(a) A water utility is hereby prohibited from installing and/or maintaining a water service connection to a person's premises where a cross connection or secondary water supply is maintained, contrary to the provisions of this division, unless the public potable water supply is protected against backflow by installing an approved backflow prevention device at the service connection.
(b) When the Authority finds that there is a cross connection or a secondary water supply on the premises; that the owner, lessee or occupant is operating the piping system in a manner that could adversely effect the piping system; when it is determined that there are frequent changes to the piping and related equipment; or when it is determined that there is undue risk because of complexity of the piping system, the Authority shall require the owner, at the owner's expense, to:
(1) Install an approved backflow prevention device at each service connection to his premises.
(2) Test such device annually or more often when deemed necessary.
(3) Properly repair and maintain such device or devices and keep adequate records of each test and subsequent maintenance and repair, including materials or replacement parts.
(c) No connection shall be made to the service line between the meter and the backflow prevention device. If a bypass around the backflow prevention device is installed, a singular backflow device shall be installed on the bypass. If the service is unmetered, the backflow prevention device shall be installed near the property line upstream from the first outlet or branch connection.
(d) Each device intended for prevention of backflow shall be approved by the Authority. The design, maintenance and testing procedures, installation requirements, other features of the device and evidence of effectiveness may be required by the Authority prior to acceptance. The Authority may accept devices approved by the state department of public health or meeting the requirements of the American Society of Sanitary Engineering or of other professional or testing organizations.
(e) The backflow prevention device shall be located in a well drained room or space of sufficient size to permit a person to have convenient access for inspection, testing and repair purposes. Installation of the device below grade or in a meter pit is not acceptable, unless specifically authorized in writing by the Authority.
(f) All devices installed in a potable water system for protection against backflow shall be maintained in good working condition by the owner, occupant or lessee. The Authority may inspect such installed devices and, if found to be defective or inoperative, shall require the repair or replacement thereof. No device shall be removed from use or relocated, or other device substituted, without the approval of the Authority.
(g) Only the devices indicated below are acceptable for protection against backflow:
(1) An approved air gap at the customer service for protection of the public water system.
(2) An air gap on the premises piping system only when specifically authorized by the Authority.
(3) A reduced pressure zone backflow preventor for all backflow protection conditions.
(4) A reduced pressure zone backflow prevention device for an automatic fire sprinkler system using an antifreeze solution approved by the Authority; and for the following specified use:
a. A low pressure boiler not subject to chemical treatment.
b. A closed recirculating system used for heating and cooling not subject to chemical treatment.
c. A water softener of the automatically regenerative type.
(5) A barometric loop for a water connection not subject to back pressure.
(6) A vacuum breaker for water connections not subject to back pressure, such as standard plumbing fixtures, lavatory sinks, lawn irrigation systems, and those submerged inlets specifically authorized by the Authority.
(h) Any atmospheric type vacuum breaker shall be installed on the discharge side of the last control valve and, on open vessels, shall be at least six inches above the flood level rim of the device; or at a distance equal to the critical level, plus such safety factor as may be specified for any given vacuum breaker by the Authority. For closed vessels the top of the device shall be treated as the flood level rim, but, in addition, a check valve shall be installed on the discharge side of the vacuum breaker.
(i) Pressure type vacuum breakers may be installed so that they are continuously subject to static line pressure. Pressure vacuum breakers shall be installed a minimum of 12 inches above the equipment or piping served, whichever is higher.
(j) All required check valves, including those which are spring loaded, shall be installed so that the force of gravity will assist in closing and holding the disc or clapper on the seat. No check valve shall be installed in the vertical position on down feed supply piping. Vertical lift check valves shall be installed only in the vertical position on up feed supply piping. Horizontal lift check valves shall only be installed in the horizontal position. If horizontal swing check valves are installed in vertical piping, the direction of normal flow shall be up, and there shall be external evidence of a hinge pin to establish the type of check valve.
(k) Safe air gap shall be maintained between the water supply inlet and the maximum overflow level of any fixture, tank, or container. Safe air gaps shall be determined as follows:
(1) Circular openings. Circular water supply inlet openings shall have an air gap equivalent to twice the diameter of the orifice; but not less than one inch and need not be more than 12 inches.
(2) Other openings. For water supply openings other than circular, the air gap shall be 2-1/4 times the square root of the area of the opening.
(3) Equations. Or in equation form: G = 2d for circular openings: G = 2.25 square root of A for other openings, where G = the air gap, D = the diameter and A = the area.
(4) Exceptions. On openings greater than four-inch diameter or of equivalent area, if the opening is other than circular, the Authority shall be consulted for minimum air gaps.
(l) Air gaps and vacuum breakers shall be installed above the spill line of the fixture or device; or positive spill openings to the outside of the flush tank, device or apparatus shall be provided if the apparatus, tank or device is equipped with overflows which might become blocked, fouled or otherwise stopped.
(Ord. No. 144, 5-16-2005)