Dames & Moore, 1999 - USDA Forest Service

samples were collected utilizing either Van Veen or Eckrnan samplers deployed from a boat. A second
survey was conducted and a video of the surface of the bar was taken before sampling was completed in
order to determine the sampling locations. The locations of the sonar and video survey. as well as the
sampling locations, were civil surveyed using existing onshore features as references.
An additional six discrete sediment samples (1 through 4 and two duplicates) were collected near the
mouth of the Stehekin River near the community of Stehekin at the northern end of Lake Chelan (Figure
3.4-4). All of the samples were collected at a depth of approximately 50 feet below the surface of the
lake. A sonar survey was conducted prior to sampling in order to select the sampling locations. The
locations of the sampling stations were civil surveyed in the field.
All Lake Chelan sediment samples collected were analyzed for metals (aluminum, arsenic, cadmium,
copper, iron, lead, manganese, and zinc) and acid volatile sulfides (AVS), grain size, total organic carbon
(TOC), total solids, pH, and total volatile solids. The results of the laboratory analyses are presented in
Section 5.5.
3.4.2 portal Drainage and Railroad Creek Flocculent
Several samples of flocculent, which are not considered sediment, but assist in characterizing the Site
chemical'processes, were collected by Dames & Moore and others at select stations in Railroad Creek. In
addition, the USGS (1994) collected samples of sediment concentrate; the sampling method included the
collection of the sediment sample and screening of the larger materials. The concentrate samples were
analyzed for geochemical purposes but did not follow standard sediment sampling protocol. The results
of the laboratory analyses are presented in Section 5.6.
The collection of portal film samples from the portal drainage near the 1500-level main portal was added
to the field program at the request of the agencies during the RI (Figure 3.4-2). Samples were collected in
July and October 1997. In addition, flocculent was collected from the substrate within Railroad Creek at
three different locations between the area immediately upstream of the confluence with Copper Creek
(RC-9), at the northeastern corner of tailings pile 3 (RC-2), and approximately 114 mile downstream of
tailings pile 3 (RC-5) (Figures 3.2-1 and 3.4-2). The samples were collected to evaluate the chemistry of
the flocculent material and in order to assess the geochemical processes associated with the formation of
the material.
The samples were obtained from precipitate and flocculent that had coated streambed cobbles, and were
sampled by mechanically dislodging'the flocculentlprecipitate coating from the cobble into a sample jar.
After collection, the sample was allowed to settle and the water decanted from the sample jar. The
precipitate/flocculent was analyzed for total metals (aluminum, arsenic, barium, beryllium, cadmium,
calcium, chromium, copper, iron, lead, magnesium, manganese, molybdenum, nickel, potassium, silver,
sodium, thallium, uranium, and zinc). The results of the laboratory analyses are presented in Section 5.6.
3.4.3 Railroad Creek Streambed .
Referring to Figures 3.4-1 and 3.9-1, the characterization of sediment in Railroad Creek was qualitatively
assessed at each aquatic habitat sampling station (see Section 3.9), and during the initial geomorphologic
survey of the creek. Observations included mapping dominant bed material (based on observation and
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