Fairfax Public Works outlines outfall restoration and sewer encasement to reduce Chesapeake Bay pollutants

Fairfax City Public Works described a combined infrastructure project intended to reduce pollutant loads to the Chesapeake Bay and protect a sanitary sewer crossing.

Satoshi Ito, Public Works Program Manager, said engineers are combining an outfall-channel restoration and a sanitary-sanitary sewer encasement at a cul-de-sac on Old Robin Street, in the Dale Lastina tributary of Accotank Creek. He explained that sediment, nitrogen and phosphorus are the pollutants of concern, and that every pound of prevented discharge generates one pollutant-reduction "credit" for Chesapeake Bay goals under the Chesapeake Bay Preservation Act and the city's municipal stormwater permit.

Ito described how erosion begins where existing concrete ends, incising channels and threatening bank stability; the project will extend protective measures, regrade and restore channel resistance to erosion, and include a landscaping plan to replant disturbed areas. He also said encasing the sanitary sewer line in concrete will protect it from damage and reduce the risk of sewage entering the stream if the line fails.

City staff framed the combined work as cost-efficient because shared access and staging reduce overall disturbance and cost compared with separate projects. No funding amounts or construction schedule were detailed in the presentation.