INSPEC09399

• Permit No: C1981012
• IBM Index Class Name: Inspection
• Doc Date: 7/8/1997
• Doc Name: OSM INSPECTION REPORT
• Inspection Date: 6/10/1997
• Media Type: D
• Archive: No

feet. The static water level was measured at 99.6 feet in TH-203 on the third terrace.
Water level measurements inGuded about 4' for the aboveground casings. According
to DMG, continual presence (but no discharge) of water in pond 008 might be evidence
of flow through the pile's underdrain, the source of which could be the water in the pile
as detected in the two piezometers. In that case, the underdrain is working as intended.
A small amount of water ponded on the west end of the first terrace probably was due to
the insufficient side slope as reflected by the field measurements described above.
Additionally, the confluence of the second terrace with the westem side slope was
partially blocked with mounded soil material.
Runoff on the RDA's operational top surtace breached a bean at the southwestern end
of the outslope and eroded a gully down to the third terrace. Coal refuse was deposited
on the third terrace to a small extent. This situation probably occurred because
drainage from most of the top surface is directed toward the RDA's southwestern
comer. No water was ponded on the top surtace; previous compliance and stability
concerns caused by ponding resulted in the surface's present grade to maintain positive
drainage. However, as a result, the southwestern side of the top surtace and the
westem side ditch convey a disproportionately large amount of runoff from the RDA's
top surface. A small seep was noted at the westem end of the third lift's outslope about
15 feet from the westem side ditch and abouttwo-thirds of the way up from the second
terrace. The soil was wet and small amounts of water ponded in depressions but water
was not flowing. The seep could be the result of continuing drainage problems on the
third terrace stemming from heavy drainage off the top surface's westem side. Mr.
Thompson was aware of the seep.
Other field measurements were taken of the RDA's side ditches and the upstream
diversion. Six measurements taken in the east, north, and west segments of the
upstream diversion yielded an average depth of about 2.86 feet and an average top
width of about 17.5 feet. No water was flowing in the upstream diversion.
Measurements taken of the westem side ditch on each of the three lifts showed an
average depth of about 1.38 feet and an average top width of about 16.3 feet. As noted
above, the westem side ditch receives much of the pile's surtace drainage, and the
Reno mattresses show the wear. Some erosion of the outer berm of the westem side
ditch on the west side of the second lift was noted. According to DMG, this segment of
the side ditch was maintained recently. Measurements taken of the eastern side ditch
on each lift showed an average depth of about 1.4 feet and an average top width of at
least 15 feet. The Reno mattress ditch lining showed rock displacement within the
gabions in a number of locations in the east and west side ditches. No water was
flowing in the east or west side ditches.
The first, second, and third lift outslopes of the RDA were top dressed and revegetated.
Depth of non-toxic cover was not checked during this review, however. As noted
above for the MWDP, operators are encouraged by DMG to document depth of cover
placement during waste bank reGamation and are cautioned to expect some verification
of cover depth in the absence of such documentation. In the absence of such
6 1997 New Elk Special Focus