Los Angeles Basin Contaminated Sediments Task Force

Summary of Upland Disposal and Beneficial Reuse Committee Meeting

on October 14, 1998

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Attendees

Michael Lyons, Los Angeles Regional Water Quality Control Board
Lauma Jurkevics, 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
Rod Nelson, Los Angeles Regional Water Quality Control Board
Jim Ross, Los Angeles Regional Water Quality Control Board
John Lindsey, ECDC Environmental
Gretchen Honan, CH2M-Hill

Landfills Disposal Alternative

Rod Nelson, Chief of the Landfills Unit at the Regional Board, presented information to the subcommittee.

Los Angeles County is responsible for providing sufficient capacity for garbage disposal, and may not wish to use up capacity to accommodate sediments. There could be a use for sediments as daily cover, but most landfills have a ready supply of dirt and would not need our material. As a rough estimate, a 10-acre active landfill area might require up to 8000 cubic yards for daily cover. If we were able to utilize daily cover as a disposal alternative, the Regional Board probably would restrict use to the dry period (e.g., June-October).

Chlorides in the sediments still present a problem for this type of use. Although most landfills are lined, the liners are not perfect and tend to leak. This usually is not viewed as a major problem, since contaminants do not tend to migrate rapidly. However, chlorides can be mobilized much more rapidly, so the Regional Board would prefer not to introduce this material into most landfills. The Regional Board might restrict sediment disposal to canyon landfills, but these landfills normally do not need daily cover (they cut down the mountain to get dirt for cover).

Brownfields Remediation

Jim Ross, Chief of the Site Remediation Unit at the Regional Board, presented background information to the subcommittee.

Brownfields Remediation streamlines the regulatory process by providing an opportunity for developers to use contaminated sites to make an economic profit. Nearly all of the sites (perhaps 95%) with contaminated sediments involve treatment and reuse, since it is too expensive to haul away the soil. The treatment process may result in the need to replace about 10% of the existing soil, due to consolidation losses during treatment. In addition, extra material could be required as developers increase grade at the site. However, stability might be a problem with the use of dredged sediment.

Several sites could require fill material in the near future: GATX/Texaco (in Carson, at Sepulveda and Alameda) may require approximately 250,000 cubic yards to fill a sump in the next year or two; Western Fuel Oil (110 Freeway at Gaffey) may need approximately 200,000 cubic yards to restore grade for a transfer facility (note: this is not really a Brownfields remediation); Chevron El Segundo has big sumps that might need filling, and other refineries (ARCO, Mobil) could be in the same position; Cal Compact Landfill (Main and 405 freeway, in Carson/Torrance) could use approximately 1 million cubic yards to compact an old landfill for development.

Most of these sites are not coastal sites, so concerns about chlorides might prevent dredged material from being used as fill. Also, since facilities at these types of developments would not be permanent, any material disposed of at these areas could be exposed in the future if uses of the site change. There also could be concerns about liability from the recipients of the dredged material.

Assignment: Michael Lyons will try to obtain a map of potential sites from the Site Cleanup Unit and identify coastal sites (where chlorides would not pose a problem)

Concrete Stabilization

John Lindsey, ECDC Environmental, presented information to the subcommittee. Laidlaw changed its name to Safety Klean, which owns ECDC and ITEX. ECDC moved 180,000 cubic yards of contaminated sediments from New York Harbor to Utah, at a cost of approximately $122 per cubic yard. They have allied with ITEX to look at treatment of sump materials.

ECDC currently is processing approximately 6000 cubic yards per day (with a high of 12,000 cubic yards) in New Jersey. Excess water is pumped to high volume tanks, where it is reused in the stabilization process. After debris removal, cement based additives (8-10% by volume) are blended into a slurry. Mixing and blending, with proprietary equipment, is the key stage in the process, which results in in-situ stabilization of the material, with dewatering through curing, an increase in the load bearing strength of the product and decreased leachability and mobility of contaminants. The stabilized material then can be used for construction, which has been done in the Port Newark Upland Beneficial Use Site and the Hudson County Upland Beneficial Use Site. The total cost for dredging, treatment and disposal in New Jersey is approximately $43 per cubic yard.

Assignment: The Ports (Larry Smith, Port of Los Angeles; Tom Johnson, Port of Long Beach) will investigate the feasibility of utilizing this process in our area.

Next meeting: Tuesday, November 17, 1998


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