REP39628

• Permit No: M1977300
• IBM Index Class Name: Report
• Doc Date: 12/1/1984
• Doc Name: EFFECTS OF RUNOFF OR SEEPAGE FROM THE SCHWARTZWALDER MINE WASTE ROCK PILES ON THE WATER QUALITY OF
• Media Type: D
• Archive: No

R. G. OTTO & ASSOCIATES
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4. CONCLUSIONS
I. Ground Water Studies.
A.~~ Ground water concentrations of all parameter=_, as
measured at a well location downslope of the
Schwartzwalder Mine waste rock piles were within the
range of observed (total recoverable) natural surface
water concentrations upstream of the waste rock piles
with the exception of uranium levels.
B. Uranium concentrations in the ground water never
exceeded the Colorado Water Quality Standard and,
on average, were <15% of the Standard Value of
59 uqm/1. Copper was present in the ground mater
at concentrations exceeding the Colorado Water
Quality Standard of 5 uqm/1. Surface water
concentrations (natural) upstream of the waste rock
piles also exceeded the Water Quality Staada:•d.
C. Observed trace metals concentrations in conjunction
with empirical considerations relating to the,
location and surface area of the remaining waste rock
pile, the grain size of the waste rock relative to that
of natural soils that underlay the pile, the water
retention capacity (moisture potential) of the waste
rock and the natural precipitation patterns in the
area do not support as expansion or contiauat.ioa of
ground water studies for purposes of assessing waste
rock pile impacts.
II. Surface Water Studies.
A. Detailed cross pile comparisons of surface water
conductivity, pH, and concentrations of sulfate,
arsenic, barium, boron, cadmium, copper, leacl, silver,
mercury, selenium, uranium, radium-226 and ra~.dium-228
demonstrate conclusively that the waste rock piles
are having no detectable long-term impact on the
water quality of Ralston Czeek.
B. The data is equivocal with regard to seasonal.
uranium concentrations. The extended series of monthly
cross-pile comparisons (18) of uranium level=_~ made is
conjunction with the Radioactive Materials License
Monitoring Program do not indicate any changes.
However, seasonal comparisons (5) made specifically for
~` purposes of this study suggest a slight, croe.s-pile
~ rise during the late summer, low flow period. Different
sampling locations used in the two studies at~d
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