Idaho National Laboratory Environmental Monitoring Plan

4.3 Groundwater
Historic waste disposal practices have produced localized areas of contamination in the SRPA
beneath the INL Site. The SRPA is the source of regional drinking water and supplies irrigation water to a
large, regional agricultural and aquaculture economy. Onsite groundwater samples are taken from wells
near each facility, in areas of known contamination, and regionally across the INL Site (including
upgradient of INL Site operations). Contaminants resulting from past INL Site operations have been
detected in the SRPA beyond the INL Site southern boundary at concentrations far below regulatory
limits. Offsite groundwater samples are taken downgradient of the INL Site near the INL Site boundary
and near the terminus of the SRPA.
Onsite groundwater is currently monitored at the INL Site by multiple organizations to:
Satisfy specific CERCLA-related remedial action objectives and/or regulatory requirements contained
in RODs, RCRA regulations, WLAPs, and DOE orders
Determine the nature and extent of groundwater contamination during CERCLA remedial
investigation/feasibility study activities
Evaluate general groundwater conditions, and contaminant fate and transport on a regional and
subregional scale (as performed by the USGS and WAG 10).
The groundwater monitoring programs established by the contractors responsible for managing and
operating INL Site facilities, at a minimum, address regulatory compliance and remediation goals at each
of the facilities for which they have management responsibility. DOE/ID-11034, “Idaho National
Engineering and Environmental Laboratory Groundwater Monitoring Plan Update,” 36 provides an
overview of the routine groundwater monitoring conducted onsite and specifies how the recommended
elements of a groundwater monitoring program under DOE Order 450.1 (Reference 1) are met. Figure 4-5
shows regional groundwater monitoring locations, and Figure 4-6 shows detailed onsite groundwater
monitoring locations.
4.3.1 INL Contractor
The INL contractor is responsible for groundwater monitoring at the MFC facility per the CERCLA
ROD, and at the RTC facility in compliance with the RTC WLAP permit. Proposed monitoring
associated with the MFC WLAP application is expected to commence in 2009.
4.3.2 ICP Contractor
The ICP contractor is responsible for groundwater monitoring conducted at all other CERCLA site
monitoring locations, WLAP compliance at INTEC, and RCRA closure monitoring at INTEC’s Waste
Calcine Facility. The ICP contractor currently performs all data interpretations to determine the
cumulative impact of all CERCLA sites at the INL Site.
4.3.3 USGS
USGS monitors SRPA wells within its defined regional network (both onsite and at boundary
locations) to study contaminant migration and determine groundwater quality and quantity as they relate
to INL Site operations. INL Site boundaries are monitored to detect groundwater contaminants entering
and leaving the INL Site. Wells within the INL Site boundary are monitored to evaluate contaminant
movement in the SRPA between facilities.
4-11 Environmental Surveillance