(A) General provisions.
(1) Unprotected cross-connections with the public water supply are prohibited.
(2) Whenever backflow protection has been found necessary, the water users shall install an approved backflow-prevention assembly at the user's expense for continued services, or before a new service will be granted.
(3) Wherever a backflow protection has been found necessary on a water supply line entering a water user's premises, all water supply lines from the city's mains entering such premises, buildings, or structures shall be protected by an approved backflow-prevention assembly. The type of assembly to be installed shall be in accordance with the requirements of this chapter.
(B) Where protection is required.
(1) Each service connection from the city water system for supplying water to the premises having an auxiliary water supply shall be protected against backflow of water from the premises into the public water system.
(2) Each service connection from the city water system for supplying water to any premises on which any substance is handled in such fashion as may allow its entry into the water system shall be against backflow of the water from the premises into the public system. This shall include the handling of process waters and waters originating from the city water system which have been subjected to deterioration in sanitary quality.
(3) Backflow-prevention assemblies shall be installed on the service connection to any premises having:
(a) Internal cross-connections that cannot be permanently corrected and controlled to the satisfaction of the State Health Department and the city; 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 cross-connections exist.
(C) Type of protection required.
(1) The type of protection that shall be provided to prevent backflow into the approved water supply shall be commensurate with the degree of hazard that exists on the consumer's premises. The type of protective assembly that may be required (listing in an increasing level of protection) includes: double check-valve assembly (DC), reduced pressure principle backflow-prevention assembly (RP), and an air-gap separation (AG). The water user may choose a higher level of protection than required by the city. The minimum types of backflow protection required to protect the approved water supply, at the user's water connection to premises with varying degrees of hazard are given in Table 1. Situations which are not covered in Table 1 shall be evaluated on a case-by-case basis and the appropriate backflow protection shall be determined by the city or State Health Department.
Table 1 | |
BACKFLOW PROTECTION REQUIRED | |
Degree of Hazard |
Minimum Type of Backflow Prevention |
Table 1 | |
BACKFLOW PROTECTION REQUIRED | |
Degree of Hazard |
Minimum Type of Backflow Prevention |
Sewage and hazardous substances | |
Premises where the public water system is used to supplement a reclaimed water supply | AG |
Premises where there are wastewater pumping and/or treatment plants and there is no interconnection with the potable water system. This does not include a single-family residence that has a sewage lift pump. A RP may be approved in lieu of an AG if approved by the State Health Department and Director of Public Works. | AG |
Premises where reclaimed water is used and there is no interconnection with the potable water system. A RP may be approved in lieu of an AG if approved by the State Health Department and the Director of Public Works. | AG |
Premises where hazardous substances are handled in any manner in which the substances may enter a potable water system. This does not include a single-family residence that has a sewage lift pump. A RP may be provided in lieu of an AG if approved by the State Health Department and the Director of Public Works. | AG |
Premises where there are irrigation systems into which fertilizers, herbicides, or pesticides are, or can be, injected. | RP |
Auxiliary water supplies | |
Premises where there is an auxiliary water supply which is interconnected with the public water system. A RP may be provided in lieu of an AG if approved by the State Health Department and the Director of Public Works. | AG |
Premises where there is an auxiliary water supply and there are no interconnections with the public water system. A DC may be provided in lieu of a RP if approved by the State Health Department and Director of Public Works. | RP |
Table 1 | |
BACKFLOW PROTECTION REQUIRED | |
Degree of Hazard |
Minimum Type of Backflow Prevention |
Table 1 | |
BACKFLOW PROTECTION REQUIRED | |
Degree of Hazard |
Minimum Type of Backflow Prevention |
Fire protection systems. | |
Premises where the fire system is directly supplied from the public water system and there is an auxiliary water supply on or to the premises (not interconnected). | DC |
Premises where the fire system is supplied from the public water system and interconnected with an auxiliary water supply. A RP may be approved in lieu of an AG if approved by the State Health Department and the Director of Public Works. | AG |
Premises where the fire system is supplied from the public water system and where either elevated storage tanks or fire pumps which take suction from the private reservoirs or tanks are used. | DC |
Dockside watering points and marine facilities | |
Pier hydrants for supplying water to vessels for any purpose. | RP |
Premises where there are marine facilities. | RP |
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. | RP |
Premises where there is a repeated history of cross-connections being established or re-established. | RP |
(2) Two or more services supplying water from different street mains to the same building, structure, or premises through which an interstreet main flow may occur, shall have at least a standard check valve on each water service to be located adjacent to, and on the property side of, the restrictive meters. Such check valve shall not be considered adequate if backflow protection is deemed necessary to protect the city's mains from pollution or contamination; in such cases the installation of approved backflow assemblies at such service connections shall be required.
('61 Code, § 5-6.03) (Ord. 541 C.S., passed 2-15-90)