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GO^~ar15(~n5 <br />•- The hig.'~est total iron coreatrations during the tray - Gctober reporting pe:•iod <br />• t:ere more than three ti,^~es higher than rreviots values reported from the G~ach <br />(AuEust, 1977 io P:arch, 19'78), tiugust and Septe_ber sacples for 1977 and 1970 <br />tiere not directly ca:,parable becaiae of d~^fereat mailability of surface ranter <br />to s~:~ie in those ttito yea_~. <br />Sil-rificance <br />State guidelines for dissolved iron are 50~ ug~l as cosapared i,•ith Sederal <br />interim standards of 7O~G ug~l of total iron. 5tevers C~lch, which is not a state <br />desig::zted strear. because of its i^.te~~:ittent nature znd lack of awztic lip"e, <br />showed exceedence of 5PG ug~i dissol~~ed iron on one date in sprang (approxi.~ately <br />two-fold or less). <br />Total iron concentrations of 7600 cg/1 Caere es:ceeded or~v duri.ZS two dates in <br />~• spring, although one concentration tfas as r..uch as 1CJ tir..es the federal standard. <br />During this p°riod there were also high levels of total iron fo•,v-.d at the control <br />station in Stevens Gulch (up to 19 times federal standards). From rid-2'.ay to <br />October 1978 there were no total iron values approaching the Sederal standards. <br />The creation of four sediment retention ponds i.n F~estnoreland Car~,•oa shoald <br />control iron.-rich sediments from enter,;ng the tlorth Fork except duzting stones <br />greater than 1G-year~21,-hour events. <br />A similar pattern was Sound i~ the ldorth Fork. During some high runoff periods <br />concentrations of total iron in the 1lorth Fork rray exceed standards by approxi^ately <br />70-fold. Tnis occurred once during the spring an' sus~aer sabpling. However, at <br />this time the control station (11:-1a) concentration was appra~ateJ,y 50 times <br />federal standards, iraicating most of the iron o ~6inated upstream of the study <br />• area. <br />There was some indication that iron concentrations Qay increase within the <br />3-22 <br />