Chad Fisher Construction is helping to re-construct a local landmark of sorts – the Holiday Market and gas station.
Skagit Valley “old timers” may remember the original Holiday Market and gas station. At the I-5 Highway 20 interchange in Burlington, it was an ultra-convenient spot to fuel up. Later this year the Holiday Market gas station will return and there’s already a buzz of excitement in the community about it.
Of course, the first order of business in constructing a gas station is getting the tanks in the ground. This starts with geological testing and permitting to make sure the site is viable. Next comes site prep to prepare for the installation of the underground fuel tanks.
That’s when the fun really starts. (At least we had fun watching our sub-contactors at work!)
First, sheet piles – big steel panels – are driven into the ground to create a cofferdam. The cofferdam creates temporary walls around the excavation where the tanks will be buried.
The metal sheets are set into place by a crane operator who uses the pile driver to essentially vibrate the sheets down into the ground. In this case, each of the 22-foot long sheets were driven into place in a matter of minutes. Soil conditions play a role in how easily the sheet piles can be driven. A wet winter contributed to the quick work on this project.
Once the cofferdam was in place, the tanks could be installed. In the past, fuel tanks were constructed of steel, which eventually would create a problem as corrosion ate away at the tanks. This kind of corrosion often caused fuel to seep into the ground and make its way into the groundwater. Today, underground fuel tanks are constructed of fiberglass, which won’t corrode. This is good news for the tank owners, who have less to worry about in regards to maintenance and replacement of tanks, and even better news for our environment.
After a crane lifts the tanks into place and crews on the ground get the tanks set, the tanks are filled with water. The water acts as ballast to hold down the lightweight tanks as soil is backfilled to cover the excavation. Without this step of filling them with water, the tanks can “float” back up to the surface, even after the hole is backfilled! Eventually, the water will be pumped out and replaced with fuel.