5 minute read
Trucked water supply for fire protection in the Canadian arctic
By Bianca Bocancea, Chris Keung, and Cam Marianayagam, EXP | Arctic
Fire truck and portable storage basin in Kingait, Nunavut.
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Fire protection must be reliable and accessible in the harsh and remote conditions of the Arctic. Most Arctic communities do not have piped water distribution systems and therefore rely on trucks to deliver water from a water source to provide fire protection for the community. The promptness and reliability of a trucked water supply for fighting fires has been a continuing concern for communities in the Arctic.
Typically, community water trucks modified with a dump valve are used to deliver water from the water supply to the scene of a fire. At the fire scene, a portable tank is set up and the water trucks shuttle back and forth from the water supply to the scene of the fire to refill the portable tank. The fire truck then draws water from the tank to fight the fire.
When a community’s water treatment system is being designed, the most efficient route for getting water to fires in the community needs to be taken into account. One of the considerations is whether moving the water treatment plant, where the trucks will be filled, should be moved closer to the community to improve the firefighting response time.
When a fire happens, time passes between the initial fire alert, the alarm sounding, the fire fighters getting to the fire hall and into their gear, and the fire truck leaving the firehall. This process taking 10 minutes or longer would not be out of the ordinary. While there are several variables at play (e.g., what caused the fire to ignite, the type and age of the building and its materials, and travel time from the firehall to the fire), what often happens is that by the time the fire truck arrives at the fire, it’s often too late to save the building and attention turns to preventing the spread of the fire to adjacent buildings.
When analyzing the process of providing fire protection, an important factor that must be considered is the potential for interruptions in the water supply. One of the main concerns with moving a water treatment plant away from a water source and closer to the community is the introduction of the need for a water pipeline. Having a pipeline introduces the significant risk of the line freezing and the potential for prolonged interruptions in water supply.
Effective fire response is highly dependent on whether the water trucks are full and available to begin moving water in the community at the time of the initial response to a fire. One of the recommendations of the 1993 NWT Fire Protection Study, prepared by the Government of the Northwest Territories, was to keep water delivery trucks full during off-delivery hours and stored in the community parking garage or fire hall. During the hours when water trucks are delivering water in the community, increasing the total number of on-duty water trucks and putting schedules in place and ensuring they are adhered to can improve the likelihood that the water trucks are staggered effectively so that there are trucks with full tanks available in the community at all times for fire emergencies.
When considering the design requirements for water treatment plants for fire protection, the 2017 NWT Good Engineering Practice for Northern Water and Sewer Systems guidelines say there should be a minimum storage volume of 60 cubic metres to provide sufficient water for firefighting purposes.
Alternatively, a raw water bypass can be provided at the water treatment
plant to reduce the need for additional onsite storage and heating of water for firefighting purposes. The raw water bypass allows operators to connect the trucks directly to the submersible intake pumps at the treatment plant, thereby bypassing the treatment process and the truckfill pumps. The intake pumps must be adequately sized. The recommended minimum emergency bypass rate is 1,000 litres per minute, or the peak day design flow for the water treatment plant if it exceeds 1,000 litres per minute. Typically, chlorine is still added when filling water trucks using a raw water bypass to fill with water for firefighting. Specific operational procedures and care must be taken to ensure the water trucks are emptied of all raw water intended for firefighting and disinfected after a fire response event so untreated water is not delivered to the community.
If all water for firefighting is obtained from truckfill stations (and the raw water bypass was not used), a standby emergency power generator is necessary. An additional injection point must be put in place and used at the truckfill station to facilitate chlorination.
Due to the large number of factors complicating the adequate and timely supply of water during response to a fire, the community could consider passive measures such as using fire-resistant building materials, public education on the importance of smoke alarms, sprinkler systems where possible, and increasing the space between buildings, to name a few. These options were discussed at length in the 1993 NWT Fire Protection Study.
Each of the Canadian Arctic territories has a position for a person with authority to make decisions about these matters. This person is generally referred to as the Territorial Fire Marshal. The preferences of communities for their individual community firefighting processes and equipment requirement should always be confirmed with the Territorial Fire Marshall of the given territory before their preferences are put into place. S
Due to the large number of factors complicating the adequate and timely supply of water during response to a fire, the community could consider passive measures such as using fire-resistant building materials, public education on the importance of smoke alarms, sprinkler systems where possible, and increasing the space between buildings, to name a few.
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