United States
Environmental Protection
Agency
Robert S. Kerr Environmental
Research Laboratory
Ada, OK 74820
Research and Development
EPA/600/S1 -90/006 July 1990
SEPA Project Summary
Performance Evaluation at a
Long-Term Food Processing
Land Treatment Site
Dante J. Tedaldi and Raymond C. Loehr
The objective of this project was to
determine the performance of a full-
scale, operating overland flow land
(OLF) treatment system treating non-
hazardous waste. Performance was
evaluated in terms of treatment of the
applied waste and the environmental
impact of the system, particularly on
surface and ground water quality.
Performance data were obtained from
the Campbell Soup (Texas), Inc. OLF
system in Paris, TX, which has been
in operation for over 24 years. Field
samples of soil, wastewater, OLF
runoff, and ground water collected
during the project and long-term
process records maintained by
Campbell Soup were used as part of
the evaluation. The long-term
operation and performance data
indicated that the OLF system
consistently achieved a very high
level of treatment and pollutant
removal, from a surface discharge
standpoint. Removals of BOD5, COD,
TOC, and TSS have been consistently
high with mean individual pollutant
removals of >92% (mass basis) and
>93% (concentration basis). Total
nitrogen removals were between 84
and 89%. Effluent mass discharges
have remained well within the
regulatory limitations for suspended
solids and BOD5 over the 24 years
that the site has been in operation.
Although the accumulation of zinc
and nickel was evident, the
cumulative soil concentrations (200
kg/ha and 85 kg/ha) were well below
EPA recommended limits (1,120 kg/ha
and 560 kg/ha) and several hundred
years of continued site use may be
expected at present average loading
rates (3 kg/d and 0.2 kg/d). The OLF
site was underlain by several meters
of a heavy inorganic clay (Bonham
Formation). A semiconfined aquifer,
partially confined from above by the
Bonham Formation clays and slowly
recharged by downward leakage of
treated wastewater and precipitation
through the Bonham Formation exists
below the OLF site. The aquifer is
confined from below by the dense,
fissile shale of the Eagle Ford Group.
Ground water below the OLF site was
moderately saline due to the
presence of sodium, calcium,
magnesium, chloride, and sulfate. No
purgeable or extractable organics
were detected. Geochemical data
indicated that sulfate-chloride fades
were dominant for the ground water
collected at three monitoring wells at
the OLF site and for lysimeter data
collected in 1968. A pattern of
increasing ionic composition over
time (1968 to 1989) with relatively
small changes in ionic ratios
suggested a trend toward the
dissolution (due to the infiltration of
large volumes of treated wastewater)
and concentration of naturally
present minerals (in the soil) in the
relatively slow moving groundwater.
This Project Summary was
developed by EPA's Robert S. Kerr
Environmental Research Laboratory,
Ada, OK, to announce key findings of
the research project that is fully,
documented in a separate report off
the same title (see Project Report
ordering information at back).
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Introduction
The Resource Conservation and
Recovery Act (RCRA) Amendments of
1984 require the U.S. Environmental
Protection Agency (EPA) to assess the
adequacy of current federal programs to
protect human health and the
environment from mismanagement of
non-hazardous and unlisted hazardous
wastes. Because the land disposal
options of concern for listed hazardous
wastes include landfills, land treatment,
waste piles, surface impoundments and
salt domes, the EPA evaluation of RCRA
Subtitle D unlisted wastes includes these
options. As a result, information is
needed to support EPA activities related
to the evaluation of Subtitle D wastes.
The EPA Office of Solid Waste (OSW)
has assessed the extent of land disposal
for Subtitle D industrial wastes. The
assessment indicated that at least 145
million metric tons of industrial non-
hazardous waste (35% of all such waste)
are managed by on-site landfills, surface
impoundments and land application. The
OSW assessment also indicated
significant missing information, especially
data related to the performance achieved
when such disposal options are used.
Much of the available data were over 10
years old and little information existed on
the impact that such operating land
disposal options have on human health
and the environment.
Objectives
The primary objective of this project
was to determine the performance of a
full-scale, operating overland flow (OLF)
land treatment facility treating non-
hazardous waste. Performance was to be
evaluated in terms of pollutant reduction
and removal from the applied waste and
the environmental impact of the system,
particularly surface and groundwater
quality. Performance data were to be
obtained from a land treatment system
that had been operating for an extended
period of time to permit the evaluation of
long-term performance trends.
OLF Site Description
The Campbell Soup (Texas), Inc. OLF
treatment system located in Paris, Texas,
was utilized for all research described in
this report. The plant processes about
one billion cans of soup per year and
employs about 1,600 people. The site
has about 364 hectares (700 ac) that are
being used for the land treatment of
vegetable processing wastewater by the
OLF method. About 16,000 cubic
meters/day (4.25 mgd) are handled in
this manner. Only the vegetable
processing! and can preparation
wastewaters are applied to the site. All
sanitary wastewaters from the plant are
discharged tb the Paris, Texas, municipal
wastewater freatment plant. In addition,
all storm water and can cooling water are
handled separately and discharged
directly to surface streams.
The size of the land treatment system
has increased over the years. The
original site (1964) consisted of 120 ha
(300 ac). Three expansions have
occurred: each of approximately 80 ha
(200 ac). Trje expansions resulted in a
total of 365 ha (900 ac) being included in
the OLF system. Not all of the site is
available for! wastewater treatment and
over 485 ha (1,200 ac) comprise the
entire site. \
The original fields have been in
operation the longest, since the 1960's.
The second set of fields began to be
used in the early 1970's and in the late
1970's the thjrd set of fields began to be
used. This allowed the opportunity to
evaluate soiljs'that have* received wastes
for different time periods.
About 1.5J cm (hydraulic application
rate) of wastewater are applied to the
wetted acre'age each day. Prior to
application, tne wastewater is screened to
remove large solids, and grease is
skimmed. The plant and the land
treatment site operate all year. No
storage is used. The wastewater is
pumped directly from a 375-cubic meter
sump (100,000-gallon) and is applied by
spray nozzles that have a spray diameter
of 30 m (150, ft). The overland flow slopes
are about 55im (170 ft) in length.,
The soils ^t site are clays and sandy
clay loams. ^ semiconfined aquifer exists
below the site. Depth to this aquifer from
the ground surface varies.between 5 m
and 10 m (15 to 30 ft). The vegetation on
the land treatment site is Reed canary
grass and [tall fescue. The crop is
harvested 2 to 3 times per year and used
as forage in the local area.
The Paris,[Texas site was evaluated in
considerable! detail in the late 1960's. The
early research focused on the surface
hydrology and treatment performance of
the system. |These early studies served
as sources of basic information and as
"background" data. In addition, many of
the CampbeII Soup personnel and the
RSKERL personnel who were involved in
the earlier research were still active and
were able to participate in this project.
Thus, considerable "historical memory"
and knowledge about the plant, available
data and the operation of the OLF system |
was available to the project.
Campbell Soup agreed to cooperate asl
actively as possible in the study, to assist!
with the sampling that was performed!
and to provide the available historical!
operational and other data. This included I
available wastewater characteristic data,!
effluent monitoring data and weatherl
data. The wastewater data represented!
the material from the sump and therefore!
the characteristics of the wastewaterl
actually applied to the site. Such datal
had been collected approximately twice!
per month for 10 years. In addition,!
effluent monitoring data have beenl
collected three times a week for 10 years
and daily climatological data covering a|
15-year period were available.
Raw Waste Characteristics
Comprehensive records of raw waste I
characteristics and flow, covering the
period between 1977 and 1988, were
made available by Campbell Soup for
this research. Composite samples were
collected from the sump several times
each month (two to three composite
samples) and typically were analyzed for
BOD5, COD, oil and grease, TSS, VSS, [
chloride, and sulfate.
Application rates (wetted area basis)
have varied substantially over the 24 |
years of operation; however, statistical
analyses of the cumulative raw data
revealed that waste characteristics and
mass loading were relatively constant
over the 10-year period of record.
The sump wastewater characteristics
for the 10-year period between 1977 and
1988 are summarized in Table 1.
Comparison of several of these
parameters with values reported from the
1960s indicated that most values from
the 1960's data were within or very near
the limits of 95% confidence intervals
about the mean of the 1977-1988 data. In
general, it appeared that waste
characteristics have remained relatively
constant without significant deviation from
the mean over the life of the site. This
constancy permitted direct comparisons
to be made of process performance over
the 25-year period of operation.
OLF System Performance
Because Federal and State regulatory
limitations have been established for flow,
BOD5 and TSS loads discharged from
the Paris, Texas site, an evaluation of the
degree of compliance within these limits
served as a convenient and common
measure of system performance. Daily
average waste loading values (monthly
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Table 1. Long-Term Mean Wastewater Concentrations and Loading to OLF Site Period: 1977-1988
Wastewater Mean Standard Deviation. Standard Deviation,
Parameters Concentration, mg/L mg/'L Mean Load kg/d kg/d
BODg
COD
Oil/Grease
TSS
VSS
cr
SO42'
NH4*-N
Org-N
NO3-N
NO2-N
Total-P
Sodium
Potassium
Calcium
Magnesium
Iron
Manganese
Aluminum
Zinc
Strontium
550
1,190
125
425
370
66
40
0.7
27
0.33
0.03
6
47
24
45
4.0
0.71
0.04
0.72
0.17
0.08
210
520
80
210
200
47
40
0.7
27
0.33
0.03
6
16
12
24
1.4
0.41
0.03
0.63
0.11
0.08
8.950
19,600
2,170
7,085
6.330
1,060
633
13
480
6
0.4
91
760
390
725
65
11
1
12
3
3
4.100
9,555
1,345
3,730
3.640
780
320
9
178
10
0.2
39
255
195
380
22
7
1
10
2
1
means) over the period between 1974
and 1988 indicated that the water quality
in Smith Creek (representing the
combined flow of OLF runoff and natural
stream flow from offsite) was
continuously well below regulatory limits.
A summary of these data (Table 2)
illustrates the exemplary permit
compliance achieved by the OLF system.
Mass balances were made around the
Paris, Texas land treatment site using
daily upstream and downstream (Smith
Creek) flow and concentration data; and
daily raw waste flow and concentration
data supplied by Campbell Soup.
Because no monthly or seasonal trends
were observed for either raw wastewater
loading or in-stream loading in Smith
Creek, the daily data were used for the
mass balance calculations.
Since the actual land treatment site
runoff was not measured, an assumption
of the applied wastewater that was
discharged as runoff was needed.
Previous research has shown that the
runoff percentage at the Paris, Texas site
varied seasonally, between 44 and 72%;
. with 60% as the mean. In addition,
variation in application rate, wetted
acreage and soil properties could have
also affected the runoff percentage.
Therefore, it was assumed that a value of
60% was a suitable estimate for the
percentage of runoff flow. As a result, the
concentration values shown in Table 3
are not exact, but are estimates which
provide an approximation of the overall
system performance.
The data in Table 3 indicate that mass
removal and concentration change
percentages for all parameters are
generally in excess of 90%. The data
from 1969 show excellent agreement with
the estimated values from the 1977-1988
period. Thus, it appears that process
performance remained relatively stable
and a high degree of efficiency was
maintained over the entire 24-year life of
the system.
Soils
Soil samples were collected at specific
wastewater application areas and at one
location onsite which had not been
subjected to wastewater application. The
soil properties within this "control" area
provided a comparative measure for the
evaluation of the long-term impacts of
wastewater application on soils within the
treatment area. In addition, where
appropriate data were available, direct
comparisons of soil properties were
made between recently collected
samples and previously published results
for the Paris, Texas site. The soils were
analyzed for organic carbon, pH, cation
exchange capacity, 24 metals, and
chloride and sulfate.
Several statistically significant (p <
0.05) trends were discerned for the total
metal soil concentration data and the
calculated pore water concentrations.
With respect to the control area,
accumulation of organic carbon,
potassium, magnesium, zinc, and nickel
in the soil at the wastewater application
areas were evident, as well as leaching of
calcium, sodium, and sulfate and
possibly chloride, zinc, and nickel.
Neither accumulation nor leaching of
chromium was evident.
Although the accumulation of zinc and
nickel was evident, the accumulation was
so small that several hundred years of
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Table 2. Effluent Loads in Smith Creek and Permit Limitations
\
Parameter3 Mean Load
95% Confidence
Interval
eoD5
rss
vss
80
445
190
71
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Table 4. Groundwater Quality at Campbell Soup Site: Mean Values and Standard
Deviation3
Constituent13
MW-1
MW-2
3Mean values and standard deviation.
h All units in mg/L, except pH.
cSingle analysis performed.
dRange provided for pH.
MW-3
Calcium
Magnesium
Manganese
Nickel
Potassium
Sodium
Zinc
Chloride
Sulfate
Alkalinity as CaCO3
roc
pH
472 ± 42
247 ± 65
0.52 ±0.11
0:03 ± 0.02
7.9 ± 1.7
2,870 ± 452
0.02 ± 0.01
2,151 ± 322
5,268 ± 834
610 ± 42
<10
6.9 - 7.2
525 ± 32
129 ± 38
1.79 ± 0.18
0.03 ± 0.02
8.8 ± 1.55
2,026 ±415
0.02 ± 0.01
1,856 ± 440
3,447 ± 76
655 ± 7
<10
6.8 - 7.0
496 ± 6.5
169 ± 49
4.20 ±0.18
0.35 ± 0.0
13.5 ± 3.7
1,623 ± 623
1.61 ± 0.21
1,200C
3,1 00C
27 ± 10
NA
4.9 - 5.4
Several graphical techniques were
used to visually examine the similarity in
water quality among the three monitoring
well locations and lysimeter data
collected at the site in 1968. Schoeller
plots of major-ion concentrations
indicated that water collected from all
three monitoring wells exhibited similar
ionic composition ratios (Figure 1). Ionic
ratios (Figure 2) of major ions in
groundwater data collected from
lysimeters at the site in 1968 exhibited
excellent agreement with comparable
ionic ratios for more recent samples
(MW-2, 1987-1989). The pattern of
increasing ionic composition with
relatively small changes in ionic ratios
strongly suggested a trend towards the
concentration of dissolved minerals in the
relatively slow moving groundwater.
The geochemical data indicated that
sulfate-chloride fades were dominant for
groundwater at all three monitoring wells
(MW-1, MW-2, and MW-3) and for the
lysimeter data collected in 1968. Thus,
the similarity of water quality among well
locations as well as the similarity in the
pattern of geochemical evolution over the
past 24 years was suggested.
The infiltration of treated wastewater,
development of semiconfined aquifer, the
dissolution of soluble minerals from the
soil and resultant effects on the quality of
gorundwater below the site were strongly
suggested by the ground water
geochemical data, soil data, the expected
rate of infiltration, field hydraulic
conductivity and water level
measurements, and the magnitude of the
volume of wastewater applied.
Conclusions
Raw Waste Characteristics
1. Over a 10-year period between 1977
and 1988 the main characteristics
(BOD5, COD, chlorides, sulfates and
solids mass loadings) of the raw
wastewater exhibited normal
distributions.
2. Statistical comparison of raw
wastewater quality between recent and
old data indicated long-term
consistency with respect to flow and
pollutant concentrations.
3. Individual metal loadings were variable
over a 12-month period.
OLF System Performance
4. Seasonally heavy precipitation (>7.5
cm/month) resulted in small increases
in TSS mass discharges (200 kg/d to
500 kg/d) within Smith Creek. These
increases were well below regulatory
mass loading limitations (values) and
no statistically significant correlation (p
< 0.05) was found between the TSS
loading and precipitation.
5. Small increases in TSS loading in
Smith Creek during periods of heavy
precipitation were due to upstream
(off-site) sources rather than losses
form the OLF site.
6. The long-term operation and
performance data indicated that the
system consistently achieved a very
high level of treatment, from a surface
discharge standpoint. In-stream
concentrations of BOD5, COD, TOC
and TSS indicated that mean removals
were greater than 93%. Total nitrogen
removals were between 84 and 89%.
Effluent mass discharges have
remained well within the regulatory
limitations for solids and BOD5 over
the past 24 years. Percent removals
(mass basis) for BOD5, COD, TOC and
TSS have been consistently high
(>92%) over the 24-year life of the
site.
Soils
7. With respect to a control area,
accumulation of organic carbon,
potassium, zinc and nickel in the soil
at the wastewater application areas
was evident, as well as leaching of
calcium, sodium, and sulfate. Neither
accumulation nor leaching of
chromium, magnesium, and chloride
was evident.
8. Although the accumulation of zinc and
nickel was evident, the rate of
accumulation was small and several
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1000 c
Ca Mg Na'K< Cl SO4 HCO3
Figure LSchoeller diagram for mean ionic' concentrations (major ions) at 3 monitoring wells.
Lysimeter G-4 -£3- Lysimeter G-11
o.or
Ca Mg Na'K Cl SO4 HCO3
Figure 2. Schoeller diagram for mean ionic concentrations (major ions) over 24 years.
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hundred years of continued site use
may be expected at present loading
rates.
Hydrogeology
9. The results of the hydrogeologic
investigation indicated that an aquifer
exists below the OLF site. The data
suggested that the aquifer was semi-
confined.
10. The results indicated that the
erosional contact between the lower
confining unit (Eagle Ford Group)
and the aquifer (Bonham Formation
within the Austin Group) may serve
as a transmission zone for
groundwater within the relative
impermeable clays of the Bonham
Formation. Measured hydraulic
conductivity values (average k
between 1CH and 10-3 cnrvs) within
the erosional contact zone between
the Eagle Ford and Austin Groups
were substantially greater than
typical values for unweathered
marine clay and shale (k between
10-11 and 10-8cm/s).
11. Groundwater level data indicated that
the general flow direction was to the
northwest with a hydraulic gradient of
approximately 0.004 m/m.
Groundwater Quality
12. Twenty-six groundwater samples
collected from three monitoring wells
between 1987 and 1989 were
analyzed. The waters were
moderately saline (TDS between
7,000 and 13,000 mg/L) due to the
presence of Na", Ca2*, Mg2*, CI".
and S042". No purgeable or
extractable organics were detected.
13. Statistical analysis of the
groundwater data indicated that, for
the major ions present, groundwater
quality at each well remained uniform
over the three-year sampling period.
Statistically significant differences (p
= 0.05) in water quality (including
calcium, magnesium, manganese,
sodium, and sulfate) between the
well locations were found.
14. State records indicated that no well
casings in Lamar County were
screened within the contact zone of
the Austin Chalk-Eagle Ford Groups.
In addition, no springs which issued
from the Bonham Formation were
identified within Lamar County or any
adjacent counties.
15. The major-ion chemistries
(expressed as ionic ratios) of the
groundwater samples collected from
the confined aquifer were similar at
all three monitoring wells. The major-
ion composition data suggested the
groundwater below the site have
undergone similar patterns of
geochemical evolution.
16. Ionic ratios of major ions in
groundwater data collected from
lysimeters at the site in 1968 closely
agreed with comparable ionic ratios
for more recent samples (1987-
1988). The pattern of increasing ionic
composition with relatively small
changes in ionic ratios strongly
suggested a trend towards the
concentration of dissolved minerals
in the relatively slow moving
groundwater.
17. The geochemical data indicated that
sulfate-chloride facies were dominant
for groundwater at all three
monitoring wells (MW-1, MW-2 and
MW-3) and for the lysimeter data
collected in 1968. Thus, the similarity
of water quality among well locations
as well as the similarity in the pattern
of geochemical evolution over the
past 24 years were strongly
suggested.
18. The moderately saline aquifer below
the OLF site was apparently the
result of the enhanced leaching of
naturally present, soluble soil
minerals due to the infiltration of
large volumes (based on estimated
percolation rates) of treated
wastewater over the past 24 years.
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Dante J. Tedaldi and Raymond C. Loehr are with The University of Texas at
Austin, Austin, TX 78712.
Bert £ Bledsoe is the EPA Project Officer (see below).
The complete report, entitled "Performance Evaluation at a Long-Term Food
Processing Land Treatment Site," (Order No. PB 90-195 389/AS; Cost:
$23.00, 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: \
Robert S. Kerr Environmental Research Laboratory
U.S. Environmental Protection Agency
Ada, OK 74820 :
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S1-90/006
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