Capacity of Filter Reduced 30 Per Cent by Ice
Insufficient Covering Resulted in Ice Formation Thickness Reached Fourteen Inches—Force of 40 Men Employed to Break Ice—Other City Filters Not Affected
Lack of an earth and sod covering for the slow sand filters at Queen Lane, Philadelphia, has resulted in a 30 to 40% reduction in winter-time efficiency of the plant, due to the heavy formation of ice on the surface of the water in the beds. The accompanying flashlight photographs show ice of an average thickness of five inches, formed after a few days of frost. The conditions shown here and on the cover are average conditions that the operating force under Superintendent Thomas Riebel must contend with. An extreme condition was afforded by the very severe winter of two years ago, when the ice on the beds was at one time over fourteen inches thick.
The Queen Lane plant contains twenty-two slow sand filters of 0.71 acres each; a total of nearly 17 5/8 acres. This plant was designed to filter at a maximum rate of 70.000,000 gallons per day. Contrary to expectations, it is now called upon to furnish water at a rate which often exceeds this quantity, sometimes going as high as 85,000,-000 gallons per day. As a matter of fact, this plant is depended upon very greatly to re-inforce other parts of the system as a whole. Consequently, the winter-time difficulties of operation of the plant tend to greatly complicate the management of the entire distribution system.
Under these conditions, the methods followed in clearing away the ice are necessarily emergency methods. When the beds become so clogged with ice that they no longer function, they are emptied three or four at a time, and a force of men sent in, equipped with sledges and shovels, to break up the ice and pile it against the walls as shown in the photographs. Some idea of the magnitude of this task can be gained from the fact, that for a considerable portion of the present winter, a force of forty men was constantly employed exclusively in the work of breaking ice as shown in the pictures. Incidentally, their rate of progress was, on an average, three beds per day.
Ice Freezes Over and Over Again
After the ice has been thus broken and piled up against the walls the bed is again thrown into operation. But its capacity has been reduced by the process to 60 or 70% of its normal value. Furthermore, when the water comes into the bed, the piles of ice lying against the wall are picked up by the water and float around on its surface, until they are again frozen into a solid mass, of still greater thickness than before. This aggregate, as it might be termed, must, in case .of continued cold weather, be again broken up. This process is continued throughout the winter, until warm Spring weather brings relief.
The customary earth and sod covering, usually provided in severe climates, is lacking. Through the thin roof the frost seems to readily penetrate and thick ice on the beds invarably follows the first prolonged cold spell. Some amelioration was effected by the waterproofing with tar and building felt of the fourteen hundred odd ventilators and thirty-five thousand feet of expansion joints on the roof. The cure for the trouble, however, seems to require more radical treatment than this and will no doubt involve great expense.
Other Philadelphia Plants Immune
The Queen Lane Filter Plant is only one of five which are comprised in the Philadelphia water system. All are, naturally, exposed to the same climatic conditions. Except for Queen Lane all are covered with earth and sod.
Queen Lane is the only one which gives serious trouble from this cause.
Newly Appointed Superintendents
Chicopee, Mass……………..Michael Dillon
Marlboro, Mass…………..George E. Stacey
Wauseon, Ohio………………Lou. Seidner
Bellevue, Ohio……………..Gus. Williams
East Youngstown, Ohio……..John McGarry