THE CEDAR RAPIDS WATER SYSTEM
The water works at Cedar Rapids, Ia., are owned and operated by the municipality. The original construction was commenced in 1875 by a private company which operated the works until 1903. Control is vested in a board of three trustees. Andrew Kydd is office manager, Benjamin F. Hazcn is superintendent of construction, John C. Childs is chief engineer at the pumping station and Lee H. Goebel is sanitary engineer. In a report on conditions in the city, the Fire Prevention Committee of the National Board of Fire Underwriters gives the following information: “Supply taken from the Cedar River is pumped to rapid filters; from the clear water basin it is again pumped directly into the distribution system in one service without equalizing reservoir or standpipe. Auxiliary supply from driven well at the station is pumped to the clear water basin; from a well remote from the station supply will be pumped directly into the system.
The Cedar River, with a watershed of 6,320 square miles, is the main source of supply through two wells upon an island in the river north of the pumping station. These wells are 82 feet in diameter and 26 feet deep, with walls of stone surmounted by conical shingled roof; each has a 30-inch cast-iron pipe extending about 60 feet into the stream, with intake submerged about 4 feet and protected by a slotted cage. Through a mainly 30-inch cast-iron pipe 1,400 feet long, water is supplied from these Wells directly to the low lift pumps or to a suction reservoir in the rear of the station. Both this pipe line and the suction reservoir are provided with 20-inch emergency connections near the station directly with the river. A driven well in front of the station is 10 inches in diameter and 1,515 feet deep; a second well similar to the first has been driven about one mile southwesterly from the station, but is not yet equipped for operation. Eight high type Jewell filters installed in 1896 and four in 1898 have a combined capacity of 3,600,000 gallons per day. Two units of the high velocity type and capacity of 2,000,000 gallons per day each, m’akc an aggregate total capacity of filters of 7,600,000 gallons per day. Two clear Water basins have a combined capacity of 600,000 gallons. In case of emergency the delivery of the filters could be somewhat increased or supply supplemented directly from the river through emergency connections. The pumping station is located on the easterly bank of Cedar River about 900 feet north from the principal mercantile district. Built in 1875, elevation of floor 98 or 4 feet above recorded high water. The total capacity of low lift pumps supplying the filters is 6,000,000 gallons per day; each has independent suction from the supply line from the island wells and discharge line to the filters. The total rated capacity of the three high lift pumps is 10,000,000 gallons per day. Each has a gated branch from a well gated loop connecting with the clear water basin of the purification plant, which loop is also connected for em’crgency with the suction reservoir, and each has independent discharge equipped with a gate and check valves into a common header outside the station; the discharge from the 2,000,000 gallon pump is provided with by-pass connection about the header to one 20-inch artery supplying the distribution system; a break in the header would put the two larger pumps out of service.. The electrically driven pump at the driven well discharges through a 10-inch pipe line to the clear water basin. The open suction reservoir in the rear of the station is 34 feet in diameter and 28 feet deep with walls of stone set in cement; it is used only in emergency. It can be supplied through the 30to 20-inch pipe line from the island wells or through a 20-inch tunnel to the river 150 feet distant. and_ is provided with a 20-inch pipe connecting with the suction loop supplying the high lift pumps. In ordinary practice the well pump is operated continuously, and one of the low lift steam pumps during the day. The 5,000,000 gallon high lift pump, sometimes supplemented by the 2,000,000 gallon unit, is operated during the day and the latter during the night; the 3,000,000 gallon unit is turned over three times a week and operated occasionally. One boiler of each pair is usually fired. The station consists of a group of three joisted brick, mill and frame buildings, 1-2 stories in height.
Consumption, Service and Meters.
The average daily consumption in 1915 was 2,724,000 gallons being 74 gallons per capita, estimating the population at 36,582. At the time of the inspection there were 7,327 taps for service connections, of which less than 300 were inactive. Meters are owned, set and maintained by the water works and are required upon practically all services. A recording gauge is maintained at the pumping station and charts are filed. The charts show pressures steadily maintained at about 63 pounds and raised to 80 pounds upon receipt of alarms of fire. There is a recording gauge at fire headquarters. At two points on the distribution system electrically-driven pumps raise the pressure for elevated residential sections. These pumps are of small capacity and the increase of pressures for fire protection is dependent upon the pumping station.
Supplied by continuous direct pumping in one service, from a 30-inch header at the pumping station, two 20-inch arteries extend into the principal mercantile district, supplying a gridiron of 10and 12-inch mains, from which a 10-inch line extends to the northeastern part of the system and two 10inch lines to the southern part; from the latter a 16-inch main extends across the Cedar River as the principal feeder to the west side of the city. The few other secondary feeders are at present supplied from the gridiron of minor distributors. In the principal mercantile district the mains are principally 10and 12-inch; in other districts 6-inch pipe with a good proportion of 8-inch and but little 4-inch form a gridiron with many long lengths of 6-inch pipe without crossconnection and with 17 miles of 4and 6-inch pipe, or 23 per cent, of the total mileage, in dead ends. All pipe is tar-coated, cast iron. Sixinch is the minimum size now laid by the city or purchased from private parties for supply to hydrants. No trouble has been experienced from tuberculation or sedimentation. Mains are flushed three times a year. The discharges from the hydrants during flow tests were clear. No trouble has been experienced from frozen mains and no mains are exposed. Pipe is purchased under the specifications of the American Water Works Association, usually Class C; at the pumping station some Class D pipe has been installed.
Gate Valves and Hydrants.
There are 516 gate valves. Valves are Uiostlv Ludlow or Eddy make. All open to the right. Those 16-inch in diameter or larger are geared. In the principal mercantile district valves are set in vaults; in other parts of the system operation is through iron gate boxes. Valves are usually set upon the property lines, although many are within the street intersections. The average length of main that would be put out of service by a single break in the principal mercantile district is 886 feet; in a representative residential district the average was found to be 1,050 feet. The total number of public fire hydrants in service in September, 1915, was 555. All are of the post type, mostly of R. D. Wood or Ludlow make, and open to the right. Each has a gate in the branch and many have frost jackets. Two hundred and fiftyone have two 2J4-inch and one 4j4-inch outlets, with 6-inch branch from a main not less than 6 inches in diameter, and 5-inch or 6inch foot valve; the remainder have two 254inch outlets, 4-inch branch and foot valve, with a very few supplied from a 4-inch main. Hydrants are usually located near street intersections, with but few outside the mercantile district in the middle of blocks. Hydrants are provided with automatic drip valves and are set with jockets of loose stone. Drainage is generally good and no trouble has been experienced at fires from frozen hydrants. A portable steam boiler is provided for thawing.
In an extreme emergency, a polluted supply could be delivered into the system through a normally closed by-pass between a 10-inch city mlain and the private systems of the T. M. Sinclair & Company’s packing plant. The plant equipment includes 6 pumps, with a total capacity of nearly 10,000,000 gallons a day. It is estimated that in an emergency this system could deliver to the principal mercantile district approximately 3,000,000 gallons a day at 20 pounds pressure, and about 1,200 gallons a minute at 75 pounds pressure, using the Underwriters fire pump and carrying 100 pounds. The private plant of the Rock Island railroad shops can also deliver river water to the system. The connecting main is 4 inches in diameter
The report contains the following conclusions: Management capable; supply from river is ample and is supplemented from a driven well. Filters can be by-passed in emergency. Capacity of high-lift pumps is not sufficient for maximum consumption and fire flow without any consideration of the reserve desirable in direct pumping systems. With the largest pump out of service, the remaining capacity would not suffice for the demands of maximum hourly consumption. The per capita consumption is moderate, considering the character of the city, but the large use of water during the midnight hours indicates leakage. The general use of meters has reduced the consumption. Domestic pressures are sufficiently high for automatic sprinkler protection, and fire pressures are adequate for effective hydrant hose streams. They can be well maintained in the principal mercantile district under a draft up to the limit of the pumping capacity, but in many other localities the friction loss under large flow is high. Main arteries are sufficient in size; secondary feeders are few in number and the minor distributors make up a gridiron in many dead ends. The installation of an 8,000,000 high lift pump was recommended.