Backflow Prevention & Pretreatment

Cross-Connection Control Program



The City of Flagstaff’s distribution system is designed to keep safe drinking water flowing to you, the customer. However, when hydraulic conditions deviate from “normal,” flow can reverse and contaminants can enter the water distribution system. The City maintains a Cross-Connection Control Program to prevent contaminants and pollutants from entering everyone’s water supply. If your business has been identified as one that requires a backflow prevention assembly, the City will typically require it to be located as close to the service connection or meter as possible. In some cases, the City may determine that installing a backflow prevention assembly in a different location is an option; however, you will be required to submit a Hold Harmless Agreement.

All backflow prevention assemblies must be tested and certified operational before water is turned on to the customer. They must also be tested annually to ensure that they are operating within their designed parameters.

As of March 15, 2012, you must enter all backflow reports through BSI Online. The City no longer receives backflow reports directly. Testers can phone BSI Online at (800) 414-4990 or visit bsionlinetracking.com to learn how to set up an account to enter results.

Links and Downloads


For information on the City’s Cross-Connection Control Program, variances, and Hold Harmless Agreements, contact James Boyer at (928) 213-2117.

Pretreatment Program



The Industrial Pretreatment Program manages the monitoring of the City’s wastewater collection system and the permitting of industrial and commercial discharges into the sewer system. Its goal is to ensure compliance with local, state, and federal-mandated pretreatment regulations and to prevent noncompatible pollutants and contaminants from entering the City’s sewer system and water reclamation plants (WRPs).

For information on the City’s Industrial Pretreatment Program, variances, and Hold Harmless Agreements, contact James Boyer at (928) 213-2117.

Septage, Grease, and River Can Haulers

The City maintains loading stations for grease and septage at the Wildcat Hill WRP. Loads are accepted at specific times during the work week. Note that dumping these wastes into the City’s collection system is prohibited.

Drying Beds for Car Wash Mudsump Wastes

The Wildcat Hill WRP has drying beds to accept car-wash interceptor wastewater and laundry-lint interceptor waste. All car wash interceptor loads must be inspected by the Industrial Pretreatment Program prior to pumping to insure that the material is acceptable for disposal. Contact James Boyer at (928) 213-2117 to schedule an inspection. If the material is acceptable for disposal, the Industrial Waste Section will generate an approval letter that the hauler and/or business owner can submit to the staff at the Wildcat Hill WRP. No waste can be accepted without the inspection and approval letter.

Please call the Wildcat Hill WRP at (928) 526-2520 for information and hours.

Links and Resources