904/9/76/003
TECHNICAL ASSISTANCE PROJECT
AT THE-
NORTHPORT, ALABAMA
WASTEWATER TREATMENT PLANT
OCTOBER 1975
s^0S*V
2
5
&\
Environmental Protection Agency
Region IV
Surveillance and Analysis Division
Athens, Georgia
-------
TABLE OF CONTENTS
Page
INTRODUCTION 1
SUMMARY . . 2
RECOMMENDATIONS 3
TREATMENT FACILITY 4
Treatment Processes 4
Personnel 4
STUDY RESULTS AND OBSERVATIONS 8
Flow 8
Waste Characteristics and Removal
Efficiencies 8
Pretreatment 10
Primary Clarifiers 12
Trickling Filter 12
Final Clarifier 13
Chlorine Contact Tank 13
Solids Handling 14
Laboratory and Control Testing 14
APPENDICES
A. Chemical Laboratory Data 16
B. Study-Methods 21
FIGURES
1. Northport Wastewater Treatment Plant 5
2. Hourly Flow 9
3. Reductions Through Unit Processes
BOD., COD, TSS 11
TABLES
1. Design Data, Wastewater Treatment Plant ... 6
2. Dissolved Oxygen at Various Locations
in Wastewater Treatment Plant 10
-------
INTRODUCTION
A technical assistance study of operation and maintenance
problems at the wastewater treatment plant (WTP) serving
Northport, Alabama was conducted during October 27-31, 1975,
by the Region IV, Surveillance and Analysis Division, U. S.
Environmental Protection Agency. Operation and maintenance
technical assistance studies are designed to assist local
WTP operators with special operational problems and to help
maximize treatment efficiencies. Municipal wastewater treat-
ment plants are selected for technical assistance studies
after consultation with state pollution control authorities.
Visits are made to each prospective plant prior to the study
to determine if assistance is desired and if study efforts
would be productive.
The specific study objectives were to:
o Optimize treatment through control testing and
recommended operation and maintenance modifications,
o Determine influent and effluent waste characteristics,
o Assist laboratory personnel with laboratory procedure
problems, and
o Compare design and current loadings.
A follow-up assessment of plant operation and maintenance
practices will be made at a later date. This will be accom-
plished by using data generated by plant personnel and, if
necessary, by subsequent visits. The follow-up assessment
will determine if recommendations were successful in improv-
ing plant operations and if further assistance is required.
Cooperation of the Alabama Water Improvement Commission
in planning the study is gratefully acknowledged. The technical
assistance team is especially appreciative of the cooperation
and assistance received from the wastewater treatment plant
personnel.
-------
SUMMARY
The 1.6 mgd trickling filter wastewater treatment plant
serving the city of Northport, Alabama was not organically
or hydraulically overloaded. However, combinations of mal-
functioning equipment and operational difficulties prevented
the facility from producing a high quality effluent.
The Parshall flume is subject to flooding from plant
influent flow surges and has not been used for several years.
Wastewater flow is estimated with a crude 90° V-notch weir
cut in a piece of plywood. The weir was located at the chlorine
contact tank discharge. Sludge flows and trickling filter
recirculation are not measured.
Removal efficiencies for Biochemical Oxygen Demand,
Chemical Oxygen Demand and Total Suspended Solids were
78%, 80% and 76%, respectively. A microorganism supplement
is added daily to the plant influent, but its necessity has
not been verified.
The chlorination facility provides adequate contact time.
Excessive water was being pumped into the digesters
with clarifier sludge because of excessively long sludge
pump cycles. The twoanerobic digesters were not operating
during the study, and plant personnel could not remember
if they had ever worked.
-2-
-------
RECOMMENDATIONS
o Investigate the existance of valves in the city water
supply lines to prevent inadvertent siphoning of waste-
water into the city system.
o Use of compressed air to clean digester sludge withdrawal
lines should be discontinued.
o Sludge from the final clarifier should be routed to the
head of the plant instead of the anerobic digesters
o Digesters should be "fed" in small increments on a routine
basis.
o Make provision for collecting samples of sludge going
to the digester. This could be accomplished by the addi-
tion of a valve or by use of an existing valve.
o Concentrations of solids going to the digesters should
be monitored and maintained at 3 to 6%.
o Volatile acids, alkalinity and pH of the anaerobic digesters
should be monitored at least three times per week per
"Standard Methods for the Examination of Water and Waste-
Water", 13th Edition, 1971.
o The digester gas collection system should be checked by
qualified persons before the digesters are placed back
in operation.
o Grit should be disposed of at a landfill rather than on
plant property.
o Remove sludge from chlorine contact tank.
o More wastewater should be recirculated to the trickling
filter to effectively increase organic loading. This
should yield more efficient treatment.
o A sharp crested standard 90° V-notch weir with a recorder
and totalizer should be installed at the effluent from
the chlorine contact tank.
o Data would best be utilized if plotted on trend charts.
o Use of the microorganism supplement should be discontinued.
-3-
-------
TREATMENT FACILITY
TREATMENT P1-' DCESSES
The wa:.ewater treatment plant (WTP) is a high rate
trickling filter facility with a hydraulic design capacity
of 1.6 mgd i:j serve an estimated 1990 population of 16000.
The present population served is about 12000. A small textile
dying opern^-on is the only industrial discharger. The plant
was originally constructed as a primary WTP in 1959; expan-
sions in th;- late 1960s converted it to the existing secondary
WTP.
A scher.:.utic of the WTP is in Figure 1; design data is
in Table 1. Wastewater is pumped directly to the WTP from
two pump st-;:. ions into a head box which also receives super-
natant return from the 2 digesters. From the head box, the
wastewater flows by gravity through a Barminutor followed by
a Parshall Hume into an aerated grit chamber. Recirculated
wastewater from the secondary clarifier effluent also discharges
into the gric chamber. Following the grit chamber is a splitter
box which feeds the two primary clarifiers. Clarifier overflow
goes into a wet well where it is pumped to the trickling filter
(TF) dosing vank, with gravity flow through the filter. From
the TF the flow passes through the final clarifier and into
a recirculation wet well. Recirculated wastewater is pumped
by a 600 gpm pump back to the grit chamber. The remaining
wastewater flows by gravity to the chlorine contact chamber.
Plant discharge is over a 90° V-notch weir into a pipe which
flows to the Black Warrior River.
Primary and secondary sludge is alternately pumped to
one of the two digesters. The digesters are fixed cover, un-
heated and have propeller mixers. Primary sludge pumped into
the digester displaces supernatant which overflows to the
head box. Pumping from the primary is controlled by a time
clock. The secondary is pumped (manual control) two times
per day. Pumping usually lasts about 15 minutes for each.
PERSONNEL
The WTP is staffed for 8 hours per day by a superinten-
dent and two maintenance men. A chemical technician works
part time and provides analytical assistance. Additional
training in plant operations for all plant personnel is
suggested.
-4-
-------
Figure 1
Northport Wastewater Treatment Plant
Northport, Alabama
Supernatant
Drying Bed Drainage
-------
TABLE 1
Design Data
Wastewater Treatment Plant
Northport, Alabama
Design Flow - 1.6 mgd
Maximum Flow - 4.1 mgd
Treatment Units
a. 18" Barminutor
1 unit
b. 6" Parshall flume
1 unit
c. Aerated grit chamber
1 unit, mechanically cleaned
grit disposal - spread on plant property
and covered with lime
d. Primary Clarifier
2 units, circular, center fed
dimensions - 45' dia. x 8' deep
area (total) - 3180 ft^
volume (total) - 190,250 gals,
weir length (total) - 282 ft.
sludge removal - pump to digesters
e. Trickling filter
1 unit, circular
dimensions - 80' dia. x 6' deep
area - 5020 ft
volume - 30,140 ft^
hydraulic loading @ 1.6 mgd - 318 gal/ft /day
f. Final clarifier
1 unit, circular
dimensions - 52' dia. x 10' deep
area - 2120 ft^
volume - 21200 ft^; 158,770 gals,
weir length - 163'
g. Chlorine contact tank
1 unit, rectangular
dimensions - 20'L x 15'W x 10TD
volume - 22,400 gals.
detention time at 1.5 mgd - 20 min.
-6-
-------
Digesters
2 units, unheated
1. 40' dia. x 18.5' deep
volume - 173,800 gals
2. 40' dia. x 18' deep
volume - 169,100 gals
Sludge drying beds
12 beds ea. 45' x 30'
total area - 16,200 ft
-------
STUDY RESULTS AND OBSERVATIONS
Significant results and observations made during the study
are discussed in the following sections. A complete listing
of all analytical data is in Appendix A. Study methods
are in Appendix B.
Surging influent flow and an 18-inch Barminutor located
between the headbox and Parshall flume prevent the use of
the flume for accurate flow measurements. The flume is
equipped with a ball float which had previously been used
to control a Penn Instruments circular chart recorder and
totalizer in the control building. This equipment has not
been used for several years.
A 90° V-notch weir located at the effluent from the chlorine
contact chamber is occasionally used by WTP personnel for
flow measurement. However, this provides only an approxima-
tion of the flow since the device is not a standard sharp
crested weir.
During the study, flow was approximated with an EPA
Stevens stage recorder located at the WTP weir. Wastewater
flow averaged about 0.5 mgd and varied from 0.2 to 1.2 mgd
(Figure 2).
Trickling filter recirculation and sludge flows are
not metered and could not be determined during the study.
WASTE CHARACTERISTICS AND REMOVAL EFFICIENCIES
Average influent and effluent wastewater analyses (based
on 2 24-hour composite samples), and treatment efficiencies
are presented in the following tabulation:
Parameter Influent Effluent % Reduction
FLOW
BOD5 (mg/1)
COD (mg/1)
Suspended Solids (mg/1)
TKN-N (mg/1)
NHo-N (mg/1)
N03-N02-N (mg/1)
Total-N (mg/1)
Total-P (mg/1)
Pb (ug/1)
190
497
109
23. 5
19. 5
40
98
26
19.0
15.6
1.2
20.2
9.4
78%
80%
76%
19%
20%
. 02
23.5
10.6
14%
11%
<100
<100
-8-
-------
FIGURE 2
HOURLY FLOW
NORTHPORT, AL
I2N 6 12M
10/28
12n 6
10/29
12M
12N
10/30
TIME - DATE
-------
Parameter
Influent Effluent % Reduction
Cr (ug/1)
Cu (ug/1)
Cd (ug/1)
Zn (ug/1)
<50
49
<10
201
<50
24
<10
55
73%
51%
Figure 3 depicts efficiencies of individual units. (Figure 1
shows sampling station locations).
A complete listing of all chemical data is given in
Appendix A.
PRETREATMENT
The Barminutor has not operated for the past year,
because replacement parts were not readily available or
obtainable. Not even rough screening of the raw wastewater
was provided since the screen at the bottom of the Barminutor
was usually submerged.
The aerated grit chamber appeared to be properly operat-
ing during the study. However, grit is periodically spread
on the WTP property and covered with lime. Plant personnel
stated that the aeration system has never been an operational
problem.
Aeration at the grit chamber influent is critical since
the incoming wastewater is septic. The DO concentration of
the wastewater leaving the grit chamber was 5 mg/1 or greater.
It remained greater than 4 mg/1 throughout the plant (Table 2).
Table 2
Dissolved Oxygen at Various Locations
in Wastewater Treatment Plant
Dissolved
Oxygen
Date Time Location (mg/1)
10/29 1100 1-1
Grit
1103 Chamber
0.2
6.2
4.5
5.0
4.3
6.4
1110 C-l
1115 T-l
1120 C-3
1125 E
10/30 1000 1-1
Grit
1005 Chamber
5.0
4.1
6.0
4.4
4.4
0.2
1007 C-l
1013 T-l
1020 C-3
1018 E
-10-
-------
-------
City water is used for foam control in the aerated grit
chamber. Plant personnel did not know if an anti-siphoning
valve was present in the piping system to prevent siphoning
of wastewater back into the public water supply.
PRIMARY CLARIFIERS
The primary clarifier's skimmers and sludge collectors
appeared to be operating properly. During the study, skimmings
were pumped to the sludge drying beds. Until a few weeks prior
to the study, skimmings had been pumped to the anaerobic
digesters. Daily measurements of the sludge blanket depth
in clarifier C-2 revealed a blanket of 1 to 2 feet. Clarifier
C-4 had essentially no blanket. A sludge depth indicator
mounted in clarifier C-2 was inoperative.
Slightly greater flow appeared to pass over the weir of
clarifier C-4 than over C-2 although both weirs are supposed
to be at the same elevation. This may have been caused by
uneven flow splitting at the splitter box.
Sludge from each primary clarifier was pumped to digester
D-l seven times per day for about 15 minutes per cycle during
the study.
TRICKLING FILTER
The trickling filter (TF) was designed as a high rate
filter (100-1000 gal/ft2/day).2./ Assuming that, the recirculated
flow is 100% of the average daily flow during the study, then
the loading rates of 1 mgd (0.5 avg. flow +0.5 recirculation)
and 1.7 mgd (1.2 maximum flow during study + 0.5 recirculation)
are 200 gal/ft2/day and 340 gal/ft2/day, respectively. The
organic loadings to the trickling filter were 20 lb BOD^/1000 ft3
at 1 mgd and 34 lb BOD5/IOOO ft3 at 1.7 mgd. These are near
the low end of normal high rate filter loading levels of 25
to 300 lb BOD5/1000 ft3.!/
Three low lift pumps (capacity could not be determined)
pumped primary clarifier effluent to the dosing box at the TF.
General observations of the TF system showed the distri-
butor arms were level, flow distribution was uniform, and
a good slime growth was present on the media. Filter flys
were present, but only in the immediate vicinity of the TF.
1/ "Operation of Wastewater Treatment Plants" by Sacramento
State College for the US-EPA, Technical Training Grant
No. 5TT1-WP-16-03, 1970.
-12-
-------
Two gallons of "Liquid Live Microorganisms" from Stero
Products, San Antonio, Texas, are added at the plant headworks
each day alledgedly to assist biological treatment. This
has been done for a long time with apparently no evidence
of its effectiveness.
FINAL CLARIFIER
The sludge collector was working properly, but the depth-
of-sludge indicator was inoperative.
Essentially no sludge blanket was detected in the final
clarifier during the study. However, twice a day pumps pumped
sludge from the clarifier directly into the anerobic digester
(D-l during study period). This sludge contained less than
0.6% solids.
To evaluate the clarifier's hydraulics, the previously
discussed estimate of recirculated wastewater was used.
Using this assumption, the average and peak flows through the
clarifiers during the study period are 1 mgd and 1.7 mgd.
The surface settling rates, weir overflow rates and detention
times are:
Flow Surface Settling Weir Overflow Detention
<-ragd) (gpd/ft2) (gpd/ft) (hours)
1.0 470 6135 3.8
1.7 800 10430 2.2
The 3.8 hour detention time is excessive relative to
usual secondary clarifier holding times of less than three
hours; however, this is not causing a problem since there
is adequate dissolved oxygen in the wastewater. The surface
settling and weir overflow rates are within accepted limits.
Occasionally during the study, the clarifier effluent
line filled to within one inch of the top of the clarifier
overflow weir.
CHLORINE CONTACT TANK
A theoretical 20-minute detention time is available
at the 1.6 mgd design flow. However, during the study, a
5-foot sludge blanket was measured in the tank, which reduced
the contact time. At flows measured during the study (average
0.5 mgd; max. 1.2 mgd) the detention times, assuming one-half
of the 10-foot depth to be available, are 30 and 14 minutes,
respectively. During the study, chlorine residuals ranged
from 0.1 to 0.9 mg/1 at the discharge from the tank. Under
-13-
-------
present operations these contact times should be sufficient
considering the 1/2 mile of pipe to the discharge point.
However, for proper operating conditions in this unit and to
prevent washout to the receiving stream, the sludge should
be removed.
SOLIDS HANDLING
During the study neither digester was operating properly.
There was no gas production, and plant personnel did not know
when gas production had last occurred. Inspection ports on
the digester D-l were open because WTP personnel periodically
tried to break up the scum mat.
One of the primary clarifiers and the secondary clarifier
had essentially no sludge; however, the "sludge" was pumped
seven times per day from the primary and twice a day from
the secondary. This indicates that the duration of the pump
cycle was probably too long resulting in excessive water
being pumped to the digester. Solids in the secondary
clarifier "sludge" (collected from the sludge pump discharge)
were less than 0.6% (primary sludge solids content was not
determined). WTP personnel do not collect samples from the
sludge pump discharge to monitor solids into the digesters.
Sludge consistency should be observed during pumping in
order to obtain a more desirable pumping cycle.
Plant drawings showed that the secondary sludge could
be pumped through existing facilities to the head of the
plant. This should be considered, since excess water in a
digester occupies needed space and has the potential of up-
setting the system.
Before the digesters can be operable they will probably
have to be cleaned out completely. All sludge and gas piping
should be inspected and replaced as needed. The gas collection
system should be inspected by a factory representative or
equally qualified person before the digesters are started back
up.
Plant personnel use compressed air to clean out sludge
withdrawal lines from the digesters. This would be extremely
hazardous if gas were being produced, since a mixture of
methane and oxygen is explosive.
LABORATORY AND .CONTROL TESTING
The laboratory facility at the STP was neatly arranged
and adequate for present operations. Analyses were accom-
plished by a part-time analyst. The chief operator has
little knowledge of laboratory operations.
-14-
-------
Control testing is needed to operate the anaerobic
digesters. Volatile acids analyses are performed by the
distillation method, but the resulting data appeared
questionable. Analyses would better be determined by the
relatively straight forward column chromatography method.
Alkalinity and pH tests also need to be performed. Methods
for these analyses are contained in "Standard Methods for
the Examination of Water and Wastewater", 13th Edition, 1971.
A relationship between volatile acids and alkalinity
can be calculated. This relationship is called the volatile
acid/alkalinity ratio (VA/ALK). This ratio is the best
indicator that an operator has concerning the conditions of
the digesters. In a healthy digester the amount of volatile
acids will be small relative to the amount of alkalinity.
Digesters in proper working nromally have a VA/ALK ratio
of less than 0.5, preferably about 0.2. Once the relation-
ship exceeds 0.5 a serious decrease in the alkalinity will
occur—/. If corrective action is not taken, the result
will be a "sour" digester.
For proper digester operation the amount of solids in
the "feed" going to the digesters is important. For best
operation 3.0 to 6.0% solids should be maintained. Solids
levels in the feed should be monitored in the laboratory.
The digesters should be fed in small amounts on a routine
basis to prevent organic overloading. For example, it would
be better to pump raw sludge to the digesters 10 minutes
each hour for eight hours than to pump continuously for
eighty minutes.
Plotting of control data on a graph is extremely helpful
to an operator. These graphs or trend charts reveal increases
or decreases and help the operator anticipate conditions and
make adjustments before a critical situation develops.
_1/ "Operation of Wastewater Treatment Plants" by Sacramento
State College for the US-EPA, Technical Training Grant
No. 5TT1-WP-16-03, 1970.
-15-
-------
APPENDIX A
CHEMICAL LABORATORY DATA
Influent & Effluent NORTHPORT, ALABAMA OCTOBER 27-31, 1975
-------
Northport, AL October 27-31, 1975 (continued)
Clariflers
// / / / A /$ / / / / / / / / / / /
/ / / / / V / C- .*y / / / / / / / / / / /
/ .o / / / /,o ¦ u \ / / // // // / / /
/ / / / / ^ / &° / / / / / / / / / / /
O&M
SAD
: it
STATION
MONTH
DATE
YEAR
TIME
//mArW^w / / / / /
A? A / / a? A* V / / / / /
' * / / / / A0 / / / / / /
0377
C-l
10
28
75
1045
i ]
<0.1 j I —'
i
0390
c-l
|10
I28
29
75
24 hr.
comp.
<0.1
76
180
37
27
i
i |
'.0407 j C-l 110
29 j
30 t 75
24 hr.
comp.
iH
O
V
3
'68
197
33
30
; 0375
1
t
1
|
C-2
10
28
75
1045
<0.1
1
\
, 0395
0416
,
C-3
10
29 j 75
1130
20
C-3
1 1
10 j 30 I 75
1005
1
j 22
; j
] I
, 4
J
i i
i
1
! 0376 j C-4
10
1
28 J 75
1045
I
<0.1 J
i
1
< 1 ! ! J
i
f
1 I
I
I
i
¦ !
1
I
J
1
i i
|
[
! i
1
i
i
j
j
1
I
i
i
1 i
-------
Trickling Filter
Northport, AL October 27-31 (continued)
' ' I '
0378 | T-l 10 | 28 j 75 | 1045
. i
!
f—i
o
V
i |
i
j | | (
1 1 i i
! !
I i i2§^ ' 1 24 hr.
0391 j T-l ! 10 p79 i 75 1 comp.
; ' i ( i i i
1 j 5 1
<0.1 1 34 i 132 | 35 I 30 j !
i i
I i
i' i 1
i i 1
i |29/. [ 24 hr. j > ! ! | |
0408 f T-l ; 10 : 75 | comp. f 0.8: 41 !, 128 j 37 j 28 |
i
! 1
1 i
1 <
I !
1 ! i
j ! ;
) !
i [
i
1 i i
; ! !
i 1 !
[ j |
f
i
i
|
i i
(
! !
1
I ;
f
1 1
I
1 ! ____
! !
i
I
i -i
1
i 1 1 :
i
X
1 ! 1 1 1
! ! i 1 !
I
i
! ! i .
; i
! 1
] i
:
1 ! 1 1
iii;
!
i
III!
i ;
1
! 1 !
! i
' J
i !
\ i
i i
i i
! 1
! I
i j
1 /
!
I I
j 1
: ; ! ' i ! I
; ! ; !
1 1 1 ! ! i
! ! i
I : I
I
!
i i
; i ! i 1 j
! 1
! 1
! 1
I
! !
! i
! 1
! ¦ J i ! 1 !
j : \ \
I
!
i I
! 1
j
1 (
i 1
! i
! I
\ i
I i i
i i
1 !
i
i
| i
! 1
! 1
\
!
1 : i
!
!
:
j J
1
1
1
!
I i
! I
i
i
i _
i ; i
! j ' !
! I f i
;
i : i
i i !
i !
i !
j
1
I
-
I
1
1 1 !
! i ! ! ;
! i ! i 1 1
1
1
1
1 .
|
1 ! I
i
1
1 1 1 ! !
1 1 1 !
1
1
i
i
i
(
I
I
i
!
f
i ;
00
J
-------
Northport, Alabama 27-31 Oct 75 (Con't)
Digester 1
Digesters - Samples taken from (Top - T, Middle - M, Bottom
7 7 7 71 7 T
A* ,\V ^
B)
0 & M
SAD
/;
STATION
i
» '
i
g r *
o ; <
a ¦_ o
¦« #
/ // >
4? / .&
S?'\V> T / -C
I * i
i 3 ;
: £ i TIME
/%>/// */
A <5/ ^ / / /
/ «V gjr
3P
if
-v -
o" /
/ - o ^ V/ 60/ V --V
^ / / A* S"/ 5" f 29 i 75 1 1515 f47.0 !
I | j52000
I j i
4040128800 j 1160 ;269200'
! !
| ,'81248
32376' i !
! : i \ i
10 130 ¦75 i 0910 ;43.0 i
! 1 i 1 i 1 1 i
j 1884; 922- ! 1 : | j
i ; ! i i !
1 ,84936 133274 1 |
i i f 1 !
10 i 30 ¦ 75 1 1300 i - | -
; 1 j
- ; 24481 883]
! ! 1 ! ! ! i i i j 1
i i 1 ! 1 ! : i 1 ! '
j 0382 i Dl-B
i 1 j j
10 !28 ; 75 i 1305 143.0 1 -
' 1 ' 1 1 ! : 1 ! ' ! ! |
- ! ! ! ! ! i ! ! i 1 i i i
j 0401 ; Dl-B
| 0410 i Dl-B
i : i i j
10 \29 ]75 ; 1515 j43.Oj -
_ ! ¦ 1 | | |
!!!!':!
i
j
10 j 30 ' 75 | 0910 | 47.o| -
t i | ;
- i ! ! 1 I
i ! 1 : ! ! i
! I ' ! ! 1 I
i
i
<
! . !
i i ! M ! ! M ! i
!
111!
! 1 1 1
i
i
i
• : i
1 0386 : SN-1 ¦
1 |
• 0396 i SN-1 i
: : i i !
10 ; 28 ! 75 j 1400 ! 10.0) 6.4
300| | |
| |
•15700
1 1 i ! I j
16750! 7750 ! ! ! ! I
1 I ,
10 29 '75 ! 1445
1 6.4
1 I
50 j I
I 1
! 1
i 1 i ! i ! i
3200 i I I : ! ! !
j 0415 ! SN-1 j
; S :
10 130 !75 ! 0930
i
i ' 1
90! ! i !
| i 1 1 ! ] 1 1 I j
J j ! 4142 I | j 4156» 1898| j 1
i : !
1 1 1
; 0397 ! SCS-1 '
| | |
1
1
1
! i I 1
} i i ; ! I i i i |
10 29 '.75 '¦ 1500
1
I
! ! | j | | | j | 5940 3920 | j j j [
-------
Digester 2
Northport, 'Alabama 27-31 Oct 75 (Cont'd)
Samples taken from Top (T), Middle (M), Bottom (B)
l
to
o
0385
D2-T
i
i io
!
1 28
1 75
I
! 1340
i
i
i
i
i
i
1
1 i
! !
i i
r rM
0402
D2-T
i
i 10
1 29
75
i
j 1520
147.0
i
:
¦
i
f
!
i
I
1
i i i i ¦
1 1 1 ! t : 1
1 1 ! i 1 1 1 '
0413
D2-T
|io
) 30
75
1
! 0910
48.0
i
r
t
,
I
! !
1 ! I
1
r- -
0384
D2-M
i10
i
; 28
75
1
j 1335
48.0
|
1
L2396i
567 2 51
1 ¦
I ! i
i
i
i
0394
D2-M
! i»
i
! 29
j
75
1115
40.0
i
I
1
1
i
... I- I'll!
0398
D2-M
1
: io
t
i 29
75
i 1510
43.0
-
i
- |32800
2580
23200
648
86000
10846:
48268
; l i ! !
1 ! ! I ;
0412
D2-M
| 10
1 30
75
0910
46.0
4944
2477
I
1
1
L13952 48644
r i
! ) 1 i
ill i
i 1 i ¦! «
0420
D2-M
i
i 10
30
75
1300
1
] 4872
2342
1
|
! i 1
L _ L ...
0383
D2-B
1
10
28
75
1330
47.0
i
i
i
i
1
1
i |
i !
; ; i i
! : i i
0403
D2-B
10
29
1
75 | 1520
51.0
| 1 j i I
! 1 ! I 1
.
0414
D2-B
10
30
75
0910
|
46.0 j
i ! 1
.
i
f
-i
I
. 1
l!|!
p : 1 1
¦;
1 i
i 1
! j
I
1
1
1 ' i
i ' i
l
!
!
j j
! 5
I ! 1
! i i
i
1
1
f
i i i
1 ! i
i
i
1
1
i 1 1
! I i
1
!
1
i
1
i
| i
i
!
i
j
! '
|
i
-------
APPENDIX B
STUDY METHODS
The plant, influent, trickling filter influent and
effluent, and plant effluent were sampled for two 24-hour
periods with ISCO model 1392-X automatic samplers. Aliquots
of sample were pumped at hourly intervals into individual
refrigerated glass bottles which were composited proportional
to flow at the end of each sampling period.
A Stevens Model F stage recorder was installed at the
effluent from the chlorine contact chamber to determine
plant flows.
The following tests were run daily:
o Settleable solids at all stations with Imhoff Cone.
o Depth of sludge blanket in clarifiers.
o Plant effluent turbidity
o Effluent chlorine residual with a Fischer and Porter
Model 17T1010 amperometrie titrator.
o Dissolved oxygen at all stations with a YSI Model
51A dissolved oxygen meter.
Daily physical observations were made of the unit
processes.
The BOD5 analysis was modified in that the incubation
temperature was not maintained at exactly 20°C during the 7-hour
transit time from Northport to Athens. Currently, comparative
tests are being run to determine what effect, if any, tempera-
ture variation and agitation has upon BOD^ results. This is
being done by setting up duplicate samples at selected plants.
One sample is then returned to Athens for analysis and the
other is analyzed at the plant.
Mention of trade names does not constitute endorsement
or recommendation by the EPA.
-21-
------- |