CASE STUDY:

Project Name: Farmers Flying Service (Sand Creek, 2013)

Location:  Bancroft, WI

Consultants/ Scientists:  Sand Creek Consultants, Wisconsin and University of Wisconsin, Stevens Point- Mark Dawson, William DeVita and Christopher Rog

Date installed:  2000

Plant Species:  834 Hybrid Poplars (Populus NM-6, DN-34, and DN-17), Eastern Cottonwood (D-105) and Hybrid Willows (Salix SX-61 and SV-1)

Contaminant:  Dinoseb at 6,600 ppb (Herbicide used against broadleaf weeds)

Farmers Flying Service was an aerial agricultural spraying service based in Bancroft, WI.  Years of pesticide storage and handling on the site caused extensive contamination of groundwater and soil.  Following the installation of a Poplar and Willow phytoremediation system, this site experienced close to a100% reduction in the concentration of Dinoseb in groundwater at the downgradient monitoring location, decreasing from a high of 1,549 ppb observed two years after planting in 2000, to no detection (<5 ppb) in 2004 and 2005 after the trees had become fully established.  In comparison, source-area concentrations remained elevated.

Phytohydraulics are believed to be the primary phytoremediation mechanism observed, with phytodegradation being a small fraction of this response due to the known challenges of degrading Dinoseb in an aerobic environment.  Nevertheless, the planting at Farmer’s Flying Service is among the most successful pesticide phytoremediation efforts to date.  Today the site is closed, but the phytotechnology planting continues its function and maintain hydraulic control.  Additional research is needed to evaluate potential Dinoseb degradation rates in the hybrid poplars by searching for Dinoseb metabolite compounds within both the rhizosphere and tree biomass.