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Assessment of the Application of an
Ecotoxicological Procedure to Screen Illicit Toxic
Discharges in Domestic Septic Tank Sludge
José López-Gastey a , Achraf Choucri a , Pierre Yves Robidoux b & Geoffrey I. Sunahara
b
a Laboratory Division, Environmental Department , Montreal Urban Community ,
Montreal , Quebec , Canada
b Applied Ecotoxicology Group , Research Institute, National Research Council of
Canada , Montreal , Quebec , Canada
Published online: 27 Dec 2011.
To cite this article: José López-Gastey , Achraf Choucri , Pierre Yves Robidoux & Geoffrey I. Sunahara (2000)
Assessment of the Application of an Ecotoxicological Procedure to Screen Illicit Toxic Discharges in Domestic Septic Tank
Sludge, Journal of the Air & Waste Management Association, 50:6, 1004-1009, DOI: 10.1080/10473289.2000.10464144
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López-Gastey et al.
TECHNICAL PAPER
ISSN 1047-3289 J. Air & Waste Manage. Assoc. 50:1004-1009
Copyright 2000 Air & Waste Management Association
Assessment of the Application of an Ecotoxicological
Procedure to Screen Illicit Toxic Discharges in Domestic
Septic Tank Sludge
José López-Gastey and Achraf Choucri
Laboratory Division, Environmental Department, Montreal Urban Community, Montreal, Quebec, Canada
Pierre Yves Robidoux and Geoffrey I. Sunahara
Applied Ecotoxicology Group, Biotechnology Research Institute, National Research Council of Canada,
Montreal, Quebec, Canada
ABSTRACT
is, after a public h earin g presen tation of th is procedure,
th is proportion dropped sign ifican tly to approxim ately
9% based on 108 an alyzed sam ples.
An in n ovative screen in g procedure h as been developed
to detect illicit toxic disch arges in dom estic septic tan k
sludge h auled to th e Mon treal Urban Com m un ity waste-
water treatm en t plan t. Th is n ew m ean s of con trol is based
on an in tegrative approach , usin g bioassays an d ch em i-
cal an alyses. Con servative criteria are applied to detect
abn orm al toxicity with great reliability wh ile avoidin g
false positive results. Th e com plem en tary data obtain ed
from toxicity tests an d ch em ical an alyses support th e use
of th is efficien t an d easy-to-apply procedure.
Th e results of a 30-m on th application of th is n ew
con trol procedure sh ow th e superior efficien cy of th e
ecotoxicological approach com pared with th e previously
used ch em ical con trol procedure. To be able to apply it
effectively an d, if n ecessary, to apply th e appropriate co-
ercive m easures, ecotoxicological criteria sh ould be in -
cluded in regulatory guidelin es.
Th is study assesses th e con trol procedure in wh ich
231 sam ples were an alyzed over a 30-m on th period. Data
clearly dem on strate th e deterren t power of an efficien t
control procedure com bined with a public awareness cam -
paign am on g th e carriers. In th e first 15 m on th s of
application, between January 1996 and March 1997, ap-
proxim ately 30% of the 123 sam ples analyzed showed ab-
norm al toxicity. Between April 1997 and June 1998, that
INTRODUCTION
Sin ce 1989, th e Mon treal Urban Com m un ity (MUC)
wastewater treatm en t plan t h as h an dled an n ually an av-
erage of 20,000 m 3 of sludge collected from dom estic sep-
tic in stallation s located with in th e MUC territory, as well
as in n eigh borin g m un icipalities (Figure 1). Carriers m ust
obtain perm its before discharging sludge and com ply with
th e con dition s of th e perm its, especially th ose forbiddin g
the discharge of toxic substances. The sludge is m ixed with
th e wastewater in flow before th e prim ary ch em ical treat-
m en t process. Th is treatm en t rem oves about 80% of sus-
pen ded solids an d total ph osph orus, 60% of th e BOD5,
an d 50% of th e h eavy m etals.
IMPLICATIONS
An integrative control procedure would help wastewater
treatment plant (WTP) managers to detect illicit toxic waste
that could be shipped to their facilities and that could
pollute the environment and/or interfere with the treat-
ment process. This powerful cost-effective procedure re-
quires minimal investment and could be easily established
in a typical WTP control laboratory and carried out by
staff of average skill. The response is fast and reliable
and allows a quick intervention.
On e of th e m ajor con cern s of th e MUC auth orities is
for appropriate m easures to be taken to en sure th at n o
toxic waste is m ixed with dom estic sludge.1 Such a prac-
tice would be attractive to h azardous waste producers be-
cause of th e h igh cost of treatm en t an d/or elim in ation of
toxic waste. In th e past, th e con trol procedure was based
on iden tifyin g abn orm ally h igh levels of con tam in an ts
by com paring the results of 12 chem ical param eters with
the data obtained through a characterization program that
involved 125 samples analyzed over a two-year period (Table
1). If the chem ical analysis results deviated significantly
Montreal Urban Community existing regulations will
need to be modified to include not only chemical but also
ecotoxicological criteria. This control procedure has to
be applied on both local and regional scales; otherwise,
carriers may tend to ship illicit sludge to peripheral areas
where control is less rigorous.
1004 Journal of the Air & Waste Management Association
Volume 50 June 2000

López-Gastey et al.
Table 1. Physicalandchemicalcharacterizationofseptictanksludge(1989–1990).
while participating in an interlaboratory study with the
Quebec Ministry of Environm ent to validate the threshold
values and to test the efficiency of the procedure to detect
other toxic substances. Meanwhile, inform ation describ-
ing this procedure and its im plications was diffused am ong
the carriers through a public hearing session of the MUC
Environm ent Com m ission held in April 1997.3
Parameter
Descriptive Statistics (n = 125)
Median
Minimum
Maximum
pH
6.5
1.26
66
5.0
0.06
6.7
8.4
26
92
Total solids (g/100 g)
Total volatile solids
(g/100 g dry weight)
Total phosphorus (mg/kg)
Th e purpose of th is study is to assess th e efficien cy of
th is n ew ecotoxicological con trol procedure after a 30-
m on th period of application .
82
4800
1255
268
0.60
0.04
0.4
0.57
11
525
80000
15000
4170
11
BOD (mg/kg)
5
a
Total oil and grease (mg/kg)
<3
a
MATERIALS AND METH ODS
Hydrocarbons (mg/kg)
<3
Phenols (mg/kg)
<0.01
<0.02
<0.1
0.17
<0.2
<0.2
0.12
Slu d ge Recep t ion a n d Sa m p lin g
Total cadmium (mg/kg)
Total chromium (mg/kg)
Total copper (mg/kg)
Total nickel (mg/kg)
Total lead (mg/kg)
0.36
3.8
Septic sludge was hauled to the MUC wastewater treatm ent
plant in tanker trucks with an average capacity of about 12
m 3. It was m ixed with the incom ing wastewater that flows
at an average of about 30 m 3/sec. Sam ples were collected
by the carrier directly from the dum ping valve connected
to the truck. A representative sam ple of the sludge from
the truck was obtained by m aking a com posite of sam ples
collected at the beginning, middle, and near the end of the
discharge process. These portions were well mixed and trans-
ferred to a 1-L high-density polyethylene bottle before be-
in g stored at 4 °C. Sam plin g was carried out un der th e
supervision of the treatment plant’s operator. The pH was
measured on-site, and if the pH was outside the normal range
or if there was evidence of abnormal physical characteristics
(i.e., oily film, color, and odor), the sample was then shipped
to the laboratory for further analysis. Otherwise, samples
were chosen randomly for analysis according to an estab-
lished frequency (e.g., one out of 10 shipments).
4.1
49
0.3
8.0
1.1
27
Total zinc (mg/kg)
9.4
84
aNot analyzed on a regular basis during the period of the study.
from th e h istorical expected value, th en adm in istrative
action was in itiated. However, th is approach seem ed lim -
ited because it could n ot ascertain , with rapidity an d con -
fiden ce, th e acceptability of sludge sh ipm en ts th at could
possibly con tain th ousan ds of toxic com poun ds. For th is
reason , th e MUC developed an in tegrative procedure to
screen illicit disch arges in dom estic septic tan k sludge by
th e use of quan titative toxicity tests. Toxicity th resh olds
were establish ed durin g th e developm en tal ph ases of th is
procedure to defin e th e n orm al toxicity of sludge. High
efficien cy was attain ed (detection of 93% of added toxic
substan ces to n on -con tam in ated sludge) wh ile avoidin g
false positives, th at is, falsely accusin g a carrier of illicit
toxic waste disch argin g.2
Descr ip t ion of t h e Ecot ox icologica l P r oced u r e
Th e con trol procedure in volved th ree stan dardized bioas-
says. Th e first, th e lettuce root elon gation test, in volved 5
days exposure of lettuce seeds (Lactuca sativa) to the sludge
sam ple. Toxicity was in dicated by an in h ibition of root
growth .4 Th e secon d, th e in h ibition of respiration test
(after a 3-h r aeration period), was
Since the beginning of 1996, the MUC Environm en-
tal Departm en t h as applied th is n ew con trol procedure
carried out after th e addition of ac-
tivated sludge to th e sam ple. Th e
presen ce of toxican ts was reflected
by an in h ibition of th e oxygen con -
sum ption rate.5 Th e th ird bioassay
was based on th e in h ibition of bac-
t erial b io lu m in escen ce (Vib rio
fisch eri) usin g th e Microtox system,
in which the microorganisms were
exposed to a contamin ated sam ple.6
For th is test, salin ity was adjusted
to 2% with reagen t-grade sodium
ch loride. Th e results obtain ed by
Figure 1. Sludge volume received at wastewater treatment plant.
Volume 50 June 2000
these bioassays were com pared with
Journal of the Air & Waste Management Association 1005

López-Gastey et al.
Table 2. Thresholds for bioassays.
Bioassay
th e th resh old values (Table 2) establish ed in earlier stud-
ies.1,2 Data outside th ese values in dicated an om alous tox-
icity. Th e en dpoin t used to defin e th e th resh old for th e
root elon gation test was expressed as th e m edian in h ibi-
tion con cen tration (IC50; i.e., th e con cen tration of sludge
estim ated to cause 50% in h ibition of m easured biological
respon se of th e tested organ ism ). Th e oxygen con sum p-
tion rate was used as th e en dpoin t for th e respiration test.
In th e case of th e Microtox test, th e large variability of
toxicity am on g th e sam ples dim in ish ed th e test’s sen si-
tivity to detect added con tam in an ts.2 Th e toxicity of in -
organ ic substan ces m easured by th e Microtox test ten ds
to in crease with exposure tim e.7-9 A previous study2 dem -
on strated th at, by expressin g th e results as th e ratio be-
tween th e IC50s after 5 an d 30 m in of in cubation , th e
Microtox test becam e sen sitive to som e in organ ic toxic
substances. As a result, tested organic com pounds could
not be detected by the Microtox test but could still be de-
tected by the other two bioassays.
Endpoint
Anomaly Zone
Root elongation
IC -5 days
<21%
50
-1
Respiration inhibition
Microtox
Oxygen consumption rate
IC -5 min/ IC -30 min
<39 mg O .L .hr-1
2
>2.1
50
50
be with in th e ran ge of 25.2 ± 5.3 m g/L as m easured by
th e root elon gation test.
Da t a An a lysis
Th e lin ear in terpolation m eth od developed by th e U.S.
En viron m en tal Protection Agen cy12 was used to estim ate
th e IC50 values for th e root elon gation test. For th e respi-
ration test, th e IC50 of th e toxic referen ce substan ce was
calculated using the Trimmed Spearman-Karber method.13,14
Th e IC50 values for th e Microtox test were calculated us-
ing the Microtox com puter-assisted program , version 7.8.15
In the event that anom alous toxicity was detected by
one or more of these bioassays, chemical analyses were then
carried out according to standardized m ethods10 in order
to identify the contam inants by com paring the results with
the historical data (Table 1). Other param eters could also
be analyzed if other substances (e.g., oil and grease) were
suspected. Results deviatin g con siderably from m edian
values were identified as chem ical anom alies.
RESULTS AND DISCUSSION
During the period of this study (from January 1, 1996 to
June 30, 1998), 1889 shipm ents were transported to the
wastewater treatment plant by 16 different carriers. An analy-
sis according to the ecotoxicological procedure was carried
out on 231 sludge samples (Table 3). Of the 47 samples pre-
senting anomalous toxicity, 24 were detected by the root
elongation test only, 13 by the respiration test only, and
one by the Microtox test only (Table 4). In n in e cases,
an om alies were con firm ed by both th e root elon gation
an d th e respiration tests. Results presen ted in Table 4 in -
dicate th at ch em ical an alyses were able to con firm th e
possible source of an om alous toxicity in 11 sam ples, wh ile
on e sam ple presen ted a dubious ph ysical ch aracteristic
(odor of h ydrocarbon s).
Qu a lit y Con t r ol
Details of quality con trol procedures were described in a
previous article.2 Briefly, all series of ch em ical an alyses
in cluded a sam ple blan k (deion ized water, ASTM type II).
With in a series of ch em ical an alyses, at least on e sam ple
was an alyzed in duplicate. A sam ple was also spiked with
a stan dard to verify m eth od recovery. Certified aqueous
an d dried sludge stan dards were used to validate th e
ch em ical an alyses.
Figure 2 sh ows th at m ost of th e an om alous sam ples
were detected durin g th e first h alf of th e study (i.e., be-
tween January 1996 and March 1997). Anom alies dropped
from approxim ately 30% (37 an om alies detected in 123
an alyzed sam ples) in th e first h alf of th e study to approxi-
m ately 8% (10 an om alies detected in 108 an alyzed
sam ples) in th e secon d h alf (Table 3). Th e public h earin g
session of th e MUC en viron m en t com m ission h eld in
April 1997, to wh ich all perm it-h oldin g carriers were in -
vited an d durin g wh ich th e procedure was presen ted, m ay
have had a deterrent effect on less scrupulous carriers. Note
that in Septem ber 1996, MUC authorities instructed carri-
ers not to m ix chem ical toilet sludge with dom estic sludge
because th e relatively h igh toxicity of th e disin fectan ts
used in th e ch em ical toilets would in terfere with th e con -
trol procedure. This action was justified, since mixing the
two distinct kinds of sludge was a common but unacceptable
Negative con trols (n o sam ple or toxic substan ces
added) were in cluded. For th ese assays, Am erican Ch em i-
cal Society reagen t-grade substan ces were also used as ref-
eren ce toxican ts (positive con trols), an d th e IC50 values
of each were determ in ed. For th is purpose, ph en ol for th e
Microtox test, 3,5-dich loroph en ol for th e respiration test,
an d m ercuric ch loride for th e root elon gation test were
used. Th e validation of toxicological an alyses was assured,
sin ce all th ese quality con trol data were con sidered ac-
ceptable accordin g to con trol ch arts11 an d oth er estab-
lish ed criteria (e.g., respon se in th e n egative con trol). For
th e results to be valid, th e IC50 of ph en ol h ad to be with in
th e ran ge of 17.1 ± 2.2 m g/L as m easured by th e Microtox
test; th e IC50 of 3,5-dich loroph en ol h ad to be with in th e
ran ge of 22.6 ± 4.7 m g/L as m easured by th e in h ibition of
respiration test; an d th e IC50 of m ercuric ch loride h ad to
1006 Journal of the Air & Waste Management Association
Volume 50 June 2000

López-Gastey et al.
Table 3. Number of discharges, samples analyzed and anomalies detected for each of the carriers.
practice, as observed in th e case of th e car-
riers coded L an d M (Table 4). Th e im pact
of th at m easure, h owever, is n ot tan gible
(Figure 2).
Code of
Number of Discharges
Number of Analyzed Samples
(Anomalies Detected)
the Carriers
January 1, 1996,
April 1, 1997,
January 1, 1996,
April 1, 1997,
Th e perform an ce of each in dividual
to March 31, 1997
to June 30, 1998
to March 31, 1997
to June 30, 1998
carrier was also studied. Of th e 16 perm it-
h oldin g carriers, on ly two (carriers coded
B an d E) h ad m ediocre results over th e
wh ole study period an d four (carriers
coded A, H, M, an d O) sign ifican tly im -
proved th e quality of th eir sh ipm en ts af-
ter th e public awaren ess cam paign (Table
3). Accordin gly, sam plin g an d an alysis fre-
quency should be established based on the
h istorical records of each carrier.
A
71
265
9
12
311
1
13 (7)
31 (3)
3 (1)
2 (0)
46 (4)
0 (0)
B
C
D
E
81
50
26
14
108
9
41
32
5
8 (0)
4 (1)
3 (1)
3 (1)
F
2 (0)
0 (0)
G
H
I
11
26
0
3 (0)
0 (0)
10 (7)
0 (0)
4 (0)
0 (0)
J
16
37
5
21
34
7
1 (0)
4 (2)
Among the bioassays used in this study,
K
1 (0)
2 (0)
the root elongation test proved to be the
m ost efficien t (Table 4). Th e results also
sh ow th at th e respiration test detected
about 28% of th e an om alous toxicity of
sludge that the root elongation test failed
to detect. Th is in dicates th at data from
these tests are com plem entary and that a
m ulti-test procedure is n ecessary to im -
prove the overall efficiency. The apparent
lack of efficiency of the Microtox test (de-
tection of only 2% of the anom alous toxic-
ity of sludge sam ples) can be explained by
the presence of contam ination of organic
origin . Backgroun d toxicity of sludge, as
m easured by the Microtox test, was rela-
tively high. Consequently, sam ples had to
be diluted about 50 tim es, which m ade this
test un able to detect th e poten tially low
concentration of inorganic contam ination
that could be encountered in the sludge.
Root elongation and respiration tests did
not suffer from this disadvantage, since the
background toxicity measured by these tests
was relatively low, probably because of the
h igh con cen tration of organ ic n utrien ts
that favored the growth of the organism s
used. Thus, the procedure could be sim pli-
fied while m aintaining high efficiency by
retaining only the two m ost reliable bioassays (i.e., the in-
hibition of respiration and root elongation tests).
The m ain purpose of developing an integrative m eans
of con trollin g th e quality of sludge sam ples is to im prove
th e efficien cy of detectin g perm it violators. Results
dem on strate th at about 74% of th e sam ples presen tin g
an abn orm al toxicity did n ot sh ow an y an om aly in th eir
chem ical com position (Table 4). If chem ical analyses failed
to iden tify th e con tam in an ts, adm in istrative action (i.e.,
L
1 (1)
0 (0)
M
N
O
P
222
15
79
1
204
38
124
14
881
33 (13)
4 (0)
23 (0)
3 (1)
9 (4)
16 (1)
1 (0)
1 (0)
Total
1008
123 (37)
108 (10)
Figure 2. Number of normal samples and anomalies detected for the period between
January 1, 1996, and June 30, 1998.
in vestigation an d en h an ced m on itorin g) was in itiated. If
th e con tam in an t respon sible for th e abn orm al toxicity
could be iden tified, th e carrier was issued a n otification
of th e offen se; if th e violation was repeated, th e disch arge
perm it was suspen ded or revoked. Sin ce th e begin n in g of
1997, th ere was a sign ifican t decrease in th e sludge
volume received at the wastewater treatment plant (Figure
1). Carriers may have shipped sludge to treatment sites where
sludge control was less rigorous, which also demon strates
Volume 50 June 2000
Journal of the Air & Waste Management Association 1007

López-Gastey et al.
Table 4. Anomalies detected by bioassays and chemical analyses during the period of this study.
Date of Reception
Code of the Carriers
Bioassaysa Detecting the Anomalies
Chemical Anomalies and Observations
96.02.15
96.02.19
96.03.06
96.04.09
96.04.13
96.04.18
96.04.26
96.04.26
96.04.30
96.05.07
96.05.15
96.05.15
96.06.12
96.06.18
96.06.25
96.07.04
96.07.03
96.07.11
96.07.23
96.07.23
96.08.03
96.08.06
96.08.27
96.09.27
96.10.22
96.11.13
96.11.18
96.11.27
96.12.04
96.12.03
O
A
Respiration - Elongation
Elongation
N.I.
Zn = 53 mg/kg
B
Elongation
N.I.
M
H
O
O
M
M
O
H
H
H
B
Elongation
N.I.
N.I.
Elongation
Respiration - Elongation
Respiration - Elongation
Elongation
Odor of hydrocarbons
Cu = 31 mg/kg, Cr = 4 mg/kg
Cu = 140 mg/kg, Zn = 300 mg/kg, Pb = 24 mg/kg
2
Respiration - Elongation
Elongation
Presence of chemical toilet sludge
N.I.
N.I.
N.I.
N.I.
N.I.
Elongation
Elongation
Elongation
Respiration
b
M
M
A
Elongation
Presence of chemical toilet sludge
b
Elongation
Presence of chemical toilet sludge
Respiration - Elongation
Respiration
pH = 12.2
M
M
A
Total oil and grease = 2.00%, Hydrocarbons = 1.56%
b
Elongation
Presence of chemical toilet sludge
Respiration
N.I.
N.I.
M
M
M
L
Elongation
b
Elongation
Presence of chemical toilet sludge
b
Elongation
Presence of chemical toilet sludge
b
Respiration - Elongation
Respiration - Elongation
Elongation
Presence of chemical toilet sludge
H
A
N.I.
N.I.
B
Respiration
N.I.
E
Elongation
N.I.
C
H
Respiration
N.I.
Elongation
Cr = 6.0 mg/kg, Cu = 40 mg/kg, Ni = 2.9
mg/kg, Pb = 7 mg/kg, Zn = 66 mg/kg
97.01.07
97.01.23
97.01.27
97.02.06
97.02.10
97.02.17
97.02.19
97.04.28
97.07.10
97.07.31
97.09.02
97.10.14
98.02.26
H
M
A
A
A
M
M
J
Elongation
Elongation
Pb = 6 mg/kg
N.I.
Elongation
Cu = 69 mg/kg
Respiration
N.I.
Respiration
N.I.
Elongation
N.I.
Respiration - Elongation
Respiration
N.I.
N.I.
B
O
J
Respiration
N.I.
Elongation
Pb = 7 mg/kg, Zn= 45 mg/kg
Respiration
N.I.
E
B
Respiration
N.I.
Respiration - Elongation
Phenols = 1.5 mg/kg, Cu = 24 mg/kg,
Pb = 8 mg/kg, Zn = 39 mg/kg
98.04.08
98.04.25
98.05.25
98.06.10
B
D
B
N
Microtox
Respiration
Elongation
Respiration
N.I.
N.I.
N.I.
Total oil and grease =11.9%, Hydrocarbons = 0.79%
N.I. = Not identified; aSee Materials and Methods; bAs reported by the carrier.
1008 Journal of the Air & Waste Management Association
Volume 50 June 2000

López-Gastey et al.
6. Biological Test Method: Toxicity Test Using Luminescent Bacteria
(Photobacterium phosphorium); En viron m en t Can ada, Tech n ology
Developm en t Directorate: Ottawa, 1992.
7. Vasseur, P.; Bois, F.; Ferard, J.F.; Rast, C. In fluen ce of Ph ysicoch em ical
Param eters on the Microtox Test Response; Toxicity Assess. Int. Q. 1986,
1, 283-300.
8. Carlson , C.E.A.; Morrison , G.M. Fraction ation an d Toxicity of Metals
in Sewage Sludge; Environ. Technol. 1992, 13, 751-759.
9. Kaiser, K.L.E.; Devillers, J. Ecotoxicity of Chemical to Photobacterium
Phosphorium; Gordon Breach : New York, 1994.
th at th e m ost appropriate solution is still a coercive ap-
proach to regulatory con trol. Th is approach is opposite
of th e policies prom oted by differen t govern m en t agen -
cies th at rely m ore an d m ore on toxic waste producers to
be respon sible an d self-con trolled rath er th an on regula-
tory en forcem en t.
10. Am erican Public Health Association , Am erican Water Works Associa-
tion , an d Water En viron m en t Federation . Standard Methods for the
Examination of Water and Wastewater; 19th ed.; Am erican Public Health
Association : Wash in gton , DC, 1995.
11. Guidance Document on Control of Toxicity Test Precision using Reference
Toxicants; En viron m en t Can ada, Tech n ology Developm en t Director-
ate: Ottawa, 1990.
12. Norberg-Kin g, T.J. A Linear Method for Sublethal Toxicity: The Inhibi-
tion Concentration (ICp) Approach; Version 2.0, Environm ental Research
Laboratory, U.S. Environm ental Protection Agency: Duluth, MN, 1993.
13. Ham ilton , M.A.; Russo, R.C.; Th urston , R.V. Trim m ed Spearm an -
Karber Meth od for Estim atin g Median Leth al Con cen tration in Tox-
icity Bioassay; Environ. Sci. Technol. 1977, 11, 714-719.
14. Ham ilton , M.A.; Russo, R.C.; Th urston , R.V. Trim m ed Spearm an -
Karber Meth od for Estim atin g Median Leth al Con cen tration in Tox-
icity Bioassay; Environ. Sci. Technol. 1977, 12, 417.
CONCLUSIONS
Th e resu lts of a 30-m on th ap p lication of th e n ew
ecotoxicological con trol procedure sh ow th e deterren t
effect th at th is powerful tool can h ave, especially wh en
com bin ed with a public awaren ess cam paign am on g th e
sludge carriers. Th ey also sh ow th e superior efficien cy of
th e ecotoxicological approach com pared with previously
used ch em ical con trol procedures.
To be able to use th e n ew procedure with full effi-
cien cy an d, if n ecessary, to apply th e appropriate coer-
cive m easures, ecotoxicological criteria should be included
in future regulatory guidelin es. Moreover, application of
such a procedure could be exten ded on a region al basis to
discourage carriers from sh ippin g sludge to periph eral ar-
eas wh ere con trol is less rigorous.
15. Microbics Corporation . Microtox Manual—A Toxicity Testing Handbook;
Carlsbad, CA, 1992.
ACKNOW LEDGMENTS
The authors wish to express their thanks to Edward Kamel,
Daniel Sirois, Pierre Purenne, and Michelet Joseph, who par-
ticipated in different phases of this study. Gratitude is also
expressed to Nancy Shewan for reviewing this manuscript.
REFERENCES
1. Robidoux, P.Y.; López-Gastey, J.; Ch oucri, A. Procédure de Dépistage
Écotoxicologique d’Ajouts Illicites dans les Boues de Fosses Septiques Reçues
à la Station d’Épuration de la Communauté Urbaine de Montréal;
Com m un auté urbain e de Mon tréal, Service de l’en viron n em en t,
Assain issem en t de l’air et de l’eau: Mon tréal, Québec, 1995.
2. Robidoux, P.Y.; López-Gastey, J.; Ch oucri, A.; Sun ah ara, G.I. Proce-
dure to Screen Illicit Disch arges of Toxic Substan ces in Septic Sludge
Received at a Wastewater Plan t; Ecotoxicology and Environmental Safety
1998, 39, 31-40.
3. López-Gastey, J.; Ch oucri, A.; Joseph , M. Bilan de l’Application de la
Procédure Écotoxicologique de Contrôle des Boues des Fosses Septiques
(Janvier 1996 à Juin 1998); Com m un auté urbain e de Mon tréal, Ser-
vice de l’en viron n em en t, Assain issem en t de l’air et de l’eau: Mon tréal,
Québec, 1998.
4. Protocols for Short Term Toxicity Screening for Hazardous Waste Sites;
En viron m en tal Research Laboratory, U.S. En viron m en tal Protection
Agen cy: Corvallis, OR, 1989.
5. Activated Sludge, In h ibition of Respiration Test (m eth od 209); Guide-
line of the OECD for Testing Chemical Products; Organ ization for Eco-
n om ic Cooperation an d Developm en t: Paris, 1984.
About the Authors
José López-Gastey (corresponding author) is head of the
Laboratory Division and Achraf Choucri is senior chemist
for the Environmental Department of the Montreal Urban
Community, 827 East Crémazie Blvd., Montreal, Quebec,
Canada H2M 2T8.
Pierre Yves Robidoux is presently a research officer
and Geoffrey I. Sunahara is the group leader of Applied
Ecotoxicology at the Biotechnology Research Institute of
the National Research Council of Canada, 6100 Royalmount
Ave., Montreal, Quebec, Canada H4P 2R2.
Volume 50 June 2000
Journal of the Air & Waste Management Association 1009