84 (148) Society for Experimental Biology and Medicine. 



Tables giving average, and high and low results of anal- 

 yses of 438 shallow wells in Brooklyn, N. Y., which are used 

 for domestic purposes ; also similar analytic data obtained for 

 14 deep wells used for manufacturing purposes. The figures 

 represent parts in 100,000. 



A. — 82 Contaminated Well Waters. 



A 

 L 

 H 



a. 



NO,. 



N0 3 . 



Free 

 NH 3 . 



Alb. 

 NH 3 . 



Total 

 Solids. 



Loss on 

 Igni- 

 tion. 



Depth of 

 Well. 



Distance From 



Source of 

 Contamination. 







4.64 

 0.70 

 9.00 



O.OOI8 

 .OOOI 

 .OIOO 



O.70 

 O.30 

 3.60 



O.0236 

 Trace. 

 .4900 



O.OO45 

 .0004 

 .04OO 



31.92 

 12.30 

 60.80 



5.20 

 1.30 

 I7.00 



29 feet. 



15 " 



65 " 



47 feet. 

 IO " 



,50 .. 



B. — 59 Suspicious Well Waters. 



A 

 L 

 H 



5.33 0.0006 

 0. 80 .0004 

 32.00 .0025 



O.634 

 Trace. 

 2.400 



0. 005 7 

 Trace. 

 .0875 



O.OO35 

 Trace. 

 .0180 



34.82 

 7.90 

 222.90 



5-49 

 0.40 



34-40 



27 feet. 



8 « 

 45 " 



45 feet. 

 20 " 

 75 " 



C. — 297 Uncontaminated Well Waters. 



A 

 L 

 H 



2.94 

 0.40 

 12. 10 



Trace. 

 None. 

 .0003 



0.582 

 Trace. 

 3.600 



0.0026 

 Trace. 

 .0190 



0.0031 

 Trace. 

 .0270 



28.41 



7-50 

 IOI.50 



4.86 27 feet. 43 feet. 

 0.30 6 " 10 " 

 39.50 52 " 100 " 



D. — 14 Uncontaminated Deep Well Waters for Brewery and Factory Use. 



A 

 L 

 II 



5.60 Trace. 

 0.80 None. 

 17.00 .0002 



0.300 0.0010 

 0.040 Trace. 

 0.400 .0030 



0.0020 50.20 

 Trace. 13.70 

 .0065 101.90 



15.00 

 4.90 

 30.70 



100 feet. 



55 " 

 227 " 1 



A, average figure. L, lowest figure used in average. H, highest figure used in 

 average. 



The highest and lowest figures which enter into the averages 

 are also given. These figures do not represent any particular 

 analyses, but are selected from the different results from which 

 the averages were made. Table D gives the average data for deep 

 wells that supply water for manufacturing purposes. These data 

 may be used as standards in judging the purity of wells whose 

 waters are used for domestic purposes. 



Of these waters, 67.9^ were considered to be of good quality ; 

 13.4^ were considered to be of suspicious quality; 18.7^0 were 

 considered to be contaminated and unfit for domestic purposes. It 

 was found impossible, as a rule, to use the figures for chlorin and 

 ammonia contents of these Brooklyn waters in judging their purity. 

 The nitrates might give some clue to the condition, but it was 

 mainly upon the nitrites that one had to depend. There was in 

 each case of condemnation ample chance of pollution through 



