Challenges in Implementing Numeric Nutrient Criteria: A Wisconsin Case Study

The 2014 Toledo water supply crisis highlighted the threats posed by nutrient pollution in the nation’s waterways, and raised the awareness of issues like hypoxia and toxins produced by algae. Sitting at the headwaters of the Mississippi and in the drainage basins of the Great Lakes, Wisconsin was one of the first states in the nation to pass a numeric phosphorus water quality standard applicable to all waterbodies. Approved by the United States Environmental Protection Agency (USEPA) in 2010, the standard now serves as the basis for calculating water quality based effluent limits, total maximum daily loads, and other regulatory limits that directly impact wastewater permit holders. The State of Wisconsin Department of Natural Resources (WDNR) has made available a number of alternative compliance options designed to mitigate the costs of implementation for permit holders by asking point source permit holders to work with nonpoint sources through water quality trading and adaptive management to implement practices to reduce nonpoint phosphorus pollution. However, as of 7.1.2015 (the date of abstract submittal), no water quality trade or adaptive management plan has yet been used by a point source to meet a permit limit.

In the absence of adaptive management or water quality trading options, most permit holders have been evaluating the costs of nutrient removal through the installation of advanced filtration treatment systems, or through aggressive chemical addition. These approaches have raised concerns not only about the costs associated with this removal, but also with the ultimate impact that this approach may have on water quality in the state’s surface waters. This led the Wisconsin legislature to pass a bill requiring the State Department of Administration to work with the WDNR) to assess whether the statewide costs of implementing the standard result in adverse substantial widespread economic and social impacts. In May of this year, the State released its preliminary determination that the cost of compliance with the standard would result in adverse, substantial widespread economic and social impacts. The State is still developing the ultimate implementation plan that will be submitted to the USEPA in late fall for approval as a multi-discharger variance applicable to qualified facilities.

This paper briefly describes the history of the Wisconsin numeric phosphorus criteria, basic mechanisms of Wisconsin’s water quality trading and adaptive management program, and the challenges that have many facilities looking toward an alternative solution through a new multi-discharger variance. Wisconsin’s experience in implementation over the last five years provides a number of lessons for states in the process of developing numeric criteria, seeking to utilize water quality or adaptive management as permit compliance mechanisms, and looking for the most effective ways to improve water quality in surface waters affected by both point and nonpoint sources.