Sediment remediation: How much does it really cost?

As the number of sediment remediation projects undertaken grows each year, an accurate estimate of the financial liability associated with managing such projects increasingly becomes a priority. Quite often, however, the remedial cost estimates prepared during the initial phases of a project vary from the actual costs subsequently incurred during the remediation phases. This variance can be the result of several factors, including weather-related conditions, water management practices, unforeseen site conditions, and environmental requirements, to name a few. As such, this paper provides a discussion of those cost factors and approaches which can be employed to arrive at cost estimates. Actual remediation experience at sediment sites is incorporated into the discussion of cost uncertainties. These experiences illustrate how several variables can affect the final costs of a remediation project. To conclude the paper, a general discussion of the reliability of such approaches also is presented. Specifically, the paper is divided into three primary sections: Discussion of the variables and uncertainties that can result in a significant increase in actual project costs; Description of three approaches to estimating costs traditional, cost-range, and Monte Carlo approaches; and Discussion of a reasonable approach to managing cost uncertainties. Throughout the paper, actual project experiencemore » with sediment remediation is used to illustrate the paper`s points.« less