A. Circumstances Requiring: Backflow prevention devices shall be installed at the ties 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 the water should a cross-connection occur; even though such cross-connection does not exist at the time, backflow prevention devices shall be installed under circumstances including, but not limited to, the following:
1. Auxiliary Water Supply; Exception: Premises having an auxiliary water supply, unless the quality of the auxiliary supply is in compliance with the Idaho Regulations for Public Drinking Water Systems, Idaho Department of Health and Welfare, Division of Environment, section 1-8306, and is acceptable to the Purveyor.
2. Incorrectable Internal Cross-Connections; Intricate Plumbing: 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.
3. Restricted Entry And Inspection: 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.
4. History Of Cross-Connections: Premises having a repeated history of cross-connections being established or reestablished.
5. Substances Under Pressure: 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.
6. Toxic Or Hazardous Materials: Premises where materials of a toxic or hazardous nature are handled in such a way that if back siphonage should occur, a serious health hazard might result.
7. Facilities Requiring Device; Exception: 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 Director determine that no hazard exists:
a. Hospitals, mortuaries, clinics.
b. Laboratories.
c. Metal plating industries.
d. Piers and docks.
e. Sewage treatment plants and pump stations.
f. Food or beverage processing plants.
g. Chemical plants using a water process.
h. Petroleum processing or storage plants.
i. Radioactive material processing plants or nuclear reactors.
j. Others specified by the Purveyor.
8. Other Premises: Other premises as specified by the Purveyor where backflow prevention devices are required to protect the public water supply.
B. Type Of Protective Device Required: The type of protective device required shall depend on the degree of hazard which exists:
1. An air-gap separation or a reduced 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.
2. 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.
C. Location Of Device: Backflow prevention devices required by this Chapter shall be installed at the meter, at the property line of the premises when meters are not used 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.
D. Supervision Of Installation: Backflow prevention devices required by this Chapter shall be installed under the supervision of, and with the approval of, the Purveyor.
E. Approval Of Device; Cost Of Installation: Any protective device required by this Chapter shall be a model approved by the Purveyor. 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 Purveyor and the Idaho Department of Health and Welfare, Division of Environment. These devices shall be furnished and installed by and at the expense of the customer.
F. Inspection And Testing; Cost: Backflow prevention devices installed pursuant to this Chapter, except atmospheric vacuum breakers, shall be inspected and tested annually, or more often if necessary. Inspections, tests and 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.
G. Underground Sprinkling Device: No underground sprinkling device will be installed without adequate backflow prevention devices at the point from which the water for irrigation is taken from the public water supply.
H. Failure To Comply: Failure of the customer to cooperate in the installation, maintenance, testing or inspection of backflow prevention devices required by this Chapter and the Idaho Regulations for Public Drinking Water Systems, Idaho Department of Health and Welfare, Division of Environment, section 1-8306, shall be grounds for the termination of water service to the premises, or, in the alternative, the installation of an air-gap separation at the customer's expense. (Ord. 288-2, 2-10-1987)