2012-03-07_HYDROLOGY - C1981033 - Laserfiche WebLink

Home Browse Search

Sandra Brown March 7, 2012 Page 7 Macromolecule Laboratory for analysis for possible humic acids and to the CDPHE laboratory for total organic carbon analysis. The CSU Macromolecule lab was unable to quantify the substance(s) in the samples. The CDPHE lab, however, was able to analyze their samples. The CDPHE lab determined that the sample from the "Edwards Portal spring" contained 65 mg/1 of total organic carbon (TOC). As noted above, these organics are not volatile or semivolatile organics (pesticides, herbicides, disinfectant byproducts, benzenes, cresols, etc., which are lower molecular weight compounds). Although there is no direct evidence that these substances are humic acids, the TOC levels are one more piece of anecdotal evidence that they do exist in the "Edwards Portal spring ". At any rate, it can be said with a fair amount of confidence, that the organic carbon present in the spring is not hazardous and based on the upstream and downstream samples; the Edwards Portal spring is not contributing TOC to the river. The color of the water is caused by organics (likely humic acid) that are not pollutants and not considered hazardous. Humic acid is a principal component of humic substances, which are the major organic constituents of soil (humus), peat, coal and many upland streams, dystrophic lakes, and ocean water. It is produced by biodegradation of dead organic matter. Dystrophic lake refers to lakes with brown- or tea - colored waters, the color being the result of high concentrations of humic substances and organic acids suspended in the water. The hillside seep above the Bear Mine yard exhibits this reddish -brown or tea colored water. In 2008 BCC sent a letter to Water Quality Control Division (WQCD) requesting full or partial relief from liability for the seepage water. BCC provided a comparison of Pond Outflow versus Hillside Seep Comparison with request (see Attachment 3). The WQCD mostly denied the amended request. WQCD stated that the data provided by the permittee showed that this water does not consistently meet the limitations for total iron without the settling pond, and therefore they do not approve the direct discharge of this source to the river without treatment. WQCD did amend the permit to reduce the monitoring frequency for WET testing to semi - annually. The data submitted to WQCD in 2008 did show concentrations of iron in the seep greater than the permit limitation of 3000 ug/1 as a thirty day average and 6000 ug/1 as a daily maximum and therefore WQCD concluded that this discharge cannot be released from the permit based on quality. In 2011 BCC indicated to the Division that the quarterly monitoring of the seep showed reduced levels of iron over the last few years. In August 2011, BCC assembled and submitted data on the hillside spring that shows one year of compliance with the CDPS iron standard prior to treatment in the pond. The data are provided as the first item in Attachment 4. As part of this review the Division requested that BCC provide all data (field and laboratory) from the hillside seep sampling for the last four years 2008 through 2011. These data were provided and are summarized in Attachment 4. Analytical laboratory reports are available. Starting in March 2008 there has been only one instance when the iron exceeded the CDPS standard. This occurred in the fourth quarter of 2010 where a value of 3.1 mg/1 total iron was detected in a grab sample from the hillside seep. All other values taken monthly since March 2008 were below the CDPS discharge limit of 3000 ug/1 daily average and 6000 ug/1 daily maximum for total iron. No other discharge limitations have been exceeded since 2008.