GCI Pollyanna #2 Acid Mine Drainage Remediation Pr

The contractor shall construct a multi-stage passive water treatment system for an AMD seep with seasonal flow of 10 to 100 gallons per minute, including mobilization, clearing and grubbing, pond dewatering, earth fill/dirt work, 415-ft limestone aggregate channel with slope of 1.5% or less, four concrete flow spreaders, 150 ft x 90 ft flushable limestone bed with 3.5-ft of AASHTO #3 limestone, underdrain manifold, 10-inch dosing siphon and concrete vault, 190 ft x 75 ft settling/oxidation pond with outlet pipes and baffle curtains, 204-ft transfer channel, hybrid anaerobic/aerobic wetland with armored earthen baffle, riprap outlet channel, wetland seeding and planting, permanent erosion control, fencing and removal of equipment and tanks.