Big Filter Plant for New York.
Work on the new filtration plant to be established in the unfinished half of the Jerome Bark Reservoir at Kingsbridge, N. Y., by which Croton water is to be filtered by the latest method as the result of an appropriation of $8,680,000 made by the board of estimate, is to be begun at once, according to Water Commissioner Thompson. Efforts have been made for many years to establish a filtration plant in New York, but always something has come up to delay the project. According to Commissioner Thompson, the new plant will be one of the best in the world. The capacity for filtration will be 400,000,000 gallons a day, or practically 100,000,060 gallons more than the present daily consumption in Manhattan and the Bronx, and equal to the total capacity of the two Croton aqueducts. The experts of the department are trying to decide upon which method to use, slow or sand filtration, or mechanical filtration. Practically the only difference between the two, it is explained, is that the mechanical filtration is much more rapid than the other, and that an artificial coagulant is used to produce the bacteria catching films. All the Croton water supplied to the city is to be filtered. It is designed to greatly improve it by eliminating the objectionable color and odor with which the water has long been impregnated. Commissioner Thompson in a letter to the board of estimate urging the appropriation, said:
“The filtration of the waters from the Croton river has been under discussion for many years, and this department, the various incumbents of the board of health department and the engineers who have reported on the subject have unanimously favored filtration as the only means of effectually safeguarding public health and furnishing a supply of water satisfactory for domestic use. There has been no difference of opinion in the matter. If further evidence were needed to demonstrate the need of filtration the experience of the past summer and fall would be more than sufficient. The Croton supply, as you know, has had such an offensive taste and odor as to make it extremely unsatisfactory for domestic use. General and just complaints were constantly received from our citizens as to the condition of the water, and doubts expressed as to its wholesomeness, although the vegetable organizations which produce the condition of the water are not detrimental to health. There are times, however, when the condition of the supply is detrimental to health, and filtration is the only known means of effectually eliminating the offensive taste and odor, while at the same time removing the pathogenic bacteria. I cannot too strongly urge the advisability of authorizing the filtration of the Croton supply without further delay. There is no question but that the Croton supply must be ultimately filtered. No other action of the board of estimate and apportionment would be of greater general benefit to the public, and, as expenditure for extension or improvement of the water system do not affect the debt limit of the city, the construction of the filter plants would in no way retard such public improvements as subways, schools, parks, etc., which are also demanded by the public.”
The Merchants’ Association of New York was about the first civic body to make a fight for filtration. In 1900 in an exhaustive report on the subject it said: “It need here only he said that we consider the time to have arrived when surface waters of the Croton, Bronx and Long Island watersheds should be filtered. It is not so much the occasional turbidity and unpleasant taste of these waters which demand this improvement, but the frequent high percentage of bacteria contained in them, due to the pollution by the population residing upon the watersheds, either brought about by surface washing of rains or in some other way, unquestionably propagating water-borne disease germs. We share this opinion with the board of health, which last year recommended a filtration of the Croton and Bronx supplies.”
In the same year John R. Freeman, who was later a member of the Burr-Herring-Freeman Commission, in a report to the comptroller said: “I venture to express the opinion that by 20 years hence, the public will have been educated to demand a higher standard of purity in public water supplies, and that all future work should be laid out with a view to filtration 19 or 20 years hence of all waters entering the distribution system.”
This commission, which formulated the genoral plans on which the Catskill water system is being constructed, in its report in 1903, had this to say on the subject: “Regarding the Croton water the commission urges that suitable lands be secured at once upon which to erect a filter plant sufficient in size to purify the entire supply obtained from this source. There are but tew sites available for such a plant of slow filters, and a long delay in procuring it may seriously affect its future cost. Examinations of the sites have been sufficiently extended to determine their feasibility and their approximate cost.”
The old aqueduct commission in 1904 made a strong plea for a filtration plant. After the typhoid epidemic early in 1907, Dr. Darlington, then president of the board of health, made an emphatic plea for filtration He pointed out that a number of cases of typhoid existed along the Croton watershed, and gave it as his opinion that it New York had a filtration plant similar to those in use in foreign cities. New York would have escaped the epidemic. Dr. Daniel D. Jackson, the chemist employed by the water depart ment, made an extended investigation of the subject of filtration in England and Germany for Commissioner Thompson, and a few weeks ago submitted a report to the commissioner, in which he strongly indorsed the mechanical method of filtration. “A mechanical filter plant,” he said, “would occupy about one-tenth of the space that would be required for slow sand filters. The relative difference in cost of operation between the two plants is a matter very difficult to estimate, but the cost per million gallons for mechanical filtration would be little, if any, in advance of slow sand filtration, and would probably be considerably less, if the interest charges on the original investment are to be considered. Many of the large slow sand filter plants established in this country are now using coagulant as an accessory, as for instance, Albany, N. Y., and Springfield, Mass. Some of those not now using it are considering its use, as at Washington, D. C. The up-to-date treatment of water supply is either mechanical filtration or slow sand filtration using methods which closely approach the methods employed my mechanical filtration.”