ing by the results obtained, there has been a pronounced increase in pollution 

 between I898 and 1930, as might be expected from the increase in population. 

 At Cherry Street bridge, which is near Station 2h9, the means of three samples 

 taken in July, August, and September were as follows: free ammonia, C.207; 

 albuminoid ammonia 0.36U; nitrite, O.OI8; nitrate, 0.28 (part per million). 

 Closely similar results were obtained for a station at Riverside Park, which 

 is about two miles from the mouth of the river. Comparison of these results 

 with those for Station 2h9 in 1930 (Table 33) il'ows larger amounts of all 

 forms of nitrogen, except nitrate, for the samples of 1930. Some of this 

 apparent increase may have resulted from a difference in dilution in the two 

 years, but, in all p robability, most of it represents a real increase in sew- 

 age pollution. The chloride content was higher, on the average, in the 

 samples of I898 than in those of 1930. However, this fact cannot be regarded 

 as evidence of heavier pollution in the earlier year, for the Maumee water- 

 shed has numerous sources of saline ground waters (Ohio State Board of Healt, 

 1899, page U20) , and the amount of inflow from such sources might vary con- 

 siderably from time to time. Dole (1909 j P-'ge 71) found that chloride in the 

 Maumee at Toledo ranged from 12 to I06 parts per million in ten-day composite 

 samples collected over a period of more than a year. Probably a number of 

 factors, including reversing currents in the river, were responsible for the 

 wide range. Neither of the two papers just mentioned contain data on the 

 water of Maumee Bay. 



In 1930, the water of Maumee River, and of Maumee Bay just outside of 

 the mouth of the river (Stations 2li9 and 2^0) showed on the average, more 

 decomposing organic matter, as indicated by albuminoid ammonia, than any 

 other station sampled durin^^ this investigation. Free ammonia also was 

 very high. Yet these stations were by no means as heavily polluted as some 

 waters reported in the literature. For example, the Illinois and Michigan 

 Canal at Lockport (carrying part of the sewage of Chicago) showed an average 

 for the years I896-I899 of 2.77 parts per million albuminoid anmonia, and 

 13.5 parts per million free ammonia. At that time, Illinois River at Avery- 

 ville, about I60 miles below Chicago, contained amounts of free and albumin- 

 oid ammonia which compare favorably with those at Stations 2U9 and 250 (see 

 Palmer, 1903, Tables III and XII, or Leighton, 1907, Table 63). Stations 

 2U9 and 250 showed considerably more free and albuminoid arimonia than sta- 

 tions in Ohio River during the same months of an earlier year (I9IU/ . Thus, 

 at a point eleven miles below Pittr;burgh, the average amounts during July, 

 August, and September '-;ere: free ammonia, 0.376 part per million; and albu- 

 minoid ammonia, 0.313 part per million (Frost et al., 192U, Table 50} . In 

 the paper just mentioned, Ohio River was compared with other rivers in the 

 United States and was found to be intermediate between the extremes with 

 respect to nitrogen content. Of the rivers used for comparison, Illinois 

 River at Joliet, immediately below the outlet of the Chicago Drainage Canal, 

 contained the largest amount of nitrogen and this was principally in the 

 form of organic rdtrogen and free ammonia. If we make allowance for the 

 fact that in Maumee River analysis was made for albuminoid ammonia nitrogen 

 rather than for organic nitrogen, this river in 1930 and Illinois River at 

 Joliet in 1921-22 appear to have been polluted to about the same degree. 

 Maumee River, then, may be regarded as a heavily polluted river. 



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