2008-04-18_HYDROLOGY - M2004078

• Permit No: M2004078
• IBM Index Class Name: HYDROLOGY
• Doc Date: 4/18/2008
• Doc Name: January 2008 groudwater quality monitoring results
• From: Civil Resources, LLC
• To: DRMS
• Email Name: CBM
• Media Type: D
• Archive: No

" (" 1r9'-^~ CIVIL RES~URCES,LLC
ENGINF_ERS & PLANNERS
April 17, 2008
Mr. Carl Mount
o ~, Division of Reclamation Mining and Safety
1313 Sherman Street, Room 215
Denver, Colorado 80203
~PR ~ ~ 20 _
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RE: Jana 2 08 Groundwater nitorin ults Lu ton Lakes Gravel Mine
N
Permit No. M-2004-078
----
Dear Mr. Mount:
The following letter report describes the results from the January 2008 Sampling Event. This report is being
submitted in general compliance with approved Groundwater Sampling and Analysis Plan (GWSAP) included
in Technical Revision 2 (TR2) to the Lupton Lakes Gravel Permit issued by the State of Colorado Division of
Reclamation Mining and Safety. Dewatering began in the area of the south sediment pond near Weld
County Road 6 in June 2007.
Groundwater Monitoring Results
The January 2008 Sampling Event includes monitoring wells CRMW01, CRMW02, CRMW04, CRMW06,
CRMW09, CRMW16, and CRMW41. The January monitoring event also included sampling at the two
recharge areas denoted as the South and North Recharge samples, respectively. The dewatering volume
being pumped from the south sediment pond area was recharged back to the natural alluvium aquifer instead
of direct discharge to the river. Refer to the attached figure for approximate locations of the recharge areas.
Following is a listing of the major results and conclusions:
• Fluoride did not exceed the PDWS or the proposed baseline levels in all wells tested.
Nitrate (as N) exceeded PDWS in five of the seven wells sampled with nitrate concentration levels
ranging from less than 1.06 up to 30.39 mg/L in CRMW01. The PDWS for nitrate is 10 mg/L. The
currently proposed site wide baseline level for nitrate is 29.9 mg/L. The baseline level for well
CRMW01 is 57.6 mg/L. Nitrate levels in all of the wells were below either the proposed site wide or
individual well baseline levels. The Recharge Area samples had concentrations of 17.96 and 15.75
mg/I which is similar to the October 2007 sampling event.
• Secondary Drinking Water Standards (SDWS) were exceeded for Total Dissolved Solids (TDS) (540
to 1,216 mg/L) consistently across the site. Chloride and sulfate concentrations slightly exceeded
the SDWS in well CRMW09. The remaining SDWS parameters tested for including pH and Iron did
not exceed the SDWS. Additional parameter test results and the summary of all laboratory analysis
results are contained in the attached table.
323 FIEfH STREET • P. O. BOX 6B~ • FRECERICK, CO 8~53~ • PHONE [phone] • FAX [phone]^