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Zone 7 Water Agency – Tennis Park Test Well Summary <br />and Production Well Design Recommendations <br /> <br /> <br /> 7 Zone 7 Water Agency <br />December 2025 <br /> <br />test well drilling and production well drilling. The amount of project yield above the baseline amount <br />allocated to City of Pleasanton (and hence, available to Zone 7) cannot be confirmed until production <br />wells are installed and tested. <br />3. PRODUCTION WELL DESIGN RECOMMENDATIONS <br />Based on our investigation of the Tennis Park site, the testing of the Tennis Park Test Well, and our well <br />yield and drawdown analysis, LSCE believes that a well constructed at the Tennis Park site could yield <br />between 3,400 and 5,100 gpm of water that would meet all current Title 22 Drinking Water Standards <br />without treatment. Utilizing the information gathered as part of the site investigation, well testing, and <br />analysis, LSCE has prepared the following design recommendations for a community supply well to be <br />constructed at Tennis Park. <br />Our proposed well design meets the requirements of the Department of Water Resources Water Well <br />Standards, Bulletin 74-81, 74-90; State Water Resources Control Board, Division of Drinking Water (DDW), <br />and accepted water well design standards. Figure 6 depicts the proposed well design. The well is designed <br />to accommodate submersible pumping equipment that could pump up to 5,100 gpm. Collapse pressures <br />for each casing type and thickness were calculated to ensure each can resist the hydrostatic pressures <br />developed during sanitary and annular seal placement. Each of the well design elements is discussed <br />below. <br />Conductor Casing / Sanitary Seal – The conductor casing will stabilize the upper portions of the borehole <br />during drilling and well construction, while ensuring that requirements for sanitary seal are met. The <br />conductor casing shall be installed in a 60-inch diameter borehole and cemented in place to a depth of 70 <br />feet bgs. At a depth of 70 feet, the conductor will terminate in a clay layer. The conductor casing shall be <br />fabricated of a 40-inch O.D. by 1/2-inch wall ASTM A-139 grade B steel. <br />Production Borehole – The production borehole shall be drilled using the reverse circulation drilling <br />method. The final borehole diameter shall be 36 inches to a depth of 780 feet bgs. <br />Blank Well Casing – Stainless steel was selected for the blank casing. Stainless steel will provide superior <br />corrosion resistance and well longevity while meeting DDW standards for NSF 60 certification. The blank <br />well casing shall be 22-inch I.D. by 3/8-inch wall ASTM A-778 Type 304L stainless steel. <br />Well Screen – Stainless steel, louvered well screen was selected to maximize screen open area and <br />efficiency, and for compatibility with the blank well casing. The 22-inch I.D. well screen will be constructed <br />ASTM A-778, Type 304L stainless steel with a slot size of 0.080-inch. At a design capacity of 5,100 gpm, <br />the screen will have a theoretical inlet velocity of 0.0377 feet/second. <br />Accessory Pipes - A 2-foot-long, stainless steel sounding port shall be installed on the well casing from <br />197 to 199 feet bgs. A 2-inch, Schedule 40, Type 304L stainless steel sounding tube shall be connected to <br />the sounding port and installed to a depth of 197 feet bgs. A 3-inch, Schedule 40, BSP gravel fill tube shall <br />be installed to a depth of 185 feet bgs.