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On December 23, 1991, the Edwards Underground Water District (EUWD) received a completed application form from the City of Schertz requesting a leak detection/location survey on its water distribution system. A pre-survey conference was held December 18, 1992 at the City of Schertz Water and Wastewater Service Center to discuss the work to be performed. It was agreed that EUWD would perform sonic leak detection on all available access points, computerized leak location as needed, record any unusual system conditions found, and submit to the utility an updated master water plat with the final report.

John E. Gapinski of EUWD began the survey on January 11, 1993, and the survey was concluded on April 2, 1993. Over the course of the survey, EUWD surveyed a total of 5,782 access points· including 4,163 customer service connections, 432 fire hydrants, 1,096 main line valves, and 91 other access points covering 99.99 miles of distribution mains. Computer leak sound correlation was performed on 7 locations.

EUWD technicians detected a total of 169 leaks. This total included 35 meter box leaks, 15 fire hydrant leaks, 8 valve leaks, 5 main leaks, 3 service leaks, and 103 customer side leaks. EUWD estimates 21,703 gallons of water per day has been saved by the repair of 46 detected leaks as of May 10, 1993. The leaks discovered during the survey range from 15,840 gallons per day to numerous small meter box leaks.

As part of the survey, EUWD located 452 main line valves, 171 fire hydrants, and 36.1 miles of distribution main not shown on the master water plats. EUWD staff were unable to locate 9 fire hydrants and 49 main line valves. An additional 39 valve stacks need cleaning and/or repair and 4 valve lids were discovered missing.