Manson Construction Co. of Seattle received an $834,000 modification to a U.S. Navy contract for dredging and pier replacement at Naval Base San Diego, informally known as the 32nd St. naval station. The deal augments a $9.6 million contract modification from Feb. 10. The Pentagon announced both deals on June 13.

Under the deal, Manson will screen dredge spoils for discarded munitions and radiological debris from the demolition, replacement and dredging project at the naval station’s Pier 12.

The work to be performed provides for a deep-draft pier to accommodate new Zumwalt-class destroyers and big-deck amphibious assault ships. It will also provide shore power for such ships.

The cumulative value of the contract after the modifications will be $120.6 million.

Work is expected to be completed in July.

The Naval Facilities Engineering Command Southwest in San Diego awarded the deal.

The USS Zumwalt is scheduled to arrive in San Diego later this year. It looks unlike any other destroyer, with its stealth design and “tumblehome” hull — an unusual design where the hull is larger at the waterline and smaller at the main deck. The Zumwalt class is also 610 feet long, compared to the conventional Arleigh Burke class destroyer, which is 510 feet long.