Water Main Puzzle at Syracuse
Superintendent Charles A. Windholz, of the Syracuse, N. Y., Bureau of Water, has a peculiar problem on his hands in the apparent rotting of an eight-inch main passing through a strong salt marsh near that city. Recently the main has caused considerable trouble, terminating with a double rupture a few days ago. What it is that caused the pipe to change its appearance and consistency so that it resembles carbon or graphite is still a mystery. No solution has yet come from the exhaustive investigation conducted by the chemists of the Syracuse University. There is, however, a belief prevalent that chemical action, resulting from the heavy charge of salt and other chemicals in the marsh and the nature of the soil, is responsible for the peculiar action of the pipe. Engineer Frederick La Tourrette, of Jersey City, suggests that the eating away of the main is due to electrolysis, but he further states that he would rather trust in cast iron than in any other type of pipe for this service. Superintendent Windholz is considering a new cast iron line supported above ground on concrete piers. In reply to an inquiry by this journal, Superintendent Windholz writes:
To the Editor: In regard to the break in the water main in Spring street, this city, I may say that this pipe is laid in marshy soil, which was formerly occupied by a number of solar salt beds, and is therefore quite thoroughly saturated with salt and it also contains mineral acids. This is an 8-inch pipe and was laid in 1908, and for the past few years has given considerable trouble. As stated in your letter, the pipe seems to have entirely lost its hardness, and, in spots can be cut with a pen knife. We do not believe that this is caused by electrolysis, as we had a low reading volt meter connected” with it and the drop between the pipe and the surrounding ground was less than 2/10 of one volt. At that time the pipe line was broken and tests made while connected to each end of the main, and the volt meter showed a drop of about 1/10 of one volt. It claimed by those familiar with this action that a drop less than to 2 volts will not cause deterioration in cast iron pipe. We believe it is due to the condition of the soil, probably organic acids in the ground.
Very truly yours,
BUREAU OF WATER,
CHAS. A. WINDHOLZ,
October 20, 1916. Superintendent.
[If the marshy soil were formerly salt beds the cast iron pipe was placed into a strong brine solution. By the laws of electrical deposition a metal placed in a salt solution will soon become filled with constituents of the salt, and the iron will pass into solution. The result is, that the cast iron pipe has become impregnated with constituents of the salts and part of the iron has passed into solution. This impregnation means that the iron has lost its cohesion—hence its strength.—Editor.]