David has significant experience in multi-media investigation and remediation of agricultural chemicals including pesticides, herbicides and fertilizers as well as petroleum hydrocarbons, chlorinated solvents and coal combustion residuals (CCRs). He has designed and implemented a variety of soil vapor extraction, groundwater extraction, dual-phase extraction, air sparging, in situ flushing and nutrient injection systems using both vertical and horizontal wells. He has also designed and implemented soil excavations and ex situ chemical oxidation treatments, as well as in situ stabilization/solidification and biological treatments for enhanced reductive dechlorination.
As a consultant, David evaluated multiple groundwater remedies for over 30 CCR impoundments at an operating coal-fired power plant. The remedies that were evaluated included in situ flushing with clean water combined with groundwater extraction, permeable reactive barrier, natural attenuation, capping the impoundments in place, and relocating the CCRs to new double-lined impoundments. At an operating fertilizer plant, David served as Senior Engineer for the design and construction of a 10,000-sq. ft. concrete cap over nitrate-impacted soil that also serves as the new dry fertilizer rail and truck receiving area. David also served as Senior Engineer for the design and implementation of a soil remediation project at a former wood treating operation that used a treatment mixture consisting of pentachlorophenol (PCP) and petroleum. The remediation consisted of ex situ chemical oxidation using Fenton's reagent for soils with lower petroleum concentrations and PCP, and alkaline-activated sodium persulfate for soils with higher petroleum concentrations and PCP.
Over the past 12 years, David has conducted Phase I and Phase II ESAs at more than 150 agricultural chemical storage and distribution facilities in the Midwest. Operations included bulk storage of liquid and dry fertilizers, including anhydrous ammonia, and the bulk storage of pesticides and herbicides. Operations also included fueling and maintenance of ground and aerial application equipment. The due diligence was conducted to support acquisitions and divestitures ranging from a single facility to portfolios of dozens of facilities. The Phase II ESAs consisted of soil sampling, and occasionally groundwater sampling, to evaluate RECs and data gaps identified in the Phase I ESAs. Occasionally, the sampling data collected during due diligence were used to support no further action determinations by state regulatory agencies.