146 SEWER DESIGN 



Mr. J. N. Hazlehurst,* refers to a lawsuit, entered into 

 because while the specifications limited the leakage into a 

 sewer system under contract to 5000, measurements made 

 after all the pipes were laid showed an average leakage of 

 44,600 gallons per mile per day. In the course of this article, 

 he refers to measurements made at Maiden, Mass., where 

 tests made directly after the completion of the sewerage system 

 showed a leakage at the rate of 50,000 gallons per mile per day. 

 This was, he intimates, in spite of the fact that all the work 

 was underdrained and cement used almost extravagantly hi 

 the hope of securing water-tight work. 



Mr. Hazlehurst also refers to the measurements made in 

 New Orleans, where an original estimate of 31,800 gallons 

 per mile per day (0.003 cubic foot per second per acre) was 

 found to be approximately correct after the sewers had been 

 built. 



Such values as have been given above seem to establish 

 the fact that many sewers can be found that are imperfectly 

 constructed and that as a consequence admit more or less 

 ground-water into the pipes. It is, moreover, probable that 

 the measurements recorded are the results of attempts to 

 reduce leakage to more moderate and reasonable figures and 

 are therefore unduly high. 



"Mr. Hazlehurst implies, however, that these leakages are 

 characteristic and says definitely that there can be no such 

 thing as a water-tight pipe line and that if an engineer, in 

 his specifications, sets a limit to the amount of leakage, it 

 behooves him to " be very sure of his ground, both literally 

 and figuratively." 



Granted, however, that it is doubtful whether a sewer can 

 be made water-tight under ordinary conditions and methods 

 of construction, it remains to be seen what is a reasonable 

 amount of infiltration. 



If the sewer is of brick, assuming first-class construction, 



* Engineering News, Vol. L, p. 179. 



