The purpose of this chapter is to protect the public water supply system from contamination due to potential and actual cross-connections. This shall be accomplished by the establishment of a cross-connection control program as required by State regulations. This chapter is adopted pursuant to Title 17, Section 7583—7605, inclusive, of the California Code of Regulations, entitled "Regulations Relating to Cross-Connections."
(Ord. 2002-01 § 1; Ord. 2020-01 § 1; Ord. 2022-06 § 1)
The cross-connection control specialist (Public Works) shall be responsible for implementing and enforcing the cross-connection control program. An appropriate backflow prevention assembly shall be installed by and at the expense of the water user at each user connection where required 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 City of Plymouth's requirements.
(Ord. 2002-01 § 1; Ord. 2020-01 § 1; Ord. 2022-06 § 1)
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. Unprotected cross-connections with the public water supply are prohibited. The type of backflow prevention assembly that may be required (listed in decreasing level of protection) includes: air-gap separation (AG), reduced pressure principle backflow prevention assembly (RP), double check valve assembly (DC), and a pressure vacuum breaker backflow prevention assembly (PVB). The water user may choose a higher level of protection than required by the City of Plymouth. The minimum types of backflow protection required to protect the approved water supply at the user's water connection to premises with varying degrees of hazard are listed in Table 1. Situations which are not covered in Table 1 shall be evaluated on a case-by-case basis and the appropriate backflow protection shall be determined by the water supplier or health agency.
Table 1
Type of Backflow Protection Required
Degree of Hazard
Minimum Type of Backflow Prevention
(a) Sewage and Hazardous Substances
 
(1) Premises where there are waste water 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 water supplier.
AG
(2) Premises where hazardous substances are handled in any manner in which the substances may enter 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 water supplier.
AG
(3) 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 or DC may be provided in lieu of an AG if approved by the health agency and water supplier.
AG
(2) Premises where there is an unapproved auxiliary water supply and there are no interconnections with the public water system. A DC may be provided in lieu of an RP if approved by the health agency and water supplier.
RP
(c) Recycled Water
 
(1) Premises where the public water system is used to supplement the recycled water supply.
 
(2) Premises where recycled water is used, other than allowed in paragraph (3), and there is no interconnection with the potable water system.
AG
(3) Residences using recycled water for landscape irrigation as part of an approved dual plumbed use area established pursuant to Sections 60313 through 60316 unless the recycled water supplier obtains approval of the local public water supplier, or the Department if the water supplier is also the supplier of the recycled water, to utilize an alternative backflow protection plan that includes an annual inspection and annual shutdown test of the recycled water and potable water systems pursuant to Section 60316(a).
DC
(d) 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).
DC
(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 water supplier.
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 private reservoirs or tanks are used.
DC
(4) Buildings where the fire system is supplied from the public water system and where recycled water is used in a separate piping system within the same building.
DC
(e) Dockside Watering Points and Marine Facilities
 
(1) Pier hydrants for supplying water to vessels for any purpose.
RP
(2) Premises where there are marine facilities.
RP
(f) Premises where entry is restricted so that inspection for cross-connections cannot be made with sufficient frequency or at sufficiently short notice to assure that they do not exist.
RP
(g) Premises where there is a repeated history of cross-connections being established or re-established.
RP
(h) Water Supply Inlets
 
(1) Water supply inlet to swimming pools or other receptors.
AG/RP/DC/PVB
(i) Premises Where There is a Swimming Pool
 
(1) Any property with an active connection to the public water system that has a constructed swimming pool on site shall have installed an RP located on the water service piping just after the City water meter. Hose bibs with built-in vacuum breakers may be installed as an option to the RP, on all exterior plumbing outlets on the premises providing subject pools meet all current City Standards and Building Codes.
 
(Ord. 2002-01 § 1; Ord. 2020-01 § 1; Ord. 2022-06 § 1)
Only backflow prevention assemblies which have been approved by the City of Plymouth 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 in a manner prescribed in Section 7603, Title 17. Location of the assemblies shall be as close as practical to the user's connection or as required by the currently adopted version of the California Plumbing Code. The City of Plymouth shall have the final authority in determining the required location of a backflow prevention assembly.
Testing of backflow assemblies shall be conducted only by qualified testers and 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. Testing of PVBs on swimming pool inlet lines and other receptors shall include verification that hose-bib type vacuum breakers are installed on all exterior hose bibs. More frequent testing may be required if deemed necessary by the City of Plymouth. 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 City of Plymouth prior to removing, relocating or replacing a backflow prevention assembly.
(Ord. 2002-01 § 1; Ord. 2020-01 § 1; Ord. 2022-06 § 1)
The cross-connection control program shall be administered by the cross-connection control specialist (Public Works or water supplier). The City of Plymouth will establish and maintain a list of approved backflow prevention assemblies as well as a list of approved backflow prevention assembly testers. The City of Plymouth shall conduct necessary surveys of water user premises to evaluate the degree of potential health hazards. The City of Plymouth shall notify users when an assembly needs to be tested. The notice shall contain the date when the test must be completed.
(Ord. 2002-01 § 1; Ord. 2020-01 § 1; Ord. 2022-06 § 1)
When the City of Plymouth 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 shall be instituted. Conditions or water uses that create a basis for water service termination shall include, but are not limited to, the following:
1. 
Refusal to install or to test a backflow prevention assembly, or to repair or replace a faulty backflow prevention assembly.
2. 
Direct or indirect connection between the public water system and a sewer line.
3. 
Unprotected direct or indirect connection between the public water system and a system or equipment containing contaminants.
4. 
Unprotected direct or indirect connection between the public water system and an auxiliary water system.
For conditions 2, 3, or 4, the City of Plymouth shall take the following steps:
1.
Make reasonable effort to advise the user of intent to terminate water service;
2.
Terminate water service and lock service valve. The water service shall remain inactive until correction of violations has been approved by the City of Plymouth.
(Ord. 2002-01 § 1; Ord. 2020-01 § 1; Ord. 2022-06 § 1)