A. Cross-Connections. No water service shall be installed or continued in use by the purveyor unless the water supply is protected by backflow prevention devices as may be required by this section. The installation or maintenance of a cross-connection which will endanger the water quality of the potable water supply of the city of Yakima shall be unlawful and is prohibited. Any such cross-connection now existing or hereafter installed is declared to be a public nuisance and the same shall be abated. The control or elimination of cross-connections shall be in accordance with this section, together with the latest addition of appropriate manuals of standard practice pertaining to cross-connection control approved by the secretary. The manager shall have the authority to establish requirements more stringent than state regulations if he deems that the conditions so dictate. The purveyor shall adopt rules and regulations as necessary to carry out the provisions of this section.

B. Use of Backflow Prevention Devices.

(1) Backflow prevention devices shall be installed at the time on the premises or the materials used in connection with service connection or within any premises where, in the judgment of the purveyor, the nature and extent of the activities, or the materials stored on the premises, would present an immediate and dangerous hazard to health and/or be deleterious to the quality of water should a cross-connection occur; even though such cross-connection does not exist at the time the backflow prevention devices shall be installed under circumstances including but not limited to the following:

(a) Premises having an auxiliary water supply, unless the quality of the auxiliary supply is acceptable to the purveyor.

(b) Premises having internal cross-connections that are not correctable, or intricate plumbing arrangements which make it impracticable to ascertain whether or not cross-connections exist.

(c) Premises where entry is restricted so that inspections for cross-connections cannot be made with sufficient frequency or at sufficiently short notice to assure that cross-connections do not exist.

(d) Premises having a repeated history of cross-connections being established or re-established.

(e) Premises on which any substance is handled under pressure so as to permit entry into the public water supply, or where a cross-connection could reasonably be expected to occur. This shall include the handling of process waters and cooling waters.

(f) Premises where materials of toxic or hazardous nature are handled in such a way that if back siphonage should occur, a serious health hazard might result.

(g) The following types of facilities will fall into one of the above categories where a backflow prevention device is required to protect the public water supply. A backflow prevention device shall be installed at these facilities unless the purveyor and secretary determine that no hazard exists.

1. Hospitals, mortuaries, clinics;

2. Laboratories;

3. Metal plating industries;

4. Piers and docks;

5. Sewage treatment plants;

6. Food or beverage processing plants;

7. Chemical plants using a water process;

8. Petroleum processing or storage plants;

9. Radioactive material processing plants or nuclear reactors;

10. Others specified by the secretary.

(h) Other premises, as specified by the manager, where backflow prevention devices are required to protect the public water supply.

(2) The type of protective device required shall depend on the degree of hazard which exists;

(a) An air-gap separation or a reduce pressure principle backflow prevention device shall be installed where the public water supply may be contaminated with sewage, industrial waste of a toxic nature, or other contaminant which could cause a health or system hazard.

(b) In the case of a substance which may be objectionable but not hazardous to health, a double check valve assembly, air-gap separation, or a reduced pressure principle backflow prevention device shall be installed.

(3) Backflow prevention devices required by this section shall be installed at the meter, or at a location designated by the purveyor. The device shall be located so as to be readily accessible for maintenance and testing, and furthermore, where no part of the device will be submerged.

(4) Backflow prevention devices required by this section shall be installed under the supervision of, and with the approval of, the purveyor.

(5) The policies, procedures, and criteria for determining appropriate levels of protection shall be in accordance with the "Accepted Procedure and Practice in Cross Connection Control Manual--Pacific Northwest Section--American Waterworks Association, Third Edition," or any superseding edition.

(6) Any protective device required by this section shall be a model approved by the manager. A double check valve assembly or a reduced pressure principle backflow prevention device will be approved if it has successfully passed performance tests of the University of Southern California Engineering Center or other testing laboratories satisfactory to the secretary and the manager. These devices shall be furnished and installed by and at the expense of the customer.

(7) Backflow prevention devices installed pursuant to this section, except atmospheric vacuum breakers, shall be inspected and tested annually, or more often if necessary. Maintenance shall be at the customer’s expense. Whenever the devices are found to be defective, they shall be repaired, overhauled, or replaced at the customer’s expense. Inspections, tests, repairs, and records thereof shall be accomplished under the purveyor’s supervision by certified testers and the customer will be charged according to the following schedule of fees: