None
Extra Cost Involved by Complexity and Novelty of Design. — An interesting example of the effect upon the contractor of the difficult labor conditions induced by the war, was shown in the comparison of bids upon two different types of sewer con- struction at Lynn, Mass., in 1920, the one involving simple mass concrete construction, the other substantially lighter reinforced concrete structure. The heavier type of structure commanded the lower bid, although there can be little doubt that under normal conditions with reasonably skilled contractors bidding, the reinforced type of structure would have proved the cheaper.^ Similarly in the letting of a contract for a 10,000,000-gal. covered concrete masonry reservoir at Dayton, Ohio, in 1917- 1918, a more attractive bid was obtained upon a reinforced, flat-slab roof supported by cylindrical columns than upon a groined-arch type of structure which would normally have yielded the lower bid. The reason for this condition was found in the fact that the local contractors had not had experience in groined- arch construction and were adversely influenced by the failure of such a type of structure built in Qeveland sometime prior thereto, whereas they were skilled in building reinforced flat-slab concrete floors and had available forms adapted to the proposed structure, which had been used on other work. In each of the above cases, therefore, abnormal local conditions governed the type of structure chosen and the minimum price. Classification of Items. — In general, costs may be segregated under the items of labor, materials, supplies, plant, general expense and overhead costs, and profit. Under general expense are usually included engineering and legal costs, bonding and liability insurance, bookkeeping, timekeeping and storekeeping, rentals, office and miscellaneous expense (telephone and telegraph, stationery, supplies, etc.), interest and discount. The cost of the major items may for convenience be further subdivided into different items. Thus, the item of excavation may be subdivided into excavation in trench, hoisting excavated material out of trench, hauling or transportation, wasting and » Eng. Netoa-Rec. vol. Ixxxv, No. 4; July 22, 1920, p. 148. SEWERAGE AND SEWAGE DISPOSAL Ijii II ^x= F= pz — fT. ^ v^ — = = 1 i = E 1 E i! 1 = = * i 1 , n — t V^l V \\\\\rV> ■40a] losufi i»d j3was^[un|ioQ uij^so^ COST ESTIMATING * 561 spoiUng, backfiUing, compacting, ramming or puddling, shoring, sheeting, etc. It may involve the use of machinery, and fair allowances for its operation, repair, rental and depreciation. The operation of the machinery may in turn involve supplies, coal, oil, water, miscellaneous items, etc. While the keeping of these subdivided elements of cost may be very helpful to the young engineer, the ascertainment of the larger elements of cost is far more important, because of their comparability with the records of others. Methods of Appljdng Data on Cost. — Special methods of apply- ing data on cost must be developed for different pieces of work. Different men may accomplish the purpose in a thoroughly satisfactory but totally different manner. Fig. 218 and Table 69 will serve to indicate methods for preparing estimates which have been used in certain cases, but it is to be clearly borne in mind that they are not generally appli- cable and apply directly only to similar conditions. In Chapter VI, Figs. Ill, 112 and 113 give diagramatic methods of showing the theoretical quantity of excavation for trenches of different depths and widths and in Chapter VII, Table 29, methods for showing quantities of lumber required for shoring sewer trenches in the manner assumed. Ih Table 69 is indicated a method of assembling data relating to the cost per linear foot of laying sewer pipe of different diame- ters and in Fig. 218 are shown curves giving the cost of pipe sewers under the different specific conditions indicated. In Figs. 219 and 220 are shown diagrams of cost of circular and semi- elUptical sewers and of vitrified pipe sewers made by the authors for use in estimating cost of sewer construction for a report in May, 1919 to the City of Springfield, Mass. These diagrams, too, are applicable only to such conditions as were assmned to prevail in Springfield at that time. They are shown merely for the purpose of indicating methods and not for the submission of specific data on cost. Progress Reports. — ^Progress reports, recording the number of men employed, the wages paid and the amount of work accom- plished along simple Unes, are also desirable. They should be prepared to meet the specific character of work, method of con- struction and form of contract, and be so simple in form as to have wide applicability and convenience in use. Table 70 is an example of such a simple form prepared for insertion in the 36 562 SEWERAGE AND SEWAGE DISPOSAL o o Z e o g o OQ o o 05 CO .a 08 WN O 00 to CS| X  o t>. CO  1 , 15 Fb Co 'Ying,ManhoJes.,Mtfs, House. nnections . Brfraordinaru Pumpim / Engineer/^ c /, Trench C«Vd, Lu'nbert50pi!rl1ff:(dalM.f— Vi-t. P'p! -Brhnd.-56 %diec. 7 I4-W WrW f!.?0 710 r Stand. Pyx S''5 in. / // May /j 1913. 1 / // // 10 9 a / /, y^ V / r'/ / //t. 27 y /, ' 1 // A ^ ?* /. /, y A /j^ 6 ^ ' 2 > '/ f ' p, i % ^ ^ -Is ^ >^ ^ -10 2 ^^ --8- ? 0 z 1 4- 6 8 10 IE 14- 16 le ZO 22 24 J Depth of Cut in ,Fe€t Fig. 219.— Cost of vitrifieri pipe » Final Estimate. — An example of a form of final estimate, upon a piece of sewer construction done by contract, is appended. The unit prices involved were abnormally high, as the work had to be let at the peak of war prices : therefore they are of no signifi- cance and are not of general applicability. COST ESTIMATING 566 SEWERAGE AND SEWAGE DISPOSAL OQ I s ^ a on S CO 88SSSSS S.^^^r^»^.^.^.S«^^. looiotoocdo ^eoa>coa6c4*-4eoc)eo*-4 00*-4 CO ^ vO> ^ aaaaaaaaaaaaaa g8ggg§Sg8§g§§§ o PiOi&QiAQiOtPi&OiOiiPiOiOt 8§SSSS§ oooooooooooooo ....... ^^^^^'^t^^^^^^^^ e^^F-i CO >o J9fi9S595S9fi9S JW 11 ^Q ^Q lw> ^B ^D ^Q ^D Bm ^D ^Q to >o coOt"^oociooo^csioooococoe*i ^^ddM*^'ei»c^*M*^ddd •R ^rt •rt •rt ^Q *Q *Q lA p d d Csl lOOiOCOM^O CO t»»H .cooco • g^ CO O MCO «*« ««.4 <*i« V4 oocoooQ»oe«*-«. • • • ■ • 2 2 . . « . . .3 9 9 c' c' S V c> «•»> 0»0 COiOQO T-4  o O 0) 0) 03 > g hi hi k. § S ^ 45 d d d hi o o o-^ o O CJ V 08 ^"tS M M S S ^ WWOtfOOOO I: 'd>0 £ b b b hi .5 w.^ 08 08 08 08 00 eoo n 'J^-S-t^S 222 t Eg fl c a d ftfto. oCoMOOoooooo^c'^oBOBaoBOooaoen 3ua«i. 2' ^A 2-§ dddddddddddddc S s ' 55 >« •-* -^ -^ -* -"^ -^ •- •- "^ •"* •- "^ — — ^td ^-.SC^OOOCOOOCOOONOOOCONOOO •c.t:^ d CS -o O u'Q «> Q COST ESTIMATING 567 SSaS SSS SS8SS888SS 888 888 Old U3^ o o o> CO CO 00 CO 00 p p p 00 00 00 22SS 888 88S§888o 6666 ^^c^ i'i'^iiii ^ 22 woocoo" " 00 « a o (3 0) ^ d o a Qoocooo a coo d pinid d « dco d^ d d 2g '" '<N « d o d rH d o d •5: 08 2 08 O (8.2 08 9 08 ^l"^ 0). 08 « O o ^^ fld d d c8 08 'o'o d d V S o s| ikl^ !■£ i i a' rt » © ^ 9 b O 0';9 1^1 g'g'g|g| gill 2 a is d d 's •2 08 « d^ s © « © M o 05 o o 08 0} >» I s o g d o o © u O © .A M u O d o O (1 ®^ "S § Ti OOON ococo CO CO OS i-hNCO 000 © « © 08 08 08 d d d 000 © © © s s d d d d © © © 08 08 08 s s s I a OS :a ■*» u © •§ d © s d s o a < e.O 0.0 O'O O'O v<*^Cb Q>Q o o O^^CJC>«e0C0C0C0C0C0C0^»O«D^.0000000»O'-"M ^_|l-Hi-ll-Hi-li-Hi-li-l^l-H*-4i-ll-HiHl-Hi-l^fHfHC4C«C4 ^ INDEX Acids, added in sludge pressing, 424, 439 disinfection, 527 in mine drainage, 527 in Monongahela River, 527 Activated sludge process, activating the sludge, 398, 399, 400 active sludge necessary, 398 adaptability of process, 403, 404 aeration periods, 404-406, 407, 413, 420 tanks, 411, 415 aerobic conditions necessary, 396, 407 agitation, 396, 407, 409 air compressors, 416, 417, 418 diffusion, 408, 413, 414, 415 requirements, 407, 408, 409 supply pipe, 413, 415 at Chicago Stockyards, 406, 424 at Cleveland, 403, 411 at Houston, 412, 424 at Lawrence Experiment Station, 395, 423 at Manchester, Eng., 395, 399 at Milwaukee, 401, 402, 403, 404, 405. 409, 410, 412, 413, 414, 419. 420, 421, 422, 424 at Sheffield. Eng., 409 at University of 111., 398, 399, 407 at Worcester, Mass., 405, 422, 424, 425 blowers, 416 character of sewage influences period of contact, 407 coagulation. 396. 397. 398 color removal, 403 defined. 15 described. 396 diff users. 408. 413, 414. 415 pipe, 413, 415 plate. 408. 413. 414, 415 early experiments, 395, 396 effect of temperature. 402, 403 effluent, 403, 404 floe, 396, 397, 400, 401 impractical at Worcester, Mass., 405 management, 425, 426 measurements, 409, 410, 411 odors removed, 403 origin, 395 Activated sludge process, oxygen require- ments, 407 preparatory treatment required, 405 progressive changes during, 404 purification secured, 403, 404 sedimentation, 396, 410, 418, 419 septic decomposition, 400 sludge, addition of acid, 424, 443 beds, 422, 423 character, 407, 420, 421, 422. 423, 429, 430 concentration, 401, 421 conditioning 424 de watering, 424. 425. 441. 442 digestion, 402 disposal, 422, 423, 424, 425 drying. 422, 423. 425, 443 fertilizer value, 423, 424, 425, 443, 445. 446. 447 floe. 396. 397. 400. 401 marketing. 423, 424, 425, 446, 447 measurements, 409,-411 nitrogen content. 423 physical properties. 400. 420 pumping. 422 • reactivating. 401. 402 return, 405, 406 soUds in. 396, 400. 401, 421 velocity in pipes, 421, 422 volume, 421, 422 standard of purification, 404 theory, 396 venturi meter, 411 winter operation. 402 Adams, Col. Julius W., run-off formula, 80, 81. 82 Aeration, blowers for compressing air. 416 periods in activated sludge process. 404, 406. 407. 413. 420 predecessor of activated sludge process. 395 requirements of various sewages in activated sludge process, 408 requires power plant, 21 tanks, 411 diffuser plates, 408, 413, 414, 415 pipe diffusers, 413, 415 with and without activated sludge, 398 Air compressors, centrifugal, 416, 417 Connersville, 417 efficiency, 418 569 570 INDEX Air compressors, General Electric, 417 Hytor, 417 Nash. 417 positive pressure blowers, 416, 417 power requirements, 418 Root, 409, 417 rotary blowers, 416, 417 lift, for pumping sludge, 393, 422, 437 Air-lock feeds for contact beds, 459 Akron, Ohio, exceptional growth, 24 Imhoff tank sludge moisture, 385 Albany, N. Y., density of population, 28 Algs, see Plankton. Alkalinity of sewage of American, English and German cities, 306 Allen, Kenneth, sludge capacity of Imhoff tanks, 386 Alliance, Ohio, leakage into sewers, 39 Altoona, Pa., leakage into sewers, 39 American Public Health Association, defini- tions, sewage disposal and treat- ment, 13-17 sewerage features, 1-3, 5, 6 oxygen consumed method, 289 putrescibility test, 291, 292 American Society for Testing Materials, specifications for castings, 134 for clay sewer pipe, 242, 243 Amherst, Mass., efficiency of sand filters, 520 intermittent filter operation, 508 Ammonia, albuminoid, 288, 306 free, 288 nitrogen cycle, 286 Anaheim, fertilizer value of air-dried Imhoff tank sludge, 445 Analyses, bacteriological, bacteria stan(^ard for waters, 301, 531 B. coli determination, 301, 302 B. coli standards, 301, 302 classification of waters by, 301 of efl3uents from filters, 469 of sewage, 296, 297 of sewage after disinfection, 530, 531 significance of, 300, 301 chemical appearance of sample, 295 care necessary, 293 comparative, water and sewage, 307 determinations, alkalinity, 371, 372 ammonia, free and albuminoid, 288 biochemical oxygen demand, 292, 293 nitrate method, 293 [relative stability method, 292 chlorine, 294 colloidal matter, 285 fixed residue, 285 fixed solids, 285 loss on ignition, 285 mineral matter, 285 nitrates, 289 nitrites, 289 Analyses, chemical, determinations, nitro- gen, 286, 287 odor, 295 organic matter, 285 organic sulphur, 287, 298 oxygen consumed, 289 oxygen dissolved, 281, 289, 204 putrescibility, 290 solids, 283, 284, 304, 805 Gooch crucible, 283 grams per capita calculation, 304, 305, 307 Imhoff glasses, 284 importance of, 280 lindtations of, 280 of sewage of American, English and German cities, 306, 307, 308 of filter effluents in Massachusetts, 520 of Massachusetts water supplies, 307 Milwaukee sewage after treatment, 404 putrescibility tests, 290, 291, 292 sampling, 281 significance of, 282 -296 sludges at Worcester, Mass., 432 solids in sewage, 305, 306 sterilizing samples, 281, 282 suspended matter, 305, 308 titrating, 371, 872 of sewage, see Analyses, bacteriological, chemical, of water, dissolved oxygen determina- tion, 281 limitations of chemical, 280, 281 of Massachusetts supplies, 307 sampling, 281 significance of bacteriological, 300, 301 solids contributed by water, 303, 304, 305 sterilizing samples, 281, 282 Andover, Mass., efficiency of sand filters, 520 flies on filter, 500 intermittent filter operation, 508 sewage flow, 40 Angle of repose, 217, 218 Arches, analysis of masonry, 119, 261 brick, 111, 264, 267, 268 concrete, 265 elastic theory, 261 forms, 268 least crown thrust, 261 materials for, 264 reinforced concrete, 265 voussoir method, 261 Ardern and Lockett, named activated sludge process, 397 Area, increase of, in cities, 27 of American cities, 29 INDEX 671 Aahton Booth cleaner, 433 Aaphalt joints, 260 Astoria, Ore., tidal range, 317 Atlanta, Ga., ImhofF tank sludge moisture- experimental tank, 385 Peachtree Cr. tanks, 885 Proctor Cr. tanks. 385 suspended matter in settled sewage, 308 Attleboro, Mass., intermittent filter opera- tion, 608 sewage flow, 40 B. coli, see also Analsrses, bacteriological, significance in waters, 301 standards, 300-301 B. tjrphosus, 301 Bach, Dr. D. W., diffusion between cham- bers in Imhoff tanks, 380 Backfilling, economic considerations, 254, 255 hosing, 254 inspection, 188 nature of material, 253 puddling, 253 ramming, 254 rolling, 254 settlement, 254, 255 should be done promptly, 255 surplus material, 255 tamping, 254, 255 Bacteria, act on organic matter, 18, 287, 297, 299. 362, 397. 403, 503 action within floe, 397, 398 B. coli determinations. 300, 301 carbon cycle, 298 classification of waters by, 301 denitrifying. 286. 300 effect of temperature, 402 of trade wastes, 297 of winds on distribution in waters, 323 oxidation, 287, 299 increase after hypochlorite disinfection, 532 in sewage, 18 influence filter bed action, 281 nitrate formers, 300 nitrite formers, 300 nitrogen cycle, 286 fixation, 286 number in sewage, 296, 297 oxidise sludge deposits on banks and shores, 313 oxygen requirements, 287 Pasteur's grouping, 296 produce nitrification, 299 reduction by application of liquid chlorine, 530, 531 removal by various methods, 469 in septic tanks, 362 Bacteria, significance in waters, 301 standard for Massachusetts drinking water, 529 standards for waters, 301, 531 sulphur cycle, 298, 299 Baffles, Imhoff tanks, 391 inlet of settling basin, 357 Baltimore, Md., butterfly valve, 499 complete system designed, 10 density of population, 28 discharges sewage into Patapsco, 11 dosing apparatus, 498 drum screen, 345 flight sewer, 141 house sewage pumped, 11 Imhoff tanks, 386, 387, 390 pumping sewage at, 11, 171 rainfall curve, 66 sewer section, 113 sewerage plan, 11 tidal range, 317 trickUng filter, 489, 491, 492, 498 Barbour, F. A., dosing siphon, 516, 517 Mansfield contact beds, 457 septic tanks, 369 North Attieboro settling tanks, 434 Bartow and Crawford, air requirements of activated sludge process, 407 Bartow and Mickle, diffuser tests, 415 Bartow and Mohlman, aerated sewage, 398 method of activating sludge, 399 sludge produced by activated sludge process, 421 Batavia, N. Y., infiltration, 36 Batter boards, defined, 187 in structural surveying, 187 to mark sewer line, 182 Bellmouth junction, 146 Berlin, radial system of sewers, 10 Birmingham, Eng., screening sludge, 349 sludge almost odorless, 431 vertical flow sedimentation, 360 Black, Col. W. Bleich, S. B., design of inverted siphons, 151 .:/'■ 672 INDEX Blowers, see Air compressors. Bolton, Eng., Fidler sludge remover, 435 Boston, Mass., cage racks, 341-343 density of population, 28 disposal by dilution at, 328 float measurements in harbor, 319 manhole step, 143, 144 rainfall curves, 58, 66 regulator, 163 screen, 350 screenings, 350 sewer sections, 113, 114, 117 Summer St. pumping station, 174, 175, 176 tidal range, 317 tide gate, 169, 170 water consumption, 32 Boston Society of Civil Engineers, report on inverted siphons, 148 Braces, deating, 221, 223, 226, 227 on curves, 230 economy in lumber, 221 extension, 226, 233, 236 hammers for driving, 235 placing on rangers, 221, 234 should be tight, 233 size, 233, 234 stay, 229 with vertical sheeting, 212, 220 Bradbury, E. G., siphon discharge formula, 515, 516 Branch sewers, construction, 252, 253 defined, 2 placing, 252 Bremen, disc screen, 348 sludge car, 433 Brewer, Bertram, designer of pumping station at Waltham, 176 Brick arches, bonding, 264 centers or forms, 267, 268 rowlock bond, 264 typical, 111 inspecting, 189 invert lining, 119 laid as headers, 278 laying, 266, 279 manhole base, 278, 279 sewers, arch forms, 268 centers for, 267 construction influences section, 261 erosion of, 99, laid on cradles, 267 laying brick, 266 profiles for, 267 sections, 255-261 stability, 119 Bridges, to carry sewers, 155 Bristol Company, diaphragm pressure gage, 88 Brockton, Mass., analysis of raw sewage, 307, 308 Brockton, Mass., analsrsis of water, 307 efficiency of sand filters, 520 infiltration, 36, 39 intermittent filter oi>eration, 508, 524 ratio of water supply to sewage, 30 sewage flow, 40 Weand screen, 345 Bronx, Borough of, N. Y.» catch basin, 130 cover, 132 inlets, 128, 132 sewer section, 110, 117 Brooklyn, N. Y., abnormal growth, 26 experience with siphon clogging, 149 sewer sections, 115, 117 typical circular sewer section, 112 use of separate and combined systems, 13 Brown, N. A., experimental grit chamber, 334 Brussels, sewer section, 118 Buffalo, N. Y., density of population, 28 Bugbee, Julius W., hypochlorite apparatus, 536 precipitation tanks. Providence, 375 Buggy for laying pipe, 247 Builders Iron Foundry water level recorder, 87 Bureau of Surveys. U. S., rainfall formula, 66 Bdrkli-Ziegler, run-off formula, 80, 81, 82, opp. 85 Calvert, Texas, splash plate and discharge tube, 481, 483 Canton, Ohio, infiltration into sewers, 36, 39 Carbon cycle, 298 Carriers of typhoid, 301 Carson, Howard A., catenary section, 259 Castings, box step, 143 catch basin, 130, 131, 132 drop manholes, 141 inlets. INDEX 573 Cesspool, defined, 1 Chairs, concrete, 272 metal, 272 on sewer construction, 268 Charleston, S. C, tidal range, 317 Chart, for sewage gages, 88, 89, 91 from Fitz Gerald gage, 58 from Fries gage, 57 Chemical precipitation, addition of clay, charcoal or soil, 370 alkalinity determinations, 371, 372 with erythrosine, 372 with phenolphthalein, 372 with calcium oxide, 370 copperas, 371 ferric sulphate, 370, 372 ferrous sulphate, 370 Ume, 370, 371, 372, 373 slaked lime, 372, 373 sulphate of alumina, 370, 372 sulphate of iron, 371 defined, 15 degree of clarification, 371 described, 370 design of tanks. 375, 376 detention period, 374 effluent, 371 formation of floo, 395 at London, 372 at Providence, 372, 373 for industrial wastes, 371 theory, 371 at Worcester, 372 Chesapeake Bay, receives Baltimore sewage, 11 Chestnut Hill, precipitation records, 60-61 Chicago Drainage Canal, 329 Chicago, 111., analysis of raw sewage, 307 of water, 307 density, 28 drainage areas, 41 dry weather run-off, 41 exceptional population growth, 26 rainfall curve, 66 sewer section, 117 suspended matter in settled sewage, 308 Chicago Stockyards, belt screen, 349 fertilizer value of air-dried Imhoff tank sludge, 445 Imhoff tank sludge moisture, 385 proportion of activated sludge in aerating tanks, 406 sedimentation tanks for activated sludge process, 419 Chimney, defined, 6 Chlorine, as disinfectant, 528 determination, 294 effect of winds on distribution in Milwaukee Bay, 324 in sewage of American, English and German cities, 306 Cincinnati, Ohio, area increases, 27 gaging chamber, 90 hourly rates of sewage flow, 46 manholes, 136 plankton cleanse stream, 302 sewage flow from industrial districts, 47 gage, 89 Cities, comparative sewages of, 306] densities, 28 growth of American, 25 in Massachusetts, daily sewage flow, 40 policy re extension, 28 population and areas of American, 29 water .consumption, 30, 31, 32 Clarification, defined, 14 Clark and Gage, aeration tanks, 411 coUcHdal matter in sewage, 423 contact beds, 463, 464, 465, 466 increase in bacteria after application of hypochlorites, 532 oxygen requirement to stabilize sewage, 407 sludge densities, 383 studies on liquid chlorine, 529 trickling filters, 475, 476, 477, 478 Clean-out chambers on inverted siphons, 149 Cleats, 221, 223, 226, 227. 230 Cleveland, Ohio, aeration tanks, 411 currents in lake, 321, 328 density of population, 28 fertilizer value of air-dried Imhoff tank sludge, 445 intercepting system plan, 19-20 sludge- produced by activated sludge process, 420 storm overflow, 167, 168 water consumption, 32 wellhole. Coagulation, in activated sludge process, 396, 397 in chemical precipitation, 370, 371, 372, 373, 374, 375 Coefficients, c in Hazen and Williams form- ula. 101, 103, 422 ci in run-off formulae, 86 n in Kutter's formula, 101, 103, 121, 122 n in Markmann formula, 120 n various values, 102 Coffin regulator, 162 Cohesion of soil, 214 674 INDEX Colloidal matter, defined, 14 Columbus, Ohio, bacteria in sewage, 297 contact bed, 450, 453 density of population, 28, 29 septic tank, 365, 366, 367 outlet, 366 sludge measurements, 429 suspended nCiatter in settled sewage, 308 trickUng filter, 489, 490 Combined sewer, defined, 2 system, allow for maximum velocities, 99 compared with separate, 8 defined, 3 in Brooklyn, 13 in Manhattan, 12 method of tabulating data for, 78, 79 relief outlet increases hydraulic gradient in, 95 Commercially dry sludge, defined, 16 Common sewer, defined, 2 Concentration, time of, 68 Concord, Mass., cleaning sand filters, 525 efficiency of sand fiilters, 520 flushing chamber, 158, 159, 160 intermittent filter operation, 508 leakage into sewers, 39 manhole invert, 137 sewage flow, 40 Concord grate, catch basin cover, 127, 132 Concrete, aggregates for sewer pipe, 246 inspection of, 189 arches, 261, 265 base, for brick manhole, 278, 279 consistency, 269, 270, 271 forms, 270, 272, 273 inspection of materials, 189 inverts, 270, 271 mixing, 269, 270, 273 placing for sewers, 269 pouring, 273 reinforcement, gives added resistance, 119 in arches, 265 in sewer pipe, 246 inspection, 189 placing, 272 sewers, 255 analysis of arches, 261, 265 built in one operation, 270, 273, 274 in more than one operation, 270, 271, 273, 274, 276, 278 construction influences section, 261 erosion of, 99, 1 19, 266 flatter inverts preferable in, 110 forms for, 268, 270, 272, 273, 274 lining, 99, 265, 266 manufacture of pipe, 246 monoliths, 119 placing concrete, 269 reinforcement, 272 Concrete sewers, pipe, 246 pouring, 273 reinforced, 119, 246, 265, 272 sections. 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 255, i;66, 257, 258, 259, 260, 261, 262 stability, 119 subject to compressive stress, 119 Connections, house, defined, 2, 3 incorrectly made to separate sewers, 9 minimum sise of house, 3 Connor, W. N., construction costs, 552 Consumption of water, 30-34 see also Water supply, consumption. Contact beds, absence of flies and moths, 449 air lock feeds, 459 arrangement of double, 448, 452 automatic control, 458-460 at Columbus, 450, 453 at Lawrence Experiment Station, 450, 454, 463, 464, 465, 466 at Manchester, Eng., 450, 451, 453, 454. 455, 456, 462, 463 at Mansfield, Ohio, 455, 457 at Plainfield. 455, 457, 462 bacterial action, 449 character of influent, 449 clogging. 451, 454 comparison with trickling filters, 500 defined. 16 depth. 454, 455 described. 448 drainage, 454 filling and draining, 449 floor, 455 foundations, 455 head, 449 loss of capacity, 451, 454 materials of construction, 452, 453 maturing, 450 multiple contact, 452 operating, 449 results, 461-166 removal of bacteria, 469, 470 size, 455 standing empty period, 450 full period, 450 theory, 449 timed siphons, 458, 460, 461 underdrainage, 454 Contamination, defined, 13 Copeland, Wm. R., activated sludge produc- tion at Milwaukee, 399 analysis of effluent from activated sludge process, 404 concentration of activated sludge, 401 effect of varying aeration periods with activated sludge process, 404 proportion of return sludge at Mil- waukee, 406 INDEX 675 Copeland, Wm. K., sweeping action of floe, 397 velocity through sedimentation tank, Milwaukee, 419 Copper sulphate, disinfection, 527 method of treating alga, 528 Cost data, cleaning out sludge, 433 Connor's studies of construction costs, 552 degreasing sludge, 447 dumping sludge at sea, 438 German sewage farms, 547, 548 Paris sewage farms, 546 reasons for excluding, vi replacing sand on intermittent sand filters, 524 trickling filter, 473 see also Prices estimating, advantages of cost keeping, 552 application of cost data, 560, 561, 562, 564, 565 bookkeeping versus cost-estimating, 551 caution on contract prices, 556 classification of cost items, 559 complexity of design influences cost, 559 construction period influences cost, 558 cost curves, 560, 564, 565, vii final estimate, form of, 564, 566, 567 functions of cost accounting classi- fied. 552 hazard elements, 556 importance of preliminary studies, 551 kinds, preliminary, progress, final, 552. local conditions influence, 554 methods described — final construc- tion costs, 554, 555 ratio to standard, 557 synthetic up-building, 554, 555 weighted price, 556, 557 of doing work — day labor, contract, 553 of payment, cost — plus, 553 lump sum, 553 unit price, 553 progress reports, 561, 563 purposes govern methods, 551 recording construction methods, 553 simplicity, 553 Cradles, construction and use, 251, 252 for brick sewers, 267 defined, 5 typical, 245 in wet work, 252 Crown, defined, 5 Crystalloids,|(defined, 285 Currents, effect of winds, 820 in Imhoff tanks. 391, 392 in Lake Erie, 321 in Lake Michigan, 320, 322 in North Atlantic. 321 lake, 20. 320-325 use of thermophone, 321 Curvature, compensation for, 120 effect on n in Kutter's formula, 121, T22 losses due to, 120 Curves in sewers, bracing, 230 compensations for, 120 loss of head due to, 120, 121, 122 D Damages, account inadequate sewers. 21. lack of repairs, 22 Dash plates, see Distributors, splash plates. Dead end, defined, 4 Definitions, miscellaneous, batter boards, 187 box sheeting, 213 cross braces, 213 ditcher, 193 dynamite, true and false, 203 poling boards, 227 quicksand, 213, 214 rangers, 213 rock excavation, 191 sewage disposal and treatment, activated sludge process. 15 aerobic bacteria, 296 anaerobic bacteria, 296 available chlorine, 528 ballast, 448 band screen, 14 bar screen, 14 biochemical oxygen demand, 292 cage screen, 14 chemical precipitation, 15 clarification, 14 coagulation, 397 coarse screen, 14 colloidal matter, 14, 285 commercially dry sludge, 16 composition, 282 concentration, 282 condition, 282 contact bed, 16 contamination, 13 crystalloids, 285 denitrification, 286 disc screen, 14 disinfection, 17, 527 disposal by dilution, 310 distributor, 17 Dortmund tank, 15 dosing apparatus, dosing tank, 17 676 INDEX Definitions, sewage disposal and treatment, drum screen, 14 efSuent, 14 facultative bacteria, 296 filtration, 541 fine screen, 14 floo, 397 fresh sewage, 299 grating, 14 grit, 16, 330 grit chamber, 14 hydrolsrtic tank, 15 hydrolysis, 287 Imhoff tank, 15 influent, 14 intermittent filter, 16 irrigation, 16 medium screen, 14 mesh screen, 14 moist combustion, 398 nitrogen fixation, 286 pollution, 14 primary bed, 448 putrescibility, 14 relative stability, 14 screenings, 16 screens, 14 scum, 16 secondary bed, 448 sedimentation tank, 15 separate sludge digestion, 16 septic sewage, 299 tank, 15 settling solids, 14 sewage disposal, 13 oxidation, 16 purification, 13 -sick land, 541 treatment, 13 slate bed, 17 sleek, 16 sludge, 15, 427 cake, 16 concentration, 16 de watering, 16 digestion, 16 drsring, 16 drjring bed, 16 pressing, 16 sprinkler noszle, 17 stability, 14 stale sewage, 299 sterilisation, 17 sub-surface irrigation, 16 surface irrigation, 16 suspended solids, 14 tank treatment, 14 tertiary bed, 448 Travis tank, 15 trickling filter, 17 wing screen, 14 Definitions, sewerage, features, basin, 5 branch sewer, 2 catch basin, 5 cesspool, 1 chimney, 6 combined sewer, 2 system, 3 common sewer, 2 cradle, 5 crown, 5 dead end, 4 domestic sewage, 2 drain, 2 drop manhole, 5 fittings, 6 flush tank, 5 ground water, 2 house connection, 2, 3 drain, 3 hydraulic gradient, 93 industrial wastes, 2 infiltration, 5 inlet, 5 intercepting sewer, 2 invert, 5 inverted siphon, 4 lamp hole, 5 land drain, 3 lateral sewer, 2 leakage, 5 main drain, 3 sewer, 2 trap, 3 manhole, 5 casting, 6 outfall sewer, 2 outlet, 6 pipe sewers, 5 plumbing, 3 regulator, 6 relief sewer, 2 roof water, 4 run-off, 4 separate sewer, 2 system, 3 sewage, 2, 23 sewer, 2 system, 3 sewerage works, 3 slant, 6 soil pipe, 4 specials, 6 stacks, 4 storm drain, 2 overflow, 6 water, 2 water overflow sewer, 2 street wash, 4 sub-main, 2 surcharged, 93 surface*water, 2 INDEX 577 Definitions, sewage features, trunk sewer, 2 underdrains, 5 waste pipe, 4 wellhoie, 5 sheeting, 213 trencher, 193 underdrains — "construction" and "permanent," 207 wales, 213 window, in sheeting, 226 Denitrification described, 286 Density of population, 27 in certain American cities, 29 Denver, Col. Dieckmann. Geo. P. cement pipe mixtures, 246 Di£Fuser plates and pipes, see Aeration. Dilution, by discharge into lakes, 20 into streams, 20 into tidal waters, 18 defined, 310 described, 310-329 see Sewage Disposal by dilution Disinfection, acids, 527 application of chemicals, constant level box, 534 orifice feed tanks, 535 Wallace and Tiernan direct feed chlorinator, 539 available chlorine, 528, 529 bacteria, removal of, 530, 531, 533 bleach, 528, 529, 531, 534-537 calcium hypochlorite, 529, 531, 534- 537 chlorates, 528 chlorinator, 539, 540 chlorine. 528-533 copper sulphate, 527 Disinfection, defined, 17, 527 efficiency, 529, 530, 531 emergency plant. 537, 538 filtration after, 532 hypochlorites, 528, 529, 532. 533 industrial wastes influence success. 533 at Lawrence experiment station, 530, liquid chlorine, 529, 530, 531, 532, 533. 538. 539, 540 mixing bleach solution, 534, 536 more effective after sedimentation, 351 osone, 528 perchlorates. 528 previous to disposal by dilution, 311 at Providence, 531, 532, 536 quantity required, 529, 530, 532, 533 solution tank, 534 time of contact, 531, 533 variation' in bacterial counts, 533 Distributors, arterial troughs, 513 defined, 17 fan shaped troughs, 513 graduated troughs, 513 revolving, 479, 480 splash plate, 481, 482 traveUng. 479, 480, 481, 482 Dodd. C. H.. designer of Summer St. pumping station, Boston, 176 patentee of tide gate chamber, 170 Domestic sewage, defined, 2 Dorking, Eng., growths on trickling filters, 499 Dorr, E. S., directed design of Summer St. pumping station Boston, 176 rainfall formula, 66 Dorr thickener. 436 Dortmund tank, defined, 15 Dosing apparatus, air controlled siphon. 614, 515, 497 automatic, 514, 515 defined, 17 mechanical, 516. 517, 518 mechanically controlled siphon, 516 Dosing tanks, 485. 486. 489, 497, 498 Ansonia at Newton, N. J., 518 defined, 17 Drain, defined, 2 see Storm drains. Underdrains. Drainage area, size in relation to run-off, opp. 85 Dresden, disc screen, 348 Drilling, cleaning holes for, 199 hand, 198 machine, 200 spacing holes, 199 Drills, auxiliary valve, 201 butterfly valve drill, 201 churn, 198 differential valve, 201 double hand, 202 37 578 INDEX Drills, hammer, 200, 202 perouBsion, 201 reoiprooaUng, 200, 202 rotary, 200 spadiig holes, 199 tapper valve, 201 Drop manhole, defined, 5 on connections, 7 to equalise flow on steep slopes, 100 Dryers for sludge, see Sludge drying, du Pont de Nemours Company, priming cartridges, 205 Dublin, sludge disposal at sea, 438 Dunbar, Dr. W. P., sewage farming, 549 Dynamite, composition, 203 exploding, 205 freesing, 203 method of charging with, 206 priming cartridges with, 205 thawing, 203, 204 boxes, 204 kettles, 203 in wet holes, 206 E Earth, adhesion, 214 angle of repose, 217, 218 cohesion, 214 excavation, see Excavation, pressures, 216 horizontal, 219 Rankine's formula, 216 at various depths, 219 weight, 218 Earth excavation, see Excavation. East Orange, N. J., leakage into sewers, 39 East River, receives Manhattan sewage, 19 Eddy, H. P. and Hartwell Fitchbury Imhofif tanks, 389 trickling filters, 487 Effluents, defined, 14 from activated sludge process, 403, 404 from broad irrigation, 543 from chemical precipitation, 371 from Mass. sand filters, 520 disinfection, 527 methods of treatment, 18, 19 odors from septic tank, 494 point of discharge into streams, 20 into lakes, 20 into tidal waters, 20 requiring treatment, 18 sedimentation of trickling filter, 495 from septic tanks, 362, 364 stability in cold weather, 403 Ejector, for pumping activated sludge, 422 Shone at Worcester, 349, 437 Elastic theory for analysis of stresses in sewer arches, 119, 261 Emsoher District, grit chamber design, 333, 334 grit in grit chambers, 332 Imho£F tank, 377, 393, 394 sludge chamber design, 893 sludge estimates, 380 submerged scumboards, 391 waste weir, 338 Erofflon of inverts, 99 Euglenas, see Plankton. Excavation, backfilling, 253, 254, 255 bracing, 212 classification of materials, 191 cost, general discussion, 208, 262 cross-sectioning surfaces, 186 dangers encountered in, 188 earth pressures, 216 for various sewer sections, 263 frost penetration, 191 general discussion, 190, 208 handwork, 192 in various materials, 213 inspection of, 188 lines of, 185 machine work, 193 opening the trench, 191 pumping in wet trench work, 206, 208 quantities, 208, 209, 210, 211 replacing old pipe lines, 193 rook, classified, 198 underdraining, 207 thawing ground, 192 trenching machines, 193 underdraining wet work, 207 Factor of safety in sewer design, 92 Fairmont, Minn., septic tank, 365, 366, 367 Fall, minimum in treatment works, 19 Fats in sludge detrimental to fertiliser value, 446, 541 in typical sewages, 307 Fertilizers, ingredients necessary, 443 poudrette, 545 preparation of sludge for, 423, 424, 425 sewage, applied directly, 541-550 value of city sewage, 542 of cottonseed meal, 445 of dried blood, 445 of goat manure, 445 of guano, 445 of Imhoff tank sludge, 445 of septic tank sludge, 445 of sludge, 423, 424, 425, 432, 443, 444, 445 of tankage, 445 Filtering through sand, previous to disposal by dilution, 311 removes suspended solids, 284 see Intermittent filters, Trickling filters. INDEX 679 Fish, dissolved oxygen requirements of, 316 effect of disinfectants on, 528 feed on sewage, 280 Fitchburg, Mass., dosing tank, 485, 486, 497 flies on filters. 500 Imhoff tanks, parallel flow, 388, 389. 391 receive secondary tank sludge, 431 nossles, 484 pumping sludge, 437 sewage flow, 40 sewage flow from industrial districts, 47 trickUng filter, 467, 473. 484, 489. 490, 491, 492, 500 Fittings, defined, 6 FitsGerald, automatic rain gage, 57 Flies, absence on contact filters, 449 breed in cesspools, 1 in septic tank scum, 363 on trickling filter, 500 Flight sewers to equalize flow on steep slopes, 100 Floats for current measurements, 318, 319 on swivel draw-off pipes, 358, 359 Floe, bacterial action within, 397 defined, 396 description in activated sludge process, 400 formation for chemical precipitation, 395 in activated sludge process, 396, 397, 407. 408 Flood flows from large areas, 86 Flush tank, defined, 5 Flushing devices, 155 automatic tiush tanks, 156 fire hose, 156 flush tank defined, 5 flushing chamber at Concord, 158, 159 from brooks, 156 inverted siphons, 149 manholes, 156 Miller flush tanks. 157. 161 Rosewater improved flush tank, 160 Van Vranken flush tank.. 160 Foaming, Imhoff tank. 393 Forms, centers, 267, 268. 269, 273, 277 collapsing, 268, 273, 275 for arches, 268 for building in two operations, 276 for inverts, 267. 268, 271 for manhole base, 278 for semi-elliptical sewer. 2/6, 277 full round wooden, 274, 275 general discussion, 272. 273. ingenuity of design. 270 lagging. 268 life of wooden, 273 moving, 273 profiles. 267, 268 protecting wooden, 275 Forms, ribe, 269 setting, 268 skeleton, support for, 274, 275 striking, 268, 273, 275 Formulas, Adams, run-off, 80, 81, 82 AUctn, sludge storage capacity, 386 Bradbury, siphon discharge, 516 BQrkli-Ziegler, 80, 81. 82, opp 85 Dorr, rainfall, 66 earth pressures, 216. 237 empirical not dependable, 119 Fuller, run-off, opp. 85 Ganguillet and Kutter. velocity of flow, 100 Gregory, C. E., rainfall, 66 run-off, 80, 81, 82 Gregory, Jn. H., run-off, 84 Grunsky, rainfall, 66 Hawksley, run-off, 80, 81, 82 Hasen and Williams, velocity, 101 Hendrick, C. W., rainfall, 66 Bering, Rudolph, run-off, 80, 81, 82 Hill, C. D., rainfall, 66 Horner, W. W., rainfall, 64 Knauff, rainfall, 66 Eops, de Bruyn, rainfall, 66 Kuichling, rainfall, 66 Kutter, velocity, 101, 103. 104-107, 121. 122 McMath. run-off, 80, 81. 83. 84, 85, opp. 85 Markmann, loss of head, 120 Metcalf and Eddy, rainfall, 64. 66 Murphy, run-off, opp. 85 Parmley. run-off. 80, 81, 82 Rankine, earth pressures, 216 resistance to pressure. 240 sand diameters, 506 Sherman, rainfall, 66 siphon discharge. 516 sludge volume. 427 Talbot, rainfall, 63, 66 U. Gravel, inspection, 189 placing around underdrains, 511 Great Britain, treats storm water, 18 Great Lakes, currents, 20, 320, 321, 322, 323. 324, 325 Lake Erie currents, 321, 328 Lake Michigan currents, 320, 322 points of discharge into, 20 Gregory, C. E., rainfall formula, 66 run-off formula, 80, 81, 82 Gregory, Jn. H., discharge of egg-shaped sewers, opp. 102 run-off formula, 84 septic tanks, Columbus, 367 defined, 16 Grit chambers, American design, 334 before septic tank treatment, 364 cleaning, 335 defined, 14 design, 332, 333, 334 object of, 330 quantity and character of deposits, 332 theory of, 331 Ground water, defined, 2 general discussion, 34 infiltration, 36, 37, 39 Growth in population, arithmetical rate, 25 curvilinear rate, 24 decreased rate, 26 exceptional, -24, 25 of Akron, 24 of American cities, 25 of Brooklyn, 26 of Chicago, 26 of Detroit, 24 of Gary, 24 of Manhattan, 26 of New Bedford, 26 of Washington, 26 percentage rate of growth, 24 Growths, killing with copper sulphate, 528 on trickling filters, 499 Grunsky, C. E., rainfall formula, 66 H Harrisburg, density, 28 water consumption, 32 Hart versus City of Neillsville, 22 Hartford, Conn., aqueduct section, 113 Hartwell, D. A., and Eddy, Fitchburg Im- hoff tanks, 389 trickling filter, 467 Hatton, T. C, analysis of effluent -from activated sludge process, 404 progressive changes in activated sludge at Milwaukee, 404 solids in Milwaukee activated sludge, 401 standard of purification by activated sludge process, Milwaukee, 404 INDEX 681 Hawksley, run-o£F formula, 80, 81, 82 Haworth, agitation at Sheffield. England, 409 Hasen, Allen, dangers of contract prices, 556 defines quicksand, 214 formula for velocity of flow, 101 German sewage farms. 548 Ohio streams pollution, 315 sand standard, 504 Hasen and Whipple, acidity of Mononga- hela River, 527 Head, in inverted siphons, 150 losses due to curvature, 120 recovery of velocity, 123, 124 refers to hydraulic gradient, 03 velocity, 123 Hendrick, C. W., Imhofif tank design, 386 rainfall formula, 66 Henry, Prof. A. J., rainfall study, 69, 70 Hering, Dr. Rudolph, advantages of sepa- rate system, 9, 10 grades on steep hills, 12 run-ofif formula, 80, 81, 82 Hill, G. D., rainfall formula, 66 Hoboken, N. J., density of population, 28 Hobrecht, radial sewerage at Berlin, 10 Holyoke, Mass., water consumption fluc- tuations, 33 Hopedale, Mass., double manhole, 138, 139 efficiency of sand filters, 520 intermittent filter operation, 508 sewage flow, 40 Hopson, E. G., data on losses due to curves, 120 Horner, W. W., allowance for time of con- centration, 68 describes use of rational method, 73 rainfall formula. 107, 108 Hydraulic elements of sewer sections, gradient. 93, 95, 145, 150 horseshoe, 105 parabolic, 106 rectangular, 104 semi-elliptic, 106 see also Sewer sections Hydraulics of sewers, 92 problems relating to, 124, 125 Hydrolysis, defined,, 287 Hydrolytic tank, defined, 15 Imho£f, Dr. Karl, grit chambers, 332, 334 screen, 334 sludge estimates, 380, 381 tank design, 377 Imhoff glasses, use of, 284 tanks, addition of lime to, 379 air Uft, 394 at Baltimore, 386, 387, 390 character of sludge, 378, 379, 383- 385, 431 at Chicago Stockyards, 385, 445 cleaning, 393, 394, 433 connecting sedimentation compart- ments, 379 defined, 15 density of sludge, 383 described, 377, 378 detention period, 381-383, 391 diffusion through, 379, 380 at Fitchburg, 388, 389 foaming, 393 gas formation, 378, 391, 393 gas vents, 378, 392 inlets, 379, 390, 391 longitudinal flow, 389 maintain sewage levels in, 379 odors 377, 379 outlets, 390, 392 parallel-flow, 389, 390, 391 quantity of sludge, 380 radial-flow, 386, 390 scum, 386, 392 skimming solids, 392 slots, 392 sludge chamber, 379, 380, 385, 391, 393 moisture, 383, 385 removal, 393, 394 storage capacity, 385, 386, 391 period, 385 for treating industrial wastes, 385, 386, 445 value of sludge as fertilizer, 445 Indiana State Board of Health, emergency disinfection apparatus, 538 Indianapolis, Ind., density of population, 29 582 INDEX Industrial Instrument Company, diaphragm pressure gage, 88 wastes, a£Fect bacteria, 297 defined, 2 influence disinfection process, 533 preparatory treatment before acti- vated sludge process, 405 treatment by chemical precipitation, 371 treatment by Imhoff tanks, 386 Infiltration, defined, 5 of ground water, 35, 36, 37, 38, 39 possibility influences section, 264 quantity depends on length of sewer, 38 Influent, defined, 14 Inlet chamber design- problem, 153 time, see Time of concentration. Inlets, authors' standard street, 127 Bronx, 128, 130 castings for, 132 clogging, 128 covers, 127, 132, 133 defined, 5 Imhoff tank, 390, 391 location, 126 precipitation tank, 375 septic tank, 366, 368 street, 126 Inspection, duties' of inspectors, 188 of backfilling, 188 of cast-iron pipe, 190 of concrete materials, 189 of excavation, 188 of sheeting, 189 of under drains, 189 of vitrified pipe, 190 Intercepting sewers, Baltimore, 10-12 defined, 2 first flushings from, 48 general description, 8 provision for storm water, 47 use of regulators on, 162 Intermittent filters, accomplishment, 502 aerobic condition necessary, 503 bacterial action in, 503, 504, 506 banks, 510 capillarity, 507 cleaning, 524, 526, 532 Clinton, 514 clogging, 521, 522 defined, 16, 507 depth, 506, 507, 508 distribution, 509, 512, 513, 514, 521 dosing, 508, 525 air controlled siphonic device, 514, 515 automatic, 514 mechanically controlled siphonic device, 516, 517 mechanical devices, 518, 519 Intermittent filters, effect oxidation of organic matter in sewage, 300 efficiency, demonstrated by analyses of effluent at 23 Mass, plants, 519, 520 effluent, 503, 519, 520 establishing bacterial action, 503 filtering material* 503 freezing, 522, 523, 525 grading surface, 310 grouping, 509 Lawrence Experiment Station, 507, 508 Marlborough, Mass., 513 mats, formation and removal, 502, 512, 522, 523 Newton, N. J., 618 North Attleboro, 512, 516 odors, 521 operating conditions in Massachu- setts, 508 operation of, 521 overdosing, 503 preliminary studies necessary to design, 510 preparation of foundation, 504 rate of filtration, 507, 508, 509 removal of bacteria, 469 require large areas of sand, 21 resting period, 524 sand, 503, 504, 505, 507, 523, 524 sise and shape, 508, 509 straining action, 502 temperature affects results, 521 underdrainage, 509, 510, 511 winter operation, 521, 525, 526 International Joint Commission, B. acreage, 543, 544, 546, 547, 550 American experience, 549, 550 application of sewage, 541. 541 at Achdres. 546 at Carridres-Triel, 546 cost, 546, 547, 548 cropping, 544, 547, 549 crops secondary consideration, 542 at Danbury, Conn., 549 defined, 16 described, 541, 542 distribution, 546, 547, 548, 550 effects of oxidation of organic matter in sewage, 300 eflSuent primary consideration, 542 effluents, 543 English experience, 542, 543, 544 French experience, 545, 546 at Fresno, Cal., 549 at Gennevilliers, 546 German experience, 547 at Hastings, Neb., 549 at Howard, R. I., 549 at Los Angeles, 549 at Magdeburg, 547 management, 541 - at Mery-Pierrelaye, 546 at Pasadena, 549 pasturage, 545 at Pomona, Cal., 549 previous to disposal by dilution, 311 previous treatment, 543, 546, 550 at Pullman, 549 rate, 543, 547 at Salt Lake City, 549 at San Antonio, 549, 550 sewage-sick land, 541 soils. 544, 548, 549, 550 supplemented by storage, 550 theory, 541 underdrainage, 546 Ithaca, N. Y., septic tank outlet, 366 Jersey City, N. J., density of population, 29 Jetting sheeting, 230 Johnson, Geo. A., bacteria in Columbus sewage, 297 Johnson, Geo. A., contact bed operation, 450 sludge measurements, 429 Joint outlet sewer. New Jersey, leakage, 39 Joints, asphalt, 250 cement, 248, 249 clay pipe, 245 effect of sise of socket, 245 filtite, 251 G-E compound, 250, 251 Jointite, 251 linseed oil preparations, 250 Marbleoid, 251 Stanford, 249 sulphur and sand, 249, 250 tar, 250 underdrain, 207 Junctions, bellmouth, 146 careful design needed, 8, 145 flat-top, 147 Philadelphia, opp. 148 K Kansas City, Mo., density, 29 Keller man, Karl F., copper sulphate as algi- cide and disinfectant, 528 Key West, Fla., tidal range, 317 Kinnicutt, L. P., sludge measurements at Worcester, 429 Knauff, rainfall formula, 66 Kops, J. de Bruyn, rainfall formula, 66 Kuichling, Emil, rainfall formula, 66 run-off formula, opp. 85 Kutter, W. R., formula for velocity in chan- nels, 101, 103, 104-107, 121, 122 Lacustrine current, effect of winds on, 320, 322 Lake Erie, 321, 328 Lake Michigan, 320, 322 Milwaukee investigations, 322, 323, 324, 325 not so marked as river currents, 20 Lagging, see Forms. 