Collection of Contaminated Groundwater
Anderson, SC: Groundwater Collection Trench, Ryobi Technologies
Geo-Con was subcontracted to perform the construction of a groundwater collection trench for collection and pretreatment of contaminated groundwater. This collection trench was constructed using the Bio-Polymer slurry trenching technique. The collection trench, installed to supplement an existing well-point system designed to extract contaminated groundwater and facilitate its pretreatment, via an onsite air stripping system, and discharge to the local water treatment facility.
The 36-inch wide collection trench, with a maximum depth of 57 feet and length of 200 feet, was excavated using a CAT 375L Excavator with Geo-Con's custom made boom and stick attachment, and backfilled with a well graded ASTM-33 Sand. The project also included the installation of three stainless steel four-inch extraction wells with co joined one-inch piezometers within the trench alignment. Each extraction well contained a three-inch Grundfos down-well pump and CU300 control unit housed in a concrete wellhead vault. With the addition of a concrete valve box containing shutoff valves and a flowmeter/ totalizer, these pumps were tied into the existing groundwater conveyance system leading to the on-site air stripping system. The system was integrated with the addition of a new control panel complete with system monitoring/shutoff switches Real-time air monitoring was performed throughout the duration of the project.
Other features of the project included clearing and grubbing, workpad construction, spoils handling-including analytical testing and onsite disposal, and site restoration/ seeding/ mulching. Geo-Con also provided onsite treatment of trench fluids using circulation/ aeration to meet analytical requirements set by the water treatment facility prior to activating the in-trench groundwater extraction system. This project demonstrated Geo-Con's ability to install a complete groundwater remediation solution including features outside the usual Geo-technical scope of work.