ROSEMONT PROJECTHYDROGEOLOGY & WATER SUPPLY              ERROL L. MONTGOMERY & ASSOCIATES, INC.
PRESENTATION OUTLINE   q EAST SIDE - MINE AREA      Ø HYDROGEOLOGY             §  Drilling & Testing Program           ...
MINE AREA   LAND CONTROL & OWNERSHIPERROL L. MONTGOMERY & ASSOCIATES, INC.
PREVIOUS GROUNDWATER        INVESTIGATIONSØ Hargis and Harshbarger (UA Study,   1975 to 1977)Ø Hargis and Montgomery (Mo...
MINE AREA HYDROGEOLOGIC           UNITSq  CONTINENTAL GRANODIORITE   Ø  Intrusive Mountain Core   Ø  Dense, consolidate...
MINE AREA        HYDROGEOLOGIC UNITSq MESOZOIC (Cretaceous) ROCKS   Ø  Tilted to east, moderately-dipping   Ø  Dense, b...
HYDROGEOLOGIC UNITSERROL L. MONTGOMERY & ASSOCIATES, INC.
WELL,PIEZOMETER     &   SPRING   (SEEP)LOCATIONS  ERROL L. MONTGOMERY & ASSOCIATES, INC.
PHASE 1 DRILLING & TESTINGØ Four wells constructed in pit area   §  (PC-1 through PC-4) during 2007Ø Depths ranged from...
PHASE 2 DRILLING & TESTINGq  Thirty wells and piezometers constructed in 2008     Ø  18 on Rosemont lands     Ø  12 on ...
PHASE 2 DRILLING & TESTINGq PC wells allowed for zonal pumping tests   using inflatable packer to isolate zonesq PZ piez...
PHASE 2 DRILLING & TESTING          (cont.)  Ø Eleven HC wells constructed in groups     outside but near pit area  Ø De...
PHASE 2 DRILLING & TESTING          (cont.)Ø Twelve RP wells constructed at distance   from pit areaØ Depths ranged from...
TYPICALDIAGRAM OF  PC & PZ   WELLS Wells PC-7  & PZ-7  ERROL L. MONTGOMERY & ASSOCIATES, INC.
TYPICAL DIAGRAM OF              PC & PZ WELLSERROL L. MONTGOMERY & ASSOCIATES, INC.
TYPICALDIAGRAM OF HC WELLS Well HC-4A ERROL L. MONTGOMERY & ASSOCIATES, INC.
TYPICALDIAGRAM OF RP WELLS Well RP-4A  ERROL L. MONTGOMERY & ASSOCIATES, INC.
PUMPING TESTSØ 24- and 12-hour zonal pumping tests at PC   wells, with PZ multi-level piezometers and   nearby wells as o...
AQUIFER PARAMETERS FROM     SHORT-TERM TESTSØ Computed transmissivities ranged from <1 to   3,600 ft2/dayØ Highly variab...
GROUNDWATER MONITORING       PROGRAMq From July 2006-March 2008, water   levels measured periodically in existing   wells...
MINE AREAWATERLEVELS ERROL L. MONTGOMERY & ASSOCIATES, INC.
GROUNDWATER LEVEL TRENDSERROL L. MONTGOMERY & ASSOCIATES, INC.
GROUNDWATER QUALITYØ Groundwater and spring samples analyzed   for common and trace inorganic constituents,   radiochemic...
GROUND- WATERQUALITY ERROL L. MONTGOMERY & ASSOCIATES, INC.
SPRINGS & SEEPSØ Seeps and springs nearest mine   monitored periodically since November   2006Ø Larger number of seeps a...
SPRINGS & SEEPSq Of 20 springs/seeps being monitored:  Ø Most are dry or moist spots on ground,    with observable flow ...
MODEL STUDY AREAERROL L. MONTGOMERY & ASSOCIATES, INC.
GROUNDWATER FLOW MODELq  Data Compilation and Evaluation    Ø Geologic framework    Ø Regional geologic framework – Pre...
GROUNDWATER FLOW MODELØ Conceptual Model Discussion        §  Groundwater Recharge and Discharge        §  Hydrogeologi...
GROUNDWATER FLOW MODELq Numerical Model Development  (Ongoing)   Ø Model Software   Ø Model Construction        §  Gri...
GROUNDWATER FLOW MODELq Numerical Model Development   Ø Model Calibration   Ø Model Projections        §  Quantificati...
WEST SIDE – SAHUARITA AREAERROL L. MONTGOMERY & ASSOCIATES, INC.
WATER SUPPLY PLANERROL L. MONTGOMERY & ASSOCIATES, INC.
WATER SUPPLY PLANq Groundwater Withdrawal Permit obtained from ADWR under A.R.S. 45-514       Ø Mineral Extraction & Met...
WATER SUPPLY PLAN             q Water Delivery System                       Ø Water supply wells                       Ø...
SAHUARITA HEIGHTS WELLS     Ø Approximately 300 domestic wells in        Sahuarita Heights area     Ø Domestic wells in ...
WEST SIDE MONITORING PROGRAMERROL L. MONTGOMERY & ASSOCIATES, INC.
WEST SIDE MONITORING PROGRAMERROL L. MONTGOMERY & ASSOCIATES, INC.
WEST SIDE HYDROGEOLOGY                    Sahuarita                     HeightsERROL L. MONTGOMERY & ASSOCIATES, INC.
WEST SIDE HYDROGEOLOGYq  Groundwater occurs in basin-fill depositsq  Hydrogeologic Units         Ø Ft. Lowell Formation...
ROSEMONT TEST WELLS  Ø Two wells constructed to depths of 1,211    (RC-2) and 1,300 feet (E-1)  Ø Characterized basin-fi...
WEST SIDE HYDROGEOLOGYERROL L. MONTGOMERY & ASSOCIATES, INC.
WEST SIDE HYDROGEOLOGYERROL L. MONTGOMERY & ASSOCIATES, INC.
WEST SIDEGROUNDWATER FLOW MODEL      q Began with ADWR Tucson AMA         Groundwater Model           Ø Numerical Basin-...
WEST SIDEGROUNDWATER FLOW MODEL q Refinement of Model Following Data     Evaluation      Ø Aquifer Parameters from Drill...
ERROL L. MONTGOMERY & ASSOCIATES, INC.
WEST SIDEGROUNDWATER FLOW MODEL        q Results of Model Calibration           Ø Overall match in study area           ...
LOCATIONS OF    CALIBRATION HYDROGRAPHSERROL L. MONTGOMERY & ASSOCIATES, INC.
ERROL L. MONTGOMERY & ASSOCIATES, INC.
ERROL L. MONTGOMERY & ASSOCIATES, INC.
ERROL L. MONTGOMERY & ASSOCIATES, INC.
WEST SIDE GROUNDWATER FLOW MODELq Rosemont Water Supply Simulations   Ø Rosemont Pumping 5,000 AF/year for 20     years ...
Upcoming SlideShare
Loading in...5
×

Rosemont Project Hydrogeology & Water Supply

426

Published on

A presentation on the hydrogeology & water supply associated with the Rosemont Copper Project developed by the Erroll L. Montgomery & Associates, Inc. This presentation was given to the Forest Service and their contractors during technical transfer meetings in November 2008.

Published in: Education, Technology, Business
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
426
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
0
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

Transcript of "Rosemont Project Hydrogeology & Water Supply"

  1. 1. ROSEMONT PROJECTHYDROGEOLOGY & WATER SUPPLY ERROL L. MONTGOMERY & ASSOCIATES, INC.
  2. 2. PRESENTATION OUTLINE q EAST SIDE - MINE AREA Ø HYDROGEOLOGY §  Drilling & Testing Program §  Groundwater & Spring/Seep Monitoring Ø GROUNDWATER FLOW MODELING q WEST SIDE – SAHUARITA AREA Ø WATER SUPPLY PLAN Ø HYDROGEOLOGY Ø GROUNDWATER FLOW MODELINGERROL L. MONTGOMERY & ASSOCIATES, INC.
  3. 3. MINE AREA LAND CONTROL & OWNERSHIPERROL L. MONTGOMERY & ASSOCIATES, INC.
  4. 4. PREVIOUS GROUNDWATER INVESTIGATIONSØ Hargis and Harshbarger (UA Study, 1975 to 1977)Ø Hargis and Montgomery (Monitoring, 1980 to 1982)Ø Montgomery & Associates (2007)ERROL L. MONTGOMERY & ASSOCIATES, INC.
  5. 5. MINE AREA HYDROGEOLOGIC UNITSq  CONTINENTAL GRANODIORITE Ø  Intrusive Mountain Core Ø  Dense, consolidated Ø  Limited fracturing Ø  Very Low Permeability and Groundwater Storageq  PALEOZOIC CARBONATE ROCKS Ø  Tilted to east, steeply-dipping Ø  Broken-up, discontinuous blocks Ø  Dense, but fractured and faulted Ø  Groundwater flow and storage are fracture & fault controlled Ø  Low permeability with locally moderate permeability along fractures and faults ERROL L. MONTGOMERY & ASSOCIATES, INC.
  6. 6. MINE AREA HYDROGEOLOGIC UNITSq MESOZOIC (Cretaceous) ROCKS Ø  Tilted to east, moderately-dipping Ø  Dense, but fractured and faulted Ø  Groundwater flow and storage are fracture & fault controlled Ø  Low permeability with locally moderate permeability along fractures and faultsq CENOZOIC (Tertiary & Quaternary) BASIN-FILL DEPOSITS Ø  Gently-dipping to flat-lying Ø  Strongly cemented, esp. near mountains and mine Ø  Strongly to moderately cemented elsewhere Ø  Groundwater flow and storage are limited and not fracture- controlled Ø  Low permeability with locally moderate permeability away from mountains ERROL L. MONTGOMERY & ASSOCIATES, INC.
  7. 7. HYDROGEOLOGIC UNITSERROL L. MONTGOMERY & ASSOCIATES, INC.
  8. 8. WELL,PIEZOMETER & SPRING (SEEP)LOCATIONS ERROL L. MONTGOMERY & ASSOCIATES, INC.
  9. 9. PHASE 1 DRILLING & TESTINGØ Four wells constructed in pit area §  (PC-1 through PC-4) during 2007Ø Depths ranged from 1,020 to 1,503 feetØ Targeted chiefly Willow Canyon Formation and cemented basin-fill deposits which will make up majority of east pit wallØ Low permeabilities, with locally moderate permeabilities along faults and/or dense fracturingØ Well yields ranged from 2 to 50 gpm ERROL L. MONTGOMERY & ASSOCIATES, INC.
  10. 10. PHASE 2 DRILLING & TESTINGq  Thirty wells and piezometers constructed in 2008 Ø  18 on Rosemont lands Ø  12 on USFS landsq  Four wells constructed in pit area (PC-5 through PC-8, and three grouted multi-level piezometers (PZ-5, PZ-7, and PZ-8) adjacent to PC wells Ø  Depths ranged from 2,000 to 2,200 feetq  PC wells completed with multiple screened intervals, separated by blank zones with annular seals, to isolate discreet aquifer zones for vertical characterizationq  PZ piezometers installed by grouting in pressure transducers at borehole intervals corresponding to perforated intervals of adjacent PC wells ERROL L. MONTGOMERY & ASSOCIATES, INC.
  11. 11. PHASE 2 DRILLING & TESTINGq PC wells allowed for zonal pumping tests using inflatable packer to isolate zonesq PZ piezometers allowed for monitoring of aquifer response to PC well pumpingq Low permeabilities, with locally moderate permeabilities along faults and/or strong fracturingq Well yields ranged from 20 to 45 gpm ERROL L. MONTGOMERY & ASSOCIATES, INC.
  12. 12. PHASE 2 DRILLING & TESTING (cont.) Ø Eleven HC wells constructed in groups outside but near pit area Ø Depths ranged from 50 to 1,000 feet Ø Generally within ½ to 1 mile of pit Ø Provided vertical characterization of aquifer properties using 2 or more wells at each site, completed at different depths Ø Low permeabilities Ø Well yields ranged from <1 to 36 gpm; average 13 gpmERROL L. MONTGOMERY & ASSOCIATES, INC.
  13. 13. PHASE 2 DRILLING & TESTING (cont.)Ø Twelve RP wells constructed at distance from pit areaØ Depths ranged from 30 to 600 feetØ Provided vertical characterization of aquifer properties using 2 or more wells at sites <3 miles from pit, and single wells >3 miles from pitØ Low permeabilitiesØ Well yields ranged from <1 to 33 gpm; average ~10 gpmERROL L. MONTGOMERY & ASSOCIATES, INC.
  14. 14. TYPICALDIAGRAM OF PC & PZ WELLS Wells PC-7 & PZ-7 ERROL L. MONTGOMERY & ASSOCIATES, INC.
  15. 15. TYPICAL DIAGRAM OF PC & PZ WELLSERROL L. MONTGOMERY & ASSOCIATES, INC.
  16. 16. TYPICALDIAGRAM OF HC WELLS Well HC-4A ERROL L. MONTGOMERY & ASSOCIATES, INC.
  17. 17. TYPICALDIAGRAM OF RP WELLS Well RP-4A ERROL L. MONTGOMERY & ASSOCIATES, INC.
  18. 18. PUMPING TESTSØ 24- and 12-hour zonal pumping tests at PC wells, with PZ multi-level piezometers and nearby wells as observation pointsØ 12-hour pumping tests at each HC and RP well, with adjacent and nearby wells as observation pointsØ Long-term (up to 30-day) pumping test planned using 5 wells in mine area; scheduled to begin in November ERROL L. MONTGOMERY & ASSOCIATES, INC.
  19. 19. AQUIFER PARAMETERS FROM SHORT-TERM TESTSØ Computed transmissivities ranged from <1 to 3,600 ft2/dayØ Highly variableØ Fracture/fault controlledØ Preliminary computed storage coefficients generally in range of 10-4 to 10-5Ø The long-term, multi-well pumping test should refine ranges and provide data to determine aquifer response to dewatering ERROL L. MONTGOMERY & ASSOCIATES, INC.
  20. 20. GROUNDWATER MONITORING PROGRAMq From July 2006-March 2008, water levels measured periodically in existing wellsq Since March 2008 Ø Water levels in wells measured and spring flow monitored monthly Ø Many wells equipped with continuous water level recording devices Ø Water quality sampling at wells and springs ERROL L. MONTGOMERY & ASSOCIATES, INC.
  21. 21. MINE AREAWATERLEVELS ERROL L. MONTGOMERY & ASSOCIATES, INC.
  22. 22. GROUNDWATER LEVEL TRENDSERROL L. MONTGOMERY & ASSOCIATES, INC.
  23. 23. GROUNDWATER QUALITYØ Groundwater and spring samples analyzed for common and trace inorganic constituents, radiochemical constituents & parameters, organic compounds, and stable isotopesØ Groundwater quality good to excellent, with very few AWQS or MCL constituents exceededØ TDS ranged from 190 - 1,480 mg/LØ Average TDS = 430 mg/LØ pH ranged from 6.9 to 7.9Ø Average pH = 7.5 ERROL L. MONTGOMERY & ASSOCIATES, INC.
  24. 24. GROUND- WATERQUALITY ERROL L. MONTGOMERY & ASSOCIATES, INC.
  25. 25. SPRINGS & SEEPSØ Seeps and springs nearest mine monitored periodically since November 2006Ø Larger number of seeps and springs monitored monthly since January 2008Ø 20 springs presently being monitoredØ Monitoring conditions and flow monthlyØ Obtaining samples quarterly where practical ERROL L. MONTGOMERY & ASSOCIATES, INC.
  26. 26. SPRINGS & SEEPSq Of 20 springs/seeps being monitored: Ø Most are dry or moist spots on ground, with observable flow only during or shortly after storms Ø Four springs have sustained flow § Rosemont Spring (~0.1 to 0.5 gpm) § MC-2 (McCleary Canyon) (~0.1 gpm) § Deering Spring (~0.1 gpm) § Questa Spring (~0.1 gpm) ERROL L. MONTGOMERY & ASSOCIATES, INC.
  27. 27. MODEL STUDY AREAERROL L. MONTGOMERY & ASSOCIATES, INC.
  28. 28. GROUNDWATER FLOW MODELq  Data Compilation and Evaluation Ø Geologic framework Ø Regional geologic framework – Previous investigations Ø Hydrogeologic data from drilling/testing programs Ø Water level and water quality data from monitoring program Ø Meteorological data from Rosemont and other weather stations Ø Data from existing wells §  Historic water levels §  Drillers logs §  Water quality data §  Well performance data ERROL L. MONTGOMERY & ASSOCIATES, INC.
  29. 29. GROUNDWATER FLOW MODELØ Conceptual Model Discussion §  Groundwater Recharge and Discharge §  Hydrogeologic Flow System §  Preliminary Assumptions ERROL L. MONTGOMERY & ASSOCIATES, INC.
  30. 30. GROUNDWATER FLOW MODELq Numerical Model Development (Ongoing) Ø Model Software Ø Model Construction §  Grid §  Extent §  Aquifer Parameters §  Groundwater Recharge ERROL L. MONTGOMERY & ASSOCIATES, INC.
  31. 31. GROUNDWATER FLOW MODELq Numerical Model Development Ø Model Calibration Ø Model Projections §  Quantification of Pit Dewatering Requirements §  Impacts to Local Groundwater Levels §  Impacts to Regional Groundwater Levels §  Evaluation of Pit Lake Presence and Fate Ø Model Sensitivity Analyses ERROL L. MONTGOMERY & ASSOCIATES, INC.
  32. 32. WEST SIDE – SAHUARITA AREAERROL L. MONTGOMERY & ASSOCIATES, INC.
  33. 33. WATER SUPPLY PLANERROL L. MONTGOMERY & ASSOCIATES, INC.
  34. 34. WATER SUPPLY PLANq Groundwater Withdrawal Permit obtained from ADWR under A.R.S. 45-514 Ø Mineral Extraction & Metallurgical Processingq Recharge of CAP ERROL L. MONTGOMERY & ASSOCIATES, INC.
  35. 35. WATER SUPPLY PLAN q Water Delivery System Ø Water supply wells Ø 17 mile pipeline (24 ) to mine site Ø Boosters Ø Design Capacity Ø Right of Ways / EasementsERROL L. MONTGOMERY & ASSOCIATES, INC.
  36. 36. SAHUARITA HEIGHTS WELLS Ø Approximately 300 domestic wells in Sahuarita Heights area Ø Domestic wells in Sahuarita Heights generally produce a few to 35 gpm Ø Local Well Owner Protection Program Ø Discussions with United Sahuarita Well Owners Ø Established 11 sites for Groundwater Level and Quality Monitoring Ø Well databaseERROL L. MONTGOMERY & ASSOCIATES, INC.
  37. 37. WEST SIDE MONITORING PROGRAMERROL L. MONTGOMERY & ASSOCIATES, INC.
  38. 38. WEST SIDE MONITORING PROGRAMERROL L. MONTGOMERY & ASSOCIATES, INC.
  39. 39. WEST SIDE HYDROGEOLOGY Sahuarita HeightsERROL L. MONTGOMERY & ASSOCIATES, INC.
  40. 40. WEST SIDE HYDROGEOLOGYq  Groundwater occurs in basin-fill depositsq  Hydrogeologic Units Ø Ft. Lowell Formation (dry in Sahuarita Heights) Ø Tinaja beds (principal aquifer)q  Silty sand with minor gravelly zonesq  Depth to water 200 to 250 feet Ø Substantially deeper during irrigation seasonq  Groundwater flow toward northwestq  Water level trends over timeØ Wells in study area produce from a few to more than 2,000 gpmERROL L. MONTGOMERY & ASSOCIATES, INC.
  41. 41. ROSEMONT TEST WELLS Ø Two wells constructed to depths of 1,211 (RC-2) and 1,300 feet (E-1) Ø Characterized basin-fill sediments and groundwater quality Ø Transmissivity ranged from 1,340 (RC-2) to 2,680 (E-1) ft2/day Ø Anticipated well production 500 to 1,500 gpm Ø Excellent groundwater quality – TDS range 210 (RC-2) – 340 (E-1) mg/LERROL L. MONTGOMERY & ASSOCIATES, INC.
  42. 42. WEST SIDE HYDROGEOLOGYERROL L. MONTGOMERY & ASSOCIATES, INC.
  43. 43. WEST SIDE HYDROGEOLOGYERROL L. MONTGOMERY & ASSOCIATES, INC.
  44. 44. WEST SIDEGROUNDWATER FLOW MODEL q Began with ADWR Tucson AMA Groundwater Model Ø Numerical Basin-Wide Model Ø MODFLOW Software Ø Updates Provided by ADWR q Model ChallengesERROL L. MONTGOMERY & ASSOCIATES, INC.
  45. 45. WEST SIDEGROUNDWATER FLOW MODEL q Refinement of Model Following Data Evaluation Ø Aquifer Parameters from Drilling & Testing Ø Update Groundwater Pumpage Ø Evaluate & Modify Groundwater Recharge Ø Santa Cruz RechargeERROL L. MONTGOMERY & ASSOCIATES, INC.
  46. 46. ERROL L. MONTGOMERY & ASSOCIATES, INC.
  47. 47. WEST SIDEGROUNDWATER FLOW MODEL q Results of Model Calibration Ø Overall match in study area Ø Match in Sahuarita Heights areaERROL L. MONTGOMERY & ASSOCIATES, INC.
  48. 48. LOCATIONS OF CALIBRATION HYDROGRAPHSERROL L. MONTGOMERY & ASSOCIATES, INC.
  49. 49. ERROL L. MONTGOMERY & ASSOCIATES, INC.
  50. 50. ERROL L. MONTGOMERY & ASSOCIATES, INC.
  51. 51. ERROL L. MONTGOMERY & ASSOCIATES, INC.
  52. 52. WEST SIDE GROUNDWATER FLOW MODELq Rosemont Water Supply Simulations Ø Rosemont Pumping 5,000 AF/year for 20 years Ø Pumpage by Other Groundwater Users Ø Recharge at USFs and WWTPs Ø Model Results (Pending) §  Impacts to Regional Groundwater Levels §  Impacts to Local Domestic Wells Ø Local-Scale Model Evaluation ERROL L. MONTGOMERY & ASSOCIATES, INC.

×