Plugging Abandoned Water Wells

Used with permission of the Wes-Tex Groundwater Conservation District

Water is one of our state’s most precious resources. It is crucial to all aspects of our economy and society. Groundwater derived from our many aquifers provides over half of the water used in the state. Protecting the quality of this vital resource is the responsibility of all Texans.

For many years, groundwater has been pumped through water wells. Over the years, many wells around homes, farms, industrial sites, and urban areas have been abandoned without being properly plugged. Not only can these abandoned wells become potential avenues for groundwater-contamination, but they can also constitute a safety hazard for children and animals. Plugging an abandoned well takes time and money, but these wells are a threat that cannot be ignored.

Texas law makes the landowner responsible for plugging abandoned wells. The landowner is also held responsible for injury or pollution related to the abandoned well. This publication is provided to help landowners understand how to plug a well properly. Before you begin the process of plugging a well, it is highly recommended that you seek advice from your local Groundwater Conservation District (GCD, or “district”), a licensed water well driller and/or pump installer in your area, or the Well Driller/Pump Installer/ Abandoned Well Referral Program of the Texas Department of Licensing and Regulation (TDLR).

Abandoned wells are regulated by the TDLR and local GCDs through the Texas Occupations Code, sections 1901.255 and 1901.256 (see ). “Well Plugging Information,” toward the end of this document, provides phone numbers and websites where you can find additional information.

What Are the Hazards Associated with Abandoned Wells?

Personal Safety

The hazard to personal safety that an unmarked and uncovered large-diameter well presents is obvious to anyone who has ever encountered one. Accidents in which people or animals fall into abandoned wells have occurred, and they continue to occur. Even when a well is covered, the soil around it may be unstable and can cave in. The liability associated with abandoned wells has not been fully tested in Texas. A landowner with an abandoned well should ask himself: “Do I want to be the first legal test case in Texas?” Groundwater Contamination

An abandoned well is a direct conduit from the surface to the aquifer below. Contaminants that enter the well are introduced directly into the aquifer with no opportunity for natural filtration by soils or geologic materials. If a contamination incident involves a concentrated chemical, the potential for reaching health-threatening levels in the underlying aquifer is high. Just a small amount of some chemicals (e.g., pesticides, solvents, and petroleum products) can contaminate millions of gallons of groundwater and spread out under many acres of land.

In addition, some contaminants break down very slowly and may affect the groundwater for decades. This puts other wells in the aquifer at risk, particularly those that are close by. Deterioration of the well casing can also allow the commingling of two chemically different aquifers.

When Is a Well Considered Abandoned?

According to state law, a well is considered abandoned if it has not been used for six consecutive months. However, even a well that has not been used for six consecutive months can be considered in use, if it falls into one of the following two categories:

• A non-deteriorated well that contains the casing, pump, and pump column in good condition.

• A non-deteriorated well that has been capped.

If you are uncertain whether your well is legally abandoned, consult a licensed water well driller, the Well Driller/Pump Installer/ Abandoned Well Referral Program of the TDLR, or the local GCD (if one exists in your area).

How Can I Report an Abandoned Well?

The TDLR Well Driller/ Pump Installer/Abandoned Well Referral Program web page, , provides a wealth of useful information, including:

• Reporting an abandoned well online.

• Reviewing the status of an abandoned well complaint.

• A checklist that can be used to determine whether a well is abandoned.

• The definition of an abandoned or deteriorated well.

• A link to Frequently Asked Questions (FAQs) regarding abandoned wells (complete with example photos).

What Are My Options if I Have an Abandoned Well?

There are three different courses of action that can be taken to eliminate the hazards of an abandoned well:

• Return the well to an operable state by making sure the casing, pump, and pump column are in good condition.

• Cap the well to prevent surface water or contaminants from entering it. The cap must be able to support 400 pounds and prevent easy removal by hand. For more information, see the Texas AgriLife Extension Service publication L-5490, Capping of Water Wells for Future Use (online, at , or by phone, at 888-900-2577).

• Plug the well from the bottom to the top with bentonite chips, bentonite grout, or cement. Large-diameter wells can also be filled with clay-based soils, compacted clay, or caliche. Details on what you should do prior to plugging your well, as well as on the well plugging operation itself, are provided in “How Do I Plug My Own Well?,” below.

Who Should Do the Work to Plug Abandoned Wells?

As the landowner, you may do the work necessary to plug an abandoned well on your property or you can hire a licensed well contractor to do the work for you. If you plan to do the work yourself, or if you have any questions about plugging your well, you may contact the Well Driller/ Pump Installer/Abandoned Well Referral Program of the TDLR or your local GCD. Well plugging specifications can be found at .

You should request a state well plugging report form from the TDLR (see “Example of a Well Plugging Report,” toward the end of this document) or you can download it from the TDLR forms web page, . Within 30 days after the well is plugged, you must enter the plugging report online or send a copy of the completed form to the TDLR. You must also send a copy to the local GCD (if one exists in your area). To enter your report online, you will need a login name, a password, and GPS coordinates (latitude and longitude). You can call the TDLR (the phone number is listed in a later section) to get your login name and password, and then go to the State of Texas Well Report Submission and Retrieval System website, <134.125.70.235/drillersnew/index.asp>, to enter your plugging report.

Some areas of Texas have assistance programs for the plugging of abandoned water wells. Contact your local GCD or Texas State Soil and Water Conservation Board representative to see if an assistance program is available in your area.

How Do I Plug My Own Well?

Well plugging may appear to be a simple process—just dump something into the open well until it’s full. That might take care of the safety hazard—people and animals could no longer fall into the well. However, unless you use the right plugging materials and methods, you will end up with a poorly sealed well, one that will continue to allow contaminants to enter the groundwater.

To do the job right, it is essential that you use the correct plugging materials and install them properly, in accordance with state regulations and any local GCD specifications that may exist. Regulations developed by the state outline the procedures and materials that are to be used for plugging abandoned wells and are reflected in this document. The Texas Administrative Code, Title 16, Section 76.1004 (which can be found at the TDLR website, at ) contains these standards. These rules may also be obtained by contacting the organizations listed in “Well Plugging Information,” later in this document. If the well is located within a GCD, consult with the district to determine if they have any additional specifications.

Steps to Follow Prior to Plugging Your Well

You can hire a licensed water well driller and/or pump installer to plug an abandoned well. In some cases, this is recommended because a well contractor has the equipment needed for the job and an understanding of local soil conditions that affect how the well should be properly plugged. As the landowner, you may also plug an abandoned well yourself. Before beginning the plugging operation, you should take the following three steps.

Step 1. Understand the regulations regarding the plugging of an abandoned water well.

You should contact your local GCD, if one exists in your area, or a licensed well contractor to help you understand the local and state regulations regarding water well plugging. Learning about the rules and regulations will also help you decide if you want to plug your well yourself or hire a licensed well contractor to do the job for you.

Step 2. Obtain the water well driller’s report for the well.

Since 1965, water well drillers have been required to submit water well driller’s reports to the State of Texas. The water well driller’s report includes details on your well’s construction and the local geology. If you don’t have this report, you may be able to obtain it from one of the following: • TCEQ Water Well Report Viewer: www.tceq.state. tx.us/goto/findwell

• TDLR State of Texas Well Report Submission and Retrieval System: 134.125.70.235/drillers-new/ index.asp, 512-936-0871

• TWDB Water Information Integration and Dissemination (WIID): http://wiid.twdb.state.tx.us/ index_explain.asp

• Texas Alliance of Groundwater Districts (TAGD): www.texasgroundwater.org, 512-590-1422

If you are unable to acquire the water well driller’s report, you are strongly advised to hire a licensed well contractor to plug the well for you—they have the tools and experience to properly assess your abandoned well.

If your water well driller’s report indicates that the well is drilled through a confining layer that separates two different aquifers, it is highly recommended that you have the well plugged by a licensed well contractor—they will be able to plug this special type of well safely and correctly.

Licensed well contractors will also be familiar with completing and submitting the required paperwork after the well is plugged.

Step 3. Determine the depth of the well and the height of the standing water in the well.

If you know the details of your well’s construction and the local geology from your water well driller’s report, or you have been able to measure the depth of the well and the height of standing water in the well on your own, you can follow the well plugging steps outlined below.

You need to take accurate measurements (not estimates) of the depth of the well and the height of standing water in the well. This will allow you to correctly calculate the volume of the well and the volume of the water in the well. These volumes are needed for determining the correct amounts of disinfection and plugging materials. It would also be wise to have extra disinfection and plugging material on hand, in case there were any errors in the measurements or calculations. Refer to “Calculating the Amount of Plugging Material You Will Need,” “Formulas for Calculating Volume,” and “Calculating the Amount of Disinfectant You Will Need,” toward the back of this document, for more information. Plugging Materials

Several materials may be used to plug an abandoned well. These materials form an impermeable plug that prevents water flow. These materials include cement, bentonite, and bentonite grout.

• Cement. A Portland or construction cement mixture of not more than seven gallons of water per 94-pound sack of dry cement, or a cement slurry that contains cement along with bentonite, gypsum, or other additives, mixed to the manufacturer’s recommendations.

• Bentonite. A sodium hydrous aluminum silicate clay mineral (montmorillonite) commercially available in powdered, granular (chips), or pellet form, which is mixed with potable (drinkable) water and used for a variety of purposes, including to stabilize borehole walls during drilling, to control potential or existing high fluid pressures encountered during drilling below a water table, and to provide a seal in the annular space between the well casing and the borehole wall.

• Bentonite Grout. A fluid mixture of sodium bentonite and potable water mixed at manufacturer’s specifications to a slurry consistency that can be pumped through a pipe directly into the annular space between the casing and the borehole wall. Its primary function is to seal the borehole in order to prevent the subsurface migration or communication of fluids.

Bentonite has unique characteristics when used as a plugging material. Bentonite clay swells to about 10 times its original size when in contact with water. The swollen clay forms a dense, virtually impermeable putty—water can take up to 80 years to penetrate 1 inch of swollen bentonite clay. Note that bentonite grout may not be used if a water zone contains chlorides above 1,500 parts per million (ppm) or if hydrocarbons are present. Bentonite also requires a two-foot-thick cement cap, which acts as an atmospheric barrier to prevent the plugging material from drying out.

Gravel is sometimes used to fill the bottom of certain types of wells. Local soils can also be used for the upper four feet of the well to complete the plugging operation. Clay-based soils can be used to plug large-diameter wells; however, you must obtain a variance from the TDLR before using clay-based soils to plug small-diameter wells.

Landowners who wish to do their own work should consider using coarse-grade bentonite chips (average size of 3/8 to 3/4 inches). The chips are easy to handle and are less likely to form a bridge within the well casing. If a bridge forms, the well will not plug properly (see Figure 4). This mistake would be expensive, requiring that the hole be bored out and the plugging procedure repeated ....

To be continued in next week’s Sunday Focus