Surface barrier research at the Hanford Site
- Pacific Northwest National Lab., Richland, WA (United States)
At the DOE Hanford Site, a field-scale prototype surface barrier was constructed in 1994 over an existing waste site as a part of a CERCLA treatability test. The above-grade barrier consists of a fine-soil layer overlying coarse layers of sands, gravels, basalt rock (riprap), and a low permeability asphalt layer. Two sideslope configurations, clean-fill gravel on a 10:1 slope and basalt riprap on a 2:1 slope, were built and are being tested. Design considerations included: constructability; drainage and water balance monitoring, wind and water erosion control and monitoring; surface revegetation and biotic intrusion; subsidence and sideslope stability, and durability of the asphalt layer. The barrier is currently in the final year of a three-year test designed to answer specific questions related to stability and long-term performance. One half of the barrier is irrigated such that the total water applied, including precipitation, is 480 mm/yr (three times the long-term annual average). Each year for the past two years, an extreme precipitation event (71 mm in 8 hr) representing a 1,000-yr return storm was applied in late March, when soil water storage was at a maximum. While the protective sideslopes have drained significant amounts of water, the soil cover (2-m of silt-loam soil overlying coarse sand and rock) has never drained. During the past year there was no measurable surface runoff or wind erosion. This is attributed to extensive revegetation of the surface. In addition, the barrier elevation has shown a small increase of 2 to 3 cm that is attributed to a combination of root proliferation and freeze/thaw activity. Testing will continue through September 1997. Performance data from the prototype barrier will be used by DOE in site-closure decisions at Hanford.
- Research Organization:
- US Department of Energy (USDOE), Washington DC (United States)
- DOE Contract Number:
- AC06-87RL10930
- OSTI ID:
- 576539
- Report Number(s):
- CONF-970208-Proc.; ON: DE98001967; TRN: 98:005160
- Resource Relation:
- Conference: International containment technology conference and exhibition, St. Petersburg, FL (United States), 9-12 Feb 1997; Other Information: PBD: [1997]; Related Information: Is Part Of International Containment Technology Conference: Proceedings; PB: 1140 p.
- Country of Publication:
- United States
- Language:
- English
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