Public Refuse Destruction a Municipal Asset, Not a Liability
GENERAL FEATURE ARTICLES
Methods of Disposal of Urban Waste by Incineration that Prevent the Escape of Noxious Gases and Smoke and Whereby all Organic Matter is Consumed and the Remainder is Free of all Objectionable Matter from a Sanitary Point of View
We Americans are a peculiar people; most, if not all, of us are of the “desire to be shown” type commonly understood by about all who resi_____le at that approximate geographical center, Missouri. Our climatic, topographic, hydrographic conditions, methods of life, business, industries are so varied that in no branch of public or quasi-public service can successful outcome in one locality be applied with confidence in another unless by and with the aid of a competent specialist. Billions of dollars have been wasted in faulty location and improper design of water works properties, and on account of failure to properly anticipate the water supply necessities of fast-growing urban communities. Millions more for similar reasons on municipal heat and lighting propositions, but in this new field the loss has been in great part due to the rapid perfection, modification and modernization of electric machines and current transmission; while every American child as well as man appreciates that we are face to face with a most serious loss—approximating a million dollars per day— in avenue, street, highway and road deteriorations—a loss that can be, in large measure, checked if due regard is given to foreign experience and success with varied traffic conditions, which now bear no relation to those of 20, 10, yes, even five years ago, on account of automobile development and use. But greatest of all in cost to us, except water supply, as measured in the lives it has taken and in cash, has been our failures and neglects in that part of the sanitary field involving sewage transit and disposal and refuse destruction or utilization. We have been spending too much money for the wants of today and letting to-morrow take care of itself; and while refuse destruction should have been an old problem long since solved for many communities, our path has been dotted with nearly 200 failures on a large or moderate scale as against but a dozen or so successes. A period of experimentation since about 1885 is now at low tide; in fact, there have been a few years of success. It is no reflection on those engineers who have worked hard during many years without effective result to give credit where it is due for success attained, or to about a half dozen American engineers as aided in whole or in part by English, German and French experience. Any community can now, if it will, solve the expensive, annoying problem of garbage, ash and rubbish removal and destruction or utilization at a profit in increased health and longevity of its people without nuisance; yet at a gain in cash over and above the cost of the service, and for such places refuse destruction is changed to a substantial asset from a heavy liability. A few facts that are general in character arc given below in a general way to show what to expect if any one course is adopted, remembering that in no one branch of the public service is it so important to have reliable data as to local details. A mile of streets in one city may require exactly the same pavement as a mile in a near-by city of equal population; or its water works pumping equipment might be exactly the same; or the same system of street lighting, city ordinances or police regulations might give equal satisfation in both places; but in refuse destruction, the plant, its location, design and operation must fit the facts, and not try to make local facts fit rosy statements, handsome pictures and printed matter. You should have the work proceed under the most rigid plans and specifications of an independent party, awarding contracts to the best but not always the lowest bidder. Of practical methods we have but few, and briefly considered as follows:
Methods of Disposal of Urban Wastes
Dumping ashes, rubbish, garbage, etc., on low lands of moderate cost often greatly enhances the value of*such land; but during the interval of such disposal a very considerable nuisance is created by favorable wind returning in finely divided condition to the citizens enough of the waste products, accompanied by nauseating smoke, odors and zymotic germs to make such disposition, from an esthetic and sanitary standpoint. serious objectionable. The small comparative return in receipts front the sale of usable material and products of such dumps is too small to compensate for the nuisance, while the enhanced value of the real estate used is often offset in great part by the destruction of structures erected thereon through unequal settlement, or on account of fires bound to occur from spontaneous combustion and other causes in embankments of this nature. Jersey City and other places have had to combat with such a condition. Insurance rates ought to be higher in such localities.
*By Joseph B. Rider, C.E., Consulting Engineer, 29 Broadway, New York,
Dumping at Sea
Contamination of bathing beaches, injury to oyster and other marine industries, the expense involved in such disposal, the general nuisance, detrimental effect on quality of water supply from large rivers, and other causes are such that this method should be abandoned wherever it is in use. It is obsolete.
Segregation of Garbage
It is impossible to do this perfectly for many reasons. Practically, the garbage will be found mixed with tin cans and various other articles, and the ashes or rubbish will likewise be found mixedq with garbage. It also involves the extra expense of separate collections, duplication of cans, and increases the local annoyances at everv back door; the neglect of servants, battered, lost and leaky garbage cans: unsystematic or too long delaved collection by public or private collector results in making hapnv homes for flies and other insects, in early morning entertainment of sleepy families by congregations of cats, and the upsetting of the cans by dogs over-hungry for the bones, resulting in hundreds of annoying and unsanitary situations and breeding places for disease in every community where this method is used. Under strict sanitary regulation results as outlined can be reduced to a minimum, but not entirely overcome, and there are instances where the separation of garbage from the ashes is accomplished to the satisfnetion of the local authorities, as at Minneapolis. Columbus and other places where the garbage and rubbish, but not the ashes, are disposed of be incineration or reduction. To separate the garbage for use as food for swine is not up to date and from every standpoint is bad practice Many health authorities agree that meat obtained from pigs fed on municipal garbage is unbealthy: the records show that fully one-third of such swine are infected with disease Again. it cannot be said that, everything considered, it is wise, prudent or to the financial advantage of a municipality to compete with the farmer in this line of business, or to give away its garbage to a private collector for such a use. Where single collection is adopted it will he found that the ashes absorb the greater portion of the liouid garbage and yet cover and protect the remainder in such a way. until final disposition, that minimum objection results, while the cost of collection is materially reduced for the moderate sized municipality, if not in the case of some of our larger cities. The economy of separate rubbish collection, paper, rags, bottles, bedding, wood, metallic articles, etc., in any case will depend on a proper analysis of the local situation as to its amount, length and grade of haul, and other factors for each district of the municipality, and the method of final disposition, but as a general proposition it might better be collected simultaneously with the mixed ashes and garbage, but from a separate system of re ceptacles.
Cremation, so called, is not a practical success on a large scale, and should be limited to the housewife casting a small amount of kitchen refuse on a hot coal fire in the winter time when garbage collection cannot proceed with regularity on account of low temperature, snow and icy streets. On a large scale cremation has proceeded at too low a temperature in such a way, due to design of plant and methods of operation, that much of the organic matter has not been consumed or cremated, while the nauseating odors and smoke from such plants have caused bona-fide objection many miles away. Most of the American failures in final disposition of refuse have been identified with garbage or refuse cremation plants, erected by “rule of thumb” methods from or without designs based on many of the early patents and ideas which did not properly comprehend the raw, wet, often most offensive waste products of a town or city could not be consumed at temperatures of 1,000 deg. F. and under without offense, nor without the addition of fuel in proper amount and in right manner used, so that combusttion would be uniform, not erratic. The latest records tend to show that of the about 250 plants erected in the United States since the first one, in 1886, more than one have been abandoned; some of the remainder are used occasionally, and a moderate number are giving local satisfaction in sections where the satisfactory accomplishments of the modern up-to-date destructor plant are unknown. What the old horse car is to modern traction, the ox team is to the automobile, the hour glass is to the chronometer, so are crematories of the past to the modern incinerator or destructor. They might do if there was nothing better. The turkey buzzards of the South do more good than all the crematories, and. in fact, have often completed the latter’s unfinished work. It is well, however, we have their pioneer work in plain sight to guide us right, not wrong, for we now know clearly as to what we ought not to do, and that it costs less money in plant and less in cost to operate to dispose of municipal refuse in a proper rather than in an offensive, detrimental, half-shod way by crematorie?.
Modified cremation or destruction by fire at temperatures of 1250 deg. and higher, in a manner and by methods that prevent the escape of noxious gases and smoke and whereby all the organic matter is consumed and the remainder, in the form of ash. clinker, etc. is free of all objectionable matter from a sanitary point of view. It is well adapted to apartments, hotels etc., and in localities where gas is largely used for fuel, or towns and cities where the majority live in apart nients, and where industries are such that the fuel content of the ashes to be disposed of by the municipality is low. Incinerators, in most instances, require coal or other fuel for their proper operation, in addition to the fuel content of the mixed garbage and rubbish disposed of in such plants. There are a few American examples of municipal incinerators operating properly without additional fuel but it is obvious that there maybe seasons of the year, with garbage content high, when such incinerator plants are liable to be made crematories by the lowered temperature of combustion at such times, unless the precaution has been taken to keep one side a considerable quantity of inflammable rubbish wood, boxes and barrels. As a general proposition incinerators are much cheaper in first cost than refuse destructors, that dispose of urban ashes as well as garbage and rubbish, and having less to consume than destructors, generally cost less to operate in labor charges and other items per capita per annum; yet to offset these advantages we have the cost for fuel to operate them, the extra cost of separate collection of garbage and refuse from the ashes, and other incidental items. At this time there are more than double the number of incinerators in operation disposing of municipal waste in the States than there are destructor plants; but the writer predicts a reversal of this sitution very soon. One of the leading incinerator companies has recently submitted the writer’s proposition to take care of the municipal ashes as well as the garbage and rubbish in a city of considerable population.
American Incinerator Plants
Most incinerator plants develop surplus heat in moderate degree, but generally sufficient for the necessary steam power to operate necessary auxiliary apparatus, and often for other purposes. A few guiding facts about American incinerator plants are below given:
Plant 1. An old style plant suburban to Chicago; population, 30,000. Incinerates 7 tons garbage per day 0.56 lb. per capita per day. Requires 360 lbs. coal per ton of garbage for proper incineration: 18 per cent by weight of coal to
garbage consumed. Coal about 9,600 B.t.u. Plant 2.New plant in central gas belt. Requires 1,000 cu. ft. natural gas fuel per ton of garbage and rubbish consumed in a satisfactory way; mixture burned contained about l per cent, of tin cans and 10 per cent of ashes.
Plant 3. In Rocky Mountain west; not a municipal plant; incinerates 7.5 tons of manure and garbage mixed per 10-hour day. Requires 115 lbs. O. coal per ton of refuse consumed 6.76 per cent, of coal by weight. Burns, 51 lbs. of the mixture per sq. ft. grate per hour.
Plant 4. Plant six years old; suburban to Chicago; population, estimated in 1918 at 25,000; mostly all resident district of better class. Incinerates 18 tons of garbage and rubbish per 8-hour day 1.44 lbs. per capital per day. Requires 200 lbs. of coal per ton of material consumed 10 per cent, of coal by weight. Stack, 160 ft. high. It is interesting tnat in this class a collection covering the small residential city reuired four days, averaging 18 tons per day; oing the work with five men, two teams and one horse and cart, costing about $20 per day, or with overhead charges, about $25 per day; or approximately $1 00 per day per 1,000 people to collect and deliver the garbage and rub. bish, while two additional men operated the incinerating plant.
Plant 5. New plant, near Chicago, not municipal; on test incinerated 6,000 lbs. in six hours or 1,000 lbs. per hour of 85% garbage and 15% rubbish. Required 280 lbs. of 9500 B. t. u. coal per ton of refuse consumed, including pre heating of furnace = 14% of coal by weight. Temperature combustion chamber, 1370° F. Average draft in inches of water, 0.71. 55 lbs. garbage + rubbish burned per sq. ft. of grate per hour. Plant operating at 75% of its rated capacity.
Plant 6-Minneapolis; population, 320,000; separate collection of garbage wrapped in paper by householder. Ashes and rubbish not consumed in incinerator, but taken to the dumps, which contain quite a per cent, of garbage. With due allowance for paper wrapping and assuming garbage at 50 lbs. per cu. ft., the amount of garbage incinerated would he about 0.43 cu. ft. per capita per day. With amount at times at 120 tons per day, the amount consumed per day (paper + garbage) is about 0.77 lbs. per capita per day. The amount 0.43 per capita per day is in close agreement with the writer’s determination of 0.4 lb. per capita per day in winter at Atlantic City, and as determined by another for one district of Boston at 0.44 lb. per capita per flay, and as hereinafter mentioned. Less than three tons of coal are required at Minneapolis per day’s work in incineration of the garbage as wrapped in paper, and which idea was, I understand, first advanced by Commissioner of Health Dr. P. M. Hall. Certain it is that the paper wrapping has very much reduced the cost of coal to operate the plant.
Average kitchen garbage weighs from 45 to 50 lbs. per cubic foot. A handy size household garbage can is 14 in. in diameter and 14 in. high, with lid. and made of galvanized iron, holding 1.l2 cu. ft. of from 50 to 56 lbs. of average garbage when full
A convenient size household rubbish can of galvanised iron, with lid and two side handles, is 20 in. in diameter and 26 in. high, holding 4.7 cu. ft.
With the moisture evaporated through combustion of the rubbish and added coal in the incinerator, average garbage then has a heating value that in part compensates tor the heat required in drying it; but any calculation as to B. t. u value should not include the fuel value of the garbage, if design is expected to comply with promise.
At Memphis. Tenrt, the garbage plus the rubbish, amounted to 1.30 tons per flay per 1,000 people.
At Columbus, O., separate collection of garbage is in use on account of the low consumption of coal, due to UHc of natural gas. and the establishment of the best example in the United States of a garbage reduction plant. The garbage of the city in the first six months of plant operation amounted to 46 tons per day, and cost $1.88 per ton to collect and deliver it to the reduction plant. It was collected by 35 tilting metal wagons holding 2.5 cu. yds. each.
Information as to the amount of rubbish per day or year from a given number of people is of little value in solving the problem of disposal at any given place, but, as near as the writer can determine, it is quite safe to count on a minimum pf from 200 to 300 pounds per day per 1,000 people. Such rubbish will have an average heating value of about 75 per cent, of its weight in coal, or in most seasons of the year the calorific value of the rubbish from 10,000 people would about equal a ton of average coal when the rubbish is used in an incinerator, and to this extent would reduce the amount of coal required to incinerate the garbage. The amount of coal would likewise depend on the fuel content of the “stray’’ ashes that might he delivered with the garbage or rubbish. It pays better to use all the rubbish in the incinerator plant, as a general rule, for fuel than to sell a part of it and burn the remainder. Average rubbish in salable condition at Buffalo amounted to about $7 per ton. The cost of separation and attendant expenses in this and most other cases about equals the revenue from its sale; hence it might better be used for fuel in plant operation without cost, rather than purchase coal or gas to take its place. In fact, as the unsalable waste carries more water content than the salable part of the rubbish, the amount of coal used in incineration must be much increased where sale is resorted to, so that the extra cost for fuel exceeds such profit as there might be on sales. Xo set rule can be applied as to the amount of garbage or rubbish, and in each place it will vary with season and in different districts in the same season: again, some places eliminate corn husks, etc., in summer from the garage and make the household take care of this. Many other factors make the problem such that if one would design correctly, local statistics gathered under competent supervision are most important. Many places in considering the design of destructor or incinerator plants must consider with care the matter of fluctuation in population or plant will he too small.
Sustain Resort Incinerators
Asbttry Park, N. J., with normal population of about 12,000, has a summer population of 100,000. During May the garbage collected varied from 41 to 60 tons per week, and during the same period the rubbish collected varied from 29 to 64 tons per week. During July the garbage collections jumped to a maximum of 174 tons and rubbish to 81 tons per week. At Atlantic City the writer’s investigation showed that with a winter population of from 50,000 to 60,000. and as high as 300,000 at many times during the summer, a variation or fluctuation of one to six. Rubbish varied from 16 to 50 tons per day and garbage from 25 to 100 tons per day in summer, with garbage as low as 10 tons per day in winter, or a minimum of 0.4 pound garbage per capita per day. The amount of garbage at Atlantic City is also influenced by the fact that many of the large hotels and other places operate their own incinerator plants. Again, it is more than likely that at times of maximum population many thousands are there for the day only and have little, if any. effect on the amount of garbage to be disposed of by the city The garbage from one section of Boston was found to be 0.44 pound per capita ner day, or in close agreement with the writer’s “inter determination at Atlantic Citv. In the Back Bay a fashionable section of Boston, the amount of garbage was found to amount to 1.44 pounds per capita per day, or it varied in the same city on a three to one basis. Such are the variations in facts that, offhand, one who had not given consideration to the matter would believe in close agreement, and show the necessity of accurate local data before proceeding with incineration problems, if money is not to be wasted and reliable outcome is to be assured.
Tn order to nronerly consider the final sten in incineration, or “modern destructor practise” wherehy rubbish and ashes are incinerated, with or without garbage, it is best to first give a few facts in relation to garbage reduction. Garbage reduction in its main features contemplates “cooking” the same by steam under pressure and obtaining the resultant crease, oil. etc., and residue. the first three finding a readv market for manufacture of perfumes, soaps, glvcerine. etc., while the “tankage” residue is of value for a fertilizer base. The grease, etc., average about 3 per cent, and the tankage residue from 8 to 10 per cent, of the total garbage, the former finding a ready market at about 3 rents per pound and the fertilizer base, or residue, at from $4 per ten up; or roughly, a gross income of about $800 is obtained for the products of 100 tons of garbage. The mnnicipal plant at Columbus O., Obtains a profit of about $2 per ton, but with no allowance for fixed charges, yet operating at about one-third designed capacity of 160 tons per day. Cleveland also operates such a plant. The private plant on Barren Island. New York City, is yet in operation using city garbage, and with a payment to the company by the city for garbage disposal, the net profit is said to be in excess of 20 per cent, on the extensive investment over all fixed charges It is the largest reduction plant in the United States. In such places as Columbus, where natural gas is used to a very large extent for fuel, garbage removal is the most diffiult of the three problems, vis., garbage, rubbish and ashes, and in such instances it would seem best to adopt either an incinerator or a reduction plant instead of a destructor. Privately owned and operated reduction plants are often the source of annoyance. It frequently happens at Atlantic City, in case of a land breeze, that the major portion of the main part of the city is enveloped in smoke and vapor from the plant, that tastes and smells just as bad as it looks, and while the city pays a contractor for this delightful accommodation about $1,000 per week, many visitors, upon whom the city depends for its existence, have refrained from taking a second trip to America’s best boardwalk and beach until they can enjoy them without molestation by such a municipal donation. Such plants can be, and are. operated by municipalities without nuisance, and at a slight profit in some cases; but it is a bad business to put in private hands except under the most stringent regulations, for private plants are not, as a rule, under such good scientific management as a municipal plant is most likely to be. Other troubles arise, and it is but a short while ago since Chicago was given notice to “pay up” a delayed or disputed payment, or no more garbage would be received for treatment. Garbage reduction involves, of course, its careful separation and collection at added cost.
Modern Refuse Destructor
The name “modern destructor” conveys to many a wrong impression, for while the main intent is to destroy, it creates in profitable degree.
First—It creates general satisfaction in. a community wherever used, if the plant is properly designed and operated, for it will do all the best incinerator can do and take care of all the urban ashes besides, and do it without nuisance or objection, even though the plant is located in the heart of a resident district.
Second—It creates as a by-product a clinker free from all organic matter that is worth an average of about $1 per ton for use in fireproof constructions, road work, fire brick manufacture and many lines of cement work; also a fine fireproof dust, collected in an appropriate chamber, of great utility in finishing concrete surfaces, etc.
Third—In its operation the last vestige of fuel content in urban ashes is burned, with generation of heat sufficient in most cases to light the streets of the municipality, pump its water supply or sewage and often to permit of sale of surplus power.
Montreal’s most attractive suburb, Westmount, population 18,000. has been furnishing electric current since 1007 for street lighting and commercial service’ from current derived from its refuse destructor plant. Havana, Cuba, is about to operate the city traction system from power so derived. Halifax, N. S., has a 50 tons per day plant, which during the official test in March last developed 258 horsepower, with equivalent evaporation from and at 212 deg. per pound refuse cosumed at 1.52 pounds. The West Brighton. New York City, plant shows about 3.500 B. t. u. ner nound of refuse consumed. The Seattle, Wash., nlant, 67 tons daily capacity, uses the power obtained for a 1,000,000-gallon pump and a 250-horsepower generator, clinker, crusher, etc., and the continuous power (in boiler horsepower) developed from the burning of from 1,600 to 1,900 tons of refuse per month has been from 180 to 210 horsepower. This approximately amounts to obtaining an evaporation of one pound of water ner pound of refuse consumed. This plant has been in operation since January, 1908. The 300 tons per day Milwaukee plant shows a net annual average of 1.34 pounds of water converted into steam front and at 212 deg. F. Other plants show similar results in such a way as to depend with confidence on an average minimum evaporation of one nound of water per pound of refuse consumed in destructor, when ashes are not sifted, and from 1,5 to 2 pounds when the ashes delivered into the destructor are sifted. A thorough investigation at Newark, N. J., by competent engineers showed they could obtain 2,330 ooiler horsepower by consuming the city refuse in destiuctor plants, or more than double en ugh to light the city. The writer’s investigation at Atlantic City showed that ample power could be derived in tnis instance to either light the city as now, operate a complete high-pressure salt water system for independent tire protection and domestic service, or electrically operate the city water works pumping station some miles distant, using in each case an independent small gas producer, gas engine unit to take care of the tiuctuation in power, due to the variation in amount of refuse to be delivered at plant. The following information may be of interest and aid in a general way:
Westmount, Que.—Population, 18,000. Annual refuse amounts to an average of 3.16 tons per 1,000 people per day. It contains 05 per cent, ashes, cinders, etc.; 15 per cent, garbage, 15 per cent, rubbish. Plant, two 50 tons per day units; consume 58 pounds refuse per square foot of grate per hour; air pressure in ash pit, 175 inches (forced draft) water; vacuum (draft) at chimney base, 0.56 inch water; water evaporated per square foot of heating surface per hour, 2.7 pounds; temp, combustion, 1,700 to 2,300 deg. F.; pounds water evaporated per pound refuse delivered, 1.1 to 2 pounds, depending on amount of cinders used, instead of unsifted ashes. Power is used to, in part, operate municipal electric plant.
Newark, N. J.—Refuse amounts to 2.25 tons per 1,000 people per day.
Boston—Ashes varied from 1.9 to 5.4 and garbage from 0.44 to 1.44 tons per capita per day in sections of the city, the higher unit quantities coming from the sections of the better class of residences.
Average American city (W. F. Morse)—Refuse per 1,000 people per day, 1.3 tons.
New York—1.7 tons.
Seattle—Of the total refuse, ashes varied from 54 per cent, to 29 per cent.; manure, front 2 per cent, to 30 per cent.; garbage, from 8 per cent, to 34 per cent; rubbish, from 12 per cent to 27 per cent.
While the amount of ashes per capita per day seems to vary from about 2.2 to 5.5 pounds as an average minimum and maximum per day in pounds per capita, the use of gas for cooking is fast modifying any but new statistics, and any information as to other cities should be used simnly as a guide in connection with accurate local information when a design of plant is under consideration.
Place about 10,000 in population (recent investigation by the writer). Refuse would amount to a minimum of 20,000 pounds per day on t,he low one ton per day per 1,000 people basis; and with the low one pound of steam per one pound of refuse consumed basis, we have 20,000 pounds of steam per day; using same in efficient steam plant with superheater, as the desire is to use the same for lighting plant and pump water supply, we will operate but 11 hours per day, average, or the average time the street lights will be in service per day, or 4,000 lamp hours per year. Using 20 pounds of steam per horsepower, we can therefore obtain 90 horsepower approximately for 11 hours per day. it will take about 40 horsepower of this to take care of the 800 25 c. p. street lights or their equivalent, leaving 50 horsepower for 11 hours toward pumping the public water supply, and which we will pump in 10 hours each day to the reservoir. This means that we will pump by steam, using 50 horsepower as furnished by the destructor plant for 11 hours per day, or we will dbtain 550 horsepower hours of work in pumping water from the destructor plant in addition to power for street lighting each day. As the 800,000 gallons of water used by the city per 24 hours can be pumped with up-to-date motor or direct driven centrifugal multi-stage pump in 16 hours with 65 horsepower, or 1,040 horsepower hours work total per day, we will require 1040 — 550 = 490 horsepower hours per day in addition to that given from the destructor plant, or an average of about 31 horsepower for the 16 hours each day. This will be supplied by a 50 or 65 horsepower gas producer-gas engine power plant, using one pound of coal per horsepower hour, instead of seven pounds used in the old steam pumping plant. In case of peak load on the electric plant or a fluctuation in delivery of refuse, the gas engine plant will at once take up the deficiency in power; or in case of inspection or repair to destructor plant, and it not being used tor a day or so about once a year, either the 56 horsepower slightly overloaded or the 65 horsepower gas engine running at nearly rated horsepower 24 hours per day will take care of both the street lighting and water pumping for the city, and with tile following result, financially:
800 street lights 25 c.p. @ $20…..$16,000.00
Coal for pumping water; 1,050 tons @ $3.80 delivered ……….. 3,990.00
New municipal electric plant…. $50,000.00
Cas engine, gas producer plant… 8,000.00
Modern Destructor, 10 tons daily capacity, with building, complete. 15,000.00
Total new investment, including pumps .$73,000.00
Expenses (over present) Interest and deposits on above @ 10% $7,300.00
Maintenance . 3,650.00
Lamp renewals, 800 x 2…… 1,600.00
Two extra men over present. 1,680.00
60 tons pea coal in year in producer, @ $5, delivered. 300.00
Net profit to city. $5,470.00
Conditions will have to be unusual where a small municipality could not do as well or better than as above considered; and as the demand for light increased or the amount of refuse troubles should be augmented, the same would be met by the plan with all-around satisfaction and at the same time with increased profit to the city. While we have some 300 foreign examples of the use of power from refuse destrutor plants in operation in public utilities, the American people are just aroused from their lethargy, and soon will realize that it is time to stop throwing away the 10 per cent, to 20 per cent, fuel value in the average urban ash, garbage and refuse wagon and pay out money for coal to operate the public utilities, or too high prices for private service; when they can get rid of the public refuse destruction problem at a profit, turning present liability and cost for refuse disposal, with its accompanying features, into an asset of substantial value, and, generally speaking, at a profit amounting to about $1 per capita per annum over all carrying charges.