44 Marshall O. Leighton 



The waters represented in Series "G" are typical of the western 

 prairie states. In such waters large amounts of organic matter are 

 always present even in the absolutely uninhabited regions. The sam- 

 ples above reported are taken from a stream that drains a large area 

 underlaid with saline deposits, which account for the high chlorine 

 content. Such waters absolutely controvert paragraph (C) of the 

 foregoing interpretations. It will be noted that the free-albuminoid 

 ratio specified in "A" (last part) is satisfied by all of the analyses. 

 There are no nitrites, and only in Nos. i, 3, and 7 does the amount 

 of nitrogen as free ammonia exceed the standard set in " D." Nitro- 

 gen as albuminoid ammonia and nitrates are not high for prairie 

 waters. Although some of the analyses look "good," the samples 

 were all grossly polluted. The first three samples were taken from 

 Kaw River i . 5 miles above Lawrence, Kans., and contain the 

 residue of pollution from the sewers of Topeka. The last four 

 samples ware taken from the same stream, but the point was 300 

 feet below the outlet sewer of Lawrence. It will be seen that the 

 samples from below town present a better analytical appearance 

 than those from above. 



We will now consider ground waters. In the address above 

 quoted there are the following statements: 



(A) .... It may be said that the best ground waters should certainly con- 

 tain not over o. oi milligram of nitrogen as free ammonia, or (B) over o . 02 milligram of 

 nitrogen as albuminoid ammonia, (C) no nitrogen as nitrites, (D) not over o . 01 milligram 

 of nitrogen as nitrates in a liter of water, and (F) chlorine not above the normal of 

 the region. When a water contains (F) more than 0.05 milligram of nitrogen as 

 free ammonia, and (G) o . 08 milligram of nitrogen as albuminoid ammonia, or 0.12 

 milligram of nitrogen as albuminoid ammonia, even if the free ammonia occurs in 

 very small amounts, it is a sign of imperfect filtration or of subsequent pollution, and 

 consequently such water should not be used for household purposes. 



It is more difficult to determine the presence of pollution in a 

 ground water by inspection than in a surface water, and in dis- 

 cussing ground-water analyses one is sometimes unable to make 

 a definite statement concerning direct pollution. We can, for exam- 

 ple, in the case of a surface water state that if the water is from 

 an uninhabited region it must be unpolluted with animal waste. 

 On the other hand, there is but one certain method of determining 

 the healthfulness of a ground water. This method has been accepted 



