METHODS OF FINDING LEAKS 135 



system at Medway, Mass., where the leakage from about n 

 miles of pipe ranging from 6 to 12 inches in diameter amounted 

 to 1.58 gallons per lineal foot of lead joint daily. 



In discussion, Caleb M. Saville, Engineer of the Hartford 

 Water Works, reported a leakage on test of 7^ miles of 42-inch 

 cast iron supply main, to which there were no service connections, 

 amounting to about 0.7 gallon daily per foot of lead joint. 



Mr. Spear, Department Engineer of the Board of Water 

 Supply of New York, reported that in the main conduit lines 

 laid recently by the Board the leakage had ranged from less than 

 i to about 2 gallons daily per lineal foot of pipe joint. 



Mr. Killam reported a test of a new line laid by the Boston 

 Metropolitan Water Board, about a mile long, 2o-inch pipe, 

 leakage equal to 0.6 gallon daily for each foot of pipe joint. 



Mr. Hawley, Engineer of the Wilkinsburg, Pa., water works, 

 stated that it was his experience " after seeing many miles of 

 pipe uncovered for the purpose of replacement with larger 

 pipe, that a large percentage of joints are absolutely tight. 

 Most of the leakage is caused by a few large leaks; some 

 is from stuffing-boxes on gate valves, which obviously has no 

 relation to diameter of pipe per length of joint. I mention this 

 so that those who have not given the matter consideration will 

 not conclude that a general leakage is to be expected." 



Mr. E. S. Martin, Superintendent of Water Works at Spring- 

 field, stated that on account of changes in grades of streets, 

 he had to relay and lower about a mile of 30-inch pipe and in the 

 whole length he did not find half a dozen joints that were even 

 sweating. This pipe was laid about 1892 and was therefore 

 over twenty years old. 



Methods of Finding and Stopping Leakage from Street 

 Mains. Foremost is to be mentioned conscientious care in 

 extending the pipe system. Testing pipes under full pressure, 

 or if possible, more than full pressure, before backfilling is most 

 important. It can usually be done except in the central and con- 

 gested parts of cities where street conditions do not make it 

 advisable to leave the trenches open long enough for it to be 

 done. 



