§ 86-238. Type of protective assembly required.

The type of protective assembly required under section 86-237 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 section 86-237 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 utilities superintendent, an undue health threat is posed because of the presence of extremely toxic substances, the utilities superintendent may require an air gap at the service connection to protect the public water system. This requirement will be at the discretion of the utilities superintendent and is dependent on the degree of hazard.

(7)

Any backflow-prevention assembly required in this section shall be a model and size approved by the utilities superintendent. 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 has 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."

The AWWA and FCCHR standards and specifications have been adopted by the utilities superintendent. Final approval shall be evidenced by a certificate of approval issued by an approved testing laboratory certifying full compliance with the AWWA standards and FCCHR specifications. The following testing laboratory has been qualified by the utilities superintendent to test and certify backflow preventers:

Foundation for Cross-Connection Control and Hydraulic Research
University of Southern California
University Park
Los Angeles, CA 90089

Testing laboratories, other than the laboratory listed in this subsection, will be added to an approved list as they are qualified by the utilities superintendent.

Backflow preventers that may be subjected to backpressure or backsiphonage that have been fully tested and have been granted a certificate of approval by the qualified laboratory and are listed on the laboratory's current list of approved backflow-prevention assemblies may be used without further testing or qualification.

(8)

It shall be the duty of the customer-user at any premises where backflow-prevention assemblies are installed to have or conduct inspections and operational tests at least once per year. In those instances where the utilities superintendent 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, water department personnel, or by a certified tester approved by the utilities superintendent. It shall be the duty of the utilities superintendent to see that these tests are made in a timely manner. The customer-user shall be notified by the utilities superintendent 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 such assemblies are found to be defective. Records of such tests, repairs and overhaul shall be kept and made available to the utilities superintendent.

(9)

All presently installed backflow-prevention assemblies that do not meet the requirements of this section but were approved assemblies for the purpose described in this section at the time of installation and that have been properly maintained, shall, except for the inspection and maintenance requirements under subsection (8) of this section, be excluded from the requirements of these rules so long as the utilities superintendent 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 utilities superintendent 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. No. 957, § 24(12-363.6—12-363.15), 12-7-92)