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The location of the proposed drill holes and drill pad shown on Map 24, Sheet 2 of 2, was transcribed to Map 17. This location is on Coutis fine sandy loam soils as keyed (34-E) to Exhibit 16. This soil generally forms on mountain side slopes of 12 to 25 degrees. The hydrologic soil group of Coutis soil is B (SCS, 1983, Soils of Colorado). Thus the soil type of Coutis B is validated for both demonstrations. A CN of 86 is appropriate to a newly graded azea of hydrologic soil group B soils. This value is more conservative than gravel surfaces (in the event that the pad is graveled). Thus a value of 86 is validated for both demonstrations. The volume of runoff from areas within the contairunent berm is demonstrated as 0.07 acre feet This value appeazs on page 6 (subwatershed hydrology detail) and is summazize on page 4 (structure summary) of the pad SAE demonstration. This value is the predicted runoff from 1.2 acres of watershed, at a slope of 12%, and a CN 86 value soil. The time of concentration determined on page 6 is conservative. These values are ok. The berm design conclusion that 0.12 acre feet of runoff could be stored behind a 100-foot reach of the berm on contour is ok (validated by independent calculation). The runoff from areas within the berm perimeter could be stored behind the berm as presented. However, impact of the runoff storage on the mud pits (operational concern) is not addressed. The grass filter SAE demonstration appears to be deficient. Erosional aspects of the demonstration for any section of the berm outslope are adequate. The demonstration is that runoff from the berm outslopes is distributed across the lower 100-foot reach of the berm (on contour, the width of the grass filter being 100 feet). Runoff from the berm outslope on the uphill and sides of the containment area would collect in ditch flow and discharge as point dischazges on either side. The demonstration does not address the treatment of these point dischazges. In conjunction with this problem, upland runoff is to be diverted around the site by the berm (see Introduction). However, runoff from disturbed azeas (the outslope of the berm) would be mixed with this flow. Thus the combined flows (point dischazges) need to be addressed. Management of ditch flow across the access road through the berm is not described. The area immediately downslope of the disturbed site is represented as an undisturbed fescue grass area. The grass is described as 4 inches tall, with an 0.67-inch spacing between stems or basal clusters (impedance to flow) (see page 6 of the grass filter demonstration). Ground cover should be at least 50% for a grass filter to be effective (HDI, 1991). These values were not validated as validation would require a site visit. The stiffness factor for fescue is commonly taken as 2, not 20 as used in the demonstration (page 6). The demonstration is that runoff from the disturbed slopes of the berm would enter the grass filter with a peak settleable concentration of 44.35 mUl (see page 7 and 4), and leave the filter with a concentration of 0.00. Corrected for a stiffness of 2 in-lieu-of 20, the demonstration would apply to the 100-foot reach of the berm at the lower side of the site. It does not address the ditch flows and other spatial issues. Page 2 of 3 pages