RECENT DEVELOPMENTS IN SCIENCE AND INVENTION

The Waste of a Great City

JOHN M. WOODBURY IN SATURDAY EVENING POST January 1 1907
RECENT DEVELOPMENTS IN SCIENCE AND INVENTION

The Waste of a Great City

JOHN M. WOODBURY IN SATURDAY EVENING POST January 1 1907

The Waste of a Great City

JOHN M. WOODBURY IN SATURDAY EVENING POST

Mr. Woodbury is ex commissioner of street-cleaning of New York City and his article gives an accurate description of the methods employed in that city to dispose of refuse. The refuse is divided into three cla-ses each of which is treated differently.

THE term waste, while apparently a statement of fact, is entirely inaccurate, for there is no such thing as waste. Matter may change its form, but it never can be destroyed, and while the usefulness of these materials may not be recognized immediately, yet the possibilities of further service remain; whether as to retention in unaltered form for remanufacture, as in paper, or in the changed form of heat, power and light, they all hold values which are recoverable.

Up to the year L902 it was the custom in New York City finally to dispose of the rubbish and ashes mixed together by dumping them into the sea. This was an absolute waste of these materials. The separated household or table refuse was recovered in the reduction plant at Barren Island. At present writing, the oils and fats are recovered from the garbage at this reduction plant and the residue made into a fertilizer; while the ashes, separated again, are placed upon the outlying lowlands near the city, and the rubbish which can be recovered for remanufacture is sold and the remainder in part burned, by which burning the Williamsburg Bridge and the adjacent plazas are lighted, the waiting-rooms heated and the air-compressors for work upon the structure driven.

We separate the wastes, for the sake of handling, into three characters of material, as already described—garbage, ashes and rubbish—and taking up these three materials in

the order in which they are named, we will discuss what is being done with them in New York and what the possibilities of future handling are along these lines.

First, the garbage. This material, if left, soon undergoes a chemical change of a fermentative order, which renders it exceedingly obnoxious to any one, and its prompt and efficient removal from its surroundings must be accomplished certainly every twenty-four hours. This is particularly true during the summer months. This material is collected in watertight steel carts from the galvanized sheet-iron cans in which the householder is required to place it, taken to the water-front and loaded upon scows, which are towed to Barren Island.

When it lands on the scow the contractor’s employees trim the material, and also cull such refuse as may be harmful to the machinery, such as cans, metal, broken dishes, etc. The scows leave the dock immediately on loading and are towed an average distance of twenty-five miles and a half to Barren Island, located a mile and a half within the entrance to Jamaica Bay. The factory is located on the northernmost end of the island, with a water-front of about 500 feet, which is necessary not only for the handling of the material, but for the receipt of coal and the shipment of fertilizer, filler and grease. The greater part of the fertilizer or tankage goes to Southern points, where it is mixed with phospate for use in the cotton belt, as it seems to be particularly adapted to the soil in that portion of the country.

It is shipped in bags which are placed on board schooners in about 500-ton lots. The grease is barreled at the plant and shipped generally to Europe, where it is refined and utilized. This garbage grease is called common soap grease and brown grease in the trades, and is sold on a sliding scale, which is governed by the price of tallow.

The method of reduction is roughly that of treating this material in large retorts or digesters, with live steam, for about eighteen or twenty hours. This is sufficient to break up the cellular structure in animal or vegetable tissue enough to permit the fats and oils to' escape. The entirely liquid material is then run off into tanks and the more solid portion subjected to pressure. The oils and fats rise to the top and are skimmed off and recovered. The residue or tankage with the compressed cake is made into fertilizer.

An interesting fact in connection with the handling of this material is that the city of New York disposes of about fifty tons of condemned fruits of varying character per day. This material contains no grease and no values that are recoverable by this process of reduction, but it does contain alcohols, flavoring extracts, citric and tartaric acid, etc., which are of great value. A very large chemical house is at work at present upon a method of distillation, which will make use of and recover these products. This simply means a further separation and utilization, the tendency being to resolve into its component parts this tj7pe of material, so that the values in each of its units may be recovered.

The ashes an(J rubbish of the city,

mixed together, were all, practically towed to sea and dumped up to May, 1902, the ash and the heavier material helping to foul the harbor and shoal the channel, while the rubbish and lighter wastes floated in to decorate the beaches. This was a great nuisance to sea-bathers every summer. In 1902 this sea-dumping was stopped and it has never been .returned to, with the exception of a short period in 1906, when the destruction of the only existing plant at Barren Island by fire rendered it necessary to tow the garbage wastes to sea and there dispose of them for lack of any other method of final disposition. Nothing of the waste of New York City is now thrown into the sea. It is well known that ashes make the best land fill upon mud flats or any soft bottom. They form a mattress, which does not sink through the mud, as is the tendency of heavier material, and create no mud wave such as follows the dumping of cellar dirt or rock.

All the ashes, rubbish and street sweepings are disposed of upon land fill, the material from Manhattan and The Bronx being hauled to the water-front, and towed in scows from the dumps , to Riker’s Island and to various other points where it has been placed upon fills behind bulkheads. Land has been made in this way at Newton Creek, Tremley Point, Shooter’s Island, Staten Island, Weehawkem, Cromwell’s Creek, Newark and Maurer, N.J.

The well-known value to> the commerce of the city of New York of the stoppage of sea-dumping, which was all too surely filling and fouling the harbor, it is not necessary to discuss, while the placing of the ashes, street-sweepings and rubbish behind cribs for land fill has produced eighty acres of land owned by the city and a large amount of land owned by private individuals.

The possibilities of this reclamation are boundless. The lowlands on Jamaica Bay afford an umlimited supply of dumping ground. This fill, in connection with the dredging for the proper channels, would produce thousands of acres of land with dock frontage, whose value would be millions of dollars.

Prior to 1901 the ashes, streetsweepings and rubbish of the borough of Brooklyn were collected and hauled to what were known as land dumps, except in one instance, where they were hauled to the river-front at the foot of Gold Street and loaded on a scow. The land dumps were scattered on the periphery on the land side of the borough of Brooklyn. It was recognized by the Department of Final Disposition several years before that the land dumps were rapidly disappearing and that it would be but a comparatively short time before ad the available dumps (that is, available for wagon haul) would be filled up, and the city would be put to an enormous espense in increased haul, number of carts, horses, drivers, stable accomodations, etc., in order to continue the landdump system. A further extension of the scow system was not practicable, as the water-front in Brooklyn is owned by private parties and not by the city, and it was found impracticable to secure a sufficient number of dumping boards.

On the twenty-eighth of July, 1993, a five-year contract was entered into with the American Railway Traffic Company for the final disposition of all rubbish, ashes and street-sweepings collected in the borough of Brooklyn. Through the operation of this contract all this waste is hauled by the electrical trolley system.

This material is collected from the houses by carts and delivered to various stations upon the trolley lines.

In order to determine the location of the receiving stations, the populated portion of Brooklyn was divided so as to be covered by thirteen circles each of a mile radius and the collection station was located as near the centre of this circle as was practicable.

These stations are of two types. The one at Thirty-eighth Street and Fourth Avenue and the East New York Station are what is known as the hopper type. The character of the ground at these points permits the carts to drive into an upper storey of the building and' dump the loads into hoppers which are sunken in the floor. The entire upper portion of the building is enclosed to prevent the escape of dust. Patent dumping-cars are run under these hoppers and the cars loaded by releasing the bottom of the hopper. These cars are then run out over the trolley lines of the city to the lowlands near Coney Island.

The remaining eleven stations are of the bin type. The carts drive in from the street on a level and dump into steel bins, which are practically seven-foot cubes and have a capacity of nine and one-quarter cubic yards. The weight of one of these bins will run when loaded from five to eight tons, depending upon the character of material. After being loaded upon the cars the bins are covered with a close-fitting canvas cover to prevent the escape of dust and refuse. The car is then taken over the trolley lines to the dumping ground.

In order, to avoid annoyance in the neighborhood the stations are as tightly closed in as is practicable, and except in freezing weather the loads of ashes are sprinkled by a jet spray while the load is being dumped.

The average haul of the trolley cars from the receiving stations to the dump is ten miles, making the round trip for the car twenty miles. The magnitude of the work can be better understood by the statement that the railway company is each year transporting li,000,000 yards of material an average of ten miles.

During the time this method of removal of refuse material has been in operation, about eighty-five acres of sunken land have been raised to the grade of the surrounding country and made good taxable area, whereas before it was of little or no value, except as a mosquito-breeding ground.

By this arrangement the borough of Brooklyn has been given a daily collection instead of a bi-weekly collection and is placed on the same footing as the borough of Manhattan.

In the boroughs of Manhattan and The Bronx the city yearly collects and disposes of about 1,640,00'0 cubic yards of light refuse or rubbish, all of which is burnable and has about the fuel value for steam purposes of green sawdust. It consists of every describable article of household waste. This material was formerly loaded on scows, mixed with ashes, and dumped into the sea, where, being light, it easily floated in, on to the beaches along the Long Island and New Jersey shores, where its presence in past years caused great complaint. In 1902 the simple destruction of this material was begun at an incinerator located at Forty-seventh Street and the North River. This simple destruction is satisfactory from both a financial and a sanitary point of view. Very soon an attempt was made to utilize the heat derived from this combustion for purposes of steaming, and,

in 1903, a small electrical plant was installed for the lighting of one of the stables of the department and of the docks and piers in that vicinity.

In 1905, the idea of economically using the rubbish wastes to light municipal structures and buildings being beyond the experimental stage, a plant was constructed beneath the Williamsburg Bridge, where daily 1050 cubic yards of light refuse are destroyed. During the night the heat is used to generate electricity to light the Williamsburg Bridge and approaches, and in these hours 350 indicated horse-power can be developed per hour. The material handled at the Delancey Street plant is about one-fifth of the total output of the boroughs of Manhattan and The Bronx.

When all the lamps are carried by the plant and are in active use there are 180 2000-candle-power arc lamps, of which 163 are on the structure and the remainder in the buildings. There are also about 767 16-candlepower incandescent lamps, three electric motors and about twenty electric heaters.

The possibilities of the extension of this system of using the rubbish wastes of the city for power, light and heat are very great. In connection with the Department of Bridges calculations have been made which determine the amount of electricity necessary to light and turn the drawbridges over the Harlem River. There are six of these which are movable, and1 one, the Washington, which is fixed. The production of this amount of power and light from the rubbish wastes is perfectly possible, and two designs of plant have been laid out— one idea that of a central station from which all of the bridges may be lighted and operated, and the other of several separate smaller plants.

The difficulties of operating one large central plant are, first, the increased length of haul of the material to the plant, and second, the inability to enter upon the conduits which carry the electric light wires in New York City. Two hundred and fifty horse-power per hour is lost in simply burning rubbish at the plant at the foot of Forty-seventh Street, which readily could be used for lighting and heating the schools within three blocks.

There has also been designed for erection at the foot of Twenty-ninth Street and the Kast Hiver a plant which w'ould be capable of lighting and heating and supplying the power for elevators for the new Bellevue Hospital. This would practically make use of all the rubbish of the Borough of Manhattan.

The operation of these plants and the use of this power would not only be a saving to the city of the amount of fuel necessary to produce the light and power, but also a saving of thirteen cents per cubic yard on every load of this material that was formerly thrown into the sea.

The sorting of the rubbish is a source of considerable revenue to the city, for valuable rubber, old garments, rags, and various grades of paper are found in it. The sorting and removal of this material are let to a contractor who keeps a force of workmen constantly picking over the refuse, all that is available being removed and packed for shipment. With the earlier methods of refuse disposal the revenue from this form of salvage .was not large on account of the impossibility of properly going through all of the material received, as it was dumped directly in cartloads from the docks into the scows; but with the installation of

an apron conveyor at the Forty -seventh Street incinerator it was at once demonstrated that very large quantities of useable material can be sorted out when it is thus elevated slowly past the sorters, who are thereby enabled to examine carefully all of the refuse. By this method of sorting an average of sixty per cent, by volume of the entire receipts is removed by the trimming contractor, for which the city receives $1.50 per ton.

The trimmers stand on four small platforms on either side of the conveyor adjacent to the division wall, where the conveyor is about ten to twelve feet above the floor. Between these platforms are light wooden bins into which the various classes of material are thrown and thus kept separate. The bins have openings at the bottom from which the sorted material is delivered to the floor for packing. The facilities for the trimming do not take up much room.

The furnaces at Forty-seventh Street and Delancey Street have proved satisfactory, the waste material burning rapidly and completeI3', with no smoke or offensive odor from the stacks. A high temperature is generated continuously in the furnaces, so that no trouble is experienced with the draft from the opening of the feed-holes—the draft, in fact, being in excess of the demands, on account of the tall stacks. The furnaces are periodically stoked by means of long bars, so as to turn over the burning material and sift out the ashes.

It is impossible, in the light of this experience, that the City of New York should ever return to the archaic method of disposing of these materials, which are not wastes in any true sense, by throwing them into the sea. The question of the burning of the rubbish wastes is one which comes widely before every city in this country that maintains a streetcleaning department. The cities which are supplied with an overhead trolley system can very well simplify the matter of collection of ashes, street-sweepings, garbage and rub-

bish by making the electrical trolley do the work where the haul becomes too long for a horse.

If the city should own the trolley line, instead of the trolley line owning the city, it would be perfectly possible to supply the fuel for this collecting and hauling, and thus make one hand wash the other.