Nutrient assimilative credits are the public acknowledgement and certification of the nutrient assimilation services. Currently, nutrient assimilative credits are not formally part of state and federal efforts to improve water quality conditions in the Chesapeake Bay. One of the objectives of this effort is to explore whether and how nutrient assimilation credits can be created and incorporated into existing water quality programs. Critical to this objective is investigating ways financial payments can be created so as to provide the private sector with reasons to explore and invest in creating nutrient assimilative credits.
Past and current efforts aim at reducing nutrients in the Bay by reducing nutrients from point and nonpoint sources by providing public subsidy or cost-share programs to install new equipment (ex. capital upgrades to wastewater treatment plants) or specific best management practices. Financial incentives to produce nutrient assimilation credits could be created if public subsidy programs paid for nutrient reductions on per pound basis. Nutrient assimilation credits providers could receive these incentive payments if this type of nutrient removal could be achieved at a lower cost than source reduction technologies.
Nutrient assimilation credits from oyster aquaculture may also be used as another way to help regulated entities meet their nutrient control requirements. For example, most Bay states have imposed stringent nutrient mass load limitations on point source dischargers. Nutrient trading programs are being designed to help point sources find ways to offset new nutrient loads from economic and population growth. In other cases, local areas may require developers to offset nutrient loads created by new development. Nutrient assimilation credits could provide another option for these regulated parties to expand without jeopardizing achievement of the water quality goals of the Chesapeake Bay.
Illustrations and Applications:
Nutrient assimilation credits in market-based nutrient trading programs
Shabman, L. and K. Stephenson “Achieving Nutrient Water Quality Goals: Bringing Market-like Principles to Water Quality Management. Journal of the American Water Resources Association. 43 (August 2007) 4: 1076-1089. Abstract
Nutrient trading with mussels in Sweden
Lindahl, O., R. Hart, B. Hernroth, S Kollberg, L Loo, L Olrog, A Rehnstam-Holm, J Svensson, S Svensson and U Syversen. 2005. “Improving marine water quality by mussel farming: a profitable solution for Swedish Society.” Ambio 34 (2005) 2: 131-138. Abstract
Nutrient assimilation credits from wetland restoration
An initiative to create nutrient assimilation credits (called nutrient farming) from the construction of wetlands in Illinois. Read more.
