Table 3l.~Sstlmate.1 Industrial and domestic pollution load. 



Columbia River 

 Segment 



Year 1950 



Year 2000' 



Critical 

 ''unioipal Industrial >!uniclpal Industrial period 

 sewage waste sewage waste mlnirmir flov; 



year 2000 



nuiilclpal 



discharge population discharge population fron table 33^ In'uiTtrial 

 persons equivalent persons equivalent c.f .s. Ibs./i'a^-^ 



Total dis- 



solvei' ojr^'Kcn Total estl- I^stlTr^ate-; 



demand mated oxygen Es tins ted dissolved 

 demand in in segment o:^£en 

 year 2C00 i;-^g^c.r.t in deficit 



Aug. - Sept. dailj' in river 



P.P.". 



r.M.r.' 



I .p, 



Above Grand 

 Coulee Dam 



Below Grand 

 Covlee and Above 

 Snake River 



Below Snake 

 River to the 

 Dalles 



Dalles to the 

 Mouth 



TOTAL 



329,000 513,000 810,000 1,000,000 



143,000 



166,000 310,000 la'',ooo 600,000 52,000 



327,000 1,900,000 310,000 3,600,000 82,000 



672,000 5,670,000 1,660 , "00 6,700,000 88,000 



l,!i95,000 9,393,JO'j J, 70c, 000 12,100,000 



315,000 



l.?6 



339,700 1.22 



1,091,000 2.I47 



531,000 1.22 



0.1 



0.1 



0.1 



o.iS 



1.2 



C.9 



1 From reference (3U) and table 232. 



2 Using growth rate of mujiiclpalltl.''3 fron flj^ure 62. Ini'.islrlnl warte:j douVjled e::ccpt for Lower OolixT'jia. 



3 Not corrected for future i~:poundment "^^r^ilation, 



h Assiuninc waste remains in T-iv-jr sejnent long enougii to e>:ert entire first stage B.O.D. fron tabic 31 

 and one-half of o?:3''gen dcr.nn-1 of next upstream ssi^.ent carrie ' to downctren-i sctrent. 



5 From refsrence {29), tcble 25 usi:is water depth of 20 feet. 



6 Assa-ning no oxygen added from photosynthesis. 



oxygen demand values shown In table ^k were 

 obtained by multiplying the populations by 

 the B.O.D. values given in table 31 and by 

 using the August-September flow rates. In 

 the upper 3 segments of the River it was 

 assumed, because of the many Impoundments 

 that will be in existence, that the waste 

 would remain in the segment long enough to 

 exert its entire first stage oxygen demand. 

 To this was added one -half of the upstream 

 segment oxygen demand to allow for oxygen 

 demands beyond the first stage. Because 

 there will be no Impoundments In the lower 

 river segment, a flow time of 2 days to the 

 river mouth wsis taken for the induBtrieuL 

 wastes and 3 days for the domestic wastes. 

 (The industries contributing the strong 

 wastes stretch further down the Columbia 

 River than does the bulk of the population. ) 

 A maximum predicted oxygen depletion of 2.5 

 p. p.m. is shown for the segment of the 

 river between the Snake River confluence 

 and The Dalles. Depletion of around 1.25 

 p. p.m. are shown for the other 3 segments. 



Heaeration of the river water takes 

 place concomitantly with this deoxygenation. 

 It is very difficult to obtain any precise 



reaeration coefficients for a stream such 

 as the Columbia. Accordingly, low values 

 of reaeration were assumed. A value of 6 

 pounds of oxygen per day, per acre of water 

 surfaces, was assimied for the upper 3 seg- 

 ments where the river will be a series of 

 Impoundments and 9 pounds was taken for the 

 more rapidly flowing (and mixing) lower 

 segment. These reaeration values do not 

 take into account any oxygen supplied from 

 photosynthesis . 



The estimated dissolved oxygen defi- 

 cit in the h river segments (table 3*^) was 

 obtained by multiplying the daily reaera- 

 tion by the segment flow time and subtract- 

 ing the product frcm the oxygen demand. 

 Deficits of around 1 p. p.m. are shown for 

 the Columbia River between the Snake River 

 confluence and the mouth. It is believed, 

 however, that there will be no actual 

 deficit in the year 2000 because minimum 

 river flows should be greater during that 

 period (unless the Canadian divert upper 

 Columbia River waters) and pbotosynthetlc 

 activities should be great in August and 

 September for oxygen production. 



95 



