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FINAL RMA OFF-POST WELL ABANDONMENT CONSTRUCTION COMPLETION REPORT

Prepared for: Rocky Mountain Arsenal Remediation Venture Office Department ofthe Army Shell Oil Company U.S. Fish and Wildlife Service

Prepared by: LATA/AG&M Team

ROCKY MOUNTAIN ARSENAL July 9, 1999
Lq 5193-1/1-D 

# ARCADIS GERAGHTY&MILLER 00016124THELATAIARCADIS GERAGHTY & MILLER TEAM

CONTENTS Section Page Acron yms ...... .. ........ ......... ..... ...................................................... .... ............. ...... v List ofFigures and Tables .....................................................................................................vi Executive Summary ............................................. ......................................................................I 1.0 Introduction . ... . ..................................................................................................2 1.1 Site History .... ............ ..........................................................................2 1.2 Description ofRemedy . ............ .......... ............................... ........................ 2 2.0 Chronology ofEvents . . ...... ..

. .................. ......................................................... ... 4 2.1 Pump Removal and Video Logging ........... ... . ................................ .............. 5 2.2 Monitoring Well Closure (37304 and 37319) ...... .............. .................................. . .... 5 2.3 Domestic Well Closures .................................. .... ....................................................5 2.3.1 Well 299A ....... .........................................................................................6 2.3.1 1 Site Preparation . . ........... ....................................... ........ 6 2.3 12 Perforation . ........ . .. ............. .... . ........................................ ...... 6 2 3 13 Grouting .. ... ................. ..

..

... ................................................... ..6 2 3 14 Decontamination ............. .. ...... ........... .... ..

. . ........... 6 2.3 15 Surface Closure and Site Repairs ................. .. . ............ 8 2.3.2 Well 985 A .. ............................. .... ..................................... ................ . 8 2.3.2 1 Site Preparation ... ..... ............ . . ... ........................................ ....... 8 2.3 2 2 Perforation ...... .... ...... .... . . . .. ................................................8 2.3 2.3 Grouting .. . ......... ..

....... . .... ......................................... .... 8 2 3 2.4 Decontamination ..... . ...... . . . ............. .. 8 2.3 2 5 Surface Closure and Site Repairs . .......................... ... 8 2.3.3 Well 395A ... .............. .................. ........................ ........... ....... . . .... 8 2 3 3 1 Site Preparation . ... . .. . . . ....... .. ........ .... ...... ............. .... 8 2 3 3 2 Perforation . ........ ....... I... . ... ............................ .............. ..

8 2.3 3.3 Grou ting ....... ..... ..... . ..... . ....... ................................. ......... ..... 8

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2.3.3.4 Decontamination .......... ...... 9 2.3.3.5 Surface Closure and Site Repairs ... ......... ............................................9 2.3.4 Well 9 14A . ......... . ... ............... . .. .... ..

............................ ..................... 9 2.3 4.1 Site Preparation .... .. . . ..... ........ .. ........... ............................. 9 2.3.4.2 Perforation ... . ............................ .. ......................... ... .................. 9 2.34 3 Grouting ....... .................... ........ ..................................................... 9 2.3.4.4 Decontamination ................ :", * ....... 9 2.3.4 5 Surface Closure and Site Repairs . . . .......... . ................ I............... 9 2.3.5 Well 1070A . . ......... ............................................................................... 10 2.3.5.1 Site Preparation. ................... .. . ........................................... 10 2.3.5.2 Perforation . ............. ..................................... .......................... 10 2.3.5.3 Grouting ..... . ..... ........... ....... ........................................................ 10 2.3.5.4 Decontamination .. .... . . ................... .... .............. ............ ............ 10 2.3.5.5 Surface Closure and Site Repairs ................ ....................................... 10 2.4 Replacement Well Construction ..... ............................. ............................................. 10 2.4.1 Well 9 14B .......................... ... ..................................................................II 2 4 1 1 Drilling Method . . .. .......................... . ........................................ 11 2.4.1.2 Well Construction . .................... ..................................................... II 2.4.1.3 Well Development . ................ ............................... .................... 11 2.4.1.4 Pump, Piping, and Connections . . .......... . ......... .. .................. 12 2 4.2 Well 1070B .. ..... . . ... ............................................... .. . ....... . .... 12 2 4 2 1 Drilling Method . . ............... . . ............................................ . .. 12 2.4 2 2 Well Construction . . ......... . ................................................ 12 2.4.2.3 Well Development ............. . . ............................................... .. 12 2 4.2.4 Pump, Piping, and Connections ... ...... .. . . ......... .... .... ... . ....... 12 3.0 Performance Standards and Clean-Up Goals ... ... ....... . ........... ........................ 12 4 0 Quality Assurance/Quality Control . . ... .. . ... .... ....... . ................. ............. . . 13 4.1 Review and Oversight .... ............ ................ ......... .... ............ ............ .......... 13 4 2 Video Logging Depth Measurements .............. ...... . ...... ..

.... ..... ............ 13 4.3 Grout Volumes .. . ..... ............. . ............ .. .......... . ........ ..... . . . ....... 14 4.4 Well Depths ......... ............. ........................... ....................................... 14 rml03/9801/toc.doc/07/09/99 iiiTHELATAIARCADIS GERAGHTY & MILLER TEAM

4.5 Documentation ......... .......................................................................... .14 5.0 Description and Rationale for Project Modifications .... ............................................ 15
M odificationI . .. ..

........................ ............... ............... ........... ... 15 M odification2 .. ............. ..................................................................... 15 6.0 Construction Quality Assurance Documentation Summary ... .......................................... 15 7.0 Final Inspection Documentation . ....... .......... ................................................................... 15 8.0 Operation and M aintenance Requirements ....... .................... . ........................................... 16 9.0 Summary ofCosts ...... ....... ....... .......................................................................... 16 10.0 Certification . ... ......... ..

......... ........................ . ................................................. 16 11.0 Supporting Documents.. .. ....... ....................... ...................................................... 16 Appendix A-Well Closure Forms . ............................................... .................................. .. A- I Appendix B-Final Inspection Attendance List ... . ......... . ................................................... B-1 Appendix C - Photographs . . .. .. ................................................................................. C-1

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ACRONYMS AND ABBREVIATIONS

CERCLA Comprehensive Environmental Response, Compensation and Liabilities Act CCR Construction Completion Report CDPHE Colorado Department ofPublic Health and Environment CPG Certified Professional Geologist DIMP Diisopropyl Methylphosphonate DOL Department ofLabor HASP Health and Safety Plan LATA Los Alamos Technical Associates Mod I First Modification Mod 2 Second Modification QA/QC Quality Assurance/Quality Control QAPP Quality Assurance Project Plan RDIS Remedial Design and Implementation Schedule RMA Rocky Mountain Arsenal ROD Record ofDecision RPD Relative Percent Difference RVO Remediation Venture Office
sow Statement ofWork TCHD Tri-County Health Department

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LIST OF FIGURES AND TABLES Tables Page Table I Chronology ofScheduled and Actual Project Milestones .... ....... . ............... ........ . 4 Table 2 Summary ofAbandonment Methods ... ................................ . ................................. 7 Table 3 Construction Details forReplacement Wells .......................... ............................ .. II Table 4 Precision ofVideo Logging Depth Measurements .................................................. 14 Table 5 Project Cost Summary .................................................................................16 Fi2ures Page Figure I Off-Post Well Location Map .. ..............................................................3

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Executive Summary This Construction Completion Report (CCR) has been prepared in accordance with the Record of Decision (ROD) as appended in the Remedial Design and Implementation Schedule (RDIS) of December 9, 1996 The purpose ofthe CCR is to document the completion ofeach implementation project under the On-Post Operable Unit ROD and, in this case, these standards have been adopted to document completion ofan implementation project for the Off-Post Operable Unit. This project involved closure ofseven (7) off-post, domestic water supply and monitoring wells to prevent downward migration ofcontaminants from the alluvial aquifer tothe Arapahoe Aquifer. Five of the wells were domestic water supply wells that were closed per requirements ofthe ROD. These wells were closed by perforating or removing the casing, followed by pressure-grouting the entire interval of the well. The remaining two wells were monitoring wells not covered under the ROD, but closed under this work scope because they were no longer being used for groundwater monitoring. These wells were closed by backfilling with a mixture ofPortland cement, bentonite, and water. Following well closure, two replacement wells were constructed in a manner that prevents downward migration ofcontaminants Because the domestic water-supply wells were on private land, pre-construction conditions were photographically documented, and care was taken to repair any damage and return work sites to their original condition. The contract forthis effort was awarded to Los Alamos Technical Associates (LATA) on July 21, 1998, closure ofwells and construction ofnew wells was completed by November 30, 1998, and all field activities were completed on December 4, 1998. A Final Inspection was conducted on December 16, and at this time satisfactory completion ofall activities in the statement ofwork was verified. In attendance were representatives from the Environmental Protection Agency (EPA), the Tri-County Health Department (TCHD), the Colorado Department ofPublic Health and Environment (CDPHE), and the RMA Remediation Venture Office (RVO)

Rml0319801/rma-rpt.doc/07/09/99THELATAIARCADIS GERAGHTY&MILLER TEAM
1.0 Introduction Under the Record ofDecision (ROD) forthe Off-Post Operable Unit at Rocky Mountain Arsenal (RMA), criteria were set for abandonment ofwells in the Off-Post Study Area. The scope ofthis effort was abandonment ofseven off-post wells, and their locations are shown in Figure 1. Five ofthe wells were domestic water supply wells that were closed perrequirements ofthe ROD These wells were completed inthe confined aquifer, and sampling results showed concentrations ofdiisopropyl methylphosphonate (DIMP) above the remediation goal of8ýtg/L. Closure ofthese wells was needed to prevent continued migration ofcontaminants from the alluvial system to the underlying confined aquifer through the well bore. These five wells were closed through mechanical perforation and, inone case, overdrilling, followed by pressure grouting. The other two wells were 2-inch diameter PVC monitoring wells that were not covered under the ROD, but were abandoned by plugging/backfilling with grout under this work scope because they are no longer being used for groundwater monitoring. One ofthese wells was completed inthe confined aquifer and the otherin the Unconfined Flow System (UFS). The UFS consists ofgroundwater flowing through alluvial materials and underlying weathered bedrock, and in the off-post study areatypically consists ofprimarily alluvial groundwater. Therefore, the UFS in the off-post study area will be referred to as the alluvial aquifer inthe remainder ofthis document. 1.1 SiteHistory RMA occupies more than 17,000 acres (approximately 27 square miles) in Adams County, approximately 8miles northeast ofDenver, CO The property was purchased by the United States Government in 1942 and was used to manufacture chemical warfare materials, such as mustard (14D), lewisite, and incendiary munitions during World War 11. From February 1953 to late 1957 RMA manufactured the nerve agent isopropyl methylphosphonofluoridate (GB or sarin). In addition to military activities, from 1947 to 1982 portions ofR-MA were leased to private industry, including Shell Oil Company, for manufacture ofpesticides and herbicides. Past activities at RMA resulted in contamination ofalluvial groundwater with DIMP, a by-product of GB production. This DIN/IP groundwater plume has migrated off-post, following the alluvial groundwater flow direction to the north Sampling results in five domestic water supply wells showed concentrations ofDIMP exceeding the remediation goal of8ýtg/L. These results indicated that the domestic well casings were either constructed improperly or deteriorated to the point where they were providing conduits for DIMP contamination to reach the Arapahoe Aquifer. 1.2 Descriptionof Remedy The ROD forthe Off-Post Operable Unit specifies that closure methods for off-post wells will be identical to closure methods for on-post wells, and the specified closure methods were used in this program Closure methods involved perforation and/or overdrilling, followed by pressure grouting the entire borehole. This method seals both the well and the annulus (area between the casing and the borehole wall) so that alluvial water can no longer flow downward intothe Arapahoe Aquifer Well casings were typically perforated over their entire length, orin some cases to the top ofthe screened interval. At one location mechanical perforation was not effective, and this well was overdrilled using the air-rotary method and the entire length ofPVC casing was removed priorto grout emplacement.

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2175000 2,180000 185 000

9144

East 117th Street

49BSA 76

395A i041hAvenue 070A Zý9A OF

2 ;3 0 Q. In 3 04 37319 East 96th Street

- - - --- - - - - - . . . . . . -L - 4L R -AA

2.175.000 Z180.000 2.185.000 Frinwry Roads Secondarv Roads Light Oury Roads cirtRoads Ibla Ma fen Railroads mftjmý Co N.- IVAdl To Be Closed Figure 1.Locations of Off-Post Wells Closed

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Because the wells were located on private property, care was taken to document pre-existing site conditions and toreturn the sites to at least equivalent condition following field work. 2.0 Chronology of Events Based on the field activities described in this report, the following major design and construction components were accomplished:

. Removed the pumps, piping-andwiring from four ofthe off-post domestic wells identified in the ROD for closure. The fifth well (299A) did not have apump in it atthe start ofthe program. 0 Video logged the five domestic wells to determine their construction details and develop abandonment strategies for them. 0 Abandoned two off-post monitoring wells using cement/bentonite grout.

- Obtained well permits from the Colorado State Engineer's Office for two replacement wells requested by the well owners (Wells 1070B and 914B) These wells replace wells 1070A and 914A. Well numbers are assigned by the TCHD Well permit numbers are issued indocuments generated by the State Engineer's Office 0 Abandoned the five domestic wells by either mechanically perforating or overdrilling their casings and filling them with cementibentonite grout. 0 Installed two replacement wells equivalent tothe existing wells, but properly constructed and sealed to avoid downward migration ofgroundwater from the alluvial aquifer tothe Arapahoe Aquifer

- Performed site repairs including providing piping and electrical service tothe replacement wells. Table I provides the major project schedule execution milestones and dates ofcompletion. The original abandonment completion milestone ofOctober 31, 1998 was extended toNovember 30because ofthe additional time required to obtain the replacement well permits and to overdrill the casing ofone ofthe wells that could not be perforated Table1. Chronologyof Scheduledand ActualProject Milestones Activity Scheduled Completion Date Actual Completion Date Scope ofWork May 22,1998 May 22,1998 Contract Award July 21, 1998 July 21, 1998 Contractor Mobilization None Established August31, 1998 Pull Pumps and Video Log wells None Established September 2,1998 Abandon Monitoring Wells 37304 None Established October 9, 1998 and 37319 Abandon/Replace Domestic November 30,1998 November 24, 1998 Wells Final Inspection None Established December 16,1998

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2.1 PumpRemovalandVideoLogging The pumps and associated piping andwiring were removed &omfour ofthe five domestic wells scheduled for abandonment to facilitate video logging the wells Well 299A did not contain any pumping equipment. The pumps, piping and wiring were stockpiled at each well site in an area designated by thewell owner unless they requestedthat the equipment be removed from the site. In these cases, the equipment was transported to RMA for recycling or disposal. Video logging ofthe wells was performed in orderto evaluate well construction and condition prior to closure. In order for downhole video logging to be effective, water within the wells must be relatively clear. To ensure water clarity inthe wells, potable water was injected into the well with a hose afterthe pumps were removed. The wells were then allowed to stand undisturbed for a minimum of24 hours before video logging wasperformed. Also, because ofthe requirement for clarity inthe water column, wells were logged downward (i.e, from surface to bottom). Inthis way, sediments were not disturbed prior to logging. In all cases, water conditions inthe wells were such that video logging was effective The wells were logged using a two-inch diameter downhole camera with a downward looking wideangle lens and self-contained light source. The downhole video tool was connected to avideo recorder and a spool that automatically records depth in the borehole. A marker on the instrument cable was used to evaluate theprecision ofdepth measurements. The marker was aligned with a specific point on the casing and depth recorded as zero When the toolwas returned to the surface, the alignment ofthis mark to the point on the casing was compared with the automated depth reading. In several cases, video logs showed obvious leakage ofwater from the alluvial to Arapahoe Aquifer. Water was seen cascading down the inside ofthewell casings at 1070A and 395A. In addition, the casing in Well 995A was observed tobe corroded, and several holes were identified in depth interval that coincided with the alluvial aquifer Video logs were recorded on standard VHS tapes suitable for playback on a VCR. These tapes were submitted tothe RMA COR as part oftheproject file. 2.2 MonitoringWell Closure(37304 and37319) Per requirements ofthe contract statement ofwork (SOW), abandonment ofMonitoring Wells 37304 (State Plane Coordinates 2182183E/197232N) and 37319 (State Plane Coordinates 2183504E/197609N) was included inthe scope ofthis project These wells were abandoned by backfilling with a mixture of Portland cement, bentonite, and water, Grout was emplaced from the bottomup using a grout pump and remie pipe to ensure that no void spaces were present. Protective surface casings were then removed and the casings were cut offand capped below ground surface The amount ofgrout placed in each of t the wells was greater than calculated casing volume. At 37304, the casing volume was 4.4 gallons and 10 gallons ofgrout was used. At 37319, the casing volume was 104 gallons and 115 gallons ofgrout was used This indicates that grout was forced outward into the annulus and/or formation, effectively closing these wells. 2.3 Domestic Well Closures Closure ofthe remaining five wells was accomplished through either perforating or overdrilling the well casing and injecting grout inside the perforated casing or open borehole through a tremie pipe.

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Perforation was performed using either a 4- or 6-inch diameter, pneumatically powered (by pressurized air) star-wheel perforator that creates 10, 0 1 -inch diameter perforations per foot ofcasing. Where the casing diameter varied from these diameters, the tool was adjusted as required to ensure perforation of the entire well casing. Sealing offofthe contaminated alluvial aquifer from the underlying Arapahoe Formation was accomplished by grouting the entire length ofthe well casing and/or borehole This method exceeds the requirements ofthe Colorado Water Well Rules which only require casing perforation and grouting across a minimum of20 feet at the confining layer boundary The wells were grouted with a mixture of Portland cement, bentonite, andwater. Quantities and ratios ofthese constituents were logged in both field logbooks and well closure forms When the wells were completely grouted, the volume ofgrout was compared with the calculated borehole volume to ensure that no void spaces were present. Borehole-volume calculation methods and the acceptable difference between grout volume and calculated borehole volume were presented in the Quality Assurance Project Plan (QAPP) for the OffPost Well Closure Project, Details ofthe abandonment ofeach ofthe five wells are provided in Table 2 and the following subsections. 2.3.1 Well 299A 2.3.1.1 SitePreparation.The activities performed atthis well to prepare it for abandonment included cutting offthe steel protective posts around the well, turning offthe power supply tothe well (including lock-out/tag-out), and drilling out the pitless adapter inside the well so that the perforator could pass down the casing. 2.3.1.2 Perforation.The well was mechanically perforated fromjust below the pitless adapter to a depth of175 feet where therewas reffisal ofthe perforator No fiirther effort was made to perforate deeper because the casing was already perforated well below theboundary between the alluvium and Arapahoe Formation, which was identified as being at a depth of47 feet on the original well log. In addition, video logs showed thatthe well casing was slotted from 173 to 274 feet so grout would fill the annulus over this depth interval 2.3.1.3 Grouting. The well casing was grouted through a tremie pipe that initially extended to a depth of 270 feet. As the grout filled the casing, thetremie pipe was removed in stages, but always remained below the grout level. The grout was allowed to settle for several days and then topped offtobring its level back to approximately two feet from ground surface, 2.3.1.4 Decontamination.All equipment used downhole at this location was decontaminated at the CERCLA plant prior to mobilization to another site.

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C 0 Table2. Vummary of AbandonmentMethods Casing Screened Well Total Casing Perforated Overdrilled Grouted Casing Grout Location Number Depth Depth/ Materials Interval/ Interval Interval Interval Volumes Volumes (state plane) Diameter Type PA 611 to 761 173'to 274' 2174790E so 299A 274' 411 to 2741 steel hand 8'to 175' NA 2'to 274' 237 gallons 365 gallons 201192N slotted 6"to 10' 985A 289' 4"to 270 steel NA 1Vto 268' NA 2'to 256' 174 gallons 270 gallons 2172683E open hole 203575N 270'to 28. 4.5"to 74' 2186226E 395A 185' open hole steel NA T- 741 NA T- 185' 217 gallons 220 gallons 202174N 74'to 185' 4"to 457' steel to 8' 260' to 457' surface to 2184647E 914A 492' open hole PVC hand NA 215' 2' to 492' 523 gallons 680 gallons 208503N 457'to 492' 8'to457' slotted

5"to 101, 120'to 193' 2171616E 1070A 193' 4"to 193' steel hand 6.5' to 190' NA 10'to 193' 157 gallons 195 gallons 201662N slotted ITHELATAIARCADIS GERAGHTY& MILLER TEAM
2.3.1.5 Surface ClosureandSiteRepairs. Surface closure and siterepairs performed at this site consisted ofcutting offthe well casing approximately two feet below ground surface, placing a watertight concrete seal ontop ofthe casing up to ground surface, cutting offthe remaining protective posts and patching the asphalt paving at these locations 2.3.2 Well 985A 2.3.2.1 SitePreparation.The activities performed at this well to prepare it for abandonment included turning offthe power supply to the well and having the utility company install an insulating boot onthe overhead power line near the well to protect it from damage during raising and lowering ofthe drilling rig mast. 2.3.2.2 Perforation.The 4-inch diameter casing was mechanically perforated across a depth range ofII to 268 feet. The 6-inch surface casing was not perforated because it only extended to a depth of 10 feet, which is well above the alluvial water table. After the perforator and drill pipe were removed from the well the casing below a depth of256 feet collapsed. 2.3.2.3 Grouting.The well casing was grouted through atremie pipe that initially extended to a depth of 250 feet. As the grout filled the casing, the tremie pipe was removed in stages, but always remained below the grout level. The grout was allowed to settle for several days and then topped offto bring its level back to approximately two feet from ground surface. 2.3.2.4 Decontamination.All equipment used downhole at this location was decontaminated at the CERCLA plant prior to mobilization to another site 2.3.2.5 Surface ClosureandSiteRepairs. Surface closure and site repairs performed at this site consisted ofcutting offthe well casing approximately two feet below ground surface, placing a watertight concrete seal ontop ofthe grouted casing up to ground surface, removing the insulating boot from the power line and replacing gravel in the driveway that had been washed away during thewell abandonment activities 2.3.3 Well 395A 2.3.3.1 SitePreparation.The main activity performed atthis well to prepare it for abandonment consisted ofhaving the utility company temporarily turn offthe powerto the site so that the overhead power lines over and near the well would not interfere with operation ofthe drill rig and other equipment during abandonment and surface closure operations The tenants living in the two houses at the site were also provided with motel rooms during well abandonment activities. 2.3.3.2 Perforation.The 4 5-inch diameter casing was mechanically perforated along its entire length from thebase ofthe well vault at seven feet to a depth of74 feet. The well bore was uncased below this depth 2.3.3.3 Grouting.The lower uncased portion ofthe well was grouted and allowed to set overnight prior to perforating the casing. The remainder ofthe well was then grouted after perforation Inboth cases the grout was injected through a tremie pipethat was always maintained below the grout level in the well. Because site closure operations had to be performed immediately after abandonment sothat power could

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be restored to the site, it was not possible to let thegrout first set up To ensure a good surface seal of the well casing, a bag ofbentonite chips was placed on top ofthe grout and a steel cap was welded to the top ofthe casing inside the well vault. 2.3.3.4 Decontamination.All equipment used downhole at this location was decontaminated atthe CERCLA plant prior to mobilization to another site. 2.3.3.5 SurfaceClosureandSiteRepairs. Surface closure and site repairs performed at this site consisted ofremoving all materials from the well vault, collapsing the upper two feet ofthe vault walls, and backfilling the vault with fill dirt from on-site. A small portion ofthe vault wall near the power pole directly east ofvault was not collapsed so that the stability ofthe power pole would not be affected (the power pole was observed to wobble when the east vault wall was disturbed) The landowner was notified ofthis action Z3.4 Well 914A 2.3.4.1 SitePreparation.The activities performed atthis well to prepare it for abandonment included turning offthe power supply to the well and cutting down a tree next to the well to allow access with the drilling rig. 2.3.4.2 Perforation.Mechanical perforation was unsuccessful at this well The upper 60 feet ofthe PVC well casing began to collapse after application ofthe perforator. This apparently resulted from the fact thatthe PVC casing was not held in place with grout below this depth (ie., the annulus was left open). A rubber "basket" was pulled from the well during perforation, and was apparently used to hold the grout from this depth to the surface. There also apparently was no seal in this well when it was originally constructed Because the casing could not be perforated below 60 feet, it was decided to first grout the lower portion ofthe well and then over drill the PVC casing to a depth well below the interface between the alluvium and the Arapahoe Formation. The lower cased and uncased portion ofthe well was grouted from total depth of492 ft up to a depth of217 feet and allowed to set overnight. The casing was then drilled out using the airrotary drilling method to a depth of215 feet Sections ofPVC casing were continuously ejected into the mud pit during these operations, indicating that the casing was removed during overdrilling. 2*

3.4.3 Grouting.Both the cased and uncased portions ofthe well were pressure grouted through atremie pipe that was always maintained below the grout level in the well The grout was allowed to settle for several days and then topped offto bring its level back to approximately two feet from ground surface. 2.3.4.4 Decontamination.All equipment used downhole at this location was decontaminated atthe CERCLA plant priorto mobilization to another site 2.3.4.5 SurfaceClosureandSiteRepairs. Surface closure and site repairs performed at this site consisted ofregrading and installing new landscaping rock inthe area around the well and the replacement well, sealing small cracks inthe concrete driveway caused by the drilling rig, re-sodding the area over the trench containing electrical and water connections to the replacement well, and repairing damage done tothe lawn sprinkler system during well abandonment and installation activities. Also, the drill cuttings produced during overdrilling of914A and drilling of914B (replacement well) were contained in drums provided by RMA and transported to RMA for management as solid waste.

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2.3.5 Well 1070A 2.3.5.1 SitePreparation.The activities performed atthis well to prepare it for abandonment included turning offthe power supply to the well and trimming limbs offofa tree next to the well to allow access with the drilling rig. 2.3.5.2 Perforation.The well was mechanically perforated from the base ofthe well vault at 6.5 feet to a depth of 190 feet. 2.3.5.3 Grouting. The well casing was grouted through a tremie pipe that initially extended to a depth of 170 feet. As the grout filled the casing, the tremie pipe was removed in stages, but always remained below the grout level. The grout was allowed to settle for several days and thentopped offwith two bags ofbentonite chips, which along with a steel cap welded to thetop ofthe casing, provides a watertight surface seal inthe base ofthe well vault. 2.3.5.4 Decontamination. All equipment used downhole at this location was decontaminated at the CERCLA plant priorto mobilization to another site. 2.3.5.5 SurfaceClosureandSite Repairs. No site repairs were required forthe existing well because the landowner requested that the well vault be kept intact. Activities performed atthe replacement well consisted ofregrading the area around replacement well, re-sodding the area overthe trench containing electrical and water connections to thereplacement well, and cleaning the garage walls near the replacement well Also, the drill cuttings produced during drilling of1070B (replacement well) were contained in drums provided by RMA and transported to RMA for management as solid waste. 2.4 ReplacementWell Construction Replacement wells were constructed for abandoned wells 1070A and 914A These wells were constructed in a manner compliant with Colorado Water Well Rules (2 CCR 402-2) and that ensures no conduit exists for contaminants to migrate from the alluvial to confined aquifer The replacement wells will be used by the property owners for irrigation. Prior todrilling the replacement wells, required permits were obtained from the Colorado State Engineer's Office. The replacement wells were placed a sufficient distance from the closed wellsto ensure that the boreholes did not intersect, and no grout contamination extended from the abandoned well to the replacement well Well 914B is approximately 50 feet northwest of914A and 1070B isapproximately 200 feet north of1070A The contaminated alluvial aquifer was sealed offfrom the confined aquifer in the replacement wellsby use ofa watertight, steel surface (conductor) casing that extended to the alluvium/confining layer (Arapahoe) interface and was grouted in place Beneath this, the wells were constructed with a 4-inch PVC, flushjointed casing and a factory slotted screen To the extent possible, the replacement wells were completed at the same depth as the abandoned wells they are replacing. Details ofthereplacement well installations are provided in Table 3 and the following subsections

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Table3. ConstructionDetailsfor Replacement Wells Well 914B Well 1070B State Plane Coordinates 208583N,2184508E 201875N, 2171661E Total Casing Depth 425 feet 200 feet Surface Casing Depth 64feet 55feet Surface Casing Size & Type 6inches -steel 8inches -steel WellCasing Size &Type 4 inches -PVC 4inches - PVC Screened Interval 255-425 feet 120 -200 feet Bentonite Interval 125 -233 feet 100- 111 feet Grout Interval 10 -125 feet 10 - 100feet Pump Depth 400 feet N/A

2.4.1 Well 914B 2.4.1.1 DriffingMethod. The surface casing for well 914B was installed and grouted through the alluvium using hollow-stem augers. Then the 6-inch diameter boring forwell 914B was initially drilled using the airrotary method. However, after atotal depth of489 feet was reached, the bottom portion ofthe borehole became unstable and the drill bit and pipe became stuck in the hole After removing the bit and pipe and several failed attempts at re-drilling the bottom portion ofthe hole, which had collapsed to a depth of430 feet, it was decided to install the well atthis approximate depth and to condition the hole with drilling mud before attempting installation ofthe casing and screen. 2.4.1.2 Well Construction.The well was constructed with the casing at a depth of425 feet with a screened interval that extended upward from thispoint to a depth of255 feet Although it was planned to install a sandpack across the screened interval, the PVC tremie pipe installed with the casing became wedged in the borehole and could not be moved In order to avoid losing equipment in the unstable hole, a rubber cement basket was attached to the casing above the screen (at 255 feet) during installation and was used to hold thebentonite and grout seal placed in the annulus above the screen. This construction method complies with State ofColorado requirements for domestic water wells 2.4.1.3 WellDevelopment. Development of914B was done in three stages First, approximately 900 gallons offresh water was circulated through the borehole after the casing and screen were installed and before placement ofthe bentonite and grout seal to dilute the drilling mud in the borehole. After all the well materials were in place, the well was bailed to remove the remainder ofthe drilling mud

Rml0319801 /rma-rpt doc/07/09/99 11THELATAIARCADIS GERAGHTY& MILLER TEAM Approximately 300 gallons ofwater were bailed from the well. Thethird phase wasto pump the well. A submersible pump was temporarily placed inthe well and used to pump approximately 700 gallons of water. 2.4.1.4 Pump,Piping,andConnections. The original pump, piping and wiring from 914A were reinstalled in 91413, as agreed upon by the landowner. Underground water and electric lines were run through a pitless adapter from the well to a location in the basement ofthe house as agreed upon by the landowner. In addition, a stick-up spigot wasinstalled in thewater line running from the new well to the house. While the wiring was completed to supply power to the well, the landowner agreed to take responsibility for completing the necessary piping to connect the well tothe irrigation system. 2.4.2 Well 1070B 2.4.2.1 DrillingMethod. The surface casing for well 1070B was installed and grouted through the alluvium and set in the confining unit using hollow-stem augers. Then the 8-inch diameter boring for well 1070B was drilled using the air rotary methodto total depth of204 feet. An 9-inch diameter hole was drilled to allow better access to install the sand pack, bentonite and grout in the annulus around the casing and screen. 2.4.2.2 Well Construction. The well was constructed with the casing at a depth of200 feet with a screened interval that extended upward from this point to a depth of 120 feet. A sand pack was placed inthe annulus across the screened interval and overlain by bentonite and grout seals (see Table 3for construction details) 2.4.2.3Well Development. Initially, the well wasdeveloped by surging and bailing Approximately 200 gallons were bailed from the well A submersible pump was then temporarily placed in the well and used to pump approximately 500 gallons 2.4.2.4 Pump,Piping,andConnections. The original pump, piping and wiring from 1070A were not reinstalled in 107013, because the landowner wished to have new equipment inthe well and took responsibility for purchase and installation Underground water and electric lines were run through a pitless adapter from the well to a location in the basement ofthe house as agreed upon by the landowner. While the wiring was completed to supply power to the well, the landowner also agreed to take responsibility for completing the necessary piping to connect the well tothe irrigation system. 3.0 Performance Standards and Clean-Up Goals The main goal ofthis project was to eliminate the potential for vertical leakage ofcontamination from alluvial aquifer downward to the Arapahoe Aquifer The measures taken to achieve this goal during abandonment ofthe five wells were as followsPerforation ofas much as possible ofthe well casings prior to grouting to seal offany voids behind the casings In all cases the perforations extended well beyond the interface ofthe alluvium and Arapahoe Formation

Rm103/9801 ftma-rpt doc/07/09/99 12THELATAIARCADIS GERAGHTY&MILLER TEAM

" Overdrilling ofthe casing at 914A, where perforation was not possible. The casing was completely removed from the borehole to a point well below the interface ofthe alluvium and Arapahoe Formation. " Filling the entire length ofthe wells with cement/bentonite grout using a tremie pipe to eliminate the possibility ofleaving voids or cavities inside the casings. The potential for downward migration from the alluvium in the replacement wells was eliminated by installing and grouting steel surface casings through the alluvium into the confining layer, and also installing bentonite and grout seals in the annulus ofthe wells fromjust above the screens to within the surface casings. 4.0 Quality Assurance/Quality Control Quality Assurance/Quality Control (QA/QC) during the performance ofthe project was maintained by adhering to the requirements ofthe QAPP developed as part ofthe Work Plan forthe project. The QA/QC checks performed during this project are described below, 4.1 Review andOversight Review and oversight offield activities for the Off-Post Well Closure project included review and approval ofproject documents by a Certified Professional Geologist (CPG), and informal field audits. During performance offield work, two informal audits were conducted by the Task-Order Manager. The purpose ofthe audits was to evaluate compliance with the requirements ofthis Field Workplan (including the QAPP) and the project Health and Safety Plan (HASP) Results ofthe informal audits are summarized below

Auditor Date Activity Findings Steve Gorin September 11. Pulling Pumps Work compliant with H&S requirements (exclusion

- Task Order 1998 zone, hard-hats, steel-toed boots, etc ) Manager Proper lock-out/tag-out ofpower supply to wells Work compliant with Work Plan and QAPP Steve Gorin October 9, Closure ofwells Work compliant with H&S requirements (exclusion

Task Order 1998 37304 and 37319 zone, hard-hats, steel-toed boots, etc.) Manager Grout mixtures/calculations compliant with QAPP, Tremic pipe maintained below grout surface during emplacement In addition to'informal audits, the Task Order Manager periodically reviewed and supervised activities throughout the field effort A geologist was also present at the work-sites throughout the field effort to supervise and direct well abandonment, construction, and site repair activities. 4.2 Video Logging DepthMeasurements The downhole video tool is connected to a video recorder and a spool that automatically records depth in the borehole. A marker on the instrument cable was used to evaluate the precision ofdepth measurements. The marker was aligned with a specific point on the casing and depth recorded as zero When the tool was returned to the surface, the alignment ofthis mark to the point on the casing was
Rml03/9801ftma-rpt.doc/07/09/99 13THELATAIARCADIS GERAGHTY & MILLER TEAM

measured and compared with the automated depth reading The differential between these two measurements for each well is provided in Table 4 All measurements were within the acceptable measurement precision of+/- 5%. Table4. PýrecisionofVideo LoggingDepthMeasurements Well Number Change in Depth Measurements Relative Percent Difference Before and After Logging Runs (RPD) 299A 1foot 0.04% 395A none 0% 914A 2feet 0.04% I 985A 1foot 0.04% 11070A I none 0%
4.3 Grout Volumes Volume ofgrout placed in abandoned wells was compared with the calculated borehole volume. Because the casing was perforated prior to emplacement ofgrout, the emplaced volume was expected to exceed the calculated borehole volume The borehole volumes shown in Table 2 were calculated using the equation provided in the QAPP. The allowable RPD between the measured and calculated grout volumes was set at >90% As can be seen in Table 2, the volume ofgrout actually used in each well was more than its calculated volume (i e , >I 00%) This indicates that the grout filled the entire casing, and was forced outward into the annulus and formation to effectively close the wells Where open hole was present below casing, grout was emplaced in two lifts and volume calculations were based upon the second lift (from bottom ofcasing to surface) 4.4 Well Depths Depths ofboreholes, wells, and construction materials in the wells were measured to the nearest 0.2 feet. 4.5 Documentation To document the proper abandonment ofthe existing wells and construction ofthe replacement wells information recorded included the following. 0 Pre-mobilization site analysis and estimate ofabandonment impact to property 0 Photographic documentation ofwell closure area's original condition, closure procedures, and post closure condition * Existing well construction information, including downhole video logs

. Field notebooks

- Well Data Sheets

Rml 03/9801 ftma-rpt doc/07/09/99 14THELATAIARCADIS GERAGHTY& MILLER TEAM

. Records ofvolumes, containers, and contents ofwaste disposed.

- Permit applications for new wells.
0 Lithologic logs and construction details for thetwo new replacement wells. These materials are stored inthe Rocky Mountain Arsenal Technical Information Center (RTIC) at RMA. 5.0 Description and Rationale for Project Modifications Two project modifications were required during performance ofOff-Post Well Closure. These are summarized below, and cost impacts are summarized in Section 9.0 ofthis Construction Completion Report. Modification1: The first modification (Mod 1)was required because the drilling subcontractor did not originally proposerates that complied with the Department ofLabor (DOL) wage determinations provided by RMA. As a result, the Contracting Officer requested a revised costproposal with approved DOL rates. This revised cost proposal was submitted to RMA on October 27, 1998. Modification2: The second modification (Mod 2) was required because well 914A could not be abandoned by mechanical perforation and had to be overdrilled Costs for overdrilling were submitted in the original proposal, but initial funding was based upon mechanical perforation in all wells. Because well 914A could not be mechanically perforated, overdrilling wasperformed to a depth of215 feet. A cost proposal forthis modification was submitted toRMA.on November 18, 1998. 6.0 Construction Quality Assurance Documentation Summary Construction quality assurance documentation for the Off-Post Weil Closure project includes the following: Pre-construction damage estimates (submitted to RMA COR) Well closure forms, including grout mixtures and volumes (Appendix A) Tapes ofdownhole video logs (submitted to RMA COR) Pre-construction photographs (submitted toRMA COR) Photographs offield activities (submitted to RMA COR) 7.0 Final Inspection Documentation A final inspection was conducted on Wednesday, December 16, 1998 toverify that wells had been properly closed, replacement wells had been constructed, and site repairs had been adequately performed In attendance were representatives from TCHD, CDPHE, EPA, and the RMA RVO Following the inspection, all parties agreed that the Off-Post Well Closure project had been satisfactorily completed Acopy ofthe attendance list is included in Appendix B.

Rml 03/9801/rma-rpt,doc/07/09/99 15THE LATA'ARCADIS GERAGHTY& MILLER TEAM 

### 8.0 Operation and Maintenance Requirements There are no operations and maintenance requirements following well closure and construction of replacement wells. 

### 9.0 Summary of Costs Table 5summarizes project costs, including modifications. The reasons for each project modification were discussed in Section 5.0. Funding was originally based uponthe cost proposal formechanical perforation, but acost proposal for over-drilling was also submitted. Mod #2 does not actually represent an increase inproposed project costs, because costs for overdrilling,were submitted in the original proposal. In fact, thesuccessful use ofmechanical perforation in the majority ofwells actually resulted in cost savings. The project cost increased by 6.4% from the original bid because ofDOL wage requirements. The increase was requested by the Contracting Officer because the rates originally provided by the driller (Layne-Western) were lowerthan the DOL ratesrequired under thecontract. The calculated percent increase isbased upon aproject cost of$133,593, which is the combined cost of the mechanical perforations and overdrilling performed. Table 5. Project Cost Summary 

### Contract) Description Cost Mod Contract Odolnal Amou~nt21 July 1998 $120,433

- Perforate 

### $192,319-Overdriil Mod#1 DOLLaborRatesforDriller $8,606 Mod#2 Overdrilling atgi4A $13,160
_________Total: $142,199 10.0 

### CERTIFICATION The Remediation Venture Office (RVO) has determined that the remedial action has been completed in accordance with the ROD, has met the intent ofthe ROD tobe protective ofhuman health and the environment and complies with the final designpackage, as modified. No Further Action is required on this implementation project

_ _ _ _ _

_ _ _ _ _ _ _ _ _ _ 0(harles -Scharmann- RemedyExecutionManager Date' 

### 11.0 Supporting Documents * Rocky Mountain Arsenal Record ofDecision forthe Off-Post Operable Unit, December 1995 " Work Plan for Rocky Mountain Arsenal Off-Post Well Closure, September 1998 " Health and Safety Plan for Rocky Mountain Arsenal Off-Post Well Closure, September 1998 " Statement ofWork for Off-Post Well Closure, July 1998 " Colorado WaterWell Rules (2 CCR 402-2) 

### 5425-1Ill-A Rml 03/9B01 Irma-rpt.dac/07109/99 

### 16 0 0 6 6T74ELATAIARCADIS GERAGHTY&MILLER TEAM

APPENDIX A. WELL CLOSURE FORMS

RM103/9801/APP-A DOC/07109/99 A-1RENfEDIATION VENTURE OMCE 

## Well Closure

Wellnumber 

## 2ýKA project Pý-( -45ý (1)61( A4AVz4ItAfaý.ge_ I of- 2 SiteLocation- 0 Avc H EP, dc ksPi Date Started Mýlqy Date Completed_ ( Surveyed Location 

## NM N Surveyed Elevation GS* TOC** Aj M E Depthto Water (TOC)/Date 

### (60ýZ 1137f6r Casing Depth (GS) 

### 2:FqDrilling Contractor L 4 ý h Type ofRig 

### 6- Prepared By_ Date


### Well Construction HistM Original Depth ofWell (GS) 

### 2 q 0 Original Bore-Hole Depth 

### ý2 Type Diameter TOP Bottom Borehole- 

### 7 :?/,r " -/. F.2/ ý- ' -4 2- 70 Casing #1 

### srýtd C 0 76 Casing #2 

### -76 C COEK f, irS,ý: Ifo Casing,11



### Closure Drilliniz Log Depth Closure BoringDrilled (feet) li-CA Diameter Closure Boring (inches) Drilling Method Depth to Water(GS) Date Sample Tkenl Sample Volume Geophysical Logs Geophysical Contractor Perforation Method C /194 i C.1 5 fA*Q tiA 6e( Perforation Depth (GS) F - / OGS Ground Surface **TOC - Top ofCasingREMEDIATION VENTURE OFFICE 

## Well Closure
wellnumber A Project im 15rtý. Page - 2-.f- 2-
Casin Removal Drilled? Footage Pulled? Footage Protective Casing Casing #1

Casing #2 Casing #3
Screen or Casing Le Screen or Diameter Material TOP Of Bottom of

Casin (Inchesl Ortype (Feet) (Feet)
Interval #1 S7 /"%Cl Interval #2 CAF(!ý2 _J 1ý1-le 

### 7ý6 -73 Interval #3 

## 4L- It /73
Interval #4 Sealing Specifics MethodofSealing ýLApup VItILIJ S ial,ý: CASt'o 1 4 ýýt:tA VA CC, C-79-ý0 4A 4t dJ DepthTremic Pipe Placed (feet belowGS)
Sand/fill (Interval Seal #1 (Interval) Seal #2 (Interval Material &44 bi.ý -

%Bentonite s-',/. Gal. Water/Bag (orEst. Grout Density) Date Added CommentsREMEDIATION VENTURE OMCE

W llnumber 

### ý57 

## Well Closure

e 

### m6mý Page_ 1 of 2 Site Location 

## E. wcxcr C0
Date Started 

### 0116 /1 F Date Completed Surveyed Location N Surveyed Elevation GS* TOC** N LM Depth toWater (TOC)tDate 3311'( 6 Casing Depth (GS) Drilling Contractor LAýAe Type ofRig Prepared By Date

Well Construction Histo[y Original Depth ofWell (GS) ýkCk

### k K&j - Original Bore-Hole Depth Ljý Pýk IA 0 LVL4 Type Diameter MAE Bottom Borehole- 

### A Agwvi Casing #1 

### T" Casing #2 /A, sCasing #3

Closure Drilliniz Log Depth Closure Boring Drilled (feet) JA 04 

### A49 Or-,1916 Diameter Closure Boring (inches) Drilling Method Depth to Water (GS) Date Sample Taken? Sample Volume Geophysical Logs Geophysical Contractor Perforation Method _5-ýAiA Cj A ee Perforation Depth (GS)

## _ 7/_
*GS - Ground Surface **TOC - Top ofCasingREMEDIATION VE'I,=RE OFFICE

- 

## -A Well Closure Page 2 of 2 well number 75 ploilct qledsý U 6 1/ tý 64

Casing Removal Drilled? Footage Pulled? Footage Protective Casing ylo-ý jýeý11046ýf Casing #I Casing #2 Casing #3
Screen or Casing Le Screen or Diameter Material TOP Of Bottom of

Casin (Inches) Ortyp (Feet) (Feet)
Interval #1 S, S'(ELL Interval #2 Interval 11 Interval #4 Sealing Specifics Method ofSealing it a Ae)lr 140joqx;!]ý m%K IML4. V&W Depth Tremie Pipe Placed (feet below GS)
Sandfrill (Interval Seal #1 (Interval) Seal #2 (Interval) Material e-e -e 'I V

%Bentonite c- r. Gal.Water Mag 

## -7, (or Est. Grout Density) Date Added CommentsREMEDIATION VENTURE OFFICE 

## Well Closure

Wellnumber 

### ý4A Prolect fos 46Afilm A4ft 6age I of 2 SiteLocation-/ 4
Date Started Date Completed_ 

### 1ý)127 A7E' Surveyed Location /YM N Surveyed Elevation GS0 . /VM TOC** /Yw E Depthto Water (TOCYDate 

# 77z/q F CasingDepth (GS) Drilling Contractor -Type ofRig Prepared By 4 Date 

# /

Well Construction HistoEy Original DepthofWell (GS) Original Bore-Hole Depth Lze Diameter LOB Bottom Borehole 6 /" 7Ld 

### iffý2 / CuingI 1 5- -ýCr- 0 8 Casing #2 CCasing #3

Closure Drilling Log Depth Closure Boring Drilled (feet) SDiameter Closure Boring(inches) Drilling Method 7'ý14Y Depth to Water (GS) Date 76 //Fbý Sample Take.? Simple Volume Geophysical Logs A o/I C-

'0 Geophysical Contractor Perforation Method 0 Perforation Depth (GS) OGS Ground Surface **TOC Top ofCasingREMEDIATION VENTURE OFFICE 

## Well Closure
wellnumber 

### Pj.rtOtT-Aes- 616- ff4 of Kpage - 2-of
Casing Removal Drilled ? Footage Pulled? Footage Protective Casing 12a Ile -eý, Casing#1 

### 20 f Casing #2 Casing #3
Screen or Casing Le Screen or Diameter Material TOP Of Bottom of

Casin (Inchesl Ortyp (Feet) t)
Interval #1 (f 0 Interval#2 Interval 11 Interval#4 Sealing Specifics Method ofSealing I)a 0g0-26A7ý- /'IAS Co,160 kdle,, 'blow tX 7- DepthTremie PipePlaced (feetbelowGS) Sand/rill (Interval) Seal #1(Interval) Seal #2(Interval Material
%

Rentonite Gal. Water/Bag (orEst.Grout Density) DateAdded 69ý12-3 12 V? CommentsRET%,IEDIATION VENTURE OFFICE 

## Well Closure

Wellnumber 

### off

-ý& ýýJj- ý1AbrLWMj4jý,,t.76p,gc_l- of SiteLocation 

### ZAjýmd, (G /94ý UCJA47Xý.11-1 CQ Date Started (04rl,7s Date Completed_ 

### ile&M fr Surveyed Location Nw N Surveyed Elevation GSO . /Yw TOC** /VM E Depth to Water (TOCYDate Casing Depth (GS) 

### ;2SIP Drilling Contractor Z /I Y tic Type ofRig CPU 

### 7sPrepared By S ý'Ope Date / le ? 7

Well Construction Histo[y Original Depth ofWell (GS) Original Bore-Hole Depth Type Diameter TOP Bottom Borehole- 

### -74" ý,, 20 

### 6 270 7p,-r, Vo -3/sý' Casing #1 

## 5; ýrcý 6 /,0/, Casing #2 .57 -1C--&-( I,-"e 0 

### 2?0 Casing #3 

## cw 2 31S- I

Closure Drilliniz Loiz DepthClosure BoringDrflled (feet) JA cr-ý- 'I Diameter Closure Boring (inches) DrillingMethod Depthto Water (GS) Date Sample Taken? Sample Volume Geophysical Logs Geophysical Contractor Perforation Method VA EC t C44 A/f V, 6d ýed Perforation Depth(GS)
_ Z/ 

## ?-6'9- *GS - Ground Surface OTOC - Top ofCasingREMEDIAMON VENTURE OFFICE 

## Well Closure
well number project P05Y 6)e ý/ 4 4,qk", "o M Page
_ 2_of- 2-

Casing Removal Drilled ? Footage Pulled? Footage Protective Casing Casing #I 7dI Ct Casing #2 Casing #3
Screen or Casing Le Sc-reen or Diameter Material TOPOf Bottomof

Casin (Inches) Ortyp (Feet) (Feet)
Interval #1 Interval #2 C,451 5-ýC& Interval #3 Interval #4 Sealing Specifics Method ofScaling 02CLý2 M fktý14 r;qdr r/fl-/`/ký or Depth Tremic Pipe Placed (feet below GS) S-0
Sand/fill (Interval Seal #1 (Interval) Seal #2 (Interval Material 6 .2

%Bcntonite Gal. Water/Bag (or Est.Grout Density) DateAdded 16 Ire Comments ý0 44 /C)RENIEDIATION VENTURE OFFICE 

## Well Closure

Wellnumber project of SiteLocation 

### or 0 ik
Date Started //5/9v- Date Completed_ --- / Iltl A ? Surveyed Location IN N Surveyed Elevation GS* AIM TOC$* E Depth to Water (TOCYDate Casing Depth (GS) Drilling Contractor L Type ofRig 

### rw PreparedBy-4 Slw` Date 141eq r
Well Construction History Original Depth ofWell (GS) Original Bore-Hole Depth Type Diameter L02 Bottom Borehole 

### =774*' ý ý20 -T'- Casing #1 -5& ,L- ( ý- 49 Casing #2 4- /0-( ;2a Casing #3 (ý20

Closure Driffina Log Depth Closure Boring DriUed (feet) If I/C Diameter Closure Boring (inches) Drilling Method Depthto Water(GS) Date Sample Takenl Sample Volume Geophysical Logs Geophysical Contractor Perforation Method 1Aj f r,6

## Awcof sýAK 61 A pc Perforation Depth (GS) 0 OGS Ground Surface **TOC - Top ofCasingREMEDIATION VENTURE OFFICE 

## Well Closure
well number 06C-4574 P-ge- 2-of-2- Casing Removal Drilled ? Footage Pulled? Footage Protective Casing klo-ý Casing #I Casing #2 Casing #3
Screen or Casing Le Screen or Diameter Material TOPOf Bottom of

Casin (Inches) ortyp (Feet) (Feet)
Interval #1 

### h5;ot% 57 

### 6 / /o/
Interval #2 CA5ýhq /0// C 

### / , q-P Interval #3 6le- X t Interval #4 Sealing Specifics J/tA-rýa/e Method ofSealing L-A ýA- a kýý I oe Depth Tremie Pipe Placed (feet below GS) Y117
Sand/fill (Interval Seal #1 (Interval) Seal #2 (Interval Material

%Bentonite Gal. WaterMag 9W (or Est. Grout Density) Date Added CommentsRENEDIATION VENTURE OFFICE 

## Well Closure

Wcllnumber off- A S-ý 

## 6J6JýA6 611 ýPage

- i of 2 SiteLocation- 

### 57E-Yf 

### 5cclq- T25 -, Date Started 

### ý?lf8- Date Completed 

# 07YT ý Surveyed Location 

### NM N Surveyed Elevation GS* 

### -5-14zq. r2 TOC** 

# 7 E Depthto Water (170C)(Date 0 1(6A 11 t Cuing Depth (GS) Dfflling Contractor 

### L AV sAF- TypeofRig 

### WE- TSPrepared By Date


### Well Construction Histo[y Origirml Depth ofWell (GS) Original Bore-Hole Depth Twe Diameter ZO.2 Bottom Borehole (A. PL ý N7W VA Casing#l 

### 50/d A/C- 4 1, 

### 1C.6- Casing #2 

### U C- 5'CoeC6 2, Cuing #I



### Closure Drilliniz Log DepthClosure BoringDrilled (feet) L4 

### 0_ý A 11p/;c A Diameter Closure Boring (inches) DrillingMethod Depthto Water (GS) Date Sample Takeril Sample Volume Geophysical Logs Geophysical Contractor Perforation Method Perforation Depth (GS) *GS Ground Surface **TOC - Top ofCasingREMEDIATION VENTURE OFFICE 

## Well Closure
wellnumber 

## 3 -Proiect OtT- Pd-'ý0& ( ( A ý-' Page
_ 2-of-2-

Casiniz Removal Drilled ? Footage Pulled? Footage Protective Casing Casing #1 Casing #2 Casing #3
Screen or Casing Le Screen or Diameter Material TOPOf Bottom of

Casin (Inches) ortyp (Feet) (Feet)
Interval #I CA$ /',Kl, 

## a" /VC- .2-/ 16.
Interval #2 Olt to V- 2 Interval 113 Interval #4 Sealing Snecifics Method ofSealing ýp U K 440 Pt4- A--r d r La e, C A al S-C DepthTremic Pipe Placed (feet below GS) 0 r4 C,(-rtd ýrCAOS6ý &J611
Sand./fill (Interval Seal #1 (Interval) Seal #2 (Interval Material CCW k ýV .2 .2.17

%Bentonite Gal. Water/Big 

# 7W/ ul:! (orEst. Grout Density) Date Added CommentsREMEDIATION VENTURE OFFICE 

## Well Closure

Wellnumber

- Project OW 464j6'1'"66Aage- 1 of 2 SiteLocation 

### 6-70 Date Started Date Completed_ Surveyed Location N Surveyed Elevation GS* TOC** Z6, 3 E Depthto Water CrOC)(Date 1-23 4 1(01qýItf Casing Depth (GS) DrillingContractor A Type ofRig PreparedBy_ 5 Date
Well Construction Histo[y Original DepthofWell (GS) Original Bore-Hole Depth Tvve Diameter LOB Bottom Borehole- 

### (6" 4 C, 27 S-.3 

# 4o (i (.sCasing #1 '5ýLel - 

### t '571 Casing#2 

# 56(.d pv(- q- fir 1 It-S ýL Casing #3 POC '57C(tettA /s* TsS-Lý.TsCIosure Drilliniz Loiz Depth Closure Boring Drilled (feet) Diameter Closure Boring (inches) Drilling Method Depthto Water (GS) Date Sample Takenl Sample Volume Geophysical Lop Geophysical Contractor Perforation Method Perforation Depth (GS) *GS Ground Surfkca **TOC - Top ofCasingREMEDIATION VENTURE OFFICE 

## Well Closure
wellnumber Pj,c 

### 0 n+ U Aý AJ 6AL,4F tAý Page

Casing Removal Drilled I Footage Pulled? Footage Protective Casing Casing#1 (t Casing#2 Casing #3
Screen or Casing Le Screen or Diameter Material TOPOf Bottom of

Casin (inches) Ortype (Feet) (Feet) 

### (VC 3 1
- Interval #1 

### C65ftý4 ( 'Pse t Interval #2 5,cgteVN 

### pvc ý5- Interval #3 V Interval #4 Sealing Specifics Method ofSealing OUVA C E VA E 'A4 I -Ju CASýKj&- DepthTremic Pipe Placed (feet below GS) I S*0 Sand(ftIt(rnterval Seal #1 (rnterva Seal #2 (Interval) Material ce KAEtt 

# 3

%Bentonite Gal. Water/Bag Z (ol .4 (orEst. Grout Density) Date Added CommentsF 0 R M STATE OF COLORADO For Office Use only "G. OFFICE OF THE STATE ENGINEER GWS-9 818 Centennial Bldg., 1313 Sherman St.. Denver, Colorado 80203 12195 (303) 866-3581 TYPE OR PRINT IN 13LACK INK 

## WELL ABANDONMENT REPORT (To Report Plugging and Sealing Wells) 

### PERMIT NUMBER OF PLUGGED WELL T-t) 1. INDIVIDUAL/COMPANY RESPONSIBLE FOR PLUGGING NAME(S) 

## tas 41A*uo_3'7e_-r_4nieW

# 4s-s-ac,lýlcs, Zýc. Mailing Address IS M Cp/,9 ýdlt'4 Y/Y 

### 5ý6_ ýS_0 City, St. zip C-dyc'n Phone (34;' 

### ),Z4,a, 3S-ý 6 2. ACTUAL WELL LOCATION: COUNTY- S PROPERTYADDRESS Ir)-T'30 

## lix. H&vJee-s-op, ý_O ý?0(6clO (Address) (City) (State) (Zip) 

### 1/4 SE 1/4, Sec. 

# 'T Twp. 

# ElN. MS., Range 6-7 0E. 0W. 9 P.M. Distancesfro-n SectionLin s 1700 Yt.fromON. NS. Line, Ft.fromME. orE1W. Line. 3. 1(we), report that an existing well was plugged and sealed for the following reason(s): The well was plugged and sealed as required under the conditions of approval ofWell Permit No. The well was not inuse and was plugged and sealed. Other (please explain) 4. The well was plugged and sealed according to the Water Well Construction Rules on OCI L

6ý 6- K IS- , 19 q90 - 5. The well was plugged with the following materials placed at the indicated intervals: AMOUNT AND TYPE OF MATERIAL METHOD OF PLACEMENT INTERVAL 7tý6-M (ý16ý from feet to feet from feet to feet f rom feet to feet f rom feet to feet INTERVALS OF CASING REMOVED4Eio INFEET from feet to 2 92feet from feet to -feet 6. 1(we)have read the statements made herein and know the contents thereof, and that they are true to my (our) knowledge. [Pursuant to Section 24-4-104 (1 3)(a) C.R.S., the making of false statements herein constitutes perjurý in the second deqree and is punishable as a class I misdemeanor.1 

### Name/Title (Please type or print) Signature Date ft(ýLtý ?-. 60r;,JI Pr,)ýJ /4-ý 1 ý1ýlq INFORMATION~ Itisthe responsibility ofthe well owner to have the well properly plugged and sealed. The Well

--

Construction Contractor isresponsible for notifying the well owner ofthe plugging and sealing requirement. This form may be reproduced by photocopy or word processing means.0 R M STATE OF COLORADO For Office Use only 0. OFFICE OF THE STATE ENGINEER GWS-9

2/95 818 Centennial Bldg., 1313 Sherman St., Denver, Colorado 80203 (3031866-3581 PE OR PRINT IN BLACK INK 

## WELL ABANDONMENT REPORT (ToReport Plugging and Sealing Wells) 

### FERMIT NUMBER OF PLUGGED WELL 1. INDIVIDUAL/COMPANY RESPONSIBLE FOR PLUGGING NAME(S) 

### Mailing Address 

### /S IF e4rLý', ýYA c2 city, St. zip C-6,ýJ6-m Phone (,?.0-3 2. ACTUAL WELL LOCATION: COUNTY AdAM 5 PROPERTY ADDRESS C790 0 E- 

## Iqv6-. viWciesv,\ C (Address) (City) (State) (Zip) 1`1771 5E-1 /4 ( J 1/4, Sec. 0 Twp. Q, EIN. E S., Range E. 1.41W. 

## 6 P.M. Distances from Section Lines -f"O Ft. from 0 N. M S. Line, / -700 Ft. from 7 E. or M W. Line, 3. 1(we), report that an existing well was plugged and sealed for the following reason(s): The well was plugged and sealed as required under the conditions of approval of Well Permit No. Z] The well was not in use and was plugged and sealed. 17 Other (please explain)

4. The well was plugged and sealed according to the Water Well Construction Rules on 

# c(-406ex, 17 -, 19 C(3 . 5. The well was plugged with the following materials placed at the indicated intervals: AMOUNT AND TYPE OF MATERIAL METHOD OF PLACEMENT INTERVAL 

## 365A/ý- - CE bti4 16,cmýjq t-ýr ýXOL&-ý tkEVA ('6 from o2, feet to -2?ý '(-feet from feet to feet from feet to feet from feet to feet INTERVALS OF CASING REMOVEýý FEET from 9 feet to 1:7 eet from feet to feet 6. 1(we) have read the statements made herein and know the contents thereof, and that they are true to my (our) knowledge. (Pursuant to Section 24-4-104 (13) (a) C.R.S., the making of false statements herein constitutes perjurN in the second degree and is ounishable as a class 1 misdemeanor.] Name/Title (Please type or print) e Date s4eý4 P. 60/'TýJ / &6j-ký L4t"' I ;V :-ý - 1//Oý

--INFORMATION-- It is the responsibility of the well owner to have the well properly plugged and sealed. The Well

Construction Contractor is responsible for notifying the well owner of the plugging and sealing requirement. Thfsform may be reproducedby photocopy or word processing means.0. OFFICE OF THE STATE ENGINEER 0 R M STATE OF COLORADO For Office Use only 818 Centennisi Bidg., 1313 Sherman St., Denver, Colorado 80203 21195 (3031 866-3581 PE OR PRINT IN BLACK INK 

## WELL ABANDONMENT REPORT (To Report Plugging and Sealing Wells) 

### ER PERMIT NUMBER OF PLUGGED WELL 30ýý'

LN 1. INDIVIDUAL/COMPANY RESPONSIBLE FOR PLUGGING
M i g City S1 N 

## M -7-r DI AME(S) 

# La, Mailing Address IS city, St. zip P 0 1 Phone (30-3 2. ACTUAL WELL LOCATION: COUNTY A V0_5 PROPERTY ADDRESS -?57Z I 

## E-, /b Ave-, vL ýtsoti _C0 FL06ý-o (Address) (City) (State) (Zip) 

### 5-F- 1/4 

## SE- 1/4, Sec. 7 Twp. ON. 22ý11 S., Range 1:1 E. 'L'A7CJ4'W. P.M. Distances from Section Lines Ft. from 1:1N. Z S. Line, L '7(3 Ft. from IKE. or7W. Line. 3. 1(we), report that an existing well was plugged and sealed for the following reason(s): The well was plugged and sealed as required under the conditions of approval of Well Permit No. The well was not in use and was plugged and sealed. Fý Other (please explain)

4. The well was plugged and sealed according to the Water Well Construction Rules on 

### IV6 ucvý_6 et,ý (3 _, 1 9_ýg . 5. The well was plugged with the following materials placed at the indicated intervals: AMOUNT AND TYPE OF MATERIAL METHOD OF PLACEMENT INTERVAL 4c 60 "6ý from 

### /Cfeetto /f3feet from feet to feet -from feet to feet

from feet to feet INTERVALS OF CASING REMOVED411ý 1\1 FEET from 9-S-_ feet to feet I 

### from feetto -feet 6. 1(we) have read the statements made herein and know the contents thereof, and that they are true to my (our) knowledge. [Pursuant to Section 24-4-104 (13)(a) C.R.S., the making of false statements herein constitutes perjurý in the second dearee and is CLInishable as a class 1 misdemeanor.] Name[Title (Please type or print) Signqture Date

INFORMATION~ It is the responsibility of the well owner to have the well properly plugged and sealed. The Well Construction Contractor is responsible for notifying the well owner of the plugging and sealing requirement. This form may be reproduced by photocopy or word processing means.STATE OF COLORADO For Office Use only 0. OFFICE OF THE STATE ENGINEER 2/95 818 Centenniai Bldg., 1313 Sherman St., Denver, Colorado 80203 IllyPE OR PRINT INBLACK INK 

## WELL ABANDONMENT REPORT (To Report Plugging and Sealing Wells) 

### E PERMIT NUMBER OF PLUGGED WELL 13

ýNQ 1. INDIVIDUAL/COMPANY RESPONSIBLE FOR PLUGGING N M City S'

AME(S) Los Alýmo-5 ý7 14 S-Cacilt4sZ C. Ij Mai

g C-1ý7 41vi, ailing Address city, St. zip Gcý' ýCfG 61 L L9 IV P 0 Phone (303 .20,1- 39 2. ACTUAL WELL LOCATION: COUNTY 

## A d'ýqmv PROPERTY ADDRESS 1;2,ziJ:( f, 11'7d--+ý 

## AV&; Hemc&vu -o co

PR (Address) (City) (State) (Zip)



## is 1/4 '!ýW 1/4, Sec. Twp. 

# ElN. Z S., Range DE.Ew. 

## 6 P.m.

I(w ) Distances from Section Lines 2 00 Ft. from 0 N. Z S. Line, 7 00 Ft. from 0 E. or W. Line. 0U Fý Tl_ P 3. 1(we), report that an existing well was plugged and sealed for the following reason(s): Fý The well was plugged and sealed as required under the conditions of approval of Well Permit No. The well was not in use and was plugged and sealed. Other (please explain)
4. The well was plugged and seaied according to the Water Well Construction Rules on CCý06Gi-0- 2ý , 19 7? . 5. The well was plugged with the following materials placed at the indicated intervals: AMOUNT AND TYPE OF MATERIAL METHOD OF PLACEMENT INTERVAL -L IqIS EVA Ký169 It/a ki ýlf- a LIC4 from 0 feet to feet from feet to feet from feet to feet from feet to feet INTERVALS OF CASINGýý/RIPPED IN FEET from 0 feet to -:ZIS-feet I from feet to feet 6. 1(we) have read the statements made herein and know the contents thereof, and that they are true to my (our) knowledge. [Pursuant to Section 24-4-104 (13)(a) C.R.S., the making offalse statements herein constitutes perjurý in the sE:cond degree and is punishable as a class 1 misdemeanor.] NamefTitle (Please type or print) e Date Plr# . j,(, ý A,.ý I / 1ý 117 j I S I

--INFORMATION-- It is the responsibility of the well owner to have the well properly plugged and sealed. The Well

Construction Contractor is responsible for notifying the well owner of the plugging and sealing requirement. This form may be reproducedby photocopy or word processing means.0 R M STATE OF COLORADO For Office Use only 0. OFFICE OF THE STATE ENGINEER GWS-9

2/95 1118 Centennial Bldg., 1313 Sherman St., Denver, Colorado 80203 (3031 866-3581 TYPE OR PRINT INBLACK INK 

## WELL ABANDONMENT REPORT (To Report Plugging and Sealing Wells) 

### PERMIT NUMBER OF PLUGGED WELL upiýlllwvl 1. INDIVIDUAL/COMPANY RESPONSIBLE FOR PLUGGING NAME(S) 7ý-s, Mailing Address 1,936' C-,ýCz0ly /S city, St. zip co ?e Of / 

### Phone (7d3 2. ACTUA WELL LOCATION: COUNTY PROPERTY ADDRESS 

### 133,;-0 Z-, M Iqvs-. (Address) (City) (State) P) 

### 1/4 56 114, Sec. ý,Z Twp. 7N."S.,Range 6;Z 7E.CRW. P.M. Distances from Section Lines 5-00 Ft. from 1:1 N. 3 S. Line, 

### 2-5'0 () Ft. from2 E.or0 W. Line. 3. 1(we), report that an existing well was plugged and sealed for the following reason(s): The well was plugged and sealed as required under the conditions of approval ofWell Permit No. The well was not inuse and was plugged and sealed. Fý Other (please explain) 4. The well was,plupged and sealed according to the Water Well Construction Rules on 0&7a

## 6ev- /6' -, 1 9-ZL. 5. The well was plugged with the following materials placed at the indicated intervals: AMOUNT AND TYPE OF MATERIAL METHOD OF PLACEMENT INTERVAL 9,451 e'e&uL- Aý,IL6 4 ; /C-- 

### 7'e0Pt 71- 

# 44,cmis- from feet to ff-feet from feet to feet from feet to feet INTERVALS OF CASING REMOVEZCIRIP from feet to feet DPE ýINFEET from feet to 7-f- feet from feet to feet 6. 1(we)have read the statements made herein and know the contents thereof, and that they are true to my (our) knowledge. [Pursuant to Section 24-4-104 (13)(a) C.R.S., the making offalse statements herein constitutes perjur-9 inthe second degree and ispunishable as aclass 1misdemeanor.] Nýrqe/Tjtle (Please type or print) Signature Date
-INFORMATION- Itisthe responsibility ofthe well owner to have the well properly plugged and sealed. The Well

Construction Contractor isresponsible for notifying the well owner of the plugging and sealing requirement. Thisformmay be reproduced by photocopy or word processing means.THELATAIARCADIS GERAG14TY &MILLER TEAM

APPENDIX B. FINAL INSPECTION ATTENDANCE LIST

RM1 03/9801/APP-A DOC/07/09/99 B-1Final Insvection Attendance List



### Attendee Organization Sam Garcia EPA Laura Williams EPA Ed Larock CDPHE Stephen Smith RVO Tim Kilgannon RVO Cindy Fullerton TCHD Hugh Blaney Army Contracting Officer James Pearce NIKE Steve Gorin LATA Neville Gaggiani Contracting Officer's Repr sentativeTHELATAIARCADIS GERAGHTY& MILLER TEAM

APPENDIX C. PHOTOGRAPHS

RM10319801/APP-A DOC/07/09/99 C-1

## Original Configuration ofWell 299A

## PullingPump at Well 914AAMEN



## Perforating Casing at Well 1070A1.



## Drilling Mud Collection forReplacement Well 914B

## Pulling Pump atWell 985A

## Mechanical Star Wheel PerforatorI I



## Mud-Rotary Drilling at Well 914A

## Drilling Replacement Well 1070B

## Well Vault at395A with Overhead Wires

# Former Site ofClosed Well 299A

# Former Site ofClosed Well 985A

# MILL

Connection/Spigot forReplacement Well 914B

# Former Site ofClosed Well 1070A

# Former Site ofClosed Well 395A

# Replacement Well 914B