ARC 8614C

ARC 8614C

Proposing rulemaking related to requirements for properly plugging abandoned wells
and providing an opportunity for public comment

A Regulatory Analysis for this rulemaking was published in the Iowa Administrative Bulletin on September 4, 2024. A public hearing was held on the following date(s):

●September 24, 2024

Servicios gratuitos de asistencia lingüística. Si habla un idioma que no sea el inglés, los servicios de asistencia lingüística están disponibles de forma gratuita. Comuníquese con el Departamento al erik.day@dnr.iowa.gov.

The public hearings will be held virtually via Zoom. See www.iowadnr.gov/Environmental-Protection/Water-Quality/Water-Quality-Rulemaking for meeting information.

Persons who wish to make oral comments at a public hearing may be asked to state their names for the record and to confine their remarks to the subject of this proposed rulemaking.

Any persons who intend to attend a hearing and have special requirements, such as those related to hearing impairments, should contact the Department and advise of specific needs.

Free Language Assistance: if you need assistance in a language other than English, contact the Department at erik.day@dnr.iowa.gov or civilrights@dnr.iowa.gov or by telephone at 515.402.7981 at least seven days before the event.

Servicios gratuitos de asistencia lingüística: si necesita ayuda en un idioma que no sea inglés, comuníquese con el Departamento al erik.day@dnr.iowa.gov o civilrights@dnr.iowa.gov o por teléfono a 515.402.7981 al menos siete días antes del evento.

ITEM 1.Rescind 567—Chapter 39 and adopt the following new chapter in lieu thereof:

CHAPTER 39

REQUIREMENTS FOR PROPERLY PLUGGING ABANDONED WELLS

567—39.1(455B) Purpose and applicability. This chapter implements Iowa Code section 455B.190 by providing a schedule and required procedures for the proper plugging of abandoned wells to protect the groundwater by permanently sealing off contamination to individual aquifers.

39.1(1) Wells covered by these rules are those accessing groundwater (withdrawing water from or injecting water into the groundwater) and can include but are not limited to public and nonpublic water wells, test wells, observation wells, monitoring wells, agricultural drainage wells, heat pump recirculation wells, and cooling water wells.

39.1(2) Wells or subsurface structures not covered by these rules include small-diameter (2-inch or less) test holes, observation wells or monitoring wells installed for a limited time that can be sealed by withdrawing the casing and allowing the hole to collapse; soil borings; septic tanks; underground storage tanks; and cisterns, if not used for accessing groundwater.

39.1(3) For additional guidance and background information, refer to “Guidelines for Plugging Abandoned Water Wells,” Technical Information Series 15, Geological Survey Bureau, Iowa DNR, 1988, available on the department’s website at www.iowadnr.gov.

567—39.2(455B) Definitions. In addition to the definitions in 567—Chapter 40, 567—Chapter 49, 567—Chapter 82, and Iowa Code sections 455B.101, 455B.171, 455B.190 and 455B.190A, the following definitions shall apply to this chapter:

“Agricultural lime” means all calcium and magnesium products sold for agricultural purposes in the carbonate form, not including quicklime or hydrated lime, of a size comparable with that of crushed stone, gravel, or pea gravel.

“Approved” means accepted or acceptable under an applicable specification stated or cited in these rules.

“Aquifer” means a water-bearing geologic formation capable of yielding a usable quantity of water to a well or spring.

“Bentonite” means a naturally occurring, highly plastic, colloidal clay composed largely of the mineral montmorillonite that expands upon wetting.

“Bentonite grout” or “slurry” means a mixture of 10 percent processed bentonite (by weight) and water that is free of contaminants, turbidity, and settleable solids.

“Bentonite pellets” means a form of processed bentonite that can be used directly for sealing applications in well plugging operations.

“Bentonite products” means the forms of bentonite that can be used for sealing material in wells, including graded bentonite, bentonite pellets, and bentonite grout.

“Capped” means the application of a layer of sealing material at the top of the well casing.

“Casing” means a tubular retaining structure installed in an excavated hole to maintain the well opening.

“Concrete” means a mixture of one sack (94 pounds) of Portland cement, up to but not exceeding an equal amount by volume of sand and up to but not exceeding an equal amount by volume of gravel or crushed stone and not more than six gallons of water that is free of contaminants, turbidity, and settleable solids.

“Confined aquifer” means an aquifer in which the groundwater is under pressure greater than atmospheric pressure. The static water level in a well tapping a confined aquifer rises to a level above the top of the aquifer.

“Crushed stone” means stone (predominantly limestone), crushed and well graded, with 100 percent passing a 1-inch sieve, in accordance with the 1984 edition of Iowa Department of Transportation (DOT) specification No. 4120.04 for Class A crushed stone.

“Frost pit” means a sunken area located directly over or within four feet of a well and used to house the equipment for discharging water from a well into the water system.

“Graded bentonite” means bentonite that is crushed and sized for pouring and easy handling. Like processed bentonite, it swells when hydrated with water and will form a plastic, essentially impermeable mass.

“Gravel” means stone screened from river sand or quarried, with 100 percent passing a ¾-inch sieve, in accordance with the 1984 edition of the Iowa DOT specification No. 4120.02 for Class B gravel.

“Groundwater” means any water beneath the surface of the earth.

“Grout” means a material used to seal the annular space between the casing and borehole or between casings, or to seal wells during plugging. Approved grouts include bentonite products, concrete, neat cement, or sand cement grout.

“Limestone” means sedimentary rock that contains greater than 50 percent calcium carbonate and has a strong reaction with hydrochloric acid (HCL).

“Neat cement” means a mixture of one sack (94 pounds) of Portland cement to not more than six gallons of water that is free from contaminants, turbidity, or settleable solids. Bentonite up to 2 percent by weight of cement may be added to reduce shrinkage.

“Pea gravel” means gravel sized from ⅛ inch to ⅜ inch in diameter.

“Processed bentonite” means bentonite that has been kiln-dried and processed into pellets for direct use in well sealing applications or into powder or coarse granules for use in bentonite grout for sealing.

“Rock” means stone screened from river sand or quarried, free of debris, foreign matter, and any toxic or agricultural chemical residue, up to 2½ inches in diameter.

“Sand” means clean, medium-textured quartz (concrete sand), at least 25 percent with diameters between 0.25 and 2.0 mm, less than 35 percent with diameters between 0.05 and 0.25 mm, and less than 5 percent with diameters between 0.002 and 0.05 mm.

“Sand cement grout” means a mixture of one sack (94 pounds) of Portland cement, an equal amount by volume of sand and not more than six gallons of water that is free from contaminants, turbidity, and settleable solids.

“Sandpoint well” means a small-diameter water well constructed by joining a screened drive point with lengths of pipe and driving the assembly into a shallow sand and gravel aquifer.

“Sealing” means the proper placement of sealing materials into an abandoned well to seal off flow into, out of, or between aquifers.

“Standby well” means a water well that is temporarily taken out of service with the expectation of being returned to service at a future date.

“Static water level” means the water level in a water well or aquifer when the well is not flowing or being pumped, sometimes referred to as the water line. The static water level for an abandoned well is determined just prior to commencing plugging operations.

“Tremie pipe” means a device, usually a small-diameter pipe, that carries grouting materials to the bottom of the hole and that allows pressure grouting from the bottom up without introduction of air pockets.

“Unconfined aquifer” means an aquifer in which the static water level does not rise above the top of the aquifer (i.e., the pressure of the water in the aquifer is approximately equal to that of the atmosphere).

567—39.3(455B) Abandoned well plugging schedule. All classes of wells that are abandoned must be properly plugged within 90 days of the date of abandonment.

567—39.4(455B) Abandoned well owner responsibilities.

39.4(1) Plugging requirements. The well owner is responsible for ensuring an abandoned well is plugged pursuant to this chapter.

39.4(2) Record. It is the responsibility of the owner to complete, certify, and submit to the department, or the local county health department when seeking private well grant funds, the well plugging form documenting that an abandoned well has been plugged in accordance with the requirements in this chapter, within 30 calendar days of the completed plugging. The well plugging form shall include confirmation of the well plugging by the designated agent for the county or a certified well contractor. The form is available on the department’s website at www.iowadnr.gov.

567—39.5(455B) Abandoned well plugging materials.

39.5(1) Sealing materials. Approved sealing materials are bentonite products (graded bentonite, bentonite pellets, and bentonite grout), neat cement, sand cement grout, and concrete. If graded bentonite or bentonite pellets are used, they may be added by pouring in place and agitating to avoid bridging.

39.5(2) Filling materials. Approved filling materials include agricultural lime, sand, pea gravel, gravel, and crushed stone. Soil may only be used to backfill the top four feet above the final sealing cap. The filling materials shall be free of debris, foreign matter, and any toxic or agricultural chemical residue. Filling materials are not required for well plugging.

567—39.6(455B) Abandoned well plugging procedures.

39.6(1) Freedom from obstructions. Abandoned wells must be checked before they are plugged in order to ensure there are no obstructions that may interfere with plugging operations. Drop pipes, check valves, pumps, and other obstructions shall be removed if practical.

39.6(2) Removal of casing and housing for all wells. Casing pipe and any curbing, frost pit, or pump house structure shall be removed to a depth of four feet below the ground surface. The remaining depth shall be sealed, as specified based on well type, backfilled with soil, and graded so that surface water is directed away from the abandoned well location.

39.6(3) Class 1 wells.

a.Class 1 wells may be plugged by pouring filling and sealing materials from the top of the well or by using tremie pipes or dump bailers. Sand cement grout or concrete placed below the static water level shall be placed by tremie pipe or dump bailer.

b.Filling materials shall be placed up to one foot below the static water level. A minimum of one foot of sealing materials shall be placed on top of the filling material up to the static water level as a seal. Filling material may then be added up to four feet below the ground surface.

c.A minimum of one foot of sealing materials shall be placed where the casing, curbing, frost pit, or pump house structure is removed. The sealing materials shall extend six or more inches beyond the outside diameter of the top of the remaining well casing and shall terminate three feet below the ground surface. The remaining three feet (below the ground surface) shall then be backfilled with soil and graded so that surface water is directed away from the abandoned well location.

39.6(4) Class 2 wells other than bedrock wells.

a.If the details of well construction are unknown or obstructions that may interfere with well plugging cannot be removed, the well shall be tremied full of neat cement or bentonite grout up to four feet below the ground surface. If bentonite grout is used from the static water level to the top of the well, it should be capped by neat cement, sand cement grout, or concrete terminating four feet below the ground surface.

b.Filling material shall be placed in the bottom of the well up to four feet below the static water level. Sealing materials consisting of any bentonite products or neat cement shall be added above the filling material up to four feet below ground surface. If bentonite grout or neat cement is used, it shall be placed by tremie pipe. Concrete and sand cement grout are permissible starting at the static water level.

39.6(5) Class 2 bedrock wells. If the details of well construction are unknown or obstructions that may interfere with well plugging cannot be removed, the well shall be tremied full of neat cement or bentonite grout up to four feet below the ground surface. If bentonite grout is used from the static water level to the top of the well, it should be capped by neat cement, sand cement grout, or concrete terminating four feet below the ground surface.

a.Bedrock wells completed in a single confined aquifer.

(1)Before the well is plugged, a bridge plug or packer shall be placed at or below the bottom of the casing to stop the flow of water where the pressure in the confined aquifer causes the water to flow from the well to the surface. In such cases, filling materials shall be placed in the lower portion of the well before the bridge plug or packer is set.

(2)Filling material shall be placed from the bottom of the well up to ten feet below the bottom of the casing or uncased confining layer, whichever is lower. Sealing materials consisting of any bentonite products, sand cement grout, or neat cement shall be placed from either the top of the filling material to at least ten feet above the bottom of the casing or uncased confining layer or to the static water level, whichever is higher.

1.If bentonite grout, neat cement, or sand cement grout is used, it shall be placed by tremie pipe. The casing shall then be filled up to four feet below the ground surface with sealing materials.

2.If bentonite grout is used from the static water level to the top of the well, it should be capped by neat cement, sand cement grout, or concrete terminating four feet below the ground surface.

(3)It is preferable to omit filling materials and use approved sealing materials to fill the entire well up to four feet below the ground surface.

b.Bedrock wells completed in a single unconfined aquifer. The plugging procedure for these wells is the same as for bedrock wells completed in a single confined aquifer, except that a bridge plug or packer is not required to stop the flow of water since this problem will not exist in this type of well.

c.Bedrock wells completed in multiple aquifers.

(1)For the lowest aquifer, filling material shall be placed from either the bottom of the well up to ten feet below the bottom of the casing or uncased confining layer, whichever is lower. Neat cement tremied in place shall then be placed as a sealing material on top of the fill and extend upward at least 20 feet. Sealing materials shall then be placed in at least the top ten feet of each subsequent aquifer and extend at least ten feet into either the confining layer or casing above, whichever is higher. The same type of filling materials and sealing procedures shall apply for each subsequent aquifer.

(2)Filling material may be placed from the top of the uppermost aquifer seal up to the static water level of the well. The casing shall then be filled with sealing materials to four feet below the ground surface. If bentonite grout is used from the static water level to the top of the well, it should be capped by neat cement, sand cement grout, or concrete terminating four feet below the ground surface.

(3)It is preferable to omit filling materials and use approved sealing materials to fill the entire well up to four feet below the ground surface. Sand cement grout or concrete shall be applied with a tremie pipe or dump bailer when applied below the static water level.

39.6(6) Class 3 wells. The preferred method of plugging a sandpoint well is to pull the casing and sandpoint out of the ground, allowing the hole to collapse and fill. If the sandpoint and casing cannot be extracted, they shall be tremied full of neat cement or completely sealed with bentonite products.

567—39.7(455B) Designation of standby wells.

39.7(1) Standby wells. All standby wells shall:

a.Be disinfected prior to being taken out of use for a long period of time and when placed back in service, in accordance with rule 567—49.24(455B);

b.Be checked for bacteria and nitrates, as a minimum, when placed back in service;

c.Not be subject to contamination by surface drainage or from other causes;

d.Be provided with an airtight well casing cover when the well is not in use; and

e.Be repaired so that there is no degradation of groundwater and it is suitable for use prior to being classified as a standby well.

39.7(2) Caveat. Nothing in these rules shall be construed as exempting public water supply wells from any other requirements set forth in state rules.

567—39.8(455B) Waivers. A waiver to these rules may be granted by the department provided sufficient information substantiating the need for a waiver is submitted in accordance with the department’s waiver procedures in 561—Chapter 10. When satisfactory justification has been submitted to the director demonstrating that a waiver to these rules will result in equivalent or improved effectiveness and equivalent protection of all aquifers penetrated by the affected well, a waiver to these rules may be granted by the director. A waiver denial may be appealed to the commission pursuant to 567—Chapter 7.

These rules are intended to implement Iowa Code sections 455B.172 and 455B.190.