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Frequently Asked Questions Related to Development of Numeric Nutrient Criteria


What are numeric nutrient criteria?

Water quality standards are established in state rules as the goals for the protection of aquatic ecosystems, safe recreation and fishing, and provision of water supplies—the essential “designated uses” of surface waters. The standards contain water quality criteria (specific numeric values) that, when achieved, protect these goals. Numeric nutrient criteria are measurable levels of nitrogen and phosphorus (nutrients) set at values that will protect the designated uses of a waterbody from the harmful effects of nutrient pollution. Measurable levels of aquatic health related to the effects of excess nitrogen or phosphorus, such as the amount of algae or the water clarity, also constitute numeric nutrient criteria.

Why are numeric nutrient criteria important?

Nitrogen and phosphorus are essential to life on earth. But excessive levels of these nutrients can harm aquatic ecosystems and threaten public health. Nutrient pollution leads to harmful algal blooms, low-oxygen “dead zones,” and the destruction of wildlife and wildlife habitat. These effects can also disrupt human activities like fishing, swimming and seafood harvesting and they can threaten public health. Excessive nutrients represent the single most significant surface water quality problem in Florida today.

Can Florida implement numeric nutrient criteria on its own or does the Department need the approval of the United States Environmental Protection Agency (EPA)?

All states are required by the federal Clean Water Act to establish water quality standards and, in doing so, to secure EPA approval. EPA also has the authority to set water quality standards for states under a variety of circumstances.

Has EPA set numeric nutrient criteria for Florida?

Yes. To settle litigation at the federal level, EPA set numeric nutrient criteria for Florida’s rivers and lakes in December 2010. EPA also proposed marine criteria late in 2012 and is scheduled to finalize them by September 2013.

How did Florida respond to EPA’s action?

In April 2011, the Department petitioned EPA to hand numeric nutrient criteria rulemaking back to the state because the Department had developed the data necessary to support the federal rules and had been working to adopt state rules for some time prior to EPA’s action. Although EPA did not immediately respond to the petition, the Department moved forward promptly with state rulemaking, keeping EPA informed along the way.

What is the current status of the numeric nutrient rules in Florida?

The Department adopted numeric nutrient criteria covering 100% of Florida’s lakes, rivers, streams and springs along with the estuaries from Clearwater Harbor to Biscayne Bay, including the Florida Keys. The Florida Environmental Regulation Commission (ERC) unanimously approved the rules on December 8, 2011. And, on November 13, 2012, the Department secured ERC approval of numeric nutrient criteria rules for Panhandle estuaries: Perdido Bay, Pensacola Bay (including Escambia Bay), St. Andrews Bay, Choctawhatchee Bay, and Apalachicola Bay.

On November 30, 2012, EPA approved the Department’s numeric nutrient criteria for lakes, rivers, streams and springs, and for south Florida estuaries and coastal waters.

On the same day, EPA also proposed criteria for remaining estuaries, coastal waters, and south Florida inland flowing waters, and also re-proposed criteria for certain flowing waters outside of south Florida.

On February 27, 2013, the Department initiated numeric nutrient criteria rule development for the next set of estuaries: Suwannee Sound; Anclote River, South and Offshore; Pithlachascotee River and Offshore; Chassahowitska River and Offshore; Crystal and Homosassa Rivers and Offshore; Waccasassa River and Offshore; Lake Worth Lagoon; Loxahatchee River; Tolomato/Guana/Matanzas Rivers; Halifax River (south); and Nassau River. The Department is also seeking public comment on development of numeric nutrient criteria for offshore (open ocean) coastal waters.

How will the Department and EPA deal with the fact that there are EPA proposed rules and DEP rules, both already adopted and under development, that appear to address the same things?

The Department and EPA entered into an Agreement in Principle and a Path Forward document on March 15 outlining joint future actions. The agreement, once carried out in full by both parties and coupled with EPA’s November 30, 2012 approval of Florida’s initial set of numeric nutrient criteria (see above),will result in Florida having state-established numeric nutrient criteria for all lakes, springs, estuaries and coastal waters, and the vast majority of its flowing waters.

What happens next?

The Department will complete rulemaking to establish numeric nutrient criteria for remaining estuaries and coastal waters no later than December 1, 2014.

The Department also anticipates state legislation during the 2013 session to provide further direction on finalizing remaining numeric nutrient criteria. That legislation will clearly authorize the Department to ensure that nutrient loads are controlled so that downstream waterbodies are protected. It is also expected to establish nutrient water quality standards for the remaining estuaries and coastal waters as their current unimpaired conditions until the Department adopts numeric nutrient criteria. The Department will report to the Governor and Legislature by August 2013 on these conditions and the status of rulemaking.

The Department has also publicly noticed upcoming rule adoption of the document entitled “Implementation of Florida’s Numeric Nutrient Standards,” dated March 11, 2013, which clarifies how numeric nutrient criteria for fresh waterbodies will be applied and implemented.

EPA will make its decisions on these state actions, both as they are expressed in state legislation and rule, before September 30, 2013. Under the Agreement in Principle and Path Forward, EPA, following its review under the federal Clean Water Act, is prepared to end federal numeric nutrient criteria rulemaking in Florida.

Once the Department’s numeric nutrient criteria rules are all in place, how will they differ from the ones EPA has set or proposed?

The Department’s nutrient rules will the most comprehensive in the United States. The Department’s rules are based on the same underlying data as EPA’s rules—data that the Department developed—but they go beyond the federal rules because they:
  • Incorporate site-specific criteria backstopped by statewide standards. Through this approach, the criteria recognize the wide variety of types and conditions of waterbodies in Florida.
  • Add biological assessments that provide a more comprehensive understanding of waterbody health. Without this deeper biological understanding, pollution impacts can be missed.
  • Include an adverse trend test to address water quality changes even in otherwise healthy waterbodies. That is, if the data reflect declining water quality trends in waters that meet water quality standards, those data will trigger action. The Department’s job is not just to restore polluted waters but to prevent healthy waters from being degraded.

Last updated: March 19, 2013

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