condition involving a feeding brook traversing extensive pasturage on the east side still remains to be corrected. BERLIN. Conditions regarding the Berlin supply have been unsatisfactory for many years, mainly due to the fact that the brook reservoir sources, although added to from time to time, have proved to be inadequate, giving rise to the necessity of resort to the Androscoggin River. While the latter source has been chlorinated for some years, this treatment has not been deemed sufficient, and accordingly, during 1924, the water company was notified that it would be required to install filtration, in case it did not substitute some other source for the river. Το this end the company secured the services of an engineer and plans were made for a filtration plant. The matter went no further, however, due to the taking over, early in 1925, of the water plant by the city. The latter was duly notified that in the absence of an approved filtration plant, pumping from the river must cease. This has led to a consideration of various plans for the improvement and extension of the supply. Early in July, 1925, a study was made by this department concerning the practicability of utilization of Success Pond. The following report to the city deals with this project, as well as embodying a review of the general situation. Hon. Joseph A. Vaillancourt Mayor of Berlin Berlin, New Hampshire Dear Sir:- Concord, July 9, 1925 In connection with the proposal of the City of Berlin to improve and to add to the supply as formerly owned by the Berlin Water Company and acquired by the city on July 1st, the following statement embodying the findings and conclusions of this department is being handed to you. As you are aware, conference was had with the board of water commissioners, board of health and yourself on July 1st relative to this matter and preliminary to a trip to Success Pond during the two days following for the purpose of investigating conditions there and collection of samples. Character of Supply For many The present supply has never proved satisfactory. years it has been open to criticism both as to its physical character and because of an infection hazard due to periodic use of inadequately treated Androscoggin River water. At one time the supply was supplemented by certain springs but most, if not all, of such sources have been found to be unfit and have been abandoned. The main source is in some brooks the water of which is collected in a number of storage and distribution reservoirs. Draft from these reservoirs is controlled by a number of valves, including manually, electrically and automatically operated. Because of the fact that these brooks drain a region heavily wooded with coniferous growths and which tends in some places to be swampy, this water has always shown a substantial coloration as well as more or less turbidity, with at times some taste and odor. For this reason it has never been popular with the consumers, although there is nothing about its character detrimental to health. At no time, however, has this brook reservoir supply proved adequate for the demand and it has accordingly been necessary during various periods of practically every year to take river water from what is now the system of the Brown Company. Such water is, from the standpoint of domestic use, very inadequately filtered, and its employment has always constituted a material hazard, which latter, in consequence of some changes in the location of the intake and the growth of the city, has in recent years become quite serious. To offset this in a measure, a number of years ago the application of hypochlorite was begun, this treatment later being replaced by the much more accurate and certain use of liquid chlorine. However, simple chlorination for a source such as the Androscoggin River at Berlin is far from sufficient treatment. While there appears to be no great degree of domestic sewage discharge into this river above Berlin, yet at this point the conditions are very poor; also a considerable amount of "incidental" contamination is bound to find its way into this stream above. Moreover the logging operations necessarily involve some contamination, both bacterial and physical, so that nothing short of treatment by an adequate process of filtration supplemented by chlorination can properly be considered sufficient as a prerequisite for obtaining a safe and satisfactory supply from this source. Accordingly early in 1924 the Berlin Water Company was instructed by this department that if this source is to be continued filtration must be applied and that we would expect such treatment to be installed within the current year. In harmony with this requirement the Company engaged the firm of Weston & Sampson to make an investigation and to submit plans, which was done during June of last year. These plans called for the construction of a rapid sand (mechanical) filtration plant at a point on the west side of the river about two miles above the city, This plant, which called for both filtration (with coagulation) and chlorination was intended for treatment of the river only as an auxiliary source, abandonment of the present brook reservoir system not being contemplated. The contract as ready for letting called for an expenditure of about $60,000. Because of negotiations with the City looking to purchase by the latter, no action on these plans was taken. During the progress of these negotiations and while a charter bill was pending in the Legislature the City was notified by the State Board of Health that in the event of purchase it must understand that use of the river source would be sanctioned only upon the installation of adequate treatment. A clause in this charter provides "that no source of water supply and no lands necessary for preserving the quality of the water shall be acquired or taken without first obtaining the approval of the state board of health, and that the location of all dams, reservoirs, wells or filter galleries to be used as sources of supply under this act shall be subject to the approval of said board." Projects For the extension and improvement of its water system, consideration may be given to the following options: (1) Distribution of the present brook reservoir water without improvement, with the addition of properly treated river water as an auxiliary supply. (2) Abandonment of the brook sources and resort to purified river water for the full supply. (3) Treatment of both reservoir and river water. (4) Abandonment of the river source entirely and substitution therefor of water taken from Success Pond as a feeder for the present reservoirs, the same with or without treatment. An objection which has been raised to (1) is that it involves the construction at substantial expense of a purification plant which will serve for the river (auxiliary) source only and that such water, clarified and materially improved, not only bacterially but physically, would then be mingled with the colored and more or less turbid main supply from the brook reservoirs. That is, it is argued that if the city is to go to the expense of constructing an expensive purification plant, the system should be so designed as to permit of treatment of the entire supply. That there is merit in this argument cannot be denied. The difficulty is in bringing the thing about. One method to this end is found in (2). This however would entail the abandonment of an expensive property as involved in pipe lines, dams, flowage rights, etc., besides the expense entailed by a pumped system. Whether such a plan should be given serious consideration will depend very largely upon financial considerations, which is not a matter this department need go into. Another consideration in this connection that should be mentioned is that, given satisfactory physical quality, a pure raw water supply is always to be preferred to one which is sewage-polluted and which must be rendered fit by artificial treatment. The reason for this is that while the former is "fool proof", the latter, for its effective operation throughout every moment of the 365 days of every year, is dependent upon the human equation. Given responsible and vigilant oversight of an adequate plant, with good and continuous laboratory control, the danger would be practically nil, but were there to be a lapse in such oversight, the resulting consequences might be serious. In this connection it should be understood that with a properly designed plant and efficient operation there is no reason why the river source should not afford a supply comparing in physical character very favorably with one from ground sources. Filtration of both river reservoir systems as contemplated by (3) would be, in view of the fact that the main supply is a gravity system drawn from a number of reservoirs through two separate pipe lines to the city, a difficult problem to solve and there is reason for belief that it is one that cannot be satisfactorily solved with any reasonable outlay for construction and maintenance. At the present time, according to information furnished us by you, there is a ten-inch line running direct to the city and fed by the Keene, Anderson and Stewart reservoirs. There is also a twelveinch line to the city fed direct from Bean reservoir, which latter also is so arranged as to deliver also into the ten-inch line first mentioned. The erection of a single gravity fitration plant at such a point as to take care of the water from all these reservoirs appears to be impracticable. Apparently the only feasible method would be in resort to installation of a number of pressure filters, units on both the ten and twelve-inch lines, with appropriate arrangement of checks and by-passes, as proposed in plan and ac companying sketch presented by Mr. Lovett, of the board of water commissioners and engineer for the city. The sketch as submitted appears to comtemplate the installation of two pressure filter equipments at the river, one for the ten-inch, the other for the twelve-inch line, with horizontal pressure filters on the line fed from Keene, Anderson and Stewart reservoirs and another set of such filters on the line from the Bean reservoir, the latter set to be by-passed so as to permit of filtered river water being pumped through either line into the Bean reservoir, subsequently to get back to the city only via the filters. The flows in either direction would be controlled through a series of check valves. Pressure Filters Reference should here be made to this device for filtration. The latter involves forcing the water through a tank filled with sand, the whole operation being at full line pressure. Objections are that the process of filtration under such pressure is not as effective as with the open gravity type, cannot be accurately controlled, does not permit of access for inspection and proper care of the sand bed, and involves no opportunity for sedimentation following the application of the coagulating chemical (sulphate or alumina), Also the latter is fed from receptacles set in on the pressure line and the dosage in such cases is always most uncertain and irregular. The washing of these filters must be effected from once to twice each twenty-four hours, which would call for the opening and closing of two valves on each filter unit at every such time. This obviously would call for practically continuous attendance on the part of one or more persons. Because of the impossibility of operation in any such effective matter as is permitted by filters of the standard gravity type, those of the pressure variety have always been looked upon with disapproval for use on water supplies for domestic practice and the number of such on municipal supplies is very small. We were unaware that there are any of this type in use for this purpose in New England until hearing Mr. Lovett's statement that the city of Fitchburg, Mass., has an equipment of this description. Because of the lesser effectiveness this department would not be disposed to sanction the use of these pressure type filters on a sewage polluted water, such as the river. Whether they would be approved for the sole purpose of clarifying and declorizing the brook water is something on which we are rather reluctant at this time to make a definite and final statement. The difficulty is in the fact that process of such clarifying and declorizing, to be really effective, must be carried out in two distant stages, (1) dosage with the chem |