REP21328

• Permit No: C1982055
• IBM Index Class Name: Report
• Doc Name: Review of 1986-1987 Hydrologic MONITORING Data
• From: MLRD
• To: ENERGY FUELS MINING CO
• Permit Index Doc Type: HYDROLOGY REPORT
• Media Type: D
• Archive: No

Mr. Gossett
- 2 - December 2, 1987
In the third quarter of 1986, the mine continued to have problems with
maintaining discharges from the sediment pond within NPDES permitted limits
for settleable solids. Much of this difficulty was felt to be due to
excessive sediment in the pond resulting from severe downcutting in the
drainages emptying into the pond. Various steps were taken to reduce the
volume of sediment being discharged including cleaning the pond and installing
check dams in the ditch south of the refuse pile. Asa result, an apparent
reduction in the amount of settleable solids being discharged was noted in the
third quarter of 1986. There were no further violations in either the fourth
quarter of 1986 or.in the first quarter of 1987; although at least one
significant rain was recorded during November. Ownership and operation of the
mine charged during the second quarter 1987 (fourth quarter of the 1986-87
monitoring year). Considerable additional effort was made by the new operator
to control the volume and velocity of flow in the disturbed area drainage
ditches; additional check dams were installed in the ditch south of the refuse
pile together with extensive rip-rap. The top of the refuse pile was regraded
to lessen the volume of water bing directed into the ditch on the north side
of the refuse pile. These measures appear to have been effective; there were
no NPDES violations noted during this quarter.
Ground Water
The operator is required to monitor water levels and water quality (field
parameters) in two local wells on a monthly basis. These are the refuse and
Iuppa wells. Analytical data is supplied for these wells each quarter. Prior
to September, 1986 the operator was voluntarily monitoring an additional well,
the Sundance well, on the same basis. As a result of budget concerns,
analytical data for the Sundance well was omitted from reports for the last
three quarters of the 1986-87 monitoring year. The analytical data supplied
during the 1986-87 monitoring year indicates the basic chemical character of
the waters in the refuse, Iuppa and Sundance wells is essentially unchanged
from previous years. Annual variations in TDS occur for all wells, but these
variations fall within the range previously recorded. The waters from the
three wells are chemically distinguishable from one another and probably
indicate separate sources or combinations of sources as previously reported
(see Annual Review of Hydrologic Monitoring Data for 1985-1986 dated
August 1, 1986).
Of the three wells, the refuse well exhibits the greatest annual variation in
TDS (and Ec). The zone across which this well is perforated or open may be
larger than in the other wells and perhaps subject to some surface recharge.
Chemically, this is also the only well of the three yielding water in which
dissolved quantities of selenium occasionally exceed drinking and agricultural
standards. These exceedances have also been true in past years. There may be
some relationship of these high selenium values to the mining operations.
Water in the adjacent sediment pond regularly contains selenium at the limit
recommended for drinking water; water from the permanent diversion ditch does
not. Water from the refuse well, however, is not put to any beneficial use.