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 THE 
 
 SEWERAGE 
 
 / 
 
 SYSTEM 
 
 OF 
 
 VICTORIA, , 
 
 BRITISH COLUMBIA. 
 
 
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 fl 
 
it 
 
 THE 
 
 EWERAGE 
 
 SYS 
 
 H 
 
 OF 
 
 VICTORIA, 
 
 BRITISH COLUMBIA. 
 

 .u 
 
.u 
 
 ^0 ike ^atef aiders 
 
 of ths 
 
 (^iiy of "l^icioria. 
 
 In view of the v^ry necessary and important sewer- 
 age works now being carried out in this City, and the 
 imperative necessity for their extension, the Sewerage 
 Commissioners desire to submit for your consideration, 
 the accompanying short paper, descriptive of the prin- 
 ciples upon which the system is founded. The work 
 has, owing to the immense quantity of rock encountered, 
 proved hitherto expensive ; but the most difficult and 
 most costly part has been performed, and a sufficient 
 sum has been retained to complete the outlet works and 
 main sewers, the latter of which aggregate 22,667 f^^et 
 in length. The Commissioners trust, that the portion of 
 the system on which work has been performed will be 
 ready for use by July, and cordially invite any rate- 
 payer, who is desirous of obtaining any information, 
 either as to what has been done, or as to what is proposed 
 to be done, to visit the engineer's office, in the 
 City Hall. 
 
 110049 
 
' / 
 
 'U 
 
 rll 
 
rll 
 
 THE SEWERAGE SYSTEM 
 
 -OF 
 
 VICTORIA, E. C, 
 
 BY- 
 
 EDWARD MOHUN, 
 
 M. Can. Soc. C. E., M. Am. Soc. C. E., Etc. 
 
 Since in spite o£ the exhaustive manner in which 
 the question of the sewerage of this City has been dis- 
 cussed in the newspapers during the past five or six 
 years, there appears to be a doubt iii the minds of some 
 of our citizens, as to the efficiency of the " separate sys- 
 tem," a few facts in relation thereto deserve the earnest 
 attention of those who have the true interest of tiie city 
 at heart. 
 
 Sewage may be classified roughly under three 
 heads, viz., 1st, The fluid and feculant refuse of dwell- 
 ings which is carried by the agency of water to the outlet ; 
 2nd, The solid matter, such as ashes, animal and vege- 
 table refuse, old boots, and the thousand and one articles 
 of rubbish, the proper place for deposit of which is the 
 dust-bin, and whose ultimate destination, with t)\e ex- 
 ception of the ashes, is the Crematory ; 3rd, The contents 
 of privies and earth-closets, which should be removed in 
 air-tight carts to the Crematory and there burnt with 
 the rest of the garbage. 
 
 It is with the first of these divisions that it is pro- 
 posed to deal under the general head of sewage. 
 
// 
 
 [ 6 ] 
 
 It will hardly be disputed that an efficient system 
 of sewerage is essential to the prosperity of any city, 
 and the health and comfort of its inhabitants. 
 
 A certain class of diseases, known as " pythogenic," 
 will inevitably appear sooner or later in any populated 
 district, in which the laws of hygiene are disregarded. 
 Among these to select one of the most typical, typhoid 
 fever is considered to entirely arise from the violation 
 of those laws. 
 
 Pure air, pure water, and a pure soil are essential 
 to health. Neither the lirst nor second of these can be 
 obtained from a soil saturated with j&lth. Pure water 
 may be conveyed from a distance, but the emanations 
 from a foul soil will contaminate the air. In order to 
 maintain our soil in a state of purity, it is essential that 
 all animal and A^egetable refuse of every description 
 should be removed with all conceivable rapidity to a 
 distance from our dwellings. 
 
 Admitting the necessity of sewerage, the question 
 arises as to tlie system which promises to be the most 
 efficient, and as a secondary consideration the least 
 costly. Here we may profit by the dearly bought ex- 
 perience of others, and while adopting only such 
 measures as have stood the test of actual practice, may 
 avoid those to which partial or entire failure has been 
 
 traced. 
 
 * 
 
 Leaving out of the question the " Pneumatic 
 System," which, though claimed by its inventor, Capt. 
 T. Liernur, as the system of the future, is too costly, and 
 perhaps too experimental to be ventured upon here ; 
 and also setting on one side the utilization of the sewage, 
 as involving a heavy additional expenditure with no 
 commensurate cdvantages ; it will be generally admitted 
 
 (It 
 
[ 7 ] 
 
 :: 
 
 (It 
 
 that our sewage must be carried to the sea, and discharg- 
 ed at a point distant enough from the mouth of the 
 Harbor to ensure its effective and inoffensive distribu- 
 tion in the Straits. 
 
 Having determined upon carrying our sowage by 
 the agency of water to the sea, the first poiL i naturally 
 arising is whether the combined or the seppr.ite system 
 should be adopted. This question the 3. tepayers liavo 
 most emphatically decided in favor of the latt'^r. 
 
 There are many however who fail to clearly dis- 
 tinguish between the two systems, and it has been 
 frequently stated that the pipes used are too small to 
 carry the surface water as well as the sewage. The 
 answer to this statement is obvious, under the "separate 
 system," the surface water is separated from the sewage. 
 
 Were the former to be admitted to the sewers, not 
 only would provision have to be made for tlie carriage 
 of the sewage but also for the . immeasurably greater 
 quantity of surface water contaminated by its contact 
 with the sewage. Taking the system now under con- 
 struction, the outlet sewer is egg-shaped, and measures 
 2 ft. 10 in. in its greatest width, and 4 ft. 3 in. in its 
 greatest depth, and has a fall or 1 in 1200 ; when the 
 depth of sewage is 2 ft. 10 in. or two-thirds of the depth, 
 according to Mr. Baldwin Latham's table the discharge 
 will be 867,569 imperial gallons an hour ; when run- 
 ning full the same sewer will discharge 530,975 gallons 
 an hour, running one-third full the discharge will be 
 110,024 gallons an hour. It is admitted that 5 gallons 
 an hour is an adequate allowance per head for each man, 
 woman and child in the area sewered ; then provision 
 has been made to carry the sewage of a population of 
 73,514 ; while under extraordinary circumstances 106,- 
 195 persons would be provided for. In order to show 
 the enormous size such a sewer would have to be to 
 
[ 8 ] 
 
 «arry the rainfall, let it be assumed that the area to be 
 provided for contains 2000 acres, that the average fall 
 of the land is 1 in 400, that the streets are partly macad- 
 amised and partly paved, and that the heaviest known 
 rainfall has been 1| inches in one hour, then by Mr. 
 Burkli Ziegler's formula (Trans. Am. Soc. C. E., Nov., 
 1881,) Cub. feet a second reaching the sewer, 
 
 =.5x1.5 X 2O0O 
 of the total rainfall 
 
 29 
 
 V_250 _392 equivalent to ,^^ 
 l/ 2000 ' ^ 100 
 
 I 
 I 
 
 The writer has found that nearly ?j of a heavy rain- 
 fall will reach the outlet under favorable conditions. 
 
 Assuming that the sewer is flowing full wdth a 
 velocity of 5 feet a second, its size if egg-shaped will 
 be 12 ft. 6 in. x 18 ft. 9 in., discharging twenty million 
 gallons an hour. It is obvious that in the absence of 
 heavy rains, the quantity of sewage which would freely 
 flow in the 2 ft. 10 in. x 4 ft. 3 in. sewer, would occupy 
 in the larger one so small an area in proportion to its 
 perimeter that a self-cleansing velocity could not be 
 maintained, and it would become as is the case with so 
 many of the large ^sewers of the combined system, a 
 sewer of deposit and an elongated cesspool. 
 
 In support of this view, probably the most eminent 
 authority of the century, Sir Robert Kawlinson says : — 
 
 "For main sewering the engineer may profitably 
 consult tables of rainfall, of areas, and of the flow of 
 water from the site, and it will be quite in order for 
 him to do so ; but if he attempts to apportion sewers so 
 as to be of capacity to receive and remove the flood 
 water, six to ten or more feet below the surface, he will 
 commit a serious and costly blunder, as heavy falls of rain 
 cannot be dealt with in such a manner. A rule of three 
 
 t 
 I 
 
I 
 
 I 
 
 t 
 I 
 
 [ 9 ] 
 
 sum, made up of " area, rainfall and dimensions of 
 sewers," cannot be safely acted upon. Heavy falls of 
 rain must pass at and over the surface as during previ- 
 ous lime, or special drains must be used if they exist, or 
 must be provided if they do not exist, and the sewers must 
 be confined in sub-sectional capacity so as to be equal 
 to the removal of waste water from houses and manu- 
 factures." 
 
 Again in the Public Health Act of England, the 
 Imperial Government lays down the following rule : — 
 
 " Main sewers must not be of capacity to contain 
 flood water of the area drained, as such flood water 
 should be passed over the surface, or by special chan- 
 nels and flood water drain; 
 
 IS. 
 
 It is perhaps not generally known that botli in 
 London and Paris, attempts have been made to keep 
 the rainfall, or storm water, and the sewage separate. 
 
 In a letter dated IGth August, 1886, received by the 
 writer from Sir Kobert Rawlinson, speaking of the 
 drainage of buildings covering a large area, that gentle- 
 man says ; " The old sewers and drains were of large 
 dimensions, sufHcient for a man to walk through, in 
 these large sewers, pipes of cast iron are laid from 4 in. 
 in diameter to IJ in. in the outlet." .Again, '• The vice- 
 regal resideu'^e in Dublin has just been drained, there 
 are two outlets, each 6 in. in diameter, there have been 
 heavy storms of rain but no flooding. The old drains 
 which were large and very foul have all been removed." 
 
 In Paris, in 1883, small pipes were hung on brack- 
 ets in the large sewers in the quarter known as " Le 
 Marais," in order to test the " Waring system," and 
 gave, it is believed, general satisfaction. 
 
[ lo ] 
 
 A consideration of the results of actual measure- 
 ment in the gaugings of flow in sewers in different parts 
 of the world will not be out of place. 
 
 In the report of the U. S. National Board of 
 Health, 1880, the result of gaugings of the dry weather 
 flow in certain sewers are given, and are quoted by- 
 Colonel Waring in his work upon Sewerage. 
 
 1. A large brick sewer, 7,000 feet long, including its 
 branches, in Madison Avenue, New York, the district 
 being about half built upon with houses of the better 
 class. 
 
 Eesult : area of greatest dry weather flow 
 equalled " 3| in. x 4 in. " or nearly enough to fill a 4^ 
 inch pipe. 
 
 2. Sewer in Providence, B. I., 1,391 feet long. Pop- 
 ulation tributary to sewer, 267. x 
 
 Result : greatest flow ;;ths of an inch in depth in a 
 b inch pipe. 
 
 3. A sewer with a single short branch in Burlington, 
 2,790 feet long. Population tributary to sewer, 325. 
 
 Result : greatest flow 11-5 inch in depth in a 6 inch 
 pipe. 
 
 4. A sewer in a closely built part of Milwaukee. 
 
 This sewer is 42 inches in diameter. Thegrade of 
 the sewer at the point where the gaugings were taken 
 was about 1 in 400. The area tributary to the sewers 
 is about 70 acres, all nearly level, closely built, contain- 
 ing -500 houses, mostly dwellings, and a total poi)ulation 
 of 4,035. One hundred and thirty-two of the buildings 
 are not connected with the sewer, tlie remaining 368 
 buildings contain a total population of 3,177, all of whom 
 are tributary to the sewer. There are several hotels, 
 
[ II ] 
 
 saloons, small factories, and livery stables, so that the 
 district is fairly representative of a very closely built 
 city area. 
 
 The greatest flow in the main 42 inch sewer on 
 "washing day", the greatest flow of the week, attained a 
 a depth of 6 inches. 
 
 5. The Hospital at Ploughkeepsie with 301 persons, 
 consuming 265 gallons of water a day each, produced a 
 sufficient amount of sewerage at its maximum to create 
 a stream in a 6 inch pipe 3| inches deep. 
 
 6. In a sewer in Ploughkeepsie, 15 inches in'diameter, 
 2,766 feet long, with a population of 426 tributary to it. 
 The greatest flow in a 6 inch pipe was 2^ inches in 
 depth. 
 
 7. The Compton Avenue sewer, St. Louis, 7 feet 
 3 inches diameter, accommodates 1,370 houses inhabited 
 by 8,200 persons, in the houses are 1,391 water taps. A 
 dam was placed across the sewer in which was built a 
 12 inch pipe 20 feet long, gaugings were taken simul- 
 taneously at there different i)oints, the average of these 
 being the assumed depth in the twenty feet of pipe ; 
 the greatest depth of flow was less than 7 inches. 
 
 8. The Ohio Avenue sewer, St. Louis, 7 feet 3 inches 
 in diameter, sewering 120 houses with a population of 
 of 760, was gauged and the greatest flow found to be 1| 
 inches in a 6 inch pipe. 
 
 9. In George St., London, a sewer 3 feet 6 inches x 5 
 feet 6 inches sewered forty-four acres o£ closely built 
 area ; in the bottom of this sewer a 12 inch pipe, 560 
 feet long, was laid through a dam at its head ; the pipe 
 was rarely observed to be more than half full at its 
 head : and it was found that the sum of the cross 
 sectio- delivering to this half full, 12 inch pipe, was 
 equal to the area of a circle thirty feet in diameter. 
 
[ 12 ] 
 
 It is useless to multiply cases to show what an 
 enormous amount of sewage, even small pipes properly- 
 laid will carry ; as however particular stress has been 
 laid upon the smallness of the sewer, an 8 inch pipe, 
 falling into the Douglas Street branch sewer, and laid 
 on Yates Street from Blanchard Street westwards, a 
 few remarks thereon will not be out of place. 
 
 The pipe provides sewerage for a total front age, 
 including both sides of the street, of 1,C80 feet, and has 
 a fall of 1 inch in 250, the least fall given anywhere to 
 an 8 inch pipe. 
 
 Let us assume that each 25 L'eet of frontage is 
 occupied by a house with five inhabitants, and that each 
 person supplies five gallons an hour of sewerage, it is 
 obvious that we have to provide for a fiow of 1,C80 
 gallons an hour ; the pipe however should nut run full, 
 and it is usual in sewerage works to calculaij its 
 capacity when running half full. 
 
 Mr. Baldwin Latham's table gives for an 8 inch 
 pipe with a fall of 1 in 250, running half full, a 
 velocity of 2.55 feet a second, and a discharge of 10,012 
 gallons an hour. 
 
 Mr. Latham's tables were however calculated 
 prior to the exhaustive experiments of Ganguillet and 
 Kutter, whose formulae are now universally adopted 
 by hydraulic engineers. By the writer's Tables of 
 Velocity and Discharge in sewers, based on Kutter's 
 Formula, an 8 inch pipe, running half full, with a fall 
 of one in 250 will, if well laid with the Stamford 
 joint, have a velocity of 2.11 feet a second, and a 
 discharge of 8,270 galhms an hour. That is to say the 
 sewer when running half full, is of ample capacity to 
 supply 1 ,054 people, which would be a population of 
 
[ 13 ] « 
 
 over 24 persons for each house of 25 ft. frontage without 
 taking into consideration the double frontage occupied 
 by corner buildings. 
 
 The writer has no hesitation in asserting that any 
 difficulty which may arise in keeping sewers clean, will 
 be due to the fact that they are much larger than 
 required for the present jiopulation ; but it has been 
 found by experience tliat in sewers of the separate 
 system it is not advisable to use a smaller pipe than 8 
 inches diameter, not because the sewage could not be 
 easily carried in a smaller pipe, but because of the 
 carelessness of the peope themselves, who alloAv all sorts 
 of rubbish to pass through their house sewers into the 
 public mains. 
 
 The first instance in which the " separate system " 
 was introduced, was when Sir Edwin, then Mr. Chadwick 
 introduced it in Alnwick, Nortlmmberland, in 1849. 
 The population was about 7,000. The water supply 
 150,000 gallons a day, with some 1,400 Avater closetc in 
 regular use. The outlet main was 18 inches diameter ; 
 the sewers 15 inches, 12, 9, and 6 inches, and the house 
 drains 4 inches in diameter. These sewers are still 
 giving every satisfaction. 
 
 It has generally occured in cities, Avhere the separ- 
 ate system has been introduced, that an outcry has been 
 raised against the size of the pipes used ; this outcry 
 has invariably been }'aised by those ignorant of the 
 principles of the system, who not having studied the 
 laws by which engineers are guided, and being unwill- 
 ing or unable to learn, pretend to teach their fellow 
 citizens that which they do not understand themselves. 
 
 It would be as reasonable to expect a man, who haa 
 not received a special training, to be competent to in- 
 struct a doctor, or a lawyer, as an engineer in his work, 
 
^ [14] 
 
 for to be successful in any of these professions requires 
 years of hard study, and hard work. If this were not 
 the case it would be quite in order for the carpenter to 
 teach the bricklayer, and the bricklayer teach the 
 plumber, and the plumber teach the stonemason, and 
 the stonemason teach the machinist, apd so on ad 
 infinitum. 
 
 In deciding whether in a given case the "combined" 
 or "separate " system, or a combination of both should 
 be adopted, the engineer has to take into consideration 
 several factors such as topography and climate. 
 
 That the " separate system " has been adopted and 
 gives general satisfaction in a very large number of 
 cities, is a sufficient proof to any unprejudiced mind 
 (under the natural favorable conditions, such as exist in 
 Victoria) of the wisdom of introducing it ; not to men- 
 tion its great recommendation to taxpayers, that its cost 
 is far less than would be incurred in the construction of 
 the " combined system." 
 
 The few brief statements following, as to the 
 sewers now being laid may be of some interest : — 
 
 1st. The sewers of the separate system are built to 
 carry sewage, and the water from the flush tanks 
 with a certain proportion of roof water. 
 
 2nd. The main outlet sewer discharges nearly at the 
 level of high spring tide, into a oiiamber from which it 
 is conveyed in a submerged steel pipe out to deep water, 
 where it is discharged beneath the surface at low spring 
 tide level. 
 
 3rd. The sewers are tight; stra'ght and true to 
 grade, all changes of direction whether horizontal or 
 vertical, are made at manholes, since it is at such points 
 that obstructions are most likely to occur. 
 
 4th. Ample provision has been made for ventilation. 
 
[ 15 ] 
 
 5th. By means of automatic flush tanks, the whole of 
 the sewers can be flushed daily or at as frequent inter- 
 vals as the feed may be set for. 
 
 6th. All junctions aie so formed that the discharge of 
 the subsidiary main into the larger stream is at such a 
 level and in suchta direction as to combine the two 
 streams without checking their flow and causing eddies. 
 
 7th. Means for inspecting every portion of ihe sewers 
 are provided, as also of access at frequent intervals. 
 
 It has been on more than one occasion publicly 
 stated that where sewers have been laid in a rock trench 
 no precautions have been taken to protect the main 
 pipes from the effects of the blasting which will be 
 necessary in order to make house connections. These 
 statements are utterly without foundation ; at each anti- 
 cipated junction, before the sewer was laid, the rock was 
 excavated at the side, so that the main pipe would not 
 be endangered by future blasting. 
 
 Such are the general principles upon which the 
 sewerage system of Victoria is now being constructed. 
 It matters not, however, how well and thoroughly the 
 main and branch sewers have been designed and exe- 
 cuted, if the house connections are faulty. The strength 
 of a chain is that of it Aveakest link. 
 
 It is a well known axiom that no man has a right to 
 do that which may imperil, or cause annoyance to his 
 neighbour ; and one defective house sewer may form a 
 centre for disease extending over a wide area. 
 
 Since it is as unreasonable to expect the average 
 householder to be a competent authority on questions of 
 sanitary science, as to expect him to be an expert in 
 physic, surgery or law, or any other profession for 
 which a special training is requisite, it becomes neces- 
 sary to take such measures, in the interest of the whole 
 community, as may place it out of the power of any 
 
1 
 
 [ i6 ] 
 
 individual to imperil the health of his fellow, either 
 from ignorance, greed or obstinacy. 
 
 To view the matter from the lowest standpoint, to 
 most of us loss of health means loss of income ; and it 
 has been estimated that every case of sickness repre- 
 sents a dead loss to the community of Ififty dollars ; it is 
 beyond a doubt the duty of civic authorities to make 
 such regulations as experience has shown are necessary 
 both for the individual and the public safety. This has 
 been done in many cities, where all connections with 
 sewers, and the plumbing of all buildings have to be in 
 accordance with certain regulations, which are enforced 
 by a strict system of supervision by competent officers. 
 
 The advaiiiages to the individual are obvious, 
 whether he buys, rents or build, he knows that all the 
 plumbing has been done under competent supervision, 
 nor is he distracted by a multiplicity of opinions which 
 may or may not be worth anything and of the value of 
 which he is unable to judge, for this is not a case in 
 which in the multitude of counsellors he will find safety. 
 
 Before closing this paper, a point which has caused 
 considerable discussion may be referred to, viz.: The 
 proposal to carry the house sewers from the public 
 sewers to the street line at the time of the construction 
 of the latter. 
 
 This proposal has been consistently urged upon the 
 Council since prior to the inception of the work, and 
 has only been prevented by legal difficulties, which 
 appear to prohibit the Council from taking any steps in 
 the matter under their present Act. 
 
 In conclusion Sir Bobert Rawlinson, C. B., Mr. T. 
 C. Keefer, C. B., and Mr. Rudolph Hering, three of the 
 most eminent engineers of the day, have expressed 
 them%elves most distinctly in favor of the system now 
 being constructed ; against it no sanitary engineer of 
 established reputation has ventured to oflEer an opinion. 
 
 ^1 
 
 vja 
 
V