A. 
The purpose of this chapter is:
1. 
To protect the public water supply against actual or potential cross-connection by isolating within the premises contamination that may occur because of some undiscovered or unauthorized cross-connection on the premises;
2. 
To eliminate existing connections between drinking water systems and other sources of water that are not approved as safe and potable for human consumption;
3. 
To eliminate cross-connections between drinking water systems and sources of contamination; and
4. 
To prevent the making of cross-connections in the future.
B. 
These regulations are adopted to comply with the requirements of the permit to operate a public water system issued to the Town by the State Water Resources Control Board (Water Board) related to cross-connection control and backflow prevention and the Cross-Connection Control Policy Handbook (CCCPH) adopted by the Water Board on December 19, 2023, which replaced previous regulations with an effective date of July 1, 2024.
C. 
No person shall at any time make or maintain or cause to be made or maintained, temporarily or permanently, any cross-connection between plumbing pipes or water fixtures being served with water by the Town water system and any other source of water supply or to maintain any sanitary fixture or other appurtenances or substances into the water system and/or the service of water pipes or fixtures of any consumer of the water system.
(Ord. 318-01; Ord. 25-537, 8/19/2025)
The following terms are defined for purposes of this chapter:
"Air-gap separation" or "AG"
means a physical vertical separation of at least two times the effective pipe diameter between the free-flowing discharge end of a potable water supply pipeline and the flood level of an open or non-pressurized receiving vessel, and in no case less than one inch.
"Approved water supply"
means a water source that has been approved by the State Water Board for domestic use in a public water system and designated as such in a domestic water supply permit issued pursuant to California Health and Safety Code Section 116525.
"Auxiliary supply"
means any water supply on or available to the premises other than the approved water supply.
"AWWA standard"
means an official standard developed and approved by the American Water Works Association (AWWA).
"Backflow"
means a flow condition, caused by a differential in pressure, that causes the flow of water or other liquids, gases, mixtures or substances into the distributing pipes of a potable supply of water from any source or sources other than an approved water supply source. Back-siphonage is one cause of backflow. Back pressure is the other cause.
"Backflow prevention assembly" or "BPA"
means 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.
"Backflow prevention device"
means devices which have passed laboratory and field evaluation tests performed by a recognized testing organization which has demonstrated its competency to perform such tests to the California Department of Health Services.
"Contamination"
means a degradation of the quality of the potable water by any foreign substance which creates a hazard to the public health or which may impair the usefulness or quality of the water.
"Cross-connection"
means any actual or potential connection or structural arrangement between a public water system, including a piping system connected to the public water system and located on the premises of a water user or available to the water user, and any source or distribution system containing liquid, gas, or other substances not from an approved water supply.
"Double check valve assembly" or "DC"
means an assembly consisting of two independently-acting internally-loaded check valves, with tightly closing shut-off valves located at each end of the assembly (upstream and downstream of the two check valves) and fitted with test cocks that enable accurate field testing of the assembly. This type of assembly may only be used to isolate low hazard cross-connections.
"Health agency"
refers to the California Department of Health Services, or the local agency with respect to a small water system.
"Local health agency"
refers to the Napa County Health Department and the Napa County Environmental Management Department.
"Premises"
means any and all areas on a customer's property which are served or have the potential to be served by the public water system.
"Public water system"
means a system for the provision of piped water to the public for human consumption which has five or more service connections or regularly serves an average of 25 individuals daily at least 60 days out of the year.
"Recycled water"
is a wastewater which as a result of treatment is suitable for uses other than potable use.
"Reduced pressure principle backflow prevention device" or "RP"
means an assembly with two independently acting internally-loaded check valves, with a hydraulically operating mechanically independent differential-pressure relief valve located between the check valves and below the upstream check valve. The assembly shall have shut-off valves located upstream and downstream of the two check-valves, and test cocks to enable accurate field testing of the assembly.
"Service connection"
refers to the point of connection of a user's piping to the water supplier's facilities.
"User supervisor"
means a person designated by a water user to oversee a water use site and responsible for the avoidance of cross-connections.
"Water supplier"
means the person who owns or operates the approved water supply system.
"Water user"
means any person obtaining water from an approved water supply system.
(Ord. 318-01; Ord. 25-537, 8/19/2025)
A. 
General Provisions.
1. 
Unprotected cross-connections with the public water supply are prohibited.
2. 
Whenever backflow protection has been found necessary, the Town will require the water user to install approved backflow prevention device by and at his or her expense for continued services or before a new service will be granted.
3. 
Wherever backflow protection has been found necessary on a water supply line entering a water user's premises, any and all water supply lines from the Town's mains entering such premises, buildings or structures shall be protected by an approved backflow prevention device. The type of device to be installed will be in accordance with the requirements of this division.
B. 
Where Protection is Required.
1. 
Each service connection from the Town water system for supplying water to 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 Town, and is approved by the public health agency having jurisdiction.
2. 
Each service connection from the Town water system for supplying water to any premises on which any substance is handled in such a fashion as may allow its entry into the water system shall be protected against backflow of the water from the premises into the public system. This shall include the handling of the process waters and waters originating from the Town water system which have been subjected to deterioration in sanitary quality.
3. 
Backflow prevention devices shall be installed on the service connection to any premises having: (a) internal cross-connection that cannot be permanently corrected and controlled to the satisfaction of the state or local health agencies and the Town, 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 device that may be required (listing in an increasing level of protection) includes: double check valve assembly (DC), reduced pressure principle backflow prevention device (RP), and an air-gap separation (AG). The water user may choose a higher level of protection than required by the Town. The minimum types of backflow protection required to protect the approved water supply at the user's water connection premises, with varying degrees of hazard, are given in the following table. Situations which are not covered in the following table shall be evaluated on a case by case basis and the appropriate backflow prevention shall be determined by the Town or Health Agency.
Type of Backflow Prevention Required
Degree of Hazard
Minimum Type of Backflow Prevention
A. Sewage and Hazardous Substances.
 
1. Premises where the public water system is used to supplement the reclaimed water supply.
AG
2. Premises where there are no 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. An RP may be provided in lieu of an AG if approved by the health agency and the Town.
AG
3. The 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 Town.
AG
4. 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 Town.
AG
5. Premises where there are irrigation systems into which fertilizers, herbicides, or pesticides are, or can be, injected.
RP
B. Auxiliary Water Supplies.
 
1. Premises where there is an unapproved auxiliary water supply which is interconnected with the public water system. An RP may be provided in lieu of an AG if approved by the health agency and the Town.
AG
2. Premises where there is an unapproved auxiliary water supply and there are no interconnections with the public water system.
RP
C. Fire Protection Systems.
 
1. Premises where the fire system is directly supplied from the public water system and there is an unapproved auxiliary water supply on or to the premises (not interconnected).
RP
2. Premises where the fire system is supplied from the public water system and interconnected with an unapproved auxiliary water supply. An RP may be provided in lieu of an AG if approved by the health agency and the Town.
AG
3. 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
D. 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
E. Premises where there is a repeated history of cross-connections being established or reestablished.
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 respective meters. Such check valve shall not be considered adequate if backflow prevention is deemed necessary to protect the Town's mains from pollution or contamination; in such cases the installation of approved backflow prevention devices at such service connections shall be required.
(Ord. 318-01; Ord. 25-537, 8/19/2025)
A. 
Backflow Prevention Devices.
1. 
Only backflow prevention devices which have been approved by the Town shall be acceptable for installation by a water user connected to the Town's potable water system.
2. 
The Town will provide a list of approved backflow prevention devices to any affected customer upon request.
B. 
Backflow Prevention Device Installation.
1. 
Backflow prevention devices shall be installed in a manner prescribed in the Cross-Connection Control Policy Handbook adopted by the State Water Resources Control Board. Location of the devices should be as close as practical to the user's connection. The Town shall have the final authority in determining the required location of a backflow prevention device.
a. 
Air-Gap Separation (AG). The air-gap separation shall be located on the user's side of and as close to the service connection as is practical. All piping from the service connection to the receiving tank shall be above grade and be entirely visible. No water use shall be provided from any point between the service connection and the air-gap separation. The water inlet piping shall terminate a distance of at least two pipe diameters of the supply inlet, but in no case less than one inch above the overflow rim of the receiving tank.
b. 
Reduced Pressure Principle Backflow Prevention Device (RP). The approved reduced pressure principle backflow prevention device shall be installed on the user's side of and as close to the service connection as is practical. The device shall be installed a minimum of 12 inches above grade and not more than 36 inches above grade measured from the bottom of the device and with a minimum of 12 inches side clearance. The device shall be installed so that it is readily accessible for maintenance and testing. Water supplied from any point between the service connection and the RP device shall be protected in a manner approved by the Town.
c. 
Double Check Valve Assembly (DC). The approved double check valve assembly shall be located as close as practical to the user's connection and shall be installed above grade, if possible, and in a manner where it is readily accessible for testing and maintenance. If a double check valve assembly is put below the grade it must be installed in a vault such that there is a minimum of six inches between the bottom of the vault and the bottom of the device, so that the top of the device is no more than a maximum of eight inches below grade, so there is a minimum of six inches of clearance between the side of the device with the test cocks and the side of the device and the side of the vault. Special consideration must be given to double check valve assemblies of the "Y" type. These devices must be installed on their "side" with the test cocks in a vertical position so that either check valve may be removed for service without removing the device. Vaults which do not have an integrated bottom must be placed on a three-inch layer of gravel.
C. 
Backflow Prevention Device Testing and Maintenance. The owners of any premises on which, or on account of which, backflow prevention devices are installed, shall have the devices tested by a person who is certified in accordance with state law. Backflow prevention devices must be tested at least annually and immediately after installation, relocation or repair. The Town may require a more frequent testing schedule if it is determined to be necessary. No device shall be placed back in service unless it is functioning as required. These devices shall be serviced, overhauled, or replaced whenever they are found to be defective and all costs of testing, repair, and maintenance shall be borne by the water user.
D. 
Backflow Prevention Device Removal.
1. 
Approval must be obtained from the Town before a backflow prevention device is removed, relocated, or replaced.
a. 
Removal. The use of a device may be discontinued and the device removed from service upon presentation of sufficient evidence to the Town to verify that a hazard no longer exists or is not likely to be created in the future.
b. 
Relocation. A device may be relocated following confirmation by the Town that the relocation will continue to provide the required protection and satisfy installation requirements. A retest will be required following the relocation of the device.
c. 
Repair. A device may be removed for repair, provided the water use is either discontinued until repair is completed and the device is returned to service, or the service connection is equipped with other backflow protection approved by the Town.
d. 
Replacement. A device may be removed and replaced provided the water use is disconnected until the replacement device is installed. All replacement devices must be approved by the Town and must be commensurate with the degree of hazard involved.
(Ord. 318-01; Ord. 25-537, 8/19/2025)
At each premises where it is necessary, in the opinion of the Town, a user supervisor shall be designated by and at the expense of the water user. This user supervisor shall be responsible for the monitoring of the backflow prevention devices and for avoidance of cross-connection. In the event of contamination or pollution of the drinking water system due to a cross-connection on the premises, the Town shall be promptly notified by the user supervisor so that appropriate measures may be taken to overcome the contamination. The water user shall inform the Town of the user supervisor's identity on, as a minimum, an annual basis and whenever a change occurs.
(Ord. 318-01)
A. 
Water System Survey.
1. 
The Town shall review all requests for new services to determine if backflow prevention is needed. Plans and specifications must be submitted to the Town upon request for review of possible cross-connection hazards as a condition of service for new service connections. If it is determined that a backflow prevention device is necessary to protect the public water system, the required device must be installed before service will be granted.
2. 
The Town may require an on-premises inspection to evaluate cross-connection hazards. The Town will transmit a written notice requesting an inspection appointment to each affected water user. Any customer which cannot or will not allow an on-premises inspection of his or her piping system shall be required to install the backflow prevention device the Town considers necessary.
3. 
The Town may, at its discretion, require a reinspection for cross-connection hazards of any premises to which it serves water. The Town will transmit a written notice requesting an inspection appointment to each affected water user. Any customer which cannot or will not allow an on-premises inspection of their piping system shall be required to install the backflow prevention device the Town considers necessary.
B. 
Customer Notification—Device Installation.
1. 
The Town will notify the water user of the survey findings, listing corrective action to be taken if required. A period of 60 days will be given to complete all corrective action required, including installation of backflow devices.
2. 
A second notice will be sent to each water user which does not take the required corrective action prescribed in the first notice within the 60-day period allowed. The second notice will give the water user a two-week period to take the required corrective action. If no action is taken within the two-week period, the Town may terminate water service to the affected water user until the required corrective actions are taken.
C. 
Customer Notification—Testing and Maintenance.
1. 
The Town will notify each affected water user when it is time for the backflow prevention device installed on their service connection to be tested. This written notice shall give the water user 30 days to have the device tested.
2. 
A second notice shall be sent to each water user which does not have his or her backflow prevention device tested as prescribed in the first notice within the 30-day period allowed. The second notice will give the water user a four-week period to have their backflow prevention device tested.
3. 
If no action is taken within the four-week period, they will receive a third notification advising of a two-week period to complete the testing of the backflow prevention device. If no action is taken, a fourth notice will provide a one-week period where the user will be notified by door hanger of pending water termination. The Town will terminate the water service to the affected water user until the subject device is tested.
(Ord. 318-01; Ord. 25-537, 8/19/2025)
A. 
In General. When the Town encounters water uses that represent a clear and immediate hazard to the potable water supply and that cannot be immediately abated, the Town shall institute the procedure for discontinuing the Town service.
B. 
Basis for Termination. Conditions or water uses that create a basis for water service termination shall include, but are not limited to, the following items:
1. 
Refusal to install a required backflow prevention device;
2. 
Refusal to test a backflow prevention device;
3. 
Refusal to repair a faulty backflow prevention device;
4. 
Refusal to replace a faulty backflow prevention device;
5. 
Direct or indirect connection between the public water system and a sewer line;
6. 
Unprotected direct or indirect connection between the public water system and a system or equipment containing contaminants;
7. 
Unprotected direct or indirect connection between the public water system and an auxiliary water system; or
8. 
A situation which presents an immediate health hazard to the public water system.
C. 
Water Service Termination Procedures.
1. 
For conditions in subsection (B)(1), (B)(2), (B)(3) or (B)(4), the Town will terminate service to a customer's premises after two written notices have been sent specifying the corrective action needed and the time period in which it must be done. If no action is taken within the allowed time period, water service may be terminated.
2. 
For conditions in subsection (B)(5), (B)(6), (B)(7) or (B)(8), the Town will take the following steps:
a. 
Make reasonable effort to advise water user of intent to terminate water service; and
b. 
Terminate water supply and lock service valve. The water service will remain inactive until correction of violations has been approved by the Town.
(Ord. 318-01)