Underground Tank Replacement Project
CommTank was awarded the project to replace the underground storage tank (UST) at the H. Olive Day School in Norfolk, Massachusetts. The estimate for our services was within the client’s budget and considered to be a more cost -effective solution compared to other construction companies’ options.
The scope of work was to upgrade the existing underground storage tank, a Highland Titan model (polymer coated steel) which used cathodic protection to prevent corrosion, to a Xerxes fiberglass double-wall UST with interstitial space for monitoring leaks.
A project delay occurred when a two-week lead time from the product manufacturer extended to 8 weeks. Based on our experience as a quality contractor, CommTank proposed removing the tank, backfilling the excavated site area with pea stone and setting up a temporary above ground storage tank to provide fuel to the emergency generator and boiler for the duration of the delay.
Our clients approved this design method and materials, and installation of the temporary tank was completed. Additional project factors included a range of addendums for replacing the aboveground storage day tank, automatic fuel oil transfer pump set and boiler room piping. The CommTank team was awarded all of this work as well.
The temporary tank was installed on the outside wall of the boiler room and supply return lines were run inside to the boiler and emergency generator. Approximately 900-gallons of fuel were transferred from the UST to the temporary tank and the system was tested. Our team installed two concrete barriers protect the tank from vehicular traffic.
The UST removal process began the following day. CommTank crews cut the concrete/asphalt and excavated the UST and piping that connected to the boiler room. The UST was opened, cleaned and removed from the ground by crane. The supply/return piping was drained and removed. After soil testing and approval from the Fire Department, the tank grave and pipe trench was backfilled and compacted.
Two hundred feet of piping was demolished in the boiler room of the building and the new Pryco day tank and Preferred Utilities pump set were installed on newly constructed concrete pads. The new equipment produced a humming noise that could be heard in the adjoining classroom and needed to be addressed. The original engineering plan did not account for the proximity of the new fuel lines to the classroom. The solution required installation of nylon gearing in the pump set to replace the original bronze gears. Additionally, flex couplings were installed above the pumps to reduce the transfer of vibration to the wall brackets, and shock mount feet were added to the base of the pump set frame to minimize vibration.
Fiberglass Underground Tank Installed
The new fiberglass underground tank was delivered by Xerxes on one day; installed by CommTank on the second day; and backfilled on the following day. Sump piping connections were completed within the next week. Soon thereafter the concrete tank pad was poured. Franklin APT product piping was installed inside XP pipe ducting to provide double-wall protection for the fuel connections between the UST and boiler room. An APT transition sleeve is used to convert the nylon underground product pipe to steel pipe inside the building. This construction work was completed while school was in session and did not interrupt school activities.
The Veeder-Root fuel tank inventory monitor/leak detector was installed in the boiler room and connected to the UST sump. The system has a 7” LCD touch screen with a 16:9 aspect ratio. The console continually monitors all probes and sensors, reporting not only normal operating conditions, but also systems malfunctions and failures.
CommTank performed tank and line tightness testing at the completion of the project to ensure the fuel system was safe to operate and provided training to the Class A/B Operator. After transferring fuel to the new UST, the temporary aboveground storage tank was disconnected and removed.