Technical Reports Document Library

On August 9, 1991, the Edwards Underground Water District (EUWD) received a completed application form from the Green Valley Special Utility District (GVSUD) requesting a leak detection/location survey on its water distribution system. A pre-survey conference was held March 31, 1993 at the GVSUD office 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 District a revised master water plat with the final report.

John E. Gapinski of EUWD began the survey on May 12, 1993, and the survey was concluded on October 29, 1993. Over the course of the survey, EUWD staff surveyed a total of 6,370 access points including 4,742 customer service connections, 129 fire hydrants, 1,233 main line valves, and 266 other access points covering 337.12 miles of distribution mains. Computer leak sound correlation was performed on two locations.

EUWD technicians detected a total of 337 leaks. This total included 27 meter box leaks, 2 fire hydrant leaks, 26 service line leaks, 20 main leaks, 19 valve leaks, and 243 customer side leaks.

EUWD staff estimates 189,813 gallons of water per day has been saved by the repair of 93 detected leaks as of October 29, 1993. The leaks discovered during the survey range from 27,648 gallons per day to numerous small meter box leaks.

As part of the survey, EUWD staff located 25 main line valves, 2 fire hydrants, and .40 miles of distribution main not shown on the master water plats. EUWD staff was unable to locate 35 main line valves and C2 customer service connections. An additional 22 valve stacks need cleaning and/or repair.