Disposal options for dredged marine sediments based on physicochemical and toxicological characterization

This paper presents a methodology of evaluating management options for dredged sediments
on the basis of an array of characterization tests and gives an example application for the
sediments of Piraeus port. A conceptual model is proposed to guide selection among three
management options. The model provides for two tiers of assessment. In tier I, disposal in
open sea is evaluated based on a sequence of characterization tests. The final decision is
based on the combination of results from chemical and toxicological analyses, supplemented
by physical characteristics of sediments. In addition, tier I provides an indication of the need
for further characterization of the sediments, in order to determine whether environmental
remediation may also be required, independently of dredging activities. Tier II evaluates the
other two management options, disposal in landfills or in confined facilities, for the sediments
that did not meet tier I requirements for open-sea disposal. Decisions in tier II are facilitated
by well-established effluent criteria applied to saltwater and wastes admitted to landfills. The
application of the decision-making model for the sediment samples from the port of Piraeus
indicated that disposal to open sea is not feasible for the more contaminated sediments from
areas with increased shipping activities. Disposal in confined facilities proved a viable option
for most of the sediments, whereas all sediments were characterized as non hazardous and
can therefore be accepted in an ordinary landfill.