132 LEAKAGE FROM STREET MAINS 



While this quantity (that mentioned by Mr. Loweth) may be ample 

 under the conditions stated, it is certainly too small after the system is 

 several years old, and the lead joints have been strained by settlements 

 and by repeated expansions and contractions of the pipes due to changes of 

 temperature; also after the packing in the stuffing-boxes of stop-valves is 

 partly decayed, the valves of fire hydrants damaged by use, and the tight- 

 ness of the plugs in taps and curb cocks impaired by frequent handling 

 or shock from water-ram in house pipes and mains. All these elements 

 must be taken into account after the work of construction is finished, and 

 hence a much different standard is applicable to old pipe systems than to 

 new contract work. 



The leakage from old or abandoned services may be important 

 and it is practically impossible experimentally to separate this 

 loss from the loss from the street pipes. Mr. J. J. R. Croes, 

 in reporting to the Merchants Association, in 1900, on the 

 Water Supply of the City of New York, stated: 



There is much leakage underground from bad joints, breaks and 

 defective stoppage of disused services. There are on the 850 miles of mains 

 in New York City at least 18,000 old service taps which have been discon- 

 tinued and more or less imperfectly plugged up. There is a great loss 

 of water from these old taps. Thousands of them are leaking continuously; 

 some but a mere dribble, but others carrying off into the sub-soil and into 

 the sewers thousands of gallons daily each. Sometimes the leakage from 

 one of them increases sufficiently to come to the surface of the ground, 

 and the water appears as a spring in the pavement of the street or some- 

 times flows off into vacant lots. If the underground channels become 

 obstructed, the water will rise to the surface and the leak will be reported. 

 Every increase of pressure in the pipes increases the leakage from these old 

 taps, and attention is called to them. The number of leaks which showed 

 themselves, when the pressure on the mains was kept down on account of 

 scarcity of water between 1883 and 1889, was about 700 annually. After 

 the new aqueduct was finished, and the pressure was increased, the number 

 of leaking services reported was over 1000 annually; and last year (1899) 

 after the full pressure had been turned on downtown by the laying of the 

 additional mains down Fifth Avenue and Elm Street, there were 2500 

 such leaks that made themselves manifest. . . . The mains themselves 

 also leak largely. There are at least 500,000 joints in the main pipes 

 underground, and from many of them water is escaping. . . . Cases of 

 leakage are constantly occurring in which the source is traced to corroded 

 cast-iron mains. For several years the average amount of old pipe which 

 has had to be taken up and replaced has been about 2 miles annually, 



