Economic Impacts of Zebra Mussels on Drinking Water Treatment and Electric Power Generation Facilities

Invasions of nonnative species such as zebra mussels can have both ecological and economic consequences. The economic impacts of zebra mussels have not been examined in detail since the mid-1990s. The purpose of this study was to quantify the annual and cumulative economic impact of zebra mussels on surface water-dependent drinking water treatment and electric power generation facilities (where previous research indicated the greatest impacts). The study time frame was from the first full year after discovery in North America (Lake St. Clair, 1989) to the present (2004); the study area was throughout the mussels’ North American range. A mail survey resulted in a response rate of 31% for electric power companies and 41% for drinking water treatment plants. Telephone interviews with a sample of nonrespondents assessed nonresponse bias; only one difference was found and adjusted for. Over one-third (37%) of surveyed facilities reported finding zebra mussels in the facility and almost half (45%) have initiated preventive measures to prevent zebra mussels from entering the facility operations. Almost all surveyed facilities (91%) with zebra mussels have used control or mitigation alternatives to remove or control zebra mussels. We estimated that 36% of surveyed facilities experienced an economic impact. Expanding the sample to the population of the study area, we estimated $267 million (BCa 95% CI = $161 million–$467 million) in total economic costs for electric generation and water treatment facilities through late 2004, since 1989. Annual costs were greater ($44,000/facility) during the early years of zebra mussel infestation than in recent years ($30,000). As a result of this and other factors, early predictions of the ultimate costs of the zebra mussel invasion may have been excessive.     

Treatment of mixed contamination in water using cyclodextrin‐based materials

This study investigated the effectiveness of a cyclodextrin‐based solid material for the removal of mixed dissolved contaminants. The solid material was prepared by condensation of α‐cyclodextrin. The removal efficiency was found to be 70 percent for total heavy metals (cadmium, lead, chromium, iron, nickel, cobalt, and mercury) to 98 percent for polychlorinated biphenyls (PCBs). The optimum pH for heavy metal removal was approximately 5 and for PCBs it was in the range of 5–7. All of these heavy metals were successfully recovered from the spent cyclodextrin‐based material using nitric acid, allowing the material to be reused for further passes. The results also showed that the presence of alkaline and alkaline earth metals did not have a significant effect on the removal efficiency, indicating that the cyclodextrin‐based material could selectively remove the heavy metals of concern without being consumed by alkaline and alkaline‐earth metals. © 2006 Government of Canada.     

Assessing the relation between the distribution of salt-marsh communities and the sediment budget of the North Norfolk coast

Very high resolution imagery from an airborne multi-spectrål scanner has been used to estimate the distribution of different salt-marsh communities along a 30-km stretch of the North Norfolk coast. Field observations have been used to develop a mathematical relationship between the vegetation, physical environment and sediment accumulation. This relationship has been used to produce provisional sediment accretion maps for the north Norfolk coast.     

Use of biological monitoring in the assessment of effects of mining wastes on aquatic ecosystems of the alligator rivers region,tropical Northern Australia

The primary objective of the biological monitoring program of the ARRRI is to develop techniques and procedures to monitor and assess effects of the mining and processing of ores on aquatic ecosystems of the Region. Studies have been made in a seasonal tributary (Magela Creek) of the East Alligator River near the Ranger Uranium Mine, and in the upper South Alligator River (SAR) near the Coronation Hill gold, platinum and palladium prospect. Ranger and Coronation Hill are enclosed by Kakadu National Park, environmental safeguards for which require the minimization of impairment of water quality in the aquatic ecosystems. Present studies on Magela Creek are designed to verify the adequacy of release standards, based on biological tests, in protecting the aquatic environment during and after releases of waste-water from Ranger during the Wet season. Detection of short-term effects will be sought by either creekside orin situ monitoring methods. The detection and assessment of any longer-term impacts, however, will rely chiefly on comparisons of post-release data with those of historical baselines. Such baseline information is provided by studies on the structure of macroinvertebrate and fish communities and/or on concentrations of elements in organisms in those communities, in Magela Creek and SAR catchments.     

A Decision‐Analytic Approach to Managing Climate Risks: Application to the Upper Great Lakes1

Brown, Casey, William Werick, Wendy Leger, and David Fay, 2011. A Decision‐Analytic Approach to Managing Climate Risks: Application to the Upper Great Lakes. Journal of the American Water Resources Association (JAWRA) 47(3):524‐534. DOI: 10.1111/j.1752‐1688.2011.00552.x Abstract: In this paper, we present a risk analysis and management process designed for use in water resources planning and management under climate change. The process incorporates climate information through a method called decision‐scaling, whereby information related to climate projections is tailored for use in a decision‐analytic framework. The climate risk management process begins with the identification of vulnerabilities by asking stakeholders and resource experts what water conditions they could cope with and which would require substantial policy or investment shifts. The identified vulnerabilities and thresholds are formalized with a water resources systems model that relates changes in the physical climate conditions to the performance metrics corresponding to vulnerabilities. The irreducible uncertainty of climate change projections is addressed through a dynamic management plan embedded within an adaptive management process. Implementation of the process is described as applied in the ongoing International Upper Great Lakes Study.