On October 15, 2010, the Environmental Protection Agency will usher in a new era of water quality regulation for Florida’s lakes and flowing waters. Known as the Numeric Nutrient Criteria (“NNC”) rule, the final rule will establish specific numeric limitations on nitrogen and phosphorous concentrations in fresh water lakes and streams.

Before the implementation of this rule, Florida water quality rules were based on a narrative standard that used descriptive language to identify polluted bodies of water. The rule also creates restoration standards for water bodies that are designated as “impaired.” Impaired waters may be waters that are deemed to be polluted to the point where they no longer are suitable for their intended use. The new rule only applies to fresh water, however a similar NNC rule for coastal waters and estuaries is slated for consideration in 2011. These new water quality standards will have significant economic and operational effects on municipalities, agricultural operations, utilities, and future development.

Rule-Making Background

Officially titled “Water Quality Standards for the State of Florida’s Lakes and Flowing Waters,” the rule is the result of a 2008 lawsuit filed against the EPA by Earthjustice, an organization representing the Florida Wildlife Federation, the Conservancy of Southwest Florida, the Environmental Confederation of Southwest Florida, St. John’s Riverkeeper, and the Sierra Club.  In the lawsuit, Earthjustice alleged that Florida’s narrative water quality standards failed to address a growing problem with impaired waters and violated the Federal Clean Water Act. In January 2009, the EPA issued a “determination letter” to the Florida Department of Environmental Protection (DEP) requiring that it adopt numeric standards for fresh water by October 2010 and numeric standards for coastal waters and estuaries the next year.

Numeric Nutrient Criteria

The new rule proposes specific numeric limits on the concentrations of nitrogen and phosphorous levels within lakes and streams. Elevated nutrient levels can cause excessive algal growth which reduces the amount of light reaching a lake bottom, damaging aquatic vegetation and fish habitat. The new criteria are intended to foster a balanced natural population of plants and wildlife in lakes and flowing waters, while also ensuring the attainment and maintenance of the water quality standards for downstream waters. What this means is that the numeric criteria for a water body must be determined based on the requirement of the stream itself, plus the requirement of any water body into which the stream flows. Because Florida contains many diverse habitats, it will be difficult to implement the same numeric limitations state-wide because higher, naturally occurring levels of nutrients do not impair certain regional water bodies.

As a response to regional concerns, the rule allows for the implementation of “site-specific alternative criteria” which is a different water quality standard that meets the requirement of protecting a water body, but it accounts for specific local conditions. Certain areas like the Tampa Bay region that have been successful with the existing state Total Maximum Daily Load (TMDL) standard will likely be allowed to continue using existing standards as a site-specific alternative criteria.

Impact of the Rule

Every industry, agency, or enterprise that manages and or discharges water may be affected by this rule. This includes agriculture, landscaping, power plants, mining, development, municipal operations and Florida’s tourism industry. Agricultural stakeholders have warned that the new rule could drive away agricultural operations in certain areas because the new standards would require the implementation of expensive “best management practices” (BMPs) to limit nutrients from fertilizer from reaching nearby water bodies. Agricultural producers fear they will no longer be able to compete in the marketplace after passing the additional costs of BMPs on to consumers. 

Many municipalities discharge stormwater runoff into surface waters via a “Municipal Separate Stormwater Systems” permit, known as a MS4 permit. The new rule may require stricter water quality standards for a city’s MS4 permit receiving water, which would require the city to implement additional treatment and management measures, usually at a significant cost to the city’s ratepayers. Some have indicated that unintended consequences may result when historically healthy waters do not meet the NNC rule and face unnecessary and potentially harmful restoration and compliance requirements. Additionally, while the rule is quite specific regarding the nutrient concentration limits, it lacks definitive provisions regarding the regulation of the rule, and the use of variances and other tools to implement the rule.       


Most acknowledge that the control of nutrient levels in our waters is of vital importance, however the NNC rule will likely create short term regulatory uncertainty with some unintended adverse environmental consequences. While some procedures will require clarification, one thing is certain: the new EPA regulations will present significant, long-term financial challenges as well as operational challenges for residents, municipalities, and businesses in Florida.