| (iii) When a new waterline crosses under a wastewater
main or lateral, the waterline shall be encased as described for wastewater
mains or laterals in clause (ii) of this subparagraph or constructed
of ductile iron or steel pipe with mechanical or welded joints as
appropriate. An absolute minimum separation distance of one foot between
the waterline and the wastewater main or lateral shall be provided.
When a new waterline crosses under a wastewater main, the procedures
in §217.53(d) of this title (relating to Pipe Design) must be
followed.
(iv) Where a new potable waterline crosses a new, pressure
rated wastewater main or lateral, one segment of the waterline pipe
shall be centered over and shall be perpendicular to the wastewater
line such that the joints of the waterline pipe are equidistant and
at least nine feet horizontally from the center line of the wastewater
main or lateral. The potable waterline shall be at least six inches
above the wastewater main or lateral. Whenever possible, the crossing
shall be centered between the joints of the wastewater main or lateral.
The wastewater pipe shall have a minimum pressure rating of at least
150 psi. The wastewater main or lateral shall be embedded in cement
stabilized sand (see clause (v) of this subparagraph) for the total
length of one pipe segment plus 12 inches beyond the joint on each
end.
(v) Where cement stabilized sand bedding is required,
the cement stabilized sand shall have a minimum of 10% cement per
cubic yard of cement stabilized sand mixture, based on loose dry weight
volume (at least 2.5 bags of cement per cubic yard of mixture). The
cement stabilized sand bedding shall be a minimum of six inches above
and four inches below the wastewater main or lateral. The use of brown
coloring in cement stabilized sand for wastewater main or lateral
bedding is recommended for the identification of pressure rated wastewater
mains during future construction.
(5) Waterline and wastewater main manhole or lateral
manhole or cleanout separation. The separation distance from a potable
waterline to a wastewater main manhole or lateral manhole or cleanout
shall be a minimum of nine feet. Where the nine-foot separation distance
cannot be achieved, the potable waterline shall be encased in a joint
of at least 150 psi pressure class pipe at least 18 feet long and
two nominal sizes larger than the new conveyance. The space around
the carrier pipe shall be supported at five-foot intervals with spacers
or be filled to the springline with washed sand. The encasement pipe
shall be centered on the crossing and both ends sealed with cement
grout or manufactured sealant.
(6) Location of fire hydrants. Fire hydrants shall
not be installed within nine feet vertically or horizontally of any
wastewater main, wastewater lateral, or wastewater service line regardless
of construction.
(7) Location of potable or raw water supply or suction
lines. Suction mains to pumping equipment shall not cross wastewater
mains, wastewater laterals, or wastewater service lines. Raw water
supply lines shall not be installed within five feet of any tile or
concrete wastewater main, wastewater lateral, or wastewater service
line.
(8) Proximity of septic tank drainfields. Waterlines
shall not be installed closer than ten feet to septic tank drainfields.
(f) Sanitary precautions and disinfection. Sanitary
precautions, flushing, disinfection procedures, and microbiological
sampling as prescribed in AWWA standards for disinfecting water mains
shall be followed in laying waterlines.
(1) Pipe shall not be laid in water or placed where
it can be flooded with water or sewage during its storage or installation.
(2) Special precautions must be taken when waterlines
are laid under any flowing or intermittent stream or semipermanent
body of water such as marsh, bay, or estuary. In these cases, the
water main shall be installed in a separate watertight pipe encasement
and valves must be provided on each side of the crossing with facilities
to allow the underwater portion of the system to be isolated and tested
to determine that there are no leaks in the underwater line. Alternately,
and with the permission of the executive director, the watertight
pipe encasement may be omitted.
(3) New mains shall be thoroughly disinfected in accordance
with AWWA Standard C651 and then flushed and sampled before being
placed in service. Samples shall be collected for microbiological
analysis to check the effectiveness of the disinfection procedure.
Sampling shall be repeated if contamination persists. A minimum of
one sample for each 1,000 feet of completed waterline will be required
or at the next available sampling point beyond 1,000 feet as designated
by the design engineer.
(g) Interconnections.
(1) Each proposal for a direct connection between public
drinking water systems under separate administrative authority will
be considered on an individual basis.
(A) Documents covering the responsibility for sanitary
control shall accompany the submitted planning material.
(B) Each water supply shall be of a safe, potable quality.
(2) Where an interconnection between systems is proposed
to provide a second source of supply for one or both systems, the
system being utilized as a second source of supply must be capable
of supplying a minimum of 0.35 gallons per minute per connection for
the total number of connections in the combined distribution systems.
(h) Backflow, siphonage.
(1) No water connection from any public drinking water
supply system shall be allowed to any residence or establishment where
an actual or potential contamination hazard exists unless the public
water facilities are protected from contamination.
(A) At any residence or establishment where an actual
or potential contamination hazard exists, additional protection shall
be required at the meter in the form of an air gap or backflow prevention
assembly. The type of backflow prevention assembly required shall
be determined by the specific potential hazard identified in §290.47(f)
of this title (relating to Appendices).
(B) At any residence or establishment where an actual
or potential contamination hazard exists and an adequate internal
cross-connection control program is in effect, backflow protection
at the water service entrance or meter is not required.
(i) An adequate internal cross-connection control program
shall include an annual inspection and testing by a licensed backflow
prevention assembly tester on all backflow prevention assemblies used
for health hazard protection.
(ii) Copies of all such inspection and test reports
must be obtained and kept on file by the water purveyor.
(iii) It will be the responsibility of the water purveyor
to ensure that these requirements are met.
(2) No water connection from any public drinking water
supply system shall be connected to any condensing, cooling, or industrial
process or any other system of nonpotable usage over which the public
water supply system officials do not have sanitary control, unless
the said connection is made in accordance with the requirements of
paragraph (1) of this subsection. Water from such systems cannot be
returned to the potable water supply.
(3) Overhead bulk water dispensing stations must be
provided with an air gap between the filling outlet hose and the receiving
tank to protect against back siphonage and cross-contamination.
(4) All backflow prevention assemblies that are required
according to this section and associated table located in §290.47(f)
of this title shall be tested upon installation by a licensed backflow
prevention assembly tester and certified to be operating within specifications.
Backflow prevention assemblies which are installed to provide protection
against health hazards must also be tested and certified to be operating
within specifications at least annually by a licensed backflow prevention
assembly tester.
(A) Backflow prevention assembly testers shall have
completed an executive director-approved course on cross-connection
control and backflow prevention assembly testing, pass an examination
administered by the executive director, and hold a current license
as a backflow prevention assembly tester.
(i) Backflow prevention assembly testers are qualified
to test and repair assemblies on any domestic, commercial, industrial,
or irrigation service.
(ii) Backflow prevention assembly testers may test
and repair assemblies on firelines only if they are permanently employed
by an Approved Fireline Contractor. The Texas Department of Insurance's
State Fire Marshal's Office requires that any person performing maintenance
on firelines must be employed by an Approved Fireline Contractor.
Cont'd... |
