The following conditions and problems shall be reviewed in all cases where the Water Department adopts a policy of requiring that the degree of hazard be based on a complete inspection of the consumer's water-using facilities. For convenience, these conditions have been divided into four groups. Section 290-8 lists plants or facilities where backflow protection will usually be required at the service connection.
The following are plants and facilities where backflow protection will usually be required at the service connection:
A. 
Auxiliary water systems.
B. 
Beverage bottling plants.
C. 
Breweries.
D. 
Buildings: hotels, apartment houses, public and private buildings or any other structures having actual or potential dangerous cross-connections.
E. 
Canneries, packing houses and reduction plants.
F. 
Chemical plants: manufacturing, processing, compounding or treatment.
G. 
Chemically contaminated water systems.
H. 
Dairies and cold storage plants.
I. 
Film laboratories.
J. 
Fire systems.
K. 
Hospitals, medical buildings, sanitariums, morgues, mortuaries, autopsy facilities, nursing and convalescent homes and clinics.
L. 
Irrigation systems, premises having separate, such as parks, playgrounds, cemeteries, golf courses, schools, estates, ranches, etc.
M. 
Laundries and dye works.
N. 
Metal manufacturing, cleaning, processing and fabricating plants.
O. 
Oil and gas production, storage or transmission properties.
P. 
Paper and paper products plants.
Q. 
Plating plants.
R. 
Radioactive materials or substances, plants or facilities handling.
S. 
Restricted, classified or other closed facilities.
T. 
Sand and gravel plants.
U. 
Schools and colleges.
V. 
Sewage and storm drain facilities.
A. 
Where protection is required - public water system.
(1) 
Each service connection from the public 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 Water Department and is approved by the Health Department.
(2) 
Each service connection from the public water system for supplying water to premises on which any substance is or may be handled in such a fashion as to permit introduction 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 process waters and waters originating from the public water supply system which have been subject to deterioration in sanitary quality.
(3) 
Backflow prevention devices shall be installed on the service connection to any premises that have internal cross-connections, unless such cross-connections are abated to the satisfaction of the Water Department.
(4) 
It shall be the responsibility of the water user to provide, test and maintain protective devices as required.
B. 
Type of protection. The protective device required shall depend on the degree of hazard. In determining the degree of hazard and the type of backflow prevention method to be used, the following criteria shall be adhered to:
(1) 
An air-gap separation or a reduced pressure principle backflow prevention device shall be used where there is an existing or potential health hazard. An air-gap shall be installed where practicable. Where it is impracticable, a reduced pressure principle backflow prevention device may be used as an alternative. Where the air-gap is used the tank shall be installed as close as practicable to the meter, and all piping between the meter and the receiving tank shall be entirely visible.
(2) 
A double check valve assembly or a reduced pressure principle backflow preventer device may be used where there is an existing or potential pollutional hazard.
(3) 
More specifically, the public water system shall be protected at the service connection as tabulated below:
(a) 
At the service connection to any premises where there is an auxiliary water supply handled in a separate piping system with no known or easily established cross-connection, the public water supply shall be protected by an approved double check valve assembly. When the auxiliary water supply may be contaminated an air-gap or an approved reduced pressure backflow prevention device shall be installed at the service connection.
(b) 
At the service connection to any premises on which a substance that would be objectionable but not hazardous to health if introduced into the public water supply is or may be handled so as to constitute a cross-connection, the public water supply shall be protected by an approved double check valve assembly or a reduced pressure principle backflow prevention device.
(c) 
At the service connection to any premise on which there is an auxiliary water supply where cross-connections are known to exist and where it is not practicable to eliminate such connections, the public water supply system shall be protected by an approved reduced pressure principle backflow prevention device.
(d) 
At the service connection to any premise on which any toxic substance or material dangerous to health is, or may be, handled in such manner as to permit its entry into the water system, the public water supply shall be protected with an approved reduced pressure principle backflow prevention device.
(e) 
At the service connection to any sewage treatment plant, sewage pumping station (including privately owned sewage pumping plants in buildings) or storm drain pumping station, the public water supply shall be protected with an approved reduced pressure principle backflow prevention device.
(f) 
At the service connection to a hospital, medical building, mortuary or other similar premise where the Health Department and/or the Water Department determines that a special hazard exists, the public water supply shall be protected by an approved reduced pressure principle backflow prevention device.
(g) 
At the service connection to premises where chemicals are manufactured or processed, the public water supply shall be protected with an approved reduced pressure principle backflow prevention device.
(h) 
At the service connection to a premise where a plating plant is operated and maintained, the public water supply shall be protected with an approved reduced pressure principle backflow prevention device.
(i) 
At the service connection to a premises where oils or gases are produced, developed or refined or are transmitted in a pipe line or where oil tank farms are maintained, including service to a property where an oil well is being drilled, developed, operated or maintained, the public water supply shall be protected with an approved reduced pressure principle backflow prevention device.
(j) 
At the service connection to a premises where a brewery is operated or maintained, the public water supply shall be protected with an approved reduced pressure principle backflow prevention device.
(k) 
At the service connection to a premises where there is maintained a cross-connection, the public water supply shall be protected with an approved reduced pressure principle backflow prevention device.
C. 
Qualification and certification of persons to inspect and maintain backflow prevention devices.
(1) 
No person shall be deemed qualified to inspect and maintain backflow prevention devices unless his qualifications have been established to the satisfaction of the Water Department as hereinafter required. To determine the qualifications of any person to inspect and maintain backflow prevention devices, the Water Department shall have the authority to conduct examinations to determine said qualifications. Upon successful completion of such examination and such training as the Water Department shall prescribe, the person so examined shall receive from the Water Department a certificate of competence. Any limitations or conditions imposed by the Water Department on the examinee in the inspection and maintenance of backflow prevention devices shall be stated upon the face of said certificate issued to the examinee. The Water Department shall make available to owners of properties on which backflow prevention devices are maintained, a list of persons qualified to inspect and maintain said devices. Every person, after receiving certificate of competence from the Water Department, shall be issued such identification as the department shall deem appropriate, and such identification shall be kept in the immediate possession of every person holding a certificate of competence while said person is inspecting or maintaining any backflow prevention device.
(2) 
Every person desiring to qualify to inspect or maintain backflow prevention devices shall make application to the Water Department. At the time of making application, every such person shall pay a fee of $25, which fee shall not be refundable. Said fee shall cover the expense of the Water Department in processing the applications, certificates of competence and any documents of identification required by the Water Department.
(3) 
Every person holding a certificate of competence issued by the Water Department under the provisions of this chapter shall be required to renew said certificate every three years. The requirement for reexamination may be waived at the discretion of the City Engineer.
(4) 
Every person receiving a certificate of competence under the provisions of this chapter shall be responsible for the competency and accuracy of all inspections and maintenance performed on any backflow prevention device by any person under his authority and control.
(5) 
Any person issued a certificate of competence who violates or fails to comply with any of the provisions of this chapter or willingly falsifies inspection or maintenance reports shall have said certificate immediately revoked and shall not be considered for recertification.
(6) 
The Water Department may, at the request of the user and the discretion of the City Engineer, make such tests or perform such installations and maintenance as may be necessary, for which the user shall pay the City the actual cost thereof, plus 10% administrative and overhead expenses.
D. 
Backflow prevention devices recommended for the prevention of cross-connection hazards.
(1) 
Nonpressure-type vacuum breakers may be used only as protection for direct or indirect water connections to all types of polluted or contaminated liquids where the vacuum breakers are not subjected to back pressures and are installed on the discharge side of the last control valve.
(2) 
Pressure-type vacuum breakers may be used only as protection for direct or indirect water connections to all types of polluted or contaminated liquids where the vacuum breakers are not subjected to back pressures. These units may be installed under continuous line pressure.
(3) 
Double check valve assemblies may be used as protection for all direct or indirect water connections through which foreign materials might enter the system in the form of concentration such as would constitute a nuisance or be aesthetically objectionable, such as steam, air, foods, beverages or other materials which do not constitute a health hazard.
(4) 
Reduced pressure principle devices may be used as protection for all direct or indirect water connections where such devices may be subject to back pressures from toxic, sewage or lethal substances.