2021-05-26_REPORT - C1994082

• Permit No: C1994082
• IBM Index Class Name: Report
• Doc Date: 5/26/2021
• Doc Name: Annual Hydrology Report Adequacy Review
• From: DRMS
• To: Twentymile Coal, LLC
• Annual Report Year: 2019
• Permit Index Doc Type: Hydrology Report
• Email Name: RAR
• Email Name: JLE
• Media Type: D
• Archive: No

Yoast Mine AHR 2019
Requirement Requirement citation Comment
10. Interim Narrative CWQCC regulation 41 No water quality data was located for Point of
Standard for Ground Water Compliance Well SGAL70.
It was determined that bedrock groundwater points
of compliance are unwarranted at the Yoast Mine.
Well SGAL70 serves as the Yoast Mine's Grassy
Creek Alluvial ground water point of compliance and
well YSAL3 serves as the alluvial ground water point
of compliance for Sage Creek. Ambient values for
site YSAL3 were below the Reg.41 standards during
the 2019 water year.
11. Sampling frequency at Tab 15,Table 15-9 of The report indicates that all frequencies were met.
surface water CDRMS mining permit
C 1994-082
12. Parameters to be Tab 15,Table 15-4 and Parameters to be sampled are conductivity
sampled at surface water 15-5 of CDRMS (umhos/cm),pH (units), temperature (C), total
sites mining permit C-1994- recoverable iron (mg/I), dissolved manganese (mg/I),
082 total mercury (ug/1), dissolved nitrate (mg/1), dissolved
nitrite (mg/I),total ammonia (mg/I), dissolved selenium
(ug/1), dissolved sulfate (mg/1),total sulfide (mg/1),total
suspended solids (mg/I) and total dissolved solids
(mg/1). All required parameters were analyzed. All
parameters were met.
13. Filing frequency of pond CDRMS regulation The sediment ponds associated with C 1994082
reports 4.05.9(17) include 010, 011,011A, 012, 012A, 013, and 014.
Quarterly pond inspections were conducted within the
appropriate quarter.
14. Timely filing of pond CDRMS regulation Quarterly pond inspection reports were submitted and
reports 4.05.9(17) received by the Division within an appropriate time
frame.
15. Content of pond reports CDRMS regulation All required information was addressed on quarterly
4.05.9(15) sediment pond inspection in water year 2019.
16. Sampling frequency of Tab 15,Table 15-8 of Ground water samples are collected from YSAL 1,YSAL3,
ground water monitoring CDRMS mining permit YAAL14, YGAL16, YOV30, YW30, YWU30, YWC33,
wells C- YWCU33. Note: No water quality data was located in the
1994-082 report for the following sites,monitored on an annual basis:
YTM32, SGAL70.
17. Parameters to be Tab 15,Table 15-4 of Parameters to be sampled are conductivity(umhos/cm),
analyzed in ground water CDRMS mining permit pH (units), temperature (C), dissolved iron (mg/1),
samples C- dissolved manganese (mg/1), dissolved fluoride (mg/1),
1994-082 dissolved nitrate (mg/1), dissolved nitrite (mg/1), dissolved
selenium (ug/1), dissolved sulfate (mg/1), and total
dissolved solids (mg/1). At measured sites all parameters
were met. However, it appears that not all sites were
measured.