Preoperational Subsurface Conditions at the Idaho Nuclear Technology and Engineering Center Service Wastewater Discharge Facility

The Idaho Nuclear Technology and Engineering Center (INTEC) Service Wastewater Discharge Facility replaces the existing percolation ponds as a disposal facility for the INTEC Service Waste Stream. A preferred alternative for helping decrease water content in the subsurface near INTEC, closure of the existing ponds is required by the INTEC Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Record of Decision (ROD) for Waste Area Group 3 Operable Unit 3-13 (DOE-ID 1999a). By August 2002, the replacement facility was constructed approximately 2 miles southwest of INTEC, near the Big Lost River channel. Because groundwater beneath the Idaho National Engineering and Environmental Laboratory (INEEL) is protected under Federal and State of Idaho regulations from degradation due to INEEL activities, preoperational data required by U.S. Department of Energy (DOE) Order 5400.1 were collected. These data include preexisting physical, chemical, and biological conditions that could be affected by the discharge; background levels of radioactive and chemical components; pertinent environmental and ecological parameters; and potential pathways for human exposure or environmental impact. This document presents specific data collected in support of DOE Order 5400.1, including: four quarters of groundwater sampling and analysis of chemical and radiological parameters; general facility description; site specific geology, stratigraphy, soils, and hydrology; perched water discussions; and general regulatory requirements. However, in order to avoid duplication of previous information, the reader is directed to other referenced publications for more detailed information. Documents that are not readily available are compiled in this publication as appendices. These documents include well and borehole completion reports, a perched water evaluation letter report, the draft INEEL Wellhead Protection Program Plan, and the Environmental Checklist

Interannual Herbaceous Biomass Response to Increasing Honey Mesquite Cover on Two Soils

This study quantified herbaceous biomass responses to increases in honey mesquite (Prosopis glandulosa Torr.) cover on two soils from 1995 to 2001 in north central Texas. Vegetation was sampled randomly with levels of mesquite ranging from 0% to 100%. With no mesquite covering the silt loam soils of bottomland sites, peak herbaceous biomass averaged (6SE) X 300 +/- 210 kg ha-1 vs. –560 +/- 190 kg ha-1 on clay loam soils of upland sites (P = 0.001). A linear decline of 14 +/- 2.5 kg ha-1 in herbaceous biomass occurred for each percent increase in mesquite cover (P = 0.001). The slope of this decline was similar between soils (P=0.135). Herbaceous biomass with increasing mesquite cover varied between years (P=0.001) as did the slope of decline (P=0.001). Warm-season herbaceous biomass decreased linearly with increasing mesquite cover averaging a 73 +/- 15% reduction at 100% mesquite cover (P = 0.001) compared to 0% mesquite cover. Cool-season herbaceous biomass was similar between soils with no mesquite, 1 070 +/- 144 kg ha-1 for silt loam vs. 930 +/- 140 kg ha-1 for clay loam soils, but averaged 340 +/- 174 kg ha-1 more on silt loam than on clay loam soils at 100% mesquite cover (P = 0.004). Multiple regression analysis indicated that each centimeter of precipitation received from the previous October through the current September produced herbaceous biomass of 51 kg ha-1 on silt loam and 41 kg ha-1 on clay loam soils. Herbaceous biomass decreased proportionally with increasing mesquite cover up to 29 kg ha-1 at 100% mesquite cover for each centimeter of precipitation received from January through September. Increasing mesquite cover reduces livestock forage productivity and intensifies drought effects by increasing annual herbaceous biomass variability. From a forage production perspective there is little advantage to having mesquite present. The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202