,transcriber ,note ,text emphasis is denoted as ,italics and ,bold4 ,whole and fractional part of numbers as #abc-d_/e4 ,farmers' ,bulletin ,no4 #abbg ,united ,states ,department of ,agriculture ,,sewage and ,,sewerage of ,,farm ,,homes ,illustration ,,disposal ,,of ,,farm ,,sewage in a clean manner is always an important problem4 ,the aims of this bulletin are twofold3 7#a7 ,to emphasize basic principles of sanitation2 7#b7 to give directions for constructing and operating home sewerage works that shall be simple1 serviceable1 and safe4 ,care in operating is absolutely necessary4 ,no installation will run itself4 ,continued neglect ends in failure of even the best designed1 best built plants4 ,if the householder is to build and neglect1 he might as well save expense and continue the earlier practice4 ,contribution from the ,bureau of ,public ,roads ,,thos4 ,h4 ,mac,d,o,n,a,l,d1 ,chief ,washington1 ,d4 ,c4 ,january1 #aibb ,,sewage ,,and ,,sewerage ,,of ,,farm ,,homes4 ,george ,m4 ,warren1 ,hydraulic ,engineer1 ,bureau of ,public ,roads4 ,,contents4 ,page4 ,introduction #c ,plans and advice #c ,sewage1 sewers1 and sewerage defined #d ,nature and quantity of sewage #d ,sewage-borne diseases and their avoidance #e ,how sewage decomposes #i ,importance of air in treatment of sewage #aj ,practical utilities #aa ,kitchen-,sink ,drainage #bf ,cesspools #bf ,septic tanks #bh ,grease traps #ec ,general procedure #ee ,,introduction4 ,the main purpose of home-sewerage works is to get rid of sewage in such way as 7#a7 to guard against the transmission of disease germs through drinking water1 flies1 or other means2 7#b7 to avoid creating nuisance4 ,what is the best method and what the best outfit are questions not to be answered offhand from afar4 ,a treatment that is a success in one location may be a failure in another4 ,in every instance decision should be based upon field data and full knowledge of the local needs and conditions4 ,an installation planned from assumed conditions may work harm4 ,the householder may be misled as to the purification and rely on a protection that is not real4 ,he may anticipate little or no odor and find a nuisance has been created4 ,,plans ,,and ,,advice4 ,though specific plans can not be sent in the absence of definite information1 and though plans and specifications can not be prepared to meet individual requirements1 the ,division of ,agricultural ,engineering1 ,bureau of ,public ,roads1 gladly gives such help as is possible4 ,to those who contemplate installing sewerage works on farms and who furnish the information outlined under the caption ,field data1 on page #eb1 plans1 advice1 or suggestions will be sent4 ,local requirements are frequently met or approximated by one of the designs on hand2 working drawings in the form of blue prints will then be furnished4 ,sometimes the designs1 slightly modified1 may suit the needs4 ,in other instances it is sufficient to send published bulletins or give written suggestions of a practical nature4 ,,sewage1 ,,sewers1 ,,and ,,sewerage ,,defined4 ,human excrements 7feces and urine7 as found in closets and privy vaults are known as night soil4 ,these wastes may be flushed away with running water1 and there may be added the discharges from washbasins1 bathtubs1 kitchen and slop sinks1 laundry trays1 washing vats1 and floor drains4 ,this refuse liquid product is sewage1 and the underground pipe which conveys it is a sewer4 ,since sewers carry foul matter they should be water-tight1 and this feature of their construction distinguishes them from drains removing relatively pure surface or ground water4 ,sewerage refers to a system of sewers1 including the pipes1 tanks1 disposal works1 and appurtenances4 ,,nature ,,and ,,quantity ,,of ,,sewage4 ,under average conditions a man discharges daily about #c-a_/b ounces of moist feces and #dj ounces of urine1 the total in a year approximating #iib pounds4#a ,feces consist largely of water and undigested or partially digested food2 by weight it is #gg4b per cent water4 #b ,urine is about #if4c per cent water4#b #a ,practical ,physiological ,chemistry1 by ,philip ,b4 ,hawk1 #aiaf1 pp4 #bba1 #cei4 #b ,agriculture1 by ,f4 ,h4 ,storer1 #ahid1 vol4 #b1 p4 #gj4 ,the excrements constitute but a small part of ordinary sewage4 ,in addition to the excrements and the daily water consumption of perhaps #dj gallons per person are many substances entering into the economy of the household1 such as grease1 fats1 milk1 bits of food1 meat1 fruit1 and vegetables1 tea and coffee grounds1 paper1 etc4 ,this complex product contains mineral1 vegetable1 and animal substances1 both dissolved and undissolved4 ,it contains dead organic matter and living organisms in the form of exceedingly minute vegetative cells 7bacteria7 and animal cells 7protozoa74 ,these low forms of life are the active agents in destroying dead organic matter4 ,the bacteria are numbered in billions and include many species1 some useful and others harmful4 ,they may be termed tiny scavengers1 which under favorable conditions multiply with great rapidity1 their useful work being the oxidizing and nitrifying of dissolved organic matter and the breaking down of complex organic solids to liquids and gases4 ,among the myriads of bacteria are many of a virulent nature4 ,these at any time may include species which are the cause of well-known infections and parasitic diseases4 ,,sewage-,,borne ,,diseases ,,and ,,their ,,avoidance4 ,any spittoon1 slop pail1 sink drain1 urinal1 privy1 cesspool1 sewage tank1 or sewage distribution field is a potential danger4 ,a bit of spit1 urine1 or feces the size of a pin head may contain many hundred germs1 all invisible to the naked eye and each one capable of producing disease4 ,these discharges should be kept away from the food and drink of man and animals4 ,from specific germs that may be carried in sewage at any time there may result typhoid fever1 tuberculosis1 cholera1 dysentery1 diarrhea1 and other dangerous ailments1 and it is probable that other maladies may be traced to human waste4 ,from certain animal parasites or their eggs that may be carried in sewage there may result intestinal worms1 of which the more common are the hookworm1 roundworm1 whipworm1 eelworm1 tapeworm1 and seat worm4 ,sewage1 drainage1 or other impure water may contain also the causative agents of numerous ailments common to live stock1 such as tuberculosis1 foot-and-mouth disease1 hog cholera1 anthrax1 glanders1 and stomach and intestinal worms4 ,disease germs are carried by many agencies and unsuspectingly received by devious routes into the human body4 ,infection may come from the swirling dust of the railway roadbed1 from contact with transitory or chronic carriers of disease1 from green truck grown in gardens fertilized with night soil or sewage1 from food prepared or touched by unclean hands or visited by flies or vermin1 from milk handled by sick or careless dairymen1 from milk cans and utensils washed with contaminated water1 or from cisterns1 wells1 springs1 reservoirs1 irrigation ditches1 brooks1 or lakes receiving the surface wash or the underground drainage from sewage-polluted soil4 ,many recorded examples show with certainty how typhoid fever and other diseases have been transmitted4 ,a few indicating the responsibilities and duties of people who live in the country are cited here4 ,in ,august1 #ahhi1 a sister and two brothers aged #ah1 #ba1 and #bc years1 respectively1 and all apparently in robust health dwelt together in a rural village in ,columbiana ,county1 ,ohio4 ,typhoid fever in particularly virulent form developed after use of drinking water from a badly polluted surface source4 ,the deaths of all three occurred within a space of #aj days4 ,in ,september and ,october1 #ahii1 #fc cases of typhoid fever1 resulting in #e deaths1 occurred at the ,northampton 7,mass47 insane hospital4 ,this epidemic was conclusively traced to celery1 which was eaten freely in ,august and was grown and banked in a plot that had been fertilized in the late winter or early spring with the solid residue and scrapings from a sewage filter bed situated on the hospital grounds4 ,some years ago ,dr4 ,w4 ,w4 ,skinner1 ,bureau of ,chemistry1 ,department of ,agriculture1 investigated the cause of an outbreak of typhoid fever in southwest ,virginia4 ,a small stream meandered through a narrow valley in which five #aj-;inch wells about #dej feet deep had been drilled in limestone formation4 ,the wells were from #ej to #djj feet from the stream1 from which1 it was suspected1 pollution was reaching the wells4 ,in a pool in the stream bed approximately one-fourth mile above the wells several hundred pounds of common salt were dissolved4 ,four of the wells were cut off from the pump and the fifth was subjected to heavy pumping4 ,the water discharged by the pump was examined at #ae-minute intervals and its salt content determined over a considerable period of time4 ,after the lapse of several #ae-minute intervals the salt began to rise and continued to rise until the maximum was approximately seven times that at the beginning of the test1 thus proving the facility with which pollution may pass a long distance underground and reach deep wells4 ,probably no epidemic in ,american history better illustrates the dire results that may follow one thoughtless act than the outbreak of typhoid fever at ,plymouth1 ,pa41 in #ahhe4 ,in ,january and ,february of that year the night discharges of one typhoid fever patient were thrown out upon the snow near his home4 ,these1 carried by spring thaws into the public water supply1 caused an epidemic running from ,april to ,september4 ,in a total population of about #h1jjj1 #a1ajd persons were attacked by the disease and #aad died4 ,like plants and animals1 disease germs vary in their powers of resistance4 ,some are hardy1 others succumb easily4 ,outside the body most of them probably die in a few days or weeks4 ,it is never certain when such germs may not lodge where the immediate surroundings are favorable to their life and reproduction4 ,milk is one of the common substances in which germs multiply rapidly4 ,the experience at ,northampton shows that typhoid-fever germs may survive several months in garden soil4 ,laboratory tests by the ,united ,states ,public ,health ,service showed that typhoid-fever germs had not all succumbed after being frozen in cream #gd days4 7,public ,health ,reports1 ,feb4 #h1 #aiah1 pp4 #afc-aff47 ,ravenel kept the spores of anthrax immersed for #bdd days in the strongest tanning fluids without perceptible change in their vitality or virulence4 7,annual ,report1 ,state ,department of ,health1 ,mass41 #aiaf1 p4 #did47 ,unsafe practices4--,upon thousands of small farms there are no privies and excretions are deposited carelessly about the premises4 ,a place of this character is shown in figure #a4 ,upon thousands of other farms the privy is so filthy and neglected that hired men and visitors seek near-by sheds1 fields1 and woods4 ,a privy of this character is shown in figure #b4 ,these practices and conditions exist in every section of the country4 ,they should be abolished4 ,deserving of severe censure is the old custom of conveying excrements or sewage into abandoned wells or some convenient stream4 ,such a practice is indecent and unsafe4 ,it is unnecessary and is contrary to the laws of most of the ,states4 ,likewise dangerous and even more disgusting is the old custom of using human excrement or sewage for the fertilization of truck land4 ,under no circumstances should such wastes be used on land devoted to celery1 lettuce1 radishes1 cucumbers1 cabbages1 tomatoes1 melons1 or other vegetables1 berries1 or low-growing fruits that are eaten raw4 ,disease germs or particles of soil containing such germs may adhere to the skins of vegetables or fruits and infect the eater4 ,upon farms it is necessary to dispose of excretal wastes at no great distance from the dwelling4 ,the ability and likelihood of flies carrying disease germs direct to the dinner table1 kitchen1 or pantry are well known4 ,vermin1 household pets1 poultry1 and live stock may spread such germs4 ,for these reasons1 and also on the score of odor1 farm sewage never should be exposed4 ,illustration3 ,,bpr-,,re #acha ,fig4 #a4--,one of many farms lacking the simplest sanitary convenience4 ,important safety measure4--,the farmer can do no other one thing so vital to his own and the public health as to make sure of the continued purity of the farm water supply4 ,investigations indicate that about three out of four shallow wells are polluted badly4 ,wells and springs are fed by ground water1 which is merely natural drainage4 ,drainage water usually moves with the slope of the land4 ,it always dissolves part of the mineral1 vegetable1 and animal matter of the ground over or through which it moves4 ,in this way impurities are carried into the ground water and may reach distant wells or springs4 ,the great safeguards are clean ground and wide separation of the well from probable channels of impure drainage water4 ,it is not enough that a well or spring is #ej or #aej feet from a source of filth or that it is on higher ground4 ,given porous ground1 a seamy ledge1 or long-continued pollution of one plat of land1 the zone of contamination is likely to extend long distances1 particularly in downhill directions or when the water is low through drought or heavy pumping4 ,only when the surface of the water in a well or spring is at a higher level at all times than any near-by source of filth is there assurance of safety from impure seepage4 ,some of the foregoing facts are shown diagrammatically in figure #c4 ,figure #d is typical of those insanitary1 poorly drained barnyards that are almost certain to work injury to wells situated in or near them4 ,figure #e illustrates poor relative location of privy1 cesspool1 and well4 ,figure #f is a typical example of a nuisance4 ,accumulations of filth result in objectionable odor and noxious drainage4 ,illustration3 ,,bpr-,,re #achhc ,fig4 #b4--,the rickety1 uncomfortable1 unspeakably foul1 dangerous ground privy4 ,neglected by the owner1 shunned by the hired man1 avoided by the guest1 who1 in preference1 goes to near-by fields or woods1 polluter of wells1 meeting place of house flies and disease germs1 privies of this character abide only because of man's indifference4 ,sewage or impure drainage water should never be discharged into or upon ground draining toward a well1 spring1 or other source of water supply4 ,neither should such wastes be discharged into ',openings in rock1 an abandoned well1 nor a hole1 cesspool1 vault1 or tank so located that pollution can escape into water-bearing earth or rock4 ,whatever the system of sewage disposal1 it should be entirely and widely separated from the water supply4 ,further information on locating and constructing wells is given in ,farmers' ,bulletin #ida1 ,water ,systems for ,farm ,homes1 copies of which may be had upon request to the ,division of ,publications1 ,department of ,agriculture4 ,enough has been said to bring home to the reader these vital points3 #a4 ,never allow the farm sewage or excrements1 even in minutest quantity1 to reach the food or water of man or live stock4 #b4 ,never expose such wastes so that they can be visited by flies or other carriers of disease germs4 #c4 ,never use such wastes to fertilize or irrigate vegetable gardens4 #d4 ,never discharge or throw such wastes into a stream1 pond1 or abandoned well1 nor into a gutter1 ditch1 or tile drainage system1 which naturally must have outlet in some watercourse4 ,illustration3 ,fig4 #c4--;,how an apparently good well may draw foul drainage4 ,arrows show direction of ground water movement4 ,a-,a1 ,usual water table 7surface of free water in the ground72 ,b-,b1 water table lowered by drought and pumping from well ,d2 ,c-,c1 water table further lowered by drought and heavy pumping2 ,e-,f1 level line from surface of sewage in cesspool4 ,well ,d is safe until the water table is lowered to ,e2 further lowering draws drainage from the cesspool and1 with the water table at ,c-,c1 from the barn4 ,the location of well ,g renders it unsafe always4 ,illustration3 ,,bpr-,,re #ache ,fig4 #d4--;,an insanitary1 poorly drained barnyard4 7,board of ,health1 ,milwaukee47 ,liquid manure or other foul drainage is sure to leach into wells situated in or near barnyards of this character4 ,,how ,,sewage ,,decomposes4 ,when a bottle of fresh sewage is kept in a warm room changes occur in the appearance and nature of the liquid4 ,at first it is light in appearance and its odor is slight4 ,it is well supplied with oxygen1 since this gas is always found in waters exposed to the atmosphere4 ,in a few hours the solids in the sewage separate mechanically according to their relative weights2 sediment collects at the bottom1 and a greasy film covers the surface4 ,in a day's time there is an enormous development of bacteria1 which obtain their food supply from the dissolved carbonaceous and nitrogenous matter4 ,as long as free oxygen is present this action is spoken of as arobic decomposition4 ,there is a gradual increase in the amount of ammonia and a decrease of free oxygen1 the latter going to support bacterial life4 ,when the ammonia is near the maximum and the free oxygen is exhausted the sewage is said to be stale4 ,following exhaustion of the oxygen supply1 bacterial life continues profuse1 but it gradually diminishes as a result of reduction of its food supply and the poisonous effects of its own wastes4 ,in the absence of oxygen the bacterial action is spoken of as anarobic decomposition4 ,the sewage turns darker and becomes more offensive4 ,suspended and settled organic substances break apart or liquefy later1 and various foul-smelling gases are liberated4 ,sewage in this condition is known as septic and the putrefaction that has taken place is called septicization4 ,the odor eventually disappears1 and a dark1 insoluble1 mosslike substance remains as a deposit4 ,complete reduction of this deposit may require many years4 ,illustration3 ,,bpr-,,re #achh ,fig4 #e4--,poor relative locations of privy1 cesspool1 and well4 7,state ,department of ,health1 ,massachusetts47 ,never allow privy1 cesspool1 or sink drainage to escape ,into the plot of ground from which the water supply is taken4 ,,importance ,,of ,,air ,,in ,,treatment ,,of ,,sewage4 ,decomposition of organic matter by bacterial agency is not a complete method of treating sewage1 as will be shown later under ,septic tanks4 ,it is sufficient to observe here that in all practical methods of treatment aeration plays a vital part4 ,the air or the sewage1 or both1 must be in a finely divided state1 as when sewage percolates through the interstices of a porous1 air-filled soil4 ,the principle involved was clearly stated #cj years ago by ,hiram ,f4 ,mills1 a member of the ,massachusetts ,state ,board of ,health4 ,in discussing the intermittent filtration of sewage through gravel stones too coarse to arrest even the coarsest particles in the sewage ,mr4 ,mills said3 ,the slow movement of the sewage in thin films over the surface of the stones1 with air in contact1 caused a removal for some months of #ig per cent of the organic nitrogenous matter1 as well as #ii per cent of the bacteria4 ,illustration3 ,,bpr-,,re #achg ,fig4 #f4--;,a typical nuisance4 7,board of ,health1 ,milwaukee47 ,a yard like this is an eyesore1 a fire menace1 a breeding place for mosquitoes and vermin1 a refuge for rats and mice1 a source of noxious odors and foul drainage1 and a violation of every sanitation code4 ,,practical ,,utilities4 ,previous discussion has dealt largely with basic principles of sanitation4 ,the construction and operation of simple utilities embodying some of these principles are discussed in the following order3 7#a7 ,privies for excrements only2 7#b7 works for handling wastes where a supply of water is available for flushing4 ,,pit ,,privy4 ,figure #g shows a portable pit privy suitable for places of the character of that shown in figure #a1 where land is abundant and cheap1 and in such localities has proved practical4 ,it provides1 at minimum cost and with least attention1 a fixed place for depositing excretions where the filth can not be tracked by man1 spread by animals1 reached by flies1 nor washed by rain4 ,illustration3 ,fig4 #g4--,portable pit privy4 ,for use where land is abundant and cheap1 but unless handled with judgment can not be regarded as safe4 ,the privy is mounted on runners for convenience in moving to new locations4 ,the privy is light and inexpensive and is placed over a pit in the ground4 ,when the pit becomes one-half or two-thirds full the privy is drawn or carried to a new location4 ,the pit should be shallow1 preferably not over #b-a_/b feet in depth1 and never should be located in wet ground or rock formation or where the surface or the strata slope toward a well1 spring1 or other source of domestic water supply4 ,besides standing on lower ground the pit should never be within #bjj feet of a well or spring4 ,since dryness in the pit is essential1 the ground should be raised slightly and #aj or #ab inches of earth should be banked and compacted against all sides to shed rain water4 ,the banking also serves to exclude flies4 ,if the soil is sandy or gravelly1 the pit should be lined with boards or pales to prevent caving4 ,the privy should be boarded closely and should be provided with screened openings for ventilation and light4 ,the screens may consist of standard galvanized or black enameled wire cloth having #ad squares to the inch4 ,the whole seat should be easily removable for cleaning4 ,a little loose absorbent soil should be added daily to the accumulation in the pit1 and when a pit is abandoned it should be filled immediately with dry earth mounded to shed water4 ,a pit privy for use in field work1 consisting of a framework of #a_/b-;inch iron pipe for corner posts connected at the top with #a_/d-;inch iron rods bent at the ends to right angles and hung with curtains of unbleached muslin1 is described in ,public ,health ,report of the ,united ,states ,public ,health ,service1 ,july #bf1 #aiah4 ,a pit privy1 even if moved often1 can not be regarded as safe4 ,the danger is that accumulations of waste may overtax the purifying capacity of the soil and the leachings reach wells or springs4 ,sloping ground is not a guaranty of safety2 the great safeguard lies in locating the privy a long distance from the water supply and as far below it as possible4 ,,sanitary ,,privy4 ,the next step in evolution is the sanitary privy4 ,its construction must be such that it is practically impossible for filth or germs to be spread above ground1 to escape by percolation underground1 or to be accessible to flies1 vermin1 chickens1 or animals4 ,furthermore1 it must be cared for in a cleanly manner1 else it ceases to be sanitary4 ,to secure these desirable ends sanitarians have devised numerous types of tight-receptacle privy4 ,considering the small cost and the proved value of some of these types1 it is to be regretted that few are seen on ,american farms4 ,the container for a sanitary privy may be small--for example1 a galvanized-iron pail or garbage can1 to be removed from time to time by hand2 it may be large1 as a barrel or a metal tank mounted for moving2 or it may be a stationary underground metal tank or masonry vault4 ,the essential requirement in the receptacle is permanent water-tightness to prevent pollution of soils and wells4 ,wooden pails or boxes1 which warp and leak1 should not be used4 ,where a vault is used it should be shallow to facilitate emptying and cleaning4 ,moreover1 if the receptacle should leak it is better that the escape of liquid should be in the top soil1 where air and bacterial life are most abundant4 ,sanitary privies are classified according to the method used in treating the excretions1 as dry earth1 chemical1 liquefying4 ,,dry-,,earth ,,privy4 ,pail type4--,a very serviceable pail privy is shown in figures #h and #i4 ,the method of ventilation is an adaptation of a system that has proved very effective in barns and other buildings here and abroad4 ,a flue with a clear opening of #af square inches rises from the rear of the seat and terminates above the ridge-pole in a cowl or small roofed housing4 ,attached to this flue is a short auxiliary duct1 #d by #ae inches1 for removing foul air from the top of the privy4 ,in its upper portion on the long sides the cowl is open1 allowing free movement of air across the top of the flue4 ,in addition the long sides of the cowl are open below next to the roof4 ,these two openings1 with the connecting vertical air passages1 permit free upward movement of air through the cowl1 as indicated by the arrows4 ,the combined effect is to create draft from beneath the seat and from the top of the privy4 ,the ventilating flue is #b by #h inches at the seat and #d by #d inches #e feet above4 ,the taper slightly increases the labor of making the flue1 but permits a #b-;inch reduction in the length of the building4 ,illustration3 ,fig4 #h4--,pail privy4 ,well constructed1 ventilated1 and screened4 ,with proper care is sanitary and unobjectionable4 ,illustration3 ,fig4 #i4--;,full privy4 ,in plan the privy is #d by #d-a_/b feet4 ,the sills are secured to durable posts set about #d feet in the ground4 ,the boarding is tight1 and all vents and windows are screened to exclude insects4 ,the screens may be the same as for pit privies or1 if a more lasting material is desired1 bronze or copper screening of #ad squares to the inch may be used4 ,the entire seat is hinged1 thus permitting removal of the receptacle and facilitating cleaning and washing the underside of the seat and the destruction of spiders and other insects which thrive in dark1 unclean places4 ,the receptacle is a heavy galvanized-iron garbage can4 ,heavy brown-paper bags for lining the can may be had at slight cost1 and their use helps to keep the can clean and facilitates emptying4 ,painting with black asphaltum serves a similar purpose and protects the can from rust4 ,if the contents are frozen1 a little heat releases them4 ,of nonfreezing mixtures a strong brine made with common salt or calcium chloride is effective4 ,two and one-half to #c pounds of either thoroughly dissolved in a gallon of water lowers the freezing point of the mixture to about zero4 ,denatured alcohol or wood alcohol in a #be per cent solution has a like low freezing point and the additional merit of being noncorrosive of metals4 ,the can should be emptied frequently and the contents completely buried in a thin layer by a plow or in a shallow hand-dug trench at a point below and remote from wells and springs4 ,wherever intestinal disease exists the contents of the can should be destroyed by burning or made sterile before burial by boiling or by incorporation with a strong chemical disinfectant4 ,illustration3 ,,bpr-,,re #achb ,fig4 #aj4--;,a well-ventilated privy in ,montana4 ,a privy ventilated in the manner before described is shown in figure #aj4 ,the cowl1 however1 is open on four sides instead of two sides as shown in figures #h and #i4 ,the working drawings 7fig4 #h and #i7 show that the construction of a privy of the kind is not difficult4 ,figure #aa gives three suggestions whereby a privy may be conveniently located and the approach screened or partially hidden by latticework1 vines1 or shrubbery4 ,vault type4--,a primitive and yet serviceable three-seat dry-earth privy of the vault type is shown in figure #ab4 ,this privy was constructed in #ahag upon a farm at ,westboro1 ,mass4 ,the vault1 made of bricks1 was #f feet long by #e feet wide1 and the bottom was #a foot below the surface of the ground4 ,the brickwork was laid in mortar1 and the part below the ground surface was plastered on the inside4 ,the outside of the vault was exposed to light and air on all four sides4 ,across the long side of the vault in the rear was a door swinging upward through which the night soil was removed two or three times a year1 usually in the spring1 summer1 and fall1 and hauled to a near-by field1 where it was deposited in a furrow1 just ahead of the plow4 ,especial attention is called to the shallowness of the vault and the lightened labor of cleaning it out4 ,the swinging door at the rear facilitated the sprinkling of dry soil or ashes over the contents of the vault1 thus avoiding the necessity of carrying dirt and dust into the building and dust settling upon the seat4 ,this privy was in use for nearly #ajj years without renewal or repairs4 ,when last seen the original seat1 which always was kept painted1 showed no signs of decay4 ,modern methods would call for a concrete vault of guaranteed water-tightness1#c proper ventilation and screening1 and hinging the seat4 #c ,directions for mixing and placing concrete to secure water-tightness are contained in an article entitled ,securing a dry cellar1 ,u4 ,s4 ,department of ,agriculture ,yearbook1 #aiai2 published also as ,yearbook ,separate ,no4 #hbd1 and obtainable for #aj cents from the ,superintendent of ,documents1 ,government ,printing ,office1 ,washington1 ,d4 ,c4 ,illustration3 ,fig4 #aa4--,screening the approach to a privy4 ,a1 ,raised platform with lattice sides1 suitable for short distances1 convenient and easily cleared of snow2 ,b1 walk hidden by lattice work2 ,c1 walk enclosed by an arbor4 ,illustration3 ,fig4 #ab4--;,a primitive vault privy in ,massachusetts4 ,note the tight1 shallow1 easily cleaned vault4 ,a1 ,brick vault #e by #f feet1 bottom about #a foot in the ground2 ,b1 water-tight plastering2 ,c1 rowlock course of brick2 ,d1 door hinged at top2 ,e1 door button2 ,f1 three-pane window hinged at top2 ,g1 passageway4 ,working drawings for a very convenient well-built two-seat vault privy are reproduced in figures #ac and #ad4 ,the essential features are shown in sufficient detail to require little explanation4 ,with concrete mixtures of #a3b3c 7#a volume cement1 #b volumes sand1 #c volumes stone7 for the vault and #a3b3d for the posts there will be required a total of about #b cubic yards of concrete1 taking #c-a_/b barrels of cement1 #a cubic yard of sand1 and #a-a_/b cubic yards of broken stone or screened gravel4 ,the stone or gravel should not exceed #a inch in diameter1 except that a few cobblestones may be embedded where the vault wall is thickest1 thus effecting a slight saving of materials4 ,,chemical ,,closet4 ,a type of sanitary privy in which the excrements are received directly into a water-tight receptacle containing chemical disinfectant is meeting with considerable favor for camps1 parks1 rural cottages1 schools1 hotels1 and railway stations4 ,these chemical closets1#d as they are called1 are made in different forms and are known by various trade names4 ,in the simplest form a sheet-metal receptacle is concealed in a small metal or wooden cabinet1 and the closet is operated usually in much the same manner as the ordinary pail privy4 ,these closets are very simple and compact1 of good appearance1 and easy to install or move from place to place4 ,in another type1 known as the chemical tank closet1 the receptacle is a steel tank fixed in position underground or in a basement4 ,the tank has a capacity of about #abe gallons per seat1 is provided with a hand-operated agitator to secure thorough mixing of the chemical and the excretions1 and the contents are bailed1 pumped1 or drained out from time to time4 #d ,among publications on chemical closets are the following3 ,chemical ,closets1 ,reprint ,no4 #djd from the ,public ,health ,reports1 ,u4 ,s4 ,public ,health ,service1 ,june #bi1 #aiag1 pp4 #ajag-ajbj2 ,the ,chemical ,closet1 ,engineering ,bulletin ,no4 #e1 ,mich4 ,state ,board of ,health1 ,october1 #aiaf2 ,health ,bulletin2 ,va4 ,department of ,health1 ,march1 #aiag1 pp4 #bad-bai4 ,illustration3 ,fig4 #ac4--,two-seat vault privy4 ,chemical closets1 like every form of privy1 should be well installed1 cleanly operated1 and frequently emptied1 and the wastes should receive safe burial4 ,with exception of frequency of emptying1 the same can be said of chemical tank closets4 ,with both forms of closet thorough ventilation or draft is essential1 and this is obtained usually by connecting the closet vent pipe to a chimney flue or extending it well above the ridge-pole of the building4 ,the contents of the container should always be submerged and very low temperatures guarded against4 ,illustration3 ,fig4 #ad4--,two-seat vault privy4 ,note the shallow1 water-tight1 easily cleaned concrete vault4 ,as to the germicidal results obtained in chemical closets1 few data are available4 ,a disinfecting compound may not sterilize more than a thin surface layer of the solid matter deposited4 ,experiments by ,dr4 ,alvah ,h4 ,doty with various agents recommended and widely used for the bedside sterilization of feces showed that at the end of #bj hours of exposure to the disinfectant but one-eighth of an inch of the fecal mass was disinfected4#e ,plainly1 then1 to destroy all bacterial and parasitic life in chemical closets three things are necessary3 7#a7 ,a very powerful agent2 7#b7 permeation of the fecal mass by the agent2 7#c7 retention of its strength and potency until permeation is complete4 ,the compounds or mixtures commonly used in chemical closets are of two general kinds3 ,first1 those in which some coal-tar product or other oily disinfectant is used to destroy germs and deodorize1 leaving the solids little changed in form2 second1 those of the caustic class that dissolve the solids1 which1 if of sufficient strength and permeating every portion1 should destroy most if not all bacterial life4 ,not infrequently the chemical solution is intended to accomplish disinfection1 deodorization1 and reduction to a liquid or semiliquid state4 #e ,annual ,report1 ,mass4 ,state ,board of ,health1 #aiad1 p4 #gbg4 ,illustration3 ,fig4 #ae4--;,chemical closet4 ,a1 ,water-tight sheet-metal container2 ,b1 metal or wooden cabinet2 ,c1 wooden or composition seat ring2 ,d1 hinged cover2 ,e1 #c or #d inch ventilating flue extending #ah inches above roof or to a chimney2 ,f1 air inlets4 ,illustration3 ,fig4 #af4--;,chemical tank closet4 ,a1 ,tank1 #b feet #c inches by #d feet #b inches1 #e_/fd-;inch iron1 seams welded1 capacity #abe gallons2 ,b1 #ad-;inch covered opening for recharging and emptying tank2 ,c1 #ab-;inch galvanized sheet-metal tube2 ,d1 #d-;inch sheet-metal ventilating pipe extending above ridge-pole or to a chimney2 ,e1 agitator or paddle4 ,a simple type of chemical closet is shown in figure #ae1 and the essential features are indicated in the notation4 ,these closets with vent pipe and appurtenances1 ready for setting up1 retail for #bj and upward4 ,a chemical tank closet1 retailing for about #hj per seat1 is shown in figure #af4 ,the ,department of ,agriculture occasionally receives complaints from people who have installed chemical closets1 usually on the score of odors or the cost of chemicals4 ,,liquefying ,,closet4 ,another type of sanitary privy1 known as a liquefying closet1 makes use of bacterial action as an aid to disposal4 ,the excretions are deposited in a tight receptacle containing water1 where fermentation and decomposition reduce a large part of the organic solids to liquid and gaseous forms4 ,much of the liquid evaporates and the gases diffuse1 so that the volume of sewage is reduced materially4 ,more or less insoluble and undigested residue1 known as sludge1 gradually accumulates at the bottom of the receptacle1 which from time to time must be cleaned out4 ,disposal of the partially clarified liquid and the sludge1 however1 involves much less labor than would be needed to handle the untreated excrements4 ,liquefying closets have been used many years with fair satisfaction4 ,the receptacle sometimes is a tight brick vault1 but more frequently a barrel or hogshead with one end nearly flush with the ground4 ,over this is mounted the seat1 sometimes with iron bars beneath to prevent accident to small children1 and the whole is inclosed in a small frame house4 ,the vault usually is bailed or pumped out two or three times a year4 ,upon farms where slope1 soil1 and drainage conditions are favorable the effluent from liquefying closets may be distributed and aerated by means of drain tile laid in the top soil or in shallow beds filled with cinders1 coke1 gravel1 or stone4 ,figure #ag shows a simple one-chamber liquefying closet with shallow distribution of the effluent in a stone-filled trench4 ,the vault or tank consists of vitrified sewer pipe1 a simple and cheap construction4 ,where a larger vault is required concrete or brick may be used1 the usual capacity being #ab or #ac gallons to a person4 ,illustration3 ,fig4 #ag4--,liquefying closet4 ,a1 ,excavation about #c feet #c inches in diameter2 ,b1 #c-;foot length vitrified ,y branch1 #bd by #d inches2 ,c1 #b-;foot length of #bd-;inch hard burned drain tile or vitrified sewer pipe2 ,d1 #d by #d inch ,y branch2 ,e1 #a-;foot length of #d-;inch cast-iron soil pipe2 ,f1 concrete bottom making water-tight seal2 ,g1 joints made water tight by use of a strand of jute or oakum and rich ,portland cement mortar or hot bituminous jointing compound2 ,h2 submerged outlet2 ,i1 removable strainer with openings #a_/d inch or larger2 ,j1 #d-;inch removable plug2 ,k1 #d-;inch drain tile laid on good slope in trench about #ae inches deep1 ends of tile butting1 joints covered with strips of tarred paper extending three-fourths of the way around the tile2 ,l1 removable seat supported by end cleats2 ,m1 #d by #d inch ventilating flue1 bottom portion removable2 ,n1 hinged door to facilitate bailing out sludge4 ,faults in liquefying closets are objectionable odor1 clogging of the screen over the outlet1 or insufficient water in the vault to insure proper bacterial action4 ,a ventilating pipe should be provided extending from beneath the seat to above the roof4 ,the outlet pipe should not be less than #d inches in diameter1 and the mesh of the screen should not be less than one-fourth inch4 ,the contents of the vault should be diluted with water at intervals1 depending upon the number of persons using the closet and the rapidity of evaporation4 ,dilution may be effected by pouring in #a or #b gallons with a pail1 or a small pipe may be led from the eaves trough of the closet to the vault4 ,the effluent may be light colored and apparently inoffensive1 but it still is sewage1 and therefore the distributing tile never should be laid in the vicinity of a well or spring4 ,,disinfectants ,,and ,,deodorants4 ,disinfection is the destruction of disease germs4 ,sterilization is the destruction of all germs or bacteria1 both the harmful and the useful4 ,antisepsis is the checking or restraining of bacterial growth4 ,deodorization is the destruction of odor4 ,unfortunately in practice none of these processes may be complete4 ,the agent may be of inferior quality1 may have lost its potency1 or may not reach all parts of the mass treated4 ,a disinfectant or germicide is an agent capable of destroying disease germs2 an antiseptic is an agent merely capable of arresting bacterial growth1 and it may be a dilute disinfectant2 a deodorant is an agent that tends to destroy odor1 but whose action may consist in absorbing odor or in masking the original odor with another more agreeable one4#f #f ,those desiring more explicit information on disinfectants and the principles of disinfection are referred to ,u4 ,s4 ,department of ,agriculture ,farmers' ,bulletins #ibf1 ,some ,common ,disinfectants1 and #ied1 ,the ,disinfection of ,stables1 and to publications of the ,u4 ,s4 ,public ,health ,service4 ,of active disinfecting agents1 heat from fire1 live steam1 or boiling water is the surest4 ,the heat generated by the slaking of quicklime has proved effective with small quantities of excreta4 ,results of tests by the ,massachusetts ,state ,board of ,health#g show that the preferable method consists in adding sufficient hot water 7#abj to #adj ,f47 to cover the excrement in the receptacle1 then adding small pieces of fresh strong quicklime in amount equal to about one-third of the bulk of water and excrement combined1 covering the receptacle1 and allowing it to stand #a-a_/b hours or longer4 #g ,annual ,report1 ,mass4 ,state ,board of ,health1 #aiad1 pp4 #gbg-gbi4 ,among chemical disinfectants a strong solution of sodium hydroxide 7caustic soda7 or potassium hydroxide 7caustic potash1 lye7 is very effective and is useful in dissolving grease and other organic substances4 ,both chemicals are costly1 but caustic soda is less expensive than caustic potash and constitutes most of the ordinary commercial lyes4 ,chlorinated lime 7chloride of lime1 bleaching powder7 either in solution or in powdered form is valuable4 ,for the disinfection of stools of typhoid-fever patients the ,virginia ,state ,board of ,health#h recommends thoroughly dissolving #a_/b pound of best chloride of lime in #a gallon of water and allowing the solution to cover the feces for at least #a hour4 ,the solution should be kept in well-stoppered bottles and used promptly1 certainly within #b or #c days4 ,copper sulphate 7blue vitriol1 bluestone7 in a #e per cent solution 7#a pound in #b-a_/b gallons of water7 is a good but rather costly disinfectant4 ,none of the formulas here given is to be construed as fixed and precise4 ,conditions may vary the proportions1 as they always will vary the results4 ,the reader should remember that few1 if any1 chemical disinfectants can be expected fully to disinfect or sterilize large masses of excrement unless the agent is used repeatedly and in liberal quantities or mechanical means are employed to secure thorough incorporation4 #h ,health ,bulletin1 ,va4 ,state ,board of ,health1 ,june1 #aiag1 pp4 #bgg-bhj4 ,among deodorants some of the drying powders mentioned below possess more or less disinfecting power4 ,chloride of lime1 though giving off an unpleasant odor of chlorine1 is employed extensively4 ,lime in the form of either quicklime or milk of lime 7whitewash7 is much used and is an active disinfectant4 ,to prepare milk of lime a small quantity of water is slowly added to good fresh quicklime in lumps4 ,as soon as the quicklime is slaked a quantity of water1 about four times the quantity of lime1 is added and stirred thoroughly4 ,when used as a whitewash the milk of lime is thinned as desired with water and kept well stirred4 ,liberal use of milk of lime in a vault or cesspool1 though it may not disinfect the contents1 is of use in checking bacterial growth and abating odor4 ,to give the best results it should be used frequently1 beginning when the vault or cesspool is empty4 ,iron sulphate 7green vitriol1 copperas7 because of its affinity for ammonia and sulphides is used as a temporary deodorizer in vaults1 cesspools1 and drains2 #a pound dissolved in #d gallons of water makes a solution of suitable strength4 ,,prevention ,,of ,,privy ,,nuisance4 ,the following is a summary of simple measures for preventing a privy from becoming a nuisance3 #a4 ,locate the privy inconspicuously and detached from the dwelling4 #b4 ,make the receptacle or vault small1 shallow1 easy of access1 and water-tight4 #c4 ,clean out the vault often4 ,do not wait until excrement has accumulated and decomposition is sufficiently advanced to cause strong and foul odors4 #d4 ,sprinkle into the vault daily loose dry soil1 ashes1 lime1 sawdust1 ground gypsum 7land plaster71 or powdered peat or charcoal4 ,these will absorb liquid and odor1 though they may not destroy disease germs4 #e4 ,make the privy house rain-proof2 ventilate it thoroughly1 and screen all openings4 ,,objection ,,to ,,privies4 ,all the methods of waste disposal heretofore described are open to the following objections3 #a4 ,they do not take care of kitchen slops and liquid wastes incipient to a pressure water system4 #b4 ,they retain filth for a considerable period of time with probability of odors and liability of transmission of disease germs4 #c4 ,they require more personal attention and care than people generally are willing to give4 ,by far the most satisfactory method yet devised of caring for sewage calls for a supply of water and the flushing away of all wastes as soon as created through a water-tight sewer to a place where they undergo treatment and final disposal4 ,,kitchen-,,sink ,,drainage4 ,a necessity in every dwelling is effective disposal of the kitchen-sink slops4 ,this necessity ordinarily arises long before the farm home is supplied with water under pressure and the conveniences that go with it4 ,hence the first call for information on sewage disposal is likely to relate merely to sink drainage4 ,this waste water though it may not be as dangerous to health as sewage containing human excrements is still a menace to the farm well and capable of creating disagreeable odor4 ,the usual method of disposing of sink slops is to allow them to dribble on or beneath the surface of the ground close to the house4 ,such drainage should be taken in a water-tight carrier at least #ajj feet downhill from the well and discharged below the surface of the ground4 ,every sink should be provided with a suitable screen to keep all large particles out of the waste pipe4 ,an approved form of sink strainer consists of a brass plate bolted in position over the outlet and having at least #cg perforations not larger than one-fourth inch in diameter4 ,provided a sink is thus equipped and is given proper care and the land has fair slope and drainage1 the waste water may be conducted away through a water-tight sewer and distributed in the soil by means of a short blind drain4 ,the blind drain may be conveniently made of drain tile in the manner shown in figure #ag4 ,a simple installation1 consisting of a kitchen sink and pump and means of disposal as described1 is shown in figure #ah4 ,,cesspools4 ,where farms have water under pressure an open or leaching cesspool is a common method of disposing of the sewage4 ,ordinary cesspools are circular excavations in the ground1 lined with stone or brick laid without mortar4 ,they vary from #e to #aj feet in diameter and from #g to #ab feet in depth4 ,sometimes the top is arched and capped at the ground surf ace by a cover of wood1 stone1 or cast iron4 ,at other times the walls are carried straight up and boards or planks are laid1 across for a cover1 and the entire structure is hidden with a hedge or shrubbery4 ,illustration3 ,fig4 #ah4--;,how to waste kitchen-sink drainage4 ,a1 ,sink2 ,b1 waste pipe2 ,c1 trap2 ,d1 clean-out2 ,e1 box filled with hay1 straw1 sawdust1 excelsior1 coke1 or other insulating material2 ,f1 #d-;inch vitrified sewer-pipe1 hubs uphill1 and joints made water tight for at least #ajj feet downhill from a well2 ,g1 #d-;inch vitrified sewer pipe1 hubs downhill1 joints slightly open1 laid in an #ah-;inch bed of coarse sand1 gravel1 stone1 broken brick1 slag1 cinders1 or coke2 strip of tarred paper on burlap or a thin layer of hay1 straw1 cornstalks1 brush1 or sods1 grass side down2 ,i1 #ab inches of natural soil2 ,j1 stone-filled pit4 ,as here illustrated1 water is drawn by a pitcher or kitchen pump 7,k7 through a #a-a_/d or #a-a_/b inch galvanized-iron suction pipe 7,l7 from a cistern 7,m74 ,the suction pipe should be laid below frost and on a smooth upward grade from cistern to pump and be provided with a foot valve 7,n7 to keep the pump primed4 ,if a foot valve is used1 pump and pipe must be safe from frost or other means than tripping the pump be provided for draining the system4 ,except under the most favorable conditions the construction and use of a cesspool can not be condemned too strongly4 ,they are only permissible where no other arrangement is possible4 ,leaching cesspools especially are open to these serious objections3 #a4 ,unless located in porous soil1 stagnation is likely to occur1 and failure of the liquid to seep away may result in overflow on the surface of the ground and the creation of a nuisance and a menace4 #b4 ,they retain a mass of filth in a decomposing condition deep in the ground where it is but slightly affected by the bacteria and air of the soil4 ,in seeping through the ground it may be strained1 but there can be no assurance that the foul liquid with little improvement in its condition may not pass into the ground water and pollute wells and springs situated long distances away in the direction of underground flow4 ,for the purpose of avoiding soil and ground-water pollution cesspools have been made of water-tight construction and the contents removed by bailing or pumping4 ,upon the farm1 however1 this type of construction has little to recommend it1 for the reason that facilities for removing and disposing of the contents in a clean manner are lacking4 ,in some instances cesspools have been made water-tight1 the outflow being effected by three or four elbows or ,t-branches set in the masonry near the top1 with the inner ends turned down below the water surface1 the whole surrounded to a thickness of several feet with stone or gravel intended to act as a filtering medium4 ,tests of the soil water adjacent to cesspools of this type show that no reliance should be placed upon them as a means of purifying sewage1 the fatal defects being constant saturation with sewage and lack of air supply4 ,to the extent that the submerged outlets keep back grease and solid matters the scheme is of service in preventing clogging of the pores of the surrounding ground4 ,where the ground about a cesspool has become clogged and water-logged1 relief is often secured by laying1 several lines of drain tile at shallow depth1 radiating from the cesspool4 ,the ends of the pipes within the cesspool should turn down1 and it is advantageous to surround the lines of pipe with stones or coarse gravel1 as shown in figures #ag and #ah and discussed under ,septic tanks4 ,in this way not only is the area' of percolation extended1 but aeration and partial purification of the sewage are effected4 ,where a cesspool is located at a distance from a dwelling and there is opportunity to lead a vent pipe up the side of a shed1 barn1 or any stable object it is advisable to do so for purposes of ventilation4 ,where the conditions are less favorable it may be best1 because of the odor1 to omit any direct vent pipe from the cesspool and rely for ventilation on the house sewer and main soil stack extending above the roof of the house4 ,cesspools should be emptied and cleaned at least once a year and the contents given safe burial or1 with the requisite permission1 wasted in some municipal sewerage system4 ,after cleaning1 the walls and bottom may be treated with a disinfectant or a deodorant4 ,,septic ,,tanks4 ,a tight1 underground septic tank with shallow distribution of the effluent in porous soil generally is the safest and least troublesome method of treating sewage upon the farm1 while at the same time more or less of the irrigating and manurial value of the sewage may be realized4 ,the late ,prof4 ,kinnicutt used to say that a septic tank is simply a cesspool1 regulated and controlled4 ,the reactions described under the captions ,how sewage decomposes1 ,liquefying closet1 and ,cesspools take place in septic tanks4 ,in all sewage tanks1 whatever their size and shape1 a portion of the solid matter1 especially if the sewage contains much grease1 floats as scum on the liquid1 the heavier solids settle to form sludge1 while finely divided solids and matter in a state of emulsion are held in suspension4 ,if the sludge is retained in the bottom of the tank and converted or partly converted into liquids and gases the tank is called a septic tank and the process is known as septicization4 ,the process is sometimes spoken of as one of digestion or rotting4 ,history4--,prototypes of the septic tank were known in ,europe nearly #ej years ago4 ,between #ahgf and #ahic a number of closed tanks with submerged inlets and outlets embodying the principle of storage of sewage and liquefaction of the solids were built in the ,united ,states and ,canada4 ,it was later seen that many of the early claims for the septic process were extravagant4 ,in recent years septic tanks have been used mainly in small installations1 or1 where employed in large installations1 the form has been modified to secure digestion of the sludge in a separate compartment1 thus in a measure obviating disadvantages that exist where septicization takes place in the presence of the entering fresh sewage4 ,purposes4--,the purposes of a septic tank are to receive all the farm sewage1 as defined on page #d1 hold it in a quiet state for a time1 thus causing partial settlement of the solids1 and by nature's processes of decomposition insure1 as fully as may be1 the destruction of the organic matter4 ,limitations4--,that a septic tank is a complete method of sewage treatment is a widespread but wrong impression4 ,a septic tank does not eliminate odor and does not destroy all organic solids4 ,on the contrary1 foul odors develop1 and of all the suspended matter in the sewage about one-third escapes with the effluent1 about one-third remains in the tank1 and about one-third only is destroyed or reduced to liquids and gases4 ,the effluent is foul and dangerous4 ,it may contain even more bacteria than the raw sewage1 since the process involves intensive growths4 ,as to the effects upon the growth and virulence of disease germs little is known definitely4 ,it is not believed that such germs multiply under the conditions prevailing in a septic tank4 ,if disease germs are present many of their number along with other bacteria may pass through with the flow or may be enmeshed in the settling solids and there survive a long time4 ,hence the farmer should safeguard wells and springs from the seepage or discharges from a septic tank as carefully as from those of liquefying closets and cesspools4 ,further treatment of effluents4--,the effluent of a septic tank or any other form of sewage tank is foul and dangerous4 ,whether or not the solids are removed by screening1 by short periods of rest1 as in plain or modified forms of settling tanks1 or by longer quiescence1 as in septic tanks1 the effluent generally requires further treatment to reduce the number of harmful organisms and the liability of nuisance4 ,this further treatment usually consists of some mode of filtration4 ,in the earliest example of such treatment the sewage was used to irrigate land by either broad flooding or furrow irrigation4 ,by another method the sewage is distributed underground by means of drain tile laid with open joints1 as illustrated in figures #ag1 #bi1 and #cb4 ,artificial sewage filters are composed of coarse sand1 screened gravel1 broken stone1 coke1 or other material1 and the sewage is applied in numerous ways4 ,since filtration is essentially an oxidizing process requiring air1 the sewage is applied intermittently in doses4#i #i ,artificial filters of various types are well described and illustrated in ,public ,health ,bulletin ,no4 #aja1 ,studies of ,methods for the ,treatment and ,disposal of ,sewage--,the ,treatment of ,sewage from ,single ,houses and ,small ,communities4 ,u4 ,s4 ,public ,health ,service1 ,december1 #aiai4 ,if properly designed and operated1 filters of sand1 coke1 or stone are capable of excellent results4 ,under the most favorable conditions it is unwise to discharge the effluent of a sewage filter in the near vicinity of a source of water supply4 ,under farm conditions filters are usually neglected or the sewage is improperly applied1 resulting in the clogging and befouling of sand filters and the discharge from stone filters of an effluent which is practically as dangerous and even more offensive than raw sewage4 ,moreover unless the filters are covered there are likely to be annoying odors1 and there is always the possibility of disease germs being carried by flies where sewage is exposed in the vicinity of dwellings4 ,hence it seems more practical for the farmer1 avoiding the expense of earth embankments or masonry sides and bottom for a filter bed1 to waste the tank effluent beneath the surface of such area of land as is most suitable and available4 ,this method of applying sewage to the soil or subsoil is often spoken of as subirrigation1 but subsoil distribution of sewage is different in principle and practice from subirrigation for the increase of crop yields4 ,subirrigation is rarely successful unless the land is nearly level1 the top soil porous and underlaid with an impervious stratum to hold the water within reach of plant roots1 and unless a relatively large quantity of water is used and the work is skillfully done4 ,on the other hand1 the quantity of sewage on farms being small1 it may be wasted in hilly ground1 which should be as porous1 deeply drained1 and dry as possible4 ,parts of a system4--,the four parts of a septic-tank installation with subsurface distribution of the effluent are outlined in figure #ai3 7#a7 ,the house sewer from house to tank2 7#b7 the sewage tank consisting of one or more chambers2 7#c7 the sewer from tank to distribution field2 7#d7 the distribution field1 where the sewage is distributed and wasted1 sometimes called the absorption field4 ,these parts will be discussed in the order named1 although the last should have the first consideration4 ,illustration3 ,fig4 #ai4--,parts of a septic-tank installation4 ,illustration3 ,fig4 #bj4--,setting line and grade for house sewer4 ,to the observer at ,a the top edges of the grade boards appear as one2 the half-driven nails are set to line4 ,house sewer4--,the length will vary with the slope of the ground and position of buildings1 well1 and distribution field4 ,fifty to #ajj feet is a fair length2 a greater is still more sanitary4 ,wherever possible the house sewer should be laid straight in line and grade4 ,figure #bj shows how this work may be done4 ,suppose the distance from ,a to ,e be #ajj feet2 that grade boards be set #be feet apart crosswise of the trench at ,a1 ,b1 ,c1 ,d1 and ,e2 that the ground at ,a be #d feet lower than at ,e2 that the top of the sewer be #b-a_/b feet below the surface of the ground at ,a and #d-a_/b feet below the surface of the ground at ,e2 the fall of the sewer between ,a and ,e is #b feet 7#d #b-a_/b - #d-a_/b #b74 ,if the fall in #ajj feet be #b feet1 in #be feet it is one-fourth as much1 or #f inches4 ,hence1 grade board ,b is #f inches higher than grade board ,a1 ,c is #f inches higher than ,b1 and so on to ,e4 ,the top edges when all the boards are set with a carpenter's level and fastened in position should be in line4 ,the grade thus established may be any convenient height above the top of the proposed sewer1 and the measuring stick used to grade the pipe is cut accordingly4 ,this height is usually a certain number of whole feet4 ,fixing the line of the sewer is a mere matter of settling nails in the top edges of boards ,a and ,e directly over the center of the proposed sewer and tightly stretching a fish line or grade cord2 nails should be set where the cord crosses boards ,b1 ,c1 and ,d4 ,if the cellar or basement contains plumbing fixtures1 the house sewer should enter #a to #b feet below the cellar floor4 ,if all plumbing fixtures are on the floors above1 the sewer may enter at no greater depth than necessary to insure protection from frost outside the cellar wall4 ,digging the trench and laying the pipe should begin at the tank or lower end4 ,the large end of the pipes1 called the hub1 should face uphill1 and the barrel of each pipe should have even bearing throughout its length4 ,sufficient earth should be removed from beneath the hubs to permit the joints to be made in a workmanlike manner4 ,the house sewer may be vitrified salt-glazed sewer pipe1 concrete pipe1 or cast-iron soil pipe4 ,the latter1 with poured and calked lead joints makes a permanently water-tight and root-proof sewer1 which always should be used where the vicinity of a well must be passed2 #d1 #e1 or #f-;inch pipe may be used1 depending mainly on the fall and in less degree on the quantity of sewage discharged4 ,as a measure of economy the #d-;inch size is favored for iron pipe4 ,if vitrified pipe is used1 either the #e or #f inch size is preferable1 as these sizes are made straighter than the #d-;inch size and are less liable to obstruction4 ,of the two the #e-;inch size is preferable4 ,the fall in #ajj feet should never be less than #b feet for #d-;inch size1 #a-a_/b feet for #e-;inch size1 #a foot for #f-;inch size4 ,figure #ba shows methods of making good joints4 ,a1 ,b1 ,c1 ,d1 ,e1 ,f1 and ,g are ordinary sewer pipe joints2 ,h1 is cast-iron soil pipe4 ,illustration3 ,fig4 #ba4--;,how to make good joints4 ,see text for directions and specifications4 ,a shows the use of a yarning iron to pack a small strand of jute into the joint space1 thus centering the pipes and preventing the joint filler running inside4 ,the joint surfaces should be free of dirt and oil4 ,the jute is cut in lengths to go around the pipe2 a small strand is soaked in neat ,portland cement grout1 then twisted and wrapped around the small end of the pipe to be pushed into the hub of the last pipe laid4 ,after the pipe is pushed home the jute is packed evenly to a depth of not over #a_/b inch1 leaving about #a-a_/b inches for the joint filler4 ,old hemp rope or oakum dipped in liquid cement or paper may be used in place of jute1 and the packing may be done with a thin file or piece of wood4 ,b shows the use of a rubber mitten or glove to force ,portland cement mortar into the joint space4 ,the mortar should be thoroughly and freshly mixed in the proportion of one volume of cement to one volume of clean sand and should be pressed and tamped to fill the joint completely4 ,c shows a section of finished joint4 ,the fresh mortar should not be loosened or disturbed when laying the next pipe4 ,d shows method of pouring a joint with grout1 which is quicker1 cheaper1 and better than using a rubber mitten4 ,a flexible sheet-metal form or mold1 oiled to prevent the grout sticking1 is clamped tightly around the joint and is completely filled with grout consisting of equal parts of ,portland cement and clean sand mixed dry1 to which water is added to produce a creamy consistency4 ,the pipes should not be disturbed and the form should not be removed for #bd hours4 ,e shows a section of grouted joint1 well rounded out1 strong1 and tight4 ,f shows the use of a pipe jointer for pouring a hot filler4 ,the pipe jointer may be an asbestos or rubber runner or collar or a piece1 of garden hose clamped around the pipe leaving a small triangular opening at the top4 ,the jointer is pressed firmly against the hub1 and any small openings between the jointer and pipe are smeared with plastic clay to prevent leakage of the filler4 ,a clay dike or funnel about #c inches high built around the triangular opening greatly aids rapid and complete filling of the joint space4 ,the filler may be a commercially prepared bituminous compound or molten sulphur and fine sand4 ,the former makes a slightly elastic joint2 the latter a hard unyielding joint4 ,with good workmanship both kinds of joint are practically water-tight and root-proof1 and cost about the same as cement mortar joints4 ,the filler is heated in an iron kettle over a wood1 coke1 or coal fire4 ,it should be well stirred1 and when at a free running consistency should be poured with a ladle large enough to fill the joint completely at one operation4 ,as soon as the compound cools the jointer is removed4 ,sulphur-sand filler is made by mixing together dry and melting equal volumes of ordinary powdered sulphur and very fine clean sand1 preferably the finest quicksand4 ,a #e-;inch sewer pipe joint requires from three-tenths to nine-tenths of a pound 7according to the kind of pipe7 of sulphur1 worth #c to #e cents per pound1 and a like quantity of sand4 ,from #a_/b to #a-a_/b pounds of bituminous filler are required for a #e-;inch pipe joint4 ,g shows section of finished joint4 ,h shows the use of a pouring ladle in making lead joints in cast-iron soil pipe4 ,this pipe is in lengths to lay #e feet1 and the metal of the barrel is #a_/d inch thick4 ,the joint is yarned with dry jute or oakum1 as described above1 and is poured full with molten1 soft1 pig lead to be afterwards driven tightly with hammer and calking tools4 ,about #a pound of lead for each inch in diameter of pipe is required4 ,prepared cements of varying composition have proved effective11 and1 as they require no calking1 are economical4 ,among the best is a finely ground1 thoroughly mixed compound of iron1 sulphur1 slag1 and salt4 ,i is a home-made pipe jointer or clay roll for use in pouring molten lead4 ,a strand of jute long enough to encircle the pipe and the ends to fold back1 leaving an opening at the top1 is covered with clay moistened1 rolled1 and worked to form a plastic rope about #a inch in diameter4 ,the jointer gives the very best results but must be frequently moistened and worked to keep the clay soft and pliable4 ,the jointer shown in ,f is frequently used for pouring lead joints4 ,obstructions in house sewers are frequent4 ,among the causes are broken pipes1 grade insufficient to give cleansing velocities1 newspaper1 rags1 garbage1 or other solids in the sewage1 congealing of grease in pipes and main running traps 7house sewer traps71 and poor joint construction whereby rootlets grow into the sewer and choke it4 ,good grade and good construction1 with particular care given to the joints1 will avert or lessen these troubles4 ,the sewer should be perfectly straight1 with the interior of the joints scraped or swabbed smooth4 ,when the joint-filling material has set1 the hollows beneath the hubs should be filled with good earth free of stones1 well tamped or puddled in place4 ,it is important that like material be used at the sides of the pipe and above it for at least #a foot4 ,the back filling may be completed with scraper or plow4 ,no running trap should be placed on the house sewer1 because it is liable to become obstructed and it prevents free movement of air through the sewer and soil stack4 ,conductors or drains for rain or other clean water should never connect with the house sewer1 but should discharge into a watercourse or other outlet4 ,where obstruction of a house sewer occurs1 use of some of the simple tools shown in figure #bb may remedy the trouble4 ,it is not likely that farmers will have these appliances1 except possibly some of the augers2 but some of them can be made at home or by a blacksmith1 and most of them should be obtainable for temporary use from a well-organized town or city sewer department4 ,the purpose of the several tools shown is indicated in the notation4 ,the tank4--,the septic tank should be in an isolated location at least #ej to #ajj feet from any dwelling4 ,this is not always possible1 because of flat ground1 but in many such instances reasonable distance and fall may be secured by raising both the house sewer and tank and embanking them with earth4 ,cases are known where tanks adjoin cellar or basement walls and the top of the tank is used as a doorstep2 in other cases tanks have been constructed within buildings4 ,such practices are bad4 ,it is difficulty to construct an absolutely water-tight masonry tank1 and still more difficult to make it proof against the passage of sewage odors4 ,in ,northern ,states1 particularly in exposed situations1 it is desirable to have the top of the tank #a to #b feet underground1 thus promoting warmth and uniformity of temperature in the sewage4 ,in ,southern ,states this feature is less important1 and the top of the tank may be flush with the ground4 ,every tank should be tightly covered1 for the reason above stated and to guard against the spread of odors1 the transmission of disease germs by flies1 and accidents to children4 ,illustration3 ,fig4 #bb4--,sewer-cleaning tools--how to use them4 ,a1 ,ordinary #a-a_/b or #b inch auger welded to a piece of -inch extra-strong wrought pipe about #e feet long2 the stem is lengthened by adding other pieces of pipe with screw couplings1 and is fitted with a pipe handle2 all cleaning work should proceed upstream2 ,b1 twist or open earth auger2 ,c1 ribbon or closed earth auger2 ,d1 spiral or coal auger2 ,e1 ship auger2 ,f1 root cutter2 ,g1 sewer rods with hook coupling1 usually of hickory or ash #a or #aa inches in diameter and #c or #d feet long2 ,h1 gouge for cutting obstructions2 ,i1 scoop for removing sand or similar material2 ,j1 claw1 and ,k1 screw1 for removing paper or rags2 ,l1 scraper2 ,m1 wire brush for removing grease1 drawn back and forth with a wire or rope2 ,n1 home-made wire brush 7for a #e-;inch sewer use a #a-a_/b-;inch wooden pole to which is securely tacked a piece of heavy rubber1 canvas or leather belting or harness leather #e-a_/b by #h inches1 spirally studded1 as shown1 with ordinary wire nails #a-a_/b inches in length74 ,considerable latitude is allowable in the design and construction of septic tanks4 ,no particular shape or exact dimensions can be presented for a given number of people4 ,one family of #e persons may use as much water as another family of #aj persons2 hence the quantity of sewage rather than the number of persons is the better basis of design4 ,exact dimensions are not requisite1 for settlement and septicization proceed whether the sewage is held a few hours more or a few hours less4 ,as to materials of construction some form of masonry1 either brick1 building tile1 rubble1 concrete1 or cement block1 is employed generally4 ,vitrified pipe1 steel1 and wood have been used occasionally4 ,a plant for use all year round should have two chambers1 one to secure settlement and septicization of the solids and the other to secure periodic discharge of the effluent by the use of an automatic sewage siphon4 ,the first chamber is known as the settling chamber1 the second as the siphon or dosing chamber4 ,the siphon chamber is often omitted and the effluent is allowed to dribble away through subsurface tile1 as illustrated in figures #ag and #ah4 ,the latter procedure is not generally advised1 but may be permissible where the land slopes sharply or has long periods of rest1 as at summer houses and camps4 ,the septic tanks shown in this bulletin are designed to satisfy the following conditions3 #a4 ,water consumption of #dj gallons per person per day of #bd hours4 #b4 ,a detention period of about #bd hours2 that is1 the capacity of the settling chamber below the flow line is approximately equal to the quantity of sewage discharged from the house in #bd hours4 #c4 ,where a siphon chamber is provided1 its size is such that the dose of sewage shall be approximately equal to #bj gallons per person2 that is1 the capacity of the siphon chamber between the discharge and low-water lines is roughly equal to the quantity of sewage discharged in #ab hours4 ,illustration3 ,fig4 #bc4--,one-chamber septic tank--does nothing more than a tight cesspool4 ,brick construction1 heavily plastered inside2 size suitable for #ahj to #bhj gallons of sewage daily 7nominally #d to #g persons74 ,a simple one-chamber brick tank suitable for a household discharging #ahj to #bhj gallons of sewage daily is shown in figure #bc4 ,a small two-chamber tank constructed of #bd-;inch vitrified pipe1 suitable for a household discharging about #abe gallons of sewage daily1 is shown in figure #bd4 ,a typical two-chamber concrete tank is shown in figure #be4 ,excepting the submerged outlet1 all pipes within the tank and built into the masonry are cast-iron soil pipe with cast-iron fittings4 ,vitrified or concrete sewer pipe and specials are generally used as they are frequently more readily obtainable and a slight saving in first cost may be effected4 ,cast iron is less liable to be broken in handling or after being set rigidly in masonry1 and the joints are more easily made water-tight4 ,the submerged outlet is midway of the depth of liquid in the settling chamber4 ,the inside depth of the siphon chamber is the drawing depth of the siphon plus #a foot #e inches4 ,the following table gives the principal dimensions with quantities of materials for four sizes of tank as illustrated in figure #be3 ,dimensions and quantities for septic tanks4 ---------------------------------------- ---------------------------- ,quantity ,settling chamber4 of ,capacity ,number sewage below -------------------------------------- of in #bd flow ,length4 ,depth4,width4 ,w4 ,x4 ,y4 ,z4 persons4 hours4 line4 ---------------------------------------- ---------------------- ,galls4 ,galls4 ,ft4 ,in4,ft4 ,in4,ft4 ,in4 ,in4,ft4 ,in4,in4,in4 #e #ahj-bhj #bdj #d #j #e #j #b #j #f #b #j #d #f #aj #cbj-dhj #dbj #e #j #e #f #b #f #f #b #c #d #f #ae #ebj-fhj #fbj #e #f #f #j #c #j #h #b #f #e #h #bj #gbj-ifj #hfj #f #j #f #f #c #f #h #b #i #e #h ---------------------------------------- ---------------------- ---------------------------------------- -------------------------- ,quantity ,siphon chamber4 ,number of sewage ---------------------------------------- -- of in #bd ,length4 ,depth4 ,width4 ,a4 ,b4 ,c4 ,d4 persons4 hours4 ---------------------------------------- -------------------- ,galls4 ,ft4 ,in4 ,ft4 ,in4 ,ft4 ,in4 ,in4 ,in4 ,in4 ,in4 #e #ahj-bhj #e #j #b #h #b #j #c #d #ae #ah-a_/d #aj #cbj-dhj #h #j #b #h #b #f #c #d #ae #bj-a_/d #ae #ebj-fhj #h #h #b #aj #c #j #d #d #ag #bj-a_/d #bj #gbj-ifj #aj #j #b #aj #c #f #d #d #ag #bj-a_/d ---------------------------------------- -------------------- ---------------------------------------- ------------------------ ,quantity ,reinforcement of in top slab ,number sewage 7strip of of in #bd ,concrete4 ,cement4 ,sand4 ,stone4 heavy stock persons4 hours4 fencing74 ------------- ,length4,width4 ---------------------------------------- ------------------------ ,galls4 ,cu4 yds4 ,bbls4 ,cu4 yds4 ,cu4 yds4 ,ft4 ,in4 #e #ahj-bhj #c #d-a_/b #a-a_/c #b-b_/c #aj #c #aj #cbj-dhj #d-a_/d #f-a_/d #b #c-c_/d #ad #c #ae #ebj-fhj #f-b_/c #i-c_/d #c #f #ae-b_/c #d #bj #gbj-ifj #h #ab #c-a_/b #g #ag-a_/b #e ---------------------------------------- ------------------------ ,siphons4--,reference has already been made to the vital importance of air in sewage filtration4 ,if the spaces within a filter or soil are constantly filled with water1 air is excluded1 and the action of the filtering material is merely that of a mechanical strainer with its clogging tendency4 ,the purpose of a siphon is twofold3 7#a7 ,to secure intermittent discharge1 thus allowing a considerable period of time for one dose to work off in the soil and for air to enter the soil spaces before another flush is received2 7#b7 to secure distribution over a larger area and in a more even manner than where the sewage is allowed to dribble and produce the conditions of the old-fashioned sink drain--namely1 a small area of water-logged ground4 ,illustration3 ,fig4 #bd4--,two-chamber septic tank1 simple and inexpensive4 ,constructed of #bd-;inch vitrified sewer pipe2 size suitable for #abe gallons of sewage daily 7nominally #c persons74 ,a1 ,house sewer2 ,b1 settling chamber1 made of one double ,t branch and one length of straight pipe1 each #c feet long and #b feet in diameter1 supported by #d inches of concrete1 all joints made water-tight2 ,c1 submerged outlet1 consisting of a metal ,t slipped into the sewer-pipe branch2 ,d1 wire screen1 #b-;inch mesh2 ,e1 siphon chamber made of one ,t branch #c feet long and #b feet in diameter2 ,f1 siphon2 ,g1 #c-;inch overflow2 ,h1 sewer to distribution field2 ,i1 tight cover with lifting ring2 ,j1 concrete protection around sewer-pipe hubs4 ,illustration3 ,fig4 #be4--,typical two-chamber concrete septic tank4 7,see table for dimensions and quantities for different sizes47 ,three types of sewage siphon are shown in figure #bf4 ,in all1 the essential principle is the same3 ,a column of air is entrapped between two columns of water2 when the water in the chamber rises to a predetermined height1 called the discharge line1 the pressure forces out the confined air1 destroying the balance and causing a rush of water through the siphon to the sewer4 ,the entire operation is automatic and very simple4 ,the siphons shown are commercial products made of cast iron2 they have few parts and none that move1 and the whole construction is simple and durable4 ,the table 7fig4 #bf7 lists stock sizes adapted to farm use4 ,manufacturers furnish full information for setting their siphons and putting them in operation4 ,for example1 take type #b1 figure #bf3 7#a7 ,set siphon trap 7,u-shaped pipe7 plumb1 making ,e 7height from floor to top of long leg7 as specified2 7#b7 fill siphon trap with water till it begins to run out at ,b2 7#c7 place bell in position on top of long leg1 and the siphon is ready for service4 ,do not fill vent pipe on side of bell4 ,illustration3 ,fig4 #bf4--,three types of sewage siphon4 ,the table gives dimensions for setting standard #c and #d inch siphons2 also the appropriate size and grade of the sewer to carry the siphon discharge4 ,transcriber ,note3 ,the data for ,type #a ,siphon has been added to the table4 ,type #b ,,inches ------------------------------- ,diameter of siphon ,a #c #c #d #d ,diameter of outlet ,b #d #d #d #d ,drawing depth ,c #ac #ae #ad #ag ,depth to floor ,d #af #ah #ag #bj ,height above floor ,e #g #i #h #aa ,clearance under bell ,f #b #b #b #b ,inside bottom of outlet1 to discharge line ,g #bj #bb #bb #be ,discharge line1 to top of wall ,h ,depth of outlet sump ,i ,length and width of outlet sump ,j ------------------------------- ,r #d #d #d #d ,s #b ft4 #b ft4 #g ft4 #h ft4 ,diameter of carrier 7,r71 and ------------------------------- minimum fall 7,s7 in feet ,r #e #e #e #e per #ajj feet ,s #a ft4 #a ft4 #b ft4 #b ft4 ------------------------------- ,r #f #f #f #f ,s #a ft4 #a ft4 #a ft4 #a ft4 ------------------------------- ,type #c ,type #a ,,inches ,,inches ------------------- ---- ,diameter of siphon ,a #c #c #d #d #d ,diameter of outlet4 ,b ,drawing depth ,c #ac #ae #ad #ag #e ,depth to floor4 ,d #ag #ag #ai #bb #ae ,height above floor ,e #ac #ac #ae #ah #ai ,clearance under bell4 ,f ,inside bottom of outlet1 to discharge line4 ,g #ai #ba #bj #be ,discharge line1 to top of wall4 ,h #f #f #h #h ,depth of outlet sump ,i #ac #ac #aa #ab ,length and width of outlet sump ,j #ah #ai #ai #ah ------------------- ---- ,the overhead siphon1 type #c1 figure #bf1 may be installed readily in a tank already built by addition of an outlet sump4 ,if properly set and handled1 sewage siphons require very little attention and flush with certainty4 ,like all plumbing fixtures they are liable to stoppage if rags1 newspaper1 and similar solids get into the sewage4 ,if fouling of the sniffing hole or vent prevents the entrance of sufficient air into the bell to lock the siphon properly1 allowing sewage to dribble through1 the remedy is to clean the siphon4 ,siphons are for handling liquid2 sludge if allowed to accumulate will choke them4 ,submerged outlet4--,the purpose of a submerged outlet is to take the outflow from a point between the sludge at the bottom and the floating solids or scum4 ,the outlet in figure #be may be readily made of sheet metal by a tinsmith4 ,wrought iron or steel pipe with elbows or light lead pipe may be used1 the pipe being set in the concrete and left in place4 ,sometimes a galvanized wire screen 7#a_/d-;inch mesh7 is fitted over the inner end to prevent large solids leaving the settling chamber and possibly clogging the siphon or distribution tile4 ,if a screen is used it should be easily removable for cleaning4 ,illustration3 ,fig4 #bg4--;,home-made reinforced concrete covers4 7#a7 ,slabs placed crosswise permit uncovering the whole tank for cleaning1 but as inspection is somewhat difficult1 cleaning is the more likely to be neglected2 7#b7 manhole1 #ah inches square2 cover1 #bb by #bb by #c inches thick1 easy to make and to slide or lift from the opening4 ,manhole frame and cover4--,the frame and cover shown in figure #be are stock patterns made of cast iron and weighing about #bej pounds per set4 ,the cover is #ba inches in diameter2 it is tight and1 on account of its weight1 is unlikely to be disturbed by small children4 ,the frame or rim is about #g inches high and #ca inches in longest diameter4 ,if desired1 light cast-iron cistern or cesspool covers obtainable from plumbing supply houses1 home-made slabs of reinforced concrete 7see fig4 #bg71 or wooden covers 7see fig4 #bc7 may be used4 ,overflow4--,the purpose of an overflow is to pass sewage to the distribution field should the siphon stop working4 ,the overflow 7fig4 #be7 is a #c-;inch riser pipe with top #c inches above the discharge line and the bottom calked or cemented into the side outlet of a ,t-branch4 ,the run of the ,t-branch should correspond with the size of the sewer from the tank to the distribution field4 ,if this sewer is #d-;inch pipe1 a #d by #c inch ,t-branch is used1 the #d-;inch spigot end of the siphon being calked or cemented into the branch1 as shown in figure #be2 if the sewer is #e-;inch1 a #e by #c inch ,t-branch is used and connected to the siphon with a #e-;inch to #d-;inch reducer 7in vitrified specials the equivalent is a #d-;inch to #e-;inch increaser72 if the sewer is #f-;inch1 a #f by #c inch ,t-branch is used and connected to the siphon with a #f-;inch to #d-;inch reducer4 ,concrete work4--,before excavation for the tank is begun1 two wooden forms should be built for shaping the inside of the settling and siphon chambers4 ,in most instances the ground is fairly firm1 so that the lines of excavation may conform to the outside dimensions of the tank1 the back of the walls being built against the earth4 ,the forms may be made of square-edged boards1 braced and lightly nailed1 as shown in figure #bh4 ,the forms should have no bottom4 ,if it is desired to lay the sides and covering slab in one operation1 the top of the forms must be boarded over4 ,all pipe and manhole openings should be accurately placed and cut4 ,the faces of the forms may be covered with paper or smeared with soap or grease to facilitate removal later4 ,the ground should next be excavated to the proper depth for placing the floors in both chambers4 ,the settling chamber floor1 being the lower1 should be placed first4 ,effort should be made to secure water-tight work1 a feature of especial importance where leakage might endanger a well or spring4 ,a concrete mixture of #a3b3d is generally preferred 7#a volume cement1 #b volumes sand1 #d volumes stone74 ,the ingredients should be of best quality and thoroughly mixed4 ,the concrete should be poured promptly and worked with a spade or flat shovel to make the face smooth and eliminate pockets or voids within the mass4#aj ,before the settling chamber floor has hardened the form should be set upon the floor and the concrete work continued up the sides4 ,the pipe form for the submerged outlet should be set4 ,when the side walls of the settling chamber have reached the bottom of the excavation for the siphon chamber1 the siphon trap with its connecting branch and short piece of pipe should be set to proper line and grade and blocked in position4 ,the floor of the siphon chamber should now be poured and the form for that chamber placed thereon1 leaving a #f-;inch or #h-;inch space 7according to the thickness of the division wall7 between the ends of the two forms4 ,pouring of all side walls and the top slab should continue without stop1 making the entire structure a monolith4 #aj ,see footnote1 p4 #ag4 ,for more detailed information on form and concrete work the reader is referred to ,u4 ,s4 ,department of ,agriculture ,farmers' ,bulletin ,no4 #dha1 ,concrete ,construction on the ,live-,stock ,farm4 ,illustration3 ,fig4 #bh4--;,forms for concrete work--how to use them4 #a4 ,make the forms as shown and to the dimensions required by fig4 #be and the table on p4 #cg2 nails to be driven from the inside and left projecting for drawing with a claw hammer4 #b4 ,excavate to lines #f or #h inches1 as may be required1 outside of the forms and to the depths required for both chambers4 #c4 ,pour settling chamber floor and place form thereon4 #d4 ,pour settling chamber walls to level of siphon chamber excavation1 inserting submerged outlet pipe at the proper height4 #e4 ,block siphon trap and connected branch and short pipes to correct line and grade1 and fill with concrete around the trap4 #f4 ,pour siphon chamber floor1 and place the form thereon4 #g4 ,continue pouring all walls to their full height1 inserting the inlet pipe when the concrete reaches that elevation4 #h4 ,do not remove forms till the concrete is hard2 with favorable weather1 forms for walls only may be removed in #a to #b days2 forms supporting a cover slab should remain #a to #b weeks4 ,steel reinforcement4--,to stiffen the cover slab and guard against cracking1 a little steel should be embedded in the concrete about #a inch above the inside top4 ,for this purpose a strip of heavy stock fencing is convenient and inexpensive4 ,the line wires should be not less than ,no4 #aj gauge 7about #a_/h inch7 and the stay wires not less than ,no4 #aa gauge4 ,the reinforcement should be cut at manholes and fastened around manhole openings4 ,if desired a standard wire-mesh reinforcement weighing about one-third of a pound per square foot may be used4 ,another alternative is to use #a_/d-;inch round rods1 spacing the crosswise rods #f inches apart and the lengthwise rods #ab inches apart4 ,poultry netting should not be used1 because of its lightness4 ,sewer from tank to distribution field4--,the length of this sewer depends on the situation of the field and the fall to it4 ,the size of the sewer depends on the fall that can be obtained and the size of siphon4 ,the table in figure #bf shows the minimum fall at which #d-;inch1 #e-;inch1 and #f-;inch sewers should be laid to take the discharge of the #c-;inch and #d-;inch siphons specified4 ,the line and grade should be set in the same manner as for the house sewer 7see fig4 #bj71 and the construction should be as specified under that caption4 ,distribution field4--,the distribution field or area is a sewage filter1 and its selection and the manner of preparing it largely determine the success of subsoil disposal of sewage4 ,as a rule farm land is not the best filtering material4 ,it is too fine grained and fertile4 ,its tendency is to hold water too long1 to admit insufficient air1 to clog when even small quantities of sewage are applied4 ,hence the distribution area should be of liberal size--on the average #ejj square feet for each person served4 ,it should be dry1 porous1 and well drained--qualities that characterize sandy1 gravelly1 and light loam soils4 ,it should be devoid of trees and shrubbery1 thus giving sunlight and air free access4 ,it should be located at least #cjj feet downhill from a well or spring used for domestic water supply4 ,preferably it should slope gently1 but sharp slopes are not prohibitive4 ,subsoiling the area is always desirable4 ,clay and other compact1 impervious soils require special treatment4 ,less sewage can be applied to them1 and hence it is well to have the area larger than #ejj square feet per person4 ,clay should be subsoiled as deep as possible with a subsoil plow4 ,in some instances dynamite has been of service in opening up the ground to still greater depth4 ,drainage and aeration should be further promoted by laying tile underdrains1 as outlined in figure #ai and shown in more detail in figure #ca4 ,after the construction work the distribution area should be raked and seeded with thick-growing grass4 ,grass is a safe crop2 its water requirement is high1 and it affords considerable protection from frost4 ,suitable grasses are redtop1 white clover1 blue grass1 and ,bermuda grass4 ,the area may be pastured or kept as grass land4 ,distribution system4--,poor distribution of the sewage and failure to protect the joints of the distribution tile account for most of the failures4 ,each flush of the siphon should be so controlled that every part of the field will receive its due proportion4 ,the distribution tile must be so laid that loose dirt will not fall or wash into the open joints4 ,different methods of dividing the flush and laying out the distribution tile are shown in figures #bi and #cb4 ,layouts #a1 #b1 and #c1 figure #bi1 are suitable for flat or gently sloping areas and are planned for the shallow siphon chambers tabulated on page #cg4 ,layout #d1 figure #bi1 is suitable for steep slopes4 ,in all four layouts use is made of one or more ,v-branches 7not ,y-branches7 to divide the flow equally among the several lines4 ,v-branches1 sometimes called breeches1 should be leveled with a carpenter's level crosswise the ends of the legs1 thus insuring equal division of the flow4 ,the size and length of distribution tile and the spacing of the lines or runs admit of considerable variation in different soils4 ,water sinks rapidly in gravels and sands1 and hence larger tile and shorter length are permissible than in close soils4 ,lateral movement is slow in all soils1 but extends farther in gravels and sands than in close soils4 ,in average soils the effect on vegetation #e feet away from the line is practically nil4 ,from these considerations1 with the siphon dose #bj gallons per person1 it is usually a safe rule to provide #ej feet of #c-;inch tile for each person served and to lay the lines #aj feet apart4 ,such provision gives a capacity within the bore of the tile lines about equal to the siphon dose1 and as some sewage is wasted at each joint a reasonable factor of safety is provided4 ,a spacing of #aj feet will1 it is believed1 permanently prevent the extension of lateral absorption from line to line1 provided the area is fairly well drained4 ,as between #c-;inch and #d-;inch tile the smaller size costs less and is better calculated to taper the dose to small proportions4 ,four-inch tile is less likely to get out of alignment or to become clogged2 a length of #bh feet has the same capacity in the bore as #ej feet of #c-;inch4 ,good-quality drain tile in #a-;foot lengths or second-quality sewer pipe in #b-;foot lengths may be used4 ,the lines are generally laid in parallel runs1 but may be varied according to the topography4 ,layouts #a1 #b1 and #c1 figure #bi1 for flat or gently sloping land1 run with the slope2 layout #d1 for steep slopes1 runs back and forth along the contour in a series of long flat sweeps and short steep curves4 ,the grade of the runs and sweeps should be gentle1 rarely more than #aj or #ab inches in #ajj feet4 ,in layouts #a1 #b1 and #c1 figure #bi especially1 it is desirable that the last #bj feet of each run should be laid level or given a slight upward slope1 thus guarding against undue flow of sewage to the lowest ends of the system4 ,fig4 #bi4--,methods of laying distribution system3 ,methods #a1 #b1 and #c for flat or gently sloping land2 method #d for steep slopes 7see also fig4 #cb72 ,a1 direction of slope2 ,b1 contour of field2 ,c1 sewer from tank1 preferably size #e inch1 though #d or #f inch may be used1 depending on the fall and the size of the siphon 7see table1 fig4 #bf72 ,d1 ,v-branch set to divide the flow exactly2 ,e1 reducer1 to #d inches2 ,f1 #a_/h bend1 #d-;inch2 ,g1 increaser1 from #d inches2 ,h1 increaser1 #c to #d inches2 ,i1 reducer1 #d to #c inches2 ,j1 distribution tile1 #c-;inch2 ,k1 distribution tile1 #d-;inch4 ,the runs should be laid no deeper than necessary to give clearance when plowing and prevent injury from frost4 ,ten inches of earth above the top of the tile is sufficient generally throughout the southern half of the ,united ,states and #ah inches generally in the ,north1 but if the field is exposed or lacks a thick heavy growth of grass the cover should be increased to #b-a_/b or #c feet near the ,canadian line4 ,what is better1 the tile in all instances may be laid with a #aj-;inch cover and in cold weather the runs may be covered with hay1 straw1 or leaves weighted down1 which may be removed in the spring4 ,illustration3 ,fig4 #cj4--;,four methods of protecting open joints in distribution lines--an all-important work4 ,sketches show cross-section and longitudinal views2 the depth from the surface of the ground to the top of the tile is about #aj inches4 #a4 ,a1 ,subsoil ground2 ,b1 #c or #d inch drain tile2 ,c1 strip of tarred paper about #f inches wide and extending three-fourths the distance around the tile1 allowing sewage to escape at the bottom2 ,d1 coarse sand1 gravel1 broken stone or brick1 slag1 cinders1 or coke1 the coarsest material placed around the tile 7where the ground is naturally very porous and well drained1 special filling in the trench may be omitted72 ,e1 natural soil4 #b4 ,drain tile covered with a board laid flat1 leaving the entire joint open4 #c4 ,drain tile laid in stoneware gutter pieces and the joint covered with stoneware caps2 gutter and cap pieces are inexpensive commercial products2 their radius is longer than that of the outside of the tile1 thus leaving open most of the joint space2 the gutter aids in keeping the tile in line4 #d4 ,vitrified sewer pipe with hubs facing downhill2 the spigot end should be centered in the hub with a few small chinks or wedges4 ,making the joints of the distribution tile demands especial attention4 ,for a short distance on the upper end of each run the tile should be laid with ends abutting2 the joint opening should be increased gradually to one-eighth inch and this increased to one-fourth in the last #bj feet of the run4 ,all joints should be protected against the entrance of loose dirt4 ,four methods are shown in figure #cj4 ,the lower end of each run should be closed with a brick or flat stone2 or1 what is better1 an elbow or ,t-branch may be placed on the end and vented above the surface of the ground1 improving the flow of sewage1 the ventilation of pipes1 and the aeration of the soil4 ,if the distribution tile must be laid in clay or other close1 poorly drained soil1 special treatment is necessary4 ,a common method is to subsoil and underdrain the area thoroughly1 as shown in figure #ca4 ,it is not always possible to run the underdrain in lines between the distribution lines as shown in figures #ai and #ca1 but it is a desirable thing to do1 as the sewage must then receive some filtration through natural soil4 ,in some instances it is sufficient to lay the distribution tile on a continuous bed1 #h to #ab inches thick1 of coarse gravel1 broken stone1 or brick1 slag1 coke1 or cinders and complete the refill as shown in figure #ah or #ca4 ,figure #cb shows two other methods of controlling the flow on steep slopes and diverting proper proportions to the several lateral distributors laid along the contour of the field4 ,this work can not be effected properly with ,t or ,y branches2 the flow tends to shoot straight ahead1 comparatively little escaping laterally4 ,to overcome this difficulty recourse is had to diverting boxes1 of which two types are shown in figure #cb4 ,these boxes involve expense1 but permit inspection and division of the flow according to the needs4 ,they may be built of brick1 stone1 concrete1 or even wood4 ,illustration3 ,fig4 #ca4--;,close soils should be deeply subsoiled and underdrained4 ,porous1 well-drained1 air-filled soil is absolutely necessary4 ,a1 ,subsoiled ground2 ,b1 #c or #d inch distribution tile2 ,c1 depth variable with the climate1 #a-a_/d to #c-a_/b feet2 ,d1 #d-;inch underdrain2 ,e1 depth such as would prepare land for good crop production1 generally #c-a_/b to #d feet2 ,f1 stone or other coarse material2 ,g1 gravel grading upward to coarse sand2 ,h1 loose soil4 ,type #a consists of a single box1 into which all the lateral distributors head4 ,it will be noted that the laterals enter at slightly different elevations1 the two opposite the inlet sewer being the highest1 the next two slightly lower1 and the next two the lowest4 ,this staggering of the outlets1 in a measure1 offsets the tendency of the flow to shoot across and escape by the most direct route4 ,type #b calls for one or more diverting boxes1 according to the number of lateral distributors1 and readily permits of wasting sewage at widely separated elevations and distances4 ,the outlet pipes enter the box at slightly different elevations1 for the reason already stated4 ,with either type1 should the outlets not be set at the right elevations1 partial plugging of the holes and a little experimenting will enable one to equalize or proportion the discharges4 ,illustration3 ,fig4 #cb4--,two systems of distribution on steep slopes--use of diverting box4 ,a ,direction of slope2 ,b1 contour of field2 ,c1 #d1 #e or #f inch sewer from tank2 ,d diverting box2 ,e1 #c-;inch or #d-;inch distribution tile4 ,sewage switch4--,the clogging of filters and soils after long-continued application of sewage has been previously referred to4 ,it is1 therefore1 desirable to arrange the distribution system in two units with a switch between them1 so that one area may drain and become aerated while the other is in use4 ,this procedure is especially desirable where the soil is close and the installation of considerable size4 ,it adds to the life and effectiveness of the distribution area and permits use of a plant in case it is necessary to repair1 extend1 or relay the tile in either unit4 ,arrangement in two units does not necessarily mean doubling the amount of tile and the area required in a single field4 ,however desirable that may be1 expense or lack of suitable ground will often prevent4 ,with open sands and gravels and the assumed siphon dose of #bj gallons per person1 #ae to #bj feet of #d-;inch tile in each unit for each person will usually suffice4 ,with more compact soil it is advisable to more nearly double the requirements previously described4 ,two simple types of switch are shown in figure #cc4 ,the switch should be turned frequently1 certainly as often as is necessary to prevent saturation or bogginess of either area4 ,illustration3 ,fig4 #cc4--,two simple types of sewage switch4 ,a1 ,sewer from tank2 ,b1 switch box2 ,c1 cover2 ,d1 blade or stop board 7in the left-hand box the direction of flow is controlled by placing the blade in alternate diagonal position2 in the right-hand box the stop works in iron guides cast integral with a short piece of light-weight pipe set in the masonry2 if desired the guides may be wood1 fastened to the masonry with expansion bolts72 ,e1 sewer to distribution area2 ,f 7right-hand box71 alternate position of outlets or additional outlets if required4 ,a complete installation4--,the general layout and working plans of a complete installation built in #aiae-af are shown in figure #cd4 ,the plant is larger than those heretofore considered1 and involves several additional features4 ,the settling chamber below the flow line has a capacity of #a1jjj gallons1 and on a basis of #dj gallons per person per day would serve #be people4 ,for many years sewage had been discharged through two #d-;inch sewers to a cesspool in the rear of the house4 ,the proximity of the well made it unsafe1 and the overflow of the cesspool dribbled over the low portion of the garden and barnyard1 creating nuisance4 ,the first step was to make borings with a soil auger in the pasture #djj or #ejj feet from the house4 ,the borings showed a heavy clay soil to a depth of about #d feet1 underlaid with a sandy stratum only a few inches in thickness4 ,it was decided to locate the distribution area in the pasture and to aid the seepage of sewage by digging numerous filter wells through the clay to the sandy stratum4 ,levels were taken and a contour plan prepared to serve for laying out the plant and establishing the grades4 ,illustration3 ,fig4 #cd4--;,a complete installation for a large rural home4 ,general layout on a contour plan and construction drawings4 ,note abandonment of old cesspool near the well and garden and removal of sewage to a lower and safer location in the pasture1 where the treatment is subsurface distribution1 aided by numerous filter wells about #d feet deep filled with coarse gravel4 ,note that sludge is removed from the bottom of the settling chamber by opening the gate on the sludge drain4 ,the septic tank is built in one corner of the barnyard1 and a #e-;inch sewer connects it with the old #d-;inch sewers to the cesspool4 ,all sewer pipe joints were poured with a flexible jointing compound4 ,the settling chamber is of hopper shape at the bottom1 and a #d-;inch sludge drain with gate provides for the gravity removal of sludge4 ,the lower end of the sludge drain is above the surface of the ground and #i feet below the flow line4 ,the end is protected by a small retaining wall1 and the sludge is readily caught in barrels and hauled out on the land for burial4 ,the outlet is low enough to drain the settling chamber completely4 ,if it is desired merely to force out the sludge1 the drain may be brought to the surface under a head of #c to #e feet1 discharging the sludge into a trench or drying bed1 to be applied later to the land4 ,a #b-;inch waste pipe about mid-depth of the settling chamber permits drawing off the clearer portion of the sewage to the siphon chamber and from thence through another #b-;inch waste pipe into the #f-;inch sewer leading to the distribution field4 ,the #d-;inch siphon has a drawing depth of #cc inches1 and as the siphon chamber is #d feet wide by #f feet long the dose is about #ejj gallons4 ,the siphon cost #ce4 ,the #f-;inch sewer to the switch box falls about #f inches in #ej feet4 ,the distribution field was thoroughly subsoiled1 and about #hjj feet of #c-;inch tile was laid in each unit4 ,at intervals of #be feet along the distribution trenches #f-;inch holes were dug through the clay stratum with a posthole digger4 ,these holes were filled with stone and constitute the filter wells previously mentioned4 ,all tile lines are surrounded with stone and coarse gravel1 and the ground has been trimmed to give a uniform cover of #ab inches4 ,all work was done by day labor in a thorough manner4 ,as the men were doing other work at the same time the actual cost is not known1 but it is believed the installation cost about #gjj4 ,cost data4--,reliable cost figures are difficult to estimate4 ,labor1 materials1 freight1 haulage1 and other items vary greatly in different localities4 ,the septic tank shown in figure #bc contains about #a1jjj bricks and is estimated to cost #fj complete4 ,the septic tank shown in figure #be for #e persons is estimated to cost #ace2 for #aj persons1 #agj2 for #ae persons1 #bdj2 for #bj persons1 #bhj4 ,in ,maryland1 in #aiaf1 the cost of installing a septic tank similar to that shown in figure #be 7for #e people71 including #hf feet of #e-;inch house sewer 7#ee feet of cast-iron pipe passing a well1 and #ca feet of vitrified pipe7 and #bad feet of second-quality #d-;inch sewer pipe in the distribution area1 was as follows3 ,excavation1 labor #g4ej ,materials delivered #df4fj ,three-inch siphon1 including freight #ae4ge ,construction1 labor #bh4jj ,supervision #e4jj ------ ,total #ajb4he ,the quotations in the following table will be found useful in making estimates of cost3 ,cost of pipe and drain tile4 7,february1 #aiba47 ---------------------------------------- ------------------------------- ,size1 in inches4 ,kind of pipe4 -------------------------------- #c #d #e #f ---------------------------------------- ---------------------------- ,extra heavy cast-iron soil pipe1 on cars ,chicago1 ,ill41 per or ,washington1 ,d4 ,c4 foot #j4cd #j4df #j4fa #j4gb ,vitrified salt-glazed sewer pipe1 on cars ,chicago1 ,ill4 do 4#ae 4#ae 4#bb 4#bb ,vitrified salt-glazed sewer pipe1 at factory near ,washington1 ,d4 ,c4 do 4#ab 4#ab 4#ah 4#ah ,clay or shale drain tile1 at factory in ,ohio do 4#jc 4#jc 4#jd 4#je ,clay or shale drain tile1 at factory near ,washington1 ,d4 ,c4 do 4#jd 4#je 4#jf 4#jg ---------------------------------------- ---------------------------- ,the cost of cast-iron fittings may be roughly estimated as follows3 ,bends1 one to one and one-half times the price of straight pipe2 ,t-branches1 two times the price of straight pipe2 reducers1 average of the prices of straight pipe at each end4 ,the cost of clay bends1 ,t-branches1 reducers1 and increasers may be roughly estimated at four times the price of straight pipe4 ,operation4--,attention must be given to every plant to insure success4 ,unusual or excessive foulness should be investigated4 ,no chemicals should be used in a septic tank2 garbage1 rags1 newspaper1 and other solids not readily soluble in water should be kept out of sewers and tanks4 ,the plant should be inspected often1 noting particularly if the siphon is operating satisfactorily4 ,if scum forms in the settling chamber it should be removed1 and the sludge should be bailed or pumped out yearly4 ,frequently tanks are not cleaned out for three or four years1 resulting in large quantities of solid matter going through to the distribution system and clogging it4 ,clogging may occur in the tile or in the adjacent soil4 ,in either case the tile should be dug up1 cleaned1 and relaid4 ,in some cases it has been found advantageous to relay the tile between the former lines4 ,when sewage is applied to fairly porous land at the slow rate here recommended and the plant is well handled the tile lines should operate satisfactorily for many years4 ,liming heavy soils tends to loosen and keep them sweet4 ,field data4--,as a basis for outlining or designing a suitable installation the following data should be known3 #a4 ,state1 town1 and whether in or near an incorporated municipality4 #b4 ,usual number of persons to be served4 #c4 ,average daily consumption of water in gallons4 #d4 ,kind and depth of well1 depth to water surface4 #e4 ,character of soil1 whether sandy1 gravelly1 loamy1 clay1 or muck4 #f4 ,condition of soil as to drainage4 #h4 ,character of underlying rock and1 if known1 its depth below the surface4 #i4 ,depth to ground water at both house and field where sewage is to be distributed4 #aj4 ,minimum winter temperature and approximate depth to which frost goes4 #aa4 ,number and kind of buildings to be connected with the sewer4 #ab4 ,number and kind of plumbing fixtures in each building4 #ac4 ,whether plumbing fixtures are to be put in the basement4 #ad4 ,depth of basement floor below ground4 ,a plan to scale or a sketch with dimensions showing property lines1 buildings1 wells1 springs1 and drainage outlets should be furnished4 ,the direction of surface drainage should be indicated by arrows4 ,the slope of the land 7vertical fall in a stated horizontal distance7 should be given or if possible a contour plan 7showing lines of constant elevation7 should be furnished4 ,,grease ,,traps4 ,farm sewage may contain from #aj to #cj pounds of grease and fats per person per year4 ,this grease1 originating mainly in the kitchen sink1 hinders septic action and clogs pipes1 filters1 and soils4 ,half the grease may be stopped by a septic tank1 but the remainder goes into the distribution system1 interfering with its action4 ,a grease trap is a device for separating the grease from other wastes4 ,the need for it may be lessened by carefully depositing waste greases and fats with the garbage2 but one should always be installed if the kitchen is carelessly managed or discharges quantities of greasy water as at institutions1 hotels1 boarding houses1 and bakeshops4 ,a grease trap should have several times the capacity of the greatest quantity of greasy water discharged into it at one time1 in order that the entering water shall be well cooled and the grease congealed4 ,the solidified grease rises to the surface of the water in the trap and is retained therein4 ,a dishpan of greasy water 7#b-a_/b to #c gallons7 is the largest quantity likely to be discharged at one time from an ordinary kitchen sink1 hence the grease trap should have not less capacity than #g or #h gallons4 ,figure #ce shows three types of grease traps suitable for farm use4 ,in each the outlet pipe has small clearance at the bottom4 ,this feature1 together with the ,v-shaped hopper bottom1 tends to create a scouring velocity and thus prevent the accumulation of coffee grounds and other solid wastes in the bottom of the trap4 ,a grease trap should be close to the sink it is intended to serve1 but not within the kitchen1 on account of objectionable odors when the trap is opened to remove grease4 ,it is good practice to place the trap in the cellar or basement1 where it is safe from frost yet close to the source of grease4 ,illustration3 ,ready-made grease trap4 ,vitrified1 salt-glazed earthenware4 ,,stock ,,sizes ,diameter4 ,depth4 ,inches4 ,inches4 #ae #bd #ah #cf #bd #cf ,illustration3 ,home-made grease trap4 ,concrete or well-plastered brick work2 elbow1 cross and increaser to be recessed drainage fittings4 ,illustration3 ,type of grease trap used at ,u4 ,s4 ,army camps4 ,fig4 #ce4--,three types of grease trap4 ,,general ,,procedure4 ,do not waste money by digging and1 partly constructing1 afterwards seeking information4 ,prepare a plan and work from it4 ,get in touch with your county agricultural and home demonstration agents4 ,advice may be obtained also from extension workers1 ,state agricultural colleges1 ,state and local boards of health1 the ,united ,states ,public ,health ,service1 and the ,united ,states ,department of ,agriculture4 ,do not guess distances and levels4 ,use a measuring tape and some type of level--engineer's1 architect's1 drainage1 hand1 or carpenter's4 ,study this bulletin1 and design1 lay out1 and construct in accordance therewith4 ,remember to3 7#a7 ,isolate the septic tank--locate it #ej to #ajj or more feet from any dwelling and1 if practicable1 to the leeward of prevailing summer breezes2 7#b7 locate the cesspool or sewage distribution field downhill from the well or spring1 and1 if possible1 #cjj feet therefrom2 7#c7 select dry1 porous1 deeply drained ground for disposal of all sewage2 7#d7 do not apply more sewage to a given area of land than can be thoroughly absorbed and oxidized2 7#e7 lay sewers straight and below the reach of frost1 ventilate them thoroughly1 and make the joints water-tight and root-proof4 ,makeshift methods1 materials1 or devices should be avoided or used sparingly4 ,do not place a vent pipe in the top of a cesspool or septic tank if near a dwelling4 ,siphon chamber and siphon may be omitted in those rare instances where it is feasible to discharge into salt water or into a large stream already badly polluted4 ,disposal of sewage in a running stream should be a last resort4 ,such practice endangers water supplies downstream1 and unless the volume and velocity of flow are good nuisance may be created in the vicinity4 ,do not neglect inspection and operation4 ,clean out settling tanks yearly or oftener4 ,all pipe lines below ground should be marked with iron or stone markers to facilitate examination1 repair1 or extension of the system4 ,there is a general but erroneous belief that the cost of sewerage is little in the city but almost prohibitive in the country4 ,all personal and realty properties in one eastern city represent a valuation of #aj1chb per home1 which pays #cee for sewers outside the cellar wall4 ,an average farm in a ,middle ,west ,state represents a valuation of #ag1bei4 ,is not the farmer justified in the small outlay required to dispose of the farm sewage8 ,because of the issuance of bonds and the apportionment of sewer assessments for a series of years the city dweller may have his burden distributed over a long period4 ,the farmer does not pay interest on these obligations1 and sewer work can be done more cheaply in the country than in the city4 ,safe disposal of farm sewage is not a passing fad but a vital necessity4 ,besides being an asset a good sewerage installation greatly promotes the wholesomeness and healthfulness of the farm4 ,moreover the benefits are far-reaching1 because farm products go into every home1 and farm and urban populations mingle freely4 99 99 99 99 99 ,transcriber ,note ,two headers 7,kitchen-,sink ,drainage and ,cesspools7 were added to the ,table of ,contents based on their formatting in the text4 ,minor typos have been corrected4 ,illustrations were moved to prevent splitting paragraphs4 ,figure #ba4 was moved adjacent to the directions and specifications on ,page #cb4 ,due to space considerations in the text only version1 emphasis of column headers were sometimes eliminated and some of the tables were rearranged4