-------
PLANT PERFORMANCE
Monthly average overall BOD reductions exceeded 95
-------
Immediately prior to start-up, 65,000 gallons of seed
sludge from the HRSD James River Waste Treatment Plant were added
to Aeration Tank No. 1 that had previously been filled with city
water. Only three of the five mechanical surface aerators, set
at low speed, were operated, and the return sludge pumps were set
to discharge about 50% of the incoming waste flow.
On Day 1 (Tuesday, January k, 1972) of NFIC-C assistance,
mixed liquor total suspended solids (MLTSS) concentrations were
in the 500 to 600 mg/1 range and the settleometer test revealed
a rapid settling sludge (SSV = 100, SSVg = 70). The Return Sludge
Flow (RSF) was immediately increased to more than 100$ of the in-
coming flow. On Day 2, the two idle aerators were turned on, with
all five units remaining on the low speed setting. On Day 3, all
five aerators were switched to the high setting, thereby increasing
the oxygen transfer capacity approximately fourfold. Sludge settl-
ing characteristics and final effluent turbidity responded favor-
ably to these operational changes as evidenced by the first week
reduction in final effluent turbidity from 16 to 6 JTU.
Effluent quality did not improve during the first few days
of the second week. In fact, the turbidity increased slightly from
6 to 8 JTU. To build up the low mixed solids concentration, primary
sludge was being pumped to the aeration tanks. This practice most
probably impeded further improvement, especially when the volume of
sludge ncreased with the increase in incoming flow. On Thursday
this practice was discontinued and all primary sludge was sent to
27
-------
the aerobic digesters. Final effluent quality then improved
dramatically and the turbidity was reduced to 2.2 JTU by the end
of the week.
Luring the third week a plant upset occurred when the
return sludge pumps and the final clarifier mechanism failed.
The aerators were also inadvertently switched from high to low,
and control became difficult due to the erratic operation of the
plant flow meters.
On Saturday of the third week, the pH of the incoming waste
suddenly dropped to 1.6 as a result of a slug of acid waste acci-
dentally released from the brewery during a weekend shutdown for
maintenance and cleaning. This destroyed all biological life in
the secondary system and caused the final effluent turbidity to
jump from h to 60 JTU.
At the start of the fourth week (Monday, January 24-th) the
idle Aeration Tank No. 2 was seeded with sludge from the No. 4
Aerobic Digester and placed in service. No. 1 Aeration Tank con-
taining the acid mixed liquor was taken out of service. All pri-
mary effluent and return sludge was then rerouted to this aera-
tion tank. Process characteristics started to improve Immediately
thereafter, and by Saturday the final effluent turbidity had been
reduced from 60 to 3.5 JTU. On Saturday the process was again up-
set by another slug of acid waste. Fortunately this acid slug was
less destructive than the previous and it was not necessary to re-
seed and switch aeration tanks again. Effluent quality was, how-
28
-------
ever, degraded almost as much as during the first slug, and by
Sunday the final effluent turbidity again increased to 60 JTU.
Even with these start-up problems in January, final efflu-
ent BOD ranged from 1.0 to 5^ mg/1 averaging 12 mg/1 for the
-£
month with an overall plant reduction of 97.7%. Suspended
solids in the final effluent ranged from 1.0 to 52 mg/1 averaging
15 mg/1, for a plant reduction of 97-^. A summary of plant per-
formance figures may be found in Table 3 (Page 9)•
As shown by the following, the average plant loading was
considerably below the theoretical treatment capability during
start-up:
Ibs. BOD /1,000 cu. ft. Aeration Tank Volume 22.5
Ibs. BOD^/lbs. MLVSS 0.23
Aeration Tank Detention Time @ Flow alone 17*2 hrs.
Aeration Tank Detention Time @ Flow & Return.... 7-5 hrs.
Final Clarifier Detention Time 5*7 hrs.
Final Clarif ier Surface Overflow Rate 138 gals ./d/sq..ft.
Despite plant upsets during this month, the average mixed
liquor sludge settling and concentration characteristics were excel-
lent and the sludge blanket remained deep down in the final clarifier
A complete listing of general operating characteristics on a
month-by-month basis is shown in Table k (Page 17), and a summary of
plant loadings and process responses for the four major project seg-
ments is shown in Table 6.
Raw Concentration - F.E. Concentration
\ f f*± ^ ^m --i * « | ^ -^L »^^T/ wm ^mf ^tf A--i^*' ^•^ w-i \f ^» ^w^p ^f ^^M- ^i*^-»» ^» -*^» •^
* Overall plant reduction = Raw Concentration
29
-------
SUMMARY OF PLANT LOADINGS AND PROCESS RESPONSES
HAMPTON ROMS SANITATION DISIEICT - WILLIAMSBURG STP
Line
No.
Column Number
1
2
3
1.
5
6
7
8
9
10
11
12
13
lit
15
16
17
18
19
20
21
22
23
2l«
25
26
27
UHIIS HI SERVICE
No. of Aeration Tanks
Ho. of final Clarifiers
AERATION INTENSITY
Average H.P.
H.P./1000 sq. ft. ASA
H.P. Hrs./MGD AFI
H.P. Hrs./lb. Influent BOD
H.P. Hrs./ASU
H.P. Hrs./lb. MLVBS
Resultant Aeration lank D.O. mg/1
PLANT LOAPniGS (to Act. SI. System)
Metered Flows in MGD
AFI - Aeration Tank Influent Flow
RSF - Return Sludge Flow
TFL - Total Flow
XSF - Excess Sludge Flow to Waste
Unit Flow Rates in Rrs.
ADT - Aeration Detention Time at AFI
ADT - Aeration Detention Time at TFL
CDT - Clarifier Detention Time at TFL
OFR - Clarifier Overflow Fate at AFI
BOD - Aeration Basin Influent
Concentration (mg/1)
Haas (log/day)
Aerator Loading (Ibs. BOD/1OOO cu. ft.)
PROCESS LOADINGS (As Functions of Ooerational Control!
ATC X ADT/mg/1 BOD
LbB RSTSS/lb. BOD
Organic Loading F/M (Ibs. BOD./ Ib. MLVSS)
j
RSP - Return Sludge Percentage (% of AFI)
SCR - Sludge concentration Ratio
AGE - Sludge Age (day)
AAG - Aerator Age (days)
Jan. Feb. & Mar.
Start-up Brewery Waste
1 2
1
1
235
18.80
3082
1A3
0.075
0.33
7-3
1.83
2.38
1*.21
0.090
17.13
7 AS
5-65
138
258
3938
22.5
0.166
15.12
0.23
130
1.75
8.82
8.36
1
1
160
12.77
1870
0.70
0.038
0.17
5-8
2.07
2A1*
U.51
0.121*
15-32
6.97
5.28
156
322
551"*
31-5
0.165
ll*.8o
0.2k
118
0.95
6.52
6. 02
April May & June
Bulking Stable Operation
3 "<
2
2
162
12.96
1751
0.61*
0.097
0.29
3-2
1*.1*1*
5-25
9.69
0.21(9
lU.17
6.U9
l*-92
167
330
12220
3U.9
0.060
7.81*
0.1*6
118
0.97
9.06
5.87
2
2
500
20.0
2139
0.76
O.lUl
0.27
l*.l
5.61*
7-99
13-63
0.293
11.20
U.61
3.50
213
329
15736
1*5.0
0.091
1U.95
0.35
11*2
0.91*
5.97
5.3U
Last Week
of Project
6/19 to 6/25
5
2
2
500
20.0
2139
0.76
0.199
0.27
1*.2
U.8U
8. 1*7
13-31
0.352
13.35
U .75
3.61
182
361
1U863
1*2.5
0.06
13.66
0.37
175
0.83
6.32
5-23
Project
Average
6
2
2
282
16.10
2131
0.83
0.081*
0.25
5-1
3-59
1*.70
8.29
0.191*
ii*.o9
6.20
l*.7l
173
317
9706
35-0
0.121
13-65
0.31
131
1.08
7-15
6.15
-------
TABLE NO. 6
(contd)
SUMMARY OF PLANT LOADINGS AND PROCESS RESPONSES
HAMPTON ROADS SANITATION DISTRICT - WILLIAMSBURG STP
Line
No.
Column Number
PROCESS RESPONSES
28
29
30
31
32
33
3>*
35
36
37
38
39
1*0
1*1
1*2
1*3
1*1*
1*5
1*6
1*7
1*8
1*9
50
51
52
53
5l+
55
Sludge Settling
SSV (cc/1)
SSV6Q (cc/1)
DOB ( ft . )
BIT (£ of CWD)
Sludge Solids (in Terms of Sludge Units)
ATC - Aeration Tank Cone. (%)
WCR - Weight to Centrifuge Ratio (KLTSS/ATC)
RSC - Return Sludge Cone. (%)
SSCg0 - Settled Sludge Cone, at t = 60 min. (£)
SCR - Sludge Cone. Ratio (SSC6o/RSC)
SLR - Sludge Ratio (RSC/ATC)
SDR - Sludge Distribution Ratio (ASU/CSU)
SDT - Sludge Detention Time (hrs.)
STR - Sludge Detention Time Ratio (ADT/SDT)
SCY - Sludge Cycles (No. per Day'
SAH - Sludge Aeration Hours (Hrs. /day)
ASU to Final Clarifier (Million SLU/day)
Clar. Floor Loading (SLU/day/sq. ft.)
Sludge Solids (in Terms of Weight)
MLTSS (mg/1)
MLVSS (mg/1)
% Volatile
RSTSS (mg/1)
RSVSS (mg/1)
$ Vol.
SVI
SDI
ML Solids to Final Clarifiers (Ibs/day)
Clar. Floor Loading (Ibs/D/sq.ft. )
Jan,
Start-up
1
760
1*20
363
9-1*6
0.051*
5-75
313
10.02
18.37
1.75
1.71*
17.80
0.1+1
18.18
3-05
22.75
0.105
7-91
1800
1578
87.7
3000
271*0
91.3
233
0.1*3
271+72
2.07
Feb. & Mar.
Brewery Waste
2
938
71+6
615
9.18
0.082
7.62
297
13.86
0.95
1.81
12.2U
0.59
12.56
3-17
22. lit
0.158
11.90
2265
211*6
94. 7
1*011
3721+
92.8
329
0.30
39103
2.95
April May & June
Bulking Stable Operation
? 1*
957
794
650
U.77
0.523
3.05
1*31
5-51
5-32
0.97
1.81
1.80
3-52
1.81*
2.1*0
15-56
0.135
5.09
1316
1231
93-5
2187
2108
96.1+
603
0.17
1+8731
1.81*
91*1
778
660
8.8r
0.118
6.51
335
11.03
10.1*5
0.9!*
1.68
8.36
0.51*
8.5!*
l*.66
21.1+8
0.367
13.82
2183
2031*
93-2
3531
321*6
91.9
356
0.28
102683
3-87
Last Week
of Project
6/19 to 6/25
5
971*
872
TJk
7.87
0.213
It.bO
1*1*1
7.12
5.86
0.83
1.55
7-1?
0.95
7-31
1*.21
20.09
0.223
8.1*0
2030
1908
91*. o
287!*
261+3
92.0
1+30
0.23
8191+2
3.09
Project
Average
o
911+
712
595
6.35
0.165
6.18
323
10.89
11.87
1.08
1.76
10.09
1.05
10.33
3-31
20.89
0.222
8.36
2000
1861
93-1
3379
3133
92.8
356
0.28
59881
2.26
-------
TABLE HO. 6
(contd)
SUMMARY OF PLANT LOADINGS AND PROCESS RESPONSES
HAMPTON ROADS SANITATION DISTRICT - WILLIAMSBUHG STP
Line
No.
56
57
58
59
60
61
62
63
61*
Column Number
PROCESS RESPONSES
Effluent Quality
F. E. Turbidity (JTU)
F. E. BODj (mg/1)
F. E. BOD, (Its. discharged)
F. E. TSS (ag/1)
F. E. TSS (Iba. discharged)
Reductions by Act. SI. Process
BOD,. »)
TSS »)
Overall Plant Reduction
BODj (%)
T3S «)
Jan.
Start-up
Feb. & Mar.
Brewery Waste
April
Bulking
May & June
Stable Oper.
Last Week
of Project
6/19 to 6/25
Project
Average
9.79
12.0
183
15.0
229
95A
87-2
97-7
97. U
6.76
11.0
1B9
17.0
293
96.6
85 .1*
98.1
9U.6
21.9
2k. 0
889
58.0
21U8
92.7
51.3
95.7
77.6
5.01
1U.3
685
12.2
571*
95-7
91.0
97.0
9U.U
2.U7
87
•j
ok?
3*7
8.1*
339
97-7
on. 8
yw.w
08 1
yO'-i-
96-2
9-29
U*.5
1*68
22.2
696
95-1*
81.6
97-3
92.0
-------
BREWERY WASTE ALONE
Daring the months of February and March, when only "brewery-
wastes were treated, effluent turbidities fluctuated widely in a
2 to 20 JTC range. One rise in turbidity, just after the start
of recovery from the second acid spill, was caused by an open valve
on the No. k Aerobic Digester effluent line which permitted digested
sludge to flow into the final clarifier, and thence to the aeration
basin as return activated sludge. This resulted in a mixed liquor
with a dark gray color. Other fluctuations during this period were
related to an overflow of digested sludge from the thickener to the
aeration tank and numerous mechanical and electrical difficulties.
Final effluent BOD ranged from 5 to 26 mg/1 averaging 11 mg/1
during these two months for an overall plant reduction of 98 «0^.
Final effluent suspended solids concentrations ranged from 5 to 38
mg/1 averaging 17-0 mg/1 for an overall plant reduction of $k.6%.
Though the February-March two-month average incoming flow
increased 15% and the BOD,- increased Uofo over January, the plant
loadings were:
Ibs. BOD /1,000 cu. ft. Aeration Tank Volume 31.5
Ibs. BOD /Ibs. MLVSS 0.2k
Aeration Tank Detention Time @ Flow alone 15-3 hrs.
Aeration Tank Detention Time @ Flow plus Return. 7-0 hrs.
Final Clarifier Detention Time 5-3 hrs.
Final Clarifier Surface Overflow Rate.. 156 gals./d/sq.ft.
33
-------
COMBINED BREWERY AND DOMESTIC WASTES
During the last week of March, sludge settling became pro-
gressively worse and the sludge blanket in the final clarifier be-
gan to rise. Since the additional load of domestic sewage was
anticipated from the City of Williamsburg, a second aeration basin
was placed in operation to use sludge dilution as a method to in-
crease sludge settling. This interim method worked for-about a
week until the system became so glutted with sludge that bulking
became inevitable. Even the addition of the second clarifier at
this time did little to improve the situation. Sludge was being
lost over the final clarifier weirs intermittently during this
period.
A sludge loss occurred even on days when the sludge blanket
was two to three feet below the final clarifier water surface be-
cause of the excessive velocity currents in the vicinity of the
weirs and around the submerged effluent pipe. Proper leveling of
the final clarifier weirs should eliminate this part of the problem
by providing uniform overflow velocities.
When waste activated and primary sludge were handled as des-
cribed on Page 5 of this report, problems were encountered. For
instance, when high sludge wasting rates were employed, the aerobic
digestion tanks frequently filled faster than the thickened sludge
could be transferred to the irrigation site. This would cause liquid
levels to rise in the tanks to the point where the aerator blades
would become submerged, overdraw amperage, and shut off. Furthermore
-------
sludge detention times in these tanks were minimal, at best, and
during periods of high wasting were insufficient for sludge stab-
ilization.
A more conventional and perhaps better method of waste sludge
handling would have been to waste sludge directly to the gravity
thickeners and thence to the aerobic digesters. This mode of opera-
tion would allow the sludge to be concentrated before digestion re-
sulting in a lesser volume of sludge to be aerobically digested.
Longer detention times would then be possible and volatile solids
reduction would probably be enhanced.
The quantity of sludge wasted cannot be accurately documented
because the meter used to measure waste sludge was inaccurate at
low flow rates. During April, however, a general effort was made to
increase sludge age by decreasing the volume of sludge wasted. The
return sludge flow was gradually increased from 3-5 mgd to 6.8 mgd.
These high return sludge flows (about 200$ of the incoming flow)
•x-
were instrumental in increasing the sludge concentration ratio (SCR)
from 0.8 to about 1.6. By the 25th of April settling was greatly
improved, no sludge was lost over the weirs, and the daily average
turbidity was again reduced to below 10 JTU.
During this period D.O- levels were maintained from about 1.5
mg/1 D.O. to 5 mg/1 D.O. Experience gained while operating other
plants since the Williamsburg project showed, however, that proper
* Sludge Concentration Ratio(SCR)=6° ***! fettled Sludge Concentration^ )
B v ' Return Sludge Concentration(RSC)
35
-------
dosages of ferric chloride and/or polymers can improve the settl-
ing characteristics of bulking sludges. It is, therefore, desirable
that facilities (feeders, meters, controllers and piping) be avail-
able at the Williamsburg plant for the emergency addition of these
chemicals when bulking occurs.
Final effluent BOD ranged from 10 to 33 mg/1 averaging 2k- mg/1
during April for an overall plant reduction of 95-7%- Suspended
solids removal in April was poor, however, with final effluent con-
centrations ranging from 3 to 300 mg/1 averaging 58 mg/1 for an over-
all plant reduction of 77-6%.
Plant loadings and detention times for April reflect the effect
of the reduced mixed liquor concentrations and the increased flow from
the City of Williamsburg as shown below:
Ibs. BOD^/1,000 cu. ft. Aeration Tank Volume 3^-9
Ibs . BOD5/lbs . MLVSS 0.1*6
Aeration Tank Detention Time @ Flow alone Ik.17 hrs.
Aeration Tank Detention Time @ Flow plus Return... 6.1*9 hrs.
Final Clarifier Detention Time 1* .92 hrs .
Final Clarif ier Surface Overflow Rate igy gals ./d/sq .ft.
36
-------
STABLE OPERATION PERIOD
The final two months of the technical assistance project
(from May 1, to June 25, 1972) were characterized by relatively
stable plant operation. Effluent turbidities were generally
below 6 JTU and higher turbidities, when they occurred, were
almost always due to an overflow of digested sludge from the
thickener to the aeration basins.
During the first two weeks of May, sludge overflowed the
thickener weirs almost daily causing an increase in turbidities
and a general degradation of sludge settling characteristics.
In order to minimize this problem it was recommended that thickener
sludge blanket levels be recorded hourly and that sludge pumping
to the thickeners be regulated closely when there was danger of the
sludge overflowing the weirs.
When the above practice was adhered to, and process demands
followed rigorously, turbidities below k JTU were not uncommon.
Final effluent turbidities for the final week of Federal assistance
(June 19 - June 25, 1972) averaged about 2-5 JTU. BOD and suspend-
ed solids averaged less than 9 mg/1 during the same period.
Final effluent BOD ranged from k to 32 mg/1 averaging lU mg/1
during the last two months for an overall plant reduction of 97.0%.
Suspended solids concentrations ranged from 3 to 37 mg/1 averaging
12 mg/1 for an overall plant reduction of 9^'5°/o.
37
-------
The higher influent flows in May and June coupled with the
increased return sludge flow percentages required to meet process
demands increased aerator loadings and lowered detention times as
shown below:
Ibs. BOD../1, 000 cu. ft. Aeration Tank Volume... if 5-0
5
Ibs. BOD^/lbs. MLVSS 0-35
5
^>
Aeration Tank Detention Time @ Flow alone 11.2 hrs.
Aeration Tank Detention Time @ Flow plus Return k.6 hrs.
Final Clarifier Detention Time 3-5 hrs.
Final Clarifier Surface Overflow Rate 213 gals ./d/sq.ft.
PLANT LOADING
According to the engineers' design figures the total BOD,-
loading to the secondary aeration tanks (k tanks) was to be 40,000
Ibs. of BODj. per day; i.e., 10,000 Ibs. of BOD,- per day per tank.
For the first three months of operation the BODj- loading to the one
tank in service averaged less than 6,000 Ibs./day or about 60$> of
the design load. With the addition of the City of Williamsburg
load in April the BOD^ load to two tanks increased to 15,000 Ibs./
day or about 75% of the design load for two tanks. Figure 2 is a
7-day moving average plot of BOD^ load to the aeration tanks in
Ibs./day.
The aerator load (Ibs. BOD.-/1, 000 cu. ft. of aeration tank
capacity) was well within the capabilities of a complete-mix acti-
vated sludge plant throughout the duration of the project. In fact
during the first four months of the project the average aerator load
(30.1 Ibs. BOD/1,000 cu. ft.) was below the somewhat conservative
38
-------
FIGURE 2
7-DAY MOVING AVERAGE OF BOD LOADING
20-
18
16-
c
c
o
H 1 1
Q12
C
in
O 10
C'
0
U
C
w
8-
6-
2.
JAN. 4
FEB. 1
MAR. 1
APR. 1
1972
MAY 1
JUNE 1
-------
.
10-Btate Standard value of kO Ibs. BOD /I,000 cubic feet.
The increased load after the City of Williamsburg came on
line caused this value to be exceeded 73% of the time during
May and June for a mean of kl-k Ibs. BOD /1,000 cu. ft. Figure 3
is a 7-day moving average plot of aerator load.
The organic loadings experienced at Williamsburg were also
well within the plant's treatment capabilities. The project
average was 0.31 lb • BOD,-./lb. MLVSS with January having the lowest
average F/M ratio of 0.23 and April the highest at O.h6. April's
average was relatively high because of the decrease in mixed liquor
solids during the bulking phase.
Hydraulic loadings in the plant were light throughout the
project. This is particularly evident in the clarifier surface
overflow rate which averaged only 173 gal./d/sq.ft. for the project.
Figure U is a 7-d.ay moving average plot of clarifier surface
overflow rates.
SUMMARY OF PLANT PERFORMANCE
The Virginia State Water Control Board has set final efflu-
ent discharge standards of 35 mg/1 BOD and 20 mg/1 suspended solids
(monthly average values) for the Williamsburg Sewage Treatment Plant.
The monthly average final effluent BOD throughout the project was
less than the State certification value and except for the month of
April, when an average of 2k mg/1 was recorded, the final effluent
BOD was consistently below 17 mg/1. With the exception of April
Recommended Standards for Sewage Works, 1971 edition.
-------
FIGURE 3
7-DAY M3VING AVERAGE OF AERATOR BOD LOADING
90
80
70
60
50
ao-
30.
I
•
t,
•
u
o 20
c
|n
CQ
jr- rn
^ S 10
D
ffl
c
I
w
TEN STATES STANDARDS VALUE - UQ LIL BOD,.71000 C.F./DAY
JAN.
FEB. 1
MAR. 1
APP. 1
1972
'1AY 1
-------
FIGURE It
7-EAY MOVING AVERAGE OF CLARIFIER OVERFLOW RATE
JAN.
JUNE 1
-------
when bulking caused the monthly average of suspended solids to
reach 58 mg/1, the final effluent suspended solids were also
consistently below 17 mg/1.
Figure 5 is a 7-day moving average plot showing the rela-
tionship of aerator influent BOD concentrations to that in the
final effluent. Also shown on Figure 5 is the dashed line repre-
senting the State certification value of 35 mg/1 BOD. The small
hump in the final effluent BOD curve towards the end of January
was due to the acid waste which hit the plant during start-up.
Figure 6 is a 7-day moving average plot of aerator influ-
ent suspended solids and final effluent suspended solids. The
plot shows that the VSWCB certification limit of 20 mg/1 suspended
solids was exceeded only during the start-up month of January,
for a short period during February (undetermined cause) and, of
course, during April when bulking was experienced. Analysis of
the BOD and suspended solids curves further indicates that final
effluent quality was more a function of operational control pro-
cedures (aerobic digesters and sludge thickeners as well as the
activated sludge system) than a response to variations in influent
flow and BOD loadings. Seven-day moving averages were used in
these plots since they tend to level out immediate fluctuations
and smooth out a curve.
Probability plots of final effluent BOD' and suspended solids
•licentrations and percent reductions were also developed to permit
-------
450
FIGURE 5
7-DAY MDVING AVERAGE OF AERATOR INFLUENT AND FINAL EFFLUENT BOD5 OWGENTRATIONS
VSWCB Certification-35
JAN
JUNE 1
-------
350
FIGURE 6
7-DAY MOVING AVERAGE OF AERATOR INFLUENT AND FINAL EFFLUENT SS CONCENTRATIONS
JAN. 4
JUNE 1
-------
more detailed evaluation of the effluent quality (See A-l to A-3l) •
A summary of this probability data is tabulated in Table 7 and 8.
Performance - Start-up vs Entire Project (Figures 7 and 8).
Figures 7 and 8 are of special interest since they show
the relationship of final effluent BOD's and suspended solids dur-
ing the start-up month of January to that of the entire project.
Entire Project Curves (January k, 1972 - June 25, 1972)
The probability plots of all the final effluent BOD and
Suspended Solids data from January k, 1972 to June 25,
1972 are labeled "Entire Project" in Figures 7 and 8.
They exhibit a wide variation in slope, which because of
the somewhat uniform aeration tank influent BOD and Sus-
pended Solids Concentrations (BOD range of 258 to 3^ mg/1
averaging 317 mg/1, TSS range of 100 to 153 mg/1 averag-
ing 125 mg/l), is indicative of changes in treatment per-
formance .
Start-up Curves (January 1972)
The BOD and Suspended Solids curves for January 1972 (Fig-
ures 7 and 8) display the same wide variation in slope as
the project curves. This variation is logical when one
considers the problems that were associated with the
Williamsburg start-up, for instance, the acid brewery
waste which killed all the aeration tank biota. The
steeply sloping portion of the January curves corres-
ponds to this acid waste period.
-------
TABLE NO. 7
SUMMARY OF BOD 5 PROBABILITY DATA
HAMPTON ROADS SANITATION DISTRICT - WILLIAMSBURG STP
Probabllity % Equal
To Or Less Than
Jan. 72
Feb. 19
March 72
April 72
May 72
June 72
Raw BOD 5 (me/1 )
50%
10%
90%
Aeration Tank Influent BOD 5 (mg/1)
50%
10%
90%
Final Effluent BOD 5 (me/1)
50%
10%
90%
Secondary Reduction in BOD 5 %
50%
10%
90%
Overall Plant Reduction In BOD 5 (%)
50%
10%
90%
580
2i»i»
626
286
150
317
8.0
2.6
29.0
96.8
83.0
98.8
98. i»
91.3
99.6
582
U60
70it
297
25I»
3UO
10.3
7.2
13. C
96.6
95.7
97.5
98.2
97.6
98.8
530
280
850
33i»
283
l»33
12.0
6. it
18.8
95.9
9i».0
98.2
97.8
95.6
98.9
500
290
955
333
273
393
2I».0
18.3
29.8
92.U
91.5
9U.8
95.3
91 .5
97. U
U55
280
7UO
332
256
i»10
17.5
9.0
26.0
95.1
92.6
96.6
96.3
92.7
98.1
5U
32U
703
3UO
25l»
1*00
1 1 .6
6.5
16.7
96.9
93.8
98.2
98.0
95.3
99.0
-------
TABLE NO. 8
SUMMARV OF TOTAL SUSPENDED SOLIDS (TSS) PRORABILITY DATA
HAMPTON ROAOS SANITATION PI STRICT - WILLIAMSBURG STP
Probab! 1 i ty ? Equal
To Or Less Than
Raw Total Suspended Sol Ms (mc/1 )
50$
10%
90?;
Aeration Tank Influent TSS (m^/1 )
50?
in?
1(1°;
Final Effluent TSS (rip/I )
50°;
10$
no*
Secondary Reduction In TSS (?)
50?
in?
90?
Qypral 1 Plant Reduction in TSS (?)
50?
in?
90?
Jan. 72
335
120
lOfiO
120
Ul
196
q
?.<4
Ul
qi.n
5B.I4
97.3
«)7.5
88.5
qq.3
Feb. 72
336
I7n
620
115
UU
311
16
9
32.3
85.0
fin. 3
95.0
9U.O
90.0
97. «
March 72
270
86
l»60
93
62
153
li»
10
27.5
82. R
7U.7
90.7
93.7
89.5
97.7
April T>.
255
118
klS
112
80
170
35
10
125
71.8
U3.6
96. U
85.0
58.0
98.5
May 72
186
82
290
100
52
380
111
5
26
86.6
71.1
97. l»
92.6
82.6
97.6
June 72
278
166
389
100
71*
200
10
l».3
15.8
91.6
83.6
95.7
96.7
92.9
99.1
-------
FIGURE 7
PROBABILITY QF FINAL EFFLUENT BODC
I I
60
50
30 J
w
20
10
30.5
29.0
I • '
10 50 90
PERCENT OF TIME LESS THAN OR EOUAL TO
-------
FIGURE 8
PROBABILITY OF FINAL EFFLUENT SUSPENDED SOLIDS
60
8 50
M
•J
c
g 40
Q
2
W
(A
S3
EH
a
K
D
30
w
20
10
I ' ' « I ' « « I
10 50 90
PERCENT OP TIME LESS THAN OR EOUAL TO
-------
FIGURE 9
PROBABILITY OF FINAL EFFLUENT BOD
I ' ' ' I
10 50 90
PERCENT OF TIME LESS THAN OP EOUAL TO
-------
FIGURE 10
PROBABILITY OF FINAL EFFLUENT SUSPENDED SOLIDS
ro
I
10 50 90
PEPCENT OF TIME LESS THAN OR EOUAL TO
-------
Performance - June 1972 vs Entire Project (Figures 9 and 10).
Figures 9 and 10 are similar to Figures 7 and 8 except
that the June BOD and Suspended Solids curves are compared to the
project curves.
Entire Project Curves (January k, 1972 - June 25, 1972)
The "Entire Project Curves/' described on Page k6, are
also reproduced on the Figures 9 and 10 for compari-
son with the "Stable Operation Curves."
Stable Operation Curves (June 1972)
The curves representing June's data are straight and
do not exhibit much slope which indicates a more
stable plant operation. The reason for this improved
performance in June was the absence of mechanical
problems and the increase in operator familiarity with
the plant and control techniques. It should be noted
that the 50 percentile effluent BOD and Suspended
Solids concentrations for June were well below the
discharge limits set by the State of Virginia; even
the 90-Perceft"kile values were below 17 mg/1 for both
BOD and Suspended Solids.
53
-------
SUGGESTED PIANT MODIFICATIONS
The following are suggested improvements for the Williams-
burg Waste Treatment Plant:
CONTROLS
It is necessary to adjust Return Sludge Flow (RSF) and
Excess Waste Sludge Flow (XSF) to meet the process demands. The
plant operators at Williamsburg were severely hampered in their
control attempts since the appropriate meters could not be viewed
by one man while the actuating valves were being turned. There-
fore, two men were required to make the flow adjustments. The
job was made doubly hard because the waste sludge and return sludge
lines branched off a common header, and any adjustment of one flow
would affect the other- The installation of remote manual control-
lers for RSF and XSF are, therefore, recommended to enable one opera-
tor to make the necessary adjustments while observing the appropri-
ate meters at the control building meter panel.
SLUDGE HANDLING
Density sensors coupled to automatic control devices are
recommended to regulate the pumping of primary sludge and thickener
sludge. Minimum sludge volumes at maximum sludge density could be
achieved by the addition of automatic controllers, thereby increas-
ing the effective capacity of existing thickeners and aerobic
-------
digesters, and minimizing the deleterious recycle of septic sludge
to the activated sludge system. While greatly reducing the number
of man-hours needed for sludge control, such controllers should
also induce improved performance of both the activated sludge pro-
cess and the waste sludge disposal system.
Most important, however, is the need to accelerate the
construction program for the sludge disposal facilities discussed
in the Engineers' report. This sytem consists of centrifuging the
thickened sludge followed by incineration.
In the future, when the Williamsburg WTP hydraulic load reaches
or exceeds the true plant capacity, additional meters and control
gates will be needed to insure accurate balancing of flows between
multiple units. The recommended additional meters and valves in-
clude :
1. Control valves and meters on the mixed
liquor inlet line to each final clari-
fier-
2. Control valves and meters on the sludge
withdrawal line from each final clari-
fier.
3- Each of the valves noted above should
be provided with remote manual control-
lers at the central meter-control panel.
55
-------
Another automatic controller that should be considered for the
Williamsburg plant when operating at design flows and loads is
a one to proportion return sludge pumpage according to the vary-
ing incoming wastewater flow rates.
-------
SUMMARY
The Hampton Roads Sanitation District and NFIC-C person-
nel demonstrated during the six-month technical assistance pro-
ject at the Williamsburg WTP that this plant when properly oper-
ated will produce an excellent final effluent when treating
brewery waste alone, or a combined brewery and domestic waste.
It should be noted, however, that during the first three months
of operation, when only brewery waste was treated, both organic
and hydraulic loads were light. During the final three months
of the project normal organic loadings were experienced but the
clarifier surface overflow rate remained low. Throughout the
project numerous mechanical and operational problems were en-
countered, but despite these problems reductions in BOD- averaged
97% (530 to 15 mg/l) while reductions in suspended solids averaged
S2/o (320 to 22 mg/l) .
Three basic problems predominated causing intermittent high
effluent BOD and suspended solids levels:
1. Acid spills entered the treatment plant during
start-up. Closer cooperation between brewery
and District personnel has prevented this prob-
lem from recurring.
-------
2. Sludge bulking during April. This bulking sludge
could probably have been controlled more effect-
ively and rapidly by the application of coagulant
aids •
3- Unwarranted recycle of septic sludge from the
sludge disposal system to the activated sludge
process. This problem should be eliminated by
the addition of the proposed sludge handling
facilities.
Elimination of these and other identified difficulties
should enhance process control and further improve overall plant
performance and final effluent quality.
A prime reason for the success of this project was that
even though process imbalances did occur frequently, the demon-
strated operational control tests that were used to monitor plant
performance permitted such upsets to be quickly recognized and
corrected.
-------
RECOMMENDATIONS
The following recommendations are made in order that the
Williamsburg Plant may consistently produce the high quality
effluent of which it is capable:
1. The use of the full series of control tests
demonstrated during the NFIC-C assistance
project should be continued.
2. Return sludge flows and waste sludge flows
should be determined by process demands.
3• An improved method of sludge disposal should
be implemented as soon as possible to replace
the temporary compromise waste sludge handl-
ing system.
k. As the incoming BOD load increases, the two
tanks now used as aerobic digesters should be
put into service as additional aeration tanks.
The first additional tank will be needed when
the average load to the aeration tanks exceeds
20,000 Ibs. BOD per day.
5. Remote manual controllers should be installed to
permit proper regulation of return sludge flow
and waste sludge flow.
59
-------
6. Installation of automatic density controllers
should be considered to regulate the concentra-
tion and pumpage of primary sludge and thickener
sludge for more efficient sludge disposal.
7. Additional control valves and meters should be
considered to enable the balancing of flows
between multiple units when the average hydraulic
load approaches plant capacity.
8- Chemical feed equipment and piping should be
installed to permit emergency addition of metallic
salts and/or polymers to the aeration tanks or
final clarifiers to assure maintenance of satis-
factory effluent quality in the event of bulking.
60
-------
APPENDIX A
PROBABILITY PLOTS
JANUARY - JUNE 1972
-------
A-l
PROBABILITY OF RAW BOD-JAN.
800 :
700
600
500
400
I
300
200
100
0.05 0.1 0.2 0.5 1 2
5 10 20 30 40 SO 60 70 BO 90 95
PERCENT OP TIME LESS THAN OR EQUAL TO
98 99 99.8 99 9
PROBABILITY OF RAW SUSPENDED SOLIDS-JAN.
800
100
__!° _ » 30 40 50 SO 70 BO 30
PERCENT OP TIME LESS THAN OR EQUAL TO
95 98 99
99.9 99.99
-------
A-2
PROBABILITY OP RAW BOD-FEB.
m
800
700
600
500
f:::
1100
1
300
200
100
0.01 0.05 0.1 0.2 as 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.8 99.9 99.99
PERCENT OF TIME LESS THAN OR EQUAL TO
800
700
600
S0(f
400
30d
200
100
9.99
E3
=
=t
— -
= =f:i
^FF
.:
— r~
— r-]- ~
99.9
1.^
-;;--
W4
• -J-
~-~
19.9
=t
— t
•-[
—
3
9
-1
*-«
'
PROBABILITY OF RAW SUSPENDED SOL
9 91 95 90 10 70 60 50 10 30 20
::::::::: :::: rttT ~qrrt ::::::::::::::::::::
-.:: J_i L: .K|irfc:J3_! .TTrn t - • : mjjj I "HUti
ijfe^ : : - 1$& .p^|p'^'Hf:P | | 1
PERCENT OF TIME LESS THAN OR E(
IDS-FEE.
10 5 2 1 0.5 0 2 O.I 0.05 0.0
;;;;i;E!EEEEi-;i!!!:;!!!E;-:ipEp
! . . f — -, .
1
!.i!::::i«»p 1
:: :::::::iz :::;: ±:::— ;- ::::?-
:::::::i:=j|- H:::r::: : ::::
- " ' 1 •- -r-|- tf-f- •- i 1 - — i — . *-i-t- ...^ .. — •
90 95 98 99 99.« 999 """"Tl
?UAL TQL
-------
PROBABILITY OP RAW BOD-MAR.
800
700
600
500
400
300
200
100
0.01 0.05 0.1 0.2 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.8 99.9
PEHffcHT OF TIME tESS THAN OR EQUAL TO
PROBABILITY OF RAW SUSPENDED SOLIDS-MAR.
99.99 99.9 99.8 99 98 95 90 80 70 60 50 40 30 20 10 5
1 0.5 02 0.1 0.05 001
W---=
11- Ui
800
700
600
0500
H
400
300
200
100
'o. 1 0-05 "•' 0'Z 0.5 1 2 5 10 20 30 40 50 SO 70 80 90 95 98 99 99.8 99 9 99 99
PERCENT OP Tim LESS THAN OR EQUAL TO
-------
PROBABILITY OF RAW BOD-APR. '
800
700
600
'500
:tru
-ffl
§
I
400
I
300
200
100
:!BEr
* -Hi-1 —1---
:-^--l=r-
cas
t
ttffl
0.01 0.05 0.1 O.Z O.S 1
5 10 20 30 40 SO 60 10 to 90 95 98 99 99.8 99.9
PERCENT OP TIME LESS THAN OR EQUAL TO
PROBABILITY OF RAW SUSPENDED SOLIDS-APR.
95 90 BO TO 60 SO 40 30 20 10 S
Z 1 O.S 0.2 0.1 0.05 °"
800
PERCENT
30 40 50 60 70
OF TIME LESS THAN OR EQUAL TO
90 95 9B 99
-------
800
A-5
PROBABILITY OP RAW BOD-MAY
0.01 0.05 0.1 0.2 0.5 1 2
0 20 30 40 SO 60 70 80 80 95 98 99 99.8 99.9
PERCENT OF TIME LESS THAN OR EQUAL TO
PROBABILITY OP RAW SUSPENDED SOLIDS-MAY
95 90 80 70 GO 50 -10 3J 2'J 10 5 2 1 O.a D 2 0.1 0.05 001
800
5 w 20 30 40 50 60 70 »0 00 ?5
.PERCENT OF TIME LESS THAN OR EOUAL TO
99 S98 999
-------
A-6
PROBABILITY OP RAW BOD-JUNE
800
700
600
500
400
300
200
100
0.01 0.05 0.1 0.2 0.5 1 2 5 10 20 30 « 50 60 70 10 90 95 98 99 99.» 99.9
PERCENT OF TIME LESS THAN OR EQUAL TO
PROBABILITY OF RAW SUSPENDED SOLIDS-JUNE
99.M 999 Wi 99 98 _ 95 90 80 70 6J 50 « M :J 13 5 I 1 O.b 0! O.I 0.05 "II
800
700
•J600
S
D 500
£ too
trr
±t±t
tn
D
I
300
200
100
ffi
-i+r-
+±
PERCENT J°OF T°IME4°LE5SS THAN° OR'"EOUAL'°TO "
-------
A-7
900 r-
800 :
PROBABILITY OF PRIMARY EFFLUENT BOD-JAN
55EET
200
100
MI 0.05 0.1 OS 0.5 1
10 20 90 40 50 60 70 80 90 9b
PERCENT OF TIKE LESS THAN OR EQUAL TO
PROBABILITY OF PRIMARY EFFLUENT SUSPEHDED SOLIDS-JJIN.
99 98 95 90 80 70 SO 59 40 30 iH !0 5
0.5 0.2 0.1 0.05
» 10 20 JO 40 SO Ml 70 80 90
PERCENT OF TINE LESS THAN OR EQUAL TO
-------
A-8
PROBABILITY OF PRIMARY EFFLUENT BOD-FEB.
900
800
' 0.01 0.05 0.1 0.2 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.S 99.9
PERCENT OF TIME LESS THAN OR EQUAL TO
PROBABILITY OF PRIMARY EFFLUENT SUSPENDED SOLIDS-FEB.
99 9' « 9° ti '0 60 50 40 30 20 10 5 21 0.5 02 0.1 0.05 001
PERCENT OF TIME LESS THAN OR EOUAL TO
99.1 99)
-------
A-9
PROBABILITY OF PRIMARY EFFLUENT BOD-MAR.
900
800
700
{J600 —
« 500
u
D
400
K
0.
200
100
0.01 0.05 0.1 0.2 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99
PERCENT OF TIME LESS THAN OR EOUAL TO
8300 Eh-:::Sr:rr
PROBABILITY OF PRIMARY EFFLUENT SUSPENDED SOLIDS-MAR.
99.99 99.9 99.8 99 98 95 90 60 70 60 50 40 3T TO 1,0 5 2 t 0 "i r ; 0 1 0 05 001
__ '0 20 30 « 50 60 Ji
PERCENT OF TIME LESS THAN
•0 Pn
OR EOUAL TO
-------
A-10
PROBABILITY OP PRIMARY EFFLUENT BOD-APR.
900
800
nm 005 0.1 0! 0.5 i
5 10 20 30 40 50 60 10 10 90 95
PEPCFNT OP TIME LESS THAN OR EQUAL TO
PROBABILITY OF PRIMARY EFFLUENT SUSPENDED SOLIDS-APR.
5? 98 95 90 80 'Ci 6: 50 40 30 13 10 5 2
i.i o; o.i o.os o_oi
0.05 0.1 02 05 1
10 20 30 40 50 to
PERCENT OF TIME LESS THAN OR EQUAL TO
-------
900
800
A-ll
PROBABILITY OP PRIMARY EFFLUENT BOD-MAY
100
0.01 0.05 0.
102051 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.8 99.9
PERCENT OF TIME LESS THAN OR EQUAL TO
PROBABILITY OF PRIMARY EFFLUENT SUSPENDED SOLIDS-MAY
9.9 996 99 99 95 90 80 70 60 50 40 30 20 10 5 21 0.5 02 0.1 0.05 001
5 10 20 30
PERCENT OF TIME
10 50
LESS THAN OR
-------
A-12
PROBABILITY OF PRIMARY RPFLUENT BOD-JUNE
900
800
700 =f
i500
. ttOO
1300
200
100
0.01 0.05 0.1 0.2 09
5 10 20 30 40 50 60 70 80 90 95 98
PERCENT OF TIME LESS THAN OR EQUAL TO
99 99.8 99.9 KM
PROBABILITY OF PRIMARY EFFLUENT SUSPENDED SOLIDS-JUNE
99 98 • 90 80 70 fO 50 40 30 20 10 5 2
0.5 0.2 0.1 0.05 001
800
0.01 0.05 01 0
5 10 20 30 40 50 GO 70 80 M 95
PERCENT OF TIME LESS THAN OR EQUAL TO
-------
90.0
A-13
PROBABILITY OF FINAL EFFLUENT BOD-JAN.
80.0
70.0
4*60.0
50.0
ao.o
ill!
Eso.q
20.0
10.0
0.05 0.1 0.2 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99
10 20 30 40 50 60 70 80 90
PERCENT OF TIME LESS THAN OR EQUAL TO
99.) 99.9 M.99
PROBABILITY OF FINAL EFFLUENT SUSPENDED SOLIDS-JAN.
98 95 90 80 70 60 SO 40 30 20 10 S 21 0.5 0 2 0.1 0.05 0 0]
10
a i o.o5 0.1 0.2 0.5 i 2
5 10 20 30 40 50 60 70 80 90 95
PERCENT OF TIME LESS THAN OR EQUAL TO
98 99 99.8 999 99.99
-------
A-14
PROBABILITY OF FINAL EFFLUENT BOD-FEB.
45.0
40.0
°0 1 05 1 02 5 1 2 5 10 20 30 «0 50 60 70 80 90 95 91 99 99.8 99.9 99.99
PERCENT OF TIME LESS THAN OR EQUAL TO
PROBABILITY OF FINAL EFFLUENT SUSPENDED SOLIDS-FEB.
99 91 95 90 80 70 60 50 40 30 :0 10 5 2 1 0.5 12 0 1 0.05
10
PERCENT OF TIME LESS THAN OR EOUAL TO
91J n.<
-------
05.0
40.0
A-15
PROBABILITY OP FINAL EFFLUENT BOD-MAR.
0.05 0.1 0.2 0.5 1
2 5 10 20 30 40 50 60 10 80 90 95 98 99
PERCENT OF TIME LESS HiAN OR BQOAL TO
PROBABILITY OF FINAL EFFLUENT SUSPENDED SOLIDS-MAR.
95 90 80 70 BO 50 40 30 20 10 > 2 1 0.5 0 2 01 0.05 001
"O. 1 0.05 0.1 0.2
20 30 40 SO 60 71
PERCENT OF TIME LESS THAN
'0 80 90 95
OR EOUAL TO
-------
A-16
PROBABILITY OF FINAL EFFLUENT BOD-APRIL
0.01 0.05 0.1 0.2 0.5 1 2
10 20 30 40 50 60 70 BO 90 95
PERCENT OF TIME LESS THAN OR EOUAL TO
99 998 99.9
PROBABILITY OF FINAL EFFLUENT SUSPENDED SOLIDS-APR.
99 9» 95 90 «0 70 80 50 40 30 20 10
10 90 95
PERCENT OF TIME LESS THAN OR EQUAL TO
-------
A-17
PROBABILITY OF FINAL EFFLUENT BOD-MAY
15.0
UO.O
35.0
< 30.0
g
« 25.0
f
£ 20.0
B 15.0
10.0
5.0
0.0
0.
Dl
0.0
5 0.1
0.2
^
0.5
:::. .
. _:£
1 2
I^^fflSftMt^U
mSifiisi
~ -
:z' :s::: ' :""; ''
~: ?si ::):::• : ::::• :;•::•;
l--i'-> T-
1 C t--
*--• i -- -- -4
~2~-:::::::::: : ::::: ::::: ::
5 10 20 30 40
PERCENT OF TIME L
^4±FF]^ FIE?!-
- -' ----r^-±- -••'•'• W^^~
• 7T;'35:±+:E:5tBEi-
1 i;;.-4it|::itt:! -'iitlr-
-! L . , -j ^,4.. _ . _| I-L
T. -~p iii:-4:|;;rif ,T4 'id
: :::::::::::|:|:::::::::;±j
: ii::::::: :•'
_ ..-..-"^[j_^i:t::: ti::iii _^
-;.! f-r
, ,- 1 TT_- U.I IT JT r _f_J
;::::::;:;; ;::r:ir;:::;:^EE
: . ±:. + ::::::+ [4. + :::::__
^ .:::-T:::::;;: -;•::::: ^::_
: :::::::::::::: ::T::::^
SO 60 70 80 90 S
ESS THAN OR EOUAL TO
2
5
/L
=:H$I
[i-f
— ^ i
m
^ r,1i: T
- 1 ' !~r ;
-t-rti
— ^E i
— rr- r i
ff -i- <
— '-M-
11 M
H^ffl
98 99
E:E —
-)-, 1
j. _ ~t
t::
i:::-~
m\
i — —
99
tftj
:-^|-
.
^
^
1 ..:.-
-, !f
~ff
--
8 99.9
1
--1-
99
PROBABILITY OF FINAL EFFLUENT SUSPENDED SOLIDS-MAY
99 98 95 90 80 70 60 50 W 30 10 13 5 ! I O.S 02 0.1 0.05 001
10
O.OS 0.1 0.2 0.5 1 2
S 10 20 30 40 50 60 7
PERCENT OP TIME LESS THAN
'0 8" 90 95
OR EOUAL TO
-------
A-18
PROBABILITY OF FINAL EFFLUENT BOD-JUNE
90.0
80.0
1 0.05 0.1 0.2 0.5 1 2 S _ 10 20 JO 40__SO «> 70 «0 '»__ " 91 "
PERCENT OF TIME LESS THAN OR EDUAL TO
PROBABILITY OF FINAL EFFLUENT SUSPENDED SOLIDS-JUNE
99 98 95 90 60 70 63 JO <0 30 :0 10 5 : I 0.5 0 2 01 0 05
10 20 30 40 SO GO 70 80 90 9S 9| 99
PERCENT OF TIME LESS THAN OR EQUAL TO
-------
90.0>-
80.0
70.0
60.0
i 50.0
I 40.0
30.0
20.0
10.0
A-19
PROBABILITY OF FINAL EFFLUENT BOD-PROJECT
90 95 98 99 99.8 99.9 99.99
0.01 0.05 0.1 0.2 O.S 1 2 i 10 20 30 40 50 SO 70
PERCENT OF TIME LESS THAN OR EQUAL TO
PROBABILITY OF FINAL EFFLUENT SUSPENDED SOLIDS-PROJECT
J9.9 99.8 99 98 95 90 80 70 60 50 40 30 20 10 5 21 0.5 02 0.1 0.05 0.01
0.
-------
A-20
PROBABILITY OF SECONDARY REDUCTION IN BOD.-JAN. 72
100 ^~r—r
0.01 0.05 0.1 0.2 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.8 99.9 9UI
PERCENT OP TIME LESS THAN OR EOUAL TO
82
it,oMM
PROBABILITY OF SECONDARY REDUCTION IN S.S.-JAN. 72
99 98 95 90 80 70 60 50 40 30 20 10 5 21 0.5 0.2 0.1 0.05 0.01
iiiimm+mT
90
80
w
B,
70
in
V)
H
§
S*
60
-P
O
o
H
in
U)
O
NJ
O
10 t=t
0.01 0.05 0.1 0.2 0.5 1
10 20 30 40 50 60 70 80 90 95 99 99
PERCENT OF TIME LESS THAN OR EQUAL TO
Ml
-------
A-21
PROBABILITY OF SECONDARY REDUCTION IN BOD5-FEB. 72
0.06 0.1 0.2 O.S 1 2
5 10 20 30 40 SO 60 70 CO SO 95 J'. 99
PERCENT OF TIME LESS THAN OR EQUAL TO
PROBABILITY OF SECONDARY REDUCTION IN S.S.-FEB. 72
99 it 95 90 80 70 60 50 40 30 20 10 5 21 0.5 0.2 0.1 0.05 0.01
005 0.1 0.2 0.5 1 2
PERCENT
20
OF
30 « 50 60 70
TIME LESS THAN OR EOUAL TO
90 ii 91 9'<
-------
A-22
100
98
96
PROBABILITY OF SECONDARY REDUCTION IN BOD5-MAK. T2.
£
.94
in
§
592
90
88
86
8«
82
ftrt
0.01 0.05 0.1 0.2 0.5
5 10 20 30 40 50 60 70 90 90 95 98
PERCENT OF TIME LESS THAN OR EQUAL TO
100
PROBABILITY OF SECONDARY REDUCTION IN S.S.-MAR. 72
9« 95 M «0 70 60 50 40 30 n 10 5
10
SO 60 70 BO 90 95
PERCENT OF TIME LESS THAN OR EQUAL TO
-------
A-23
100
PROBABILITY OP
SECONDARY REDUCTION IN BOD^-APR. 72
0.01 0.05 0.1 0.2 0.5 1 2
5 10 20 30 40 SO 60 70 to
PERCENT OP TIME LESS THAN OR EOUAL TO
100'
PROBABILITY OP SECONDARY REDUCTION IN S.S.-APR. 7f
99 98 95 90 80 70 60 SO 40 30 20 10 5 ^ 10502010 OS 0.01
10 20
PERCENT OF
30 40 50 60 70 60 SO 85 36
TIME LESS THAN OR EOOAL TO
-------
PROBABILITY OP SECONDARY REDUCTION IN BOD. ...» .-
100
' 0.01 0.05 0.1 0.2 0.5 1 2 i 10 20 30 40 50 60 70 BO 90 95 it 99
PERCENT OF TIME LESS THAN OR EOUAL TO
999 99.9 99.99
100
PROBABILITY OP SECONDARY REDUCTION IN S.S.-MAY 72
99.9 99.8 99 98 95 90 80 70 60 50 40 30 20 10 5 2 1 0.5 0 2 0.1 0.05 0.01
20
10
0.01 0.05 0.1 0.2 0.5 1 2 5 10
20 30 40 50 60 '<
PERCENT OF TIME LESS THAN
'0 10 » 95 98
OR EQUAL TO
-------
100
A-25
PROBABILITY OF SECONDARY REDUCTION IN BODs-JUNE 72
0.01 0.05 0.1 0.2 0.5 1 2 5 10 20 30 40 50
95 98 99 99.8 99.9 99.> 9
PERCENT OF TIME LESS THAN OR EOUAL TO
80
82
PROBABILITY OF SECONDARY REDUCTION IN S.S.-JUNE 72
99 98 95 90 80 70 60 50 40 30 20 10 5 2 1 0.5 0.2 0.1 0.05
10
5 10 20 30 40 50 60 70 80 91
PERCENT OF TIME LESS THAN OR EQUAL
10 95
TO
99 99.8 99.9
-------
A-26
PROBABILITY OF PLANT REDUCTION IN BOD^-JAN.
100
98
82
1C 20 30 40 50 f" 70 80 90 95 98 99 99.8 99.9 99.99
PERCENT OF TIME LESS THAN OR EpUAL TO
100'
PROBABILITY OF PLANT REDUCTION IN S.S.-JAN. 72
r)5 "0 BO 70 60 50 40 30 20 10 5 2 1 0.5 0 2 0.1 0.05 0.01
82
PEPCEJJT OF TIMH T.FS? THAN OR P""'T ,m
-------
A-27
100
PROBABILITY OF PLANT REDUCTION IN BODg-FEB.
0.01 0.05 0.1 0.2 0.5 1
10D'
5 10 20 30 40 50 60 70 10 90 95
PERCENT OF TIME LESS THAN OR EQUAL TO
PROBABILITY OF PLANT REDUCTION IN S.S.-FEB. 72
95 90 80 70 60 50 40 30 20 10
2 1 0.5 0.2 0.1 0.05 0.01
p, —
82
~0 5 0.1 0.2 0.5 1 2
20 30 40 50 60 70 80 90 95 98 99
PERCENT OF TIME LESS THAN OR EQUAL TO
-------
A-28
PROBABILITY OF PLANT REDUCTION IN BODg- ,„„.
100
98
82
0.01 0.0% 0.1 0.2 05 1 2
20 30 4C 50 60 70 8& 90 95 98 99
PERCENT OF TIME LESS THAN OR EOUAL TO
99.1 99.9 99.99
100
98
PROBABILITY OF PLANT REDUCTION IN S.S.-MAR. 72
W9 991 M 9« 95 90 SO 70 60 50 40 30 20 10 5 2 1 0.5 02 0.1 0.05 001
W
-5:rj7t±
Hit1
u
K
U
6.
w
u
e
.,
VO
N»
-^~
--H^--,--H-:^M
'.O
o
g88
t-
O- 86
" —T
CD
ro
-f
-1-
h-
10 J'j » 40 so f ;o u 9o 45
PERCENT OF TIME LESS THAN OR EOUAL TO
-------
A-29
100 r-
PROBABILITY OF PLANT REDUCTION IN BODg-APR.
' 0.01 0.05 0.1 0.2 0.5
12 5 10 20 30 40 50 60 70 80 90 95 98 99
PERCENT OF TIME LESS THAN OR EQUAL TO
PROBABILITY OF PLANT REDUCTION IN S.S.-APR. 72
95 90 80 70 60 50 40 30 ?0 10 5 2 1 0.5 0.2 0.1 0.05 0.01
90,
80
70
§50
40
30
20
10
:rtt
Ji±::
1
0.05 0.1 0.1 OJ 1 2
5 10 20 30 40 50 60 70 80 90 95
PERCENT OF TIME LESS THAN OR EQUAL TO
-------
A-50
PROBABILITY OP PLANT REDUCTION IN BOD.-MAY
100
0.01 0.05 0.1 02 0.5 1 2 5 10 2Q 30 40 SO 60 70 80 90 95 98 99 99.8 99.9 99.99
PERCENT OF TIME LESS THAN OR EOUAL TO
82
100
PROBABILITY OF PLANT REDUCTION IN S.S.-MAY 72
99 IS K 90 10 70 60 50 40 30 10 10 5
0.5 o? o.i 0.05 o.m
0.01 0.05 0.1 0,2 OS 1 2
20 30 40 50 60 70 10 90 95 98 99
PERCENT OF TIME LESS THAN OR EQUAL TO
-------
A-31
100
98
96
PROBABILITY nF PLAI1T REDUCTION IN BOD,-JUNE
9U
0) !
w
A.
in
n
92
90
EH
U
g
88
86
£E£
82
0.01 0.05 0.1 0.2 0.5 1 2
5 10 20 30 40 50 60 70 80 90 95 98 99 99 8 99.9
PERCENT OF TIME LESS THAN OR EOUAL TO
100"
98
96
PROBABILITY OF PLANT REDUCTION IN S.S.-JUNE 72
95 90 80 70 60 50 40 30 20 !0 5 2 1 0.5 0 2 0 1 0 05 0 01
EEEF
-I-M-!
rfrt!
=liE
dill
g
92
90
88
86
84
frr1
5F
ru.;
820^—'— 0.05 o.i oT
PERCENT OP TIME*"LESS THAN7" OR
95 98 99 99.8 99.9 99.99
-------
APPENDIX B
SYMBOLS AND TERMINOLOGY
USED IN
ACTIVATED SLUDGE PROCESS CALCULATIONS
-------
SYMBOLS AND TERMINOLOGY
USED IN
ACTIVATED SLUDGE PROCESS CALCULATIONS
AAG Aerator Age (Days sludge under aeration)
ADT Aeration Detention Time (Hours - based on
AIF + RSF)
(Sludge ADT will differ from Sewage ADT in
"STEP" operation)
AFI Aerator Flow - Inf luent
"(MOD of "waste Water)
AGE Calculated Sludge Age (Days)
ASU Aerator Sludge Units
ATC Aeration Tank Concentration
t$> by Centrifuge)
AVP Aeration Tank Volume (Cu. Ft.)
AVG Aeration Tank Volume (Gallons)
-------
B-2
BLT Clarifier Sludge Blanket Thickness
(Either in feet, or fraction of CWD)
BLV Glarifier Sludge Blanket Volume
(Either in gallons or fraction of CVG)
BLX Clarifier Sludge Blanket Index
BOD Biochemical £xygen Demand
T5-day - Unless stated otherwise)
CDT Clarifier Detention Time
THOUTS based on TFL)
GET Clarifier Effluent Turbidity
Tin JTO)
CFI Clarifier Flow - Influent
ITFL - XMF in MGD)
CFO Clarifier Flow - Out
TCFI - CSF in MOD)
CMC Clarifier Mean Sludge Concentration
TATC + Rscj
( 2 )
CSA Clarifier Surface Area
TSquare Feet)
CSD Clarifier Sludge Flow Demand
CSF Clarifier Sludge Flow ~"
TRSF + XRF in
CSP Clarifier Sludge Flow Percent
TRSF + XRF as a % of CFI)
CSU Clarifier Sludge Units
Tin sludge blanket)
CVF Clarifier Volume
Tcubic Feet)
CVG Clarifier Volume (Gallons)
CWD Clarifier Mean Water Depth (Feet)
-------
B-3
DOB Depth Of Sludge Blanket
"(Feet from Water Surface)
ESU Final Effluent Sludge Units
(Total~Suspended Solids lost in
Final Effluent - expressed as SLU)
FEC Final Effluent Concentration
^Suspended Solids converted to
by Centrifuge)
FET Final Effluent Turbidity (J1U)
FLI Raw Flow - Into Plant (MGD)
FLO Effluent Flow - Out of Plant
JTU Jackson Turbidity Units
LOD Load (Lbs. BOD/Day to Aerator)
Lod Load (jng/1 BOD to Aerator)
MLTSS Mixed Liquor Total
Suspended Solids (mg/l)
MLVSS Mixed Liquor Volatile
Suspended Solids (mg/l)
-------
OFR Clarifier Overflow Rate
(Gal./Sq. Ft./Day based on CFO)
OIX Oxidation Index
"(Based on Optimum SSV)
PET Primary Effluent Turbidity
TJTU)
PFI Primary Flow Into Primary Sedimentation Tank (MGD)
PFO Primary Flow Out of Primary Sedimentation Tank (MOD)
PSF Primary Sludge Flow (MOD)
RFD Return Sludge Flow Demand (MOD)
RFP Return Sludge Flow Percentage
as a % of AFI by meter)
RSC Return Sludge Concentration
T# by Centrifuge)
RSF Return Sludge Flow (MGD)
RSP Return Sludge Percentage
T# of AFI - Usually calculated
from ATC and RSC)
RSTSS Return Sludge Total Suspended Solids (mg/l)
RSU Return Sludge Units (To aerators)
RSVSS Return Sludge Volatile Suspended Solids (mg/l)
-------
B-5
SAH Sludge Aerator Hours (Hours per day in aerator)
SAP Sludge Aerator Hours iu Percent of Day
"(Either % or decimal fraction)
SCO Settled Sludge Concentration - ttt Optiiuuci
(Optimum SSC - ^ by Centrifuge)
SCR Sludge Concentration Ratio (SSC/R3C)
SCY Sludge Cycles (per day)
SDR Solids Distribution Ratio
"(Between aerators and clarifierc -- ASU/CSli)
SDT Sludge Detention Time
in clarifiers)
SIB Sludge Ratio (RSC/ATC)
SIU Sludge Units
"(Volume in gallons x % concentration
as a decimal fraction)
SSC Settled Sludge Concentration
Tcalculated $ by Centrifuge)
SSV Settled Sludge Volume
Tcc/1 in Settleometer )
SVO Settled Sludge Volume at Optimum
tcc/1 in Settleometer)
TDT Total Sludge Detention Time
TADT + SDT in Hours)
TFI Thickner Flow Into (MOD)
TFL Total Flow
out of aeration tanks)
TFO Thickener Flow Out (MGD)
^n^ Ratio (AVG/CVG)
-------
B-6
TSF Thickener Sludge Flow (MGD)
TSS Total Suspended Solids (MQ/i)
TSU Total Sludge Units
TASU + csu)
TXU Total Excess Sludge Units So Waste
TXSU + ESU)
XFP Excess Sludge Flow (As Percent of Sewage Flow)
XMF Excess Mixed Liquor Sludge Flow To Waste (MGD)
XRF Excess Return Sludge Flow To Waste (MGD)
XSF Total Excess Sludge Flow To Waste (MGD)
XSU Excess Sludge Units To Waste
-------
APPENDIX C
OPERATIONAL CONTROL TREND CHARTS
-------
C-l
SETTLED SLUDGE VOLUME - SS\?
M
1/2U/72
-------
C-2
SETTLED SLUDCE CONCENTRATION - SSC
M
1/2U/72
M
1/31/72
M
2/7/72
M
2/1U/72
M
2/21/7
-------
C-3
FINAL EFFLUENT TURBIDITY
00
80
70
60
= 30
K
-3
v20
o
00
Q£
=>
j 5
I H
M
1/2U/72
M
1/31/72
M
1/7/72
M
2/1U/72
M
2/21/72
-------
EXCESS SLUDCZ UNITS WASTED/EAY - XSU/t&Y
0.09
0.08
0.07
0.06
0.05
O.OI»
0.03
0.02-
0.01
0.009
0.008
0.007
0.006
0.005
O.OOl*
0.003-
0.002-
Zttto
Z&O.O
ZEKO
Zeoo
M
1/2U/72
M
1/31/72
M
2/7/72
M
2/1U/72
M
2/21/72
-------
, C-5
BLANKET THICKNESS-ELT
0.8
0.7 •
0.6 -
0.5 •
O.J» -
0.3 -
0.2 -
zO.l •
£0.09
* 0.08
£0.07
H0.06
""0.05
OQ
0.01*
0.03-
0.02-
1
M
2/U/72
—r
M
2/21/72
M
1/2U/72
M
1/31/72
M
2/7/72
-------
C-6
SLUDGE DETENTION TIME - SDT
9.0
8.0
7.0
6,0
5.0
U.O
3.0
CO
C£.
2.0
o 1.0
K .9
£ .8
K .7
o .6
tit r
I in
_J
to
i 3
B '
.2 -
M
1/2U/72
M
1/31/72
M
2/7/72
M
2/1U/72
M
2/21/7
-------
C-7
SSV CURVE'S ~ HfcSD
SSC CUEVES ~ HESD
tooo
c
In
O
'/fe/72 - 1200
FAST-
10 !•> 20 W -90
SST- SLUDC^fc
40
60
TIME-
10 («> 20 25 30 40 50
SST~ sc.uoc,cr serr«-i>iQ TIME-
-------