Laserfiche WebLink
..W ■ <br />recognized that manual discharges must meet the primary effluent limitations for Outfall 001 found <br />• in Colorado Discharge Permit #CO- 0038024. <br />In accordance with Rule 4.05.2(4) runoff from the haul and access roads will not pass through <br />sedimentation ponds unless within the portal or refuse disposal areas. Check dams to slow the <br />velocity of water collected in ditches alongside the roads were installed during the construction <br />phase. All ditches have been revegetated and check dams inside ditches are no longer used. <br />Water relief bars divert water out of the ditches into natural drainages at appropriate points. <br />IV.J.2 Installation Diversion ditches and dikes which intercept runoff from undisturbed areas and <br />direct it away from disturbed areas and into the natural drainage system were installed prior to <br />grading activities in an area. Ditches within disturbed areas were constructed during grading <br />activities in an area. Sediment ponds in the Refuse Disposal area were installed prior to grading <br />activities. <br />The sediment pond for the D Portal Area could not be constructed prior to grading activities since it <br />was located on top of the Scullion Gulch stream diversion pipe and it could not collect runoff from all <br />of the "D" Portal Area until most of the 2,750- foot -long diversion pipe was in place. Construction of <br />the Scullion Gulch diversion had to be completed concurrently with the "D" Portal Area grading since <br />it was covered with fill material cut from the bench areas above the bottom of the Gulch. <br />Construction of the Scullion Gulch diversion pipe started at the lower end of the "D" Portal Area. <br />• Construction of the Portal Area sediment pond began immediately after the Scullion Gulch diversion <br />pipe installation was completed above the pond location. The installation of the diversion and <br />sediment pond was completed within 6 months after construction work began. <br />When construction began, it was determined that suitable clay materials for construction of the <br />Portal Area sediment pond could not be found in the Portal Area, suitable clay material was <br />imported from areas to be disturbed in the Refuse Disposal Area. All material borrowed from the <br />Refuse Area was replaced with material from the "D" Portal Area that is suitable for use as nontoxic <br />fill material. <br />To control sediment from the disturbed "D" Portal Area which might have been carried down <br />Scullion Gulch during the first summer of construction, a series of three loose rock check dams were <br />constructed in the Scullion Gulch stream bed below the sediment pond location. The dams are <br />approximately 100 feet apart and the spillway bottoms are approximately two feet high above the <br />streambed. These rock check dams are shown on Map 32. <br />• Technical Revision #68 (01/2011) IV -4 0 <br />