Virginia Law

A. Pipe joints. The method of joining pipe and the material used shall be included in the design specifications in accordance with ASTM or other nationally recognized standards and the joint material and joint testing shall conform to the appropriate standards and specifications.

1. Sewer joints shall be designed to prevent infiltration and to prevent the entrance of roots.

2. When clay sewer pipe is used, the joints shall be compression joints, made in conformance with the appropriate ASTM specification.

3. When concrete pipe is used, single rubber ring gasket joints shall conform to the appropriate ASTM specification.

4. When asbestos cement pipe, truss pipe, or ductile iron pipe is used, joints using couplings and gaskets shall be made in conformance with the requirements of the appropriate ASTM specification.

5. Joints for plastic material pipe may be of compression gaskets, chemical welded sleeves, or chemical fusion joints per manufacturers' recommendations.

Heat fusion joints may be used for high density polyethylene pipe.

B. Leakage. An acceptance test shall be specified for all gravity sewer lines. The test may be either a hydrostatic test or an air test.

1. Where hydrostatic testing is specified (infiltration or exfiltration), the leakage outward or inward shall not exceed 100 gallons per inch of nominal pipe diameter per mile per day (2,400 gpd/mi maximum) for any section of the system. Manholes should be tested prior to pipeline testing. Where the exfiltration test is employed, the line shall be subjected to a minimum of four feet of head, or up to the head to the top of the previously tested manhole, whichever is the lesser, above the crown of the pipe at the upstream manhole of the section being tested.

2. The infiltration test shall be allowed only when it can be shown that the hydrostatic head outside the pipe is a minimum of four feet or exceeds the upstream manhole depth, whichever is the lesser, above the crown of the pipe for the entire length of the pipe being tested.

3. Where air testing is specified, test methods and acceptability criteria shall be in accordance with the appropriate ASTM specification. Air testing shall generally be acceptable for all types of pipe materials. If air testing is employed, the manholes shall be tested by exfiltration.

4. Manhole leaking standards as specified in 9VAC25-790-350 shall be obtained.

C. Building sewers. Sewerage service lines from buildings (sewers) shall be constructed in accordance with either the Uniform Statewide Building Code of Virginia or this chapter and standards contained in this chapter, depending on jurisdictional considerations as outlined in Part IV (9VAC25-790-940 et seq.) of this chapter. An interceptor, or separation basins, may be required under the provisions of state or local building codes or standards and the provisions of this chapter.

1. Connections shall be made to sewers by replacing a length of pipe with branch fittings, or a clean opening cut with tapping equipment and a "y" type of connection completed and sealed. In some instances a tee-saddle or tee-insert may be attached to the sewer submain to provide a connection.

2. All connections to sewers and manholes shall be made so as to prevent structural damage and infiltration. To meet future needs, stubs, wyes, and tees may be installed if plugged tightly.

D. Trench construction. Class A, B, or C bedding (American Society of Civil Engineers (ASCE) Manuals and Reports on Engineering Practice—No. 36, 1974, Water Pollution Control Federation (WPCF) Manual of Practice—No. 9, 1970, and American Waterworks Association (AWWA) for Installation of Ductile-Iron Water Mains and their Appurtenances (ANSI/AWWA C600-82), 1982, bedding class shall be provided for rigid pipe, and appropriate installation shall be provided for flexible pipe material in accordance with recognized standards and manufacturers' recommendations.

1. Trenches shall be carefully backfilled with excavated materials approved for backfilling, consisting of earth, loam, sandy clay, sand and gravel, soft shale, or other approved materials free from large clods of earth or stones larger than one inch in diameter, deposited in six inch layers, and thoroughly and carefully tamped until the pipe has a cover of not less than one foot.

2. The remainder of the backfill shall be placed in the trench in layers not exceeding two feet and thoroughly tamped. No stone or rock larger than five inches in its greatest dimension shall be used in backfilling.

3. Trenches in public roadways shall be excavated, backfilled and compacted in accordance with the standards specified in the Virginia Department of Transportation's Road and Bridge Specifications or other acceptable criteria.