Washington Navy Yard Sand Filter Retrofit

Technical Description:

• (2) Jellyfish^® Filters with (9) 15” hi-flo cartridges and (3) 15” drain-down cartridges each

The Washington Navy Yard (WNY) is a former shipyard and ordnance plant for the United States Navy and currently serves as a ceremonial and administrative center for the U.S. Navy.

The Navy Yard had two underground sand filters providing water quality treatment. Regular maintenance was needed to prevent trash and sediment from clogging the filters. This process was time-consuming, expensive and messy. As a result, engineers at the Naval Facilities Engineering Command (NAVFAC) researched alternatives to provide the desired treatment level per District Department of the Environment (DDOE) standards, and reduce maintenance. The solution they chose was to retrofit the existing sand filters into Jellyfish Filters from Contech Engineered Solutions.

The Jellyfish Filter is a stormwater quality treatment technology featuring pretreatment and membrane filtration in a compact stand-alone system. The compact design and high surface area cartridges provide effective fine sand and silt sized particles removal, combined with high removal percentage for particulate bound pollutants including nutrients, metals and hydrocarbons. The Jellyfish Filter offers easy maintenance, is available in multiple configurations for site specific design and has numerous agency approvals, including NJDEP certification of a TARP field test. It was important to the NAVFAC to design the Jellyfish units to work within the existing size and elevations of the sand filter vaults. Contech provided full engineering support and designed the units to require minimum modifications to the existing infrastructure.

The retrofit process involved cutting an opening in the top slab of the vaults, removing the existing internal components and pouring two new flow control baffles as directed by Contech. A Contech representative was onsite to assist the contractor with installing the aluminum Jellyfish decks and filter cartridges. After the internals were installed, the contractor set a new top slab with a hatch cast-in on each system as designed and provided by Contech. The installation was completed in just two days.

Technical Description:

• (2) Jellyfish^® Filters with (9) 15” hi-flo cartridges and (3) 15” drain-down cartridges each