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..~h <br />Pwsults <br />• The pH values Sor the April to October period ranked from 7.0 to E•3 (q•7*) <br />s-ith interrediate values beinC most common. L.1.1 values were on 'the al}:aline side, <br />but values observed bettaeen the April - June period tended to be loner by zn o vier <br />of 1~2 pH unit as ccc~pared to surmer and fa71 values, There xere no si~+;''icant <br />differences indicated among statio:~ , except for one unasually high pH value of <br />q.7 at station 27F-!.a in rrid-Octcber. A longitu:'inal survey of one section of the <br />rlprth. Fort: suggested some slight changes (7.6 to 7.4) occurring in the upper <br />section (see Figure 3)• <br />pH values soseti~aes differed by as rrsch as one pH unit t^_thin a short period <br />of one xee}:. Tne lo~rer values appeared to be associ.aied x•ith periods of highar <br />runoff in the river, hoi:erer lack of records on river flor.~ and rain: all ir. the <br />upper area prevents a good correlation. <br />• 7ir,ited data on the DH of the lower b:innesota Cree}: short values xithin the <br />range found in the river and Stevens Gulch. <br />Comparisons <br />Previous data from the north Fork indicated a range of 7.0 - 8.8, xhich is <br />xithin that found Sor the present study period except for the one high value of. <br />9.7. <br />Significance <br />Present state guidelines for pH are 6 - 9. The present values are similar to <br />those lcior:n from past studies and indicate no problem extent for the single 9.7 pH <br />value. Since this value occurred dust belox the mouth of Stevens Ch:lch it is <br />I • possible that the result was mine-influenced, although no other high values have <br />+ value possibly suspecti <br />3-8 <br />