Integrated Training Area Management EA and Final FNSI

complicated topography, and micro-climatic variability make prediction of permafrost difficult. Isolatedpatches of permafrost are found in areas under sandy gravel from 2 to 40 feet below ground level, withthickness varying from 10 to 118 feet. A relatively large portion of the landscape has discontinuouspermafrost, but existing and abandoned river channels, lakes, wetlands, and other low-lying areas arelikely permafrost-free (Williams 1970). Gerstle River Training Area has a shallow permafrost table(below 10 to 20 inches) that occupies a broad outwash plain (Rieger et al. 1979). Permafrost conditions atBlack Rapids Training Area are assumed to be similar to those of Donnelly Training Area.Only a small proportion of Donnelly Training Area is presently affected by permafrost degradation,which is indicated by the presence of thaw ponds. Permafrost degradation appears to be less compared toFort Wainwright due to the cooler climate and higher elevations, and the prevalence of thaw-stable,gravelly soils at Donnelly Training Area. However, areas dominated by loess or other silty sediments maybe more vulnerable to permafrost degradation. Continued climatic warming or disturbance of the groundsurface may increase the amount of thermokarst at Donnelly Training Area.3.1.2 Environmental ConsequencesAlternative 1: Continue ITAM Program without a Management Plan (No Action)Under this alternative, the ITAM program would continue but without a management plan. TRI wouldcontinue to provide administrative and logistical support to ensure timely and efficient implementation ofthe ITAM program. GIS would continue to provide mapping and spatial assistance in characterizing soilsand soil impacts to support and enhance management efforts. Impacts of the TRI, LRAM, SRA, andRTLA programs on soil resources are discussed below.TRIThe TRI program would ensure land management practices that meet the Army’s needs while minimizingimpacts on the environment. Range facility inventories, terrain analysis, training area configuration, andtraining land distribution are measures utilized under this program to integrate natural resourceconditions, including soils, with range operations and training requirements.LRAMAlthough any project involving earth moving will result in soil disturbance, most LRAM projects wouldresult in long-term beneficial impacts to soils.Site selection for gravel pit development would be based on soils and hydrology maps, ground truthing,and sample testing. These methods would identify areas that minimize natural resource impacts whilemeeting construction needs. Due to the lack of adequate gravel sources in Yukon Training Area, gravelextraction in this training area would include blasting bedrock with explosives and subsequent crushingand mixing to create gravel. The proposed quarry area, pending drill core testing, would be the northernBravo Battery in the northwest area of Fort Wainwright. Selection of this site would followrecommendations from a gravel inventory conducted for the Salcha-Delta Soil and Water ConservationDistrict during the summer of 2004 (Engebretson 2005).Permafrost areas would be avoided when possible, and consultation with the Department of Public Worksis necessary for all projects to determine if dig permits are required. Gravel extraction procedures wouldspecify that surface overburden (soil and vegetation) be rolled to the outer edges of the pit, then placedand notched to facilitate adequate drainage. This overburden would be reused for gravel pit reclamation.Side barrow (gravel extraction along roadsides) would typically be associated with trail and road upgrade_____________________________________________________________________________________________Environmental AssessmentUnited States Army Alaska, Integrated Training Area Management ProgramManagement Plan 19