168 CITY MILK SUPPLY 



The percentage of farm wells that are polluted probably varies con- 

 siderably in different dairy districts. Kellerman and Beckwith in 1906 

 examined the wells of dairies supplying Washington, B.C., and found 16 

 good, 15 fair, 17 suspicious and 12, or 20 per cent., unfit for use. The 

 reports of the health officer of the District for the 4 years from 1905-06 

 to 1908-09 show that the wells on 881 dairy farms were tested and that 

 519 were good, 69 suspicious and 293, or 33.3 per cent., were condemned. 

 The location of these wells is not given but they are presumably for the 

 most part in Virginia, Maryland and the District of Columbia. Keller- 

 man and Whittaker in their investigation of the farm water supplies of 

 Minnesota tested 79 carefully selected and typical rural water supplies 

 and found that 59 were polluted, usually because of careless or ignorant 

 management. They estimate the proportion of polluted supplies in 

 rural districts at 35 per cent. Prescott examined the water supplies 

 of 202 dairy farms situated within 25 to 40 miles of Boston and found 14.4 

 per cent, so badly polluted as to be unfit for use as drinking water or for 

 other domestic purposes. 



Wells are valuable property and when one is found to be polluted it 

 should be saved if possible, rather than condemned. Sometimes the 

 relocation of a sink drain, a privy or a hog pen or the addition of a new 

 curbing or cover is an effective cure of the pollution. 



Prescott suggests the following form for use in inspecting farm water 

 supplies. 



Water-supply inspection 



Name of tenant Water piped to barn 



No. of people in family Character of tank, if any 



Children, servants or laborers Kind of pipe 



General health of family General character of soil 



Source of water, well, spring, etc If well, when last cleaned 



Depth of well General appearance of farm surround- 



Distances of sources from house drain ings 



(a) Is water used for cooling milk or food 



Distance from cesspool or privy (6) Sample taken at 



Distance from .barnyard (c) Analytical data 



Surface wash 20C. count 



Immediate surroundings 37C. count 



Protection against contamination from Litmus lactose agar count 



cattle, manured fields, etc Acid formers 



Covering, if any Presumptive test, dextrose broth 



Date Presumptive test, lactose bile 



Town and State B. coli 



Water piped to house Remarks 



The quantity of water needed on the farm as estimated (Trullinger) 

 is given in Table 50. 



