Note: Prior ordinance history: Ords. 1499 and 1584.
The city council shall from time to time by resolution adopt cross-connection control standards that establish the city's requirements for design, construction, installation, and maintenance of backflow prevention assemblies. The purpose of these standards is to protect the potable water supply of the city of Davis from the possibility of contaminants, pollutants, or water from unapproved sources entering the city's water distribution system through cross-connections. Any person receiving or using water from the city's water distribution system shall comply with all provisions of the city's then current cross-connection control standards, and the violation of any provision thereof shall constitute an infraction. In the event a water customer is found to be in violation of the cross-connection control standards by the director, the customer's water service may be terminated. The foregoing provisions shall be cumulative and in addition to any other remedy provided under any applicable law or regulation, including without limitation the administrative penalty provisions of Article 1.02 Administrative Citations.
(Ord. 1738 § 1; Ord. 2676, 8/19/2025)
As used in this article, the following words and phrases shall have the following meanings:
Approved.
Accepted by the director as meeting an applicable specification stated or cited in this article or as suitable for the proposed use.
Approved testing laboratory.
A person or entity that is competent and possesses the necessary facilities, as determined by the director, to investigate and evaluate backflow prevention assemblies.
Auxiliary water supply.
Any water supply on or available to the premises other than the purveyor's approved public potable water supply. These auxiliary waters may include water from another well, or "used waters" or "industrial fluids." These waters may be polluted or contaminated or they may be objectionable and constitute an unacceptable water source which does not have sanitary control.
AVWA backflow prevention assembly tester certification.
A required backflow prevention assembly certification from the California-Nevada Section of the American Water Works Association to be certified to perform testing of backflow prevention assemblies owned by customers of the City.
Backflow.
The undesirable reversal of the flow of water or other liquids, mixtures or substances under pressure into the distributing pipes of a potable water supply system from any source or sources other than its intended source.
Backflow preventer or backflow prevention assembly.
A mechanical assembly designed and constructed to prevent backflow, such that while in-line it can be maintained and its ability to prevent backflow, as designed, can be field tested, inspected, and evaluated or, for an air-gap separation backflow prevention assembly, inspected and evaluated.
Back-siphonage.
The undesirable reversal of the flow of water or other liquids, mixtures or substances into the distributing pipes of a potable water supply system from any source, other than its intended source, caused by the sudden reduction of pressure in the potable water supply system.
Contamination.
An impairment of the quality of the potable water by sewage, industrial fluids or waste liquids, compounds, or other materials to a degree which creates an actual hazard to public health through poisoning or through the spread of disease.
Cross-connection.
Any physical connection or arrangement of piping or fixtures between two otherwise separate piping systems, one of which contains potable water and the other nonpotable water or industrial fluids of questionable safety, through which, or because of which, backflow or back siphonage may occur into the potable water system. A water service connection between a public potable water distribution system and a customer's water distribution system which is cross-connected to a contaminated fixture, an industrial fluid system or a potentially contaminated supply or auxiliary water system, constitutes one type of cross-connection. Other types of cross-connections include connectors such as swing connections, removable sections, four-way plug valves, spools, dummy sections of pipe, swivel or change-over devices, sliding multiport tube, solid connections, etc.
Customer.
Any person or entity to whom water is furnished or sold from an approved public water system.
Director.
The department director or designee that administers the Cross Connection Control program.
Hazard, criteria for evaluation of.
A standard procedure and criteria for analysis of a water customer's water system encompassing the use of that water system, appurtenances connected to that system, and the potential for contamination of the public water system by the property owner's use of the private water system to evaluate the degree of hazard and to determine if backflow prevention measures are required, and, if so, the type of backflow prevention to be used.
Hazard, degree of.
The degree of hazard which is derived from an evaluation of the potential risk to public health and the adverse effect of the hazard upon the potable water system.
(1) 
Hazard, Health. Any condition, device, or practice in the water supply system and its operation which could create, or in the judgment of the director may create, a danger to the health and well-being of the water consumer. An example of a health hazard is a structural defect, including cross-connections, in a water supply system.
(2) 
Hazard, Plumbing. A plumbing-type cross-connection in a customer's potable water system that has not been properly protected by a vacuum breaker, air-gap separation or backflow prevention device. Unprotected plumbing-type cross-connections are considered to be a health hazard.
(3) 
Hazard, Pollution. An actual or potential threat to the physical properties of the water system, or to the potability of the public or the customer's potable water system, which would constitute a nuisance, be aesthetically objectionable or could cause damage to the system or its appurtenances, but would not be dangerous to health.
(4) 
Hazard, System. An actual or potential threat of severe damage to the physical properties of the public potable water system or the customer's potable water system; or a similar threat of pollution or contamination which would have a protracted effect on the quality of the potable water in the system.
Industrial fluids system.
Any system containing a fluid or solution which may be chemically, biologically or otherwise contaminated or polluted in a form or concentration such as would constitute a health, system, pollution or plumbing hazard if introduced into an approved water supply. This may include, but is not limited to, the following: polluted or contaminated waters; all types of process waters and "used waters" originating from the public potable water system, which may have deteriorated in sanitary quality; chemicals in fluid form; plating acids and alkalis, circulated cooling waters connected to an open cooling tower and/or cooling towers, which are chemically or biologically treated or stabilized with toxic substances; contaminated natural waters from wells, irrigation canals or systems, etc.; oils, gases, glycerine, paraffins, caustic and acid solutions and other liquid and gaseous fluids such as those used for industrial or firefighting purposes.
Pollution.
The presence of any foreign substance (organic, inorganic, or biological) in water which tends to degrade its quality, so as to constitute a hazard or impair the usefulness or quality of the water to a degree which does not create an actual hazard to the public health, but which does adversely and unreasonably affect such waters for domestic use.
Water, non-potable.
Water which is not safe for human consumption or which is of questionable potability.
Water in lieu of water service line protection.
Protection of the public water system that may be achieved through other than "service line protection," and may consist of the installation of an approved backflow prevention assembly at one or more locations other than at the "water service connection," or other methods or provisions that will provide adequate protection to the public water system as determined and as approved by the director.
Water, potable.
Any water which, according to recognized standards, is safe for human consumption.
Water-purveyor.
Any person, corporation, public utility, municipality, district or other agency or institution that operates a public water system.
Water service connection.
The terminal end of a service connection from the public potable water system, i.e., where the city loses jurisdiction and sanitary control over the water at its point of delivery to the customer's water system. If a meter is installed at the end of the service connection, then the service connection shall mean the downstream end of the meter. There shall not be any unprotected takeoffs from the service line ahead of any meter or backflow prevention assembly located at the point of delivery to the customer's water system. Service connection shall also include water service connection from a fire hydrant and all other temporary or emergency water service connections from the public potable water system.
Water service line protection.
Protection of the public water system achieved through the installation of an approved backflow prevention assembly at, or as near as is practical, at the "water service connection" as defined in this section.
Water system.
(1) 
The water system shall be considered to be made up of two parts: the utility system and the customer system.
(2) 
Utility system shall consist of the source facilities and the distribution system, and shall include all those facilities of the water system under the complete control of the utility, up to the point where the customer's system begins.
(3) 
The source facilities shall include all components of the facilities utilized in the production, treatment, storage, and delivery of water to the distribution system.
(4) 
The distribution system shall include the network of conduits used for the delivery of water from the source to the customer's system.
(5) 
The customer system shall include those parts of the facilities beyond the termination of the utility system which are utilized in conveying utility-delivered domestic water to points of use.
Water, used.
Any water supplied by the city from a public potable water system to a customer's water system after it has passed through the point of delivery and is no longer under the sanitary control of the city.
(Ord. 1738 § 1; Ord. 2676, 8/19/2025)
The director shall be responsible for the protection of the public potable water distribution system from contamination or pollution due to the backflow or back-siphonage of contaminants or pollutants through the water service connection. If, in the judgment of the director, an approved backflow prevention assembly is required at the city's water service connection to any customer's premises or at other locations in the customer's water system for the safety of the public water system, the director shall give the customer notice in writing to install such an approved backflow prevention assembly at each service connection to his premises. The notice shall clearly state that: (a) the customer must apply for a permit to correct the hazard within two working days; (b) when applying for a permit, the customer may request a hearing with the director regarding the need for a cross-connection assembly on the premises; and (c) water service will be discontinued should the customer fail to apply for the permit and install the assembly(s) required by this article. The director may order immediate disconnection without prior notice whenever hazardous conditions exist justifying such action pursuant to Section 39.04.040.
(Ord. 1738 § 1; Ord. 1499 § 2; Ord. 2676, 8/19/2025; Ord. 2684, 3/3/2026)
(a) 
Cross-Connection Protection Required.
(1) 
No water service connection to any premises shall be installed or maintained by the city unless the water supply is protected as required by this article, Sections 7583 through 7605 of Title 17 of the California Code of Administrative Regulations, and other applicable state laws and regulations. The city shall discontinue service of water to any premises in the following situations: if a backflow prevention assembly required by this Code is not installed, tested and maintained; if a backflow prevention assembly has been removed or bypassed; or if an unprotected cross-connection exists on the premises. Service will not be restored until such conditions or defects are corrected.
(2) 
The customer's system shall be open for inspection at all reasonable times to authorized representatives of the city to determine whether cross-connections or other structural or sanitary hazards, including violations of this Code and state laws and regulations, exist. When a hazardous condition becomes known, the director may deny or immediately discontinue service to the premises by providing for a physical break in the service line until the customer has corrected the condition(s). Hazardous conditions which may require immediate disconnection are: (A) those situations which would require an approved air-gap or an approved reduced pressure principle assembly; and (B) those situations where a customer has previously had a hearing and/or applied for a compliance permit but has failed to comply with subsection (b) of this section.
The study of cross-connection control has provided regulatory authorities with sufficient information to establish a list of those commercial, industrial, irrigation and residential premises where a potential hazard may exist. A list of commercial and industrial premises was established where the potential hazard is so great that protection of the public water system requires that these premises be isolated from the public water system by positive and reliable means. These types of situations represent conditions that are easily definable and are listed in Title 17, of the California Code of Administrative Regulations, Sections 7583 through 7605, Table I, and in the rules and regulations adopted pursuant to Section 39.04.060 of this chapter. Other situations that are not clearly definable by the characteristic of the activity, but could result in a contamination problem as a result of a particular activity or water use, shall be evaluated on a case-by-case basis. Typical situations that should be evaluated on a case-by-case basis include all types of commercial water use not specifically listed and multifamily and/or single-family residential services for which a cross-connection may exist.
(3) 
An approved backflow prevention assembly shall be installed on each service line to a customer's water system at or near the property line, but, in all cases, before the first branch line leading off the service line, wherever the following conditions exist:
(A) 
In the case of premises having an auxiliary water supply which is not, or may not be, of safe bacteriological or chemical quality and which is not acceptable as an additional source by the director, the public water system shall be protected against backflow from the premises by installing an approved backflow prevention assembly in the service line appropriate to the degree of hazard.
(B) 
In the case of premises on which any industrial fluids or any other substances are handled in such a fashion as to create an actual or potential hazard to the public water system, the system shall be protected by an approved reduced pressure principle assembly at the service connection.
(C) 
In the case of premises having: (i) internal cross-connections that cannot be permanently corrected and controlled; and (ii) intricate plumbing and piping arrangements; or (iii) systems where entry to all portions of the premises are not readily accessible for inspection purposes, so that it is impracticable or impossible to ascertain whether or not dangerous cross-connections exist, the public water system shall be protected against backflow from the premises by installing an approved reduced pressure principle backflow prevention assembly at the service connection.
(D) 
New commercial/industrial shell buildings with unknown future uses shall leave sufficient space (one foot per inch of service, plus one foot) after the meter box for possible future installation of an approved back-flow prevention assembly.
(4) 
The type of approved backflow prevention assembly required under subsection (a)(3)(A) or (B) shall depend upon the degree of hazard which exists as follows:
(A) 
In the case of any premises where there is an auxiliary water supply, as stated in subsection (a)(3)(A) of this section, which is not covered by subsections (a)(3)(B) through (G) which follow, the public water system shall be protected by an approved air-gap separation or an approved reduced pressure principle backflow prevention assembly.
(B) 
In the case of any premises where there is water or substance that would be objectionable but not hazardous to health if introduced into the public water system, the public water system shall be protected by an approved double check valve assembly.
(C) 
In the case of any premises where there is any material dangerous to health which is handled in such a fashion as to create an actual or potential hazard to the public water system, the public water system shall be protected by an approved air-gap separation or an approved reduced pressure principle backflow prevention assembly. Examples of premises where these conditions will exist include sewage treatment plants, sewage pumping stations, chemical manufacturing plants, hospitals, mortuaries and plating plants.
(D) 
In the case of any premises where there are "uncontrolled" cross-connections, either actual or potential, the public water system shall be protected by an approved air-gap separation or an approved reduced pressure principle backflow prevention assembly at the service connection.
(E) 
In the case of any premises where, because of security requirements or other prohibitions or restrictions, it is impossible or impracticable to make a complete in-plant cross-connection survey, the public water system shall be protected against backflow or back-siphonage from the premises by the installation of a backflow prevention assembly at the service connection. In this case, maximum protection will be required; that is, an approved air-gap separation or an approved reduced pressure principle backflow prevention assembly shall be installed at each service connection to the premises.
(F) 
In the case of premises with cross-connections to sewage lines, pumps, flushers, etc., the public water system shall be protected by an approved air-gap separation or an approved reduced pressure principle backflow prevention assembly. Examples include sewage treatment plants and pumping stations.
(G) 
In the case of tanker and spray tanks, an approved air-gap separation or an approved reduced pressure principle backflow prevention assembly is required.
(5) 
Cross-connection control devices (backflow prevention assemblies) may be installed at locations other than at the water service connection if the alternative location(s) provide adequate protection to the public water system as determined by the director. Installation of devices at alternative locations require written approval of the director and shall be approved only after a thorough site investigation and consideration of alternatives.
(6) 
Any backflow prevention assembly required herein shall be of a model and size approved by the director. The term "approved backflow prevention assembly" means a device which has been manufactured in full conformance with the standards established by the American Water Works Association entitled: AWWA/ANSI C511-92 Standards for Reduced Pressure Principle and C511-91 for Double Check Valve Backflow Prevention Assemblies; and which has met completely the laboratory and field performance specifications of the Foundation for Cross-Connection Control and Hydraulic Research of the University of Southern California. The AWWA and FCCC&HR standards and specifications have been adopted by the city. Final approval shall be evidenced by a "certificate of approval" issued by a recognized testing laboratory certifying full compliance with said AWWA standards and FCCC&HR specifications.
(7) 
The customer at any premises where backflow prevention assemblies are installed shall have certified inspections and operational tests performed by a certified tester, as defined by Section 39.04.060, at least once per year. In those instances where the director deems the hazard to be severe, certified inspections and testing may be required at more frequent intervals. Back-flow prevention assemblies shall be repaired, overhauled or replaced at the customer's expense whenever said assemblies are found to be defective. Records of such tests, repairs and overhaul shall be kept and a certified report must be forwarded to the director within two weeks of completion of the test, repair or overhaul.
(8) 
All presently installed backflow prevention assemblies which do not meet the requirements of this section but are still functioning properly, testable, repair parts still available, and which have been properly maintained, shall, except for the inspection and maintenance requirements under subsection (a)(7) of this section, be excluded from the requirements of these rules so long as the director is assured that they will satisfactorily protect the utility system. Whenever the existing device is removed from the present location, requires more than minimum maintenance or constitutes a hazard to health, the unit shall be replaced by a backflow prevention assembly meeting the requirements of this section.
(9) 
Should a water consumer wish the removal of an existing backflow prevention device, said customer may submit a written request to the director for re-evaluation of potential hazards and/or recommendations for in-lieu of water service line protection. Within thirty days from receipt of the written request, the director will have scheduled an on-site inspection of the premises with a written report of findings to the consumer issued shortly thereafter. Should the consumer disagree with the findings of the director, an appeal may be filed with the backflow prevention advisory panel.
(b) 
Compliance Schedules.
(1) 
After written notification of a backflow/back-siphonage hazard pursuant to Section 39.04.020 of this article, the customer shall apply within two working days for a permit to correct the hazard. The compliance permit shall specify a maximum allowable time period for installation by the customer and satisfactory testing of the specified backflow prevention assembly. The customer shall pay the applicable permit fee.
(2) 
Should the consumer dispute the existence of a backflow/back-siphonage hazard requiring either the installation of a backflow prevention assembly under this article or other means of mitigation of the hazard, the water consumer may request a hearing with the director. This request shall be made at the time of application for the compliance permit. The hearing with the director shall be held as soon as possible within the period of time specified on the permit for installation and inspection of the assembly or for correction of the condition. lf the director determines that the assembly is not required under this article, the permit fee shall be refunded to the consumer, but if a determination is made that the assembly is required or if other means of mitigating the hazards are required, installation of the assembly or other means of correction shall proceed in accordance with the compliance permit.
(3) 
Should the director order immediate disconnection without prior notice pursuant to subsection (a)(2) of this section, the customer shall be given notice in writing as soon as possible. The notice shall clearly state: (A) the reason for the disconnection under this article; (B) the steps the customer must take under this article in order to have water service restored, and (C) the opportunity for a hearing on the matter with the city manager.
(4) 
Failure to comply with the procedures specified in subsections (b)(1), (2), and (3) of this section within the time limits stated, or any customer who violates any of the provisions of this article, or later bypasses or renders inoperative any backflow prevention assembly installed under the provisions of this article will result in discontinuance of water service without prior written notice. Water service shall not again be rendered until such violations have been corrected as ascertained by the director and after payment of applicable permit and connection fees. Any violation of the provisions of this article or rules and regulations promulgated thereof, shall be a misdemeanor punishable as all misdemeanors are punishable under state law. Each day that a violation exists shall constitute a separate and distinct offense.
(Ord. 1738 § 1; Ord. 2634 § 15, 2022; Ord. 2676, 8/19/2025)
(a) 
Application for Certification. Any person desiring certification as a backflow prevention assembly must complete the backflow prevention assembly tester application. Each application shall be accompanied by a fee, in an amount to be set by resolution of the city council. Said fee shall not be refundable or transferable.
(b) 
Certification of Testers. Testers must register for an account with the City of Davis' third-party backflow testing portal.
(c) 
Certification Renewal. Testers must renew their application annually. Each application shall be accompanied by a fee, in an amount to be set by resolution of the city council. Said fee shall not be refundable or transferable. Approved application along with other required documents must be submitted to the City of Davis' third-party backflow testing portal.
(d) 
Certification Suspension or Revocation.
(1) 
If the cross-connection control coordinator determines that a certified tester has failed to comply with any requirement of this article, the tester will be suspended from the City of Davis' third-party backflow testing portal.
(Ord. 1738 § 1; Ord. 1499 § 2; Ord. 2634 § 15, 2022; Ord. 2676, 8/19/2025)
The director is authorized to make all necessary and reasonable rules and regulations with respect to the enforcement of this article. All such rules and regulations shall be consistent with the provisions of this article and shall be effective thirty days after being filed with the city clerk.
(Ord. 1738 § 1; Ord. 1499 § 2; Ord. 2634 § 15, 2022; Ord. 2676, 8/19/2025)