In the non-hydranted areas of rural America, the presence of reliable static water supplies plays an important role in the delivery of fire protection services. If naturally occurring water supplies are not present, then the creation of fire protection water supply sources becomes very important. The use of underground storage tanks is a common means by which to develop fire protection water supplies in areas without other water supply sources.
In Carroll County, Maryland, local government is involved in the planning, funding, installation, maintenance, and repair of regional 30,000-gallon underground fire protection water storage tanks. One such tank was recently installed in the Gamber area of Carroll County and we had the opportunity to video chronicle its installation.
The County was granted use of the parcel of land where the tank was installed through a deed of easement by the property owner. This agreement is critical to the success of the regional tank program because it takes all the burden of tank maintenance and repair off of the landowner and gives the local government full responsibility for the operational readiness of the tank.
The Gamber installation was awarded through a competitive bid process to Stambaugh's Inc - a local construction firm that completed the work in short order while having to work around numerous days of torrential rain. Public records show the project bid was awarded at a cost of $119,500.
Once installed, a 30,000-gallon tank generally meets the ISO requirements for a "credited source" since it can supply 250 gpm for 2 hours, is outfitted with a dry fire hydrant connection, has a lift less than 15 feet, and is accessible year round. In addition, the Carroll County tank must flow a minimum of 1,000 gpm and pumper access must be 8-ft or less from the tank's suction connection.
More information (included design drawings and specifications) about 30,000-gallon underground storage tanks for fire protection can be found in our Members Area.
A local news article about Carroll County underground tanks is available at the link shown below:
Once the tank arrives the goal is to waste no time getting it in the ground. Digging and preparing the hole is very important and it is important to follow all installation instructions regarding tie-downs and tank base preparations.
The small parcel of land used for the tank installation was granted using a deed of easement process where the property owner gives the government authority permission to install the tank. More importantly, the deed of easement also gives the County full control over the inspection, maintenance, and repair of the tank.
The tank is delivered and stored on site while the hole is dug.
Folks work in the excavation area to prepare the base on which the tank will rest and be secured. Note the "step-back" of the soil in order for the hole to be classified as an excavation and not a trench. This step-back is important for the safety of the workers.
The initial, on-site meeting between County officials, the contractor, and the property owner to review the plans and proposed work schedule.
Survey work was completed by the County in preparation for the contractor's excavation work.
Stambaugh's, Inc was awarded the $119,500 contract for the installation of tank.
The 30,000-gallon tank is 10-feet in diameter and the final installation must be able to support a 1,000 gpm flow.
The tank is in the ground and strapped down to the concrete base. Gravel is now being used as backfill around the tank.
The tank is held in place by using stainless steel tie-down straps that keep the tank from "floating" should ground water become and issue.
The tank looks quite formidable before installation!
Almost ready to be covered over.
Preparing the concrete pad that protects the top of the tank and the tank fittings.
The pad is slated to be 4-inch reinforced concrete.
Fittings supplied by ETT, LLC waiting for attachment.
This man way will be set in the concrete pad to allow access to the tank's man way entry. Entry into the tank will most likely never be needed, but access is provided just in case.
Steel pipe awaiting installation as protective bollards.
Restoring the soil and prepping for the pumper access pad.
Compacting the soil that was placed over the gravel fill.
A 4-inch thick reinforced concrete pad is poured around the tank fittings. The yellow fitting is the suction head, a 6-inch NST male fitting. The black fitting is the fill connection, a 4-inch Storx fitting, and the while pipe is an sight/vent assembly made by ETT, Inc. The sight/vent assembly not only vents the tank but also visually displays if the tank is full of water.
Protective concerete-filled, steel pipe bollards are installed at the end of the concrete pad to protect the tank fittings from vehicles.
The finished project includes an asphalt pad for pumper positioning.
