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EXAMINATION OF WATER SUPPLIES.
The following tabulation, giving descriptions of water works, and chemical and biological examinations of many sources of water supply in the State, is a continuation of similar tabulations published in two previous reports.
The systematic examination of the water supplies of the State was begun June 1, 1887, and has been continued up to the present time. The results for the two years ending June 1, 1889, may be found in the Special Report of the Board upon the Examination of Water Supplies, 1890, and for the nineteen months from June 1, 1889, to Dec. 31, 1890, in the last (twenty-second] annual report of the Board. The present report contains the results for the year 1891.
The Special Report contained a description of each water supply in the State; to avoid repetition, the last report and the present one contain only descriptions of new works and those which have been materially changed.
An alphabetical arrangement by towns has been adopted, as in previous reports. Sources of water supply are tabulated under the name of the town supplied, other waters under the name of the town in which they are situated. The analyses of water from the larger rivers not used as sources of water supply are given in a subsequent tabulation, headed “Rivers."
The chemical examinations in this report were made in the same manner as heretofore, and are presented in the tables in precisely the same form as last year. Since June 1, 1889, the waters containing suspended matter have been filtered before determining the residue on evaporation. Before that date these determinations were made with the unfiltered water.
A few cases will be noted in the tabulated results in which one or more chemical determinations differ somewhat widely from others in the series. Such a condition of the water might result from floods or other unusual disturbance of a stream, or from carelessness in collection ; or an error may have been made in the analysis. In such cases the determination has been underlined, and has not been included in the average.
The color of waters is expressed by numbers, which increase with the amount of color. Water having a color of 1.0 is a decided yellowish-brown when seen in small bulk, as in a tumbler.
In the microscopical examination of the waters there has been a decided advance from time to time in the methods employed for determining quantitatively the number of organisms present. These methods were so far perfected on Nov. 6, 1890, however, that since that date there has been no material modification, and the results given in this report are therefore comparable with those of the last two months in the last report. One important change, however, has been made: the amount of so-called Zoöglæa in the water, which was formerly ignored in making the examinations, is now determined. As the masses of this substance are of varying size, each individual mass is not counted, but an area, equal to 2,500 square microns, or .0025 square millimeters, has been adopted as the unit. Owing to the uncertainty which attaches to the precise nature of the substance which is here classed as Zoöglæa, it has been inserted under the heading “ Miscellaneous," rather than under " Fungi."
The present method of determining the number of microscopical organisms in the water is fully described in a subsequent chapter of this report.
In publishing the results of the microscopical examinations the same system is followed as last year. The Plants are classified in four groups, viz. : Diatomaceæ, Cyanophycex, Algae and Fungi, The Animals are grouped as Rhizopoda, Infusoria, Vermes and Crustacea
The names of the different genera in each group are given with the numbers of each per cubic centimeter, except that, to avoid making the tables excessively long, they are omitted when present only in very small numbers. It is not feasible to make regarding omissions a single rule applying to all cases, because it is desirable to include smaller numbers of animals than of plants, and of the larger animals than of animals generally. Moreover, there are exceptional cases in which it is desirable to indicate the presence of even very small numbers of the more important plants or animals. Two general rules, however, have been adopted in printing the results, namely:
1. All genera of Plants are included in which the total umber observed in twelve months amounts to 6 or more per cubic centimeter, or in other words averages as much as 0 5 per month.
2. All genera of Animals are included in which the total number observed in twelve months amounts to 1.5 or more per cubic centimeter.
The larger microscopic animals, such as some of the Crustacea, are included even when present only in very small numbers.
Fractions are omitted from the table, the nearest whole number of organisms per cubic centimeter being given. Where the number is 0.5 or less, the fact that the organism was present is indicated by the abbreviation “pr.”
EXAMINATION OF WATER SUPPLIES.
WATER SUPPLY OF ANDOVER.
Chemical Examination of Water from Haggell's Pond, Anilover.
Odor, none. - The sample was collected from a faucet at the pumping station, while pumping. The surface of the pond was fourteen inches below high-water mark.
Microscopical Eramination. Diatomacea, Asterionella, 1; Cyclotella, 23; Epithemia, pr.; Melosira, 7; Naricula, 1; Synedra, 11; Tabellaria, 2. Cyanophyceæ, Microcystis, pr. Infusoria Trachel
Miscellaneous, Zoöglia, 2. Total, 47.
WATER SUPPLY OF ASHBURNHAM. - NAUKEAG WATER COMPANY.
The small reservoir, fed mainly by springs, which was formerly the source of supply for the village of Ashburnham has been increased in size by building a higher dam and deepening the reservoir to a maximum depth of about 16 feet. The slopes are very abrupt, and much of the reservoir is excavated in ledge. The length of the water line at the dam is 190 feet, and the distance from the dam to the opposite side is 145 feet.
Owing to seams in the ledge which forms the bottom of the reservoir there is so much leakage that the reservoir does not fill. It is proposed to concrete the bottom.
[Parts per 100,000.)
Odor, none. The sample was collected from the pond about four feet beneath the surface. The surface of the water in the pond was about four feet below high-water mark at the time the sample was collected.
Microscopical Examination. Algx, Botrycoccus, pr.; Chlorococcus, 10. Miscellaneous, Zoöglæa, 31; Starch grains, 1. Total, 42.
WATER SUPPLY OF ATHOL. Chemical Examination of Water Collected at the Small Reservoir in Phillipston.
[Parts per 100,000.]
Odor, vegetable. The sample was collected from the brook, because, owing to the dry weather, the reservoir was empty.
Microscopical Examination. Diatomacex, Asterionella, 2,046; Cyclotella, 1; Diatoma,1; Navicula, pr.; Surirella, 2; Synedra, 2. Cyanophyceæ, Anabæna, 14. Algæ, Closterium, 1; Pandorina, 1; Sorastrum, 1. Fungi, Crenothrix, 74. Iufusoria, Trachelomonas, pr. Miscellaneous, Zoöglvu, 372. Total, 2,516.
Chemical Examination of Water from the Large Reservoir in Phillipston.
[Parts per 100,000.)
Odor, vegetable. The sample was collected from the reservoir near the gate house, at the sur. face.
Microscopical Examination. Diatomaceæ, Asterionella, 20; Melosira, 540. Cyanophyceæ, Anaboena, 3,520; Chroöcoccus, 20, Miscellaneous, Zoöglæa, 1,180. Total, 5,280.
ATHOL. Chemical Examination of Water from Faucets in Athol, supplied from the Works
of the Alhol Water Company.
[Parts per 100,000.]
Microscopical Examination. No. S004. Diatomaceæ, Asterionella, 3. Cyanophyceæ, Anabæna, 9. Miscellaneous, Zoöglæa, 304. Total, 316.
Yo. 8240. Diatomaceæ, Asterionella, 37; Cyclotella, 1; Diatoma, 1; Melosira, 14; Synedra, 35; Cyanophyceæ, Anabæna, 12. Algæ, Chlorococcus, pr.; Pediastrum, pr.; Scenedesmus, 2; Stauras. trum, 10. Fungi, Crenothrix, 27. Infusoria, Dinobryon cases, 1; Peridinium, 1. Vermes, Anurea, pr.; Rotatorian ora, pr. Miscellaneous, Zoöglæa, 140. Total, 281.
WATER SUPPLY OF THE ATTLEBOROUGH FIRE DISTRICT,
A new covered tank, 30 feet in diameter and 125 feet in height, has recently been built, thereby furnishing a greater pressure for fire and other purposes throughout the town, and increasing the storage capacity of the works. The old tank is retained, and kept filled with water directly from the river by an independent pump. A line of pipe has been laid from this tank through the village as far as the railroad station, in order to supply locomotive and other boilers with the river water, which is much softer than the water from the well.
In the latter part of 1891 an investigation was made with reference to obtaining a new water supply* for the fire district, and many samples were collected from tubular test wells and other sources within the limits of the town, the analyses of which are given in the tables which follow.
* The advice of the State Board of Health to the water supply committee of the Attleborough Fire District may be found on page 22 of this report.