Former Timber Products Sawmill, Fort Bragg, California, National Lumber Products Manufacturer

Sampling, analysis, and evaluation was conducted of sediments collected from nine mill ponds up to 5 acres in size for the presence of constituents of concern, including hydrocarbons, metals, PCSs, and dioxins/furans. Field activities required the fabrication of a pontoon mounted, direct-push sampling rig to coll ect continuous core samples through 35 feet of sediment deposit ed over native bedrock.

 

Port of San Diego, San Diego, California Former Whittaker Corporation Boatyard

Marine sediment samples were collected and analyzed to assess whether the operating boatyard represented a source of the constituents of concern present. Transport and fate modeling was conducted to assist in assessing whether onsite or offsite sources were contributors.

Sediment Mapping, 6-Mile River Segment, Washington

One of our professional staff conducted and served as a technical advisor for PCB sediment mapping for the a major river system in Washington. A section of the river approximately 6 miles long was contaminated by PCB. Extensive sampling of the river sediment was conducted, but an accurate PCB distribution map was needed to guide the cleanup activities. Utilizing his expertise in statistical and geostatistical techniques, our professional staff evaluated the performance of several mapping techniques including kriging, inverse distance weighted (IDW), and Thiessen Polygon methods. He examined the differences in these methods, suggested ways to improve the sediment mapping, and provided suggestions on how to assess sediment-mapping uncertainty.

Sediment Visualization and Calculation, Northeast Florida

In a project in northeastern Florida, one of our professional staff utilized visual imagery to visualize and calculate the 3-D distribution of PAH contamination in sediment. The 3-D delineations and calculated volumes were crucial in the development of an excavation plan.

Geology and COC Distribution in Sediment, West Washington

In western Washington, one of our professional staff developed a 3-D model of the site including the upland area and part of a major lake. He visualized the geology and COC distribution in both the upland and the lake sediment to assist remedial design.