Dames & Moore, 1999 - USDA Forest Service

Tailings Pile 3
Tailings pile 3 is located to the east of tailings pile 2, and is estimated to be 22 acres in size. The pile is
bounded to the north by Railroad Creek, the east by a wetland area and trees, and to the south by a conifer
tree-covered slope which climbs to the south. The surface of the pile is generally covered with rounded
gravel. Areas of relatively young coniferous vegetation are present on the surface. Grasses were reportedly
drilled into the surface of the pile and are apparently relatively successful when augmented with fertilizers.
Mature coniferous trees are present near the northern edges of the tailings pile, near the top of the slope
leading to Railroad Creek; the trees apparently were reseeded naturally (personal communication with Keith
Anderson, 1996). Portions of the surface are covered with miscellaneous woody debris in an attempt to
increase the success of revegetation (PNL, 1991). Other experimental test plots are present which are being
studied by the USFS (personal communication with George Shearer, USFS, 1997). '
A series of steel pipe monuments associated with the groundwater monitoring wells exist across the surface
of the pile. An interceptor trench trends across the southern portion of the pile, which drains to the southeast
comer and then into Railroad Creek, after crossing through a small wetlands area. The trench is lined with a
permeable geofabric and small rip rap; some of the rip rap has decomposed to coarse sand:
An avalanche reportedly occurred during the winter of 199511996, which reached the southern margin of the
tailings pile (personal communication with Keith Anderson, formerly of the USFS, 1996). The source of
the avalanche was the relatively steep slope and drainage feature to the south of the tailings pile.
Springs are observed in the area to the east of the tailings pile, in the area of wetlands. Iron oxide staining is
evident in much of the wetland area. The water which drains from the wetlands flows along the southern
margin of the area and eventually into Railroad Creek.
4.1.2.3 Railroad Creek
Railroad Creek was assessed during the RI nearly continuously from an area several miles to the west of the
Glacier Peak Wilderness boundary, to the mouth of Railroad Creek at Lucerne; due to health and safety
concerns, the only portions of the creek bed not evaluated were a series of waterfalls near the mouth.
Referring to Figure 4.1-2 and based on the review of topographic maps, the stream gradient is moderate
from the base of Lyman Glacier to Lyman Lake before descending Crown Point Falls. The gradient of the
streambed is moderate as it enters Hart Lake, approximately four miles west of the Site. Near the Site, the
stream gradient lessens, continuing downstream of the Site. Several miles west of the mouth of the creek,
the stream gradient steepens, descending several waterfalls before flattening near the mouth.
Upstream of the Site, the creek is in a relatively pristine state; however, limited precipitation of apparent
iron oxides, which appeared to be naturally occurring, was observed on rocks within the stream bed.
Natural iron stain on stream pebbles is a common feature regardless of whether mining has occurred in a
drainage basin. The undersides of stable cobbles are usually not stained. It may be caused by slow
weathering of iron minerals in the rocks, by adsorption of dissolved iron from the water column or by
entrapment of natural iron flocculent by organic matter. The Site is situated in a watershed with naturally
occurring iron mineralization. A visit to Lyman Lake, located approximately 10 miles upstream of the Site,
disclosed the presence of naturally occurring iron cementation of the substrates of several small drainages
located on a glacial moraine deposit; the streams flow eventually into Railroad Creek.
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17693-005-019Uuly 19. 1999:4:51 PM;DRAFT FINAL RI REPORT