2023-01-22_REPORT - C1994082

• Permit No: C1994082
• IBM Index Class Name: Report
• Doc Date: 1/22/2023
• Doc Name Note: 2020 October Through @pyember 2021
• Doc Name: Annual Hydrology Report Adequacy Review
• From: DRMS
• To: Peabody Energy
• Annual Report Year: 2020
• Permit Index Doc Type: Hydrology Report
• Email Name: RAR
• Email Name: JLE
• Media Type: D
• Archive: No

Yoast Mine AHR 2021 Water Year 2020 October through 2021 September
Requirement Requirement citation Comment
15. Sampling frequency of Tab 15,Table 15-8 of Ground water samples are collected from 10 monitoring
ground water monitoring CDRMS mining permit wells: YSALI, YSAL3, YAAL14, YGAL16, SGAL70,
wells C1994-082 YOV30, YW30,YWU30,YWC33, YWCU33.
16. Interim Narrative CWQCC regulation 41 Monitoring comprises 10 wells. It was determined that
Standard for Ground Water bedrock groundwater points of compliance are
unwarranted at the Yoast Mine. Two groundwater points
of compliance are nevertheless established and
monitored.
Well SGAL70 serves as the Yoast Mines' Grassy
Creek Alluvial ground water point of compliance and
well YSAL3 serves as the alluvial ground water point
of compliance for Sage Creek.
No exceedances of the GWPOC standards occurred
at YSAL3 for the 2021 water year. SGAL70
exceeded the cadmium standard however the lab
detection limit exceeded the cadmium water quality
standard.
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 C1994-082 dissolved manganese (mg/1), dissolved fluoride (mg/1),
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.
18. Basic Standards for CWQCC regulations 41.4 The Yoast Mine did not generate significant amount of
Ground Water and 41.5 leachates in 2021.
19. Restoration of ground CDRMS regulation Well YWC33 casing is damaged and prevented water
water recharge to 4.05.12(3) level measurement. For the 2021 water year, it appears
approximate pre-mining rate that water levels at measured wells fell within their
historic ranges, except for wells YOV30 and SGAL70
where levels were low. All alluvial wells displayed
seasonal water level fluctuations in response to periods
of precipitation recharge and long term drought.
20. Prevention of adverse CDRMS regulation Compliance with the Basic Standards for ground
impacts to ground water 4.05.11(1) water, as per item 10,indicate the permittee is
systems outside permit area preventing adverse impacts to ground water
quality outside the permit area.
Note: Water level reports as presented in Appendices B
and C of the AHR Hydrology Report static water levels
and depth to water.
All alluvial wells showed seasonal water level
fluctuations in response to periods of precipitation or,
lack thereof. Overburden and coal well water levels are
fluctuating in response to the precipitation recharge and
ground water flow from the reclaimed mine pits.
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