Current through Register Vol. 41, No. 3, September 23, 2024
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.
Statutory Authority
§ 62.1-44.19 of the Code of Virginia.
