Plugging Abandoned Water Wells
Used with permission of the WesTex Groundwater Conservation District
-Conclusion
Steps to Follow in Plugging Your Well
Step 4. Remove all obstructing materials from the well.
It is critical that fill materials do not slump or settle; therefore, obstructions that may cause incomplete filling of the voids must be removed. Remove the pump, pump rods, pipes, wiring, any other equipment, and as much trash as possible from the well. Floating debris, such as wood staves, should also be removed. One method used to accomplish debris removal is flushing. If water is pumped into the well, floating debris will move to the top as the well fills with water. Flushing may not be possible with larger-diameter wells, due to the volume of water required. In any event, you must remove as much obstructing material as possible from the well before plugging.
Step 5. Disinfect the well by adding household bleach.
It is recommended that all wells containing standing water be disinfected prior to plugging the well in order to kill existing microorganisms. Disinfection can be accomplished by adding liquid chlorine product (do not use any scented or solid products!) at the rate of 1 gallon of bleach for every 500 gallons of water—this is equivalent to a “shock” chlorination concentration of 100 parts per million chlorine. The chlorination process ensures that diseasecausing microorganisms are not sealed in the aquifer. Disinfect the well for 8 to 10 hours prior to plugging. For more information, refer to “Calculating the Amount of Disinfectant You Will Need,” toward the back of this document.
Step 6. Remove as much casing from the well as possible.
State plugging specifications require that you remove all removable casing from the well. You must attempt to pull the casing out of the well. However, if the casing cannot be pulled out, you are required to cut it off at least 4 feet below the ground surface (i.e., “plowable” depth), or as far below the ground surface as possible.
Step 7. Fill the well with plugging materials.
Plugging procedures vary depending on which of the following categories you well falls under:
Large-diameter wells up to and including 100 feet deep.
Large-diameter wells more than 100 feet deep.
Small-diameter wells with up to and including 100 feet of standing water.
Small-diameter wells with more than 100 feet of standing water. 8 Revised March 2010 TCEQ publication RG-347 Landowner’s Guide to Plugging Abandoned Water Wells Large-diameter wells Large-diameter wells are defined as being 36 inches or more in diameter.
Large-diameter wells up to and including 100 feet deep
Completely fill the well from the bottom to the ground surface with clay-based soils, compacted clay, caliche, or cement (see Figure 1), or with bentonite chips or bentonite grout (cement cap required;).
Note that bentonite grout may not be used if a water zone contains chlorides above 1,500 ppm or if hydrocarbons are present.
If clay-based soils, compacted clay, or caliche are used, mound the plugging material above the ground surface to compensate for settling.
If bentonite chips are used, alternate pouring in equal amounts of chips and water in order to properly hydrate the bentonite as the well is filled.
If bentonite grout or cement are used, completely pressure-fill the well by using a tremie tube (see Figure 3). When the well is pressure-filled with a tremie tube, some plugging material may also enter any annular space that may exist outside of any non-removable casing.
If bentonite chips or bentonite grout are used, the plug must be capped with cement at least 2 feet thick. The cement cap acts as an atmospheric barrier (see Figure 2) and can be positioned in two ways:
It can be set at the ground surface. Or,
It can terminate within 4 feet of the ground surface and then be topped off with local soils. In this case, you must mound the local soils above the ground surface to compensate for settling.
Large-diameter wells more than 100 feet deep
Using a tremie tube, completely pressure-fill the well with bentonite grout or cement from the bottom of the well to the ground surface (see Figure 3). When the well is pressure-filled with a tremie tube, some plugging material may also enter any annular space that may exist outside of any non-removable casing.
Note that bentonite grout may not be used if a water zone contains chlorides above 1,500 ppm or if hydrocarbons are present.
Alternatively, pressure-fill the well with cement to within 100 feet of the ground surface, and then finish the plugging operation by following the directions above for a large-diameter well that is up to and including 100 feet deep.
Small-diameter wells Small-diameter wells are defined as being less than 36 inches in diameter. A bridge can form in a small-diameter well if the plugging materials are poured too quickly. To prevent bridging and ensure a complete fill without air pockets, pour the materials slowly or use a small-diameter pipe to agitate the materials as they settle. In addition, floating bentonite fines can also contribute to a bridging situation within a small-diameter hole—these fines can be separated from the chips using a screen and added to the cap near the completion of the plugging operation.
Small-diameter wells with up to and including 100 feet of standing water
Completely fill the well with bentonite chips, bentonite grout, or cement from the bottom of the well to the ground surface.
Note that bentonite grout may not be used if a water zone contains chlorides above 1,500 ppm or if hydrocarbons are present.
If bentonite chips are used, alternate pouring in equal amounts of chips and water in order to properly hydrate the bentonite as the well is filled.
If bentonite grout or cement are used, completely pressure-fill the well by using a tremie tube (see Figure 3). When the well is pressure-filled with a tremie tube, some plugging material may also enter any annular space that may exist outside of any non-removable casing.
If bentonite chips or bentonite grout are used, the plug must be capped with cement at least 2 feet thick. The cement cap acts as an atmospheric barrier, and can be positioned in two ways:
It can be set at the ground surface. Or,
It can terminate within 4 feet of the ground surface and then be topped off with local soils. In this case, you must mound the local soils above the ground surface to compensate for settling.
Small-diameter wells with more than 100 feet of standing water
Using a tremie tube, completely pressure-fill the well with bentonite grout or cement from the bottom of the well to the ground surface (see Figure 3).
Note that bentonite grout may not be used if a water zone contains chlorides above 1,500 ppm or if hydrocarbons are present.
If bentonite grout is used, the plug must be capped with cement at least 2 feet thick. The cement cap acts as an atmospheric barrier (see Figure 2), and can be positioned in two ways:
It can be set at the ground surface. Or,
It can terminate within 4 feet of the ground surface and then be topped off with local soils. In this case, you must mound the local soils above the ground surface to compensate for settling.
TCEQ publication RG-347 Landowner’s Guide to Plugging Abandoned Water Wells
Step 8. Complete and submit a state well plugging report.
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. To enter your report online you will need a log-in name, a password, and GPS coordinates (latitude and longitude). You can call the TDLR (the phone number is listed in the next section) to get your login name and password, and then go to the Texas Well Report Submission and Retrieval System, at <134.125.70.235/ drillers-new/index. asp>, to enter your plugging report. You can also request a plugging report form from the TDLR, or download it from the TDLR website, on the web page
Water Well Driller and Pump Installer Program Texas Department of Licensing and Regulation P.O. Box 12157 Austin TX 78711 800-803-9292, 512463-7880
If the well is located within a GCD, you must also comply with that GCD’s reporting requirements. An example of a completed state well plugging report form can be found in “Example of a Well Plugging Report,” toward the back of this document.
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 find out if an assistance program is available in your area.
Well Plugging Information
State Agencies, Programs, and Resources
Texas Department of Licensing and Regulation (TDLR)
Well Driller/Pump Installer/Abandoned Well Referral Program www.license.state.tx.us/wwd/wwd.htm, 800-803-9202, 512463-7880
State of Texas Well Report Submission and Retrieval System 134.125.70.235/drillersnew/index.asp, 512936-0871
Well Construction and Plugging Specifications www.license.state.tx.us/wwd/wwdspecs. htm
Frequently Asked Questions (FAQs) on Abandoned Wells www. license.state.tx.us/wwd/wwdfaq.htm#adw Revised March 2010 13
Landowner’s Guide to Plugging Abandoned Water Wells TCEQ publication RG-347
Texas Commission on Environmental Quality (TCEQ) Groundwater Planning and Assessment www.tceq.state.tx.us/goto/groundwaterplanning, 512-239-4512
Water Well Report Viewer www.tceq.state.tx.us/goto/findwell
Texas Groundwater Protection Committee (TGPC)
Abandoned Wells www.tgpc.state.tx.us/ WaterWells.htm#Aband
Texas Water Development Board (TWDB)
Water Information Integration and Dissemination (WIID) http://wiid.twdb.state. tx.us/index_explain. asp
Texas State Soil and Water Conservation Board
www.tsswcb.state.tx.us, 800-792-3485, 254-773-2250
Texas AgriLife
Extension Service
(TAES)
texasextension.tamu.edu, 979-845-7800
About Groundwater Conservation Districts
Texas Alliance of Groundwater Districts (TAGD) The TAGD represents the majority of the GCDs in the state. www.texasgroundwater.org, 512-590-1422
TCEQ’s GCD Web Page The TCEQ’s GCD web page lists the most current map of Texas GCDs, a summary description of GCDs, and a contact list for created and confirmed GCDs. www.tceq.state.tx.us/goto/gcd Publications
What Is a Groundwater Conservation District (GCD)? Texas Groundwater Protection Committee. www.tgpc.state.tx.us/subcommittees/POE/FAQs/GCDs_ FAQ.pdf
How Do You Form a Groundwater Conservation District (GCD)? Texas Groundwater Protection Committee. www.tgpc.state.tx.us/subcommittees/POE/FAQs/ FormingGCDs_FAQ.pdf
Questions about Groundwater Conservation Districts in Texas, by Bruce J. Lesikar, Valeen Silvy, and Ronald A. Kaiser. Texas AgriLife Extension Service, pub. no. B-6120. https://agrilifebookstore.org 14 Revised March 2010
TCEQ publication RG-347 Landowner’s Guide to Plugging Abandoned Water Wells
Calculating the Amount of Plugging Material You Will Need
For a well with a diameter of 2 inches, one (94-pound) sack of cement will plug 50.3 linear feet, while one (50-pound) bag of bentonite chips will plug 31.3 linear feet,
For a well with a diameter of 16 inches, one sack of cement will plug 1.0 linear foot, while one bag of bentonite chips will plug 0.*48 linear feet.