Why Testing Waterflow Switches Is Important for Fire Systems

Make sure waterflow switch testing passes compliance.

When is there too much water? Depending on where you conduct business you may have come across the issue of not being allowed to flow water from a water-based fire suppression system if it would lead to a river, creek, estuary, storm drain system or other water channel. This includes the water that would be produced from opening either an inspector test valve or main drain valve. The same issue could apply if part of your business is to test fire pumps or private main systems. For this article, I will limit the discussion to just the testing of waterflow switches; but understand that the same points raised would apply to the other tests and systems noted above.

The Clean Water Act became a federal law in 1972. Its formal name is the Federal Water Pollution Control Act, and within it are mandated requirements to reduce pollutants that may enter the nation’s water system. Over the years, one source of polluted water has been identified as sprinkler system water. The concern is primarily with chlorides that reside within the water.

MS4 Requirements May Constrain Testing

Throughout the nation there are municipal separate storm sewer systems, also known as MS4. These are generally controlled by municipalities, counties, flood control districts and road and transportation departments.

Through the U.S. Environmental Protection Agency, MS4 permits are issued to the local agencies or departments that control storm water. The MS4 permits require these agencies or departments to legally ban and prevent all illicit discharges of nonstorm water from entering their MS4.

This is where the testing of a waterflow switch can come into conflict with the requirements that may be within a MS4 permit. The standard of care for the testing of waterflow switches that may be connected to an automatic fire alarm system is outlined in NFPA 72, National Fire Alarm and Signaling Code. Within Chapter 14 – Inspection, Testing and Maintenance – of the 2013 edition is this requirement in Table

Mechanical, electrosonic, or pressure-type waterflow device. Water shall be flowed through an inspector’s test connection indicating the flow of water equal to that from a single sprinkler of the smallest orifice size installed on the system for wet-pipe systems, or an alarm test bypass connection for dry-pipe, pre-action, or deluge systems in accordance with NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems.

Thus the dilemma: NFPA 72 and 25 state to flow water from the water-based fire suppression system, but the MS4 permit issued to a particular agency may restrict water from entering into the storm water system. As a fire alarm service provider, you need to be aware of the local requirements for the discharge of water from a water-based suppression system, and the acceptable methods of mitigation. These include, but are not limited to:

  1. Having the water flow through a dechlorinator
  2. Ensuring the flow does not cause erosion
  3. Directing the flow to a landscaped or green area
  4. Directing the flow into a large paved area that has no storm drains and allowing the water to evaporate
  5. Protecting any storm drains that water may flow toward with wattles, sand bags, booms or barricades
  6. Having a vacuum truck or wet/dry vacuum to remove any water about to reach an open storm drain
  7. Flowing the water into a portable tank, which can then be transported to a waste deposal site for proper release
  8. When practicable and allowed, diverting the water into the waste sewer system

In all cases, the direction of the flow path should be determined before the valve is open so the proper mitigation measures may be put into place.

Protect the Environment, Plus Your Wallet

Why is this important? Beyond the protection the environment, the Clean Water Act allows for fines in excess of $30,000 for violations. By knowing the local requirements and working with the agencies that regulate the discharge of water into the storm drains you can avoid a potentially hefty penalty. The MS4s are not there to prevent the testing of water-based fire protection systems, but they are charged with the protection of the environment. Dutiful fire alarm service providers can help ensure that both efforts coexist.

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About the Author


Shane Clary, Ph.D., is Security Sales & Integration’s “Fire Side Chat” columnist. He has more than 37 years of security and fire alarm industry experience. He serves on a number of NFPA technical committees, and is vice president of Codes and Standards Compliance for Pancheco, Calif.-based Bay Alarm Co.

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