GENERAL52039

• Permit No: C1981020
• IBM Index Class Name: General Documents
• Doc Name: ENVIRONMENTAL ASSESSMENT
• Permit Index Doc Type: GENERAL CORRESPONDENCE
• Media Type: D
• Archive: No

-iv-

• 21 Flow measurements wi12 be taken guar*_erly from siCe S[a-? and water
samples will be taken quarterly .rom sites S~J-1, s[J-q, and a new
monitoring site required in the ~~Juncer Canyon permit to be established
along East Salt Creek.
3) The water samples will be chemically analyzed for the parameters
specified below:
pH
Specific Conductance
Temperature (field)
Dissolved Oxygen (field)
Total Suspended Solids
Total Dissolved Solids
Total Combustible Solids
Total Hardness
Sodium Absorption
Ra ti o
Bicarbonate (NC03)
,Magnesium It9g+2)
Sodium (Na )
Sulfate (SOq)
aluminum (A1)
Arsenic (As)
aoron (B)
Cadmium (Cd)
Copper (Cu)
Iron (£e)
:e ad (Pb)
Manganese (~t7i)
Mercury (Hq)
FJOlybdenum (:?o)
Selenium (Se)
4) The results of all monitoring will be submitted to the regulatory
authority within 30 days of data collection and analysis.
The operation is in compliance with the requirements of this section.
Sediment and Runoff Control
• Information dealing with sediment and runoff control is presented in Sections
2.2.7, 2.3.Z, 2.3.q, 2.3.5 of Volume I and Appendix ;! of volume v of the permit
application. This information has been reviewed by the Division for compliance
with the Rules and Regulations and the resulting analysis is presented below.
The proposed pond at the mine bench is designed to hold a volume of runoff and
sediment of .q5 acre-feet. This capacity allows for the rtorage of runoff
resulting from the 10-year, 24-hour storm event (.24 acre-feet), as we 1l as
storage of the sediment produced from the disturbance over a two-year period
(.2 acre-feet). The Division requires that a marker Se installed in the pond
to indicate the 60e sediment storage _'evel (approximately the .12 acre-foot
sediment storage •oolume).
The collector ditch into the pond will be.stabie under the flow from the 10-year,
24-hOUr storm event. The emergency spillway is designed to convey flow from
the 25-year, 24-hour event without erodinc. The design of the pond as presented
in the application does got include provisions fora de watering device r_o
dewater the pond down to the maximum sediment storage level. This dewatering
device is reovired by the Division in the stipulation which foL ows.
The proposed sediment oord _°or the waste disposal oi_'e is designed fcr a toC3l
^3Dd C2 tV of .i85 acre-feet. .This will allow for the detention of the volum
of runof_° _`rom the ZO-year, 2q-.hour =vent (.12 acre-feet; in addition to a
tv ee-year accvmulatien of sediment .rom the disposal pile (.J62 acre-feetl.
.a .mangier indicating the o0a sediment storace :e•;e' must also :,e _'nstai:ad at
_~_s cond.
•