United States
Environmental Protection
Agency
Municipal Environmental Research
Laboratory 7 ,
Cincinnati OH 45268
Research and Development
EPA-600/S2-83-012 Apr. 1983
&ER& Project Summary
Effects on Cattle from Exposure
to Sewage Sludge
J.C. Baxter, D. Johnson, W. D. Burge, E. Kienholz, and W.N. Cramer
This research was initiated to ex-
amine the effects of sewage sludge
disposal on agricultural land and the
potential for transmitting sludge con-
taminants into the food chain. Soils,
forages, and cattle grazing on a sludge
disposal site were examined for trace
metals and persistent organics. Cattle
were also fed diets containing digested
sludge to simulate worst-case condi-
tions of cattle grazing on sludge-fertil-
ized pastures.
Soils at the sludge disposal site had
increased concentrations on Zn, Cu,
Ni, Cd, and Pb. Forages from these
soils treated with sludge had higher
levels of Zn, Cd, Cu, and Ni and lower
Pb concentrations than forages from
soils that had not received sludge.
Cattle fed digested sewage sludge as
a percentage of their diet remained
healthy. The sludge had no positive or
negative effects on cattle performance
other than to act as a diet diluent. The
direct ingestion of sewage sludge led
to increased levels of Cd and Pb in
kidney and liver tissues. The amount
of Cd increase was related to: (1) the
concentration of Cd in the diet; (2) the
Cd source (Fort Collins sludge versus
Metro Denver sludge), and (3) the time
period of sludge ingestion. Concentra-
tions of Cu, Pb. and Cd in liver tissues
were shown to increase in a linear
fashion during sludge ingestion. Cad-
mium did not decrease in liver or kidney
tissues when sludge was removed from
the diet; however, Cu and Pb in liver
decreased significantly.
Fat tissue from all sludge ingestion
studies showed significant increases
in Pea's DDE, dieldrin, and oxychlor-
dane. DDE and dieldrin decreased
significantly when sludge was removed
from the diet, but PCB's did not
The effects to cattle from exposure
or ingestion of sewage sludge appear
benign. Thus, the principal health
hazards associated with grazing cattle
on sludge-fertilized pastures would be
an increased level of heavy metals
entering the human food chain through
kidney and liver consumption.
Additional studies were conducted
measuring the die-off rate of pathogens
in liquid sludge as the sludge dried in
earthen basins. Analysis showed that
as the sludge dried, the number of fecal
coliforms, total coliforms, salmonellae,
f 2 and T7 bacteriophage, andAscaris
ova decreased to low levels within
periods ranging from weeks to months.
This Project Summary was developed
by EPA's Municipal Environmental Re-
search Laboratory. Cincinnati, OH, to
announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
Although sewage sludge contains a
number of valuable nutrients and humus
materials that can be used to increase soil
fertility, problems are associated with the
recycling of sewage sludge. Much of our
sewage is not only derived from garbage
or fecal material but is the product of an
industrial society; thus, heavy metals and
persistent organics, many of which are
products or byproducts of industry, turn
up in sludge. In addition to these elements
and compounds, there is a disease po-
tential. The problems associated with
many of these elements, compounds, and
biological agents become particularly acute
when they are potentially harmful to crops,
animals, or the human food chain. The
principal objective of this research was to
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examine cattle exposed to varying amounts
of sewage sludge to determine whether
and to what extent contamination of cattle
tissue had occurred as a result of sludge
exposure To accomplish this objective
several separate, but interrelated, studies
were conducted.
The Metropolitan Denver Sewage Dis-
posal District No. 1 (Metro Denver) had
been recycling sewage sludge to land
since 1969. The sludge had been applied
to the soil surface, plowed under, and
planted to forages such as winter wheat
oats, sorghum, or sudan grass. A herd of
beef cattle that had been on the sludge
recycling site since the inception of sludge
disposal there subsequently grazed these
forages. These cattle had been exposed to
sewage sludge for 6 years and had ample
opportunity to ingest contaminants by
consuming sludge enriched forage or by
direct ingestion of soil and sludge. This
situation represented a unique opportunity
to examine some long-term effects of
cattle exposure to sludge from a somewhat
typical ongoing practice.
Soils, forages, and cattle from the sludge
disposal site (the abandoned Lowry Bombing
Range or LBR) were examined for heavy
metals and persistent organics. Disease
incidence, tissue heavy metal concentra-
tions, and persistent organics in fat tissues
from these cattle exposed to sludge were
compared with range cattle from a nearby
control ranch (no sludge exposure) and
with a larger group of cattle of known age
and no exposure to sludge.
Kidney and liver tissues (tissues known
to accumulate heavy metals) from cattle of
known age and no exposure to sewage
sludge were also examined so that infor-
mation concerning normal background
concentrations- of these tissues could be
developed. This information was then
compared with metal concentrations found
in tissues of cattle exposed to sludge.
Additional feeding studies were designed
around the premise that the application of
sludge to soil or pasture land will result in
the direct ingestion of sludge constituents.
To assess the magnitude of uptake of
heavy metals and persistent organics into
edible and other tissues of cattle, the
effects on cattle directly ingesting sludge
were examined
Three sludge feeding studies were con-
ducted: (1) young feed-lot steers were fed
0%, 4%, or 12% Metro Denver sludge (20
ppm Cd) for 3 months; (2) young feed-lot
steers were fed 0% and 12% Ft Collins
sludge (100 ppm Cd) for 3 months; (3)
older cows and young steers were main-
tained on 0% and 1 2% Ft Collins sludge
diets for 9 months, which was followed by
a 4-month withdrawal period in which no
sludge was fed. The quantities of sludge
were chosen to bracket likely ingestion
ranges including a worst-case situation.
Although cattle might ingest 12 % soil, the
likelihood that they would ingest 12 %
sludge is indeed remote. Special pains
were taken to feed a digested sludge
relatively high in cadmium concentration.
The objective was to have enough sludge
with enough cadmium to produce a measur-
able uptake and then attempt to relate
uptake to health effects.
This report also describes work that
examined the time required for the destruc-
tion of human pathogens. Pathogens
such as enteric viruses, bacteria, protozoan
cysts, and helminth ova have been shown
to survive anaerobic digestion of sewage
sludges, although the numbers of these
organisms are usually greatly decreased if
not eliminated by this process. Air drying
in beds and storage in stockpiles has the
potential to completely eliminate these
organisms. Anaerobically digested liquid
sewage sludge was placed in earthen
drying basins. The survival of endemic
saimonellae, fecal coliform, inoculated
Ascaris ova, and inoculated f2 and T7
bacteriophages were followed until these
indicator organisms could no longer be
detected.
Results
Heavy Metal Levels in Cattle
Tissue
Certain nonessential trace metals such
as Cd and Pb have been shown to increase
in specific tissues (kidney, liver, and bone)
during the life span of animals. Concentra-
tions of Fe, Zn, Cu, Cd, and Pb in kidney
and liver tissues of cattle not exposed to
sewage sludge were examined to augment
existing information concerning normal
tissue levels of these trace metals in cattle
exposed to different conditions. These
cattle served as control animals for the
LBR tests.
The selected cattle had known birth
dates and no previous exposure to sewage
sludge; the selection also provided a range
of dietary regimen, sex, and age. Animals
chosen for the study were: 4 beef cows
from the University of Wyoming; 25 range
beef cows from the same ranch in eastern
Colorado; 15 dairy cows from Colorado
State University; and 12 young feed-lot
steers used as controls in sludge feeding
trials. The 29 range cows varied in age
from 5 to 15 years, the steers were
approximately 18 months old, and the
dairy cows ranged in age from 2 to 8 years
at the time of slaughter.
Table 1 shows the mean concentrations
of Zn, Cu, Cd, Pb, and Fe in kidney and liver
tissues from the dairy and range cattle.
TheCu concentrations in liver tissues from
the dairy cattle were for the most part an
order of magnitude greater than those in
liver tissues from the range cattle. The
large difference in liver Cu concentrations
was probably because the dairy cattle
received dietary trace salt supplements
added directly to their feed, whereas the
range cattle would not have received simi-
lar supplementa The significant difference
in kidney Cd concentrations between the
range cattle and dairy cattle was caused by
Table 1. Mean Concentration of Trace Metals Determined in Kidney and Liver Tissues from
Control Cattle of Known Age
Tissue and
Element
Kidney:
Zn
Cu
Cd
Pb
Fe
Liver
Zn
Cu
Cd
Pb
Fe
fig/g (dry weight)
Range Cattle of Known Age
88.4
15.8
13.4
3.6
225
132
21.3
1.06
1.8
256
±
±
+
±
+
±
±
±
±
±
17.6*
3.2af
8.0a
1.7
73
25
32.3at
0.6
1.1
99
Dairy Cattle of Known Age
96
21.7
2.8
1.9
293
118
216
0.74
1.0
250
± 46
± 2.6 b
± 1.7b
± 1.3
± 64
± 26
+ 966
± 0.9
± 1.0
+ 72
* Mean ± standard deviation.
t Values followed by different letters are significantly different at the 1 % level using Student's t-
test
t If the 4 range cows from Wyoming are excluded from this analysis, the mean of the 25 Colorado
range cows becomes 9.5 ±3.18 ftg/g Cu. The difference between range and dairy cattle is still
significant
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a difference in age; the range-cattle age
averaged 10 years, whereas the dairy-
cattle age averaged 4 years (Figure 1). The
range of Cd concentration was from 0.83
ppm in a 2-year-old dairy cow to 31.2 ppm
in a 13-year-old range cow. Levels of
other metals did not increase or decrease
in liver or kidney tissues with the age of the
animals.
Heavy Metals and Persistent
Organics at the LBR Sludge
Disposal Site
The heavy metal status of soils at the
LBR sludge disposal site showed that
concentrations of Zn, Cu, Ni, Cd, Pb, and
Hg were increased (Table 2), and concen-
trations of As, Se, Mo, and 22 organics
were unaffected by sludge amendment
Forage crops grown on these sludge-
amended soils showed increased tissue
concentrations of Zn, Cu, Cd, and Ni (Table
3); however, none of the metal concentra-
tions were elevated to a phytotoxic level or
to a range that would be considered ab-
normal for forage tissues. Concentrations
of As, Se, and Hg in forage tissues were
unchanged, and Pb concentrations de-
creased as a result of sludge applications.
None of the forage tissues examined con-
tained detectable levels of 22 persistent
organics.
Heavy Metal and Persistent
Organics Content of Cattle
Tissues from the LBR Sludge
Disposal Site
Twelve older range cows, which had
been on the LBR sludge disposal site since
the beginning of disposal operations, were
slaughtered and various tissues sampled
for heavy metals and persistent organics
analysis. Heavy metal concentrations in
25
20
15
10
5
5 '
i
8 r
11 T
3 L-rh
12 j. rn N- J
A Rl II II
t
}
n
5
5
A
2 4 6 S /O 12 14
Age (years)
Figure 1. Mean concentration of Cd in
kidney tissues (dry weight) as a
function of cattle age. Numbers
above bars represent number of
animals for each group. Tick
marks represent standard devia-
tion for each group.
kidney, liver, and muscle tissues were, for
the most part, within a range that is
considered normal for older beef-type cows
(Table 4). Muscle tissues, the primary
food tissue, contained levels of Cd and Pb
that were below detection limits. The Cu
concentrations of liver tissues were un-
expectedly low. These low liver Cu levels
indicated that dietary Cu levels must have
been low; thus, little sludge could have
been consumed by the cattle.
Fat tissues were the only tissues to
show any detectable levels of organic
residues. Detectable levels of alpha-BHC,
HCB, DDE, dieldrin, and PCB's were found
in both the sludge-exposed cattle and
cattle from a nearby control ranch; however,
there were no differences between the
two groups that appear to be attributable
to sludge.
Cattle grazing the LBR sludge disposal
site were healthy and showed no greater
incidence of disease or death loss than
other herds in the area not exposed to
sludge. Postmortem pathological examin-
ation of internal organs showed no signifi-
cant differences between the LBR-site
cattle and a nearby control herd.
Effects of Sludge Ingestion by
Cattle
Three separate experiments were carried
out in which dried sewage sludge was fed
to cattle (as a percentage of their diet) to
simulate worst-case conditions of cattle
grazing on sludge-fertilized pastures. All
of the cattle in these experiments remained
healthy throughout the duration of the
experiments, and the sludge was shown
to have no negative or positive effects on
Table 2.
Mean, Median, and Range of Heavy Metals in Surface Soil Samples from Areas of
Sludge Application and Control Areas Within LBR Site
IJtg/g (dry weight)
No Sludge Applications
Areas of Sludge Application
Element
Zn
Cd
Cu
Ni
Pb
As
Se
Hg
Mean
50.8
0.43
10.6
11.8
18.2
<3
<1
<0.027
Range
39.5
0.18
6.75
6.0
14.0
<3
<1
0.010
-62.5
- 0.72
- 18.8
-43
-22.0
- 3
- 0.090
Median
93
1.45
11.0
21.8
36.2
3
1
0.150
Range
40
0.43
8.6
6.00
14.2
<3
<1
<0.010
-252
- 4.40
- 50.0
- 43.0
- 101
- 5
- 2
- 0.580
Table 3.
Element
Heavy Metal Concentrations of Forages from the LBR Site
fig/g (dry weight)
No Sludge Applications
Mean
Sludge Applied
Median
Range
Zn
Cd
Cu
Ni
Pb
As
Se
Hg
11.7
0.11
2.28
<0.57
2.3
<0.25
<0.35
0.024
75.8 37.2 - 153
1.08 0.25 - 3.70
12.5 3.80 - 22.0
2.80 0.25 - 15.5
0.75 <0.65 - 4.0
<0.25 <0.2S
<0.25 0.25
0.020 0.010 - 0.100
Table 4.
Mean Tissue Concentration of Control Range Cattle (Known Age) and Sludge Exposed
Cattle at LBR Site
Tissue
Kidney:
Control (range)
LBR Site
Liver
Control (range)
LBR Site
Animals
Sampled
29
12
29
12
/jg/g (dry weight)
Cd
13.4a*
16a
1.1 a
0.8a
Cu
15.8a
16.1 a
9.5a
4.6b
Zn
88.4a
93a
132a
129a
Pb
3.6 a
0.8a
1.8a
0.3a
Fe
225
NDt
256
ND
* Values followed by different letters within a column are significantly different at the 1% level
(Student's t-test).
fNot determined.
-------
cattle performance other than to act as a
diet diluent
The first feeding study was conducted
with the use of young feed-lot steers that
were fed feed-lot rations containing 0%,
4%, or 12% (dry weight) Metro Denver
sludge. In the second feeding study,
similar steers were fed feed-lot rations
containing 0% or 12% (dry weight) Ft
Collins sludge-sludge with Cd and Cu
levels five times and two times, respectively,
that of the Metro Denver sludge. Other
metal concentrations were similar for the
two sludges The duration of both feeding
studies was approximately 3 months.
Analysis of kidney and liver tissues revealed
significant increases of Cd and Pb because
of the increased dietary levels of these
metals (Table 5). The estimated availability
or absorption and retention of Cd from the
sludges into the cattle tissues measured
0.07% for the Ft. Collins sludge and
0.02% for the Metro Denver sludge. Not
all of the cattle tissues were analyzed for
uptake of heavy metals; thus, total uptake
by all cattle tissues could be higher, but
probably less than 1 % at best Even a 1 %
uptake through consumption of sewage
sludge is significantly less than the 2% to
9% reported by other researchers utilizing
Cd salts and a variety of other animal
species; thus indicating that Cd uptake
from both sources of sewage sludges
were less available for tissue uptake and/or
retention. Muscle tissues showed no
heavy increases due to the sludge ingestion
after this 3-month period.
It is known that young animals of most
species absorb greater percentages of
dietary heavy metals (particularly Pb) than
older animals, but the extent to which this
might occur in cattle had not been investi-
gated. The feeding trials described herein
used young feed-lot steers; thus, the metal
uptake levels could have been higher in
select animal tissues than would have
occurred with older animals. Another as-
pect not examined in these studies was
the possibility that some portion of the
sludge-borne tissue contaminants could
be eliminated once the sludge was removed
from the cattle diet
A third sludge-feeding study was then
conducted. An older group of 16 Hereford
cows (3 to 7 years old) and a group of 16
Hereford steers (6 months old) were each
divided into two groups of eight each and
fed maintenance diets consisting of 0%
(controls) or 1 296 (dry weight) Ft Collins
sewage sludge. Thus, the 12% sludge
diet was fed to eight cows and eight steers
(two of the four treatment groups) for 9
months. At the end of the 9- month period.
four cows and four steers from each
treatment group were slaughtered. The
remaining animals were kept on test for
another4 months, but sludge was removed
from the diet of those that had been fed
sludge. All of the remaining animals were
then slaughtered at the conclusion of the
4-month sludge withdrawal period. Periodic
bone and liver biopsies taken over the 13-
month test period permitted a more detailed
investigation of uptake and depletion rates
of heavy metals in these tissues.
Analyses of liver biopsies from the sludge
fed cattle showed that Cd increased in liver
tissues with time in a linear fashion (Figure
2). Cu and Pb also increased significantly,
but decreased when sludge was removed
from the diet (Figures 3 and 4).
The ingested sludge resulted in signifi-
cant increases of Cd, Pb, and Zn in kidney
tissues (Table 6). Cadmium concentrations
did not decrease after the sludge with-
drawal period, but Pb concentrations appear-
ed to have decreased slightly during the
withdrawal period
Fat tissues were analyzed for 22 persis-
tent organics. DDE and TNC increased
significantly in fat tissues due to the sludge
ingestion, but decreased significantly
during the 4-month withdrawal period.
Table 5. Mean Cd Zn, Cu, and Pb of Ft Collins and Metro Denver Sludges and Tissue
Concentration from Cattle Fed These Sludges
Tissue Types and %
iig/g(dry weight)
Sludge in Diet
Ft Collins Sludge:
Kidney -0%
Kidney- 12%
Liver - 0%
Liver- 12%
Metro Denver Sludge:
Kidney - 0%
Kidney- 12%
Liver -0%
Liver- 12%
Cd
98
1.2 a*
14 b
0.1 9a
4.9 b
21
1.1 a
2.4b
0.2a
0.4b
Zn
1700
93a
96a
142a
132a
1500
84a
82a
87a
101b
Cu
1700
23a
21b
127 a
113a
710
17 a
15b
124a
240b
Pb
470
0.95a
11 b
0.31 a
4.3 b
780
0.9a
15.8b
0.2a
4.6b
* Means followed by different letters within a column and tissue type are significantly different at
the 5% level (Student's t-test).
Sludge Fed Steers
y = 2.38X + 0.74
r = 0.999
12'
5
O
X
Sludge Fed Cows
y =1.85x^0.75
r = 0.98
O
X
Sludge
Feeding
Period
O Sludge Fed Cows
X Sludge Fed Steers
Control Cows
A Control Steers
No Sludge
in Diet
6 9
Months
11
13
Figure 2.
Cadmium concentrations (dry weight) of liver biopsies during the 9-month sludge
ingestion period and 4-month withdrawal period.
-------
400-1
Sludge Fed Steers
y-37.3x + 83
r = 0.52
Sludge Fed Cows
v = 17.8x^113.4
Sludge Fed Steers
Y = -62x + 547
r = 0.53
Sludge Fed Cows
y = -19x + 430
/ = 0.56
Control Cows
Control Steers
6 5
Months
11 13
O Sludge Fed Cows
X Sludge Fed Steers
Control Cows
& Control Steers
Figure 3. Copper concentrations (dry weight} of liver biopsies during the 9-month sludge
ingestion period and 4-month withdrawal period.
Sludge Fed Cows
y - O.Sx + 1.98
r = 0.87
Sludge Fed Steers
y = 0.35*+ 2.60
r = 0.69
Sludge Fed Cows
y = -1.2x + 17
r = 0.87
Sludge Fed Steers
y = -0.83x + 73.2
r = 0.73
Control Cows
Control Steers
-A-
3
i
4
6 9
Months
\
-wV
e
A
;/ 13
O Sludge Fed Cows
X Sludge Fed Steers
Control Cows
& Control Steers
Figure 4. Lead concentrations (dry weight) of liver biopsies during the 9-month sludge
ingestion period and 4-month withdrawal period.
which indicates that both compounds were
either metabolized or eliminated from fat
tissues. Dieldrins, PCB's, HCB, and oxy-
chlordane all showed significant increases
because of sludge ingestion and decreased
after sludge withdrawal. These decreases
were not statistically significant however.
Trace levels of DDT, heptachlor epoxide,
and chlordane were found in most fat
samples analyzed but were not elevated
because of sludge ingestion.
Microbiological Studies of Air-
Dried Sludge
The microbiological studies showed that
with adequate drying and residence time
in earthen drying beds, any enteric pathogens
remaining in the sludge after anaerobic
digestion should be destroyed. The virus
indicator organism f2 had a maximum
survival time of 19 weeks even though
initial concentrations were orders of mag-
nitude in excess of any enteroviruses.
Salmonellae and fecal coliform bacteria
persisted for 70 and 73 weeks, respective-
ly, because of their ability for regrowth.
Sludge desiccation may have been the
most important factor in bringing about
the disappearance of these persistent or-
ganisms. Salmonellae were not detectable
after the sludge had dropped to about
3096 moisture. Fecal coliforms were de-
tectable at less than 5% moisture, but at
very low concentrations. Ascaris ova were
also sensitive to moisture. Only a small
portion of the inoculated ova were viable
when the sludge moisture content had
dropped to 7.796.
Storage of sludge for a year with a
resulting decrease in sludge moisture to
1096 or less should reduce any pathogenic
organisms left after anaerobic digestion to
undetectable levels. The likelihood of
pathogenic microorganisms moving from
the sludge into the groundwater before
being inactivated is negligible.
Conclusions
The effects on cattle from exposure or
ingestion of sewage sludge appear to be
benign. The ingestion of high levels of
sewage sludge by cattle will, however,
raise heavy metal concentrations of a
number of tissues (mainly kidney and
liver) and will also raise the persistent
organics content of fat tissues. The de-
gree of elevation, of course, is a function of
the amount of ingestion and concentration
of these substances in the sludge. The
data collected permit estimates of the
elevation to be made as a function of the
extent of ingestion.
Muscle tissue, the principal food tissue
for man, was effectively screened from
-------
excessive accumulations of the contamin-
ants examined in this study. The entry of
Cd and other heavy metals into the diet of
man would be largely through liver con-
sumption. Although high levels of Cd
were reached in liver and kidney tissues of
cattle consuming Ft Collins sludge for 9
months, this was an extreme case and is
not likely to occur under normal agricul-
tural practices. It appears that cattle would
act as an effective screen against these
metals if sludges are properly used for the
fertilization of agricultural land. Thus, if
low metals sludges, such as the Metro
Denver sludge, are applied to calcareous
soils as a fertilizer and subsequently tilled
into the plow layer, there would appear to
be little potential hazard to the food chain.
The full report was submitted in fulfill-
ment of contract No. 68-03-2210 by the
Metropolitan Denver Sewage Disposal
District No. 1 underthesponsorshipofthe
U.S. Environmental Protection Agency and
the office of the Associate Director for
Physical Science, U.S. Food and Drug
Administration.
Table 6. Heavy Metals Concentrations in Kidney Tissues of Cattle After 9 Months of Sludge
Ingestion and a 4-Month Withdrawal Period
/jg/g (dry weight)
Treatment
Cows:
Control *
Sludge Fedf
Sludge Withdrawn §
Steers:
Control*
Sludge Fedf
Sludge Withdrawn §
Cd
7.4at
54.0b
69.0b
3.5a
57.06
64.0b
Pb
1.4a
4.3b
3.4b
1.1 a
5.2b
3.4b
Zn
77a
88b
131c
82a
98b
116c
Fe
320a
281 a
343a
255a
290a
247 a
Cu
17a
15a
17 a
19a
16a
16a
* Average of all control animals, 9-month and 4-month withdrawal period.
t Values within a group followed by different letters are significantly different at the 5% level using
Student's t-test
t Cattle fed diet containing 12% sludge and slaughtered at 9 months.
§Cattle fed diet containing 12% sludge and slaughtered after 4-month withdrawal period.
J. C. Baxter is with Metropolitan Denver Sewage Disposal District No. 1. Denver,
CO 80229; D. Johnson andE. Kienholz are with Colorado State University. Fort
Collins, CO 80705; W. D. Burge and W. N. Cramer are with the U. S, Department
of Agriculture. Beltsville, MD 20705.
Gerald Stern is the EPA Project Officer (see below).
The complete report, entitled "Effects on Cattle from Exposure to Sewage
Sludge," (Order No. PB 83-170 589; Cost: $16.00, subject to change) will be
available only from:
National Technical Information Service
5285 Port Royal Road
Springfield. VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Municipal Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
U. S. GOVERNMENT PRINTING OFFICE: i!983/6S9-095/1924
-------
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Environmental Protection
Agency
Center for Environmental Research
Information
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