Two reports on the state of the Schuylkill River, 1867

Excerpts from the Annual Report of the Chief Engineer of the Water Department of the City of Philadelphia, Henry P. M. Birkinbine, presented to Councils Jan. 31, 1867.
Pages 60-67

PURITY OF WATER.

Before…any further extensions are made to the Works located on the Schuylkill, the importance of maintaining the purity of the water should receive your attention. Within no equal period of time has the amount of impurities drained into the Schuylkill increased to such an alarming extent as during the past year. This has been the result of the stimulation of manufactures, and the erecting of a number of new works in Manayunk and vicinity, such as paper-mills, oil refineries, &c., all discharging their refuse into the dam [section of river] from which the water supplied to the City is taken. The discoloration occasioned by these impurities is plainly discernible as far as the Falls, and sometimes at Columbia Bridge.

This subject has so often been urged upon your consideration that it is scarcely necessary to add anything to the many facts communicated in my former teports. Yet, that it is one of vital importance is evident from the following, among other facts that might be adduced: “When the cholera visited London, in 1853, the parts of the city supplied with impure water suffered three and a half times as much as those supplied with better water; the deaths being 37 to 10,000 in the one case, and 130 to 10,000 in the other.”

It was the intention of the Department to give you a detailed account of all impurities drained into the dam, and of the sources from which they come, but unforeseen circumstances prevented the procuring of the requisite data. Enough has been ascertained, in addition to what has been communicated in former reports, to call for immediate action on the part of the City. It may be too late to prevent all this objectionable drainage, as a large amount of capital is invested in these manufactories, and a large and increasing population now inhabits the region drained immediately into the dam. Enough can be seen by the most casual observer to satisfy him of these facts, When the river is not turbid the water flows over Flat Rock Dam and among the rocks, limpid, bright, and beautiful as a mountain stream; but follow it down a few hundred yards, and after passing the paper-mills, the river, for one half its width, is of a dark-brown color. Further down, it receives the refuse from dye-works and manufactories of every kind, the entire sewage of Manayunk, and the refuse from the Gas Works.

Below Manayunk, the river assumes a dark, dirty, milky appearance, and is covered with soiled waste and shreds from shoddy mills; but by the time the water flows to the Falls, it assumes almost its original brilliancy. Here, again, it receives more objectionable matter from the chemical and dye-works, but at the Columbia Bridge it seems to have deposited or destroyed all objectionable matter; and at Fairmount has apparently regained its original purity. But there is no doubt that a constant deterioration in quality is going on, which, if not arrested, will ultimately force the City to abandon the Schuylkill as a source of supply, if the time to do so has not already arrived.

“The waters of rivers which traverse the grand centres of population become more impure in proportion to the development of industry; for while the mass of the water remains the same, the causes of impurity become daily more abundant.” So with the numerous creeks draining the undulating surface of our City, many of which, once bright and beautiful, are now befouled by refuse from manufacturing establishments, and are being covered out of sight, one after another, as objects too loathsome to look upon, whose fetid waters would spread disease and death, were they not thus hidden. Is there no remedy for this? Shall our industry only tend to make the most beautiful and necessary of objects loathsome, or shall we, by the strong arm of law, protect the purity of the water, and force manufacturers to find some other means of carrying away refuse matter?

The City has invested a large amount of money in the Works for pumping water from the Schuylkill, and the purity of the water supplied is a matter of great importance. If it is determined to continue this as a source, a large expenditure for the purpose of securing pure water, will be warranted.

If the drainage from factories and other sources could be prevented from flowing into the dam, the quality of the water would be unexceptionable, except in time of freshet, when, for a few days, the water is always turbid. This could be prevented by subsiding reservoirs of sufficient capacity. A city with the wealth and number of inhabitants of Philadelphia, should, at least, be able to supply itself with an abundance of pure water.

The project of purchasing the property on both sides of the lower part of the dam, and using it as a park, is a valuable suggestion, and worthy of your approval. It would do much to prevent objectionable drainage in the immediate vicinity of the Works; but this alone, will not insure the purity of the water; some disposition must be made of the objectionable drainage from above.

HYDROGRAPHICAL SURVEY OF THE SCHUYLKILL RIVER.

The dam at Fairmount forms a subsiding reservoir in which the water of the Schuylkill is allowed to partially purify itself before being pumped into the reservoir. It is, therefore, of the utmost importance that it should be kept as free as possible from shallow, stagnant pools. For the purpose of ascertaining the amount of mud deposited, and the general features of the river, a survey was made in 1861, extending from Fairmount to Columbia Bridge, (see my Report for that year, pages 9-18.) Between these points, a large percentage of the matter held in suspension in the water is deposited, owing to the slow current; viz:—two miles per day.

This was compared with a partial survey made in 1852, under the direction of the Schuylkill Navigation Company, which showed that some portions of the river were rapidly filling up, and that great alterations in its general features were taking place.

In 1864, a second survey within the same limits was made and compared with that of 1861, when great changes in the shore and channel were found, (see my Report for that year, pages 4-13)

These changes were great, and increased so visibly that, in order to ascertain the physical laws controlling the deposits, a third survey was made, in November and December of the past year. It was more extensive and thorough than either of the others, embracing the river from the Wire Bridge at Fairmount to the Reading Railroad Bridge at Schuylkill Falls. From it the accompanying map was made. This map is an exact plot of the river between these points, and exhibits the general topography of the shore and islands, the location of buildings near the river, the position of bridge-piers arid wharves, lines of soundings, etc., and the line of shore, in 1861. The principal boundaries are the Philadelphia and Reading, Pennsylvania Central, and Junction Railroads.

The transverse sections are taken at various points, A-A1, B-Bl, C-C1, &c., which best show the general prism of the river; and in those embraced in the other surveys, the variation is shown by dotted lines. Thirty-eight such transverse sections were taken, averaging 500 feet apart, and, on these, soundings were taken every twenty feet. The longitudinal section exhibits the deepest soundings on each of the thirty-eight lines, and is on a scale of 200 horizontal to 1 vertical.

The rapidity of these changes will appear from the following data. The amount of water contained in the river, between Fairmount Dam and the Columbia Bridge, and the amount of deposit, is as follows:

The mean daily average discharge of the river, exclusive of stormwater, is estimated to be 87,162,240 cubic feet. Accordingly, this reservoir is more than emptied each day. The contents of the river were equal in

1861, to the amount discharged in 23 hours, 11 minutes.
1864, to the amount discharged in 22 hours, 16 minutes.
1866, to the amount discharged in 20 hours, 26 minutes.

The general appearance of the river has changed considerably, as will be seen by following the dotted line which exhibits the shore line of 1861. Long Island, just below Columbia Bridge, has enlarged and changed its position somewhat. [Sweet] Briar Creek has made a bar at its mouth, and the bar opposite it, outside of the canal, is increasing. Below the rolling-mill, on the opposite side of the river, the shore has made out considerably into the stream. Under the eastern end of Girard Avenue Bridge, the shore is now nearly out to the end of the Schuylkill [Spring Garden] Water Works’ wharf; and along the Park, the shore line has, in several places, encroached considerably upon the river. The most prominent of these encroachments is below Turtle Rock and the Skating Club House, where, for 800 feet, light batteaux cannot approach to within 100 feet of the original shore line. There is also a large deposit just above the steamboat wharf at Fairmount.

The greatest and most prominent deposit in this portion of the river is, however, opposite the Twenty-fourth Ward [West Philadelphia] Water Works, where an island 1,100 feet long, and averaging 160 feet wide, has been formed. The tow path, between the points D¹ and G1, is now useless, as even light-draught boats cannot, in some places, approach within 500 feet of it. Three-fifths of the whole deposit in the river, nearly 6,000,000 cubic feet, is contained in this island and in the encroachment of the shore between those points. These deposits have necessarily contracted the river, and reduced the superficial area about nine per cent.

The mean sectional area, or the prism of the river, is less than in 1861. The stream has increased in depth and decreased in breadth. The decrease of the sectional area and width, and the increase of depth, will demonstrate that, in time, a mere channel will take the place of the large subsiding reservoir which was formed by the construction of Fairmount Dam; and the water drawn into the pumps will have less opportunity to be at rest, and to deposit matter held in suspension.

No comparisons of contents, area, &c., can be made with that portion of the river between Columbia Bridge and the Reading Rail Road Bridge, as no survey was made of it, prior to 1866.The present survey will be a basis for future comparisons. Columbia Bridge is about midway between Fairmount Dam and the Reading Rail Road Bridge, being 8,750 feet from the former, and 8,420 feet from the latter. It may be interesting to compare these two portions of the stream.

From these data it will be seen, that, while the superficial area of the portion above the Bridge is nearly as great as that below, yet the cubical contents are one third less. The breadth of the stream is more regular, and the mean depth less.

The above data will be of great service in any plan for main, tainting the purity of the water. The Department is not prepared to suggest a plan, as further investigations will be necessary.