Final report : 2004 monitoring well installation and sampling at Centralia,Kansas.

LaFreniere, L. M.

Argonne National Laboratory

关键词: Organic Compounds;    Attenuation;    Dechlorination;    Stabilization;    Us Epa;   

DOI  :  10.2172/885498
RP-ID  :  ANL/ER/TR-04/011
RP-ID  :  W-31-109-ENG-38
RP-ID  :  885498

美国|其它

来源: UNT Digital Library

【 摘 要 】

This document reports on monitoring well installation and sampling in 2004 at the location of a grain storage facility formerly operated in Centralia, Kansas, by the Commodity Credit Corporation (CCC) of the U.S. Department of Agriculture (USDA). Argonne National Laboratory is conducting environmental investigations of carbon tetrachloride contamination in groundwater at this site for the CCC/USDA. With the approval of the Kansas Department of Health and Environment (KDHE), Argonne installed six monitoring wells at the former facility in July 2004 to supplement existing monitoring points (piezometers) installed during Argonne's Phase I investigation in 2002. Together, the monitoring wells and piezometers constitute a monitoring network designed to (1) confirm the lateral distribution of carbon tetrachloride in the groundwater, (2) track any migration of contaminants that might take place, and (3) monitor aquifer geochemical characteristics. To verify that the six new monitoring wells had been developed adequately, they were sampled after their installation in July 2004 for analysis for volatile organic compounds (VOCs). The monitoring wells were sampled again in August 2004, after a stabilization period of four weeks. Five of the Phase I piezometers were also sampled in August 2004. Results of analysis of the August 2004 groundwater samples for VOCs confirmed the Phase II investigation's findings (based on sampling in March and April 2003) that carbon tetrachloride contamination in groundwater is generally confined to the boundary of the former CCC/USDA facility. Little migration of contamination from the former facility has been evident. Nevertheless, the network of monitoring wells now in place may not be adequate to delineate the extent of the plume. Future expansion of the network will proceed per agreement between the CCC/USDA and the KDHE. The groundwater samples collected in August 2004 were also analyzed for attenuation parameters that are helpful in determining whether the subsurface environment is suitable for natural in situ biodegradation of carbon tetrachloride. A preliminary screening of the results with a protocol of the U.S. Environmental Protection Agency showed limited evidence for active reductive dechlorination, one of the anaerobic processes by which carbon tetrachloride is biodegraded. These results indicate that additional monitoring of the groundwater contamination at the former CCC/USDA facility at Centralia is merited. On the basis of the findings and conclusions of the Phase I and Phase II investigations, as well as the results of the 2004 well sampling, a program of twice yearly groundwater monitoring in the expanded network is recommended to collect the data necessary to (1) monitor changes in plume dynamics and (2) evaluate the suitability of monitored natural attenuation as a remedial option for the Centralia site. This monitoring program should be conducted for a minimum of two years. After completion of the two-year monitoring program, remedial action objectives and potential corrective action alternatives are to be developed to address the groundwater contamination at Centralia.