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Title: 100-OL-1 Operable Unit Pilot Study: XRF Evaluation of Select Pre-Hanford Orchards

Prior to the acquisition of land by the U.S. Department of War in February 1943 and the creation of the Hanford Site, the land along the Columbia River was home to over 1000 people. Farming and orchard operations by both homesteaders and commercial organizations were prevalent. Orchard activities and the associated application of lead arsenate pesticide ceased in 1943, when residents were moved from the Hanford Site at the beginning of the Manhattan Project. Today, the residues from historical application of lead arsenate pesticide persist in some locations on the Hanford Site. In 2012, the U.S. Department of Energy, U.S. Environmental Protection Agency, and Washington State Department of Ecology established the 100-OL-1 Operable Unit (OU) through the Hanford Federal Facility Agreement and Consent Order, known as the Tri-Party Agreement. The pre-Hanford orchard lands identified as the 100-OL-1 OU are located south of the Columbia River and east of the present-day Vernita Bridge, and extend southeast to the former Hanford townsite. The discontinuous orchard lands within 100-OL-1 OU are approximately 20 km2 (5000 ac). A pilot study was conducted to support the approval of the remedial investigation/feasibility study work plan to evaluate the 100-OL-1 OU. This pilot study evaluated the usemore » of a field portable X-ray fluorescence (XRF) analyzer for evaluating lead and arsenic concentrations on the soil surface as an indicator of lead arsenate pesticide residues in the OU. The objectives of the pilot study included evaluating a field portable XRF analyzer as the analytical method for decision making, estimating the nature and extent of lead and arsenic in surface soils in four decision units, evaluating the results for the purpose of optimizing the sampling approach implemented in the remedial investigation, and collecting information to improve the cost estimate and planning the cultural resources review for sampling activities in the remedial investigation. Based on the results of the pilot study, the recommendations for the revision of the work plan are as follows: • characterize the surface soil using field portable XRF measurements with confirmatory inductively coupled plasma mass spectroscopy sampling for the remedial investigation • establish decision units of similar defined areas • establish a process for field investigation of soil concentrations exceeding the screening criteria at the border of the 100-OL-1 OU • define data quality objectives for the work plan using the results of the pilot study and refining the sampling approach for the remedial investigation.« less
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Resource Type:
Technical Report
Research Org:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
Sponsoring Org:
Country of Publication:
United States
LEAD; ARSENIC; SOILS Hanford; XRF; orchard; 100-OL-1; lead; arsenic; lead arsenate; soil