I read with some interest a blog on Baltimore’s disposal plant at Back River, where it was stated that the Outfall Sewer, which connects to the plant, has sunk about four feet and that millions of dollars will be spent to correct this problem. (For 35 years working in the water department, it always amazed me that there was work going on non-stop at Back River. Billions of dollars’ worth. Nothing for the drinking water side though!) It was also mentioned that this ‘sinking’ was possibly caused by poor construction and engineering. I guess it is easier to blame people who are no longer around that can defend their work! The system is over 100 years old. Below is some info on construction.
1906 – The Board of Police Commissioners caused a census of the city to be taken by the Police Force, which was completed about April 10, 1906, and showed that by the police computation the population of the city at that time was 543,034. A later estimate made in September, 1906, gives the city a population of 555,000. The capacity of the system in whole, will be for a projected one million persons. The Outfall Sewer extends from Chase and Durham streets to Monument street and Loney’s Lane inside the city limits, a distance of 7,016 feet, or 1.33 miles. This portion is under contract and construction was begun on December 24th. From Chase and Durham streets to Madison and Luzerne streets the sewer will be 10 feet 9 inches high and 12 feet wide; thence to the Disposal Plant it will be 11 feet high and 12 feet 3 inches wide. It will be built of concrete, the lower half being lined with brick. From the city limits the line continues east in Monument street to the Union Railway, thence on the south side of the Union Railway, and with a general easterly and southeasterly direction in Fayette street extended and across private property to the Disposal Area on the west shore of Back River south of Eastern avenue, a distance of 23,354 feet, or 4.42 miles, in Baltimore County, making the total length of the Outfall Sewer 30,369 feet, or 5.75 miles.
1908 – Disposal Works – The fact of being able to intercept two-thirds of the City’s sewage and carry it by gravity to the disposal works, where the sewage of the entire City is to be treated, is an item that future generations will appreciate, as it means an enormous saving for all future time in the cost of operation of the sewerage system.
1908 Engineer Hendrick’s report – “It has been our endeavor to treat the work, both as to letting contracts and the employment and promotion of the men, entirely on a business and merit basis, resulting in an excellent class of work and men, including both contractors and engineers. I wish to express thanks to Mr. W.W. Crosby, Chief Engineer of the Maryland Geological Survey and State Roads Commission, for making various rattler tests on brick; to Dr. E. B. Mathews, Professor of Mineralogy and Petrography, for making examinations of various stones, and to Prof. Earle B. Phelps, of Boston, for his assistance in our chlorine experiments at Walbrook. Considering the many difficulties arising daily in constructing two separate systems of sewers (sanitary and storm water) among the vast number of underground obstructions, in streets crowded with traffic and the rapidity and satisfactory manner in which the work has moved forward, which could not have been accomplished if it had not been for the faithfulness and devotion of everyone connected with the work, regardless of overtime and weather, I take this opportunity of expressing my high appreciation of the faithfulness of my staff, consisting of Mr. Albert M. Brosius, First Assistant Engineer; Mr. Herbert M. Knight, Storm-water and Low Level Divisions; Mr. Oliver W. Connet, High Level Division; Mr. Ezra B. Whitman, Disposal Division; Mr. Thomas D. Pitts, Office Division; also, including the engineers, rodmen and inspectors. As stated in a recent address I made to the Society of Civil Engineers in Washington, D. C., the sewage problem as a world factor is forcing itself to the front very rapidly, and our country is approaching a point where it will have to deal with the sewage question on a broad scale. As rivers run from one State to another, the States cannot deal with the problem without clashing, and it will soon have to be dealt with by a National Sewage Board, similar to those abroad. We have heretofore, on account of the vastness of our country and the size of our rivers, simply disposed of the sewage in the most economical manner at the time, regardless of results, such as dumping it directly into lakes and rivers. This has been a short sighted policy from the fact that large expenditures have been entered into in the way of sewers, which will necessarily have to be readjusted in order to conform to sanitary laws now being passed requiring the treatment of sewage before discharging it into rivers or lakes. The City of Baltimore is showing the same progressive spirit in handling this great sanitary problem that she has shown in many other enterprises of world-wide interest, causing cities all over the world to send committees and engineers to study the plans and methods of prosecuting our work.”
Here are the engineers that built this structure. It appears to me that if this brick-lined conduit did sink 4′ that there would be a mass amount of broken brick and concrete?