Choosing a Consultant to Delineate the Wellhead Protection Area

Barbara C. Cooper, Water Quality Education Specialist
Jane R. Frankenberger, Extension Agricultural Engineer
Fred Whitford, Coordinator, Purdue Pesticide Programs

How Large an Area Do
You Need to Protect?
How Do You Choose a
What's Next?
Useful Publications
Indiana Information Contacts
Safe drinking water is vital to our communities, to our economy, and to our health. The best way to ensure a safe water supply, now and for the future, is to protect the area nearest a community public supply well from potential hazards.
Wellhead Protection Planning Overview
  • Local planning team
  • Delineation of the wellhead protection area
  • Identification of potential sources of contamination
  • Management of the wellhead protection area
  • Contingency plan
  • Public participation, education, and outreach
  • This publication offers some guidelines for water supply operators and wellhead protection planning teams who must hire a qualified ground water scientist to delineate a wellhead protection area.

    What Is a Wellhead Protection Area?

    The wellhead protection area includes much more than just the wells themselves. Delineation is the process of identifying how much of an area around those wells needs to be managed to protect the water supply.

    The delineated area is important because it serves to focus the attention of the wellhead protection planning team on what activities within that area might be potential contributors to ground water pollution. "Potential" is the important word here, in that Indiana’s Wellhead Protection Rule (327 IAC 8-4.1) emphasizes prevention rather than remediation. Once activities are identified, the wellhead protection planning team can begin developing voluntary best management programs and outreach efforts designed to educate those living and working within the wellhead protection area on how they can all contribute to safe-guarding the water supply.

    How Large an Area Do You Need to Protect?

    The rule says that if your water supply system currently draws more than 100,000 gallons a day you need to delineate an area around the well that would protect your community’s ground water for five years. In other words, ground water directly underneath the bound-aries of the delineated wellhead protection area would require approximately five years to travel to the pumping well (Figure 1).

    To determine the exact shape and size of the wellhead protection area, a qualified ground water scientist must be hired to collect information about the geology of the underground area through which the water flows, the volume of water that is pumped each day, predicted increases in water use, and other factors. The scientist enters the information into a computer program that simulates the way the water flows through the subsurface. Analytical models, semi-analytical models, or numeri-cal models can be used for this simulation. The modeling method recommended by the consultant will depend on the size of the system, the complexity of the geology, and the intended type of management.

    Systems that pump less than 100,000 gallons per day are not required to hire a consultant to perform a detailed and scientific delineation. They have the option of delineating a 3000-foot radius around the supply well as the wellhead protection area. You can learn more about this option in WQ-29, "A Shortcut to Wellhead Protection Delineation for Some Systems." (See "Useful Publications.")

    How Do You Choose a Consultant?

    Scope of Services

    When you request a proposal from a potential consultant, you should know exactly how much you are asking the consultant to do. Do you want only the approved delineation or a contaminant source inventory as well? Is the consultant going to set up a geographic information system (GIS) for you that can be updated periodically for a negotiated fee? Or will you receive only paper maps? Decide exactly what you need before you begin selecting a consultant.
    Suggested Steps for Hiring a Consultant
    1. Decide on the scope of services desired.
    2. Request proposals from qualified
      consulting firms.
    3. Evaluate the proposals.
      • Contact the references.
      • Interview the applicants.
    4. Negotiate a contract.

    The consultant may offer to do the entire wellhead protec-tion plan for a fee. Beware of accepting this option. If the community does not document its involvement through the local planning team, the plan will be incomplete and will not be approved by IDEM.

    Provide a list detailing your expected deliverables to each potential consultant. Make sure each consultant addresses every item in the bid. Provide the phone number of a contact person who can answer questions about the proposal for the consultants. Attempt to choose from among three or more consultants who have submitted similar proposals for consideration.

    Completion Time

    Delineations are complex and can require considerable time and effort. A delineation may require from three weeks to three months to complete. Get a clear estimate from the consultant on how much time the delineation will require. Make sure the date agreed to by each of the partners is stipulated in the contract.

    Types of Models to Use

    You may not know if you need an analytical, semi-analytical, or numerical model for the delineation. The most complex model is the numerical model. The least complex is the analytical model. Generally, the model needed is dictated by the geology of the area, available data, and the management tools available to your commu-nity. If the geology is very complex, you need a more sophisticated model and more data to validate the model. If you plan to pass zoning ordinances, the model needs to be legally defensible. You should question potential consultants about what model they recommend and why. If several consultants recommend the same type model for delineation, you will have more confidence in the recommendation.

    A five-year travel-time boundary will be determined from the model. Inside this boundary is the delineated wellhead protection area. This area is not usually in the shape of a circle. Because ground water, like surface water, generally flows from a certain direction, the area that needs protecting will extend farther in one direction than in another. The delineated area may be more of a strip or an odd oval shape like the one shown in Figure 1.

    A modeled delineation is complex and according to Indiana’s Wellhead Protection Rule (327 IAC 8-4.1) must be completed by a "qualified ground water scientist." But what exactly is a "qualified ground water scientist"?

    There is no specific license or certificate which will identify a "qualified ground water scientist." A Certified Professional Geologist (CPG) or a Professional Engineer (PE) should also have background and experience in the field of hydrogeology.

    When you hire a consulting firm, you are usually hiring one person, perhaps with the assistance of support personnel, who will ultimately provide the finished delineation.

    Determine the qualifications of the individual you are hiring. A large firm may have a hydrogeologist on staff; however, a firm could also subcontract with another firm for the services of a hydrogeologist. The indi-vidual responsible for modeling the delineation is the person to inter-view.

    Educational and professional qualifications are the most important aspects to consider when hiring a consultant, but there are other considerations as well. The following are some suggestions that may be helpful in choosing a consultant for your delineation.

    Communications Skills

    Good consultants can clearly communicate the technical details of what they are trying to do. A knowledgeable consultant does not have to "snow" you and will appreciate having a well-informed client. Ask the consultant to describe in simple language how he or she will actually develop the delineation maps. If you can understand this explanation, it’s a good indication that he or she will probably be able to explain the details of the delineation model as well.


    The consultant you choose should be accessible. If you have a question or concern, request assurance that you will be able to talk directly with the consultant within a reasonable period of time.

    Questions for Potential Consultants

    Questions for Former Clients

    Ask the potential candidates about contacting former clients. You should speak with some of the people who have previously used this consultant to find out whether the consultant can deliver what he or she promises. Consider asking former clients the following questions.

    Contract Negotiation

    The contract should state that all or part of the payment will be made contingent on a delineation which is approved by the Indiana Department of Environmental Management. If the delineation is not approved, the contract should state that you are under no obligation to pay for the remaining charges. The contract should specify that regular meetings between the consultant and the contract monitor will be held to discuss the progress made on the delineation.

    What’s Next?

    The consultant you hire will help you start on the road to wellhead protection. After the Indiana Department of Environmental Management has approved your delinea-tion, the wellhead protection planning team can complete the inventory of potential contaminants in the delineated wellhead protection area. The team can also begin working on formulating management and contingency plans, and developing a program for public education about wellhead protection.

    Useful Publications

    The following Purdue Extension publications provide information about other aspects of the wellhead protection process.

    All are available free of charge through your county Purdue Extension office or by calling 1-888-EXT-INFO.

    The USEPA has an informative publication, "Wellhead Protection, A Guide for Small Communities," EPA/625/R-93/002 available free by calling the USEPA Publication Office at 1-800-490-9198.

    Indiana Information Contacts


    The authors wish to express our appreciation to the following people for their review of this publication:

    Martha Clark, Indiana Department of Environmental Management, Office of Water Management, Drinking Water Branch;

    Mary Hoover, Indiana Department of Environmental Management, Office of Water Management, Drinking Water Branch; and

    Don Jones, Department of Agricultural and Biological Engineering, Purdue University.

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