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Proposed Nutrient Criteria for Missouri Lakes and Reservoirs

Environmental Protection Agency (EPA or the Agency) proposes to establish federal Clean Water Act (CWA) nutrient criteria (i.e., total nitrogen, total phosphorus and chlorophyll a) for lakes and reservoirs under the State of Missouri’s jurisdiction, to protect designated uses from the effects of exposure to harmful levels of nutrients and algal blooms. 

In 2009, Missouri submitted to EPA for review and approval numeric criteria for total nitrogen, total phosphorus, and chlorophyll a for the State’s lakes and reservoirs.  EPA acknowledged the importance of Missouri’s proactive efforts to address nutrient pollution by adopting numeric nutrient criteria.  However, EPA concluded that Missouri had failed to demonstrate the criteria would protect the State’s designated uses as required by 40 CFR §§131.6(b) and (c) and disapproved most of Missouri’s criteria on August 16, 2011. 

On February 24, 2016, the Missouri Coalition for the Environment (MCE) sued EPA for failure to perform its mandatory duty under the CWA to propose and promulgate criteria to address EPA’s 2011 disapproval.  On December 1, 2016, EPA entered a consent decree with MCE that committed EPA to sign a notice of proposed rulemaking by December 15, 2017 to address EPA’s 2011 disapproval, unless the State submits and EPA approves, nutrient criteria that address the disapproval on or before December 15, 2017.  At the time this proposal was signed, Missouri had not adopted and submitted its rule for EPA Clean Water Act 303(c) review. EPA will not proceed with final rulemaking (or will withdraw its final rule, if applicable) to address its 2011 disapproval if Missouri adopts and submits criteria to address EPA’s 2011 disapproval and EPA approves them as meeting CWA requirements.

Public Hearings

Comments on the Proposal

The 61-day comment period for this proposal opened on December 27, 2017 and closed on February 26, 2018.

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