§ 6-145. Cross-connection control and backflow prevention.

(a)

The purpose of this section is to protect the public potable water supplied by the department from the possibility of contamination or pollution by isolating within the customer's internal distribution system or the customer's private water system such contaminants or pollutants which could backflow into the public water system. This section also provides for the maintenance of a continuing program of cross-connection control with a goal to systematically and effectively prevent the contamination or pollution of the city's water system by containment.

(b)

In this section:

(1)

Air-gap 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 (overflow) rim of such vessel. An approved air-gap shall be at least double the diameter of the supply pipe, measured vertically, above the top of the overflow rim of the vessel; and in no case less than one (1) inch.

(2)

Approved means accepted by the superintendent as meeting and applicable specification stated or cited in this section, or as suitable for the proposed use.

(3)

Approved tester means a person accepted by the superintendent who has appropriate training and equipment for performing tests on backflow prevention devices.

(4)

Auxiliary water supply means any water supply on or available to the premises other than the purveyor's approved public water supply. These auxiliary waters may include water from another purveyor's public potable water supply or any natural source 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.

(5)

Backflow means the reversal of the normal flow of water caused by either back-pressure or back-siphonage.

(6)

Backflow preventer means a device or means designed to prevent backflow.

(7)

Back pressure 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.

(8)

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

(9)

City means the city and/or the water and sewer department.

(10)

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.

(11)

Cross-connection means any physical connection or arrangement of piping or fixtures between two (2) otherwise separate piping systems one (1) of which contains potable water and the other nonpotable water 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 sections of pipe, swivel or changeover devices or sliding multipart tube.

(12)

Cross-connections, controlled means a connection between a potable water system and a nonpotable water system with an approved backflow prevention device properly installed and maintained so that it will continuously afford the protection commensurate with the degree of hazard.

(13)

Cross-connection control by containment means any of the following:

a.

The installation of one (1) approved backflow prevention device at the water service connection to any customer's premises where it is physically and economically infeasible to find and permanently eliminate or control any or all actual or potential cross-connections within the customer's water system.

b.

The installation of an approved backflow prevention device on the service line leading to and supplying a portion of a customer's water system where there are actual or potential cross-connections, within the customer's premises which cannot be effectively eliminated or controlled at the point of the cross-connection.

(14)

Department means the water and sewer department.

(15)

Double check valve assembly means an assembly of two (2) independently operating approved check valves with tightly closing shutoff 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 of a recognized and approved testing agency for backflow prevention assemblies. To be approved these devices must be readily accessible for in-line testing and maintenance.

(15A)

Dual check valve assembly means an assembly consisting of two (2) independent and internally loaded check valves. Each check valve shall be drip tight in the normal direction of flow and shall permit no leakage in the direction reverse to normal flow under all conditions of pressure differential. The backflow preventer shall meet the requirements of the ASSE 1024 standards.

(16)

Hazard, degree of 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.

(17)

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

(18)

Hazard, pollutional means an actual or potential threat to the physical properties of the water system 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 the health of the water consumer.

(19)

Hazard, system means an actual or potential threat of severe damage to the physical properties of the public potable water system of 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.

(20)

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 or pollutional 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 alkalies, 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 wells, springs, streams, rivers, bays, harbors, seas, irrigation canals or systems, etc., oils, gases, glycerine, paraffins, caustic and acid solutions and other liquid and gaseous fluids used in industrial or other purposes or for firefighting purposes.

(21)

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 water's domestic use.

(22)

Reduced pressure principle device means an assembly of two (2) independently acting approved check valves together with a hydraulically operating, mechanically independent 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 shutoff 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 approved testing agency for backflow prevention assemblies. The assembly shall operate to maintain the pressure in the zone between the two (2) check valves at an acceptable level less than the pressure on the public water supply side of the device. At cessation of normal flow the pressure between the two (2) 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 (2) pounds per square inch or less, the relief valve shall open to the atmosphere. To be approved these devices must be readily accessible for in-line testing and maintenance and be installed in a location where no part of the device will be submerged.

(23)

Superintendent means the superintendent of the department, who 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 section.

(24)

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

(25)

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

(26)

Water purveyor means a supplier of water.

(27)

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 backflow prevention device located at the point of delivery to the customer's water system. Service connection 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.

(28)

Water system means the department system and the customer system. The department 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 department, up to the point where the customer's system begins. The source shall include all components of the facilities used 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. The customer's system shall include those parts of the facilities beyond the termination of the department distribution system which are used in conveying department-delivered domestic water to points of use.

(29)

Water, used means any water supplied by a water purveyor from a public potable water system to a consumer's water system after it has passed through the point of delivery and is no longer under the sanitary control of the water purveyor.

Cross reference— Definitions and rules of construction generally, § 1-2.

(c)

The superintendent 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 public potable water service connection. If, in the judgment of the superintendent an approved backflow prevention device is required at the customer's water service connection, the superintendent or his designated agent shall give notice in writing to the customer to install such an approved backflow prevention device at his service connection. The customer shall immediately install such approved device at his own expense. Failure, refusal or inability on the part of the customer to install, have tested and maintain the device shall constitute grounds for discontinuing water service to the premises until such requirements have been satisfactorily met.

(d)

Pursuant to subsection (c), the following requirements are part of the departments policy for protection of the water supply:

(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 laws and regulation and this section. Service of water to any premises shall be discontinued by the water purveyor if a backflow prevention device required by this section is not installed, tested and maintained, at the customer's expense, or if it is found that a backflow prevention device has been removed, or bypassed. Service will not be restored until such conditions or defects are corrected.

(2)

The customer's system shall be open for inspection at all reasonable times to authorized representatives of the department to determine whether cross-connections or other structural or sanitary hazards, including violations of these regulations, exist. When such a condition becomes known, the superintendent or his designated agent shall give notice in writing to such customer to install such an approved backflow prevention device at his service connection.

(3)

An approved backflow prevention device shall also be installed, at the customer's expense, on each service line to a customer's water system at or near the property line or immediately inside the building being served; but, in all cases, before the first branch line leading off the service line wherever the following conditions exist:

a.

In the case of premises having an auxiliary water supply which is not or may not be of safe bacteriological or chemical quality and which is not acceptable as an additional source by the superintendent the public water system shall be protected against backflow from the premises by installing an approved backflow prevention device in the service line appropriate to the degree of hazard, at the customer's expense.

b.

In the case of premises on which any industrial fluids or any other objectionable substance is handled in such a fashion as to create an actual or potential hazard to the public water system, the public system shall be protected against backflow from the premises by installing an approved backflow prevention device in the service line appropriate to the degree of hazard, at the expense of the owner of the premises. This shall include the handling of process waters and waters originating from the utility system which have been subject to deterioration in quality.

c.

In the case of premises having internal cross-connections that cannot be permanently corrected and controlled, or 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 device in the service line, at the expense of the owner of the premises.

d.

Any service connection two (2) inches or larger in diameter.

(4)

The type of protective device required under paragraph (3) shall depend upon the degree of hazard which exists as follows:

a.

In the case of any premises where there is an auxiliary water supply as stated in paragraph (3) of this subsection and it is not subject to any of the following rules, the public water system shall be protected by an approved air-gap separation or an approved reduced pressure principle backflow prevention device, at the expense of the owner of the premises.

b.

In the case of any premises where there is water or substance that would be objectionable but not hazardous to health, if introduced into the public water system, the public water system shall be protected by an approved double check valve assembly, at the expenses of the owner of the premises.

In addition, dual check valves shall be required in all low hazard residential units and single low hazard offices.

c.

In the case of any premises where there is any material dangerous to health which is handled in such a fashion as to create an actual or potential hazard to the public water system, the public water system shall be protected by an approved air-gap separation or an approved reduced pressure principle backflow prevention device, at the expense of the owner of the premises. Examples of premises where these conditions will exist include sewage treatment plants, sewage pumping stations, chemical manufacturing plants, hospitals, mortuaries and plating plants.

d.

In the case of any premises where there are uncontrolled cross-connections, either actual or potential, the public water system shall be protected by an approved air-gap separation or an approved reduced pressure principle backflow prevention device at the service connection, at the expense of the owner of the premises.

e.

In the case of any premises where, because of security requirements or other prohibitions or restrictions, it is impossible or impractical to make a complete in-plant cross-connection survey, the public water system shall be protected against backflow from the premises by either an approved air-gap separation or an approved reduced pressure principle backflow prevention device on each service to the premises, at the expense of the owner of the premises.

(5)

Any backflow prevention device required herein shall be a model and size approved by the superintendent. "Approved backflow prevention device" means a device that has been manufactured in full conformance with the standards established by the American Water Works Association entitled "AWWA C506-78 Standards for Reduced Pressure Principle and Double Check Valve Backflow Prevention Devices," and has met completely the laboratory and field performance specifications of the Foundation for Cross-Connection Control and Hydraulic Research of the University of Southern California established by the publication "Specifications of Backflow Prevention Devices - #69-2", dated March, 1969 or the most current issue thereof.

(6)

The customer shall install an approved thermal expansion relief device in his water system whenever a backflow prevention device is installed.

(7)

All testable backflow prevention devices shall be tested annually by the department or an approved tester, at the expense of the customer, and all non-testable dual check valves are to be replaced every ten (10) years.

(8)

Reduced pressure backflow prevention devices shall be installed in such a manner as to prevent submergence of the device. Pit installations are prohibited.

(Ord. No. 17-88, §§ I—IV, 6-16-88; Ord. No. 02-03, 2-6-03; Ord. No. 03-03, 2-6-03; Ord. No. 58-03, §§ 1, 2, 11-20-03)