Hearings and Business Meetings
Mar 30 2006
SD-366 Energy Committee Hearing Room 02:30 PM
Mr. Larry Becker
Statement of Laurence R. Becker
State Geologist and Director
Vermont Geological Survey
VT Department of Environmental Conservation
VT Agency of Natural Resources
Before Senate Energy and Natural Resources Committee,
Water and Power Subcommittee
S. 2054, “Vermont Water Resources Study”
March 30, 2006
Madam Chair and Members of the Subcommittee, I am Laurence R. Becker, Vermont State Geologist and Director of the Vermont Geological Survey, a Division of the VT Department of Environmental Conservation. Thank you for the opportunity to represent the State of Vermont in response to S. 2054 the “Vermont Water Resources Study”
The State of Vermont understands that groundwater is a fundamental resource and strongly agrees that characterizing the resource to support sound water supply and protection decisions is a necessary step to plan for the future. Vermont needs to insure that the resource will be there for wise use and long-term sustainability that encompasses both quantity and quality. We strongly support this bill and urge this body to move this water resource study authorization forward. It is recognized that such a study will take financial resources and personnel to complete. Coordination with Vermont in the proposed language is a necessary step to create a meaningful partnership between the State and the Federal Government. A viable study will meet the needs of our citizens. Local control is an important element of the Vermont ideal and the State can work best with USGS to bring the operational considerations and results of the study to our towns and municipalities.
Groundwater Use and Need for Information
Sixty-six percent of Vermont’s population depends on groundwater for their drinking water supply including municipalities, fire districts, agricultural, industrial, and commercial users and homeowners. Fisheries habitat is supported by groundwater discharge to surface waters.
For future supplies, the State has little knowledge of the location of potential high yield aquifers. Natural contamination in well water from uranium, radium, and arsenic that exceeds public health standards has also been an issue in a number of geologic settings in Vermont. Information on where the contaminants can be found is needed statewide. Vermont has seen well interference problems in tight geologic formations made worse by periods of drought. These areas need characterization. Resource vulnerability can vary depending on the nature of the geology overlying groundwater resources and this has been little characterized in relation to aquifers.
S. 2054, the “Vermont Water Resources Study”
The bill directs the United States Geological Survey in coordination with the State of Vermont to conduct a study of water resources in Vermont with an emphasis on groundwater. The focus is on aquifers, availability, existing and potential future supplies, potability, potential recharge, and the interaction of groundwater with surface water. A component of the study is the characterization of surface and bedrock geology including the effect of that geology on groundwater yield and quality. Two years after enactment, the Secretary of the Interior shall submit a report describing the study to the Senate Committee on Energy and Natural Resources and the Committee on Resources of the House of Representatives.
Groundwater Sources and Studies
In Vermont, the primary aquifers are saturated sand and gravel and water in fractured bedrock. Under all of Vermont lies the state’s bedrock geology. These rocks are tightly folded and broken as a result of the uplift of the Green Mountains. On top of the bedrock are earth materials—boulders, gravel, sand and clay—deposited as the glaciers retreated more than 12,000 year ago. Since that time, the landscape has been reworked by water. All of these layers comprise the vessel that contains Vermont’s groundwater. Surface water and groundwater are connected. Stream flows and water temperature are supported by groundwater discharge. Surface water can, in certain cases, discharge back to the subsurface to sustain higher groundwater levels.
Wells intercept groundwater flow and the water is pumped for a variety of uses. Some of the higher yield wells are screened in saturated sand and gravel to meet municipal supply needs (500-1000 gallons per minute). Higher yield bedrock wells can serve some smaller cities and towns and groupings of houses such as condominium complexes. Domestic users most often obtain water from drilled wells in bedrock that can supply as little as 2 gallons per minute to meet family demand. Springs are natural discharges where groundwater meets the surface of the land. Some water bottling companies are tapping this resource in Vermont.
Following a drought in the mid-1960s, Vermont took the first steps towards understanding the groundwater resource. This work included research on the sand and gravel aquifers in the valley bottoms. Since the 1960s, mapping has been performed at increasing levels of detail and but in decreasing degrees of coverage that has resulted in few areas of the State being completed.
In recent years, the Vermont Geological Survey is focusing on characterization of the surficial and bedrock geology at a town scale (1:24,000). Locating existing water well data provided by the State’s Water Supply Division compliments geologic mapping to produce derivative groundwater resource maps that are necessary for local and regional water supply and land use planning purposes. Resulting maps can include an overburden thickness map; an aquifer recharge potential map; a water table and/or pressure surface map and aquifer flow directions. With adequate information, aquifer maps delineating the determinable aerial extent for both the sand and gravel and bedrock aquifers can be produced that will guide town planning efforts. Mapping can indicate both the local and regional nature of Vermont aquifers and where a town may need to coordinate with neighbors to promote groundwater resource and protection goals.
These town-by-town studies are progressing slowly as limited resources are available. Approximately seven or eight towns are mapped or in progress at this time.
In relation to potability, naturally-occurring contaminants of concern pose a health risk to Vermonters. The location and severity of these threats in groundwater are not well understood. The Vermont Geological Survey has completed some initial detailed research and mapping on radioactivity, arsenic, and radon. These are localized studies. Comprehensive investigations are needed to protect the public health
Nitrate in groundwater studies are underway next to a large farm to ultimately provide information for best nutrient management practices in relation to protecting groundwater. Groundwater quality studies for other contaminants have been conducted but are in discrete areas. The nature of background groundwater quality statewide is little understood.
A developing information base for bedrock studies is a cooperative effort between the USGS and the Vermont Geological Survey to produce a new state bedrock geologic map. This will contain invaluable data on bedrock type and structure that will inform future groundwater studies of potential well yield and to understand the threats of contamination from natural and manmade sources.
Report to the Legislature
The 2002 Vermont Legislative Session recognized the importance of the resource and requires the Secretary of the Agency of Natural Resources to prepare a report on the status of groundwater and aquifers in Vermont. A January, 2003, “ Report on the Status of Groundwater and Aquifer Mapping in the State of Vermont” concluded that while Vermont appears to have an abundance of groundwater, Vermonters need to be vigilant to maintain our apparent good water quality and quantity. As Vermont’s population and economy grow, the demands for groundwater increase. Understanding Vermont’s groundwater system can help predict the location of useable groundwater supplies. Without the knowledge of aquifers and the groundwater system, this valuable resource may not be sustainable for the multiple uses in the future.
This 2003 report identifies three levels of study to develop groundwater and aquifer maps of increasing accuracy. Each level builds upon the previous level in detail and time using increasingly sophisticated tools, technical expertise, and scientific evaluation. Recent State prototype work has focused on the second level of effort at a town planning scale. The report concludes that most obvious obstacle to completing aquifer mapping statewide is the lack of a dedicated funding source for employing people to analyze and compile data, to provide contracts and grants to partners, and to purchase scientific equipment to collect data.
The State’s compelling interest is that this valuable and necessary groundwater resource be understood to protect existing uses, plan for growth, and insure for the sustainability of the health and well being of Vermonters. In the present information vacuum, towns and the State will be hard pressed to balance economic needs against protection of the resource. Given the statewide nature of the proposed study, two years seems to be a very tight window to provide such information.
With the information base that this bill supports, sound decisions can be made at the local and state level. This bill is that first necessary step to create the information template for future planning. The coordinated information gathering and studies supported by this bill will bring a range of expertise together to accomplish the task. For example, USGS brings expertise in the area of drilling, pump test analysis, groundwater modeling, and determination of sustainable yield that are necessary for a comprehensive study. The Vermont Geological Survey is already using new surficial and bedrock mapping to bring forward groundwater resource planning information. A strong partnership with USGS that takes the needs of Vermont into account is a beneficial and necessary step to meet the goals of S. 2054.
Thank you, Senator Murkowski, for the opportunity to present this testimony. As the committee deliberates, the State of Vermont is more than happy to provide any assistance that you require. I will be pleased to answer questions you and other Members of the Subcommittee may have.