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Home My WebLink AboutDRC-2010-004142 - 0901a068801ad509DENISO MINES July 26, 2010 SENT VIA PDF AND FEDERAL EXPRESS Oonison Rffinet (USA) Corp. 1090 17th Straat Suits 950 Denvar, CO 8G26S USA Tel:303 828-779t Fax: 303 3894129 www.denisonminM.coni - 20 10-004 U2 Mr. Phil Goble Hydrogeologist State of Utah Department of Environmental Quality 195 North 1950 West Salt Lake City, Utah 84114-4850 Re: Response to Request for Information Dated June 24, 2010 White Mesa Uranium Mill - As-Built Report for Chloroform Monitor Well TW4- 26. Dear Mr. Goble: This letter and attachments respond, in part, to your request for information of June 24, 2010, regarding the Denison Mines (USA) Corp. (Denison) White Mesa Mill Groundvi^ater Quality Assurance Plan. Specifically, Item 5 of your letter requests that Denison submit, within 60 days of completion, the As-built report for MW-26. In response to your request, this letter transmits for your review and use two copies of the As- Built report, prepared by Hydro Geo Chem, Inc., for Chloroform Monitor Well TW4-26 which was installed on May 26, 2010. The report includes: 1. Narrative on construction, completion and development. 2. Location map indicating the location of the new well. 3. As-built schematic. 4. Lithologic log. Please advise me if you require any fiirther information on this well. Yours truly, .Jo C c>K.-c>i^- Jo Ann Tischler Director, Compliance and Permitting cc: David C. Fryenlund Ron F. Hochstein Ryan Palmer Harold R. Roberts David E. Turk Kathy Weinel Enclosures DENISO MINES HYDRO GEO CHEM, INC. Environmental Science & Technology July 23, 2010 Mr. David Frydenlund, Esq Denison Mines (USA) Corporation 1050 17* Street Independence Plaza, Suite 950 Denver, Colorado 80265 Dear Mr. Frydenlund, This letter report provides a brief description of the installation of new temporary perched zone well TW4-26 during May 2010. The approximate location of TW4-26 is shown in Figure 1. Well installation procedures were similar to those used previously at the site for the construction of other temporary perched zone wells (HOC, 2005)'. As before, drilling and construction were performed by Bayles Exploration, Inc., and borings logged by Mr. Lawrence Casebolt under contract to Denison Mines (USA) Corporation (DUSA). A well construction schematic based on information generated by Mr. Casebolt is provided in Figure 2. The depth to water shown in the construction schematic is based on measurements taken at the time of installation. A 12 % inch diameter tricone bit was used to drill a boring of sufficient diameter to install an 8-inch-diameter, schedule-40 PVC surface (conductor) casing. This surface casing extended to a depth of approximately 10 feet below land surface. Once the surface casing was in place, TW4-26 was drilled by air rotary using water and/or foam when needed to maintain circulation. The well was then drilled to total depth using a 6% inch diameter tricone bit. Drill cuttings were logged at 2 V2 -foot depth intervals and samples were collected in labeled, self-sealing, plastic bags and labeled, plastic, cuttings storage boxes. A copy of the lithologic log submitted by Mr. Casebolt is provided in the Appendix. Fluids and cuttings brought to the surface during drilling were routed to a pit excavated for that purpose adjacent to the boring. In general, air was used as a drilling fluid until poor cuttings retrieval necessitated the use of water and/or foam. The boring was advanced into the Brushy Basin member of the Morrison Formation, then backfilled with Colorado Silica Sand™ to a depth approximately 3 feet below the contact prior to well casing installation. ' Hydro Geo Chem, Inc. 2005. Perched Monitoring Well Installation and Testing at the White Mesa Uranium Mill, April through June 2005. Submitted to International Uranium Corporation. H:\718000\tw26\wellrepoi1\iw26inst.doc - iC 51 West Wctmore, Suite 101 Tucson, Arizona 85705-1678 520.293.1500 520.293.1550-Fax 800.727.5547-Toll Free Mr. David Frydenlund July 23,2010 Page 2 TW4-26 was constructed using 4 inch diameter. Schedule 40, flush-threaded PVC casing and 0.02-slot, factory-slotted PVC screen. Colorado Silica Sand ™ was used as a filter pack and installed to a depth approximately 4V2 feet above the screened interval. The annular space above the filter pack was then sealed with approximately 5 feet of bentonite and grouted to the surface using Portland cement. The completed well was developed by surging and bailing. Please call me in Tucson if you have any questions or comments. Sincerely, Stewart Smith Associate Hydrogeologist Attachments H:\718000\tw26\wellrepoit\rw26inst.doc ATTACHMENTS FIGURES 1 Site Plan Showing Perched Perched Well Locations and Approximate Location of Well TW4-26, White Mesa Site 2 TW4-26 As-Built Well Construction Schematic APPENDIX A Lithologic Log FIGURES TW4-19 o niz-i •f TW4-20 TW4-23 EXPLANATION perched monitoring well temporary perched monitorrng weN perched piezometer perdied monitoring well instailed April, 2005 temporary perched monitoring well instailed April, 2005 temporary perched monitoring well installed May, 2007 ^ TWM-1 temporary perched nitrate monitoring well - TW4-26 temporary perched 1? monitoring well wildlife pond HYDRO GEO CHEM, INC. siTrrosR SHOWING PERCHED WELL LOCATIONS AND APPROXIMATE LOCATION OP WELL TW4-26 , WHITE MESA SITE vpnovED SJS H:/718000/tw26/tw26.srf 10 20 30 40 50 60 CL lij Q 70 80 90 100 4 INCH DIA. PVC CAP OMINAL 12 3/4 INCH DIA'.5r BOREHOLE^ lO'-O" " SURFACE CASING (8 INCH DIA PVC) PORTLAND CEMENT GROUT 4 INCH DIA SCH 40 FLUSH THREAD PVC CASING BENTONITE SEAL NOMINAL 6 3/4 INCH DIA. BOREHOLE COLORADO SILICA GRAVEL PACK STATIC WATER LEVEL 4 INCH DIA SCH 40 FLUSH-THREAD 0.02 SLOT PVC SCREEN NOT TO SCALE HYDRO GEO CHEM, INC. TW4-26 AS-BUILT WELL CONSTRUCTION SCHEMATIC Approved" SS Data Author Date 07/21/10 MAC 07/21/10 7180247A riguTB APPENDIX A LITHOLOGIC LOGS 7-IS-lO; 9:S0AM;SILVER ARROW STONE ;928B43732S Dqfe S'2$'f^lP Genln^l^R^:ftf^»/^ DrlMing r.o.'^^/f^/At £itft7i>kfi'»A Hole TW-^^ Propertyli^tisJl^tS&Mu Project AA/arf/ern fni/iiti'<^siibi^]^\\ HQ Counfy JliiL^jkM . SJate UfAh Locotioh _M^22A__A2i£2Z Sec._22_ Twp. JZi_ Rge. Elev.^l6£2_ T.O. PKoae JO(>.S T.O. OHILL . J&OO REMARKS iii liFSiil IHii iiniii lEll [iHiili 113111 idll lEli v»^^\u r^.hL'^ gmt'W. inii iEJii mm mm IHii siaag 1511 flrMshjf Boaift- Cor>W IS fH.o^i, fih^faga lias HYDRO GEO CHEM, INC. Environmental Science &• Technology DRC-2010-004142 July 23, 2010 Mr. David Frydenlund, Esq Denison Mines (USA) Corporation 1050 17* Street Independence Plaza, Suite 950 Denver, Colorado 80265 Dear Mr. Frydenlund, This letter report provides a brief description of the installation of new temporary perched zone well TW4-26 during May 2010. The approximate location of TW4-26 is shown in Figure 1. Well installation procedures were similar to those used previously at the site for the construction of other temporary perched zone wells (HGC, 2005)'. As before, drilling and construction were performed by Bayles Exploration, Inc., and borings logged by Mr. Lawrence Casebolt under contract to Denison Mines (USA) Corporation (DUSA). A well construction schematic based on information generated by Mr. Casebolt is provided in Figure 2. The depth to water shown in the construction schematic is based on measurements taken at the time of installation. A 12 % inch diameter tricone bit was used to drill a boring of sufficient diameter to install an 8-inch-diameter, schedule-40 PVC surface (conductor) casing. This surface casing extended to a depth of approximately 10 feet below land surface. Once the surface casing was in place, TW4-26 was drilled by air rotary using water and/or foam when needed to maintain circulation. The well was then drilled to total depth using a 6% inch diameter tricone bit. Drill cuttings were logged at 2 Vi -foot depth intervals and samples were collected in labeled, self-sealing, plastic bags and labeled, plastic, cuttings storage boxes. A copy of the lithologic log submitted by Mr. Casebolt is provided in the Appendix. Fluids and cuttings brought to the surface during drilling were routed to a pit excavated for that purpose adjacent to the boring. In general, air was used as a drilling fluid until poor cuttings retrieval necessitated the use of water and/or foam. The boring was advanced into the Brushy Basin member of the Morrison Formation, then backfilled with Colorado Silica Sand^'^ to a depth approximately 3 feet below the contact prior to well casing installation. ' Hydro Geo Chem, Inc. 2005. Perched Monitoring Well Installation and Testing at the White Mesa Uranium Mill, April through June 2005. Submitted to International Uranium Corporation. H:\7l8000\tw25\wellreport\lw26inst.doc , y(2 51 West Wctmore, Suite 101 Tucson, Arizona 85705-1678 hl^" 520.293.1500 520.293.1550-Fax 800.727.5547-ToIl Free Mr. David Frydenlund July 23,2010 Page 2 TW4-26 was constructed using 4 inch diameter. Schedule 40, flush-threaded PVC casing and 0.02-slot, factory-slotted PVC screen. Colorado Silica Sand ™ was used as a filter pack and installed to a depth approximately 4'/2 feet above the screened interval. The annular space above the filter pack was then sealed with approximately 5 feet of bentonite and grouted to the surface using Portland cement. The completed well was developed by surging and bailing. Please call me in Tucson if you have any questions or comments. Sincerely, Stewart Smith Associate Hydrogeologist Attachments H:\718000\tw26\wellrepoit\tw26inst.doc ATTACHMENTS FIGURES 1 Site Plan Showing Perched Perched Well Locations and Approximate Location of Well TW4-26, White Mesa Site 2 TW4-26 As-Built Well Construction Schematic APPENDIX Lithologic Log TW4-1fl O REZ-1 IIW-31 • TW4-20 <^ TW4-23 EXPLANATION perctied monitoring well tem|»rary perched monitonng well perctied piezometer percfied monitoring well installed April, 2005 temporary perctied monitoring well installed April, 2005 temporary perched monitoring well installed May, 2007 A temporary perched nitrate monitoring well ^ TW4-26 ri*" ternporary perched V monitoring well iwildlife pond HYDRO GEO CHEM, INC. STTTPLAN SHOWING PERCHED WELL LOCATIONS AND APPROXIMATE LOCATION OF WELL TW4-26 WHITE MESA STFE SJS H:/718000/tiw26/tw26.srf 10 20 30 40 50 Ul UJ u. 60 Q. UJ Q 70 80 90 100 4 INCH DIA. PVC CAP ^T#NOMINAL 12 3/4 INCH DIA.gf ^BOREHOLE SURFACE CASING (8 INCH DIA PVC) PORUAND CEMENT GROUT 4 INCH DIA SCH 40 FLUSH THREAD PVC CASING NOMINAL 6 3/4 INCH DIA. BOREHOLE COLORADO SILICA GRAVEL PACK 4 INCH DIA SCH 40 FLUSH-THREAD 0.02 SLOT PVC SCREEN NOT TO SCALE HYDRO GRO ^ CHEM, INC. TW4-2e AS-BUILT WELL CONSTRUCTION SCHEMATIC Approved " SS Saw* 07/21/10 Author AMC Data 07/21/10 FaeNaifie 7180247A 7-i6-lO; 9:S0AM;SILVER ARROW STONE ;9286437328 5/ Date d'-Zt'^/a &^a\n^^^^sAio/T^ Drilling r.n. 'if^///i £y}/b/6filA Hole Wo Ti^J^I-ZS, Property ^iffii M//Project 6Mori>if'^ fn/f3f(j^^ffy[in\\ No. Sec._22__ Twp. Rge. County J4iL2k<l4^_ Slote -i^j/y Locotion ^i^H'f.'Jl* /f^?-^7; Elev.?5&£2_ . OF. r.o. Fito»e lo/y.^ T.O. OHILL . JQOO REMARKS