Hi Kirk,
Here is the current City Standard and Code requirements:
5.0040 - BACKFLOW PREVENTION
Back flow prevention devices shall be required on all 1-1/2" and larger water services as provided for in
Oregon Administrative Rules, Chapter 333, and as directed by the Public Works Director.
When a backflow device is needed, I am directing all businesses or multi-living facilities to install new backflow devices in a vault at the meter with in the right-of-way or provide an easement for access. We do not have a current standard drawing, however I have include a simple sketch to better explain what we are looking for.
In addition, once the design is complete plans and specifications must be submitted the City for review. Please let me know if you have additional questions.
Below are City Code requirements for the approved devices and installation there of:
13.04.276 Approved devices and installation thereof—Methods of backflow prevention required.
A. New Assemblies. All backflow prevention assemblies required under this policy shall be of a type and model approved by the Oregon Health Division, and shall be installed in accordance with Oregon Administrative Rules 333-61-071 Sections (1) through (4), as now existing or later amended. Suitable pressure-relieve devices to prevent damage from thermal expansion shall be required in conjunction with the installation of all new backflow prevention assemblies.
B. Existing Assemblies. Backflow prevention assemblies installed before the adoption of the policy and which were approved by the Oregon Health Division at the time they were installed, but are not on the current list of approved assemblies, shall be permitted to remain in service provided they are properly maintained, are commensurate with the degree of hazard, are tested at least annually, and perform satisfactorily. When assemblies of this type are moved, or require more than minimum maintenance or are on services that are modified, changed size or remodeled, they shall be replaced by assemblies, which are on the Health Division list of approved assemblies.
C. Methods Required. The method of backflow prevention required under this policy shall at a minimum be commensurate with the degree of hazard which exists, and not less than the following:
1. When the substance which could backflow could be hazardous to health, an approved air gap of at least twice the inside diameter, but not less than one inch, of the incoming supply line measured vertically above the top rim of the vessel shall be installed, or an approved reduced pressure backflow (RPBA) assembly shall be installed.
2. When the substance, which could backflow, is objectionable but does not pose an unreasonable risk health, an approved double check valve assembly (DCVA) shall be installed. An approved double check valve assembly shall be the minimum protection for fire sprinkler systems using piping material that is not approved for potable water use and/or which does not provide for periodic flow through during each 24-hour period.
3. An approved pressure vacuum breaker assembly (PVBA) or an atmospheric vacuum breaker (AVB) shall be installed where the substance which could backflow is objectionable but does not pose an unreasonable risk to health and where there is no possibility of backpressure in the downstream piping. A shutoff valve may be installed on the line downstream of a pressure vacuum breaker but shall not be installed downstream of an atmospheric vacuum breaker. (Ord. 2002-02 §11)
Best Regards,
Jennifer Cline, P.E. | Public Works Director
Licensed in OR, WA
117 N Molalla Ave. | PO Box 248 * |Molalla, OR 97038
O: 503.759.0218 | F: 503.829.3676
