Dames & Moore, 1999 - USDA Forest Service

The calculated total numbers of fish caught at RC-6 and RC-1 were 64 and 128 per hectare, respectively.
The fish caught were a combination of rainbow and rainbowfcutthroat hybrids. The fish length ranged from
approximately 70 to 90 millimeters.
Adjacent to Tailin~s Pile 1 RC-9
The portal drainage enters Railroad Creek approximately 1,200 meters upstreah from RC-9 and is a source
of metals loading to Railroad Creek, primarily cadmium, copper, and zinc. The RC-9 station was established
downstream of the Portal Drainage confluence (P-5), near the northeast corner of tailings pile 1,
immediately upstream of the confluence of Copper Creek. The station location was selected due to the
transition of the presence of iron-oxide staining on the substrate of the creek within the 100-meter length of
stream reach.
The average total number of benthic macroinvertebrates collected in the eight replicate samples was 330 per
square meter. However, the actual values in the replicate samples ranged from 10 per square meter at within
the area of iron-oxide staining and flocculent (suspended iron-oxide precipitate) to 15 10 per square meter at
in upstream portion of the sampling station without staining.
The species of aquatic insects also changed from the upstream to downstream portions of the sampling
station. The number of organisms that feed by collecting detrital materials in the stream substrate were
reduced in the area of iron-oxide staining. However, three species of filter feeding insects were found
unique to the segments of the RC-9 and RC-7 sampling stations which contained the iron-oxide staining.
This is considered significant because filter feeders are generally more affected by contaminants in the water
column due to their greater exposure to water. In addition, bioassays were completed by Ecology (Johnson,
et al. 1997) utilizing a sensitive filter feeder, cladocerans (Ceriodaphnia) and Railroad Creek water collected
upstream, immediately downstream of the tailings, approximately three miles downstream of the site, and at
the mouth of Railroad Creek; the results indicated no adverse effects.
The total calculated number of fish caught at RC-9 were 114 per hectare. The fish caught were exclusively
cutthroat trout. The lengths of fish ranged from approximately 180 to 260 millimeters. The fish were all
caught outside the iron-oxide stained area.
Adiacent to Tailings Pile 3 (RC-7)
The RC-7 sampling station was located adjacent to tailings pile 3, upstream of the RC-2 water quality
station. The sampling site was situated in an area of iron-oxide staining and flocculent.
The average total number of benthic macroinvertebrates collected in the eight replicate samples was 64 per
square meter. The actual values in the replicate samples ranged from 10 per square meter to 140 per square
meter. As noted above at the RC-9 station, three species of filter feeding insects were found unique to the
RC-7 sampling station.
The calculated number of fish caught at RC-9 were 10 per hectare, and exclusively cutthroat trout. The
length was approximately 180 millimeters.
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17693-005-019Uuly 28, 1999;12:26 PM:DRAFT FINAL RJ REPORT