Sewage Treatment Plant Contamination of the Annapolis River: Economic Implications for the Soft-shell Clam Industry

Abstract

The Annapolis Basin soft-shell clam fishery has been impacted by frequent closures due to sewage contamination from overflow at the Town of Digby sewage treatment plant. The harvesters that derive a livelihood from this traditional fishery have suffered economic losses that have not been widely acknowledged, addressed, or quantified.

For years, individuals and organizations in the Annapolis Basin area pushed to have the sewage treatment plant in Digby upgraded to remediate the environmental damage that its under-capacity was causing. The investment in the upgrade was estimated at $2.2 million, while the cost of doing nothing was never measured.

The objective of this thesis is to examine the economic implications for the soft-shell clam industry of the contamination of the Annapolis Basin using a simple cost-benefit framework. By isolating the interaction between the sewage treatment plant upgrade and the soft-shell clam fishery, the analysis identifies and estimates principal costs and benefits, measuring the net present value of the prevention of fishery closure resulting from the upgrade. Results of the analysis demonstrate that the investment in the upgrade is justified under a range of closure scenarios and deviations in key assumptions and variables.