2018-08-08_HYDROLOGY - M1977348

• Permit No: M1977348
• IBM Index Class Name: Hydrology
• Doc Date: 8/8/2018
• Doc Name: Water Monitoring - Groundwater
• From: Golder Associates
• To: DRMS
• Annual Report Year: 2018
• Email Name: AME
• Media Type: D
• Archive: No

July 31, 2018
Ms. Amy Eschberger
Colorado Division of Reclamation Mining and Safety
Department of Natural Resources
1313 Sherman Street, Room 215
Denver, Colorado 80203
RECEIVED
AUG 0 8 2018
Division of Reclamation, Project No. 1899205
Mining & Safety
FIRST SEMI-ANNUAL EVENT 2018 GROUNDWATER SAMPLING AT THE BOETTCHER QUARRY
Dear Ms. Eschberger:
On behalf of Holcim (US) Inc., Golder Associates Inc. is pleased to submit analytical laboratory results for the first
semi-annual 2018 groundwater sampling event at the Boettcher Limestone Quarry near La Porte, Colorado.
Attached are Tables 1 through 7, summarizing the results, and a copy of the laboratory report. In addition to
sampling wells MW -1 through MW -7, a field duplicate at MW -1 (MW -20) and a field blank (MW -15) were collected.
The locations of monitoring wells MW -1 through MW -7 are presented in Figure 1.
In December 2016, the Colorado Division of Reclamation Mining and Safety approved a revision to change the
required groundwater monitoring frequency from quarterly to semi-annually (Revision TR07) based on evidence
that the groundwater wells were not fully recharging between sampling events. Figure 2 presents a graph of the
monitoring well water elevations measured during each sampling event from 2013 to present. Recent water levels,
taken in May 2017, November 2017, and May 2018 after more than six months of recharge, are higher than the
previous range of levels observed for wells that are purged dry prior to sampling (MW -2, MW -3, MW -4, MW -6, and
MW -7), indicating more recharge, and further evidence that the groundwater wells were not fully recharging between
sampling events.
If you have any questions, please call the undersigned at [phone].
Sincerely,
GOLDER ASSOC ATES INC.
L
/iraHarkins, PG
Geologist
P_. r1li l 4AA- 41
Randy March, PE, PG
Principal Geological Engineer
Attachments: Table 1 - Summary of Monitoring Results for MW -1
Table 2 - Summary of Monitoring Results for MW -2
Table 3 - Summary of Monitoring Results for MW -3
Table 4 - Summary of Monitoring Results for MW4
Table 5 - Summary of Monitoring Results for MW -5
Table 6 - Summary of Monitoring Results for MW -6
Table 7 - Summary of Monitoring Results for MW -7
Figure 1 - Location Map
Figure 2 - Groundwater Elevations vs. Time
Attachment 1 - ACZ Laboratory Report
Golder Associates Inc.
44 Union Boulevard, Suite 300 Lakewood, Colorado, USA 80228 T. [phone] [phone]
C \usersAskmnehgolder associates\1899205, hoicim boettcher quany 2018 co - reports\boeftcher_samplresults_lsthalf2018_fnl_31tu118\1899205 boetfchergwsamp1sthalf2018_fnl-
31tul18 docx
Golder and the G logo are trademarks of Golder Associates Corporation golder.com