International Dredging Review

International Dredging Review

Speakers Present Views on 30 Years of Progress in Dredging and Environmental Issues

WEDA Environmental Commission Panel – June 8 2010

The Environmental Panel at the Western Dredging Association (WEDA) conference in Puerto Rico was presented on June 8 by four dredging professionals who have dealt with environmental issues in their careers. Chaired by Craig Vogt formerly with the Environmental Protection Agency and now heading his own consulting company Craig Vogt Inc. the panel included Dr. Robert Engler Senior Environmenal Scientist at Moffatt & Nichol; Paul Quinn vice president of Ellicott Dredging Inc. and president of WEDA; Tom Wang senior partner Anchor Environmental QEA and Norman R. Francingues Senior Project Engineer OA Systems Corporation. The following are synopses of the talks.

Dr. Robert Engler
“The Foundation of Today’s Environmentally Sensitive Dredging Technology –
30+ Years of USACE Dredging Research 1973 – Present”

In 1972 the Clean Water and Ocean Dumping Acts were passed giving broad environmental regulatory and protection authority to the Corps. A significant Great Lakes confined disposal facility (CDF) construction program was also initiated in 1972. Both required technology advances. Moreover this follows closely the late 60’s advent of the Western Dredging Association (WEDA).

Dredging and dredged material disposal and wetlands protection were priority issues needing a fundamental and applied technology base in order to implement or comply. The Corps responded with the largest ever Civil Works R&D Program – the Dredged Material Research Program (DMRP) a $30-million five-year effort started in 1973. The DMRP addressed aquatic and confined disposal wetlands creation beneficial uses and regulatory implementation and compliance. Hundreds of reports summary documents and manuals were produced and two major conclusions reached; 1) No single disposal alternative is most suited for a region or project and 2) long-range regional planning is required for effective disposal management of dredged material. The DMRP formed the technical foundation in making the Corps a world leader in the environmental aspects of dredging and dredged material management. It also established the Corps as a competent environmental regulatory agency and the Waterways Experiment Station as their technical lead.

Shortly after the DMRP the Corps established the Dredging Operations Technical Support (DOTS) Program as the technology transfer and training arm that forms the largest world-wide dredging information base. The DOTS Program is maintained today at and encompasses the following: research data bases beneficial use case studies publications guidance documents (manuals) models Center for Contaminated Sediments expertise training dredging resources education center and worldwide related sites.

The Long Term Effects of Dredging Operations (LEDO) Program (1979-2002) addressed short and timely work efforts at risk-based procedures for effects assessment exposure assessment and risk characterization for managing contaminated sediments. In 1985 to 1991 the Field Verification Program (FVP) validated environmental assessment and regulatory manuals for upland aquatic and wetlands placement of contaminated sediment. During 1986-1994 the Dredging Research Program (DRP) directed applied research with the engineering side of the equation.

From 1998 to the present the Dredging Operations and Environmental Research (DOER) Program has been keeping the Corps current and at the cutting edge in: dredged material management environmental resource protection operations technologies and risk in support of the Corps navigation dredging mission. The program also supports CERCLA (Super Fund) TOSCA RCRA and numerous WRDA initiatives dealing with contaminated sediments and dredged material management.

Paul Quinn
“30 years of progress in dredging design and operation to address environmental issues”

Quinn gave examples of how dredging technology has changed through the years producing machines that are more energy efficient and environmentally friendly.

Tom Wang
“Has improved understanding of environmental impacts outpaced the ability of technology to mitigate impacts?”

Over the last 30 years in the dredging industry there has been much effort devoted (by USACE USEPA NOAA universities) to better understand the science behind environmental impacts caused by dredging and ancillary activities. As our understanding of the science associated with potential environmental impacts has grown there has not always been a commensurate advancement in either engineering design or construction technologies to address rapidly changing environmental policy.

Policy makers and regulatory authorities tend to rely on the science at times not equally considering the engineering and constructability considerations when setting new policy. Dredging contractors have been making technological improvements to dredging equipment positioning methods and operations especially in the area of contaminated sediment management. However expectations of regulators may be getting set higher due to the high profile nature and exchange of information from contaminated sediment projects without a comprehensive recognition that contaminated sediment projects are unique and perhaps should not be applicable when considering how to regulate non-remedial dredging projects.

Based on experience environmental policy that balances the sciences and engineering/construction capabilities results in the lowest overall environmental impacts. Policy that focuses too strongly on either side of the equation (e.g. heavily weighted toward engineering and construction or heavily weighted toward sciences) may unintentionally result in overall greater impacts.

The presentation gave several examples of changes over the past 20-30 years in the dredging industry on various changes and their implications. Examples included increased types and numbers of chemicals of concern monitoring method changes dredging technologies and operational changes positioning and surveying technology changes. The presentation concluded by asking several key questions:

• Do environmental regulations need to be revisited to account for newer measurement and monitoring technologies? Many existing environmental criteria were developed based on older technologies

• Are recent changes in regulatory policy based only on newer science without allowing for dredging technology to catch up?

• Are remedial dredging projects redefining the expectations for maintenance dredging performance and is that a positive outcome?

• How can the dredging industry keep up with the ever growing science of how dredging can impact the environment?

• How can the dredging industry actively work with policy makers and regulators to help develop more balanced policy and regulations?

Norman R. Francingues Jr.
“Three Decades of Environmental Dredging – How far have we come?”

The term “environmental dredging” has been used to describe a wide variety of dredging operations which include terms like restoration cleanup remedial hazmat precision surgical and even hybrid. Sometimes the term is used to describe highly specialized equipment or approaches to remove highly toxic waste materials remaining from historical discharge practices. In these cases the emphasis is entirely on environmental remediation.

“Environmental dredging” is also used to describe equipment and practices used to assist navigation dredging projects in meeting existing regulatory requirements for environmental protection. Dredging of navigation projects results in the removal of sediments from an existing or future channel to a depth and width adequate to support anticipated vessel traffic into or through the area. These projects tend to involve much larger sediment volumes and impact areas. Still environmental concerns may be significant ranging from protecting nearby sensitive habitat from the deposition of clean sediments to water quality and sediment toxicity concerns associated with mildly contaminated sediments.

Although dredging has been conducted for centuries to increase and maintain navigation depths in harbors and waterways the concept of environmental dredging is young in comparison. Much of the publicly available information on environmental dredging based on cleanup experience has been developed within the past 15 to 20 years. The TAMU/WEDA Meetings have provided a key forum to present environmental dredging technologies and strategies and to track their evolution. Approximately 80 technical papers related to environmental dredging have been presented at the WEDA annual meetings along with three separate sessions; two of them were in cooperation with the International Navigation Association PIANC.

Francingues gave a brief overview of the evolution of environmental dredging by examining what has been presented during the WEDA meetings through the years.