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On March 15, 1994, the Edwards Underground Water District (EUWD) received a request from the Bexar Metropolitan Water District (BMWD) to perform a leak detection I location survey on their two newly acquired water systems. These systems were formerly owned and operated by the Lackland City Water Company. A pre-survey conference was held March 15, 1994 at the BMWD Service Center to discuss the work to be performed. It was agreed that EUWD would perform sonic leak detection on all available access points and computerized leak location as needed. A final report, including any unusual system condition found and an updated master water plat would be submitted to BMWD at the conclusion of the survey.

Mark L. McGinnis of EUWD began the survey of the Northwest system on March 23, 1994. The Northeast system survey was started on April 11, 1994 by John E. Gapinski of EUWD. The Northeast survey was concluded on February 3, 1995 followed by the Northwest survey that was concluded on February 24, 1995. Over the course of the survey, EUWD surveyed a total of 22,319 access points including 18,239 customer service connections, 898 fire hydrants, 1,855 valves, and 207 other access points covering 175.93 miles of distribution main. Computers leak sound correlation was performed on 17 locations by EUWD and numerous other locations by UMWD personnel.

EUWD surveyors detected a total of 741 leaks. This total included 194 service leaks, 137 meter box leaks, 27 main line leaks, 22 fire hydrant leaks, 10 main valve leaks, and 351 customer side leaks. EUWD estimates 559,797 gallons of water per day has been saved by the repair of 387 detected leaks as of March 17, 1995. The leaks discovered during the survey range from 54,864 gallons per day to numerous small meter box leaks.

As part of the survey, EUWD located 340 valves of various types, 90 fire hydrants, and 59,385 feet of main not shown on the master water plats. EUWU surveyors were unable to locate 287 service connections, 171 valves of various types, and 2 fire hydrants shown on the master water plats. An additional 196 items were discovered to need some type of repair or adjustment.