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~J <br />Nutrient Se 'tive Water <br />• State surface water classificatio <br />• Jordan Lake designated in 1983 <br />• 1997 Clean Water Responsibility Act ( 515) ~ <br />- Set nutrient limits (TP = 2 mg/L. TN = 5 5 mg ) <br />- Option to develop a nutrient response model to <br />justify different nutrient limits <br />Model ( - ation of <br />Current Condl inps <br />(annual average) \\ <br />Percent Days \ <br />> 40 pglL _. \ \\ <br />0-5% <br />O 5-10% <br />10-15% u <br />15-20% <br />30-00% <br />• Federal requirement under Cleali~Ut` <br />• Upper New Hope Arm of Jordan La <br />designated in the 2002 303(d) List <br />e Impairment based on chlorophyll a st <br />e Modeling indicates both nitrogen and <br />phosphorus are co-limiting factors <br />Act <br />Nutrient Res nse Model <br />e Developed by Tetra Tech. Inc\~~ <br />• Originally funded by nine municipal fes~at <br />about $400,000 total project cost \~~ <br />• Coupled hydrodynamic and water qualit <br />model (EFDC and WASP) <br />e Model simulates conditions from 1997 to <br />2001 <br />• Model endpoint is chlorophyll a in the lake <br />Mad~ulation of <br />Current Conditions <br />(yROwing season average) <br />Percent Days <br />a 40 pg/L <br />0-5% ~ <br />O 5-10% n - <br />10-1>% <br />IS-20% <br />?0-30% <br />[~ 30-40% <br />Water to lia ty Management <br />Plannin ~ole <br />,,, ~ ;I,r ~ -- <br />„~ .. ~b5,,, ~,t,~ ~, ~~~ <br />_ \ <br />7 <br />'ii <br />4i u ~i -' t IYi+,- . <br />s,l, <br /> <br />