S. DeGoede Well (COW)

1/06 Technical Provisions TP 31.0 Individual Water Well Drilling Page 1 TECHNICAL PROVISION 31.0 INDIVIDUAL WATER WELL DRILLING 31.01 Scope The work covered by this section includes the furnishing of all plant, labor, transportation, tools, equipment and materials, and performing all operations in connection with the drilling, casing, screening, developing, and testing of individual water wells for home sites, and site cleanup, all in accordance with these specifications and applicable drawings. 31.02 General The Contractor shall drill cased wells at the locations indicated on the location plans. The well(s) shall be drilled no deeper than the depth directed by the Project Manager for that particular site without authorization from the Project Manager or Contracting Officer. If a satisfactory yield is obtained at a lesser depth, the drilling shall be terminated and the well developed at that depth. Wells shall be constructed to meet or exceed the Washington State Administrative Code (WAC) Standards for Construction and Maintenance of Wells. 31.03 Drilling Rig The drilling shall be accomplished by a cable tool, mud rotary, or air rotary drilling machine. Equipment used shall be in good repair and capable of drilling to a depth of 400 feet. 31.04 Materials and Equipment 31.04.01 Casing Casing used as a permanent part of the well structure shall be seamless or electric resistance welded steel pipe conforming to ASTM A53, Type E or S, Grade B, black wall, meeting the following specifications. It shall be of standard brand manufacture and have the brand name clearly printed on each length of pipe. Manufacturer rejected pipe shall not be used. Nominal size: 6-inches Outside diameter: 6.625-inches Wall Thickness: 0.250-inches Weight per Foot: 17.01-pounds 31.04.02 Drive Shoes If permanent steel casing is to be installed by driving methods the use of drive shoes is required. The type and weight of drive shoes shall be determined by the Contractor and approved by the Project Manager. The use of drive shoes is considered incidental to the drilling and casing of the well, and no additional payment will be allowed. -- 1 of 9 -- 1/06 Technical Provisions TP 31.0 Individual Water Well Drilling Page 2 31.04.03 Screen Design: Continuous slot; outer windings welded to longitudinal bars. Materials: ANSI Type 304 stainless steel Length: As directed by the Project Manager. Fittings: The type of bottom fitting depends on method of screen installation. The fitting must close off the bottom of the screen and shall be of mild steel. The packer shall be self-sealing neoprene with a mild steel or stainless steel collar. The contractor shall also use a 5-foot minimum riser pipe on the top of the screen. A 2- foot extension pipe shall be attached to the bottom of the screen. Slot size: The screen shall be sized to permit the maximum practical sand-free yield after development. The diameter shall be as stated in the Bid Schedule. The slot size shall be based on a sieve analysis of the formation and approved by the Project Engineer prior to installation. The length of the screen shall be dependent upon the length and type of aquifer encountered. Length shall limit the entrance velocity to a maximum of 0.1 feet per second. The screen opening size, length, and diameter shall be approved by the Project Manager before ordering or placing the screen. Manufacturer: Johnson Screens, Alloy Machine Works, or approved equal. 31.04.04 Liner Pipe All liner pipe shall be of steel or PVC, and must be in new, or like new condition. Steel liner pipe shall meet or exceed the minimum ASTM A-53 A or B specification for steel pipe. PVC liner pipe must conform to ANSI/ASTM F 480-81, or the most recent version; shall be of type 1220 or 1120, SDR 21 (Class 200) or higher pressure rating; and must conform to National Sanitation Foundation (NSF) Standard 14-84, or the most recent version. PVC liner joints must be watertight. 31.04.05 Sanitary Grout Cement Grout: Cement conforming to ASTM C-150, Type 1 or Type 3 (high early strength) with the least quantity of water -- not over 6 gallons per cubic foot of cement -- required to give a mixture of such consistency that it can be forced through the grout (tremie) pipe. Bentonite clay may be added in amounts from 3 to 5 pounds per cubic foot of cement to reduce shrinkage and improve fluidity. In -- 2 of 9 -- 1/06 Technical Provisions TP 31.0 Individual Water Well Drilling Page 3 this case up to 8 gallons of water per cubic foot of cement may be used with the approval of the Project Manager. Wet Bentonite: Bentonite grout shall be Baroid Aquagel or equal mixed 75 pounds per 100 gallons of water. This type of bentonite shall not be applied dry. Dry Grout: Dry grout shall be granular or pelletized dry bentonite. 31.05 Drilling Drilling shall commence at the location as indicated on the site drawings or as staked by the Project Manager. The Contractor shall begin drilling with an oversize bit for the first 18- feet or as directed by the Project Manager. This oversize hole shall be used to allow a 2-inch minimum grout seal to be positioned around the casing. Drilling shall continue below this point with a bit large enough to install the casing. In unconsolidated formations, the Contractor shall drive the casing closely to the drill bit location with a drive block to prevent caving. Properly sized drive shoes shall be attached to the bottom of the casing to prevent possible damage. Drilling shall be terminated after an adequate aquifer is encountered. The determination to stop drilling when an adequate aquifer is encountered shall be made by the Contractor and confirmed by the Project Manager. The determination to stop drilling when no aquifer is encountered shall be made by the Project Manager. The Project Manager may require the Contractor to perform a yield test by using a bailer in the encountered aquifer. No additional payment shall be made for this check. 31.0…