Which Tolleson businesses need a backflow assembly?

Subsection (A) sets the floor: "An approved backflow preventive assembly of the type specified in this section shall be the minimum installation of each service connection, (whether from a fire hydrant, temporary, regular or other water service connection) to the following type of premises or systems." A table follows. Each row is a type of premises, and a mark under one of four columns (double check, reduced pressure, air gap, pressure vacuum breaker) says which assembly is the minimum.

"Minimum" is the important word: the table sets a floor. Subsection (B) has a second, shorter table for fire protection systems, which this page does not cover.

Per the table as published on Municode, nearly every row is marked reduced pressure (RP). Exceptions: buildings with house pumps or potable water storage carry both DC and RP marks, and water trucks and hydraulic sewer cleaning equipment carry both RP and air gap.

• Service connection: the code does not define it. The ordinary reading is the point where the premises' water line connects to the public system. The section says it applies whether the connection is from a fire hydrant, temporary or regular.
• The Department: Section 10-7-1 defines it as "The Building Department" of the city, which holds enforcement authority for the program.
• Approved: under Article 10-7, accepted by the Department as meeting the specification in the article and suitable for the proposed use.
• Premises over three stories or 34 feet: the table's wording. The code does not say how the height is measured.

The user. The code does not define that word, and the ordinary reading is whoever takes water service at the connection. The user pays: Section 10-7-3 says each required assembly "shall be installed by and at the expense of the user." That can fall on a tenant or on the owner depending on the lease. The table only reaches premises on its list. A single-family home is not named in it. Irrigation systems with non-potable piping one inch and larger, and irrigation systems with separate systems, are.

A food manufacturer in an industrial park. Food processing is listed, so the service connection gets an RP assembly.

A restaurant in a strip center. The table has no restaurant row, so 10-7-5 does not name it. The restaurant is still caught by the Tolleson amendment to IPC 608.17.1.1: "The water supply connection to each carbonated beverage dispenser shall be protected by a Reduced Pressure Principal Backflow Assembly." Any other cross-connection in the kitchen falls under the "any premises where a cross-connection is maintained" row.

The edge case: a dental office. Medical and dental buildings are listed, so the table marks an RP at the service connection for a dental tenant moving into a space. In Youngtown the same type of building is marked DC.

1. 1Find your business type in the table. If it is not there, check the cross-connection row and the carbonated beverage amendment.
2. 2Look at Section 10-7-4 before you pick a spot: assemblies go "at the service connection or near the property line" before the first branch line, in a location the Department approves.
3. 3Show the assembly on the building and engineering plans. Section 10-7-4 says approval is obtained before building or engineering permits are issued.
4. 4Contact Development Services at DevelopmentServices@tolleson.az.gov or City Hall Customer Service at 623-936-7111.
5. 5Plan the install. An RP goes above ground, and the code bars installing assemblies "less than 12 inches or more than 24 inches above grade level" except as it provides, with no bypass around them.
6. 6Book the first test and inspection before the certificate of occupancy. See the companion page on Tolleson testing.

• Assuming restaurants are exempt because they are not listed. The soda dispenser rule and the cross-connection row still apply.
• Assuming the table is a wish list. It is the minimum. The Department can require more.
• Reading a neighbor city's table as Tolleson's. Glendale marks shopping centers DC where Tolleson marks them RP, and Youngtown marks food processing DC.
• Skipping the retrofit rule. Section 10-7-10 says an assembly that does not meet current standards must be retrofitted if the Department determines it.

The rule is Tolleson City Code 10-7-5 on Municode. This page explains it and does not replace the city's own answer. HQ tests and repairs domestic backflow assemblies.