilis utilizes specialized RADAR signals from satellites to illuminate the area of interest and collects the resulting reflected signals. These signals are analyzed and processed to identify specific indicators of wet soil saturated with potable water. The result is a map showing likely leak locations [LLL], or Points of Interest [POI]. These results typically encompass 5% of the entire system length. Only locations where there is expected to be a leak are inspected. This is where Vessel comes in.
CAW started to inspect LLLs identified by Utilis in December 2017. The results are consistent with other Utilis projects and much better than traditional boots-on-theground [TBOTG] methods, as shown in the table. Utilis directed performance at CAW is a nine times improvement over TBOTG in the number of leaks found per mile inspected and three times better on the leaks per day metric.
Canines possess a sense of smell many times more sensitive than even the most advanced man-made instrument. The leak detection team, Vessel, and her handler Tim Preator are sent out to areas identified by Utilis to search for leaks. Vessel is put to work using the command “Find Leak,’ making a broad sweep of the LLL and then pinpoints the leak. She shows a passive alert, laying down and barking when a leak is found. She is rewarded for her efforts with tennis ball play.
Vessel is over 90% accurate in detecting leaks. She has been working in the field since October 2019. CAW staff performs conventional acoustic correlation pinpointing to specifically locate the leak so that crews can dig and repair the pipe This reduces the number of leaks found per day in the field due to confirming Vessel’s indication with human validation. As more confidence is gained in the efficacy of Vessel s pinpointing ability and the ability of the handler to accurately read her body language, the number of leaks pinpointed per day will rise. Overall efficiency will improve In one case Vessel found a non-surfacing leak that was between a 6-inch valve and the tapping saddle off of a 12-inch cast-iron main under a concrete parking lot. The lot is built over a gravel base, which allowed the water to flow directly into a storm drain. This leak alone was costing CAW 2.3 MGD.
Leak detection has evolved from old-school divining rods and listening sticks to space-age satellites and now back to basics, using the innate capabilities found in nature.