try and in this connection I have been interested to obtain the opinion of the Chief Engineer of the Virginia State Board of Health. Briefly, such opinion is unfavorable to pressure filters and with such unfavorable opinion I also learn that the Superintendent of the Lynchburg Water Works is in agreement.

Even so, at Lynchburg they do have a coagulating and subsidence chamber, this being a steel tank 50 feet in diameter and 50 feet high set in on the line, this giving a subsidence period of about 31⁄2 hours. Manifestly, to impose on each of the three lines in your case a settlement chamber of adequate size, while perhaps feasible, would be a rather expensive thing to do. Yet this is something for you to consider. I think I am warranted in saying at this time that our department would not be disposed to favor the pressure plant proposition unless such an adjunct were included.

So much for the pond and pressure filters. As to a supply taken exclusively from the River, in saying that there is much to recommend such a plan I do so while having fully in view the precept that "a pure water is always better than a purified one." In this case there is but little pollution of the Androscoggin River above Berlin and with a well designed filtration plant, carefully operated and skilfully controlled you would be justified in expecting to have a water supply practically all of the time equivalent in physical character to a good ground water.

If the city is willing to go to the expense of putting in an adequate treatment of the pond-reservoir water, and there was no question as to adequacy of the pond, then this would without question be the thing to do. The point I wish to make is that the treatment as proposed would not be adequate to give satisfactory results. Very truly yours,

CHARLES D. HOWARD, Chief of Division

Later in 1925 a new project involving resort to the Upper Ammonoosuc River was advanced, and an investigation was made by this department, the following reports being made in this connection.

A survey of the Upper Ammonoosuc River, a proposed source of water supply for the city of Berlin, was made by this department

October 28-29 for the purpose of observing the character of the catchment area and obtaining samples of the water for examination.

From a point known as Bog Dam, the catchment area above is about 20 square miles, all of which lies within the boundaries of the National Forest Reserves. A few years ago forest fires devastated about fifty per cent of the area, leaving only the upper portion of the watershed forested. Numerous small tributaries drain high mountain slopes situated on both sides of the main stream; the character of the land is typical of our mountainous sections, the steep slopes being quite rocky, the gentle slopes densely wooded and having good forest floors.

With two minor exceptions there is no residential habitation upon the catchment area. Located at the Pond of Safety is a cabin used occasionally by the owner when on fishing and hunting trips. Similarly, Camp 19 owned by the United States Forestry Department, simply serves as a shelter for the hunter or the fisherman. Since the area is only accessible by two trails, one 21⁄2 miles from the nearest road, and the other 5 miles, the problem of the ordinary tourist or picnicker is eliminated. The only, invasion of the waterIshed will be that of the hunter or fisherman.

The source of the river is a spring-fed pond known as the Pond of Safety, some 10 or 12 acres in extent. The Pond appears to be shallow and inclined to be somewhat swampy, although the melting snow may have been the cause of the condition. Unlike that of Success Pond there were no portions of the pond filled with a large growth of vegetation. The outlet of the Pond is quite small and is obstructed with fallen trees and large amounts of debris. Some distance below the outlet the river is enlarged by a tributary and from this point down the stream bed and banks appear to be in good condition, the bed made up wholly of rocks and sand, the banks relatively free from debris and underbrush.

From the outlet to a point three miles downstream the river is a gushing mountain stream and upon reaching this point, for a little over a mile to Bog dam, it flows through a territory known as the Bog. Generally a bog is thought of as being a quagmire, a swampy place full of decaying vegetable matter, but this is not typical of this section, the bottom of the stream bed is sandy and the banks far from swampy. The Bog is simply a level section in which the mountain torrent gives up its rushing velocity and settles down to a slower moving stream. There are, however, sections of the Bog that should be cleaned and the banks trimmed back.

It appears that if the old Bog Dam be replaced and an intake placed at this point considerable storage could be obtained, al

though this procedure would require the stripping of the banks for a distance upstream.

Samples were taken at the following poings: outlet of the Pond of Safety; Camp 19, U. S. Forestry Camp; London Camp; Bog Dam; and the west branch of the Ammonoosuc River.

Inasmuch as this project involves a comparatively large expenditure of money for its completion and the whole purpose being to secure a water that is of such a quality as will not require filtration, it would appear to be unwise to attempt to base everything upon the three sets of samples. Rather, an analytical study ought to be made over a period of at least a year, and preferably longer, for the purpose of obtaining accurate knowledge as to the prevailing character of the water, as influenced by dry weather flow, flood conditions, melting snow, etc. The immediate question for which such an analytical study would serve to provide definite answer is whether it is going to be advisable to establish a filtration plant at the Bog Dam, or possibly at a point lower down, or whether by incurring the expense of a little longer pipe line, i. e. by going to a point above the bog, the prevailing quality would be enough better to avoid fitration.

Respecting the Upper Ammonoosuc River water supply proposed, there is being enclosed a brief report of a preliminary sanitary survey as made October 28-29 by Mr. Marner, of this department, also results of analysis of a series of samples as collected by him at that time, with which, for convenience of comparison are included results on two other lots of samples taken from this source a short time earlier. In addition, the writer gained some impression of what is involved from a trip made into this section on October 26th. The original proposal, as brought to our attention, was to establish an intake on the main stream, either at Godfrey (?) dam, or at the Bog dam, so called, some distance above the first, the water to be carried to Berlin through a 24′′ wood-stave surface-laid main of about seven or eight miles. Objection arose to this proposal in the fact that the analysis of two samples of water, collected from the Bog dam and from the West Branch on September 15, 1925, both showed an impossibly high degree of coloration to permit of acceptance as a public water supply. There was also some turbidity and

sediment, and, in those particular samples, evidence of fecal pollution. On the evidence of these two samples alone it would appear that this source afforded no advantage whatsoever as to quality over that of the present reservoir supply, which latter has always been a source of some local criticism. In fact, on the date in question the color of these waters was very substantially greater than that generally observed for the reservoir supply.

However, two samples collected about a month later (October 20), one from the Bog dam, the other from "Above the Bog" both showed greatly reduced color (0.45 and 0.35 as against 0.80), that of the second, while substantial, being within limits such as to warrant consideration as a source without filtration. The color it may be noted, is about that of Massabesic Lake supply of Manchester. It is worth knowing in this connection that the lake supplies of such towns as Concord, Contoocock, Pembroke, Hillsborough, etc. will show less than half of this (around 0.12) while that in the stream supplies of Littleton, Lancaster, Groveton, Bartlett, Troy, Jaffrey, etc., is still lower, these latter being virtually spring waters as regards physical character.

This matter of color is important, not only because it is in a degree a measure of the amount of dissolved vegetable matter but because the modern demand is for a water virtually free from this characteristic. Certainly it should not be in such degree as to be perceptible in the ordinary tumbler when viewed in a good light. In this connection it is well to bring out the following pronouncement of the United States Public Health Service included in its newly announced "Drinking Water Standards", as involving the question of fitness for train use; "Color should not exceed 0.20 and preferably should be less than 0.10."

It is obvious that whatever proposal the city may finally adopt, a considerable expenditure will be involved. It would be very unwise to adopt any plan which did not afford a guaranty of water of acceptable quality beyond question. If filtration will be necessary to secure this, such should be included with the installation.

The question involved therefore comes down to whether the physical quality would be for most days in the year entirely acceptable for water taken from the Bog dam or below, and if not whether it would be preferable from a financial standpoint to install a filtration plant at such place or (if such should appear feasible) go to the expense of a longer pipe line in case water acceptable without filtration might be taken farther upstream. Apparently the question of sanitary quality (i. e. freedom from appreciable likelihood of contamination) can already be definitely answered by stating that there is no such likelihood.

It is also believed so far as can be judged at this time from the analyses, that it is extremely unlikely that water collected from the Bog dam would be acceptable without filtration It is regretted that neither the survey referred to nor the samples thus far collected afford sufficient data for the drawing of any accurate conclusions as to the likelihood of obtaining water physically satisfactory without filtration by going above the Bog. The sample of October 20th does have favorable significance in this connection and this is also very distinctly true of the series collected October 28-29, the colors of all which (including even the Bog dam and the West branch, at this time) might permit of acceptance without filtration. However, it must be appreciated that at the last date the ground was more or less frozen and there was considerable melting snow, also that the fact cannot be escaped that earlier than this (Sept. 15) the coloration was very heavy.

What the prevailing color would be could only be arrived at, as Mr. Marner has pointed out, by collecting samples at different periods and under different weather conditions over a considerable period of time, this being the course always followed by the larger cities as a preliminary to action.

Inspection of the "Pond of Safety", the source of the main stream, afforded some interesting information, although even here we were hampered by the fact that the watershed was at this time snow-covered and the pond frozen over. It appears, however, that this small pond has but a small watershed, that it is comparatively shallow, and although the shores are comparatively very good and there is comparative freedom from weedy growths, yet the water has considerable color. In any case it would seem that as storage for maintenance of the volume of stream flow, this pond has but slight value. Large dependence must be placed upon the accessory water entering the main stream below the pond outlet.

The survey indicated that the shores of this stream are clean and free from excessive vegetable growths, that the stream bed is clean and rocky, and down to where the "Bog" begins, the conditions would seem to be very favorable for the collection of clean water. As to the "Bog" there seems to be some difference of opinion as to its character. As observed by Mr. Marner, it did not appear to be either of very large area, or truly partaking, in his opinion, of the nature of the bog, or swamp. If I remember correctly, however, Mr. Graves' observation did not quite tally with this. It has occurred to us that if it is a fact that the width is but small and the depth of mucky deposit but slight, it might prove feasible to strip this area, as it appears that the latter would afford an excellent