United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Cincinnati OH 45268
EPA * 3 205
<78
Research and Development
&EPA
Treatment of
Packinghouse
Wastewater by
Intermittent Sand
Filtration
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2 Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-78-205
September 1978
TREATMENT OF PACKINGHOUSE WASTEWATER
BY INTERMITTENT SAND FILTRATION
by
M. L. Rowe
East Central University
Ada, Oklahoma 74820
Grant No. S-803766
Project Officer
Jack L. Witherow
Food and Wood Products Branch
Industrial Environmental Research Laboratory
Corvallis, Oregon 97330
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U. S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental Research
Laboratory, U. S. Environmental Protection Agency, and approved for publica-
tion. Approval does not signify that the contents necessarily reflect the
views and policies of the U. S. Environmental Protection Agency, nor does
mention of trade names or commercial products constitute endorsement or re-
commendation for use.
ii
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FOREWORD
When energy and material resources are extracted, processed, converted,
and used, the related pollutional impacts on our environment and even on our
health often require that new and increasingly more efficient pollution con-
trol methods be used. The Industrial Environmental Research Laboratory -
Cincinnati (IERL-Ci) assists in developing and demonstrating new and improved
methodologies that will meet these needs both efficiently and economically.
This report evaluates a full scale wastewater treatment system consist-
ing of a novel extended aeration unit and intermittent sand filter. This
demonstration project is an extension of previous development research to
meet future industrial discharge limitations. The treatment system was
designed to meet the special needs of small plants. The report will be of
interest to those involved with treatment of wastewaters from the meat and
poultry processing industries. For further, information contact Food and
Wood Products Branch, Industrial Pollution Control Division, IERL-Ci.
David 6. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
ill
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ABSTRACT
The primary objective of this research project was to evaluate the use
of intermittent sand filters as a means of upgrading waste treatment systems
for small packinghouses. The project was conducted at the W. E. Reeves
Packinghouse in Ada, Oklahoma, and the treatment system consisted of an ex-
tended aeration lagoon in series with an intermittent sand filter.
With a hydraulic loading rate of 0.36 mgad and a sand source having an
effective diameter of 0.35 mm and a uniformity coefficient of 2.5, a filter
run of 109 days was observed. The average BOD5 and TSS of the filter eff-
luent was 10.4 mg/1 and 11.1 mg/1 respectively. In relation to the 1983 BAT
limitations, the effluent met the maximum day limit for TSS but the 30-day
average value for TSS was exceeded (but only within the accuracy of the test).
The maximum day and 30-day average limits for BOD5 were exceeded. The efflu-
ent met the limits for fats, oil, and grease and pH. The NH3~N in the efflu-
ent from the treatment system met the BAT limits which were rescinded by the
court. The fecal coliform limits were also exceeded.
A secondary objective of the project was to determine the most economi-
cal means of meeting the NPDES monitoring requirements. The conclusion was
that the small packinghouse managers should use a commercial laboratory when
monthly or quarterly analyses are specified.
The report contains information on the cost of construction and opera-
tion of the treatment facility. The study revealed an installation cost of
$1.40/gpd capacity and a treatment cost of $0.29/lb BOD5 applied. The report
also contains the information needed to select, design, and construct an
intermittent sand filter.
This report was submitted in fulfillment of Grant No. S-803766-01 by
East Central University under the sponsorship of the U. S. Environmental
Protection Agency. This report covers the period June 1, 1975, to February
28, 1977, and work was completed as of February 28, 1977.
iv
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CONTENTS
Foreword [[[
Abstract [[[ iv
Figures [[[ vi
Tables [[[ vii
Abbreviations and Symbols ............................................. ix
Conversion Factors [[[ x
1 . Introduction .................................................. 1
2 . Conclusions [[[ 3
3 . Recommendations ................................ . .............. 5
4 . Evaluation of Monitoring Procedures ........................... 6
5 . Development of Treatment Facility ............................. 12
6 . Design and Construction ....................................... 16
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FIGURES
Number Page
1 W. E. Reeves treatment facilities 17
2 Cross-section of intermittent sand filter 18
3 Top view of intermittent sand filter .- 19
4 Sand filter construction site 20
5 Construction of clay embankments of sand filter 21
6 Stem wall of sand filter 21
7 Preparation of bottom of sand filter 22
8 Underdrain system of sand filter 23
9 Manhole with automatic valve 24
10 Distribution system of sand filter 25
11 Completed sand filter 26
12 Sample collection box 26
13 Chemical treatment effectiveness 46
vi
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TABLES
Number Page
1 National Effluent Guidelines 1
2 Turbidity vs. TSS 1
3 Manometric BOD vs. Standard BOD Procedure 8
h Equipment Costs for Monitoring Requirements 10
5 Labor Costs for Monitoring Requirements 11
6 Commercial Laboratory Costs for Monitoring Requirements 11
7 Intermittent Sand Filters-Pilot Study 1^
8 Pilot Sand Filter Discharges vs. Effluent Limitations 15
9 Length of Filter Runs 28
10 Wastewater Characteristics and Percent Removal 30
11 Total Suspended Solids 31
12 Intermittent Sand Filter Effluent Characteristics 33
13 Comparison of Discharges and NPDES Limitations 3^
lU Biochemical Oxygen Demand 35
15 Fats , Oil, and Grease • 35
16 Ammonia Nitrogen 37
IT Total KJeldahl Nitrogen 37
18 Nit rate/Nitrite Nitrogen 38
19 Total Phosphorus 38
20 Dissolved Oxygen 39
21 Total Solids and Total Volatile Solids 39
vii
-------
22 Chemical Oxygen Demand
23 Chloride
2k Temperatures and Precipitation
25 Flow Rates and Liveweight Killed
26 Concentrations and Removals (During Aeration Study)
27 Concentrations and Removals (During Filter Study)
28 Alum Treatment Study
29 Chemical Treatment-Sedimentation Study
30 Treatment Costs for Full-Scale System
viii
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LIST OF ABBREVIATIONS AND SYMBOLS
ANOVA
avg
BAT
BOD5
BPT
ci-
COD
DO
eff. dia.
F/M
FOG
ft
gal
gpd
hp
in.
JTU
Ib/ft2
lb/1000 Ibs LWK
LWK
M-F
mgad
rag/1
MLSS
nun
MPN/100 ml
n
NH3-N
N03~/N02~-N
NPDES
Pt-Co
SRI
SVI
TKN
T-N
T-P
TS
TSS
TVSS
unif. coeff.
— Analysis of Variance
— average
— Best Available Technology Economically Achievable
— 5-day biochemical oxygen demand
— Best Practical Control Technology Currently
Available
— chloride ion
— chemical oxygen demand
— dissolved oxygen
— effective diameter
— food/microorganism ratio
— fats, oil, and grease
— feet
— cubic feet
— gallons
— gallons per day
— horsepower
— inches
— Jackson Turbidity Unit
— Ibs/square foot
— lbs/1000 Ibs of liveweight killed
— liveweight killed
— membrane filter
— million gallons per acre per day
— milligrams/liter
— mixed liquor suspended solids
— millimeter
— most probable number/100 milliliters
— number
— ammonia nitrogen
— nitrate/nitrite nitrogen
— National Pollutant Discharge Elimination System
— platinum-cobalt
— sludge retention index
— sludge volume index
— total Kjeldahl nitrogen
— total nitrogen
— total phosphorus
— total solids
— total suspended solids
— total volatile suspended solids
— uniformity coefficient
IX
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CONVERSION FACTORS
To convert from
inch (in)
foot (ft)
foot2 (ft2)
foot3 (ft1)
degree Celsius (°C)
horsepower (hp)
pound (Ib)
pound per day (Ib/d)
gallon (gal)
gallon per day (gpd)
million gallon per
acre per day (mgad)
cost/gallons per
day($/gpd)
cost/pound ($/lb)
pound per foot2 (Ib/ft
pound per 1000 Ibs
(lb/1000 Ibs)
to
Multiply by
millimeter (mm)
meter (m)
meter (m2)
meter3 (m3)
degree Fahrenheit (°F)
watt (w)
kilogram (kg)
kilogram/day (kg/d)
meter3 (m *)
meter 3/day (m3 /d)
meter 3/hectare/day
(m3/hec/d)
cost/meter3/day
($/m3/d)
cost/kilogram ($/kg)
kilogram/meter2 (kg/m2)
kilogram/1000 kilogram
(kg/kkg)
2.540 x 101
3.048 x 10"1
9.290 x 10~2
2.832 x 10~2
t0p = 1.8 t0c
7.457 x 102
4.536 x 10"1
4.536 x 10"1
3.785 x 10~ 3
3.785 x 10~ 3
9.353 x 103
3.785 x 10 ~3
4.537 x 10"1
4.882
1
Metric Practice Guide. ASTM Designation E-380-74, American Society for
Testing and Materials, Philadelphia, Pennsylvania, November, 1974. 34pp.
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SECTION 1
INTRODUCTION
The primary objective of this project was to determine the use of inter-
mittent sand filters as a means of upgrading waste treatment systems for
small meat packing plants to meet discharge requirements. The meat industry
was cited in Public Law 92-500 as an industry requiring standards for waste-
water discharges and the National Pollutant Discharge Elimination System
(NPDES) permit limitations have been imposed. The industry must meet the
maximum limits referred to as the "best practical control technology currently
available" (BPT) by July 1, 1977, and the "best available technology econo-
mically achievable" (BAT) by July 1, 1983. These BPT and BAT limits for 5-
day biochemical oxygen demand (6005), total suspended solids (TSS), and
fats, oil, and grease (FOG) and the New Source Limitations for ammonia-
nitrogen (NH3~N) are given in Table 1 (1).
TABLE 1.
NATIONAL EFFLUENT GUIDELINES
(lbs/1000 Ibs LWK)
Parameters
Simple
slaughter-
houses
30-day avg.
Low
packing-
houses
30-day avg.
Complex
slaughter-
houses
30-day avg.
High
packing-
houses
30-day avg.
1977 limitations (BPT)
BOD5
TSS
FOG
.12
.20
.12
New source limitations
(include the above plus NH3-N)
NH3-N .17
.17
,24
,08
.24
.21
.25
.08
.24
.24
.31
.13
.40
1983 limitations (BAT)
BOD5
TSS
FOG*
NHs-N*
.03
.05
10
4
.04
.06
10
4
.04
.07
10
4
.08
.10
10
4
*Values in mg/1.
al lb/ 1000 Ibs = 1 kg/1000 kg; conversion factors are presented in the
prefatory pages.
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The maximum limits for any one day are twice those shown in Table 1 for
all parameters except FOG. The FOG maximum limits for any one day are the
same as the 30-day average limit. Limitations for pH require that all eff-
luent samples have pH values greater than 6.0 and less than 9.0, and the max-
imum allowable fecal coliform bacteria limitations are 400 MPN/100 ml. The
NPDES system also requires the monitoring of the temperature of wastewater.
In 1975, after initiation of this project, a Federal court rescinded the
BAT limits on NH3~N and the TSS limits for complex slaughterhouses. More
recently amendments to Public Law 92-500 have made necessary re-evaluation
of all future limits.
Waste treatment investigations began at the W. E. Reeves Packinghouse,
Ada, Oklahoma, in 1970. These investigations were conducted as a cooperative
effort of the Environmental Protection Agency, W. E. Reeves Packinghouse and
East Central University. After the NPDES guidelines more precisely defined
the technologies needed by the industry, the scope of the investigations were
enlarged to meet these needs. Also, since the use of full-time waste treat-
ment personnel is not practical for small meat packers, minimum operation
requirements have been viewed as a basic criteria for suitable treatment sys-
tems for small operations. The full-scale processes investigated at the W. E.
Reeves facility were aerobic and anaerobic lagoons and extended aeration oper-
ated in a batch mode. Pilot-scale studies included overland flow and inter-
mittent sand filtration systems. Earlier publications by Witherow et al. (2,
3, 4, 5) reveal the results of these investigations.
In the past few years, researchers (6, 7, 8) have demonstrated the eff-
ectiveness of intermittent sand filters in reducing TSS from domestic waste-
waters which had received prior treatment, such as lagoon treatment. Based
upon this work and the results of the pilot study conducted at the Reeves
facility, a full-scale intermittent sand filter was installed in series with
the batch operated extended aeration unit. This treatment system was designed
to minimize and automate the mechanical equipment, and to demonstrate a dis-
charge that would meet NPDES limitations within the manpower constraints of
small meat packing operations.
A secondary objective of the project was to develop a simple and econom-
ically feasible means of meeting the NPDES monitoring requirements for small
meat packers. The analytical tests required for the NPDES monitoring reports
necessitate trained personnel and laboratory facilities, or the contracting of
analytical services by a commercial laboratory. Either of these methods can
be expensive and various analytical techniques were examined to see if the
monitoring requirement could be simplified and made less expensive, and if
laboratory facilities and personnel were feasible for the small meat packer.
The final objective of the project was to provide the small meat packers
with the information needed to design, construct, and operate an intermittent
sand filter system.
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SECTION 2
CONCLUSIONS
During this investigation, packinghouse wastewater treated in an extended
aeration unit was discharged to intermittent sand filters in an attempt to
upgrade the quality of the wastewater to meet NPDES discharge limits. The
effluent from the filter units met all BPT limits, with the exception of fecal
coliform bacteria. The effluent also met the new source limitations for
NH3-N. The demonstration revealed that the treatment system used at the W. E.
Reeves facility could meet these discharge limits for small packinghouses if
a disinfection system was incorporated into the existing treatment plant.
The effluent results were also compared to the BAT limits. Fats, oil,
and grease limitations were met and all effluent samples had pH values between
6.0 and 9.0. The effluent met the maximum day limit for TSS. The 30-day
average value for TSS was exceeded, but only within the accuracy of the
measurement. The effluent also exceeded both the maximum day and 30-day aver-
age limits for BOD5. The NH3~N in the effluent from the treatment system met
the BAT limits which were rescinded by the court. (See Table 11)
A major economic factor in the use of intermittent sand filters is the
length of filter run, that is the period of time the filter can be operated
before cleaning is required. Factors affecting the length of filter run are
the concentration of suspended solids, hydraulic loading rate, and size of
filter media. The influent to the filter had an average TSS concentration of
41 mg/1. During this investigation, sand having an effective diameter of
0.2 millimeters (mm) and a uniformity coefficient of 4 was used with hydraulic
loading rates of 0.86 million gallons/acre/day (mgad) and 0.55 mgad. These
investigations resulted in filter runs of 10 days at the higher hydraulic
loading rate of 0.86 mgad and 15 days at a loading rate of 0.55 mgad. When
this sand was replaced with sand having an effective diameter of 0.35 mm and
a uniformity coefficient of 2.5, the hydraulic loading rate was lowered to
0.36 mgad. The length of filter run in this test was 109 days. This dramatic
change from two or three cleanings per month to three cleanings per year made
the intermittent sand filter economically feasible for small meat packers.
A number of analytical techniques were evaluated in an attempt to find
accurate and inexpensive procedures which would provide the necessary waste-
water monitoring data. With one exception, no other analytical tests evalu-
ated were found to be more practical than those given in Standard Methods for
the Examination of Water and Wastewater (9) or EPA Methods for Chemical Analy-
sis of Water and Wastes (10). The Hach manometric BOD5 method was found to be
an acceptable substitute for the traditional BOD5 procedure for monitoring of
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these wastewaters. An economic evaluation of the necessary laboratory and a
trained technician needed to meet the NPDES monitoring requirements indicate
that the small meat packer should use a commercial laboratory when monthly or
quarterly analyses are specified.
Information on methods and costs of construction and operation of the
intermittent sand filter system is provided in this report. This report gives
the small packer the information needed to select, design and construct an
intermittent sand filter. (See Sections 6, 7, 8 and 9)
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SECTION 3
RECOMMENDATIONS
The quality of the effluent from the filters either met or was close to
the BAT limits for BODs and TSS; therefore, investigations into methods of
improving the removal efficiencies should be conducted. One method which
showed promise and should be further examined is chemical treatment in the
batch operated aeration unit with coagulants.
The major operational difficulties encountered during this investigation
were those related to mechanical failures of the aerator and the automated
valves. Difficulty was also encountered with the timers which actuated the
aerator and valves. On several occasions, the valve between .the extended
aeration pond and the filter unit failed to close at the proper time. When
the aerator was placed in operation while the valve-was still open, the filter
would be dosed with mixed liquor and clogging of the filters would occur. More
dependable electronic controls should be utilized to prevent such occurrences.
Auxiliary aerators and valves are recommended to reduce non-treatment periods
to a matter of a few hours.
Ammonia, total Kjeldahl nitrogen (TKN), and nitrate/nitrite nitrogen
(N03~/N02~-N) readings taken during this investigation indicated that both
nitrification and denitrification was occurring. Because the system removed
90% of the total nitrogen, investigations concerning the fate of nitrogen are
recommended.
For small meat packers with NPDES permits which require either monthly
or quarterly chemical analyses the following are recommended:
1. NPDES report preparation, sample collection, and measurement of
pH and temperature should be done by plant personnel.
2. A commerical laboratory should be used to obtain TSS, 8005, NH3~N,
FOG, and fecal coliform analyses.
3. An overflow weir should be installed to enable plant personnel
to monitor the discharge flow.
4. A daily inspection of the facilities should be conducted by plant
personnel.
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SECTION 4
EVALUATION OF MONITORING PROCEDURES
The NPDES system requires packing plant managers to monitor wastewater
for a number of parameters including flow, TSS, BODs, NH3-N, FOG, fecal coli-
form bacteria, pH, and wastewater temperature. For a small plant with a per-
mitted BOD5 discharge of approximately 4 Ib/day, these monitoring requirements
add significantly to the wastewater treatment costs. The first NPDES permit
proposed for the W. E. Reeves Packinghouse required these analyses three times
per week. This was estimated to cost $15,000/year which was about 250% of
the remaining treatment costs. The permit was modified to monthly analyses
which amounted to about 15% of the remaining treatment costs. An objective
of this project was to investigate less costly direct and indirect methods of
monitoring for compliance with the permits. These methods should require annu-
al expenditures of less than $1000/year and equipment costs of less than $2000.
Those parameters which are of particular concern are BOD5, TSS, NH3-N,
FOG, and fecal coliform bacteria, since all of these require that the analyses
be performed in accordance with EPA approved laboratory procedures. When
approved analytical techniques are used it is necessary that scientifically
equipped laboratory facilities are available and that the work is done by
trained technicians. Each parameter referred to above is discussed in this
section.
TOTAL SUSPENDED SOLIDS
The approved TSS test is a gravimetric analysis which requires the use
of an analytical balance, a drying oven, a vacuum filtration system, and
numerous items of glassware and laboratory apparatus. To reduce the need
for this costly equipment and time consuming analyses, an investigation into
the feasibility of substituting a spectrophotometric procedure for the gravi-
metric analysis was conducted. The spectrophotometric concept of monitoring
TSS above 30 mg/1 has been demonstrated feasible in the works of Kiskowitz (11),
Krawczyk (12), and the Hach Chemical Company (13).
Some effluent samples from the sand filter unit were analyzed for TSS
by the approved gravimetric procedure and then absorbance readings were made
on the same sample using a Bausch and Lomb Spec-20 spectrophotometer with a
one-half in. cell. Absorbance measurements were made at various wavelengths
but the failure to obtain reproducible readings in these low absorbancy ranges
led to the discontinuation of the spectrophotometric work.
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The samples with known TSS concentrations were analyzed for turbidity
using a Hach 2100 turbidimeter. A comparison of the corresponding TSS and
turbidity readings is given in Table 2. The turbidimetric method did not
reflect the magnitude of the changes which occurred in the TSS concentrations.
The correlation coefficient of the turbidity and the TSS was 0.08. Therefore,
the substitution of the turbidimetric procedure for the gravimetric procedure
would not be reasonable.
TABLE 2. TURBIDITY VS. TSS
Number
Mean
Standard deviation
Turbidity (JTU's)
39
6.9
2.2
TSS (mg/1)
39
11.7
8.0
Correlation coefficient (R) = 0.08
The investigations revealed that the spec-20 spectrophotometer (with a
one-half in. cell) or the Hach turbidimeter could not be used for the monitor-
ing of suspended solids in the low concentration ranges characteristic of the
filter effluent. This conclusion is not in conflict with the work of other
researchers cited earlier since their work involved the TSS monitoring of
sewage, not wastewater with TSS concentrations of approximately 10 mg/1.
The gravimetric procedure should be used for the monitoring of the treat-
ed meatpacking wastewater since the spectrophotometric methods were not found
to be accurate procedures for the monitoring of low range TSS samples.
FIVE-DAY BIOCHEMICAL OXYGEN DEMAND
The EPA approved procedure for performing a BOD5 test requires that the
dissolved oxygen (DO) concentration of the wastewater is determined at the
time the test begins and a second DO reading is taken after the wastewater is
incubated for 5 days. The DO procedure employed is usually performed by a
chemical test such as the azide procedure (10), but a DO meter can be used.
The BOD5 procedure would require a 6005 incubator, high quality distilled
water, and various items of glassware and apparatus. A number of chemicals
are required for the procedure if the azide procedure is used. If the DO
meter is used, the chemicals would not be necessary.
A manometric procedure for BOD5 is available in which a direct reading
can be taken from a mercury column (14). A comparison of the results obtained
by the standard procedure and the manometric procedure was made. A series of
samples of raw wastewater, filter influent, and filter effluent were analyzed
by both procedures in triplicate. The results, shown in Table 3, revealed no
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significant difference at the 5% level (p <.05) when the student t-test was
used. Therefore, either procedure could be used for monitoring the BOD5 of
the packinghouse wastewater.
TABLE 3. MANOMETRIC BOD5 VS. STANDARD BOD5 PROCEDURE
Raw wastewater
Std. Manometric
Filter influent
Std. Manometric
Filter effluent
Std. Manometric
Number
Mean
(mg/1)
Minimum
(mg/1)
Maximum
(mg/1)
12
504
400
627
12
508
415
630
15
45
30
64
15
44
30
60
15
13
4
28
15
12
5
25
The manometric procedure does offer the advantage of providing a simplier
technique, however, it requires the use of a special manometric apparatus
which costs approximately $250.00. The cost figure of the manometric unit is
approximately the same as the cost of glassware and chemicals for the standard
procedure. Both procedures require the use of an incubator. Therefore, the
manometric procedure offers no savings in equipment costs, but there are sav-
ings in labor cost, since the technique requires less time.
Some chemical oxygen demand (COD) techniques were considered as possible
substitutes for the 6005. (15, 16) These procedures involve the use of lab-
oratory glassware and chemicals and do not require expensive apparatus. When
the COD procedures are used, results can be obtained much faster than with
the standard BOD5 procedure. However, since there is no universal correlation
between BOD5 and COD, the only way this substitution could be acceptable would
be if a BOD5/COD correlation study was done for each packing plant. The
additional laboratory work would cause the substitution of a COD test for the
BOD5 to be impractical at a small plant where monthly or quarterly analyses
are required.
FATS, OIL, AND GREASE
A survey of the literature reveals that all of the acceptable FOG proce-
dures consist of an extraction, distillation, and gravimetric measurement.
Any of these procedures would require extraction apparatus, such as a soxhlet
extractor, a distillation unit, and an analytical balance, as well as special-
ized glassware and chemicals. No alternate procedure for those approved meth-
ods was investigated.
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AMMONIA NITROGEN
Acceptable NHg-N procedures consist of a distillation followed by a tit-
ration. These procedures require apparatus such as Kjeldahl distillation
unit, special glassware, and chemicals.
One alternate procedure which was considered for the project was the use
of an ammonia specific ion electrode. However, a disadvantage of this tech-
nique would be the level of expertise required of the analyst, as the standard-
ization and calibration techniques require sophisticated laboratory skills.
Economics is another disadvantage, because the specific ion electrode procedure
still may require the distillation apparatus, in addition to the specific ion
electrodes (approximately $300) and an expensive instrument capable of pro-
viding a millivolt readout. Therefore, the traditional distillation-titration
procedure would be the most practical procedure for small packers.
FECAL COLIFORM BACTERIA
A review of the technical literature and an investigation of some manu-
facturers literature revealed that most of the commercially available simpli-
fied methods for fecal coliforms are suitable as screening techniques (17).
The membrane filter (M-F) technique is an approved procedure which has gained
wide acceptance and is the preferred procedure because the cost is comparable
to the simplified methods. This technique requires the use of an incubator,
filtering apparatus, glassware, media, and cellulose filters. The most expen-
sive item is the incubator which is also needed if the simplified procedures
are used. Therefore the M-F technique was used in the investigation.
pH AND TEMPERATURE
The monitoring of pH should present no problem for packinghouse managers,
since this test could be performed easily and economically. Plant employees
could be trained to take pH readings with an inexpensive pH meter (approxima-
tely $250.00) or with pH hydrion paper. Temperature readings could also be
taken by plant personnel and would require no equipment other than a thermo-
meter.
FLOW
The monitoring of flow is a parameter which should be considered in the
initial design of the treatment system. The system should be designed to
allow for the installation of an overflow weir to monitor the flow. If plant
personnel do not have the capability of establishing the flow monitoring
program, the services of a consultant or an extension agent can be acquired
to install a discharge weir which could be maintained and monitored by plant
personnel.
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COST
The choices which are available to the plant manager are to establish a
monitoring laboratory (assuming that one is not available) and acquiring a
trained technician to do the analyses, or acquire the services of a commercial
laboratory.
Estimates of monitoring costs were made and are presented in Table 4.
These are intended to be used as general guidelines because the cost of esta-
blishing and stocking a laboratory, acquiring a technician, etc. may vary
from those used by the principal investigator.
TABLE 4. EQUIPMENT COSTS FOR MONITORING REQUIREMENTS
Instrument
Analysis
Cost
Analytical balance
pH meter
Drying oven
BOD5 incubator
Bacteria incubator
Vacuum filter apparatus
M-F - filtering apparatus
Soxhet apparatus
Distillation rack
Distilled water system
Glassware
Miscellaneous apparatus
Chemicals
Total
TSS, FOG
pH, NH3-N
TSS
BOD5
Fecal coliform
TSS
Fecal coliform
FOG
NH3-N
$1000.00
250.00
250.00
800.00
600.00
100.00
100.00
350.00
600.00
550.00
1600.00
850.00
1000.00
$8050.00
The estimates of time for the activities in Table 5 were made with allow-
ance for the preparation of reagents and the establishment of quality control
procedures. By amortizing the laboratory cost over five years and using a
technician salary of $5.00/hour, the monthly cost of monitoring would be
approximately $320.00/month. These cost figures did not include a cost for
laboratory space, remodeling, or laboratory utilities. Some states which
require monitoring reports specify that all analyses must be performed in a
certified laboratory. No allowance was made in these cost estimates for such
laboratory certification fees.
10
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TABLE 5. LABOR COSTS FOR MONITORING REQUIREMENTS*
Activity Hours
Sample collection and shipment 2
BOD5 analysis 4
TSS analysis 2
FOG analysis 4
NH3-N analysis 3
Fecal coliform analysis 2
Calculation and report preparation 2
Total 19
*Assuming monthly monitoring of BOD5, TSS, FOG, NH3-N, and fecal coliform
bacteria.
Table 6 presents the cost estimates based on monthly analyses for
TSS, fecal coliform bacteria, NH3-N, and FOG by a commercial laboratory. The
cost of monitoring flow, sample collection, pH, temperature, and report pre-
paration was calculated on the basis of 4 hours of plant personnel time at
the rate of $5.00/hour. The cost figures for BOD5, TSS, fecal coliform bac-
teria, NH3-N, and FOG are the average costs based on price quotations from
five commercial laboratories. These figures vary between laboratories.
TABLE 6. COMMERCIAL LABORATORY COSTS FOR MONITORING REQUIREMENTS
Item Cost
BOD5 analysis $15.00
TSS analysis 5.00
NH3-N analysis 15.00
FOG analysis 20.00
Fecal coliform bacteria analysis 20.00
Labor of plant personnel 20.00
Total $95.00
Based on the data in Tables 4, 5, and 6, monitoring costs by plant per-
sonnel are estimated to be approximately $320.00/month, compared to a cost of
$95.00/month if the analyses were performed by a commercial laboratory.
Neither of these cost studies included the cost of daily flow monitoring and
inspection of the facilities which would require 15 to 20 manhours per month.
Other points that plant managers need to consider would be the necessity of
setting floor space aside for a laboratory, even though the laboratory space
would be utilized only a small portion of the time. Acquiring a trained tech-
nician to be utilized for laboratory analysis on a part-time basis might also
be a problem.
11
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SECTION 5
DEVELOPMENT OF TREATMENT FACILITY
DEMONSTRATION SITE
The demonstration site for this study was the W. E. Reeves Packinghouse
in Ada, Oklahoma. The plant slaughters 500 to 700 cattle per month and 600
to 800 hogs per month, or about 10,000,000 pounds of liveweight killed (LWK)
annually. The W. E. Reeves facility has been used as a demonstration site
for a number of other wastewater treatment investigations conducted over the
past five years. All of the research activities conducted at the W. E. Reeves
Packinghouse were the result of the cooperative efforts of the Environmental
Protection Agency, the W. E. Reeves Packinghouse and East Central University.
Previous investigations, which were conducted at the W. E. Reeves facil-
ity, were concerned with aerobic and anaerobic lagoon treatment, extended
aeration treatment, and overland flow. After the national discharge guide-
lines were established, the research activities were directed toward the
development of feasible treatment systems for small plants which would meet
the NPDES effluent guidelines. This meant that practical systems should
produce a high quality effluent and should be designed to minimize and auto-
mate the mechanical equipment. Systems of this type would be practical for
small plants since the need of a full-time waste treatment operator would not
be necessary.
Immediately prior to the installation of the intermittent sand filter
study, the full-scale treatment process in use at the site consisted of ex-
tended aeration operated in a batch mode followed by two aerobic lagoons in
series. However, the effluent from this treatment system failed to meet the
proposed national discharge limitations. Therefore, there was the need for
incorporating some process with the existing treatment facility which would
upgrade the quality of the effluent to meet the discharge limitations. The
intermittent sand filter was proposed for accomplishing that task.
HISTORY OF SAND FILTRATION
The use of sand filtration for the treatment of water and wastewater is
not a recent innovation in the United States. A survey of the literature re-
veals the existance of sand filtration for the improvement of drinking water
supplies in the United States as early as 1828 (18). The population growth
in the United States, especially in the eastern cities, created a demand for
larger volumes of drinking water, and around the turn of the century a number
12
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of slow sand filters were put to use in the United States for the treatment of
drinking water supplies.
Just as the population growth in the United States had created a demand
for methods of treating larger volumes of drinking water, the need arose for
methods of treating the increasing volumes of wastewater produced by the
municipalities and intermittent sand filtration was viewed as a wastewater
treatment method. An experimental intermittent sand filter unit for the treat-
ment of sewage was built in Lawrence, Massachusetts in 1888 (19). The opera-
tion of the intermittent sand filter proved successful. However, a rapid in-
crease in the number of sand filter units for the treatment of sewage was not
experienced in the United States until the 1940's. The determining factors
for the increased usage of intermittent sand filter units were the availability
of natural sand sources meeting the desired specifications and the require-
ment of large tracts of land.
Following World War II, the rapidly increasing number of subdivisions,
mobile home parks, and resort areas in Florida created a need for economical
and practical treatment systems which would produce an effluent of suitable
quality. This need for simple and economical sewage treatment units for small
volumes of wastewater led investigators at the University of Florida to test
various designs for intermittent sand filter units (19). Much of the present
knowledge concerning intermittent sand filters has come from these early stud-
ies at the University of Florida.
The early designs of intermittent sand filters have seen little change
over the years that they have been in'use. The units usually consist of an
underdrain of open-jointed tile or perforated pipe. The underdrain network
is covered with approximately 18 inches (in.) of gravel ranging in diameter
from 1/8 to 3 in. Filter sand is placed on the gravel at a depth that varies
from 24 to 60 in. In the design of an intermittent sand filter, emphasis must
be placed on sand specifications. It must be a well-graded sand with the
proper effective size and uniformity coefficient. The effective size is
usually between 0.15 and 0.35 mm, and the uniformity coefficient is usually
less than 3.0. Hydraulic loading rates for sand filters vary depending on
the filter media and the amount of suspended solids in the raw wastewater.
All of these factors must be considered in order to design a filter unit cap-
able of experienceing a feasible period of operation before clogging of the
filter media occurs.
In the past few years, workers have demonstrated the effectiveness of
intermittent sand filters in reducing the TSS concentration of domestic waste
which has received prior treatment in lagoon systems. Evidence of the effect-
iveness of intermittent sand filters for the reduction of TSS concentration
can be found in the published works of Reynolds (6), Marshall (7), and Walter
(8). Other supportive evidence for intermittent sand filters as a means of
lowering TSS values can be found in reports by Grantham (20), Furman (21), and
Middlebrooks (22).
13
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PILOT-SCALE STUDY
A review of the work by the authors previously cited assisted Witherow
and Rowe in the design of a pilot sand filter study. The purpose of the pilot
study was to determine if the effluents from the intermittent filter units
would meet the BPT and BAT discharge limits. Two pilot scale intermittent
sand filter units were used in the study. Each was constructed by welding
two 55 gallon (gal) barrels end-to-end. Effluent lines were installed in the
bottom of the units and an 18-in. layer of gravel, ranging in diameter from
0.25 to 1.25 in. was placed in the bottom of each unit. The larger particles
of gravel were placed in the bottom of the units. The gravel layers were
covered with 36 in. of washed sand having an effective diameter of 0.2 mm.
During the three month investigation, the filters were operated 5 days/week.
They were loaded at approximately 10 a.m. each day with 30 gal (0.5 mgad) of
effluent. Cleaning of the filters was not required during the three month
study.
Filter No. 1 was loaded with the settled effluent from the extended aera-
tion pond and Filter No. 2 was loaded with effluent from the first aerobic
lagoon. Grab samples of effluent from both filters were collected and analyzed
for 8005, TSS, NH3-N, TO, COD, total volatile suspended solids (TVSS), pH,
and fecal coliform bacteria. The filter receiving the effluent from the
aerobic lagoon usually had higher removal efficiency with respect to TSS
values. However, this was due to the higher concentration of TSS in the aero-
bic lagoon effluent. The difference in the concentrations of pollutants in
the discharge from the two filters was not significant. The mean concentra-
tions for the various parameters and the removal efficiencies are given in
Table 7. Weekly analyses were made over a 3 month period.
TABLE 7. INTERMITTENT SAND FILTERS-PILOT STUDY
(Mean values)
Influents (mg/1)Effluents (mg/1)Removals (%)
Items Filter 1 Filter 2 Filter 1 Filter 2 Filter 1 Filter 2
BOD5
COD
TSS
TVSS
NH3-N
T-N
T-P
26.0
71.2
35.5
25.4
4.3
10.3
2.9
28.7
99.7
46.8
32.3
2.7
6.5
4,3
10.4
40.4
23.8
14.4
0.3
3.3
0.8
8.1
48.1
22.2
11.1
0.1
3.3
2.1
60
44
33
44
93
68
73
72
52
53
66
96
50
52
In addition to the TSS analyses, TVSS analyses were determined on the
influent and effluent for both filters. An initial washout of fines was
expected to increase the TSS concentrations in the effluent, but was not ex-
pected to increase the TVSS values, since the fines would be nonvolatile.
Since the washout of fines was expected, the 44% and 66% removal of TVSS was
considered more representative of the filter performance than the values for
TSS.
14
-------
The filtered effluents from the extended aeration unit and aerobic lagoon
met the limitations for BPT limits, but neither met the BAT values. The BOD5
values from both pilot sand filters exceeded the BAT limits, but only within
the accuracy of the measurement. The BAT limits for TSS was greatly exceeded,
and an additional reduction would be necessary to meet the BAT limits. The
filter effluents are compared to BPT and BAT limits in Table 8.
TABLE 8. PILOT SAND FILTER DISCHARGES VS. EFFLUENT LIMITATIONS
(lb/1.000 Ibs LWK)
Items
BOD5 mean
BOD5 max.
TSS mean
TSS max.
Filter
No. 1
.05
.11
.11
.22
Filter
No. 2
.05
.09
.11
.22
Low Packinghouse
BPT BAT
.17
.34
.24
.48
.04
.08
.06
.12
During the period of investigation from September to December, the aver-
age water temperature dropped from a high of 25 C to a low of 5°C. Little
change was observed between the influent and the effluent temperatures. The
wastewater from the extended aeration unit consistently showed an increase in
DO as a result of the filtration process. However, the DO content of the
wastewater from the aerobic lagoon was increased only about 50% of the time.
The DO concentrations in the effluent samples from the two filters ranged
from 5.0 mg/1 to 9.8 mg/1.
FOG measurments of influents to the filters ranged from 5 to 26 mg/1.
Analyses on the effluents from the filters revealed that all samples tested
contained FOG concentrations of less than 5 mg/1, which is the level of accu-
racy of the test. The pH values of all effluent samples from both filters
met the discharge requirements. The N03~/N02~-N value of the influent to the
filters was usually increased about 1 mg/1, but a total nitrogen removal was
accomplished by both filters.
The analyses for fecal coliform bacteria was made on influent and eff-
luent samples for both filters three times during the investigation. For the
six sets of influent-effluent values, five showed a reduction in the fecal
coliform count. However, all values collected exceeded the discharge limits
of 400 MPN/100 ml. The maximum and minimum counts on the effluent samples
from the filters were 14,000 MPN/100 ml and 1,000 MPN/100 ml, respectively.
15
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SECTION 6
DESIGN AND CONSTRUCTION
After a review of the literature and an evaluation of the pilot scale
intermittent sand filter study, plans were made for the incorporation of an
intermittent sand filter unit into the existing treatment facility at the
W. E. Reeves Packinghouse. The existing facility consisted of three full-
scale lagoons.
The first lagoon, which received the wastewater from the packinghouse,
was operated as an extended aeration unit. The extended aeration unit was a
batch treatment process which allows aeration and settling in one basin with-
out the need of a mechanical sludge collection system. The extended aeration
pond was in the shape of an inverted, truncated pyramid and had a volume of
18,500 cubic feet (ft3) at a 9-foot (ft) water depth. Accumulation of one
day's flow of wastewater from the plant resulted in a water level increase of
6 to 9 in.
Oxygen for the pond was supplied by a 10 horsepower (hp) Peabody Welles
floating aerator with a variable oxygen transfer valve. The aerator was
operated from 6 a.m. to midnight and settling of solids was allowed to occur
from midnight to 2 a.m. After the two hour settling period, an automatic air
activated valve was opened between 2 and 6 a.m. and the supernatent from the
pond was allowed to flow through a 6-in. line to the second lagoon. The valve
was installed in a manhole for ease of maintenance and both the aerator and
valve were controlled by electrical timing devices.
The site chosen for the sand filter unit was such that wastewater from
the extended aeration pond or the two aerobic lagoons could be loaded to the
filter bed by gravity flow. Figure 1 shows the layout of the treatment facil-
ities at the W. E. Reeves Packinghouse.
The design for the sand filter was based on an average wastewater flow of
18,000 gallons per day (gpd) with a maximum flow of 30,000 gpd. In the early
planning state, the intent was to construct one sand filter unit with a sur-
face area of 2,400 square feet (ft2). However, before construction began,
the plans were changed to call for two filter units of unequal size. This
change was made so that it would be easier to evaluate several hydraulic load-
ing rates. Also, two filters would give the advantage of having one filter
for operation while the other was being cleaned or repaired. The final plans
called for the construction of two filter units with sand surface areas of
975 and 1275 ft2. The design of the filter unit is shown in Figures 2 and 3.
The specifications for construction of the intermittent sand filter are given
in the appendix.
16
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Extended
aeration
pond
Stabilization
Pond
«-
«-
-
-
>
«-
e
I
-c
LJ
[] ]
Distribution box
?_jk.__r~1 Collection box
To stream
Figure 1. W. E. Reeves treatment facilities.
-------
2.5 to 1
00
18" Gravel'
Stern^ wall
60"
36"
Freeboard
Sand
8'
dike
Clay
6" xClay
Figure 2. Cross-section of intermittent sand filter.
-------
Stem wall
15'
23'
2.5 to 1.0
slope
8'
Top
of
dike
Figure 3. Top view of intermittent sand filter.
-------
The design called for a distribution box between the manhole adjacent to
the extended aeration pond and the intermittent sand filters so that the daily
wastewater flow could be loaded to either filter or the daily flow could be
equally divided and simultaneously loaded on both filters. Based on the
average flow of 18,000 gpd, the larger surface area could be used for the eva-
luation of hydraulic loadings of approximately 0.6 and 0.3 mgad and the smaller
surface area could be used for the evaluation of hydraulic loadings of approx-
imately 0.9 and 0.45 mgad.
The W. E. Reeves Packinghouse possessed the necessary equipment and the
manpower to complete the construction project and all phases of the construc-
tion were completed by the company. Construction of the intermittent sand
filter units began in September, 1975, and was completed in early December of
that year. One factor that lengthened the construction time was the fact that
the site selected was underlain by rock and extensive blasting was required
(Figure 4).
Figure 4. Sand filter construction site.
Plans called for each of the filters to be formed by clay embankments on
three sides (Figure 5), and the fourth wall of each was to be formed by a
common concrete wall (Figure 6). The purpose of the common concrete wall was
20
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Figure 5. Construction of clay embankments of sand filter,
Figure 6. Stem wall of sand filter.
21
-------
to reduce the land that would have been required if a clay embankment were
used to separate the two units. All clay used in the construction had to be
hauled to the location from an area approximately one mile from the construc-
tion site.
A factor which determined the dimensions of the bottom of the sand fil-
ters was the space required for the normal operation of heavy equipment, such
as a dozer, during the construction phase of the project. The dimensions of
the bottom of the structure were 15 ft by 38 ft. Location of the stem wall
was such that the bottom dimensions of the small and large filters would be
15 by 15 and 15 by 23 ft. The dimensions at the sand surface of the small and
large filters were 37.5 by 26 and 37.5 by 34, respectively. The bottom of the
filter was formed by compacting six inches of clay and the bottom of the filter
was sloped toward the effluent outlet to insure proper drainage from the unit.
After the bottom of the filter unit was properly compacted, the clay em-
bankments were formed. The clay embankments were constructed so that the in-
terior of all the dikes were sloped at a ratio of 2.5 horizontal units to 1.0
vertical units from the bottom of the filter to the top of the dike. The
specified elevation from the bottom of the filters to the top of all the dikes
except one was 9.5 ft. The top of the dike adjacent to the extended aeration
pond was 12 ft from the bottom of the filter. This was necessary since the
existing dike of the pond was used. The 9.5 ft elevation was selected to
allow 1.5 ft of gravel, 3 ft of sand, and 5 ft of freeboard. The 5 ft of free-
board was recommended based upon the maximum depth of wastewater and the maxi-
mum expected rainfall allowance. The tops of the embankments were built to a
width of 8 ft and these surfaces were leveled. The 8-foot width was selected
so that vehicles and machinery could have access to the filter units.
Figure 7. Preparation of bottom of sand filter.
12
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After the bottom and the embankments were formed and compacted, the stem
wall was poured. Then the underdrain of each filter unit was installed. The
underdrain network of each filter consisted of a series of perforated pipes
having 5-in. diameters. These pipes were placed three feet apart, and then
each of the horizontal lateral lines was connected to a 6-in. pipe which ser-
ved as the drain from the filter unit (Figure 8). The two drain lines pro-
jected through the wall of the dike and emptied into a sample collection box
before discharging the effluent to a stream. The 6-in. steel drainlines were
installed as the dike was constructed to prevent seepage and erosion around
the pipe. This allowed soil compaction by heavy equipment and prevented later
disturbance of the soil by installation of the drain.
Figure 8. Underdrain system of sand filter.
After the underdrain network was installed, the filter media was added
to the system. Eighteen inches of gravel, ranging from a diameter of 0.25 to
1.25 in. were placed in the bottom of each filter unit. Then 36-in. of sand
was placed on the gravel. Several local sources of washed sand were examined
as the potential filter media. Each sample was screened and the uniformity
coefficients and effective diameters were calculated. The sand selected had
a uniformity coefficient of 4 and an effective diameter of 0.2 mm. The uni-
formity coefficient of 4 was greater than the recommended limits, but this
sand source was selected because it was readily available and inexpensive.
The 36-in. depth of sand was selected so that the filter units could be
23
-------
cleaned several times by removing about three inches of surface sand before
the addition of new sand would be necessary.
A manhole existed between the extended aeration pond and the aerobic
lagoon, which was used to house the automatic valve and control the flow of
wastewater from the extended aeration process (Figure 9) . This manhole was
used for the connecting line to the sand filter units. A 6-in. diameter line
was installed from the manhole to a distribution box for the sand filters.
The flow of wastewater into this 6-in. line was regulated by the automatic
valve. After the addition of this line, it was possible to direct the flow of
Figure 9. Manhole with automatic valve.
wastewater from the extended aeration process to the lagoon or to the sand
filters. These dual secondary treatment systems provided a safeguard in that
the wastewater could be diverted to the lagoon in the event that the filters
were inoperable.
A concrete distribution box was used to divide the flow to the filters.
A 6-in. line connected the control manhole to the distribution box, and was
extended from the distribution box down the inside slope, and across the width
of each filter bed (Figure 10). The lines to the filters were designed so
24
-------
Figure 10. Distribution system of sand filter.
that they could be plugged at the distribution box. This system provided a
means of loading wastewater onto only one filter, or onto both filters simul-
taneously. Wastewater was discharged from the distribution box and onto the
filter beds through the 6-in. lines by gravity flow. That portion of each
distribution line which was in contact with the filter bed was perforated with
1-in. diameter holes. This allowed even distribution to the filter beds
(Figure 11).
The underdrain line from each filter unit extended into a concrete sam-
ple collection box (Figure 12). The discharge from both filters was then
carried underground from the sample collection box to the stream by means of
a 6-in. plastic line.
The original plans for the sand filter units specified that the clay
embankments would be sprigged with bermuda grass. This was not done upon the
completion of the filter units because the project was completed in December.
Just prior to the time the evaluation began, a heavy rainfall caused extensive
erosion of the embankments and clay was washed onto the sand surface. The top
sand layer had to be replaced, and the erosion of the embankments necessitated
repairs. Shortly after this incident, bermuda grass sod was placed on the
embankments which prevented additional erosion problems during the evaluation
period.
25
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Figure 11. Completed sand filter.
Figure 12. Sample collection box.
.•
-------
SECTION 7
OPERATION
An inspection of the system was done daily, Monday through Friday, bet-
ween 8 a.m. and 11 a.m. Samples were collected for routine analysis twice
each week, with samples for TSS being collected more frequently. The selection
of the dates for sample events for each week was made to meet the schedules
of the laboratory personnel. Each sample event consisted of:
1. A composite sample of the raw wastewater over the normal operational
hours at the packinghouse.
2. A composite sample of effluent from the extended aeration unit
between 5 a.m. and 9 a.m. the following morning. (This composite
period corresponds to the time the filter is loaded.)
3. A grab sample of filter effluent three hours after loading of
the filter.
The composite samples were collected in iced containers and all samples were
taken directly to the laboratory and stored at 4°C until analyses.
Daily flow measurements were made and in situ measurements were taken
for DO and water temperature. Air temperatures and precipitation measurements
were obtained from a local weather station. Analyses routinely performed on
the samples were those for 6005, COD, total solids (TS), TVS, TSS, pH, T-P,
TKN, N03~/N02~-N, and NH3-N. Other measurements were total alkalinity,
hardness, chloride, fecal coliform bacteria, FOG, iron, color and turbidity.
Liveweight killed values were acquired from packinghouse records. All analyses,
except some 6005 analyses, were performed according to EPA Methods for Chemi-
cal Analysis of Water and Wastes (10). After determining the accuracy of the
manometric method, this procedure was used for BOD5 analyses from October 21,
1976 to the end of the project.
Evaluation of the intermittent sand filter units began in March, 1976.
During the firt phase of the evaluation, sand with a uniformity coefficient
of 4 and an effective diameter of 0.2 mm was used. The average hydraulic load-
ing rates examined during this portion of the study were 0.86 mgad and 0.55
mgad. The length of filter runs were monitored, as well as the quality of the
effluent during this evaluation. The filter run is the length of time from
the first loading of a filter to the time the filter is plugged (when the
wastewater loaded onto a filter remained on the filter surface for more than
24 hours).
27
-------
When the filters were placed in operation in March, 1976, some mechanical
problems were encountered. These resulted due to malfunctions of the newly
installed valve and the automatic timers. Problems of this type were minimal
after the initial start-up period. During the start-up period the operational
scheme of the aerator was changed. Prior to this change the aerator was in
operation from 6 a.m. to midnight and settling of solids was allowed to occur
from midnight to 2 a.m. and the supernatent was discharged from the pond bet-
ween 2 a.m. and 6 a.m. In an attempt to decrease the amount of solids dis-
charged in the supernatent, the aerator was operated from 9 a.m. to 11 p.m.
and settling of solids was allowed to occur from 11 p.m. to 5 a.m. After the
6-hour settling period, an automatic air activated valve was opened between
5 a.m. and 9 a.m. to allow the supernatent to flow onto the filters.
The first test conducted consisted of loading both filters each day ex-
cept Sunday by dividing the daily wastewater flow from the extended aeration
lagoon. Clogging of the small filter occurred after only 6 days.
After this first test, a series of operating schemes were conducted which
consisted of using one filter and loading that filter daily until clogging
occurred, using both filters, and loading each filter on alternate days. Dur-
ing these investigations, raking of the sand surface was done to see if it
lengthened the filter run. No significant increase was shown. This phase of
the project revealed that the critical operating or design criteria for the
utilization of the intermittent sand filter units would be that which length-
ened the filter runs. Significant reduction in the BOD5 and TSS concentra-
tions was observed, but none of these trials revealed a filter run which was
long enough to be practical (Table 9).
TABLE 9. LENGTH OF FILTER RUNS
Loading ratebandAverage tliter run
(MGAD) (Eff. dia.) (Unif. coeff.) (Days) (Number of runs)
0.86
0.55
0.36
0.20 mm
0.20 mm
0.35 mm
4.0
4.0
2.5
10
15
109
5
6
1
In September, 1976, after an evaluation of the results of the first phase,
further investigation of the sand in the filters was conducted. This investi-
gation revealed that the original screening data was correct, and that the
sand did have a uniformity coefficient of 4 and an effective diameter of 0.2
mm. The sand samples were also checked for clay content to see if clogging
was due to the erosion of clay from the dikes. The samples were found to have
a low clay content but did have a large number of fines. It was decided that
clogging was due to the filter media and that the sand should be replaced
with another sand source.
28
-------
In early October, the original sand was replaced with a washed sand hav-
ing a uniformity coefficient of 2.5 and an effective diameter of 0.35 mm.
Since the filter run in the preceding tests had been so short, the decision
was made to also decrease the hydraulic loading rates even though the larger
sand source was being used. The hydraulic loading rate used in this trial
was 0.36 mgad.
Only the large filter was used in this trial, and the filter was loaded
daily except Sunday. The study began on October 20, 1976, and the large fil-
ter was operated for 109 days (Table 9) until February 23, 1977, at which
time the filter was shut down due to clogging. During this interval, the
filter was not in operation from November 20, 1976, to November 23, 1976,
because the aerator required maintenance. The flow was diverted to the aero-
bic ponds during this non-treatment period. The filter was not used from
January 8, 1977, to January 16, 1977, because the plant was closed due to an
unusually severe snow storm.
The investigation conducted with the sand having an effective diameter
of 0.35 mm and a uniformity coefficient of 2.5 resulted in a much longer fil-
ter run than what had been observed with the original sand source. The re-
duced hydraulic loading rate could account for some increase in the length of
filter run, but the major factor responsible for the increase in the filter
run was the new filter media. The number of pounds of suspended solids coll-
ected on the sand surface before plugging of the filter occurred was calcul-
ated for the various investigations. With the sand having a uniformity co-
efficient of 4.0 and an effective diameter of 0.20 mm, and with a hydraulic
loading rate of 0.86 mgad, plugging of the filter occurred after the accumula-
tion of 0.049 Ibs of suspended solids/ft2 of filter surface. With the same
sand and a hydraulic loading rate of 0.55 mgad, 0.047 Ibs of suspended solids/
ft2 of filter surface accumulated prior to clogging. The accumulated suspend-
ed solids value for the trial using the larger sand (0.35 mm eff. dia.) was
0.225 lbs/ft2 of surface area.
29
-------
SECTION 8
RESULTS
FILTER RUN
The investigation revealed that the successful operation of the inter-
mittent sand filters was highly dependent on the filter media. By changing
the filter media to a sand having a uniformity coefficient of 2.5 and an
effective diameter of 0.35 mm, the length of the filter run was increased by
an order of magnitude. The evaluation with the larger sand source also repre-
sented a lower hydraulic loading rate (0.36 mgad) than had been used in the
earlier test with the sand having a uniformity coefficient of 4. The investi-
gation established that an intermittent sand filter was a practical treatment
process for meatpacking wastewaters and that the critical design criteria was
the selection of the filter media. Determining the optimum operation of the
filter utilizing a high hydraulic loading rate was not possible due to fund-
ing limitations.
OVERALL REMOVAL EFFICIENCIES
The wastewater characteristics and removal efficiencies of the system for
the entire evaluation period (March, 1976 to January, 1977) are summarized in
Table 10. A significant reduction of 8005, TSS, NH3-N, and FOG are experi-
enced by the extended aeration-sand filter system at the W. E. Reeves facility.
TABLE 10. WASTEWATER CHARACTERISTICS AND PERCENT REMOVAL
Parameters
BOD5
TSS
FOG
NHa-N
(mg/1)
(mg/1)
(mg/1)
(mg/D
n
46
27
16
16
Raw
waste.
672.0
392.0
138.7
14.8
n
51
42
10
14
Ext.
eff
41.
41.
29.
3.
aer.
•
0
0
1
1
n
57
63
10
14
Filter
eff.
10.
11.
5.
1.
4
1
0
9
Percent
removal
98.
97.
96.
87.
5
1
4
2
30
-------
SUSPENDED SOLIDS
The efficiency of removal of TSS is of extreme interest since the BPT
and BAT limits proposed for this parameter are those most commonly exceeded by
discharges from the meat industry. Also the existing treatment facilities at
the W. E. Reeves Packinghouse failed to reduce TSS to these levels. Total
suspended solids analyses are presented in Table 11. The mean TSS concentra-
tion of 27 samples of untreated wastewater was 293 mg/1. Forty-three compos-
ite samples of effluent from the extended aeration unit were analyzed and the
mean TSS value was 41 mg/1. This value of 41 mg/1 represented the TSS concen-
tration loaded onto the sand filters. The data in Table 11 are grouped by
hydraulic loading rates. The hydraulic loading rates investigated, with the
sand having a uniformity coefficient of 4, were 0.86 mgad and 0.55 mgad. The
sand with a uniformity coefficient of 2.5 was investigated at a rate of 0.36
mgad. The mean TSS concentrations of the effluent resulting from hydraulic
loading rates of 0.86 mgad, and 0.55 mgad, and 0.36 mgad were 10.6 mg/1, 11.8
mg/1, and 10.6 mg/1 respectively. An examination of the data using the anal-
ysis of variance (ANOVA) indicates that there was not a significant difference
(p < .05) in these values; so the effect of hydraulic loading rate on TSS
concentration was considered minor within the range tested. The pilot scale
filters reduced TSS from 40 mg/1 to 22 mg/1, while the full-scale filters
reduced TSS from 41 mg/1 to 11 mg/1.
TABLE 11. TOTAL SUSPENDED SOLIDS
mgad
Minimum"
Maximum
Mean
TSS (mg/1) 0.36
Raw wastewater 2
Filter influent 8
Filter effluent 8
TSS (mg/1) 0.55
Raw wastewater 11
Filter influent 19
Filter effluent 28
TSS (mg/1) 0.86
Raw wastewater 14
Filter influent 16
Filter effluent 27
TSS (mg/1) combined
Raw wastewater 27
Filter influent 43
Filter effluent 63
116
19
5
160
19
3
246
19
3
116
19
3
198
71
17
694
79
45
861
111
32
861
111
45
157.0
35.5
10.6
377.0
44.2
11.8
437.0
40.1
10.6
392.0
41.0
11.1
The BPT 30-day average limit for TSS is 0.24 lb/1000 Ibs LWK, and the
BAT 30-day average limit is 0.06 lb/1000 Ibs LWK. The maximum day limits for
both BPT and BAT guidelines are two times the 30-day average values. The test
31
-------
using the sand with a uniformity coefficient of 4 revealed an average value
of 0.07 lb/1000 Ibs LWK and a maximum of 0.30 lb/1000 Ibs LWK. The average
and the maximum TSS values for the test with a sand source having a uniformity
coefficient of 2.5 were 0.07 and 0.11 lb/1000 Ibs LWK, respectively. Upon
comparison of the mean and maximum TSS concentrations from the tests and the
BPT and BAT guidelines, it is evident that the effluent value met the BPT
guidelines. However, the discharges from both sand sizes exceeded the BAT
30-day average by 0.01 lb/1000 Ibs LWK, which is within the accuracy of the
analyses. The maximum day value corresponding to the sand with the uniformity
coefficient of 2.5 met the BAT limits while that with a coefficient of 4.0
did not. A summary of the TSS concentration is shown in Table 12 and a
comparison of the quantity discharged to the NPDES limitations is given
in Table 13.
FIVE-DAY BIOCHEMICAL OXYGEN DEMAND
A total of 46 samples of the untreated wastewater were analyzed for 6005
and the test results revealed a mean BOD5 value of 672 mg/1. Composite samples
of the effluent from the extended aeration unit were also analyzed and the
values for 51 analyses had a mean concentration of 41 mg/1. Fifty-seven sam-
ples of effluent from the sand filters were analyzed for BOD5 and were found
to have an average value of 10.4 mg/1. This represented a 98.5% BOD5 removal
by the treatment system. The 57 samples of sand filter effluent were repre-
sentative of the trials with two sand sources and three hydraulic loading
rates. The average 8005 values were calculated for the trials for each hy-
draulic loading and each sand source. Based on the ANOVA statistical test,
there was not a significant difference in the mean concentrations for these
trials. Quantitative information pertaining to BOD5 values is shown in Table
14.
The average BODj values from the various trials were converted to lb/1000
Ibs LWK and compared to the BPT and BAT limits for low packinghouse discharges.
This information is revealed in Table 13. The values obtained from these
trials indicated that the intermittent sand filter systems produced an eff-
luent which would meet the BPT limits for 8005; however, the quality of eff-
luent failed to meet the BAT limits. Pilot scale results indicated the addi-
tion of an intermittent sand filter would meet BAT limits. Removal of 8005
in the two pilot filters was 60% and 72%. Removal of BOD5 in the full-scale
filter was 75%. The failure to meet the BAT limits was caused by a higher
average concentration (41 mg/1) from the extended aeration unit. A previous
12 month evaluation (3) recorded an average effluent from the extended aera-
tion unit of 17.0 mg/1 of 8005.
32
-------
TABLE 12. INTERMITTENT SAND FILTER EFFLUENT CHARACTERISTICS
OJ
OJ
Parameters
BOD5 (mg/1)
TSS (mg/1)
NH3-N (mg/1)
FOG (mg/1)
Fecal coliform
(MPN/100 ml)
n
21
27
3
1
15
0.86 MGAD
Sand A
10.2
10.6
2.4
<15.0
2.75 x 104
n
26
28
6
6
16
0.55 MGAD
Sand A
10.5
11.8
1.9
<5.0
1.39 x 104
n
10
8
5
3
6
0.36 MGAD
Sand B
10.2
10.6
1.6
<5.0
1.02 x 104
n
57
63
14
10
37
Combined
Data
10.4
11.1
1.9
£5.0
1.88 x 104
Sand A - uniformity coefficient of 4; effective diameter of 0.2 mm.
Sand B - uniformity coefficient of 2.5; effective diameter of 0.35 mm.
-------
TABLE 13. COMPARISON OF DISCHARGES AND NPDES LIMITATIONS
Low packinghouse limits Sand A results Sand B results
Parameter 30-day avg. max-day 30-day avg. max-day 30-day avg. max-day
1977 limitations
BOD5
TSS
FOG
.17
.24
.08
.34
.48
.16
.07
.07
<.03
.17
.30
< .03
.07
.07
£ .03
.10
.11
£.03
New source limitations
(include above + NH3>
NH3-N .24 .48 .01 .03 .01 .02
1983 limitations (BAT)
BOD5
TSS
FOG
NH3-N
10
4
.04
.06
mg/1
mg/1
20
8
.08
.12
mg/1
mg/1
£5
2
.07
.07
mg/1
mg/1
-C5
4
.17
.30
mg/1
mg/1
.07
.07
^.5 mg/1
2 mg/1
<5
3
.10
.11
mg/1
mg/1
Test Results A - Data collected from filter at loading rate of 0.86 and 0.55 mgad and sand with
uniformity coefficient of 4 and effective diameter of 0.2 mm.
Test Results B - Data collected from filter at loading rate of 0.36 mgad and sand with uniformity
coefficient of 2.5 and effective diameter of 0.35 mm.
All values in Table 13 are in lbs/1000 Ibs LWK except BAT limits for FOG and
-------
TABLE 14. BIOCHEMICAL OXYGEN DEMAND
Minimum
Maximum
Mean
BOD5 (mg/1) 0.36
Raw wastewater 8
Filter influent 9
Filter effluent 10
BOD5 (mg/1) 0.55
Raw wastewater 22
Filter influent 28
Filter effluent 26
BOD5 (mg/1) 0.86
Raw wastewater 16
Filter influent 14
Filter effluent 21
BOD5 (mg/1) combined
Raw wastewater 46
Filter influent 51
Filter effluent 57
511
24
5
299
19
4
412
26
4
299
19
4
902
43
15
1126
72
20
1017
90
26
1126
90
26
735.0
32,
10.
700.0
41.7
10.5
654.0
45.4
10.2
672.0
41.0
10.3
FATS, OIL AND GREASE
On ten sample dates during the evaluation period, grab samples for fats,
oil, and grease analyses were collected in one-liter glass containers. These
samples were collected to represent untreated wastewater from the plant, eff-
luent from the extended aeration unit, and sand filter effluent. Mean values
for the untreated wastewater and extended aeration pond effluent were found
to be 139 and 29 mg/1, respectively. Effluent samples from the sand filter
were consistently less than 5 mg/1, the limit of detection of the test. Since
the effluent concentrations were low, the number of analyses was reduced in
the last part of the study.
The treatment system removed more than 96% of the FOG from the wastewater
and the effluent met all BPT and BAT limits with respect to FOG. Since the
variation in the concentrations of FOG for the three hydraulic loading rates
was not meaningful, the combined FOG results are presented in Table 15. The
comparison of the discharge quantity to the NPDES limits is shown in Table 13.
TABLE 15. FATS, OIL, AND GREASE
Minimum
Maximum
Mean
FOG (mg/1)
Raw wastewater
Filter influent
Filter effluent
10
10
10
66
11
5
231
48
5
139
29
5
35
-------
FECAL COLIFORM BACTERIA
During the evaluation period, 37 filter effluent samples were analyzed
for fecal coliform bacteria. The mean number for these 37 values was 1.88 x
10^ MPN/100 ml. Analyses for fecal coliform bacteria in the untreated waste-
water and the extended aeration pond effluent were not done because both of
these sources had been shown in past evaluations to be extremely high (i.e.
1.0 x 106 MPN/100 ml) with respect to fecal coliform bacteria. All fecal
coliform values for the filter effluents exceeded the established 400 MPN/100
ml limits, except the one value for the date of June 9, 1976, which was 300
MPN/100 ml. Disinfection of the effluent would be necessary to meet the dis-
charge standard.
pH
Routine pH measurements were performed on all samples collected. The
untreated wastewater discharged from the packinghouse had an average pH value
of 7.4, with minimum and maximum values of 6.0 and 8.4, respectively. The
effluent samples from the extended aeration pond had an average pH of 7.6,
with the minimum and the maximum of 7.1 and 8.2, respectively. The inter-
mittent sand filter was found to have little effect on the pH, as the average
pH value of the sand filter effluent was 7.6, and the minimum and maximum
readings were 7.2 and 7.9, respectively. None of the sand filter effluent
samples were in violation of NPDES guidelines since none of the readings were
below a pH of 6.0 or above 9.0.
AMMONIA NITROGEN
Since the OTDES effluent standards have limits for NH3-N, routine NH3-N
determinations were done; the results are in Table 16. Sixteen untreated
wastewater samples were analyzed and were found to have a mean value of 14.8
mg/1 NH^-N. The mean value of the discharge from the extended aeration unit
was 3.1 mg/1 NH3-N which was based on readings from 14 samples. All fil-
ter effluent samples were lower than the corresponding influent samples with
the exception of one value. On September 16, 1976, an influent reading of
0.5 mg/1 NH3-N was recorded and the corresponding effluent sample had an NH3-N
reading of 0.8 mg/1. The mean filter effluent, based on 14 determinations,
was 1.9 mg/1 NH3-N. The total treatment system showed an average removal of
87.2% with respect to NH3~N. Calculations, using mean values, also showed
that the NH3~N concentrations of the filter influent, was reduced by 61%. The
average NH3~N values of the discharge were converted to lb/1000 Ibs LWK and
were found to be well below both rescinded BAT limits and the new source limits
for NH3-N. The comparison to NPDES limitations is given in Table 13.
36
-------
TABLE 16. AMMONIA NITROGEN
n Minimum Maximum Mean
NH3-N (mg/1)
Raw wastewater
Filter influent
Filter effluent
16
14
14
4.7
.5
.4
23.8
7.1
4.0
14.8
3.1
1.9
TOTAL KJELDAHL NITROGEN AND NITRATE/NITRITE NITROGEN
As stated earlier, the treatment system was found to be effective in re-
ducing the NH3-N. The same effect was shown with respect to TKN (Table 17).
The average concentration of TKN in the untreated wastewater was 68.8 mg/1
and this was reduced to 11.0 mg/1 by treatment in the extended aeration unit.
The TKN concentration was further reduced to an average value of 4.5 mg/1 by
the intermittent sand filter.
TABLE 17. TOTAL KJELDAHL NITROGEN
n Minimum Maximum Mean
TKN (mg/1)
Raw wastewater
Filter influent
Filter effluent
13
13
14
44.1
6.0
2.0
103.1
16.4
8.7
68.1
11.0
4.6
Nitrate/nitrite nitrogen analyses were also completed on the wastewater
samples (Table 18). A large variation in the N03~/N02~-N concentration was
found in the untreated wastewater, with a minimum of 0.11 mg/1 and a maximum
of 4.08 mg/1. The average concentration of N03~/N02~-N in untreated waste-
water was 1.26 mg/1 and the average concentration in the discharge from the
extended aeration process was 1.23 mg/1. An examination of the mean values
seems to indicate that a slight reduction occurred as a result of treatment in
the extended aeration system; however, when 16 sets of N03~/N02~-N values for
the untreated wastewater and the extended aeration pond effluent were reviewed,
a significant increase in N03~/N02~-N concentration was apparent in 10 sets of
data.
A comparison of the N03~/N02~-N concentration for the extended aeration
effluent and the corresponding intermittent sand filter effluents revealed
that an increase in N03~/N02~-N concentrations occurred in all sets of data
except one. The mean values for the pond effluent and filter effluent, 1.23
mg/1 and 2.19 mg/1, respectively, indicates that nitrification did occur in
the sand filter. This N03~/N02~-N concentration increase is small in compari-
son to the TKN decrease, therefore the treatment system accomplished a total
nitrogen reduction.
37
-------
Both NH3-N and TKN concentrations decreased in the extended aeration unit
with only a small percentage of the decrease accounted for by the N03~/N02~-N
increase. Denitrification occurred, most likely during the 6 hours each day
when the aerator was not in operation.
The TKN concentration was decreased as the wastewater passed through the
filter unit and the NH3-N concentration was decreased in all samples except
two. The N03~/N02~-N concentration of the wastewater was increased in all
samples except one. Based on mean values, the increased N03~/N02 -N concen-
tration accounted for approximately 30% of the total nitrogen reduction. This
indicates that both nitrification and denitrification occurred in the sand
filter.
TABLE 18. NITRATE/NITRITE NITROGEN
N03-/N02~-N (mg/1)
Raw wastewater
Filter influent
Filter effluent
n
18
16
16
Minimum
0.11
0.41
0.85
Maximum
4.08
2.16
4.15
Mean
1.26
1.23
2.19
PHOSPHORUS
Total phosphorus analyses were performed on untreated wastewater and the
intermittent sand filter influent and effluent samples (Table 19). The con-
centration of phosphorus in the untreated wastewater showed a considerable
variation, with a minimum of 0.18 mg/1 T-P, a maximum of 14.5 mg/1 T-P, and a
mean concentration of 7.7 mg/1 T-P. The mean phosphorus value of both the
influent and effluent of the sand filter was 2.4 mg/1 T-P, indicating that
phosphorus removal was not accomplished by intermittent sand filtration. The
5 mg/1 reduction observed in the treatment system was accomplished by the
extended aeration process.
TABLE 19. TOTAL PHOSPHORUS
T-P (mg/1)
Raw wastewater
Filter influent
Filter effluent
n
22
22
21
Minimum
.8
.4
.3
Maximum
14.5
4.5
4.5
Mean
7.7
2.4
2.4
DISSOLVED OXYGEN
The DO concentration of untreated wastewater showed a large variation due
to the variable nature of the waste discharges at the packinghouse (Table 20).
38
-------
The filter influents were consistently low, but all samples did have a measur-
able DO concentration. The low values are due to the fact that the aerator
was not in operation for several hours prior to and during discharge to the
sand filter. The influent to the filter had an average DO value of 0.94 mg/1,
a minimum of 0.1 mg/1, and a maximum of 3.0 mg/1. In all sets of analyses,
passage of the wastewater through the sand filter increased the DO concentra-
tion. The analyses of the effluent samples revealed a mean value of 4.4 mg/1,
with a minimum of 1.9 mg/1 and a maximum of 7.9 mg/1. The increase in the
DO concentration, as a result of sand filtration, occurred in warm weather as
well as cold weather.
TABLE 20. DISSOLVED OXYGEN
DO (mg/1)
Raw wastewater
Filter influent
Filter effluent
n
68
68
68
Minimum
0.8
. 0.1
1.9
Maximum
6.6
3.0
7.9
Mean
3.6
0.9
4.4
TOTAL SOLIDS AND TOTAL VOLATILE SOLIDS
The samples of untreated wastewater and the influent and effluent samples
of the sand filter were analyzed for total solids (TS) and total volatile sol-
ids (TVS). A summary of the data is in Table 21. The effluent from the ex-
tended aeration unit was lower in TS than the untreated wastewater. However,
there is little change in the TS concentration of the influent and effluent
samples of the filter. The average values for the TS of the filter influent
and effluent were 1155 mg/1 and 1128 mg/1, respectively. A slightly larger
variation existed for the filter influent and effluent with respect to TVS.
This would be expected, due to the larger amount of organic materials in the
form of suspended solids in the influent. The influent had a TVS value of
166 mg/1 and the average value for the TVS of the filter effluent was 104 mg/1.
TABLE 21. TOTAL SOLIDS AND TOTAL VOLATILE SOLIDS
n Minimum Maximum Mean
TS (mg/1)
Raw wastewater 51 855 2771 1916
Filter influent 50 812 1807 1155
Filter effluent 55 814 1639 1128
TVS (mg/1)
Raw wastewater 17 329 1545 761
Filter influent 20 95 246 166
Filter effluent 19 65 175 104
39
-------
CHEMICAL OXYGEN DEMAND
Since future standards may be promulgated on COD values, COD analyses
were performed on collected samples during the evaluation. The untreated
wastewater had an average COD value of 1553 mg/1 and the average COD value of
the filter influent was 114 mg/1. Effluent from the filters had a COD of 68
mg/1, which represented a COD removal of 95.6%. The COD data is presented in
Table 22.
TABLE 22. CHEMICAL OXYGEN DEMAND
n Minimum Maximum Mean
COD (mg/1)
Raw wastewater
Filter influent
Filter effluent
45
43
41
629
66
26
5021
392
158
1553
114
68
CHLORIDE
Water quality standards in some geographical locations require the moni-
toring of chloride and it is also one parameter used to evaluate the feasi-
bility of land disposal of wastewater. For these reasons, chloride analyses
were performed on a total of 22 series of samples representing raw wastewater,
filter influent, and filter effluent. These results are presented in Table 23.
An examination of the mean values reveals that the effluent from the extended
aeration system was higher (82 mg/1) than the mean value of the wastewater.
This increase was also found in a previous investigation (3) and is attributed
to the sampling schedule. A major salt load is discharged to the treatment
system on Saturday when the brine cellar is cleaned. However, samples are not
collected on Saturday. The discharge of the chloride is picked up in the
effluent samples taken the following week. The sand filtration process resul-
ted in a decrease of 46 mg/1. This is not a significant decrease but could
be due to the removal of suspended solids containing chloride, since the sand
filter would not remove ionic species such as chloride.
TABLE 23. CHLORIDE
n Minimum Maximum Mean
Cl~ (mg/1)
Raw wastewater 22 280 745 459
Filter influent 22 435 635 541
Filter effluent 22 405 650 495
40
-------
TURBIDITY AND COLOR
Since color and turbidity are sometimes used in evaluating water quality,
these parameters were monitored during the investigation. In all instances,
the turbidity was reduced by passage of the wastewater through the intermittent
sand filter units, thus producing a higher quality effluent. The average of
39 turbidity analyses of the filter influent samples was 20 Jackson Turbidity
Units (JTU's) and the wastewater discharged from the sand filters had an aver-
age value of 7 JTU's.
The average value of the color readings of 64 filter influent samples was
133 Platinum-Cobalt (Pt-Co) color units and the average value of 59 effluent
samples was 53 Pt-Co color units. The color of the raw wastewater was not
measured because of the extremely high color range. The intermittent sand
filter was found to be beneficial in color removal.
TEMPERATURE AND PRECIPITATION
The air temperatures and precipitation readings were obtained from the
local weather station. In situ measurements of the temperature of the sand
filter effluent were taken. The monthly average values for these parameters
are given in Table 24.
TABLE 24. TEMPERATURES AND PRECIPITATION
Month/year
3/76
4/76
5/76
6/76
7/76
8/76
9/76
10/76
11/76
12/76
1/77
Average
air temp.
°C
17
21
21
28
28
33
28
17
11
7
5
Average
effluent temp.
°C
24
25
23
24
25
26
25
22
10
5
5
Monthly rainfall
inches
2.96
4.04
5.21
2.72
1.43
2.55
1.22
3.99
1.17
1.73
1.40
FLOW AND LIVEWEIGHT KILLED
Flow measurements of the raw wastewater were made on the days that the in-
termittent sand filters were in operation. These values were taken by a
Steven's depth recorder and a 3-in. Parshal flume. Due to recording device
error, only 53 reliable flow values are available. The LWK values for the
project period were obtained from the packinghouse manager. The flow data and
LWK values are summarized in Table 25.
41
-------
TABLE 25. FLOW RATES AND LIVEWEIGHT KILLED
n Minimum Maximum Mean
Flow (gallons) 53 15,490 25,120 19,756
LWK (Ibs) 81 10,090 57,380 24,617
42
-------
SECTION 9
EXTENDED AERATION UNIT
The extended aeration unit is an adaptation of the activated sludge pro-
cess. The unit incorporates the activated sludge process (growth of bacterial
floe, mixing and aeration of the floe, separation of the floe, and discharge
of the supernatent) into one pond. The pond is in the shape of an inverted,
truncated pyramid, and has a volume of 18,500 ft3 of wastewater at a 9-ft
depth. Aeration is accomplished by a 10-hp Peabody Welles floating aerator.
The operation of the aerator is controlled by timers. Timers are also used
to control an automatic outlet valve to discharge the clear supernatent after
the settling of the floe is accomplished.
The extended aeration unit at the Reeves facility has been operated for
several years and during a one-year evaluation, the effluent from the process
met the BPT limitations, except for the maximum day limits for TSS and the
limits for fecal coliform bacteria (3). During the one-year evaluation period
the aerator was operated from 6 a.m. until midnight. Settling occurred between
midnight and 2 a.m. and discharge of the supernatent was done between 2 a.m.
and 6 a.m. The summarized results of this evaluation are shown in Table 26.
TABLE 26.
Parameter
BOD5
COD
TSS
FOG
NH3-N
N03~/N02~-N
TKN
T-P
CONCENTRATIONS
n
42
46
45
10
44
44
46
46
AND REMOVALS
Influent
(mg/1)
714.8
1630.2
535.8
138.6
12.5
0.4
79.0
11.0
(DURING AERATION
Effluent
(mg/1)
17.0
121.6
65.4
11.9
1.9
2.6
7.8
3.3
STUDY)
Removal
(%)
98
93
88
91
95
90
71
During this one-year evaluation the extended aeration unit was loaded with
lower organic and hydraulic loads than those which are normally used for acti-
vated sludge processes. The food to microorganisms ratio (F/M) averaged 0.06
Ib BOD5/lb mixed liquor suspended solids (MLSS). The mean hydraulic detention
time was 9.8 days and the average sludge retention index (SRI) was 64 days.
43
-------
Sludge was wasted 5 times during the 12-month period.
3350 mg/1 and the sludge volume index (SVI) was 217.
The average MLSS was
Prior to the time the evaluation of the sand filter began, the aerator in
the extended aeration system had been out of operation and the wastewater in
the pond had become anaerobic. The aerator was operated for several weeks
before the sand filter evaluation began. After one week of the evaluation,
sludge was wasted from the extended aeration pond because the MLSS value was
found to be 7600 mg/1. Sludge was wasted from the pond again on April 9, 1976
because the MLSS value was 5210 mg/1. After that removal of sludge, the MLSS
value of the mixed liquor in the pond was 1915 mg/1. Sludge was not wasted
again during the evaluation period until September 21, 1976. The concentra-
tions and removal efficiencies of the extended aeration system for various
parameters during the period of time the sand filter was evaluated are given
in Table 27.
TABLE 27. CONCENTRATIONS AND REMOVALS (DURING FILTER STUDY)
Parameter
BOD5
COD
TSS
FOG
NH3-N
N03-/N02~-N
TKN
T-P
n
46
45
27
16
16
18
13
22
Influent
(mg/1)
672.0
1553.0
392.0
138.7
14.8
1.26
68.1
7.7
n
51
43
42
10
14
16
13
22
Effluent
(mg/1)
41
114
41
29.1
3.1
1.23
11.0
2.4
Removal
(%)
94
93
90
79
79
2
84
69
During the period of time the sand filter evaluation study was done, the
aerator in the pond was operated from 9 a.m. to 11 p.m. The aerator was off
from 11 p.m. until 5 a.m. in order to allow a longer settling time than the
one used during the previous evaluation of the extended aeration pond. The
supernatent was discharged from the pond and onto the filters between 5 a.m.
and 9 a.m.
The F/M ratio during this evaluation was .045 Ib BOD5/lb MLSS and the
mean hydraulic detention time was 7.5 days. The SRI for this evaluation was
38 days. The average MLSS value was 2750 mg/1 and the average SVI was 120.
The BODj removal efficiencies accomplished by the extended aeration unit
during the first year evaluation and the sand filter evaluation period are
98% and 94% respectively. However, during the one-year evaluation prior to
the incorporation of the sand filter, the average 8005 of the effluent from
the pond was 17 mg/1 as compared to 41 mg/1 for the effluent loaded onto the
sand filter.
44
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During the one-year evaluation of the extended aeration unit, the unit
showed a removal efficiency with respect to TSS of 88%. The average TSS of
the discharged waste was 65.4 mg/1. An examination of the data for the ex-
tended aeration unit during the time the sand filter was evaluated reveals
that the extended aeration unit removed 90% of the TSS and that the average
TSS of the wastewater loaded onto the sand filter was 41 mg/1. The use of
the average values is misleading, because during the one-year evaluation the
TSS value of 65.4 mg/1 occurred as a result of the exceedingly high TSS values
during the first few months of operation of the extended aeration unit. After
the first two months of operation, the TSS values dropped to approximately
20 mg/1 which is considerably lower than the corresponding 41 mg/1 values ob-
served during the evaluation of the sand filter.
The wastewater discharged from the extended aeration unit to the sand
filter was higher with respect to BOD5 and TSS than the effluent from the unit
during an earlier investigation. This deterioration in the quality of the in-
fluent could account for the fact that the effluent from the sand filter did
not meet BAT limits for BOD5 and TSS as expected.
COAGULATION-FLOCCULATION STUDY
After considerable data had been acquired on influent and effluent samples
of the sand filter, calculations were made to see if the effluent would meet
NPDES guidelines. The calculations revealed that the effluent might not
meet all BAT guidelines for TSS and
Based on these observations, consideration was given to methods which
might improve the efficiency of the treatment system (23, 24). One method
considered as a possible means of improving the quality of the effluent was a
batch chemical treatment of the wastewater in the aerated lagoon. This pro-
cess would be simple, as chemicals could be added directly to the extended
aeration pond and mixing would be accomplished by the aeration unit. If low
cost chemicals were found to be effective, this process would also be econom-
ically feasible. Favorable results with alum and lime have been demonstrated
by Rea (25) in a single cell activated sludge system.
The first investigation conducted in reference to the feasibility of
batch chemical treatment consisted of taking samples from the extended aera-
tion pond and subjecting these to chemical addition. These samples were
treated with various concentrations of alum and lime. Turbidity measurements
were taken at various time intervals and these results were compared to tur-
bidity readings taken on settled samples from the pond which had not been
subjected to chemical treatment. Turbidity measurements were used as an
index to the effectiveness of the chemicals since it is much faster and easier
to perform than the TSS readings. The results of one test using alum addition
equivalent to 0.8 lb/1000 gal and lime equivalent to 1.0 lb/1000 gal are shown
in Figure 13.
45
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H
•-3
x x no chemical treatment
0 0 chemical treatment
4-
10 15 20
Minutes of settling
25
30
Figure 13. Chemical treatment effectiveness.
In a second investigation, effluent samples from the extended aeration
pond were subjected to chemical treatment with alum at the rate equivalent to
0.8 lb/1000 gal and lime at the rate of 1.0 lb/1000 gal prior to filtration
through the pilot scale sand columns. These results were compared to filtered
wastewater samples which had not been subjected to chemical treatment. These
results are shown in Table 28.
TABLE 28. ALUM TREATMENT STUDY
Without chemicals
With chemicals
Parameter
TSS (mg/1)
Turbidity (JTU's)
Avg.
11.9
8.0
n
18
18
Avg.
10.5
6.2
n
18
18
Laboratory jar tests using alum and ferric chloride were conducted on
mixed liquor from the aerated pond. The samples were separated into three
portions. One portion was allowed to settle without chemical treatment. A
second portion was treated with alum and lime and the third portion was treat-
ed with ferric chloride and lime. The test was repeated three times using
various concentrations of alum or ferric chloride. The concentration of lime
46
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was 1 lb/1000 gal in all tests. All samples were subjected to mixing for 5
minutes. After a settling time of 30 minutes, TSS analyses were performed on
the settled portions of the mixtures. These results are shown in Table 29.
TABLE 29. CHEMICAL TREATMENT-SEDIMENTATION STUDY
Chemical dosage
lb/1000 gal
n
Avg. TSS
(me/I)
Mixed liquor
Trial 1
Trial 2
Trial 3
Combined
Mixed liquor with alum
Trial 1
Trial 2
Trial 3
Combined
Mixed liquor with ferric chloride
Trial 1
Trial 2
Trial 3
Combined
0.4
0.8
1.6
0.4
0.8
1.6
3
3
3
9
3
3
3
9
3
3
3
9
49
46
46
47
37
30
35
34
42
37
32
37
Since quantitative studies were not completed, definite conclusions can-
not be made, but the brief studies did reveal that batch chemical treatment
might be economically and technically feasible. Polyelectrolytes were not
used in the brief studies but the use of polyelectrolytes should be investi-
gated as a possible method of improving the quality of the effluent from the
extended aeration system. A supplemental request for $18,867 to demonstrate
the utilization of batch chemical addition to the system at the W. E. Reeves
Packinghouse was denied.
47
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SECTION 10
COSTS
One of the objectives of the project was to develop a treatment system
which would be economical to construct, operate, and maintain.
An earlier publication by Witherow (2) revealed that the cost of the
three lagoons and appurtenances was $20,000. From this figure, the cost of
the first pond and appurtenances, which was used in conjunction with the sand
filters, was calculated to be $6,700. Equipment included for this system was
the floating aerator, control panel, automated valve, air compressor, pneuma-
tic and electrical supplies. The cost figure for these items was $6,000.
This figure also included the cost of installation. The cost of construction
of the intermittent sand filter system was $13,300. Of this figure, $1,800
was the cost of the sand. The capital cost of the system evaluated in this
study included the cost of the pond, equipment, and sand filter unit. The
total capital cost was $26,000.
Other expenditures would be incurred for operation and maintenance labor,
equipment repair, power, monitoring, and reporting. The annual equipment re-
pair cost based on experience during the study was set at 8% of capital cost,
or $480/year. The electrical power cost was based on monthly billings for
the treatment facility. That cost figure was $1100/year.
The operation and maintenance labor cost was based on 8 to 10 man-hours/
week. This would include routine maintenance and repairs, daily inspection,
and weekly sample collection. The cost figure for this activity was $2600/
year.
Sand replacement cost was calculated to be $600/year. This figure would
allow for a replacement of 1 foot of sand per year at a cost of $6.75/cubic
yard.
The monitoring costs were based on the assumption that the plant employees
would collect monthly samples and ship the samples to a commercial laboratory
for analysis of those parameters listed on the NPDES permits. Plant personnel
would then be responsible for completing and forwarding the NPDES report forms.
The estimated cost of this activity was $980/year.
The annual cost of the extended aeration system followed by intermittent
sand filtration was derived by amortizing the structures at a rate of 7% over
20 years, and amortizing the equipment at 7% over 10 years. This results in
a total annual cost of $8,500. These figures are summarized in Table 30.
48
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TABLE 30. TREATMENT COSTS FOR FULL-SCALE SYSTEM
Capital costs
Extended aeration pond $ 6,700
Sand filter 13,300
Installed equipment 6,000
Capital cost $26,000
Annual costs
Amortized structure (7% - 20 yrs.) 1,890
Amortized equipment (7% - 10 yrs.) 850
Equipment repair (8%) 480
Operating and maintenance labor 2,600
Electrical power 1,100
Monitoring and reporting 980
Sand replacement 600
Total annual costs $ 8,500
Installation cost: $1.40/gpd capacity
Treatment cost: $0.29/lb BOD5 applied
These cost figures did not include the cost of incorporating a disinfec-
tion system into the existing facility or the cost of land acquisition.
49
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REFERENCES
1. The Federal Register, 39 (5): 7767-7914, February 28, 1974.
2. Witherow, J. L., A. J. Tarquin, and M. L. Rowe. Manual' of Practice -
Waste Treatment for Small Meat or Poultry Plants. Food Processing Waste
Research, EPA, Corvallis, Oregon, 1976. pp. 16-18.
3. Witherow, J. L. Small Meat Packers Waste Treatment Systems. Proceedings
of the 28th Industrial Wastes Conference, Purdue University, Lafayette,
Indiana, May, 1973.
4. Witherow, J. L. Small Meat Packers Waste Treatment Systems II. Proceed-
ings of the 30th Industrial Wastes Conference, Purdue University, Lafay-
ette, Indiana, May, 1975.
5. Witherow, J. L., M. L. Rowe, J. L. Kingey. Meat Packing Wastewater
Treatment by Spray Runoff Irrigation. Proceedings of the 6th National
Symposium on Food Processing Wastes, EPA, 1976. pp. 256-279.
6. Reynolds, J. H., S. E. Harris, D. W. Hill, D. S. Filip, and E. J.
Middlebrooks. Intermittent Sand Filtration for Upgrading Waste Stabili-
zation Ponds. Presented at Water Resource Symposium Number Nine, Univer-
sity of Texas, Austin, July 22-24, 1975.
7. Marshall, G. R. and E. J. Middlebrooks. Intermittent Sand Filtration
to Upgrade Existing Wastewater Treatment Facilities. PRJEW 115-2, Utah
Water Research Laboratory, College of Engineering, Logan, Utah, February,
1974.
8. Walter, C. M. Progress Report, Blue Springs Lagoon Study, Blue Springs,
Missouri. Prepared for presentation at the Symposium on Upgrading
Wastewater Stabilization Ponds to meet Discharge Standards, sponsored by
EPA and Utah State University, Logan, Utah, August 21-23, 1974. pp. 1-9.
9. American Public Health Association, American Water Works Association,
and Water Pollution Control Federation. Standard Methods For the
Examination of Water and Wastewater, 14th Edition. Washington, D.C.,
1976.
10. Manual of Methods for Chemical Analysis of Water and Wastes. #625-7147
67, Environmental Protection Agency, USGPO, 1974.
11. Liskowitz, J. W. Suspended Solids Monitor. EPA-670/2-75-002, April,
1975, GPO #1975-657-592/5351.
50
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12. Krawczyk, D. and N. Gonglewski. Determining Suspended Solids Using a
Spectrophotometer. Sewage and Industrial Wastes, 31(10): 1159, 1959.
13. Hach Chemical Company. Photometric Method for Water and Wastewater.
Sewage and Industrial Wastes, 31: 1159, 1959.
14. Hach Chemical Company. Introduction to the Hach Manometric BOD Apparatus,
15. Jeris, John S. A Rapid COD Test. In: Water and Wastes Engineering,
May, 1967. pp. 89-91.
16. Hirlinger, Karl A. and C. E. Gross. Rapid Analysis of Packinghouse
Wastes. Sewage and Industrial Wastes, 25(5): 958-962, 1953.
17. Hedberg, M. and D. A. Connor. Evaluation of Coli-count Samplers for
Possible Use in Standard Counting of Total and Fecal Coliforms in
Recreational Waters. Applied Microbiology, 30(5): 881, 1975.
18. Daniels, F. E. Operation of Intermittent Sand Filters. Sewage Works
Journal, 17:1001-1006, 1945.
19. Reynolds, J. H., S. E. Harris, D. W. Hill, D. S. Filip, and E. J.
Middlebrooks. Single and Multi-stage Intermittent Sand Filtration to
Upgrade Lagoon Effluents. Presented at EPA Technology Transfer Seminar
on Wastewater Lagoons, Boise, Idaho, November 19-20, 1974.
20. Grantham, G. R., D. L. Emerson, and A. K. Henry. Intermittent Sand
Filter Studies. Sewage Works Journal, 21:1002-1014, 1949.
21. Furman, T., W. T. Calaway, and G. R. Grantham. Intermittent Sand Filter
Multiple Loadings. Sewage and Industrial Wastes, 27:261-275, 1955.
22. Middlebrooks, E. J. and G. R. Marshall. Stabilization Pond Upgrading
with Intermittent Sand Filters. In: Upgrading Wastewater Stabilization
Ponds to Meet New Discharge Standards, Utah State University, Logan,
Utah, November, 1974.
23. Black, A. P. Basic Methods of Coagulation. Journal of American Water
Works Association, 52(4):492, 1960.
24. Singley, J. E. F. Birkner, C. L. Chen, J. M. Eohen, R. W. Ockershausen,
K. E. Shull, W. J. Weber, Jr., E. Matyervi, and R. F. Packham. State
of the Act of Coagulation. Journal of American Water Works Association,
63(10):49, 1969.
25. Rea, J. E. Single Cell Activated Sludge Using Fill and Draw Combined
Industrial/Domestic Waste Treatment Plant. Proceedings of the 32nd
Annual Purdue Industrial Waste Conference, Purdue University, Lafayette,
Indiana, May, 1977.
51
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APPENDIX
SPECIFICATIONS FOR CONSTRUCTION OF AN
INTERMITTENT SAND FILTER SYSTEM
The specifications described herein are for the construction of an inter-
mittent sand filter system for East Central Oklahoma State University. This
system will be located adjacent to the Reeves Packinghouse, which is located
1-1/2 miles west of Ada, Oklahoma. Access to the job site is by paved county
road. This system contains one unit separated by a 6-inch concrete wall to
form two intermittent sand filters.
The system appurtenances consist of a manhole, a diversion box, inlet
and outlet devises for each filter unit, base and pipe, sewer, flow measuring
devises, automatic sampling devises and weirs and valves.
SITE INVESTIGATION AND REPRESENTATION
The Contractor acknowledges that he has satisfied himself as to the nat-
ure and location of the work, the general and local conditions, particularly
those bearing upon availability of transportation, disposal, handling and
storage of materials, availability of labor, water, electric power, roads,
and uncertainties of weather, river stages, or similar physical conditions at
the site, the conformation and conditions of the ground, the character of
equipment and facilities needed preliminary to and during the prosecution of
the work and all other matters which can in any way affect the work.
The Contractor further acknowledges that he has satisfied himself as to
the character, quality, and quantity of surface and sub-surface materials to
be encountered from inspecting the site, all exploratory work done by the
Owner, as well as from information presented by the Drawings and Specifica-
tions made a part of the Contract. Any failure by the Contractor to acquaint
himself with all the available information will not relieve him from respon-
sibility for estimating properly the difficulty or cost of successfully per-
forming the work.
The Contractor warrants that as a result of his examination and investi-
gation of all the aforesaid data that he can perform the work in a good and
workmanlike manner and to the satisfaction of the Owner.
The Contractor will be responsible for all clearing and grubbing, ex-
cavation preparation of land to be filled, filling land, spreading, compaction
and control of the fill, all necessary work to complete the grading of the
cut and fill areas to conform to accepted plans. Contractor will be responsi-
ble for the furnishing of all materials, equipment, tools, labor, and super-
intendence and other services necessary to construct an intermittent sand
filter system according to plans and specifications.
52
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AUTHORITY OF THE ENGINEER
The Engineer will be the individual selected by the Owner. The Engineer
shall have the authority to reject all work and materials and to stop the work
whenever such rejection and/or stoppage may be necessary to insure execution
of the work in accordance with the intent of the plans and specifications.
DUTIES AND RESPONSIBILITIES OF THE ENGINEER
The Engineer shall make periodic visits to the site of the project to
observe the progress and quality of the work and to determine, in general, if
the work is proceeding in accordance with the plans and specifications. He
shall not be required to make comprehensive or continuous inspections to
check quality or quantity of the work, and he shall not be responsible for
construction means, methods, techniques, sequences, or procedures, or for
safety precautions and programs in connection with the work. Visits and
observations made by the Engineer shall not relieve the Contractor of his
obligation to conduct comprehensive inspections of the work and to furnish
materials and perform acceptable work, and to provide adequate safety pre-
cautions.
The Engineer will establish the center lines of principal structures,
roads, pipelines, and facilities, set slope stakes when required, and set
bench marks convenient for the Contractor's use as necessary to establish the
basic layout. All labor and stakes will be provided by the Owner. It will
be the Contractor's responsibility to lay out the work from the lines set by
the Engineer.
One or more inspectors may be assigned to observe the work and to act in
matters of construction under this Contract. It is understood that such in-
spectors shall have the power to issue instructions and make decisions with-
in the limitations of the authority of the Engineer. Such inspection shall
not relieve the Contractor of his obligations to conduct comprehensive inspec-
tions of the work and to furnish materials and perform acceptable work, and
to provide adequate safety precautions, in conformance with the intent of the
Contract.
REJECTED MATERIAL
Any material condemned or rejected by the Engineer or his authorized
inspector because of nonconformity with the Contract Documents shall be re-
moved at once from the vicinity of the work by the Contractor at his own
expense, and the same shall not be used on the work.
ROCKS
When fill material includes rocks, no large rocks shall be allowed to
nest and all voids must be carefully filled with earth, properly compacted,
53
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No large rocks will be permitted closer than twelve inches (12") below the
finish grade except on the inside slope of the dikes.
MOISTURE CONTENT
The fill material shall be compacted at the optimum moisture content of
20 to 25 percent specified for the soil being used.
COMPACTION OF FILL LAYERS
Compaction shall be by sheepsfoot rollers, multiple-wheel pneumatic-
tired rollers or other types of suitable compaction equipment. Compaction
equipment shall be of such design that it will be accomplished while the fill
material is at the specified moisture content. Compaction of each layer shall
be continuous over its entire area and the compaction equipment shall make
sufficient trips to insure that the required density has been obtained.
DENSITY TEST
Ninety-five to ninety-eight percent proctor density is required. Field
density test shall be made by the Inspector of the compaction of each two
foot (21) lift of fill. Where sheepsfoot rollers are used the soil may be
disturbed to a depth of several inches. Density tests shall be taken in the
compaction material below the disturbed surface. When these tests indicate
that the density of any layer of fill or portion thereof is below the required
density, the particular layer of portion shall be reworked until the required
density has been obtained. Sufficient density tests shall be taken in each
layer to show uniform compaction of the layer.
Operate compacting equipment so that full width of the fill is covered.
A coverage shall be considered as one continuous trip from end-to-end and
shall overlap previous coverage by not less than 3 inches. For pipelines laid
in the fill, construct fill surface to at least an elevation 2 feet above the
top of proposed pipeline prior to starting trench excavation for installation
of pipelines. Sprinkle fill material with water as necessary to produce sat-
isfactory compaction. If material is too wet for proper compaction, aerate
by blading and discing as required. Upon competion, grade surface to proper
elevations and cross sections. Dress side slopes as indicated.
FINISH ELEVATION
The fill operation shall be continued in six inch (6") compacted layers,
as specified above, until the fill has been brought to the finished elevations
shown on the engineering plans.
54
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PREPARATIONS FOR PLACING BACKFILL
Do not backfill around concrete structures until the concrete has ob-
tained a compressive strength equal to 2/3 of the specified compressive
strength. Remove all form materials and trash from the excavation before
placing any backfill. Obtain the Engineer's approval of concrete work and
conditions prior to backfilling.
Do not operate any heavy earth-moving equipment within 5 feet of walls
of concrete structures for the purposes of depositing or compacting backfill
material unless approved by the Engineer. Compact backfill adjacent to con-
crete walls with pneumatic tampers or other approved equipment that will not
damage the structure.
SUPERVISION
Supervision by the Contractor and certification by the Inspector shall be
continuous during the fill and compaction operations and construction of the
appurtenances necessary to construct this waste treatment system.
DISPOSAL OF EXCESS EXCAVATION
All excess excavation, not required or suitable for backfill or filling,
shall be disposed of in the waste area designated by the Owner. The waste
area shall be uniformly graded to conform to existing contours, left with a
neat appearance, and be free-draining.
PLACING TOPSOIL
After grading hereinbefore specified is completed and approved by Engin-
eer, spread topsoil over entire graded area, excluding the graveled surfaced
area inside dike slopes and bottoms of filter and sprig Bermuda grass.
SETTLEMENT
Any settlement noted in backfill, fill, or in structures built over the
backfill or fill within the one-year guarantee period will be considered to
be caused by improper compaction methods and shall be corrected at no addi-
tional cost to the Owner. Any structures damaged by excessive settlement shall
be restored to their original condition by the Contractor, also, at no addi-
tional cost to the Owner.
CLAY PIPE
Clay pipe where called for in plans and specifications shall be standard
strength clay sewer pipe and conform to ASTM Designation C 13-50t. When pipe
is being placed the lower 90 degree arc of the barrel of the pipe will be in
55
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firm contact with undisturbed earth. Small excavations will be made for the
bells. These should be no larger than necessary to clear the bell. Where
clay pipe is to be laid on rock where the surface is unsmooth and irregular a
four inch (4") layer of sand, crushed rock or small aggregate will be placed
under pipe for complete support. Clay pipe will be laid also with correct
alignment and slope. Joints must be watertight to hold infiltration to a
minimum. Trenches should be kept water-free during jointing and for a suffi-
cient period thereafter to allow the jointing material to become fully set and
completely resistant to water penetration.
TRENCH EXCAVATION AND BACKFILL
Excavation and backfill shall be performed as required for the installa-
tion of piping and appurtenances in conformance with these Specifications and
the Plans.
TRENCH EXCAVATION
Obstructions to the construction of the trench, such as tree roots, stumps,
abandoned structures, and debris of all types, shall be removed by the Contrac-
tor at his own expense without additional compensation from the Owner.
TRENCH WIDTH
Minimum width of unsheeted trenches in which pipe is to be laid shall
be 18 inches, except by permission of the Engineer. Sheeting requirements
shall be independent of trench widths.
GRADE
Carry the bottom of the trench to the lines and grades shown or as esta-
blished by the Engineer with proper allowance for pipe thickness and for base
or special bedding when required. Correct any part of the trench excavated
below the grade at no additional cost to the Owner, by placing the sand over
the full width of trench in thoroughly compacted layers not exceeding 6 inches
to the established grade.
TRENCH STABILIZATION
If, in the opinion of the Engineer, the material in the bottom of the
trench is unsuitable for supporting the pipe, the Contractor shall excavate
below the flow line as directed by the Engineer and backfill to the required
grade with sand.
56
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EXCESS EXCAVATED MATERIAL
All excess excavated materials from the trench backfill operations shall
be used for plant site fill.
BASE FOR PIPE
Sand base shall be placed to the thickness shown for each pipe. The base
shall be placed for the full width of the trench with the top of the base at
bottom of the pipe. The gravel base shall be placed and raked to grade ahead
of the pipe laying operation.
PIPES THROUGH EMBANKMENTS
Where pipes pass through embankments, no granular pipe base or pipe zone
material shall be used. Instead, the pipe shall be laid on the trench invert.
EXCAVATE FOR BELLS
Steel pipe joints shall be welded. Backfill with selected trench side
material as approved by the Engineer.
MATERIALS
GRAVEL
Gravel for the filter units must be a minimum of 1/4 inch and a maximum
of 1 1/2 inch in diameter. Gravel must meet the approval of the project
Engineer.
SOIL EMBANKMENT
The embankments of the filter unit must be of bank run granular fill
material. The fill material must meet the approval of the project Engineer.
SAND
Concrete run washed sand with an effective size of 0.170 mm. The sand
must meet the approval of the project Engineer.
CONCRETE AND GROUT
Conform to applicable portions of Section Concrete. Standard premixed
mortar conforming to ASTM C 387 may be used at the Contractor's option.
57
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Polymeric Water Gel may be used to join the Keylock precast manhole sections.
FORMS
Exterior exposed surfaces shall be plywood; others shall be matched boards,
plywood, or other approved material. Form all vertical surfaces. Trench
walls, large rock, or earth will not be approved form material.
PRECAST SECTIONS
Precast manhole sections conforming to ASTM Standards, with circular, re-
inforcement, may be used. Diameter shall be as shown in the plans.
CONCRETE BASE
Remove water from excavation. Construct concrete base so that first sec-
tion of precast manhole has uniform bearing throughout full circumference.
Deposit sufficient grout on base to assure watertight seal between base
and manhole wall or place the precast section of manhole in concrete base
before concrete has set, if preferred. The section shall be properly located
and plumbed.
If material in bottom of excavation is unsuitable for supporting manhole
excavate below the line shown as directed by Engineer, and backfill to re-
quired grade with 3-inch minus, clean, pit-run material.
INSTALLATION
FLOW MEASURING AND SAMPLING DEVISES
The Contractor shall install flow measuring and sampling devises furnished
by the Owner. A Parshal flume of the type produced by Thompson Pipe and Steel
Company with a three-inch throat width, stilling well, and Stevens recorders
shall be installed prior to the diversion box as shown in the plans. A
Stevens type recorder will be installed in the final outlet devise as speci-
fied by the Engineer. The Contractor shall provide facilities to enable in-
stallation of automatic samples, Model PPD2 by Nappe Corporation or equivalent
at the diversion box, and effluent lines from the filter units.
FILTER PARTITION
The Contractor shall furnish the necessary material and install a water-
tight barrier between the two filter components. The barrier shall be made of
6 inch concrete.
58
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GENERAL CONDITIONS
MATERIALS AND APPLIANCES
Unless otherwise stipulated, the Contractor shall provide and pay for
all materials, labor, water, tools, equipment, light, power, transportation,
and other facilities necessary for the execution and completion of the work.
ACCESS FOR INSPECTION
The Contractor shall furnish, without extra charge, the necessary test
pieces and samples, including facilities and labor for obtaining the same, as
requested by the Engineer. When required, the Contractor shall furnish cer-
tificates of tests of materials and equipment made at the point of manufacture
by a recognized testing laboratory.
The Engineer and his representatives shall at all times have access to
the work wherever it is in preparation or progress, and the Contractor shall
provide facilities for such access and for inspection, including maintenance
of temporary and permanent access.
If the Specifications, the Engineer's instructions, laws, ordinances, or
any public authority require any work to be specially tested or approved, the
Contractor shall give timely notice of its readiness for inspection. Inspec-
tions to be conducted by the Engineer will be promptly made, and where prac-
ticable, at the source of supply. „If any work should be covered up without
approval or consent of the Engineer, it shall, if required by the Engineer, be
uncovered for examination at the Contractor's expense.
Re-examination of questioned work may be ordered by the Engineer; and,
if so ordered, the work shall be uncovered by the Contractor. If such work
be found in accordance with the Contract Documents, the Owner will pay the
cost of re-examination and replacement. If such work be found not in accor-
dance with the Contract Documents, the Contractor shall correct the defective
work at no additional cost to the Owner.
SAFETY PRECAUTIONS
The Contractor shall take all necessary precautions for the safety of
employees on the work and shall comply with all applicable provisions of
Federal and State safety laws and building codes to prevent accidents or in-
jury to persons on, about, or adjacent to the premises where the work is being
performed. The Contractor shall, without further order, provide and maintain
at all times during the progress or temporary suspension of the work, suitable
barricades, fences, signs, signal lights, and flagmen as are necessary or
required to insure the safety of the public and those engaged in the work.
The operations of the Contractor, for the protection of persons, and the guard-
ing against hazards from machinery and equipment, shall meet the requirements
of the applicable State laws and the current safety regulations.
59
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DIVERSION AND CARE OF WATER
The Contractor shall construct the necessary ditches, provide the neces-
sary pumps, and take such precautions as are required to protect the work.
Divert or pump the streamflow and drain the construction area so the work may
be carried on in a satisfactory manner. Drain or otherwise dewater all exca-
vation areas as required to permit satisfactory operation at all times.
ACCESS ROAD
The Contractor shall maintain the access road between the county road and
the work site during construction and leave the road suitable for continued
use by autos.
USE OF COMPLETED PORTIONS
The Owner shall have the right to take possession of and use any completed
or partially completed portions of the work, notwithstanding the time for
completing the entire work or such portions may not have expired, but such
taking possession and use shall not be deemed an acceptance of any work not
completed in accordance with this document.
CLEANING UP
The Contractor shall, at all times, at his own expense, keep property on
which work is in progress and the adjacent property free from accumulations
of waste material or rubbish caused by employees or by the work. Upon comple-
tion of the construction, the Contractor shall, at his own expense, remove
all temporary structures and equipment, rubbish, and waste materials resulting
from his operations.
60
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-78-205
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Treatment of Packinghouse Wastewater
Sand Filtration
by Intermittent
5. REPORT DATE
September 1978 issuing date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
M. L. Rowe
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
East Central University
Ada, OK 74820
10. PROGRAM ELEMENT NO.
1BB610
11. CONTRACT/GRANT NO.
S-803766
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final Report 6/71-2/77
14. SPONSORING AGENCY CODE
EPA/600/12
15. SUPPLEMENTARY NOTES
16. ABSTRACT
A full scale wastewater treatment system consisting of a novel extended aeration
unit and intermittent sand filter was demonstrated. The treatment system was designed
to meet the special needs of small plants and to meet future industrial discharge
limitations.
With a hydraulic 'loading rate of 0.36 mgad and a sand source having an effective
diameter of 0.35 mm and a uniformity coefficient of 2.5, a filter run of 109 days
was observed. The average BOD5 and TSS of the filter effluent was 10.4 mg/1 and
11.1 mg/1, respectively. The cost of construction and operation of the treatment
facility is presented. The study revealed an installation cost of $1.40/gpd capacity
and a treatment cost of $0.29/lb 8005 applied. Information needed to select, design,
and construct an intermittent sand filter is also presented.
The project evaluated the most economical means of meeting the NPDES monitoring
requirements. The conclusion was that the small packinghouse managers should use a
commercial laboratory when monthly or quarterly analyses are specified.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Food Processing, Industrial Wastes,
Aeration, Sand Filtration, Waste water
Meat Packing Industry,
Slaughterhouses, Poultry
Processing Industry ,
Extended Aeration, Waste-
water Treatment
68 D
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
71
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLE 61
tr U.S. GOVBWMEllTPWirniK OFFICE 197»— 657-060/1490
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