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evidence that values used were appropriate. In addition, the State Engineer notes that <br /> shales of this type are usually considered hydraulic seals. <br /> Certain parties commented with respect to whether the proposed rules utilized <br /> appropriate values for the distance from the pumping well to the nearest potential <br /> point at which depletions could occur. Specifically, these parties questioned whether <br /> the rules should consider all intermittent and ephemeral streams, as well as all <br /> perennial streams, as points of depletion to a"natural stream" for purposes of the <br /> definition of nontributary water at C.R.S. § 37-90-103(10.5). The State Engineer <br /> does not need to reach this issue with respect to these rules. In his analysis, Mr. Witt <br /> relied upon a Glover-Balmer model to calculate an offset from the boundaries of the <br /> proposed designated nontributary area. Pursuant to this analysis, the proposed area is <br /> demonstrated nontributary if there are no potential points of depletions to a natural <br /> stream within the calculated offset area. In this instance, there were no perennial, <br /> intermittent, or ephemeral streams located within the offset area. Accordingly, the <br /> analysis convincingly demonstrated the proposed area to be nontributary regardless of <br /> whether intermittent and ephemeral streams are considered points of depletion to a <br /> "natural stream." <br /> The State Engineer's finding is also based upon testimonial evidence from Duane <br /> Zavadil, M.S., Laura Mauro, E.I.T., and Mr. Witt demonstrating that the delineated <br /> area is geologically disconnected from the surface water system by a lithologic <br /> discontinuity or structural separation. The State Engineer finds that the lack of known <br /> Desert Creek Member outcrops in Colorado, as well as water chemistry data showing <br /> produced water from the Desert Creek Member to have a total dissolved solids <br /> concentration more than 7 times greater than sea water,provides clear and convincing <br /> geologic evidence that groundwater within the hydrocarbon reservoir rocks of the Desert <br /> Creek Member of the Paradox Formation are disconnected from Colorado's surface water <br /> system. The State Engineer similarly finds that the extremely low permeability of the <br /> Hovenweep Shale and Gothic Shale Members, the fact that these Members naturally <br /> contain little, if any, free water, and the greater than 4-mile separation from age <br /> equivalent rocks outside the delineated area provide clear and convincing geologic <br /> evidence that ground water within these formations is nontributary. <br /> In summary, the inputs to the Glover-Balmer and geologic analyses are appropriate <br /> and based upon site specific data. All inputs to the analyses are within the expected <br /> range. No aspects of the analyses are indicative of errors that would cause <br /> meaningful error in the proposed lines derived from the model delineating the <br /> division between tributary and nontributary ground water. Accordingly, the State <br /> Engineer finds the geologic and Glover-Balmer analyses provide clear and convincing <br /> evidence in support of the State Engineer's adoption of rules identifying water <br /> withdrawn from the Hovenweep Shale, Gothic Shale, and Desert Creek Members of <br /> the Paradox Formation within the delineated area of the Paradox Basin to be <br /> Produced Nontributary Ground Water Rules 2 CCR 402-17, Statement of Basis and Purpose <br /> -18- <br />