Article II

The purpose of the cross-connection control program ("program") is to protect the public water supply system from contamination due to potential or actual cross-connections and is established pursuant to California Health and Safety Code Section 116375 and the regulations relating to cross-connection control with-in the California Code of Regulations. (Ord. 1176 § 4, 2013)

"Air-gap separation" means a physical vertical separation between the free flowing discharge end of a potable water supply pipeline and an open or non-pressurized receiving vessel.

"Approved water supply" means a water source that has been approved by the department for domestic use and designated as such in a domestic water supply permit, pursuant to Section 64254.

"Auxiliary water supply" means any source of water that does not meet the definition in Section 64750.12 that is either used, or equipped to be used, as a water supply and located on, or piped to, the premises of a water user. (The term "equipped" in this definition means that appurtenances such as inactive wells, pumps, power supply, intakes, suction lines, pipelines, connection fittings, or storage tanks are in place and readily available for use.)

"Backflow" means a reversal of flow caused by differential pressure in which any liquid, gas, or other substance enters the public water system.

"Backflow prevention assembly" means a device intended to prevent backflow.

"Cross-connection" means any actual or potential unprotected connection or structural arrangement between a public water system, or a piping system connected to the public water system and located on the premises of a water user, and any source or distribution system containing liquid, gas, or other substances not from an approved water supply.

"Cross-connection control program specialist" means a person who is certified as a crossconnection control program specialist by the California-Nevada Section of the American Water Works Association or an organization with equivalent certification requirements.

"Double check valve assembly" means two independently-acting, internally-loaded, check valves with shut-off valves located upstream and downstream of the two check valves, and test cocks to enable field testing.

"Premises" means the property under the ownership or control of the water user and served, or capable of being served, with water via a service connection with the public water system.

"Pressure vacuum breaker assembly" means the combination of an independently-acting, internally-loaded check valve and an independently-acting loaded air inlet valve located on its discharge side, with test cocks and shutoff valves attached at each end of the combination.

"Reduced pressure principle assembly" means two independently-acting, internally-loaded check valves with an automatic differential-pressure relief valve located between, shut-off valves located upstream and downstream of the two check-valves, and test cocks to enable field testing.

"User's service connection" means the point of connection of a water user's piping to the public water system.

"Water supplier" means any person who owns or operates a public water system. A water supplier shall be responsible for protecting the public water system from backflow by complying with the requirements of the Public Health Department.

"Water user" means any person that is authorized to receive water from the public water system. (Ord. 1176 § 4, 2013)

The Inyo County public works director ("director") shall be responsible for implementing and enforcing the cross-connection control program. The director or designee shall assess the degree of potential health hazard to the public water supply to determine if the installation of a backflow protector is necessary to prevent cross-connection. Such assessment shall be made in accordance with the criteria below and shall include a survey of the water system to identify those connections from which cross-connection is likely to occur and may comprise an initial field and/or office assessment of the premises within its service area.

• A. The assessment shall consider:

  1. The existence of actual or potential cross-connections;

  2. The type and use of materials handled;

  3. The degree of piping system complexity and accessibility;

  4. The probability of a backflow occurring; and

  5. The potential for piping system modification.

• B. Subsequent to the initial assessment described in subsection A, the community water system shall:

  1. Conduct an assessment of the premises of each new water user connected to the public water system; and

  2. Re-evaluate the premises of an existing water user if changes within the water user's premises or any backflow incidents occur.

• C. Each hazard assessment shall be performed by the director or designee, unless the department approves an alternative based on its review of system size, types of water users, treatment, distribution system, and any previous hazard assessment. Special consideration shall be given to the premises of the following types of water users:

  1. Premises where substances harmful to health are handled under pressure in a manner which could permit their entry into the public water system. This includes chemical or biological process waters and water from public water supplies which have deteriorated in sanitary quality.

  2. Premises having an auxiliary water supply, unless the auxiliary supply is accepted as an additional source by the water supplier and is approved by the health agency.

  3. Premises that have internal cross-connections that are not abated to the satisfaction of the water supplier or the health agency.

  4. Premises where cross-connections are likely to occur and entry is restricted so that cross-connection inspections cannot be made with sufficient frequency or at sufficiently short notice to assure that cross-connections do not exist.

  5. Premises having a repeated history of cross-connections being established or reestablished.

  6. Premises using recycled water or graywater.

• D. The water supplier shall not be responsible for the abatement of cross-connections which exist within a user's premises.

After such evaluation, an appropriate backflow prevention assembly shall be installed by and at the expense of the property owner (also referred to herein as water user) at each user connection where required by the director or designee to prevent backflow from the water user's premises to the domestic water system. It shall be the water user's responsibility to comply with the requirements of the program.

(Ord. 1176 § 4, 2013)

The type of protection that shall be provided to prevent backflow into the public water supply system shall be commensurate with the degree of hazard, actual or potential, that exists on the water user's premises, as determined by the director or designee. Unprotected cross-connections with the public water supply are prohibited. The director or designee shall determine the type of backflow prevention assembly that may be required, which may include one of the following (listed in decreasing level of protection): air-gap separation (AG), reduced pressure principle backflow prevention assembly (RP), and a double check valve assembly (DC). For roadway right-of-way irrigation systems where there is no potential for backpressure, such as roadway right-of-way irrigation systems, a pressure vacuum breaker assembly shall be considered more protective than a double check valve assembly. If more than one of the hazard criteria applies to the premises of a water user, the criteria requiring the greatest degree of protection shall apply. The water user may choose a higher level of protection than required by the director or designee. The minimum types of backflow protection to premises with varying degrees of hazard are listed 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 protection shall be determined by the director or designee or the health agency as defined in Section 4.18.150.

Text read from an image; its layout may differ:
Hazard Required Level of Protection
(1) Auxiliary Water Supplies
(A) Auxiliary supply that is interconnected with a piping Air gap separation
system connected to the public water system (PWS)
(B) Auxiliary supply that is not interconnected with a Reduced pressure principle
piping system connected to the PWS and has piped water
conveyed under pressure in a piping system less than 200
feet from the piping system connected to the PWS
(2) Fire Protection Systems

Text read from an image; its layout may differ:
Hazard Required Level of Protection
(A) Fire protection system interconnected with a piping Air gap separation
system connected to the PWS and an onsite auxiliary water
supply for fire fighting
(B) Fire protection system supplied by the PWS with an Reduced pressure principle
interconnection to on-site storage facilities and pumps, or
combined fire and industrial water
(3) Marina or Port Facilities
(A) Residential Reduced pressure principle
(B) Nonresidential Reduced pressure principle
(4) Premises with Multiple Service Connections to the Reduced pressure principle
PWS
(5) Recycled Water
(A) Recycled water supply system that is:
1. Interconnected to a piping system connected to the Air gap separation
public water supply system (PWSS) that contains water
received from a PWS
2. Not interconnected to a piping system that contains Reduced pressure principle
water received from a PWS
(B) Recycled water supply used only for landscape
irrigation in an approved dual-plumbed use area established
pursuant to Sections 60313 through 60316, which is used
for:
1. Individually owned residential units Double check valve
2. Sites other than individually owned residential units Reduced pressure principle
(6) Graywater (see graywater definition in Section
14876 of the California Water Code)
A system that produces, or collects and distributes,
graywater, and is:
1. Interconnected to a piping system connected to the Air gap separation
PWSS
2. Not interconnected to a piping system connected to the Reduced pressure principle
PWSS
(7) Sewage and Hazardous or Potentially Hazardous
Substances
(A) Wastewater treatment processes, handling and/or Air gap separation
pumping equipment interconnected to a piping system
connected to the PWS

Text read from an image; its layout may differ:
Hazard Required Level of Protection
(B) Wastewater treatment processes, handling and/or Air gap separation
pumping equipment not interconnected to a piping system
connected to the PWS, except that no backflow protection
is required for a single-family residence that has a sewage
lift pump unless there are other hazards present on the
property
(C) Premises handling a substance in any manner in which Air gap separation
the substance may enter a piping system connected to the
PWS
(D) Recreational vehicle dump station that is not Reduced pressure principle
interconnected to a piping system connected to the PWS
(E) Piped irrigation system interconnected to a piping Reduced pressure principle
system connected to the PWS, into which fertilizers,
herbicides, or pesticides are, or are intended to be, injected
into the irrigation water
(F) Piping system conveying a fluid not from an approved
water supply that is:
1. Interconnected to a piping system connected to the Air gap separation
PWS
2. Not interconnected to a piping system connected to the Reduced pressure principle
PWS
(8) Roadway Right-of-Way Irrigation System Pressure vacuum breaker
Interconnected to a Piping System Connected to the
PWS, and There is No Potential for Back Pressure
(9) Water Storage Facility not Under Control of the Air gap separation
PWS

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 protection is deemed necessary to protect the town water systems from pollution or contamination; in such cases the installation of approved backflow devices at such service connections shall be required. (Ord. 1176 § 4, 2013)

Only backflow prevention assemblies which have been approved by the director or designee shall be acceptable for installation by a water user. A list of approved backflow prevention assemblies will be provided upon request to any affected customer. Backflow prevention assemblies shall be installed according to the criteria set forth below. Location of the assemblies shall be as close as practical to the user's connection. The director or designee shall have the final authority in determining the required location of a backflow prevention assembly.

• A. For air-gaps, the following shall apply:

  1. The receiving water container shall be located on the water user's premises at the water user's service connection unless an alternate location has been approved by the water supplier.

  2. All piping between the water user's service connection and the discharge location of the receiving water container shall be above finished grade and be accessible for visual inspection unless an alternative piping configuration is approved by the water supplier.

  3. The water supplier shall ensure that the air-gap specified in Section 64760(a) has been installed.

• B. A reduced pressure principle backflow prevention assembly shall be installed such that the lowest point of the assembly is a minimum of twelve inches, and a maximum of thirty-six inches, above finished grade, unless an alternative is approved by the water supplier.

• C. A pressure vacuum breaker assembly shall be installed a minimum of twelve inches above all downstream piping.

• D. A reduced pressure principle or double check valve backflow prevention assembly installed after July 1, 2013 shall have a minimum side clearance of twelve inches, except that a minimum side clearance of twenty-four inches shall be provided on the side of the assembly that contains the test cocks.

• E. Backflow protection shall be located at the water user's service connection unless one or more alternative locations have been approved by the water supplier. The water supplier shall obtain access to the water user's premises and shall ensure that the on-site protection meets the requirements of this chapter for installation, testing and inspections.

• F. Each backflow prevention assembly and air gap separation shall be accessible for field testing and maintenance.

All required field testing shall be performed by persons who are currently certified in the testing of backflow prevention assemblies by the California-Nevada Section of the American Water Works Association, the American Backflow Prevention Association, University of Southern California Foundation for Cross Connection Control and Hydraulic Research, California Rural Water Association, or other certifying agency approved by the director or designee. Testing will be the responsibility of the water user. Backflow prevention assemblies must be tested at least annually and immediately after installation, relocation or repair. More frequent testing may be required if deemed necessary by the director or designee. No assembly shall be placed back in service unless it is functioning as required. These assemblies 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. Approval must be obtained from the director or designee prior to removing, relocating or replacing a backflow prevention assembly.

(Ord. 1176 § 4, 2013)

The cross-connection control program shall be administered by the director. Inyo County public works shall assure that a minimum of one person is trained in cross-connection control for purposes of implementing the cross-connection control program. Inyo County public works will establish and maintain a list of approved backflow prevention assemblies as well as a list of approved backflow prevention assembly testers. The director or designee shall conduct necessary surveys of the premises to evaluate the degree of potential health hazards. Inyo County public works shall notify users when an assembly needs to be tested. The notice shall contain the date when the test must be completed. Inyo County public works shall maintain records of the locations, testing and repairs of backflow preventers. (Ord. 1176 § 4, 2013)

When the director or designee encounters water uses that represent a clear and immediate hazard to the potable water supply that cannot be immediately abated, the procedure for terminating water service set forth in Title 4 of the Inyo County Code, including, but not limited to, Section 4.10.130, shall apply. Conditions or water issues that create a basis for water service termination shall include, but are not limited to, the following:

• A. Customer service lateral broken providing hydraulic continuity between water in the service lateral and the immediate surroundings external to the lateral.

• B. Refusal to install or test a backflow prevention assembly, or to repair or replace a faulty backflow prevention assembly.

• C. Direct or indirect connection between the public water system and a sewer line.

• D. Unprotected direct or indirect connection between the public water system and a system or equipment containing contaminants.

• E. Unprotected direct or indirect connection between the public water system and an auxiliary water system.

• (Ord. 1176 § 4, 2013)