ON THE PRESENT CONDITION

OF CERTAIN RIVERS OF MASSACHUSETTS.

By an order of the legislature, passed April 6, 1872, the Board of Health were instructed to inquire into certain matters connected with the questions of sewage, sewerage and the water-supply. The text of this order may be found on the tenth page of the last (fourth) Annual Report, and in compliance therewith a report upon these questions was made a year ago to the Board by Dr. Derby, Secretary of the Board, and the writer.

During the present year the inquiry has been prosecuted further, having more especially in view a reply to the third clause of the article referred to,-"the increasing joint use of water-courses for sewers and as a source of supply for domestic use by the people of this Commonwealth."

It has been thought desirable to investigate the present condition of the running streams, partly to learn the extent to which they are now made the carriers and receptacles of refuse materials, and partly to put on record some detailed statements, to which future reference can be made in the event of apparently increasing contamination. This inquiry was begun last year on the Blackstone River, and this year has been made to embrace several of the rivers of Eastern Massachusetts, principally the Merrimack, Blackstone, Sudbury, Concord and Charles.

In endeavoring to ascertain the character of a natural water, and especially of a running stream, whether the examination be undertaken simply for scientific purposes or with reference to employing the water as a source of supply for domestic uses, it is important not to base too general statements upon the results of a single examination. The greater the number of conditions under which the samples

can be taken, and the larger the number of samples, the more complete will be the answer to the inquiry proposed. Many loose statements find their way into reports of water committees and water boards, in which the estimate of the character of a running stream is based upon the results of a single examination, made, possibly, under extremely favor able or extremely unfavorable circumstances. It has therefore been thought better for the present year not to extend the work over a very large number of streams, but rather to choose a more limited number of streams, and to make examinations at several different times during the summer, fall and winter. It has been proposed further to examine the water at the same localities once or twice during the spring of 1874.

Great care has been exercised in collecting the water for chemical examination, and, having a very strong feeling of the importance of this part of the investigation, I have made personal visits to the localities indicated in the tables, and have taken the samples, except in one or two instances, with my own hands, using every necessary precaution.

The chemical examination of the waters was made as soon as possible after the collection, being, as a rule, begun and finished on the following day. A somewhat detailed statement of the methods employed will be found in the Appendix to this Report. Most of the analytical work has been performed by Miss Ellen H. Swallow, A. M., in the laboratory of the Massachusetts Institute of Technology, under my own direction. I take pleasure in acknowledging my indebtedness to her valuable assistance, and in expressing my confidence in the accuracy of the results obtained.

THE MERRIMACK RIVER.

The Merrimack rises in New Hampshire. Its head-waters are the streams flowing from the granitic regions of the White and Franconia mountains; and Lake Winnipiseogee serves as a huge storage reservoir to equalize the flow of the river during the summer months. Of the 110 miles of its course, 40 are in our own State. Both in New Hampshire and in Massachusetts it receives contributions to its volume from almost innumerable brooks and small streams, and from

other tributaries of considerable size, such as the Pemigewasset, Contoocook, Suncook, Souhegan, Nashua, Concord, Shawshine and Spicket. The manufacturing interest upon its banks is very great. Concord and Manchester (N. H.), and Lowell and Lawrence (Mass.), lie directly upon the river, taking advantage of its waters as a source of power, drawing from it in some cases their water-supply, and using it also as a means of removing a greater or less portion of the refuse from their factories and their dwellings. The population of the principal towns upon the river was as follows, according to the census of 1870

A few figures may give some idea of the extent of the manufacturing interest on the Merrimack within the borders of our own State. At Lowell there are some 75 mill buildings, in which about 16,000 operatives are employed. About 10,000 horse-power is derived from the river, and, in addition, steam-power is used to the extent of 6,000 horse-power. The Merrimack Manufacturing Company alone consumes, among other things, 7,500 gallons of oil per annum, 225,000 pounds of starch, 1,100 barrels of flour, 2,500,000 pounds of madder, 50,000 of copperas, 170,000 of alum, 200,000 of sumac, 1,120,000 of sulphuric acid, 300,000 of bark, 350,000 of soda-ash, and 40,000 of soap.*

At Lawrence there are some 25 mills (buildings), employing 9,000 operatives. The manufacturing industry is less at Lawrence than at Lowell, but it is still very considerable. The Pacific Mills, which is the largest corporation, use some 800,000 pounds of starch, 540 barrels of flour, 8,300 gallons of oil, etc.†

These figures are taken from the "Statistics of Lowell Manufactures, January, 1873," published by Stone & Huse, Lowell.

+ "Statistics of Lawrence Manufactures, January, 1872." Published by Geo. S. Merrill & Co., Lawrence.

Character of the River-Bed.

The river, as has been said above, has its beginning in the mountain-streams of New Hampshire, and for the greater part of its course flows over a rocky or gravelly bed, the banks becoming in some places quite high. In the vicinity of Concord, N. H., there are beds of clay, and in times of freshet considerable quantities of earthy matter are washed into and carried down by the river. The water ordinarily is clear, and possesses little color. At times of freshet, however, for some two months and more during the year,* there is a large quantity of suspended matter, made up of particles of sand and silicious minerals and, to some extent, of clay. The aggregate amount of this earthy material is enormous. Dr. Dana, of Lowell, a number of years ago attempted to estimate it, but of course the data for any such calculation are far from being sufficient. He says:

"In the year 1838, during 23 days of freshet, from May till November, no less than 71,874,063 pounds of geine [i. e. organic matter.-W. R. N.] and salts rolled by the city of Lowell, borne seaward. During the five days of the great freshet, from January 28th to February 1st, 1839, no less than 35,970,897 pounds of the same matter rolled by at from the rate of 112,128 pounds to 20,405,397 pounds per day; cach cubic foot of water bearing onwards from 1 to 30 grains. This is only the suspended matter. That which is chemically dissolved by the waters, the fine, filmy deposit, which occurs in a few days after the coarser and grosser matters subside, and the matter ordinarily suspended in the water of the river, added to the above for the year 1838, give a grand total of 839,181 tons of salts and geine which were rolled down in the water of the Merrimack River."†

The periods during which this state of turbidity exists are "not usually of long duration, perhaps never more than three or four weeks at a time. Observations made and records kept at the Pacific Mills show the amount of turbidity is in direct proportion to the height of water in the river, and that it exists to a troublesome degree only after the water reaches a certain height; while the records of the Essex Company, extending over a series of years, show that the total number of days in each year when the water is at or above that height is less than 90.”—Lawrence City Documents, 1872: Report on proposed Water-works, p. 31.

† A Muck Manual for Farmers, by Samuel A. Dana. 16mo. Lowell, 1843, p. 180.

Dr. Dana made a chemical examination of the suspended matter, and states the composition of the coarser part, that which deposits more readily, to consist of—

Mr. Burbank, of Lowell, has more recently examined this suspended matter. He found that a portion settled very rapidly, and consisted almost entirely of minute grains of fine, sharp sand; the portion of the deposit which settled after a longer interval of time was made up of finer sand, of scales of mica, of clay, of silicious infusorial remains, and of flocculent vegetable matter. The entire sediment from three gallons of river-water, taken April 29, 1869, and allowed to stand until it became perfectly clear, measured (wet) of a cubic inch.

82

100

The character of the country from which the Merrimack gathers its supply, and the nature of its bed, would lead us to expect to find the water naturally quite free from organic impurities, and this expectation has been borne out by chemical examination.

Present Condition of the River.

The results of the chemical examinations of water from different points of the course of the river are given in Table I., in which table the results are stated in "parts per 100,000." As, however, it has been the custom with many to give such results in "grains per gallon," a second table (Ia.) is appended, in which they are so expressed.

The samples of water have been taken from the following localities:

A. Tyngsborough, near the bridge now building, about eight miles above the dam at Lowell.

B. Pawtucket Dam, Lowell.-This dam is situated at the upper part of Lowell, just above the bridge which connects. Lowell and Dracut. The dam diverts the water on the