« PreviousContinue »
ratus getting out of order and at other times the amount of chlorine applied has been apparently insufficient to bring about satisfactory
sterilization. I would therefore recommend :
1. That the village continue to exercise the most careful and thorough operation of the chlorine apparatus under constant supervision.
2. That in order to prevent the necessity of placing the apparatus out of commission for repairs, the village install a duplicate apparatus or secure sufficient duplicate parts to provide for instantaneous repairs to the apparatus as now installed.
3. That in order to secure an additional safeguard of the sanitary quality and also to secure a supply of a more satisfactory physical quality, the village consider the installation of a modern filtration plant or the securing of a new supply of unquestionable purity, possibly by the development of a gravity supply from upland sources, as soon as the
village finances will permit such a course. As the carrying out of recommendation No. 3 involves numerous engineering and economic problems, it is suggested that before action is taken in this matter, the village authorities secure the advice of a competent water supply engineer.
Chief Engineer ALBANY, N. Y., January 16, 1917
Results are expressed in parts per million. + Present. Absent.
Abbreviations used to describe odors of water: 0, none; 1, very faint; 2, faint; 3, distinct; 4, decided; 5, strong; 6, very strong; a, aromatic; d, disagreeable; e, carthy; f, fishy; g, grassy; m, musty; V, vegetable.
HERMANN M. BIGGS, M.D., State Commissioner of Health:
I beg to submit the following report on a reinspection of the chlorination plant operated in connection with the public water supply of the village of Whitehall, Washington county, N. Y., made by Mr. Henry Ryon, inspecting engineer in this Department, on November 9, 1917:
General information Location.- Whitehall is located in the central northern part of Washington county. It is on the D. & H. railroad, about 78 miles north of Albany.
Population.- About 4,700. Nearly all of the houses in the village are oonnected with the public water supply.
Source of supply.- Mettawee river. The intake is located about 112 miles above the center of the village.
Consumption.- About 500,000 gallons per day or 110 gallons per capita per day.
Distribution system. The water is pumped directly into the village mains, the surplus going to a storage reservoir.
Storage.- The capacity of the storage reservoir is 5,000,000 gallons.
Records of previous references.- Investigations of typhoid outbreaks in Whitehall were made by this Department in 1904–1906 and 1907. The results of these investigations are covered by reports published in the 27th Annual Report of this Department, beginning on page 263, and in volume 2 of the 28th Annual Report, beginning on page 388. In February, 1915, an engineer from this Department was detailed to Whitehall to inspect the conditions and make arrangements for the installation of a chlorinating plant. A report covering the results of this investigation will be found on page 697 of the 36th Annual Report. On August 16 of the same year the chlorination plant was inspected and a report covering the matter will be found on
36th Annual Report. Other inspections of the chlorination plant were made on February 15, 1916, and December 19, 1916. Reports covering the results of these reinspections were submitted to you under dates of April 13, 1916, and January 16, 1917. In the last of these reports it is recommended that the village authorities exercise the most careful supervision over the operation of the plant; that they install duplicate apparatus or secure sufficient duplicate parts to provide for making, instantaneous repairs to the apparatus as now installed; and that they consider the installation of a modern filter plant or the development of a new water supply of unquestionable purity. The village authorities have evidently endeavored to carry out the two recommendations first mentioned, but owing to the large expenditure which would be required to carry out the last recominendation, no steps have yet been taken toward the installation of a filter plant or the development of a new source of supply.
The water supply of the village is taken from the Mettawee river immediately adjacent to the pumping station, which is located on the west bank of the river, about 112 miles upstream from the center of the village. At the time of the inspection the water of the river was almost clear, having a turbidity of only about 10 parts per million, measured by the platinum wire method.
A 24 by 15 direct-acting steam pump is used to force the water into the village mains. This pump is said to be operated continuously except for short periods, when, for making repairs or to avoid taking water that is too turbid, the pump is stopped and the village supply drawn from the storage reservoir. At the time of the inspection the pump was operated at a speed of 18 strokes (complete) per minute, giving a rate of discharge of approximately 475,000 gallons per 24 hours.
The apparatus used for applying chlorine to the water is of the solution feed type, manufactured by Wallace & Tiernan. A scale is provided for weighing, the chlorine cylinder. According to the weights recorded in the note book kept by the engineer at the plant, chlorine has been applied to the water at the rate of from 1.8 to 2.0 pounds per day; or, assuming an average of 500,000 gallons per day as thë amount of water pumped, from .42 to .48 parts per million.
When the inspector from this Department reached the plant, the pump was running at the speed noted above, but the decidedly unsatisfactory bacterial results of the analysis of a sample of water taken before the apparatus was adjusted. The engineer in charge of the plant explained that the apparatus then in use was an emergency machine, being used because the regular apparatus had been shipped to the factory for repairs, and that it d'id not work as well as the regular apparatus. He also stated that the valve on the chlorine cylinder then in use did not work properly. After the machine was adjusted so that the rate of application of chlorine, as estimated from the impulses of the meter connected with the apparatus, was about 0.4 parts per million, the treated water showed an excess of chlorine of 0.11 parts per million whereas no excess was found before the adjustment took place.
Analyses of the treated water are made by G. E. Wilcomb, sanitary engineer, every two weeks, and the results obtained by him indicate that in general the water delivered to the village has been of satisfactory sanitary quality. The bacterial count has been low, and the tests for colon bacilli in 10 c.c. inoculations have usually given negative results. The results, however, of the examination of a sample of water taken by Mr. Wilcomb about November 1, 1917, showed a very high count and indicated bacteria of the colon type in 1 c.c. inoculations. These unsatisfactory results were in all probability due to the failure of the chlorine apparatus to deliver chlorine to the water at a uniform, rate. The matter of the uniformity of the application of chlorine is one of vital importance, and should be given proper attention by the village authorities, for, even though the total amount of chlorine applied during 24 hours may be sufficient for the satisfactory treatment of the water, if the apparatus fails to work and the flow of chlorine is stopped or materially reduced for only a few minutes, the results may be quite serious.
Samples of the raw and treated water were taken at the time of the inspection, and the results of the examination of these samples together with the results of the examination of samples taken during 1916, are given in the appended table. These results are in accordance with the conclusions that would naturally be arrived at from the physical examination of the water supply.
The results of the chemical analyses of the water studied in connection with the results of the bacteriological examination of the raw water indicate that the raw water while undoubtedly polluted, is of such a quality as could readily be purified by proper methods. The fact that the sample taken just before the inspector from this Department reached the plant on November 9, 1917, and the sample taken by Mr. Wilcomb about November 1, 1917, both show a high bacterial count and bacteria of the colon type in 1 c.c. show that the present method of treatment cannot always be relied upon unless the operation of the plant is very carefully carried on. A comparison of the results of the bacteriological examination of the samples of treated water taken on November 9, 1917, before the chlorination apparatus was adjusted to feed chlorine into the water at a proper rate with those of the examination of samples of the treated water taken after the adjustment was made, indicates very clearly the importance of careful operation and the necessity of applying chlorine to the water at the proper rate at all times. As a result of the investigation it may be concluded:
1. That the raw water of the Mettawee river is seriously polluted.
2. That the operation of the chlorinating plant, judging from available records and an examination of the plant, seems, in general, to have been carried on in a satisfactory manner, although at times the apparatus has failed to deliver chlorine at the proper rate.
3. That although the chlorinating plant when operating properly renders the water supply to the village comparatively safe, the variable quality of the water, its extremely turbid condition at times and the frequent failure of the apparatus to work properly, indicate that the only way to assure a supply of unquestionable purity is to install a complete modern filtration plant with the chlorination continued as a supplementary method of treatment.
I would, therefore, recommend:
1. That the village authorities exercise the most careful supervision over the operation of the plant, giving attention to the uniformity of the application of the chlorine as well as to the total quantity applied per day.
2. That the operation of the chlorinating plant, judging from available quality of the water and also to secure a supply of most satisfactory physical quality, the village authorities consider the installation of a modern filtration plant, or the securing of a new supply of unquestionable purity, possibly by the development of a gravity supply from upland sources, as soon as the village finances will permit.
Chief Engineer ALBANY, N. Y., December 7, 1917
RESULTS OF WATER ANALYSES
d, disagreeable; e, earthy; f, fishy; g, grassy; m, musty; v, vegetable
Raw water, Metta wee river... 12/19/16
adjustment of chlorine ap-
adjustment of chlorine apparatus