Laserfiche WebLink
~, <br />~/' Mr. ^cnry Danc~ • -2- • ,iu7q 22, 1981 <br />1, The operator may provide a scrlimcnt storngc volume based on 0.1•acre- <br />~feet of storage volume for each acre of distnrhnnce. (This option is not <br />available if the ratio of undistcuhrd land to disturber] land is high - deter- <br />mined on a case-by-case basis.) Se dimr_nt is to be removed at the 60o storage <br />level. <br />2. The operator may provide for a sediment storage volume of sufficient size <br />to contain three years of sediment accumulation. The formula to be used for <br />soil loss is left to the operator, but must he approved by the Division. ('Phc <br />Division accepts the U.S.L. E. method and Utah [9a ter Research Laboratory method, <br />but does not accept the P.S.I.II.C. mr_thod. Zf questions arise concerning thn_ <br />appropriateness of the method, contact the Division.) Sedimr_nt is to be removed <br />at the 60~ storage level. <br />3. In situations of exis tinr7 ponds or ponds 7ocatcd in arras of limited <br />space, the Division accepts a third option. 1'he opr. rn toe may provide for nny <br />reasonable sediment storage volume provided he~commits to removing the scrlimcnt <br />at such intervals so as to always provide a sediment storage volume of suf- <br />ficient size to contain the sediment generated from a ten-year event. For <br />_ example, the operator may provide for 6 months' sediment storage plus the <br />.. volume of sediment generated during a ten-year event. The operator would <br />theoretically clean the pond every six months so thnC there is always the <br />additional capacity to handle the sediment from n 10-yoar event if it should <br />occur before the pond was cleaned. (The opnrator would he required to calr•u7ate <br />the sediment generated from a 10-year event using an applicable method such <br />as M.U.S.L.E.) <br />The rationale for. requiring three years of scdimr•nt s <br />fact that l.he 10-year design storm event may generate <br />worth of sediment. If the pond was designed for only <br />storage and a 10-year event occured, the se dime_nt may <br />storage capacity of the pond. This would result in a <br />clogging of the dewatering device. <br />`_n ra qe is bascrl on the <br />more than a ycar~' <br />12 moo tl+s of sed.i meat <br />exceed the sediment <br />reduced pond capacity and <br />If you have any questions concerning our policy, would like assistance, or <br />would like to propose some alternatives, please contact me and we will discuss <br />this issue. <br />Sincerel ~-~~`--_ -~~~~' <br />i' <br />~ /. <br />Robert. r„ T,irld.7.e <br />Reclamation Speciniist <br />RGL/mmt <br />