Frequently Asked Questions
GROUND WATER BASICS
What is ground water?
It is slow-moving water that passes through the tiny spaces in soils and gravels, the fractures in rock layers, or through channels and caverns in limestone or dolomite. The spaces where ground water moves are called "aquifers."
Who uses ground water?
Ground water is such a part of our lives that we take it for granted. Some people don't know that the water they are consuming is derived from ground water. In Virginia, we use almost 50 billion gallons of ground water each year for homes, farms, industries, and businesses.
Where does my well water come from? What are the ground water and geological characteristics of the different parts of Virginia?
Ground water moves laterally to pumping wells. The "recharge area" for a well depends on how deep the well is and in what types of rock or sediment it is located. Throughout Virginia's five major physiographic provinces, shallow dug or bored wells are not much deeper than the water table and usually obtain water that infiltrated relatively nearby, typically less than a mile. Recharge areas for deeper wells are more variable. Recharge to wells drilled into rocks in the Piedmont and Blue Ridge also is fairly localized. Wells drilled into rocks in the Valley and Ridge sometimes intercept water that has traveled as far as several miles, particularly in limestone areas with large cave systems. In the Coastal Plain, wells drilled into deep sand layers can intercept water that traveled several tens of miles, from recharge areas that may be several counties away.
What is in my well water and how did it get there?
Several chemical constituents called "major ions" originate from the mineral grains in the rock or sediment with which ground water is in contact, and usually make up the bulk of the dissolved material. In Virginia, especially in limestone areas of the Valley and Ridge, "hard" water can have high concentrations of certain major ions that can cause scaling of plumbing fixtures and other problems. Other "minor" elements also originate from the minerals that ground water contacts, but are at lower concentrations because they do not dissolve easily or are less abundant in the minerals.
Nevertheless, some problems commonly result from certain minor elements. Large amounts of iron in the rock in some areas, particularly the Piedmont and Blue Ridge, result in iron "staining." Sulfide in ground water in parts of the Valley and Ridge where coal or natural gas is present produces an obnoxious odor.
Ground water also can be contaminated by human activities. Bacteria from septic systems, and nitrate from both septic systems and fertilizer applications, are among the most common contaminants. A wide variety of other chemicals, including organic compounds spilled from fuel and solvent storage facilities and metals from waste-disposal operations, can also contaminate ground water, but they usually affect relatively small areas. Anyone suspecting possible contamination of a water-supply well should contact their county health department.
How are surface water and ground water connected?
Most ground water comes from precipitation that falls on "recharge areas" or from the flowing water in rivers and streams. (Pollutants that it encounters on the way can be carried into the aquifer.) Most ground water doesn't just stay underground until a well is dug, though. On average, about 30 percent of stream flow is from ground water; it may reach 100 percent during droughts. Streams, lakes, springs, and wetlands continuously receive ground water discharge.
I hear a lot of technical terms when I listen to experts talk about ground water. What do these terms mean?
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GROUND WATER QUALITY, POLLUTION, AND CLEANUP
What land uses or human activities pose potential threats to ground water?
[insert Prority 5 from "Strategy"]
Which agrichemicals are the most likely polluters of well water?
Many people would think that pesticides would be most likely to appear as contaminants in ground water being used for wells, but they actually appear infrequently. Nitrogen in its various forms (nitrate, nitrite, and ammonia) is more likely to show up in ground water. Nitrogen and its "associates"--nitrate, ammonia, and nitrite--come from fertilizers (both organic and synthetic) containing nitrogen, a primary nutrient for plants. Having nitrogen in any form in the ground water is like having "too much of a good thing"--although nitrogen is good for plants, it can cause health problems for humans. In particular, it can cause "blue baby syndrome" in infants. The limit on the amount of nitrogen in drinking water is 10 parts per million, and more than that can cause health problems in humans, especially infants and small children.
How can I tell if my well water has too much nitrogen?
Have a sample of your well water tested for "total Kjeldahl nitrogen" and for nitrate. The results will tell you if you have too much nitrogen in your well water and what form the nitrogen has taken. [BD: where is info for interpreting results?]
What should I do if my well water has too much nitrogen? Who is responsible?
Give bottled water to small children and infants to drink until the problem is solved. How to solve the problem depends on what form the nitrogen takes in the ground water. If the nitrogen is in ammonia form, allowing the water to sit in the open air after pumping it from the well will allow the ammonia to volatilize. If the nitrogen is in nitrate form, you will need to consult with an engineer or an expert in ground water remediation.
Proving who caused the nitrogen to get into your well water can be extremely difficult because nitrogen comes from a number of different sources and can be present in ground water for years after having entered it. You would have to consult an attorney about whether or not the cause of the contamination can be proved legally.
How can development be planned to protect the ground water supply?
For existing water supply wells, the ground water flow system that provides water to the wells needs to be understood in sufficient detail to identify the recharge areas. Boundaries of flow systems, which often encompass considerably more than the immediate vicinity of the wells, need to be determined to delineate the area through which ground water flows before reaching the wells. Activities that are potential contaminant sources need to be excluded [managed??? BD?] from recharge areas, and practices that reduce the potential for contaminant release need to be adopted. For proposed water supply wells, the ability of the flow system to yield more water beyond the existing demand needs to be determined. Conservation measures may be needed to expand the supply. Proposed well site locations need to be evaluated for (1) possible interference with existing water supply wells and surface water systems, and (2) existing potential sources of contaminants to the proposed wells. For both existing and proposed wells, the element of time needs to be considered; ground water travel times are generally from years to decades, and planning for ground water protection is necessarily long term. Ultimately, limits on the extent and manner of development need to be planned.
Can a city's, county's, or town's comprehensive plan be a useful tool for ground water protection?
The comprehensive plan is a logical starting point for ground water protection since it provides the foundation for all programs and land use management tools at the local level. It sets forth goals and policies to guide future land use and development policies of a community. In the event that a community's ground water protection program is ever challenged, one of the best defenses will be a well formulated comprehensive plan which provides the basis and rationale for the challenged action.
Virginia law requires that local governments prepare comprehensive plans and update them at least once every five years. Provisions were added to the code in 1988 and 1990 to indicate that jurisdictions shall study matters such as ground water and geology in preparing their plan and may subsequently adopt provisions to protect the ground water resource. These provisions apply both to private wells serving individual households and businesses, and to various types of public wells.
Area-wide planning studies for public wells might examine land use types and densities in relation to ground water vulnerability, and result in designating areas where conservation and protective measures are needed. Techniques such as DRASTIC mapping could be employed to assess vulnerability. This evaluation process can help localities to understand the nature of any potential threats to their drinking water supply, and provide an impetus for establishing goals to protect these valuable resources.
Site specific studies around individual wells can provide the basis for planning and goalsetting on a site by site basis. In some cases, the individual results may suggest that the community revisit its development concepts and policies in order to address recurrent issues or problems.
Localities that fall under the Chesapeake Bay Preservation Act are already familiar with using comprehensive plans to evaluate development patterns and their impact on water quality protection. In order to comply with the Act, Chesapeake Bay jurisdictions must prepare comprehensive plans which identify the relationships between water quality protection and other land use considerations. The Chesapeake Bay Local Assistance Department's Local Assistance Manual includes a section on wellhead and ground water protection and provides useful guidance for all localities regardless of location.
Can a locality's Capital Improvements Program (CIP) play a role in ground water protection?
Often included as an element in a comprehensive plan, a capital improvements program - or CIP - provides a schedule for financing, constructing, repairing, or replacing major public facilities needed by a locality. Section 15.1-464 of the Code of Virginia permits a locality to prepare a capital improvements program based upon its comprehensive plan, but does not make it mandatory. It states that:
"...Such capital improvement program shall include the commission's recommendations, and estimates of cost of such facilities and the means of financing them, to be undertaken in the ensuing fiscal year and in a period not to exceed the next four years, as the basis of the capital budget for the county or municipality...."
Capital improvements planning is an important component of a ground water protection program, given the role that local government infrastructure plays in fostering development. In planning areas for future development, local governments must ensure that there will be adequate potable water supplies. If ground water is to be relied on as the primary source of drinking water, this means considering the need for and the location of new wellfields. In addition, furnishing infrastructure to a region, or not doing so, can act as a means of locating future development in areas away from wellheads in order to lower vulnerability to ground water contamination. The CIP also plays a role in contingency planning. In the event that a public well needed to be phased out, replacement supplies - either from surface or ground water sources - would need to be identified, planned and linked to a source of funding.
My community has zoning and subdivision regulations--can these be used as ground water protection tools?
The ability of a locality to control land uses through zoning can provide a strong basis for a successful ground water protection program. Along with the part of the code dealing with the comprehensive plan, Section 15.1-489 of Virginia's zoning law was also amended to incorporate language allowing localities to include "reasonable" zoning provisions to protect ground water. Wellhead protection is a prime example of the type of program envisioned when the state enabling laws were expanded. While the term "reasonable" is not defined in the statute, it can be assumed that a reasonableness standard applies to all zoning and, therefore, that ground water protection measures must be no less reasonable than other zoning measures.
Zoning can be used as a tool to protect wellhead areas from contamination in a number of ways, depending on the level of development surrounding the wellfields. It is most effective for directing future development in a planned fashion - it is much less effective once an area is developed. This is a good reason to take a preventive and anticipatory approach in dealing with wellhead areas.
If a wellhead area is currently undeveloped, the most direct approach for protecting it would be to zone the wellhead area for uses compatible with ground water protection. Other uses, such as certain commercial or industrial activities, could be directed to other locations where the ground water and surface water resources may be less vulnerable.
In addition, there are several specific types of zoning controls that are especially applicable for wellhead protection, although others may be appropriate as well. The techniques that will be discussed here are: overlay zones, density restrictions and cluster development, conditional zoning and special permits, and subdivision requirements.
Are there other tools that can be used for groundwater protection?
Yes, these include conservation easements, purchase of development rights, water conservation, household/farm/business hazardous waste collection, "Best Management Practices" (BMPs), and cost share approaches.
Innovative public education programs on ground water topics can develop interest in ground water. These can cover the role of ground water in meeting public needs, methods for preventing ground water contamination, and helpful actions for residents, property owners, and business managers to take.
VIRGINIA'S GROUND WATER PROGRAMS & REQUIREMENTS
What is the Agricultural Stewardship Act?
The Agricultural Stewardship Act (ASA) is a new Virginia law and program that seeks to help farmers correct problems in their operations that are causing or will cause water pollution.
Does the Agricultural Stewardship Act (ASA) apply to ground water?
Yes, it applies to ground water as well as surface water.
What will happen if an agricultural activity is found to be causing ground water pollution?
The farmer who is responsible for the agricultural activity in question will be asked to develop a plan to correct the problem in his operation that is causing the pollution. Once the farmer's plan is approved, the farmer must implement it within a specified period of time. If the farmer doesn't develop a plan or does not implement it, then the Commissioner of the Virginia Department of Agriculture and Consumer Services (VDACS) will issue an order to the farmer directing him to complete the necessary action. If the farmer still does not comply, then he is subject to civil penalties of up to $5,000 per day per violation. The Commissioner can also seek an order from a court to force the farmer to take the necessary action.
Given that it is difficult to prove that any activity on the land's surface caused a specific pollutant to reach ground water, how will complaints regarding agricultural activities' alleged contamination of ground water be handled?
When VDACS is unable to prove a complaint, agency staff will still take the opportunity to encourage the farmer to adopt the appropriate best management practices to prevent ground water contamination voluntarily. With ground water, VDACS sees education and voluntary adoption of best management practices as the major role of the ASA.
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Page Last Modified 9-5-97