The Early Warning Drilling Program (EWDP) was initiated as part of  the  Nye  County  Nuclear Waste Repository Project Office (NWRPO)  Independent Scientific Investigations Program (ISIP).  The  program  is intended  to  provide  geologic  and hydrologic information that is needed and has been missing from DOE's program. The targeted area is located in a complex hydrogeologic  system  and  it  is  one of  the least understood hydrogeologic  systems  in the vicinity of Yucca Mountain.  The questions that are being investigated are: 1)  the origin of the spring deposits; 2) the geology and hydraulic properties of the valley-floor sediments;  3) the recharge; and  4)  ground-water flow patterns.  By understanding  this critical information, the monitoring system can be better designed to protect the water resources of the Nye County.   

PHASE I STATUS
Drilling of the EWDP Phase I drillholes was completed during 1999.   Phase I  drillholes included:    NC-EWDP-1D, NC-EWDP-1DX,  NC-EWDP-1S,  NC-EWDP-2D, NC-EWDP-3D, NC-EWDP-3S,  NC-EWDP-5S,  NC-EWDP-9S, NC-EWDP-9SX, and NC-Washburn-1x.  Drillholes NC-EWDP-1D and NC-EWDP-9S were only cored, and were subsequently abandoned.

PHASE II STATUS
Phase II drilling was initiated during 2000.  Phase II drillholes  included:  NC-EWDP-2DB, NC-EWDP-3DB, NC-EWDP-4PA, NC-EWDP-4PB, NC-EWDP-5SB, NC-EWDP-7S, NC-EWDP-7SC, NC-EWDP-12D, NC-EWDP-12PA, NC-EWDP-12PB, NC-EWDP-12PC, NC-EWDP-15D, NC-EWDP-15P, NC-EWDP-19D, and NC-EWDP-19P.

PHASE III STATUS
All Nye County EWDP Phase III field work was completed as of 3/31/02.  Nye County water sampling at the EWDP III piezometer wells will be from 8/26/02 to 8/30/02 and in the multiple-screen monitoring wells from 9/9/02 to 9/13/02. 

Exploratory Geologic Sampling Boreholes
Drilling efforts on Nye County's NWRPO EWDP Phase III and the second year of the Alluvial Testing Complex (ATC) began on 07/10/01.  Eklund Drilling arrived onsite 07/09/01.  Eklund used a reverse circulation method to sample the geology at NC-EWDP-19IM1A, and NC-EWDP-19IM2A (on the ATC site),  and NC-EWDP-10SA and NC-EWDP-22SA in the lower Fortymile Wash area on the Nevada Test Site (NTS).  NC-EWDP-19IM1A was drilled to 900 feet from 07/10/01 to 07/13/01.  NC-EWDP-19IM2A was drilled to 900 feet from 07/13/01 to 07/17/01.  NC-EWDP-10SA was drilled to 1200 feet from 07/23/01 to 07/28/01 and NC-EWDP-22SA was drilled to 1200 feet from 7/28/01 to 8/02/01. 

All sampling boreholes were grouted back to the ground surface upon completion.  The purpose of these boreholes was to characterize alluvial stratigraphy and to identify the underlying Tertiary rock units.  Samples were collected and logged over 2.5 foot depth intervals in the alluvium and over 5 foot depth intervals from underlying units.  Every other alluvium sample (i.e. on 5 foot intervals) was sent to a testing laboratory for particle size analysis. All of this work was completed within budget and Eklund Drilling did an outstanding job.

Multiple-screened Completion Wells
Beylik Drilling Co. used flooded mud reverse circulation methods to complete two wells, each well with 5 screened intervals, at the ATC location.  NC-EWDP-19IM1 was completed to a depth of 1012.5 feet on 08/26/01 and NC-EWDP-19IM2 was completed to a depth of 965.6 feet on 09/13/01. In addition, Beylik completed multiple-screen wells NC-EWDP-10S to a depth of 900 feet on 10/01/01 and NC-EWDP-22S to a depth of 1196.5 feet on 10/25/01 on the Nevada Test Site.  These multiple-screened wells were constructed to permit determination of aquifer properties and water chemistries of different screened intervals.

Dual Completion Piezometer Wells
THF Drilling Co. used casing advance and standard rotary drilling methods to complete piezometer wells NC-EWDP-18P to a depth of 890 feet on 10/21/01. Casing advance methods only were used to complete NC-EWDP-10P to a depth of 910 feet on 01/04/01 and NC-EWDP-22PA to a depth of 780 feet on 1/31/02.  These wells were sampled, logged, and tested in a similar manner as the exploratory boreholes drilled by Eklund Drilling Co.  In addition, nearly 30 linear feet of 0.33 foot diameter drive core samples were collected from selected  saturated zone depth intervals and from 4 unsaturated zone depth intervals in NC-EWDP-10P and -22P. Eklund Drilling returned in February and completed additional piezometer wells NC-EWDP-22PB and NC-EWDP-23P.  NC-EWDP-22PB contains a piezometer screen from 880 to 980 feet and one from 1140 to 1180 feet.  Geologic samples were taken at NC-EWDP-23P down to 1340 feet.  However, the borehole caved back to 712 feet and piezometer screens were installed from 460 to 520 feet and 650 to 690 feet.

Testing
During October, 2001 Nye County completed 48-hour aquifer pump/spinner tests in both of the new multiple-screen wells at the ATC.  In addition, Westbay packers, casing, monitoring ports and hydraulic ports were installed and groundwater was sampled in all 5 zones of NC-EWDP-19IM1.  Westbay instrumentation was installed into NC-EWDP-19IM1 on 11/15/01 and pressure and temperature are being monitored by Nye County and the U.S. Geological Survey under the ATC cooperative agreement. Cross hole testing, directed by the U.S. Department of Energy, began at the ATC on 12/11/01 starting with a 48-hour hydraulic confirmation test of zones 5, 6, and 7 in NC-EWDP-19D.

Additional aquifer testing was completed during February and March 2002 at NC-EWDP-10S and NC-EWDP-22S.  Subsequently, Westbay casing, packers, monitoring and hydraulic ports were installed into these wells.

PHASE IV STATUS
Eklund Drilling arrived onsite on 10/19/02.  The abandonment of NC-EWDP-5S and -2D was completed on 10/20/02.  Drilling of NC-EWDP-28P began on 10/21/02.  The borehole was drilled to a total depth of 2,080 feet for geologic sampling, plugged back to 455 feet, and completed with a single-screen piezometer from 370 to 450 feet. Drilling of NC-EWDP-27P began on 11/20/02.  The borehole was drilled to a total depth of 1,900 feet, plugged back to 631 feet, and completed with a single-screen piezometer from 580 to 620 feet on 12/12/02.  Drilling of NC-EWDP-16P began on 12/13/02. The borehole was drilled to a total depth of 2,900 feet, plugged back to 560 feet, and completed with a single-screen piezometer from 489 to 549 feet on 1/27/03. 

Phase IV drilling was then suspended until 6/24/03, when Eklund Drilling began work on NC-EWDP-29P.  The borehole was drilled to a total depth of 791 feet, plugged back to 405 feet, and completed with a single-screen piezometer from 340 to 390 feet. Drilling of NC-EWDP-24P began on 7/16/03.  The borehole was drilled to a total depth of 1,860 feet, plugged back to 447 feet, and completed with a single-screen piezometer from 400 to 440 feet.

Phase IV drilling ended with the construction of sonic corehole NC-EWDP-19PB by Boart Longyear Co.  Drilling began on 12/2/03.  The corehole was drilled to 350 feet, at which point sonic coring was conducted to a total depth of 634 feet.  The corehole was then plugged back to 545 feet and a dual-string piezometer was completed with screens from 376 to 395 and 515 to 535 feet.

PHASE V STATUS
Well Drilling and Completion
Boart Longyear started drilling sonic corehole NC-EWDP-22PC on 10/14/2004.  The hole was drilled to 460 feet using reverse-circulation air rotary methods, cased, then the corehole was advanced from 460 to 763 feet using sonic coring methods.  The corehole was completed on 11/23/04 with a dual-string piezometer with screens from 510 to 580 feet and 665 to 755 feet.  Drilling of NC-EWDP-13P began on 6/16/05.  The borehole was drilled to a total depth of 1,559 feet for geologic sampling, plugged back to 476 feet, and completed with a single-string piezometer with screen from 426 to 466 feet on 8/12/05.

Drilling of NC-EWDP-24PB began on 1/29/06.  The borehole was drilled to a total depth of 1,394 feet and completed with a single-string piezometer with a screen from 729 to 770 feet on 3/26/06.  In addition to the piezometer, the well was also completed with u-tube instrumentation that will be used during future tracer testing.

The two final holes drilled during Phase 5 included NC-EWDP-32P and –33P.  Both of these wells are located south of U.S. Highway 95 and were drilled after being sited near volcanic anomalies.   The Right of Way grant for DOE borehole VA-5 was transferred to Nye County, and the borehole was completed on 3/9/06 as well NC-EWDP-33P.  NC-EWDP-33P was completed with a triple-string piezometer with screens from 211 to 250 feet, 485 to 524 feet, and 601 to 640 feet.  Drilling of NC-EWDP-32P began on 3/28/06. The borehole was drilled to a total depth of 1,000 feet and completed with a triple-string piezometer with screens from 239 to 278 feet, 464 to 483 feet, and 698 to 737 feet on 4/25/06. 

Tracer Testing
Nye County tracer testing was conducted at site 22 during Phase V.  Two single-well push/pull tracer tests were conducted at well NC-EWDP-22S and two cross-hole tracer tests were conducted at wells NC-EWDP-22S, NC-EWDP-22PA, and NC-EWDP-22PC between 12/02/04 and 10/13/05.

PHASE VI STATUS
Well Drilling and Completion

Drill Tech began drilling NC-EWDP-4PC on June 9, 2008.  The borehole was drilled to 460 feet using dual-wall reverse-circulation rotary methods.  Due to problems encountered during drilling, the borehole was plugged back and abandoned.  Abandonment operations were completed on July 10, 2008.

Drilling on NC-EWDP-4PD began on July 12, 2008.  This borehole was drilled to a total depth of 1,860 feet using conventional-circulation mud rotary methods.  The borehole was completed as a multiple-screen monitor well, with screens from 317.6 to 397.9 feet, 498 to 638.8 feet, 738.9 to 999.9 feet, 1,059.9 to 1,260.5 feet, 1,480.5 to 1,550.6 feet, and 1,780.8 to 1,851.2 feet.

Well Testing

Following development activities, isolated-zone aquifer tests were conducted in each screen of NC-EWDP-4PD.  These tests started with screen #6 on February 25, 2009, and were concluded with screen #1 on June 30, 2009.  Water quality samples were collected from each screen during aquifer testing activities.

SUMMARY DRILLING INFORMATION

To view a map of the Phase I, II, III, IV and V drilling locations, click on the adjacent thumbnail image.

To view a Phase I and II Summary Information Table for wells drilled during EWDP Phases I and II, click either the Adobe Acrobat (.pdf) or the MS-Excel spreadsheet (.xls) version below.

Well Summary Table Phases I and II.pdf       
Well Summary Table Phases I and II.xls

To view a Phase III Summary Information Table for wells drilled during EWDP Phase III, click either the Adobe Acrobat (.pdf) or the MS-Excel spreadsheet (.xls) version below.

Well Summary Table Phase III.pdf    
Well Summary Table Phase III.xls

To view a Phase IV Summary Information Table for wells drilled during EWDP Phase IV, click the Adobe Acrobat (.pdf) file below.

Well Summary Table Phase IV.pdf 

ALLUVIUM GEOLOGIC CROSS-SECTION (PHASE I, II, & III)
Alluvium Cross Section.pdf

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