parts of said city and town, may utilize said trunk line and main branches as an outlet of a system of sewerage and drainage for said city and town and said parts of said city and town respectively; and to show the same by plans and maps. Fourth. To employ such engineering and other assistance as may be necessary for carrying out the objects of this resolve, and to cause such surveys and levels to be made as will enable said board to determine with accuracy the location and grades of said trunk line and main branches, and also such surveys and levels in said city and town, and parts of said city and town, as will enable said board to determine with accuracy the methods by which said city and town, and parts of said city and town, may respectively utilize said trunk line and main branches, and to report such methods by plans showing the main lines by which each may so provide for itself a system of sewerage and drainage with its outlet into said trunk line or main branches. Fifth. To define the size and capacity of said trunk line and main branches, and the materials of which they should be constructed and manner of construction, and such other particulars as will enable said board to determine the probable expense thereof; and to ascertain and report the cost of the construction of said trunk line and main branches and outlet, and to report a recommendation as to the methods of apportioning said cost. All expenses incurred by said board under the provisions of this resolve shall be reported to the governor and council, and all such expenses when approved by them shall be paid out of the treasury of the Commonwealth; but the total expenditure shall not exceed three thousand dollars. The Commonwealth shall be reimbursed for such expenditure under this resolve as shall have been approved by the governor and council in the following manner: - The town of Peabody and the city of Salem shall each pay such proportion of the above expenditure as the said board shall deem to be equitable, and the amounts so to be paid by each shall be assessed and collected by the treasurer of the Commonwealth at the time required for the payment of the state tax of said town and said city respectively. Said board shall make all reports required by this resolve to the general court on or before the first Wednesday of January in the year eighteen hundred and ninety-six. [Approved May 29, 1895.

[CHAPTER 69, RESOLVES OF 1896.]

RESOLVE EXTENDING THE TIME FOR THE REPORT OF THE STATE Board of HEALTH RELATIVE TO SEWAGE DISPOSAL AND DRAINAGE IN SALEM AND PEABODY.

Resolved, That there be allowed and paid out of the treasury of the Commonwealth a sum not exceeding one thousand dollars, to be expended by the state board of health in continuing the investigations relating to a general system of drainage and sewerage for the city of Salem and the town of Peabody, provided by chapter one hundred and twelve of the resolves of

the year eighteen hundred and ninety-five, said amount being in addition to the three thousand dollars provided for in said resolve; the Commonwealth to be reimbursed for such additional expenditure herein provided for as shall be approved by the governor and council, in the same manner as provided in said resolve. The time allowed for the completion of the report of said state board of health relative to said general system of drainage and sewerage for the city of Salem and the town of Peabody is hereby extended, and said board is directed to submit said report in print, together with plans and estimates of cost, to the city of Salem and the town of Peabody on or before the first day of July in the present year, and to present a duplicate of said report to the general court on or before the first Wednesday of January in the year eighteen hundred and ninety-seven. [Approved April 17, 1896.

The nuisances caused by the discharge of sewage about Salem have been the cause of complaint for many years, and much money has been expended in various ways to improve the sanitary condition of the city. The shores about Salem are generally low, and large areas of flats are exposed at low tide. The flats in many places have become offensive on account of the discharge of sewage upon them, and new sewers have been built from time to time to remove the sewage to other points of discharge.

The worst nuisance existing at present is found in the North River. This stream is the natural drain of a territory containing numerous tanneries and similar establishments, sewage from which is discharged directly into the stream. The sewage from these works is of a particularly offensive character, and contains a much greater amount of putrescible organic matter than is contained in an equal quantity of ordinary domestic sewage. Several house sewers are also discharged into this stream, but the quantity of house sewage is probably very small compared with the quantity of manufacturing sewage.

Above North Street bridge the North River is confined generally in a narrow channel, while below the bridge there is a wide tidal estuary. The slackening of the current of the river when it enters this estuary causes a deposit of the heavier matters from the sewage, and it is understood that dredging has been resorted to from time to time in order to remove deposits from the bottom of the river in this vicinity.

Nuisances exist in several other places about Salem, particularly in the South River and in Palmer's Cove. An intercepting sewer

recently constructed removes a small portion of the sewage formerly discharging into the South River and some of the sewage formerly discharging directly into the harbor to a point of discharge near the Philadelphia & Reading coal wharf; but this place of discharge is not likely to prove satisfactory, on account of the large areas of flats in the vicinity of the outlet and the slow currents in the harbor. Should the present conditions continue, the nuisances will inevitably grow worse with the increase of population and the consequent increase in the quantity of domestic and manufacturing sewage that will be discharged into the streams and tidal waters about Salem.

The Board has not thought it necessary to describe in further detail the existing nuisances, since the conditions are well known to the inhabitants of Salem and Peabody, and several attempts have been made in the past to provide a satisfactory remedy. Permanent relief from existing nuisances can be obtained only by purifying the sewage before discharging it near the shores, or by conveying it in a crude state to some point of discharge at such a distance from inhabited shores that it will become well diluted before any portion of it can reach any shore.

From a consideration of the whole question, it is evident that the most appropriate and least expensive method of disposing of the domestic and manufacturing sewage of Salem and Peabody is by discharging it into the sea, rather than by attempting to purify it upon land or to clarify it by removing the suspended matters so far as possible by the use of chemicals.

In order to determine the most appropriate point of discharge in Salem harbor, a careful study of the tidal currents at several points has been made by means of floats. The results of these experiments show that the tidal currents in Salem harbor are slow and weak, as compared with those in Boston harbor, at the places where the north and south metropolitan sewer systems discharge; and no strong tidal current is found at any point near the shore into which the quantity of sewage that is likely to be produced by Salem and Peabody could be discharged without danger that some of the solid matters from the sewage might be deposited upon the shores in the vicinity of the outlet. The experiments show that the sewage could be safely discharged at Great Haste Island at all stages of the tide without danger that it would produce a nuisance upon any shore, and

this is the most appropriate place for the disposal of the sewage; but the cost of conveying the sewage to this point would be so great for the present population that it is desirable to select a point nearer the shore, even though the conditions are somewhat less favorable for the satisfactory disposal of the sewage. Float experiments indicate that if the sewage should be discharged at Great Aqua Vitæ Beacon, about half a mile east of Fort Pickering, there is danger that with easterly or northerly winds floating matters from the sewage might be carried to the shore of Salem harbor, or even to the Marblehead shore on the south; but the wind would be likely to have less influence upon a body of water covered with sewage than upon the floats, and probably little if any trouble would be experienced from discharging the sewage at this point for several years. In view of the circumstances, it is recommended that the works be built to discharge the sewage at Great Aqua Vitæ Beacon, and if this point of discharge becomes objectionable the outlet can then be extended to Great Haste.

Investigations were also made to determine the feasibility and probable cost of disposing of the sewage by discharging it at a favorable stage of the tide at some point close to the shore of Salem harbor, and providing a reservoir to hold the sewage between the tides. A location for a reservoir was found upon Winter Island, and the investigations indicated that it would be practicable to dispose of the sewage by discharging it off Fort Pickering Light upon the outgoing tide; but on account of the extra cost of the reservoir, this plan would be more expensive than the plan for discharging the sewage continuously at Great Aqua Vitæ Beacon, and it would be less satisfactory.

The proposed sewer begins at the junction of Walnut and Central streets, near Peabody Square, in the town of Peabody, and extends through the valley of the North River into Salem, crossing the main line of the eastern division of the Boston & Maine Railroad, near the northerly end of the tunnel, and along the shore of Collins Cove to a proposed pumping station on the north-easterly side of the Philadelphia & Reading coal wharf at the shore of Salem harbor. The elevation of the bottom of the sewer at the point of beginning is 12.47 feet above mean low tide, and its diameter is 3 feet 2 inches. The grade of the bottom at the pumping station is 0.67 of a foot above mean low tide, and its diameter 6 feet.

At the pumping station all of the sewage will be raised by pumps to a height varying with the height of the tide, and will be discharged at all stages of the tide at Great Aqua Vitæ

Beacon.

The sewer at its lower end at the pumping station has a capacity sufficient to remove 38,000,000 gallons of sewage in twenty-four hours if running two-thirds full, or 48,000,000 gallons if running full. The capacity of the sewer has been based upon an estimated daily quantity of 80 gallons of ordinary sewage per inhabitant for a population of 102,000, which may be reached at the present rate of growth in 1935, and upon a liberal estimate of the amount of manufacturing sewage that may be produced in the district within that time, with allowances for irregularity in the discharge of sewage into the trunk sewer.

The main trunk sewer is designed to receive sewage only, and the entrance of large quantities of storm water should be prevented. To this end, the connections of existing sewers in Salem, which now receive both sewage and surface water, with the main trunk sewer, should be provided with automatic regulators, as is done in the case of connections between sewers which receive storm water and the intercepting sewers in the city of Boston and in the metropolitan sewerage district, in order to prevent the flooding of the main trunk sewer and other tributary systems by these sewers at times of storm. The mingled sewage and storm water from existing sewers may at such times be allowed to discharge at present outlets.

It will also be necessary to limit the quality of the sewage that may enter the main trunk sewer or any of its tributaries so as to exclude substances from manufacturing sewage that will not flow through the sewers or will have to be taken out of the sand-catcher, and all matters that may clog the pumps.

In some mechanical and manufacturing processes a considerable portion of the water used may not be fouled to an appreciable extent, and such water should not be discharged into the sewers, but should be disposed of by discharging it into the sea or into some suitable drainage channel.

The total cost of the main trunk sewer, with pumping station and other appurtenances complete, having an outlet at Great Aqua Vitæ Beacon, is estimated to be $440,116.

On account of the topography of Salem and Peabody, and the fact