Shenandoah WWTF Improvements

The project involves expanding the 2.25 MGD plant to 3.4 MGD by constructing a new treatment train, including improvements to the influent pump station, new headworks, an aeration basin, clarifiers, filters, UV treatment, and post-aeration. The second phase involves expanding to 6 MGD by upgrading the existing orbital aeration basin and converting the clarifiers to digesters.

The location of the proposed Phase I improvements conflicted with existing electrical duct banks and existing influent and discharge piping. Lakeshore Engineering and its electrical subcontractor constructed a temporary overhead power and control system to maintain the operation of existing equipment and enable the construction of the new structures. The temporary power system eliminated the need for costly portable generators.

The existing plant effluent line ran through the proposed clarifier location. Lakeshore re-aligned the proposed effluent piping to include a dog house manhole over the existing effluent line. This enabled the construction of the clarifier and reduced bypass pumping of the 3.25 MGD plant effluent from several months to less than a week.

The site’s spatial limitations required the design and implementation of a detailed earthwork plan, including proper sequencing of structure excavations and stockpiling of backfill material. Because the bottoms of the proposed structures are approximately 10 feet below the groundwater table, an extensive dewatering system was installed to maintain stable working conditions.