| Question: 14-12 | Code Section: 7 | Date: 17 September 2014 | OBC 2012 Reference: 7.6.2.6 |
Question Submitted:
7.6.2.6. Premise Isolation
(1) Buildings or facilities where a moderate hazard or severe hazard may be caused by backflow shall be provided with premise isolation of the potable water system by the installation of a backflow preventer selected in accordance with Clauses 5.3.4.2. (b) And (c) of CSA B64.10, “Selection and Installation of Backflow Preventers”.
Does this clause require a premise isolation to be installed on the main water supply (unmetered) for a building (office administration/maintenance bldg.), classified as a Group D occupancy containing a F2 occupancy within it. The F2 is a welding shop and a fork lift storage area. No vehicle repairs to be completed inside. The kicker is that this building is supplied with potable water by a well on property and not a municipality supplied system. Please indicate type of device required for degree of hazard if any.
Interpretation:
There are possibly 2 answers to this question since it is unclear if this is (1) an existing building or (2) a newly constructed building. We will deal with both scenarios.
1. If this is an existing building: 7.6.2.6.(1) could not be enforced as there is no jurisdiction to apply the code if construction has taken place, inspected and approved previously. Typically an older building the city may have a Cross Connection Control Program which will allow them to enforce their program, be it “premise isolation” only or a “full program”. An older building on a well is not governed by a municipal purveyor but would be regulated by the Board of Health (BOH)
2. If this is a newly constructed building or one undergoing extensive renovation where a building permit has been issued, 7.6.2.6.(1) would be enforceable. What must be kept in mind is that Sentence 7.6.2.6.(1) of the Building Code only requires a building where a moderate hazard or severe hazard may be caused by backflow, to be provided with premise isolation of the potable water system by the installation of a backflow preventer selected in accordance with Clauses 5.3.4.2. (b) and (c) of CSA B64.10 Although the well construction and water quality are governed by the BOH, if the well water is being used as the primary source of potable water supply for human consumption within the building, the premise isolation requirement is still applicable.
A DCVA may suffice, but more likely it will require an RP.