Wood ash experiments: South Bay 2000

Abstract

The experimental use of wood ash produced by the Ear Fall saw mill as an amendment of tailings/rock mixtures along the Backfill raise ditch and on Mill pond was tested during growing season 2000. Very good growth was obtained with the addition of the material on the seeded plots. It's use as part of reclamation efforts appears of acid mine drainage sites appears dictated given the need for reusing/recycling wastes rather than landfill. With this philosophy in mind the material was also used to test its effects of both Boomerang and Mud Lake. We have found that in the laboratory, in test containers and in enclosures in the lakes themselves, the wood ash has had a beneficial effect on lake water chemistry. The wood ash has increased PU and decreased metal acidity. However as a water treatment the application levels are relatively high as the particles sink quickly to the sediment. Its neutralization capacity in the sediments is being tested in lake. Based on short term experiments we would probably need to add between 430 to 860 tones of wood waste to Boomerang Lake, and/or additional 215 tones to Mud Lake to reach a water pH of 4.0. The long-term neutralization to the sediment is underdetermined yet. At these application levels we were concerned about effects on sediment and in turn the lake biota, especially the moss cover on the lake bottom. However at the lower end of these application rates, the plants appeared normal. At high application rates, the plants were detrimentally affected. Finally, the concentration of metals added by the wood waste is negligible compared to the metal content of both lakes. The test in Boomerang Lake enclosures to use the wood-ash as sediment amendment are ongoing and we hope we obtain permission to continue.