HR: 0800h
AN: H11A-0148    [Abstracts]
TI: Hydrologic Monitoring in the Deep Subsurface to Support Repository Performance
AU: * Hubbell, J M
EM: joel.hubbell@inl.gov
AF: INL, PO Box 1625, MS 2107, Idaho Falls, ID 83404, United States
AU: Heath, G L
EM: gail.heath@inl.gov
AF: INL, PO Box 1625, MS 2107, Idaho Falls, ID 83404, United States
AU: Scott, C L
EM: clark.scott@inl.gov
AF: INL, PO Box 1625, MS 2107, Idaho Falls, ID 83404, United States
AB: The INL has installed and operated several vadose and ground water monitoring systems in arid and humid sites to depths of about 200m. Some of these systems have been in continuous operation for over 12 years. It is important that the systems be physically robust, simple, yet versatile enough that it can operate for extended time periods with little or no maintenance. Monitoring instruments are frequently installed and run to characterize the site, collect data during site operation, and continue to run for long-term stewardship, necessitating sensors that can be maintained or serviced. Sensors are carefully chosen based on the perceived data requirements over the life of the site. An emphasis is given on direct measurements such as tensiometers (portable and advanced), neutron probe, drain gauge, temperature, wells or sampling for fluids and gases. Other complementary data can include using TDR/capacitance, radiation detectors, and larger scale geophysical techniques (3-d resistivity and EM) for volumetric measurements. Commercially available instruments may have to be modified for their use at greater depths, to allow multiple instruments in a single borehole or to perform the intended monitoring function. Access tubes (some open at the bottom) can be placed to allow insertion of multiple sensors (radiation, neutron and portable sensors/samplers), future drilling/sampling and to install new instruments at a later time. The installation techniques and backfill materials must be chosen and the measurement technique tested to ensure representative data collection for the parameters of interest. The data collection system can be linked to climatic data (precipitation, barometric pressure, snow depth, runoff, surface water sources) that may influence the site's subsurface hydrology. The instruments are then connected to a real-time automated data collection system that collect, stores, and provides access to the data. These systems have been developed that allow easy access, automatic data quality checks with notification, processing, and presentation of the data in real time through the web. The systems can be designed to manipulate/test the system remotely. Data from several sites will be presented showing that continuous monitoring is necessary to detect rapid changes in the deep vadose zone and ground water at fractured rock sites.
DE: 1835 Hydrogeophysics
DE: 1895 Instruments and techniques: monitoring
DE: 5104 Fracture and flow
DE: 5194 Instruments and techniques
DE: 8045 Role of fluids
SC: Hydrology [H]
MN: 2007 Fall Meeting