Well Installation Section – Frequently Asked Questions

Geological Survey Program fact sheet
Missouri Geological Survey Director: Joe Gillman

What is the law?
Missouri Law Sections 256.600 to 256.640 RSMo was passed to protect groundwater in Missouri by providing minimum construction standards of private wells and permitting well drillers and pump installers. The law is posted on the Missouri General Assembly’s website: moga.mo.gov/mostatutes/ChaptersIndex/chaptIndex256.html.

What are the benefits of the law?
The law helps protect the state’s groundwater. The law ensures that wells are constructed properly which helps prevent contamination of the groundwater. Also, the well is registered as a certified well and may increase the property value.
Whom does the law affect?

Everyone who owns a well or utilizes water from a public water supply that gets water from wells, or who has anything to do with installing wells.

Why have the law?
The law is here to ensure that all private water wells are constructed to minimum standards. Improperly constructed wells create a health risk for well owners and their neighbors and threaten the quality of the state’s groundwater supply.
When was the law passed and when did the rules take effect?

The bill was signed into law August 1985, and the rules became effective October 30, 1987.

Does the law apply to wells constructed before October 1987?
Yes, but only concerning how these wells are plugged after they are no longer needed.
To which type of water wells does the law apply?

All wells must be reported by the driller when completed. The construction standards specified in the rules and regulations manual apply to domestic wells (private water supplies). The manual includes definitions of well types (such as multiple family wells, irrigation wells, community wells, non-community wells and others).

What are my responsibilities with respect to the law?
Potential well owners are responsible for finding a permitted well driller to construct their wells properly. Also, new well owners must pay an $80 processing fee when their wells are completed. This fee is for the cost of registering your well with the state. Registering your well gives you a source of information and technical advice for problems with your well.

Who administers the law?
The Missouri Department of Natural Resources’ Missouri Geological Survey administers the Well Drillers’ Law. The mailing address is PO Box 250, Rolla, MO 65402-0250. The physical address is 111 Fairgrounds Road, Rolla, MO 65401-2909.

Do other states have a similar law?
About 40 other states have a law regulating water well construction.

Is my tax money being used to implement the law? Where does the money from the fees go?
The department’s water well drillers’ section is fee-supported. Money collected for permit fees and well registration is used to administer the law.

Who can give advice about the law?
The Department of Natural Resources’ Missouri Geological Survey is the best source of information about the law.

How many wells are drilled in the state each year?
About 6,000 to 10,000 new wells are drilled each year in Missouri. These include water wells, heat pump wells, monitoring wells and mineral exploratory wells.

Does everyone need a permit to have a well drilled?
Only professional well drillers and pump installers, who charge for their services, must have
a permit to construct a well. There are certain exceptions to the permit required for some landowners (see 256.607 RSMo). The driller files a Water Well Record within 60 days after the well is drilled. When the record is filed with the Department of Natural Resources, it is reviewed. If it meets the minimum standards, it is assigned a certification number and the owner will receive a certification letter.

What is the most critical part of the well? Why is this so important?
The proper amount of casing and a good seal around the casing are critical to ensure safe drinking water. Casing is an impervious, durable pipe used to prevent the walls from caving and to prevent surface drainage of undesirable fluids from entering the well.

How much casing does my well need?
The amount of casing required for each well varies, dependent on the geology of the area where you live. Regions are defined in the rules and regulations manual.

What can I do to be sure that my well is constructed properly?
Contact Department of Natural Resources’ Missouri Geological Survey at 573-368-2165 before your well is drilled to discuss what to ask for while your well is being constructed. We will help you in any way possible.

From what sources can my well be contaminated?
Septic tanks, lagoons, feed lots and improperly abandoned wells are common sources of contamination to wells.

Can I tell whether my well is contaminated by the water’s taste or smell?
If your water has an odd taste or smell, you should have your water tested. However, your water may be contaminated even though it doesn’t have a bad smell or taste. It is wise to have your water tested periodically.

How often should I have my water tested? Who should test it?
It is wise to test your water twice a year. The results of the analysis will establish a track record and may increase your property value. Private laboratories will test the water quality of a well as will the Missouri Department of Health.

Can contaminated wells be repaired?
Most contaminated wells can be repaired, but it may cost more to repair them than it does to construct them properly the first time.

Can my neighbors’ well contaminate mine?
A neighbor’s well can contaminate yours when the water moves through water-bearing zones or aquifers.

How do I disinfect a well?
Chlorine bleach or sodium hypo chlorite (HTH) tablets, available at most hardware stores, can disinfect your well. Your driller or pump installer is required by the rules to disinfect your well when he completes the work. Information on how to disinfect your well is available from the division or your well driller and pump installer.

What does the presence of coliform bacteria indicate?
The presence of coliform bacteria in a well indicates that water contaminated by organic material has entered your well.

Why are there different construction requirements for different types of wells?
Construction requirements are based on well yield, use of well, (i.e., single-family use, multiple-family use, public use) and the region in which your well is located, and vary throughout the state according to the geology of the region.

How many homes can use the same private well?
Three single-family residences may use one well. Wells that serve between three to approximately eight families, called multiple-family wells, have a different set of minimum construction standards.

Am I liable if my well contaminates the groundwater?
Yes, you may be liable if your well contaminates the groundwater, especially if willful negligence is proven in court.

What is the proper procedure to abandon a well?
The correct way to plug or seal a well varies and depends on type and depth of the well. A brochure is available from the division that explains the process of plugging a well.

How do I locate a permitted driller?
To locate a permitted well driller or pump installer, check your telephone directory for companies that advertise as state-permitted companies. Check with the Department of Natural Resources to learn which permitted drillers are in good standing. Ask new well owners for the names of their drillers and whether they had or are having any problems.

What is the purpose of permitting the drillers and pump installers?
Issuing permits to well drillers establishes a minimum standard of competency and enables the state to enforce minimum construction standards.

How can I tell whether my driller is permitted?
Permit numbers should be affixed to the well driller’s equipment. To ensure that the permit is current, you can check his permit card for an expiration date or call the division for this information.

How often are the driller and pump installer permits reviewed?
Permits are reviewed annually for renewal, or when specific incidents occur that warrant immediate attention.

What is a Water Well Record?
A water well record is a form that is completed and filed by the contractor. It certifies that the well is constructed according to the minimum construction standards. It is filed with the Department of Natural Resources’ Missouri Geological Survey in Rolla, Mo. The $80 fee for registering a certified well is paid by the well owner. Should problems arise in the future, both the owner and the state have a record of the well’s construction. Also, a potential buyer, lender, or realtor is assured of a certified well.

Who actually certifies my well? How is the state involved?
The well driller reports on the construction of the well by completing the Water Well Record form. If the well is constructed properly, the state then issues a certification number.

If I have two different companies working on the well, which one should charge the $80 certification fee?
The driller involved in the drilling procedures should collect the $80 certification fee and send it to the division.

Who wrote the rules?
Department of Natural Resources’ staff members developed the Rules and Regulations booklet, with the aid of reputable water well contractors statewide.

How can I get a copy of the Rules and Regulations?
Rules are available at the Missouri Secretary of State’s website: https://www.sos.mo.gov/adrules/csr/current/10csr/10csr.asp#10-23.

Where are the most sensitive areas of the state?
The most sensitive areas of the state are those of rapid development or urbanization, where the geological features cause the groundwater to be particularly vulnerable, and where natural pollutants and water quality of shallow zones causes potential pollution of larger aquifers.

How were the boundaries determined for different regions’ minimum construction standards?
The boundaries determined for different region’s minimum construction standards were based on geologic conditions, groundwater hydrology of the area and drilling conditions.

Where can I find the legal description of my property?
Legal descriptions of property boundaries can be found on tax receipts, courthouse records, property deeds, county maps and abstracts.

Are there restrictions on the location of a well?
Yes, restrictions on the location of a well are covered in the regulations manual in Chapter 3. The regulations are based on the distances from sources of contamination, such as septic tanks, lagoons, houses, cemeteries and drain fields.

For more information:
Missouri Department of Natural Resources
Missouri Geological Survey
Wellhead Protection Section
111 Fairgrounds Road
PO Box 250
Rolla, MO 65402-0250
Phone: 573-368-2165
Fax: 573-368-2317