PERMFILE48309

• Permit No: M1993041
• IBM Index Class Name: Permit File
• Doc Date: 6/1/1993
• Doc Name: APPLICATION FOR REGULAR 112 PERMIT DOWE FLATS MINE
• Media Type: D
• Archive: No

• CAiI.RB -Exhibit G
Water Informedw
Page 4
sumrttarized in Table G-4. SVC-2 is located on St. Vrain Creek ai East County Lane Road near
Longmont. -- ''
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surface water Q~ii 'ly Monitorin¢ ~°~~~ ~ ~~lc`~~
To ,three quartets of surface water quality daha have been obtaitted from existing surface
wa6er ons. The water quality data were collected quarterly, starting in June, 1990, . ~?
pursuant to an application for a mine permit. Chemical analyses of the guat~rlY d~a _nmmade ~ _ _ I,
background surface water quality data to provide baseline watea quality. The chemical dale are
summarized in Table G-5. 1,(IG~~
alr-ov~'

Three surface water monitoring stations, deli DFSW-1, -2, and -3, located (Figure G-2) in aMOiM+-r
~o(xt~e,~,
the vicinity of the mine. Station D W-1 is ]orated upgradient of the rnrxtosed mires ~~ ,~~~s
dowrtgradient of the Syntex facility. DFSW-1 is situated about 100 feet south of DFMW-1 (NW 1/4 ~ ~-
~ °
`
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NE on , T3N, R70W in an ephemeral strrarrt channel. Station DFSW-2 is lordted upstream '"'
'
• of the proposed mine project, along the north bank of St. Vrain Creek, west of the bridge on the
Southwestern Portland Cement entrance mad (NEl/4 SWl/4 21 _T3M, R90W). Station
-- $.,,,,y~
DFSW-3 is 1 o the mine
of St Vrairr Creek north of the J
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bridge on County Road 63 North (SE 1/4, NE 1/4, Section 27, T3 to upgradient station /
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provides background water quality data and stations DFSW-2 and DFSW-3 deteaminatio(t of the ~-Q
impact on St. Vrain Creek water quality from the proposed mining activities. ~~ "~'
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Surface water quality data collected at stations DFSW-2 and DFSW-3 correlate moderately well art
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show a slightly bicarbonate water. Monitoring point DFSW-1 is located in an ephemeral stream arYB -' -p~„~
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the analytical restilts do not correlate well with the other ]orations. The historical data listed in Table 1
G~ does however correlate moderately with data collected from DFSW-2 and DFSW-3. The
Colorado Departntertt of Health (CDH) Water Qwlity Commission has designated St. Vtain Creek
as a Class 2 Recreational stream.
S rs-dace Water Quality Compared to Drinking Water Standards
The CDH Water Duality Commission has established maximum contaminant levels (MCLs) and
monitoring requirements to assure the safety of the public watea supply. MCLs refer to several
• categories of chemicals, physical properties, radioactive, and microbiological parameters. Many of