• The existing dry pond provides limited water quality treatment.
• Various components within the existing facility are failing and in need of maintenance or replacement.
• Structural deficiencies include sediment accumulation, failing and rusting pipes, no trash rack to collect floating debris, and drains clogged with debris and sediment.
• There is no direct access to suitably maintain the facility.

• Retrofitting the existing dry pond facility to a SGSMS will improve facility function by addressing structural deficiencies within the current stormwater management system to provide sediment and pollutant reductions before stormwater enters the Potomac River Watershed.
• The SGSMS retrofit will also provide increased detention capacity to better manage stormwater volume during heavy rain and storm events, reducing instances of flooding and improving community resiliency.
• Replacing rusting metal infrastructure with a concrete riser will extend the facility’s longevity and help reduce future maintenance requirements (managed by the County).

The retrofit will be achieved through the following design elements:

• Excavating the existing sloped pond bottom
• Re-grading the existing pond side slopes to increase active stormwater storage volume.
• Replacement of metal structures with concrete structures.
• Removalof two rusting metal pipes that have reached the end of their service life and replacement with concrete pipes.
• Installation of gravel media.
• Construction of a feature at the pond inlet to capture sediment and trash, which is then removed during regular maintenance.
• Establishment of permanent access to the facility from Connecticut Avenue.
• Installation of native vegetation to support water quality treatment and improve overall aesthetics.

• Construction is currently scheduled to begin in January 2025 and will last approximately five to six months. Most excavation and truck traffic will occur within an 8-10-week window in the middle of construction.
• Community members will have the opportunity to review concept plans before construction at various points in the planning process and will be invited to walk the site with the GreenVest team before and after construction.
• The project must pass rigorous review processes led by County, State and Federal agencies developed to maximize facility safety, minimize environmental impacts and ensure modern design standards are met.
• Temporary staging and construction access and parking will occur along Connecticut Avenue.
• GreenVest will work to relocate the existing maintenance access feature from where it currently exists within the Oxford Crossing community to Connecticut Avenue.
• Tree removal will be limited to a small street tree and several evergreens along Connecticut Avenue to provide construction access to the site. Any trees removed will be replaced post-construction with community input on tree selection.
• The project must pass rigorous review processes led by County, State and Federal agencies developed to maximize facility safety, minimize environmental impacts and ensure modern design standards are met.

Submerged gravel stormwater management systems (SGSMS) are small-scale filters that mimic natural hydrologic and ecological processes to capture and treat stormwater runoff, filtering sediment and pollutants through a combination of wetland plants and gravel media. The systems are designed to capture and treat 1” of rainfall over a 24-hour period.