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Environmental Investigation & Remediation

ENW’s Environmental Investigation & Remediation Division has performed numerous environmental investigations and designed remedial systems for impacted sites. As former regulators, our professionals are intimately aware of environmental regulations and the data requirements to satisfy state environmental and natural resource agencies. Our environmental professionals have a cumulative 20 years on the staffs of state and federal natural resource agencies, and a cumulative 15 years of experience working in the private sector for environmental engineering companies. 

Work performed for Remedial Investigations (RI) and Feasibility Studies (FS) have the following overall objectives:

ENW staff have worked on a wide variety of contamination projects, including:


Prominent Environmental Investigation & Remediation Projects

Car-Crushing Facility, Multnomah County, OR
Lynn Green was the Project Manager for the soil and groundwater investigation conducted to assess the historical release of petroleum products, heavy metals, and PCBs, assisting another consulting firm. Complicating this project were complex historical activities which included two periods of anthropogenic fill activities. One of the fill sources was the City’s former municipal incinerator. Additionally, the area had a complex hydrogeologic nature, due to surface water management controls, tidal influences, river stages, and fluvial transport.  Lynn also assisted in the development of the human health and ecological assessments of risk for this site.

Former Hospital, Multnomah County, OR
Lynn Green was the Project Manager for the Phase I and Phase II Environmental Site Assessments for a large, former hospital facility. The Phase II investigation focused on historical waste disposal activities (cesspools, septic tanks) and USTs. Due to the nature of the site and complex site renovations over time, a geophysical survey was used to map out the site drainage and disposal features. Results from this geophysical survey assisted in identifying previously unknown/unrecognized site features, including a boiler room septic tank that was found partially full of petroleum product, and an emergency generator UST that still contained diesel fuel.

Former Auto & Truck Sales facility, mid-Willamette Valley, OR
The facility was active from the 1950s through the 1980s. Two USTs were decommissioned on-site in 1989, in preparation for sale of the property. During the accompanying environmental investigation, a large groundwater contamination plume was discovered which extended over 400 feet. A pool of floating gasoline product extended from the site to other commercial properties on the far side of a busy, five-lane commercial highway. Other discontinuous floating pools were present as well. Neil Woller directed the investigation, modeled groundwater flow and contaminant migration, and evaluated potential remedial scenarios. He designed the remedial system for the site and wrote the Corrective Action Plan accepted by the Oregon Department of Environmental Quality.

Former Chemicals Warehouse, Multnomah County, OR
Neil Woller directed the environmental investigation of this vacant chemicals warehouse.  Trichloroethylene was discovered in groundwater below the site. Neil sited and designed the monitoring well system that showed the presence of a thin perching layer that controlled the distribution of the contamination.

Landfill, Southern Oregon Coast
In order to address environmental concerns by regulatory agencies, Neil Woller directed and wrote the Site Characterization Study for the landfill. The landfill accepted both demolition and municipal waste during earlier periods of operation.  Neil mapped the geology and characterized the hydrogeology of the site. He designed a monitoring well system to determine the characteristics of the leachate produced by the landfill, and began the surface-water-monitoring program to determine impacts to a slough and other water bodies near the landfill.

Service Station, Southern Willamette Valley, OR
Neil Woller was the Senior Hydrogeologist for the immediate response team that addressed the catastrophic release of 22,000 gallons of unleaded gasoline from a UST at this service station. Neil supervised the aquifer characterization activities, and then performed groundwater modeling to design a system to capture the released contamination. Because of the very high transmissivity of the aquifer, the groundwater capture system installed on-site and down-gradient consisted of 7 wells pumping a cumulative 400 gallons per minute. 

Site Response, Department of Environmental Quality, OR
As Senior Hydrogeologist for the Western Region of the Oregon Department of Environmental Quality, Neil Woller was Project Manager for several high priority contamination sites.  He negotiated with representatives of responsible parties to perform necessary characterization, reviewed submittals from technical consultants including Scope of Work documents, Remedial Investigations, Feasibility Studies, and Risk Assessments. He negotiated the requirements of administrative and judicial Orders to complete investigations and remedial actions. He reviewed analytical data and field activities for completeness and compliance with QA/QC requirements.

Service Station, Clatsop County, OR
Lynn Green was the Senior Scientist for the cleanup and monitoring work conducted on-site, addressing the historical release of both gasoline and used oil from several USTs at this service station. Lynn supervised the aquifer characterization activities and performed groundwater modeling to estimate the mobility of the released contamination. Additionally numerical modeling was used to estimate the ground water plume geometry to assist in further remedial activities.

Former Recycling Facility, Multnomah County, OR
Lynn Green was the Senior Scientist for the groundwater investigation conducted addressing the historical release of gasoline, diesel, pentachlorophenol, and polychlorinated biphenyls released from several abandoned USTs. Mr. Green supervised all aquifer characterization activities.

Convent, Northern Willamette Valley, OR
Lynn Green and Neil Woller of ENW co-managed the characterization of a former sewage treatment facility located on the Convent’s grounds. The characterization plan was designed to determine the feasibility of landfilling the facility on-site. Samples of trapped water, sewage, sludge, and soils underlying the leach field were collected and analyzed for a complete suite of potential contaminant compounds. The laboratory analytical results were evaluated in comparison with Environmental Protection Agency Region IX Preliminary Remediation Goals and the Oregon Department of Environmental Quality’s Water Quality Standards. 

Convent, Northern Willamette Valley, OR
Lynn Green and Neil Woller of ENW co-managed the characterization of the former domestic refuse disposal area (i.e., unregulated dump) located on the Convent’s grounds. The characterization plan was designed to determine the feasibility of abandoning the refuse on-site with no further action taken. The “dump” site was located in close proximity to a sensitive ecological area (delineated wetland). Samples of ground water, leachate, and soils underlying the refuse were collected and analyzed for a complete suite of potential contaminant constituents.