Installation Restoration Program Stage 3. McClellan Air Force Base, California. Remedial Investigation/Feasibility Study Groundwater Sampling and Analysis Program Data Summary


Book Description

Concentrations of purgeable halocarbon and aromatic compounds detected in samples collected from 40 monitoring wells and Six Area D extraction wells exceeded state and federal drinking water standards. These 32 monitoring wells are located on base in Areas A, B, C, D, and Adjacent On-Base Areas, and off-base in the Northwest and Southwest Areas. There was no definable increase from the previous sampling period (1 April through 30 June, 1988). The Area D extraction system is effectively operating to change hydraulic gradients based on differences in hydraulic heads specified for the system. Contaminant concentrations continue to decrease in deep zone monitoring wells. Samples from several middle zone monitoring wells show and decreasing trend except for this sampling period when concentrations increased. Decreasing contaminant concentrations have recently stabilized in shallow zone monitoring wells located outside the extraction system well-field. (FR).




Installation Restoration Program Stage 3. McClellan AFB, California Remedial Investigation/Feasibility Study Groundwater Sampling and Analysis Program January Through March 1989 Data Summary


Book Description

This Data Summary presents the results of groundwater sampling activities conducted on and in the vicinity of McClellan Air Force Base from the sampling period of January through March, 1989. Concentrations of purgeable halocarbons and aromatic compounds detected in 336 wells (26 monitoring wells are located on base in Area A, B, C, D, and adjacent on-base areas and off-base in the Northwest and Southwest areas. There was no detected increase in the areal extent of contaminated groundwater, nor was there any increase in the depth that contaminated groundwater was detected. The Area D extraction system is effectively operating to change hydraulic gradients, so groundwater in Area D flows toward the extraction wells. Contaminant concentrations have decreased in Area D deep zone monitoring wells. Samples from three middle zone monitoring wells located in Area D also show decreases in contaminant concentration during this sampling period. Decreasing contaminant concentrations have stabilized in shallow zone monitoring wells located off-base, west of Area D.










Installation Restoration Program, Stage 3, McClellan Air Force Base. Preliminary Groundwater Operable Unit Remedial Investigation (Hydrogeologic Assessment) Sampling and Analysis Plan


Book Description

This report presents the sampling and analysis plan for the hydrogeologic assessment to be conducted at McClellan AFB, California. Objectives of the assessment are characterization of hydrogeologic conditions and further definition of the extent of groundwater contamination beneath McClellan AFB. The primary uses of the data from the assessment will be to determine which areas may require groundwater operable unit remedial investigations and to evaluate groundwater remedial alternatives in future work. The hydrogeologic investigation is intended to: identify geologic and hydrologic characteristics of hydrogeologic units: determine continuity of waterbearing zones and aquitards; more clearly define horizontal and vertical determination. Data obtained from the assessment will provide a framework within which potential groundwater operable units may be determined and more effectively evaluated in the future. The scope of work includes: lithologic and geophysical logging of 19 pilot holes to depths of 360 feet; construction of as many as 51 monitoring wells in 19 well cluster locations; installation of 34 piezometric wells; sampling and analyses of all new monitoring wells; performance of 2 multiple-well and 40 single-well aquifer tests; and evaluation of the effects of local groundwater flow due to on-base water supply wells. (EDC).







Installation Restoration Program. Stage 3. McClellan Air Force Base. Quality Assurance Project Plan


Book Description

This document has been prepared for the United States Air Force for the purpose of aiding in the implementation of final remedial action plan; and the ongoing nature of the Remedial Investigation/Feasibility Study, along with the evolving knowledge of site conditions and chemical effects on the environment and health, must be considered when evaluating this document, since subsequent facts may become known which may make this document premature or inaccurate. (The attached Radian document has been reviewed as a matter involved in litigation and has been approved for release to the general public.) This document is the McClellan AFB RI/FS Quality Assurance Project Plan (OAPP), and contains procedures for the collection, analysis and documentation for all anticipated sampling and analysis tasks. These include groundwater monitoring well installation, geophysical techniques, and sampling and analysis for groundwater, surface water, sediment, soil, soil vapor, and air. Keywords: Sampling procedures; Analytical procedures; Quality assurance procedures. (JHD).




Installation Restoration Program (IRP) Stage 3. Groundwater Sampling and Analysis Program for McClellan Air Force Base, California, October Through December 1993. Data Summary


Book Description

This Data Summary presents the results of groundwater sampling activities conducted on and in the vicinity of McClellan Air Force Base during the sampling period of October through December 1993. Concentrations of purgeable hydrocarbons and aromatic compounds detected in wells (44 monitoring wells, 6 extraction wells, and 1 extraction well composite) exceeded state and/ or federal drinking water standards. These wells are located in Sectors A, B, C, and D.




Installation Restoration Program (IRP) Stage 3. Groundwater Sampling and Analysis Program for McClellan Air Force Base, California, April Through June 1993. Data Summary


Book Description

This Data Summary presents the results of groundwater sampling activities conducted on and in the vicinity of McClellan Air Force Base during the sampling period of April through June 1993. Concentrations of purgeable hydrocarbons and aromatic compounds detected in wells (48 monitoring wells, 5 extraction wells, and 1 extraction well composite) exceeded state and/or federal drinking water standards. Twenty-nine (29) monitoring wells exceeded the maximum concentration levels (MCLs) for one or more inorganic analytes. Nineteen of the 29 wells exceeding MCLs have not been sampled since the implementation of the nonfiltering procedure. These wells are located in Sectors A, B, C, and D.




Installation Restoration Program (IRP) Stage 3. Groundwater Sampling and Analysis Program for McClellan Air Force Base, California, April-June 1994. Data Summary


Book Description

This data summary presents the results of groundwater sampling activities conducted on and in the vicinity of McClellan Air Force Base during the sampling period of April through June 1994. Concentrations of one or more contaminants equaled or exceeded state and/or federal drinking water standards in 111 wells (100 monitoring wells, 10 extraction wells, and one extraction well composite). These wells are located in Sectors A, B, C, and D.