Laserfiche WebLink
Page 3 <br />9. Instream Numeric <br />Standards <br /> <br />CWQCC regulation <br />33.0 <br /> <br />Fish Creek: <br />Two PSCM monitoring sites exist within the Fish <br />Creek Drainage: The NPDES Pond 004 outfall and <br />Site SSC10. These sites discharge to Cow Camp <br />Creek which discharges into Fish creek. The <br />applicable stream segment is Segment 13g of the <br />Yampa River basin (New segment as of December <br />31, 2014). This reach is classified as agriculture, <br />aquatic life (Warm 1) and Recreation E. The <br />following exceedances were noted: <br /> SSC10 – Mercury, June and July 2016 <br /> <br />It is unclear if the Mercury standard was actually <br />exceeded. The Method Detection Limit (MDL) for <br />Mercury is .2 ug/l and the stream standard is .01 ug/l. <br />Given this, the MDL is higher than the standard. <br /> <br />According to the AHR, there is a temporary <br />modification (expired December 31, 2018) of the <br />Selenium standard as “current conditions”. <br />Therefore, the excursion of the Selenium standard is <br />not considered an exceedance. <br /> <br />Little Grassy Creek: <br />Two PSCM surface water monitoring sites exist <br />within the Little Grassy Creek drainage: The <br />NPDES Pond 002 outfall and SSLG5. SSLG5 drains <br />the upper portion of Little Grassy Creek which are <br />undisturbed by mining. Both sites discharge into <br />Grassy Creek which is on Segment 13i (Upper <br />Grassy Creek) of the Yampa River basin. This <br />stream standard came into effect as of December 31, <br />2014. The stream standards for Upper Grassy Creek <br />are classified as agriculture, aquatic life (Warm 2) <br />and Recreation N. The following exceedances were <br />noted on Table 15 of the AHR: <br /> SSLG5 – Total Rec. Iron, April through June <br />2016 <br /> SSLG5, Total Mercury in April through June <br />of 2016 <br /> SSLG5, Selenium in June of 2016 <br /> <br />According to the AHR, the Iron excursions is a result <br />of high suspended solids and that a temporary <br />modification (expires December 31, 2018) of the Iron <br />standard as “current conditions”. Given this the <br />AHR indicates this excursion is not considered to be <br />a standard exceedance. <br /> <br />It is unclear if the Mercury standard was actually <br />exceeded. The Method Detection Limit (MDL) for <br />Mercury is .2 ug/l and the stream standard is .01 ug/l. <br />Given this, the MDL is higher than the standard. <br /> <br />No exceedances were report for NPDES Pond 002.