Vacaville Municipal Code Ch. 13.14 Control of Backflow and Cross-Connection to the Municipal Water System

Pursuant to the Federal Safe Drinking Water Act of 1974, as amended, and the State Water Resource Control Board's Cross-Connection Control Policy Handbook effective July 1, 2024, the city has the primary responsibility for preventing unapproved water sources or other contaminants from entering the public potable water system. The city shall require that any unprotected cross connection be eliminated or that the water system be protected with an approved backflow prevention assembly. The purpose of this chapter is:

A. To protect public health and the public potable water supply of the city from the possibility of actual or potential contamination or pollution by isolating within the customer's internal distribution system(s) or the consumer's private water system(s) such contaminants or pollutants which could backflow into the public water systems, in compliance with California's Cross-Connection Control Policy Handbook regulations and the federal Safe Drinking Water Act; and

B. To promote the elimination or control of existing cross-connections, actual or potential, between the consumer's in-plant potable water system(s) and nonpotable water system(s), plumbing fixtures and industrial piping systems, or recycled water systems; and

C. To provide for the maintenance of a continuing program of cross-connection control which will systematically and effectively prevent the contamination or pollution of all potable water systems.

(Ord. 2016, 3/24/2026)

A. The Director of Utilities shall be responsible for the protection of the public potable water distribution system from contamination or pollution due to the backflow of contaminants or pollutants through the water service connection. If the Director of Utilities or their designated agent determines, based upon State regulations or local conditions, that an approved backflow prevention assembly is required at the city's water service connection to any customer's premises for the protection of the water system, the Director of Utilities or their designated agent shall give notice in writing to the customer to install such an approved backflow prevention assembly(ies) at specific location(s) on their premises.

B. The customer shall complete the required action at their sole expense within the time specified, but in no event to exceed 30 calendar days unless extended by the city for good cause. The customer is responsible for the installation and repairs of the approved backflow prevention assembly(ies). The city is required to annually inspect and test the backflow prevention assembly(ies) as required by the CCCP, as that term is defined herein. Failure, refusal or inability on the part of the customer to install, have annually tested by certified testers, and maintain the assembly(ies) shall constitute a ground for city installation of such assembly(ies) at the customer's own expense, or for discontinuing water service to the premises until such requirements have been satisfactorily met. The city may require testing more frequently than annually if deemed necessary by the Director of Utilities or their designee dependent on the degree of hazard at a user's premise.

(Ord. 2016, 3/24/2026)

For the purpose of this chapter, the words set out in this section shall have the following meanings:

"Airgap"

means the unobstructed vertical distance through the free atmosphere between the lowest opening from any pipe or faucet supplying water to a tank, plumbing fixture, or other device and the flood level rim of the vessel. An approved airgap shall be at least double the diameter of the supply pipe, measured vertically, above the overflow rim of the vessel; and in no case less than one inch. "Approved" means accepted by the Director of Utilities as meeting an applicable specification stated or cited in this chapter, or as suitable for the proposed use.

"Approved Backflow Preventer"

means an approved backflow prevention assembly as one that has been manufactured to and meets the performance standards of the American Water Works Association and the Foundation's own laboratory and field evaluations. Approved assemblies are listed in the USC-FCCCHR's official List of Approved Backflow Prevention Assemblies.

"Atmospheric Vacuum Breaker (AVB)"

means a backflow prevention device that stops back siphonage by allowing air into the water line when pressure drops below atmospheric levels. It consists of an air inlet valve, a check seat, and an air inlet port, which opens to admit air to prevent the potable water from being contaminated by non-potable water. AVBs are designed for non-continuous use, typically not operating under continuous pressure for more than 12 hours in a 24-hour period and require installation at least six inches above the highest downstream outlet. AVBs are required on hose bib connections and commonly used as anti-siphon valves for irrigation systems.

Auxiliary Water Supply.

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 public potable water supply, non-potable supply, recycled or reuse water, or any natural source(s) such as a well, spring, river, stream, harbor, 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 reversal of the normal flow of water caused by either backpressure or back siphonage.

"Backflow preventer"

means an assembly or means designed to prevent backflow.

"Backpressure"

means the flow of water or other liquids, mixtures or substances under pressure into the distribution pipes of a potable water supply system from any source or sources other than the intended source.

"Back siphonage"

means the flow of water or other liquids, mixtures or substances into the distribution pipes of a potable water supply from any source other than its intended source caused by the reduction of pressure in the potable water supply system.

"Certified tester"

means a tester accepted by the Director of Utilities and chief operator as meeting applicable requirements stated or cited in this chapter under CCCP. Certified testers are also certified repairers, if their certification includes repair authorization.

"Complex Plumbing System"

means the elaborate network of pipes, fixtures, and equipment needed for a large buildings or high-rise structures, as opposed to a simple single-family dwelling.

"Contamination"

means 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 or potential hazard to the public health through poisoning or through the spread of disease.

"Controlled cross-connections"

means a connection between a potable water system and a non-potable or otherwise objectional water system with an approved back-flow prevention assembly properly installed and maintained so that it will continuously afford the protection commensurate with the degree of hazard.

"Cross-connection"

means any physical connection or arrangement of piping or fixtures between two or more otherwise separate piping systems one of which contains potable water and the other unapproved, non-potable, or industrial fluids of questionable safety, through which, or because of which, backflow may occur into the potable water system. This would include any temporary connections, such as swing connections, removable sections, four-way plug valves, spools, dummy section of pipe, swivel or change-over devices or sliding multiport tube.

"Cross-connection control by containment"

means the installation of an approved backflow prevention assembly commensurate with the degree of hazard at the water service connection to any customer's premises to find and permanently eliminate or control all actual or potential cross-connections within the customer's water system.

"Cross-Connection Control Program" (CCCP)

means a documented and enforceable strategy administered by the water supplier to protect the public potable water system from contamination or pollution due to actual or potential cross-connections. The program shall apply to all new and existing connections where a potential cross-connection hazard exists, including but not limited to irrigation systems, fire sprinkler systems, commercial and industrial facilities, and auxiliary water supplies.

"Degree of hazard"

is a term derived from an evaluation of the potential risk to public health and the adverse effect of the hazard upon the potable water system.

Director of Utilities or His Designated Agent.

The Director of Utilities or his designated agent in charge of the cross-connection program of the city 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.

"Double check valve assembly"

means an assembly of two independently operating approved check valves with tightly closing shut-off valves on each end of the check valves, plus properly located test cocks for the testing of each check valve. The entire assembly shall meet the design and performance specifications as determined by a laboratory and field evaluation program resulting in an approval by recognized and city approved testing agency for backflow prevention assemblies. To be approved these assemblies must be readily accessible for in-line testing and maintenance.

"Double Check Valve Detector Assembly (DCDA)"

means a backflow prevention device for fire sprinkler systems that combines a double-check valve assembly with a bypass containing a water meter to detect water usage, preventing contamination of the potable water supply. The main double-check valve protects against backflow from a non-health hazard, while the bypass with a meter and a secondary, smaller double-check assembly records any flow, signaling unauthorized use or leaks.

"Health hazard"

means any condition, device, or practice in the water supply system and its operation which could create, or in the judgment of the Director of Utilities or his designated agent, may create a danger to the health and well-being of the water consumer.

"High Hazard"

means an actual or potential connection between a public water system and another system or source that could introduce substances into the potable water supply, creating a significant and immediate threat of poisoning, disease, or serious injury.

"Industrial fluids system"

means 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 not be limited to: 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 alkaline, circulating cooling waters connected to an open cooling tower and/or cooling towers that are chemically or biologically treated or stabilized with toxic substances; contaminated natural waters such as from well, springs, streams, rivers, bays, harbors, seas, irrigation canals or systems, etc., oils, gases, glycerin, paraffins, caustic and acid solutions and other liquid and gaseous fluids used in industrial or other purposes or for fire-fighting purposes.

"Licensed Plumber"

means an individual, firm, corporation, partnership, or association duly licensed by the State of California to perform the type of work and repairs to be done as shown on approved plans.

"Low Hazard"

means an actual or potential connection between a public potable water system and another source that could cause a water impairment to the point of affecting the water's aesthetic qualities for domestic use but does not create a public health hazard.

"Non-potable water"

means water which is not safe for human consumption, or which is of questionable potability.

"Plumbing hazard"

means a plumbing type of cross-connection in a consumer's potable water system that has not been properly protected by an approved air-gap or approved backflow prevention assembly.

"Pollution"

means 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.

"Pollutional hazard"

means an actual or potential threat to the physical properties or to the potability of the public or the consumer's potable water system but which would constitute a nuisance or be aesthetically objectionable or could cause damage to the system or its appurtenances but would not be dangerous to health.

"Potable water"

means any water which, according to recognized standards, is safe for human consumption.

"Pressure Vacuum Breaker (PVB)"

means a backflow prevention device that protects a potable water supply from back siphonage conditions only, consisting of a spring-loaded check valve and an air inlet valve that opens to admit air and break a vacuum. It operates under continuous pressure and is required to be installed at a minimum height above the highest downstream outlet for effective function.

"Recycled Water"

means water treated to meet state standards for non-potable reuse, subject to additional cross-connection controls under CCR Title 22.

"Reduced pressure principle assembly"

means an assembly of two independently acting approved check valves together with a hydraulically operating, mechanically independent differential pressure relief valve located between the check valves and at the same time below the first check valve. The unit shall include properly located test cocks and tightly closing shut-off valves at each end of the assembly. The entire assembly shall meet the design and performance specifications as determined by a laboratory and a field evaluation program resulting in an approval by a recognized and city approved testing agency for backflow prevention assemblies. The assembly shall operate to maintain the pressure in the zone between the two check valves at an acceptable level less than the pressure on the public water supply side of the assembly. At cessation of a normal flow the pressure between the two check valves shall be less than the pressure on the public water supply side of the device. In case of leakage of either of the check valves the differential relief valve shall operate to maintain the reduced pressure in the zone between the check valves by discharging to the atmosphere. When the inlet pressure is two pounds per square inch or less, the relief valve shall open to the atmosphere. To be approved these assemblies must be readily accessible for in-line testing and maintenance and be installed in location where no part of the assembly will be submerged.

"Reduced Pressure Principle Detector Assembly (RPDA)"

means a backflow prevention device designed for fire sprinkler systems, combining a main line Reduced Pressure Principle (RP) assembly with a bypass containing a water meter and a smaller RP assembly. This configuration prevents backflow and also detects water usage or leaks by measuring flow through the bypass meter, which is activated by low flows that bypass the main assembly's checks. RPDAs are required for high hazard fire prevention systems that use chemicals, booster pumps, or in the presence of an auxiliary water source.

"Single Check Valve Assembly"

A single check valve or swing check is a non-testable one-way valve that uses a hinged disc, or "flapper," to automatically permit fluid to flow in one direction and block reverse flow. As forward-flowing fluid pushes the disc away from its seat, it opens. When the pressure decreases or reverses, gravity or a spring pulls the disc back onto the seat, closing the valve to prevent backflow.

"Smart Assembly"

means a backflow prevention assembly equipped with integrated digital monitoring features that enhance cross-connection control compliance. Smart Assemblies must meet all performance and approval standards required for conventional backflow prevention assemblies, including listing by the University of Southern California Foundation for Cross-Connection Control and Hydraulic Research (USC-FCCCHR), and must be testable by a certified backflow prevention assembly tester.

"Spill Resistant Vacuum Breaker"

means a backflow prevention device that prevents back siphonage while preventing water spillage during normal operation or startup by a diaphragm seal. Unlike standard pressure vacuum breakers (PVBs), the SVB incorporates a seal that closes the air inlet before the check valve opens, ensuring that water doesn't escape the device.

"System hazard"

means an actual or potential threat of severe damage to the physical properties of the public potable water system or the consumer's potable water system or of a pollution or contamination which would have a protracted effect on the quality of the potable water in the system.

"USC-FCCCHR"

means USC Foundation for Cross-Connection Control and Hydraulic Research.

"Water – Service Connection"

means the terminal end of a service connection from the public potable water system; i.e., where the water purveyor 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 should be no unprotected takeoffs from the service line ahead of any meter or any backflow prevention assembly located at the point of delivery to the customer's water system. Service connections 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 – Used"

means any water supplied by a water purveyor 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 water purveyor.

(Ord. 2016, 3/24/2026)

A. Water System.

1. The water system shall be considered as made up of two parts, the city system and the customer system, which consist of the following:

a. The city 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 city, from the source of supply up to the point where the customer's system begins. The source 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 customer's system.

b. The customers' system shall include those parts of the facilities beyond the termination of the utility distribution system which are utilized in conveying utility-delivered domestic water to points of use. The city shall not be responsible for any costs associated with the modification of private plumbing beyond the point of service, and such costs shall be borne by the customer when modifications are necessary to meet legal or regulatory requirements.

B. Policy.

1. No water service connection to any premises shall be installed or maintained by the water purveyor unless the water supply is protected as required by state and federal laws and regulations and this cross-connection control chapter. Service shall be discontinued if a backflow prevention assembly is not installed, tested, and maintained in accordance with this chapter, or if it is found that a backflow prevention assembly has been removed, bypassed, no longer meets the requirements commensurate with the degree of hazard 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 to inspection to authorized representatives at all reasonable times to determine whether cross-connections or other structural or sanitary hazards, including violations of this code and State laws and regulations, exist. If a health, plumbing, pollutional, or system hazard or violation exists, service may be denied until corrected.

3. The city is not responsible for any costs relating to any plumbing issue, including but not limited to reduced flow or thermal expansion, that may arise out of or result from the city's implementation of the mandated cross-connection control program as set forth in this chapter.

4. An approved backflow prevention assembly must be installed by a licensed plumber on each service line to a customer's water system at or near the property line, above grade, directly behind the water meter or, if approved by the Director, an alternate location may be approved following a hazard assessment. Backflows shall be tested by a certified tester immediately after installation and/or repair.

a. For premises with an auxiliary water supply, the public water system shall be protected against backflow from the premises by installing an approved Reduced Pressure (RP) or Air Gap (AG) backflow prevention assembly in the service line.

b. For premises on which any industrial fluids or any other objectionable substance is handled, the public 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.

c. For premises with (a) internal cross-connection that cannot be permanently corrected or controlled, 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 dangerous cross-connections exist, the public water system shall be protected against backflow from the premises by installing an approved backflow prevention assembly in the service line.

5. The type of protective assembly required depends on hazard: air gap (AG), reduced pressure principle (RPP), Reduced Pressure Principal Detector Assembly (RPDA), double check valve (DCV), or Double Check Valve Detector Assembly (DCDA).

a. To comply with the Cross-Connection Control Program, the following is a list of the required minimum types of backflow protection devices required to protect the potable water supply at the user's connection per the hazards identified. Each point of service shall be evaluated by the Cross Connection Control Specialist upon change of use and/or change of ownership of property to determine the actual or potential for hazards and required cross connection control methods to protect the water system. Evaluated connections may require protection above what is listed if determined by the Cross Connection Control Specialist. All backflow preventers shall be installed above grade.

i. Potable Water Service Connections. The type of backflow protection required for potable water service connections must be consistent with the degree of potential health hazard to the public water supply presented by hazards on a customer's premises. The higher the potential health hazard, the higher the required level of protection.

(A) Containment. The types of backflow protection that may be required for containment at connections to the public water system, listed according to increasing level of protection, are a double-check valve assembly (DC), reduced pressure principle backflow prevention assembly (RP), and air gap separation. The required levels of protection in the city are set forth in Table 1 of this section.

(B) Isolation. For isolation of a hazard within a property, the minimum level of backflow protection must be as set forth in the California Plumbing Code, except that an RP is required in the situations specified in Table 2 of this section.

(C) Auxiliary Water Systems. Potable water service connections to properties with onsite auxiliary water systems must have a containment RP at the point of connection to the public water system. In addition, if potable water is used as makeup water to an auxiliary water storage tank, an air gap is required.

(D) Air Gap Separation. An air gap is a physical break between a supply pipe and a receiving vessel. Air gaps can be fabricated from commercially available plumbing components or purchased as separate units and integrated into plumbing and piping systems, but they must be outside of the receiving vessel and able to be visually verified during inspection. Requirements for air gaps are set forth in the California Plumbing Code, Chapter 6, Section 603 and as follows:

(1) The outlet of a pipe and the top of the reservoir (overflow rim) or drain must have a vertical separation of at least twice the inner diameter (ID) of the pipe upstream of the air gap or one inch, whichever is greater.

(2) If the air gap is near a wall, where "near" is defined as less than three times the ID of the pipe, the vertical separation must be at least three times the ID of the pipe or one and one-half inches, whichever is greater.

(3) If the air gap is near a corner, where "near" is defined as less than four times the ID of the pipe away from intersecting walls, the vertical separation must be at least four times the ID of the pipe or two inches.

Table 1: Hazard Criteria and Required Backflow Protection for Containment Attention: See footnotes for important information.

Notes for Table 1:

Table 2: Hazard Criteria and Required Backflow Protection for Isolation of Hazards within a Property

6. Application to Install Backflow Prevention Assemblies. Prior to the installation of any backflow prevention assembly between the public water system and the owner's facility, the owner or contractor shall make application and receive approval from the Director of Utilities or their designated agent. Application forms are available from the Utilities Department.

7. All backflow prevention assemblies shall be tested immediately after they are installed, relocated or repaired and placed in service.

8. Any backflow prevention assembly, as defined herein, required under this Chapter shall be a model and size approved by the Director of Utilities or their designated agent. This means, at a minimum, the backflow prevention assembly:

a. Has been manufactured in full conformance with the latest revisions of the standards established by the American Water Works Association entitled "AWWA C511 Standards for Reduced-Pressure Principle Backflow Prevention Assembly & AWWA C510 Double Check-Valve Backflow Prevention Assembly"; and

b. Have completed the laboratory and field performance specifications of the Foundation for Cross-Connection Control and Hydraulic Research of the University of Southern California established by Specifications of Backflow Prevention Assemblies, Section 10 of the most current issue of the Manual of Cross-Connection Control.

Said AWWA and FCCC and HR standards and specifications have been adopted by the Director of Utilities. Final approval shall be evidenced by a "Certificate of Approval" issued by an approved testing laboratory certifying full compliance with the said AWWA standards and FCCC and HR specifications.

The following testing laboratory has been qualified by the Director of Utilities to test and certify backflow preventers:

Testing laboratories other than the laboratory listed above will be added to an approved list as they are qualified by the Director of Utilities.

Backflow preventers which may be subjected to backpressure or back siphonage that have been fully tested and have been granted a certificate of approval by said qualified laboratory and are listed on the laboratory's current list of "approved backflow prevention assemblies" may be used without further test or qualification.

9. The city shall perform annual inspections and operational tests at any premises where backflow prevention assemblies are installed on the service line for containment. Inspections may be more frequent for high hazards. These inspections and tests shall be at the expense of the water user. The customer/user shall be responsible for all repairs, maintenance, and replacement costs. Repairs shall occur within 30 days of written notice from the city, unless the Director of Utilities determines that an imminent hazard exists, in which case repairs or corrective action shall be required immediately. Records of such tests, repairs and overhaul shall be submitted in hard copy or digital form to the city and kept by the Director of Utilities or their designated agent.

10. All presently installed backflow prevention assemblies which do not meet the requirements of this section shall be replaced by an approved backflow prevention assembly meeting the requirements of this section at the expense of the customer/user. Replacement shall occur within 30 days of written notice from the city, unless the Director of Utilities determines that an imminent hazard exists, in which case replacement or corrective action shall be required immediately. Upon written request, the Director of Utilities may grant an extension of up to 90 days if the customer demonstrates good cause, such as verified supply chain or scheduling constraints.

(Ord. 2016, 3/24/2026)

The customer/user shall pay to the city the fee specified by council resolution for the testing and inspection of all backflow prevention devices required under the terms of this chapter, adjusted annually for inflation per the Consumer Price Index. The Director of Utilities may reduce fees in the event that unusual circumstances, not the fault of the user or owner, necessitate repeated inspection, or for low-income households or nonprofits.

(Ord. 2016, 3/24/2026)

A. All billing charges for installation of any backflow prevention assembly(ies) by the city or its designated agent(s) pursuant to this chapter shall be made by the city; all charges shall become delinquent 60 days after the billing date. Notices may be sent electronically.

B. If the bill remains unpaid after the date of delinquency, the city shall be entitled to a delinquency fee. However, the delinquency fee shall not be assessed until 15 days after notification of the delinquency to the property owner and the recipient of service. Delinquency fees shall be set by the city council by resolution.

C. Should the bill remain unpaid at the expiration of the 15 days, the Director of Utilities may initiate proceedings pursuant to Government Code Sections 54354, 54354.5 and 54355, to create a lien on the real property on which the backflow prevention assemblies were installed.

D. The lien will be officially recorded in the county recorder's office. The lien may carry such additional administrative charges as set forth by city council resolution. The property owner shall be notified by the director of Utilities that the delinquency charges and administrative charges and any administrative fees are due, and a lien has been recorded.

(Ord. 2016, 3/24/2026)