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EPA 904/9-77-023
TECHNICAL ASSISTANCE PROJECT
AT THE
ROCK HILL WASTEWATER TREATMENT PLANTS
ROCK HILL, SOUTH CAROLINA
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TABLE OF CONTENTS
Introduction 1
Summary 3
Manchester Creek Wastewater Treatment Plant 3
Wildcat Creek Wastewater Treatment Plant 4
Recommendations 6
Manchester Creek Wastewater Treatment Plant 6
Wildcat Creek Wastewater Treatment Plant 7
Manchester Creek Wastewater Treatment Plant 8
Treatment Facilities , 8
Treatment Processes 8
Personnel 8
Study Results and Observations 12
Flow 12
Waste Characteristics and Removal Efficiencies 15
Industrial Lagoons 19
Trickling Filters 19
Aeration Basin 20
Clarifiers 23
Chlorination ..... 27
Laboratory 28
Wildcat Creek Wastewater Treatment Plant 31
Treatment Facility 31
Treatment Processes 31
Personnel 31
Study Results and Observations. . . 31
Flow 31
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Waste Characteristics and Removal Efficiencies
35
Aeration Basins
35
Clarifiers
AO
Chlorination
42
Anaerobic Digester
42
References
43
Appendices
A. Laboratory
B. Aeration Basin Dissolved Oxygen - Manchester Creek WTP
C. General Study Methods
D. Dissolved Oxygen - Wildcat Creek WTP
E. Project Personnel
F. Oxygen Uptake Procedure
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LIST OF TABLES
I. Design Data - Manchester Creek WTP , , 10
II. Flow - Manchester Creek WTP 13
III. Waste Characteristics and Removal Efficiencies - Manchester Creek WTP. .15
IV. Lagoon Treatment Efficiency 19
V. Trickling Filter Treatment Efficiency 20
VI. Activated Sludge Operational Parameters - Manchester Creek WTP .... 21
VII. Secondary Clarifier Operational Parameters - Manchester Creek WTP. . . 25
VIII. Effluent Turbidity 27
IX. Results of Chemical Analyses on Split Samples 30
X. Design Data - Wildcat Creek WTP 33
XI. Waste Characteristics and Removal Efficiencies - Wildcat Creek WTP. . . 36
XII. Activated Sludge Operational Parameters - Wildcat Creek WTP 36
XIII. Oxygen Uptake Rates 39
XIV. Secondary Clarifier Operational Parameters - Wildcat Creek WTP 40
XV. Anaerobic Digester Solids .... 42
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LIST OF FIGURES
1. Manchester Creek WTP 9
2. Influent Flows - Manchester Creek WTP
3. BOD and Solids Profile
4. Average Nutrient Profiles
5. Temperature and pH Profile
6. Aeration Basin Dissolved Oxygen 22
7. Activated Sludge Settleability - Manchester Creek WTP^ ^4
8. Clarifier Dye Study - Manchester Creek WTP 26
9. Wildcat Creek WTP 32
10. Plant Flow - Wildcat Creek WTP 34
11. Activated Sludge Settleability - Wildcat Creek WTP # ^ 37
12. Clarifier Dye Study - Wildcat Creek WTP 4^
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INTRODUCTION
A technical assistance study of operation and maintenance problems at
the Manchester Creek and Wildcat Creek wastewater treatment plants, Rock
Hill, South Carolina was conducted April 25 through 29, 1977 by the Region IV,
Surveillance and Analysis Division, U. S. Environmental Protection Agency.
Operation and maintenance technical assistance studies are designed to assist
wastewater treatment plant personnel in maximizing treatment efficiencies,
as well as assisting with special operational problems.
The selection of these plants was based on a request from the US-EPA
Enforcement Division. The study was coordinated with the US-EPA Enforcement
and Water Divisions and the South Carolina Department of Health and Environ-
mental Control (SC-DHEC). Both wastewater treatment plants were chosen because
of difficulty in achieving design treatment efficiencies. The specific study
objectives were:
(1) To optimize treatment through control testing and recommended
operation and maintenance modifications;
(2) To introduce and instruct plant personnel in new operation control
techniques;
(3) To determine influent and effluent wastewater characteristics;
(4) To assist laboratory personnel with any possible laboratory
procedure problems; and
(5) To compare design and current loading data.
A follow-up assessment of plant operation and maintenance practices will
be conducted by August 1977. This will be accomplished through utilization
of data generated by plant personnel. If necessary, subsequent visits to
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the facility will be made. The follow-up assessment will determine if
recommendations were successful in improving plant operations and if
further assistance is required.
The cooperation of the South Carolina Department of Health and
Environmental Control is gratefully acknowledged. The technical assistance
team is also especially appreciative for the cooperation and assistance
received from personnel of the City of Rock Hill, South Carolina.
2
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SUMMARY
MANCHESTER CREEK WASTEWATER TREATMENT PLANT
The 12 mgd Manchester Creek WTP was placed in operation in May 1970
as a high rate diffused air activated sludge process preceded by three high
rate trickling filters and designed to achieve 85 percent BOD,, reduction.
The average flow during the study was 9 mgd. Approximately 65 percent of
the influent flow was from industrial sources. The reductions in BOD^
and TSS during the study period were 76 and 67 percent, respectively.
Major study observations are listed below:
(1) All of the activated sludge had been lost from the system the
week prior to the TA study. In an effort to re-build the MLSS concentration,
no wasting of sludge occurred.
(2) Sludge settleability demonstrated an old sludge with extremely
heavy straggler floe.
(3) The dissolved oxygen concentrations in the aeration basins were
too low and were not balanced equally within and between basins.
(4) In order to obtain an F/M ratio of 0.4, the MLSS concentration
would have to be about 5p00 mg/1 (MLVSS 3,800 mg/1). This high FILSS
concentration would overload the final clarifiers and the air supply system.
(5) The extremely high return sludge flow rate (7.4 mgd), coupled
with the low MLSS concentration, resulted in the absence of a sludge blanket
in the final clarifiers.
(6) Low flows over the weekend caused hydraulic problems with the
final clarifiers through Tuesday of each week.
(7) The pH of the influent wastewater from the pretreatment lagoons
was 11.4.
(8) The organic load to the aeration basins was 97 lbs BODj/day/1,000 cu.ft.
3
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(9) An extremely high chemical chlorine demand resulted in a zero
effluent chlorine residual at chlorine dosage rates of 1,100 pounds/day.
(10) Plant personnel were in the initial stages of setting up an
operational control sampling and data interpretation program.
WILDCAT CREEK WASTEWATER TREATMENT PLANT
The Wildcat Creek WTP was originally constructed in 1962 as a 0.25
mgd conventional activated sludge system. The WTP design capacity was
increased to 0.5 mgd in 1970. The average flow during the study period
was 0.44 mgd and consisted primarily of domestic wastewater. Five day
BOD during the study was reduced by 76 percent while during the same
period effluent TSS increased by 7 percent.
Major observations made during the study are listed below:
(1) Large quantities of solids were being lost over the final clarifier
effluent weirs.
(2) Large quantities of greasy, tan foam were observed on the final
clarifiers. A filamentous bacteria, Actinomycetes, was suspected as the
cause.
(3) The dissolved oxygen concentration in the aeration basins was too
low.
(4) Surface turbulance on the aeration basins indicated plugged
diffusers.
(5) Seattleability tests revealed a fairly good settling sludge leaving
an extremely clear supernatant.
(6) Scum and foam plugged influent flow ports encouraging short
circuiting through the clarifiers.
4
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(7) Return sludge was pumped
sludge detention time resulting in
the aeration basins.
(8) Poor mixing was observed
from a wet well which added to the
anaerobic sludge being returned to
in the anaerobic digester.
5
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RECOMMENDATIONS
Based on observations and data collected during the study, it is
recommended that the following measures be taken to improve wastewater
treatment and plant operation. By observing treatment responses to gradual
process changes, optimum treatment efficiency can be obtained.
MANCHESTER CREEK WASTEWATER TREATMENT PLANT
(1) Slow sludge wasting should be performed while gradually increasing
the MESS concentration.
(2) As an initial attempt to reduce the return sludge flow (RSF),
only two return sludge pumps (4 mgd) should be operated; one pump for each
set of two final clarifiers. Operational control testing will determine
the optimum RSF.
(3) The dissolved oxygen concentration in the aeration basins should
be balanced and maintained at 1 to 2 mg/1, and monitored regularly with an
electronic DO meter.
(A) Settlometer tests as well as TSS and VSS analyses should be run
on the combined flow from each set of eight aeration basins.
(5) The quantity of solids in each aeration basin, return sludge and
waste sludge should be determined once during each shift by centrifuge.
(6) The depth of the sludge blanket below the water surface should
be measured in each clarifier during each shift.
(7) Waste sludge and return sludge should be analyzed for TSS and VSS.
(8) In order to optimize treatment, the tests mentioned in recommenda-
tions 4 through 7 should be conducted on a routine basis. Coupled with
data already generated by laboratory personnel, trend charts should be
6
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plotted and posted in order to assess responses to operation changes.
Suggested trend chart parameters are F/M, effluent turbidity, return
sludge flow, waste sludge flow, plant effluent flow, sludge blanket:
depth, settlometer (especially the 5 and 60 minute reading), return
sludge concentrations, settled sludge concentration, aeration basin
dissolved oxygen, MLSS, and influent and effluent BOD^, TSS, and COD.
(9) The influent organic load dictates a high MLSS concentration
in order to achieve high degrees of BOD removal. However, the diffused
aeration syBtem was designed for lower MLSS concentrations. The MLSS
concentration should be increased to a maximum value At which the air supply
system is capable of maintaining a DO concentration of 1 to 2 mg/1 through-
out the aeration basins. This MLSS concentration should be maintained for
at least 2 weeks. Process response will dictate subsequent process changes.
WILDCAT CREEK WASTEWATER TREATMENT PLANT
(1) Air diffusers should be kept clean to allow efficient air flow
to the areation basins.
(2) The dissolved oxygen concentration in the aeration basins should
be maintained at 1 to 2 mg/1 and monitored regularly.
(3) Sludge wasting should be increased in order to eliminate the
filamentous organisms.
(4) Recommendations 4 through 8 for the Manchester Creek WTP will
also apply for the Wildcat Creek STP.
7
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MANCHESTER CREEK WASTEWATER TREATMENT PLANT
TREATMENT FACILITIES
Treatment Processes
A schematic diagram of the 12 mgd Manchester Creek Wastewater Treatment
Plant (WTP) is presented in Figure 1 and design data are enumerated in Table
I. Approximately 65 percent of the influent flow was from industrial sources,
primarily textile mills. The major industrial contributor was the Rock Hill
Print and Finishing Company (6 mgd). The existing treatment facility was
constructed and placed into operation in May 1970.
Three pretreatment lagoons were used primarily for settling, concentration
of waste activated sludge, and flow equalization. Effluent from the three
pretreatment lagoons was treated by three roughing filters prior to combina-
tion with domestic wastewater and subsequent flowage into the activated
sludge aeration basins. Chlorinated final effluent flowed several hundred
yards into the Catawba River.
Waste activated sludge was concentrated in the lagoons. As a lagoon
became filled with sludge, it was drained and the sludge removed to a nearby
land disposal site.
Personnel
The WTP was manned on a 24-hour basis. Staffing at the facility
consisted of an assistant superintendent, four operators, a'-laboratory
technician and four maintenance men. Of these ten, four were certified;
two class A, one class C, one class D and two operator trainees.
8
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FIGURE I
MANCHESTER CREEK WTP
ROCK HILL, S C.
EFFLUENT
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TABLE I
DESIGN DATA
MANCHESTER CREEK WTP
ROCK HILL, SOUTH CAROLINA
FLOW MEASUREMENT
Design Flow
Lagoon Influent
Domestic
Industrial
Domestic Influent
Total Filtered
Total Return Sludge
Waste Sludge
12 mgd
Venturi
Venturi
Venturi
Venturi
Venturi
Venturi
Meter
Meter
Meter
Meter
Meter
Meter
LAGOONS
Number
Dimensions
Volume (total)
800x200x6 ft.
18 m.gal.
GRIT CHAMBER
Volume
Aeration
1,496 cu. ft.
Diffused Air
TRICKLING FILTERS
Number
Diameter
Depth
Area (total)
Volume (total)
206 ft.
6 ft.
99,987 sq. ft.
599,920 cu. ft.
AERATION BASINS
Number
Dimensions
Volume (total)
Aeration
Blowers
Number
Size (each)
16
86x20x13.5 ft.
360,000 cu. ft.
Diffused
11,000 cfm
FINAL CLARIFIERS
Number
Dimensions
Area (total)
Volume (total)
Weir Length
94x41x9.75 ft.
15,416 sq. ft.
150,300 cu. ft. (1.12 m.gal.)
896 ft.
10
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TABLE 1 CONTINUED
CHLORINATION
Equipment Capacity 2,000 lbs/day
PUMPS
Influent Domestic
//I 700 gpm
#2 1,000 gpm
it3 1,000 gpm
Influent Industrial
//I 11,200 gpm
#2 11,200 gpm
//3 16,800 gpm
Return Sludge Pumps
Number 6
Size 1,400 gpm
Waste Sludge Pumps
Number 2
Size 700 gpm
11
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STUDY RESULTS AND OBSERVATIONS
A complete listing of all analytical data and general study methods
are presented in the Appendices. Significant results and observations
made during the study are discussed in the following sections.
Flow
Plant flow was measured on the following wastewater streams; total
flow to the aeration basins, total return sludge flow, domestic influent,
waste sludge, and industrial and domestic wastewater flows into the pretreat-
ment lagoons. All flows were measured using Venturi meters. Average daily
flows for these various waste streams are presented in Table II. Hourly
flows for the lagoon effluent and domestic influent are presented in
Figure 2.
On Friday April 29, at 10:00 a.m. the total filtered sewage flow was
19.7 mgd. According to plant personnel high flows are observed often.
The flow meters had been checked recently and are believed to be recording
accurately.
One pretreatment lagoon is usually out of service for cleaning and
refurbishing. The remaining two lagoons are not of sufficient capacity
to accomplish complete flow equalization, consequently, the drop in flow over the
weekend causes operational problems lasting until approximately the Tuesday
of each week. During periods of low flow there is not sufficient flow to
keep the Influent industrial pumps operating at all times. As the wet
well is pumped down to a low level, the pumps cut off. The water level
in the lagoons must Increase in order to discharge sufficient flow for
proper operation of the industrial influent pumps to the trickling filters.
12
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TABLE II
*FLOW
MANCHESTER CREEK WASTEWATER TREATMENT PLANT
DATE **TOTAL TOTAL DOMESTIC LAGOONS
FILTERED SEWAGE RETURN SLUDGE INFLUENT INDUSTRIAL DOMESTIC WASTE SLUDGE
Tue.
4/26
9.5
7.3
0.95
5.9
0.0
Wed.
4/27
8.6
7.4
0.87
6.2
2.1
0.0
Ttaur.
4/28
8.8
7.4
0.89
6.1
2.1
0.0
AVG.
9.0
7.4
0.90
6.1
2.1
0.0
*A11 average daily flows recorded in mgd.
** Total flow to the aeration basin including filtered plus domestic influent.
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FIGURE 2
WASTEWATER FLOWS
MANCHESTER CREEK WTP
APRIL 26
APRIL 27
APRIL 28
APRIL 29
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Waste Characteristics and Removal Efficiencies
A chemical description of the influent and effluent wastewaters and
intermediate sampling points are presented in Table III. Profiles of
selected parameters through the WTP are presented in Figures 3, 4, and 5.
TABLE III
WASTE CHARACTERSISTICS AND REMOVAL EFFICIENCIES
MANCHESTER CREEK WTP
ROCK HILL, SOUTH CAROLINA
Mil MIL MID MFR ME TOTAL*
(mg/1) (mg/1) (mg/1) (mg/1) (mg/1) REDUCTION
(%)
BODc
900
760
238
483
197(159)
76
COD
2,077
1,575
593
1^266
728
62
TSS
389
167
273
167
125
67
VSS
324
129
204
153
115
63
TOC
307
298
109
240
174
39
TKN-N
21:5
22.0
18.7
17.8
14.3
32
nh3-n
6.9
6.6
10.5
5.2
3.6
50
no3-no2-n
1.1
0.71
0.05
0.23
0.06
94
TOTAL P
5.6
4.9
8.8
4.8
4.2
29
Pb
<0.084
<0.080
<0.080
0
Cu
0.967.
<0.068
0.344
64
Cr
3.025
<0.050
0.602
80
Cd
<0.01
<0.01
<0.01
0
Zn
1.131
0.162
1.078
0
* Calculated based
on total
Influent
(sampling
stations Mil
& MID).
( ) - Soluble BOD^
The WTP was attaining poor reductions for all parameters listed.
Figure 4 shows little nitrification was taking place through the treat-
ment system. Many factors including low MLSS concentrations, absence of
nitrifying bacteria, and low DO concentrations were possible causes for
the lack of nitrification. The influent ammonia nitrogen concentration
was also low.
15
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FIGURE 3
BOO.COO AND SOLIDS
PROFILE
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FIGURE 4
AVERAGE NUTRIENT PROFILES
MANCHESTER CREEK WTP
TOTAL-P
1.0
0.5
NO3NON
Mil MIL MFR MID ME MM MIL MFR MIO ME
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30
28
_ 26
o
o
0.24
2E
in
22
20
18
FIGURE 5
TEMPERATURE ป pH PROFILE
MANCHESTER CREEK WTP
MA-AERATION BASIN NO.3
12.0
II.0
10.0
I 9.0
CL
8.0
7.0
e.oL '
Mil
-L
ฑ
_L
MIL MID MFR MA ME
18
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A pH profile through the WTP is presented in Figure 5. The pH of
all wastewater streams, except domestic influent, was high as would be
expected with the textile wastewaters.
Industrial Lagoons
Three, six-million gallon lagoons were utilized for flow equalization
and pretreatment of industrial and a small amount of domestic wastewater.
Waste activated sludge was also pumped to the lagoons. During the study,
two lagoons were operating while the third was being prepared for service.
As needed, each lagoon is alternately drained, the sludge removed to a land
disposal site and then refurbished and placed back into operation.
The pH of the wastewater entering and leaving the lagoons was about
11.4 standard pH .units (Figure 5). The percent reduction of various para-
meters in the lagoon system is presented in Table IV. Reduction in concen-
trations are presented graphically in Figures 3 and 4. A substantial amount
of solids were removed by the lagoons, but there was little effect on most
other parameters.
TABLE IV
LAGOON TREATMENT EFFICIENCY
PARAMETER % REDUCTION
BOD I5
COD 24
TSS 57
VSS 60
Trickling Filters
A portion of the effluent from the industrial pretreatment lagoons was
treated by three high rate trickling filters operated in parallel with recycle.
19
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The quantity of wastewater treated by the trickling filters was dependent
on the influent flow and recycle flow rate. The pH of the wastewater flowing
to and from the filters was 11.4 and 10.2, respectively (see Figure 5).
There was no growth on the surface of the filters. However, an
active biological population existed under the rocks and further down
into the filter media. The percent reduction of various parameters
provided by the filters is presented in Table V. These reductions
are presented graphically in Figures 3 and 4. The lack of solids
reduction was due to sloughing from the filters. The organic loading
to the trickling filters was 87 lbs B0D5/day/l,000 cu. ft. This loading
was typical for a high rate trickling filter.
TABLE V
TRICKLING FILTER TREATMENT EFFICIENCY
PARAMETER % REDUCTION*
BOD 36
COD 20
TSS 0
VSS -19
*-Based on only the portion of flow treated by the trickling filters.
Aeration Basin
Grab samples were collected daily from each of the sixteen aeration
basins and from their combined discharge. The quantity of solids in each
basin was determined by centrifuge. Combined aeration basin samples (sampling
stations MS-12 and MS-34) were analyzed for TSS, VSS, percent solids by cen-
trifuge, and settleabllity as determined by the settlometer. Presented in
Table VI are various activated sludge operational parameters based on data
20
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collected during the study and the corresponding recommended values for
the conventional activated sludge process. The WTP was designed as a high-
rate activated sludge system to be operated at organic loadings exceeding
those recommended in Table VI. The design organic loading was 100 lbs BOD^/
day/1,000 cu. ft.
TABLE VI
ACTIVATED SLUDGE OPERATIONAL PARAMETERS
MANCHESTER CREEK WTP
MEASURED RECOMMENDED (2)(5)(7)
MLSS (mg/1) 957 1,500 - 3,000
MLVSS (mg/1) 800
Hydraulic Detention Time (hrs) 7.2 4-8
Lbs BOD5/day/lbs MLVSS (F/M) 1.9 0.2 - 0.4
Lbs COD/day/Lbs MLVSS 5.1 0.5-1.0
Lbs BOD/day/1,000 cu. ft. 97 20 - 40
Aeration Basin
Return Sludge Rate (% of average 82 25 - 50
plant flow)
An unexplained loss of solids from the aeration basins occurred the
week prior to the study. Consequently, the low MLVSS concentration resulted
in an exceptionally high F/M ratio. Based on the present organic load to
the aeration basins, a MLSS concentration of about 5,000 mg/1 (MLVSS 3,800
mg/1) would be necessary in order to operate at an F/M of 0.4 and achieve
a high degree of BOD removal. However, according to Wiedeman and Singleton
Engineers the diffused aeration system was not designed for high MLSS con-
centrations .
Aeration was supplied by*three 11,000 cfm blowers. Diffusers were
located along one side of each basin. The air supply could be varied by
throttling valves on each diffuser and by the number of blowers operating.
Aeration basin dissolved oxygen (DO) concentrations are presented in Figure
6 and Appendix B. In general DO concentrations were too low, and were
poorly balanced between basins and within individual basins. As the MLSS
concentration increases toward optimum, DO profiles ihould be run routinely
21
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FIGURE 6
AERATION BASIN DISSOLVED OXYGEN
MANCHESTER CREEK WTP
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
0.05
0.05
3 15
? 45
0.1
0.1
1.2
2.8
275
3.7
2 4
2.05
40
3.8
59
0.15
0.07
3.35
0.1
0.9
0.15
2.4
0.15
2.1
0.1
0.3
005
005
0.1
3 4
2.55
0.1
2.4
3.0
0.5
0.75
0.15
035
0.2
3.4
2.25
0.13
I.I
2.6
0.6
0.7
0.4
2.9
3.1
0.5
0.2
1.75
0.25
0.5
0.5
0.7
2.85
0.2
2.5
245
0.55
0 45
2 2
0.7
0.9
1.3
1.6
0.1
0.5
0.25
0.65
3.6
2.05
0.76
3.0
0.25
I.I
1.7
1.4
1.7
0.15
t.l
1.0
0.7
0.2
0.75
2.8
2.23
2.85
0.1
0 1
0.9
02
0.2
0.15
4.7
2.0
3.65
3.3
2 7
1.6
5 3
0.43
0.25
2.93
0.05
0 2
0.2
1.0
3.7
3 5
16 15 14 13 12 II 10 9
APRIL 26, 1977
ONE BLOWER OPERATING
16 15 14 13 12 II 10 9
APRIL 27, 1977
TWO BLOWERS OPERATING
16 15 14 13 12 II 10
APRIL 28, 1977
THREE BLOWERS OPERATING
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to balance DO throughout the aeration basins. These profiles should be
checked on the weekend to determine if fewer blowers are necessary.
Activated sludge settleability was determined by the settlometer test.
These results are presented in Figure 7 and the data enumerated in Appendix
A. The dark color and extremely heavy straggler floe concentration caused
difficulty in the reading of settled sludge volume during the first 15
minutes. The large concentration of straggler floe, and dense, granular
old sludge resulted in two zones of settling. Results of the settlometer
suggest that the lighter straggler floe were the solids being lost in the
effluent, while the older, heavier sludge was being retained in the system.
These observations indicate that controlled sludge wasting should be
performed to remove old sludge while trying to gradually increase the MLSS
concentration.
Excessive foaming posed a significant problem in the aeration basins
and was controlled by froth sprays.
Clarifiers
The major problem encountered with the four rectangular final clarifiers
was excessive solids carry-over. Based on observations of the poor activated
sludge settling characteristics (Figure 7), this condition is one that could
be expected.
The measured and recommended operating parameters for secondary
clarifiers following the conventional activated sludge process are pre-
sented in Table VII.
The clarifiers were operating within recommended design criteria except for
hydraulic' detention time. The high return sludge flow rate was partly
responsible for the hydraulic detention timaswhich were less than those
recommended.
23
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FIGURE 7
ACTIVATED SLUDGE SETTLE ABILITY
MANCHESTER CREEK WTP
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Results of the dye study are presented in Figure 8. Dye was first
observed along the outside wall of each clarifier. These data indicate
some short-circuiting. This condition is common in rectangular clarifiers
with effluent weirs located against the end wall.
TABLE VII
SECONDARY CLARIFIER OPERATIONAL PARAMETERS
MANCHESTER CREEK WTP
MEASURED RECOMMENDED (3)(4)(7)
Hydrualic Loading
(gpd/sq,ftฆ) 584 400 - 800
Solids Loading
(lbs/day/sq.ft.) 8.5 20 - 30
Hydraulic Detention (hrs) 1.6* 2.0 - 2.5
Clarifier //I 1.4**
#2 0.7**
#3 1.6**
#4 0.9**
Weir Overflow Rate
(gpd/lin.ft.) 10,000 <15,000
* - Calculated as volume/flow.
** - Measured by dye study.
The depth of the sludge blanket below the clarifier surface was measured
daily. As a result of high return sludge flow rates and low MLSS concentra-
tions there was no sludge blanket during the study period.
The return sludge flow was 7.4mgd, or about 82 percent of the influent
plant flow. Six 1,400 gpm return sludge pumps were placed such that three
pumps were available for each pair of clarifiers. During the study, three
pumps were pulling from clarifiers It1 and #2 with two pumps pumping from
clarifier #2. Two pumps were operating on clairifers #3 and #4, one pump
per clarifier. A reduction in the return sludge flow would help create a
sludge blanket and increased return sludge concentration (RSC). This could
be accomplished by operating two return sludge pumps (4 mgd), one pump for
each set of two final clarifiers. Monitoring the RSC and sludge blanket
depth will assist in optimizing the return sludge flow.
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FIGURE 8
CLARIFIER DYE STUDY
MANCHESTER CREEK WTP
ROCK HILL, S.C.
TIME (MIN)
-------
Effluent from each of the four clarifiers and the final effluent were
analyzed for turbidity. The average results are presented in Table VIII.
The values in parenthesis were measured after allowing samples to settle
for one hour. These results are a further indication of the high solids
concentration in the final effluent and show approximately equal suspended
solids losses from each clarifier. The high 60 minute turbidity values
indicate that poor effluent quality was not a result of inadequate clarifier
capacity. Additional settling time did not significantly improve effluent
quality.
TABLE VIII
EFFLUENT TURBIDITY
AVG. TURBIDITY
(NTU)
Clarifier #1 117 (108)
#2 120 (106)
#3 126 (104)
#4 121 (102)
Final Effluent 127
Waste sludge was pumped into the industrial pretreatment lagoons by
two 700 gpm waste sludge pumps. In order to build the MLSS concentration,
no sludge was intentionally wasted during the study period.
Chlorlnation
About 1,100 pounds of chlorine were added dally to the effluent,
however, a detectable chlorine residual was not maintained. This may have
been the result of a high chlorine demand of the industrial wastewaters.
The unusually high chlorine demand resulted in no chlorine available for
disinfection. The chlorine injection nozzle and distance to point of
chlorlnation restricts the maximum chlorine capacity to 1,100 pounds/day.
Chlorine contact time was accomplished by time of travel in the effluent
pipeline from point of chlorlnation to the diffusers located in the Catawba
27
-------
River. Using a dye, the travel time was seven minutes at a flow
of 10.4 mgd.
Laboratory
The laboratory is located in the Manchester Creek WTP main control
building, and was staffed by a laboratory technician and an assistant.
Laboratory personnel conducted routine analyses for the Manchester Creek
and Wildcat Creek WTPs and the College Downs Lagoon. These analyses
included: BOD5, COD, TSS, settleable solids, alkalinity, fecal coliform,
pH, temperature, DO, and chlorine residual. The laboratory and laboratory
records were adequately maintained.
While at the WTP various analytical procedures were discussed and
the following observations were made:
(1) The laboratory personnel were conscientious, and in general,
exhibited good analytical technique.
(2) The orthotolidine method was used in determining chlorine residual
in the plant effluent. The determination of residual chlorine in samples
containing organic matter presents special problems, therefore Standard
Methods (8) recommends a back titration method for determining residual
chlorine in wastewater.
(3) The sodium thiosulfate titrant which was used in calibrating the
IX) probe was not being standardized. The procedure for and importance of
standardizing were discussed.
It was suggested that a quality control program be started. This
program should include setting up duplicates on approximately 10 percent of
the samples, and analyzing standards, where available, approximately 20
28
-------
percent of the time. This would help the analyst in determining the
precision and accuracy of this data.
Eight 24 hour composite samples collected on April 26-27 and April
27-28, 1977, were split between EPA and Manchester Creek WTP personnel.
The results of the analyses are given in Table IX. The average percent
difference and range between EPA and Manchester Creek WTP results were:
(1) BOD5 - 19%; 1 - 63%, (2) COD - 21%; 10-30%, and (3) TSS - 34%; 0 - 106%.
STANDARD METHODS give precision data for the same test of B0D5(15%), C0D(13%),
and TSS(0.76 to 33%).
The in-plant control testing program included influent BOD^; aeration
basin TSS, SVI, settlometer, centrifuge, and DO (surface); clarifier sludge
blanket depth and turbidity; and sludge density. It was suggested that the
following tests also be Included in their program: (1) aeration basin and
return sludge volatile suspended solids, and (2) anaerobic digester volatile
acids. It was further suggested that trend charts be established and main-
tained. Useful parameters for plotting include MLSS, sludge settleability,
significant influent and effluent waste characteristics, flow (plant, return
sludge, waste sludge), depth of clarifier sludge blanket, volatile acid to
alkalinity ratio, and MCRT. Experience will dictate which of these parameters
are necessary for successful plant operations. These suggested parameters
should serve only as a guide and are intended to establish trends so that
gradual changes in plant conditions can be noticed prior to deterioration
in effluent quality.
29
-------
TABLE IX
RESULTS OF CHEMICAL ANALYSES ON SPLIT SAMPLES
PARAMETERS (mg/1)
BOD5 COD TSS
STATION
DATE
EPA
MCW*
EPA
MCW
EPA
MGW
Mil
4/26-27/77
1,060
1,130
2,614
2,112
332
300
Mil
4/27-28/77
880
840
1,901
1,344
435
531
MID
4/26-27/77
219
265
428
528
188
157
MID
4/27-28/77
245
255
748
595
287
310
ME
4/26-27/77
250
236
842
614
175
175
ME
4/27-28/77
207
205
732
806
80
131
WE
4/26-27/77
92
34
335
298
180
263
WE
4/27-28/77
46
25
138
96
67
138
^Manchester Creek WTP
30
-------
WILDCAT CREEK WASTEWATER TREATMENT PLANT
TREATMENT FACILITY
Treatment Processes
A schematic diagram of the 0.5 mgd Wildcat Creek WTP is presented
in Figure 9. Design data are enumerated in Table X.
The original WTP (0.25 mgd) was constructed in 1962 and was modified
in 1970 to the existing 0.5 mgd conventional activated sludge system. The
expansion included the addition of three sludge drying beds, a laboratory
building, digester sludge heater, one blower and increased capacity of
influent pumps.
Personnel
The WTP was staffed 24-hours daily during weekdays and eight hours
per day on the weekend by three persons, one Class A operator and two operator
trainees.
STUDY RESULTS AND OBSERVATIONS
A complete listing of all analytical data and general study methods
are presented in the Appendices. Significant results and observations
made during the study are discussed in the following sections.
Flow
Wastewater flow into the Wildcat Creek WTP was measured with a Parshall
flume and a recorder installed on the effluent line immediately following
the clarifiers. Average effluent wastewater flow during the study was
0.44 mgd and ranged from 0.25 to 0.70 mgd* Hourly WTP flows during the
study are presented in Figure 10.
There were no provisions for measuring return sludge or waste sludge
flow. The only means of determining return sludge flow was to utilize
the manufacturers pump rating of 175 gal/min (0.25 mgd per pump).
31
-------
FIGURE 9
WILDCAT CREEK WTP
ROCK HILL, S C.
SLUDGE DRYING BEDS
-------
TABLE X
DESIGN DATA
WILDCAT CREEK WTP
ROCK HILL, SOUTH CAROLINA
FLOW MEASUREMENT
Effluent
Design Flow
AERATION BASINS
Number
Dimensions
Volume (total)
Aeration
Blowers
Number
Size
FINAL CLARIFIERS
Number
Dimensions
Area (total)
Volume (total)
Weir Length (total)
Return Sludge Pumps
ANAEROBIC DIGESTER
Number
Diameter
Depth (avg.)
Volume
CHLORINE CONTACT CHAMBER
Volume
SLUDGE DRYING BEDS
Number
Dimensions
Total Area
6 in. Parshall flume
0.5 mgd
2
90x18x12.5 ft.
33,000 cu. ft. (.25 m. gal.)
Diffused
3
1-50 hp; 2-40 hp
2
31x10x11 ft.
620 sq. ft.
6,050 cu. ft. (.045 m. gal.)
50 ft.
2-175 gpm
1 (heated)
30 ft.
30 ft.
20,000 cu. ft.
1,040 cu. ft. (7,700 gal.)
5
51x25 ft.
6,375 sq. ft.
33
-------
FIGURE 10
WASTEWATER FLOW
WILDCAT CREEK WTP
APRIL 26 APRIL 27 APRIL 28 APRIL 29
-------
Waste sludge was measured according to the draw and fill depths
of the digester. On April 26 and 27, 1977 the digester was filled to
a total height of 8 inches which equalled approximately 3,950 gallons
of sludge being wasted into the digester.
Waste Characteristics and Removal Efficiencies
A chemical description of the WTP influent and effluent wastewaters
with calculated treatment reductions is presented in Table XI. Analyses
were performed on 24-hour, flow-proportional, composite samples, collected
on three consecutive days during the study period. Percent reductions
were calculated from the averaged results.
Treatment efficiencies for all parameters are poor and less than
NPDES permit limitations. The increase of effluent solids over influent
solids concentrations was due to the bulking nature and hydraulic washout
of mixed liquor suspended solids from the final clarifiers.
A pH profile was run daily throughout the WTP and showed a pH variation
of only 6.4 - 6.9 during the study.
Aeration Basins
Presented in Table XII are various conventional activated sludge
operational parameters based on data collected during the study and the
corresponding recommended values for the conventional activated sludge
process.
The measured results presented in Table XII are within recommended
limits. The hydraulic detention time was longer than expected for con-
ventional activated sludge processes but should not adversely affect
treatment efficiency.
Activated sludge settleability as determined by the settlometer test
is presented in Figure 11 The settling characteristics on April 26 were
35
-------
TABLE XI
WASTE CHARACTERISTICS AND REMOVAL EFFICIENCIES
WILDCAT CREEK WTP
PARAMETER
INFLUENT
EFFLUENT
REDUCTION
(mg/1)
(mg/1)
(%)
BOD
267
64
76
COD
429
246
43
TOC
98
97
1
TSS
111
119
-7
VSS
93
111
-16
TKN-N
23.2
14.1
39
nh3-n
14.0
9.2
34
NO3-NO2-N
0.06
1.4
-
Total - P
7.1
6.5
8
Pb
<0.08
<0.08
0
Cr
<0.05
<0.05
0
Cu
0.03
0.03
0
Cd
<0.01
<0.01
0
Zn
0.09
0.10
0
CI2 Residual *
1.8
-
Dissolved Oxygen*
0.2
2.2
-
* - Cased on grab samples.
TABLE XII
ACTIVATED SLUDGE OPERATIONAL PARAMETERS
WILDCAT CREEK WTP
MEASURED
MLSS (mg/1) 1,626
MLVSS (mg/1) 1.380
Hydraulic Detention Time (hrs.) 13.6
Mean Cell Residence Time (days) 6.6
Lbs. BOD/day/lb. MLVSS (F/M) 0.34
Lbs. COD/day/lb. MLVSS 0.55
Lbs. BOD/day/1,000 cu. ft. Aeration Basin 30
Return Sludge Rate (% of average plant flow)
RECOMMENDED (3) (4) (7")
1,500 - 3,000
4
5
0.2
0.5
20
25
;8
15
0.4
1.0
40
50
36
-------
FIGURE II
ACTIVATED SLUDGE SETTLE ABILITY
WILDCAT CREEK WTP
OJ
20
10
o
o
BASIN
NO. 1 ,
APRIL 27 - 28
x
X
BASIN
NO. 2,
APRIL 27 - 28
BASIN
NO. 1 ,
APRI L 26
~
>
BASIN
NO. 2,
APRIL 26
_L
10
20 30 40
SETTLING TIME (MIN)
50
60
-------
significantly different than those on April 27 and 28. The cause for the
difference in settleability was unexplainable. However, a clear supernatant
was observed on all three days, indicating that a clear supernatant should
be obtainable in the final clarifiers.
Dissolved oxygen profiles in the aeration basins were determined on
April 27. These data are presented in Appendix D. In general the DO con-
centrations were too low, with the lowest concentrations measured in basin
#2 Observations of surface turbulence indicated that a number of diffusers
were partially plugged. Diffusers were usually checked and cleaned once
per year by WTP personnel. A more frequent maintenance schedule should be
initiated to insure efficient air flow to the aeration basins.
A microscopic examination of a tan greasy appearing foam accumulated on
top of the aeration basin, plus mixed liquor solids and return sludge, showed
an abundant growth of filamentous organisms. The foam was.;primarily comprised
of intertwined small turfs of filaments and small particles of floatable
solids. Examination of the mixed liquor solids and return sludge demonstrated
a similar growth Staining of the organisms revealed small branching filaments
that were forming arthrospores. These characteristics are applicable to the
organisms classified as Actinoraycetes. Actinomycetes are normally present
in domestic waste, but in small undetectable concentrations. Under conditions
of low DO these organisms are documented to grow prolifically causing condi-
tions as observed at the WTP.
Activated sludge quality was further determined by measuring the
oxygen uptake rate of the sludge by the procedure presented in Appendix
F. The results of this procedure are called load ratios (LR), and are
presented in Table XIII. The first oxygen uptake measurement revealed
that 78 percent of the uptake was a demand exerted by the sludge alone.
After aerating twice, the sludge uptake was observed still to be 60 per-
cent of the fed uptake rate. Sludge used in these two uptake rates came
-------
from the sludge wet well, from which return sludge was being drawn. In
the third uptake rate the sludge was fresh from the clarifiers. The
oxygen uptake rate for this sludge was 0.54 mg/l/min, as compared to the
two previous measurements of 2.1 and 1.6 mg/l/min. An unfed uptake rate
of 0.54 mg/l/min is typical of a good stable return sludge, therefore the
LR of 2.5 is certainly within the usual range of 2 to 4 as observed with
conventional activated sludge WTPs.
Based on the oxygen uptake rates of the sludge from the sludge wet
well, DO concentrations throughout the WTP, and the microscopic examination,
it is concluded that a poor quality septic sludge was being returned and
the filaments were the result of these unhealthy sludge conditions. Septic
sludge, near septic influent raw wastewater, and inadequate air distribution
throughout the aeration basins were the major causes of poor sludge quality.
Increasing the aeration basin DO concentration plus increasing sludge wasting
would begin to remove these undesirable filamentous organisms and allow
more desirable organisms to develop.
TABLE XIII
RS 1/ URS 2/ FRS 3/ Load Ratio
DATE (%) (mg/l/min) (mg/l/min) (FRS/URS)
4/28/77 45 2.10 2.70 1.29 4/
45 1.60 2.60 1.60 5/
45 0.54 1.36 2.50 6/
37 RS - Return sludge.
2/ URS - Unfed return sludge.
3/ FRS - Fed (raw influent plus) Return Sludge.
4/ Sludge from return sludge well prior to pumping to aeration basins.
V Same sludge as 4_/ reaerated after the initial demand.
6/ Return sludge as drawn from the final clarifier.
39
-------
Clarifiers
The major problems with the clarifiers were excessive solids carryover
and scum. Measured and recommended operating parameters for secondary
clarifiers following the conventional activated sludge process are presented
in Table XIV.
TABLE XIV
SECONDARY CLARIFIER OPERATIONAL PARAMETER
WILDCAT CREEK WTP
Hydraulic Loading
(gpd/sq.ft.)
Solids Loading
(lbs/day/sq.ft.)
MEASURED RECOMMENDED (3)(4)(7)
710 400 - 800
15 20 - 30
1.6 2 - 2.5
Hydraulic Detention (hrs)
Clarifier #1
Clarifier #2 1*3
Weir Overflow Rate 8,800 <15,000
(gpd/lin.ft.)
* - Calculated as volume/flow assuming one return sludge pump operating.
** - Measured by dye study.
The data in Table XIV indicate that the final clarifiers were
operating within recommended design criteria, except for hydraulic
detention time. Results of the dye study (Figure 12) indicate probable
Bhort-circuiting. Sharp peaks in dye concentration were measured at
26 and 36 minutes for clarifiers ill and #2, respectively. According
to the curves in Figure 12, the flow split into the two clarifiers was
about equal, although clarifier #2 was receiving slightly greater flow
than itl.
Effluent turbidity ranged from 4 to 104 NTU. On April 27 the turbidity
ranged from 4 to 44 NTU. Allowing samples to set for one hour resulted in
_ , , ohout 4 NTU. These data demonstrate that a good
turbidity measurement of about
40
-------
FIGURE 12
CLARIFIER DYE STUDY
WILDCAT CREEK WTP
ROCK HILL, S.C.
-------
effluent was possible until hydraulic or other factors took over. Although
both clarifiers bulked, the //2 clarifier appeared to be more severe.
Chlorlnation
Effluent from the final clarifiers was disinfected in the chlorine
contact chamber (CCC) prior to discharge into Wildcat Creek. The chlorine
dosage was 25 pounds/day resulting in an average chlorine residual of 1.8
mg/1.
Anaerobic Digester
Waste sludge was conditioned in a single stage anaerobic digester
and then dewatered on sludge drying beds. The digester temperature ranged
from 91 to 98ฐF. Poor gas production was being achieved. The results
of all digester sampling are presented in Appendix A. Results of solids
analyses are summarized in Table XV.
TABLE XV
ANAEROBIC DIGESETR SOLIDS
WILDCAT CREEK WTP
TSS VSS
(mg/1) (mg/1)
180 170
280 280
Supernatant
Heat Exchanger
Sludge to Drying Beds 55,194 31,610
Waste Sludge to Digester 9,950 5,150
Poor gas production coupled with malfunction of the Perth gas
mixing system resulted in poor digester mixing. This condition is
evident from the data presented in Table XV.
42
-------
REFERENCES
1. McKinney, Ross E. and Gram, Andrew. "Protozoa and ActivatGd
Sludge," Sewage and Industrial Waste 28 (1956): 1219-1231.
2. US-EPA, Operation of Wastewater Treatment Plants. A Field Study
Training Program, Technical Training Grant No-5TTl-WP-16-03
1970.
3. US-EPA Technology Transfer, Process Design Manual for Suspended
Solids Removal, January 1975.
4. American Society of Civil Engineers, Sewage Treatment Plant Design.
Manual of Engineering Practice No. 36, 1959. '
5. Metcalf and Eddy, Inc., Wastewater Engineering. 1972.
6. West, Alfred W., Operational Control Procedures for the ActivafpH
Sludge Process. Part I., Observations, EPA-330/9-74-001-a April
1973.
7. Great Lakes - Upper Mississippi River Board of State Sanitary
Engineers, Recommended Standards for Sewage Works. Revised
Edition, 1971.
8. American Public Health Association, Standard Methods for the
Examination of Water and Wastewater, 13th Edition. 1971.
9. US-EPA Technology Transfer, Process Design Manual for Upgrading
Existing Wastewater Treatment Plants, October 1974.
10. Black and Veatch, Estimating Costs and Manpower Requirements for
Conventional Wastewater Treatment Facilities. October 1974.
11. Homer W. Parker, Wastewater Systems Engineering. 1975.
12. From Script for slide tape XI-43, "Dissolved Oxygen Analysis -
Activated Sludge Control Testing", prepared by F. J. Ludzack,
NWTL, Cincinnati.
13. Alfred W. West, Operational Control Procedures for the Activated
Sludge Process, Appendix, March 1974.
43
-------
APPENDIX A
-------
appendix A
LABQRATORJT DATA
MANCHESTER CREEK AND WILDCAT CREEK WTP
Home HT.T1 c o
INFLUENT AND EFFLUENT
IL10
MID
H
H
77
>300 -
l.ll...
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-------
Appendix A
Laboratory,Data ,
Manchester Creek and Wildcat ICreek WTP
- - - " r.
TRICKLING FILTER EFFLUENT AND PLANT. INFLUENT AND EFFLUENT
-------
APPENDIX A
LABORATORY DATA
MANCHESTER CREEK AND WILDCAT CREEK WTP
ROCK HILL. S.g. '
AERATION BASINS
-------
APPENDIX A
LABORATORp DATA
Manchester creek and wildcat creek wtp
-ROCR hxt.t.. s.c.
AERATION BASINS
///////// // / / / / / / /
/ / f f f f f f f f f f f / / / / *
/ / / J / / /i / / / / / / / / / / /
STATICS
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-------
APPENDIX A
LABQRtTORff DATA
MANCHESTER CREEK AND! WILDCAT CREEK .WTP
BOflK HIJiTi. fi.C.
AERATION BASINS
i ,/ljk.f. s :
to~ฆ Ifffij
-------
APPENDIX A
. LABORATORY jDATA
MANCHESTER CREEK AND WIIDCAT CREEK WTP
mS. tttLl. S.C..
AERATION BASINS AND RETOKN SLUDGE
-------
APPENDIX A
LABORATORY!' DATA .
MANCHESTER CREEK AND WILDCAT CREEK WTP
Rnpg HTTi g c .
CLAKXFIERS
om
SRD
<#*
STATION
H
O
o
<
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xixs 1
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/ / / / / / / / / / / / / / /
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/ / /
/ / /
/ / /
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77
/
-------
APPEND IjX A
LABORATORY DATA
MANCHESTER CREEK AND ^WILDCAT CREEK WTP
ROCK HILL. S.C.
ANAEROBIC DIGESTER
/ J*
A
/>
A
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/ ฃ/ / / / / / / / /
Aspy /'///////
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ykฐ cฐ &/ฃ/$/ *ฆ*
-------
APPENDIX B
AERATION BASIN DISSOLVED OXYGEN
-------
APPENDIX B
AERATION BASIN DISSOLVED OXYGEN
MANCHESTER CREEK WTP
BASIN
STATION
DATE 1977
DO(tng/l)
1 FT.
5 FT.
10 FT.
13 FT,
a
b
c
a
c
a
c
a
b
c
a
c
a
c
a
b
c
a
c
a
c
a
b
c
a
c
a
c
a
b
c
4-26
4-26
4-26
4-27
4-27
4-28
4-28
4-26
4-26
4-26
4-27
4-27
4-28
4-28
4-26
4-26
4-26
4-27
4-27
4-28
4-28
4-26
4-26
4-26
4-27
4-27
4-28
4-28
4-26
4-26
4-26
0.6
0.2
0.15
0.8
0.45
0.2
0.3
0.1
0.05
0.4
0.1
0.1
0.25
0.2
0.2
0.5
0.1
0.05
1.1
0.1
0.2
2.75
0.75
0.3
0.15
2.6
0.9
1.75
3.7
0.15
0.05
0.05
0.6
0.1
0.25
2.4
0.35
0.05
0.07
0.7
0.15
0.5
2.05
0.20
0.1
0.15
0.5
0.05
0.05
0.75
0.28
0.15
0.15
0.05
0.05
0.35
0.05
0.05
0.20
0.08
0.15
0.5
0.1
0.05
0.75
0.4
0.17
0.25
0.05
0.08
0.35
0.08
0.05
0.20
0.15
0.17
-------
APPENDIX B
AERATION BASIN DISSOLVED OXYGEN
MANCHESTER CREEK WTP
BASIN
STATION
DATE 1977
DO (mg/1)
1 FT.
5 FT.
10 FT
L3 FT.
a
c
a
c
a
b
c
a
b
c
a
c
a
b
c.
a
b
c
a
c
a
b
c
a
c
a
c
a
b
a
b
c
4-27
4-27
4-28
4-28
4-26
4-26
4-26
4-27
4-27
4-27
4-28
4-28
4-26
4-26
4-26
4-27
4-27
4-27
4-28
4-28
4-26
4-26
4-26
4-27
4-27
4-28
4-28
4-26
4-26
4-27
4-27
4-27
3.45
3.45
3.40
2.35
2.6
2.5
0.2
0.15
0.2
0.3
0.08
0.4
1.2
0.5
4.0
3.4
3.4
3.35
2.9
2.4
2.4
0.7
3.8
2.25
2.55
2.45
3.1
3.0
2.8
2.85
5.90
0.13
0.1
0.1
0.5
0.15
0.2
2.1
0.25
0.05
1.7
2.8
3.7
3.35
3.40
3.35
2.27
2.55
2.40
0.15
0.1
0.05
0.20
0.05
3.40
3.45
3.35
2.3
2.57
2.45
0.15
0.08
0.05
0.20
0.05
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APPENDIX B
AERATION BASIN DISSOLVED OXYGEN
MANCHESTER CREEK WTP
BASIN
STATION
DATE 1977
DO (mg/1)
1 FT.
5 FT.
10 FT.
13 FT.
10
11
12
13
14
a
c
a
c
a
c
a
c
a
c
a
b
c
a
c
a
c
a
b
c
a
c
a
c
a
b
c
a
c
a
c
4-28
4-28
4-26
4-26
4-27
4-27
4-28
4-28
4-26
4-26
4-27
4-27
4-27
4-28
4-28
4-26
4-26
4-27
4-27
4-27
4-28
4-28
4-26
4-26
4-27
4-27
4-27
4-28
4-28
4-26
4-26
0.55
0.15
3.0
2.95
0.6
0.15
0.95
0.25
2.45
2.95
3.6
5.3
0.45
0.1
1.3
0.15
0.65
1.6
3.0
2.93
1.4
0.75
1.0
0.25
2.7
0.55
0.1
0.9
0.2
0.2
0.5
3.3
0.78
0.25
1.7
0.7
0.2
1.1
3.65
2.45
2.85
0.47
0.05
3.0
2.90
0.62
0.08
0.8
0.25
2.48
2.80
0.45
0.05
3.0
2.95
0.55
0.08
0.85
0.22
2.45
2.88
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APPENDIX B
AERATION BASIN DISSOLVED OXYGEN
MANCHESTER CREEK WTP
BASIN STATION DATE 1977 DO (mg/1)
1 FT. 5 FT. 10 FT. 13 FT.
a
4-27
0.7
c
4-27
0.2
a
4-28
0.1
c
4-28
2.0
a
4-26
2.05
2.05
2.1
2.1
c
4-26
0.45
0.43
0.45
0.45
a
4-27
1.1
c
4-27
0.2
a
4-28
0.15
c
4-28
3,5
a
4-26
2.65
2.5
2.48
2.55
c
4-26
2.3
2.23
2.2
2.25
a
4-27
2.2
b
4-27
1.0
c
4-27
0.9
a
4-28
1.6
c
4-28
4.7
-------
BASIN
STATION
a
b
c
a
b
c
APPENDIX B
DISSOLVED OXYGEN
WILDCAT CREEK WTP
DATE 1977
4-27
4-27
4-27
4-27
4-27
4-27
DO (mg/1)
1 FT.
0.15
0.3
0.85
0.05
0.05
0.3
5 FT.
0.05
0.25
0.8
0.05
0.05
0.15
10 FT.
0.05
0.35
0.85
0.05
0.0
0.2
INFLUENT 4-27 0.2
EFFLUENT 4-27 2.2
CLARIFIER EFF. 4-27 0.15
RETURN SLUDGE 4-27 0.1
NOTE: Station a
b
c
- Influent end of aeration basin
- midpoint of aeration basin
- effluent end of aeration basin
-------
APPENDIX C
GENERAL STUDY METHODS
-------
APPENDIX C
GENERAL STUDY METHODS
Methods used to accomplish the stated objectives included
extensive sampling, physical measurements and daily observations.
ISCO Model 1392-X automatic samplers were installed on the lagoon
influent and effluent, domestic influent, trickling filter effluent
and final effluent at the Manchester Creek WTP as well as on the
influent and effluent at the Wildcat Creek WTP. Samples were collected
for three consecutive 24-hour periods. Aliquots of sample were pumped
into individual refrigerated glass bottles which were composited pro-
portional to flow at the end of each sampling period. Influent and
effluent grab samples for oil and grease were collected at the Manchester
Creek WTP. An influent grab sample for oil and grease was collected at
the Wildcat Creek WTP.
All flows were measured from plant recorders and/or totalizers. All
dissolved oxygen measurements were determined using the YSI Model 57
dissolved oxygen meter. Temperatures and pH were measured at various
stations throughout both WTPs with a thermometer and portable pH meter.
Depth of the secondary clarifier sludge blankets were determined daily
using equipment suggested by Alfred W. West, EPA, Cincinnati (13). Sludge
activity was determined by the oxygen uptake procedure presented in
Appendix F. A series of standard operational control tests were run
daily!
(1) Settleability of mixed liquor suspended solids (MLSS) as
determined by the settlometer test;
-------
(2) Percent solids of the mixed liquor and return sludge
determined by centrifuge;
(3) Suspended solids and volatile suspended solids analysis
on the aeration basin mixed liquor and return sludge and
(4) Turbidity of each final clarifier effluent.
Daily effluent total chlorine residual concentrations were determined
using an amperometric titrator (Fischer and Porter Model 1771010).
The procedure for the BOD^ determination deviated from Standard
Methods (8). Samples were set up and returned to Athens, Georgia in
an incubator where the analyses were completed.
Visual observations of individual unit processes were recorded.
Mention of trade names or commercial products does not constitute
endorsement or recommendation for use by the Environmental Protection
Agency.
-------
APPENDIX D
DISSOLVED OXYGEN
-------
APPENDIX D
DISSOLVED OXYGEN
WILDCAT CREEK WTP
BASIN STATION DATE 1977 DO (ag/l)
1 FT. 5 FT. 10 FT.
a
4-27
0.15
0.05
0.05
b
4-27
0.3
0.25
0.35
c
4-27
0.85
0.8
0.85
a
4-27
0.05
0.05
0.05
b
4-27
0.05
0.05
0.0
c
4-27
0.3
0.15
0.2
INFLUENT
EFFLUENT
CLARIFIER EFF.
RETURN SLUDGE
4-27 0.2
4-27 2.2
4_27 0.15
4_27 0.1
NOTE: Station . - iBflu.it end of aeration b..ln
b - midpoint of aeration baain
_ effluent end of aeration basin
c
-------
APPBNDIX E
PROJECT PERSONNEL
-------
APPENDIX E
PROJECT PERSONNEL
Ronald Barrow Sanitary Engineer
Herbert Barden Microbiologist
Lavon Revells Chemist
Tom Sack Technician
Eddie Shollenberger Technician
ShanetHitchcock Co-op Student
-------
APPENDIX F
OXYGEN UPTAKE PROCEDURE
-------
APPENDIX *
OXYGEN UPTAKE PROCEDURE U
Apparatus
1. Electronic DO analyzer and bottle probe
2. Magnetic stirrer
3. Standard BOD bottles (3 or more)
4. Three wide mouth sampling containers (approx. 1 liter each)
5. DO titration assembly for instrument calibration
6. Graduated cylinder (250 ml)
7. Adapter for connecting two BOD bottles
Procedure
1. Collect samples of return sludge, aerator influent and final
clarifier overflow. Aerate the return sludge sample promptly.
2. Mix the return sludge and measure that quantity for addition
to a 300 ml BOD bottle that corresponds to the return sludge
proportion of the plant aerator, i.e. for a 40% return sludge
percentage in the plant the amount added to the test BOD bottle
is:
300 X .4 _ 120
1.0 + .4 ~ 174 " 86 ml
3. Carefully add final clarifier overflow to fill the BOD bottle
and to dilute the return sludge to the plant aerator mixed
liquor solids concentration.
4. Connect the filled bottle and an empty BOD bottle with the
BOD bottle adapter. Invert the combination and shake vigorously
-------
APPENDIX (Continued)
while transferring the contents. Re-invert and shake again
while returning the sample to the original test bottle. The
sample should now be veil mixed and have a high DO.
5. Insert a magnetic stirrer bar and the previously calibrated
DO probe. Place on a magnetic stirrer and adjust agitation
to maintain a good solids suspension.
6. Read sample temperature and DO at test time t*). Read and re-
cord the DO again at 1 minute intervals until at least three
consistent readings for the change in DO per minute are ob-
tained (ADO/min). Check for the final sample temperature.
This approximates sludge activity in terms of oxygen use
after stabilization of the sludge during aeration (unfed
sludge activity)
7. Repeat steps 2 through 6 on a replicate sample of return sludge
that has been diluted with aerator influent (fed mixture) rather
than final effluent. This A DO/minute series reflects sludge
activity after mixing with the new feed. The test results in-
dicate the degree of sludge stabilization and the effect of the
influent waste upon that sludge.
The load factor (LF), a derived figure, is helpful in evaluating,
sludge activity. It is calculated by dividing the DO/min of fed sludge
by the DO/min of the unfed return sludge. The load ratio reflects the
conditions at the beginning and end of aeration. Generally, a large
-------
APPENDIX (Continued)
factor means abundant, acceptable feed under favorable conditions. A
small LF means dilute feed, incipient toxicity, or unfavorable conditions.
A negative LR indicates that something in the wastewater shocked or poi-
soned the "bugs".
Taken from "Dissolved Oxygen Testing Procedure," F.J. Ludzack and
script for slide tape XT-43 (Dissolved Oxygen Analysis - Activated
Sludge Control Testing) prepared ty F. J. Ludzack, NERC, Cincinnati.
-------