Unprotected cross connections are prohibited.
If backflow protection has been found necessary on a water supply line entering a water user's premises, then any and all water supply lines from the public water system entering such premises shall be protected by an approved backflow prevention device. The device installed shall be in accord with the requirements of this article.
A. Cost: Whenever protection against backflow is required, the city will require the water user to install an approved backflow prevention device at the user's expense.
B. Where Protection Is Required:
1. Each service connection from the public water system to a premises having an auxiliary water supply shall be protected against backflow of water from the premises into the public water system unless the auxiliary water supply is accepted as an additional source by the city and is approved by the health agency.
2. For each premises on which a substance is handled so that it may enter the public water system, each service connection from the public water system to such premises shall be protected against the backflow of water from that premises into the public water system. This requirement shall apply to each premises on which persons handle process waters and waters originating from the public water system which have been subjected to deterioration in sanitary quality.
3. Backflow prevention devices shall be installed on a service connection to a premises having: a) internal cross connections that cannot be permanently corrected and controlled to the satisfaction of the health agency and the city, or b) an intricate plumbing and piping arrangement which make it impracticable to ascertain whether cross connections exist.
Backflow prevention devices shall also be installed on a service connection to a premises where all portions of the premises cannot be readily accessed for inspection purposes, making it impracticable to ascertain whether cross connections exist.
4. If an interstreet main flow may occur through two (2) or more services supplying water from different street mains to the same building, structure, or premises, then a standard check valve shall be installed adjacent to, and on the property side of, the respective meters. Such check valve shall not be considered adequate if a backflow prevention device is deemed necessary to protect the public water system's mains from pollution or contamination. In such cases the installation of approved backflow prevention devices shall be required.
C. Type Of Protection Required: The type of protection required to prevent backflow into an approved water supply shall be commensurate with the degree of hazard that exists on the water user's premises. The minimum types of backflow protection required to protect the approved water supply are set forth in table 6-1.5.1 of this section. However, the water user may choose a higher level of protection than required by the city.
Situations which are not covered in table 6-1.5.1 of this section shall be evaluated on a case by case basis and the required backflow protection shall be determined by the city or health agency.
Degree Of Hazard | Minimum Type Of Backflow Prevention Device
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Degree Of Hazard | Minimum Type Of Backflow Prevention Device
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1. Sewage And Hazardous Substances: | |
a. Premises where the public water system is used to supplement the reclaimed water supply. | AG |
b. Premises where wastewater pumping and/or treatment plants are located, and where there is no interconnection with the potable water system. This does not include a single-family residence that has a sewage lift pump. An RP may be provided in lieu of an AG if approved by the health agency and the city. | AG |
c. Premises where reclaimed water is used and there is no interconnection with the potable water system. An RP may be provided in lieu of an AG if approved by the health agency and the city. | AG |
d. 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. An RP may be provided in lieu of an AG if approved by the health agency and the city. | AG |
e. Premises where there is an irrigation system into which fertilizers, herbicides, or pesticides are, or can be, injected. | RP |
2. Auxiliary Water Supplies: | |
a. Premises where there is an auxiliary water supply which is not an approved water supply, and which is interconnected with the public water system. An RP or DC may be provided in lieu of an AG if approved by the health agency and the city. | AG |
b. Premises where there is an auxiliary water supply which is not an approved water supply, and there are no interconnections with the public water system. A DC may be provided in lieu of an RP if approved by the health agency and the city. | RP |
3. Fire Protection Systems: | |
a. Premises where the fire protection system is directly supplied from the public water system and there is an auxiliary water supply on or to the premises which is not interconnected with the public water system and which is not an approved water supply. | DC |
b. Premises where the fire protection system is supplied from the public water system and inter-connected with an auxiliary water supply which is not an approved water supply. An RP may be provided in lieu of an AG if approved by the health agency and the city. | AG |
c. Premises where the fire protection system is supplied from the public water system and where either elevated storage tanks or fire pumps which are supplied by private reservoirs or tanks are used. | DC |
4. Restricted Entry: Premises where entry is restricted so that inspections for cross connections cannot be made with sufficient frequency, or upon sufficiently short notice, to assure that cross connections do not exist. | RP |
5. Cross Connection History: Premises where there is a history of cross connections being established or reestablished. | RP |
(1988 Code)