THE COST OF ENVIRONMENTAL PROTECTION IN MAINTENANCE DREDGING

摘要

The cost of safeguarding the environment during maintenance dredging may have risen with the passage over time of more and more legislation to protect the environment. One way to examine the impact is to study components of and trends in the cost of environmental protection. To keep this examination manageable the study is limited to maintenance dredging contracts in the continental United States planned, designed and contracted by Jacksonville District, U.S. Army Corps of Engineers. The Jacksonville District oversees maintenance dredging of fourteen deep-draft and seventeen shallow-draft Federal harbor projects.A companion paper (publication in progress) addresses the cost of environmental protection in construction dredging contracts. Maintenance contracts warrant scrutiny since they may involve dredging equipment such as hopper dredges not commonly used in construction. Hopper dredges have features such as turtle deflectors on their dragheads that intend to protect the environment and for which there is a cost, both to equip the dredge with the draghead and also in lower production rates. Hopper dredging contracts contain additional bid line items such as sea turtle trawling.The major objective of this paper is to present, analyze and interpret data on costs of protecting the environment during maintenance dredging events.Line item pricing data collected from solicitation bid summaries was analyzed. Trends over time were noted and examined. Emphasis is placed on costs to protect the environment that are incurred during the dredging process.The major result of this study is the observation that although intuitively one senses from qualitative examination of the planning, design and construction process that more and more funds are spent on environmental protection as time goes by, quantitatively this idea cannot be substantiated from an analysis of bid pricing information. This may be because many measures are put in place to protect the environment that are not tangible.