WATER SUPPLY OF CUMBERLAND CITY, MD.
Cumberland City, Md., intends having its water supply en larged and improved. It has, therefore, had the sources of that supply investigated so as to determine whether a new source shall be secured or the water from the existing one, the Potomac river, purified. The driven well source is rejected as impracticable as the water would be either too hard or else salt. The artesian well is in the same category, owing to the uncertainty accompanying it. As to surface water: Salvage river has a watershed which is sparsely settled, and, unless mining operations should be developed there, is never likely to be populous. It possesses several good sites for an impounding dam, whence the water would reach the city under such a head as to enable the pumping stations to be entirely dispensed with, at a saving of $4,500 a year. Hut the cost, $700,000. renders such a scheme prohibitory. Kvitt’s creek has a flow of 2,000.000 gallons per day—a bare sufficiency, allowing no margin for the increased consumption in the near future. A dam might be built to impound 150,000,000 gallons, which would te an ample supply, a pumping station erected at this site, and a main laid down to connect with the city main at a probable cost (not including the pump—the present new pumping engine being utilized for the new station) of $116,000 and an expense of about $1,000 more for pumping than at present. This source, therefore, is recommended; but, as the water is impure, it would need filtration—the reservoir furnishing a sufficient settling basin when used in connection with filter beds. If,however, the Potomac is to be retained as the source of supply, then its water must be rendered wholesome and palatable. To do so land must be secured immediately above the intake and two settling basins built, with a capacity of 3,,000000 gallons each, and three filter beds of a total area of 43.560 square feet; the water to be pumped through a fourteeninch pipe by a duplex, campound,condensing pump of 4,000,000 gallons daily capacity. Air will be forced into the pipes with the water and, traveling with it for 1.600 feet under pressure, will be thoroughly mixed with it, so as to oxydi/e the organic matter held in suspension. For further aeration the force mains will project eight feet above the surface of the water in the settling basins and the raw water will be discharged over a bell shaped cap surmounting the main, and will spread out as it falls. It will flow into the filter beds after forty eight hours of sedimentation. The cost of such a plant is set down at $30,558.50(including probable ccst of land,$6,000—$8,000 if enough is bought for future needs and to keep the site clear of polluting causes ) The cost of maintenance and repairs after the first year is estimated at $1.50 per million gallons—Professor Hazen estimates it at $1.25. Sand filtration is the method proposed, though, doubtless, the city authorities would not necessarily be wedded to that system.