Fire Sprinkler Water Conservation
The Fire Sprinkler systems are a highly valuable component of fire protection and it is important that each system is maintained correctly and is fully operational in the event of a fire. Unfortunately, the regular maintenance of these systems does consume a significant amount of water, and sometimes more than is required.
There are several opportunities that have been identified which can dramatically reduce the wastage of valuable drinking water.
Initially a very low cost and easy to implement a solution are to adjust the pressure settings. This involves increasing the pressure relief valve to reduce the amount of water going down the drain during testing. This can be achieved at most pump boosted installations.
Most of the discussion around water conversation has been focused on switching weekly testing to monthly. In fact, it has been estimated that consumption could be cut by more than 50%.
Reducing pressures from pumps that over pressurise can bring significant reductions in the volume of water consumed by weekly testing of fire sprinkler systems. The recirculation of water drawn from a tank for the regular tests will impact considerably on water consumption. Implementing a tank with recirculation will be particularly effective when there are pressure relief valves in pumping systems and they discharge directly into drains.
The water used in the testing of Fire Sprinkler systems cannot be used due to the metals in the water calling this greywater.
Drain down consumption is certainly a significant opportunity to save water for Shopping Centres in particular where they have frequent refitting of tenancies. If a Shopping Centre has 50 fit-outs per year then on average the annual drain down consumption is approximately 600,000 liters.
There are certainly affordable initiatives available to reduce water consumption for Fire Sprinkler systems.
SYSTEM MAINTENANCE
Water-based fire suppression systems are normally closed systems. That is until the systems are called upon to react to fire. During a fire emergency, they are designed to consume a preset amount of water, over a specific amount of time. The best opportunity for conservation is the control of wastage through leaking underground piping, pressure relief valve operations, and water used for fire pump cooling. Despite being permissible by regulatory agencies, underground systems experiencing leaking not only waste treated water but can also lead to undermining and eventual pipe failure. Pipe failures create large water flows, property damage, and major impairments to protection systems. With some systems having thousands of feet of underground main, leakage from a pipe failure can be measured in tens of thousands of gallons and the high costs associated with repairing damages.
Pressure relief valves are designed to operate if a fire pump-supplied system produces pressure beyond that for which the system is designed. The valve is intended to open, drop the pressure, and then close, protecting system components from overpressure and possible component breakage. A faulty valve, or one improperly set, can operate for extended periods discharging large quantities of water and resulting in significant extraneous costs. Leading practices to improve system maintenance include:
Having regular recorded inspections of underground mains and sprinkler systems to identify leaks and making repairs immediately upon any being found.
Maintaining specialty sprinkler systems, such as dry pipe and pre-action systems, to a high degree of reliability. This will help avoid false activations that necessitate flushing and draining of the systems.
Adjusting pressure relief valves to avoid unneeded discharge.
TESTING
The testing of sprinkler system components is vital to ensure continued reliability and is required to meet local fire codes and insurer requirements. Most tests involve flowing limited quantities of water; however, in the case of annual fire pump flow tests, they can disperse thousands of gallons. To the uninformed, these tests may appear wasteful. Leading practices to improve water consumption during testing include:
Perform tests only when required based on applicable codes and insurer requirements.
Add maintenance to systems that have a history of test failures to avoid the likelihood of retesting.
Preplan tests so that water consumption is minimized.
Maintain tanks, service ponds, and reservoirs to minimize evaporation and leakage. Open sources should be covered and linings maintained. All check valves should be regularly serviced.
Conduct internal inspections of storage tanks using remote video cameras, ultrasonic technologies, or even qualified commercial scuba divers as opposed to the traditional drain and inspect method.
EQUIPMENT MODIFICATIONS
As noted above, regular maintenance and testing can prevent an inadvertent waste of water resources. There are also several equipment modifications that may conserve water and actually improve the reliability of the fire suppression systems.
The cost-effectiveness of the upgrade is dependent on the configuration of the system. One example is with sprinkler system water flow alarm tests. This type of test typically does not discharge significant quantities of water. However, in areas where even this discharge quantity needs to be controlled, there are innovations where circular flows can be arranged to test the flow detection device. This piping must be carefully designed and installed such that the intent of the jurisdictional authority and/or the insurance protocols are not compromised.
CATCH AND REUSE
Several communities and contractors are now providing services where they will capture the water from fire system tests and recycle it, leading to more potential cost savings. This service can take several forms:
Capturing fire pump test water involves one or more large tanker trucks or portable “ponds” as these tests discharge large quantities of water very quickly. Depending on the arrangement of the system, the captured water may be considered acceptable for use in cooling systems or other industrial uses but is not normally acceptable for human consumption.
Hydrant flushing is another test where innovations provide a means to avoid waste. Several companies provide a truck-mounted system where hydrant discharge is piped through a series of tanks and filters and actually reintroduced into the underground fire main system.
Sprinkler system test water is not potable, but if captured may have used as a “grey” water source. Uses may include irrigation and or introduction into a plant’s greywater system.
CONCLUSION
Implementing a combination of general-water-use and fire protection-water use conservation strategies can yield positive, long-term financial returns for organizations, whether or not they are in a resource-sensitive area. To maximize the return on such investments, typically companies conduct cost-benefit analyses of the various approaches to account for any additional costs or impact on their sites.
Our experts are prepared to assist clients with carrying out the necessary inspections and analyses if they are interested in exploring the possibility of improving water conservation at their facilities while maintaining reliable fire protection systems.
Our fire protection specialists can help you assess the risks at affected facilities and increase the confidence in your decisions regarding how best to manage your water usage through the entire life cycle of the protection system or building.
From designing systems to retro-fits, ensuring compliance and effective fire control, and all the way through building business cases for installation and longterm maintenance, our services help you maximize capital use and investment, leverage your water conservation efforts, and reduce fire risk to your business.