IMPROVING WATER SUPPLY IN NONHYDRANT AREAS: ONE DEPARTMENT`S APPROACH
BY ALLEN S. WILLIAMS AND STEPHEN D. HALFORD
Too often many fire departments believe their efforts are doomed when fighting fires in areas where public water service is unavailable. This need not be so. By carefully analyzing required fire flows, assessing the impact of simple suggested improvements, and challenging its operational status quo, Anne Arundel County (MD) EMS/Fire/Rescue has made significant progress in its fire protection capabilities in nonhydrant areas and has created a road map for the future.
Protecting the lives and property of citizens in our communities is always challenging. Our nation`s fire service has achieved a significant reduction in life and property loss over the past three decades with the advent of smoke detectors, increased public fire prevention education, residential sprinklers, and other such measures. Despite these quantum leaps, however, fire and its tragic consequences for the citizens of our communities are always a threat, and the fire service must continue to improve its combat ability to complement its community risk-reduction strategies.
The old firefighting axiom “Put the wet stuff on the red stuff” sounds simple enough. In communities served by pressurized public water systems, the wet stuff is generally located on the street in front of the red stuff and it is usually not too difficult to connect the wet with the red. Many of our nation`s communities, however, are not served by public water and must locate the wet stuff and deliver it to the scene of the red stuff before it can sustain a successful fire attack. Establishing and sustaining appropriate volumes of water flow during fire operations in nonhydrant areas is one of the fire service`s greatest challenges.
ANNE ARUNDEL COUNTY
Anne Arundel County, Maryland, is typical of many suburban communities located close to large urban areas. Located on the Chesapeake Bay in the corridor between Baltimore and Washington, D.C., its population of 463,800 is dispersed on 416 square miles and is protected by one of the largest combination fire departments in the United States. Anne Arundel County EMS/Fire/Rescue, consisting of 606 career employees and 680 response certified volunteer firefighters, is charged by county charter to provide fire protection and emergency medical services for citizens from its 29 fire stations. Many of the 42,821 dispatched calls to which Anne Arundel County EMS/Fire/Rescue responded during 1996 were structural fires located in nonhydrant areas.
ADEQUATE FACILITIES ORDINANCE
Less than half of Anne Arundel County is protected by a public water system. Since 1978, required fire flows for various occupancies in the county have been mandated by the Anne Arundel County Adequate Facilities Ordinance, Ten Year Master Plan for Water and Sewer. Required fire flows for fire protection purposes vary from 1,000 gallons per minute (gpm) at 20 pounds per square inch (psi) for two hours for residential occupancies to 3,000 gpm at 20 psi for three hours for industrial occupancies.
Areas not protected by an adequate public water system, a substantial portion of the county, could not sustain additional development after 1978 unless the developer met the requirements of another section of the county`s Adequate Facilities Ordinance, which required installation of underground water storage tanks (residential occupancies) or a water supply system approved by EMS/Fire/Rescue for other occupancies. Fire department approval would be based on National Fire Protection Association (NFPA) 1231, Standard on Water Supplies for Suburban and Rural Fire Fighting.
Since most buildings in nonhydrant areas of the county are residential development, residential community developers have installed approximately 270 underground water storage tanks since 1978. The county`s Adequate Facility Ordinance called for the installation of a minimum 5,000-gallon underground water storage tank in any new development containing more than five homes. Underground water storage tanks are required to have appropriate drafting connections, fill pipes, venting, and other features mandated by EMS/Fire/Rescue. Additionally, such tanks must be located within 2,000 feet, measured in road access distance, of any home in the development. The developer was responsible for installation and maintenance costs until a public works agreement was completed to turn the tank(s) over to the county. At that point, the county became responsible for the tank`s repair and maintenance. The 1997 cost of a 5,000-gallon underground storage tank, not including site preparation, was approximately $20,000.
Although underground water storage tanks appeared to be a part of the solution to the county`s water supply problems in nonhydrant areas, a great deal of the unprotected areas had been developed prior to the 1978 enactment of the ordinance. Additionally, the county began to see a host of maintenance problems with the tanks as they began to age, which required a considerable investment of time and cost to keep up with the problems.
PROVIDING WATER SUPPLY IN NONHYDRANT AREAS
Anne Arundel County was last rated by the Insurance Services Office (ISO) in 1984. The county received a Class 4 rating in areas where a public water supply was provided for fire protection and a Class 9 rating in areas where no public water supply was pres-ent. Most likely, the county will not have another rating done be-cause insurance premiums in jurisdictions with populations of more than 250,000 are set by the fire loss experience of the jurisdiction, not the ISO.
Prior to the recent thorough review of its effectiveness in providing a system to deliver water in nonhydrant areas, Anne Arundel County EMS/Fire/Rescue believed for several decades that it had adequately dealt with the challenge of fire protection in nonhydrant areas. In terms of static water sources, senior fire officials believed the numerous static bodies of water–such as the Chesapeake Bay, rivers, and many ponds and lakes, coupled with underground water storage tanks–more than amply provided the raw resources needed to fight fires. All of the personnel charged with operating fire department pumpers and water tankers were certified in their specialty after receiving training and testing in pump operations. Several standard operating procedures had been developed regarding the laying and pumping of supply lines in nonhydrant areas. Without the extension of public water supply to nonhydrant areas or the possibility of prospective residential sprinkler ordinances to assist in keeping pace with the fire protection problem, it was assumed that nothing more could be done. Department officials assumed that the existing fire protection methodology to suppress fires in nonhydrant areas was adequate and that the public accepted the existing level of protection provided for these areas.
CITIZENS DEMAND IMPROVED WATER SUPPLIES
During the early part of 1994, a series of residential fires in nonhydrant areas occurred, resulting in total losses. For the first time in our department`s history, there was public criticism of our operations used for fire calls.
We had problems maintaining an adequate water supply during our fire operations on these particular calls for a host of reasons, none of which were acceptable to our customers. Letters to the editor in local newspapers openly criticized our department. Communities located in several nonhydrant areas began to wonder if adequate water supplies existed for fighting fires in their communities. Various community associations approached elected officials in the executive and legislative branches of our county government, seeking assurances that their homes were adequately protected.
The county was not in a fiscal position to extend public water services beyond its projected capital planning projects and also was not in a position to install hundreds of underground water storage tanks that were not required prior to 1978. While no overall crisis appeared to exist, it was obvious that Anne Arundel County EMS/Fire/Rescue needed to take the leading role in addressing this issue.
A STUDY LAUNCHED
Battalion Chief Allen Williams, who serves the area of Anne Arundel County least protected by public water, was given the challenge to study this issue. The first action was to determine and graphically illustrate the percentage of the county not protected by fire hydrants. This task was accomplished by color coding the numerous mapped “box areas” of the county (Figure 1).
Similar to other fire department mapping systems, the box areas are small, community-sized geographical divisions used for dispatch purposes. Each box area was color coded to indicate the availability of fire hydrants. Blue box areas have fire hydrants; red ones do not. Uncolored box areas are not the responsibility of the county. They include separate jurisdictions contained within Anne Arundel County such as the City of Annapolis, the United States Naval Academy, Fort George G. Meade, and the Baltimore/Washington International Airport.
After color coding the box areas, it became immediately apparent that a large percentage of the county was not protected by fire hydrants. A preliminary conclusion that additional underground water storage tanks should be installed to gain retrospective compliance with the county`s Adequate Facilities Ordinance was discounted because of the cost and the project`s enormous scope. Additionally, Anne Arundel County`s General Development Plan indicated that there was limited ability to extend public water services to most of these unprotected areas. Clearly, additional research was needed to assist in solving our water supply problem.
Our initial research led us to focus on several principal resources. These resources included NFPA 1231; The Fire Department Water Supply Handbook, by William Eckman (Fire Engineering Books and Videos, 1994); and numerous articles appearing in fire service trade magazines.
MASTER PLANNING APPROACH
Many analytical methods were used to study this issue. The approach used most closely resembles the process of “Water Supply Master Planning” described by Eckman in his book (page 28), which recommends a process that includes the following steps:
1. Determine fire flow requirements.
2. Determine your ability to provide fire flow requirements.
3. Determine how to get the most from present resources.
4. Develop a long-range plan.
The basis for our master plan involved completing each of these steps for all box areas that did not have fire hydrants. A more detailed description of these steps follows.
Step 1. Determine fire flow requirements.
To determine fire flow requirements, we used recommendations from the ISO schedule along with formulas from NFPA 1231 (1993). According to Eckman (page 53), the ISO bases the minimum required fire flow on the structure in an area requiring the fifth largest fire flow. To complete this step, field personnel of Anne Arundel County EMS/Fire/Rescue searched each box area within their first-due areas for this structure. After taking measurements and collecting other information on those structures, formulas from NFPA 1231 (1993) were used to determine the “minimum water supply” and the “delivery capacity.”
The minimum water supply is the quantity of water that should be available on the fireground. It is calculated as follows:
Cubic feet of Structure/ Occup. Hazard Code (OHN) 2 Const. Class. No. (CCN) 2 Exposure Factor (EF)
As an example, the minimum water supply for a 30-foot 2 60-foot two-story wood-frame dwelling with an attic and basement would be calculated as follows:
50,400 (Total Cubic Feet)/ 7 (Occupancy Hazard Code) 2 1 (CCN for Dwellings) 2 1 (EF) = 7,200 Gallons
NFPA 1231 (1993) describes the delivery capacity as the quantity of water that must be maintained in a shuttle or hose relay. The specific delivery capacity required is dependent on the minimum water supply (Table 1).
The minimum water supply requirement for our sample dwelling was 7,200 gallons, which falls between 2,500 and 9,999 gallons of water. Our sample dwelling, therefore, would require a delivery capacity of 500 gpm. Although the figures varied with the box area studied, the average delivery capacity requirement for the structure with the fifth highest fire flow in a box area was 600 gpm.
Step 2. Determine ability to provide fire flow requirements.
Next, we determined our ability to deliver the necessary fire flow (delivery capacity). Before we could do this, however, we had to complete an analysis of our static water sources and fire apparatus.
To analyze the water sources, we did a meticulous search of the county, which included the following: (a) physically searching each box area not protected by fire hydrants, (b) reviewing aerial photos taken periodically by the County`s Planning and Zoning Department, and (c) obtaining information from the County Soil and Conservation Department. After compiling a list of all available static water sources, we categorized them as follows:
* Class A. Accessible virtually 365 days a year via a maximum of 20 feet of hard tube and is of a sufficient capacity to pump for a minimum of two hours at 1,000 gpm.
* Class B. May not be accessible 365 days a year but has a sufficient capacity to pump for a minimum of two hours at 1,000 gpm.
* Class C. Accessible virtually 365 days a year via a maximum of 20 feet of hard tube but has insufficient capacity to pump for a minimum of two hours at 1,000 gpm.
* Class D. May not be accessible 365 days a year and has an insufficient capacity to pump for a minimum of two hours at 1,000 gpm.
The self-imposed requirement that the source provide a minimum of 1,000 gpm for two hours was established to be consistent with the ISO. Eckman (page 26) indicates that in1980, the ISO permitted alternative water supplies to be used instead of fire hydrants. To receive the credit, the fire department must demonstrate the ability to attain a minimum of 250 gpm within five minutes after arrival and maintain that flow for a minimum of two hours. As a result, we considered only the use of Class A sources for our study.
Next, we analyzed the fire apparatus that would be used to transport the water. The most important piece of information concerning these units is their “handling time”– the sum of dump time and fill times. The specific handling times for our apparatus were compiled during a seminar presented by Eckman in the fall of 1994 (Table 2).
After compiling that data, we could then determine the delivery capacity for each apparatus. This figure is the quantity of water in gallons per minute a unit can deliver via a shuttle to the fireground; it is determined by the following formula from NFPA 1231 (1993).
BR> Delivery Capacity (gpm) = Capacity of Tank/Travel Time + Handling Time 110%
The 10 percent in the formula is subtracted to account for spillage and incomplete filling. Since the size of the tank of any apparatus and its handling time are consistent, the only variable factor in the formula is travel time. The travel time depends on the distance to a fill site. It is calculated by another formula in NFPA 1231 (1993), where travel time = 0.65 + XD where x is a factor for average speed and D is the distance. As an example, the travel time for two miles at the average speed of 35 mph (factor 1.7), would be calculated as follows:
.65 ` 1.7 (2) = 4.05 minutes.
Thus, if we used a water source two miles away (four miles round trip), the total travel time would be .65 ` 1.7 (4) = 7.45 minutes. Using the example below, we found that the delivery capacity for Tanker 1, using a water source two miles away would be 146 gpm.
146 gpm = 3,000 Gallons/7.45 (Travel Time)` 11 (Handling Time) 110%
Armed with the handling time for each apparatus, it was now possible to complete Step 2 and determine our water-carrying potential to every box area in the county not protected by fire hydrants. During these calculations, we considered only the apparatus that could arrive to an area within 15 minutes. We chose this time frame to coincide with additional ISO standards. According to Eckman (page 35), the ISO rating a jurisdiction receives when it demonstrates the ability to deliver 250 gpm within five minutes of arrival can be increased if the flow can be raised to 100 percent of the required fire flow for the fifth largest structure within 15 minutes.
Table 3 illustrates an analysis of one box area listing all resources that can arrive in that particular area within 15 minutes with their typical assignments and delivery capacities.
This flow analysis indicated we could provide only 90 gpm (18 percent of the 500 gpm) required for the structure with the fifth largest flow in this box area. When this process was completed forthe “fifth largest” in all box areas throughout the county, it was learned that we could provide only an average of 52 percent of the required fire flow (Figure 2).
Step 3. Determine how to get the most from present resources.
After seeing our deficiencies, we conducted brainstorming sessions to determine what improvements could be accomplished on a short-term basis to increase our ability to deliver larger quantities of water. Some of these suggestions included the following:
Larger tank fills on engines. During our handling-time calculations, we found that the 750 gallon-tanks on our standard engine took an excessive amount of time to fill (four minutes). The reason for this was that the tanks were being filled through the pump via a 112-inch tank fill. However, we did have one engine that had a 212-inch tank fill directly into its tank, which filled in half the time.
Larger water tanks on engines. It was believed that a larger tank, perhaps 1,000 gallons, could contribute significantly to the quantity of water that could be delivered.
Portable tank operations. For years, we always established our tankers as on-scene reservoirs (nurse tankers). We used engines to shuttle water from the source to the on-scene tanker. Knowing there were other options, we wondered what the impact would be if we used portable tanks.
Gravity dumps on tankers. Because we had not used portable tanks, we wanted to know what the impact of installing gravity dumps on our tankers would be.
Although the items suggested as a result of our brainstorming sessions did not represent extremely expensive purchases if planned and phased in over a short period of time, we wanted to know what the increase in our delivery capacity would be before committing to any of them. We conducted a “what-if” analysis to determine what each improvement, if implemented, would contribute to additional flow capability. We would then determine what the sum effect would be if all suggested improvements were implemented in each specific nonhydrant box area of the county. The next several paragraphs detail this process.
The assessment process
We first analyzed the brainstorming suggestion of increasing the diameters of our engine tank-fill pipes. From prior analysis, we knew that the handling time would be at least two minutes less for an engine with a 212-inch tank fill than it would be for our standard 112-inch tank fill. Thus, the handling time per unit would be reduced from nine minutes to seven minutes. As can be seen in Table 4, increasing our tank fill size to 212 inch-diameters on the engines increased the total delivery capacity in our sample box area to only 104 gpm (21 percent of the required amount). When applied to each box area in the county, we found that departmentally increasing our fill-pipe size increased the percentage of the required fire flow that could be delivered from 52 to 56 percent.
Next, we studied the impact of increasing the tank size on our engines from 750 to 1,000 gallons, as also had been suggested in our brainstorming session. This single improvement brought our total delivery capacity in our sample box area up to 120 gpm, or 24 percent, of the required fire flow (Table 5). Departmentally, it increased the percentage of fire flow that could be delivered to 58 percent.
Moving forward with our brainstorming suggestions and what-if analysis, we found the first significant impact on increasing our delivery capacity when we studied the use of portable tanks. Although we lost the flow from one engine by having to draft from a portable tank, we were able to take better advantage of our tankers` larger delivery capacities. This change increased our flow in the sample box area to 203 gpm, or 41 percent, of the required fire flow (Table 6). Departmentally, it increased the percentage of fire flow we could deliver throughout the county to an average of 77 percent (Figure 3).
The last brainstorming idea to be plugged into our what-if analysis was to study the impact of gravity dumps on our delivery capacity. In our sample box area scenario, Tanker 1 did not have a gravity dump and had to pump its tank into a portable tank. We expected the flow of a 10-inch square dump to reduce its handling time from 11 minutes to seven minutes. This brought our delivery capacity in the sample box area up to 50 percent of the required fire flow (Table 7).
Up to this point, we had studied each improvement separately. We wondered what the impact would be if we incorporated all four things: (a) 212-inch tank fills, (b) 1,000-gallon tanks on engines, (c) portable tanks, and (d) gravity dumps on all tankers. As summarized in Table 8, these changes increased the delivery capacity in our sample box area scenario to 266 gpm.
We arrived at several conclusions after completing our what-if analysis. First, it would probably not be cost-effective to increase tank fills or tank sizes, since those two items increased our delivery capacity by only six percent. Our efforts would be more cost-effective if we changed our operational procedures to use portable tanks and added gravity dumps to our tankers. Although these changes would increase the percentage of the required fire flow that could be delivered to a county-wide average to 100 percent, the percentage was far less than that in many individual box areas. In the sample box area illustrated in the various tables of this article, our best efforts brought the flow up to only 50 percent of that required. Figure 4 graphically illustrates the percentage of the required fire flow that could be provided throughout the county. More had to be done.
Step 4. Develop a long-range plan.
To increase our delivery capacity to 100 percent of the required fire flow in all box areas, we developed a long-range plan to provide additional resources. Examples of these items included purchasing additional tankers, upgrading water sources, adding water sources, and using large-diameter hose. To plan for these items and study their impact, we did additional analyses.
Additional tankers. We considered establishing five-mile tanker coverage areas for each of our tankers. A five-mile limit was chosen to coincide with the distance that ISO typically credits for tankers (Eckman, page 38). From overlaying the Tanker Coverage Map on top of the map in Figure 4, we could see where additional tankers would be best used. As a result, we generated a map to illustrate proposed tankers at Stations 5, 9, and 40 (Figure 5). One of the newly proposed units, Tanker 9, is illustrated in the analysis in Table 9. Its purchase would raise the total delivery capacity to within 26 gpm of the required amount in our sample box area.
Upgraded water sources. In some box areas, our inability to deliver the necessary water flow was limited by the excessive distance to a Class A water source, not inadequate apparatus. Through our water analysis, we learned we could deliver approximately 500 gpm from the resources from the first-alarm assignment when the water source was 1.2 miles away. To illustrate areas that needed closer water sources, we generated a map showing a 1.2-mile coverage area from all of our Class-A water sources. Next, Class-B water sources within these areas were surveyed to see if any could be upgraded by installing a drafting pipe or providing better road access to make them Class A sources. We identified 11 sites that would enable us to deliver the required fire flow requirements to additional box areas by reducing the travel time to the water source.
Additional water sources. In other instances, there were no water sources in the area to upgrade. In these instances, the installation of large-capacity underground water cisterns was recommended. Their size would depend on the fire flow requirements. The minimum size was 30,000 gallons, which, if supplied with a 500-gallon, large-capacity well, could deliver 500 gpm for a minimum of two hours. Eleven of these were recommended, which reduced the travel time to water sources and allowed us to deliver the required fire flow requirements to additional box areas. Although such large-capacity tanks are expensive, their cost pales in comparison with that of extending public water to these areas.
Large-diameter (five-inch) hose (LDH). In some areas, we considered using an engine relay to the water source. However, to maintain the standard set earlier that would require the flow to be established within 15 minutes, we believed that the relay would have to be restricted to no more than two engines. Large-diameter hose provides the advantage of generating substantial flows with a two-engine relay. In table 10, Eckman (page 403) provides specific quantities for various distances.
After reviewing the areas in which this would be most applicable, we determined that we would equip various apparatus with LDH, which would allow us to deliver the required fire flow into additional areas. This option would make it possible for us to deliver the required fire flow to nearly every box area.
WHERE WE ARE TODAY
Since our initial master plan was originally completed in February 1995, many changes have occurred within our department. Four additional tankers or tanker/pumpers have been purchased, another is on order, and two more are in the planning stages. We have incorporated the use of portable tanks into our operational procedures and developed a water supply officer class. “Performance Standard Evolutions” that define specific tasks and standard times for their completion measure our effectiveness. We have been conducting numerous tanker shuttle drills during which we actually test our ability to deliver the quantity of water expected in the analysis of various box areas. Better maps and reference charts provide easy methods for accessing water sources and checking apparatus requirements. More importantly, a new attitude has been instilled in our personnel regarding the delivery of water in areas not protected by fire hydrants.
As a result of this study, several additional ideas are under consideration. We are considering removing or adding to the requirements in our Adequate Facilities Ordinance for underground water storage tanks in nonhydrant areas. We are contemplating requiring developers to pay into a fund that would be used to purchase more fire department water tankers for such areas. Additionally, and to keep pace with development in these areas, we are considering drafting legislation that would require builders to advise potential homeowners of the advantages of residential sprinkler systems and to offer them as an option in their construction package.
In 1995, the National Association of Counties (NACo) recognized Anne Arundel County EMS/Fire/Rescue for the study and initial progress made in addressing the rural water supply needs of its citizens.
A current water supply master plan is an essential tool for any department serious about providing cost-efficient and effective water delivery systems. It clearly provides a mechanism for measuring your capabilities and objective methods for determining the impact of various improvement plans. In an era of increasing demands with decreasing resources, it is an invaluable tool. n
Acknowledgments: The assistance of the following is gratefully appreciated: William Eckman, Lieutenant Michael Bauer, Lieutenant Michael Cox, EMT/FF II Eric Lamb, Mapping Technician Mark Edwards, and all personnel assigned to the BLS/Fire/Rescue Bureau of Anne Arundel County EMS/Fire/Rescue.
ALLEN S. WILLIAMS, a 21-year veteran of the fire service, is a battalion chief with Anne Arundel County (MD) EMS/ Fire/Rescue. He has an A.A. degree in fire science technology and a B.S. degree in fire service management from the University of Maryland and is an NFSQB-certified Fire Officer IV and Instructor III.
STEPHEN D. HALFORD, a 26-year veteran of the fire service, is the chief of Anne Arundel County (MD) EMS/ Fire/Rescue. He has an A.A. degree in fire science technology and a B.S. degree in fire service management from the University of Maryland and is a graduate of the National Fire Academy`s Executive Fire Officer Program. He is an NFSQB-certified Fire Officer IV and Instructor III.
Figure 1. Fire Hydrant Coverage.
Figure 2. Percentage of required fire flow that could be provided in 1995.
Figure 3. Percentage of required fire flow that could be provided using portable tanks in 1995.
Figure 4. Percentage of required fire flow that could be provided in 1995 using (a) 212-inch tank fills, (b) 1,000-gallon tanks on engines, (c) portable tanks, and (d) gravity dumps on tankers.
Figure 5. Five-mile road distances from selected fire stations: 43, 10 and 13, 40, 19, 1, 9, and 42.
Figure 6. Percentage of required flow possible that could be provided in 1995 using previous improvements plus additional tankers at Stations 5, 9, and 40.
Figure 7. Percentage of required fire flow that could be provided in 1997.