Tennessee Environmental Law Blog

Florida, like Tennessee, had adopted a narrative water quality criterion for nutrients. Tennessee’s criteria for fish and aquatic life is as follows:

Nutrients - The waters shall not contain nutrients in concentrations that stimulate aquatic plant and/or algae growth to the extent that aquatic habitat is substantially reduced and/or the biological integrity fails to meet regional goals. Additionally, the quality of downstream waters shall not be detrimentally affected.

Interpretation of this provision may be made using the document Development of Regionally-based Interpretations of Tennessee’s Narrative Nutrient Criterion and/or other scientifically defensible methods.[3]

For recreational uses, the waters cannot contain nutrients that would impact recreational uses.[4] The above criteria may be used to interpret this impact. Pickwick lake has a numeric limit for chlorophyll a as part of its nutrient response plan for recreational uses. Florida’s nutrient criteria applied to so-called Class I and Class III waters. Class III waters are much like the uses for fish and aquatic life and recreational uses. Class I is for potable waters. This use classification would be similar to Tennessee’s domestic water supplies. Tennessee has not adopted a nutrient criterion for those classified waters.

EPA made a determination on January 19, 2009 that numeric water quality criteria were necessary to protect designated uses from nitrogen/phosphorus pollution for Class I and III waters. EPA considered Florida’s “unique and threatened ecosystems, the large number of impaired waters due to existing nitrogen/phosphorus pollution, and the challenge associated with growing nitrogen/phosphorus pollution associated with expanding urbanization, continued agricultural development, and a significantly increasing population.”[5] EPA determined that Florida’s case-by-case interpretation of its narrative criterion was not sufficient to ensure protection of designated uses. EPA cited statistics that show about 8% of assessed river and stream miles and 26% of assessed lake acres are impaired by nutrients. The population of Florida was expected to grow 75% by 2030 from 2000 data.

Tennessee appears similar in many respects to Florida. For example according to the University of Tennessee the population will be increased by nearly 77% by 2030 from 2000 data (compared to the 75% in Florida).[6]

The 2010 305(b) report issued by the Tennessee Division of Water Pollution Control, shows that 13% of Tennessee waters are impaired because of nutrients.[7] For lakes and reservoirs, the report states that 5% of the impairments are from nutrients. While significantly less lakes are impaired, it is not clear whether or not EPA would consider Tennessee’s own case by case interpretation of the narrative criterion to be effective.  For example, in the 2002 305(b) report, only 10% of the streams were impaired because of nutrients. In addition, the Division does not have a reference approach method for assessing lakes and reservoirs.

In 2004 the Water Quality Control Board promulgated an emergency rule to implement nutrient narrative criterion after the Chancery Court in Davidson County ruled that the Division did not have the authority to place effluent limits in permits for nitrogen based upon organic enrichment. That rule became permanent following comment period and was approved by EPA. As noted above the numeric interpretation of the narrative criteria for flowing streams is derived on a case by case basis by comparing the stream in question to its reference streams and determining whether the levels for nitrates + nitrates and phosphorus are within 90% of the that for the reference stream.  The current triennial review is on-going, and the draft changes for public comments did not reflect any move to establish a numeric nutrient criterion.[8]

EPA estimated the incremental costs of implementing the rule as between $135/5 million/year and 206.1 million/year.[9]  This cost will be born by municipal wastes water treatment plants, industrial dischargers and agriculture.  The cost in Tennessee would most likely not be as high because much of the cost is related to discharges to estuaries in Florida. 

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