HYDRO29779 - Laserfiche WebLink

Home Browse Search

evident in the water quality data presented above. If there was AMD, the sulfate concentration would be in the parts-per-thousand, rather than the parts-per-million (ppm or mg/L) as observed. Additionally, there would be metal concentrations in the hundreds of ppm rather than the low (1-4) ppm and the parts-per-billion (ppb or ug/L) seen in the data. There would also (most likely) be the telltale "yellow-boy", which is the iron staining of the rocks that is observed with AMD. There would be no vegetation in the area either, as it would not be able to withstand the acidic conditions and/or the extremely high metals concentrations. Humic acids are long carbon chain molecules with atomic weights ranging from approximately 700 Daltons up to approximately 100,000 Daltons~ (a Dalton is one atomic mass unit or AMU, corresponding to the weight of one proton or one neutron). Among other things, they aze used as an amendment for agricultural soils2, for cleaning up waste streams for superfund sites3 and are a major source of buffering capacity for lakes and streams3. While humic acids and their uses have been and continue to be extensively studied, it has been more from the standpoint of "how can they be used" and "what benefits do they impart". Their structures and overall chemistries are very complex and, as such, very little information in those areas exists. The reason that there is a strong possibility that the coloration from the Edwards Mine Portal spring is from humic acids lies in their origins and the nature of these molecules and the circumstantial evidence from the available literature. Humic acids are precursors of petroleum and coal4 and are found and mined in areas that are either used for or associated with coal mining. Finally, "dissolved humic substances, the main constituents of the dissolved organic carbon pool in surface water... commonly impart ayellowish- brown color to the water systemi5. The basic process for the formation of humic acid is that vegetation was laid down during the Carboniferous Period and subsequently underwent heating and compaction. This compaction squeezed out the organic acids present in the vegetation and they formed a pool on the top of the bed. Over time the pool dried and aged and eventually formed Leonardite shaleb (this was happening simultaneously with the compaction of the lower organic layer which formed the coal reserves). It is the final statements of the above two paragraphs that make the most compelling case for the Edwards Mine Portal spring. The fact that the water coming from the spring is a yellowish-brown and the fact that the main source of humic acids is from Leonardite shale is very compelling. A review of the geology portion of the Bear No. 3 Mine permit (Section 2.04.6, pages 2.04-12 through 2.04-29) states that both the overburden and the underburden for the B and C seams is shale. The permit also states that portions of both the floors and the roofs of the mine were exposed at various times during mining, as they were determined to be of competent material. The drill logs confirrn this and also show layers of interbedded shale throughout. Since the Leonardite shale is consistent with other shales, it would have only been identified by the driller as "shale". Also, given that Leonardite shale is formed in conjunction with coal formation, there is a very strong