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map inventories and research continued, a major part of the programs was devoted to interdisciplinary efforts to provide products that were directly applicable to landuse and related water-resources planning and management, including ground-water protection. This new direction had its roots in the 1960's, in response to increasing public demand that future development and growth should be in harmony with the environment. The State of Connecticut, which by 1980 had a relative abundance of natural-resource data, provided an ideal laboratory for determining how those data could be integrated into planning and management activities. The Connecticut Geology-Soil Task Force, an informal volunteer group that included members of the USGS, U.S. Soil Conservation Service, and five State agencies, was created in 1969 to “help resolve conflicts between limitations imposed by the natural environment and the requirements of our expanding population.” As part of their activities, members of the Task Force selected the area covered by the Ellington 7.5-minute quadrangle map in north-central Connecticut as a demonstration area for studying ways to develop flexible interpretation systems for planners and those empowered to regulate land and water use. The report on this work showed how geologic, hydrologic, and soil data could be integrated to provide a base for land- and water-use planning and management. Single-factor maps were the key tool used in evaluating intended land or water use. These maps, developed at a common scale, included existing inventory products, such as topographic maps, and derivative products, such as depth-to-bedrock maps, that aggregated information from soil surveys, geologic mapping, and hydrologic studies (table 1). The Ellington example demonstrated how the relevant singlefactor maps could be selected from management guidelines or regulations and used, either singly or stacked together as overlays, in order to rule out areas unsuitable for a particular use or to locate areas where characteristics may be suitable or even ideal for a particular use. These single-factor maps were in a sense paper forerunners of the integrated, on-line data bases that form the geographic information system now being developed. In 1971, the USGS began the Connecticut Valley Urban Area Project (CVUAP).
The goal, similar to that of the Connecticut Geology-Soils Task Force, was to provide “earth-resource information in a form that is readily understandable and readily available to planners and other decision makers responsible for land use and resource management.” The CVUAP study area included about 5,000 square miles in parts of Connecticut, Massachusetts, New Hampshire, and Vermont, and was selected owing to the availability of naturalresources information (particularly in Connecticut) and the success of the methodology developed for the Ellington area. The study was conducted in cooperation with the States of Connecticut and Massachusetts. During a 6-year period, more than 200 single-factor maps were produced. After 1976, in order to finish selected hydrologic products, the study was continued in Connecticut as part of that State's cooperative program. During the CWUAP, demonstrations on the applications of the map information were given continuously to groups of State, regional, and local planners in order to encourage the subsequent use of natural-resource information in decisionmaking. The NRC has continued this dialogue with the user community through workshops, guidebooks, and other outreach programs for local land-use commissions. The final phase of the integration process, the use of natural-resource information in ground-water protection programs, began in 1977 with the State “208” program, mandated by Section 208 of the Federal Clean Water Act. The Connecticut program included cooperative studies with the USGS to assess areas of existing and potential ground-water contamination and to develop methods for defining recharge areas of major aquifers and areas contributing flow to major pumping centers. This work used much of the information on ground-water flow systems and aquifer boundaries obtained through earlier cooperative inventories and hydrologic research, the techniques of single-factor map production and aggregation developed by the CWUAP, and new techniques of simulation modeling of stratified-drift aquifer systems that were developed through USGS research. As an example of the use of naturalresource information for ground-water protection that was developed through the “208” program, researchers were able to
* 1 = Primary importance; 2=Secondary importance; 3 = Indirectly related
delineate the three land areas that are sources of recharge for a stratified-drift aquifer in western Connecticut (fig. 5). The first area includes land overlying the aquifer where recharge is derived from precipitation that percolates to the water table. The limits of this area were determined from surficial geologic maps and hydrogeologic maps. Adjacent till and bedrock areas that are not drained by perennial streams also contribute recharge,
either from subsurface inflow or from infiltration of runoff near the margins of the aquifer. Finally, studies of this aquifer and others elsewhere in Connecticut show that they are hydraulically connected to the streams that traverse them. Pumping is therefore likely to induce recharge from the stream, and the entire upstream drainage area that contributes runoff will constitute a third recharge area. The limits of this area can also be defined by the drainage divides as determined from topographic maps. This three-fold division of recharge areas and the technique for estimating their extent are applicable to most of the stratified-drift aquifers in Connecticut, and this knowledge can provide a framework for local aquifer-protection programs. Many towns in Connecticut have adopted programs that regulate activities in the recharge areas through zoning and site-plan review. For large stratified-drift aquifers, flow modeling has been used to limit the protection to the area that contributes flow to a specified pumping center.
The concepts and products developed from the CWUAP, the drainage-basin studies, and the “208” cooperative programs influenced the Department of Environmental Protection to extend standards and classifications to ground water. The drainagearea maps provided a suitable physical framework for classifying both surface and ground water in most of the State. Within each basin unit, existing information on aquifer boundaries, locations of publicsupply wells and known or potential contaminant sources, water quality, and land use was plotted, tabulated, and updated where necessary. To identify areas of the State where hydrogeologic conditions were most favorable for the discharge of wastes, criteria were first developed for factors such as the lithology and thickness of materials above and below the water table and their proximity to ground-water discharge zones. Single-factor maps of these features were developed and used to aid in identifying suitable areas.
Ground-Water Protection in the Future
Today Connecticut has a comprehensive ground-water protection strategy, an abundance of natural-resources information to aid in protecting this resource, and, in the State's Natural Resources Center (NRC), a central facility for disseminating this information to the user community. But where will the State go from here? What natural-resources information will be
protection programs and will require a thorough understanding of the hydrology of each major drainage basin. Cooperative programs are continuing to move from natural-resource inventories to monitoring and process-oriented research. Current ground-water protection activities include monitoring of surface-water quality, streamflow, and ground-water levels to characterize dynamic changes; a comprehensive water-use program; investigations of the hydraulic characteristics of till; and studies of the occurrence of natural radionuclides and pesticides in ground water. In two other studies that are funded by the Federal program, hydrologists are investigating relations between ground-water quality
Figure 5. Delineation of recharge areas for a stratifieddrift aquifer near Cannondale in southwestern Connecticut. (Information retrieved and plotted through the Connecticut Geographic Information System.)
needed in the future? The general direction is clearly toward basinwide management of all water in order to satisfy competing demands for this resource. This demand for water will result in the continued integration of surface- and ground-water quality
0 1 2
Drainage area upstream
and land use in stratified-drift aquifers and the factors that control induced recharge. Two State management programs that are in their infancy illustrate the general direction of future cooperative efforts to protect ground water. The development of an Aquifer-Wellhead Protection Program for high- and moderate-yield aquifers proposes several management measures that range from land acquisition of well sites to regulatory prohibitions and Zoning controls. Successful implementation will be highly dependent upon hydrogeologic data, maps, and analytical methods for accurately defining aquifer boundaries, areas of aquifers contributing water to pumped wells, potential well sites, and aquifer recharge areas. Some information exists for all of the 158 high- and moderate-yield stratified-drift aquifer areas identified in Connecticut (fig. 6), but this information is often insufficient to meet the needs of this program. Providing comprehensive scientific information needed for each area in a reasonable time frame presents a significant challenge. Through the cooperative program, new applications of geophysical methods for characterizing stratified-drift aquifers are presently being tested. The State's Water Use and Allocation Program presents another challenge for the cooperative program. Competition for
| Moderate-yield aquifer study area
| High-yield aquifer study area
finite water resources has already caused degradation in the quality of surface waters in some basins to the extent that careful monitoring will be required to prevent further degradation of these waters to the point where they fail to meet water-quality criteria. As more ground water that would normally discharge to these streams is diverted by pumping from wells, the water-quality problems will intensify. The Department of Environmental Protection (DEP) has instituted a permit system for water use and withdrawal in order to make the best use of the available resources. Permit decisions will rely heavily on flow models of stream-aquifer systems, longterm streamflow data (particularly lowflow characteristics), water-quality data, and predictive water-quality models. Water-use information will also be relied upon to quantify existing water use in each basin and to estimate future uses and demands. The DEP, using data from USGS cooperative studies, has identified other major information needs that are essential for managing ground water and will develop a new long-range plan to meet these needs. Foremost among these are information on the nature of the ground-water flow system in fractured bedrock; relations between land use and ground-water quality in bed
rock aquifers; the transport and fate of grated, and disseminated? Through the chemical contaminants in the subsurface; cooperative program, a USGS/NRC pilot and the suitability of fine-grained glacial project in 1985 demonstrated the efficiency deposits for waste disposal. and flexibility of computerized geographic
How will all the existing and new information systems for such tasks. This information be managed, analyzed, inte- pilot project led to the creation of the
Figure 7. Map of the Broad Brook quadrangle in north-central Connecticut showing selected information for water-supply planning. (Information retrieved and plotted through the Connecticut Geographic Information System.)