2015-06-03_REPORT - M1999120

• Permit No: M1999120
• IBM Index Class Name: REPORT
• Doc Date: 6/3/2015
• Doc Name: Report
• From: LG Everist, Inc
• To: DRMS
• Email Name: ECS
• Media Type: D
• Archive: No

DRMS ANNUAL REPORT - GROUNDWATER MONITORING REPORT
SITE: L.G. Everist, Inc. - Fort Lupton Sand and Gravel, M-1999-120
DATE: June -2015 Page 1 of 2
Fort Lupton monitoring well data from January -2013 through May -2015 is attached. Data
through 2012 was submitted during the DRMS permit amendment in October -2012. A map of
the monitoring well locations is also attached. (MW = monitoring well)
All wells that are listed in the data file are also shown on the map. Some of the wells have been
abandoned for various reasons (usually they have been mined through). The abandoned wells
are shown in the data file and map for this report, but will be removed in future reports.
The majority of the monitoring wells have maintained groundwater levels within the baseline
ranges established in L.G. Everist's (LGE) final adequacy response for the DRMS permit
amendment in October -2012. This includes wells in areas where we are not yet mining, and
also wells along the perimeters of slurry walls - showing that the water is still flowing around the
slurry walls in natural patterns.
A few monitoring wells at Fort Lupton have hit groundwater level trigger points (as per the
groundwater monitoring program agreed on in the Oct -2012 DRMS amendment). These wells
have passed outside of their baseline ranges. Fortunately, in many cases the groundwater
levels have returned to being within baseline ranges. Although trigger points were hit, no
outside parties were affected, so no mitigation for outside parties has been required.
Following is a listing of those wells which have exceeded baseline ranges at some point within
the last few years, with an explanation of the raw data and also external factors contributing to
fluctuations. We have also noted any investigation work and mitigation measures we have
completed. There have been no adverse effects on neighbors with any of these wells.
MW4 - The well is clearly internal to LGE, as it is located in the southwest section of the Fort
Lupton West cell, within the slurry wall, and so changes in water levels would only affect the
operator, therefore no mitigation is necessary. The groundwater levels were outside the
baseline ranges in this well, but have recently come back within the baseline ranges.
MW6 and MW7 - Due to dewatering the south end of the Sandstead cell, MW6 and MW7 are
outside the baseline ranges. These wells are located outside of, and on the west side of the
Swingle -North slurry wall (MW7) and Swingle -South slurry wall (MW6), but are considered
internal to LGE operations as the entire Sandstead cell is located to the west. Because the
wells are internal to LGE and water levels would only affect the operator, no mitigation is
necessary. Note that the nearest external well, MW20, located on the west side of Sandstead,
has stayed within baseline ranges.
MW8 - This well is located on the south side of CR18, directly across from a neighboring mining
operation, and their dewatering efforts are clearly having an effect on the nearby groundwater
level. There are no residential neighbors nearby to be affected. This well was within baseline
ranges for the first few years. The well has been below the lowest threshold number since
January 2007 - soon after mining and dewatering began in the mine north of CR18. The well
has generally been low since then (as noted in the 2012 amendment paperwork). The well got
close to baseline ranges after the flooding in the fall of 2013, due to surface water.
MW9 - This well is quite far north of any LGE operations, but is located directly across CR25
from the adjoining mine's (see MW8) main entrance. Again, their dewatering efforts are causing
the local groundwater to decrease. There are no residential neighbors nearby to be affected.
The same conditions exist as noted under MW 8.
FL-DRMS-AnnRpt&GrWtrMon-2015-060315.docx