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centralize sampling points to a single location. Also, if needed, it would provide an additional pond <br />for settlement or treatment if water from SDH#2 were of poor quality. Pipes were laid on the ground <br />with positive flow towards the SDH#3 pond. At the road crossing, for the line coming from the <br />SDH#2 pond, an 8" culvert was installed for the 6" line to pass through. The pipe used was a 6" <br />aluminum pipe. It carried discharge from the SDH#2 dewatering hole, either directly or from the <br />lower pond discharge pipe, to the process pond located at the SDH#3 site. No water discharge <br />through any sump dewatering hole has taken place since the mine fire of January 31, 1996. <br />SDH#3 and SDH#5 pumped into the SDH#3 pond until the mine fire. The primary spillway for this <br />pond was sized to handle 307 gpm of mine discharge. See Map 140 for spillway rating. Therefore, <br />the inflow of these three sources did not exceed the 307-gpm capacity of that spillway. <br />Construction of the light use road to access B Seam ventilation shaft facilities required installing <br />culverts at three places along the access route. Two locations each have a 72-inch culvert; the third <br />location has a 30-inch culvert. Map 151 shows the locations and dimensions of the culverts <br />installed. The 25-year 24-hour runoff from the watershed above the proposed 30-inch culvert was <br />modeled using SEDCAD. These runoff volumes as well as the culvert sizing calculations for the 30- <br />inch culvert are included in Illustration 44. <br />From Illustration 10, the 25-year 24-hour peak runoff for the SGW-1 watershed, shown on Map 23, <br />• is 235 CFM. Using 235 CFM, the culvert sizing utility in SEDCAD was used to size the two culverts <br />where the access road crosses Scullion Gulch. These calculations demonstrate that a 72-inch <br />culvert is adequate to pass this flow. These calculations are also included in Illustration 44. <br />IV.J.1 Control Systems Control systems consists of the following: <br />a. Diversion dikes and ditches which reroute runoff from undisturbed areas around <br />disturbed areas into natural drainage systems. <br />b. Diversion ditches that collect runoff from disturbed areas and direct it into sedimentation <br />ponds. <br />c. Sedimentation ponds hold runoff from disturbed areas a required length of time <br />(theoretical detention time) to allow most of the solids to settle out and release the <br />supernatant back into the natural drainage system. <br />d. Rock check dams in areas otherwise hard to control. <br />e. Rip-rap lined ditches. <br />f. Use of a chemical flocculent such as Nalco Enact 7888 or equivalent for decreasing <br />settling time in sediment ponds. <br />In the "D" Portal Area, special washdown facilities in and around the preparation plant are provided <br />for areas where significant amounts of fine coal dust might accumulate. Water from plant <br />• r'L=nrnY cfLv: d ~ i iJc'L`li2% iV'-3d' <br />