trihalolucthunc formation potentials in lake...
TRANSCRIPT
•
•
•
TrihalOlucthunc Formation Potentials in Lake Menlphreluagog
A the\l\ \UIH11Iltcd to the Faculty of Graduatc Studlcs and Rescarch in parllal fui tï Il Illcnt of the reql11rcmcnts for the degree of Master of EnglllL'er ing .
Rachel Yang
l\1arch 1993
Dcpartmcnt ot Civil Engineering
McGi11 University, Montreal
([) Rachel Y.mg. 1993
•
•
•
ABSTRACT
In rcsponsc to the Itkdy rlltur~ change 1I1 the C.lI1.lt!l.lll (illlddtnL'\ ICglll.lllll~ till'
maximum allowablc COllccntratlon of tnhalolllcthalh.'s (rHM) III pot.lbk \\,Itl'r, ,Ill
investigation into the possible came~ and vanablltty of TH 1\1 prC(llr\or-; \\'.1\ l'Olldllctl'd
during the summcrs of 1990 and 19\)1 al Lake Mcmphremagog III \olltll l\l\tl'fIl ()Ul'hl'(
A number of <issoclated parameter!:-. were corrc1ated \. Itll TIIM 101111.111011 potl'Iltl.ll
(THMFP) with respect to seaSOIl, dcpth and pO\I!lon on the 1,lke. rhl' '1'111\11·1' W,I\
quantified indtrectly by mca~llnng the 'l'HM conccnlra1101l prl'\l'11l al Il'I chlofillalHlIl
under standard conditions.
THM concentrations 111 tlle samples were found 10 exccl'd l11e liS EPA \Iandard
of 100 J.tg/L, sometimcs conslderably. There dit! Ilot appear to he any \Iall\tllally
significant contnbution to THMFP from human acllvlly. No clo'ie <lgrl'ellll'Ilt W.I ...
observed between THMFP and any of the m~oclated parameler\ lor Lhe lakc :1\ a wholc
A few correlatIOns were fOlllld bctwccn THMFP and lluLncnl concentratlon\ al IIHhvldual
sites.
•
•
•
ABSTRAIT
En répof)',c aux c!t,lIlgcmcnt<, prévu~ à la rég lcmcntatlon canadienne concernant
la concentration IllaXlIllalc de tnhalométhanc\ CnlM \ pcn11l~e dan~ l'cau potable, une
recla:rchc a élé réall\é, durant Ie~ élé~ 1990 et 1991 au lac Memphremagog dans les
('.lIlton'\ de l'e ... t. pour détermlllcr le, cause.., et les varwtIOns possibles chez les agents
précuro.,cur\ dl' 'l'HM Dan\ le but d'établir une corrélation cntre le potentiel de
formation de THM Cn-IMFP) ct œrtaln~ factellr~ a~socié '."lar rapport aux ~aJsons, à la
profolldeur ou la p()~ltIon dan~ le lac, le THMFP a été tléterminé indirectement en
I11c'\urant la concentration cn l'HM aprb chlorinatIon dans d\:s conditions standards.
La concentratIOn en THM pour la plupart des échantillons dépassait la limite de
100 ug/L établie par l'EPA, par une marge considérable parfois. Il ne semble pas y
aVOir aucune contnbutIOn statistIquement signIticatIve au THMFP de la part des activités
huma\l1es. Aucun lIen n'a pu I.!tre établI entre les paramètres assocIés et le THMFP pour
l'ensemble du lac. Entin ccrtailles corrélatIOns ont pu être établI entre le THMFP et la
concentration en éléments Ilutntlf~ pour certains sites .
•
•
•
1 nh tl'"1h:lh Ill<' l ,'rllllll"11 \",\, 11\111, III 1 .II., i\1<l1I1'i11l11l1,·,,~ ---------------------------------------
TAULE OF CO~TE~TS
1.0 Introduction ............................ ..
'2.0 literature Rcvlew .. .. ......... . ...... ..... ... . ..... . 2.1 Introduction................................. . ........... . 2.2 Regulations.... ...... ................. . .............. .. 2.3 Aquatlc humlc matenab .... .... .... ............ .
2.3.1 Ddïml10n of hUl1llC \llb!\taJlœ~ ........ .. 2.3.2 Molecular wCIght dl~tribll1101l ofTII~l prL'l'lI''>(l''>
2.3.3 Model compollnds ............ .. 2.3.4 Slirrogatc pararnclers ........... ... . . .
2.4 Aigae and thelr cxtracellular products.. .. ....... . 2.4.1 Aigae a~ THM precllr~ors ......... ...... . 2.4.2 Aigae as preclirsors of other organohahdc\ 2.4.3 Seasonal and dlel/dillrnal cffect~ . ........ .. ......
, , . ,
-, 'i ()
S \)
Il Il 15 Itl
3.0 Lake Memphremagog ............... ............... .. ..... ..... .. 20 3.1 General charactcnstics .............................. ..... . 20 3.2 Aigae m Lake Memphrcmagog ...... ....... ....... .... . .. .... 21
3.2.1 Algal specles vanatlon ......................... .. ............. 21 3.2.2 Phosphorolls llltlllence ...... ........ . ...... ..... 22
4.0 Memphremagog 1990/1991 sampling campalgn ................. .. 4.1 Sampling sites ................................................. .. 4.2 Sampling schedlile ............................................. . 4.3 Sampling eqlllpment ..... .................. .. .. .... ..
23 ..... . 2.1
21 .. 24
5.0 Methods... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ..... . .. ...... .. . . 25 . ... 2)
25 .26
..26 26
.. 27 . ... , 2X
Hl .. m
5.1 Preparation of samples .................................. .. 5.1.1 THMFP and chlorine dernand ~ampk~ . .. .. .. 5.1.2 Orgamc carbon ~amples ... ............... .. .. .
5.2 Analysis of the THM samples ........ ..... .. ......... . 5.2.1 Prelimmary expenments wlth the Cie/MS .. . 5.2.2 Preparation of the l!1~trllments ................. . 5.2.3 Analysis procedure .............................. .. 5.2.4 Detection limit and confidence mterval. .. .... . 5.2.5 System efficlency... .... ............. .. ............. .
• rnll,t!<IIIlLlll Hll- l "rm,lllOll Put.:nll,ll, III Llk.: l\kll1phrcmagog - -- ------ -----
') 1 All,tl y\l\ ot the oll1er par,lrlleters.. ..................... . ................ 31 ') 3 l Orgarllc carbon )<lmrJc~ . ..... ............................ 31 ') 3 2 WatL:r ljllallty p,trall1eter) ..................................... 31 i J 3 Nlltnent data. ......... . .. ........... .. ............ 32
fl () Re\ull\ and J)!\ClI\\101l ........ . ................................................ 33 h 1 Chlorotonn vanatlOI1 over "pace and tlme. .. .......................... 33
fi 1 1 Pcnder and Incllan ~all1pllllg ~ltcs .................................. 33 t) 1.2 Border \,unplll1g )Ite ............................................... 36 Il. 1 3 Centr,lI ... ampllng )Ite ............................................... 37 () lA North ~alllplll1g ~ltC. .. ............................................. 38 () J 5 Nonh-"ollth (Ii fferencc~ ..... ... ..... .. ......................... 38 Il. 1 Il VanatHlll over deplh al Central ~Itc ................................ 40
7 () V,lfIatlOI1 of a.,\oclated paral11eler~ over ~pace and tune ....................... 42 7 1 ()rganlc carbon ................................................................ 42 7.2 Chlorophyll (1 ............................................................... 45 7 J '('()tal Pho~phonl\ ........................................................ 46 7 -+ 'rotai Nltrogcl1 .................................................................. 47 7.5 Nltnlgel1:Pho~phoru~ Ratios .................................................... 49
• 7.6 pH and AlkalJI11ty .............................................................. 51 7. 7 Su~pel1dcd )olJ(b and turbldlty .......... .. ................................... 52 7.g Secclll depth ...................................................................... 54 79 Tabulatcd values ................................................................ 55 7. 10 'reillperature ......... ............................................................ 56 7.11 (:l~ l)cllland ...................................................................... 58 7.12 PreclIeted hUlllle contnbutlon on the basts of colour ....................... 58
l'i.O ('orrelatlons betwCèn paramcters ........................................................ 60
9.0 COI1CIU~IOns ........................................................ 65
Cilo'isary ..... . . ............................................................. 67
References ..... ................................................................. 69
AppcndlCC~ . ................................................................ 76
• 1\
• LIST OF l;IGURES
Figure 1. LocatIOn of ~al1lpllllg. ~Itl?~ on Ltke ~klllphr~II1.\gllg .. AI Figure 2. CalIbratlon curve for the allaly~ls of THf\.lFP :\ .'
Figure 3. Seasonal vanatlOn of THf\.lrp at Pender ... BI Figure 4. Seasonal vanation of THMFP at Indl.ll1 ........... BI Figure 5. Seasonal varIation of THt-.1FP at Border ..... . .. ... B2 Figure 6. Seasonal variation of THl\IFP at Central ......... .. B2 Figure 7. Seasonal variation of THMFP at North ............. lU Figure 8. Monthly averages of untïltcred THMFP al ail \Ite\ . B4 Figure 9 Monthly averagcs of tïllcred THMf-P at ail '>Ite ..... B-l Figure 10. Seasonal vanatlon of untïltered THMFP .lt Central (-l. depth\) Bi Figure Il. Seasonal vanatlon of tïltcrcd THMFP at Ccntr,t1 (4 depth\) B5
Figure 12. Seasonal vanatlon of TOC and untïltcreu TIIMFP al Pl'Ilder <'1 Figure 13. Seasonal varIation of DOC and tiltcrcd THMFP al PCll(kr. .Cl
• Figure 14. Seasonal vanatlon of TOC and untïltcnxl THMFP al l/l(han . ('2 Figure 15. Seasonal variation of DOC and tiltereu THMFP al IndIan .. ('2 Figure 16. Seasonal variation of TOC and untï1tercd THMFP at Border. C, Figure 17. Seasonal vanation of DOC and tïltcrce! THMFP al Bordcr C\
Figure 18. Seasonal vanatlOn of TOC and unlïltcrcd THMFP at Central ( '4
Figure 19. Seasonal variation of DOC and tïlteree! THMFP al Central ('4 Figure 20. Seasonal variation of TOC and untïltcrcd THMFP al North CI)
Figure 21. Seasonal vanatlon of DOC and filtcrcd THMFJ> al North. (')
Figure 22. Monthly average~ of TOC/DOC and THMFP al l'ender . .. . ('() Figure 23. Monthly averages of TOC/DOC and THMFP at Indlan ....... ('()
Figure 24. Monthly averages of TOC/DOC and THMFP al Border. ('7 Figure 25. Monthly averages of TOC/DOC and THMFP at Central ... C7 Figure 26. Monthly averages of TOC/DOC and THMFP al Norlh ex Figure 27. Monthly average') of TOC at ail slte~ ....................... CX
Figure 28. Seasonal vanatlOn of chi ([ and THMI'P al Pender ... 1>1 FIgure 29. Seasonal variallon of chi ([ and THMFP at Inclian 1>1 Figure 30. Seasonal variatIOn of chI ([ and THMFP at Border .... .. D2 Figure 31. Seasonal varIation of chI a and THMFP at Central 1>2 F;~ure 32. Seasonal varIatIOn of chI ([ and THMFP at North .. I>~
FIgure 33. Seasonal variation of chi a for ail ~lle5 ......... D~
• III
•
•
•
1 Igun.: ~4.
lIgure -'5. Flf! lire 36. hgllle 37. , Igl.re -'R. lIgure 39.
"Igure 40. hgure 41 FIgure 42 "Igure 41 FIgure 44 hgure 45
FIgure 46. FIgure 47. Figure 4X. FIgure 49. FIgure 50. Figure 51.
Sca\ollal \ anatJol1 01 TI> and THMFP at Pcnder . ................... ... El Sea\OI1.l1 variation 01 l'JI and THMFP at Indlan ............................ El ~c<Ir.,()n;.1 variation 01 TI> and THMFP at Border ......................... E2 Sea\OIul varlatlOI1 of TP and THMFP at Central .......................... E2 Sea\onal varlatJ()!l 01 TP and THMFP at North .......................... E3 Monthly average.., of TP .It ail ~Ite~ ......................................... E3
Sca\onal vanatlon of TN and THMFP al Pender ........................... FI Sca<,onal vanatlon of TN and THMFP al Indian ............................ FI Sca~onal variatIon 01 TN and THMFP at Border ........................... F2 Sea\onal variation of TN and THMFP at Central ........................... F2 Sea\llnal variatIon of TN and THMFP at North .......................... F3 MOlltllly average) of TN at ail ~Ites ......................................... F3
Sca\onal variation of the N:P ratIO THMFP al Pender ..................... 01 Sca~onal variation 01 the N: P ratio THMFP at Indian .................... G 1 Sca~onal variatIon of the N:P ratIo THMFP at Border ..................... G2 Sea~onal variation of the N:P ratIO THMFP at Central ................... G2 Seasonal variatIon of the N:P ratio THMFP at North ..................... G3 Montilly avcrages of N:P ratio for a11 sites .................................. G3
Figure 52. Sea~onal variation of pH at ail sites (1990) .................................. Hl FIgure 53. Scasonal variation of alkalinity at a11 sites ................................... Hl FIgure 54. Scasonal variation of alkalil1lty and THMFP at Pender ................... H2 FIgure 55. Scasonal vanatlon of suspended ~ohds for ail sites ........................ H2 Figure 56. Scasonal vanatlon of turbidlty for aIl sites .................................. H3 FIgure 57. Sca~ollal vanatlon of solIds and turbldIly at Pender ....................... H3 FIgure 58. Scasonal variation of ~olId~ and turbldity at Indian ........................ H4 FIgure 59. Scasonal vanatlon of sollds and turbidity at Border ........................ H4 Figure 60. Scasonal vanatlon of solIds and turbidity at Central ....................... H5 FIgure 61. Seasonal vanatlon of solids and turbidity at North ......................... H5
FIgure 62. Seasonal vanation of secchi depth and THMFP at Pender ................. Il Figure 63. Scasonal vanation of secchI depth and THMFP at Indian .................. Il FIgure 64. Scasonal variation of secchI depth and THMFP at Border ................. 12 FIgure 65. Seasonal vanation of secchi depth and THMFP at Central ................ 12 Figure 66. Seasonal vanatlon of ~ccchi depth and THMFP at North .................. I3 Figure 67. Monthly avcrages of secchi depth at aIl sites ................................. I3
Figure 68. Temperature proti'es for May-June 1991 at Central ........................ 11 Figure 69. Temperature protiles for July 1991 at Central ................. " ............ 11 Figure 70. Temperature protiles for August 1991 at Central ........................... 12
IV
•
•
•
FIgure 71. Surfacc tcmpcr,ltun: protïk n\'cr Itll)1 \,lIl1pltI'g \C,l\t)n ,II (\'nll,lI J2 Figure 72. SI!rfaœ Icmpcr,lturc \',\llall011 bclwccn \lll'\ (1 l)q 1) J ~
Figure 7:'. Scasonal V:lnatIon ot TH Î\ 1 FP and djinn IlC lklll.l\ld .ll Pl'ndl'I "Ill' (19900nly) ..... , ............... , hl
fIgure 74. Sca<ional vanatlon 01 THr-.lFP anu L'hlonnc lk-ln.ll1d .11 IlllII.lIl \lll' (1990 only) .......... ...... ........ . KI
Figure 75. Seasonal vanallon of THr-.tFP and chlnnnc dcmand .II Bordcl "Ill' (1990only)........ ................ ........ K2
Figure 76. Sea~onal vanatIon of THMFP and l'hlnnl1c dCllland al (\'1111,11 \lle (1990 only) .......... . .. ... ......... K2
FIgure 77. Seasonal vanatlon of THMFP and chlnnnc dcmand al North 'IlL' (l9900nly) . ... ......... ""'" K\
FIgure 78. PrcdIctcd hUll1lc and algal L'omponcl1l,> 01 TIlr-.tFP ,II \\'lllk'1 '>IIL' (1990 only) ......................... ,
f-Igure 79. Prcdictcd 11lI1l11c and algal L'ompOnelll' of TIIMFP al Il1dl,\I1 'Ill' (1990 only) ......... . . ...... . ... .
Figure 80. Prcdlcted hlll11lC and algal componcnl~ ot TIIMFP al Border 'Ile (19900nly) .................................................... .
FIgure 81. Predlcted hlll1lic and algal L'omponCnl'i ot THMFP al CCIII rai 'Ill' (19900nly) .............................................. ..
Figure 82. Predlcted hllnuc and algal componcnt'i of TIIMFP al NOIth '>lll'
Figure 83. Figure 84. Figure 85. Figure 86. FIgure 87. Figure 88. Figure 89. Figure 90. Figure 91. Figure 92.
FIgure 93.
(1990 only) .............................. , ................ .
Correlation betwccn untïltcrcd THMFP and \ceclll dcplh CorrelatIon bctween tï1tercd THMFP and \CCclll dcpth Correlation bctween lIntïltcred THMFP and \CCclll deplh al Pende! CorrelatIOn bctwecn tiltcrcd THMf'P and \ccclu dcpth <lt Pcnder Correlation between lIntï1tercd THMFP and ... ccchi dcplh al 1\1(lIan Correlation between tïltcrcd THM FP and 'iccchl dcpth at 1 milan Correlation betwe~n unfiltcrcd THMFP and TP at Pcndcr Correlation betwe,;!n tï1tered THMFP and TN at North .... Correlation bctwecn lIntï1tcrcd THMf'P and SolId'i al North CorrelatIon between prcdlctcd algal THMFP and chi li
(unfiltered 1990 only) ............. ..... . ......... .. Correlation bctween prcdlctcd algal THMFJ> and chi li
(tïltered 1990 only) ............................... ..
Untïltered THMFP versus total orgalllc carbon.... . FIltered THMFP verslI'" dl",\olved orgalllc carbon
1 1
LI
1 2
1.2
. 1 . .\
MI Ml M2
.. M2 M3 M1
. M4 M4 Mi
., M6
Figure 94. Figure 95. Figure 96. Untïltered THMFP vcr~us chlorophyll a .............................. ..
NI .NI
., N2
v
• l'liure (n, hltcrcd TIIMFP \cr\l1\ chlororhyll {/ ." .. " ... " ...... N2 1 1F-'llre (JH IJllllltL:rcd TlIt\ll P \Tr\ll'> total!lItrogcn ..... ,," .......... "." ........... N3 1 1 g li re ()l) FIIlcrcd THMI'P VCr\ll~ total nttrogcn ...... " ..... "" .................... N3 hgllrc 100 (Intlltcrcd TIIMFP ver\ll\ total pho~pllOroll\. .. .................... N4 1 1 g lIrc 101 hllcn:d THMI'P vcr\l1\ total pho'iphoroll\ .. "" ................ ,, ........ N4 IIi-' LI Il' !O2 1 Jnttltcrcd THMf P ver\lI\ N'P rdtro " .... "."" .......... " ... " ... " ... N5 1 I~' li rc J03 Flltcrcd rr HM! P vcr\lI\ N'P ratIo , ... " " .. """ ...... " .............. N5 l, 1 f' li! e !04 Ilntïltcrcd 'l'HM!'P VCN!) \lI\pclldcd \oll(h ..... " ..... " ........... " N6 i'I g lIrc 10') ! t1tcrcd l'HM FP vcr\lI\ ~lI~pcndcd \obd\ .... " .... " ...... " ............. N6 h)2l1rc 106 Ilntïltcrcd THt\lFP vcr'lll'l alkalll1!ly ..... "" .. "" ................... N7 1'1 gu rl' 107 1 Iltcrcd THM FP vcr~lI'l alkahlllty ....... "........... . .................. N7 1 Igll!C IOX, 1 Inti Itcred 'l'HM Fi> \ l'r)lI~ turbldlly .... .. .... . ............... N8 l'II.! lIrc IOl) hltcred l'lfMFP vcr"u'l tllrl1lClily .... " ............................... N8
•
• VI
• LIST OF TABI,ES
Table 1. General Characten\tl\:~ of 1 a"c l\lclllpllll'lll.lgllg .'l) Table 2. VanatIOn of \Vater quallty paramCk'!\ '(1
Table 3. CorrelatIOn matnx for 1I1lfiltClcd \:llllpk'\ Id
Table 4. Correlation matrlx for rlltcrcd \.unpll'\ (d Table 5. CorrelatIon coeftÏclŒl', for 1l1l\IFP .lIld \\.IICr qll.lltty p.II.llllL'lcl\
(lin tïltcrcd ~all1plc~) (J \
Table 6. Correlation CoeftïCIŒI" lor THl\Il'P dl HI w.lll'r qll.lllI\ p.Il,II11L'IL'!\ (tï1tcrcd ~alllpks) (1 \
•
• VII
•
•
•
1 I:'\'TROf)CC110:"
Tnll.1I ()l11ethane~ (ni l\h) were ti r)t ! II1ked to tlle cillon nation of natural waters
III Ilnt (Rook, 1977). The tour I1l0~t commonly occurrIng THMs are chlorolorm
((' 1 Hï Il, hromoforrn (CH Br \). hromodichloromethane (CHBrCI 2), and
(lIhrolllochlorllmethane (CHBr~CI) THM prccursors are known to 1l1c1ude humlC and
f lJlVIC :Icld .... whll'Il con<;lllulL Ihe major portIOn of orgal11cs 111 sorne natural waters, as
wdl a ... algac alld thclr e;..tr.lcdlular prodLlct~ (Scully l'f al, 1988). As It I~ suspected to
he a hlll11an c.lfclllogcn. chluroform. the mo~t commonly oecurnng THM, has been
hallilcu twm ll"'C III food or drllg~ by the U.S. fDA ~Il1CC 1978 (Trussell and Umphres,
197X)
Thcre 1 ... a pO)~lhIlJty that the present Canadlan gUldeline for the maximum
acceptable 'l'HM concentration 111 firw,hed \véHers (350 I-'g/L) will be lowered in the near
future. The 1l1O~t heavtly arfected hy lhe proposed new guidelines WIll be drinking water
trcalment pl.lIll~ WI11Ch dl~\I1fcCI \vtth c\llonne as the pnmary treatment and have as a raw
water ~()llrce ~.l1lall lakes whlch may be eutrophie or even hypertrophie. Ayotte (1987)
tOlllld that. \\ hile only one out of 99 ~mall Québec municipahties surveyed had THM
conl'l~ntratllHl\ c\ceedlllg .150 ~(g/L. 27 of them exceeded lOO I-'g/L. In arder to avoid
the l1e~e~~lty llt L'\lX?ml\'L' [rc.ltment processes to remove excess THMs, effective
management ~trateglt.~~ \\111 h,l\e to be developed. The variatIon of the THM precursor
L'onL'Cl1tr.ltllln~ ln the I.ü,c'\ on <l ~easonal and diel basls Will have to be Investtgatéd, as
• will the use of surrogate par,lIn~tl'r~ Il'!" r,lpld ,1~"Il.'~"I1ll1'11 1 pI Il tll,lli.ll1ll'l h,\lW l'fenil ,pr
(THMP) concentratlons.
An II1vc~t1gatton was Cnndlll.'t~d dllrtng July ln SL'pll'1ll1k'l 1 \)\)0 .\1 III 1\1.1)' III
September 1991 of Lake l\1emphrcmagog 111 ~ollth-ca\t~rn QUl.'bl'l' 1 hl.' Phll'l.'ll\'l'''I 01 11lt'
study were ta ascertain the \cvd of the total TIIt,,! formatron plllcntlai (rrI lf\tFP) prl"l'Ilt
in the lake in compari~on wlth dnnklng waler \t.\IHlard~; ln l'\aIl1IIH.' IhL' \'.ln.IIIOIl\ 01
THMFP over space and tlllle dunng tlle \UIllIllCr \ca"lon: .\IId lu \c.lrl'h fOI 'Ill mg.lll'
parameters and eVlc1cllcc of algal l:ontnbutlollS.
•
• 2
•
•
•
Tnh,J!OlllLlhdrlC rorm,lllOn Pol.:nll.Jh rn Ldke Mcrnphrcrnagog
2 LlTERATURE REVIEW
2.1 lutr'odu('t iOIl
ln 1974, Rook publJ\hed an investigation of the Rotterdam water utIiity which
\!Jowed the prc~erlcc of haloformli 111 significant Icvels followlIlg chlonnation. In the
Il.S that \ame year. Bellar ('f al (1974) reportcd sigl11ficant levels of organo-halides III
..,OIne dnnkl!lg \vatcr..,. Both Iinkcd the production of halogenated organics to the
c!Jlonnatlon 01 natural watcr~ whlch contalllcd orgal1lcs. The princIpal compound found
wa\ chloroform.
The followlI1g year, the U.S. EPA published the results of the Natlonal Organics
RCCOlll1al\'iancc Survey (NORS) (Symons (!{ al, 1975). The sllrvey of 80 cilies found
'l'HM., to be pn.:..,cnt 111 almo~t every tïl11~hed water (concentrations ranged from non
dctectablc to 482 Itg/L) but only occasionally, and In ~rnall concentrations, in raw water
~upplIe~. In 1976 the V.S. National Cancer Institute published a report stating that hlgh
doses of chloroform callscd cancer in rats. As a resllIt. the U.S. FDA banned its use as
an additive 111 food or drllgs (rrussel and Umphrcs, 1978).
2.2 Regulations
ln 1979. the LI.S. EPA published drinking water regulations settll1g the U.S.
IInjll~ on total THf\1 (rrHM) concentrations in tïnished drinking waters to 100 fJ.g/L
(U.S. EPA. 1979). Pre~ently. the U.S. EPA IS developing new disinfection by-product
3
• (DBP) regulattons as dlrected by the 1986 amendmcnts to the Safc Dnnk1l1g \\' ,lll.'r Act
These rcgulatIOns may lower the e:\l~tll1g ~tandard for tot .. ll THt\h. In addlllllll. the EPA
may also regulate lIldivlduul THMs and promulgate !'>tand.mb tor other \)BP ... (Kt, .... ncl
et al, 1991).
In Canada. Foley and Mls~1I1gham (1976) '1l1rveyed 1 J watel" trc,lImcnt plant ... In
Ontario, of which 3 produced tïl1l~hcd water THM concentratlOll'" of glcatcl tlt,\Il 100
}-'g/L. A natIOnal survey conductcd 111 1977 (Nawmal Survcy. .• Il)ï7) cOVl.'rcd 70
mUl1lcipalities across the country and round the Illcan value ot tPe l.'Ollccntrallllll 01 TIIT\h
111 Canadian drinking waters to be 21 ,Hg/L. apparently weil below the 1I.S <lvcrage ut
68 }-'g/L found 111 the NORS (Symons CI lIl, 1975). Howcver, the ... urvey had hren
• conducted in mid-winter and failed to takc mto accOllnt pO<.;'>lble ,casonal ,lIld temperature
effects. Seasonal effects were sllbsequcntly exalllllled by William ... li' (// ( Il)XO) The
Canadian guideline for the maxImum allowahlc concentration ot TH 1\.1\ III dflllklllg walel
was introduced at 350 }-'g/L. Therc \'> a pO"islbtlity that thl\ Will he lowcrl'd III the Ilcar
future (GUldelines ... , 1989).
2.3 Aquatic humic matcrials
Since the dlscovery that humic ~ub~tancc<; appear 10 be the m,ilOT TIIM precuNH'>
in most natural waters (Rook, 1977; Babcock and Singer, 1979; OlIver and J ,awrencc,
1979), many researchers have stlldicd hllI11IC '>lIb~tancc') to better lInder\land the TIIM
formation reaction, and examlllc the cnvlronmental effccb on the rate and exlent of
• 4
•
•
•
1 nhJllHm Ih,IIIL rorm,IIIOII P"ll:lItl,d~ III Llkc McmphrcmJ.)!o)! - -- -- ----- ----- ----
re,letlon 111I1Il1C'> have al,>o heen ,>Wc/leu a'i modd compounu~ and \urrogatc parameters.
2.3. J Definition (If hUlIlic "uh"tancc~
111IJl1IC ,>ub\tance"l are a gencral cla'l~ of hctcrogcncom. blOgemc, rcfractory,
ydlow-black. orgallic 'IlIh..,tancc'i that arc Ublqultoll~ to ail cnVIf()J1ll1cnts. They serve as
a lIl,qor re,"'l'rVOlr of organlc carbon for the global carbon cycle. Extrcmely reactlve,
they arc Important partH.:ipant ... III many gcochcnllcal rcactlOl15. and proccs5.es (Alken el
ill, 1 ()X5)
Ihllmc ... uh\tancc~ do not corrc~pond to any 1I1l1quc chcl11lcal entlty and cannot be
descnbcll in lInamhlguou\ \trucwral or functlonal tenm. The clas5.ic definitions of
hllllllll, hUllllC <lcld. and flllvic aCld. I~olatcd l'rom thclr el1Vlronments. are from soil
'iClcncc and arc ha~ed Dn ~olllbilIty (GJCSSlIlg, 1976):
hUll1lc aCllI - the fractloll of hUl1llc matcnal that I~ I11soluble 11l water below pH
2 but soluble ln watcr of highcr pH;
fulvlc aCld - the fraction 01 hUllllC matcnal that 15 ~olublc 111 watcr at ail values
of pH;
hllnllJ1 the fraction of hlll11lC matenal that I~ I11soluble in water at any pH.
More rccently, Thurl11an an.:1 Malcolm (1981) dctincd aquatIc humus clS the matenal
which atborb'i 011 an XAD colllllln from an acaj aqlleolls solution. The portion of the
adsorbcll matenal soluble 111 aCld and hase is fulvlc aCld, whde the portion insoluble in
aCld 1"'; humic aCld .
5
• While it is not possible 10 wnlC lIle exaCI \lnl\:lun.~\ for hUlllll' \Uh"t,lIlL'I'\. II 1:-'
possible to charactenze [hem nn Ihe baSlS of thclr phY\'L'o-cllclllll"ll bdl.lvlour
Molecular welght (l\1\V) IS an important detïnlllg cntenon, "tlll fulvlc al'Id, I.mgl' ltom
500 to 5000, while soIl hUl1llc aCld'i average JOOO 10 Hf t~tL"L'llllh., 1l}~5). Aqu.llle hUllll\.'
substances have lower 11l0lecular wClghts th an thCl r "lot! (ollntcrp.1I1\, pl'I h.lp ... IIHII.:.lt 1 \'l'
of their various sources, which can be ellher <1Ulo.:hthoIlOll'i (forl11cd 110111 plan "'Ion III thl'
water) or allochthonous (Ieached II1tO Ihe WalL"r from IL"rrL"~tnal pl,lIl1"" k.11 !tttel. \011,
or subsurface depŒlIs).
2.3.2 Molecular weight distribution of TIII\1 pI'CClII'MU"
• The molecular weight distnbullon of THM precur\ors ha\ heen ... Iudled w a\ to
obtain a better understandlllg of the nature and ~ource ... 01 THM P<; and devclop \llitahle
methods for their removal. Trus~cl1 and Umphrcs (1978) rcpOltcd that f\lW.., lor IlIlvlc
aClds probably range bctween 100 and 1000, and hUl1l1C aCld" prohahly h.lVL' MW\ 01
100,000 or higher. Humlc aClds were reported 10 react more aClIvdy wllll l hlorJnc.
producing 117% more CHCJ, per untt TOC than fuJvlc aCld". and 10 Ill' 01 !-'.fl'ater
importance in THM productIOn Howcvcr, data gathercd Indlcalcd tllal the hulk ()f
aquatic humus present was in the 10,000 to 20,000 MW range; the htlmll dCld fractl()1l
being so small as to be insignitïcanl.
In contrast, Schnoor ('/ al (1979) tound that l)O'Yr, 01 tlle orgamc\ III tlle Iowa
River were of MW Jess than 3000, and that 75 % of the THM" were deflved f rom Iim
• 6
•
•
•
lower MW fraction, fulvlc aCld gcnerally contnbuting over 90% of the humics III natural
w,lter,> (Ollvl:r anu Thllrman, 1 S':-S3). The 11Ighc~t THM concentratIon denved from the
1700 10 ~OO() MW range, whlle the highc~t THM yield was from preclirsors In the 2100
10 :')()OO MW range (Schnoor el al. 1979). The fraction of hllmlcs < 1000 MW,
IIlcludll1g the fulvlc aCld,>, wa~ found to be Important to THM formation, as was the
> 50,000 MW fraction
SlInllar oh\crva!l()n~ on the MW fraction of THMPs were made by OlIver and
Illllrlllan ( 19X3) and a nUl11ber of other rescarcher~. Bruchet el al (1984) and Collms ('{
li/ (1 9R6) al~o round \lgl1llïcant THMP concentratIOns at < 1000 MW, whlle Collins er
a/ (1986) ob\crvcd signdicant contnbutions [rom fuI vic aClds in the 10,000 to 30,000
MW range and EI-Rehalll and Weber (1987) noted major contributions from humic aClds
III the 30n to 40,000 MW range. Llkewise, Oliver and Visser (1980) found that 1000
10 10,000 MW was the Illost Important fractIon for fulvic acids while 10,000 to 20,000
MW was the 1110st Important fraction for hUITIlC acids. They also found no difference
bet\Vcen the l'HM potentlal of humlc and fulvlc aCld. This supports observations made
hy Oliver and Lawrence (1979) but contradlcts fïndings by Babcock and Singer (1979),
who found that hunuc acid produced twice that of fulvlc acid (from peat). The fulvic
aCld fraction was more Important than the humlc acid fraction, producing roughly 72%
to XOI;{) of the total THMs (OlIver and Visser. 1980) .
7
• rnh.II"I1l.·I" 'I\l' 1 "flll.lll"ll 1\'I .. ·nll.lI, III 1 Il .. l I\kllll'h"·IIl.II"')! -----------------------------------------2.3.3 Model compoullds
Model cornpollnds havc a ~1I111lar fI .. 'a(tlOl1 \\'lIh , ... hll)llnl' ,l'" n,Hul,1l 1'111\1
precursors and will abo havc roughly the "unc )'Idd... l'hc)' ,lit' Il'''L'd III ... \lIdv Ih'
kmetics of the THM formation reactlon and Ihe ctTcL'1 of envI ronmcnl.1I condition .. on the
potential yield. A 1111mber of researchers have u ... ed humlL' 'lIh,l,lIlcc, a ... IlHHkl
compounds. These arc' elther pllrcha\ed cOlllmerclally or denvcd fIoll1 lIalur.t1 ,OUIl'l'\
(Babcock and Singer, 1979; OlIver and VI\:-.er, 19~(), Urano ('( tll. IlJH3; Ball'hdor (" al,
1987; Reckhow and Singer, 1990, Adlll (" III, 1991). Roo'" (Il)HO), 111 .\ dd.\Ibl ... Iully
of humic acids as THMPs, noted that hUllllC aClt!:-. are ben/cne and .\lOlllatll' IlL'Il'f()cydll
rings substituted with methoxy-, hydroxy-, and carboxyllc fUIH:llOllallllc .... Ile 100IIId thal
• methylated compollnds did not rcact wlth chlonnc at hlgh plI, tllat hromllll' wa\ more
reactive with methoxy- compounds, and that phenollc hydroxy- COlllpOlllHh .\ll' Il'qllllCd
for the incorporatIOn of chlonne into aromatrc g, ()Up~.
Humlcs are complex compollnds that rcqllirL. t cleavage \tep pnor lu leactlllg Wllh
chlorine. Other work has been donc wlth smaller or more readlly av,II1abic orgallll'\
Stevens el al (1976) found that Illcthyl Ketoncs Will reaet WltlJ cillorine 10 fOrln 'J'IIM\,
and that ethanol can be OXldlzcd by hypochlorite to be a TH M preclIr\or Morn \ and
Baum (1978), however, pOInted out that al pH 7, the t\lne reqlllred for Ille reactlO!l of
meth yI ketones wnh chlonne to go to complctlon, wOllld be almo\t Olle ycar 1\ ... llIore
likely compounds, they !lugge~tcd fi-dlkctonc') \lIch a ... rc \orc 11101 , \trllclure ... Will! a
pyrrole ring, and acetogenins. whlch are rc~pon\lble lor rnany natllral plgmellt\.
• 8
•
•
•
Tnhalollll .. I/i,lI11! FllrmalHln PIlt.:nll.th Hl L.t"l! tl.krnphrl!rnagog ------- --------------
Argucllo ('11I1 (1979) tOlmd that acctonc wa5 the ollly methyl ketone that produced
TH Mc." Phcl1o!c., and anlllllcc., wcre good CHCI 1 precur~ors al 11Igh pH, and meta- and
para-dlhydroxyaromatlc compollnd~ ~uch a~ rcwrclIlol were very CftïClcnt precursors.
'l'lm agrccd wnh Rook (1977), who ~tlldlCd resorclnol, pyrogallol, ethanol, and 1,3-
cyclohexanctllol undcr \llIlulatcd water trcatment condItions. Dore (:{ a/ (1982)
IIlvcc.,l'gatcd a nllmbcr of organic compollnds and found that resorclI1ol gave a maximum
ylcld of CHel 1 at pH 7 10 H, whlle the maximum ylcld occurred at pH Il with acetone.
Cooper and Kagal10wlcz (19R5) ~tudied a-mcthylbenzylamme (Ct'-MBA) as a
THMP and round It to he a good approximatIOn to precursors 111 natural waters. The
THM conccntration incrcascd wlth pH. Trchy el a/ (1986) and Scully el al (1988)
lIlvcstlgatcd the chlonnation reactlons of vanous protems and ammo acids, although
Oliver and Lawrence (1979) had prevlOusly noted that amino aClds, although present at
concentratIons up to 200 J-tg/L, do not contribute much as THM precursors.
2.3.4 SUlTugatc pamIllctcl's
Surrogate parametcrs are cOllll110nly detined as those whose concentratIOns are
Itnearly proportlonal to the concentration of the target parametcr, THMs in this case, and
whlch arc caSIer, chcapcr, ,md/or faster to measure than the THMs. A number of
rcsearchcrs have round rdatlOnshlps \VIth total orgamc carbon (TOC) (Symons et al.
1l)75: Glazc and Rawley. Iq79: Veenstra and Schnoor, 1980: Engerholm and Amy,
1 Q8J), whik Oliver and Lawrence (1979) found a good correlatIOn (r2 = 0.97) between
9
• TOC and total organohahde~ (TOX), Olivcr (l9S0) and I111ehn Cf ,d t 1 qS .. l) round Ih,\I
although THMP lcvels vaned wldcly over tune, roc l.'lllll'l'nll,1I10n\ Il'll1al11l.'d t~\IrlY
constant.
Edzwald et a/ (1985) cvaillated UV absOfbancl' C~S..t \llll) ,1,> .\ p.lr,lIl1L'll'l Illr \lon
purgeable TOC and THM preellfson, 111 Iwo natllral walefS .lntl III ful\'ll.' ,Il'Id l\llllOugh
mtrites and bromlde were found to absorb UV hght. and nOIl <110 III ,II Il.' 0f!~.lnll'\ would
not absorb UV light while stIll eontalllll1g TOC. a very good corrd,tlloll \\'.1\ dcll'fIIl1l1cd
between raw water total THMFP and total UV .lbsorhancc
Batchelor ('( al (1987) propmcd ll\II1g lodolorl1l alld hrol1l0lorlll torlllallllll
potentials (IFP and I3FP) to precltet THMFP, Both are fa'\tef 10 lllea,Ufe Ihan TI lM, and
• the iodme and bromll1e reaetlons wIth the THMP~ arc ~ll1l1laf 10 Ihal 01 chlol'lne Nt'ulral
pH haloform formation potential tests wcrc better prC(l!clofs than TOC .lIld 1 IV
absorbtion, and showed a greatcr trend to be proportlOnal to 'l'HM FI'
Reckhow and Edzwald (1991) ll~ed a large number 01 dllTerent w.lter\ 10 11..',1
various IFP and BFP tests, The van et y of water\ wa\ ~llpp()\cd to cncol1lpa\'\ !Juill Iype\
of THMP structures hypotheslzcd to exist in natural hUl11lC matcnah and III raw watcr ...
One is the aromatic, hlghly reactivc, rcsorcInol type of precuro.,or. and the other the
aliphatic, less reaetive but longer Itvcd, ketoJ1e type 01 prccLlf\Or The 2 hotll \Iandard
IFP (SIFP) test was judged to be the be~t. ft wa~ a~ accurate a,> (ltrect IIV Â ;1'\ a
surrogate parameter for THMFP, and more accu rate than dlw>lveù orgalllc carbo!l
(DOC). The alkahne IOdoform test had a \lIghtly hetter correlation wlth THMFP than
• 10
•
•
•
TnhJloflll.lh,IIlC FormJtlon Polcnllah 111 LJ.kc Mcmphrcmagog
the ~h ~I1'P tt..:~t, III "'plte of the dl!Terent rcactlon of lodme at hlgh pH, where liS
reactlvlty \VIth mcthyl ketonc~ becomes ql11te prormnent. ThIs agreed wlth Argllello et
0/ (1 (79) who Illund that compounds ylcldmg a positive iodoform test re~ult dld not
[leœ\~anly rcact ln form CHCI, LInder condition~ of high pH, lemperature. or shorter
re,tctJOTl tlme..,.
A nUlllher of rc~carcher~ have proposcd models for predictIon of THM formau',)11
lI~IJlg ~oll1e of the abovc ~lIrrogatc paramcters a~ weil as pH, chlonne dose, reactlon
tllne, tempcrature, and brollllde Icvel~ (Urano el al, 1983; Engerholm and Amy, 1983;
Morrow and MlIlcar, 1987; Ailly el (J/, 1987a; Amy Cl al, 1987b; Adm el al, 1991) .
2.4 AI~ac and thcir cxtracclluhu' products
204.1 Aigac as 111M prccUl'sOI's
AItholigh early work on trihalomethanes and thelr precursors centred on humic
~llb~lances as the major source of THMP, algae and thelr extracellular products are now
also conslucrcd to be prceursors of sOllle importance. Algae wOllld be a sigmf1cant factor
III eutrophIe or hypertrophie lakcs, and thelr vanatlons, ln precursor concentration and
al:tJvlty, are more IIkely to be IIltlucnccd by seasonal and diel patterns than other sources
of THMP.
Hochn el al (1978) \Vere amongst the tirst to suggest algal blomass and algal
~xtracclllliar products (ECP) a~ prccursors for THMs. They found a correlation between
the 'l'HM and chJorophyll (/ conccntrations dunng the June to November 1975 penod of
Il
• 1 nh.d"llldh.III'· t "1111.111,111 1\\I,·\lII.Ii, III 1.11" l\"'IIII'IIIlIll.II.:,'),: ---------------------------------------------------study of the Occoquan reservOIr III North Vlrgll1l,l
Anahllena cyluulricli was Inve~tlgated by Bnley el ,If ~ ll}~()) IlH I\', rlll\l
precursor potenttal. Similar bchavlOur \\<1'i oh~er\'L'd Inr rHI\"" re:-.ulllllg flllm the
chlonnation of bath the algal blOl1lass and ECP; the e\ponentlal growlh pha'le L'\hlhlled
a large increase 111 the THM concentration followed bv a rL'dllctHHl dllnn~ thL' \Iatlonar\' - . .
growth phase. Although the biomass wa~ round 10 react more \Iowly th,Hl tllL' ITP, Il
was nonetheless responsible for the greatl'r portIOn or the 'l'IIM ... prndlll'ed Tolalorganl\.'
carbon (TOC) was found to be a pOOf IIldlcator of 'l'HMP (1\ Il wOllld conllnue 10
increase W'ith increasing culture age.
Hoehn el al (1980) rcachcd ~Illlllar conclu~lon ... \tlldylllg Iwo green ,dg,K',
• Ch/orella pyrenoidosa and Scefledes/1/lls ljlwdricoudll, and two blue-green algal :-'pCClCS,
Osclllatorw lemilS and Ana!Juel1u./lm-aqulIe, dC"ipltc thc fact that 111\111 liclcnl ch 1011 Ile had
been added in some of the expenmcnts so as to leavc no rl'sldual. The randoll1 VilllallOll
of the CHC13 ta TOC ratio wlth culture age mdicatl'd that organlc compound ... (rom thL'
algae at different stages of the IIfe cycle ddTerl'd comldcrahly III thclr allll1ty 10 ylcld
THMs, and that a high ECP THMFP was prc'icnt in the late expollcntlal growlh pha\c.
The algal species studied produccd ECP"i whlch Ylcldcd, lIpon chlonnalloll,
concentrations of CHCl1 per unit TOC at Ica'it as hlgh a ... thml.! rcportcd for hllll11C and
fulvic acids. Another suggestIon wa\ the grcatcr "'Igm lïcancc 01 ECJI ... ovcr al gal bIOIll(l"'\
during water treatment due to their fa ... tcr rl'actlOll tllTIe. ft W<l'i al\o 110Ied Ihat h,:Clena
readily degraded algal ECPs, pO~~lbly altenng the ... Iruclurc 01 the LCP ... ln rnake thl.!/ll
• 12
•
•
•
[nh.dulm,lh.tIlL f'tJrm.lllIJll Pulcnlwh Ifl L.thc Mcmphrcmagog
Illort.: amcfl,lblc ln rcactlon wlth chlonne.
Nakwéq ko l'f al (1970) ..,howcd that bactcnal growth Hl al gal ECP could result m
LO/l\lIlllptloll (lf up to XO% of the ECP Wlthlll 7 to 8 hours wlth slgmficant Intake
occumng wltlll!1 the tiN :2 hour\. In addition, Oliver and Visser (1980) observed that
aller \cvcral lIlo/lth..,. Il1lcrohlOloglcally produccd hUIllIC and fulvlc aClds had roughly the
\allle THM}-P .1\ naturally occurrJng hllmlc matcfldf. The raie played by bacteria was
COll fi rmcd by lIochn el a/ 111 1984 _ They round that algal ECPs in a lake water were
Il yd rophoblc 1 ather than the u..,lIal h yd roph JI hc, \uggcstmg that heterotrophlc activity
could have allcrcd the characlcr of the ECPs, posslbly to the point that they become
II1dl~tlJlgul~hablc l'rom other organic matter III the lake. IndicatIons were found that aigal
ECPs do not affect the overall ~olubility-c1ass distribution of organic matter or the
fraction of DOC produclIlg THMs III the lake. They also observed indicators suggestmg
~hlns III THMFP Imght he attriblltcd to slllfts III dominant algal types, as different spe~les
probahly have (i1fferent THM ylClds.
Oliver and Shll1dler (1980) exammed 7 speclcs of cllltured algae and a few natural
samples for THM prcclIrsors. Vpon chlorinatIon, the dlfferent species yielded THMs
111 thc range of 1 A to 7.3 J-Lg CHCl\/mg matenal at pH 7 and 5.3 to 47 J-Lg CHC13/mg
matcnal at pH Il. They found that the mechal1lsl11s of chlonne reaction with cellular
carbon compounds dIffer from those \VIth hllllllC materials. Nelther the extracellular nor
the mtracdlular matcnals accoullted for more than :20% of the total CHCI3 production.
The maJonty of prccursors appcarcd to be associated with algal cells or ceU fragments .
13
• rnh.lI"m':lh.lll' l ,'mlllh'lI 1\'1"1111.11, III 1 11,..' 1\1. IIlphl"1I\ I~"l' ----------------------------------------AlthC'ugh MOrris and Baull1 (197R) found CHe1, l'rom thl.' chlllllll,ltlllll nI' l'hllllOphyll Il.
Olt vt.'r and Shmdlcr (1980) 1I1d lcated that algal plgml?l1ts \\'l~n_' IH lt P,lI \L~:ul,lIl y Ill1pOIl,1I11
THMPs a~ l!tt'e correlation was apparcnt bCt\Vl'CI1 the algal l'hlt'roph\'ll cl l·llllù'lltl.Lllllll
and the CHCI l ylelds from the cultures.
Kariml and Singer (1991), ~tlldyiJ1g SlIver Ltke Re~er\'OIr III Call1llll1l,l, lounll
THM concentrations rangcd l'rom 16 10 71 N?.IL Ali lllnC.I ... c III 1'111\1 .\IIt! T():\
productIon of 9.1 J.1g/L and 63.5 J.1g/L, re~pectlvdy, wa,> ub'>LTwd .11 tILl' Il'\L'\"\'OIl oulle!
The lower THM incrcase may have bcen duc 10 Ihc volallllly of Ihe Il1l\h l·Olllp.\Il'd tll
the non-volatile TOX compounds. The 'l'HM and TOX IIlcrea"c \VII" allnhllll'd tn (L1~al
growth in the open reservoir and the additIon of chlonne to control Ihc'>l' groWlh<; 1\11
• association between algal population and maximum THMFP wa ... oh ... crvcd, wlth abolll
25 /J-g/L of maxImum THMFP produccd pcr 1,000 ASUImL 01 algal l'cll\
Althollgh vary1l1g conslderably ln I11ctahoile acllvlly and 111 Ihe Olg,IlllC prodUCh
of metabolism, prote1l1s represent the largc~t Single 1 ractlon of orgalllc COlllpo\ll'lIl ... 01
man y algae and are an cspcclally I1npOltant EC'P of blllc-green algac I..)clIlly (', li/
(1988), studying N.E. Tani Lake Hl Colorado, IClll1d Ihal protClll'" alld allllllO .lcld"
appeared to contnbute 8 to Il % of the total CHei l prcclIr ... or\, and "" ... uch, haw thl'
potential for producmg 115 Il-g/L CHCI] rcgardlc ...... ot any 11\II11IC or 1 1I1VIC aCI<!... pre ... c Il 1
in the water. They compared the chi on natIOn rcactiOr1\ of bOVIIIC ... Cflllll albullIltl (uSI\),
pepsin, renin, and cytochrome c wlth that of humlc aCld. 1\11 protclIl" had .... lIndar llloJar
CHCI3 ylelds of 0.2 to 0.5% compared to O.7R% for hllllllC aCld ï ht: raIe ... 01 reacllO/l
• 14
•
•
•
1 nhJlomclhJnc FormJllOn P()lCnllab ln LJ!,.c Mcmphrcmagog
wlth thlOfille were Illuch ... Iower for the protCJl1S than for the humlc aCld. In fact, Trehy
('1 li/ (llJXfl), 111 II1vc\t1gatlng the reactlon of all1ll1O aClds wlth chlonne, tndicated that
al111110 aCI(!<., \\ould tend tn be precl1r~ors for the non-volatile compollnds while humics
would he more eftiClcnt prccLlr ... or~ for volatiles (~uch as THMs).
2.4.2 t\1~ae:1' preCllr~ors of other organohalides
Van Stecndcrcn ('/ al (1988) ~tudlcd a pure culture of M1CroCy.\·f/:o. acrugll1o.w:
forIlla j!O\-(Ujlllll'. lJndcr condition ... of phosphorous 1 11111 tatlon, the dcath of thls alga
n;<.,ulted l!l a large rclca ... c of TOX (6.7 mg/L), otherwl~e, there wa~ a graduaI release of
TOX a ... algal growth contlllucd. Even then, the COJlcentratlon of TOX excreted after 14
d.ty ... cxcceded 1 mg/L, hlghcr than rcported values for other green algae.
Oliver (1983) examll1ed the productIOn of dihaio-acetomtriles (DHAN) from algal
preCUr'iOf'i. More DHAN was produccd from fulvic add th an algae at pH 7, although
only 1 to ] % of the orgal11c IlItrogrr 10 the fulviC aCld was converted. Anabaena algae
prodllccd more DHAN than S('(JI/l'lÙ'\'I/1l1.\, possibly due to havll1g a hlgher organic
IlItrogen content.
\Vachter and Andel man (1985) studled 2 green algae, Ch/orella vulgans and
Ch/orella 1"·Iel/oulo.\{[. and one blue-green algae specles. Anahaena jlos-aquae, for the
tormallOll ot 110n-\ olatllc organohaltdes (NPOX). This was in response to studies
~ho\\'1I1g that Ilon-purgeable orgalllc-bound chlorine generally exceeds the volatile fractIOn
produœd upon the chlonnatlon ot orgalllcs III water supplies, and that non-purgeable
15
• organics in fil11~hed water arc more Illutagelllc than thl'Ir prl'l'ur"'l)I~. Illl.' mallHlly l)1 thl.'
organohalides generated from algal EC'P were non-purgl',lbk rhe l'tltratl' ot tlll':1 t!o.\-
olJuae produced more NPOX than the two ~pIXIl'''' of grl.'l.'ll ,lIg.tl'. \)Inl'rl'Ill'l'~ III the
respective amollnts of ECP cxcrcted accounted for roughly sor';, ni the llh ... l'f\'c,,'d
differences among algal specles 111 NPOX formatIon. Il wa" ob~l.'r\'l'd th,1I an .IVl'r.lgl.'
of 8.3% of the chlorinc dcmand III the algai tïltratc~ wa~ .Iccollntl'd lor by NPOX
formmg reactions, highcr than prcvlOlisly reported.
2.4.3 Seasonal and dicl/diurnal cffcct~
THMs and thelr precursor concentratlOn~ vary on a rl'gular ha"'I"', .1'> do 1ll:llIy
• other aqueous polllltants. Algal precursors, though, may he more \lI"CCPllhk to \\.';I"ol1a:
and diel effects. Veenstra and Schnoor (19HO) round an extra peak III the MW
distribution (AMW 40,000 and greatcr) of the THMP\ III the Iowa River dllflng the
summer and autumn. The cause was suggestcd tu he IIIcrea\cd algal actlvlly alld IUIIO"
AIthough the heavler MW orgal1lcs ( > 40,000) dld not conlrltlule "Ignllicantly tu the total
THM concentration, THMP and TOC Ievcls werc 11Ighe'it dUring the \UIllIllCr alld
autumn. The seasonal variation III the THM lcvel.., wa'i due ln the nature 01 the org,1I11c
precursors and not the environ ment. Oliver and VI,,\cr (l9HO), however, found Ihal the
major CHCl 1 precursors m aquauc hUll1lc matcnal werc the < 30,000 MW fraction" and
that there was little seasonal effect.
Stevens el al (1976) have sugge"tcd lempcratur:! a) the cau"c of the '>Igfllfïcant
• 16
•
•
•
---~------
rnhJlorTIClh,lOC Fotrn.illon PolcOllal, 10 L.ikc Mcmphrcmagog
dlf fen.:ncc\ o!J<.,crved betwecn <.,urnmcr and wlIlter THM Icvels. Arguello el al (1979),
\urvcylllg 14 utJlltlC, ovcr one ycar, found large variations In the THM levels present in
thc tim,>hcd \uppllc\, generally les,> 111 wIllter. Williams el al (1980) found THM
vanatlon\ rangll1g l'rom 13 J-I.g/L 111 January to 120 to 160 J-I.g/L during the summer in the
Ottawa/Hull .. y .. tcm. McGlIIre and Meadow (1988), ~urveying 910 V.S. utllitles, found
a fllcdlan maXllllUI11 THM concentration or 65 J-I.g/L in summer and 50 J-I.g/L III wmter.
Alarcôn-Hcrrcra ('1 al (1992) II1vc~llgatll1g vanatlOl1S III humlc substances 111 a nver,
round high hllll1lC concentration') dunng the fllonth of AprIl and the summer months
whlch corre~pondcd with hlgh total THM levels :\1 the drinking water.
Hochn et a/ (1984) examll1ed the dlel varIatIOns 111 THMs as a result of
charactenstics of algal behavlollr. They studied THMP vanations in a hypertrophie lake.
M/('IIwy.\1I.\ \pP was tOlllld to be the dOlTIll1ant algal type dunng the summer period,
glV1l1g way 10 ChllIllIyt!0/110ll{l.\ dunng the autumn. THMP was highest in early August
whcn algal dcnsity was 1I1crcasmg. Maximum diel THMP occurred at 8 am. A
'>lgl11ticant THMP was also observcd dunng the I1lght wlth a rise in CO2, indieating
IIlcrcascd hctcrotrophic actlVity. THMP decrcase after the noon hour was thollght to be
duc 10: the II1tcnse photo-rcs.plratory ~tate of the algae, a downward nllgration of the
algae away l'rom the midday IIght, oxygen-induced inhibition of the bacteria, destruction
of Iow MW cOl11pollnd~ or hydrolysis of high MW compounds (ECP) by heterotrophic
hactena, or IIlcorporatlon of precursors II1tO mari (CaC03) at hlgh pH. DOC showed
\lJght vanatlon during thIS penod. Kanml and Singer (1991) interpreted this as
17
• lI1dicatmg that ECPs released t'rom photoresptrlng alg.1C aIl: In\\ i\tW Illl'l.lhoItIC~ Ih.11
have a low THM formattop pOlentIal. \\hlle compound" rck.l"l'd dunng .\l'tln'
photosynthesis are high MW metaboltte~ \VIth hlgh TIli\ll'P
It will be useful to mentIon the pnnclpal L'Ollclmlon" 01 four RU""lan \tudll'\
examinmg the diel vanability of ECPs. KO~L·IlJ...O (1\)7'+), IIl\'C"tlg.ltlllg 11/0"(//'1/(/
varwbilis, observed a noticeablc drop III c~tracdllll,lr carbohydratc" \\'Ilh a dCL'll""'C III
light; carbohydrates were consumcd partlcularly rapHJly III Ihe d;\1 J... 1 le "llggl'''ICd Ih.1l
prevlously released extraccllular carbohydralc" were bcmg Cllll'li lIll'd Ily Ihe .dg.ll' 10 1Ill'l'1
energy requirements.
Sakevich el al (1979.1980), ~tudylI1g the change'i 111 the 1 :cp" or M/('/on'\l/\
• aeruginosa dunng dlffcrent growth pha'ie~ and hghl condlllol\~. tound Ihal Ihe
concentration of ECPs generally 1I1crcascd undcr advcr,c cnvlronmenl.1I c()ndll\()n~. The
ECPs were composed of polysacchandes, protCI/l'i, allllllO iICI(I" a!col!ol ... , c~tcr"
orgamcs acids, carbon yi compound~, and al11l11c.... The co lcenlratlon 01 1 J'\,,, ranged
[rom 17 to 131 mg/L at the ~tart, to 259 to 325 mg/L .LI the end 01 the cxpoJlentlal
growth period. The ECP to blOma~s ratio Il1crea"ed at the "tart 01 growlh, ,tnd WéI"
lowest in the old cultures. Contrary to van Stecndcren ('( al (Il)HX), II wa ... round Ihal
under nitrogen or phosphorous ItmJtmg condltion~, thcre may he a reductloll III organlc
compounds due to heterotrophlc fecding by the algae. 1 f thl'> decrea"c precede, cell ly"I~,
posthumous release would mcrca~c the ECP kvel.
There was a peak in the ~oluble orgal11c matter al the ... tart 01 the log growtIJ
• 18
•
•
•
rnh .. dlllTIclh.lOc 1 Orln.ltlon P()tcnli..th 10 Llkc Mcmplm:magog
pha'le, although the concentration wa) falrly constant by the end of the growth phase.
A redllctlon In IJ:P content dllnng penod~ of Inten~lve ccII growth was suggested. In
ct natural water body. the ~olllbie orgamc matter was observcd to decrease at the ~tart of
tlle Iight penod, Ihen Incrca~c 10 a maximum at 3 pm (Sakevich el al, 1980). In sorne
ca'le). )Ignlficant II1crca<;c\ ln the dark were observed. Although daily changes in the
'loluhlc orgal11c 1l1atter arc al)o affectcd by accompanying bactenotlora, the cause and
cffœt reiallOn<,lllp bctwccn them wa~ not c1ear.
Sakcvlch and O~I pov (1983) ~tudled aigologicall y pure cultures of Microcyslis
aerugll/osa and l!l/aho{'l/(J m/'whl!t.\. and axemc cultures of A. variabilis and NoslOc
111 Il.\ (,()/'I1111. The algal bioma)~ IIlcrease over time was highest during the exponential
growth pha)c, when thcre wa-; the most Intense photosynthesls, and approximately zero
dunng the lag pha~c. The tïltercd COD increase over time was high dunng the lag phase
and hlghest (29.8 mg/L-d) whcn thcre was greater mortality. An inverse correlation was
ob)crvcd bctwccn the algal biomél)s Incrcase and the tïltered COD increase over tIme for
the axel1Ic cultures. but duc to the mtluence of bacteria. this was not clear In the
algologlcally pure cultures .
19
• 3 L<\KE I\lEI\lPIIRE:\lAGOG
3.1 General charactcl'Ï~t ics
Lake Memphrcmagog (lat. '+5°0('1' N, long. 7~" 17' W) l' .l long (-10 1-.11l) • \Il Il
narrow (2,..1. km mean wldth) me~o-olIgotrophil' I.II-..e ly1l1g tlll thl' ()Ul'ill'l' Vl'lllllll1t
border. Although the Canadlan portion of the lal-..e', w.ltl'r ... hl'd 1 ... Itttk de\'L'lupl'tI. IIL'.\Ilv
70% of the 1689 km2 watcr~hcd 1'> drall1l:d hy tlnee Vermollt II\'L'I'" the ('1yde. the
Black, and the Barton, whlch enter the lake al It~ "ulIthl'fIl el1d l'IIL''''l' 11\ L'I ... L"1I1 V
agncultural runoff and ~cwagc l'rom ~cveral "mali town ... , .\IIt! l'(l\Itnhute X F;, ni thl'
phosphorous loadlllg 11110 the lake. A north-~ollth (!eI..:rca<,JIlg I1UtllCl1t gl.tdll'Ilt may hl'
• responslble for observed gra(lIcnt<., 111 pnmary and ,>econd,H y productlvlly (RU'>,> .\IItt
Kalff, 1975).
The lake is morphometncally dlvlded 11110 .\ ba\m!-. 011 the ha"l'" 01 dq>lh The
general charactenstlcs of each baslIl are glven III Table 1 (WaI\OIl. l'nt))
Table 1. General Charactcnstlc\ ot I.ah.: Ml'll1phrclllagog
Basin 1 Arca Volume Mean Dcpth /kpth 01 Mlxc(J Llyt.:r (x 107m2
) (x lO"m 1) (m)* (In )
South 4.4 3.2 7.0 7 (J
Central 2.2 10 51.0 1 () ') --
North 1.0 2.8 13.5 l) . ') --..
*( Ross and Kal tt, 1975)
• 20
•
•
•
Tnhdlolllcth.mc Formation Potcntl.ll~ III Ltlo.c Mcmphrcmagog ----------------------------------=---..:.......;:-
3.2 Aigae in Lake Mcmphrt>magog
3.2.1 Aigai "p{'de~ variation
Wat .,011 (i 979) conductcd a detalled exammatlOn of the phytoplankton dynamlcs
ln Lake MClllphremagog. The lindlng~ arc preslimed to be stIll val id for the lake as
prc.,ent nutnent levels arc not apprcclably dlffcrent from those previously observed (Ross
and Kalff, 1975; Wat<>on, 1979). Watl,on ob~erved that in spnng, ail stations exhlbited
11Igh bloma<;<; concentratlon~ of D/(/!O/1/11 tel/Ile var. dongatum, which was rapldly
<,uccccdcd by O.\('ll/owrÎa Reddei a~ ternperatures 1I1creased. ThIs was accompamed by
CeflillUI1l 11Irllllllull'lIll, Me/O.\lIël lIa!JclI 'iubsp . . wbarcflca, and Oscillaroria cf. rubescens
in the south basll1: C. IlIfllllûlI1ella and Fragllaria croronel1.\is 111 the central basin; and
F. CWfOl1l'll.\l.\, Rillzoso/elllll e,.,el1.\I.\, and BorryococclIs BraUIIlI 111 the north basin. In
the late autUI1ln, a ~Igmficant 1I1crease III M. ua/Ica slIbsp. subarcrica occurred in the
south basin, and was observed much later Hl the central basin. Water column II1stability,
duc to wind and tcmpcrature cffects, cau~ed the populatiOns of blue-green O. Redekei to
surfer, bClIlg sllpplantcd in areas by ~llrface blooms of Anahaena jlm-aquae.
The nctplankton specles ( > 35JlIll) were characteristically penodlc 10 occurrence
although CI1'{JlOmmlll.\ rosrrar{!omu.I', A.\rerionella Jormosa. and Fragilaria croronensis
\Vere often present. The nanoplankton « 35Jlm) specles: Rhodomonas minuta,
CrqmmlOf/aS Afll1xwf/il, C. ('rosa, C. /(ilexa, and Chl)'sochromu/ina parva occurred in
allllo~t ail s<lmples and were frequcntly slgmficant contnbutors to the total biomass. The
relatlve proportion of percent nanoplankton blOmass decreased signiticantly over the
21
•
•
•
season with increased trophlc kv~1. Zooplankton gra/1ng •• \lthough ù1Il:-'ltler.üllL'. l'au~l'd
only short term lI11balanccs 111 the nanopJankton. \Vith l1lcr("I~~d 10t.11 hlOlIl.I'S theu: w.t,
an increase In the number of :-'pCClCS observcd but .\ 'lg\1llic.\1ll dcelc.l'l' 111 thl'
communIty dlversIty and evenness.
3.2.2 Phosphorous influence
Total phosphorous (TP) levcl~ w~re round to have hpk IIllluCIlù' 011 the rd.III\'"
proportions of netplankton or nanopJanklon 111 Ihe Jake, althollgh the data lIulle.lted an
indirect effect on the slze distnbutlon. Under conditIoll~ of Jowcr pllO'phoroll' ll'wh.
the prominent spring blooms of Bacll/ar/ophylcl and Cyallophwll were redllccd 01 absl'ht.
as were the autumn peaks of CI}'PlOplly('('oe. The relative Importance of the Olrv,\Oj,I!W([
was unchanged but there was no slgmticant relalion with TP. TP wa ... tOllnd to h.lve bttle
relation with short term tluctuatlons in speclcs COmpml110n.
22
•
•
•
rnh,llllnlelhane rormellinn POlentlel" ln Like Mcmphremagog
4 .\tEMPIIRE\IAGOG 1990/1991 SAMPLING CAMPAIGN
4.1 Samplill~ ... ite~
Flve ~IIC\ wcre cho\cn for \amphng on Lake Memphremagog ,Figure 1). Pender
and !mlIan '>Ite,> arc \Itllated at the ~outhern tlp of the lake In the shallow ~outhern baSIn.
Border sIte il) located on the Canada-U .S. border and IS also wlthin the area of the
\outhcrn ba\lIl. Ccntral 'lIte 1') located at about the Icve! of the Limnology Research
\tallon, rollghly wherc the central basm is deepcst. The firth samplmg site, North, IS
locatcd III the north ba,)111 hal fway bctween Central site and the northern tip of the Jake,
wlH.:rc Il is drallicd by the Magog River. The sites were chosen to Investigate north-south
thffercnccs along thc Il.!ngth of the lake. Although mixmg occurs wlthin each of the three
ha~lIls, the baslIls do not IllIX between themselves. As Central site was located at the
dccpcst pOlllt on the lake, bath eplhmlllon and hypolimnion samples were taken from this
pom!. Thrce ~alllpllllg ~ites \Vere cho~en in the southern baSIn. two Sites at the tip,
hccall~e thlli area wa~ consldcred IIkcly to be more actIve due to the greater population
dCIlSlty arollnd thc ~ollthcrn end of the lake and the relative shal!owness of the basin .
.... 2 Samplin~ schedule
During the 1990 prelimlllary sampJing season, samples were taken approximately
cvcry two WCC~S from July lIntIl the fal! turnover JO late September/early October. The
1991 ~al1lplillg scason cOllllllcnœd at the beglllning of May, after the spnng turnover, and
23
• samples were takcll cvery 10 day~ to two \\ecb 1Il1til thL' l'llllll! July. S.Ullpltng I..'oliid
not be conllllued unlll the faH turnover. a~ planned, duc ln I..'qlllpllll'lll lilrtïL'lIltll..'~
4.3 Sarnplillg cquiprncllt
Data collection \Vas often wcather dcpcndcllt Wall'r \ampk.. .Ulli 11/ .\1/11
measurements were taken l'rom the boat oncc Il was anchmL'd .lt thl..' \IIL' Sel'dll l!L'plh
measurements were takcn wlth a Secchi dl~k, whlie pH and tl..'lllperalllll..' WlTl' n.'cullkd
by a pH meter wlth the probe lowercd to the dC\lred depth Intq"I.ltl·d l'plllllllllOIl
samples \Vere taken from the tirst tiv\..' ll1eter~ of the water I..'Olumn \Vllh .1 polYl'lhyll'ne
tube. Depth samples were taken wlth a Van Dorn bnttk lowered to the dC\lIed dcpth.
• Samples were stored in nnsed polyethylene bottlc~. 1I1ltii the rclurI1 to thL' \tatloll Will'IC
they were transferred into prepared aCld-wa~hed amber gla\"i botth.~) \Vith PT"'!: llllcd
caps. Bottled samples were ~tored at 4 oC lllltli transportcd !lad to MOllt r(".11
• 24
--------
•
•
•
rnh.JluII1Llh.tnc FnrmJllOri Plllcnllah JO L.Jkc Mcmphrcmagog
5 l\1ETIIOUS
5.1 Preparation of ~ample~
5.1.1 TIIMFP and chlo.-ine dt'JlulIld ~amples
For the preparation of the liltercd THMFP and chlorine demand samples, the lake
willer wa~ liltered wlth 0.45 /lm glas\) fibre tïlters that had been prewashed four times
wlth dl\)tllied water to rcmove any orgalllc carbon. Pnor to sample preparatIon, the 250
IllL Illctnc round amber bottlc~ were washed wlth chrolTIlc aCld, following method #1070
III Standard Meth{)d~ (ÂPHA (" vi, 1':>89) and ovcn baked al 218°C for three hours. To
the bottlc~ were ddded 5 mL of pH 7 phosphate butTer ta stabiltze the pH, and an
appropnate ,lInolint of doslIlg ~oll1tlon. The dosing solutIon of chlonne used was
~aturated chloril1e watcr wlth approxllnately 4.98 mg C12!L as titrated according to
Standard Mcthod #4500-Cl B. Gencrally 2 to 4 mL of chlonne water was added to each
~ample bOUle, dcpending upon the cxpccted strength of the sample, such as to leave a
rcsldual of only 1 mg!!.. The bottles were then tïlled wlth sample such as to leave no
aIr spacc. Rcagent blanks contamed only the phosphate butTer and the sample water.
Control blank~ were tïlled WIth MIlllpore waler instead of dlstllled water so as to not
exert any chlorine demand. MIlllpore waler was generated usmg a combination of the
MIIII-R041{ and Milli-QR systems. After pretiltenng and reverse osmosis removed ail
panleles from the water, It was stored in a reservoir before the next stage. This involved
the use of actlvaled carbon tiller, Ion exchange, and MIllipack 0.22 J.tITI tilter cartridges
25
• Tnh.dllllll·lh.1I1l l "rln.llll'n 1\'1.'1111.11, 111 L .lI,,' ~"llll'hll111.lp'g ----------------------------------------to remove orgal1lcs and lon~ from th~ \Vata. Sal1lpk'~ \\~r~ \tlln:d for .lX hllur\ at 20"('
III the dark. At this pOlllt the ~hlon:lc (kmand ~al11pl~'i \\crc .1Ilaly/~d lollowlng Stand,ud
Method #4500-CI B, The chlonne r~sldllal 111 th~ THl\lFP \.lInplc~ \\.l\ 1I1'1IIr,11t/cd \\'tlh
approximately 2 mL of a 0.02 N ~ollltlon of ~odilll11 tIWJ\lllf.ltl.? l'hl' \.unpk\ \\l'rC
stored in the dark at 4 oC unlll analysls.
5.1.2 Organic cm'bon samples
Dissolved orgal11c carbon (DOC) ~all1plc~ \Ven: lilterl.?d \\'1111 0,45 Itlll gla .. ~
microtibre tilters in a glass tiltrallon apparatll'i to reduI:C ally pO\ .. lIl1l1ly 01 orgallll'
contribution from plastic vessels. Only 10 to 15 mL of ~ample \Vcre rl'qulll.?d for orgallll'
• carbon analysis. The samples were contamcd III ~l11all chrollllc aCld W,l'ihl'd gl.I\\ vIal ...
The glassware preparation procedure for the total orgalll~ carbon cn)( ')/D()(' \,llllple~
was the same as that for the THMFP ~amplcs. Sample~ were pre .. erwd wilh olle drop
of concentrated nitnc acid and ~ton~d at 4 oC untll analy'ils.
5,2 Analysis of the TIIM samples
5.2.1 Prclirninary expcrirncnts with the Ge/MS
The THMs were cxtractcd from the .. ample\ by aulornalcd purge ,Ille! 1 raI'
(Tekmar ALS 2016, LSC 2000) pnor to detcrmmattoll by ga ... chroméllography ll'olng
Standard Method #6230 B. The InttIaI ga~ chromatograph ( je) h.ld a ilia" .. \/H;ctromelt:r
(MS) as a detector. In order to takc advantage of th,,,, the Intentt()11 W,I\ onglnally lo
• 26
•
•
•
Tnh,domcthanc FormatIOn P[)tcntloll~ 10 Llkc Mcmphrcmagog
Invl!\t1gate the prC'lencc of other orgamc halldes such as dIchloroethane, trichloroethane,
dlchloroaœtlc and tnchloroaœtJc aCld, and cven posslbly halomtnles in addItIOn to the
four THM~. In the analYlcd ~amplc~, however, only chloroform was found to be
pre\cnt, althollgh there were oecasionally trace amollnts of the other THMs.
Unfortllnately, the Vanan Satllrn GC/MS, wlth its high sensltIvity, was very often
eontamHlated. The source of the contamHlatIon proved to be the 10 j.A.g/L standards with
whlch attempts werc beIng made to tune the Instrument. The tlow rates requIred by the
purge and trap wcre 1~1r too hlgh for the MS and were caUSIng the contammatIon.
Atternpts were made to operate the purge and trap at lower tlow rates. In order for thls
to be slIcccssful, a cryogenie eoolmg system was needed for the GC to cool it to -50°C.
The low temperatures and long GC clution times were supposed ta compensate for the
low tlow rate throllgh the column. ThIS method, however, was extremely time
conslIming duc 10 the analy~ls lIme reqlllred for each sample and very expensive due to
the large qllantltIcs of IIqUld IlItrogcn that were rcqlllred. Eventually, the GC/MS was
abandoncd for a conventlOnal Vanan model 3700 Ge wIth an electron capture detector
(ECD).
5.2.2 Preparation of the in~t"ull1ents
The pressures of the helilll11 carrier gas and the mtragen makeup gas were 80 psi
(551.6 kPa). Only ultrapllre gases were used and these were tirst tïltered through oxygen
traps befme cnterIng the Illstruments. The tlow rate of helium through the purge and
27
• trap umt was 40 cm3/min. The purge and Irap \',11\'1..' ,md Illw tl'll1lk'latlln.'<; "l'rl' \I..'t ,II
iOO°C and the ready Icmperature \Vas set al < JO"C, l'he pUI gl' ,lIld Ir,lp I1ll'thod u\l'd
was a mod1tied versIOn of the EPA lllcthod #624 \\'Ith a L~ mll1utl' purgc. No dry purgl'
was used as there was a mO\~ture control module (~lC~t) to l'lI 111 1 Il ,li C l'lIlr.UIIl'd \\'.III..'r
from the system. The desorb stage al 180°(' lastcd 5 IlllllutC'" The tr.11l \\.1\ h.ü,l'd
afterwards for 7 minutes at 260°C.
The tlow rate of the hchlllll through the l'Ollllllll (V()('OI DB-()24 l.lptll.lrv
column) was approxlmalely 9 cm \/111111 or rollghly 14 p" (90.5 \,,\1,1) 1'1l11l11l11 (lll' ...... url'
The now rate through the detector ot thc combllled ga~i..'\ l'Duit! Ilol I:\l'i..'i..'d W 1..'1111/111111
The temperature of the ECD wa~ ... ct at JOO"(' ,Iml allowl'd to dl ill '>Ollll'what al., 111L'
• temperature control was not precise. The Ge ll1ethod ... tarted wllh Ihe 0\'1..'11 telllpel.trllll'
at 30°C for 8 minutes. The GC Illethod wa~ ... tarted automallcally lly Ihe IlItl'gr.llor whcll
the purge and trap entered the desorb ~tage. The oYen temperalllle then IIlCn,\I\cd al
15°C/mm to 120°C. where 1t remamcd ... teady lor .2 mll:t1te\ ()nglll.tlly, thl' OWIl
temperature 1I1creased to 2l0°C to en~lIre that therc would he no re\ldue III the loltllllll
This had to be reduced when it wa~ dl'icovered Ihat at hlghcr telllper.ttllrl''> the portloll
of the column Inside the detector expenenccd bleedll1g of the padlllg Illaienai
5.2.3 Analysis procedure
The Tekmar LSC2000 ha ... 16 IndlVldualll1Jclllon port ... wltll 5 Ill/. volullle ~Ia\..,
sample vials. A maxImum of 15 sarnplcs were analY/cd dUring each cOlllpkte rlill (olle
• 28
•
•
•
port wa'l ,t1way'l l-.ept lor watcr blank<i only, to aVOId nsks of contaminatIon). One
complete run la<.,ted roughly 12 hour'l. Thc ambient temperature and the degree of
vcntllatlon ln Ihc room controlled the amount of tlme required for the system to return
to Il) n:ady tCll1pcrature and lIltluŒccd thc run lIInes. The vIals were c1eaned with
Mllliporc water and bakcd for 2 hour~ at 450°C in a mume furnace. The sam pIe was
plpellcd IIltn tlle \.'Iab wlth dl~po~ablc borosllicate glass pipettes. The pipette was nnsed
thrœ tlIllC'l \1; Ilh Milliporc water. th en three time~ wlth the ~ample berore actually taking
thc 'lamplc volulllc. Thc holllc'l v.,'cre vlgourou~ly "haken pnor to opemng to redlssolve
any volatilc" that 111Ight have !cft 'lolutlOn.
1~ICh day a few 100 fJ.g/L ~tandard~ (CHCI\ ln methanol) were analyzed to check
for <.letcctor dnft. If the ~tandard~ \Vere not wlthin 10 % of the known concentratiOn and
reproduclblc, the lIl~trlll1lCnt wOllld be rccaltbrated. After this a MIlltpore water blank
wa~ run 10 chccl-. for rC~ldlic or entratnJ1lent on the trap or ln the GC column. Regular
wœkly recallbratIon of the lIl~trull1ent was performed and a new standard curve
gCllcratcd (FIgure 2) A SI\ pOInt calibration curve was used. The inItial range was
Illghcr but provcd not to be nece~sary. At thiS tlme a number of samples were repurged
and rc-analY/cd 10 chcck the cfftclency of the purge process. Dunng the purge stage,
thc venl on the purge and trap would be plugged 10 check the system for leaks. The
purgt: and trap do~'i Ilot dcvclop leaks very readll y although it is very sensitive to the
prc~t:nce of any lcak.s 111 the ~ystem. When no leaks are present ll1 the SyStf''i1 the
prc~~llre blilldup \\ i11 MOp Ihe bubbling wllhin the vials .
29
•
•
•
5.2.4 Detection limit and contid('nce int(,l'\'al
The detcctIon lima and contïdcnœ Illterval \\cre c.lkul.ltcd U\lIlg the lollowlIlg
equatlons (IUPAC):
CI
where XI
XII
m
k Sil S, Sm
= k {SBl + S/ + ((1 - \)/m)]SI1I!} 1 l
111
- smallest dlsccrnable 'iignal = mean of blanks = analytlcal ~cn~ltl VI t Y (~Iopc of llIlcar rl'gn:\~llIll) = 1I1tercept = 3 = standard dcviatlon of mcan = ~tandard devtation of intcrccpt = standard deviation of slope
The detection limlt calculatcd from ~lIcces~ive run ... wa ... lound 10 hc 3 ~3 Ilg.!1
standard deviation for the rcpcated 100 f.1.g CHCIJL ~al11ple~ W,I\ le ... \ thall 1 OH N!/I ,
The confidence lI1terval, calculated from <.;cveral ~cnc~ 01 \tandard ... run on dlllcrcnt day\,
also accounted for the error contnbutlon lrom detcctor drllt. The confidence IIlterv,d
was found to be 2l. 2 f.1.g/ L.
5.2.5 System efficiency
Dore el al (1982) found that the conversion of re\orclI1ol, <1\ a precur\or, ln
THMs was 91.5 % based on the mas ... balance, Re\orclI1ol wa ... u..,ed to te ... t the overa!!
efficiency of the system. Known concentratIOn ... of rc ... orclnol were preparee! and
analyzed following the same methodology a~ that for the "ample..,. Recovcry 01 the
30
•
•
•
Tnhalomcth.wc ForrnatlOn PotcntlJl~ 10 Lake Mcmphrcmagog
'l'HM.., relative tn the ongmal amount of rcsorcmol was 88.2%. Ba~ed on the findings
of Dore l'l al (1982) tlm would appcar to indlcate that the overall process had an
el fïcll~ncy 01 C)fi 4 %
5.3 t\n~lly~i~ of the other paral11eter~
5.3.1 OrganÎC clU'hon sHmplcs
Thc organlc carbon samplcs wcrc analyzed on a Dohrman De-80 carbon analyzer.
I1m II1strument med the persulfate-ultravIOlet oXldatlOn method. The analysis was
~olldl1cted wlth the II1strUI11Cnt caltbratcd in the 10 to 400 mg/L range. The reactor tluid
and thc calibratIOn .. tandards were made according to the procedures given in the
operaling manual. Each ~amplc volume of 100 ,uL was injected by synnge lOto the
Il1strumcnt which was ~tartcd slIllultaneously. At least three repeat injections were
pcrformcd for cach samplc.
5.3.2 \-Vahl" quality pal'ilmetcl's
The turbiduy I11ca~uremcnt~ were done on a Hach 2100 turbidimeter. A 25 mL
samplc wa., IIlscrtcd, 111 a dedicatcd vial, into the instrument. The calibration was done
with ~calcd vials cOl1tall1l11g standard suspensions. The suspended solids and alkalinity
mcasurcl11cnts were pcrformcd followlJ1g Standard Methods (APHA et al, 1989).
31
•
•
•
5.3.3 Nutrient data
Chlorophyll a. totall11trogen and phosphorous . .,cechl d!';\'" .\lul telllperaturl' d.lla
were obtamed from the Ltmnology Rcscarch Group al t\.h:(,t11. Tot.\1 I1Itrogl.'ll .,.Huple.,
were digested with persulfate and measured on a ultravIolet ~peçtrophotoll1l'ter (Smith t'f
al. in press). The total phosphorous samples also underwl.'111 per<;ulphatl.' dlgl.'!\llllll. \vlllk
the final bIlle colour was al~o read on a ~pcctrophotollleter (101111.,011. Il)? 1) The
procedure for chlorophyll a was dcvclopcd by Bergman and Pl'tl'r~ (19XO).
32
•
•
•
Tnh.l)DmClhanc Form.lllOn Potcnllah III Lake Mcmphremagog
6 RESlJLTS AND DISClJSSIOl'\
In a complcx natural ~y ... tem iIkc Lake Mcmphrcmagog, It was not surprising that
no ObVlOliS cau\e-and-cffect rclatloll'lhlp was round between any single associated
parametcr and the 'l'HM concentrations observcd. Given the Interdependency between
the para1l1cter~. 1 t wa!! il1lpo~~lblc to draw concretc conclusions from the data as to the
exact naturc of the tactor!-> IntlucnclI1g the THM formatIon potentlal (THMFP).
Ilowcver, an attempt has bccn made to present a hypothesls on the possIble relatlOnships
cXl\l1ng wltlul1 the lake bctWCCI1 the parametcrs and the THMFP .
6.1 Chloroform variation OHr space and time
6.1.1 Pender and Indian sampling sites
The ~easonal vanations 111 the tnhalomethane formation potential (THMFP)
concentrations at the Pcndcr and Indlan sampling sites are shown In Figures 3 and 4
(Appendlx B). The only THM detccted in the chlorinated samples was chloroform
(('Bell). The variations obscrved at each site were quite similar. This was not
... urpnslllg glwn that thcse Iwo sItes are 111 close physlcal proximity to each other.
At Pendcr. a large peak was observed in both the filtered and untïltered samples
late in the 1990 season at 1808 (dates are glven as ddmm). Dunng 1991. peaks were
notlccd at 0506 and 2606 III the llntiltercd THMFP. wlth the first peak cOlnclding with
a maXlIll11tn \11 the tïltercd TH~tFP. The peaks observed during the early 1991 season
33
• (almost 200 J.l.g/L at 2606) \\ cr~ not a~ gr~at a~ that ob~~r\ l'li durll1f. th~ 1.1t~ 1 ql)O \l\\\llll
(over 300 p.g/L at 1808).
At Indian dunng the late 1990 ~cason tltcrc wa~ a ~11I111.1r rH1\II' p lK\l~ .lI 1 XOX
in the unfiltercd sample (over 280 Itg/U. Tite Til 1\1 Fi> 01 the fllll'rl'd ".\lnplL' dl'l'Il':l\l'd
from a probable maXlmUIll of 180 ftg/L at 1808 10 120 ft)!./!. .\t nOl) rhc thl kl~nl'l'
observed between the filtcrcd and lInlïltcred TH1\lFP 1:-' ~lIppo\cdly duc 10 thl' .dgal
biomass only, whlch makes a grcatcr contnbutlOn ovcrall althollgh Ihe Jo('Ps .\rI.'
supposedly more reactlve (Briley l'I a/, 1980). Durtng the ~arly 1991 \ca\on, .\ :-.mall
increase in THMFP to 0506 was ob~crvcd 111 the 11l1tïltercd \ampk, WIIll'llhn)!. wlth a
peak in the tïltered sample. A large peak ( 190 Itgl L) wa ... aho ob\~rvcd III t h~ lin t IItcll~d
• sample at 2606.
Although It IS not pOSSIble to know whcthcr the late \lI111mer peak\ prl'~cnt ln
1990 would also have been present 111 1991, thcrc I~ a strong pO\:-'lbihty that tlm II1lghl
have been the case as it is not ~lIrpnsing to tïnd higher THMFP whcn alg,t! growtIJ p~ak\
during the late summer (Kanml and Singer, 1991). An CXall1l11atlO1l of tlte Lhlorophyll
a data for the periods in questIon indlcate that there wcrc 111gh concentratlon\ dllllllg thc
late summer and early allturnn of both 1990 and 1991 (Flgllrc\ 2R 10 :n, AppelHllx 1).
The THMFP peaks observed likely rcprcscnt precur\or tncrca ... c\ dlle to large relea\c\
of algal extracellular prodllcts (ECPs) and IJlcrc<l\cd al gal bIOllltl\ ... durtllg growlh
Examining the 1991 ~cason, the Initial THMFP 1 ... cxpcclcd lo have beell 1ll00lly
from humic material entering the lake W1 th the runoff, augmcntlllg that prodllced 111 the
• 34
•
•
•
Trlh.llornclh.tnc rormallOn Pulcnlldl~ ln Lake Mcmphrcmagog
lake The IÏr,>t ob<,crvcd THMFP peak occurred dunng the period of the spring (or early
<,ulTlrner) hloorn,> whcn the dommant alga 1~ Dwtoma [e/lue var. elol/,~arllm and probably
rcpre<,ents a prcclmor rclea<,c l'rom algal blomass and ECP dunng the exponential growth
pha,>e. Aigai relea'ie of ECP I~ Illghe<,1 dunng the cxponential growth phase (Sakevich
and OSlpOV, 19R3), whlch 111Ight explarn the observation of only the single filtered
THMFP peak al 0506. The large peak, appeanng only in the untïltered sample a few
weeks later 1'> Itkcly to he the contnbutlon of malnly blomass dunng the late statlOnary
growlh/death pha,>cs, cspcclally a~ there IS a ~hift In d01ll1l1ant algal specles to
o.\(,ll/aIOl'lli tl'dt'kl'l and ather blue-greens around thls pcnod. One would expect, then,
that the major ECP~ would he poly~accharides, glycohc aCld, and polypeptides
(Watanabc, 1980).
On the ba~l~ of s1l11llar levcls of obscrvcd chlorophyll a and other nutnents during
the late summer of 1990 and 1991, one cou Id expcct that a rHMFP peak should eXlst
III late SUllll11er 1991 of a 5.lI11ilar magl1ltude 111 concentration as 1990 (Hoehn el al, 1978;
Veen5.tra and Schnoor, 1980: Alecon-Herrera e[ al, 1992). The high THMFP levels
ob~ervcù at ~lImmcr's end arc likely the rcslIlt of a combination of the maximum algal
growth Icveb, a ~Illft in ~pccles domInation due to changmg conditions, and a decrease
111 SpCCICS dlvcrslty wlth 1I1creasing algal populations 111 the lake (Watson, 1979) .
35
•
•
•
6.1.2 Border sal11pling site
The seasonal variation at the Border sampllllg 'Ite IS shO\\'1l 111 Figure:" (Appt'ndlx
B). There was a late season maXlll1UI11 111 THMFP in the unlï1tl'll'd .... lI11pll' al lXOX,
although thls was not as hlgh as lhat obscrvcd at Pender and Indlan (1 X) ILg/1 Vl'rSU\
roughly 300 jl.g/L). The THr..,lFP peak in the liltered ~,lI11ple. 110\\'e\'l.'r. OL'Llllred at o·tOl)
instead of at 1808. This was posslbly duc to the plw~pholOll\ dcticlcncy at Borllel \Il the
period pnor to this. Stress conditions cOllld have l\UI,ed th\.' .1Igal' ti.! kl'd
heterotrophlcally on the preVIOll'lly released [CPs such that they hecollll.' lInavallahk a\
precursors. This might explaln the low concentration of THI\'1FP (140 N~/l ) oh<;crwd
in the tiltered sample for 1808. The delaycd peak at 0'+09, pO\\lhly dlle tll the decr\.'a,cd
N to P ratio at that penod, could then have bccn the rC~lIlt of:t large PO\thlllllOliS rl'le;,\e
of ECPs (Sakevich et al, 1980).
Dunng the early 1991 ~ea~on, thc varIation of THMFP over tllne W,I'> vcly
similar for both the filtered and lIntilterrJ samples. ln both ca\c~, the THMI'P IlIcrca\cd
gradually to a maximum at 1506. Thcre was no second, larger llnlïltl'fed pcah oh .. ervcd
a few weeks later as al Pender and Indian. The peak III the unftlkred ,>ample appccucd
later than al Pender and IndIan and the concentration wa .. ,>llghtly lower than th,lt at the
two other southern basin sItcs.
The fiItered THMFP maXIITIUI11 occurred ovcr the OS()() to 1 ~Oh penod at Perl(kr
and Indian, whereas al Border thcrc wa<; a ,>harper peak of a .. llghtly lowcr concentratIOn
at 1506 (145 jl.g/L versus 160 p.g/L). Although Il I~ pm"lole that the ob .. crvcd peak at
36
•
•
•
Tnh.!lornLlh,lOe Formation Potentl.!l.., lfI Llkc Mcmphrcmagog
Border at 1506 wa\ actllally the rc\ult ~olcly of the precllr~ors from the exponential
growth pha~c, It 1\ not IIkely, becau~e an cxpected peak from precursors released during
ccli ly\l~ wa~ Ilot ob~crved at any tlme during the ~ubsequent samphng periods. A more
prohable cxplanallon 1\ that therc were no c1carly dcfined growth stages for the algal
population at Border a<,; a wholc and that the delaycd peak observed was actually the
ovcrlappll1g II1tlucncc of the prccur~or~ from the growth and death stages.
6.1 . .' Ccntml "ampling ~itc
The sca~onal vanatlon of the THMFP at Central IS shown in Figure 6 (Appendix
B). The untïltercd peak tluring laIe 1990 covered the 1808 and 0409 samphng dates and
was smallcr than the peaks obscrved at the ~outhern sites (160 jJ.g/L). The filtered peak
appcared to he ~hghtly ~hiftcd to 0409, WhlCh cOllld be a response to a phosphorous
III1lItation dunng the Imd-summcr penod. slmIlar to the Border site. The lower THMFP
concentrations could abo be due 10 a lower level of al gal growth, due to nutrient
dcticlcncy, which the lnw chlorophyll (/ level at the same penod would suggest.
DlInng the 1991 ~cason. the variation of the tï1tered and lInfiltered THMFP
appcarcd to follow the saille pattern as Pendcr and Indml1. The tirst peak of the
unliltercd samplc, dllring the pcriod of suspected algal exponentlal growth, occurred at
0506 and \Vas of the saille magllltude as those at Pender and Indian, while the second
peak at 2606 was ~maller (170 J.tg/L versus 190 jJ.g/L). The peak for the tïltered sample
was of a similar concentratIOn as that at Border (145 jJ.g/L), although occlIrrmg earlier.
37
•
•
•
6.1 A North sampling site
The seasonal variation uf the THMFP at North I~ ~hll\\'n 111 Flgur~ 7 (Appendl\
B). Althollgh little can be ~~lld abolit the rdative\y low THt\tl·'P 1~\'~'I .. dUf1l1g th~ lat~
1990 season, one can conjecture that they arc the rcsu1t of hd~rotmplllc k~dlllg hy the
algae in response to the phosphorous limitcd cond·tlons at the tlllle ,1Ild 01 redul'\:d
population levels of algae as indicated by chlorophyll li Icvcls.
The variation 111 the 1991 THMFP Icvels at North l, \lmllar to that oh .. erved at
Pender, Indmn, and Central. Although the carly l1!ltïltercd TIIMFP peak 1\ ni the \;\l11~
concentration as that at Central (165 jlg/L), the filtered peak 1\ grcatcr (157 Itg/L),
roughlyequal to those at Pender and Indian. ThiS 'il!Cll1l1lgly small cOlltrlbullOn hy th~
algal biomass dunng the exponentlal growth pcriod '" not rcllccted dunng the laler
growth/death stages where the untiItercd THMFP l' or thc ~aJl1C conccntratlon a ... Pcndcr
and Indian (190 jlg/L).
6.1.5 North-south differenccs
If similar THMFP trends are assumed for late \lllTIl1lCr 1991 a, occurrcd dllrlng
late 1990, the expected late ~llmmer peak would he slgnl ticantly largcr than thl: carllcr
summer peaks at Pender and !m1!an, but approxlIllatcly the ,ame ""l: or \Jllallcr al lhe
other sites. This may be due to "hift5 111 dOllllllancc betwccn the algal "l'cele,
accompanying O. redekel In the vanou~ ba~ln" III re,pon,e to varylng Jcvch of Illltncnl
availability. There might also have becn an lI1t1ucncc 111 the ,olllhern tlp of Alla!Jon/a
38
•
•
•
rnh.llorm.tlune FOrrn.ltHlIl P()lcntldl~ ln Like Mcmphrcmagog
/lo\-aquae, a" the "hallower \ollthern tlp would be more likcly to have Instabllity ln the
water colurnn due to tempcraturc or wmd ctfcct~.
Figure" 8 and 9 (Âppendlx 13) arc thc THMFP 11l0nthly averages for ail sites,
unfiltcrcd and filtcrcd, rcspectlvcly. Gcncrally, the late ()cason 1990 THMFP at Pender
and Indm!1 can he \een ta be greater than at the olher sites. During carly 1991, however,
whde tllI'; appcar'i to be also "lIggc~tcd by the data, the differences between the sites are
<;mall. ThiS l1Iay be duc to the fact that the chlorophyll cl levels measured between the
"Ite" dunng carly 1l)91 arc Ie~s vanablc than those dunng late 1990. Chlorophyll a
levcls obscrved at the northern ~ilcs dunng Ihe laie 1990 season are lower than at the
southern ~ltes at the same tlme. although they are slIl1Jlar to northern levels observed
dunng the carly 1991 ~cason. This ~llggcsts that the lower THMFP observed may be due
10 a less abundant algal blOl11a~s rather than a less reaetlve nature of the algae present.
Comparmg the filtercd and untïltcrcd samples, it appears that Pender and lndian
had grcatcr contnbutlons to the THMFP from the algal biomass than the other sites
dunng carly 10 mld-Sll\l1l11Cr 1991 (assuming the dlfference between the tiltered and
unliltercd THMFP can be attnbutcd 'iolely ta biomass). This may have been due to a
grcalcr dcgrce of fœdmg on the ECPs by heterotrophic bactena at the southern tlp of the
lakc. The direct Impact, cspeclally on the southern basin, of human activities on
TH~lFP call1lot rcadIly he identiticd as being separate from the algal contribution.
Howcvcr, an lIl(hrcct Impact on THMFP. perhaps due to human contribution of nutnents
1I1tO the lakc, 15 qlllte likc1y. glven the relatively small volume of water contained in the
39
• l'nh.II11Illl'lh.llll· l ,'rlll.lll"1l 1'.,1l·I\II.II, III 1 .II-.l I\kllll'hrl·II\.I~").! -------------------------------------------southern tip.
Overall, the TH~IFP concentrations found ln Lah' ~kl1lphn.'l11agog \Vere 'Imllar
to thase found by other rescarcher~ Hochn ef al (1l)~4) tOlllld TH~lFP III lllL' ~OO ln 700
J.Lg/L range in Crater Lake. Edzwald e( a/ (1985) found rl',crVOlr Icvels of lTH~tFP III
the 200 to 400 /lg/L range, while Vcell~tra and Schnoor (Il)HO) roulld lowl.'r kwls 01
CHCl3 (120 to 260 J.Lg/L) 111 a river.
6.1.6 Variation over drpth at Central ~itl'
Figures 10 and Il (Appelldlx B) ..,how Ihe ,ea~oll,t1 v,mallOll 01 TII~lI'P ,II
Central site for different samplillg deplhs (untïllcred and tïllcred. I"c"'pecllwly) A, l.'.\Ch
• layer of the stratItied lake theorettcally mixes complelely WllllIl1 Il .... ell, .111 CX,ll1lllldllOIl
of the epilimnion and the hypolllnl11on will glve an IIH.llcalIOIl 01 the vertical V,1rI.111011 01
THMFP wlthlll the lake. WhIle the 1990 ~all1plc'i were laken III the eplllflllllOIl and Ihe
hypolimnion, the 1991 samples were taken al 4 dCplh'i to Il1vc .... tlgatc ally vanallOIl~ III
THMFP as the depth of the boundary bclwecn the layers changcd. '/ here wa, aho Ihe
possibility of different algal spccles domlllatlllg at (hl fererH deptl1<;, dependlilg IIpOIl
individuallight requirements (Watanabe 1980), although Ilw. dld not appear very Ilkcly
as the trophic zone was not extremely deep III the lakc.
The untiltered sample~ Illdlcatcd a major d Il fcrencc betwccll 1111' 'l'II M 1· P oj Ille
layers during the suppmed perlod of cxponcntIal growth. ï hl ... wa.., Ilkely duc ln the lact
that the biomass contnbution during thls penod wa ... prohably only avatlablc 111 the
• 40
•
•
•
1 rsh,dOflll..lh,wc ForrndlllJn Polcnlldh ln L..Ikc Mcrnphrcmagog
trophlc zone: the lUne of Iight penctratlon and active photosynthesls. No slgmficant
dlffen:ncc wa ... ob..,crved betwccn the laycr~ during the period thought to be the cell Iysis
"'1,lge Algai ccl/) would have cllhcl ..,cttlcd or Imgratcd out of the epiiimmon over ume
... lIch thaL a rdea ... e uf l'HM precLlr~or ... lIpon ccli Iys!s would have been available over
a lll11ch largcr portIon of Lhe watcr cul uml1. Once ~ettled out, the cells would not have
bœn resll~pcndcd back II1to the upper layer.
The t Iltcred ... ample,,> generall y show no slgn! tïcant dl fference betwecn the layers
dUflng Ihe early and laIe \UIllJl1Cr. The unly rcal dlffercl1cc observed was between the
samplcs lake:l al lhe 5 III and 20 III dcplhs dUflng the cxponentml growth period. This
wa~ Irkely the rc ... ull of the clevated Jcvcls of photosynthetlc actIvity al the tllne, but
wuld have lI1(hcatcd the presence ot heterotroplllc bactena grazing on the ECPs .
~l
• 7 VARIATION OF ASSOCIATED PARAMETERS O\'ER SP.\CE .\~n 11:\11-:
7.1 Organic carbon
The scasonal vanatIOns M tOlal and dl s ... olved orgamL' l'.11 hon ( r< l( " I)()(') .11 L'
plotted with the respective THMfP ()b~erved at e,lch ... lle ll\ Ftgurl· ... 12 to 21 (:\PPt'lldl\
C). The TOC vanatlOns over tllne <lt the Pender ,llld Indl,\ll ... lll· ... \\L'IL' qUII\..' 'Illllll,lr
Over the ITIld-sUI11I11Cr penod, Pender hac! ... lIghtly hlgher 1'0(' \ ,tlllC"', III tllL' Il i III l)
mg/L range (average 7.6), while Indlan W.l'\ III the 5.) tll X mg/I I.llige (.I\'l'I,I)!C Il t)
High TOC concentratIOm were ob\crvcd at both .,Ile ... al the hegllllllllg 01 tht' Il)l) 1
season, The TOC levels decrcased l'rom Il 10 I~ mg/L 10 hovl'r III thL' i tll Il ') Illg/I
• range, wlth a peak 111 the 1111d-\ummcr The hlgh IIHlial L'OIlL'ellll.IIIOn\ Wl'IL' Itkdy
allochthonous matenal due to runo!'f entenng the I,tke alld re\lI\pL'Il\lllll 01 hollOiIl
material during turnover. Ounng the late 1990 \Ca'll)ll. there \Va" ,1 l'OC IlL'.l" oh'll'fwd
at 1808, while the THMFP was at a maXlmUI11. Wilde Llm wa" perh,IjJ'l a rl'lkctloll 01
higher al gal activlty, ft l~ IIkely IIMt tilt.! TOC ob'lervcd \Va" Il()t \()lL'ly dlle t()
phytoplankton activlty, as this actlvlty ha~ been fOUlld 10 be nol \Igili 1 1 c;lI Il III L'xplallllllg
seasonal variations in TOC (Storch and Saundcr,>, !IJ7X)
DOC seasonal vanatlon clmcly follow,> the lllllïllercd THMI P trend Buth
Pen der and Indian. during the carly \Ul11mcr, havc I1lgh Illltlal /)()(' v,tlue... Alter
turnover, this drops off sharply, down to the 5 10 ~ mg/L rangt.: Two pCclb wt.:n:
observed, at samplmg dates 0506 and 2606, Ci<; had been generally IOllnd lor ï HMl'P
• 42
•
•
•
ï Ill) 1) In cOlltra..,t to the graduaI decn.\t'lc ovcr the ~ca~on of the TOC levels and the
'>lIlall ob\erved IlIld-~lIrnIllCr peak occurnng a few week~ later than the DOC peaks. In
I.lte .,urnrner, the DOC vanatlon ubserved \\-as '1lmIlar to that of the TOC, wlth
m3XllllllIn'l at lX08 of '11rnIlar magnitude
Border \\(1\ thc only 'lIte where sl!11llar trends for both THM and orgamc carbon
concentratIon were observed over lime. Both TOC and DOC levels at Border were
gellcrally '11lllilar to thO\c at Pender and lndlan, ln the -+ to Il mg/L (TOC) and 4 to 8.5
mg!l. (DOC) I.lngc., Dunng the c,uly .,cason, there was a peak at 1506 for both
THMI'» and 'l'Oc. \\hrIe ,( DOC peak ovcr the 0506 and 1506 samphng dates
corre\ponded to the tiltered 1506 THf\.tFP peak. Dunng the late season, TOC and DOC
IIlcrea'led over AlIgll~t and Septcmber.
Althollgh the DOC concentration al Central \vas sll111lar to Pender and Indian In
both vanatlon and magnItude, the change In the TOC levels followed the same general
trend ,\\ Border The TOC Ic\'cl dccltned sharply after runoff. wlth a peak dunng the
carly \uml11er, and a graduai Illcrea)c over August and September slmllar to that at
Border The DOC concentratIon, arter the Illltial decrease, remains steady through the
carly '1UllllllCr untIl the ... lIght lIlcrease at 2606. The lale 1990 summer measurements
lIldll'ate a generally IIlcreaslIlg level of DOC over the Jate Sllmmer and autumn, None
ot the rOC/DOC pe,lh. ... cOlllclded \VIth THM peaks. However, the large TOC peak al
150ô l'lluld he the I,\rge algalcontnbutlon to the orgal11c carbon pool associated with the
laIe 'i1.ltIOnary gnl\\ th pha~e (F\.?dorak and H uck. 1988) .
• rnh,llllllk'lh,1I1~ r"rnl,lll<lll l'tlll'Illl,'" III l ,11..,' :\"'lIll'llI"IIl.I~ll~ -----------------------------------------------
North has SInl11ar rL\I1gc~ of TOC/DOC a., othcr "He" rhe roc heh.IVllllll
follows that of the THMFP, \Vith both having peak<-. III 260b and gr.ldll.11 Inl'll"l"l'~ O\'l'r
August and September. Overall, the vanatIon at North was c1o~cr III hl..'h.l\'lour 10 Pcnder
and Indlan than Border or Central. At North, then: \\'a~ .11<;0 li graduaI TOC dl..'cre.l"c
dunng the early summer wlth a mld-~lll1lmer TOC pe.t!-o. ol'l:lIrnng roughly Iwo wccks
after the DOC peak. The DOC Ievcls dunng the late ~lIlllll1l..'r pcah.ed ,It 1 XO~, .\\ ,It mo"t
sites, except Border, which is shlftcd later.
The monthly averages (FIgures 22 to 27) glYe a hetter Idea 01 the "l\l ... onal
variation. TOC and DOC generally followcd ~lInIlar trell(\<;. The exception \Va ... Central,
where DOC dechned from a high in May, whde TOC wa<; lnCrea\lI1g betwcen May and
• June before decreasing. The TOC behavlollr wa~ gencrally the ..,alllc a" lor Ihl..' DOC
levels with a maximum occurnng III May. Central i!l Itkdy 10 cxhlhlt il dlltcn:nl pattcfII
of TOC vanation from the olher sites becau~e it IS much dccper, alld therelorL' thc l.trgcr
water volume possibly dllutes any TOC conlnblllion trom rUllo!'r and the rC"'ll\pell\IOIl
of bottom matenal dunng the ~pnng. The l110nthly average ... aho \ugge ... t Ihal the 1990
TOC levels may have been margInally hlghcr th<.n Iho~c 111 1991 ï he org.ulIc carhon
levels in Lake Memphremagog are modcratc 10 h Igh compared to value" 10l1l1d hy other
researchers: Veenstra and Schnoor (1980) round TOC leveh of 4 to 15 mg/L, Hochn e/
al (1984) found DOC levels of 1.9 1O 4.3 mg/L, and Ed/.wald ('laI (19X5) lound JlOIl
purgeable TOC levels of 3 to 6 mg/ L.
• 44
•
•
•
l flh,dorm:lll ... nc FlIrm.!llon Plll<:nllal\ ln L.!kc Mcmphrcmagog
7.2 CIILOROPIIYLL a
The variatIon ovcr tl/nc and ~pace of chlorophyll a IS shown 10 Figures 28 to 33
(Appcndlx D) The variatIOn III chlorophyll a observed during the 1991 ~eason was qUlte
~lIl11lar for aIl 'lItes: a chlorophyll (J peak al 1506, followed by a graduai decrease JO
conccntratlorl to 2307, after which Il Incrca~cs ~harply. One can hypotheslze that these
rcrrcscnt carly and late algal bloOim.
Thcrc 1:-' a \lIll1lar pattern 111 11)90. althollgh it IS less ~harply dctined and has more
v,trIatlon bctwecn the sites. The North and Pen der sites showed mueh less seasonal
varIatIOn ll1 1990. wlth North stay1l1g between 2 to 4 Ilg/L and Pender keepmg qUlte high
over the scasoll between 5 to 7 Ilg/L. Chlorophyll li values in 1990 and 1991 appeared
10 he of roughly the sa me magnitude, 10 the 2 to 8 Ilg/L range (except for large increases
at Pcnder for the end of the 1991 sca<ion).
While there IS no obvlous relatlonshlp with the THM levels found, the observed
chlorophyll li pcaks gcncrally occur one sampling penod (roughly two weeks) after the
~lIppo~ed algal cxponcntIal growth peab contrIbution to THMFP (at 1506 and 0409).
lt may be conJceturcd that the~e peab oceurred dunng the statlonary growth phase where
blOl11ass concentrations werc hlgh but ECP release was low. Also in late 1990, the
chlorophyllll Icycls for Pendcr, IndJaIl. and Border sites were high, correspondlOg with
higher THMFP Icvel~, wlllle Central and North had low chlorophyll a and also low
THMFP levcls. In carly 1991, there was httle dlfference between sites, but Pender had
tugher chlorophyll (/ and THMFP Icvels than the others, although the difference between
• Pen der and the site with the next highest conccntr,ltinn. IIHI1,m. \Vas not I.\rgl.'
7.3 Total Phosphorus
During the 1990 samphng season. the sea~onal vanall0n~ of lolal pho:--pllOrus (TP)
at Pender, Indian. and Border were ~1I11l1ar to earh other a~ \Vere Ihll~C al ('cm rai and
North (Figures 34 to 39, AppendlX E). The TP at the \outhern '>Ite~ expl.'ncIKcd .l
maximum in June. decreased dunng July. and ro~e agalll ~llghlly III AlIgu,>1 and
September. At Central and North, the phmphoroll~ levc\'i dccrea,>cd ,>l1ghtly over the
season, but were essenttally stable l'rom May unul Scptembcr
During the 1991 samplmg ~cason. the vanatlon of the llIonthly avcI.\gc\ lor
• phosphorous at each site was similar to that of 14.)90, but gcnerally more :--uhducd. There
was an overall decrease in TP over the tïr~t hall" of the ~ca'ion, although Pendel ami
Indian both had smaller peaks in June th an 1990 and lll11ch larger one'i 111 Âugll'it.
coinciding with the early and late sUlllmcr al gal growth pCrJ()(h. Ovcrall. there wa\ Ic:--\
difference in total phosphorus levels bctwccn ~ltes for 14.)91 than for 1l)4.)() The l'ender
levels of total phosphorus in 1990 and 1991 wcre roughly the \;mw, although the IlJ91
levels were shghtly higher than thmc for 1990 at the other "'Ite\.
No relatlOnship was ob~erved bctwccn the change ... 1!1 phmphorol!\ COl\ccntratlon"
and THMFP, although it is hkely that THMfP levch wcrc 1I1tlucIlccd by thc lowcr to!,il
phosphorus amounts avallable. Thl~ collid pO'islbly call~c a ':.hlft to a le,>,> rcactlvc \pCCle'i
rather than simply lower populatlOn~ of thc eXI~t1l1g '1pCcle ... , ,>mcc thcrc 1'> IIttle
• 46
•
•
•
r nh.l!orm:lh..tnL rOrn1.llIOn PolcnllJh ln Lake Mcmphn:magog
,)lIgge~tioJl of that ln the lhlorophyll (J lcveb. DlInng 1991 the Pender, Indlan, and
Bordl!r "'Itc~ had ... mall phmphorll~ pcab roughly at the penod of exponentIal growth,
wllh \l11allcr peak'-> al Pender and Indlan dunng the celllysis ~tage. Dunng late summer
1l)l)O, TP IIlcrea ... cd at Pender and Indmn around the 1808 sampling date and al Central
,lIld Border Ju ... t pnor 10 lhi~ The monthly averagcs II1dlcate ~lmllar trends between TP
and THMFP Pcndcr and Indl<ln ... Iles peak dllring August, Central site IS stable during
the late 'illlnmCr, and North IIlcrca~c~ over AL1gu~t ta Septernber.
Thcre wa ... no rcal relatIOn ob~crvcd betwecn total phmphorus and chlorophyll a
levch. In 1990, carly total phmphorus peab were not rctlccted II1 chlorophyll a levels,
WhlCh remained ... tcady. Then while total phosphorus remaII1ed steady after mld-summer,
chlorophyll li lcvcb Incrcascd at ail ~Ites. Dunng the carly 1991 season, chlorophyll a
pcakcd two 10 thrce wceb aftcr total phosphorus. Bath levels appeared to decrease until
the end of J ul y, when there was a large TP lIlcrease at Pender and Border, but no
~lgl11tïcanl change at the other sites. In the same period the chlorophyll a concentration
IIlcrca~cd 1Iigni tïcantly at Pender and 1 ndmn and to a lesser degree at the other sites.
7..1 Total Nit rogell
The l1lonthly avcrages arc lIsed here for greater clarity wh en discussing the
'ieawnal vanation betwcen sItes (Figures 40 to 45, Appendlx F). The Pender and Indian
"Itc~ gcncrally had the hlghest total nitrogen (TN) concentrations. while North had the
lowe~t. On avcrage. total I1Itrogen lcvds were 11Igher III 1991 than In 1990 (range of
of7
• 300-700 f.Lg/L compared \ .. ,\th ~50-5 50 l<g/L) ~arl y III thl' ,.1l1lplll1g 'l'.\~on. hllt :\ lIgu '\t
and September levels were simJlar (c'\cepl Pender \\'Ith 11Igh AlIgll~t TN k\'l'\<').
The variation was also qultc dlffcrent betwcl'll the lINO .\Ild lql)l 't'a\llll'\. hl!
1990, aU sites started with fmrly hi.gh \cvcls and deL're.l'il'll. ThIel' Sltl'~. Pt'Illkl. Indlan.
and Central, rebollndcd III Jllly. dropped III Al1g11~t. only 10 lIlere.I"l' .lg.1I1l III SL'Jl\l'lllht'l
Total mtrogen concentrations at the Border and North 'iltes reachl'd ,1 1ll11l11l111111 III July,
then ~radually Increased toward~ Ihe end 01 the ~ea"on.
TN Levels 111 1991 ~tartcd l1111ch lowl'r Ihan tho.,e \Il lINO. ,ml! Inl'fl'.I\l'd ln 1t1lK',
generally peaking dllnng the expollClltial growlh penod • .lpproxlIllalcly two Wl'C\"'., ,lIter
the THMFP peaks. This sugge~t'i that the 11Igh level'i 01 IlltrogCIl art' t'on"'lIllll'd d\lrrng
• algal growth and the smaller IIlcrca~e OCClIrrtng rollghly a Illonth ,lltcr ward.., wa ... tllL'
relea~e (\f nitrogen back rnto the water aftcr cell Iy'il'>. Blue-grccn "Igae can he l,lige
relea~Jers of nitrogenous substances .,llch a~ allllllO aCld~ and polypq>llde ... (lklkhu.,l,
1974). The TN levels at Border, however, pea\...cd at nver 700 Itg/I al ())()() and
declined thereafter. A po~slble explanatroll for thl'> could he thal .dg,t! ~'rowlh .\Ild Ihe
production of THM precursors at Border occurrcd ln overlapplllg ... Iage,> ovcr lite whole
season rather than ln two drwnct bloom,> a., wa~ .,uggc.,ted. 'l'lm wOlild IllC.lI1 Ihat the
mtrogen uptake and return to the water from dead ccII ... wOlild be dll fïcull 10 dl.,ccrn
Dunng 1990, Il was harder 10 ~cc the rclatlon"llIp'> a., Pender, In<lIan, .\Ild Bonkr
aH had Increased total mtrogen and THMfP peak,> In Ihe ,>arne pCflOt!. At Norlh, Ihe
later occurrence of the THMFP peak wa" perhap,> due 10 low tOlal rllirogl'/l Icveh At
• 4X
•
•
•
fflh .. tlllmclh .. mc Form..lllOn Plltcnll..lh ln LAc Mcmphn::m.tgog
Central, an Illvcr~e total mtragen tu THMFP relatlonshlp was observed dunng the late
growth pcnod. ft I~ IJkcly that other factors werc playmg the dommant roles in this
Jn~tancc.
Gcncrally, ~Jtcs with 11Igher total nitrogen Icvels were a1so hlgher in chlorophyll
(J levels. Although therc wa~ no obvlOus relationshlp, simllar trends in behavlOur were
observed for both paramctcrs during 1990 and 1991. For 1990, both chlorophyll a and
lotalllltrogcn decrca~cd to a mJnlmul1lll1ITI1d-~ummer. and then gradually Increased until
the fall turnover, wlth a large total I1Ilrogen peak at Pendcr ~ite 111 July. This was
relleeted in a srnall chloraphyll li peak occurring at the same time. In 1991, both TN
and ehlorophyll (J levels pcaked In June, early III the summer, and then declined over
tlllle. The sharp chlorophyll li Increase at the end of the summer, however, was not
retlccted ln total I1Itrogen Icvels exccpt at the Pender sampling SIte.
7.5 Nih'ogen to Phosphonls Ratios
Lake Memphremagog IS a pho~phorous limited lake. ThIS is faIr1y clear from the
1111rogcn to phosphorus (N to P) ratios. which arc generally above 20. and sometimes
well above that (Figures 46 to 51, Appcndix G). Looking at monthly averages, the N
to P ratIO trends appear to be almmt opposite for 1990 and 1991. Dunng 1990, there
were fairly hlgh lIlitial ratio values of 28 to 38, which fell in June sueh that part of the
lake (south basin) becamc no longer phosphorous limtted. The N to P ratio then
gradually incrcascd to its orig1l1al value over the rest of the summer, peaking In July or
.+9
•
•
•
August. For the 1991 season, lhe ratio ~lartcd Iowa liS 10 JO), .\Ill! lIlL'fca\l'd III JUIll.'
or July before decreasing to generally the saille lcvels a~ 1Il the lIpnng.
ThIS seasonal variatIon was 1I1t1uenccd grcatly by llltai phosphorll~ prak~ III June
1990, which depressed the ratio, and total nitrogcn pcab III June 1991 Wllldl l'lev,lIed
it. The very large TP peak observed in August 199 1 wa~ balanœd hy ,\ COI n: ... pondlllg
large TN peak at the same tJlne. ThIS greater avatlability of l1utnellts would l':-.plalll the
hlgh mcrease ln chlorophyll (/ levcl~ bctwccn July and August 01 199 1. RC~l1'1pcll\lon
of nutrients that had settled out of the water column 1'\ a posslhle explanatlon for llll'
source of peaks. However, the peaks were not obscrved at l11dlan, whlch Illlght he
expected, as the two sites are quite close. It is more reasonable to prop0'\l' that the
nutrients were contnbuted by a few point sources at the ~()uthern tlp of the lake, clther
Newport or one of the three nvers, Black, Barton, or Clyde.
The 1990 data appear to indicate that al 1808, Border, Central, and North were
all severely phosphorous limlted (N to P ratIos of 38 10 43). Thc~e valucs drop dunng
the next period (to 28 to 30 for Border and Central, and l'rom 4.1 to 3X for North). TllI~
was likely the reason that while Pender and Indtan had fïltered and unlïltcrcd THMFP
peaks at 1808 (N ta P ratio around 25), Border and Central had Ihe liltered THMI·'!>
peaks delayed by two weeks and North had no rcal tiltered peak 10 \peak ot. Thl\
temporary phosphorous deficlency dunng the exponenttal growth pha..,c could have cau\cd
temporary heterotrophic feedmg by the algae on the ECP'I relea\cd, parllcularly 'Imcc Ihe
nitrogen and phosphorous levels at Border, Central, and North were alrcady ralher low
50
•
•
•
l'nhJI''lm:lhJoc FormJllOO PolcntlJh 10 LJ"c Mcmphrcmagog
al the tlme.
ln 1991, no Indlvldual pattcrn~ ofvanallon in N to P ratio were observed between
thl: ,>lte\). 'l'lm war.; nol surpmmg SInCC the total pho~phorus and total mtrogen seasonal
vaflatIon~ wcrc \Imllar for ail ~ltCS. Levels of both dunng early season were higher
rel<ltIve to 1990 RatiO values \tayed 111 the 25 to 38 range ail season except dunng the
very beginnmg and end of the ~ampling year where some of the southern sites dropped
down to 20 or below
7.6 pli and Alkalinity
On-sile data for the pH levels ln the lake were available only for 1990 (Figure 52,
Appcndlx H). The pH generally remallled in the 7.5 to 8 range. There was little overall
vanatlon betwccn ~ites and over tllne. The exception was a sharp drop in pH at 1808
for ail sites occurnng at the ~amc tllne as the 11lghest llntïltered THMFP peaks. The
largcr THMFP pcaks cOlnclded WIth smaller pH rcdllctlons. A possible explanation IS
the ~lIghtly lowcr alkahl11ty Icvcls for 1808 whlch, coupled wlth high light intenslty and
hlgh pH, could have mduced conditions whereby active photosynthesis would be limited
hy COl leveJs. This situation favours the release of glycolic acid, the most common one
hbratcd hy algac (Hellcbllst, 1974; Watanabe, 1980), whlch mlght cause a temporary
rcductlon in pH. The pH v,matlOl1 between sites at 1808 mirrored that of alkalinity.
Alkahl11ty Icvcls gcncrally dld not exhlbit much seasonal variation (Figure 53,
Appcndix H). DlInng the I11ld- to laie Slllllmer of 1990, il hovered in the 52 to 60 mg/L
51
•
•
•
as CaC03 range, whlle It rcmall1cd 111 the 50 to 55 mg/L r,mge lor the l\\rly to nml
summer penod of 1991. The exceptIOn was the Pcndcr site (Figure 5..+). wl1lch dl\plaYl'd
a fair degree of vanation in both late 1990 (bctwcen 55 to b5 mg/l ) ,md l'.\rly Iql)! ('i0
to 62 mg/L). Ounng the carly 1991 season. Pender had alkalll1lty peaks at OSOh and
2606, which corresponded to the untï1tercd THMFP pcah.s l)h~er\'L'd The IIll.:re,l\C 111
alkalinity to 0506 was hkely due to Illcreased algal adlvlly. althnugh III the t .. \\e 01
Pender, it may also have been intlucnced by h111llan i.ll.:llvllies. rhe \olllhelll III' wht'Ie
the Pender site 15 SItuated is relatJvely 'ihallow and does not conlalll ,1 1,lr!!,c volullle 01
water so that point sources may have a slgntlïcanl Impact
Although 1990 appears to have had hlgber aikalilllty level'l Ih,llI ll)l)l, tlm Illay
not actually have been the case, a~ the penods covered were Ilot exactl y lhe \,lIlll' 101 the
mid-summer levels for each year. The highcr ranges al aIl ~Ite~ dunng the mal to late
summer of 1990 may have been the result of II1crea~ed level'l of algal actlvlly \IIlCC Iim
is the period of greatest algal actlVIty.
7.7 Suspended solids and tllrbidity
Figures 55 to 61 (Appcndlx H) ~how the vanatlOIl'l 111 \lI\pended \oltd\ ,1IId
turbidity over the 1990 and 1991 ~ampltng ~ea~om SlI'Ipendcd \011(1'1 (SS) conœntratlon\
for 1990 and 1991 were roughly In the ~amc range, gCllerally 0.5 to 3 IIlg/L. Dl/rIng the
mid- to late summer of 1990, althollgh thcrc werc no '1lgmlÏcélnt dllfcrenœ ... I>etwccn
sites, the southern sites appeared ta have ~llghtly hlgher SS Ievel ... lhan ('entraI and
52
•
•
•
l f1i1Jlorm.lh..ln~ FOrrTlJllOn P()l~nllah ln Lake Mcrnphrcrnagog
North. Although thcrc wa~ no grcal ~ca~onal vanatlon over the penod exammed, the
bchavlour wa\ the ~amc for ail 'lites and there appeared to be a graduai Increase In SS
occurnng ovcr Augu")t and Scptcmbcr.
()unng thc early to mld-~lImmer of 1991, therc were simllar trends in seasonal
vanatIOn ob\crvcd betwecn Pender, Indran, and Border, and for Central and North.
Thac was no vanatlOl1 ovcr ~pace bctwecn the southern sites. The SS levels there
peaked at 1506, t'cil gradually to 2307, and then appeared to II1crease again. The
bchavlour ln 1990 and 1991 .ll Border, !ndran, and Pcndcr appeared to follow patterns
sIIllIIar to tho~e of chlorophyll li, whlch Imght be expected If algae were supposed to be
the pnmary ~ollrce of slIspcnded so!rds ln the water column. This IS not tht! case for
Central and North, both of willeh have tllrbidity levels II1creasing over the season to
maxi mums al 2606. The 1111 liai peak at 1506 at the sOllthern sites possibly retlected the
contnbutlon of partlculale matter 10 the lake by ~pnng rllnoff. The particulate matter
wou Id not have ~ettled as readdy 111 the shallower ~outhern basm and might therefore
have bccn morc prescnt 111 the upper layer sampled. Ali Sites have a second untïltered
THMFP peak at 2606 that IS larger th an the ll1itlal 0506 peak, except Border which peaks
al 1606. This was posslbly the late ~tatIOnary growth/death stage of the first algal bloom
wlth (1 rclca~c of precursors as a result of ccII lysls.
The late ~ulllmcr resul ts of 1990 lI1d icate a turbldlty peak at or Just after 1808.
slIl11lar to chlorophyll a, \VIth the peak cOInciding wlth THMFP observed levels. In
11)') l, Pcndcr. Indran, and North ail had peaks at 0506, while Border peaked at 1506,
53
• and ail sites had high turbidtty levcls at 1007 (5 ln b NTlI). The tir ... 1 III 'a 1.. " l'Olill'Ilkd
with THMFP peaks. The maxImum turbidity lcvels nb~crvrd a fcw wœb after dl(' ~60b
THMFP peak were not necessanly slIrpnslI1g. ~incc Jt i~ lil..dy 10 he 11Irbldity dm' 10 the
contribution t'rom dead cclls. Unfortllnatcly, the SS ... ample fwm the ~.lInL' date .1\ the
turbidity sam pie was contal11lllated and thercforc 1I1l1l~ahle, bul gl\'l'Il the .l ... ~Ol'iatlOll
between the two parameters, one wOllld cxpcct 10 have also oh ... crvcd SS pe.11.. <; for .111
sites at 1007. For both 1990 and 1991, thcre was gcnerally not a gre.1l deal 01 dllfercllce
In turbidity levels between sItes. Turbidlty Icvds dunng Il)l)() appear hl have hecn lowl'I
th an the 1991 levels (0.5 10 3 NTU comparcd 10 1 10 b NTl! range)
• 7.8 Secchi depth
There was a considerable al110unt of vanatlon III \ccchl dcpth Il1Ca~lI[eIllCllt~ trom
one sampling date to the next for ail sites (Flgurc ... 62 tn 67, Appelldlx 1). 'l'lm lIIay Ilot
be entlrely due to vanatlOns In lake water qualtty lI\ \ecchl rcadlllg ... ,Ile aho IIlllucnccd
by light intensity (time of day, cloud covcr), wlnd cllœt~, 'lrHI thc dcgrec of calmne .....
of the water. Such readings arc much more ~L1bjcctIVC than othcr data.
The monthly averages Indicatc that dllnng 1990 there wa .. a clear dr!ferellce
between the sites with lIlcreasing secchi dcpth rcading lrom the ... ollthcrn-IllO\I tlp of Ihe
lake to the north. ThIs mdicate~ an tncrca~c 111 the degrec of potenllal Iight pcnetratlon
into the water column. The dlffcrencc betwccn north and \outh wa\ Ilot a .. c1car 111 1<)<) 1
This was partly because the Pender, Indlan, and Border .. ecchl dl .. k readtng\ were hlgher
• 54
•
•
•
rnh .. domdh,ln\! FormaLlJn PolcnllJb ln Ldke Mcmphremagog
than ln 1990, whlle tho~c at Central and North wcre roughly the same (in 1990,2 to
5 111; ln 1991, 2.5 to 5.5 rn) dunng the early and mid-summer. By the late summer,
howevcr, therc was a dcfinitc north-south dlffercnce agam.
Pcnder and Indian had Incrca~ed ~ecchi rcadings m July, at the same time as a
dccrcasc ln THMFP and chlorophyll a levels. Oddly, there were also high levels of
turoldlty at ail \Itcs, although lowcr secchi disk readIngs would have been expected while
turbldity W(ll) l11gh.
7.9 Tnbulatcd values
The water quality data rneaslired dllnng the 1990 and 1991 seasons cannot really
hc comparcd becau~e thcy do not coyer the same penods. The 1990 sampling season
covercd mid to late summer, while the 1991 season covered generally carly to mid
Slllllmcr (Table 2). For alkahl11ty, there was a defïnite increasing north-south gradient
dllrmg 1990 and 1991 wlth Indtan, Border, and Central sites roughly the same. The
1990 pH levcl~ cxhlblt the same behavlOur. Therc was an observed north-south gradient
In sllspcndcd ~nhds measllred for 1990, but there appeared to be no trend in 1991. There
was no rcal vanatlon observcd in turbidity levels. Secchi depth readmgs can be
comparcd bctwecn 1990 and 1991, as they covered roughly the same period. There was
a north-south gradlcnt and 1991 ~ccchi values appeared to be higher than those during
1990 .
55
• Table 2. VanatIon of waler qualily paralllctcI,
Site Alkalinity SS pH Turbldlty SCl.TIlI
(mg/L CaC01) (mg/L) (NTll) (111 )
Pender 1990 62 + 3 - 2.2 ± 0.5 7.73 ± 0.33 l.~ ± 1.0 2 J lO.5 1991 55 ± 6 1.7 ± 0.7 3.0 ± 1.5 J.I ~~ 0.5
Indian 1990 57 ± 2 2.1 ± ,'.9 7.69 ± 0.31 IS±()l) 2 X t O.b 1991 53 ± 4 1.8 ± 0.7 2.6 ± lA 3A t OA
Border 1990 57 ± 3 1.6 ± 0.3 7.69 ± 0.39 1.5 ± O.X 3.2 t-04 1991 53 ± 1 1.5 ± 0.7 2.5 ± 1.6 3 H -1- o.()
Central 1990 56 ± 2 1.4 ± 0.6 7.64 ± 0.64 1. J +: O.S '.X i 0.6 1991 53 ± 1 1.8 ± 0.8 2.6 ± 1.7 4.3 1: 0 X
• North 1990 55 ± 2 1.1 ± 0.4 7.56 ± 0.75 1.4±O.5 4.2 J O.H 1991 52 ± 1 2.5 ± 2.2 2.7 ± 19 4.5 J: 0 6
Note: Values glven are the averages ± the standard dCvlatlon over the ~alllpllilg ,ca.,on
7.10 Temperature
Temperature profiles mdicate the changlllg thickne''I'I 01 the /Illxl'd layl:r
(epilimnion) over time in responsc to a change 111 tcrnperatun.: (hgure, (JK 10 70.
Appendix J). At spring overturn, the cntrrc watcr COIUlllll 1\ cOII\lden:d to IllIX wlthlfl
itself. This actually occurs dunng the wholc 'lca::-.on ln the .,outh ba\ll1. whlch 1\ qUIIL:
shallow (mean depth 7 m), and even at Border. whlch 1'> decpcr (1111:all depth 01 10 Ill)
As temperatures lI1crease, the water column ..,tratdïc~ Into layer,> Ihe CprllllHlIoll, the
• 56
•
•
•
rnh.t hJlm:lhJoc F,)rrnJll<lO PlllcOll..lh ln Llkc Mcmphrcmagog
lIletallll1rl10n. dlHj t he Il ypolllnn Ion \VIth lemperalure change over the season, the
thll.kne ...... ot the epllllllllJOn WIll gradually IIlcrea~c and ~qut!eze the metahmmon (reglon
wilh change 111 tClllperaturc ot roughly 1 ~C'/m) lilleh that the temperature protile ln the
I.tke hecorne ...... harper
Tlm can Il Ive an d teet on algal actlvlty and THMP as density differences prevent
nllxlIlg bClwcen the layer~ Nulncnl\ or algae Icavmg the trophle zone, due to settling
out or ln re\p<lIl\c 10 <.,lre~<., condItion ... , will no longer be productive as they Will not be
reclfculateu 1I1to the upper rcglon of the \vater column where active photosynthcsis
OCClIr'l Il 1<., neœ ...... ary to knm\' the cllange~ In the dcpth of the l111xed layer to examll1e
depth efkct<., nunng the early ... ea~on a 10 m depth IS weil in the hypolimmon while by
late ... ull1ll1cr 15 111 Iii barcly consldcred still hypolimnetic .
The ~ca~onal VdnatIon ot waler ~urfacc tc. ,peralure (Figures 71 and 72) indlcates
that 111 1991 the penod of ma\1 mum algal growth occurred dunng the period of highest
water ~llrfacc tcmpcraturc. Il abo ~llgge~t~ that the end of June would be a hkely period
to expect the replacement ot "'pnng algal bloom by those specles makmg up the large late
<"Ull1lller .llgal bloOim. 'l'hcre was no ~Ignttïcant north-south temperature gradient
nb~erved dunng the early ~al1lpiIng ~eason although the southern sites appeared to warm
up f.\\ICr, perhap~ due 10 the ~l11allcr volume of water.
57
•
•
•
7.11 CI: Demand
The chlonne demand observcd 111 the lalc ~lll1ll1lcr .... Hllpl~\ of IlNO IIldh.:.\tC thc
same behavlour at ail sites: a graduai (kcrcasc for both thc rIltered ,\Ild llntiltclcd \.\lllpk~
over time (Figures 73 to 77, Appcn(hx K). It I~ odd that .ll (}20~. tiltclcd dCIll,md
exceeded untiltered demand. \Ince thls IS nut alsn rctlccted 111 TII!\ll'P \',\IUl'\. Il I~
unlikely to be due to the contnhutloll of an orgalllC dcmand dunng Ilitration <1\ thclc an:
no correspondingly large DOC \'alllc~. Il \Va'! Illon: IIkely bccau\c ni ('1. dCIll,lIld for
oxidatIOn pllrpo~es pnor to I,crvll1g the tkmand 01 thc THl\.l pn"'cur~or\ Iknc.l\cd
demand wIth tluctuations in THM FP could he duc 10 the ch,mglllg natuIl' 01 Ihe
precursors. Blue-green algae. the dominant 'ipCCIC~ pn:\cnl. l'XCl~!e III or l' IlllrogenoU\
compounds than other algae (up to 30% ot N 1I11akc) (Hcllcbu ... t, 1l)74), hut thl''>c lend
to be precursors more for the non-purgcablc fraction 01 TOX (l'Ichy ('/ al. 19X(1) ,md il ...
such mayexert Ch demand but not be obscrved a,> contnbutlllg 10 rHMI'p
7.12 Predicted humic contribution on the ba~i ... of colOllr
Colour data were avallable only for the Imd- to lalc <,UlIllllcr 01 )l)()() "1 he hUJllll
contnbution to THMFP i~ prcdlctcd u'>lng the tollowlIlg equalloll 1 rom Oliver and
Thurman (1983):
Pred. humic THMFP (J.l.g CHCI/mg C) = 14 * (colour/l1l!-, C) t 17
where colour IS the spectrophotometnc ahl,orbancc at 400 n rn lllllltlpllcd hy 1100 ï lIt y
found good agreement for those lake') of very low pH, hut up to W'Yr, deVléI!J<H! lor tlIo)c
58
•
•
•
Tnh..llolllClhJm .. Form.HIlIO P()lCnlWI~ 111 Lake Mcmphremagog
lakt.:) of normal pH 7 range (llke Memphrcmagog), and concluded that the difference was
llkely duc to algal contnbutlon.
Therc appearcd to he a decrca~mg north-~ollth gradient bath in the predlcted
hUlllIc THMFP and the calclliated algal contribution (difference between TTHMFP and
the hlll11lC THMFP) (Figures 78 to 82, Appendlx L). Ali sites had a hllmic peak at 0208
(0208 to 18m~ for Pender and Indlan), whlch was followed by a peak In the calculated
algal THMFP. l'lm would appcar to Indlcate a later al gal intluence than supposed. The
untîltcrcd hllllllC and algal THMfP~ were generally in the same range, while there was
a ~lgl1ltïcant dlfference hetwecn the hllllnc and algal THMFP for the tiltered sampi es ,
wlth the hUl11lc contnbutlon bClI1g the larger. Bath mdlvidually had THMFPs of over
100 p.g/L.
The hUllllC peak could have been the rC~lllt of earher algal actlvity, assurning that
Il IS l'rom autochthonolls ~()urccs (detntus) and not allochthonolls (runoff). Sorne
rcscarchcr~ (Hoelln el al. 1984: Oliver and Visser, 1980) have found that bacteria can
alter the character of ECP~, pos~lbly making them more reacUve and perhaps aitering the
ECPs ~lIch that they bccolllc II1dlstingulshable l'rom hlllnIC and flllvIC acids .
59
• 8 CORRELATIONS BET"'EEN PARAl\IETERS
Attempts were made to tind corrdations bet",ccn the THf\tFP ,ml! the 1I1\'L',tlg,Ul'd
parameters: orgamc carbon, chiorophyllll, total Illtrogcn, total pho\phoru\, ~l'l'l'ill depth,
suspended solids, alkalinity, turbldlty, and N to P ratIo. Flltercd .lIld unttltl'rl'd \,unpk\
were treated scparately. Thc graphs of THl\1FP \'l'rSU\ l',\ch parallll'tl'r .Irl' glwn III
Appendix N. The correlatIOn Illatrtce~ lor the li Itcrl'd and un t Iltl'rl'd \alllpll.', arc ,IHm Il
In Tables 3 and 4. Gencrally, attcmpts to lit the pOll1t~ tn à <;tr;\lght 1 Ille \Vl'Il' Ilot \'l'Iy
successful because thcre was a grcat dcal of \catter ln the data 'l'hl .... l',1Il hl' rl'adlly 'l'l'II
in the correlation matnx. Althollgh SOIllC re~carchcr\ round corrl'latlOn\ het\\'l'clI TOC
• and THMs (Symons et al, 1975, round a correlatIon between lion-volatile '1'0(' .1Ild tot,t1
THMs WIth an r 2 value of 0.98; Glazc and Rawley, 1979, round TOC ver<;u\ (ï ICI 1 wlth
a correlation coeffiCIent of 0.586), Il wa~ very poorly corrclated lor the penod \tlJ(lled
Van Steenderen et al (1991) round a low r2 valuc \VIth 'l'HM vcr\u\ TOC l'Ile \allle
applies for chlorophyll (1, aIthollgh Hochn ('{ a! (IlJ7H) lound a rclatHII1\llIP hetWl'C1I
chlorophyll a and THM in the Occoquan RC<:iervOlr.
• 60
• 1 nhJl"llll:lh.1Ile 1 orrn-tllon P()tenIIJI~ ln Llke Memphrcmagog
Table 1 Correlation matnx for untiltcred samples
TOC chI a TN Tf> N to P SS Alk. Turb. Secc. THM
TOC' 1.00 0.45 0.11 0.45 -0.43 0.11 0.22 0.09 -0.22 0.08
chI a 1.00 0.38 0.68 -0.42 0.40 0.09 0.07 -0.40 0.23
TN l.00 0.59 0.19 0.30 -0.09 0.41 -0.30 0.22
TI' 1.00 -0.65 0.24 0.01 0.15 -0.58 0.40
N 10 P 1.00 -0.05 -0.07 0.14 0.43 -0.25
SS 1.00 0.09 0.56 -0.45 0.33
Alk. 1.00 -0.20 -0.05 0.39
'l'url>. 1.00 0.05 0.05
Secc 1.00 -0.63
'J'HM 1.00
Table -l. Correlation matnx for fîltered samples
DOC chi a TN TP N to P Alk. Secchi
DOC 1.000 0.264 -0.020 0.133 -0.185 -v.153 -0.168
chi a I.DOO 0.382 0.678 -0.425 0.086 -0.403
TN 1.000 0.587 0.190 -0.092 -0.300
Ti> 1.000 -0.654 0.014 -0.577
N 10 P 1.000 -0.065 0.434
Alk. 1.000 -0.045
Sœclu 1.000
• 61
•
•
•
For the lake as a whok the b\!~t agrœment \\'a~ Ù)lI1Hi het\\l'l'll l1{~tFP .\Ild
secchi depth (Figures 83 and 8-+, App\!llthx M). \VIth corrdatlon Clll'ftïcll'lll\ nt () h2H
and -0.601 for ulltiltered and tiltered ~a1l1pk~ rc~p\!l·tl\dy. The TH~lI'P 10 'l'ù'hl dql!1l
relatlOnshlp can be clearly scen 10 be Illver~e, altllOugh the l.'orrdatlOll l'odllCIl'nt W,I' Ilot
very hlgh. This IS due to the degrœ of ~catter present. The rcl,lIlO11,hlJ> tnrllled W.l'
simllar for the tïltered and non-tiltered ~amples:
unfiltered THMFP = -26.49 '" dcpth + 256.-+-+ r = -0 h2H
tiltered THMFP = -29,87 li< dcplh + 2-+5,l)() r -=:: 0.601
A multIple regres~lOn wa~ performed on the lï1tered ,1I1d unfJllercd ',llllpk'> betWl'l'n
THMFP and the parameters IIlvestlgatcd. Thl~ gave a belter correlatIon cod Ill'Il'nt than
any one varIable. The regresslOn equatlon I~:
untiltered THMFP = -126.97 - 0,92 TOC - 7 09 chi (1 - 0 40 TN t 16 25 TP -/-
r = 0.761
filtered THMFP
r = 0.715
5.85 NP + 9.93 SS + 1.94 Allo. 1- 12.40 Turh 1(1.7X secchi
-7.26 - 2 62 TOC - 8.33 chili - O.IH TN + 10.70 TI' j
2.4 7 NP + 2. 19 AI k - 18 1 g ... eec h 1
The THMFP was alw corrclatcd wlth ail paramctcr\ for each IIldlvldual '>,lfllpltng
site (Tables 5 and 6). Although the data are ~ttll qlllte \cattered (lew data pOlflh), "OIllC
possible correlations were found (Figure,> 85 tu 91, Â ppendlx M) Pender and 1 ndlétn (a ...
weil as North, to a degree) had wcak correlatIOn) wlth ... ecchl depth lor buth thl: lïltcred
and unfiltered samples, although the~c were better Ihan the correlation lor the l,lkc a ... a
whole. Pender also exhlbited a rea~onablc correlation wllh total
62
..-------------
• rnl"tlonldh.mc Forrn.lIIlH] pl)ICnIIJI~ ln La!.c Mcmphrcmagog
Tahle 5. CorrelatIon coefficient.., for THMFP and watcr qualtly paramcters (unfiltered samples)
Pemlcr Indlan Border Central North
TOC 0.045 0.023 0.110 0.039 0.141
chi a 0.032 0.138 0.184 0.045 0.313
TP 0.778 0.210 0.221 0.055 0.290
TN 0.032 0.045 0.210 0.134 0.534
N Lo P 0.371 0.190 0.566 0.045 0.114
Alk 0.489 0.329 0.134 0.017 0.363
SS 0.274 0.237 0.402 0.230 0.786
Turh 0.138 0.170 0.089 0.141 0.387
Secchi 0.619 0.528 0.369 0.387 0.566
• Table 6. Correlation coefficlent~ for THMFP and water quality parameters (filtered samples)
Pcnder Indlan Border Central North
DOC 0.366 0.084 0.257 0.524 0.155
chi a 0.006 0.068 0.399 0.016 0.015
TP 0.389 0.05'5 0.465 0.041 0.311
TN 0.014 0.032 0.382 0.148 0.851
N tn P 0.344 0.145 0.205 0.148 0.118
Alk 0.268 0.424 0.217 0.049 0.422
Secchi 0.629 0.617 0.210 0.055 0.484
• 63
•
•
•
phosphorous (r = 0.778) for the lIntïltcred ~ampk. Thcrc \,crc Illl ... twng l'llrrd.1t1011\
found for the Border and Central ,Iles. Generally tl1c,c two ~Ill?, \"-'rc \'cry pomlv
correlated for ail parameters. North was corrdatcd w\lh total IlItrogl'll lor thl' tïltcfl'd
sample (r = 0.851) and with su~pellded soltd~ for the 1I1lfiitered ".\lllplc (r -=- 07Xtl).
The predlcted algal cOlltnblltlon to THJ\lP \\'a~ plottL'd \l~I 'ill'" chlolOphyll li
(Figures 92 and 93, Appendlx 1\1) for the unflltcrcd samplc \VIth .\ l'Ond.ltiolll'lldlÏl·lcnt
of 0.382. While thls was better than the correlation for total THI\1FP vcr"'lI" l'hlorophyll
a (r = 0.228), It is stilliow clue lO ~cattcr III the data. The flltered ".unpk' pOIIlt<, Wl'Il'
very few and highly scattered .
64
•
•
•
1 nh.doITH:lh,tnC !llnn..t[Jun Polcnttul, 111 LJkc McmphrclTIJgog
9 CONCLUSIONS
ln a nat ura 1 ~y~tem ~llch <le; Lake Memphremagog there was not any one
p.1ralllctcr ob\ervcd that exerted a ~lgl1lticant 1I1tlllencc on the THMFP of the lake as a
whole. Il wa~ rather a cornblllation of ~everal of the assoclatcd parameters that Ylelded
the clmest correlation wlth the THM concentrations found 111 the analyzed samples. ThiS
Wél\ perhap\i expccted duc to the complexlty of the ~)stern and the fact that sorne of the
parameter\ wcre Inter-dcpcndent It was not ternbly o;;urpnsmg that the correlatIOn
bclwccn THMFP and ~ecchi dcpth lor the lake as a whole was the closest for any of the
parameterl). Secchi tilsk readlllg\ arc affcctcd by vanatlOns 111 several other parameters .
Some corrcldtlom bctwcen THMFP and the parameters were round when the sites
were cxamined IIldlvldually. The correlation between THMFP and TP at Indlan site
posslbly retleeled a phmphorou~ III1lltalion due 10 lower levels at Indlan relative to the
rcsl of the South ba'il11. The correlations tOlll1d al North sile bctween TN and sohds and
THMFP wcrc hkely due to thclr low levels. Nltrogcn was likely a hnllt1l1g factor to
algal growth and thercfore to precursor formation al North.
Contrary to expectatlons. no (IIrect relationships could be found between the
THI\tFP and the TOC or chlorophyll (/ concentrattons. ThIS was hkely due to the
combllll'd dfecb of the hU1ll1C contributIon to THMFP and the varIatIOns in formation
potentlal due 10 change~ III the algal 1l1ctabolnes. The contnbutlon to the THMFP from
hU1l11C ~l1b~tancc~ wa'i estllllated to he roughly ~Imllar to that from algal actlvlty .
65
• The THMFP lc\'cls b~t\Vœll the \'anou~ l1.\~lns of the 1.1"-1.' were gellel.llly ln the
same range. Although therr was a lI1crca\1Ilg Ilorth-\outh l'llIlCI..'lltr.\tHlII gr.uhl'nt at
certain periods, the overall variation hetweell ~Ite~ \\'.l'i Ilot ~t.ltl~tl~:ally "'lgllllll"\I\t This
appeared to mdicate that therc \Vas not a ~lgl1llïcallt contnbutlOIl to rH~1FP fllllll humall
actIvlty.
Although the lake is Ilot consldcrrd 10 be very produCI1\'l' III tl'fln ... lit algal
activlty, the THMFP prc~cnt wlthlll thc lal-.e 1\ ~tlll al a Icvc1 that gl'llcr.\lly e\cl'cth Ihl'
US EPA standard of 100 }.Lg/L and could be cOllsldeled \Ig11l11l.'anl FlIrlhl..'l ... tlldy mIn
the nature and causes of the THM precur\or\ will be necL'~'i;\ly, partll'Ul.lrly Il 11ll'
Canadian GUldelines were to be lowered III futurc to a ~ll11rlar lL'vcl a ... thal ul the US
•
• 66
•
•
•
[ nh.ilurncth,lOe FurrnatlOn Pnlcnll.ih ln Lake Mcmphn:rnagog
(;U)SSARY
Algat.: - Ph()to~ynthctlc mlcro~coplc plants whlch in cxccss can contribute taste and odollr to potablt.: \vélter and dcplctc dlssolved oxygen on decomposltlon.
AlhallllIty - The capaclty of watcr to neutrahze acids, a property Imparted by carbonates, hlcarhonates, hydroxldc~, and occasionally borates, silicates, and pho<;phate~. It I~ cxprcsscd in milligrams of equlvalent calcium carbonate per litre.
AlIochthorllHI\ - HlIl11lC <;ubl,tanccs entcnng a lake from the surrounding watershed lhrough rlillofr
AlIt()chthollou~ - HlIll1lC \lIb~tanœl) produccd wlthlll the lake ltself.
Bloma<.,'i - The ma'iS of hlOloglcal malcnal contalllcd within a system.
B1oom<., - Large Illas~c~ of mlcrmcoplc and macrmcoplc plant IIfe, such as green aigae, occurnng 1I1 bodlc~ of watcr.
Chlonne demand - The quantlty of chlonne that wou Id be consumed 111 a specific pcnod by rcaction wIth substances present in water, if the chlonne sllpply were not Iilmted. The demand for any given water vanes WIth both tlllle of contact and temperature.
Chlorophyll ([ - Compound pre~cnt in plant cells resultlllg 111 the green colour; used as an 1I1dicator of algal concentrations.
nid dfccts - Those occurnng ovcr a complete Iight-dark cycle.
Extracellular product~ (ECP~) - Compounds produced by algae and secreted through the cell \Valls 1I1to solutIon.
EpIllll11l101l - ln a ~tratJlïeù lake. the upper ll11xed layer of the water where photmynthc~l~ OCCllrl)
HlIl1llC substancc'i - A generai class of heterogeneous, biogemc, refractory, yellowblack, organlc ~ubstanccs that are Important participants in many geochemlcal rcactIons and processcs. They consist of hllmic and fulnc .1Cld~ and hllI11I11 .
67
•
•
•
Hydrophihc -
Hydrophoblc -
Hypolimmon -
Metalimnion -
HavlIlg a ~trong .1ftïl1lty for \\ atl'r
Havmg a ~trong avcr~lon to watl'r
The deepest, non-ll1l\.mg Iay~r of ",lt~r III a ,>tLltlflcd lahc.
IntermedIate layer bctwcen the CpIlll11l1l0n alld tlll' hypohllllllOll, tCgllll1 wlth a temperature change of roughly l "C/m.
Organic carbon - Carbon from orgamc sources; dl~solvcd orgal1lc carbon (D()( ') I~ tlle portIOn of the total orgalllc carbon (TOC) that 1'> 111 ~olllt Ion.
Organohalides (OX) - Orgal1lc compounds that l'ontalll halogl'n atull1'>
Phytoplankton - Plankton con~ist\llg of plants, ~lIch a~ alpe.
Secchi depth - Measuremcnt of the depth of the Iight penetratloll 11110 Ille lIppel I,LYer of water III a lake.
Surrogate parameters - Those parameters whme concentratloll~ .Ire IInl':l/ly proportion al to the concentratton of the target P;1/ alllcter.
Suspended sohds - Insoluble whcb that clthcr tloat 011 thc ,>url.lcl' 01, or ,Ill' III
suspension JI1, watcr or other Itq 111d '>.
Trihalomethanes - Compounds that arc dcnvatlvc<.; of Illcthane, ('H ,. In wlllch thrcc halogen atoms (chlonne, hrolllll1C, or IOdlllc) arc '>lIh\t Itllted lm three of the hydrogen atoms.
Trihalomethane formatIOn potential - The potcl1tml of a compollnd 10 rcaU wlth ,\ halogcn, lIndcr 'ltandard condlllon'l, to Imm
tnhalomcthanc ...
Trihalomethane prccu rsors - Compound that will rcact, lI\lIally Wllh chlol'lllC, to
rorm tnhalomcthane'l.
Trophlc zone - The zone 111 the upper layer 01 the watcr III whlch photmYlllhc'll\ occurs.
Turbidity - A condItIon 111 water cau~cd by the prc'lcncc of 'lll~))(,:ndcd rllattcr
68
•
•
•
rnh .. dOlm:thane FormatIOn Putcntlal~ ln Lake Mcmphrcmagog
REFERENCES
ADIN, A., KATZHENDLER, 1., ALKASLASSY, D., & RAV-ACHA. C., 1991. Tnhalomcthane formal1on In chlonnatcd dnnking water: a kInetlc model. War. Res. 25:7'797-805.
AlKEN, G.R., MCKNIGHT, D.M., WERSHAW, R.L., & MACCARTHY, P., 1985. IntroductIOn ta humic substances, ln Iflllmc substances ;11 ~oil, sediment, and water: geodll'I111.\I1Y, isola/lOll, and c!wf(Jctenzation, cd: Alken, G.R., Mcknight, D.M., Wcr~haw. R.L., & Maccarthy, P., Wtlcy and Sons, New York, 1-12.
ALARCON-HERRERA, M.T., I3ISWAS, N., & BEWTRA, J.K., 1992. Seasonal vanatlon in hUlnlC ~ub~tancc~ and thclr reductlon through water treatment processes. ln proCCCdlllg~ of the 151h International symposium on wastewater treatment and 4th worbhop on dnnklllg water, AQTE/Env. Canada/ ... , Nov. 17-19, Montreal, Quebec.
AMY, G.L., COLLINS, M.R., KUO, C.1., & KING, P.H., 1987a. Comparing gel pcrmeation chromatography and ultratïltratton for the molecular welght characterization 01 aquatic orgamc mattcr. Jour. A WWA. 79: 1 :43-49 .
AMY, G.L., CHADIK, P.A., & CHOWDHURY, Z.K., 1987b. Developing models for predlctll1g tnha1ol11cthanc formatIOn potcntial and kinetlcs. Jour. A WWA. 79:7:89-97.
APHA, AWWA, & WPCF, 1989. Standard Methodsforrhe examination (?fwaters and \l'([S{('\', 171h cd.
ARGUELLO, M.D .. CHRISWELL, C.O., FRITZ, J.S., KISSINGER, L.D., LEE, K.W., RICHARD, J.1., & SVEC, H.J., 1979. Tnhalomethane in water: a report on the occurrence, seasonal vanation III concentratIOns, and precursors of trihalomethanes. Jour. A WWA. 7 t :9:504-508.
A YOTTE, P., 1987. Micropolluallls organiques: campagnes d'échanllllonnage 1986. Mil1l~tèrc de l'EnvIronnement (Québec). Dlrectlon des eaux souterraines et de consommation.
BABCOCK, D. B. & SINGER, P.C., 1979. Chlonnation and coagulation of humic and fulvlc aClds. ./ou/'. A WWA. 7 t: 3: 149 .
69
•
•
•
BATCHELOR, B .. FUSILIER. D .. & MURRA Y. EH. 1l}87 Dcvdoplllg h.\lofllrm formation potenttal tests. JO/II. A ~V\V:t. 79: 1 :50-55.
BELLAR, T.A., LICHTENBURG. J.1 .. & KRONER. R.C, Il.>74. The lh.'l·lIrIl·nœ ul organohalides m timshed drinkmg waters. Jour. A W\\t:"1. bb: 1 ~ 703-70b
BERGMAN, M. & PETERS. R.H .. 1980. A sImple retlcctant Illethod for llllW;lIn.·lHenl of particulate pigments in lake watcr and ilS appll\:ation 10 pho\ph.lte chllllllphvii ... l· ... lon relationships. Cano Jo li r. Fi.\heries & Aq. SCll'/1I'l' 37: 111-114.
BRILEY, K.F., WILLIAMS, R.F., LONGlEY. K.E .. & SORBERT. (' A, 14XO. Trihalomethane production from algal precursor'i. W(/fi'r CIJ/O/'l!Ill1101/: FI/\'Ilol/I//t'I/fal
Impact and Hea/Ill Eflècls, Vol. 3, cd: Jollcy, R.L.. Brllngs. W.A, ('U11\ 1l111lg, R B & Jacobs, V .A., Ann Arbor SCience, Ann Arbor, Mlch.
BRUCHET, A., TSUTSUMI, Y., DUGUET. J.P., & MALLEVIALLE. J. 19X·l Characterization of total halogcntaed compounds dunng vanoll<' \Val!~r 1 n:.\1I1\cnl processes. Wa/er Ch/orÎI1a/Îol/: EIIV//'Ol/me1llallmp{/cl (/I/(/ 1/('(//117 1:/k('I.\. Vol. 5. cd' Jolley, R.L., Bull, R.J., Davis, W.P., Katz, S., Roberts. M.H. Jr.. & Jacoh", V A , Lewis Publishers Ine.
COLLINS, M.R., AMY, G.L., & STEELINK, C.. 19H6. Molccul.lr wClghl distributIOn, carboxyhc aCldity, and humlc substances contcnt of aquatlc orgalllc malle!' implication for removal dunng water trcatment. Env. Sc!. &. 'l'l'ch 20. 10: 1028-10.\2
COOPER, W.J. & KAGANOWICZ, D.M., 1985. Novel prccur~or 01 tnhalomcthane ... in water chlorinatlOn. Warer Ch/orlna/lOn: Ellv/1'(m/1/cfllal Impact und 1 kalth Nlc('t.\. Vol. 5, ed: Jolley, R.L., Bull, RJ. DaVIS, W.P , KatI, S .. Rohert .... M Il Jr, & Jacobs, V. A., Lewis Publishcrs Ine.
DORE, M., MERLET, N., DE LAAT, J., & GOJCIION, 1., 1982 halogens wlth aqueous micropollutants: a IllCChanl"l11 for the trihalomethanes. Jour. AWWA. 74:2: 103-107.
I{eacllvlly 01 1 orlllal 1011 01
EDZWALD, J.K., BECKER, W.L., & WATTIER, K.L.. 1985. Slirrogatc p,lraJl1cter<, for monitoring orgal1lc matter and THM precllr~or<,. Jour. AWW/l 77 4.122 1 \2.
EL-REHAILI, A.M. & WEBER. W J., 1987 CorrelatIOn 01 hUlllIC ~lIb)tanœ
tnhalomethane fOl'matlon potentlal and ad':>orptIon behavlollr 10 lIlolecular wl:lght distribution In raw and che/nIeall y trcated water\. Wa/. Rl'\ 21. 5.57.1· ') X2
70
•
•
•
[nh.do.TlLlh 1I11.! Form..lllOn Potcnll..lh 111 L..Ikc Mcmphrl.!magog -------------------------_._------------=--.......;:.......::..-
I:N(il:rUjOLM. BA & AMY, G.L.. 1983. A predictive model for chloroform forlllation 1 Will hUllllC aCld . .four. A WWA. -"5:8.418-423.
j'L!)ORAK, JI M. & HUCK, PM., 1988. Mlcroblal metabolism of cyanobactenal product,>· batch culture ,>tUelIC'> \VIth applications to elrinking water treatment. WQr. Res. 22'10.1267-1277
HJLLY, P)) & MISSINCiHAM, (i.A, 1976. Monitoring of communIty water '\uppllc\ 10111 :1 WWA. 68'2: 105-111.
(iJESSIN(i. ET, 1976. PII\'I/('(1/ al/d chel171ca/ Chart1Cfenlf/CS of (U/LIOUC hUl1/us. Ann Arbor SClcnce, Alln Arbor, M:ch.
GLAZE, W If. & RA WLEY, R., 1979. A prehmlnary survcy of tnhalomethane levels 111 ,>dectcd E.l,>t Tcxa'i watcr \upphc'i . .four. A WWA. 71 :9:509-515.
GllldellllC\ for Callachan dnnl-..\Ilg watcr quahty, 1989. 4th ed., Health and Welfare ( '<in.Hla
HELLEBUST, J A.. 1974 Extraccllular products. In A/gal PhySlOlogy and [J{()C!Jl'IIIf.\rrV, cd: Stc\vart, W.D.P., Blackwcll SCI. Pub!., Oxford, 838-863.
HOEHN, R.C., BARNES, D B., THOMPSON, B.C., RANDALL, C.W., GRIZZARD. T.J., & SHAFFER, P. T.B., 1980. Aigae as sources of trihalomethane precursors. Jour, AWWA. 72:6:344-350.
HOEHN, R.C., DIXON, K.L.. MALONE, J.K., NOVAK, J.T., & RANDALL, C.W., 19H4. BJ010gically lIH.1l1ccd vanatlons In the nature and removablhty of THM precursors hy altlll1 trc.ltmcnl JOUl./lWWA. 76:4:134-141.
HOEHN, R.C., RANDALL. C.W., GOODE, R.P., & SHAFFER, P.T.B., 1978. Chlonnatloll and wat~r lrcalment for mmInl1zmg tnhalomethanes III drmking water. W(J{('I' ChlOf'/f/ll{IOf1. Emuof1I11('J1(a/lmpac{ {[f/(i Hca/r/z Effecrs, Vol. 2, cd: JoUey, R.L., Gorchcv, H., & HamIlton, D H. Jr, Ann Arbor Science, Ann Arbor, Mich.
JOHNSON, D.L .. 1971 SlInultancolis determ1l1atJOI1 of arsenate and phosphate. Env. Sd 1'1.'('h .5 : 41 1-4 14.
KARIMl, A.A. & SINGER, PC., 1991. Tnhalomcthane formatIOn in open reservoirs. Jour . . H\!WA XYJ:84-88 .
71
•
•
•
KOSENKO, L. V.. 1974 D'lIl)' \',matioll 111 the l'OIln.-Iltr,ltloll 01 l.'\tr,ll'dlul,u carbohydrates in a culture of 1I1111hal'l/ll \,(//whtll.\. 1/\'(/10"/11 ./0111 10:3 5~-5).
KRASNER, S.W., GRAMITH, J.T., f\tEENS. E.G., PATANIA, NI, NAJf\t. 1 N . AIETA, E.M., & MONTGOt\1ERY, J.M., IL)91. FormatIon and control OllllllJl\\I1ated ozone by-products. In procœdmgs of the 1991 A WW A Annual C'lm Il.'rl.'lll.'l.', J li Ill.' ~J 27. Philadelphia. PA.
MCGUIRE. M.l. & MEADOW, R G , 1988. A WW ARF tnh,liulllcth,lIll' 'lIl\'l'y )11//1.
AWWA. 81:1:61-68.
MORRIS, J .C. & BAUM, B., 1978 Precur~ors and IllCChaIlI'>Ill\ of h,lIolOl III formation
111 the chlorination of water ~upphc~. Woœr ChlOlIl/aflol/: EII\'/lol/II/('Ilfa/ fmpC/l'l IlIId Hea/rh Effecrs, Vol. 2, cd: Jolley, R.t., Gorchev. H .. & Hamilton. () Il Il . AI1I1
Arbor Science. AIlIl Arbor. Mlch.
MORROW, C.M. & MINEAR. R.A.. 1987. U~C or regrc~~loll 11lotk'j<., to 11111-- I.I\\'
water characteristlcs to trihalolllcthane coneen tratlon'i JJ1 d fi Il k mg \V .llL'r WOI Rf.' 21:1:41-48.
NALEWAJKO, C., DUNSTALL, T.G., & SHEAR, H., IY76 Kllletlc'iol l'xtr,lcdlul.lI release in axemc algac and in InIxed algal-bactenal culture.., "'lgIllIK\U1CC III l·..,tlllltltIOJl of total (gross) phytoplankton cxerctlon rates. )o/ll'l/u! 0/ PIJ\'c%,!!y, 1: l ')
NatIOnal Survey for Halomethanc~ ln Dnnk1!1g Water, 1977 1 kalth .1IId Wei l'arc Canada. 77-EHD-9.
OLIVER, B.G., 1980. Effeet of tcmpcratllrc, pH and broll1lde concentration Oll the tnhalomethane reaction of chlonnc wlth aqllatlc IHlIIlIC matcflal. Wa/a ClJlolllwnol/ Envlronmenral Impact and fll'al!h Elfecf.\·, Vol. 3, cd: Jolley, R. L , Brullg.." W.A , Cummmg, R.B., & Jacobs, v.A., Ann Arbor SClcnce, Ann Arhor, Micil
OLIVER, B.G., 1983. Dlhaloacctol1llnlc~ 111 dnnklllg water: algal: and 11IIvlc éllld a.., precursors. Env. Sei. & Tech. 17'2:80-83.
OLIVER, B.G. & LAWRENCE, J., 1979. Halolonn<, 111 drtnklng watt:r' a ..,tudy III
precursors and prceursor rcmoval Jour. Il WWA. 71 :3'161-163.
OLIVER, B.G. & SHINDLER, D.B, 1980. Tnhalomethanc<, l'rom tllc chlortll.ttlOJl of aquatlc algae. Env. 5C/. & Tech. 14: 12'1502-1505.
72
•
•
•
Tnh .. dolllcLlwrlc FormatIOn Potentl"" ln L"kc Mcmphrcmagog
OLlVLR, B (1. & THURMAN, E M., 1983. Influence of aquatlc humlc substance propertH!~ on InhalolllClhane potentlal. Water Ch/o,.,nallon: Envlronmemal Impact and lleu/tlI I:ï/l'C/I, Vol. 4, cd' Jollcy, R L., Brungs, W A., Cotruvo, J.A., CummIng, lUi, Malllcc, J .S., & Jacob~, V. A, Ann Arbor Science, Ann Arbor, Mich.
OLIVER, B (, & V JSSI:R, S. A., 1980 Chloroform productIon from the chlorinatlon ot aqu.ttlc hUIl11C matcnal. thc cffcct of molecular welght, environ ment and season. WUI. Rl'\. 14:1137-1141
IŒCKHOW, DA. & EDZWALD, J K., 1991. Bromoform and Iodoform formatIOn po!cntlal te"t" a" "lIrrogatc~ l'or THM formation pOlentlal. Jour. AWWA. 83:5:67-73.
RECKI-IOW, D.A & SINGER, p.e, 1990. Chlonnatlon by-products In drinking watcr\: l'rom fOrllMtlOIl protcntlab to tïnl~hed waler concentratIOns. Jour. A WWA. X2:4. 1 TJ- 1 7l)
ROOK, J.1., 1977. Chlonnatloll rcations of fulvlc aClds 111 natllral waters. Env. Sel. & Tech. II :5:47X-482.
ROOK, J.1., 1 \)80. PO~~lblc pathway~ for the formation of chlorinated degradation prodllct~ durmg chlonnatloll of hUll1lC aClds and resorcinol. Warer Ch/arma/ion: 1~1/I'lIol1lt/('l1ralll1/p(Jc( {{I/(I llea/th 4,{ecfs, Vol. 3, ed: Jol1cy, R.L., Brungs, W.A., C'1I11l1l1I11g, R.B., & Jacobs, V.A., Ann Arbor SClcnce, Ann Arbor, Mich.
ROSS, P. & KALFF, J, 1975. Phytoplankton productIon In Lake Memphremagog, QUl:hcc (Canada) - Vl:rmont (USA). Verh. lm. Ver. Lunnol. 19:760-769.
SAKEVICII. A.I , OSIPOV, L.f., & TSARENKO, V.M., 1979. The orgal11c matter 01 culture 1ll1:(lIa for bluc-green algac. lf.vdroblOi. Jour. 15:54-58.
SAKEVICH, A.I., OSIPOV, L.F., & TSARENKO, V.M., 1980. Daily variations In
lh~ content of cxtracellular orgalllc matter 111 a culture of blue-green algae and in natllral \\.Itcr dunng an .llgal b100111. lIyclrohlOl. JOllr. 16:2:75-80.
SAKEVICH. A.1. 8.: OSIPOV, L. F., 1983. Re1atlonshlp of growth rates of algal mass to conœntratlom of cxtraccllular orgalllc compounds. Hydrohiol. Jour. 19:5:41-44.
SCHNOOR, J L , NITZSCHKE. 1.L., LUCAS, R.D., & VEENSTRA, J.N., 1979. Tnhalollll:thane yldd" as a fUI1ctlOn of precursor molecular welght El/V. SCI. & Tech. 13:9: 1 U4-1 US .
73
•
•
•
SCULLY, F.E., HOWELL, G.D., KRAVITZ, R., & JE\\'EI.I., J.T .. 1l)~~. Proll:lIl., ln natural waters and thclr relatIOn lO the formation of ~hlllnllat~d l)rg.llll~" dUllng wilter dislnfectlon. Env. Sel. and Tcch. ~2:5:5J7-5~2.
SMITH, V.H., SHUTER, D., & CORDIS, P \V, A modllÏl'd IK'r,ulphatl' dlge,tloll method for total I11trogen ll1 lake~. Lill/nol. (~ ()(,{/Ilogr. (Ill pre.,~)
STEELINK, C., 1985. Elemcntal ~haracten~lI~~ of hllll1l~ :-'lIh~t lll'l':-', III 111111/1('
substances III !JO/l, .\edl/1/enr, and ware/': gcochel/ll\rr\' , I.\O/al/Oll, (/!lt! chti/(/('1l'II:/lrlOl/, ed: Alken, G.R., Mckl1lght, D.M., Wcrshaw, R.L., & ~1.1ccarthy, P , WlIey and Son" New York, 457-476.
STEVENS, A.A., SLOCUM, c.J , SEEGER, D.R , & ROBECK, (i.(I, 1l)7() Chlonnatlon of organics 111 dnnkll1g \Vater. 711l' En\'lf'OlIfl/Cllflil III/pl/('f 0/ \Va!('/'
Ch/OrinallOn, cd: R.L. Jolley. Proccedlllg<.; of the conl'crenœ h~ld ,It (),II-. Rldgl' National Laboratory, Oct. 22-24, 1974, O,lI-.. RIdge, Tl'Iln
STORCH, T.A. & SAUNDERS, G. W., 1978. Phytopl,lIlktOll l'xtraœllular rl'lea:-.c and its relation to the seasonal cycle of dl'i\olvcd organlc carbon \l1 a cutropluc I.II-.c 1./1111/01.
& Oceanogr. 23:112-119 .
SYMONS, J.M., BELLAR, T.A., CARSWELL, J.K., DEMARCO, J., KROPP, KI. ROBECK, G.G., SEEGER, D.R., SLOCUM, C.J., SMITH, B.L., & STI~VI~NS, A.A , 1975. National Orgamcs Reconnals)ancc Survey for Halog~llat~d 01 g,1I11l·'. /0/1/
A WWA. 67: 11:634.
THURMAN, E. & MALCOLM, R., 1981 Pr~paratlvc l..,olallol1 (lI <l411,IlIC hUllllC
substances. Env. Sel. Tech. 15:463-46/l
TREHY, M.L., YOST, R.A., & MILES, CJ., 198/l. ('lIlonllallol1 hyproduCI\ 01
ammo aClds m natural waters. l::nv Sel. & 'l'ccl/ 20' II' 1117 -1 122
TRUSSELL, R.R. & UMPHRES, M.D., 197X. The !Oflllà!lOIl of Inhalolllt:lhalll'" Jour. AWWA. 70:11:604-612.
URANO, K., WADA, H., & TAKEMASHA, T, 1983. EmplrtCal fdte cqudllOIl lor tnhalomethane formation wllh chlorinatlOn 01 hUITIIC \ub:-.tancc) III walcr W{/r. /(('.\ 17: 12: 1797-) 802.
U.S. EPA., 1979. NatIOnal Intenm pnmary dnnkrng waler reguI.IIIO/l.." cO/ltrol of tnhalomethanes in dnnklllg water; tinal rule. l'cd. Heg. 44, 211, (JH624 (Nov 2l))
74
•
•
•
1 nhJlon1Llh,iOC rormdllOn PolcnllJb III Ldke Mcrnphremagog
VAN STI:ENDI:REN, RA, PIETERSE, M.l., & BOURNE, D., 1991. THM formation 111 potable water\ wlth refcrcncc to rclatcd vanables and heaIth data bases. Wl/(l'r SA, 17 4' 269-272
VAN STEENDEREN, RA, SeOTr. W.E., & WELCH, D.I., 1988. MicrocysrÎCs (/{'I/Igu/(}\{/ a\ an organohalogcn precur\or. Waler SA, 14:1:59-62.
VEENSTRA, J N & SCHNOOR. J.L.. 1980. Seasonal vanations 10 trihalomethane kveh 11l an Iowa river water ~lIpply. Jour. A WWA. 72: 10:583-590.
WACHTER, J K. & ANDr.LMAN, J.B., 1985. Nonpurgeable organohalide formatIon on chlorIn,ltIO!l of algal cxtraœlllllar matcnal. Warer Chlorinallon: Env/ronmenral IIIl/wcl (lIIdl/('o/,1l Nj'('CI.\, Vol 5, cd: Jolley, R.L., Bull, R.J., DavIs, \V.P., Katz, S., /{o!>crh, M.II. Jr., & Jacob\. V.A, LcwI~ PublI~hers Ine.
WATANABl:, Y.. 1980. A ~tlldy ut the excretlon and cxtraccllular produets of natural phytoplankton Ifl Lake Nakanuma, Japan. Imernll(uJf1a! Revue der Gesanren IIwJrohlO/O,l!,/(' , (Bcrllll) 65:6:809-H34
WATSON, S., 1979. Phytoplankton dynarTIlcs In Lake Memphrcmagog and thelr rclatI01l\hips to tropluc 'itatc. McCilll UlllVerSlty Master's thesls.
WILLIAMS, )) l'.. OTSON, R., BOTHWELL, P.D., MURPHY, K.L., & ROBERTSON, LI.., 1980. Tnhalomethane levels in Canadlan drinking water. lnr. SV#1/p. on /Jw!w('(/rhol/\ (ll/d !Ja/ogclI(I{cd lIydrocarhon.\ lIT rhe Aquanc En Vlronmem. cd' Afghan, B.K. & Mackay, )), Plenum Pre'is, N.Y .
75
•
APPENDIX A
•
• 76
•
• ...~----V€..,..oMT
• Al
Lake Memphremagog Project Limnology Research Group Dept. of Blology McGIII University Quebec, Canada
figure 1. Sampling sites on
Lake ~1ernphremagog
• 700
600 -f--------------.---- -- ------- ---- ------
500 "C Q) (il -ttI "0 400 ... c: C) ttI Q) CI) -5; ::1
0 ttI .I:: 300
+--------------~_.!-_-------- -----
+------------------------ - -- ----Q) t::. ... « r=O 99992
200 +---------:.y-' -----------------------
/
100 +---,------------------------ ---, f
0 1 i f
0 50 100 150 200 250 300 CHCI3 concentration [JJg/L]
Figure 2. Calibration curve for the analysis of THMFP
•
• /\2
•
APPENDIX B
•
•
• 320 , 300
280
260 ::::ï -- 240 Cl 2. a. 220 u. :E 200 J: 1-
180
160
1\ ._--- -- - ---- - -----
- .-
f \ -----
f \ ----- --------~
! \ - ------/ \.\
--r \ --\--~/ --~~-; ..
140 1 ~/ + .. -- -----1-
1
120 1607 1808 2309 1505 0506 2606 2307
1990 Sampllng date 1991
1- nonflltered + •••• hltered J Figure 3. Seasonal vanatlon of THMFP at Pen der '>Ite
• 300
280
260
240 ::ï --C')
220 .3-0-U. 200 :E :r 1-
180
160
140
A ---
1\ ---- ---- - -
1 \ ---- ------
1 \ - - ---~-
1 \ -------
1 1. \ \
1 \\ .-. / 'r----
\
J...... \ ~ - 1 "'\::::=:: --- -1
.. r----\ j -------~- -
t
l ,
120 1607 1808 2309 1505 0506 2606 2307
1990 Sampllng date 1991
I--+- nonhltered .. flltered~
• Figure 4. Seasonal vanatlon of THMFP at Indlan ~ltc
BI
• 190
180
170
160
....J 150 r::Jl 2- 140 a. lL. 130 :: l
120 ~
A 1\ ;\
~\-~ \/ / \ /1 \ --\ 1 V
,
/ ) ~ ..d
\ 1 ,..- V l
\/ 1 .. t.
Y 1 1
110
100 ---1--
90 - 1
HO L.
1607 1808 2309 1505 0506 2606 2307 1990 Sampllng date 1991
I-+- nonflltered -+ • flltered
FIgure 5. Sea~()nal vanatlOn of THMFP al Border SIte
• 170
160
150
::::::ï -0, 140 3-Q.
, u. :! 130 l ~
1",-'" ~ "
120
110
100 1607 1808 2309 1505 0506 2606 2307
1990 Samplmg date 1991
I-+- nonflltered .-+.. filtered
• Figure 6. Seasonal \ anatIon of THMFP at Central site
B2
• 200
190
180
::::J 170 ê;; 2-Q. 160 LL ::iE J: 150 .....
140
130
-----
/\ ----
7\ -
7 '\ " l~ ~L / \
,j .
/ r -
/ f •••••••
1 • 1 +
120 1607 1808 2309 1505 0506 2606 2307
1990 Samphng date 1991
j-t-- nonfiltered . -t •• - flltered
• Figure 7 _ Seasonal vanatlOn of THMFP al North ~llC
• B3
•
•
•
280
260
240
-.J 220 en 2-(L. 200 LL ~ l 180 1-
160
140 -
120
Figure H
350
300
;ï' 250 en
.3. (L. LL :E 200 l 1-
150
100
!" / , ,
• /
1 ..
--- ~ . -...., '-------= .....
~ ~-" ~
// J(/ ...
i i i i -07/90 08/90 09/90 05/91 06/91 07/91
month/year
--- Pender "Indian -.- Border
--- Central - North
Monthly averagcs or unfiItered THMFP at ail sites
~.
\ \
\. ~ ~-
~ ~~ ..... --==-
08/90 09/90 05/91 month/year
06/91
--- Pender .. _.- Indian -.- Border
--- Central -- North
07/91
Figure 9. ~lonthly avcragcs of filtered THMFP at ail sites
13-+
• 170
160 ~r--------=.---------------~~~--f~~---------
150
::r --Cl 140 3.
--j +---I-++--------+-~'--__\\_,o'---.-L----- i
a.. u.. ::E 130 J: 1-
120 ------1------------------
110 +----------_._---+-------------- - . _.-
100~r_~-~--~~--~-~~--~--~~-_r_~1--·~ 16070208180804092309 15052705050615062606100723072208
1 990 Samphng date 1991
I-.-sm 10m -+- lSm - 20m
Figure 10. Seasonal VariatIon of untiltcrcd THMFP al Central 'Ile (at ·l d~plh..,)
• 150
140 +----..,.,..--------+-----'1:---------------
130 +------*-------------~~---~------------. :::J --Cl 3. a.. 120 u.. ::E J: 1-
110
100 +---------\-----------_ ..... _--_ .. __ ..... __ .. -
90~r-~--.-_r--~--~--r_-~1---.,--~,---.--_r--~
0208 1808 0409 2309 1505 2705 0.506 1 506 2606 1 007 2307 2208 1990 Samphng date 1991
l...tIrsm --- - 10 m -+- 15 m - 20 m
• Figure Il. Seasonal variatIOn of filtercd THMl·P at ('t:ntral \Ilc (;tl l clepth\)
135
•
APPENDIX C
•
• -- ---- -------
•
•
•
:::J r.:n ,.. c: ()
0 1-
13 -
12
11
10
9
e
7
6
1
1---- /\ __ R ___
/ \ -~_J \ •
.~ ~ \~
- 1
1 ~ \ A 1
~~_,7\~ ~
1---- -- - - \----' -'
,.-' 5
1607 1808 2309 1505 0506 2606 1 ~91
2307 1990 Sampllng date
1-- nOi1f1tt THM - TOC __ --1
320
300
280
260 ~
240 en .3. a.
220 ~ J:
200 1-
180
160
140
Figure 12. Sea~onal vanallon of TOC and ~Intïltered THMFP at Pen der site
:J --~
Cl .s ü 0 a
95 r-------
9
85 --<--
8
75
7
65
6
55
5
45 1607
~
1
\ \ \
- \ ~ -
\ \ \ \
1 1 1
1808 2309 1990
-T
:
.i----:...
,,~.::/ ~
1 1 1
1505 0506 Sampllng d~te
I-+- filt, THM _. DOC
T '\ ' \
\
....--
2606 1991
:
"1 _ ... -2307
320
300
280
260
240 :J -Cl 2-
220 a. u.
200 :E J: 1-
180
160
140
120
FIgure 13. Seasonal vanallon of DOC and tiltered THMFP at Pender slte
Cl
•
•
•
12
11
10
:J 9 -.. en E 8 ()
0 ..... 7
6
5
4
~-------------------------------------------~JOO
+--------ft-------------------------------- 280
+----1-+-------------------------- 260
+-----+--1-------------------4------------ 240 :::::J rn 3.
+------f--t----------------.....---------- ~O li. u..
+-__ +-----'"-+-____________ 0--____ - --- -- 200 i!=
~
+---~--+-----------------__I_--\-----'o- -- --- 1 HO
+----t--~~:...----------::.=. __ ---- --- -- - ~-- -1 GO _-------. ......--
...L.-..i----,.----r-----r---,---.,..----""T"--...,- -....,,--~--~, -~~f--~-L 140 1607 1808 2309 1505 0506 2606 2307
1990 Sampling date 1 991
1 ~ nonfltt THM - TOC
Figure 14. Seasonal vanallon ot TOC ,1I1d 111ltïltereu THt\II'P ,II Indl.tll '.Ill'
::J' --en .§.. () 0 0
14
13
12
11
10
9
8 -7
6
5
4 1607
'.
~
\
\ \ \
- \ \ 1
1808 2309 1990
~
f--.
/ 7
\ / \.j -
Y..
1505 0506 Sampling date
"\
\
-
\.
2606 1991
I-+- tilt THM - DO~J
190
--180
-
--- 170
------- -~ 160
-- --
150 ------
- )
',7 140
--130
120 2307
Figure 15. Seasonal vanatlon of DOC and tïltcrcd THMFP al Jndlitn )Ite
C2
::::; r:n 2-li. u... ::! I .....
•
•
•
11 -
10
9
...J 8 al
E 0
7 0 f-
6
5
4 1607 1808 2309
1990
/ ,
(
1505 0506 Sampllng date
E- nonfllt THM - TOC
2606 1991
2307
190
180
170
160 :::ï Ôl 2-
150 a.. LI.. ~
140 l f-
130
120
110
FIgure 16 Seasonal variation of TOC and untiltered THMFP at Border site
:::ï al E -0 0 0
85
8
75
7
65
6
55
5
45
4 1607
-
... A
~ /\ 1 \ 1 \
, 1 1
-T-
j 1
1808 2309 1990
- ~ ~ ....
:
:
-
1505 0506 Sampllng date
1--- fitt.THM -- DOC
>-
.~
~
-
2606 1991
-
'1
---"-
2307
150
140
130
120
110
100
90
80
Figure 17. Scasonal variatIon of DOC and tiltered THMFP at Border site
C3
:::ï --Cl ..3. a.. LI.. ~ l 1-
•
•
•
12 170
11 ---- 165
10 160
9 ::ï :r -- 155 O'l Cl) 2-E 8 a..
Ü li.
0 150 :! 1- 7 ------- - -- I
1-
6 145
l . 5 ~------ 140
4 1 ~15 1607 1808 2309 1505 0506 2606 2307
1990 Samplmg date 1991
I-+- nonfllt THM - TOC
Figure 18. Seasonal vanatIon of TOC and untïltered THMFP al ('cntral '.lle
:r --CI
.s 0 0 0
12
11
10
9
8
7 \
6
5
4 1607
.i..
-A
- 1\ A
1 \! 1 \ i 1 y
.'\ ~ -:'
/ \ "
...;..
\ \
1808 2309 1505 0506 1990 Samphng date
1-- filt THM - DOC
\ \ \ ,~
2606 1991
-
--
-
-
--
-
2307
150
145
140
135 ::ï
130 O'l
.3.. a..
125 li. :! I 1-
120
115
110
105
Figure 19. Seasonal vanatIon uf DOC and fïltcrcd THMFP at Central ~Jlc
C4
•
•
•
::::J 01 E
ü 0 ~
13
12
11
~O
f)
8
7
-6
S --
4 1607
~
/
(
200 -
A 190
/ \ 180
/ \ :'~/ ~ \
170 ::::J --01 .3-
160 a. u..
1 1 \/ .J ::E
150 J: ~
/ v 140
,1 / ..::.. ....
( 130
--'
120 1 808 2309 1505 0506 2606 2307
1990 Sampllng date 1991
1-- nonfllt THM _ .. TOC
Figure 20. Seasonal vanatIon of TOC and untiltercd THMFP at North sIte
12
11
10
::::J 9 è; E 8
ü 0 0 7
6 -5
-4
1607
-
:...
..-
1808 2309 1990
-A..
/\ / \
/ \ / \
/ .' .'~' ~
f - ~. ~
1505 Sampllng date
0506 2606 1991
1-- fllt THM _.. DOC
160
155
150
145
140
135
130 ~
125 .... 120
2307
Figure 21. Seasonal vanatlon of DOC and tiltered THMFP at North site
CS
::::J --Cl .3-0-u.. ::E J: ~
• 13
12
11
::::J 10 --en .§. 9 ü 0 Cl 8 --Ü 0
7 f-
6
t \ -
\ '\ ~\ \ \ .~ \ ----
L \ ---
'/\ \1 \ -'f \, 1 ••
~~ ....
320
300
280
260 ::::J
240 Cl)
2. a.
220 u.. ::! I
200 f-
180 1
5 '\r' --.. - 160 /~
4 :;....----. ' ..
140 05/9006/9007/9008/9009/90 05/91 06/91 07/91 08/91 09/91
rnonttllyear
1 ~ tlltTHM - unfllt THM -+- TOC i DOC
Figure 22. Monthly averagcs of TOC/DOC and THMFP .Il l'enlier "'Ite
• 11 240
'ïJ 230 10
.. : ., 220 \
9 210 ::J 200 -- ::J en .§. 8 ---- en
U 190 2-
0 0-180 u..
Cl 7 :! --U ::c 0 170 f-I-
6 160
150 5 è
140
4 130 05/9006/9007/9008/9009/90 05/91 06/91 07/91 08/91 09/91
rnonth/year
1 = tilt THM ,~ .. unfltt THM -+-- TOC i DOC
• Figure 23. Monthly averagcs of TOC/DOC and THMFP al IlI(l!an 'lIte
C6
• 11 180
la 170
9 ~7 160 Ol ::::ï E --B Cl
0 .3-
150 0.. 0 LI.. 0 7 ----- ::E 0 k 0 140
l-I--
6 ----
'5 ---- 130
4 120 05/90 06/90 07/90 08/90 09/90 05/91 06/91 07/91 08/91 09/91
month/year
1-- fIIt THM ... unfllt THM -+- TOC +---DOC ~
FIgure 24 Monthly avcragl!~ of TOC/DOC and THMFP at Border ~lte
• 9 165
85 160
8 155
150
145 ::::ï ---Cl 3.
140 0.. LI..
135 ~
:::J 75 èn E 7 -
0 0 Q 65 --0
1-
130 0
6 1-
55 125
5 120
45~~--~--~--r---r---r-~r---r-~~~--~~ 115 05/90 06/90 07/9008/90 09/90 05/91 06/91 07/91 08/91 09/91
month/year
I--'-+-- 111t. T ... .~-- unfllt.THM ----+- TOC ---+-- DOC
• FIgure 25 _ ~Ion' i THMFP
C7
• 13 170
12 Hi5
11 ------ 160
::J 10 155
-- ::J Cl 150 E ,- Cl - 9 ------- .3-Ü 145 Cl. 0 LI.. 0 8 ---._- :! -- 140 Ü I 0 7
l-I-
1:35
6 ~
t-- - 130
5 - l')e: ... ;J
4 -,- 120 05/9006/9007/9008/9009/90 05/91 Oti/91 07/91 08/91 mm1
ITlonth/yem
1-,,;- tilt THM • unfllt THM -+-- TOC t DOC~
Figure 26. Montilly avcrages of TOC/DOC .1l1e1 TIll\lFP .11 North "IlL'
• 13
12
11 +---------------.-+---------------
10 +--------------~'t--'t.------------ -::J --Cl 9 oS
+----------------\--\'I--;r---- ---- -----
ü B 0 1-
+------._-oc:=!!!L------...... "---r'l'r-...lo,- --------- ---
\ 7
6
+----:?~--_7"'-'----------p~,----'r-, ---- ------ ----
-'-\ "" '~"--T--
5 +--------------------~7'-~-- --l
4 ~~----~---~----~--~---.---.----~~ 07/90 08/90 09/90 05/91 06/91 07/91 08/91
month/year
~ Pen der Indlan -.- Border
-+- Central - North
• Figure 27. Monthly averages of TOC al ail 'lite., (untiltcred)
C8
----------~---- -----
•
APPENDIX D
•
•
1 1
• 14 320 .. 300
12 ------- -<1---280
10 260
::::J 240 3' -- en en .3. 3- 8 220 a.. ra li..
1: 200
:::! C,) l
6 1-
A,-- 180
4 11)0
~ , t 140
2 i i i f i j i 1 i 1 l' t' 1 20 1805 0806 1607 1808 2309 1505 0506 2606 ~307 (]{)09
1 990 Sampllng date 1 991
1~-+-____ n_o_n_fl_He_r_e_d __ i ___ fl_He_r_e_d ____ ,. __ -__ C_,h_l_a ____ ~
Figure 28. Seasonal vanatlon of chi a and THMFP al l'ender ,Ile
• 10 300
9 280 -----
8 i 260
240 :r ":J --. 7 ----,
220 r:n
Cl 2. 2. a.. ra 200 IL
1: 6 1
~ ----+---C,) l
1-180
5 1G0
4 1 140 . Jo
3 120 1805 0806 1607 1808 2309 1505 0506 2606 2307 0609
1990 Sampllng date 1991
I-+- nonflHered of·· flHered ........ chla
• Figure 29. Seasonal vanation of chi a and THMFP al Indlan 'Ille
Dl
-----~
• g 190
180 8
170
7 ---- 160
, 150 ::J ...J & ---b ------ 0) 01 .L 140 .3. 3. r ----- a. !li 130 u.. :c ') ----- :E u ::r:
120 f-
4 - 110
100 :3
90
2 80 1805 0806 1 fi07 1808 2309 1 505 0506 2606 2307 0609
1990 Sampllng date 1991
I-+- nonflltered .. - flltered -â- chia
Figure 30 S,'a,,>onal vanatIon of chi a and THMFP al Border ~lle
• 10 170
9 160
8 150
::J 7
en .3. 6 tU
:::J --140 0)
2. a. u.
:c 130 :E u 5 ::r:
f-
4 120
3 110
2 100 1805 0806 1607 1808 2309 1505 0506 2606 2307 0609
1 990 Sampilng date 1991
I--+- nonflltered .. - flltered -â- chI a
• Figure 31. Seasonal v,matIon of chI a and THMFP al Central site
D2
•
•
•
::J ---Cl .3.
t'CI
::2 (.J
65
6
55
5
45
4
35
3
2.5
2
--- --- --- + ---
r +--------"-----'1-+-..:.........--------- -- - -1-,.. -
1
..?OO
190
·180
170
H;O
1')0
140
130
1 5 .......,-,..---,.--,----,r--.--r---r--.,.---r----r-,.--,----r--,--r---r---r-L 1 20 1805 0806 1607 1808 2309 1 SOE OSOG 2GO{i ~:J07 O[i09
1990 Samplmg date 1991
1-- nonflltered ~ flltered -.- chia ~
Figure 32. Seasonal vanatlon ot chI a and rHMI'p al North ,>lIl'
::r ---Cl ..3. t'CI
:2 (.J
14
12
10
8
6
4
2 +-----~-----~----------------------- . --0
1805 0806 1607 1808 2309 1505 1990 Sampllng date
0506 260fj
1991
-e- Pender -+- Indlan ... Border
-+- Central - North
2307 (Jfj09
Figure 33. Seasonal vanatlon of chI a lor aIl \llC\
D3
-l
Dl d. a... u.. ::! I 1-
-------------- ---
•
APPENDIX E
•
•
• 40 320
300
35 280
260
30 240 ::::ï :J' en -- .3. en .3. 220 a.. Il.. u...
:! ~ 25 200 I t-
-180
20 -------- 160 /
140
15 120 1805 0806 1607 1808 2309 1505 0506 2606 2307 U609
1990 Samplrng date 1991
1-- nonflltered .. --- flltered --.- TP
Figure 34. Seasonal variation of TP and TH M Fr al Pender \lIe
• 24 300
280 22
260
20 240 ::::ï
::::ï èn 0, .3. .3. 18 a..
u. a. :E l-I
16 t-
160 14
140 1
12 120 1805 0806 1607 1808 2309 1505 0506 2606 2307 0609
1990 Sampllng date 1991
1-- nonflltered ~ - flltered --.- TP
• Figure 35. Seasonal vanation of TP and THMFP al Indlan \!lc
El
•
•
•
::::J en 2. a..
28~------------------------------------------~
26+-----#--------+~--------------._----------_f
24+---~'~------~~------------_r~----------_;
190
180
170
160
150 ::; --en 140 .3.
a.. 130 LI..
1- 16 ::E J:
120 1-
14+----+-110
12 100
10~-------------~~--------------------------~ 90
8 ~ 00 1805 0806 1607 1808 2309 1 505 0506 2606 2307 0609
1990 Sampllr.g date 1991
I--+--- nonflltered ... Mere i
Figure 36. Seasonal vanation of TP and THMFP at Border slte
:::i --en .3. a. 1-
24 ~---------- --------------------~--------~170
22
.20
18
16
14
160
150
:::i --140 en .3. a.. I.L
130 :E J: 1-
\ ....... , 120 +-----*-----------------------------~~~~~
/ 12
10 +-______ ~~~~~~+_--------------------~~110
8 100 1805 0806 1 607 1808 2309 1 505 0506 2606 2307 0609
1990 Samphng date 1991
I--+--- nonflhered .... flltered AIIr- TP
Figure 37. Seasonal variatIOn of TP and THMFP at Central site
E2
•
•
•
22 200 ~
\
20 190
18 180
16 170 ::J --Cl .3- 14 160 a. 1-
12 1fiO
la • 140 ---,
8 1
130 ----
6 120 1805 0806 1607 1808 2309 150b 0506 2606 2307 0609
1990 Sampl!ng date 1991
1 ~ nonfiltered .-+ flltered ......-TP
Figure 38. Seasonal variation of TP and THMFP al North ... \te
40~------------------------------------------------~
35+---------------------------------------~~----~
30+---------------------------------------~--~--~
~ 25+-----~r_------------------------------~-----+---~ Cl .3-~ 20t-~~~~~~~----.-------~~~~--~~--·~~_1
--10+-----~~~~=F==-r----------------------~~ ' ...... --
5~~--~--_r--_,--_,--~,_--r_--._--_r--_r--_,~
05/90 06/90 07/90 08/90 09/90 05/91 06/91 07/91 08/91 09/91 month/year
~ Pender ... Indlan ......- Border
--+- Central --- North
Figure 39. Monthly averages of TP for ail ~itcs
E3
::J 0'1 2-G-U-:.! l 1-
•
APPENDIX F
•
•
• 700 320
650 300
f 280 600
260
550 240 ::::J
:J' \ CIl
ÔI 2-2- 500 220 Cl..
Z u. ~ 200
:! 450 I
~
180 400
.--i 160
350 ~ 140 4
300 120 1805 0806 1607 1808 2309 1505 0506 2606 2307 0609
1990 Samphng date 1991
I-+- nonflltered +.. flltered
Figure 40. Seasonal vanatIon of TN and THMFP al Pender \lIe
• 650 300
600 280
260 550
240 ::::J
:J 500 en -- 220 3. 0)
.3. Cl..
Z 200 u.
450 :::! ~ I ~
180 400
160
350 140
"1
300 120 1805 0806 1607 1808 2309 1505 0506 2606 2307 0609
1990 Samphng date 1991
, -+- nonflltered + .. flltered ....... TN
• Figure 41. Seasonal vanatlOn of TN and l'HM FP al Indlan \Ile
FI
• 750 190
700 180
650 170
600 160
150 :1 :1 550 --- c; al T
140 2. 2- 500 Cl.
Z .( 130 u. ...... , ~ 1- 450 ~--- l .... l 120 1-
400 110
350 100
300 -- 90
250 80 1805 0806 1607 1808 2309 1505 0506 2606 2307 0609
1990 Samplrng date 1991
I-+- nonflltered +. flltered -Jllk-TN
FIgure 42. Scasonal vanatlOn of TN and THMFP at Border site
• 550 170
500 160
150 450
:::J :1 '-140 C) -- .3-C)
2. 400 Cl.
Z u. 130 ~ l- l
350 1-
120
300 110
250 100 1805 0806 1607 1808 2309 1505 0506 2606 2307 0609
1 990 Sampllng date 1991
I-+- nonflltered + •• - flltered -Jllk-TN
• Figure 43. Sea~onal \'anatton of TN and THMFP at Central site
F2
• 600 200
550 190
500 180
450 170 :J ::::ï al -- .3.. al 3. 400 160 a.. Z u.. t- :!
350 150 I 1 t-
1 ....
300 140
250 130 t -1
200 120 1805 0806 1607 1808 2309 1505 0506 2606 2307 0609
1990 Sampllng date 1991
1 ~ nonflltered • flltered -.- TN
Figure 44. Seasonal vanatlon of TN and THMFP al Norlh "Ile
• 700
650
600
550
::::ï 500 --Cl 3- 450 z t- 400
350
300
250
200 05/90 06/90 07/90 08/90 09/90 05/91 06/91 07/91 08/91 09/91
month/year
~ Pender - Indian -.- Border
-+- Central - North
• Figure 45. Monthly averages of TN for ail )ltc~
F3
•
APPENDIX G
•
•
• 35~--------------------------------------------~ 320 ~
\
\ 300
\ 30+---------~--~4_----------------~~------_+ 280
260
25+-~~--~~~--~~--------------------~---+ 240 ::.J 1 Cl
1 2-
/ 220 CL lL.
200 :! l
0..
Z 20+---~--+__+------~~---A----------------~-~
t-
180
15+-----~------------~----- 160
140
10 120 1805 0806 1607 1808 2309 1 505 0506 2606 2307 0609
1 990 Sampllng date 1 991
1---- nonfrltered + filtered- -â- N P
Figure 46. Seasonal vanation of the N:P ratio and THMf-Jl al Pender "'Ite
• 45 300
280 40
260
35 240 ::.J
220 rj)
CL 2-Z 30 0..
200 ~ l t-
25 180 , , .. 160
20 140
l'
15 120 1805 0806 1607 1808 2309 1505 0506 2606 2307 0609
1990 Sampllng date 1991
1---- nonflltered ...... flltered -â- NP
• Figure 47. Seasonal vanatlon of the N' P ratio and THMFP al lndmn ... Ile
Gl
•
•
•
a.. Z
50 ~----------------------------------------~190
45 ~ __________ ~M-____________ ~ __________ ~180
40 170
160
T-~------~r-~~~------~~~r-~--------~150 ~ 35
30
25
20
15
Ôl 140 2.
~~---------+J~~~----~----~----~~----~ a.. 130 ~
t---~------~~~--~--------------~~~~~120 ~
+-__ ~ __ -+ ______________________________ ~110 100
r----t~----~~----------------------~ 90
10 1805 0806 ~~~~--r-r-r-~~.-.-~-.-.~~~~~~80
1607 1 808 2309 1505 0506 2606 2307 0609 1990 Samplmg date 1991
I-+- nonflltered +" filtered -:*- N"P
Figure 48. Seasorml vanatIOn of the N:P rallo and THMFP at Border sIte
45~----------------------------·~--------~170
40~ ________ +-__ ~~~ ____ ~L-~~~ ______ ~160
25+---------------~----~~--~~------~ l ....... , 120
20r----------------------~--------------~ 110
15 1805 0806 1607 1808 2309 1505 0506 2606 2307 0609100
1990 Samphng date 1991
I-+- nonflltered . + •• - iiltered .....- N:P
Figure 49. Seasonal variation of the N:P ratio and THMFP at Central site
G2
•
•
•
45 200
40 190
35 180
170 30
a. Z 160
25 150
20 140
15 130 ...... ' ., 10 120
1805 0806 1607 1808 2309 1505 0506 2606 2307 0609 1990 Sampllng date 1991
I-+- nonflltered .... flltered -â- NP
Figure 50. Seasonal varIatIon of the N'P ratIo and THMFP .H North \lle
40~---------------------------------------------~
35+-~-----7----~----~----------~~--~------"~
20+---'~~~~----------------~~--------~~~~~
15+-----~-----------------------------------~----~
10'~~--~--~--~---.----.---r---~--.----r--~~ 05/90 06/90 07/90 08/90 09/90 05/91 06/91 07/91 08/91 09/91
month/year
___ Pender . -- Indian ....... Border
-+- Central - North
Figure 51. Monthly averages of N:P ratIo for ail ~Ite~
G3
::J en .3. Cl.. u. :! I t-
•
APPENDJX H
•
•
•
•
•
J: a.
8.5
N 8
~ 75 ----~~-
7
65+-------------------------------~~~----~---__4
1: .L.
6~_r----,_----~--~----_r----~----._----._--_.~
1805 0806 1607 Samphng date
1808
--- Pender - Indlan - Border ......... Central - North
2309
Figure 52. Seasonal varIatIon of pH al ail ~lles ( 1990 only)
65~----~--------------._-----------------------_,
M 60 0 () ra ()
tJ) 55 7 ra
...J --Cl ... É.. • .~
50
:3 ,ij .x • ;( 45
+
40 1805 0806 1607 1808 2309 1505 0506 2606 2307
1990 Sampllng date 1991
--- Pender ---+- Indlan -~.- Border
-...... Central --- North
Figure 53. Seasonal varIation of alkalmlty al ail ')ItC~
Hl
•
•
•
G6 320 ....
G4 300
62 280 M 0 60 260 () (1]
() 58 240 UI
(1]
.-J OJ 56 220 E - 54 200 ~ ::
52 180 Iii .x ~ 50 160
48 V ~ ···i 140
46 120 1805 0806 1607 1808 2309 1505 0506 2606 2307
1990 Samphng date 1991
1-- nonflltered ~ .. filtered ......... alkalinity
Figure 54. Scasonal vanatIon of alkailmty and THMFP at Pender site
7~------------------------------------------------~
6+-------------------------------------------------~
5+-------------------------------------------------~
::::i' ~ 4+---------------------------------------~--------~ E UI
~ 3+---------------------~~------------~--~------~ (5 en
2+-----------~~~~~~------------~~~------~~
0806
+
1607 1808 2309 1 505 1 990 Samphng date
0506 2606 1991
--- Pender -- Indian -= Border t···· Central _.. North
FIgure 55. Seasoanl \'analton of suspended soltds for ail sites
H2
2307
:::J --m .3-a. u. ::E J: 1-
•
•
•
7
6
5
S-I--~ 4
~ "0
3 :ë ... ::::1
1--
2
0 1805
Figure 56.
3
2.8
2.6
2.4
:J" 2.2 --0)
§. 2
CI)
:2 '0 1 8 (J)
1.6
1.4
1.2
1 1805
-----
•
• l
... T
0806 1607 1808 2309 1505 0506 2606 1990 Sampllng date 1991
--- Pender ~ Indlan - Border
-t ••• Central - North
Seasonal variatIOn of turbldlty for ail '>Ites
0806 1607 1808 2309 1505 1990 Sampllng date
0506 2606 2307 1991
1 ..... susp.sohds -- turbldlty
2307
55
5
45
4
35
2
1 5
1
05
Figure 57. Seasonal vanation of ~ohds and turbldny at Pcndcr '>1 te
H3
:::l 1--Z -~ "0 B :5
1--
•
•
•
35
3
25 ::J" OI E - 2 VI "Q ëi CI)
1 5
Figure 58 .
2.6
2.4
2.2
2 :r --en 1.8 É.. VI :2 1 6 ë CI)
1 4
1 2
0
1607 1808 2309 1505 1 990 Samphng date
0506 2606 2307 1991
1 ........ susp.solids ~ turbidity
Seasonal variation of sohds and turbidity at Indian site
0806 1607 1808 2309 1505 1990 Samphng date
0506 2606 2307 1991
1 ........ susp.solids -,3- turbidity
Figure 59. Seasonal vanation of solids and turbidity at Border site
H4
6
5
4 5' t-~
3 .~ "0 :a "'-::1
2 t-
1
6
5
4 5' .... ~
3 ~ 0 :a "'-::1
2 ....
• 3.5 6
3 5
2.5 4 _
::r ::J -- 1-al Z .§. -(/1 2 3 ~ :g 1)
ë5 .0 en :;
1.5 1-
/
0.5 0 1805 0806 1607 1808 2309 1505 0506 2606 2307
1990 Samphng date 1991
1-... susp.sohds ~ turbldlty
Figure 60. Seasonal variatlon of solids and turbldlty al Central sile
• 7 7
6 6
5 5
::r -- 4 C)
§. VI :2 3 ë5 en
::J 1-
4 Z ~
~ 1)
3 .0 :; 1-
2 2
1
o 0 1805 0806 1607 1808 2309 1 505 0506 2606 2307
1990 Sampllng date 1 991
/-..... susp.sohds - turbidrty
• Figure 61. Seasonal varIation of sohds and turbldity al North 'lIte
H5
•
APPENDIX 1
•
•
• 4 320
300
3.5 280
". 260 AL :J 3 240 Ë 01 - 2..
.c. 220 0-iS. ". u. Cl) ::: "0 2.5 200 l
t-
180
2 /~
160 ~/ .....
140
1 5 120 1 805 0806 1607 1808 2309 1 505 0506 2606 2307 0609
1990 Sampllng date 1991
I-+- nonflltered f .. • flltered --.- depth
Figure 62. Seasonal vanatlon of ~ecchl deplh and TH M FP al l'entier \Ile
• 4~--------------------------------~~----~ 300
280
3.5+----+~------~--------r_------_*----~--~ 260
240 :J
220 01 2.. Ë --0-
200 u. ::: l
.c. a. Cl)
"0 2.5+-~~----~+-~~~--------------~~---------~ t-
180
2+------------r~~+-------~--~--~ __ r_--~ 160
.. ' 140 1
1.5 120 1805 0806 1607 1808 2309 1505 0506 2606 2307 0609
1990 Sampllng date 1991
I-+- nonflltered f . flltered --.- depth
• Figure 63. Seasonal variatIOn of secchi depth and THMFP at Inel!an \lIe
Il
•
•
•
E ..c;
Ci. QJ
"0
5~----------------·------~-------------------r190
180
45+-------------~4_------~----~~----------~ 170
160
4 150 :::i'
140
130 35
120
110 3+-4-----~------~~----------~~----------~100
90
25 80 1805 0806 1607 1808 2309 1505 0506 2606 2307 0609
1990 Sampllng date 1991
I-+- nonflltered .. flltered ........ depth
--en .3-0-u. :E J: 1-
Figure 64. Seasonal vanation of secchi depth and THMFP at Border site
55~-------------------------------~------~--T170
5+-________ ~--__ -=~------~--~~~--~----~160
150 45+-----------~~_.~~--_+---4------~~----~
:::i' --140 en .3-0-u..
130 :E
35+---~----~------~-----C~~----~--------~ ~
120
3+--.~--------------r-----------------------~110
2.5 100 1805 0806 1607 1 808 2309 1505 0506 2606 2307 0609
1990 Sampllng date 1991
I-+- nonflltered .... - flltered ........ depth
Figure 65. Seasonal vanatlon of secchI depth and THMFP at Central SIte
12
• 6 200
190 55
f 180
5 170 ::J
l Cl 3.
.r:: 45 160 a IL LL
Q) :: "C I 150 ~ 4
140
3.5~~~----------~--------+------------------130
•• 1
3 120 1805 0806 1607 1808 2309 1505 0506 2606 2307 0609
1990 Sampllng date 1991
I-+- nonflltered .. flltered ~ depth
Figure 66. Seasonal vanatlon of ç,ecchl dcpth and THMFP at North ..,lIe
• 5.5
5
4.5
l 4
.r:: 35 -a. Q)
"C 3
2.5
2
1 5~~---r--~----~--~--~----~--'---'-r--~----~ 05/90 06/90 07/90 08/90 09/90 05/91 06/91 07/91 08/91 09/91
month/year
___ Pender .. Indlan -;.c- Border
-+- Central -- North
• Figure 67. Monthly averages of 'ieCChl depth at alI \Ites
13
•
APPENDIX .J
•
•
•
•
•
22~------------------------------------------~
20 ------...
18
Ü 16 .!... il) .... ::l 14 -'--'-'-'-'--ca .... il) 12 a. E ~ 10 -.--
8 • •••• , ••••• , •• , ............. , •• , ••••• , .... , •••• 1 ••• :;-·:-;-
6 -------
o 2 4 6 8 1 0 12 1 4 1 6 1 8 20 22 24 26 Depth [ml
1···'···· 1505 0506 -+- 1506 - 2606
Figure 68. Temperature protiles for May-J une 1991 at Central site
24
22 20 ......
0 .!... 18 il) .... ::l - 16 ca .... il) a. E 14 il)
1-12
~
~ \\
\\ \ ,
\,\ \....'\
10 -._~
~ 8
o 2 4 6 8 1 0 1 2 1 4 1 6 1 8 20 Depth [ml
1- 1007 -+- 2307
Figure 69. Temperature profiles for July 1991 at Central ~ite
JI
• 24
22 ....... ----- --:--
20 .--(J 18 .!!.... Q) ~ 16 ::J -cu ~
Q.) 14 a. E Q) 12 ~
10
8
'\ _\
\\ \ \ \\ \ ~ ~
'1
6 o 2 4 6 8 10 12 14 16 18 20
Depth [ml
1- 0908 - 2208
Figure 70. Temperature profiles for August 1991 at Central site
• 24 -22
20
IT 18 .!.... Q) .... ::J - 16 cu .... Q) a. E 14 Q)
t-
12
10
/ ~
1 .........
/ ---./
/ 1
/ /
/ 8
1 805 0506 1506 2606 1007 2307 0908 2208 Sampllng date
• Figure 71. Surface temperature protile over 1991 sampling season at Central site
12
• 20
18 ,--
-'. ---.. ....... 16 ü .e.-al 14 ... ~ -ca ... al 12 a. E ~ 10
8 --
...,. 6
Pender Indlan Border Central North Samphng site
1-- 1505 • :) .. 0506 -.- 1506
Figure 72. Surface temperaturc vanatlOn bctween \ltcS (J 99 J)
•
• 13
•
APPENDIX K
•
•
• 320
300
280
260 ::J --C)
240 3-Il. IL. 220 :E J: ~
200
180
1 !If,
\ • //~ - \ /' ~ --
\/ ~ 'loi( \ / .~
/ ~ \ 1" --... \
30
25
:::ï
20 a; E -"0 c: ('(1
15 E <li
"0 <li c:
10 ;:: 0 1: 0
"-5
160 �a_._
140 ,
0 1607 0208 1808 0409 2309
Sampllng date
I-+- unfilt. THM ... ~ .. fIIt THM ...... unfllt CI - fJIt CI
Figure 73. Seasonal variation of THMFP and chlonne demand Olt Pl'rHh:r \1 te ( Il)l)() on 1 y)
• 300 22
280 20
260 18 :::ï
240 16 en - E
~ -- "0 0)
.3.. 220 14 c: ('(1
Cl. E u. 200
<li
::E 12 "0
:I: <li ~ S
180 10 0 :ë
160 0
8
140 6
120 • 4 1607 0208 1808 0409 2309
Samphng date
I-+- unfitt.THM .. ~- hlt THM --- unfllt CI - fllt CI
• Figure 74. Seasonal variation of THMFP and chlonne demand al Indlan .. rle () 990 only)
KI
•
•
•
....J
en .3-a.. lJ.. ~ I 1-
190 -180 -170
l
160
l'iO ~- -\ , 140
130
120
\
--- \/ \(
110
100
90
80 1607 0208
f\.
/ ,
/ "",
1 /
/ "',
''''. .~ '~
1
1808 Samphng date
.~ ,........
"" •... 0409
1-- unfllt THM t·.. tilt THM ~ unfilt CI
20
18
16
~ :::r --14 en .s 'C
12 c ni E
10 al 'C al C
·1 8
;:: a :2
6 ü
. ....• 4
2 2309
•.• tilt. CI
Figure 75 Seasonal vanatlon of THMFP and chlonne demand at Border site {1990 only)
:::r Ci .3-a.. u. ~ :I: 1-
160
150
140
~---~---~~--------~====~~--------T18
16
14 :::r en
12 §. 'C C ni
+---------~~----~------------~~------~10 E al
130
\. ~ +-__________________ ~~~-----------\~.------_18 '§ 120
110
100
". 1 _ .. __ ........... .
:E 6 ü
4
~---r------~--------~------~~------~--~2 1607 0208 1808 0409 2309
Sampllng date
1-- untilt THM t· filt.THM ~ unfllt.CI .... tilt.CI
Figure 76 Seascnal variation of THMFP and chlonne demand at Central site (1990 only)
K2
• 150 20 •
18 145
16 :::J
140 14 en E :::J --- "0 Cl
3- 12 e lU
~ 135 E LL 10 ru :E "0
:I: ru 1- e
130 8 ;:: 0 1:
6 0
125 - 4
120 2 1607 0208 1808 0409 2309
Sampling date
I-+- unfllt. THM .-t.... filt. THM --- unfllt.CI _. tilt CI
Figure 77. Seasonal vanatlon of THMFP and chlonne demand al Nnrlh '>lle (!lJ90 only)
•
• K3
•
APPENDIX L
•
•
•
•
•
350
300
250
:7 --Cl 200 3-Il.. u.. :E 150 J: 1-
100
50
0
...
1607
• • •••• ••• • •••• 1
0208 1808 Sampllng date
0409
- unfilt.total ... tllt.total -+- unfllt hurnlc
.... ~.... tilt humic ...... unfllt algal ... tilt algal
2309
Figure 78. Predicted humlc and algal componenh of THMFP al Pcndcr ( 1990 only)
300
250
:::; 200
--0)
2-a.. 150 u. :E
.· ......... ---.....Lk .. ' J: 1- 100
50 ... : ...
() 1607 0208 1808 0409 2309
Sampllng date
-- unfllt.total ... filt.total -+- unfllt humlc
.. _~-- tilt humlc ...... unfilt algal .- tilt algal
Figure 79. Predlcted humlc and algal componenh ot THMFP al lndlan (1 <)<)0 only)
LI
•
•
•
:::::ï 01 .3. Cl.. u. ~ :r: f-
200
150
100
50 \
0
50~--~--------~------~~------~--------~--~ 1607 0208 1808
Samplrng date 0409
- unfllt total .. .. fllt total -+- unfllt hum.c
+. fllt humlc -.- unf.1t algal •.. filt.algal
2309
Figure 80. Prcdlctcd hUn1lc and algal components of THMFP at Border (1990 only)
180
160
140
:::::ï 120 0, .3-a.. 100 u. ~ :r: 80 f-
60
40
20
/ t'
1607 0208
..........
1808 SampJlng date
0409
- unfilt total ...... filt total -+- unf.lt.hum.c
+.. tilt hum.c -â- unfilt.algal •. tilt algal
2309
Figure 81. Prcdlcted hUI111C and algal components of THMFP at Central (1990 only)
L2
•
•
•
160
140
120
::r 0, 100 2. 0-U. :E 80 :c .....
60
40
20
~
1607
~
~ .... -1,
/~" ------/
/ 0208
~r / 't-
/ l
1808 Sampllng date
~
..
0409
- unlltt total tltt total -+- unfltt hUnllc
•.... fltt humlc -â- unfltt algal .. litt algal
-----
--
---
2309
Figure 82. Predlctcd hUITIIC and algal cornponenl~ 01 TIlr>.lFP .It North (Il)l)() only)
L3
•
APPENDIX 1\1
•
•
•
•
•
350
300 1
250 ::ï --Cl .3-a.. 200 LI.. ---1
~ J: 1-
150
100
50 1 5 2
--~-
1 ----1
r ="0.628
~ 1 1
l ,,, 1 1 J 1
1 1
l'~, 1
------------25 3 3.5 4
depth [ml 45 5 55 fj
Figure 83. Correlatlon between untïltcrcd THMFP and ~eL'Chl depth
::ï --Cl .3. a.. LI.. ~
i!:
350
300
250
200
150
100
50 1.5
1
1
'~, r ="0.601
1 1 1
~.' 1
1 1 1 1 1 1 1 1 ______
-----... 1
2 2.5 3 35 4 45
depth [ml
Figure 84. Correlation between filtered THMFP and !lccchl clcpth
Ml
--
5
•
•
•
:::J --, O'l
3-a.. u.. ~ I 1-
320
300
280
260
240
220
200
180
160
140
120 1.5
1
1 , '-~ 1
"~ r ="0.619
~ '~
1 ~ --..
2 2.5 3 35 4 depth [ml
Figure 85. Correlation bctween untiltered THMFP and secchl depth at Pender site
350
300
:::J en 250 .3.. a.. u.
~ 200 1-
150 .
100 1.5
1
~ 1
~29 1
'~ 1
2 2.5 3 3.5 4 depth [ml
Figure 86. Correlation between tïltcred THMFP and secchi depth at Pen der site
M2
•
•
•
300
280
260
::i' 240
--Cl 220 3.
a. ~ 200 l 1-
180
160
140
120 1.5
1
----
2
-
~r='0528 1
1 ___________
1 ~--1 ~
2.5 3 3.5 4 depth [m]
Figure 87. Correlation between untiltcrcd THMFP and secchI deplh al Ifl(han "He
.......
....J --Cl 3. a. LI.. ::E l 1-
220
210
200
190
180
170
160
150
140
130
120 1.5
1
-~
2
-
1
------ r ="0.617 --
---~ ~I
" ..... -. 1
2.5 3 3.5 4
depth lm]
Figure 88. Correlation between tïltered THMFP and ~ecchl depth al lndlall ..,He
M3
•
•
•
320
300
280
::J 260
--0> 240 .=.
a. u.. 220 ::2 I f- 200
180
160
~
~ r = 0.778 ~ 1/ 1
/1 1
/~ 140 v---
16.5 17 17.5 18 18.5 19 19.5 20 20.5 21 21.5 TP [ug/L]
Figure 89. Correlation between untïltered THMFP and TP at Pender site
........
...J -0> 3. Il. u.. ::2 l f-
160
155
150
145
140
135
130
/ r=0.851/
/ 7 1
1 125 1/ 120
300 350 400 450 500 TN [ug/L)
1
1
/
550 600
Figure 90. Correlation bet\\,'cen tiltered THMFP and TN at North site
1\14
•
•
•
:::r -Cl 2-a.. u. ::E l t-
200
190
180
170
160
150
140
130
120 o
1
1
/ /
1 1
1
1 2
/' /' r = 0.786
3 4 5S [mg/L]
" //
5
1_-
--,
, ,
6 7
Figure 91. CorrelatIOn between untïltered THMFP and Solld'i at North .,11l!
MS
•
•
•
160 1
140 1
1
120
100
:J 80 Cl .3-a.. 60 u.
1 r = 0.382 ----1
~ 1 1
~ 1 1
1 ---:E J: 40 1-
1
20 1
1
0
-20 1
40 1 2 3 4 5 6 7 8 9 10
chi a (ug/L]
Figure 92. CorrelatIon bctween predlcted algal THMFP and chi a (unt1itered 1990)
:J --Cl 3-a.. u. :E J: 1-
120
100
80
60
40
20
o 3
1
1
Il
1
4 5
1
1
1
6 7 chi a [ug/L]
1
r = 0.072
1
8 9 10
FIgure 93. CorrelatIOn between predlcted algal THMFP and chi a (tïltered 1990)
M6
•
APPENDIX N
•
•
• 150 r = 0083
:300
::J 250 Ol .3. ~ I 1- 200 , ,
" , 'II
150 , l, . ,
, , , , , , , , 100
4 5 6 7 8 9 10 11 12 13 TOC [mg/L]
FIgure 94 . Untïltercd THMFP versus total orgamc carbon
• 350
r = 0.054 300
250 -
:::ï Ôl
200
150 , 1 , l" ,
I~ ,
'1 ,
Il l ,l' 1 , ,
100
50 4 5 6 7 8 9 10 11 12 13 14
DOC [mg/L]
• FIgure 95. FIitercd THMFP vcrsus dlssolved organic carbon
NI
•
•
•
350
300
:::ï 250 Ci .3. ~ J: t- 200
150
100 o
r = 0 228
1 Il
1
\ 1
1 1
2
1
1 , 1 1
1
" 1
,I 1
4
1
1
Il
\ 1
1 1 1 1
1 1 1
1
1 1
1 1
1 1 1
1 1
1
6 8
chi a [ug/L]
1 1
1
Figure 96. Unfiltered THMFP versus chlorophyll a
:J" -.. Cl
.3. ~ J: .-
350
300
250
200
150
100
50 o
r = 0.136
1
1 1 1 1 1 1111
1 1
1
2 4
1
1
1 1
Il 1
Il Il
1
1 1
1
Il 1 1
1
6 8 ch! a [ug/L]
1
Figure 97. Filtered THMFP versus chlorophyll a
N2
Il
-- -
----
10 12 14
--
10 12 14
• 350
r = 0221
300 1
::::J 250 1 0, 1 3-~ l
200 l- I 1 1
1 1 1
1 1 1 1
1 1 1 1 1 1
150 " 1
1 '/1 III
1
Il Il
1 1
100 200 300 400 500 600 700 800
TN [ug/L]
Figure 98. Untïltered THMFP versus total 111 trogen
• 350
r = 0.394 1
300
250
::::J -- 1 Cl .3- 200 ~ 1 J: 1 1-
150 1 \ 1 1 Il r
Il 1 1 Il 1 1 1
1 \ 1 1 1
1 100
50 200 300 400 500 600 700 800
TN [ug/L]
• FIgure 99. Filtered THMFP versus total mtrogen
N3
•
•
•
350
300
::J' 250 --C)
.3-:E ~ 200
150
100 5
,
r = 0.397
1
, , , , , 1
1 , "
l, , , , ,
10
1
1
1
1 1 1 1
1 1 ,
1 , , , Il, Il'' 1
, , , ,
15 20 25 30 TP [ug/L]
Figure 100. Unfiltered THMFP versus total phosphorou<;
::J' --C)
.3. :E :r: 1-
350
300
250
200
150
100
50 5
r = 0.324
, , , " , ,
10
,
,
, , , , "
, " ., III , , ,
-' '",' \,' , " ,
15 20 25 30 TP [ug/L]
Figure 101. Filtered THMFP versus total phosphorou!-.
N4
35 40
35 40
•
•
•
350
300
::J 250 C1l d ::!
~ 200
150
tOO 10
r = 0 250
, ,
15
, ,
, , , ,
,
20 :5
,
,
, , ,
, , , , , , ,
1
30 N:P ratio
, , ~ 1 , ,
, , ,
35
Figure 102. Unfiltered THMFP versus N:P ratio
::J -. C1l d ::! J: 1-
350
r = 0.264
300
250
200
150 ~
100
50 10
1 ,
15
,
20
,
, 1
1
25
, ,
" ,\
1 1 1
1 1
30 N:P ratio
" 1 , "1
1
35
Figure 103. FIItercd THMFP versus N:P ratio
N5
,
\' , , , , , ,
40 45 50
1
III 1
1
1
1
40 45 50
•
•
•
350~------------------------------------------------~
r = 0.330 300 ----- --------
::::ï 250 ---.------en .3.. :E J: 1- 200-- , ,
150
1 'II ,
, ' " --- - L - ' l ',- ~ l ',- - "
, ,
, '
100+------,---------------------.------.------.------~ o 2 3 4
SS [mg/LI 5
Figure 104. Untïltered THMFP versus ~u~pcndcd ,>ollds
G 7
350~-----------------------------------------------
r = 0.267 300
250
, , " 150+-------,-·-, -'---. ~- • ----1--;- -
.' •
• ,f , 1
100~-----·------- ------ - ------------
50+----,------r-----.------.------r------r----~ o 2 3 4 ') G 7
SS [mg/LI
Figure 105. Filtered THMFP versus ~uspendcd \ofJd~
N6
____ ...J
•
•
•
350
300
:::::ï 250 en
..3-~ l .- 200
150
100 40
r = 0393
1
1
45
1
1 1 1
1
1 1 1 1 1 1 1
1,1 , , 1 1
1 l, l , 1 ,
1 , , 1
1
50 55 Alkallnlty [mg/L as CaC03]
Figure 106. lJntïltcrcd THMFP versus alkahnity
:::J ô; .3-:E l .-
350
300
250
200
150
100
50 40
r = 0.084
,
45
, 1 1 1 , 1 1
1 : ': 1 ,
Il 1 , , 1
50 55
1
,
Alkallmty [mg/L as CaC03]
FIgure 107. FtItcred THMFP versus alkahlllty
N7
1
1
1 1
1 , ,
1
60 65
1
1
1 , ,
1 , ,
60 65
•
•
•
350
300
:::J' 250 en .3.. ::E ~ 200
150
100 o
r = 0.046
1
1
"1 , 1 , 1 1
: 1 1 1
1 1
1
1
1
1 1
1 1
1 1 1
1 1 Il 1 1
1 Il
1
1
2 3 4 Turbldlty [NTU]
Figure 108. Unfiltered THMFP versus turbldlty
:::J' ""-0> .3.. ::E J: 1-
350
300
250
200
150
100
50 o
r = 0.040
1 , , 1 1
III Il , 1 ,
1
1
1
1
1 1
1 1 1 1 1
III , 1
1 1 1 1
2 3 4 Turbldlty [NTU]
Figure 109. Filtered THMFP ver~us turbldlly
N8
--
1 1
1 Il
5 6 7
--
-1
1
1 l'
5 6 7