Specifications include, but are not limited to: The work for this project will consist of completing comprehensive acoustic leak detection surveys on the distribution systems of the water systems listed in Appendix A, issuing reports, and communicating with water systems and NHDES. NHDES understands this Scope of Work may not fully describe all services required to carry out the project; therefore, the firm may make modifications to the Scope of Work based on their professional expertise in this subject area. The firm is also encouraged to incorporate items deemed necessary to meet the needs of NHDES in completion of the project, including receiving input and allowing NHDES to review preliminary results. A. Field Work The leak detection surveys shall be conducted in accordance with the fourth edition of the AWWA Manual of Water Supply Practices M36: Water Audits and Loss Control Programs. The leak detection surveys must be performed in two phases: an initial screening of the distribution system to identify suspected leaks followed by a pinpointing phase to locate the suspected leaks. A detailed report of the survey findings must be filed with NHDES and the water system at the conclusion of each leak detection survey. It will be the responsibility of the water system to repair any leaks found. 2023-12-15 www.des.nh.gov Page 2 of 6 PO Box 95, Concord, NH 03302-0095 (603) 271-2513 a. Initial Survey i. The firm shall utilize specialized equipment to “listen” for sounds on the water mains as well as on a comprehensive spread of direct contact points including, but not limited to, main line gate valves, fire hydrants, meter/curb valves, and blow-offs. ii. The water systems in this project range from clustered condominium complexes to mobile home parks to larger municipal systems. The water systems also vary in pipe materials, pipe sizes, number of contact points, and accuracy of information about the distribution system (ex. quality of maps). As a result, the methodology will vary from water system to water system.
