(A) Health Regulations: Regulations of the Nevada State Department of Public Health and the drinking water standards of the United States Public Health Service prohibit unprotected cross connections between the public water supply and any unapproved source of water.
(B) District Requirements: To comply with the regulations of these health agencies, the District will require the installation of approved double check valves or other approved backflow protection devices by and at the expense of the customer before service will be granted under any of the following conditions:
1. Where an unapproved fresh water supply is already available from a well, spring, reservoir or other source. If the customer agrees to abandon this other supply and agrees to remove all pumps and piping necessary for the utilization of the supply, the installation of backflow protective devices will not be required.
2. Where salt water or water otherwise polluted is available for industrial or fire protection purposes.
3. Where the premises are or may be engaged in industrial processes using or producing process waters or liquid industrial wastes, or where the premises are or may be engaged in handling sewage or any other dangerous substance.
4. Where the circumstances are such that there is special danger of backflow of sewage or other contaminated liquids through plumbing fixtures or water using or treating equipment, or storage tanks and reservoirs.
(C) Plumbing Changes Required: In special circumstances, when the customer is engaged in the handling of especially dangerous or corrosive liquids or industrial or process waters, the District may require the customer to eliminate certain plumbing or piping connections as an additional precaution and as a protection to the backflow preventive devices. In making plumbing connections, the customer shall be guided entirely by local or State plumbing ordinances and not by the District.
(D) Relief Valve Required: As a protection to the customer's plumbing system a suitable pressure relief valve must be installed and maintained by him, at his expense, when check valves or other protective devices are used. The relief valve shall be installed between the check valves and the water heater.
(E) Backflow Protection on Additional Water Supply Lines: Whenever backflow protection has been found necessary on a water supply line entering a customer's premises, then any and all water supply lines from the District's mains entering such premises, buildings or structures shall be protected by an approved backflow device, regardless of the use of the additional water supply lines.
(F) Inspection of Backflow Protective Devices: The double check valve or other approved backflow protection devices may be inspected and tested periodically for water tightness by the District. The devices shall be serviced, overhauled or replaced whenever they are found defective and all costs of repair and maintenance shall be borne by the customer.
(G) Discontinuance of Service for Defective Apparatus: The service of water to any premises may be immediately discontinued by the District if any defect is found in the check valve installations or other protective devices, or if it is found that dangerous unprotected cross connections exist. Service will not be restored until such defects are corrected.
(H) Pressure Regulators: Where reduced or increased pressure is desired, the customer shall be responsible for installing and maintaining the necessary regulators, pumps and relief valves. In such cases, the equipment shall be installed on the customer's side of the service connection and at his own risk and expense in such a manner as not to endanger the water system.