BARRIERS TO IMPLEMENTATION

ERDC TN-DOER-T2

December 2000

or the mixing with other fill components. The resulting stabilization, however, is expected to

significantly reduce the potential for leaching of the contaminants. A significant barrier to use of the

resulting material, however, is the lack of regulatory standards for use of the product. Fill product

criteria based upon total contaminant levels are not likely to significantly expand the potential uses

of this material while fill product criteria based upon regulatory leaching tests may not receive

sufficient community acceptance.

Thermally based treatment/destruction technologies have the advantage of significant destruction of

at least the organic contaminants in the dredged material. Conventional incineration faces

significant community acceptance issues despite the potential for achieving essentially complete

destruction of the bulk of the contamination. The production of blended cement, lightweight

aggregate, or glass from the dredged material is likely to receive greater community acceptance.

The blended cement process includes dredged material with other components used to produce

cement. The use of cement kilns raises air emissions permit and community acceptance issues

similar to those for a conventional incinerator. The production of lightweight aggregate from

dredged material employs rotary kiln technology for the destruction of contaminants and production

of the aggregate, and similar air emission permitting and community acceptance issues arise. The

production of glassy products from dredged material employing a plasma torch has been proposed.

This process is related to the technology used for in situ vitrification and has similar energy

requirements and capital costs. Despite the production of a relatively clean product, the plasma

torch may be more applicable to small volumes of highly contaminated dredged material due to the

energy requirements and relatively high cost per unit weight of treated material.

The treatment of CDM becomes more attractive if alternative management options, such as disposal

in a less secure (and less expensive) landfill, are not available. Some benefit may be gained from

partial decontamination; but if there is no potential for expanded use of the residual dredged

material, it is unlikely that these processes can compete economically with direct disposal of the

dredged material in a landfill. The products of each of these processes have the opportunity to offset

part of the cost of treatment although introduction of these products to the marketplace in large

volumes will likely significantly negatively impact their value in the marketplace. The costs of these

decontamination processes are also likely to be high. An exception will be when a large-volume

dredged sediment stream can be guaranteed to allow the economies of scale. It has been estimated,

but not demonstrated, that all processes except the plasma torch technology can be applied for

between $30 and $70 per cubic yard of dredged sediment if amounts greater than 100,000 cu yd per

year for between 10 and 20 years can be guaranteed. The success of the various technologies and the

products they produce currently depends upon community and regulatory acceptance of their

respective operations and the proposed uses for the resulting products as well as demonstrated

effectiveness at a competitive cost.

BARRIERS TO IMPLEMENTATION: A number of barriers to technology implementation have

been identified:

The integration of treatment technologies into overall dredged sediment management.

Conventional short-term, competitive procurement processes that hinder capital invest-

ment and limit the ability of the TDF to buy supplies at the lowest possible price.