Long time-series of water levels in major aquifers serve as critical baseline data for resource management and analyses of aquifer response to pumping, climatic variability, drought hazards, seawater intrusion, and interaction with streams and their ecosystems. The Delaware Geological Survey (DGS) currently monitors groundwater levels in a network of 68 wells in Delaware. The data are maintained in a relational database and served to stakeholders via a web interface. DGS periodically reviews the network to ensure it is meeting the needs of the State. Recent studies (Army Corps of Engineers, 2008; He and Andres, 2011) indicated that the existing hydrologic information of New Castle County , including time series of water levels, is not adequate for characterizing groundwater availability and proactively managing the groundwater resource. Over the last several years the DGS has given presentations to the Delaware Water Supply Coordinating Council (WSCC) describing a proposed workflow for addressing this need.
As part of this project we are automating data collection, reduction, and archiving to increase efficiency and quality control while sustaining growth of the statewide network over time. We are inspecting the condition of wells in the current monitoring network (see map) in addition to wells that may be included at a later date, using down-hole videos, slug tests, and wellhead security assessments. This supports evaluation of the long-term availability and sustainability of the groundwater supply, management of the resource, and a myriad of uses by the environmental management, engineering, and science communities.
Progress as of July 24, 2012
A corehole to 819 feet below land surface was completed at Woodland Beach Wildlife Area (WBWA).
A corehole to 776 feet below land surface was completed at the the Town of Smyrna's High St. water plant.
All core samples (525) and photographs (225) have been cataloged and are available for inspection on request. Processing and analysis of core samples to date has included grain-size testing of more than 100 samples, moisture content and density testing of 45 samples, and sub-sampling of 35 cores for chemical and mineralogic testing.
Water pressure/temperature data loggers have been installed and activated in six additional existing monitoring wells.
A cooperative agreement has been executed with the US Geological Survey (USGS) to operate stream gages on Dove Nest Branch and Spring Mill Branch. These stations are now operating and data are available on the USGS web site.
Media coverage has appeared on the University of Delaware web site, The News Journal, (June 8), and WBOC-TV Salisbury (June 8).