Rules & Regulations of the State of Tennessee
Title 1220 - Tennessee Public Utility Commission
Subtitle 1220-04 - Division of Public Utilities
Chapter 1220-04-03 - Water Regulations
Section 1220-04-03-.26 - STANDARDS OF CONSTRUCTION

(a) Depths of Mains - Water mains shall be placed at such a depth below ground level, or otherwise protected, as will prevent freezing during the coldest weather experienced in the community in which laid, and to prevent damage by traffic.

(b) Dead Ends - Insofar as practicable, the utility shall design its distribution system so as to avoid dead ends in its mains. Where dead ends are necessary, the utility shall provide hydrants or valves for the purpose of flushing the mains. Mains with dead ends shall be flushed as often as necessary to maintain the quality of the water.

(c) Segmentation of System - Valves or stopcocks shall be provided at reasonable intervals in the mains so that repairs may be effected by the utility with interruptions to the service of a minimum number of customers.

(d) Disinfection of Water Mains - All new mains shall be thoroughly disinfected before being connected to the system. The method of disinfecting shall be in compliance with State Department of Health practices.

(e) Grid Systems - Wherever feasible the distribution system shall be laid out in a grid so that in case of breaks or repairs the interruptions of service to the customers shall be at a minimum.

(a) Size of Service Pipe - The size, design, and material and installation of the service pipe shall conform to such reasonable requirements of the utility as may be incorporated in its rules and regulations, provided, however, that the minimum size of the pipe shall not be less than nominal size except under unusual circumstances which shall be clearly defined.

(b) Depth of Service Pipes - All service pipes shall be laid at such a depth as will prevent freezing, except when services are not intended for use during freezing weather, and are actually drained during such periods.

(c) Inspection of Service Pipe --In the installation of a service pipe the customer shall leave the trench open and pipe uncovered until it is inspected by the utility or other duly authorized agency and shown to be at proper depth, free from any tee, branch connection, connection, irregularity, or defect.

(a) Whenever normal excavation discloses unsatisfactory foundation one or more of the following corrective measures shall be adopted:

(b) Pipe on a highway bridge shall be located so as to reduce hazard to a minimum and be protected from freezing.

(c) Pipes laid in trench with other facilities.

(d) Pipe laid shall be tested and made tight before being placed in service.

(e) The ditch underneath, around and over the pipe shall be backfilled with good material thoroughly tamped to secure a firm support. To disclose any settlement of the backfill which may need correcting, newly filled ditches shall be reinspected at intervals for sufficient period of time subsequent to completion of backfilling operations.

(f) Service connections may be tapped into cast iron mains if the diameter of the hole does not exceed one-quarter of the diameter of the main. Otherwise, and in mains other than cast iron, a saddle, sleeve or welded connection may be used or a tee cut into the line.

(g) The service connection at the main or the run of service pipe shall allow for a reasonable amount of flexibility to prevent fractures or leaks at the connection with the main.