ST ool sprrrryT Tre lo s el nt T BR ra im 7 a ian te Me« Mar Ore Lae x “a upon Sisiha Rwe Y ft sign toy Me IVC SEY MB ee - - INV STIGATION OF TYE SANITARY SIDE OF Tim LANSING SERVE RAGH SYSTEM, A THESIS SUEMITTED TO THN FACULTY OF TEN MICHIGAN ASRICULTURAL CCLLRan. . BY “3 o a aw : “4 b. f wr Candidates for the Degree of Bechelor of Science. JUNE 1915 e wh _{* wichael 5..Jegsen rl’ Irving Lonkey PHEStS. INTFODUCTION. To sain the gre.icsat benefits from ac lleze thesis, it is necessary that the investi ators undertake a subject that is not beyond their ranze of vision; cne that will interest, as woll as instruct. To this eni, we Rev. chosen to investigate a section of the Sewer System instulled in the City of Lo nsinzg, with special regard to the sanitary system, <~iming to su zest remcdics for the preaent unsatisfactory conditions. We have been guided by text—books on this subject, and have been profited by the advice and help of men who have gained experience and prestizve in the engineering world. We were greatly aided in our work by ijctcalf & Fday's "Anerican Sewera.e Practice", Vslumes 1 and 2, and, by Flolwell's Seweraze, ootaining valuable ideas and formulas. We wisn to thank Nr. Fich, State Sanitary Fnzgineer, “fe JOhn Gunnell, Assistant City "nzineer of Lonsinz, andi, A-slistant Professor ‘ehring, for the courtcous treatment and assistance ziven us. 100252 The city of Lansing, the capital of Michigan, is situa- ted in the mid-e-central »art of the state, and, is almost strict - ly a manufacturing city. The Grand River flows north through the city, dividing aiso esually in two parts. The general drainage slope is from the western limits ina general fall to the river. Owing to the lack of time, we were unable to :.ake our in- vestigation cover the entire City of Lansing, s0 we confined our efforts to everything west of the Grand River, which dis- trict covers practically all the business and about half of the residential district. The general plan of operation for our work, was as fol- LOWS;- 1.-Determination of people tributary to each manhole. 2.-Determination of quantity of sewage flowing from each manhole. 3.-Determination of theoritical velocities between ench manhole. 4,-Determination of the actual velocities between each manhole. 5.-Determination of the depth of flow. In determining the peonle tributary to each manhole, we obtained prints of the sewer districts 2, 3, 4 and 5. Our boundaries included all of districts 2 and 3, with part of dis- tricts 4 and 5. We counted the houses on both sides of the streets throughout our district, and, made a very thorough sur- vey of the town, allowing five peopie for each, this being the average number of peonle in a house. - l- During this cperation, we inspected several manholes, lampholes, and, the outlets. The manholes we inspected were in good shape, and, the outlets we could see were in very g00d shape. Several of the cutlets were submerged, partly on acccunt of high w ter, snd, pertly on account of the way they were laid. Practically all the manholes on the streets which were not paved were covered with mud, thus shutting of> the ventilation. Item #3.- In the aetermination of the quantity of sewerage flow- ing into each nanhole, we were generally zoverned by advice and engineerin. practice. Several books «nd advices we ccon=- sulted ueed different amounts of water per capita, and, we decided to use 125 ga.lons per capita per day, as the aver- age amount of water sed. This seems to be 2 general aver- age, and, a fair amount in such an estimation. Item #3.- The velocities were all tiken frcm diayrams based on Kutter's formula:- 66 7ASELL Qg. 0902g/ Ve (8 TAREE - )rrs I+ eZ 66 £ o.coze/) 2 —* en Where- V-the mean velocity of the water, R-Hydraulic mean radius, S-Slope of water surface per unit of length, N-Coefficient of roushness of the wetted perimeter. The diagram we used for round pipes flowing full was taxen from hetcalf & Eddy, Vol. 1, American Sewerage Prac- tice, page 94. This authcr recommended .013 as a coeffic- | lent N. For ezgy-shaped brick severs, runnin; full, we used N-.Q15. This diagram is fvund in the same volume. The val- ues Of N which we used, are those recommended by the lead-— ing Sanitary Engineers in the country. Pages 97-98, Netcalf Eddy, Vol.l1, American Sewereége Practice. The velocities were corrected after we had taken the depth of flow. Items #4 & #5.- The totel quantity of sewage fluwing in the y;ire for O24 hours was comyuted, also the cezpacity, and, then the depth of flow was taken from tables Nos. 13-14, Passes 53- ot, Folwell's Sewage. Fclwell asserts that if the depth of flow is less than 2", ‘eposits occur. From these tables, the velocities were also corrected. Man 'reo 'Quaen ' Grade ' Size of ! 'Depth of ' Cor- Hole ‘ple 'tity ' between' Pice ' Total 'flow, in ' rected num ' of ' man- ' Quantity'inches. ' veloc - bers ' 'sewage' holes ! ,' ' ity. 1-2 80 7500 «85 lo” 7500 45 2e25 2-3 33 30" 75°0 3 91 453 60 75006 1.40 8" I.P. 7500 4 1.33 3=5 63302 B4x36 B 15000 1 1.2 S-5 100 12500 05 8" vp 12500 -- -- 5-7 30 3750 1332 -B4x36 B 31250 1.44 95 8-7 110 13750 40 ©4©696" UP 13750 62 1.3 7-9 10 1250 133 «84x36 46250 1.8 1.06 10-9 30 3750 50 gn 3750 .6 06 9-11 633 B4xZ6 50000 ~—s-«<.1.9 1.06 12-11 10 1250 .68 gn 1250 .8 86 11-13 60 7509 79 2-B4x38 58750 sd. 1.50 12-14 234 28x39 58750 1.6 1.09 l.=15 30 3750 134 88x39 6-500 1.6 b.09 30-19 40 3900 1.33 gn 5090 18 1.3 19-18 40 5000 .67 gn 16c00sid2 1.18 18-16 45 5625 628 0 3Sx54 15625 1.8 . 87 17-16 40 5000 35 gn 20625 12 85 16-15 20 3500 623 © - 38x54 31625 1.9 87 21-15 40 5000 250 = 10" 5000 1.5 1.21 15-22 65 8125 623 40x60 97750 3.0 1.01 115 105 45 140 115 110 70 130 75 85 105 65 35 110 Quan- tity 5700 6250 9625 14375 13175 96289 17 500 1::375 3000 2570 1875 17500 10625 96285 137 50 8750 16250 9375 10625 6875 131355 8125 6925 13275 Grade Size 10" 40x60 gn gn 8 tt 40x60 gt 12" 48x72 Sr 12" 48x72 gn gn an gn gn gn gt en gt 12" 12" gn 27 500 147750 17500 27875 175825 3500 4375 180000 10625 5625 13750 220900 28750 381 29 48750 66 75 20000 28135 76875 13375 20 8 8 1.2 Be4 1.3 1.2 1.6 28 1.2 Deo 9 Cor- rected velocity aw aw DP ase = “Dee =) === aw SOe CED oe 8 ee oe? OR ewe 82 ow «es 2 oe GD = 9 SD ee OEE ge SD ee wes we ie ee, ee ee es ee 8 Se oe eee Ss 2 wg SE? GE ae = ep am oP 1.87 072 87 lel 075 « 83 1.14 079 1.37 1.14 1.58 1.73 90 1.65 1.57 1.30 1.26 028 1.08 1.00 «80 Grede Depth Correc- ted velocity. oe a re OP = ee wre 8 -e ® e S O ee 088 © cg SD OF 088 oe RP cme SD OD 98 gs SP ge SE er er ee ee wee ee Oe ee oe ee Oe ee Oo 8 OP Owe = oe 115 50 60 39 2Q 20 100 85 65 85 12375 1250 6875 S000 3000 6350 6875 2000 3 900 12500 10625 8375 10655 250 2 OO e 50 2 00 ¢ OO 1.10 1.6 1s" et gt gt 15" 15" 20" 24" 4" 48x72 18" Lo" 139315 139315 339 565 79500 13125 353065 2500 2500 2900 9000 10685 372060 106°:5 20209 6 1.2 08 1.2 1.6 20 Be 36 1.8 1.0 1.0 3.6 1.0 1.3 1.0 1.5 1.6 303 08 1.15 1.15 1.00 1.15 1.15 1.5 9 1.4 97 1.11 1.55 De O% Bel 279 LOO arade 1.8 041 097 033 1.17 0535 Size 43xc3 gt gn Qn 43x33 gt 46x68 gN 8 tt gr 16" +OxXx63 Totel Quant ity 378560 7500 7500 19375 6250 39-4185 12500 437310 3125 6875 3123 2500 13850 48850 65100 5167 85 Correc-— ted ve- locity Be 20 Depth. 1.2 8 3e15 8 3.15 05 08 08 1.0 3215 1.0 1.5 08 1.8 8 08 08 1.0 39 1.1 3.15 MeH. Peo- ple. Quan- tity. Grude Size Total Correc- ted ve- Depth. nnn nnn nn nr rrr nr nner ee --------locit yw- -------- 97-96 96-98 116-114 115-114 114-113 113-112 112-111 111-110 117-110 119-118 118-110 110-198 109-108 108-105 107-106 106-105 105-103 104-103 103-99 102-100 101-100 100-99 99-98 $8-120 121-120 3Q o5 o 65 80 60 30 20 3750 6875 675 87 50 37 50 LOGO? A375 7500 =a ed MP wo e CN gn tOxX63 gt gn gn ron 15" gn on gn 18" gn 20" gn gt 24" gn 24" 37 50 527410 639 8125 18750 18750 18750 19375 8750 37 50 37 D0 31875 LOC60 41875 635 1250 45625 629 92000 7 500 37 50 2000C 75COO 608210 7500 a) e _~ O) ~~ e Od W 1.00 1.14 Be 70 073 « 76 1.73 1.60 1.00 1.80 079 1.8 08 200 08 08 Bo 4 08 Be4 08 8 1.0 20 4.5 8 te He Peo= Quan- Grade Size Total Correc= Depth ple tity. Zuentity ted ve- locity. 122-120 60 7500. 1.90 88 7500 1.58 48 120-133 50 6850 125 48x64 633660 3.65 4.5 125-1283 55 6875 1.32 gM 6375 1.3 .8 124-123 35 275 .70 2013" £375 1.3 1.2 123-126 60 7500 625 48x64 635910 2.66 4.6 127-126 50 6250 .80 gt 6250 1.0 .8 126-128 85 10885 625 42x64 6523785 3.66 4.6 133-131 15 1875 .33 3" 1875 7 .8 131-159 20 3500 1.50 6" 4375 1.4 .8 130-129 10 1350 1.0 6" 1350 1.15 g 129-128 45 5625 1.5 10" 11350 1.65 1.0 128-133 65 8135 1.98 40x60 672160 4.45 4.6 138-133 65 8125 1.0 15" 8125 1.4 1.5 137-135 60 7500 3.5 6M 7500 3.2 .8 136-135 60 7500 3.2 6" 7500 1.? 8 135-133 30 3750 1.1 ©1101 12750 1.4 1.0 133-139 50 62350 1.44 <0x60 703285 3.7747 140-141 45 5625 93 6" 5625 .86 6 142-141 45 5625 650 6" 5625 685 6 141-143 60 7500 250 6" 18750 1.00 7 143-123 35 4375 1.5 6" 13135 1.2 2.0 144-145 40 5°00 620 6" 18000 72 3.0 145 -- ---- 623 26x79 18000 76 20 1.3 263-268 125 15625 1.65 2" 15625 1.48 8 Tetal Suantity tei ve- Correc- locity. — = © oe S28 oe oe © eee 8 88 O88 Oa ows Se ee we Oe 8 es 8 ee ee ee ee ie Oe — oe ee es es ae eee oe SP ee Se ee <8 we We ame ee ee ee 264-360 261-260 260-259 5 6-259 260-259 359.258 266-267 267=-68 263= 269 370-369 264-269 269-271 274-873 37 5=273 273-72 276-272 373-271 371-258 258-257 257-279 27 2=277 278-277 27 7-279 - CD S) 115 65 DO 35 60 35 oO 79 39 30 65 O00 BO 80 60 CO 20 3125 LOCOQO 7OCO 375 7505 BO00 1.16 0O- 1.85 «80 6" git 6" Qn Ql Qr 6" gn Qn 61 st gt en 078 047 1.3 097 1.17 1.30 1.5 weantity crade 5S Total quantity vOorrece=- Depth. —- =~ GE ewe @e CD 8S oe Gwe awe SS ww 2-8 3 2 aes 9 8 SE we oe a SO ow — oe em 2p GED OOD SE ee ee ee 8 oe ee OED wwe cep oe ee es a Oe ie ee ee Se ee ee -— aD 382-385 385-284 “84=583 283-282 383-281 281-280 280-290 2 On B= ool B01-24 200-249 2 :9=-248 25 3-324 Z33—B28 2 87-2328 LOO 165 150 No89 6875 T5900 3125 4375 1.0 6" g1n iQ" ll- LOCO 61285 13750 L750 19375 23500 28750 126875 BQOESO 39375 687 5 O27 350 NEA OD VAN OD » hie the reo—- Quantity Grade Size Total Correc= Depth. ple. Quantity ted ve- locity. 288-334 25 2175 187 BM 10085 =—i«dz005ti(iti 334—=335 40 5000 6 gn 15625 .86 .8 335-289 20 2500 6 gn 18125 86 .8 281-289 35 4375 5 gf 4375 79 .8 389-290 55 5875 6 gn 29375 66 336-890 25 1375 6 6M 4375 72 .6 290-303 45 5625 .5 24x36 206250 3.6 9.6 304-303 40 5000 6 gn 5000 86 .8 305-363 40 5000 1.0 an 5000 1.15 .8 303-302 350 750 5 54x26 367000 7.7 ° 12.0 333-331 15 1875 663 6" 1875 68 .6 331-330 35 4375 75 6" 5350 79 .6 329-320 35 4325 6 6n £375 78 .6 30-326 40 5000 3.0 8" 11625 1.62 6e 328-326 30 3750 .8 gt 7750 1.05 .8 337=3°6 70 8750 653 6" 8750 66 6 286-322 40 5000 .6 gn 33125 1.18 lel 325-323 35 4375 1.15 an 1375 1.22 8 BD4-323 30 2750 1.C 6" 3750 90 6 33-388 55 $875 1.0 6" 50% SO 6 323—310 50 3350 228 gt A7105 leit 89123 "11-310 35 3125 2.02 6" 3125 1.30 .6 310-3°8 55 6875 4 6" 57175 1.2 1.8 309-308 30 2500 5 12" 25 0 1.18 1.3 31-313 25 3155 1.0 6" 3105 50 6 we tie Peo= Quon- Greae Size Total Correc- repel. ple Sity Quantity tes vel- ocity. 313-308 450~=“«‘z* TS OUS!!COCMS”*~«~iSSC“(‘(O™*C‘;UC‘«WNSC;‘éCRSSSO™SC*™” 305-306 30 2750 .5 6m 23175 1. 3 3.4 307-306 3O 3375 8 6" ETS 079 of $51-c19 55 £675 45g 6875 73 8 520—319 EO) S009 1.4 6" HCC 1.36 03 319-317 OO 3730 20 on Loe325 079 0 3 1L8—317 ote E875 87 6" 6875 1.08 2S G17=$51¢ oO 62S A) 13" 28750 1.15 1.3 214-315 a0 BOO? 08 8" BOO 1.C° 8 15-215 S55 S125 36.05 &" 1056 5 1.64 8 S16—-30S 65 G1e5 03 15" 47 S00 1.GG 1.0 5S06=302 o0= OB900 ef 15" 1313609 1.29 bed 308-290 175 21875 1.54 18" 413175 20S 2.6 301-300 10° 12500—Ci A 6" L3EE00 oo? 06 299—098 LOO 1e5c90 23 18" 4£413°C Be 7 ed 300-399 L155 193535 .4 6" GBB125 1.04 1.5 E97—39¢ 75 O735 1.5 6" 9275 1.11 0S o96~—0294 135 Lo5é eO on 50000 098 1.8 6935-204 175 21575 1.85 13" 21875 2.05 lee OO -=—O98 LOO 18550 1.3 18" 55275 Beng 1. 29B8=2598 Lad 15655 .9 8" L:s35 07S 5 OG EarOIE 100 12500 1.4 8" LE500 1.36 08 ES 3~-B25 350 r375C0 Ow SG 18" 57 6950 Bet De + Ok Q—6:1 40 D000 ote on 50C0 07D ae 825-84] 60 750° 1.5 ot 7500 1.20 06 -13- i ke ee mA ry |" Or =—540 2: 4-840 4) oc Oo My . ee SO Pece ble oo ee OO ee oo oo ~ | aoe C) © 1 ~ iJ C1 Ys e3 t? ‘ o-- “GL aan tity -— © See = owe ee S&S GP Of w= & @e Dw ew 7 a aes @ —— C- Ge G&G om oe OF aoe Moxa a —- 6350 21289 B70 2500 5000 A= = é he 7 oO —_ 51285 J1E5 LE5G0 D625 D000 10900 96 45 25 20 1.¢5 020 Grade Si-e - 12" 1g" on gn gn 15" QN O) O? 3 =3 © 2 18" 18" en gt gn gn 18" gn 18" gt et gn COX235 gtr Total cuent lty 18750 43125 Ba4a4 25 T5C° 7oGC 11875 607950 65 81385 11250 B1675 277175 280700 aT EN wes 2 VV 39-5506 208175 16750 ~l4- correc- ted ve- Cot Ye 1.15 1.05 1.77 ™~ Vy,st?- LiCl i.e eo Om ew ee ee ee Pe MMe Ee — GR ee em]. = 0S 1.2 BeO 8 1.2 3.6 1.1 3.6 ° CO Cd CO lie tie Pece= Qu'n- Grade Size Total “orrec- TCepth. pie tity. eu ntity tea ve- lizcity. 6236-55 £0 SOC O 2D gM Ss oe om &® ao Ge Oe GE w= ao a es ee GE = ees oe OE ee OS owe ne em Oe ge Om c= 6. oe Oe es OO ee oe ae 9 1.2 1.2 1.8 1.2 1.8 1.93 71.0 08 1.0 395<393 394-293 393-392 353 to cutlet 1-471 471-463 470-469 469-478 468=467 467-466 460-466 466—=461 460%457 459=457 4 58--:57 457-456 oa 115 1 No. 070 000 1.5 1.13 1Q. 15" 20" 10" 10" 10" Total Quantity 14375 206895 37 50 6875 LQ625 15135 3 S550 6 875 1162850 6875 6875 6875 ~ -A 29005 Correce- ted vee locity. 1.19 1.0& 1.78 1.59 LCepth. 1.5 20 06 26 8 1.0 ,* elle Peo- Quan— Grade Size Total Ccrrec= De ple tity Auantity ted ve- locity. 56'-458 55 6875 13 8m 6875. dle Ot—iB™” ; “56-445 25 3125 1.75 18" 151875 3.21 1.8 455-451 115 1:775 .45 10" 14375 ae 1.0 453-453 30 3500 145M 3500 76 8 451-452 85 10685 <5 en" 10625 76 .8 158-451 45 563 147 gn 18150 £79 .8 451-450 60 7500 .60 10" 40225 1.16 1. 450-448 60 7500 1.85 10" 48125 1.58 lel 249-438 70 8750 2.6 8" 8750 1.80 8 446-4:7 65 6125 1.85 10" 85060 1.68 ll i%ei:5 85 8125 1.85 12" 73125 1.68 1.3 46-445 60 7500 1.0. an 7500 1.15 .8 445-241 120 15000 .40 34" 247500 1.65 2.4 144-442 40 §cC 1.0 2 500% 1.15 .8 443-443 35 4375 1.5. 6" 1375 1.33 08 442-411 20 2500 1.9 10n 11875 1.88 1.0 441-431 25 3125 1.9 2320" 322500 3.06 2.0 435-434 85 10625 1.65 8" 10625 1.44 8 434-:33 80 10000 3.5. en 30685 2.16 .8 433-431 -- -—— .70. gn 30685 4 8 432-431 75 9375 650 «lon 3375 97 1.0 <21-428 40 5000 2.4 gon 857500 3.°2 23.0 440'=@440 -- -—-- 1.3. 8M ---- ---- 440-438 30 2502 3.31 8m 7500 3.08 .8 130-372 75 9275 1.04 8" O275 1.15 aw @@em ean 8 ew © oe enn 2D @ egw =~ © ap 2 OF oe Gh we eo Pe a= o- G2 SD Be OF aw @ co @ we OF © ao OP 2 we & om ow @® GF = ow aw GF ew GB SW a ew © & wo ame eee eee owe ow ew OD oe a a 424-433 423-422 4223=417 431-419 430—=/19 419-418 418-417 417-413 416-415 415-413 414-413 413-402 404-403 403-402 412-411 411-4083 50 35 75 Quan= tity 8125 6875 9375 5375 8750 8750 6875 3000 5000 8750 3125 2000 1350 8135 3750 7 500 8750 6350 3185 9375 iraede 1.8 1.8 1.8 el BO rn GeO 04) 090 ae) 4.5 ~61 Size 2°X36 gn 10" 1o" 10" 28x42 gn gn 10" Lo" 28x +2 gn Sn 10" 30x45B gn gn gn gt C2 Total Ouentity 8750 406285 +0685 386875 50 00 ia \) 87 1 16875 19375 407500 6290 3125 18500 Correc- ted ve=- locity. 1.01 B40 087 1.0 of 1.1 8 00d 1.0 8 1.0 1.0 303 08 8 1.0 1.0 323 8 8 1.0 3.0 me He People Quan—- Grade Size Total Correc— Depth. tity Quantity tei ve- ~ocity 409-408 15 1875 3.0. en 1875 1.98 .8 410-408 60 7500 1.21 8M 7500 1.36 8 408-405 40 5000 ..07~«8n 36875 2.34 .8 407-405 30 3750 23.8. sf 3750 1.91 8 406-405 35 1375 .60. an 4375 . 8 .8 405-402 50 6250 leit 10" 41250 1.58 1.6 402-400 30 3750 .41 30x45 486875 2.4 3.1 401-400 40 5000 3.0 10" 5000 1.94 1.0 400 outlet-—- ---— od] 30" 491875 1.94 308 Outlet No. li. 400-474 20 2500 .30 18" 2500 1.15 1.8 ar 2 — .33. 18" 3500 1.15 1.8 473172 = ---- .33 1g" 2500 1.15 1.8 472 outlet Iron Pipe ZOCO 1.15 1.8 ( O9 O1 { -conclusions drawn from our data sheets.- Population of district -- 19,625. Total quantity of sewaze--2,453,5-5 gal. per 24 hrs. Theat the pipes are ad quate from & g nitary stand- point. System is mide ug of vitrified clay pips, ranzing from 6" to 30". Trunk sewers are brick, with tne invert lined ith limestone. Tney range in size from 2'x3!' to 4'xé!'. dy O) i Conclusions and faults of the system. The sewer system, as it stcnds in it's present condit- ion, is pr-.ctically <= replica of the system in any city, where the work is done piece-meal. In a way, this is un- avoidable, for, to build for the neds of fifty years hence moy be argued unnecessary, because cof the change in the meth- ods of doinz work, the materials used, the expansion of the city in ways different than that supposed when the system was desi-necd. However, the system we investigated, is capable of tak- ing care of the domestic and manufacturing wastes, to 2 cer- tain degree, clthouh, it is not capable of handling both the storm water, end, sanitary wastes. Metcalf & Eddy, Vol.1, says that in order to avoid de- posits in a pipe, the velocity should be one and one-half feet per second, or more. Our data sheets show many velo- cities lower than one and one-half feet, but, that is due to the fact that our velocities are fisures for a steady flow, during the 24 hours. This condition, it can be plain- ly seen, will not be prevalent, as the house wastes come in spurts, and, it is altozether likely the velocities caused cy thee wastespurts are self-cleansing. The jeposition of w stes are lessened by the fact that after any considerable rainfall, the laterals are flowing full, or practically s0, so that the deposits are cleaned out, but, this advantaze is a disadvantage, in that the pipes are not capable of carrying such a large amount of -27- water, causing the same to back up, and, flood cellars, thereby destroying property, and, becoming 2 menace to the health of the occupants. At the outlet of the big sewer that runs clony the Grand River, emptying into the river at the foot of Willow St., North Lensing, the odor of sewer gas was very obnoxicus at the time we inspected the outlet. This was the only place that we noticed any presence of sewer gZase we found there were thirteen outlets into the west side cf the Grand River, and, one would think this would be det- rimental to public health end a menace, but, taken from good authority, samples of water taken two miles above the city, and, two miles below were identical. The pollution of the river, throuzh the city, amounts to practically nothing, be- cause the outlets which discharse in the city limits on the we3t side of the river, carry a very small emount of sewage. The Outlets were #ll of C.I. pipe, from 10" to 24" in diameter, and, from 50' to 150' long, except numbers 12 end 13, at the foot of Ottawa Street, which outlets empty di- rectly from the retaining wall to the river. Outlet No. 13 was only noted in our investigation, as it is only a storm water system drainage, a part of the west central part «f the city, and, by the way, is not adequate, and, should be enlarged. From our data, we estimated the p opulation of the city, in our district, to be avout twenty-thcusand. This is a fair approxination, SS == ——— = Ee —_ 1293 030 3 MA