Fiscal Year 2003 Integrated Monitoring Plan for the Hanford Groundwater Monitoring Project

Abstract

Groundwater is monitored at the Hanford Site to fulfill a variety of state and federal regulations: the Atomic Energy Act of 1954 and its implementing orders, the Resource Conservation and Recovery Act, the Comprehensive Environmental Response, Compensation, and Liability Act, and Washington Administrative Code. Separate monitoring plans are prepared for various requirements, but sampling is coordinated and data are shared among users to avoid duplication of effort. The U.S. Department of Energy manages these activities through the Hanford Groundwater Monitoring Project. This document is an integrated monitoring plan for the groundwater project. It documents well and constituent lists for monitoring required by the Atomic Energy Act of 1954 and its implementing orders, includes other established monitoring plans by reference, and appends a master well/constituent/ frequency matrix for the entire site. The objectives of monitoring fall into three general categories: plume and trend tracking, treatment/ storage/disposal unit monitoring, and remediation performance monitoring. Criteria for selecting wells, constituents, and sampling frequencies for the latter two categories are documented in site-specific plans. Criteria for selecting Atomic Energy Act of 1954 monitoring networks include locations of wells in relation to known plumes or contaminant sources, well depth and construction, historical data, proximity to the Columbia River, water supplies, or other areas of special interest and well use for other programs. Constituent lists were chosen based on known plumes and waste histories, historical groundwater data, and, in some cases, statistical modeling. Sampling frequencies were based on regulatory requirements, variability of historical data, and proximity to key areas. For sitewide plumes, most wells are sampled every 3 years. Wells monitoring specific waste sites or in areas of high variability will be sampled more frequently.

A New Approach to Quantify Shallow Water Hydrologic Exchanges in a Large Regulated River Reach

“…Based on historical records over the past 40 years, the range of stage spans 105 m to 109 m based on the North American Vertical Datum of 1988 (NAD88), with a maximum daily fluctuation of 2 m. In this study, the river stage observations were recorded by a pressure transducer logger (SWS-1) installed inside our study domain since the year 2001. Nearly 100 monitoring wells were constructed over the past 40 years around the 300A Area to record the inland water levels and solute concentrations for environmental monitoring purposes [49]. In this study, one monitoring well (Well 2-3), about 150 m from the river, was selected as the reference point for the inland water level.…”

“…Measurements used in this study were all collected from sensors installed in the alluvial layer. Several sandbar islands were deposited in the center of the river, forming a deep primary channel with a meandering thalweg on one side of the islands and a relatively shallower secondary channel on the opposite side of the islands (Figure 1 [49]. In this study, one monitoring well (Well 2-3), about 150 m from the river, was selected as the reference point for the inland water level.…”