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Costs for Controlling Dreissenid Mussels Affecting Drinking Water Infrastructure: Case Studies

Dreissenid mussels—zebra mussels (Dreissena polymorpha) and quagga mussels (Dreissena rostriformis bugensis)—have infested various North American waters used for drinking water, causing clogging of water intakes and pipes and contributing to the formation of disinfection by‐products. The management and control of mussels that have infested various treatment plant components (e.g., intake structure, pipes) is a priority for facility managers. Ten case studies of drinking water facilities contending with ongoing mussel infestations illustrate the capital costs and operations and maintenance (O&M) costs related to mussel control. The O&M‐based unit costs of mussel control varied from $34.32/mil gal for 1‐mgd capacity to $12.63/mil gal for 2,640‐mgd capacity. The capital cost and O&M‐based equivalent annual unit cost for treatment varied from $78.56/mil gal for 1‐mgd capacity to $13.41/mil gal for 2,640‐mgd capacity. Costs for larger water treatment plants (i.e., >10 mgd) varied between $1.00/mil gal and $13.00/mil gal.