FIRE HOSE AS A CONTAINMENT DEVICE
VOLUNTEERS CORNER
You receive a call that a barge is leaking oil on the river, a fuel oil truck is leaking its product down the storm sewer into a nearby stream, or a pleasure boat is leaking gasoline at the marina. How are you going to contain the spill so that it will not grow larger and possibly have an impact on other areas of the lake or river or maybe even contaminate intakes for cooling systems or potable water supplies?
The floating boom, which long has been used to contain petroleum products and other low specific-gravity chemicals spilled into a water system, is one answer. The boom, generally designed as a tube and filled with a buoyant material, has a 12-to 18-inch skirt that hangs down to keep the product from passing under the boom. Booms, however, can be too expensive for some fire departments and hazardous-materials teams, making it prohibitive to carry large quantities of them. Spill contractors, the Coast Guard, and some private industries have quantities of floating booms loaded on trailers for quick response, but that response sometimes can be several hours away.
FIRE HOSE AN ALTERNATIVE
In New Jersey the North Arlington Fire Department, haz-mat team, and First Aid Squad; the Nutley Fire Department, haz-mat team. First Aid Squad, and dive team; and the Lvndhurst Fire Department dive team recently joined together in an exercise to test an inexpensive quick-response method for a spill on water.
That method involved charging three-inch cotton double-jacketed fire hose with air and floating it across a river to contain a spilled product.
By drilling and tapping a standard 2 1/2-inch hose (end or butt) cap and inserting a 1/4-inch National Pipe Thread nipple, an air shutoff valve and male quick coupler can be attached to supply the three-inch hose with air. The shutoff valve allow s the air cylinders to be changed without any air escaping. The male quick coupler allows the hose to be bled off, since it does not contain a check valve like the female quick coupler or air chock. The system is completed by placing a butt cap on the other end of the hose, hooking up an air supply to the male quick coupler, and inflating. To supply air. one-hour, 4,500-psi SCBA cylinders were used with a step-down regulator from an air chisel kit. The regulator could be adjusted from 0 to 400 psi. Air also could be supplied by a portable compressor or from an air outlet on a truck air-brake system. Fire hose is not airtight and will leak at the couplings or small holes that may be in the hose, making it necessary to maintain a constant air flow.
THE EXERCISE
In August 1991, the units gathered in a park in North Arlington to try this method on the Passaic River. The park provided access to the river’s eastern bank and room to lay out the equipment.
Initially, 800 feet of three-inch hose was flaked out on the ground and connected. The butt caps were installed, and the hose was charged to 50 psi to remove any kinks.
A boat was used to deploy 1/4-inch nylon rope across the river and transport a crew to the western side to pull the hose across. We decided not to pull the hose directly with the boat because we did not know how the hose would react in the current while being stretched across the river. Two other boats were positioned, one upstream and one downstream, to warn any pleasure boats approaching the area and to act as safety teams if someone were to go into the water. All personnel working in and around the river bank were equipped with personal flotation devices.
The hose was pulled across the river at about a 20-degree angle upriver from the eastern river bank. We hoped that the current then was push the spilled product along the hose to the eastern side of the river, where it could be collected by a vacuum truck or another spill cleanup technique.
The air pressure in the hose then was reduced to 20 psi, increasing the displacement of the hose in the water. The hose maintained its round shape and displaced about one-half of its diameter, or 1 1/2 inches.
To simulate a spilled product, popcorn was dispersed on the river by the upstream boat. Popcorn was used because it would float and be subject to the water’s current as well as any surface winds, much like a real spill would react. It also is biodegradable, and the fish love it.
It turned out that the distance to the western river bank had been overestimated. We decided to shorten the hose by folding it over on itself to contain the air within it, reducing the length to 400 feet. The butt cap, with the air connection, then was placed on the shortened hose to maintain the air pressure at 20 psi.
The popcorn floated downriver and was stopped by the hose. However, the angle of the hose from the eastern river bank was not sharp enough to direct the popcorn to the park riverbank area. The crew on the western side of the river was directed to move its end of the hose upriver to increase the hose angle to about 30 degrees. This worked as far as directing the popcorn to one side of the river, but moving the hose pulled it over some of the popcorn, allowing the popcorn to escape containment.
LESSONS LEARNED
- A constant air supply must be maintained, since air can leak through the hose or at the couplings.
- A second hose should be deployed downstream to contain any
- product that escapes past the first hose. Doing this makes it possible to adjust the angle on the upstream hose so that the current will push the product to one shore. The second hose also will serve to contain product that piles up behind the first hose and reaches a depth greater than the draft of the hose.
- Any size soft fire hose can be used. The displacement will be about one-half the diameter of the hose, depending on the pressure maintained in the hose. Synthetic or rubber hose will displace slightly less water but will be easier to clean and decontaminate.
- The nature of the spilled product and the type of hose will dictate whether the hose can be decontaminated or must be discarded. This factor must be considered before the hose is deployed. Many states require the spiller to reimburse a fire department for any lost or contaminated equipment.
- Air-charged fire hose also could be used to contain a spill on land by completely ringing the product or diverting it from a storm sewer. It also can be used in a water or thin-ice rescue.
- This is a quick, temporary answer to a spill on water. It is not as effective as a commercial containment boom, but it does work.
Overall, we were satisfied that we had an inexpensive tool that could be deployed quickly should a spill occur on the river. While we were aware that the hose did not have any kind of skirt to prevent spilled product from passing under the hose if the spill became thicker than 1 1/2 inches, we felt this problem could be solved by deploying multiple hoses. Using a gated street hydrant or a gated wye would allow several hoses to be supplied by one air source.
Hose works best as a containment device for materials that do not evaporate quickly. Take into consideration that all types of hose are not impervious to all types of spilled products, The product might ruin the hose, and you might have to throw the hose out after containment.
