Griffin Dewatering Discovers Two Centuries-Old Ships


Griffin has successfully completed phase one of a complicated two-part project on the waterfront in Alexandria, VA where two centuries-old ships were discovered by archeologists. (New York Times)

“The bottom line is that we would not be where we are today in our archeological studies if it wasn’t for the dewatering system.” – EYA Superintendent

The Problem

Donohoe needed an 1100-ft wellpoint system for a large, commercial residential project on coveted Alexandria waterfront real estate. EYA was performing preliminary archeological work that was going to extend below the groundwater level and worked out an agreement with Donohoe to have Griffin come in early and install the wellpoints planned for the construction phase of the project. The EYA superintendent on site said that they would not have been able to perform the archeological work that is currently taking place without the Griffin wellpoint system.

The Solution

Griffin placed an initial line of wellpoints around the perimeter of the site. Once that is completed, they will remove the header pipe and equipment, leaving the wellpoints capped in the ground. Donohoe will then place a large slurry wall underground due to the presence of close nearby residential housing – essentially making the site a giant bath tub. Phase two is to install more well points around the system, connect everything, and then empty the bath tub. Donohoe can then safely and effectively excavate.

The original agreement started at 1100 feet of well points going 24 feet deep on 7.5 ft centers with 200 feet of discharge. Supplemental work lead to another 110 wellpoints, or an additional 800 feet.

The wellpoint system extends around the perimeter of the site.

A complicated project like this one with high stakes serves as an example of why it can be extremely risky for contractors or owners to attempt to self perform dewatering. Griffin worked with both contractor and owner to ensure a safe, effective and timely dewatering project.

Donohoe went with Griffin due to their proven track record providing best-in-class dewatering services. Griffin successfully executed two similar projects at Hotel Indigo, adjacent to this project, and Old Dominion Boat Club, right down the block.

More Resources

For more information on how wellpoint systems work, click here.