To protect the public potable water supply from the possibility of contamination or pollution through backflow or back-siphon of contaminants or pollutants into the public water system, the following regulations are established. In addition to those terms defined in the Uniform Plumbing Code adopted for the purpose of this article, the following terms shall hereby be defined to mean:

(a)   Air Gap is a physical separation between a supply and receptor, of at least twice the supply outlet diameter, but never less than one inch.

(b)   Backflow is the unwanted reverse flow of water, other liquids, gases, mixtures, or other substances into the distributing pipes of a potable water supply from any source or sources. For specific conditions of backflow, see back-siphon age and back-pressure.

(c)   Backflow Preventer, Reduced Pressure Principle Type is an assembly of two internally loaded, specifically designed, and independently operated check values including an intermediate relief valve specially designed to maintain a zone of reduced pressure between these check valves, with an automatically opened spillage port to the atmosphere. This assembly is also incomplete without tightly closing, resilient seating shut-off valves immediately upstream and downstream of the device (i.e., ball valve shut-offs or resilient wedge gate valves).

(d)   Back-Pressure is pressure in a plumbing system higher than the supply pressure, which causes a reversal of flow. (Examples: pumps or thermal expansion from boilers).

(e)   Back-Siphon age is a backflow resulting from negative or sub-atmospheric pressures in the distributing pipes of a potable water supply.

(f)   Barometric Loop is a loop of pipe raising at least 35 feet, at its top-most point, above the highest fixture it supplies.

(g)   Contaminant is any substance that, upon entering potable water supply, would render it a danger to life and health, as determined by the health officer.

(h)   Cross Connection is any physical connection or arrangement between two otherwise separate piping systems, one of which contains potable water, and the other of which contains water of unknown or questionable safety, or stream, gases or chemicals, where there may be flow from one system to the other. (Note - No physical cross-connection shall be permitted between public and private water distribution systems without prior approval of the director of water and sewer, and protection by an approved backflow prevention device.)

(i)    Director is the director of water and sewer for the city or his or her designated representative.

(j)    Double Check Valve Assembly is a device consisting of two independently acting, internally loaded soft-seated check valves with resilient seated, positive shut-off valves (ball valve or resilient wedge gate valves) on both upstream and downstream ends, and properly located test ports.

(k)   Free Water Surface is a water surface that is at atmospheric pressure.

(l)    Plumbing is the practice, materials and fixtures used in the installation, maintenance, extension and alteration of all piping fixtures, appliances and appurtenances in connection with any of the following: Sanitary drainage, venting system, storm drainage facilities, and the on-site water supply systems, within or beyond the supply point to any building, structure or conveyance; also, the practice and materials used in the installation, maintenance, extension or alteration of storm water, liquid waste or sewage, and water supply systems of any premises to their connection with any point of public disposal or other acceptable terminal.

(m)  Pollutant is any foreign substance (organic, inorganic, radiological or biological) in water that tends to degrade its quality, but does not constitute a health hazard, as determined by the health office.

(n)   Pressure Vacuum Breaker is a device consisting of both upstream and downstream resilient seated shut-off valves, and at least one tight seating check valve with a relief zone to atmosphere. The valve member opening to atmosphere shall be spring loaded to open under continuous pressure.

(o)   Type R means general residential dwelling unit classification or district.

(p)   Vacuum is any absolute pressure less than that exerted by the atmosphere.

(q)   Vacuum Breaker is a device that permits air into a water supply distribution line to prevent back-siphon age.

The potable water supply system of the city and the potable water system of private users shall be designed, installed and maintained to best prevent contamination or pollution by no potable liquids, solids or gases from being introduced into the potable water supply through cross-connections or any other piping connections to the system. All public or private users being supplied city water directly or indirectly shall conform to standards set by the city.

Connections to the potable water supply system for the following is prohibited unless protected against backflow:

(a)   Bidets.

(b)   Operating, dissection, embalming and mortuary tables or similar equipment. In such installation the hose connected to the public water supply shall terminate at least 12 inches away from every point of the table or attachments.

(c)   Pumps for no potable water, chemicals or other substances. Priming connections shall be made through an air gap or an approved reduced pressure principle assembly.

(d)   Building drainage, sewer or vent systems.

(e)   Commercial buildings or industrial plants using a contamination or polluting substance.

(f)   Any other fixture of similar hazard.

Except when potable water provided for a refrigerator condenser or cooling jacket is entirely outside the piping or tank containing a toxic refrigerant, the inlet connection shall be provided with an approved backflow preventer. Heat exchanges used to heat water for portable purposes shall be of the double wall type.

Before any device for the prevention of backflow or back-siphon age is installed, a recognized testing laboratory first shall have certified it. Devices installed in a building potable water resupply distribution system for protection against backflow shall be maintained in good working condition by the person responsible for the maintenance of the system.

Devices for the prevention of backflow shall be installed as follows:

(a)   Atmospheric Vacuum Breakers. Atmospheric vacuum breakers shall be installed with the critical level at least six inches above the flood level rim of the fixture they serve and on the discharge side of the last control valve to the fixture. No shutoff valve or faucet shall be installed beyond an atmospheric vacuum breaker.

(b)   Pressure Vacuum Breakers. Pressure vacuum breakers shall be installed with the critical level at least 12 inches above the flood level rim but may have control valves downstream of the vacuum breaker.

(c)   Reduced Pressure Principle Backflow Preventer. A reduced pressure principle type backflow preventer may be installed subject to full static pressure.

(d)   Devices of All Types. Backflow and back-siphon age preventing devices shall be accessible located, preferably in the same room with the fixture they serve. Installation in the utility or service spaces, provided they are readily accessible, is also permitted. No installation shall be made in pits or any other location not properly drained.

(e)   Installers. The installation, repair or replacement of a reduced pressure principle assembly, double check valve assembly, or pressure vacuum breaker shall be by a certified technician or licensed plumber.

(a)   Installation. Approved devices to protect against backflow or back-siphon age shall be installed at all fixtures and equipment where backflow or back-siphon age may occur and where a minimum air gap cannot be provided between the water outlet to the fixture or equipment and its flood-level rim.

(b)   Connections not Subject to Backpressure. Where a water connection is not subject to backpressure, an atmospheric vacuum breaker shall be installed on the discharge side of the last valve on the line serving the fixture or equipment.

It shall be the responsibility of building and premise owners to maintain all backflow preventers and vacuum breakers within the building or on the premises in good working order, and to make no piping or other arrangements for the purpose of bypassing or removing backflow devices.

The director of the water department may refuse to deliver water through pipes and mains to any premises where a condition exists which might lead to the contamination of the public water supply system, and may continue to refuse the delivery of water to the premises until the condition is remodeled.

If the director determines that the condition of the plumbing constitutes an extreme hazard to the potable water supply, the director shall notify the owner of the premises as to the hazardous condition. Immediate action, within 24 hours, to correct the condition shall be taken or water service will be shut off until that condition no longer exists. In the event of any addition, repair, replacement or alterations are made to such plumbing, other than routine maintenance, the entire system shall be brought into compliance with provisions of this article.

All automatic fire suppression systems of 30 hours or more, or having a fire department connection, other than dry systems, shall be protected from backflow with an approved double check valve assembly. Backflow preventers shall be no smaller than the line size of the underground lead. Any fire suppression system into which chemicals of any type (corrosion, anti-freeze, etc.) can be added shall be protected at the service connection with an approved reduced pressure principle assembly. In lieu of such protection, an anti-freeze loop may be individually protected with an approved reduced pressure principle assembly, in addition to proper service line protection. All existing fire suppression systems shall be retrofitted within five years of the passage of their requirements to meet the requirements provided herein.

Any corporation, railway, common carrier, company or individual violating any of the cross-connection provisions of sections 14-201 through 14-211, inclusive, is guilty of a misdemeanor and, upon conviction, shall be punished by a fine not to exceed $500 or by imprisonment of not more than six months, or by both such fine and imprisonment. Each day any violation hereof is found to exist or continues to exist shall be a separate offense and punishable as such hereunder