ACOE Core Sampling Complete

Hi George --

Were you able to get the sampling completed last week? How did it go?

Rob Montgomery

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Steve,

George Millar and I collected sediment samples on 1 Jul 10 at the 5 locations shown in the attached file. The lake was high (779.18') and sediment samples representative of potential dredge cuts were taken to 772' and an additional sample was collected from 772' to 771' at each site. Grain size analyses will be performed on all 10 samples, while chemical analyses will be performed on the six samples collected from sites 1, 2 and 3. An initial attempt was made to use a 48" core sampler to collect the samples; however, problems were encountered with part of the sample being "sucked" out of the sampling tube. We switched to a stainless steel hand auger and that worked fine.

In general, there was little variability between the sites. Typically the upper layer consisted of fine sand with silt/clay and varying amounts of organic matter (peat), while the lower 1' layer contained greater amounts of peat. Site 3 was different than the others in that the predominantly peat layer was at a higher elevation. We originally collected samples for chemical analysis at site 4, but when we saw that the profile at site 3 was somewhat different than the other four sites, we decided to switch the chemical analysis to site 3.

The samples were shipped to Pace Labs in Green Bay for chemical analysis and the results should be available in two weeks. Grain size analyses will be performed in-house. Please let me know if you have any questions.

Thanks,
David P. Bierl
Hydrologist
U.S. Army Engineer District, Rock Island Water Quality and Sedimentation Section