"Approved"as used in this chapter in reference to a water supply, means a water supply that has been approved by the state health official having jurisdiction. In reference to an air gap, a double check valve assembly, a reduced pressure principle backflow prevention assembly or other backflow prevention assemblies or methods shall mean an approval by the health officer.
"Approved backflow prevention assembly (See definition below of backflow prevention assembly)"means an assembly that has been manufactured in full conformance with standards established by the American Water Works Association (AWWA) entitled "AWWA/ANSI C510-92 standard for double check valve backflow prevention assemblies" and "AWWA/ANSI C511-92 standard for reduced pressure principle backflow prevention assemblies;" and, have met completely the laboratory and field performance specifications of the University of Southern California Foundation for cross-connection control and hydraulic research (USC FCCCHR). Said AWWA and USC FCCCHR standards and specifications have been adopted by the city of Millbrae and the department of health services.
"Auxiliary water supply"means any water supply on or available to the premises other than the purveyor's approved public water supply will be considered as an "auxiliary water supply." These auxiliary waters may include water from another purveyor's potable water supply or any natural sources such as well, spring, river, stream, etc., or used waters or industrial fluids. These waters may be contaminated or polluted or they may be objectionable and constitute an unacceptable water source over which the water purveyor does not have sanitary control.
"Backflow"means the undesirable reversal of flow of water or mixtures of water and other liquids, gases or other substances into the distribution pipes of the potable water supply of water from any source or sources.
"Backflow prevention assembly"means an assembly or means designed to prevent backflow. Such means are described as the following:
1. "Air gap"means a physical separation between the free flowing discharge end of a potable water system supply pipeline and an open or non-pressure receiving vessel. An approved air gap shall be at least double the diameter of the supply line measured vertically above the overflow rim of the vessel in no case less than one inch.
2. "Reduced pressure principle backflow prevention assembly"means a device containing two independently acting approved check valves together with hydraulically operating, mechanical independent pressure differential relief valve located between the check valves and at the same time below the first check valve. The unit shall include properly located resilient seated test cocks and tightly closing resilient seated shutoff valves at each end of the assembly. This assembly is designed to protect against a non-health hazard (pollutant) or a health hazard (contaminant). This assembly shall not be used for backflow protection of sewage or reclaimed water.
3. "Double check valve backflow prevention assembly"means an assembly composed of two independently acting, approved check valves, including tightly closing resilient seated shutoff valves attached at each end of the assembly and fitted with properly located resilient seated test cocks. This assembly shall be only used to protect against a non-health hazard (pollutant).
"Backpressure"means any elevation of pressure in the downstream piping system above the supply pressure at a point of consideration which would cause, or tend to cause, a reversal of the normal direction of flow.
"Backsiphonage"means a form of backflow due to the reduction in system pressure which causes sub-atmospheric pressure to exist at a site in the water system.
"City"means the city of Millbrae.
"Consumer"means any resident or business located in the city of Millbrae who uses or consumes water.
"Consumer's system"consists of those parts of the facilities beyond the termination of the water purveyor's distribution system which are utilized in conveying potable water to point of use.
"Contamination"means an impairment of the quality of water which creates an actual hazard to the public health through poisoning or through the spread of disease by sewage, industrial fluids, waste, or similar means.
"Cross-connection"means any unprotected actual or potential connection or structural arrangement between a public or a consumer's potable water system and any other source or system through which it is possible to introduce into any part of the potable water system any used water, industrial fluid, gas, or substance other than the intended potable water with which the system is supplied. Bypass arrangements, jumper connections, removable sections, swivel or change-over devices, and other temporary or permanent devices through which or because of which backflow can or may occur are considered to be cross-connections.
"Degree of hazard"means either a pollutant (nonhealth) or contamination (health) hazard and is derived from the evaluation of conditions within a system.
1. "Health hazard"means an actual or potential threat of contamination of a physical or toxic nature to the public potable water system or the consumer's potable water system that would be a danger to health.
2. "Plumbing hazard"means an internal or plumbing type cross-connection in a consumer's potable water system that may be a pollution or contamination type hazard. This includes but is not limited to cross-connections to toilets, sinks, lavatories, wash trays, and lawn sprinkling systems. Plumbing type cross-connections can be located in homes, apartment houses, hotels and commercial or industrial establishments. Such a connection, if permitted to exist, must be properly protected by an appropriate type of backflow prevention assembly.
"Health officer"means the city of Millbrae is invested with the authority and responsibility for the implementation of an effective cross-connection control program and for the enforcement of the provisions of this chapter, and shall be deemed the health officer.
"Industrial fluids"means any fluid or solution which may be chemically, biologically or otherwise contaminated or polluted in a form or concentration which would constitute a health, system, pollutional or plumbing hazard if introduced into an approved water supply. This may include, but not be limited to: polluted or contaminated used waters; all types of process waters; and, used waters originating from the potable water supply, which may deteriorate in sanitary quality.
"Pollution"means an impairment of the quality of water to a degree which does not create a hazard to the public health but which does adversely and unreasonably affect the aesthetic qualities of such waters for domestic use.
"Potable water"means any public water supply which has been investigated and approved by the health agency.
"Service connection"means the terminal end of a service connection from the public potable water system. If a water meter is installed at the end of the service connection, then the service connection shall mean the downstream end of the water meter.
"State health official"is in charge of the San Mateo Environmental Health Cross-Connection Control Program. The state health official is any authorized representative from the San Mateo Environmental Health Cross-Connection Control Program.
"Used water"means any water supplied by a water purveyor from public potable water system to consumer's water system after it has passed through the service connection and is no longer under the control of the water purveyor.
"Water purveyor's system"refers to the source facilities and the distribution system of the city and shall include all those facilities of the water system under the complete control of the water purveyor up to the point where the consumer's system begins. The source facilities shall include all components of the facilities utilized in the production, treatment, storage, and delivery of water to the distribution system. The distribution system shall include the network of conduits used for the delivery of water from the source to the consumer's system.
(1976 Code § 8-2.02; Ord. 689 § 1)