FIG. 3. FIG. 3. Horizontal section of bottom of tank, showing arrangement of screen collecting tanks beneath the sand. One foot from the bottom of each tank is arranged a series of collecting pipes (Fig. 1, S. S. and Fig. 3), over which is a bed of sand four feet deep. Each collecting pipe consists of a central core of iron of star shape, (Fig. 2) around which is wound a No. 12 copper wire, with an interspace of 1-5,000 of an inch between each strand, thus leaving four spaces about the central core for the collection of the water. The ends of these collecting pipes, which are ten inches in circumference, are embedded in the walls of the filter, and the centre is supported by girders from a cross beam on the top of the tank. By means of an apparatus especially constructed, a solution of sulphate of aluminum, of definite strength, is allowed to mingle with the water in the sup ply pipe at a short distance before it enters each tank. The peculiar properties of the aluminum salts are quickly made manifest by an increased amount of the floculent matter in the water. The salts gather together by coagulation, in sponge like masses of varying size, the organic matter held in the water, and thus reduces it to a condition readily to be entrapped in the sand bed of the filter. The aluminum salt becomes mingled with, and retained in, the coagulum, and remains on the filter bed, from which it is removed when the filter is washed, and consequently does not affect the water that has passed through the filter. Supply pipe A. (Fig. 1) discharges the pond water into the filter through a series of openings (I. L. Fig. 1) on the sides of the tank, about eight inches above the level of the sand. The water gravitates through four feet of fine sand to the bottom of the filter, where it is collected by pipes (Fig. 1, S. S. and Fig. 3) and discharged through the outlet pipe (B, Fig. 1) into a large and deep cistern, from which it is pumped into the city mains and into the reservoir. This is a brief outline of the process of purifying the water. Another important step remains unfinished, i. e., the thorough cleansing of the filter beds after they have performed a certain amount of work. This cleansing process is simple and effectual, and is accomplished by a series of pipes conveying water, under a pressure of sixty-five pounds to a square inch, from the reservoir. If we assume a tank is to be cleansed, the supply pipe from the pond and the outlet pipe are shut off by valves (a and b, Fig. 1). The gate H. is now opened, reservoir water from the pipe R. enters the wash pipe P. and is forced into the tank beneath the sand, through the perforated pipe P. F. A section of pipe P. is arranged to rotate between points K. K., thus enabling the lever arm L. to sweep the perforated pipe around the bottom of the tank beneath the sand and the collecting tubes. The water rushing through the perforation in the pipe washes a pathway before it, and thus enables the pipe to be slowly swept under the four feet of sand. The sand is thrown into violent agitation as the water is forced upwards, and all the impurities are washed to the surface. At the same time a flow of reservoir water enters through gate I. into the screen collecting tubes, and washes out any material that may have collected between the strands of wire, and assists in washing upwards the impurities collected in the sand. The water, laden with the collected organic matter and other impurities, gradually rises in the tank and flows out through openings on its side (O. L. Fig. 1), and thence in the waste pipe W, by which it is carried beyond reach of again contaminating the pond. After the washing, which requires about twenty minutes for each tank, the sand is left as clean and as pure as when first put into the tank. Relative to the amount of water to be filtered, the Newport filter plant is the largest in the country. The main points wherein it differs from the recognized Hyatt filters are: That the filter beds are much larger in proportion to the work required, thereby allowing a slower filtration; the water gravitates through the sand, thus rendering impossible the forcing of organic matter through the filter bed, which is likely to happen whenever pressure is used; the sand is washed from beneath the collecting tubes, which are of a different construction. The capacity of the pump for raising the water into the reservoir is 3,000,000 gallons per day, and the filters are designed for this amount, although capable of filtering a much larger quantity of water. The amount of water that actually passed through the filter and was used in the city during the past summer was 2,000,000 gallons a day. The filter plant has as yet been in use only during the few months of the past summer, but as soon as further alterations, which are now being carried on have been completed, it is understood that the filter will be in use during the whole year. That there is a necessity for an uninterrupted use of the filter throughout the whole year is very apparent, for our city water contains an excess of vegetable matter. During the period the filter was in operation experiments were constantly carried on to improve the filtration, the perfection of which depends chiefly upon the quality of sand in the filter bed, and the character and amount of aluminum salts. When these two points are satisfactorily determined, our citizens can look forward to a supply of water clear in color, and of a degree of purity that is surpassed by few cities. The company are at present engaged in raising the heighth of the dam, and thereby raising the heighth of the water in the pond about eighteen inches. This will be an additional aid in purifying the pond water, for it will hasten the destruction of the little remaining vegetable growth along the shallow edges of the pond, a growth which heretofore has been one of the causes of the vegetable matter in the water. The Board of Health deem it their duty to again call the attention of your honorable body to the great importance of instituting measures for the more thorough protection of the city water shed from matter of a character which may defile the water. We recommend a sanitary inspection to be made of the city water shed, and power granted to remove all unsanitary conditions, if any exist, that are in close proximity to the streams which flow into the pond. The company is to be commended for their enterprise and efforts to purify the water, and it certainly behooves the city to take equal interest in guarding the water from pollution, for perfect though a filter may be, it is not beyond the possibility that germs of disease having gained entrance into the water may pass through the filter. The mortuary tables for 1890, herewith appended, exhibit the number of deaths and the causes, also the sex, color, social condition, nativity, and ages of decedents, and the number of deaths in each ward. Respectfully submitted, FRANCIS H. RANKIN, M. D., Secretary of Board of Health. 1. NEW SHOREHAM. 2. Health Officer, Herbert S. Millikin. 3. Only very small prevalence of contagious or infectious diseases in town during 1889, except Diphtheria, 4 cases, 2 deaths; February. 6. Inspections of premises were made where sickness prevailed as to the sanitary condition of the cellars, sinks, sink-drains, cesspools, out-house privies, distance of wells from accumulations of filth, etc. Of the places inspected the sanitary condition was found to be good. 7. No sanitary inspections were made during 1889 by order of the town council. 8. No known location in town that seems to be particularly unhealthy to any considerable number of persons. 9. Should report to the town council nuisances dangerous to the public health when known. 10. No serious disease of domestic animals has prevailed. 1. TIVERTON. 2. Health Officer, none appointed, town council act. 3. Have no knowledge of any epidemics or any large prevalence of contagious or infectious diseases during 1889. 6. Very few inspections of premises were made during 1889. 8. No location in town that seems to be particularly unhealthy. 9. The town council would act if nuisances dangerous to the public health were known. 10. No serious disease of domestic animals. No report from the following towns in Newport County: 3. No epidemics or any large prevalence of contagious or infectious diseases in this town during 1889 except the following: Diphtheria, Pascoag, 5 cases, 2 deaths; Harrisville, 3 cases, 1 death; Mapleville, 3 cases, 1 death. Iufluenza, all about, scores of cases, no deaths; December. 6. Condition of many cellars and cesspools bad. Distance of cellars from privies and sink-drains from three to ten feet in some cases. Water in some cellars. 7. I have made cases known to the town council as to sink-drains, and they gave me no answer; they are very slack. 8. As to locations in town that seem to be unhealthy to any considerable number of persons, there are plenty, and can be removed or abated. 9. It would be of no use to report to town council nuisances dangerous to the public health, or unsanitary premises within my knowledge. 10. No serious discase of domestic animals has largely prevailed. CRANSTON. No report. 1. EAST PROVIDENCE. 2. Health Officer, Mason B. Wood. 3. Have no knowledge of any epidemics or any large prevalence of contagious or infectious diseases in town during 1889. There is no ordinance requiring the physicians of the town to report cases, excepting such as are in the Public Laws. 4. In cases of diphtheria, scarlet fever, whooping cough, measles and chickenpox among school children isolation was maintained where the physicians in attendance requested me; six cases in all. 5. I believe the proportion to be very small. 6. Inspections of premises were made as to the sanitary condition of the cellars, cesspools, out-house privies, accumulations of filth, etc. See report appended. 7. No sanitary inspections were made during 1889 by order of the town council. They were made on request of physicians or tenants. 8. Do not know of any location positively unhealthy to any considerable number of persons, although there is a place known as Carrigan's Hollow, near Fort Hill, in the village of Watchemoket, where there is a standing pool of dirty, filthy water. 10. Have no knowledge that any serious disease of domestic animals has largely prevailed during the year. REPORT OF HEALTH OFFICER. EAST PROVIDENCE, R. I., March 1, 1890. To the Honorable Town Council of East Providence: The annual report of the Health Department is herewith submitted, and is as follows: The total number of complaints of all kinds received are 78, and may be classified as follows: Material assistance has been rendered to this department by the Police Department on all occasions where deemed necessary. There has been a general acquiescence in the suggestions and requests made by this department on the part of those complained of, so that resort to the law by prosecution has not been necessary in any instance. There seems to be urgent need of some change in the manner of collecting and disposing of swill. At present whoever will, may take out a permit and gather swill anywhere, and at any time, as personal interest or whim may lead. Numerous complaints have been made that parties in the compact portions of the town had no way of disposing of swill accumulations. Respectfully submitted, MASON B. WOOD, Health Officer. 1. FOSTER 2. Health Officer, Henry Arnold. |