Laserfiche WebLink
Shale, which has naturally elevated concentrations of selenium and <br />dissolved solids. NPDES Sites did not flow this year, so they are not <br />responsible for the stream selenium exceedances. <br />HGT runs mercury tests with a Method Detection Limit (MDL) of 0.2 (or <br />sometimes 0.4) ug/1. All test values this year were less than the MDL. <br />The aquatic life ammonia standard is dependent on pH and temperature. <br />The detection limit for ammonia is 0.05 mg/1. All values above detection <br />limit are compared to table standards found on this website, page 87: <br />http://www.epa.gov/wa-lersci.ence/criteria/ammonia/99update.pdf <br />No ammonia excursions occurred this year. <br />The sulfide values provided in Table 4 differ from the values reported <br />in Appendix B. The sulfide data presented in Appendix B are the total of <br />both the ionized (S-) and un -ionized (HzS) forms of hydrogen sulfide. <br />The un -ionized form is the potentially toxic form, and is what the CDPHE <br />water quality standard is based upon. A procedure for calculating the <br />un -ionized form may be found on the website: <br />http://www.mullalyengineering.con..au/images/product/file/Problem of Hydr <br />ogen Sulphide in Sewers.pdf page 5, Table 1. The results of those <br />calculations are presented in Table 4 of this AHR. This year, no sulfide <br />excursions occurred. <br />Ground Water <br />Ground water quality reports for this year are presented in Appendix B. <br />Data provided includes a water quality report for this year, a water <br />level report, sampling remarks and a listing of a regression plot of <br />historic TDS data. <br />Well HGDAL3 is downgradient of the Loadout. It was drilled in 1993. It <br />displays a decreasing TDS trend; however, the peak TDS value occurred in <br />June 1997. <br />