PARENT SESSION
TP7 - Water Quality Criteria
Chair: Canton, Steve1, 1 Chadwick Ecological Consultants, Littleton, CO
2:10 PM to 5:30 PM - Tuesday, 19 November 2002
Room Ballroom A
(464) Site-specific Nutrient Criteria: An Alternative to the US EPA Eco-regional Nutrient Criteria.
Parkhurst, Benjamin*,1, Warren-Hicks, William2, Bartell, Steven3, Smart, Miles4, 1 The Cadmus Group, Inc., Laramie, WY, USA2 The Cadmus Group, Inc., Durham, NC, USA3 The Cadmus Group, Inc., Oak Ridge, TN, USA4 Smart and Associates, Cary, NC, USA
ABSTRACT- U.S. EPA has published guidance for developing eco-regional nutrient criteria for lakes and reservoirs, rivers and streams, and estuaries. EPA is using these methods to develop nutrient criteria for each eco-region in the United States. Unless states and tribes develop their own nutrient criteria, by the end of 2004 EPA will promulgate nutrient criteria for them based on its eco-regional criteria. It is likely that the EPA eco-regional nutrient criteria may be more stringent or less stringent than necessary for many water bodies. If that is the case, site-specific nutrient criteria can be established. EPA, however, does not provide guidance for developing site-specific nutrient criteria. We present methods for developing site-specific nutrient criteria for lakes and reservoirs, rivers and streams, and estuaries. The methods include three, increasingly detailed and data intensive, tiers of procedures. Tier 1 methods are similar to the EPA methods for developing eco-regional criteria, except they focus on site-specific as opposed to eco-regional data. Tier 2 methods expand on the Tier 1 approach by using empirical analysis of possible relationships between nutrients and the response variables to determine site-specific nutrient criteria. Tier 3 analyses focus on a process-level evaluation of the site-specific relationships between nutrients and the values of the selected response variables. The methods for each tier are presented, as well as a case study example of their application.
Key words: nutrients, water quality criteria, site-specific, methods