PERMFILE134580

• Permit No: M1999002
• IBM Index Class Name: Permit File
• Doc Date: 3/4/1999
• Doc Name: COPY SENT TO DMG OF BOB TOBINS WATER QUALITY CONCERNS
• From: ROBERT TOBIN
• To: DMG
• Media Type: D
• Archive: No

L•
1~
CNAPTER ~~ `o~ ^ ~`' Affected Environment ,
The potentio e Lower .Aquifer shows groundwater elevations and potentiometric ~ ~ ~ ~.ti•
contour confi to those of the Upper Aquifer. Horizontal hydraulic gradients in Sri, rr?se)
the Lower Aq 20 to 130 feet per mile, and the flow direction is generally from s~~f _•,
the southwest t. The horizontal gradient in the Project Area is estimated to be t~'r'-
approximatel le towazd the northeast. , 1 ~µ Fri..,' • •-~ ~ 3-ao
t19 `.
3.4.1.3 Grou ~ ir'~ I L.
Concentrations of total dissolved solids (TDS) in the Upper and Lower Aquifer range from /~ le boa d
approximately 400 milligrams per liter (mg/1) neaz the basin mazgins to 40,000 mg/1 in the north-
central part of the basin. Increases in TDS with depth also occur within the basin (Robson and
Saulnier 1980). These lateral anc>f vertiFal variations in water quality occur as a result of ~
geochemical changes taking place°~ae[on~ the groundwater flow path from rechazge azeas near the
basin mazgins to discharge azeas along the major streams (e.g., Piceance Creek and Yellow ,~~
Creek). Figure 3.4-1, showing idealized groundwater If~ow paths within the basin, indicates the ~~°
potential for water from the Lower Aquifer, which is rv y high in TD and of poorer quality, t,. ~ p, •` o
to flow upwazd into the Upper Aquifer and ultimate) to dischazge to cree s. ~`.yti` c 9~S .
Groundwater in the alluvial aquifers of the basin aze classified as a sodium bicazbonate type, with 1
TDS concentrations ranging from 470 to 6,720 mg/I. Higher TDS levels typically found tip''' `
downstream towazd the White River aze attributed to irrigation water return, groundwater inflow ~ ~e ~ i
from bedrock aquifers, and the concentrating ef~'ect of evaporation (Weeks and Welder 1974). Q.rh's '
tw+~•1
Groundwater in the Upper Aquifer is ~assified as a sodium bicazbonate type, with TDS values -
for the saturated portion of the Uinta Formation ranging from 550 to 1,060 mgA in the Project
Area located in the central part of the basin (Robson and Saulnier 1980). TDS values measured ~~~'
for the Pazachute Creek Member of the Upper Aquifer range from 610 to 1,900 mg/1 neaz the a~~,FSyS
basin's center. Based on existing data. groundwater in the upper portion of the Upper Aquifer n~ s t
would be classified by EPA as an underground source of drinking water (USDW) based on water ~ ~-~S ~'7'
quality data collected by American Soda. ~^ d~ •
Groundwater in the Lower Aquifer is generally classified asodium-bicazbonate-n.h~ide type {1 ~u -%{•. ti
with TDS concentrations ranging from approximately 600 mg/1 along the basin azgtns to Mot ~ve0 ~ 1 L
greater than 45,000 mg/l in the northern part of the basin. In the Project Area TDS values range
from approximately 830 to 9,700 mg/f (Robson and Saulnie~~980). Site evaluation studies for J J .)y,e~
the U.S. Bureau of Mines experimental oil shale mine in Rio Blanco County included one site pjy ~; ~tn~2
located in close proximity to the proposed project. TDS iso-concentration maps produced for ~Mpr~,~';~• 1
that study shgwed ~; tLiilar TDS val r the Upper and Lower Aquifers similar to those • • ~'
described b Robson and Saulnier (1980) n the vicinity of the proposed project. Salinity and ~''b ~'
TDS increase rapidly wt n e ow r Aquifer as the Dissolution Surface is approached (Welder ~,{e s
and Saulnier 1978). The poor quality f water in the Lower Aquifer indicates that it is not a ct S~^P
b.+
USDW. u ~'~ ~~'
}ge-cent. +~'e QS SAvw'fDs )+ss 1F•rn ~. o.t~
~-OCG n• ~ t. ~Of prtCl~. W 1n~ .wp't-
3.4.1.4 Groundwater Use i ~ y ~~•' ~ i
A well record search was conducted of the Project Area (Piceance Site, the pipeline corridor, and
Pazachute Site} through the Water Well Division of the Colorado Departrnent of Natural
Groundwater 3-17