Laserfiche WebLink
• In order to bring ditch designs into compliance with Federal regulatory <br />standards, ditch designs for the permanent refuse stockpile were reviewed, <br />modified and the associated ditches were reconstructed in 1989 to provide <br />adequate capacity to pass peak flows from the 100-year, 24-hour design <br />storm event. Ditch design included calculation of flow velocities during <br />the design event. If calculated velocities for any ditch segment exceeded <br />5 feet per second, riprap was sized and installed to protect the ditch <br />channel from erosion. <br />As refuse placement operations progress, EFCI will remove topsoil and <br />vegetative materials from the foundation zone ahead of the advancing <br />stockpile face. A tracked dozer will be utilized to clear large trees, <br />shrubs, boulders, logs and other deleterious materials from the foundation <br />area. EFCI will then remove and stockpile any recoverable topsoil and <br />vegetative materials utilizing either tractor scrapers or wheel loaders <br />and trucks. Topsoil removal will be sequenced so that a minimum 15 foot <br />buffer is maintained between the toe of the advancing stockpile and <br />undisturbed areas at all times. <br />To the extent possible, EFCI will directly replace freshly stripped <br />topsoil on regraded stockpile areas. This approach offers significant <br />benefits, effectively maintaining biological and chemical characteristics <br />of topsoil materials and encouraging natural re-invasion of native <br />vegetation through seed, roots and other plant propagules contained in <br />direct replacement topsoil. If sufficient regraded areas are not <br />available, newly stripped topsoil will be placed in short term stockpiles <br />for use in later reclamation. Any necessary short term stockpiles will <br />be located either on the refuse stockpile immediately behind the advancing <br />crest (Stockpile M-4) or in an area to the southwest of the completed <br />refuse stockpile (Stockpile M-5) and will be located and placed to <br />minimize potential for wind or water erosion or contamination of topsoil <br />resources. <br />• in order to provide for effettive drainage fram the statkpiie foundation, <br />Dorchester constructed a rock subdrain extending under the existing refuse <br />pile. As a result of concerns relative to the importance of effective <br />2.05.3-34 <br />