Minneapolis Water Supply and Officials
The story of the Minneapolis pure water supply is that of the present municipal water works system that in years has grown from less than 15 miles of mains and $2,000 revenue to more than 500 miles of mains and $500,000 annual revenue, and now includes a new filtration plant at a cost of $1,500,000. The sketch is opportune because in Minneapolis will be held on June 23 to 27, inclusive, the thirty-third annual convention of the American Water Works Association. Special interest attaches to it becaust it discloses how the metropolis of the great Northwest provides one city improvement up to the standard of perfection now demanded by the public—shows the method of solution of one of several similar problems confronting that and other western cities during a period of rapid and continuous growth. The source of the Minneapolis water supply is, and always has been, the Mississippi River. The first pumping station was built in 1866 near the famous St. Anthony Falls in the center of the city, and which still furnishes power to grind some of the millions of barrels of flour that Minneapolis manufactures annually. It was a private plant, intended only to provide lire protection to three of the large sawmills that at that time formed the principal part of the city’s industries. The little plant with its limited equipment was purchased about a year later by the city, so it may as well be said Minneapolis has always owned its own water works system. The city put into operation in 1807 at the plant near the falls its first pump, a “Holly Rotary” of about 1,500,000 gallons capacity, working ordinarily against 49 pounds pressure, but capable of pumping against InO pounds fire pressure The pipe laid during those years were of light sheetiron. covered with cement, both inside and outside. Those pipes were replaced in 1870 with wooden (log) pipe and some cast-iron pipe Thirteen consumers were furnished by the system in 1873, as compared with more than 48.000 to-day. The total number of gallons numped was 146,000,000 in 1871, against nearly 10,000,000,000 last year.
The Pumping Capacity
Six additional pumps were installed between 1876 and 1886 to keep pace with the constant increase in demands. Three pumps of 3,500,000 gallons capacity each were installed between 1876 and 1883, and three more each of 10,000,000 gallons capacity, and so-called “Jumbos” were installed—one each year from 1881 to 1886. All six were manufactured in Minneapolis and driven by water power, although the three small ones could have been driven with steam. All were located just above St. Anthony Falls, but divided between two stations on opposite banks of the river. They later fell into disuse because the quality of the water at that location gradually depreciated, resulting later in new plants further up stream and finally the new filtration plant. Early pumping stations were so located that the water power at the falls might be utilized. While seemingly all right at first glance, it soon developed that, in order not to pollute the river water, all sewers had to be emptied below the falls, entailing large extra expenditures. Natural drainage, factory refuse, private sewers and other drains turned into the river soon developed unsanitary conditions, and the authorities were compelled to take cognizance of the fact. Many analyses of the river water at Minneapolis were made by bacteriologists in government, State and city employ, during the following years, and with somewhat varied results. Professor A. R. Leeds, of Hoboken. N. J., in 1888 made investigations that resulted in an agitation that ended with the erection of the Camden pumping station. which is still in use, with its equipment of two Worthington high-duty pumping engines of 15,000,000 gallons capacity each. The location is about four miles above the falls, still inside the city limits. The plant was first known as “Shingle Creek Station.” because of the fact that a small stream empties into the river just above the site. The station should have been located above the stream, as stated in a paper read by I ity Engineer F. W. Cappelen before the American Water Works Association not long afterward. “Rut engineers had nothing to do with the buying of the 12-acre tract for station purposes,” he added, “that being done by the city fathers in the usual way.” The supply from that station was the best until breaks occurred in the machinery or until the demand in the summer months was greater than this station could supply, and the city was compelled to fall back upon the lower pumps.
Introductions of Filter Systems
Health officials made protest after protest against the use of the lower plants, and in 1894 Engineer Cappelen made an investigation which eventually led to construction of reservoirs and the new filtration plant. Mille Lacs Lake, St. Croix River, and an artesian supply were considered, and various filters then in use in the United States were inspected, and Mr. Cappelen recommended continuation of the use of the Mississippi River supply source and filtration with installation of additional pumps that the lower stations might be permanently abandoned. The report was adopted by the city council. Construction of two 50,000,000-gallon clear water reservoirs with the necessary pipe lines and other appliances followed and was completed in 1897. The new plan marked the change practically from the direct pressure to the gravitv system in the Minneapolis water works system. The reservoirs were located at Columbia Heights and served as the raw water basins for the present filtration plant. During the years that followed, the reservoirs were used as setting basins before the water was distributed and considerably improved the quality of the water. The Northeast pumping station, now the principal plant, was completed in 1904 and equipped with two Holly triple expansion upright pumps of 15,000,000 gallons capacity each. The latest addition to the pumping equipment was afforded through the purchase, in 1911, of two 20,000,000-gallon, electric-driven centrifugal pumps, built by Henry Worthington and installed, one each in the Camden and Northeast stations. These two units, especially that at the Northeast station, now carry the. burden of forcing the river water to the filtration plant, although the steam pumps are held ready for emergencies. Power for the operation of the electricdriven pumps is furnished by the Minneapolis General Electric Company, a private corporation, at the rate of $4 per 1,000,000 gallons pumped, against a dynamic head at 240 feet and with a pump efficiency of 72 per cent. The new pumps were thoroughly overhauled early this year, a few minor defects were remedied, and Chief Engineer Edward York, of the pumping stations, states that the pumps are as good as ever Minneapolis’ new filtration plant will be its proudest boast and center of technical attraction during the coming convention of the American Water Works Association. An idea of the plant and its construction can be gained in the accompanying compact tables. It stands on Columbia Heights overlooking the city from the northern limits. Street cars pass within a mile of the plant, hut the convention entertainment committee plans to furnish automobiles, that every visitor and del -gate may visit it ; also souvenirs are being planned. River water is forced from the pumping stations on opposite sides of the Mississippi through two 50-inch force mains to the filtration plant more than three miles away. There it is filtered by the rapid mechanical process. The plant was put into operation late in January this year, but Superintendent E. I. Rirdsall, formerly superintendent of filtration at Rock Island. Ill., declares it is adjusted to a nicety and doing perfect work. The marvel of the plant is its clear water basin, wh ch is covered with two feet of earth on its reinforced concrete roof. This may he viewed by visitors possibly only from the inside and by special arrangement. Its 944 big pedestals and columns supporting the groined arches of the roof form a principal item in the construction bill. One of tbe original settling basins, before referred to, was changed into this clear water basin. The filter house, head houses and other buildings are of ornate design, and the whole construction and equipment is of a standard of which the designing and. constructing engineers declare themselves proud. Walking through the high-vaulted, bright and wellventilated filter house, the visitor will see the 12 large filter beds filled with yellow silica sand, imported from Red Wing, a river town 60 miles distant, and below which are the fills of gravel of varying coarseness, held in place with costly wire screens and strainer plates. Electric controlling panels and other appliances are aligned on either side of the main aisle, just inside the heavy rail of nolished brass. The furnace room, laboratories, and all other rooms, including the shower bathrooms for employes, will he open for inspection. Alum is used for coagulation, and during the first weeks of operation a very small percentage of hypochloride of lime was added to avoid any chance of any but safe, pure water reaching the mains. Tests both at the station and in many parts of the city have been uniformly satisfactory, according to the officials Inauguration of the new plant marked suspension of the hypochloride of lime purification plant installed at the Northeast station during the most serious epidemic of typhoid fever which the city experienced in 1900.
Procuring a Pure Water Supply
The quest for pure water, a naturally pure supply, or the host method of purification, began in earnest in Minneapolis about eight years ago, although it had been the subject of agitation nearly 25 years. H. W. Cappelen, then and now city engineer. read a paper on the subject at the 1891 convention of the American Water Works Association in Minneapolis. Outbreaks ot typhoid fever, charged by health authorities to impurity of the city water supply, resulted in the first real work in 1904. Engineer Cappelen and Allen Hazen, of New York City, were employed to consult with City Engineer Andrew Rinker and report, after investigation, the feasible methods of securing an improved water supply. The report c, lllUltssiim, which went to the city council September 9, 1904, reviewed the comparative merits of possible supplies, including artesian wells. Superior and Mille Lacs lakes, and various plans for sand or mechanical filtration, and recommended the slow sand process of filtration. City officials at that time believed the publicity given the investigation was sufficient to educate the public to the importance of a pure water supply, but found themselves n error when votes were counted in the election in 1904 on the question of issuing bonds necessary to provide a filtration plant. While the great majority voting favored the bond issues, only aliout half the voting population expressed any choice, and the total affirmative ballots iell far short of the twothirds majority required to authorize the bond sale. The proposition was again submitted at a subsequent election with a similar result, and the final solution of the financial problem was obtained in an act of the State legislature of 1909 authorizing a $1,(MX),000 bond issue for filtration plant purposes. Only $1500,000 of the total authorized was sold, however, the balance being paid from the regular water works revenue fund. Continuance of the agitation brought about creation of a Citizens’ Pure Water Commission, composed of 25 leading business and professional men, with Joseph Chapman, Jr., as chairman. The committee made an extended investigation and study of the subject but its report to the council was divided. The majority, including Mr. Chapman, recommended filtration of the Mississippi River water; the minority favored further investigation of the proposal for a supply from Mille Lacs Lake, about 80 miles from Minneapolis. I o avoid possible public criticism and assure, through careful research, the council adopted the minority report, and in June, 1909, the entire council of 20 aldermen, with K. (i. Smith, professor of chemistry in Beloit College, and City Bacteriologist Corbett, as expert advisers, made an investigation trip to Mille Lacs Lake. Exhaustive discussions followed; and when there was no sign of an issue taking definite form, Rudolph Hering, of New York City, was retained by the city as consulting engineer to go over the situation and made recommendations He spent 40 days studying conditions and reviewing reports, and made his report March 17, 1910. Eliminating the artesian well and Lake Superior proposals, for various reasons, he concluded his recommendations with the following paragraph, referring to the Mississippi River and Mille Lacs Lake propositions:
“The quality of the two waters after proper treatment would in both cases be clear, bright, equally healthful and oi good taste. But as the quality available from the Mississippi River will always he abundant, while that from Mille Lacs Lake would sometimes he insufficient, as an adjoining river will give more of an uninterrupted perpetual delivery than a single pipe line 80 miles in length and as a supply from the Mississippi River is much less expensive, I do not hesitate to recommend to your city the adoption of the latter after purification by rapid mechanical filtration as having no doubtful feature in any part of the works.”
The recommendations were adopted by the council, and Mr. Hering’s firm—Hering & Fuller, New York City—was immediately commissioned to prepare plans and specifications for a rapid sand filtration plant. City Engineer Andrew Rinker undertook supervision of the work under the day labor instead of the contract system and W. N. Jones, just from the Cincinnati filtration project, was engaged as engineer in actual charge of construction. The council committee on water works acted in an advisory capacity, and the construction was begun and finished in 18 months actual working tune. The product of the big plant is used for drinking purposes everywhere in Minneapolis. It will be sampled—liberally praised, Minneapolis people believe — by visitors at the water works convention in June. Following are the water works and filtration plant officials: Mayor. Hon. Wallace G. Nye; president of city council, Hon. Karl De Laittre; city engineer, E. W. Cappelen; registrar of water works, William R. Young: supervisor of water works, J. H. McConnell; chief engineer, Edward York; superintendent of filtration, L. I. Birdsall; city council committee on supervision—Alderman A. P. Ortquist, chairman; William Hooker, Frank Heywood, J. H. Chase and Harry L. Moore.
Minneapolis Filtration Plant in Tabloid Form
Filters, etc. (new) . 625,000
Reservoirs (old) . 502,000
Operation (yearly) . 50,000
Purification (1,000,000 gallons). 4
Bonds—authorized . 1,000.000
Bonds—issued . 600,000
Water works revenue invested. 25,000
Labor payrolls . 285.000
Materials . 340,000
Actual time, months . 18
Earth handled, yards . 256,000
Concrete poured, yards . 30,000
Reinforcing steel, pounds . 800,000
Structural steel, pounds . 112,000
Filter sand, yards . 1,332
Filter gravel, yards . 200
Pipe, tons . 414
Last item includes 1,547 feet of 42, and 40 feet of 60-inch pipe.
ON DAILY CAPACITY.
Maximum gallons .60,000,000
Maximum, per capita . 170
Average, per capita . 75
Demand, 1913—estimated .25,000,000
Site, 110 acres; plant, 20 acres; reservoirs— raw, 9; clear, 8 acres; filter beds 14,000 square feet; head house, 7,500 square feet; plant maximum, 1,800 by 830 feet.
At the plant may he seen the finest pipe gallery in the world. Expert concrete construction done under clay labor system.
Clear Water Basin.—The largest covered water receptacle in the United States. Capacity approximately 45,000,000 gallons, roof built without reinforcement, concrete for roof made of cinders from pumping station.
Construction Item.—500,000 feet of lumber for forms, 4 cars lime, 600000 brick, 500 feet iron railing, doors and windows costing $1,400, 27,000 asbestos shingles, 14,000 squares of roofing and 15,000 feet radiation.
Mechanical Equipment. — Rock crusher for crushing lime, 2 lime mixers of 40 feet capacity each, electric elevator of 6,000 pounds capacity, bucket elevator of 10 tons hourly capacity, vacuum cleaner of 85 feet displacement, 24 centrifugal pumps capacity from ⅛ to 50 horsepower, 2 trolley systems for handling chemicals, gas plant to supply 30 burners, 3 ventilating fans —one run by 50 horsepower steam engine, and others by electric motors—12 marble operating tables, brass wire screens and bronze strainer plates costing $9,500. Completely equipped and finely appointed chemical and bacteriological laboratories.