SITE INFORMATION AND CORRESPONDENCE

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CH2MHILL SAC Tel 916-286-0295 Fax 916.614-3615 To: Orville Hrabe From: Christopher Regilski Company: WDC Date: October 27, 2009 Fax No.: 530-662-8052 Total Pages: 3 Voice No.: 800-873-3073 Message: Orville, CH2M HILL is interested in obtaining an updated quote for the subsurface investigation for a new pipeline project in Tracy, CA. The original quote request was dated June 22, 2009. The site is located to the north of the City of Tracy and 1-205 as shown in the attached Figure 1. The investigation is planned to start on November 16th. The investigation involves the drilling and sampling of eleven (11) borings to the following depths: B-1, B-3, B-6, & B-7: 25 feet using hollow stem auger B-2 & B-8: 40 feet using hollow stem auger or mud-rotary(price based on mud-rotary) B-11: 45 feet using mud rotary B-4, B-5, B-9, & B-10: 60 feet using mud rotary For a total of 465 lineal feet of proposed drilling. Soil samples would be obtained at 5-foot intervals(2.5', 7.5', 12.5',etc). Sampling requirements will be standard geotechnical procedure, driving unlined split spoon samplers 18 inches with an automatic-trip hammer and recording the blow counts for each 6-inch interval. Where appropriate, Shelby tube samples will be obtained. If the fine-grained materials are too hard to permit Shelby tube samples, a 3.0-inch split-barrel sampler will be driven, immediately followed by an SPT-sampler below.Assume driller is to supply 20 Shelby tubes and 280 brass liners for pricing purposes. Subsurface conditions will be logged by a CH2M HILL representative. Drill cuttings from the borings can be spread at the site and it is assumed that no hazardous materials are present.Water will be available at a hydrant at the Tracy WWTP. All borings will be grouted with cement-bentonite grout per San Joaquin county Health Department requirements(with the exception of the borings discussed below).All backfilled borings will be subject to County inspection and costs should include stated time related to County grout inspection. Borings B-2, B-4, and W8 will be completed as 6-inch PVC monitoring wells with 8-inch diameter sand pack (may require overdrilling to enlarge borehole), up to 40 feet of 40 slot well screen per well, and bentonite well seal in accordance with County and State requirements. Driller to provide and install locking steel surface completions with concrete seal. Develop wells using bailing and swabbing techniques and/or overpumping with a submersible pump until the development water is clear.