Frequently Asked Questions Related to Development of Numeric Nutrient Criteria

 

What are numeric nutrient criteria?

Water quality standards are established in state regulations as the goals for the protection of aquatic ecosystems, safe recreation and fishing, and provision of water supplies. Such standards contain water quality criteria that are established at values that, if achieved, protect these goals. Numeric nutrient criteria are measurable levels of the amount of nitrogen and/or phosphorus allowed in a waterbody that maintains the goals. The measurable levels of aquatic health related to the effects of excess nitrogen and/or phosphorus, such as the amount of algae or the water clarity would also constitute numeric nutrient criteria.

Why are numeric nutrient criteria important?

Excess nitrogen and phosphorus pollution (nutrient pollution) in waterbodies can cause harm to the aquatic ecosystems and threaten public health. Nutrient pollution leads to significant water quality problems such as harmful algal blooms, low-oxygen “dead zones” in water bodies, and declines in wildlife and wildlife habitat. These effects can also disrupt recreational activities and pose threats to public health. FDEP recently found that 16% of Florida’s assessed river and stream miles, 36% of assessed lake acres, and 25% of assessed estuary square miles are impaired by nutrients (2008 Integrated Water Quality Report).

Why aren’t numeric nutrient criteria adopted now?

Florida currently implements a narrative nutrient criterion that states, “In no case shall nutrient concentrations of a body of water be altered so as to cause an imbalance in natural population of flora or fauna.” The derivation of specific numeric nutrient criteria to complement the narrative is very complex. Since nutrients are essential to life, a balance must be understood to provide adequate nutrients to sustain aquatic life while not providing excessive nutrients which alter the aquatic ecosystem through species shifts. Each waterbody can have very different and unique nutrient requirements. In order to best develop the thresholds at which a health aquatic environment can be sustained, it is best to develop a reliable measure of the biological condition of the waterbody. FDEP recently developed such measures for lakes and streams, the Lake Condition Index (measuring plants) and the Stream Condition Index (measuring insects), and is currently working on an additional stream biology measurement (measuring plants). Once the biological measurements are developed, studies can be launched regarding the effects of varying nutrient conditions on the biological measurements. The fieldwork associated with such studies was implemented in 2008.

How has FDEP implemented to narrative criteria to date, and how will numeric criteria help?

FDEP implements the narrative nutrient criterion in two main ways. For point sources (wastewater facilities discharging to surface waters), FDEP interprets the narrative criterion on a site-specific basis and establishes Water Quality-Based Effluent Limitations (permit limits) for nutrients. To better address nutrient impairment from nonpoint (non-regulated) sources, FDEP recently revised the Impaired Waters Rule to include numeric nutrient impairment thresholds. These thresholds helped to expedite the assessment of Florida’s waters, but were set for variables that measure the response to nutrient over-enrichment (like levels of algae in the water), rather than the concentration of nutrients. Development of numeric nutrient criteria will help to expedite both the development of permit limits and the identification of waters impaired by nutrients.

Does EPA’s determination have any legal effect?

Yes, the determination by EPA that numeric nutrient criteria are necessary under the Clean Water Act obligates EPA to propose numeric nutrient criteria. In EPA’s determination, a 12 month timeframe was established to propose criteria for lakes, rivers, and streams; and a 24 month timeframe was established to propose criteria for estuaries.

When will the new criteria be adopted?

EPA’s timeline calls for proposal of the criteria for lakes and streams to occur within 12 months, and proposal of criteria for estuaries within 24 months. If EPA proposes the criteria, the Clean Water Act directs the Administrator to promulgate the criteria within 90 days. FDEP will begin the process to derive and adopt the criteria in lieu of EPA. If the State adopted the necessary criteria and EPA approved the criteria prior to the established timeline, EPA would not be obligated under the Clean Water Act to propose or promulgate the criteria.

Will EPA or FDEP propose and adopt the criteria?

FDEP issued a notice of rule development for the adoption of numeric nutrient criteria on January 30, 2009. FDEP fully intends to propose and adopt the criteria into State Water Quality Standards. However, if the State is unable to derive, adopt, and receive EPA approval prior to the established 12-month timeframe (24 months for estuaries), EPA will be compelled to propose the numeric criteria in lieu of the State. EPA may also be compelled to promulgate the criteria shortly after proposal for the same reason (if EPA proposes the criteria, the Clean Water Act directs the Administrator to promulgate the criteria within 90 days). This will not prevent the State from continuing its process of adoption, and once the State has adopted and EPA has approved the criteria, the federal water quality standards may be withdrawn.

How do these actions relate to the current litigation filed by EarthJustice claiming that EPA must promptly set numeric nutrient standards?

EarthJustice filed a lawsuit against EPA last summer in an attempt to compel the adoption of numeric nutrient criteria. Specifically, the lawsuit claimed that EPA had previously made the determination that numeric nutrient criteria are necessary under the Clean Water Act. The lawsuit further alleges that, given this determination, EPA was obligated to promptly propose such criteria for any State that did not adopt numeric criterion. Today’s action by EPA does, in fact, make a formal determination that numeric nutrient criteria are necessary under the Clean Water Act. FDEP agrees that numeric nutrient criteria are necessary to enhance the control of nutrients, and will be working collaboratively with EPA to derive the criteria. The effect of EPA’s determination on that lawsuit is unknown at this time.

Will permit applicants/municipalities/stakeholders be provided an opportunity to request site specific alternative criteria?

Yes, there will be a mechanism/process to have site specific alternative criteria established if sufficient data are available. Any site specific alternative criteria must fully protect the designated use of the water body and are subject to formal approval by the U.S. Environmental Protection Agency. The Department is proposing an additional type of site specific alternative criterion that uses biological health assessments as evidence of aquatic life use protection.

How do interested parties get involved in the process for deriving and adopting numeric criteria?

FDEP maintains a web page where individuals can track progress, access materials, and learn about public meetings. [http://www.dep.state.fl.us/water/wqssp/nutrients] In addition, citizens can review the Florida Administrative Weekly to see notices of public meetings and notices of proposed rules.