A. Conditions For Requiring: An approved backflow prevention assembly shall be installed on each service line to a customer's water system at or near the property line or immediately inside the building being served; but in all cases, before the first branch line leading off the service line wherever the following conditions exist:
1. In the case of premises having an auxiliary water supply that is not or may not be of safe bacteriological or chemical quality and that is not acceptable as an additional source by the Water Systems Operator, the public water system shall be protected against backflow from the premises by installing an approved backflow prevention assembly in the service line, appropriate to the degree of hazard.
2. In the case of premises on which an industrial fluids or any other objectionable substances are handled in such a fashion as to create an actual or potential hazard to the public water system, the public system shall be protected against backflow from the premises by installing an approved backflow prevention assembly in the service line, appropriate to the degree of hazard. This shall include the handling of process waters and waters originating from the utility system that have been subject to deterioration in quality.
3. In the case of premises having: a) internal connections that cannot be permanently corrected and controlled; or b) intricate plumbing and piping arrangements or where entry to all portions of the premises is not readily accessible for inspection purposes, making it impracticable or impossible to ascertain whether or not dangerous cross-connections exist, the public water system shall be protected against backflow from the premises by installing an approved backflow prevention assembly in the service line.
B. Type Of Assembly: The type of protective assembly required under subsection A of this Section shall depend upon the degree of hazard that exists as follows:
1. In the case of any premises where there is an auxiliary water supply as stated in subsection A1 of this Section and it is not subject to any of the following rules, the public water system shall be protected by an approved air-gap separation or an approved reduced-pressure principle backflow prevention assembly.
2. In the case of any premises where there is water or substance that would be objectionable but not hazardous to health, if introduced into the public water system, the public water system shall be protected by an approved double- check valve assembly.
3. In the case of any premises where there is any material dangerous to health that is handled in such a fashion as to create an actual or potential hazard to the public water system, the public water system shall be protected by an approved air-gap separation or an approved reduced-pressure principle backflow prevention assembly. Examples of premises where these conditions will exist include sewage treatment plants, sewage pumping stations, chemical manufacturing plants, hospitals, mortuaries, and plating plants.
4. In the case of any premises where there are "uncontrolled" cross-connections either actual or potential, the public water system shall be protected by an approved air-gap separation or an approved reduced-pressure principle backflow prevention assembly at the service connection.
5. In the case of any premises where, because of security requirements or other prohibitions or restrictions, it is impossible or impractical to make a complete in-plant cross- connection survey, the public water system shall be protected against backflow from the premises by either an approved air- gap separation or an approved reduced-pressure principle backflow prevention assembly on each service to the premises.
6. In the case of any premises where, in the opinion of the Water Systems Operator, an undue health threat is posed because of the presence of extremely toxic substances, the Water Systems Operator may require an air gap at the service connection to protect the public water system. This requirement will be at the discretion of the Water Systems Operator and is dependent on the degree of hazard.
C. Standards And Specifications:
1. Any backflow prevention assembly required herein shall be a model and size approved by the Water Systems Operator. The term approved backflow prevention assembly shall mean an assembly that has been manufactured in full conformance with the standards established by the American Water Works Association titled: AWWA C510-89, Standard for Double Check Valve Backflow Prevention Assembly; and AWWA C511-89, Standard for Reduced-Pressure Principle Backflow Prevention Assembly, and have met completely the laboratory and field performance specifications of the Foundation for Cross- Connection Control and Hydraulic Research of the University of Southern California, established by "Specification of Backflow-Prevention Assemblies", section 10 of the most current issue of the Manual of Cross-Connection Control.
2. Said AWWA and FCCHR standards and specifications have been adopted by the Water Systems Operator. Final approval shall be evidenced by a "certificate of approval" issued by an approved testing laboratory certifying full compliance with said AWWA standards and FCCHR specifications.
3. The following testing laboratory has been qualified by the Water Systems Operator to test and certify backflow preventers: Foundation for Cross-Connection Control and Hydraulic Research, University of Southern California, University Park, Los Angeles, CA 90089.
4. Testing laboratories, other than the laboratory listed above, will be added to an approved list as they are qualified by the Water Systems Operator.
5. Backflow preventers subjected to back pressure or back siphonage that have been fully tested and have been granted a certificate of approval by said qualified laboratory and are listed on the laboratory's current list of approved backflow prevention assemblies may be used without further testing or qualification.
D. Certified Inspections: It shall be the duty of the customer/user at any premises where backflow prevention assemblies are installed to have certified inspections and operational tests made at least once per year. In those instances where the Water Systems Operator deems the hazard to be great enough, certified inspections may be required at more frequent intervals. These inspections and tests shall be at the expense of the water user and shall be performed by the assembly manufacturer's representative, Public Works Department personnel, or by a certified tester approved by the Water Systems Operator. It shall be the duty of the Water Systems Operator to see that these tests are made in a timely manner. The customer/user shall notify the Water Systems Operator in advance when the tests are to be undertaken so that the customer/user may witness the tests if so desired. These assemblies shall be repaired, overhauled, or replaced at the expense of the customer/user whenever said assemblies are found to be defective. Records of such tests, repairs, and overhaul shall be kept and made available to the Water Systems Operator.
E. Systems Not Meeting Requirements: All presently installed backflow prevention assemblies that do not meet the requirements of this Section but were approved assemblies for the purpose described herein at the time of installation and that have been properly maintained shall, except for the inspection and maintenance requirements under subsection D of this Section, be excluded from the requirements of these rules so long as the Water Systems Operator is assured that they will satisfactorily protect the utility system. Whenever the existing assembly is moved from the present location, requires more than minimum maintenance, or when the Water Systems Operator finds that the maintenance constitutes a hazard to health, the unit shall be replaced by an approved backflow prevention assembly meeting the requirements of this Section. (Ord. 110, 3-22-1994)