Fire Water Storage Capacity in Rural Areas

[Geofzx]

We are working on site design for the expansion of a small commercial development in an area with a mix of municipal and self-served water service (wells). This particular development is in an area with no municipal water service. Based on a required fire flow of 1,500 gpm for 2 hours, storage of 180,000 gallons would be necessary (neglecting the well output, since it is negligible compared to 1,500 gpm). This size tank is well outside the economic reach of small commercial developments. Section B103.1 of the International Fire Code states:

"Decreases. The fire chief is authorized to reduce the fire-flow requirements for isolated buildings or a group of buildings in rural areas or small communities where the development of full fire-flow requirements is impractical."

Given the lack of infrastructure in many areas of the community, this issue comes up anytime there is a commercial development proposed outside the area of established water infrastructure. Historically in this area, the fire marshal approved single 10,000 gallon fire water storage tanks for just about any commercial development, which is not acceptable to the current fire chief and fire marshal representative. Is there any rule of thumb or standards for determining an appropriate reduced storage capacity in rural communities?

 

[77JQX]

I'm not aware of any standards. In the past projects I have worked on have had reduced fire flow requirements for installing fire sprinklers, or based on the largest pumper truck that could respond in a reasonable time frame.

 

[Twinkie]

What is your closest natural water source? Does the local FD (and surrounding stations) have tanker trucks? Tanker trains are pretty common in rural America, the tankers go back and forth to the local creek or pond, pull water, dump it into portable pools at the fire location.

I have been a fireman for over 20 years, trust me, anything that needs 1500 gpm for 2 hours will not be standing after 2 hours. Chief needs to be a little more realistic.

 

[civilman72]

Good points above. Rather than a tank, can you look at a lined pond? In rural areas, building a pond is usually much less expensive than a tank.

You can generally lower the fire demand requirements by 50% if the buildings are sprinkled (so 90,000 gpm). Then talk to the fire chief about how much water they can truck in during that two hours (depends on a lot of factors). I'm working on a new golf course clubhouse in a rural area and the local fire department plans on bringing in 30,000 gallons, so we are proposing 60,000 gallons of on-site storage.

 

[TerryScan]

For comparison, in Delaware, the regulations require sprinklers "in all buildings exceeding 10,000 square feet of aggregate, gross floor area."
Exception No. 1: One- and Two-Family dwellings.
Exception No. 2: Where no public or private water distribution system is available, a Class “B” Fire Barrier may be utilized
to subdivide a one story building into fire areas of less than 10,000 square feet.
Exception No. 3: Buildings or structures of one story in height where:
1. This Exception does not apply to places of assembly, educational or institutional occupancies.
2. The exterior and interior bearing walls, columns, beams, girders, trusses or arches are constructed of
noncombustible material, per the Standard on Types of Building Construction, NFPA 220, as adopted and/or modified by
these Regulations; and
3. The construction is noncombustible; and
4. The occupant load is low; and
5. The means of egress components comply with these Regulations and the Life Safety Code, NFPA 101, as
adopted and/or modified by these Regulations; and
6. The fuel load is identifiable, permanent, and noncombustible.
Note: Exception No. 3: It is the intent of this exception not to require the installation of automatic sprinklers
in buildings or structures in excess of 10,000 square feet when used for the storage of an identifiable,
noncombustible fuel load where the number of occupants is low. For example a building used for the storage
of concrete block, concrete pipe, steel, etc.

Perhaps you can offer fire walls in the new construction that will minimize the risk.

 

[bimr]

You don't state what type of use the building will be. The use is an important consideration.

It would be prudent to run this question past the state ISO. ISO's engineering unit accounts for variance in construction, occupancy, and fire protection in developing PML assessments.

http://www.iso.com/Research-and-Ana...nsurance-Underwriting-An-ISO-Perspective.html

ISO developed the needed fire flow through a review of actual large-loss fires. ISO recorded the average fire flow and other important factors, including construction type, occupancy type, area of the building, and exposures. Those factors are the foundation of the needed fire flow formula.

http://www.isomitigation.com/downloads/ppc3001.pdf