What is open water disposal?
Open-water disposal is a state and federal approved dredged material disposal program where unconfined dredged material is placed at designated sites in oceans, estuaries, (a bay may be a large estuary) rivers and lakes in a manner that dredged material is not isolated from the adjacent waters during placement.
Placement is generally via release from pipelines, barges or hoppers. (Dredged Sediment is released into the environment from a pipe or by opening the bottom of a barge and allowing the material to drift down to the bottom).
Open water sites can be either dispersive or non-dispersive (retentive or non-retentive) depending on whether the sediment is transported out of the site or remains within the designated boundaries. Generally, clean or mildly contaminated sediments are disposed of in open water, although the disposal of highly contaminated material can also be considered with appropriate control measures.
Regardless of the type of in-water disposal, placing dredged materials in the aquatic area raises several key concerns, including sediment and water quality, sediment transport, water circulation, impacts to fisheries, and impacts to biological communities, especially endangered/threatened species.
Sediments placed in water must meet sediment quality regulations outlined in the Dredged Material Evaluation Framework. The majority of sediment disposed in the estuary's aquatic area consists of coarse, clean sand dredged from maintained navigation channels. This material must meet the water and sediment quality standards (SQS).After sediment is placed in an open water disposal site, some or all of it is eventually transported to other areas, potentially resulting in adverse impacts to shallow productive areas and fishing areas, resulting in an increase in dredging requirements on other projects. (Creating a cycle of dredging and additional clean up).The sediment transport patterns at in-water sites need to be assessed prior to disposal.
Disposing of material in-water usually creates a mound or otherwise obstructs water flow. Consequently, water circulation patterns in the vicinity of the disposal site are altered. These changes can have detrimental effects. For instance, unexpected erosion or accretion can occur downstream from the disposal site. Conversely, the changes can sometimes be beneficial. For example, the scouring of the channel can be increased. In all cases, the potential effects that may result from circulation changes need to be assessed prior to undertaking disposal.
In-water disposal often results in the direct smothering of benthic organisms at the disposal site and indirect impacts to organisms living down current from the site. Disposal often impacts commercial fisheries by decreasing the size and depth of net drifts, potentially creating snags in fishing areas, and obstructing fishing access with dredging equipment.
As of 2003, the US Army Corps of Engineers (USACE) biennial report states that 78,883 cubic yards of dredged material has been disposed at the Bellingham Bay open water disposal site.
The USACE estimate that the site can absorb up to 181, 500 additional cubic yards over the next 50 years.
The Bellingham Bay site was closed in the 1960’s, but re-opened in the 1980s. There is no record of the contaminants that were dumped during the 1950s and 60s. Nor has the site been monitored for contaminants since it was re-opened during the 1980s. Both the tribes and the City objected to the site, but it was crammed down our throats anyway.
Who can use the site? We don’t have all of the answers, but in the I & J Waterway PSDDA Sediment Characterization Sampling and Analysis Plan, RETEC (Port of Bellinham Consultant) estimates that mercury laced dredged materials that pass chemical and biological guidelines may be disposed of at the Rosario Straits dispersive site, or the Bellingham Bay non-dispersive open water disposal site as part of the proposed clean up project for Bellingham Bay.
Additional information regarding the dredging of the I & J Waterway can be found on the Dept of Ecology website under the I & J Waterway PSDDA Characterization and Sampling Analysis Plan.
Hence, the Port of Bellingham plans to use the Bellingham Bay site, or the Rosario site to dispose of “low level” contaminated dredged materials from the I&J Waterway, the Whatcom Waterway and Squalicum Harbor clean up. All of the materials contain low to high levels of contaminants.
The Bellingham Bay disposal site has been used off an on since the 1960’s to dispose of contaminated sediments. Early dredged materials were not tested for contaminate levels prior to dumping.
To date, the site has not undergone thorough testing to determine toxicity levels or the suitability of the site for future dredged material disposal.
Local tribes have long referred to the Bellingham Bay site as a dead zone for fishing.
How can I learn more?
The USACE publishes biannual DMMP reports on the Region 10 website. The reports are easily accessed through Ecology’s Aquatic Lands Cleanup webpage. Scroll down to the bottom of the page. Click the DMMP Biennial Reports link under the “other links” heading and you will be taken to the Region 10 website with four DMMP reports for Puget Sound.Again, there is very little information published on the Bellingham Bay open water disposal site. To date, reports state that only partial monitoring studies have been completed for the Bellingham Bay Disposal site.
The WA State Department of Natural Resources (DNR) has recently placed Bellingham on a list of proposed open water disposal sites to be evaluated, tested and monitored over the next two years by a private consulting firm. By statutory requirement, DNR provides, manages, and monitors aquatic land disposal sites on state owned aquatic lands for materials dredged from rivers, harbors, and shipping lanes. Currently, permits to dispose dredged materials at the Bellingham Bay site are issued by the Army Corps of Engineers DMMP program. Federal law does not require publication of permits for open water disposal.
Bellingham is one of twelve open water dredged material disposal sites in Washington. (Six are currently in use).
An EPA diver report on Bellingham Open Water Disposal site:
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: 48o 49' 40" N Lat. and 122o 31' 30" W Long. in Bellingham Bay; 48o 31' 04" N Lat. and 122o 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.
There are dozens of reports and studies on this topic.
Seattle PI Article regarding disposal of PCB contaminated sediment: http://seattlepi.nwsource.com/local/331350_port12.htmlLinks to other sediment management agency sitesUS Army Corps of Engineers Seattle District HomepageDredged Material Management Office - US Army Corps of Engineers Seattle District Dredged Material Management Program (DMMP)/Puget Sound Dredge Disposal Analysis (PSDDA) Clarification PapersDMMP Biennial ReportsEnvironmental Protection Agency Region 10 HomepageEPA Region 10 Sediment LinksWashington Department of Natural Resources HomepagePuget Sound Water Quality Action Team HomepagePuget Sound ProtocolsOpen Water Disposal Techniques (great pictures)http://el.erdc.usace.army.mil/workshops/08apr-doer/9_OpenWaterDisposal_Bailey.pdfI&J Waterway document: http://www.ecy.wa.gov/programs/tcp/sites/blhm_bay/sites/I_and_J_Waterway/I&J%20Seds%20RIFS%20App%20B%20Text.pdfMichigan Governor bans open water disposal of certain chemicals in Lake Michiganhttp://www.michigan.gov/gov/0,1607,7-168--84861--,00.htmlErosion of Cohesive Dredged Material inOpen-Water Disposal Siteshttp://el.erdc.usace.army.mil/elpubs/pdf/drp1-07.pdfToxic Contaminants of Sediments in Puget Sound http://gbic.tamug.edu/gbeppubs/T3/gbnepT3_51-56.pdfApplicable Washington Administrative Code authorizing open water disposal of dredged materials WAC 332-30-166http://apps.leg.wa.gov/WAC/default.aspx?cite=332-30-166