A firewater system is a dedicated, independent pressurized water supply and distribution network designed exclusively to provide a reliable and adequate supply of water to all fixed fire suppression systems, fire hydrants, and hose reels located throughout a mine or processing facility. The firewater system is designed, constructed, and maintained to recognized international engineering standards and is completely separate from the plant's process water and potable water systems to ensure its availability is not compromised by normal plant operational demands.
The firewater system at a mine typically comprises one or more dedicated firewater storage reservoirs with sufficient capacity to sustain the maximum calculated fire demand for a specified duration, typically two to four hours, without replenishment. Firewater storage may be provided in above-ground steel tanks, reinforced concrete reservoirs, or excavated and lined dams, depending on the site topography and available land. The storage volume is calculated based on the simultaneous demand from the largest single fire area requiring suppression, including allowance for hose stream flows at surrounding hydrants.
Firewater pumping stations comprise duty and standby pumps, typically electric-motor-driven centrifugal pumps with diesel-engine-driven backup pumps to ensure operation during power failures. The pumping system maintains a minimum residual pressure at the most hydraulically remote hydrant or suppression system outlet, typically in the range of 7 to 10 bar. Jockey pumps maintain system pressure between fire events and detect system leaks.
The firewater ring main or grid distribution piping network is designed and pressure-tested to NFPA 24 or equivalent standards, with isolation valves, pressure relief valves, drain points, and pressure gauges installed at regular intervals to allow system sectioning for maintenance without impairing protection to the remainder of the site. Regular firewater system flow tests, pump tests, and infrastructure inspections are required to verify and document continued system performance and regulatory compliance.