Well_Abandonment_Handbook_2021_State_of_Arizona.pdf

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PHONE: 602-771-8500

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September 2008 www.new.azwater.gov

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Well Abandonment Handbook

Arizona Department of Water Resources i

Table of Contents

I. Introduction 1

II. Overview of the Well Abandonment Process 2

III. Surface Seal Requirements Applicable to the Upper 20 Feet of All Wells to be Abandoned and Special Requirements for Debris-Filled or Obstructed Wells 5

A. Surface Seal Requirements 5

Surface Casing Removal Option 5

Surface Casing Non-Removal Option 5

B. Special Requirements for Debris Filled or Obstructed Wells 5

IV. Abandonment Methods 5

A. Standard Abandonment Method 5

B. Alternative Abandonment Methods 6

Alternative 1 – Applies to wells that do not penetrate aquifers, including wells that have gone dry, and no vadose zone contamination issues exist 6

Alternative 2 – Applies to wells that do not penetrate aquifers, including wells that have gone dry, and vadose zone contamination issues exist 6

Alternative 3 – Applies to wells that penetrate single or multiple aquifers, and water quality contamination issues exist 6

Alternative 4 – Applies to wells that penetrate a single aquifer only without vertical flow components, and no water quality contamination issues exist 8

Alternative 4 (Variance Option) 8

Alternative 5 – Applies to wells that penetrate single or multiple aquifers with vertical flow components, and no water quality 9

Alternative 5 (Variance Option 1) 9

Alternative 5 (Variance Option 2) 9

References 12

APPENDIX A – A.A.C. R12-15-816, The ADWR Well Abandonment Rule 13

APPENDIX B – Definitions 15

APPENDIX C – Questions and Answers about the Abandonment Handbook 19

Figure 1 Well Abandonment Process 4

Figure 2 Alternative Abandonment Methods Applicable to Five Commonly Occurring

Vadose Zone and Aquifer Conditions 7

Table 1 Acceptable Well Abandonment Materials and Mixtures 11

Arizona Department of Water Resources 1

I. Introduction

The Arizona Department of Water

Resources (“ADWR”) regulates the abandonment of wells in Arizona. ADWR adopted a rule setting forth requirements for well abandonment in 1984 and amended the rule in 1990. The amended rule is published in the Arizona Administrative Code

(“A.A.C.”) as Rule R12-15-816. A copy of the rule is attached to this Handbook as

Appendix A.

ADWR’s well abandonment rule requires that well abandonment be accomplished

“through filling or sealing the well so as to prevent the well, including the annular space outside the casing, from being a channel allowing the vertical movement of water.”

A.A.C. R12-15-816(G). The rule prescribes the fill materials that must be used in certain aquifer conditions. A.A.C. R12-15-816(H).

The rule also requires the filing of a pre-abandonment notice with ADWR (unless the well is a new well being abandoned in the course of drilling the well) and the filing of post-abandonment reports. A.A.C. R12-15-

816(B), (E) and (F).

The purpose of this Handbook is to provide a step-by-step guide to the abandonment of a well in a manner that complies with

ADWR’s well abandonment rule. The

Handbook describes the abandonment process from the filing of a Notice of

Intention to Abandon with ADWR prior to commencing abandonment, to the filing of post-abandonment reports by the well owner and well driller. Most importantly, the

Handbook describes procedures that may be used to adequately abandon a well, including fill materials and emplacement methods.

A standard abandonment method is described that may be used for any well, regardless of the aquifer and vadose zone conditions applicable to the well. Five alternative abandonment methods are also described for five different vadose zone and aquifer conditions. In most cases, the alternative abandonment method will be less expensive than the standard method.

However, a well owner may need to demonstrate to ADWR that the well to be abandoned falls within the condition to which the alternative method applies before that method may be used. For that reason, the abandonment process may take longer if an alternative abandonment method is requested.

The well abandonment methods described in this Handbook are presented in much greater detail than in ADWR’s well abandonment rule. However, the Handbook is not intended to change any of the requirements in the rule or to impose any additional requirements. The purpose of including the abandonment methods in the Handbook is to assist well owners and well drillers in complying with A.A.C. R12-15-816(G) by informing them of fill materials and emplacement methods ADWR considers to be adequate to seal a well in a manner that will prevent the well from being a channel allowing the vertical movement of water. A person who abandons a well in accordance with the applicable well abandonment method described in this Handbook will be assured of complying with A.A.C. R12-15-

816(G).

The next section presents an overview of the abandonment process. Section III describes surface seal requirements for the upper 20 feet of all wells and special requirements for debris-filled or obstructed wells. Section IV describes the standard abandonment method and the five alternative methods. Appendix

B contains definitions of terms used in this

Handbook and Appendix C contains questions and answers regarding this

Handbook.

2 Arizona Department of Water Resources

II. Overview of the Well Abandonment Process

Legal authorization from the ADWR is required to abandon most types of wells in the State of Arizona. The types of wells for which abandonment authority from ADWR is required are described in the question and answer section of this Handbook (Appendix

C).

The process that must be followed to obtain well abandonment authority starts with the filing of a notice of intention to abandon a well (NOIA) (see Figure 1). NOIA forms may be obtained from the ADWR

Groundwater Management Support Section office in Phoenix, or at local ADWR offices located in Prescott, Casa Grande, Tucson and Nogales. The NOIA form must be signed and filed by the well owner.

However, the licensed well driller or a consultant may assist the well owner in filling out and filing the NOIA.

Information that must be submitted in the

NOIA form includes the following:

� A well construction diagram showing all existing well construction features and the proposed abandonment specifications.

� A description of the type and condition of the casing. Although this information may not be completely known prior to abandonment, this description should be a “best estimate” of the conditions.

� A description of the proposed method of abandonment. The casing removal techniques (such as pulling by hydraulic jacks, overdrilling, etc.), or casing non-removal techniques (such as casing perforations, brushing, sonar jetting, etc.) must be described. If the casing is to be perforated, the perforation method, size, and intervals to be perforated must be described.

� A description of the method of emplacing the sealing or fill materials

(such as “tremie pumped” or “pressure grouting”, etc.).

� The specific type and estimated amount of grout material to be used, and the ratios of water, cement, and/or other grout materials.

If the well owner or well driller has any questions during the abandonment planning stages prior to submittal of the NOIA, it is recommended that they contact the ADWR

Hydrology Division. ADWR will gladly work with the well owner or well driller to answer any questions and conduct a preliminary review of the proposed abandonment plan. ADWR may be contacted at:

602-771-8500 (Phoenix metro area)

(outside metro Phoenix)

After the NOIA is filed, ADWR performs a completeness review of the notice (See

Figure 1). The completeness review entails the examination of the NOIA to determine if all required information has been properly submitted. After the ADWR determines that the NOIA is complete, a substantive review is performed to determine whether the proposed abandonment methods and materials meet the requirements of the

ADWR well abandonment rule (See Figure

1). If the standard method of abandonment described on page 5 of this Handbook is selected, which may be used for any well regardless of the aquifer and vadose zone conditions applicable to the well, the NOIA will be approved without further review.

If an alternative abandonment method is selected, the NOIA will receive additional substantive review to determine whether the

Arizona Department of Water Resources 3 well falls within the condition to which the alternative method applies and whether appropriate fill materials were chosen.

During the review process ADWR may contact the well owner to request additional information or discuss modifications to the proposed abandonment plan, if necessary.

Once the proposed well abandonment methods and materials meet the requirements of the abandonment rule, a well abandonment authorization card is mailed to the designated well driller and well abandonment operations may begin

(See Figure 1).

Within 30 days after a well is abandoned, the well owner is required to file a Well

Owner’s Notification of Abandonment; and the well drilling contractor is required to file a Well Abandonment Completion Report with ADWR which describes the actual methods and materials used to abandon the well (See Figure 1). Information that must be submitted in the Well Abandonment

Completion Report includes the following:

� The specific type and amount of grout and/or fill materials used as well as the mixing ratio of water, cement and/or other grout materials used.

� A description of the type and condition of the casing.

� A description of the actual method of abandonment. The casing removal techniques (such as pulling by hydraulic jacks, overdrilling, etc.), or casing non-removal techniques (such as casing perforations, brushing, sonar jetting, etc.) must be described. If the casing was perforated, the perforation method, size, and intervals must be described.

� A description of the method of emplacing the sealing or fill materials

(such as “tremie pumped” or “pressure grouting”, etc.).

� The latitude, longitude and well elevation of the abandoned well, and the method used to determine these data.

Latitude and longitude coordinates determined from readily available

Global Positioning System (GPS) equipment are preferred because of the high level of accuracy and comparative ease of measurement. If GPS equipment is used to determine these coordinates, the general grade of equipment should be specified (for example: survey grade or hand-held). Latitude, longitude and well elevation coordinates may also be obtained from conventional surveying methods or through estimation from a topographic map.

4 Arizona Department of Water Resources

Figure 1

Well Abandonment Process

Well owner files a Notice of Intent to Abandon (NOIA) a well with the ADWR

Completeness review of NOIA (Has all required information been provided?)

Substantive review of NOIA (Was the standard abandonment method selected?)

Substantive review of NOIA (Are the selected alternative abandonment methods and materials appropriate for the applicable aquifer and vadose zone conditions?)

Well Abandoned

Well Abandonment Card issued?

Well Owner Files Notification of Abandonment

(within 30 days)

Well owner supplies additional information or makes corrections to NOIA as requested

Well owner supplies additional information or makes corrections to NOIA as requested

Request for additional information or to modify abandonment plan if needed

Well Driller Files Well Abandonment Completion Report

(within 30 days)

Request is made to well owner to supply required information or to make corrections to NOIA if needed

No

No

No

Yes

Yes

Yes

Arizona Department of Water Resources 5

III. Surface Seal Requirements Applicable to the Upper 20 Feet of All Wells to be Abandoned and Special Requirements for Debris- Filled or Obstructed Wells

In addition to the well sealing and abandonment methods and materials that are discussed in the following section, ADWR’s well abandonment rule requires a cement grout surface seal (plug) to be installed in the upper 20 feet of any well that is abandoned. Special requirements may also be necessary if casing obstructions and/or debris hamper the abandonment of a well.

These requirements are described below:

A. Surface Seal Requirements

Surface Casing Removal Option

If the casing is removed from the top 20 feet of the well, a cement grout plug must be set extending from two feet below the land surface to a minimum of twenty feet below the land surface, and the well must be backfilled above the top of the cement grout plug to the original land surface.

Surface Casing Non-Removal Option

If the casing is not removed from the top 20 feet of the well, a cement grout plug must be set extending from the top of the casing to a minimum of twenty feet below the land surface, and the annular space outside the casing must be filled with cement from the land surface to a minimum of twenty feet below the land surface.

B. Special Requirements for Debris Filled or Obstructed Wells

In situations where casing obstructions and/or debris hamper well abandonment, the problems should be indicated on the NOIA form. In most instances a reasonable attempt to clear debris and obstructions from the well will be required. However, site-specific conditions will determine the actual method of abandonment.

IV. Abandonment Methods

A. Standard Abandonment Method

The ADWR standard abandonment method meets the requirements of ADWR’s well abandonment rule under any given combination of aquifer and vadose zone conditions. The standard abandonment method may be followed to obtain expedited processing of an NOIA and issuance of a well abandonment authority.

Under the standard abandonment method, the entire length of well casing must be removed or the entire length of the casing must be reperforated (from 20 feet above the highest historic water level to the total depth of the well) with a minimum of two cuts per foot. If it is determined that the disturbance of the casing and/or gravel packed zones would negatively influence the sealing of the well, then an appropriate alternative abandonment method must be used (see

Figure 2 for examples).

The well must be completely filled with neat cement, cement-bentonite grout or, except where free-product contamination is present, high-solids bentonite grout (granular or powder mixtures) with a minimum of 25% solids by weight. Materials or mixtures must be emplaced under sufficient pressure to fill all voids, including all annular space(s), and displace water from the well.

A tremie pipe must be used to emplace the grout from the bottom up. The end of the tremie pipe must remain in close proximity to the rising grout surface, as the grout is pumped into the well.

In order to receive expedited processing, the

NOIA should be filled out completely, and the “Standard method” should be selected in the proposed well abandonment method section of the NOIA form. The specific type

6 Arizona Department of Water Resources and estimated volume of grout material should be specified on the NOIA form. Any discrepancies between the estimated volume of grout to be used, and the actual amount of grout that was used for abandonment should be reported and explained on the Well

Abandonment Completion Report.

B. Alternative Abandonment Methods

There are five alternatives to the standard abandonment method described above.

Each alternative method is designed for a different vadose zone or aquifer condition, and only one alternative method is appropriate for a specific well. The conditions described at the beginning of each alternative and the depictions in Figure

2 should be carefully reviewed to determine the appropriate alternative method if the standard abandonment method is not selected. If an alternative method is selected, the method must be identified by number in the NOIA and the well owner may be required to submit information demonstrating that the applicable vadose zone or aquifer conditions exist for the well.

Alternative 1 – Applies to wells that do not penetrate aquifers, including wells that have gone dry, and no vadose zone contamination issues exist.

If the well does not penetrate an aquifer or has gone dry, and vadose zone contamination issues do not exist, the well must be filled with one or more of the following materials or mixtures: clean fine sand, cement grout (including neat cement grout, cement-bentonite grout and sand-cement grout), concrete grout, sand-bentonite grout, high-solids bentonite grout

(granular or powder mixtures) with a minimum of 15% solids by weight, high-solids bentonite chips or high-solids bentonite pellets. See Table 1 for mixing ratios. High-solids bentonite chips and high-solids bentonite pellets must be hydrated to manufacturer’s specifications.

The materials or mixtures are recommended to exceed the casing volume by approximately 30 percent.

In the course of drilling a new well, the well may be abandoned using drill cuttings from the well being drilled if the well does not penetrate an aquifer, and no vadose zone contamination issues exist.

Alternative 2 – Applies to wells that do not penetrate aquifers, including wells that have gone dry, and vadose zone contamination issues exist.

If the well does not penetrate an aquifer or has gone dry, and vadose zone contamination issues exist, but there is no free-product contamination, the well must be filled with one or more of the following materials or mixtures: cement grout

(including neat cement grout, cement-bentonite grout and sand-cement grout), concrete grout, sand-bentonite grout, high-solids bentonite grout (granular or powder mixtures) with a minimum of 15% solids by weight, high-solids bentonite chips or high-solids bentonite pellets. See Table 1 for mixing ratios. High-solids bentonite chips and high-solids bentonite pellets must be hydrated to manufacturer’s specifications.

The materials or mixtures are recommended to exceed the casing volume by approximately 30 percent.

If free-product contamination issues exist, the entire well must be sealed with neat cement grout.

Alternative 3 – Applies to wells that penetrate single or multiple aquifers, and water quality contamination issues exist.

If the well penetrates a single or multiple aquifer system and water quality contamination issues exist, then site-specific conditions will determine the appropriate seal material and emplacement method. The seal material must be no more permeable than the formation being sealed. A target

Arizona Department of Water Resources 7

Figure 2 Alternative Abandonment Methods Applicable to

Five Commonly Occurring Vadose Zone and Aquifer Conditions

Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Wells That Do Not Wells That Do Not Wells That Penetrate Wells That Penetrate Wells That Penetrate

Penetrate Aquifers Penetrate Aquifers Single or Multiple A Single Aquifer With Single or Multiple

Including Wells That Including Wells That Aquifers No Vertical Flow Aquifers With

Have Gone Dry Have Gone Dry Components Vertical Flow

(No Vadose Zone (Vadose Zone (Water Quality (No Water Quality (No Water Quality

Contamination Issues Contamination Issues Contamination Issues Contamination Issues Contamination Issues

Exist) Exist) Exist) Exist) Exist) hydraulic conductivity of 10 -7 cm/s may be used for sealant materials. The types of acceptable materials or mixtures are: cement grout (including neat cement grout and cement bentonite grout), high-solids bentonite grout (granular or powder mixtures) with a minimum of 15% solids by weight, high-solids bentonite chips or high-solids bentonite pellets. See Table 1 for mixing ratios. A minimum of 15% bentonite solids will be acceptable in most cases. However, a higher minimum of bentonite solids may be required in areas of high water quality contamination. Acid resistant cement (see definitions) may be required in certain areas where corrosive

(low pH) groundwater conditions are encountered. The materials or mixtures are recommended to exceed the casing volume by approximately 30 percent.

If there is no free-product contamination at the well site, the vadose zone portion of the well may be sealed with the same material that is used to seal the well below the water level. High-solids bentonite chips and high-solids bentonite pellets must be hydrated to manufacturer’s specifications if used in the vadose zone. If free-product contamination issues exist, the vadose zone portion of the well must be sealed with neat cement grout.

Materials or mixtures must be emplaced under sufficient pressure to fill all voids, including all annular space(s), and displace water from the well. A tremie pipe must be used to emplace the grout from the bottom

up. The end of the tremie pipe shall remain in close proximity to the rising grout surface as the grout is pumped into the well.

Except as provided below for recently constructed monitor wells, if the casing is not removed, either the entire length of the casing must be reperforated (from 20 feet

8 Arizona Department of Water Resources above the highest historic water level to the total depth of the well), or the condition of the casing perforations must be determined by running a video log that must be submitted to the ADWR for review. If a video log demonstrates that the existing perforations are sufficiently open for grout to enter the annular space outside the casing, no additional perforations or casing treatments will be required. If the video log demonstrates that the existing perforations are not sufficiently open for grout to enter the annular space outside the casing, additional perforations and/or casing treatments such as mechanical brushing, scraping or sonic cleaning will be required, unless it is determined that disturbance of the casing and/or gravel packed zones would negatively influence the sealing of the well.

Casing perforation and/or casing cleaning requirements for wells with water quality contamination issues will be made by

ADWR on a case-by-case basis.

Wells requiring additional perforations must be perforated a minimum of two cuts per foot and sealed by pressure grouting. The intervals to be perforated must be determined based on site-specific information. However, if no vadose zone contamination issues exist, the perforations need only extend 20 feet above the static water level in the well.

Video logging and/or casing re-perforation may not be required in the case of the abandonment of recently constructed monitor wells. However, that determination must be made by ADWR on a case-by-case basis.

Alternative 4 – Applies to wells that penetrate a single aquifer only without vertical flow components, and no water quality contamination issues exist.

If the well penetrates an aquifer and hydrogeologic and stratigraphic information is available for the well at an acceptable level of confidence to determine that no aquifer boundaries and no vertical flow components exist within the length of the well, and if water quality contamination issues do not exist, the well must be filled with one or more of the following materials or mixtures: cement grout (including neat cement grout, cement-bentonite grout and sand-cement grout), concrete, high-solids bentonite grout (granular or powder mixtures) with a minimum of 15% solids by weight, high-solids bentonite chips, high-solids bentonite pellets, and sand-bentonite grout. See Table 1 for mixing ratios.

In the course of drilling a new well, the well may be abandoned using drill cuttings from the well being drilled if the well does not penetrate an aquifer, and no vadose zone contamination issues exist.

The vadose zone portion of these types of wells may be filled with any of the mixtures or materials described above or allowed in

Alternative 1. High-solids bentonite chips and high-solids bentonite pellets must be hydrated to manufacturer’s specifications if used in the vadose zone. The materials or mixtures are recommended to exceed the casing volume by approximately 30 percent.

Materials or mixtures must be emplaced under sufficient pressure to fill all voids, including all annular space(s), and displace water from the well. A tremie pipe must be used to emplace the grout from the bottom

up. The end of the tremie pipe shall remain in close proximity to the rising grout surface as the grout is pumped into the well.

Alternative 4 (Variance Option)

A variance option is available to abandon wells that are 8 inches or greater in diameter and that fall under Alternative 4 aquifer conditions. Alternative 4 (Variance Option) allows the use of clean fine sand to fill the well.

Arizona Department of Water Resources 9

Please note that anyone wishing to use this alternative abandonment method must first apply to ADWR for a variance from the well abandonment rule.

Alternative 5 – Applies to wells that penetrate single or multiple aquifers with vertical flow components, and no water quality contamination issues exist.

If the well penetrates a single or multiple aquifer system with vertical flow components, and if water quality contamination issues do not exist, the well must be sealed to prevent the vertical migration of fluids with cement grout

(including neat cement grout, cement-bentonite grout and sand-cement grout), high-solids bentonite grout (granular or powder mixtures) with a minimum of 15% solids by weight, high-solids bentonite chips or high-solids bentonite pellets of sufficient volume, density, and viscosity to prevent fluid communication between aquifers. See

Table 1 for mixing ratios.

The vadose zone portion of this type of well may be filled with any of the mixtures or materials described above or allowed in

Alternative 1. High-solids bentonite chips and high-solids bentonite pellets must be hydrated to manufacturer’s specifications if used in the vadose zone. The materials or mixtures are recommended to exceed the casing volume by approximately 30 percent.

Materials or mixtures must be emplaced under sufficient pressure to fill all voids, including all annular space(s), and displace water from the well. A tremie pipe must be used to emplace the grout from the bottom

up. The end of the tremie pipe shall remain in close proximity to the rising grout surface as the grout is pumped into the well.

If the casing is not removed, it is recommended, but not required, that the condition of the casing perforations be determined by running a video log. If the video log demonstrates that the existing perforations are sufficiently open for grout to enter the annular space between the casing and the well bore, no additional perforations or casing treatments are necessary. If the video log demonstrates that the existing perforations are not sufficiently open for grout to enter the annular space outside the casing, additional perforations and/or casing treatments such as mechanical brushing, scraping or sonic cleaning are recommended, unless it is determined that disturbance of the casing and/or gravel packed zones would negatively influence the sealing of the well.

A well requiring additional perforations should be perforated a minimum of two cuts per foot and sealed by pressure grouting.

Alternative 5 (Variance Option 1) Alternative 5 (Variance Option 1) is available to abandon wells that are 8 inches or greater in diameter and that fall under

Alternative 5 aquifer conditions.

Alternative 5 (Variance option 1) allows the use of alternating layers of 50 feet of clean, fine sand and 10 feet of one of the approved

Alternative 5 materials or mixtures mentioned above.

Please note that anyone wishing to use this alternative abandonment method must first apply to ADWR for a variance from

ADWR’s well abandonment rule.

Alternative 5 (Variance Option 2) Alternative 5 (Variance Option 2) is available to abandon wells that are 8 inches or greater in diameter and that fall under

Alternative 5 aquifer conditions.

Alternative 5 (Variance Option 2) allows the installation of seals at aquifer boundaries if boundaries exist and if hydrogeologic and stratigraphic information is available for the well at an acceptable level of confidence to determine the depth(s) of aquifer boundaries. Aquifer boundary seals must be composed of one of the approved Alternative 5 materials or mixtures mentioned above.

10 Arizona Department of Water Resources

Aquifer boundary seals must extend at least

50 feet above and 50 feet below aquifer boundaries to provide a reasonable level of confidence that the boundaries will be sealed. The intervals of the well above and below the seals must be filled with clean, fine sand or one of the approved Alternative

5 materials or mixtures mentioned above.

Please note that anyone wishing to use this alternative abandonment method must first apply to ADWR for a variance from

ADWR’s well abandonment rule.

Arizona Department of Water Resources 11

Table 1 Acceptable Well Abandonment Materials and Mixtures

Mixing Ratio

C a te g o ry

Specific Material

Solids Water P e rm e a b il it y

(c m

/s e c

A p p li c a b le

A b a n d o n m e n t M e th o d s

Special Considerations

Neat Cement or Neat Cement Grout

One 94 pound sack of cement

Not more than six

(6) gallons water

10 –5

To 10 –7

Standard Method and Alts. 1-5

Must be pumped with tremie pipe.

Not for use in low pH environments.

Concrete or Concrete Grout

Cement, sand and aggregate with no less than seven (7) 94 lb.

sacks of cement per cubic yard of concrete

Not more than seven (7) gallons water per sack of cement

— Alts. 1,2,4,5 Cannot be used under Alternative 2 if free-product contamination issues exist.

Sand-Cement Grout One part cement and no more than one part sand by volume

Not more than six

(6) gallons water

2x10 –5 to 5x10 –8

Alts. 1,2,4,5 Cannot be used under Alternative 2 if free-product contamination issues exist.

Cement-Bentonite Grout

One sack of cement (94 lb.) & 3-5 lbs.

bentonite

Not more than six and one-half (6.5) gallons water

10 –5 to 10 –11

Standard Method and

Alts. 1-5

Cannot be used under Alternative 2 if free-product contamination issues exist. Also cannot be used in vadose zone portion of an Alternative 3 well if free-product contamination issues exist.

Sand-Bentonite Grout Equal parts sand and bentonite by volume

Slightly more than one (1) gallon water per pound of sand

— Alts. 1,2,4

May be difficult to pump; the sand may be dumped into place while the bentonite slurry is pumped via tremie pipe. Cannot be used under Alternative 2 if free-product contamination issues exist.

C e m e n t, S a n d

C o n c re te

B e n to n it e M ix tu re

Acid Resistant Cement (Pozzolanic Cement)

One sack of cement (94 lb.) and seventy-four (74) lbs. pozzolans (fly-ash, perlites, etc.)

2% to 6% of bentonite by weight is needed if perlites are used

Not more than ten

(10) gallons of water per sack of cement

See special considerations

Typically used in areas where low pH groundwater is encountered. If perlites are used bentonite is needed to keep perlites from floating. Chemical admixtures and plastizers may be used to reduce viscosity.

W e ll

C u tt in g

Clean cuttings from the well being drilled and abandoned

NA NA — Alts. 1,4

Only permissible for wells that do not penetrate aquifers or wells that only penetrate a single aquifer with no vertical flow components. No vadose zone and no water quality contamination issues may exist.

High-Solids Bentonite Grout (powder or granular mixture) with a minimum 15% solids by weight Minimum grout density = 9.2 lbs./gallon

Fifty (50) lbs. dry bentonite powder (powder mixture) or One hundred fifty (150) lbs. granular bentonite

& 1 qt. Polymer (granular mixture)

Thirty–four (34) gallons (powder mixture) or

One hundred

(100) gallons

(granular mixture)

10 –7 to 10 –8

Alts. 1-5

A minimum of 15% solids bentonite will be acceptable in most cases. However, a higher minimum of bentonite solids may be required in areas of high water quality contamination.

Cannot be used under Alternative 2 if free-product contamination issues exist. Also cannot be used in vadose zone portion of an Alternative 3 well if free-product contamination issues exist. Granular mixtures generally require the addition of polymers.

High-Solids Bentonite Grout (powder or granular mixture) with a minimum 25% solids by weight Minimum grout density = 10.0 lbs./gallon

Fifty (50) lbs. dry bentonite powder (powder mixture) or One hundred fifty (150) lbs. granular bentonite

& 1 qt. Polymer (granular mixture)

Eighteen (18) gallons (powder mixture) or

Fifty-four (54) gallons (granular mixture)

10 –8 to 10 –9

Standard Method

Cannot be used if free-product contamination issues exist. Granular mixtures generally require the addition of polymers.

F o rm s o f B e n to n it e

,2

High-Solids Bentonite Chips and Pellets

NA NA — Alts. 1-5

Rate of pour should not exceed 50 lbs. / 5 minutes. Must be hydrated to manufacturer’s specifications if used in vadose zone. Cannot be used under Alternative 2 if free-product contamination issues exist. Also cannot be used in vadose zone portion of an Alternative 3 well if free-product contamination issues exist.

Notes: 1) Additives will be considered on a case by case basis (i.e., fly ash, CaCl, etc.).

2) Manufacturer’s specifications should be followed to achieve a minimum 15% and 25% solids mixtures–mixing ratios listed in this table are approximate.

12 Arizona Department of Water Resources

References

1. Alsay-Pippin Corporation, 1980, Handbook of Industrial Drilling

Procedures and Techniques, 40 pp.

2. American Water Works Association, 1998, AWWA Standard for Water

Wells, ANSI/AWWA A100-97, 73 pp.

3. Arizona Department of Water

Resources, 2001, Statutes and Rules

Governing Minimum Well Construction

Standards and the Licensing of Well

Drillers, 32 pp.

4. American Society for Testing and

Materials (ASTM) Standard D5299-92, 1993, Standard Guide for

Decommissioning of Ground Water

Wells, Vadose Zone Monitoring

Devices, Boreholes, and Other Devices for Environmental Activities, ASTM 1993 Annual Book of Standards, vol. 04-

08, p. 1318-1333.

5. Baroid Drilling Fluids, Inc., 1999, Industrial Drilling Products Brochures, Houston, Texas.

6. Burgin, M. J., et. al., 1988, Grouting and Plugging of Domestic Water Wells in Georgia, Department of Natural

Resources, Circular #13, 14 pp.

7. Driscoll, F.G., 1986, Groundwater and

Wells. 2nd edition, Johnson Filtration

Systems, St. Paul, Minnesota.

8. Eversoll, D.A., Hay, D. L., and

Tremblay, R. J, September 15, 1995, Guidelines for Decommissioning Water

Wells, How to Plug Water Wells, Nebraska Department of Health, Misc.

Publ #37, 22 pp.

9. Kurt, C.E. and Johnson, R.C., Jr., 1982, Permeability of Grout Seals Surrounding

Thermoplastic Well Casing: Ground

Water, Vol. 20, no. 4, p. 415 - 419.

10. Lamb, B. and T. Kinney, 1989, Decommissioning Wells - Techniques and Pitfalls in Proceedings of the Third

National Outdoor Action Conference on

Aquifer Restoration, Ground Water

Monitoring and Geophysical Methods, National Water Well Association, Dublin, Ohio, p.217 - 228.

11. Lutenegger, A. J., and DeGroot, D. J., 994, Hydraulic Conductivity of

Borehole Sealants in D.E. Daniel and

S.J. Trautwein (eds.), Hydraulic

Conductivity and Waste Contaminant

Transport in Soils, ASTM STP 1142, Philadelphia, Pennsylvania, p. 439-460.

12. Michigan Department of Public Health, Michigan Water Well Grouting Manual, 1988, 83 pp.

13. Portland Cement Association, 1988.

Design and Control of Concrete

Mixtures. 205 pp.

14. Smith, S.A., 1994. Well and Borehole

Sealing: Importance, Materials, Methods, and Recommendations for

Decommissioning. EPA - 542/K94/005.

Wisconsin Water Well Association. 69 pp.

15. U.S. Environmental Protection Agency, 1975, Manual of Water Well

Construction Practices, EPA - 570/9-75-

001. 156 pp.

16. U.S. Environmental Protection Agency, March 1991, Handbook of Suggested

Practices for the Design and Installation of Ground-Water Monitoring Wells, EPA- 600/4-89/034. 221 pp.

17. Wyo-Ben Inc., 1999, Groundwater &

Mineral Exploration Products Brochure.

Billings, Montana.

Arizona Department of Water Resources 13

APPENDIX A – A.A.C. R12-15-816, The ADWR Well Abandonment Rule

R12-15-816. Abandonment

A. Well abandonment shall be performed only by a licensed well drilling contractor or single well licensee.

B. Except as provided in subsection (F) of this Section, the owner of a well shall file a notice of intent to abandon the well prior to abandonment, on a form prescribed and furnished by the Director, which shall include:

1. The name and mailing address of the person filing the notice.

2. The legal description of the land upon which the proposed well to be abandoned is located and the name and mailing address of the owner of the land.

3. The legal description of the location of the well on the land.

4. The depth, diameter and type of casing of the well.

5. The well registration number.

6. The materials and methods to be used to abandon the well.

7. When abandonment is to begin.

8. The name and well drilling license of the well drilling contractor or single well licensee who is to abandon the well.

9. The reason for abandonment.

10. Such other information as the Director may require.

C. The Director shall, upon receipt of a proper notice of intent to abandon, mail a well abandonment authorization card to the designated well drilling contractor or single well licensee.

D. Except as described in subsection (F) of this section, a well drilling contractor or a single well licensee may commence abandoning a well only if the driller has possession of an abandonment card at the well site, issued by the Director in the name of the driller, authorizing the abandonment of that specific well or wells in that specific location.

E. Within 30 days after a well is abandoned pursuant to this Section, the well drilling contractor or single well licensee shall file with the Director a Well

Abandonment Completion Report on a form prescribed and furnished by the

Director which shall include the date the abandonment of the well was completed and such other information as the

Director may require.

F. In the course of drilling a new well, the well may be abandoned without first filing a notice of intent to abandon and without an abandonment card. If the well is abandoned pursuant to this subsection without first filing a notice of intent to abandon and without an abandonment card, the well drilling contractor or single well licensee shall provide the following information in the

Well Abandonment Completion Report:

1. The legal description of the land upon which the well was abandoned and the name and the mailing address of the owner of the land.

2. The legal description of the location of the well on the land.

3. The depth, diameter and type of casing prior to abandonment.

4. The well registration number.

5. The materials and methods used to abandon the well.

14 Arizona Department of Water Resources

6. The name and well drilling license number of the well drilling contractor or single well licensee who abandoned the well.

7. The date of completion of the abandonment of the well.

8. The reason for abandonment.

9. Such other information as the Director may require.

G. The abandonment of a well shall be accomplished through filing or sealing the well so as to prevent the well, including the annular space outside the casing, from being a channel allowing the vertical movement of water.

H. A well not penetrating an aquifer shall include a surface seal which shall be accomplished as follows:

1. If the casing is removed from the top 20 feet of the well, a cement grout plug shall be set extending from two feet below the land surface to a minimum of twenty feet below the land surface, and the well shall be backfilled above the top of the cement grout plug to the original land surface.

2. If the casing is not removed from the top ten feet of the well, a cement grout plug shall be set extending from the top of the casing to a minimum of twenty feet below the land surface, and the annular space outside the casing shall be filled with cement from the land surface to a minimum of twenty feet below the land surface.

I. In addition to the surface seal required in subsection (H):

1. A well penetrating a single aquifer system shall be filled with cement grout, concrete, bentonite drilling muds, clean sand with bentonite, or cuttings from the well.

2. A well penetrating a single or multiple aquifer system with vertical flow components shall be sealed with cement grout or a column of bentonite drilling mud of sufficient volume, density, and viscosity to prevent fluid communication between aquifers.

J. Materials containing organic or toxic matter shall not be used in the abandonment of a well.

K. The owner or operator of the well shall notify the Director in writing no later than 30 days after abandonment has been completed. The notification shall include the well owner’s name, the location of the well, and the method of abandonment.

Arizona Department of Water Resources 15

APPENDIX B – Definitions

For the purposes of this Handbook, the following terms have the following meanings:

Acid Resistant Cement (also known as

Pozzolanic cement) (generic mixture):

means a cement mixture that has improved resistance to corrosive fluids. Acid resistant cement is developed by adding silicious materials, pozzolans, to Portland cement.

Pozzolans from both natural materials of volcanic origin such as perlites (volcanic ashes), heat treated clays, shales, tuffs, opaline cherts and diatomaceous earth, and artificial materials consisting of by-products from glass factories, furnace slag, and fly ash may be used. A common mixing ratio is

74 pounds of pozzolans per 94 pound sack of cement and not more than ten (10) gallons of water per sack of cement. If perlites are used, 2 to 6 percent of bentonite by weight is needed to keep the perlite from floating.

Acid resistant cement is typically recommended for well abandonment material in areas where low pH groundwater is encountered (such as near some mine sites).

Aggregate (generic mixture): means sand or gravel with particle size up to ¼ inch.

Annular Space: “means the space between the outer well casing and the borehole wall.

An annular space also means the space between an inner well casing and an outer well casing.” A.A.C. R12-15-801(1)

Aquifer: “means an underground formation capable of yielding or transmitting usable quantities of water.” A.A.C. R12-15-801(2)

Aquifer Boundary: means a vertical change in aquifer properties indicated by a difference in hydraulic conductivity between aquifer layers that is at least greater than two orders of magnitude (100 times greater).

Bentonite “means a colloidal clay composed mainly of sodium montmorillonite, a hydrated aluminum silicate.” A.A.C. R12-15-801(5)

Cement Grout or Grout: “means cement mixed with no more than 50 percent sand by volume, and containing no more than six gallons of water per 94 pound sack of cement.” A.A.C. R12-15-801(15)

Cement grout is sometimes referred to as

“sand-cement grout”, when sand is in the mixture.

Grout is often used as a synonym for slurry which is a generic term that means a thin mixture of liquid, commonly water, and any of several finely divided substances such as cement or clay particles.

Cement-Bentonite Grout (generic mixture): means a mixture of cement, bentonite and water at a ratio of 6.5 gallons of water per each 94 pound sack of cement with not more than 3 to 5 pounds of bentonite per sack of cement.

Concrete or Concrete Grout (generic mixture): means a mixture of cement, sand, coarse aggregate and water, with not less than seven (7) 94 pound sacks of cement per cubic yard of mixture and not more than seven (7) gallons of water per sack of cement.

Exploration Well: “means a well drilled in search of geophysical, mineralogical, or geotechnical data”. A.A.C. R12-15-801(13)

Free-Product Contamination: means any known hazardous substance that is essentially immiscible (non-soluble) in water. Some typical examples of free-product contamination are gasoline and carbon tetrachloride.

16 Arizona Department of Water Resources

Hazardous Substance: has the same meaning prescribed by A.R.S. § 49-201.

High-Solids Bentonite Grout (granular or powder mixture) with a minimum of 15% solids by weight: means a mixture of granular bentonite or powder bentonite that yields a grout that has a minimum 15% bentonite solids by weight.

High-solids bentonite grout with a minimum of 15% solids by weight can be prepared from a mixture of granular bentonite

(nominal 8 to 20-mesh particle size), water and polymer at a ratio of one hundred-fifty

(150) pounds of granular bentonite and one hundred (100) gallons of water premixed with one (1) quart of polymer.

High-solids bentonite grout with a minimum of 15% solids by weight can also be prepared from a mixture of bentonite powder (nominal 200-mesh particle size) and water at a ratio of fifty (50) pounds of dry bentonite powder and thirty-four (34) gallons of water.

High-Solids Bentonite Grout (granular or powder mixture) with a minimum of 25% solids by weight: means a mixture of granular bentonite or powder bentonite that yields a grout that has a minimum 25% bentonite solids by weight.

High-solids bentonite grout with a minimum of 25% solids by weight can be prepared from a mixture of granular bentonite

(nominal 8 to 20-mesh particle size), water and polymer at a ratio of one hundred-fifty

(150) pounds of granular bentonite and fifty-four (54) gallons of water premixed with one (1) quart of polymer.

High-solids bentonite grout with a minimum of 25% solids by weight can also be prepared from a mixture of bentonite powder (nominal 200-mesh particle size) and water at a ratio of fifty (50) pounds of dry bentonite powder and eighteen (18) gallons of water.

High-Solids Bentonite Chips: means chips of coarse bentonite ranging in size from 0.25 to 0.75 inch.

High-Solids Bentonite Pellets: means pellets of fine compressed bentonite (200-mesh) ranging in size from 0.25 to 0.50 inch.

Neat Cement or Neat Cement Grout

(generic mixture): means a mixture of one

(1) 94 pound sack of cement with not more than six (6) gallons of clean water.

Pressure Grouting “means a process by which a grout is confined within the borehole or casing of a well by the use of retaining plugs, packers, or a displacing fluid by which sufficient pressure is applied to drive the grout into and within the annular space or interval to be grouted.” A.A.C.

R12-15-801(23)

Sand-Bentonite Grout (generic mixture):

means a mixture of equal parts sand and bentonite by volume with slightly more than one (1) gallon of water per pound of sand.

Sand-Cement Grout (generic mixture):

means a mixture of one 94 pound sack of

Portland cement, sand and water in the proportion of not more than one (1) part by volume of sand to one (1) part of cement with not more than six (6) gallons of water per 94 pound sack of cement.

Sealing: means the conscious effort to construct a positive permanent barrier within a well that restricts or prohibits the vertical movement of groundwater and/or any other fluids or materials.

Vadose Zone Well “means a well constructed in the interval between the land surface and the top of the static water level.

A.A.C. R12-15-801(26)

Arizona Department of Water Resources 17

Vadose Zone Contamination Issue: means any hazardous substance that is found in the vadose zone at or in the vicinity of the well at concentrations that exceed established state or federal standards.

Water Quality Contamination Issue:

means any known hazardous substance that is found in groundwater at or in the vicinity of the well at concentrations that exceed established state or federal standards.

Well: means any man-made opening in the earth through which water may be withdrawn or obtained from beneath the surface of the earth including: 1) all water wells, monitor wells and piezometer wells;

2) geothermal wells for which the rules of the Arizona Oil and Gas Commission do not require the reinjection of all water associated with the geothermal resource to the producing strata; and 3) all exploration wells and grounding or cathodic protection holes, except those that are less than 100 feet in depth and do not encounter groundwater.

The question and answer section of this

Handbook contains additional information concerning the types of wells that are subject to ADWR’s well abandonment rule.

Well Abandonment “means the modification of the structure of a well by filling or sealing the borehole so that water may not be withdrawn or obtained from the well.” A.A.C. R12-15-801(28)

18 Arizona Department of Water Resources

Arizona Department of Water Resources 19

APPENDIX C – Questions and Answers about the Abandonment Handbook

Why was it necessary to provide a separate well abandonment Handbook when there is an existing well abandonment rule?

ADWR has become aware of some misunderstanding among well owners and well drillers concerning the requirements of the well abandonment rule, A.C.C. R12-15-

816. This Handbook is intended to provide guidance to well owners and well drillers on what is required by the rule.

In addition, this Handbook describes the procedures and materials that should be used to abandon wells not detailed in the rule.

The well abandonment rule requires a person abandoning a well to fill or seal the well in order to prevent the well, including the annular space outside the casing, from being a channel allowing the vertical movement of water. Any well owner or well driller who abandons a well in compliance with this Handbook will be deemed to be in compliance with this requirement.

Q. What types of wells are subject to

ADWR’s well abandonment rule?

A. The well abandonment rule applies to man-made openings in the earth through which water may be withdrawn or obtained from beneath the surface of the earth, including all water wells, monitor wells and piezometer wells.

The well abandonment rule also applies to geothermal wells for which the rules and regulations of the Arizona Oil and

Gas Commission do not require the reinjection of all waters associated with the…