2021-12-02_REPORT - C1981044

• Permit No: C1981044
• IBM Index Class Name: Report
• Doc Date: 12/2/2021
• Doc Name: Annual Hydrology Report Adequacy Review Response
• From: DRMS
• To: Moffat County Mining, LLC
• Annual Report Year: 2020
• Permit Index Doc Type: Hydrology Report
• Email Name: RAR
• Email Name: JLE
• Media Type: D
• Archive: No

CWQCC The receiving waters (Segment 13b) are designated "Use-
8. Basic Standards for Regulation 31; Protected".
Surface Water Antidegradation
standard Reg 38.1
The Williams Fork Mines are located on Segment 13b of the
Lower Yampa/Green River Sub-basin of the Lower Colorado
River Basin. CWQCC lists numeric standards for Segment 13b
in its regulation 37. The permitee monitors water in the
Williams Fork River at a site upstream of the mine (WF1),as
CWQCC well as downstream from the mine (WF2).
9. Instream Numeric Regulations 31
Standards and 37 Data over time from the upstream site indicate the Williams
Fork River naturally exceeds the numeric standard for iron,and
occasionally the lead and manganese standards.
Comparisons of the upstream and downstream data indicate
mining and reclamation operations at the Williams Fork Mines
do not cause the exceedances.
The WF1 and WF2 sites were monitored in accordance with the
approved sampling plan. Additional monitored surface water
Exhibit 29; sites comprise mine discharge points(NPDES#003 and#024)
10. Surface water and oils spring 1 SP PDES#022
monitoring sampling CDRMS mining p p g )
permit C-1981-
frequency. p per MCM appears to be sampling the surface water NPDES
044 discharge monitoring sites in accordance with their permit.
MCM needs to be timely in submitting surface water monitoring
information to The Division.
Exhibit 29 All required parameters were sampled.
11. Parameters sampled CDRMS mining
at surface water sites permit C-1981-
044
12. Prevention of Surface water features in the permit area consist of the
impacts to surface CDRMS Williams Fork and Yampa Rivers. The post mining land uses
water that adversely regulation of rangeland/wildlife,pastureland and cropland can be expected
impact the post 4.05.1(2) to use water for watering of wildlife and livestock. Mining and
mining land use reclamation operations at the Williams Fork Mines do not
appear to have impaired surface water for these uses.
13. Pond Report filing CDRMS All filing dates were not met. DRMS has no record for quarter
frequency regulation two pond inspection report.
4.05.9(17)
14. Timely filing of CDRMS Inadequate,at a minimum a note to DRAIN of no discharge is
pond reports regulation 4.05. required.
9(17)
The sediment ponds associated with Williams Fork Mine in
2019 comprise 5P1, 5P2, 5P3 (outfa11007); 9AP1 (018);
9AP2(019); 9AP3 (020; 9AP4(021); 9P1 (024), 9P2, 9P3
CDRMS (024); 904(014); 9P5 (017), 9P6(015), 9P7(013), 9P8(016);
15. Pond report content regulation 4.05. HRP1A,HRP1B (004); SHP1 (011), SHP2(012); 5AP1
9(17) (009). Recently reclaimed outfalls comprise 5P5, 596, 5P7
(outfall 003),wastewater(023)reclaimed. Other discharge
monitored is spoil spring 1 SP(022). When submitted,content
is adequate. There was no recorded discharge from sediment
ponds in 2020.
16. Interim Narrative CWQCC Not reviewed
Standard for Ground regulation
Water 41.5.C.6
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