Sediment Management Studies

ASARCO Cap Survey, Ruston, WA

What: At the request of the Environmental Cleanup program, the EPA Region 10 Dive Team surveyed the Superfund sediment cap at the ASARCO/Ruston site.

Why: Diver survey objectives were to: 1) describe the baseline physical nature of the bottom, 2) photograph & locate objects and features of the cap such as mounds and debris, and 3) assess the amount or presence of cap material under-pier.

Where: ASARCO Superfund Site, Ruston, WA

When: Dive surveys were conducted in June, 2007.

How: Diver investigations included several dives to collect bottom samples and video.

Results: Divers found mounds of cap material, probably due to thicker placement areas. An assortment of life was found including crabs, various bivalves, and anemones in some areas. Limited cap material was found under-pier. Black sand (likely slag) was found mixed in with cap material in places.

More Details: http://yosemite.epa.gov/R10/CLEANUP.NSF/webpage/Asarco+Smelter+-+Ruston

Contact: Joe Goulet (206) 553-6692, Goulet.joe@epa.gov

Piling on the cap & diver Rob Rau holding GPS float (All photos from Dive #1 taken by Divemaster Bruce Duncan)	Ledge with anemones	Mounded area
Diver Rob Rau noting objects on cap	Surface view of cap area being surveyed/dock in background	Georeferenced photo locations and transect map of baseline diver survey

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Capping Contaminated Sediments (Denny Way Combined Sewer Overflow, Seattle, WA)

What: The EPA Region 10 Dive Team assisted the regional Water Resources Assessment Section by evaluating the capping of contaminated marine sediment in Elliott Bay in front of the Denny Way combined sewer overflow (CSO). Cap materials were clean upriver sands from the Duwamish River.

Why: Diver survey objectives were to: 1) describe the physical nature of the cap, 2) document conditions on the perimeter of the cap, and 3) evaluate colonization of the cap.

Where: Myrtle Edwards Park, Seattle waterfront, Washington. Approx. 47^o 37' 04.7" Lat; 122^o 21' 36.5 Long.

When: The 3-ft cap covering 3 acres was completed March 30, 1990. Dive surveys were conducted May 16, 1990.

How: Diver investigations included photographing and videotaping biota and sediment type along transects placed on top and adjacent to the cap.

Results: The cap was compact sand in a series of rolling mounds (4-6 ft relief). The surface was covered by an easily suspended organic deposit. Leaves and golf balls were common. Infauna appeared to be absent but mobile epifauna were common (crabs, sea stars, flatfish, nudibranchs, etc.).

More Details: Internal agency reports.

Contact: Rob Pedersen at pedersen.rob@epa.gov

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Coeur d’Alene Lake Benthic Flux Instrument Deployment

What: The EPA Region 10 Dive Team helped USGS to deploy an in-situ benthic-flux meter (lander) to support a pilot study by the Region 10 Superfund program and USGS.

Why: The pilot study was designed to determine the magnitude of benthic flux of trace metals (Cd, Cu, Mn, Hg, and Zn) and nutrients (ammonia, nitrate + nitrite, oxygen, orthophosphate, and silica) from contaminated lake bed sediments into the water column of Coeur d’Alene Lake. The primary question posed in this pilot study was, “Is the magnitude of the benthic flux of metals and nutrients in Coeur d’Alene Lake significant relative to riverine inputs?”

Where: Coeur d’Alene Lake, Idaho

When: The field work was conducted over a two-week period in August, 1999.

How: Divers submerged with the instrument, ensuring upright placement and a good seal on the lake bottom so that data collection would occur properly.

Equipment Used: USGS vessel with GPS; down lines.

Results: In this pilot study, flux estimates were made using both in-situ lander deployments and laboratory based core-incubations. While results were successfully collected using the lander, there were discrepancies between results of the lander and core-incubations. If further studies are planned, then concerns regarding the core incubation study would need to be resolved. To conclusively answer questions regarding benthic flux of nutrients and metals, a more spatially and temporally comprehensive study is recommended.

More Details: http://yosemite.epa.gov/r10/cleanup.nsf/sites/cda and http://water.usgs.gov/pubs/wri/wri004132/

Contact: Anne Dailey at dailey.anne@epa.gov


Flux instrument	Flux instrument deployment

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Disposal of Dredged-material at Open-water Sites

What: The Region 10 Dive Team participated in an interagency effort to assess benthic conditions at dredged-material open-water disposal sites in Bellingham and Padilla Bays, located near Bellingham and Anacortes, WA, respectively.

Why: At Bellingham Bay there was concern that the 58 acre marine disposal site lacked the capacity to contain additional dredged material from Corps of Engineers and Georgia Pacific dredging projects. At Padilla Bay, state resource agencies wanted to evaluate the effect of disposing of 150,000 cubic yards of sandy Swinomish Channel dredged material on an existing silt bottom. It was believed that a sandier substrate might improve Dungeness crab habitat at the disposal site.

Where: Center coordinates for the disposal sites are: 48^o 49' 40" N Lat. and 122^o 31' 30" W Long. in Bellingham Bay; 48^o 31' 04" N Lat. and 122^o 33' 05" W Long. in Padilla Bay.

When: The Bellingham Bay site was inspected in February 1979 and April 1982. The Padilla Bay site was inspected in April 1982.

How: Benthic observations were made along transects radiating out from the approximate center of the disposal areas. A buoy was located near the center of each site. Still photographs were taken. No sediment samples were taken.

Results: In 1979 at Bellingham Bay, the divers noted that 1) the bottom was composed mainly of compacted clay and silty sand, 2) the profile in the disposal area was very uneven (hummocky), and 3) some of the dredged material was located outside of the established disposal site (it was unclear whether the cause was "drift" from the site or short-dumping). By 1982, the profile at the Bellingham Bay site appeared to be much more even and the dredged material appeared to have settled. No evidence of erosion was observed and benthic animals were recolonizing the area. In Padilla Bay, the divers noted that despite the disposal of sandy dredged material, the dominant substrate still appeared to be silt. Based on the observations, the interagency dive teams recommended that continued dumping could occur at both disposal sites.

More Details: Dive report.

Contact: Rob Pedersen; pedersen.rob@epa.gov

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Diver Core Sample Collection, Portland Harbor Superfund Site, Terminal 4

What: The EPA Region 10 Dive Team assisted the Superfund program in conducting sampling at Terminal 4 within the Portland Harbor Superfund Site.

Why: Divers collected core samples to assist the Project Manager in recommending cleanup actions for this Non-Time Critical Removal.

Where: Under piers located at Terminal 4 at 11040 N. Lombard, Portland, OR approx. Latitude 45° 36.0’ N Longitude 122° 46.3’ W. (Core locations, PDF, 869Kb)

When: March, 2004.

How: Divers utilized three and one foot core tubes depending on the depth of sediment. In rip-rap areas, jars were used to collect surface sediment. Due to frequent combined sewer overflow (CSO) in the Portland area, decon procedures were necessary. See the safety / SOP page for more information on diver decon and polluted water scientific diving.

Results: Divers found that most under pier areas were covered with rip-rap and that available sediment for sampling was limited. At the berth between Slip 3 and Wheeler Bay, substantial sediment depth was encountered, allowing the three foot core tubes to be used.

More Details: http://yosemite.epa.gov/R10/CLEANUP.NSF/sites/T4

Contact: Sean Sheldrake, sheldrake.sean@epa.gov.


Rob Pedersen, UDO with 1 foot cores and jars.	Divers under pier in slip1	View of the bottom in 1 ft visibility: a thin layer of sediment over rip-rap under pier in Slip 3

Divers entering the water off the EPA vessel Monitor	The Monitor in Wheeler Bay with divers in the water under-pier	Sampling in low visibility: Diver collecting a jar sample off the bottom where there was core refusal.

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Occidental Survey, Hylebos Waterway, Tacoma, WA

What: The EPA Region 10 Dive Team with support from EPA Environmental Response Team divers (Edison, NJ) assisted the Superfund program in providing a video and hand-held Hydrolab survey, as well as installation of piezometers, passive diffusion samplers, and seepage meters for nearshore sediments off the Occidental site.

Why: Due to the discharge of contaminated ground water from the facility, Diver survey objectives were to locate any seeps that were visible to divers and document water quality in transition zone groundwater.

When: Dive surveys were conducted April through August, 2004.

How: Diver investigations included searches for seeps, water quality measurements on the bottom via Hydrolab, and installation of piezometers, passive diffusion samplers, and seepage meters. For more information on sample collection techniques used, see the EPA presentation at the March 2006 American Academy of Underwater Sciences (AAUS) conference (30 pp, 4.5 MB pdf). For more information on the AAUS, go to the AAUS website

Surface supply was used for seepage meter emplacement/retrieval and for retrieval of the diffusion samplers. Diver decon was necessary due to the contaminants being discharged from the site. See the safety / SOP page for more information on diver decon and polluted water scientific diving.

Adaptation of Ground-Water Sampling Tools for Underwater Deployment, AAUS, 2007 (20 pp. 1.23MB, About PDF)

Results: Though areas of visible, emerging seepage were not located on these dives, divers found white precipitate in areas where seepage had been reported in the past. Divers installed a number of piezometers across the facility (see Figure below). Water produced by the piezometers at times had pH exceeding 11, indicating the persistence of upland contamination in transition zone groundwater. Passive diffusion samplers were left in place for 3 weeks.

Where: Hylebos Waterway, approximately N47 16.89 W122 24.34

More Details: http://yosemite.epa.gov/R10/CLEANUP.NSF/webpage/Hylebos+Waterway

Contact: Bruce Duncan, Duncan.Bruce@epa.gov


Bruce Duncan (R10) and Rich Henry (USFWS attached to ERT dive team) discuss tasks	Rob Pedersen preparing to videotape zone of precipitate


Preparing to tie up at piezometer station #P6	Typical finger pier, riprapped shoreline, and facility tanks



Plotted GPS locations of piezometer installations	Aerial photo of site - (4 MB .ppt)



Tubing connected to the piezometer is released to the surface	Video: Precipitates on the bottom (broadband only, 24MB)

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Rhone Poulenc Groundwater Investigation, Duwamish River,
Seattle, WA

What: The EPA Region 10 Dive Team assisted the Superfund program in participating in a groundwater investigation at the Rhone Poulenc site in the Duwamish Waterway.

Why: Diver survey objectives were to install piezometers and provide core samples to assist in a groundwater/surface water interface study to determine the fate of organic and metals contamination known to be in groundwater.

When: Dive sampling was conducted in August, 2004.

How: Diver investigations included installation of piezometers and collection of core samples. Due to contaminants in sediments and the water column, diver decon was necessary to accomplish the scientific diving mission. See the safety / SOP page for more details on diver decon used by Region 10 and polluted water scientific diving in general.

Adaptation of Ground-Water Sampling Tools for Underwater Deployment, AAUS, 2007 (20 pp. 1.22MB, About PDF)

Results: Diver assisted sampling helped to better understand the diffusion of chemicals into the river environment, and what threat these chemicals pose to aquatic receptors. See the attached report below for more information.

Where: Duwamish River, approximately N47 31.127 W122 18.309

More Details: See the attached data report (15 pp, 2 MB .pdf), appendix (30 pp, 775 KB .pdf), QASP (PDF, 20pp. 170KB), and dive plan (9 pp 350 KB pdf):

http://yosemite.epa.gov/R10/CLEANUP.NSF/LDW/Rhone-Poulenc+Incorporated

Contact: Bruce Duncan, Duncan.Bruce@epa.gov



Divers Rob Pedersen and Lisa Macchio discuss sediment core collection aboard the vessel Monitor	Upland sampling occurring of seepage areas


Diver on tether brings piezometer tubing to surface for sample collection	Final adjustments for diver Rob Pedersen before descending.

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