Built to Spill
Why some of the ITM requirements in NFPA 25 call for the discharge of water, even in time of drought. BY MATT KLAUS
MANY PARTS OF THE UNITED STATES, particularly California and the Southwest, have experienced drought conditions for some time now. A significant lack of rain, combined with a reduced winter snowpack at higher elevations, mean the water levels of many lakes, rivers, and reservoirs are at all-time lows. There seems to be no end in sight, and the scarcity has led to increased scrutiny of practices where water is being used excessively or not being conserved as efficiently as possible.
One of the areas flagged is water usage as part of an inspection, testing, and maintenance (ITM) program for mechanical building systems, including fire sprinklers. Many states have adopted NFPA 25, Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, as the ITM standard for water-based systems, either through law or by reference through a building or fire code. NFPA 25, as a mechanism to confirm that systems are in proper working order, often requires ITM service providers or building owners to discharge water onto the ground. While the majority of the ITM activities in NFPA 25 do not require the discharge of water, there are some system features and characteristics that cannot be adequately assessed without flowing water—even in a time of drought.
The tests that have been scrutinized recently as “water wasters” are the annual fire pump flow test, the forward flow test for backflow preventers, and the main drain test. While these tests require a considerable amount of water to be flowed, they are vital to ensuring that the sprinkler system and its water supply (in the case of the pump test) will be available when called upon. The NFPA 25 technical committee is aware of concerns over water usage, specifically with these activities, and has provided guidance over the last few revision cycles to assist with limiting the amount of water discharged on the ground.
For the main drain test, the committee has been clear that this is not a system demand test, but rather a test to make a pressure comparison and to make sure valves are open. As such, they recommend only leaving the main drain valve open until the flow is stabilized and residual pressure can be recorded. Many technicians and building owners will leave the valve open for excessive amounts of time as they calculate and confirm the demand flow rate, but this practice can waste thousands, or tens of thousands, of gallons of water each time a main drain test is conducted.
For the pump flow test requirement, the technical committee has provided an option to allow for closed-loop, metered tests to be conducted every two out of three years as a means for completing the test. By exercising this option, building owners can save tens of thousands of gallons of water each time the test is conducted. Similarly, the technical committee added language to the annex for the backflow preventer test, saying that “closed-loop flow can be acceptable if a flowmeter or sight glass [a component that allows for the visual confirmation of flowing water] is incorporated into the system to ensure flow.”
The technical committee has already taken steps to provide options for limiting water usage and continues to address the problem. At the close of the Second Draft meeting for the 2017 edition of the standard, the technical committee established a water usage task group to further study ways that the standard can address these concerns as they arise. The task group will submit a request to the Fire Protection Research Foundation to compile water usage literature and data, with the intent of using this information to support changes to the standard for the 2020 edition.