2020-01-30_REPORT - C1982056

• Permit No: C1982056
• IBM Index Class Name: Report
• Doc Date: 1/30/2020
• Doc Name: Annual Hydrology Report Adequacy Review
• From: DRMS
• To: Twentymile Coal, LLC
• Annual Report Year: 2018
• Email Name: TNL
• Email Name: JDM
• Media Type: D
• Archive: No

Sandstone),008-77-58(Wadge overburden),008-AU3 (Fish Creek
alluvium),008-AT-1(Trout Creek alluvium),and 008-AV-2 (Foidel
Creek alluvium.) The mine's annual hydrology reports contain
long-term data from these wells. The Division compared the water
quantity and quality data collected in 2018 to the maximum,
minimum and average levels reported for each monitoring site and
the Table 3 numeric standards for ground water for agricultural
use. See item no. 17 for the results of the Division's review.
The ground water point of compliance well for the Trout Creek
alluvium,008-AT-1,was identified as being destroyed in November
of 2012. As such, no data has been collected for the Trout Creek
alluvium since April of 2012. A determination of compliance since
April 2012 cannot be made due to a failure to collect and submit
the required data. Site 008-AT-1 was re-established in the
summer of 2014 and monthly water monitoring has been ongoing
since the re-establishment of the well.
Surface water monitoring approved plan is contained in Exhibit 14-
7 through 14-9. Table A Lists the sites and frequency with
different requirements depending on month.
• Exhibit 14(Ex 14-11)Table B, lists Cadmium(total
recoverable)as a required parameter in Surface water,
spoil springs, natural springs,and mine discharge. This
parameter does not appear in the water quality data.
Please ensure the correct parameters are being
measured.
Foidel Creek: 4 sites include; site 800 upstream,site 14 upstream,
site 8 downstream of pond G, and site 900 downstream before
at Sampling frequency Middle Creek confluence. Site 304 was removed with TR 42 in
at surface water sites, Exhibit 14 of CDRMS mining Springs and Mine permitC-1982-056 2003.
Discharge. Site 90OA:
• Listed in current permit Table A approved 9/17/2015
• This site was monitored by the operator during the
observed sampling event in July 2019, however data from
this site is not in the AHR.
• Per permit page 2.06-25.9 site 900A will be monitored for
at least one year prior to any mining related impacts to
site 900,which is within 4RT longwall panel of the WCR.
The approved mine plan currently has this area scheduled
to be disturbed at some point in 2021. Monitoring at this
site should begin in 2020 and data reported in the AHR.
Fish Creek: 9 sites include; 16A upstream of Fish Creek Borehole
and site 115,307 downstream of FCB,302 2 miles downstream of
3