I would, therefore, recommend:

1. That the Grand Gorge Water Company either abandon the present supply and develop a new supply adequate in quantity and satisfactory in quality or provide means for properly purifying the present supply by filtration supplemented with liquid chlorine sterilization;

2. That, pending permanent improvements, steps be taken by the water company to install at once and properly operate apparatus for the sterilization of the supply with liquid chlorine;

3. That, in order to determine the most feasible method whereby to secure a permanently safe water supply, the water company retain the services of a competent engineer to advise in detail as to the development of such a supply.

4. That, providing the present source of supply be retained, steps be taken to place the watershed in as sanitary a condition as possible and if necessary, apply to this Department for the enactment of rules and regulations for the protection of the supply.

I would further recommend that copies of this report be transmitted to the water company, the local health officer and to the sanitary supervisor of the district.

Results are expressed in parts per million.

+ Present.

Absent.

1+2

0+3

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, earthy; f, fishy; g, grassy; m, musty; v, vegetable.

GRANVILLE

HERMANN M. BIGGS, M.D., State Commissioner of Health:

I beg to submit the following report on an investigation of the sanitary condition of the water supply of Granville, Washington county, N. Y., made by Mr. Henry Ryon, inspecting engineer in this Department, on November 8, 1917.

General information

Location.- Granville is located in the eastern part of Washington county, adjacent to the state line between New York and Vermont. It is on the D. & H. R. R. about 70 miles north of Albany.

Population.— About 4,000. Practically all of the houses in the village are connected with the public water supply.

Source of supply. The Mettawee river.

Consumption. Estimated at about 500,000 gallons per day, or 125 gallons per capita per day.

Distribution system. The water is pumped directly into the mains, the surplus supply going to a storage reservoir from which the supply is drawn when the pumps are not in operation.

Pressure.- Varies from 90 pounds at the pumping station to 60 pounds in the higher parts of the village.

Storage. The capacity of the storage reservoir is 1,250,000 gallons, the equivalent of a little over two days' consumption.

Purification.—The water is treated with liquid chlorine.

Reference to previous investigations.— The water supply of the village was investigated in 1912 and a report on this investigation will be found on page 670 of the Thirty-third Annual Report. The supply was reinvestigated on February 10, 1916, and a report covering this reinvestigation submitted to you under date of April 14, 1916. On June 16, 1916, the health officer of Granville notified this Department that there were several positive cases of typhoid in the village; and on June 17 an engineer from this Department was sent to Granville to install a temporary chlorinating plant. A report covering the installation and operation of this plant was submitted to you under date of July 22, 1916.

The water supply of the village is taken from the Mettawee river at a point within the corporate limits of the municipality but above the built-up section of the village. The intake is on the north bank of the river about one-fourth mile above the power dam and pumping station. At the time of the inspection the condition of the river near and immediately above the intake was entirely satisfactory from a sanitary standpoint. The bed and banks of the stream were clean; and, with the exception of a few floating leaves, the water appeared to be free from color, turbidity and foreign material.

From the intake the water flows by gravity to the pumping station. This station is located at the power dam and operated in connection with the electric power station. Two triplex pumps are provided for handling the water. The older pump is a Gould 8 by 12 arranged to be operated either by water or electric power. This pump has a rated capacity of 790,000 gallons per day when operated at 36 R.P.M.; but owing to its condition the slip estimated from the readings of the meter located on the discharge line appears to be approximately 25 per cent. The actual rate of discharge therefore is only about 11.5 gallons per revolution, or 590,000 gallons per 24 hours. The new pump, a Rumsey 14 by 14, is arranged to be operated by electric power only and appears to be in good condition. Making a reasonable allowance for slip, the rate of discharge of this pump when operating at its usual speed of 28 R.P.M. is about 26.5 gallons per revolution, or 1,050,000 gallons per 24 hours. There is no meter on the discharge of the Rumsey pump and although a counter was purchased for the pump several years ago it has never been attached. It would seem advisable that this counter be put in place immediately. as its readings would be of considerable service in checking up the rate of application of the chlorine to the water. Both pumps discharge directly into the city mains, the surplus going to the 1,250.000 gallon concrete reservoir. There is no direct line from the pumps to this reservoir.

The water supply is not filtered but is treated with liquid chlorine applied at a point in the intake line about 15 feet from the pumps and just above where the branch suctions to the pumps connect. A Wallace & Tiernan wet feed apparatus is provided for regulating the rate of application of the chlorine. This apparatus appears to be in good condition and is said to

operate satisfactorily except at times of extreme high water when the vacuum in the suction line with the Gould pump in operation drops so low that the chlorine solution will not feed into the water. There appears to be no reason, if the connections from the apparatus are tight and properly made, why this apparatus should not work under such conditions. Since the river carries more polluting material at times of high water than at times of low, it is important that the necessary repairs be made to this apparatus and its connections without delay. In the meantime, should high water occur, the pumping should be done entirely with the large pump.

At the time of the inspection liquid chlorine was being applied to the water at the rate of about 0.88 pound per 24 hours regardless of the rate at which the water was being pumped. This figure is based on computations made by using the chart furnished by the manufacturers of the apparatus for estimating the flow of chlorine by timing the pulsations of the meter. It was impossible to check this figure by weighing the chlorine cylinder, for although a scale is provided for weighing the cylinder no records of its weight taken at any time could be found, and the date on which the cylinder was put in use was not known. Furthermore, there was no record of the quantity of water pumped or the time during which the pumps had been operated.

Assuming the rate estimated by timing the pulsations of the meter to be correct, chlorine has been applied to the water at the rate of 0.10 part per million with the Rumsey pump in operation and 0.18 part per million with the Gould pump in operation. When the attention of the attendants was called to this obvious error in the rate of application of the chlorine they stated that they knew it to be incorrect but that they were carrying out the instructions of the men who installed the apparatus and the written directions which they had in their possession seemed to bear out their statements.

The rate of application of the chlorine should be at least 0.2 part per million at all times regardless of which pump is in use; and should be increased above this figure during times of high water. Two-tenths of a part per million is equivalent to a rate of 0.98 pound per 24 hours for the small pump and 1.78 pounds per 24 hours for the large pump. Tests of the water made on the day of the inspection when the chlorine was being applied at the above minimum rate of 0.2 part per million indicated an excess of 0.12 part per million of chlorine in the treated water. The counter mentioned above should be attached to the Rumsey pump and a record of the quantity of water pumped should be kept. Likewise a record of the weight of chlorine applied to the water as determined by weighing the cylinder should be kept, and the rate of application of the chlorine computed from these records should be used to check the rate indicated by the pulsometer.

No device is provided for shifting from an empty cylinder to a full one, but since the pumps are not operated continuously the use of such a device does not appear to be necessary.

There were at the time of the inspection six positive cases of typhoid in the village, all located in a small area at the north end of the municipality. The health officer was unable to assign any cause for the outbreak. The milk used by the families in which the cases occurred was delivered by four different milkmen, and apparently there was no other food or drink used in common. Although the families in which the cases of typhoid occurred were located in a small area in one end of the village, it is apparent, from the fact that the available information indicates the public water supply as the only article of food or drink used in common and from the fact that the methods of operation of the chlorine apparatus for disinfecting the supply have not been conducive to satisfactory results, that the water supply may be considered as a possible cause of the outbreak.

Samples of the raw and treated water were taken by the inspector at the time of the investigation and by the health officer four days later. The results of the bacteriological and chemical examination of these samples together with the results of the examination of samples taken in 1916 are given in the appended table. There were at the time the samples were taken positive cases of typhoid in the Minogue and Brayton residences on Pine street and a case in the Albous residence on North street.

The results of the analyses seem to indicate that although the raw water is polluted the treated water usually has a low bacterial count and is generally free from bacteria of the colon type. The difference in the quality of the tap water before and after the installation of the chlorination apparatus on June 19, 1916, and before and after the adjustment of the chlorination apparatus, on November 8, 1917, is very closely indicated by the results of the examinations given in the appended table.

In interpreting these analyses the fact that the treated water has usually been free from bacteria of the colon type should not be taken as conclusive evidence that the small amount of chlorine normally applied to the water will give satisfactory results under all conditions. The raw water on November 8, 1917, the date on which the samples were taken, was very clear and free from polluting matter, and the fact that satisfactory results were obtained then by applying a small amount of chlorine by no means proves that the same quantity would be equally effective under different conditions such as might occur after rain. Experience in other places indicates that generally the quantity of chlorine applied must be increased as the turbidity and organic condition of the water increases.

As a result of this investigation it may be concluded:

1. That the chlorine used for the treatment of the water has not been applied in sufficient quantity and that it has not been applied at a uniform rate.

2. That the turbidity of the water is much greater at times of high water and the rate of application of the chlorine should be accordingly increased at such times.

3. That proper records of the amount of water pumped and the quantity of chlorine applied to the water have not been kept, and that the keeping of such records is necessary for the satisfactory operation of the plant. 4. That the chlorine apparatus does not operate properly under high water conditions.

In view of the above, I beg to offer the following recommendations:

1. That chlorine be applied at all times at the rate of at least 0.20 part per millon.

2. That after rains and at times when the organic content of the water is high the rate of application be increased above 0.20 part per million. 3. That proper records of the amount of water pumped and the weight of chlorine applied be kept and used to check the rate of application of the chlorine to the water.

4. That the necessary repairs or alterations be made to the connections of the chlorine apparatus to secure positive operation of the apparatus at times of high water.

I would further recommend that copies of this report be transmitted to the village authorities with the recommendation that they carry out the suggestions outlined herein.

Respectfully submitted,

THEODORE HORTON,
Chief Engineer

ALBANY, N. Y., December 6, 1917

RESULTS OF WATER ANALYSES

NOTE.- The water supply of the village has been treated with liquid chlorine since June 19, 1916.

BACTERIOLOGICAL