Current through Vol. 41, No. 13, March 15, 2024
(a)
Cross connections. Avoid
cross connections in the system.
(1) Do not
allow a physical connection between a line carrying a public drinking water
supply and a line carrying water of unknown or questionable quality.
(2) Do not allow connections from any PWS
system to any device or system that poses a health threat unless it is equipped
with an air gap of at least 6 inches or two pipe diameters, whichever is
larger, above the overflow or drain pipe. The installation of a reduced
pressure zone backflow prevention device will be considered in lieu of an air
gap. To allow maintenance on the backflow prevention device, the design shall
include a diversion line with equal backflow prevention. Do not locate backflow
prevention devices in a pit or vault where they can become submerged. A fire
suppression system is not considered a hazardous water supply.
(3) Do not allow a cross-connection between a
public water system and any private water system.
(4) Provide an air gap at all points where
finished water is discharged to a drain.
(b)
Cooling water. Designs
proposing the return of steam condensate, cooling water from engine jackets or
other heat exchange devices are not allowed by the DEQ.
(c)
Interconnections. Obtain
approval from the DEQ for interconnections between potable water
supplies.
(d)
Water loading
stations. To prevent contamination of the PWS, provide the following:
(1) a device on the fill line to provide an
air break and prevent submerging the line,
(2) construct the fill line and cross
connection control device so that when hanging freely it will terminate at
least 2 feet above the ground surface, and
(3) the discharge end of the fill line must
be unthreaded or constructed to prevent the attachment of additional line,
piping or other appurtenances.
(e)
Chemical feed equipment.
Provide cross-connection control to assure that:
(1) service water lines discharging to
solution tanks or pots are protected from backflow. Provide a minimum 6-inch
air gap between the end of the service water line and the spill line of the
solution tank. An air gap of less than 6 inches in conjunction with an approved
backflow preventer is acceptable,
(2) no direct connection will occur between
any sewer and a drain or overflow from the feeder, solution chamber or tank by
terminating all drains at least 6 inches or 2 pipe diameters, whichever is
greater, above the overflow rim of a receiving sump, conduit or waste
receptacle, and
(3) discharge all
drain and overflows from feeder(s), solution chamber(s), and tank(s) that
discharge to sanitary sewers through a sump. Terminate drain and overflow lines
a minimum of 6 inches or 2 pipe diameters whichever is greater above the
overflow rim of the sump.
(f)
Piping.Design and install
all piping to eliminate possible back-siphonage in conformity with the latest
American Standards Association, Recommended Practice for Backflow
Prevention and Cross-Connection Control, Manual of Water Supply
Practices,C14, 3rd Edition, 2004. Provide
an air gap for all filter-to-waste connections. Filter pipe gallery floors and
pump rooms must be protected from flooding by backflow from filter waste lines,
sewers or drains.
Added at 18 Ok Reg 1612,
eff 6-1-01