PERMFILE134266

• Permit No: C1980007
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: EXHIBIT 70 REFUSE PILE EXPANSION
• Media Type: D
• Archive: No

REFUSE PILE EXPANSION
the stream. This culvert was designed to pass [he
100-year 24-hour event as described previously.
The design is contained in Appendix L.
• :i
The haul road will be relocated for the latter part of
Phase 3 and Phase 4. This conceptually designed
road will extend from Elevation 6400 MSL. The
grade of this road will be relatively flat. The culvert
on Sylvester Gulch will be relocated and will be the
same size as the initial culvert for the haul road. The
initial haul road and culvert will be removed and
reclaimed upon completion of the second road. Prior
to construction of this second road. MCC will submit
a revision to CDMG for additional design detail
regarding the road.
8.0 MONITORING
8.1 Quality Control
Quality control will be implemented for all four
phases and include complete construction
management and inspection. Density tests will be
taken of all non-refuse soils to verify compaction to
90 percent of the maximum dry density as specified
in Section 4.10.4(3) of the regulations of the CMLRB
for Coal Mining, (refer to section 8.4 for more details
on compaction testing). Refuse compaction
monitoringwill involve the observancethat the refuse
is not placed in lifts greater than two feet and that
there are adequate passes of a compactor.
8.2 Groundwater, Leachate, and Water
Quality Monitoring
Two groundwater wells have been installed up-dip
and down-dip of the limits of [he RPE. These wells
will be measured three times per year (similar
schedule as other monitoring wells on the WEM site)
for water levels. Field parameters of pH,
conductivity and temperature will be measured.
Annual analyses during the third sampling period will
-.., include laboratory analyses of pH, conductivity,
l~temperature, total dissolved solids (TDS), calcium,
magnesium, sodium, SAR, hardness, bicarbonate,
chloride, un-ionized ammonia, nitrate/nitrite,
phosphate (PO,'' as P), sulfate, iron (total and
dissolved), manganese (total and dissolved), arsenic,
cadmium, lead, mercury, selenium and zinc. All
parameters will be analyzed for their dissolved form
unless stated otherwise.
Underdrain flows to the RPE pond will be sampled
seasonally. NPDES flow and water quality will be
measured quarterly if the pond is discharged. This
data will be reported in the Annual Hydrology
Reports.
8.3 Slope Stability
The stability of the RPE will be monitored with the
use of permanent survey mirror stations. These
mirrors will allow the x, y and z coordinates to be
calculated four times a year to see if any movement is
occurring. The location of the mirrors is presented in
Appendix O.
8.4 Compaction Testing
The refuse material will be compacted to 90 percent
maximum dry density. ASTM method D-698-78
(reapproved 1990),1.1.4 Method D (Standard Proctor
Density) or ASTM method D-1557 (Modified Proctor
Density) will be used to determine moisture-density
relationships of the refuse-soil aggregates.
Equivalent AASHTO standards may be used at the
discretion of the Engineer.
Field density tests will be performed by one of the
following methods:
I . ASTM D- 1556, Sand Cone Method
2. ASTM D-2167, Rubber Balloon Method, or
3. ASTM D-2922,NucelarMethod.
The following density testing parameters will be
utilized. They are as follows:
•Moisture content-dry density relationship (Proctor)
tests will be performed for each quarterly testing as
scheduled by Mountain Coal Company. the proctor
sample will include particle size for percent of
aggregate larger than three (3) inches, percent
aggregate from the three quarter (3/4) inch size to
Harding Lawson Associates ~ 6