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Home My WebLink About6 Drilling Report I GROUND WATER EXPLORATION DRILLING REPORT Truckee, California Prepared for: Truckee Donner Public Utility District 11570 Donner Pass Road Truckee, California 96160 October 2003 PO. Box 18793 • Reno Nevada 89511 s (775)250-9700 a Fax (775)841 0946 0 Dw idl Carlson@ msn.com Section Table of Contents 1.0 EXECUTIVE SUMMARY 1.2 Findings 1.3 Recommendations 2.0 PROSSER DAM ROAD EXPLORATION SITE Photograph and findings Geologic chip trays Water chemistry bar graph 3.0 FIBER BOARD EXPLORATION SITE Photograph and findings Geologic chip trays Water chemistry bar graph 4.0 TANK EXPLORATION SITE Photograph and findings Geologic chip trays Water chemistry bar graph 5.0 HASS EXPLORATION SITE Photograph and findings Geologic chip trays Water chemistry bar graph FIGURE Figure 1. Location Map 1.0 EXECUTIVE SUMMARY 1.2 Findings Prosser Dam Road site • A nominal 6-inch diameter borehole was drill to a total depth of 1,200 feet below ground surface. Geologic samples and water quality samples were collected to total depth. A geophysical survey was also completed to total depth. • During the drilling of the borehole a 100 foot section of cinders was encounter from 300 to 400 feet. Between 400 and approximately 600 feet, the material encountered was primarily basalt. From 600 to approximately 900 feet, alluvial material which contained very little clay was encountered. Below 900 to total depth the alluvial material encountered contained upwards to 70% clay. From total depth, air-lift results were calculated to be 222 gpm. • After the geophysical survey was completed, the borehole was abandoned per State of California standards. Fiber Board site • A nominal 6-inch diameter borehole was drilled to a total depth of 1,200 feet below ground surface. Geologic samples and water quality samples were collected to total depth. A geophysical survey was completed to a depth of 1,100 feet. • During the drilling of the borehole an approximate 300 foot section of cinders were encountered from 280 to 580 feet. Below approximately 600 feet, a 100-foot section of alluvial material was encountered, followed by a basalt zone to total depth of 1,200 feet. Near the bottom of the borehole, 217 gpm of air-lift water was being made. Below 640 feet, the water contained an arsenic level which exceeded drinking water standards. • The bottom portion of the borehole below 250 feet was abandoned per State of California standards. The portion of the borehole from ground surface to 250 feet was completed as a 2-1/2-inch PVC, schedule 80 monitoring well. 50-slot screen was installed from 180 feet to total depth. This monitoring well was completed to meeting monitoring requirements of the Old Greenwood Golf Course. Tank site • A nominal 6-inch diameter borehole was drilled to a total depth of 930 feet below ground surface. Geologic samples and water quality samples were collected to total depth. A geophysical survey was completed to a depth of 350 feet. During the drilling of the borehole from 600 feet to total depth of 930 feet zones of coarse rounded gravels were encountered. From 800 feet to 930 feet, the material was completely course rounded gravels with little to no clay. Drilling could not proceed below 930 feet because the gravels were coming into the borehole as fast as they were being air-lifted form the borehole. Water production from the bottom of the borehole ' was in excess of 220 gpm. After the geophysical survey was completed to 350 feet, the borehole was abandoned per State of California regulations. Hass site • A nominal 6-inch diameter borehole was drilled to total depth of 1,200 feet below ground surface. Geologic samples and water quality samples were collected to total depth. A geophysical survey was completed to total depth of 1,200 feet. �4 • During the drilling of the borehole a significant gravel zone was encountered below 700 feet. At total depth of 1,200 feet, the geologic material was described as coarse sand. Water production from the bottom of the borehole was in excess of 220 gpm. Based on geologic cuttings and the geophysical survey, a production well at this site would be `s capable of producing in the range of 2,000 to 3,000 gpm. Analysis of the water samples collected indicated that from the very first water encountered to total depth, the water contained arsenic which exceeded drinking water standards. As a result of the water quality, this site should not be considered as a domestic production well site at this time. After the geophysical survey was completed, the borehole was abandoned per State of t California regulations. R 1.3 Recommendations The following are the proposed recommendations based on information collected during the drilling, geophysical survey analysis, and water quality results of the four ground water exploration boreholes. 4 • Prosser Dam Road site At this location, it is estimated that a production well constructed to a depth of approximately 900 feet will produce in excess of 1,000 gpm. The quality of the water will meet State of California drinking water standards for iron, manganese, and arsenic based on the samples collected during the exploration program. 7i Tank site At this location, it is anticipated that a production well constructed to a depth of 1,000 to 1,200 feet will be capable of producing between 1,000 and 2,000 gpm. Because the exploration borehole was only drilled to a depth of 930 feet, the production rating of this well may be conservative. Final production of the well may exceed 2,000 gpm. Based on results of the water samples collected during exploration drilling, it is anticipated that the production well water pumped will meet State of California drinking t water standards for iron, manganese, and arsenic. 1# • Fiber Board site (municipal) At this location a municipal production well should be drilled and construction to a depth of 600 feet. Based on the geophysical survey, geologic drill cuttings, and water quality results, it is believed that a production well constructed to the proposed depth would yield approximately 1,000 to 1,500 gpm. Based on water quality results, ground water produced from this well would meet State of California drinking water standards for iron, manganese, and arsenic. 1` • Fiber Board site (irrigation) At this location an irrigation well should be drilled and constructed to tap the aquifer below 600 feet to a total depth of 1,200 feet. Ground water samples collected during the exploration program indicate that the water exceeds drinking water standards for arsenic, while meeting the standards for iron and manganese. Because of the high volume of ground water(estimated to be in the range of 1,000 gpm) that is available from 600 to 1,200 feet, water produced from a production well constructed to this depth should be used for irrigation only. If this site were to be utilized for irrigation only, a single production well drilled and constructed to a depth of 1,200 feet might be capable of producing in the range of 2,000 ff to 2,500 gpm. • Hass site Because of the poor quality water that was encountered at the Hass site for nearly its entire saturated thickness (200 to 1,200 feet), this site should not be considered at this time as a municipal production well site. At this site, levels of arsenic and manganese exceeded drinking water standards. If in the future technology is found to allow the water produced at this site to meet drinking water standards, then a production well drilled and constructed to a depth of approximately 1,200 feet would be capable of producing in the range of 2,000 to 3,000 gpm. t �.,t — 3 1 Ste) i 9U v x., y G Prosser V'—IOage Wen 1 583i ' t _ r 1 x PIo55Q IW1IX WCII t .Prosser Dam Road ade ♦ �, , y 40 1,2 , / e " ,,�Op I a�„ r Prosser HagMs well Tank site Hass sne ". -- — 4 e /,,,MT,' I i 6 L Rd / Sa dm wd Glerishr 'e' y`` � � I i- - oerger.Driv� aer r y Mansvevww� ._.. t 5oufttle we➢ (i a IO co"a, ib CKEE T HOE Aip PrJR scan r\ \ \Y R T l S t ck \. t$ w a� f AUP ell t EVADA CO TN�IMN - ISh� OK IUU tkkl G `.Ltl tOYI M.Fi(fl$ Prmtedf mTOPGI(S�2DPl Naifotmt OecereoM F3okm+es(wxw-towmm) µf Figure 1 tti Location Map li