Table 15. --The normal conditions of the surface of Lake Erie, summer of 1929 



In the following summer of 1929, it was decided 

 to extend investigations throughout practically the en- 

 tire lake and also to test conditions in the more im- 

 portant harbors which were suspected as being sources 

 of domestic and industrial pollution. 



Normal lake conditions are represented by results 

 from 55 stations on Lake Erie (table 15). The turbidity 

 averaged consistently higher at both ends of the lake 

 where the water is more shallow, and the chloride con- 

 tent was lower at the west end. Abnormalities can 

 easily be detected in a given sample by comparing 

 its analysis with the normal values. 



Buffalo Harbor 



At the beginning of the July cruise of the Shear - 

 water, samples were taken from the Black Rock Canal 

 at the Naval Reserve Dock and from the lake at the 

 Buffalo water intake crib. The oxygen saturation was 

 82 percent at the surface of the canal, while the sur - 

 face and bottom samples at the crib showed saturations 

 of 92 percent and 98 percent respectively. The pres- 

 ence of free carbon dioxide together with 14. 2 p.p. m. 

 of chloride in the canal, as compared with a negative 

 carbon dioxide content and a chloride content of 12. 1 

 p.p. m. at the intake crib, indicated the existence of 

 undesirable conditions in the canal. 



On the third day of August the canal surface at the 

 same dock showed an oxygen saturation of 86 percent 

 and a chloride content of 14. 8 p. p. m. At a point 

 50 yards within the north entrance to Buffalo Harbor 

 the surface oxygen saturation was 89 percent and the 

 chloride value had fallen to 12. 7 p.p. m. At the in- 

 take crib the oxygen saturations were 98 percent for 

 the surface and 96 percent for the bottom, with cor- 



responding chloride values of 12. 1 p.p. m. and 12. 3 

 p.p. m. (fig. 40). 



The percentage of saturation of oxygen in the 

 canal surface on September 3 was 87 percent with 

 15. 1 p. p. m. of chlorides, 2. 5 p.p. m. of free carbon 

 dioxide, and a pH value of 7. 6. The canal surface 

 was coated with an oil film, and gas bubbles rose 

 through the water. On the same day at the intake 

 crib the oxygen saturation of the surface was 93 jser- 

 cent; chlorides were 11. 8 p. p. m. ; the pH value was 

 8. 1; and a negative carbon dioxide value was found. 



The difference between the canal and intake 

 samples in all cases, and the gradation from the 

 canal to the lake shown by the August samples, in- 

 dicate that polluting materials were present in the 

 harbor water. If no wastes were emptied into the 

 harbor at Buffalo, the canal and harbor water would 

 show the same or very nearly the same analysis that 

 the lake water does, for most of the canal and har- 

 bor water flows direct from the lake. Buffalo Creek 

 makes the only other addition of importance. 



The fact that wastes in the canal were no more 

 concentrated than found was due to the continuous 

 flow of water down the canal. This flow carried the 

 putrefactive matter away from the harbor, thus elim- 

 inating the pronounced effects which would have been 

 obtained if there were no outlet. The cleansing 

 action of increased flow from the lake because of 

 westerly winds, could be detected by the increase of 

 oxygen saturation, lowering of the chloride content, 

 and change in the hydrogen -ion concentration after 

 strong winds. 



The drainage afforded to Buffalo by the Black 



112 



