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<br />Impacts to this area from mining and to the Bolton Draw AVF <br />will be monitored at Well 2, although monitoring parameters <br />should be changed to reflect the stipulation under the Ground- <br />water section of this TEA. It is vital that monitoring be used <br />to detect changes in the alluvial water table as this might indi- <br />cate that surface water is being degraded, particularly as <br />regards the increase in salt loading and contamination from high <br />SAR hazards present at the mine site. Water retention from sedi- <br />ment ponds, however, should have minimal impact to Bolton Draw <br />water yields as flow from only 396 acres will be impounded. How- <br />ever, a more severe impact to the alluvium along North Fork down- <br />stream of the permit area could be realized by water impoundment <br />since it is part of a much smaller watershed. Direct impacts to <br />the alluvial water table should be minimal since none of the <br />Bolton Draw alluvium will be physically disrupted by mining. <br />Dewatering should not occur because the steeply-dipping strata <br />underlying the alluvium do not appear to be hydraulically <br />connected with the alluvium and mining operations are up-dip of <br />alluvial deposits. <br />Bolton Draw <br />Based primarily on results of previous investigations con- <br />ducted by the OSM during the TEA stage of the Canadian Strip Mine <br />re-opening (July, 1980) and by Kerr Coal Company for the Marr <br />Mine permit application (Marr Strip Mine TEA-January, 1981), it <br />must be concluded that a segment of Bolton Draw as shown on <br />Exhibit 2, Addendum I, is determined to be an alluvial valley <br />floor. Bolton Draw exhibits these characteristics indicative of <br />an AVF: extensive alluvium and flood plain deposits, significant <br />subirrigation, water storage and diversion capacities, historical <br />flood irrigation practices, and some similarity to regional flood <br />irrigation practices. <br />The applicant has provided arguments for disputing the <br />possibility that Bolton Draw is potentially flood irrigable <br />(p.l1-114, Val. 1 and pp.9-12, Addendum I of the permit applica- <br />_gg_ <br />