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~ iiiiiiiiiiiuiiiiii <br />Pusive Mine Dn inane trea[menr <br />An L[fettiva Lar Coat Al[erwtive <br />J. David Nolm, gupervisory Reclamation Specialist <br />Colorado Mined Land Rec lama[ion Division <br />Stott Jones, Mining Engineer <br />Snormua Cotl Caapany <br />Aba[nct <br />Introduction <br />Tro prototype Ptsaive Mine Drainage Tre a[ment Sye[ems have been designed and <br />cone[ rutted in Colorado. These projects have addressed acid mine drainage from <br />inactive tool nines. Metal removal for both systems is act omplieh ed usinR simulated <br />peat bogs composed of aphegnum moss and hypnum moss retained by loose rock check <br />dams. At id neutralization ie actompliahed acing crushed lime atone filled channe le. <br />Neat ralizec ion end ae ration are enhanced rich drop ac ructurea and racerfalla plsc ed <br />in the drainage thannel. Preliminary rater quality results ehor dramatic treatment <br />of [acts rich [he PNDT syet m. <br />This invest iRetion presents cost data <br />ty stems. Cost projections for periodi <br />with • suggested method for finant ing <br />first system installed ere presented. <br />Mine drainage treatment rya[ems are designed and <br />c on st rusted to neu[ralice ae idicy end remove <br />metals from mine rater. The term Passive Mine <br />Dra inege Treatment (PMDT) refers [o the range of <br />available techniques rh ich do no[ require con- <br />tinual electrical or Chemical inputs or frequent <br />maintenance opera[ ions. This type of system hee <br />been described by various ^uthors ^s • " low <br />tech or low coat/lw maintenance rys[em", <br />"biogeothemital system", or an "art if is itl vet <br />lands tretteent gstem". These techniques in- <br />clude the use of biological and organic media <br />normally found in natural vet lends (eg. aphegnum <br />moss, cattail[, rater hyacinth, peat, rood <br />chips) end inorganic xdia (eg. ceolite s, <br />glacial till, sterile tailings) to adeorb~ and <br />filcei out setals. Also included in PMDT sys- <br />tems are techniques [o oxygenate and aerate nine <br />drainage using uatades, reterfal L, gro ins and <br />gabions. Long term neat ra lica[ion of acidity is <br />provided rich limestone filled thannel• or bar- <br />riers. <br />At id mine drainage from hundreds o[ metal mines <br />and approx itmte ly 25 awl mince impacts end <br />degrades many of the vatereheds in Colorado. <br />Most of the drt fining abandoned mines in Colorado <br />discharge less than one hundred gallons per <br />minute. Rorever, even mush smaller discharges <br />can degrade the quality of relatively large <br />receiving streams. The presents of high tan- <br />centutions of toxic heavy meuL in [he ae dir <br />charges creates public health hoards and <br />serious enviro,sental problems. Most at id mine <br />draiwge sources Ire in relatively teaoce <br />area. Poor acceuabili[y. lark of eleccriul <br />porer and severe Tinter re other makes Tear round <br />operation and min[enance o[ Conventional [reec- <br />men[ rys[ema iryrae[iul ^[ abandoned mines in <br />Colorado. <br />for design and tons[ ruction of [he fro PMDT <br />t ma intenen~ ! require~.enca are provided along <br />maintenance costs. Perfoneence dace for the <br />Once the formation and discharge of acid mine <br />dta inege begins, [here •re no simple end per- <br />manent me one available to abate [he <br />problem.Aulkhead mine seals usually are not <br />feasible given the excenaive vertical ro rkings <br />in most me [al mines. Sealing such nines could <br />result in cecascrophit bulkhead failures due to <br />hydrostat is Dreseu Tee exerted upon the mine <br />seal. Bulkhead scale Could also promote the <br />formation o! multiple ner acid seeps in tones of <br />rtructural veakneu ed jatent to the mine. <br />Air seals at the portal rhith provide for con- <br />tinuous derater ing of [he mine are Renerally not <br />effective in completely eliminating all air <br />infil[rat ion to the mint. Therefore, [he Dro- <br />duttion of acid IDine drainage continues of i[ is <br />rele^sad from the drain in [he air seal. Such <br />se ale may result in incremental impravemencs co <br />mine rater quality, however. Air ae ale may be <br />toot eff<ttive components of some PXDT systems. <br />in moat cols, [restmen[ of the acid mine drain- <br />age is the only means of abating the problem. <br />The ton teD[ of passive mine drainage treatment <br />hat developed from the need for for Cost and for <br />to intenante ryatema, natural ob se rvationa in the <br />fieldl.~, experimental rorkl.~, and full <br />set le demonstret ion projecta5, 6, <br />This report presence detailed eoet data for two <br />P1mT systems now oDerat ing in Colorado. Syscen <br />per[ormence dace is presented for the first <br />iw ullation. Eoth systems were <onetncced ac <br />abandoned coal mince There acid mine drainage <br />we impost ing high qualiq receiving streams. <br />The fire[ system ws designed and cons[ Tuned b7 <br />the Colorado Mined Lend Reclamation Division <br />(CMLRD) at the Marshall • S Coal Mine nut <br />gould<r, Colorado. The second fins[ alla[ion vas <br />designed by [he ClfLRD end constructed by the <br />Snormau Coal Company e[ the Thompson • Z Cwl <br />