Rural water supply
By Joey Cherpin
Considerations for rural water supply and attack technique
By Joey Cherpin
I had the misfortune of running my first fatal structure fire about a year and a half before writing this. The fatalities that day were not a direct result of action or inaction of the department, but it gave me a sick feeling that even if we were closer, the outcome may not have been different. Since that call, I have done tremendous amounts of research and implemented a large number of small operational and equipment changes in my department in rural Saskatchewan. I would like to share the information I learned to help educate others who may also feel ‘stuck’. I know that I am not the only one who has had a bad call, nor will I be the last.
Many departments accept the reality of not being able to save every house that burns in rural settings. Sometimes that is the outcome even when we truly do the best we possibly can. Many organizations, and even the one I come from, struggle to avoid the ‘doing the best we can’ mantra, and in doing so do not look to create much change. The largest reason for this inaction that I have observed is an educational division between outdated tactics and updated research. Fire service members may preach about modern synthetic combustibles, lightweight construction, open concepts, and the apparent dangers of such, but don’t adjust accordingly. With respect to prevention, education, and code writers, fire fighting is largely a reactive organization. It’s time to react!
It can be difficult to keep up with the frequent updates in the fire service and change may feel overwhelming. Perhaps some small, simple changes may have more impact than you might think.
Water supply and application is the foremost critical issue with fires in areas lacking hydrants or other pressurized sources. It is imperative to know that water flow requirements correlate to fire heat release rate (HRR), square footage, occupancy type, content loading and percentage of involvement. In the rural setting, with an often naturally delayed response (on call personnel and/or long responses), fires are able to grow to a larger level of involvement, requiring increased water supply and rates of flow. Gallons per minute (GPM) as a measurement of water flow is the critical measurement relating to combatting and defeating the HHR. Insufficient flow rates provide no support in extinguishing a fire. It is critical to find a balance point of adequate water flow and sustained water flow. If we restrict the GPM because we only have so much water, then all of the water may be wasted. On the flip side, if we choose to use a 1250 GPM deck gun with 1000 gallons on board and no water on route, we may make a significant knock on the fire, but lack the ability to complete the extinguishment.
It is important to know the difference between heat release rate and temperature. Ten candles burning side by side all burn at the same temperature as a single candle, however the 10 candles will have 10 times the heat release rate of a single candle. Synthetic materials such as plastics release more energy per pound of solid fuel than natural combustibles like paper, and wood. When we look at the increased heat release rates, we must also consider a correlating increase in flow requirements to absorb the heat. (A Quantitative Approach to Selecting Nozzle Flow Rate and Stream, Part 1 in Fire Engineering,).
With regard to the fact that departments vary in size, structure, and equipment, the National Fire Protection Association (NFPA) Standards 1410 and 1710 both call for the first two handlines on a fire (residential) to flow a combined 300 GPM. Although the standard 1710 was created for career departments, fire behaves the same regardless of boundaries, so we must consider similar tactics. Based on the standard mentioned, the commonly accepted practice in the fire service is to flow no less than 150 GPM on any handline. These flows are designated because modern furnishings have a far higher HRR, which is conducive to a need for higher flow rates. Paper has a HRR of around 7,000 British thermal units/ pound (BTU/lb). Wood has a slightly higher HRR at 10,000 BTU/lb, and plastics can be as high as 22,000 BTU/lb, which is comparable to gasoline, as reported on risklogic.com/plastics/ in 2020. Simply put, if we cannot produce enough water to both control HRR and reduce temperatures in the room, then we are not accomplishing what we need to.
Around my home in Saskatchewan especially, residential structure fires in a rural setting are at a point of heavily involved or partially involved upon our arrival. Generally an exterior attack that is defensive in nature is the common approach. This approach has become instinctual, pushing members away from making an interior attack when it is permitted. Directly applying water to the seat of the fire through either form of attack is the most efficient way to use water. It minimizes total water consumption, increases occupant survivability, and increases firefighter safety., as noted in the text Impact of Fire Attack Utilizing Interior and Exterior Streams on Firefighter Safety and Occupant Survival: Full Scale Experiments.
Fire fighter safety is increased by minimizing total work time on a fire scene and removing heat output. Close to 50 per cent of firefighter fatalities are cardiac related from exertion (apps.usfa.fema.gov/firefighter-fatalities/fatalityData/incidentDataReport). Statistically, firefighters are more likely to be killed on the exterior or following a long fire event than working inside a structure fire. Faster fire suppression means shorter working time, less exertion, and in turn decreases the likelihood of a cardiac event.
The number one job of the fire service is to save lives. It is our duty, and responsibility to verify occupancy of buildings. Even when the resources available cannot completely extinguish a fire, we should be capable of holding the fire back long enough to search as much as possible. Appropriate flow rates allow for the search to take place. A heavily involved house may look like a loss, but perhaps a heavy exterior application of water streams, for a short time, can allow members to perform a vent-enter-search in one or two rooms that are not yet involved in fire. That application rate may not be sustainable, but if it permits us to search any searchable space, then we are truly doing the best we can.
Whether your department is in a position of being able to put out very large fires with a large chain of tenders on route, or the best you can hope for is to hold the fire at bay to perform some searches, you have to be efficient. Synthetic furnishings and combustibles are releasing tremendous amounts of energy. The only way we can combat it is through adequate flows. Even when adequate flows cannot be sustained, the short time we have to flow may just be enough to permit a search and possibly save a life.
Not every structure that burns is going to stay standing. That is the unfortunate reality of fire fighting with delayed responses, and lack of pressurized water supply. However, it is my hope that the departments who may have operated with more of a water conservation approach begin to understand why effective water usage is not a matter of how long to make it last, but rather efficiency of HRR absorption, and its ability to in turn make the job safer for us, and those we protect.
Special thanks to Deputy Fire Chief of Prevention Pete L’Heureux with the City of Swift Current Fire Department for editorial assistance and mentorship.
Joey Cherpin has been a paid on call firefighter for eight years, currently making a transition to the career service with a highly reputable department in southern Saskatchewan. Joey strives to provide the best possible customer service at all times, and through endlessly questioning the status quo, he tries to find ways to improve the way we deliver our services.