well abandonment handbook - usda...well abandonment handbook 2 arizona department of water resources...

Well Abandonment Handbook

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 Abandonedand 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 havegone dry, and no vadose zone contamination issues exist. .............................................. 6Alternative 2 – Applies to wells that do not penetrate aquifers, including wells that havegone dry, and vadose zone contamination issues exist. ................................................... 6Alternative 3 – Applies to wells that penetrate single or multiple aquifers, and waterquality contamination issues exist.................................................................................... 6Alternative 4 – Applies to wells that penetrate a single aquifer only without verticalflow 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 verticalflow components, and no water quality contamination issues exist................................. 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 OccurringVadose Zone and Aquifer Conditions..................................................................... 7

Table 1 Acceptable Well Abandonment Materials and Mixtures ...................................... 11


Arizona Department of Water Resources 1

I. IntroductionThe Arizona Department of WaterResources (“ADWR”) regulates theabandonment of wells in Arizona. ADWRadopted a rule setting forth requirements forwell abandonment in 1984 and amended therule in 1990. The amended rule is publishedin the Arizona Administrative Code(“A.A.C.”) as Rule R12-15-816. A copy ofthe rule is attached to this Handbook asAppendix A.

ADWR’s well abandonment rule requiresthat well abandonment be accomplished“through filling or sealing the well so as toprevent the well, including the annular spaceoutside the casing, from being a channelallowing the vertical movement of water.”A.A.C. R12-15-816(G). The rule prescribesthe fill materials that must be used in certainaquifer conditions. A.A.C. R12-15-816(H).The rule also requires the filing of a pre-abandonment notice with ADWR (unless thewell is a new well being abandoned in thecourse of drilling the well) and the filing ofpost-abandonment reports. A.A.C. R12-15-816(B), (E) and (F).

The purpose of this Handbook is to providea step-by-step guide to the abandonment of awell in a manner that complies withADWR’s well abandonment rule. TheHandbook describes the abandonmentprocess from the filing of a Notice ofIntention to Abandon with ADWR prior tocommencing abandonment, to the filing ofpost-abandonment reports by the well ownerand well driller. Most importantly, theHandbook describes procedures that may beused to adequately abandon a well,including fill materials and emplacementmethods.

A standard abandonment method isdescribed that may be used for any well,regardless of the aquifer and vadose zoneconditions applicable to the well. Fivealternative abandonment methods are also

described for five different vadose zone andaquifer conditions. In most cases, thealternative abandonment method will be lessexpensive than the standard method.However, a well owner may need todemonstrate to ADWR that the well to beabandoned falls within the condition towhich the alternative method applies beforethat method may be used. For that reason,the abandonment process may take longer ifan alternative abandonment method isrequested.

The well abandonment methods described inthis Handbook are presented in much greaterdetail than in ADWR’s well abandonmentrule. However, the Handbook is notintended to change any of the requirementsin the rule or to impose any additionalrequirements. The purpose of including theabandonment methods in the Handbook is toassist well owners and well drillers incomplying with A.A.C. R12-15-816(G) byinforming them of fill materials andemplacement methods ADWR considers tobe adequate to seal a well in a manner thatwill prevent the well from being a channelallowing the vertical movement of water. Aperson who abandons a well in accordancewith the applicable well abandonmentmethod described in this Handbook will beassured of complying with A.A.C. R12-15-816(G).

The next section presents an overview of theabandonment process. Section III describessurface seal requirements for the upper 20feet of all wells and special requirements fordebris-filled or obstructed wells. Section IVdescribes the standard abandonment methodand the five alternative methods. AppendixB contains definitions of terms used in thisHandbook and Appendix C containsquestions and answers regarding thisHandbook.


2 Arizona Department of Water Resources

II. Overview of the WellAbandonment ProcessLegal authorization from the ADWR isrequired to abandon most types of wells inthe State of Arizona. The types of wells forwhich abandonment authority from ADWRis required are described in the question andanswer section of this Handbook (AppendixC).

The process that must be followed to obtainwell abandonment authority starts with thefiling of a notice of intention to abandon awell (NOIA) (see Figure 1). NOIA formsmay be obtained from the ADWRGroundwater Management Support Sectionoffice in Phoenix, or at local ADWR officeslocated in Prescott, Casa Grande, Tucsonand Nogales. The NOIA form must besigned and filed by the well owner.However, the licensed well driller or aconsultant may assist the well owner infilling out and filing the NOIA.

Information that must be submitted in theNOIA form includes the following:

� A well construction diagram showing allexisting well construction features andthe proposed abandonmentspecifications.

� A description of the type and conditionof the casing. Although this informationmay not be completely known prior toabandonment, this description should bea “best estimate” of the conditions.

� A description of the proposed method ofabandonment. The casing removaltechniques (such as pulling by hydraulicjacks, overdrilling, etc.), or casing non-removal techniques (such as casingperforations, brushing, sonar jetting,etc.) must be described. If the casing isto be perforated, the perforation method,size, and intervals to be perforated mustbe described.

� A description of the method ofemplacing the sealing or fill materials(such as “tremie pumped” or “pressuregrouting”, etc.).

� The specific type and estimated amountof grout material to be used, and theratios of water, cement, and/or othergrout materials.

If the well owner or well driller has anyquestions during the abandonment planningstages prior to submittal of the NOIA, it isrecommended that they contact the ADWRHydrology Division. ADWR will gladlywork with the well owner or well driller toanswer any questions and conduct apreliminary review of the proposedabandonment plan. ADWR may becontacted at:

602-417-2400(Phoenix metro area)

1-800-352-8488(outside metro Phoenix)

After the NOIA is filed, ADWR performs acompleteness review of the notice (SeeFigure 1). The completeness review entailsthe examination of the NOIA to determine ifall required information has been properlysubmitted. After the ADWR determines thatthe NOIA is complete, a substantive reviewis performed to determine whether theproposed abandonment methods andmaterials meet the requirements of theADWR well abandonment rule (See Figure1). If the standard method of abandonmentdescribed on page 5 of this Handbook isselected, which may be used for any wellregardless of the aquifer and vadose zoneconditions applicable to the well, the NOIAwill be approved without further review.

If an alternative abandonment method isselected, the NOIA will receive additionalsubstantive review to determine whether the



well falls within the condition to which thealternative method applies and whetherappropriate fill materials were chosen.During the review process ADWR maycontact the well owner to request additionalinformation or discuss modifications to theproposed abandonment plan, if necessary.

Once the proposed well abandonmentmethods and materials meet therequirements of the abandonment rule, awell abandonment authorization card ismailed to the designated well driller andwell abandonment operations may begin(See Figure 1).

Within 30 days after a well is abandoned,the well owner is required to file a WellOwner’s Notification of Abandonment; andthe well drilling contractor is required to filea Well Abandonment Completion Reportwith ADWR which describes the actualmethods and materials used to abandon thewell (See Figure 1). Information that mustbe submitted in the Well AbandonmentCompletion Report includes the following:

� The specific type and amount of groutand/or fill materials used as well as themixing ratio of water, cement and/orother grout materials used.

� A description of the type and conditionof the casing.

� A description of the actual method ofabandonment. The casing removaltechniques (such as pulling by hydraulicjacks, overdrilling, etc.), or casing non-removal techniques (such as casingperforations, brushing, sonar jetting,etc.) must be described. If the casingwas perforated, the perforation method,size, and intervals must be described.

� A description of the method ofemplacing the sealing or fill materials(such as “tremie pumped” or “pressuregrouting”, etc.).

� The latitude, longitude and wellelevation of the abandoned well, and themethod used to determine these data.Latitude and longitude coordinatesdetermined from readily availableGlobal Positioning System (GPS)equipment are preferred because of thehigh level of accuracy and comparativeease of measurement. If GPS equipmentis used to determine these coordinates,the general grade of equipment shouldbe specified (for example: survey gradeor hand-held). Latitude, longitude andwell elevation coordinates may also beobtained from conventional surveyingmethods or through estimation from atopographic map.



Figure 1Well Abandonment Process



III. Surface Seal RequirementsApplicable to the Upper 20 Feetof All Wells to be Abandonedand Special Requirements forDebris-Filled or ObstructedWellsIn addition to the well sealing andabandonment methods and materials that arediscussed in the following section, ADWR’swell abandonment rule requires a cementgrout surface seal (plug) to be installed inthe upper 20 feet of any well that isabandoned. Special requirements may alsobe necessary if casing obstructions and/ordebris hamper the abandonment of a well.These requirements are described below:

A. Surface Seal Requirements

Surface Casing Removal OptionIf the casing is removed from the top 20 feetof the well, a cement grout plug must be setextending from two feet below the landsurface to a minimum of twenty feet belowthe land surface, and the well must bebackfilled above the top of the cement groutplug to the original land surface.

Surface Casing Non-Removal OptionIf the casing is not removed from the top 10feet of the well, a cement grout plug must beset extending from the top of the casing to aminimum of twenty feet below the landsurface, and the annular space outside thecasing must be filled with cement from theland surface to a minimum of twenty feetbelow the land surface.

B. Special Requirements forDebris Filled or Obstructed WellsIn situations where casing obstructionsand/or debris hamper well abandonment, theproblems should be indicated on the NOIAform. In most instances a reasonableattempt to clear debris and obstructions fromthe well will be required. However, site-

specific conditions will determine the actualmethod of abandonment.

IV. Abandonment Methods

A. Standard AbandonmentMethodThe ADWR standard abandonment methodmeets the requirements of ADWR’s wellabandonment rule under any givencombination of aquifer and vadose zoneconditions. The standard abandonmentmethod may be followed to obtain expeditedprocessing of an NOIA and issuance of awell abandonment authority.

Under the standard abandonment method,the entire length of well casing must beremoved or the entire length of the casingmust be reperforated (from 20 feet above thehighest historic water level to the total depthof the well) with a minimum of two cuts perfoot. If it is determined that the disturbanceof the casing and/or gravel packed zoneswould negatively influence the sealing of thewell, then an appropriate alternativeabandonment method must be used (seeFigure 2 for examples).

The well must be completely filled with neatcement, cement-bentonite grout or, exceptwhere free-product contamination is present,high-solids bentonite grout (granular orpowder mixtures) with a minimum of 25%solids by weight. Materials or mixturesmust be emplaced under sufficient pressureto fill all voids, including all annularspace(s), and displace water from the well.A tremie pipe must be used to emplace thegrout from the bottom up. The end of thetremie pipe must remain in close proximityto the rising grout surface, as the grout ispumped into the well.

In order to receive expedited processing, theNOIA should be filled out completely, andthe “Standard method” should be selected inthe proposed well abandonment methodsection of the NOIA form. The specific type



and estimated volume of grout materialshould be specified on the NOIA form. Anydiscrepancies between the estimated volumeof grout to be used, and the actual amount ofgrout that was used for abandonment shouldbe reported and explained on the WellAbandonment Completion Report.

B. Alternative AbandonmentMethodsThere are five alternatives to the standardabandonment method described above.Each alternative method is designed for adifferent vadose zone or aquifer condition,and only one alternative method isappropriate for a specific well. Theconditions described at the beginning ofeach alternative and the depictions in Figure2 should be carefully reviewed to determinethe appropriate alternative method if thestandard abandonment method is notselected. If an alternative method isselected, the method must be identified bynumber in the NOIA and the well ownermay be required to submit informationdemonstrating that the applicable vadosezone or aquifer conditions exist for the well.

Alternative 1 – Applies to wells thatdo not penetrate aquifers, includingwells that have gone dry, and novadose zone contamination issuesexist.If the well does not penetrate an aquifer orhas gone dry, and vadose zonecontamination issues do not exist, the wellmust be filled with one or more of thefollowing materials or mixtures: clean finesand, cement grout (including neat cementgrout, cement-bentonite grout and sand-cement grout), concrete grout, sand-bentonite grout, high-solids bentonite grout(granular or powder mixtures) with aminimum of 15% solids by weight, high-solids bentonite chips or high-solidsbentonite pellets. See Table 1 for mixingratios. High-solids bentonite chips andhigh-solids bentonite pellets must behydrated to manufacturer’s specifications.

The materials or mixtures are recommendedto exceed the casing volume byapproximately 30 percent.

In the course of drilling a new well, the wellmay be abandoned using drill cuttings fromthe well being drilled if the well does notpenetrate an aquifer, and no vadose zonecontamination issues exist.

Alternative 2 – Applies to wells thatdo not penetrate aquifers, includingwells that have gone dry, and vadosezone contamination issues exist.If the well does not penetrate an aquifer orhas gone dry, and vadose zonecontamination issues exist, but there is nofree-product contamination, the well must befilled with one or more of the followingmaterials 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 powdermixtures) with a minimum of 15% solids byweight, high-solids bentonite chips or high-solids bentonite pellets. See Table 1 formixing ratios. High-solids bentonite chipsand high-solids bentonite pellets must behydrated to manufacturer’s specifications.The materials or mixtures are recommendedto exceed the casing volume byapproximately 30 percent.

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

Alternative 3 – Applies to wells thatpenetrate single or multiple aquifers,and water quality contaminationissues exist.If the well penetrates a single or multipleaquifer system and water qualitycontamination issues exist, then site-specificconditions will determine the appropriateseal material and emplacement method. Theseal material must be no more permeablethan the formation being sealed. A target



Static Water Level

?Upper AquiferLower AquiferUpper Aquifer

Lower Aquifer

or Vadose ZoneVadose Zone

Depth to AquiferBoundary May orMay Not BeKnown

or

Vadose ZoneContamination

Groundwater Contamination

Vertical FlowComponents

Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5Wells That Do NotPenetrate AquifersIncluding Wells ThatHave Gone Dry

Wells That Do NotPenetrate AquifersIncluding Wells ThatHave Gone Dry

Wells That PenetrateSingle or MultipleAquifers

Wells That PenetrateA Single Aquifer WithNo Vertical FlowComponents

Wells That PenetrateSingle or MultipleAquifers WithVertical FlowComponents

(No Vadose ZoneContamination IssuesExist)

(Vadose ZoneContamination IssuesExist)

(Water QualityContamination IssuesExist)

(No Water QualityContamination IssuesExist)

(No Water QualityContamination IssuesExist)

Figure 2Alternative Abandonment Methods Applicable to

Five Commonly Occurring Vadose Zoneand Aquifer Conditions

hydraulic conductivity of 10-7 cm/s may beused for sealant materials. The types ofacceptable materials or mixtures are: cementgrout (including neat cement grout andcement bentonite grout), high-solidsbentonite grout (granular or powdermixtures) with a minimum of 15% solids byweight, high-solids bentonite chips or high-solids bentonite pellets. See Table 1 formixing ratios. A minimum of 15%bentonite solids will be acceptable in mostcases. However, a higher minimum ofbentonite solids may be required in areas ofhigh water quality contamination. Acidresistant cement (see definitions) may berequired in certain areas where corrosive(low pH) groundwater conditions areencountered. The materials or mixtures arerecommended to exceed the casing volumeby approximately 30 percent.If there is no free-product contamination atthe well site, the vadose zone portion of the

well may be sealed with the same materialthat is used to seal the well below the waterlevel. High-solids bentonite chips and high-solids bentonite pellets must be hydrated tomanufacturer’s specifications if used in thevadose zone. If free-product contaminationissues exist, the vadose zone portion of thewell must be sealed with neat cement grout.

Materials or mixtures must be emplacedunder sufficient pressure to fill all voids,including all annular space(s), and displacewater from the well. A tremie pipe must beused to emplace the grout from the bottomup. The end of the tremie pipe shall remainin close proximity to the rising grout surfaceas the grout is pumped into the well.

Except as provided below for recentlyconstructed monitor wells, if the casing isnot removed, either the entire length of thecasing must be reperforated (from 20 feet



above the highest historic water level to thetotal depth of the well), or the condition ofthe casing perforations must be determinedby running a video log that must besubmitted to the ADWR for review. If avideo log demonstrates that the existingperforations are sufficiently open for groutto enter the annular space outside the casing,no additional perforations or casingtreatments will be required. If the video logdemonstrates that the existing perforationsare not sufficiently open for grout to enterthe annular space outside the casing,additional perforations and/or casingtreatments such as mechanical brushing,scraping or sonic cleaning will be required,unless it is determined that disturbance ofthe casing and/or gravel packed zones wouldnegatively influence the sealing of the well.Casing perforation and/or casing cleaningrequirements for wells with water qualitycontamination issues will be made byADWR on a case-by-case basis.

Wells requiring additional perforations mustbe perforated a minimum of two cuts perfoot and sealed by pressure grouting. Theintervals to be perforated must bedetermined based on site-specificinformation. However, if no vadose zonecontamination issues exist, the perforationsneed only extend 20 feet above the staticwater level in the well.

Video logging and/or casing re-perforationmay not be required in the case of theabandonment of recently constructedmonitor wells. However, that determinationmust be made by ADWR on a case-by-casebasis.

Alternative 4 – Applies to wells thatpenetrate a single aquifer onlywithout vertical flow components,and no water quality contaminationissues exist.If the well penetrates an aquifer andhydrogeologic and stratigraphic informationis available for the well at an acceptable

level of confidence to determine that noaquifer boundaries and no vertical flowcomponents exist within the length of thewell, and if water quality contaminationissues do not exist, the well must be filledwith one or more of the following materialsor mixtures: cement grout (including neatcement grout, cement-bentonite grout andsand-cement grout), concrete, high-solidsbentonite grout (granular or powdermixtures) with a minimum of 15% solids byweight, high-solids bentonite chips, high-solids bentonite pellets, and sand-bentonitegrout. See Table 1 for mixing ratios.

In the course of drilling a new well, the wellmay be abandoned using drill cuttings fromthe well being drilled if the well does notpenetrate an aquifer, and no vadose zonecontamination issues exist.

The vadose zone portion of these types ofwells may be filled with any of the mixturesor materials described above or allowed inAlternative 1. High-solids bentonite chipsand high-solids bentonite pellets must behydrated to manufacturer’s specifications ifused in the vadose zone. The materials ormixtures are recommended to exceed thecasing volume by approximately 30 percent.


Alternative 4 (Variance Option)A variance option is available to abandonwells that are 8 inches or greater in diameterand that fall under Alternative 4 aquiferconditions. Alternative 4 (Variance Option)allows the use of clean fine sand to fill thewell.



Please note that anyone wishing to use thisalternative abandonment method must firstapply to ADWR for a variance from the wellabandonment rule.

Alternative 5 – Applies to wells thatpenetrate single or multiple aquiferswith vertical flow components, andno water quality contaminationissues exist.If the well penetrates a single or multipleaquifer system with vertical flowcomponents, and if water qualitycontamination issues do not exist, the wellmust be sealed to prevent the verticalmigration of fluids with cement grout(including neat cement grout, cement-bentonite grout and sand-cement grout),high-solids bentonite grout (granular orpowder mixtures) with a minimum of 15%solids by weight, high-solids bentonite chipsor high-solids bentonite pellets of sufficientvolume, density, and viscosity to preventfluid communication between aquifers. SeeTable 1 for mixing ratios.

The vadose zone portion of this type of wellmay be filled with any of the mixtures ormaterials described above or allowed inAlternative 1. High-solids bentonite chipsand high-solids bentonite pellets must behydrated to manufacturer’s specifications ifused in the vadose zone. The materials ormixtures are recommended to exceed thecasing volume by approximately 30 percent.


If the casing is not removed, it isrecommended, but not required, that thecondition of the casing perforations bedetermined by running a video log. If the

video log demonstrates that the existingperforations are sufficiently open for groutto enter the annular space between thecasing and the well bore, no additionalperforations or casing treatments arenecessary. If the video log demonstratesthat the existing perforations are notsufficiently open for grout to enter theannular space outside the casing, additionalperforations and/or casing treatments suchas mechanical brushing, scraping or soniccleaning are recommended, unless it isdetermined that disturbance of the casingand/or gravel packed zones wouldnegatively influence the sealing of the well.A well requiring additional perforationsshould be perforated a minimum of two cutsper foot and sealed by pressure grouting.

Alternative 5 (Variance Option 1)Alternative 5 (Variance Option 1) isavailable to abandon wells that are 8 inchesor greater in diameter and that fall underAlternative 5 aquifer conditions. Alternative5 (Variance option 1) allows the use ofalternating layers of 50 feet of clean, finesand and 10 feet of one of the approvedAlternative 5 materials or mixturesmentioned above.

Please note that anyone wishing to use thisalternative abandonment method must firstapply to ADWR for a variance fromADWR’s well abandonment rule.

Alternative 5 (Variance Option 2)Alternative 5 (Variance Option 2) isavailable to abandon wells that are 8 inchesor greater in diameter and that fall underAlternative 5 aquifer conditions. Alternative5 (Variance Option 2) allows the installationof seals at aquifer boundaries if boundariesexist and if hydrogeologic and stratigraphicinformation is available for the well at anacceptable level of confidence to determinethe depth(s) of aquifer boundaries. Aquiferboundary seals must be composed of one ofthe approved Alternative 5 materials ormixtures mentioned above.



Aquifer boundary seals must extend at least50 feet above and 50 feet below aquiferboundaries to provide a reasonable level ofconfidence that the boundaries will besealed. The intervals of the well above andbelow the seals must be filled with clean,fine sand or one of the approved Alternative5 materials or mixtures mentioned above.

Please note that anyone wishing to use thisalternative abandonment method must firstapply to ADWR for a variance fromADWR’s well abandonment rule.



Table 1Acceptable Well Abandonment Materials and Mixtures

Mixing Ratio

Cat

egor

y

Specific Material

Solids Water Perm

eabi

lity

(cm

/sec

)

App

licab

leA

band

onm

ent

Met

hods

Special Considerations

Neat CementorNeat Cement Grout

One 94 pound sack ofcement

Not more than six(6) gallons water

10 –5to

10 –7

StandardMethod and

Alts. 1-5

Must be pumped with tremie pipe.Not for use in low pH environments.

ConcreteorConcrete Grout

Cement, sand andaggregate with no lessthan seven (7) 94 lb.sacks of cement percubic yard of concrete

Not more thanseven (7) gallonswater per sack ofcement

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

Sand-Cement GroutOne part cement andno more than one partsand by volume

Not more than six(6) gallons water

2x10 –5 to

5x10 –8Alts. 1,2,4,5 Cannot be used under Alternative 2 if free-product contamination issues exist.

Cement-BentoniteGrout

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

Not more than sixand one-half (6.5)gallons water

10 –5to

10 –11

StandardMethod and

Alts. 1-5

Cannot be used under Alternative 2 if free-product contamination issues exist. Alsocannot be used in vadose zone portion of anAlternative 3 well if free-product contaminationissues exist.

Sand-Bentonite Grout Equal parts sand andbentonite by volume

Slightly more thanone (1) gallonwater per pound ofsand

— Alts. 1,2,4

May be difficult to pump; the sand may bedumped into place while the bentonite slurry ispumped via tremie pipe. Cannot be usedunder Alternative 2 if free-productcontamination issues exist.

Cem

ent,

Sand

, Con

cret

e &

Ben

toni

te M

ixtu

res

1

Acid ResistantCement(Pozzolanic Cement)

One sack of cement(94 lb.) and seventy-four (74) lbs. pozzolans(fly-ash, perlites, etc.)2% to 6% of bentoniteby weight is needed ifperlites are used

Not more than ten(10) gallons ofwater per sack ofcement

— See specialconsiderations

Typically used in areas where low pHgroundwater is encountered. If perlites areused bentonite is needed to keep perlites fromfloating. Chemical admixtures and plastizersmay be used to reduce viscosity.

Wel

lC

uttin

gs Clean cuttings fromthe well being drilledand abandoned

NA NA — Alts. 1,4

Only permissible for wells that do notpenetrate aquifers or wells that only penetratea single aquifer with no vertical flowcomponents. No vadose zone and no waterquality contamination issues may exist.

High-Solids BentoniteGrout (powder orgranular mixture) witha minimum 15%solids by weightMinimum groutdensity = 9.2lbs./gallon

Fifty (50) lbs. drybentonite powder(powder mixture)

orOne 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 –7to

10 –8Alts. 1-5

A minimum of 15% solids bentonite will beacceptable in most cases. However, a higherminimum of bentonite solids may be requiredin areas of high water quality contamination.Cannot be used under Alternative 2 if free-product contamination issues exist. Alsocannot be used in vadose zone portion of anAlternative 3 well if free-product contaminationissues exist. Granular mixtures generallyrequire the addition of polymers.

High-Solids BentoniteGrout (powder orgranular mixture) witha minimum 25%solids by weightMinimum groutdensity = 10.0lbs./gallon

Fifty (50) lbs. drybentonite powder(powder mixture)

orOne hundred fifty (150)lbs. granular bentonite

& 1 qt. Polymer(granular mixture)

Eighteen(18) gallons

(powder mixture)or

Fifty-four(54) gallons

(granular mixture)

10 –8to

10 –9StandardMethod

Cannot be used if free-product contaminationissues exist. Granular mixtures generallyrequire the addition of polymers.

Form

s of

Ben

toni

te1,

2

High-Solids BentoniteChips and Pellets NA NA — Alts. 1-5

Rate of pour should not exceed 50 lbs. / 5minutes. Must be hydrated to manufacturer’sspecifications if used in vadose zone. Cannotbe used under Alternative 2 if free-productcontamination issues exist. Also cannot beused in vadose zone portion of an Alternative3 well if free-product contamination issuesexist.

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.



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

13. Portland Cement Association, 1988.Design and Control of ConcreteMixtures. 205 pp.

14. Smith, S.A., 1994. Well and BoreholeSealing: Importance, Materials,Methods, and Recommendations forDecommissioning. EPA - 542/K94/005.Wisconsin Water Well Association. 69pp.

15. U.S. Environmental Protection Agency,1975, Manual of Water WellConstruction Practices, EPA - 570/9-75-001. 156 pp.

16. U.S. Environmental Protection Agency,March 1991, Handbook of SuggestedPractices for the Design and Installationof Ground-Water Monitoring Wells,EPA- 600/4-89/034. 221 pp.

17. Wyo-Ben Inc., 1999, Groundwater &Mineral Exploration Products Brochure.Billings, Montana.



APPENDIX A – A.A.C. R12-15-816, The ADWR Well Abandonment RuleR12-15-816. AbandonmentA. Well abandonment shall be performed

only by a licensed well drillingcontractor or single well licensee.

B. Except as provided in subsection (F) ofthis Section, the owner of a well shallfile a notice of intent to abandon the wellprior to abandonment, on a formprescribed and furnished by the Director,which shall include:

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

2. The legal description of the land uponwhich the proposed well to beabandoned is located and the name andmailing address of the owner of the land.

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

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

5. The well registration number.

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

7. When abandonment is to begin.

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

9. The reason for abandonment.

10. Such other information as the Directormay require.

C. The Director shall, upon receipt of aproper notice of intent to abandon, maila well abandonment authorization cardto the designated well drilling contractoror single well licensee.

D. Except as described in subsection (F) ofthis section, a well drilling contractor ora single well licensee may commenceabandoning a well only if the driller haspossession of an abandonment card atthe well site, issued by the Director inthe name of the driller, authorizing theabandonment of that specific well orwells in that specific location.

E. Within 30 days after a well is abandonedpursuant to this Section, the well drillingcontractor or single well licensee shallfile with the Director a WellAbandonment Completion Report on aform prescribed and furnished by theDirector which shall include the date theabandonment of the well was completedand such other information as theDirector may require.

F. In the course of drilling a new well, thewell may be abandoned without firstfiling a notice of intent to abandon andwithout an abandonment card. If thewell is abandoned pursuant to thissubsection without first filing a notice ofintent to abandon and without anabandonment card, the well drillingcontractor or single well licensee shallprovide the following information in theWell Abandonment Completion Report:

1. The legal description of the land uponwhich the well was abandoned and thename and the mailing address of theowner of the land.

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

3. The depth, diameter and type of casingprior to abandonment.

4. The well registration number.

5. The materials and methods used toabandon the well.



6. The name and well drilling licensenumber of the well drilling contractor orsingle well licensee who abandoned thewell.

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

8. The reason for abandonment.

9. Such other information as the Directormay require.

G. The abandonment of a well shall beaccomplished through filing or sealingthe well so as to prevent the well,including the annular space outside thecasing, from being a channel allowingthe vertical movement of water.

H. A well not penetrating an aquifer shallinclude a surface seal which shall beaccomplished as follows:

1. If the casing is removed from the top 20feet of the well, a cement grout plugshall be set extending from two feetbelow the land surface to a minimum oftwenty feet below the land surface, andthe well shall be backfilled above the topof the cement grout plug to the originalland surface.

2. If the casing is not removed from the topten feet of the well, a cement grout plugshall be set extending from the top of thecasing to a minimum of twenty feetbelow the land surface, and the annularspace outside the casing shall be filledwith cement from the land surface to aminimum of twenty feet below the landsurface.

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

1. A well penetrating a single aquifersystem shall be filled with cement grout,concrete, bentonite drilling muds, clean

sand with bentonite, or cuttings from thewell.

2. A well penetrating a single or multipleaquifer system with vertical flowcomponents shall be sealed with cementgrout or a column of bentonite drillingmud of sufficient volume, density, andviscosity to prevent fluid communicationbetween aquifers.

J. Materials containing organic or toxicmatter shall not be used in theabandonment of a well.

K. The owner or operator of the well shallnotify the Director in writing no laterthan 30 days after abandonment has beencompleted. The notification shallinclude the well owner’s name, thelocation of the well, and the method ofabandonment.



APPENDIX B – DefinitionsFor the purposes of this Handbook, thefollowing terms have the followingmeanings:

Acid Resistant Cement (also known asPozzolanic cement) (generic mixture):means a cement mixture that has improvedresistance to corrosive fluids. Acid resistantcement is developed by adding siliciousmaterials, pozzolans, to Portland cement.Pozzolans from both natural materials ofvolcanic origin such as perlites (volcanicashes), heat treated clays, shales, tuffs,opaline cherts and diatomaceous earth, andartificial materials consisting of by-productsfrom glass factories, furnace slag, and flyash may be used. A common mixing ratio is74 pounds of pozzolans per 94 pound sackof cement and not more than ten (10) gallonsof water per sack of cement. If perlites areused, 2 to 6 percent of bentonite by weight isneeded to keep the perlite from floating.Acid resistant cement is typicallyrecommended for well abandonmentmaterial in areas where low pH groundwateris encountered (such as near some minesites).

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

Annular Space: “means the space betweenthe outer well casing and the borehole wall.An annular space also means the spacebetween an inner well casing and an outerwell casing.” A.A.C. R12-15-801(1)

Aquifer: “means an underground formationcapable of yielding or transmitting usablequantities of water.” A.A.C. R12-15-801(2)

Aquifer Boundary: means a verticalchange in aquifer properties indicated by adifference in hydraulic conductivity betweenaquifer layers that is at least greater than twoorders of magnitude (100 times greater).

Bentonite “means a colloidal claycomposed mainly of sodiummontmorillonite, a hydrated aluminumsilicate.” A.A.C. R12-15-801(5)

Cement Grout or Grout: “means cementmixed with no more than 50 percent sand byvolume, and containing no more than sixgallons of water per 94 pound sack ofcement.” A.A.C. R12-15-801(15)

Cement grout is sometimes referred to as“sand-cement grout”, when sand is in themixture.

Grout is often used as a synonym for slurrywhich is a generic term that means a thinmixture of liquid, commonly water, and anyof several finely divided substances such ascement or clay particles.

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

Concrete or Concrete Grout (genericmixture): means a mixture of cement, sand,coarse aggregate and water, with not lessthan seven (7) 94 pound sacks of cement percubic yard of mixture and not more thanseven (7) gallons of water per sack ofcement.

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

Free-Product Contamination: means anyknown hazardous substance that isessentially immiscible (non-soluble) inwater. Some typical examples of free-product contamination are gasoline andcarbon tetrachloride.



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

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

High-solids bentonite grout with a minimumof 15% solids by weight can be preparedfrom a mixture of granular bentonite(nominal 8 to 20-mesh particle size), waterand polymer at a ratio of one hundred-fifty(150) pounds of granular bentonite and onehundred (100) gallons of water premixedwith one (1) quart of polymer.

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

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

High-solids bentonite grout with a minimumof 25% solids by weight can be preparedfrom a mixture of granular bentonite(nominal 8 to 20-mesh particle size), waterand polymer at a ratio of one hundred-fifty(150) pounds of granular bentonite and fifty-four (54) gallons of water premixed withone (1) quart of polymer.

High-solids bentonite grout with a minimumof 25% solids by weight can also beprepared from a mixture of bentonitepowder (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 chipsof coarse bentonite ranging in size from 0.25to 0.75 inch.

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

Neat Cement or Neat Cement Grout(generic mixture): means a mixture of one(1) 94 pound sack of cement with not morethan six (6) gallons of clean water.

Pressure Grouting “means a process bywhich a grout is confined within theborehole or casing of a well by the use ofretaining plugs, packers, or a displacingfluid by which sufficient pressure is appliedto drive the grout into and within the annularspace or interval to be grouted.” A.A.C.R12-15-801(23)

Sand-Bentonite Grout (generic mixture):means a mixture of equal parts sand andbentonite by volume with slightly more thanone (1) gallon of water per pound of sand.

Sand-Cement Grout (generic mixture):means a mixture of one 94 pound sack ofPortland cement, sand and water in theproportion of not more than one (1) part byvolume of sand to one (1) part of cementwith not more than six (6) gallons of waterper 94 pound sack of cement.

Sealing: means the conscious effort toconstruct a positive permanent barrier withina well that restricts or prohibits the verticalmovement of groundwater and/or any otherfluids or materials.

Vadose Zone Well “means a wellconstructed in the interval between the landsurface and the top of the static water level.”A.A.C. R12-15-801(26)



Vadose Zone Contamination Issue: meansany hazardous substance that is found in thevadose zone at or in the vicinity of the wellat concentrations that exceed establishedstate or federal standards.

Water Quality Contamination Issue:means any known hazardous substance thatis found in groundwater at or in the vicinityof the well at concentrations that exceedestablished state or federal standards.

Well: means any man-made opening in theearth through which water may bewithdrawn or obtained from beneath thesurface of the earth including: 1) all waterwells, monitor wells and piezometer wells;2) geothermal wells for which the rules ofthe Arizona Oil and Gas Commission do notrequire the reinjection of all water associatedwith the geothermal resource to theproducing strata; and 3) all exploration wellsand grounding or cathodic protection holes,except those that are less than 100 feet indepth and do not encounter groundwater.

The question and answer section of thisHandbook contains additional informationconcerning the types of wells that aresubject to ADWR’s well abandonment rule.

Well Abandonment “means themodification of the structure of a well byfilling or sealing the borehole so that watermay not be withdrawn or obtained from thewell.” A.A.C. R12-15-801(28)



APPENDIX C – Questions and Answers about the AbandonmentHandbookWhy was it necessary to provide a separatewell abandonment Handbook when there isan existing well abandonment rule?

ADWR has become aware of somemisunderstanding among well owners andwell drillers concerning the requirements ofthe well abandonment rule, A.C.C. R12-15-816. This Handbook is intended to provideguidance to well owners and well drillers onwhat is required by the rule.

In addition, this Handbook describes theprocedures and materials that should be usedto abandon wells not detailed in the rule.The well abandonment rule requires aperson abandoning a well to fill or seal thewell in order to prevent the well, includingthe annular space outside the casing, frombeing a channel allowing the verticalmovement of water. Any well owner orwell driller who abandons a well incompliance with this Handbook will bedeemed to be in compliance with thisrequirement.

Q. What types of wells are subject toADWR’s well abandonment rule?

A. The well abandonment rule applies toman-made openings in the earth throughwhich water may be withdrawn orobtained from beneath the surface of theearth, including all water wells, monitorwells and piezometer wells.

The well abandonment rule also appliesto geothermal wells for which the rulesand regulations of the Arizona Oil andGas Commission do not require thereinjection of all waters associated withthe geothermal resource to the producingstrata, as well as exploration wells andgrounding or cathodic protection holesgreater than 100 feet in depth (regardlessof whether they intercept groundwater).

Q. What types of openings in the earth arenot subject to ADWR’s wellabandonment rule?

A. The well abandonment rule does notapply to:

1. man-made openings in the earth notcommonly considered to be wells,such as construction and miningblast holes, underground mines andmine shafts, open pit mines, tunnels,septic tank systems, caissons,basements, and natural gas storagecavities;

2. an injection well or vadose zone wellthat is subject to regulation by theArizona Department ofEnvironmental Quality (ADEQ),provided that ADEQ has issued aletter or other document assertingexplicit regulatory authority over thewell;

3. oil, gas, and helium wells drilledpursuant to the provisions of Title27, Arizona Revised Statutes (wellsregulated by the Arizona Oil and GasCommission); and

4. boreholes in the earth less than 100feet in depth which are made forpurposes other than withdrawing orencountering groundwater (such asexploration wells and grounding orcathodic protection holes less than100 feet in depth), except that ifgroundwater is encountered in thedrilling of the borehole, the wellabandonment rule will apply.

Although the well abandonment ruledoes not apply to these types of wellsand boreholes, it is neverthelessrecommended that unused wells or



boreholes that are not regulated underADWR’s well abandonment rule beabandoned in a manner that will protectthe aquifer.

Q. What is the benefit of abandoning anunused well, as opposed to capping thewell (which is also allowed underADWR’s rules)?

A. Proper well abandonment is favoredover well capping for bothenvironmental and safety reasons.

Unused and unabandoned wellsconstitute actual or potentialenvironmental hazards because they canserve as vertical conduits for hazardoussubstances to cross-contaminateaquifers. For example, during the lastseveral decades, serious and costlyvertical cross-contamination of amultiple aquifer system has occurredthrough unabandoned conduit wells atthe Indian Bend Wash Superfund site inScottsdale, Arizona. Owners of unused,unabandoned wells should also realizethat they may be held legally responsiblefor secondary contamination if it isdemonstrated that their well served as aconduit for vertical cross-contaminationof an aquifer system.

Public safety issues also favor wellabandonment over well capping.Capped wells are often tampered with,and once the well cap is removed there isa real danger for humans or animals tofall into the well, or for the well to beused for the illegal disposal of hazardousmaterials.

Q. Why is it generally required to run avideo log to determine the condition ofthe casing perforations in areas wherewater quality contamination exists ifthe casing is not ripped?

A. Because significant conduit flow canoccur through the annular space outsidethe casing, it is essential to seal thispathway to prevent potential verticalcross-contamination. Therefore, whenwater quality contamination issues exist,unless the well casing is removed or thecasing is re-perforated over its entirelength from 20 feet above the highesthistoric water level to the total depth ofthe well, the well owner must run avideo log to determine whether the groutmaterial can flow through the casingperforations and seal the annular spaceoutside the casing.

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

In areas where water qualitycontamination issues do not exist, if thecasing is not ripped, a video log isrecommended, although not required, todetermine perforation conditions. It isimportant to make sure that the well andthe annular space outside the casing areproperly abandoned even when there areno current water quality contaminationissues. This is because the water couldbecome contaminated in the future.

It should also be pointed out thatadditional benefits can be derived fromrunning a video log. Those benefits mayinclude: the determination of thestructural integrity of the well casing, thepresence of casing anomalies andobstructions, the presence of perched orcascading water, etc. This informationcan be very important in developing aneffective abandonment design.

Q. Under what circumstances is itpermissible to use drill cuttings toabandon a well?



A. In the course of drilling a new well, thewell may be abandoned using drillcuttings from the well being drilled onlyif the well does not penetrate an aquiferor the well penetrates a single aquiferonly, with no vertical flow components.Drill cuttings may only be used toabandon the well from which they wereoriginally removed. Drill cuttings maynot be used to abandon wells orboreholes that have water quality and/orvadose zone contamination issues.

Q. How can it be determined whethervertical flow components exist in anaquifer or aquifer system?

A. The determination of vertical flowconditions in an aquifer can be achallenging task. However, verticalflow conditions can be assessed byevaluating water level data collected inpiezometers or monitor wells that arecompleted at different depths within anaquifer or aquifer system at the samelocation. Vertical fluid movement canalso be evaluated in non-pumping wellsusing various geophysical loggingtechniques such as flowmeter logging,spinner logging or tracer logging. Theobservation of cascading water or waterseeping into a non-pumping well belowstatic level is a clear indication ofvertical flow conditions within the well.

Because unit-specific water level dataare typically unavailable, andgeophysical logging may be impracticalor too costly, it is best to assume thatmost aquifers or aquifer systems havesome component of vertical flow, andwell abandonment methods andmaterials should be chosen accordingly.

Q. What should I do if I have furtherquestions concerning a wellabandonment project?

A. Contact ADWR Hydrology Division at:

602-417-2400(Phoenix metro area)

1-800-352-8488(outside metro Phoenix)

well abandonment handbook - usda...well abandonment handbook 2 arizona department of water resources...

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