Wolf Neck biosolids work gets staging-area approval; council discusses odor mitigation and schedule

The Sussex County Council on April 29 approved a credit on the Denali sludge-removal contract and authorized purchase order funding to build a permanent staging area for the Wolf Neck Regional Wastewater Facility project.

Engineering staff told the council the Wolf Neck work includes dredging lagoons to remove biosolids and constructing a staging area that will serve both the biosolids contractor and the county's eventual wastewater treatment facility parking needs. The council approved Change Order No. 1 to the Denali sludge-removal agreement as an aggregate credit (read into the record at $35,000) and subsequently approved a purchase order to A.P. Kroll & Sons for the staging-area construction in a not-to-exceed amount of $482,027.50.

Dredging schedule and odor mitigation

County staff described the dredging plan: initial dredging will be done with floating dredges that remove sludge underwater beginning as early as July, with operations expected to continue several months and to carry past Labor Day before the supernatant is pumped and remaining sludge is exposed. Staff said potential odor issues are most likely during the period when sludge is exposed on the surface.

To reduce odor risk, staff described two countermeasures included in the contract: a lime-stabilization option (to treat exposed solids) and an odor-masking component (a scenting product described in the contractor bid). Staff said both measures are imperfect but available if monitoring indicates they are needed.

What the council approved

- Denali credit/change order: Approved Change Order No. 1 as an aggregate credit amount read in the record as $35,000. (Motion carried.)

- Staging area construction: Approved a purchase order to A.P. Kroll & Sons for a permanent staging area at Wolf Neck, not to exceed $482,027.50. Staff said the staging area will be built to county specifications and will also serve future county parking needs for the treatment plant. (Motion carried.)

Why it matters

The Wolf Neck work is intended to remove accumulated biosolids, improve lagoon operations and advance construction of the county's new wastewater treatment facility. The staging area and contractor mobilization timing are tied to Denali's schedule; county staff said the staging area design had to meet Sussex Conservation District permitting requirements and county specifications. Council members asked about odor risk for nearby neighborhoods; staff said mitigation options are included in contractor pricing and that exposure and odor events are expected to be limited but possible.

Next steps

Engineering will issue the purchase order and start staging-area construction; staff will monitor dredging operations and deploy lime stabilization or odor-masking measures if needed. The council will receive updates as work proceeds.