페이지 이미지
PDF
ePub

source in such quantity as would probably be necessary for the supply of the town, imperfectly purified water from the sewage-polluted sources in the vicinity may enter the wells, and under the circumstances the Board does not consider this well a safe source of domestic water supply.

WARE. The water commissioners of Ware applied to the Board, May 27, 1896, for its advice relative to the quality of the public water supply, in consequence of the appearance at times of a considerable amount of organic matter in the water. The Board replied to this application as follows:

Boston, July 3, 1896. The State Board of Health has considered your application for advice with reference to the quality of the water of your present water supply, and has caused an examination of your works to be made, and samples of the water to be analyzed.

The analyses show that the water as it comes from the ground is colorless and free from taste and odor, and contains only an insignificant amount of organic matter. The water of your distributing reservoir, on the other band, contains at times a large amount of organic matter, and microscopical analyses show that it contains large numbers of organisms which impart to the water a disagreeable taste and odor. Complaints as to the character of the water supplied to consumers are doubtless due to the deterioration of the water stored in your distributing reservoir, and the annoyance caused by the presence of minute organisms in this water. The sample of material collected from a faucet and sent in by you was probably composed of some of the larger organisms which are developed in the distributing reservoir.

The remedy for the trouble with the water is to keep it from exposure to light from the time it is drawn from the ground until it is delivered to the consumers. To accomplish this, it will be necessary to cover the present distributing reservoir or build a new covered reservoir or tank.

There is no reason to think that, if the quality of the water of your present sources remains as good as at present, it will support any growth that will cause the water to deteriorate if kept entirely from exposure to light.

WELLESLEY. The water supply committee of Wellesley applied to the Board, May 15, 1896, for advice relative to certain plans proposed by the committee for increasing its water supply and protecting the present sources from pollution. The Board replied as follows:

Boston, June 4, 1896. The State Board of Health received from you on May 15 an application for advice with reference to increasing the water supply of the town and protecting the purity of the present supply. You request, in particular, advice with reference to the following matters :

1. The curtailment of waste. 2. The construction of a number of low dams to hold back the water of

Rosemary Brook, with the hope of increasing the yield of the present sources by filtration from the brook into the well and

filter gallery. 3. The taking of water directly from Rosemary Brook as an additional

supply. 4. The construction of a filter gallery or system of tubular wells in the

valley of Rosemary Brook, west of Cedar Street and north of

Worcester Street, above your present works. 5. The necessity of preventing the pollution of Rosemary Brook and

its tributaries. 6. The removal of a small factory and buildings south of the driveway

from Cedar Street to the pumping station. 7. The purchase of land south of the pumping station.

In connection with the question of constructing a filter gallery or system of tubular wells in the valley of Rosemary Brook, above your present works, you submit a plan showing the location of test wells, and samples of the soil from these wells collected in 1892. With reference to the first question, — the curtailment of waste,

- the Board is informed that, notwithstanding the fact that water is generally supplied through meters to consumers in the town, only about fifty per cent. of the water pumped is accounted for. The consumption of water per inhabitant in Wellesley in 1895 amounted to 42 gallons, which is not excessive, as compared with the consumption in other towns similarly situated. If, however, the consumption of water, as shown by your pumping records, could be reduced one-half, there would be a saving in the cost of pumping, and the necessity for an additional supply might not appear for a time. It is, therefore, desirable that an investigation be made, to determine whether a large quantity of water is lost by leakage or otherwise, and whether this loss can be prevented.

Judging from your experience last year, when dams were constructed upon Rosemary Brook, in the vicinity of your present sources, it appears that a considerable increase in the quantity of water entering the well and filter gallery was obtained by the construction of these dams. It is probable also that in previous years, before the construction of these dams, a

.

portion of the water entering your present sources was derived by filtration from the brook. Analyses of samples of the water of the well and filter gallery have been made from time to time by the State Board of Health, and its quality has apparently always been satisfactory. The well and filter gallery, however, are both situated close to the brook, and the chief danger from increasing the quantity filtering from the brook is that some of the water may pass too directly through the ground into the filter gallery or well, and not become satisfactorily purified in its passage. cases water taken from sources situated as yours are has continued to be satisfactory for many years, while in others, after a longer or shorter period of use, the quality of the water has deteriorated, owing to the imperfect filtration of the water from the stream or pond near by. Increasing the height of the water in Rosemary Brook by means of dams will tend to cause the water to filter more rapidly through the ground, thereby producing conditions more favorable to imperfect filtration.

With reference to the use of water taken directly from Rosemary Brook for the supply of the town, and the necessity of preventing the pollution of Rosemary Brook and its tributaries, the Board has caused an examination of this brook to be made by one of its engineers, and, finds that it is exposed to direct sewage pollution from factories and dwelling-houses on its banks, and to pollution from farms and cultivated lands upon its watershed, and is, therefore, a dangerous source from which to take water directly for domestic purposes, and such water should not be distributed to your people. The watershed of the brook drains a part of the villages of Needham and Highlandville, and the population upon it is likely to increase rapidly in the future, so that it would not be possible, without excessive care, to prevent the pollution of the stream. Nevertheless, in view of the nearness of your present well and filter gallery to the brook, it is desirable that it be kept free from pollution, as far as is practicable.

An examination of the results obtained from test wells driven in the valley of Rosemary Brook, west of Cedar Street, and north of Worcester Street, in 1892, does not indicate that the conditions are favorable to obtaining a large amount of water from the ground there. South of Worcester Street the results of investigations were more favorable, judging from the samples of material submitted. The tests appear to have been confined to the vicinity of the north-westerly shore of Longfellow's Pond, and it is possible that better conditions could be found near the upper end of the pond and in the valley of the brook above, where the character of the surface indicates that the soil may be more porous.

The information available to the Board is not sufficient to enable it to advise you definitely at present with reference to the best method of increasing the water supply of Wellesley. The town is growing rapidly, and

in the selection of an additional water supply provision should be made for a large increase in the consumption of water in the future. The examinations thus far made in the valley of Rosemary Brook, above your present sources of supply, by means of test wells, have been unfavorable to obtaining a large increase in your present supply here; but, as already stated, the conditions appear, from surface indications, to be somewhat more favorable farther up the valley, and it is possible that a large addition to your present supply can be obtained in this region.

It is to be considered, however, that the population in the valley of Rosemary Brook is already large, and may increase rapidly in the future, owing to its nearness to the metropolitan district; and, before deciding upon a plan for increasing the water supply of Wellesley by the construction of further works in this valley, the question of the feasibility of obtaining a supply of water for domestic purposes here that can be maintained in a satisfactory condition for a reasonable time in the future, without excessive cost, should be carefully considered. It is also very important, before deciding definitely as to a source of additional water supply, that you determine the feasibility and probable cost of obtaining a supply from, or in connection with, the metropolitan district.

The presence of a small factory and other buildings between Cedar Street and the wells south of the driveway from Cedar Street to the pumping station does not appear to be, under present conditions, a serious menace to the quality of your water; and the removal of these buildings is not essential, if means are taken to prevent sewage from polluting the stream or from getting into the ground, and so passing to the filter gallery or well.

With reference to the advisability of purchasing any of the land lying east of Cedar Street, south of the pumping station, it may be said that, if water from this territory finds its way into your present sources of supply, it is desirable that the land be owned and controlled by the town. It is not feasible to determine how much of this land it is desirable for the town to control, except by experiment.

In conclusion, the Board would advise that you have the whole subject of your present and future water supply thoroughly examined by a competent engineer, to determine what measures are necessary to protect the purity of your present sources of supply, and the most appropriate source from which to take an additional supply.

The Board will, upon application, advise you further in this matter when you have the results of further investigations to present.

WILLIAMSBURG. The selectmen of Williamsburg applied to the Board, Feb. 11, 1896, for its advice relative to a water supply for

The

the town to be taken from the East Branch of Mill River. Board replied to this application as follows:

BOSTON, Oct. 1, 1896. The State Board of Health has carefully considered your application with reference to a proposed water supply for Williamsburg, to be taken from the East Branch of the Mill River, upon which it is proposed to construct a small reservoir above the village, and has caused an examination of the proposed source to be made by one of its engineers, and samples of the water to be analyzed.

About three-fourths of a mile up stream from the place where it is proposed to locate the reservoir the East Branch is joined by Bradford Brook, and at the point of junction the two streams have nearly equal watersheds. These streams will furnish by far the greater portion of the water which will enter the proposed reservoir, and samples from each of them, collected at different seasons of the year, have been analyzed with a view to comparing the quality of the water.

The water of the East Branch above the Bradford Brook is soft, has very little color, and contains a small amount of organic matter for a surface water. The water of Bradford Brook, on the other hand, is harder, and has at times considerable color, and contains a greater amount of organic matter. The quality of the water of the proposed reservoir would be somewhat better than the Bradford Brook water, but not so good as the water of the East Branch, above Bradford Brook.

The watershed above the proposed reservoir contains a considerable number of farmhouses, though the population per square mile is small. Several of the buildings are located near the streams, particularly in the Bradford Brook watershed, and provision will have to be made to prevent sewage from these houses entering the streams and polluting the water supplied to the town. In the watershed of the East Branch, above Bradford Brook, the houses are more remote from the stream than in the Bradford Brook watershed, and the population per square mile is considerably smaller.

Considering all the circumstances, therefore, a more satisfactory supply for the town could be obtained by taking water from the East Branch, above the Bradford Brook, than at the point proposed.

With regard to the quantity of water that would be furnished by the East Branch, below Bradford Brook, it may be said that the indications are that the quantity would be ample at all times for the supply of Williamsburg. It is also probable that an ample supply would be obtained by taking water from the East Branch, above the Bradford Brook; and, in case an additional supply should be needed at any time, provision might be

« 이전계속 »