Attendees
Michael Lyons, Los Angeles Regional Water Quality Control Board
Jim Raives, California Coastal Commission
Larry Smith, Port of Los Angeles
Tom Johnson, Port of Long Beach
Mitzy Taggart, Heal the Bay
Dean Smith, Los Angeles County Beaches and Harbors
Tony Risko, U.S. Army Corps of Engineers
Steven John, U.S. Environmental Protection Agency
Gretchen Honan, CH2M-Hill
The group reviewed potential disposal options:
Landfills
Gretchen Honan presented some information from the study conducted by CH2M-Hill for the Army Corps of Engineers regarding potential use of landfills as disposal sites. The major obstacles for use of landfills in Southern California appear to be limited capacity and unacceptability of material due to chloride content. High cost becomes an issue for transport of material to landfills outside of California. A new landfill is being permitted in Riverside (Eagle Canyon), which could be a potential disposal site for contaminated sediments. Since contaminated sediments are below hazardous waste levels, the presence of contaminants does not appear to be an obstacle for disposal at landfills.
Assignments: Jim Raives will get background info on use of dredged sediments in landfills in the San Francisco Bay area (Region 2), Gretchen Honan will look for more background info from her contacts, Michael Lyons will discuss capacity and chloride issues with landfill staff at Los Angeles region. Due date = August 30th.
Constructed Fill
The Port of Los Angeles and Port of Long Beach both have experience with using contaminated sediments within new sites created for port facilities (e.g., new container facilities). Fine-grained material causes problems in trying to compact the material.
Assignment: Larry Smith (Port of LA) and Tom Johnson (Port of LB) will review past projects to assemble possible criteria for this disposal option. Due date = September 30th.
Blending is one way to utilize fine-grained material (i.e., mix it with coarser material to obtain a structurally acceptable blend). However, it is not that simple to blend large quantities of sediments thoroughly enough to remove all pockets of soft material. This may require some type of dedicated machinery.
Assignment: Tom Johnson (Port of LB) and Moffatt and Nichol will review existing information. Due date = September 30th.
Treatment
The COE has been looking at physical separation of sediments (probably centrifugation), which ideally would separate clean, coarse-grained material from contaminated, fine-grained material. This procedure would have two advantages: production of good material for beach replenishment or other uses, and reduction of the volume of contaminated material for disposal. The technique appears promising; however we need to investigate the nature of any return water/process water (would it be contaminated?) and method of disposal. The method must be tested with marine sediments to ensure success.
Assignment: Moffatt and Nichol will do some background investigation on these issues. Due date = August 30th.
The COE also has been looking into concrete stabilization, which could be used to render contaminated coarse-grained material suitable for use in constructed fill projects. This process would require space for implementation and could be expensive (@$60 per cubic meter). We also need to be sure that this technique locks up chlorides and organics.
Assignment: Moffatt and Nichol and Gretchen Honan will review previous projects to provide initial information on these issues. Due date = August 30th.
Another potential reuse method is to utilize contaminated sediments in the manufacture of asphalt, but this technique is not proven with marine sediments.
Brownfield Remediation
The technique of placing contaminated material onto remediation sites, capping it and paving over the site, appears promising as a means of disposal. We need more background info on this process and criteria for use.
Assignment: Steven John (EPA) will conduct preliminary investigation. Due date = August 30th.
Next meeting: Wednesday, September 9, 1998, 10 am to noon, LA Regional Board office (Monterey Park)
Return to the Contaminated Sediments Task Force Committee Meetings page.
Return to the Contaminated Sediments Task Force home page.
Return to the California Coastal
Commission's home page.