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Nutrient SeZrs'tive Water <br />• State surtace water ciassificatio <br />• Jordan Lake designated in 7983 <br />• 1997 Clean Water Responsibility Act ( 515) ~ <br />-Set nutrient Ilmits (TP = 2 mglL. TN = 5 5 mg ) <br />- Option to develop a nutrient response model to <br />justify different nutrient Ilmits <br />Model i ation of <br />Current Condl ioCs <br />(mmual average) \M1 <br />Percent Days ,N`- \ <br />> 40 pglL <br />0-5 % <br />~5-10% u ,\. <br />10-IS% <br />15-?0% <br />O ?0-30% <br />30-40% <br />• Federal requirement under Cleali~~~ <br />• Upper New Hope Arm of Jordan LakE <br />designated in the 2002 303(d) List. <br />• Impairment based on chlorophyll a st~ <br />• Modeling indicates both nitrogen and <br />phosphorus are co-limiting factors <br />Act <br />Nutrient Res nse Model <br />• Developed by Tetra Tech, Inc\\~ <br />• Originally funded by nine municipal t'es~a~ <br />about $400,000 total project cost ~-~ <br />• Coupled hydrodynamic and water qualit \~~ <br />model (EFDC and WASP) <br />• Model simulates conditions from 1997 to <br />2001 <br />• Model endpoint is chlorophyll a in the lake <br />Modulation of <br />Current Conditions <br />(growing season a~mrage) <br />Percent Days <br />> 40 pglL <br />0-5% ~ <br />O 5-10% w <br />70-75% <br />0 IS-20% - <br />O ?0-30% <br />30-0D% <br />Management <br />~ ,I u„ ~ 'iii n'~ <br />iY _ v' <br />~ ap: <br />~ , u `oa..- ,i i~~,,4 <br />r ~ ~~,i~i ,,t un~ ;.. xx ._r. <br />/~ <br />~J <br />7 <br />