Cooperative Agreement S23AC00100

ABANDONED MINE DRAINAGE (AMD) FROM THE OTTO COLLIERY AIRSHAFT DISCHARGE (OTTO DISCHARGE) IS ONE OF THE LARGESTSOURCES IN THE SCHUYLKILL RIVER WATERSHED. THE DISCHARGE CONTRIBUTES THE MAJORITY OF STREAMFLOW TO THE MUDDYBRANCH AT THEIR CONFLUENCE. THE MUDDY BRACH FLOWS FROM THE WESTERN BOUNDARY OF THE WATERSHED TO THE WEST WESTBRANCH OF THE SCHUYLKILL RIVER WHICH THEN JOINS THE WEST BRANCH SCHUYLKILL RIVER. BECAUSE OF METAL LOADING FROMTHE OTTO DISCHARGE AND OTHER AMD SOURCES, THE ENTIRE WEST BRANCH OF THE SCHUYLKILL RIVER IS DESIGNATED IMPAIREDON THE PENNSYLVANIA DEPARTMENT OF ENVIRONMENTAL PROTECTIONS 303(D) LIST OF IMPAIRED WATERWAYS. AN ASSESSMENT,COMPLETED IN 2000, THAT FOCUSED ON NONPOINT SOURCE POLLUTION IN THE UPPER SCHUYLKILL WATERSHED, RANKED THE OTTODISCHARGE AS ONE OF THE MOST SEVERE IN THE WATERSHED DUE TO ITS HIGH FLOW AND IRON CONCENTRATIONS AND RECOMMENDEDTHAT ITS REMEDIATION BE GIVEN HIGH PRIORITY.IN SEPTEMBER 2005, AN AMD TREATMENT SYSTEM WAS COMPLETED NEAR THE DISCHARGE LOCATION ADJACENT TO THE COMMUNITYBALLFIELD IN THE VILLAGE OF BRANCHDALE. THIS SYSTEM CONSISTS OF A DIVERSION STRUCTURE, SMALL AERATED CHANNEL,OXIDATION POND, TWO AEROBIC WETLAND CELLS, AND AN OXIC LIMESTONE DRAIN. THIS PROJECT WAS FUNDED BY A US EPA 319GRANT AS AN EARLY ATTEMPT AT AMD REMEDIATION.THIS SYSTEM HAS NOW BEEN IN OPERATION FOR APPROXIMATELY 11 YEARS AND A COMBINATION OF VEGETATIVE GROWTH AND IRONSEDIMENT HAS CAUSED THE AEROBIC WETLAND CELLS TO REACH THEIR CAPACITY. THIS SEDIMENT AND GROWTH IS CAUSING SOMEOVERFLOW IN UNINTENDED AREAS WHICH COULD ULTIMATELY LEAD TO A FAILURE OF A POND BERM IF THIS IS NOT RESOLVED.CLEANING OF THE SYSTEM WILL BE THE FIRST PRIORITY OF THIS CONSTRUCTION GRANT AND COULD BE COMPLETED AS A SEPARATECONTRACT PRIOR TO THE CONTRACT TO CONDUCT MORE EXTENSIVE REVISIONS TO THE SYSTEM.ORIGINALLY THE SYSTEM HAD AN INFLUENT IN-LINE HYDRAULIC AERATION SYSTEM PROPOSED WHICH CONSISTED OF VENTURINOZZLES BUT THIS DEVICE WAS ELIMINATED DUE TO OVERALL PROJECT COST BEFORE IT COULD BE CONSTRUCTED. THIS LEFT THESYSTEM WITH VERY LITTLE ABILITY FOR AERATION EVEN THOUGH THERE IS AN APPROXIMATE 20-FOOT GRADE DIFFERENCE FROMTHE DISCHARGE TO THE SEDIMENTATION POND. ALSO REMOVED FOR COST SAVINGS WAS A FLUSHING SYSTEM IN THE OXICLIMESTONE DRAIN, THIS LEAD TO THE CLOGGING OF THE DRAIN WITHIN THE FIRST FEW MONTHS OF OPERATION. THE OMISSIONOF THE INFLUENT AERATION HAD THE MOST IMPACT ON THE EFFECTIVENESS OF THIS TREATMENT SYSTEM AS REPORTED INPASSIVE AEROBIC TREATMENT OF NET-ALKALINE, IRON-LADEN DRAINAGE FROM A FLOODED UNDERGROUND ANTHRACITE MINE,PENNSYLVANIA, USA (CHARLES A. CRAVOTTA III, AUGUST 2007) DOCUMENTING THE EXISTING SYSTEM REMOVED LESS THAN 35 OF THE IRON, AND FAILED TO DRIVE OFF THE DISSOLVED CO2, AND INCREASE THE PH.THE PROPOSED PROJECT WILL BE TO CLEAN-OUT THE EXISTING SYSTEM OF ACCUMULATED IRON SEDIMENT AND VEGETATIVE MATTER,CONSTRUCT A MORE EFFECTIVE, AND MAINTENANCE FRIENDLY TREATMENT SYSTEM BASED ON PREVIOUS EXPERIENCE AT THIS SITE,SUCCESSFUL TREATMENT DEVICES AT OTHER TREATMENT LOCATIONS, AND THE CHEMICAL NEEDS OF THIS PARTICULAR DISCHARGE.THIS WILL BE ACHIEVED THROUGH THE MODIFICATION OF THE EXISTING POND LAYOUT, THE ADDITION OF CURB AERATORS BETWEENPONDS, THE ADDITION OF A DISTRIBUTION POND AND DRAIN PIPING, AND THE CONSTRUCTION OF CURB AERATORS IN THE STREAMCHANNEL ABOVE THE INFLUENT DIVERSION STRUCTURE. THEREFORE, THIS PROJECT WILL MORE EFFECTIVELY REDUCE AMDLOADINGS FROM THE OTTO DISCHARGE TO THE MUDDY BRANCH BY USING MORE EFFECTIVE AERATION DEVICES SETTLING FOR THISAMD TREATMENT SYSTEM.