FILTRATION AT READING.
Reading, Pa., has long been exercised over the subject of the purification of its water supply; but the water commissioners have
hesitated to make any recommendations definitely favoring filtration, principally because of the great cost attending both the installation of filtration plants and the expense of operating them as applied to [Reading’s] water works system. Another question considered was: Is the water supplied impure to a degree to endanger seriously the life and health of the citizens? And another: Will the majority of our citizens aoprove of an expenditure of $300,000 for filtration, in view of the fact that there is no constant senous contamination and the water nearly always clear?
The commissioners have, therefore, examined all these questions very carefully, and after due investigation have come to the conclusion that cities which filter their water have not water in its crude state of such uniformly good character as that of Reading, while many larger cities use unfiltered water which is much more contaminated. At the same time they consider that the water supply of Reading should be filtered at whatever cost—ealth and life being paramount to the expense. They believe that, as at Reading, so in every progressive city in the United Slates, the sentiment will sooner or later prevail, and that the “next ten years will witness filtration in use” in these cities. The commissioners add :
Recognizing the fact that, with the constantly increasing use of ihe Maidencreek water, our citizens are exposed to the dangers of typhoid fever (by reason of its large and uncontrolable drainage area),and that the waters of the Antietam supply will be by filtration freed from the occasional objectionable taste and odor from vegetable growths therein, we recommend that the entire supply be filtered as early as practicable— first, the Maidencreek supply, next the Antietam, the Bernhart, and the Egelman.
To carry out this recommendation will take money. This, the commissioners suggest, should be provided for by a loan; while the cost of maintenance, operation, and interest will be made up in part by increasing the annual water rates by restoring the fifty cents taken off by the hydrant charge a few years ago. The surplus revenues of the department will not Ire sufficient to provide for the additional expenditure.
In the joint report on the subject of the filtration of the water supplied to Reading, Emil L. Nuebling, superintendent and engineer, and Allen Hazen, consulting engineer, point out that the supply comes from five sources, the first of which consists of certain springs in the neighborhood of the Hampden reservoirs, which yield a “ limited amount of water of very satisfactory quality ” and not requiring filtration.
The second, or Egelman supply,is from an impounding reservoir, holding 2,500,000 gallons upon a watershed of 0.54 of a square mile. There are several houses upon this watershed. The geological formation of this drainage area consists of about thirty-five per cent, of Potsdam sandstone and sixty-five percent, of gneiss. About one-half of the drainage is woodland. The quality of the water is ordinarily good, excepting that algce growths at times give rise to unpleasant tastes and odors, and after heavy rains the water becomes muddy. The Egelman reservoir supplies the high service district.
The third source of supply is from the Bernhart reservoir, with a capacity of 42,000,000 gallons supplied by a drainage area of 2.56 square miles, There are about thirty houses on this watershed. The geological formation of this drainage area consists of eighty per cent. Potsdam sandstone and twenty per cent, of gneiss, and thirty per cent, of it is woodland. The water is considerably harder than the Egelman, and suffers occasionally from mud and alga: growths. The water receives, and is made much harder by the water of several springs, which aie much harder than the surface sources. This excess of hardness is apparently due to contact with subterranean deposits of limestone. The capacity of the pipe line from this reservoir to the city is 2,500.000 gallons per day, and the elevation is such that it just serves for the supply of that part of the city lying below a contour of 270. and known as the low service district. At dry seasons more water is required in this district than can be supplied from the Bernhart watershed, and the deficiency is at present made up with water let down from the intermediate service; but it is the intention, after certain Changes in the pipe line shall have been made, to supply this deficiency and the natural increase in consumption in this district with water pumped from Maidencreek to the Bernhart reservoir direct.
The fourth source of supply is the Antietam reservoir, holding 101,000 009 gallons, supplied with water from a drainage area of 5.44 square miles. There are about eighty houses on this watershed. [The water commissicn] board has within the last few yeirs purchased those places upon the watershed which were nearest to the reservoir, and which from their locations probably contributed in greatest measure to its pollution. The geological formation of this drainage area Consists of twenty-five per cent, of Potsdam sandstone, and seventyfive per cent, of gneiss. The water from this watershed is quite soft The water from this reservoir is occasionally muddy, and has algae growths, which make it quite unpleasant in taste and odor. The conditions of the water in the Antietam reservoir will be considerably improved by works now under construction—namely, a series of small damsalong the streams supplying the reservoir, which dams are to be so constructed as to aerate the water as it flows over them. The capacity of of the present pipe line from the reservoir to the city in 3.500.000 gallons per day, and the elevation is such as to a’iow its use without pumping in the intermediate service.
The fifth source of supply is Maidencreek. Water is pumped from this creek at a point where its drainage area is 2ro square miles. There is no storage reservoir on the creek. The geological formation of this watershed consists of seventy per cent, of slate, twenty-one per cent, of limestone, and nine per cent, of other formations—the larger part of the limestone being on the watershed of Willow creek, a tributary entering Maidencreek about half a mile above the pumping station. There are several small villages and institutions upon the watershed of Maidencreek, some of which are sewered, and the sewage is discharged untreated into the creek or its tributaries. The water of Maidenhead is considerably harder than that from the Antietram and Egelman reservoir. It is not subject to the disagreeable tastes and odors resulting from alga: growths. It is muddy after heavy rains, and the discharge of sewage into the streams renders the use of this water it its raw state more or less injurious to health and objectionable.
The printed records of the city hall show that during the list two decades the typhoid fever death rate in Reading is slowly increasing—due probably to the increased use of water from the Maidencreek supply, which is more directly polluted with sewage from the other sources of supply. From 1877 to 1886 inclusive the death rate from typhoid for each 19,000 of the population averaged 2 74; from 1887 to 1896 inclusive, 4.52.
The report, therefore, adds
The problems presented are: (1), the removal of the mud from all of the waters after heavy rains; (2), the removal of the tastes and odors resultingfrom algae growths from the waters of the Antietam, Bernhart, and Egelmar. reservoirs; and (3), the removal of the bacteria, which are, or may be injurious to health, discharged into the Maidencreek by the aDove mentioned sewers or other sources of pollution, and of similar germs from the reservoir waters, in case such germs are present or should be introduced from the inhabitants living upon the respective drainage areas.
The disease, which is believed to be most frequently caused by polluted water supplies, and the presence of which in a city is most characteristic of such pollution is typhoid fever. 1 yphoid fever is caused in other ways than by polluted water supplies; but its continued and excessive presence in a large city, unless otherwise explained, is an indication of such pollution, and, incase of known pollution, can be taken as an approximate index of the damage resulting from it—being far more reliable in this respect than other diseases also caused by polluted water, but whose occurrence is more dependent upon other causes not connected with the water supply.
With respect to the algm growths in the reservoirs, the report points out that,while they often give rise to very offensive tastes and odors, which are in themselves objectionable, and which should be removed, water charged with such growths m ly cause diarrhee 1 or other disturbances in the system of certain people, particularly those not accustomed to the water; but, as far as known, no serious disease is caused by the pres, ence of these organisms in wa er. The algre are vegetable growths, complex in their nature, and entirely different from bacteria which cause typhoid fever, cholera, and other zymotic diseases.
The report of the water commissioners just published comprises previous reports of the board on the subject of filtration, the joint report of Superintendent and Engineer Emil L. Nuebling and Consulting Engineer Allen Ilazen, with recent opinions on the subject of filtration by Professor Erastus G. Smith, Professor Wm.P. Mason, and Rudolph Hering, and is of very interesting reading even to those who are not water works experts.