Los Angeles Basin Contaminated Sediments Task Force

Summary of Upland Disposal and Beneficial Reuse Committee Meeting

on April 7, 1999

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Attendees

Tom Johnson, POLB
Larry Smith, POLA
Michael Lyons, LARWQCB
Tony Risko, Corps
Russ Boudreau, Moffat & Nichol
Alistaire Callender, Hart Crowser
Dean Smith, LA County
Lauma Jurkevics, CCC

Constructed Fill Disposal Alternative

Port of Long Beach has offered to have a consultant (Wolfgang Roth, Dames & Moore) talk to us about his experiences with the port’s design of fill projects and the criteria used for design and acceptability (e.g. blending ratios, thickness of critical layer, physical method to blend good and bad material). This discussion will occur at the next subcommittee meeting (May 4th, 1-3 pm). Russ Boudreau, Moffatt & Nichol, also will look into geotechnical issues. Tom Johnson recapped the Port’s prior projects: Pier C involved having the contractor move around lots of substandard material with a bulldozer, but there is not much record of the details; the Pier J fill involved pouring soupy material from the LA River Estuary dredging into the fill site, but no real blending – this took a long time to settle and the project is not viewed as a success; the current Slip 2 fill was designed to provide earthquake stability and the necessary load bearing characteristics. Larry Smith recapped the Port of Los Angeles’ past experiences: Pier 300 accepted fine-grained sediments with contaminants from the main channel – there was no blending, they just pumped material in and sealed the site, resulting in fines being squeezed out through the dike and a lengthy surcharge process (approximately 15 years to become useable). Current Port of LA criteria call for not accepting fine-grained or contaminated material.

Constructed fill appears promising as a disposal alternative, but it is difficult to identify specific sites or when they will be available. We should write up the strategy to deal with this as a generic alternative, but recognize that we will need other disposal options (e.g., CAD sites). At this time, it looks like the Port of Long Beach will develop Pier K in the next several years (comparable to Port of Los Angeles’ Pier 400 project); although the size of the fill project has not been determined, it could accommodate a large quantity of contaminated fine-grained sediments over perhaps a 1-1.5 year period. The Port of Los Angeles probably will not have any large constructed fill projects in the foreseeable future.

Status Report Presented at March CSTF Meeting

The group discussed the one-page summary provided at the last CSTF meeting. We agreed to separate the landfill disposal option (a) into two sections: disposal at local landfills and disposal outside the local region (e.g., Utah). The outside landfills have some pros (unlimited capacity, willingness to accept material, train transportation), but cons include high costs, need for dewatering and site for stockpiling the material. Another con for local landfill use would be traffic and air quality concerns. We should add reuse for road base to our set of treatment options: work has been done on combining shredder fluff + contaminated sediments to create road base material (Hart Crowser will provide some info on East Coast experiences). For Brownfield remediation, we still need a list of sites.

Data Gaps/Additional Studies

  1. Concrete stabilization – how well does it lock up chlorides and petroleum hydrocarbons?
  2. Physical separation – would dewatering flow need to be treated prior to discharge back to ocean?
  3. Air pollution – can we quantify contribution from trucks needed to transport dredged material?
  4. Siting study – need to evaluate cost and feasibility of siting treatment and rehandling facilities (cost = @ $100,000 – 200,000).
  5. Physical separation – would LA River material be suitable for this process?
  6. Pilot study on how to blend (actual mechanical mixing process)?
  7. What is the critical thickness for the top layer in a constructed fill project?

Miscellaneous

Tom and Larry will talk about a Scope of Work to hire a consultant to conduct an Internet search for info on upland disposal and reuse. This should be available within a few weeks.

Next Meeting: May 4, 1999 – 1-3 pm, California Coastal Commission


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