SEWAGE TREATMENT — KEEFER 389 



of objectionable features and at a reasonable cost. Most modern 

 plants are mechanized so that a much smaller personnel is required, 

 and what were formerly disagreeable working conditions have been 

 largely eliminated. An increase in the use of such sewage-treatment 

 plant byproducts as sludge gas, dried sludge, and plant effluents will 

 most likely continue. The art of sewage treatment has reached such 

 a degree of perfection that there should be no excuse for the failure 

 to maintain a sewage-treatment plant other than in a first-class con- 

 dition. The gross pollution of watercourses with untreated sewage 

 should be regarded with disfavor both by the taxpayer and by city 

 and State officials, since adequate means are available for maintaining 

 them in a satisfactory condition. 



REFERENCE 

 McCallum, G. B. 



1955. 6,685 sewage plants and trunk lines will cost $5.33 billion. Wastes 

 Engineering, vol. 26, p. 504. 



Reprints of the various articles in this Report may be obtained, as long 

 as the supply lasts, on request addressed to the Editorial and Publications 

 Division, Smithsonian Institution, Washington 25, D. C. 



