-------
the solids concentration in the aeration basin. After about 1 hour under
this condition the amount of solids in the aeration basin for the example
will decrease from 16,660 pounds to 16,000 pounds.
The loss of solids from the aeration basin, of course, will be added
to the sedimentation basin, increasing the inventory from 740 pounds to
1,400 pounds. The volume occupied by the solids will approach 34 percent
of the sedimentation basin volume. The solids flux rate will increase
from 13 Ib/day/sq ft to 24 Ib/day/sq ft.
In the conventionally designed plant, the same circumstances will
cause the volume occupied by the sludge in the final basin to increase
from 36 percent to 63 percent. The solids flux rate increases from 27
Ib/day/sq ft to 43 Ib/day/sq ft.
Therefore, as the extended aeration plant remains within reasonable
operating parameters for high quality treatment, the conventionally
designed plant approaches marginally acceptable conditions. In effect
the conventionally designed plant would require operational procedures
to adjust for the change in hydraulic load, such as increasing the recycle
rate.
The shift in solids inventory is actually more pronounced than the
example depicts since the peak daily hydraulic load does not occur upon
onset of equilibrium conditions dictated by the average hydraulic load,
but occurs after the night-time minimum hydraulic conditions which cause
the solids inventory to shift to the aeration basin. The greater solids
concentration in the aeration basin at onset of peak hydraulic load causes
higher sedimentation basin solids influx than depicted. The management
of solids inventory for the conventionally designed plant is as important
during the minimum flows as during the maximum flows to compensate for
this effect.
Any biological design is concerned with the amount of sludge produc-
tion and disposal procedures. The extended aeration activated sludge
process has certain inherent advantages. The long SRT's at which these
plants operate (20-30 days) results in a well stabilized, aerobically
digested sludge. In a conventional plant having an SRT of from 4 to 10
days, the sludge, if placed on drying beds or on the land, will be odorous
and objectionable because of the relatively high biodegradable organic
content of the sludge. Aerobic digestion of the sludge for 7 to 15 days
will result in a stable product suitable for disposal on drying beds or
the land. The total sludge age prior to disposal will be from 15 to 20
days. In effect then, the extended aeration process itself provides a
sludge stability comparable to that from conventional activated sludge
and separate aerobic digestion.
Attached Growth Biological Treatment
Processes which may be categorized under the general heading of
attached growth biological treatment include:
27
-------
Trickling Filters - or biofliters wherein stationary media is
arranged over an underdrain system and the wastewater is distributed
over the media. Various media used include rock, plastic, and redwood.
Rock media trickling filters flow schematics have been highly
variable insofar as staging of filters, the presence or absence of inter-
mediate clarification, and the source and quantity of recycle water.
The array of alternative flow schemes which the rock media trick-
ling filter system may be applied, reflects the uncertainty of the cri-
tical parameters which determine the trickling filter performance.
Plastic media trickling filters are most commonly a single stage
process. The media is piled or stacked to a greater depth than rock
media and recirculation is commonly taken directly from the trickling
filter underflow, but in instances is taken from the clarifier underflow.
Plastic media is manufactured in various forms. Plastic media manufac-
turers strive to obtain large surface areas per cubic foot on the premise
that media surface area is a prime performance parameter. Another sub-
stitute for rock media in trickling filters is redwood media. The red-
wood media is manufactured in the form of slats which are fabricated in
the form of pallets which are stacked in the trickling filter.
Rotating Biological Media - where the media is rotated slowly
through a bath of the wastewater. The media is almost universally con-
structed of synthetic materials and is available in the form of discs
or a structural lattice.
Rotating biological media systems were developed in Europe and
recently have been applied in the United States. There are several
domestic manufacturers. The process differs from the concept used for
trickling filters by moving the media through the waste (in a bath) in-
stead of passing the waste through the media. The media rotates slowly
through the bath exposing the attached growth to the wastes, and through
the atmosphere for oxygen supply. Recirculation of liquid around the
rotating media unit process is not practiced.
The media originally introduced into the United States was a series
of closely spaced, parallel, flat discs. This media is still commonly
used in Europe. The major manufacturers in the United States currently
offer a lattice structured media, made of thinner plastic sheets, but
structurally supported by closely spaced intermediate bracing. The
current design offers about 50 percent more available surface area
per unit volume.
Full scale installations to date (1976) use mechanical rotational
drives; however, one manufacturer offers an "air drive" system which has
been tested in pilot and bench scale units. Several projects currently
under design are reportedly intended to incorporate the "air drive". Air
is injected below the media causing a combination of an off-center byoyancy
of the media and an air lifting of the liquid which effects media rotation.
The air also provides added oxygenation. Design and operating data for
28
-------
this type of rotating biological* media systems are not established suffi-
ciently to include in this report.
The media is almost always externally protected by constructing a
superstructure over the rotating biological media system or by covering
each shaft with an individual cover specially constructed and provided
by the manufacturer. Media construction by one manufacturer is offered
with larger specific surface areas (square feet of exposed media per cubic
foot) intended for use in second stage systems or nitrification where
solid pluggage is less likely. ' . .
The application of attached growth systems generally requires pre-
treatment, including screening of debris from the waste stream and primary
sedimentation. The attached growth system as applied to organic removal,
requires subsequent sedimentation to remove synthesized bacteria and
accumulated inhert sewage solids.
Rational Design Basis for Attached Growth Systems
A sound design for attached growth biological systems requires the ':
designer to be familiar with the basis of the design procedures employed,
the adequacy of these procedures to predict performance, and the differences
between real data and procedural predictions.
The rational design of attached growth biological systems has been
elusive. Empirical curve fitting has been substituted for a rational
design basis with limited success requiring the design for a specific
effluent condition to be conservative.
Traditionally the concept of attached growth systems has been
visualized as a decreasing concentration of organics passing over a film
of attached bacterial growth. The organics move from the carriage water
to the growth in proportion to the organic concentration. Likewise
oxygen in the air is transferred to the carriage water and then to the
bacterial growth. Theoretically then, the surface area of the media
should have a major effect on performance. The greater surface area
per unit volume will support more bacterial growth, cause a thinner film
of carriage water per unit flow of water, thus increasing oxygen transfer
and slow the rate of carriage water over the bacterial growth.
The predictive techniques used for design of attached growth systems
may be categorized into empirical models and rational models. Empirical
models comprise the vast majority of techniques available for attached
growth system design and are the procedures used by almost all design
engineers. These procedures are based on statistical curve fitting of
plant data to variations in plant operating conditions and physical
facilities. Since the many available models tend to give varying-results,
it is likely that they do not express the true removal phenomena.
/ -I Q Q\
Recently many investigators ' ' have- attempted rational develop-
ment of attached growth design conditions. The Williamson and McCarty
biofilm model is a well presented sample representing the rational
29
-------
approach. This model considerd many factors which describe substrate
utilization by biofilms but may be too complex for general usage by de-
sign engineers. Basically, the model predicts soluble substrate removal
from limitations of diffusion of oxygen and substrate through the liquid
and the biofilm to the bacteria and the simultaneous effects of biochemical
i reactions. The surface area of biofilm becomes a key design parameter.
j The limitations on the usage of the model may include the absence
of the effect of suspended biological growths in the bulk liquid, the
absorption/adsorption of substrate, and the physical removal of insoluble
substrate. The degree of influence of these potential limitations is
not know; however, there is indication that the influence is significant.
Gulp in comparing two similar trickling filter systems, one recycling
plant (secondary clarifier) effluent and the other recycling trickling
filter underflow directly showed that the improved treatment resulted
from recycling directly. It may be hypothesized that improved treatment
resulted from recycling suspended biological growth. Slechta reported
on pilot studies where comparative parallel tests were conducted. One
system used a trickling filter with direct recycle (trickling filter under-
flow) and the second system used final clarifier underflow. The system
using final clarifier underflow showed almost twice the removal capability
as the direct recycle system. The conclusion is that the amount of sus-
pended biological growth in the bulk liquid will significantly affect the
performance of the attached growth system.
The "rational approach" exemplified by the Williamson-McCarty bio-
film model may be limited in its predictive capability for real systems;
however, the investigators do make observations from their model which
are useful to a better understanding of the removal phenomena in an
attached growth system.
1. "Any change in environmental conditions that encourages biofilm
growth such as an increase in k (Monod maximum utilization rate), DC
(diffusion coefficient in biofilm), Xc (bacterial concentration within
biofilm), or So (bulk liquid substrate concentration) will not result in
as large an increase in the substrate removal rate. The k value would
have to be increased by a factor of 2...One implication is the under
adverse environmental conditions, the substrate removal rate is not de-
creased as drastically for biofilms as it is for dispersed growth systems."
2. "On the basis of...(the model and certain rate assumptions) sub-
strate utilization in these two reactors (trickling filters and rotating
biological media) are predicted to be dependent on D.O. concentrations
for all cases in which the soluble BOD exceeds approximately 40 mg/1."
3. "...The D.O. concentration required to avoid oxygen flux limi-
tation would have to be 2.7 times the ammonia-N concentration (for nitri-
fication in attached growth systems)."
'These conclusions represent a portion of the removal phenomena
because they relate only to attached growth. If significant suspended
biological growth is carried in the bulk liquid, the limitation imposed
30
-------
by oxygen concentration is lower than in attached growth systems. Also
significant suspended growth in the bulk liquid will reduce the soluble
substrate concentration and reduce the level of effort by the attached
biofilm.
Although the biofilm kinetic models are enlightening, insofar as the
removal phenomena of the attached growth is concerned, the use of these
models may be limited to conditions wherein suspended growth is< dispersed
or is not significant. For real systems this confines the evaluation of
attached growth systems to previously developed empirical relationships.
There is a large school of thought that the surface area of media is
the primary criteria for trickling filter sizing. That is, a media having
more surface area per unit volume may permit a smaller volume than a -media
having less surface area per unit volume. The complicating multiple
conditions which occur in an attached growth system makes such a simple
premise doubtful. From the previous discussion, it was stated that the
specific surface area will have less effect on the design when greater
concentrations of suspended growths are carried in the bulk liquid., On
the other hand when suspended growth concentrations are minimal in the
bulk liquid, specific surface area may have greater effect on the design.
A later section reviews available data on various media to ascertain
the difference in treatment capability associated with greater unit
specific surface area.
Empirical predictive techniques for the attached growth biological
process have been presented by several investigators. The more generally
used formulae are presented in this section. More complete reviews of
attached growth biological system models are presented elsewhere ' '
Of the more commonly used formulae, the earliest was developed by the
National Research Council (NRC), where:
E = 1 for first stage (1)
1 + 0.0561 W_ h
VF
Where E = fraction of BOD removed
W/V = Ib BOD /day/1,000 ft3
F = (1+R)/(1+0.1R)2
R = ratio of recirculation to influent flow
Following several formulae based on estimation of fluid travel time
through attached growth systems, Eckenfelder presented the formulae:
Le_ = 1 , (2)
Lo 1 +
31
-------
Where: Le = BOD out
Lo = (Li + RLe)/(l + R)
Li = BOD in
D = filter depth, ft
Q = hydraulic flow to filter, mgd
A = filter area, acres
R = recycle ratio
Galler and Gotaas later proposed a formula incorporating more
variables and fitted by regression analysis to existing trickling filter
plants:
0.13
Le = 0.464 Lo1'19 (l+R)0'28^ (3)
Where: T = temperature, C
Manufacturers of plastic media trickling filters increased the general
usage of the Velz equation in the following form:
(4)
Where : q = flow rate gpm/sq ft excluding recycle flows
A similar equation form has been developed during this study for
general usage with all attached growth media systems. This equation was
developed primarily to assess the removal phenomena as a function of
hydraulic loading rate per unit volume.
Rock Media Trickling Filters
Considerable data are available to judge the accuracy of design for-
mulae. Most data reported represent averages and certain of the parame-
ters must be assumed in order to calculate values from the various models.
A summary of data is shown on Table 2. Using physical description and
operating parameters given, the predicted values for the several more fre-
quently used empirical formulae have been calculated.
Equations (4) and (5) are generally not applied to rock media trick-
ling filters. Because these equations are in general usage for media other
32
-------
TABLE 2
COMPARISON OF TRICKLING FILTER MODELS WITH DATA
Plant
Location
Q/A
(mgd/acre)
Predicted Effluent BOD (mg/1)
NRC
Eckenf.
Caller/
Gotaas
Aurora, 111.
Dayton, Ohio
Durham, N.C.
Madison, Wise.
Richardson, Tx.
PlainfieId, N.J.
Great Neck, N.Y.
Oklahoma City, Ok,
u! Freemont, Ohio
Storm Lake, Iowa
Richland, Wa.
Alisal, Ca.
Chapel Hill, N.C.
Dallas, Texas
Bri dgepo rt, Mi.
Cass City, Mi.
Charlotte, Mi.
Hillsdale, Mi.
Lapler, Mi.
State Prison, Mi.
Vassar, Mi.
6
7.5
7
10
6.5
6
4
6
3.3
8
4.5
3.2
4.25
7.5
6
6
6
6
5.8
8
5.6
Estimate
-
-
-
-
-
0.6
1.0
1.0
1.5
2.1
2.8
3.1
2.0
0.5
1.2
1.3
-
-
0.3
0.1
1.7
2.1
3.5
1.9
2.4
3.9
2.4
7.8
16.3
19.0
21.5
19.6
20.8
16. 3
5.6
20.6
10
7.7
3.6
13.5
3.8
9.2
4.4
12
13
6.4
13.3
25
20
78
41
62
44
53
19
21.4
29
23
29
10
22
13
6
Average
14
33
68
33
20
13
20
66
21
61
20
24
44
37
42
33
63
32
23
17
29
34
7
22
44
17
20
14
19
83
20
88
23
39
11
41
24
34
34
19
16
25
9
29
17
11
22
34
16
22
8
21
59
23
50
17
31
13
32
25
31
36
22
20
23
LI
26
16
14
30
61
24
27
12
26
71
23
61
19
46
14
43
19
28
33
22
16
30
_8
29
14
-------
than rock, the applicability has been reviewed for data from rock media bio-
filters as shown in Table 3. The value of k (Equation 4) and K (Equation 5)
is dependent upon the surface wetting rate as shown on Figure 13. Also the
effect of depth does not seem to affect the results more so than volume.
Plastic and Redwood Media Trickling Filters
The several forms of fabricated media available include:
Plastic media - stacked
Plastic media - random dumped
Redwood Media - stacked
The data on Table 4 indicate that both k and K are variable, imply-
ing factors other than flow will influence the predictability of the
degree of treatment. However, the domestic waste treatment as represented
by Chipperfield imply media volume is as representative of a treatment
parameter as is depth. The application of formulae developed for rock
media trickling filters to the plastic media trickling filters will not
produce successful predictions. For instance, as a general rule, the
Galler/Gotaas equation (Equation 3) which is successful with rock media
trickling filters, will predict a much lower effluent BOD from plastic
media trickling filters than is experienced.
The data on Table 4 imply that the capability of the plastic media
with an effective surface area of 25-30 square feet/cubic foot is about
the same as the redwood media having an effective surface area of about
14 square feet/cubic foot. A more direct comparison of the capability
of the two media was made in Salem, Oregon and is shown on Figure 14.
These data indicate little difference in capability of the two media,
and in this presentation no differentiation will be made in the design
procedures. Furthermore, when compared to performance of rock media having
a surface wetting rate above 0.35 gpm/sq ft, the plastic or redwood media
trickling filters appear to provide, equal treatment per unit volume.
Rotating Biological Media
The design approach for rotating biological media has been a graphical
relationship between the effective surface area of the media and the per-
cent removal efficiency as shown on Figure 15. Basically this relationship
implies beneficial results for higher specific unit surface areas. Media
is manufactured in the form of discs which have a specific unit surface
area of 20-25 sq ft per cubic feet and in the form of lattice structure
which has a specific unit surface area of 30-35 sq ft per cubic foot.
A higher specific unit surface area is available (45-50 sq ft/cu ft) for
use in the latter stages of the system which purportedly reduces the over-
all volume of the media. The usage of the high specific surface area media
in early stages of the rotating biological media system often results in
clogging due to the smaller clearances and is not recommended. As men-
tioned in previous sections of this report, the disc type media is no
longer available from the two major domestic manufacturers; however, a
34
-------
TABLE 3
ROCK MEDIA BIOFILTERS
DATA EVALUATION FOR DEPTH AND VOLUME EFFECTS
Plant Location
Aurora, 111.
Dayton , Ohio
Durham, N.C.
Madison, Wise.
;Richardson, Texas
Plain fie Id, N.J.
Great Neck, N.Y.
Oklahoma City, Okla.
Freemont , Ohio
Storm Lake , Iowa
Richland, Washington
Alisal, Calif.
Chapel Hill, N.C.
Dallas, Texas
Bridgeport, Mich.
Cass City, Mich.
Charlotte, Mich.
Hillsdale, Mich.
Lapler, Mich.
State Prison, Mich.
Vassar, Mich.
Depth
(ft)
6
7.5
7
10
6.5
6
4
6
3.3
8
4.5
3.2
4.25
7.5
6
6
6
6
5.8
8
5.6
q
(gpm/sqft)
0.034
0.056
0.030
0.038
0.062
0.024
0.062
0.130
0.121
0.111
0.082
0.081
0.087
0.090
0.15
0.07
0.214
0.057
0.160
0.050
0.090
Wetting
Rate
(gpm/sqft)
0.034
0.056
0.030
0.038
0.062
0.038
0.125
0.260
0.30
0.34
0.31
0.33
0.26
0.13
0.329
0.160
0.2.14
0.057
0.214
0.060
t
0.231
BOD
in
(mg/1)
70
137
261
138
118
76
117
300
95
381
118
185
77
130
99
152
119
91
65
153
59
Average
BOD
out
(mg/1)
14
33
68
33
- 20
13
20
66
21
61
20
24
44
37
42
33
63
32
23
17
29
Depth
k
0.05
' 0.04
0.03
0.03
0.07
0.06
0.11
0.09
0.16
0.08
0.11
0.18
0.04
0.05
0.07
0.09
0.06
0.052
0.09
0.06
0.05
0.07
Volume
K
0.12
0.12
0.09
0.09
0.17
0.11
0.22
0.22
0.29
0.21
0.24
0.32
0.09
0.14
0.16
0.17
0.21
0.13
0.16
0.17
0.13
0.17
35
-------
TABLE 4
PLASTIC AND REDWOOD MEDIA BIOFILTERS
DATA EVALUATION OF EQUATIONS (4) AND (5)
Location
13
Indianapolis, IN
14
Stockton, CA
15
Wiskeywaste
15
Domestic
15
Domestic
16
Corvallis, OR
16
Corvallis, OR
Idaho Falls,
Idaho1
17
Madera, Calif.
18
Akron , Ohio
Buena Vista,
Mich.1
19
Bay City, Mich.
Essexville,
Mich.1
Greenville ,
Mich.19
19
Rockwood, Mich.
Media
Plastic
Plastic
Plastic
Plastic
Plastic
Redwood
Redwood
Redwood
Redwood
Plastic
Dumped
Plastic
Plastic
Plastic
Plastic
Plastic
Depth
(ft)
21.5
21.5
34
6
18
14
14
21.5
12
25.5
20
21.5
21.5
21.5
22
q
Wetting
Rate
(gpm/sqft) (gpm/sqft)
2.
0.
0
28
NA
0.2-0.8
0.6-2.3
0.
1.
0.
0.
0.
0.
0.
0.
0.
0.
94
12
34
20
36
46
90
75
46
32
2.
0.
0
71
NA
0.2-0.
0.6-2.
3.
4.
1.
3.
0.
1.
1.
1.
0.
0.
8
3
3
3
0
2
75
20
1
50
50
97
BODIn
(mg/1)
112
240
950
a
a
100
192
60
220
120
54
79
23
62
61
BODout
(mg/1)
57
40
65
a
a
24
72
9
25
20
21
18
11
15
23
De
0.
.0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
pth
k
04
04
04
11
06
10
07
05
08
48
03
005
03
05
03
Volume
K
0.20
0.20
0.20
0.28
0.25
0.37
0.28
0.24
0.28
0.22
0.14
0.31
0.15.
0.21
0.12
36
-------
0.3
(K1)-
0.2
X.
6
0.1
0.1
0.2
0.3
0.4
WETTING RATE, gpm/sq ft
ROCK MEDIA TRICKLING FILTERS
EFFECT OF WETTING RATE
ON EVALUATION CONSTANTS
37
FIGURE 13
-------
100
80
HI
DC
O
8
HI
m
_i
o
3?
60
40
REDWOOD MEDIA-21 ft = D
A PLASTIC MEDIA-21 ft a D
NOTE: *DENOTES DATA WITH 1:1 RECYCLE
(2GPM/SQ FT) ALL OTHER DATA HAS NO
RECYCLE (1 GPM/SQ FT)
20
.20 40 60 80 100 120 140
160
180
BOD LOADING, ( lb/day/1,000 cu ft)
REDWOOD & PLASTIC MEDIA
TRICKLING FILTERS
SOLUBLE BOD REMOVAL EFFICIENCY
38
FIGURE 14
-------
O>
Q
O
m
UJ
m
3
UJ
D
_l
U.
li.
UJ
30 i
20
15
10
INFLUENT SOLUBLE BOD, mg/l
150 1!
BIO-SURF PROCESS DESIGN CRITERIA
DOMESTIC WASTEWATER TREATMENT
Wastewater Temperature = 13°C
4Stage Operation
50
40
30
20
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
HYDRAULIC LOADING, gpd/sq ft
ROTATING BIOLOGICAL MEDIA
MANUFACTURER'S DESIGN APPROACH
FIGURE 15
39
-------
review of data from existing installations is helpful to assess the effects
of varying specific surface areas.
One manufacturer's (Autotrol) design approach is based on soluble
BOD in the influent and effluent. Much of the existing data indicates
the effluent BOD from the RBM final clarifier will be 50 percent soluble
and 50 percent suspended material. This is consistent with the limited
data from other attached growth systems. However, the influent soluble
BOD portion is highly variable. For example, the following results have
been reported for primary effluent at various locations.
Plant Percent Soluble BOD
Pewaukee, Wisconsin 66
Seattle, Washington 31-50 (41 average)
Tucson, Arizona 50-75 (67 average)
The use of soluble influent BOD as a critical design parameter, if
applicable, will be unwieldy because of the general lack of data for this
parameter and the variability even at a single plant location.
To provide a more consistent design approach with other attached
growth systems and to enable realistic data evaluation, equation (5) has
been applied to the RBM systems. It is impractical to attempt to evaluate
the manufacturer's design approach unless data are generated for soluble
influent BOD .
The data which are available are evaluated and summarized on Table 5.
These data are from discs and lattice type RBM systems and represent full
scale and pilot plant installations. Individual data have been shown to
indicate the range of calculated K values.
The conclusions which may tentatively be made from the available RBM
data are:
1. The Pewaukee pilot plant data and full scale data, as well as
the Gladstone pilot plant data and full scale data may be correlated
reasonably well by use of equation (5).
2. The K value evaluated for discs and lattice media do not
indicate that higher unit specific surface area is a factor in BOD
removal.
3. For BOD removal, a design value for K of 0.30 appears
appropriate.
Field data from other RBM installations are limited and are presented
below:
40
-------
TABLE 5
ROTATING BIOLOGICAL MEDIA
PERFORMANCE DATA
Plant
Pewaukee,
Wisconsin
(10)
Media
5.75 ft diam
disk
Volume
(cu ft)
197
Pewaukee,
Wisconsin
(11)
10 ft diam disk 10,450
Edgewater/12)12 ft diam
6,110
New Jersey
lattice
Q
(gpm)
8.06
6.90
3.40
3.38
1.50
1.77
0.83
0,83
4.95
8.50
15.30
133
132
199
202
242
157
184
195
302
239
242
275
340
388
432
419
409
393
405
329
223
273
BODin
(mg/1)
205
183
175
192
111
170
112
134
104
139
128
150
148
129
100
100
110
110
108
158
90
109
166
177
132
89
113
133*
92*
154
171
208
164
BODout
(mg/1)
37
34
22
30
17
19
12
10
22
30
44
24
16
27
22
18
14
14
21
23
18
23
42
49
27
20
31
34
22
32
39
75
43
*Estimated temperature correction
**System biological growth predominated by Beggiota.
Km
"lw^i
0.35
0.31
0.27
0.24
0.16
0.21
0.15
0.17
0.25
0.32
0.30
0.21
0.25
0.22
0.21
0.26
0.25
0.27
0.22
0.33
0.24
0.24
0.29
0.30
0.40
0.40
0.35
0.35
0.36
0.40
0.34
0.19
0.28
T
(F)
54
50
42
42
44
39
45
40
55
58
61
47
45
46
49
55
61
65
66
65
61
56
72
65
58
54
52
54
58
65
72
76
78
^2O
f*\j
0.36
0.36
0.39
0.34
0.21
0.33
0.20
0.26
0.25
0.32
0.30
0.26
0.33
0.28
0.24
0.26
0.25
0.27
0.22
0.33
0.24
0.24
0.29
0.30
0.40
0.42
0.37
0.37
0.36
0.40
0.34
**
**
0.30(AVE)
0.27(AVE)
0.36(AVE)
-------
Plant
Media
Gladstone, 4 ft diam
Michigan
disks
(14)
Gladstone, ' 12 ft diam
Volume
(cu ft)
196
16,300
Michigan
lattice
TABLE 5
(continued)
_2_
(gpm)
10.4
6.9
3.5
5.2
508
543
608
539
BODin
(mg/1)
100
85
62
111
117
99
105
102
BODout
(mg/1)
32
13
9
21
24
17
19
20
Kp
0.26
0.35
0.26
0.27
0.28
0.32
0.33
0.30
T
(F)
56
56
62
50
52
58
62
65
0.26
0.35
0.26
0.31
0.30
0.32
0.33
0.30
0.30(AVE)
0.3KAVE)
to
-------
Plant
Design Current Volume Media BOD BOD BOD
Location Flow Flow of Media Description Raw Primary Final T
(mgd) (mgd) (cu ft) (lattice) (mg/1) (mg/1) (mg/1)
Woodland,
Washington 0.45 0.15 2,413 12 ft diam 270 175* 28 0.38
Kirksville,
Missouri 5.0 1.30 63,100 12 ft diam 252 164* 15 0.29
Georgetown,
Kentucky 3.0 1.10 25,240 12 ft diam 230 150* 21 0.34
*Estimated; BOD is not measured on primary effluent.
These data generally confirm the conclusions reached concerning BOD
removal relationships for the RBM system.
There are many European manufacturers of rotating biological media
systems (primarily discs) . The design relationships presented by Schuler/
Stengelin have been evaluated in terms of equation (5) and an average
K value of 0.30 was obtained.
Temperature
The temperature effects on effluent quality and system design require-
ments for attached growth systems are usually critical for cold weather
conditions. For a year-around effluent quality criteria, the cold weather
conditions will determine the size of the attached growth reactor because
the lower biological reaction rate. An extensive evaluation of data which
assesses temperature effects was made by Caller/ Gotaas. In their formulae,
temperature affects on effluent quality may be stated:
= 20 '
L620 T
Where : T = temperature , celcius
Le = effluent BOD mg/1 at temperature T
Le = effluent BOD mg/1 at temperature 20C
For example: To obtain an effluent BOD at 30 mg/1 at a temperature
of IOC, the effluent BOD at 20C would need to be 27 mg/1.
Eckenfelder states the effect of temperature as:
-(T-20)
E = E X 9 Where: 9 = 1.035 to 1.040
(21)
In a presentation of actual data, Benzie, et al provided a basis
to evaluate 9.
43
-------
Of the 17 plants reported, 6 plants had a value for 0 exceeding that
predicted by Galler/Gotaas (1.011). Of these 6 plants, 5 plants employed
recirculation, whereas, of the eleven plants having a calculated 9 value
below 1.01, only two plants employeed a 1:1 recirculation.
A comparison of plants employing recirculation from different sources
by Gulp indicates that the location of the source of recirculation
effects the results. The calculated 9 value are as follows:
Warm Weather Cold Weather
T-C E T-C E 9
Direct Filter Recirculation 18.3° 60.5 10.4 56.2 1.009
Recirculation from Final Effluent 18.6 51.4 9.4 38.6 1.032
The conclusions which may be derived from these data support the
conclusions reached by Williamson/McCarty that diffusion of the organic
through the bulk liquid and biofilm are limiting rather than biological
reaction rates under specific circumstances. Where high recirculation
rates are employed, or final effluent is recirculated, a larger tempera-
ture effect relationship is likely applicable where1 9 may be as much as
1.035. This may be caused by the cooling tower effect.
The temperature effect in plastic media 'biofilters has been calcu-
lated from plastic media manufacturer's literature on a common basis and
a 9 value of 1.018 appears to have been used widely.
RBM data evaluated in this report are shown on Figure 16 and indicate
temperature has no measurable effect above 13C. Below 13C, the relation-
ship shown on Figure 16 would be appropriate.
Nitrification
The conventional design of an attached growth biological system for
nitrification has also been based on experience and empirical relationships.
The EPA, Technology Transfer Process Design Manual for Nitrogen Control
reports that in rock media trickling filters, the organic load must be
limited to 10-12 pounds per day per 1,000 cubic feet to obtain efficient
nitrification.
(22)
From the same reference data were collected from the literature
relating nitrification efficiency to organic loading (lb/day/1,000 cu ft).
The relationship shown is reprinted as Figure 17.
The reported data from second stage trickling filters shows mixed
results which defy confident prediction of results from one plant to the
next. Data which have been reported are shown below.
Second Stage Filter Nitrification Efficiency
Location BOD Load Effluent NH -N NH -N Removal
(lb/day/1,000 cu ft) (mg/1) (mg/1) (%)
Johannesburg, SA 3.4 4.4 20.8 83
4.3 9.1 12.9 59
6.3 8.3 15.6 65
Northhampton, E 3.7 11.2 . 21.8 66
44
-------
O PEWAUKEE FULL SCALE
PEWAUKEE PILOT PLANT
EDGEWATER FULL SCALE
A GLADSTONE PILOT PLANT
GLADSTONE FULL SCALE
0.5
0.4
0.3 '
0.2
SUPERIMPOSED TEMPERATURE
CORRECTION RELATIONSHIP
AFTER ANTONIE (18)
0.1
10
'T-
IS
20
25
TEMPERATURE,C
ROTATING BIOLOGICAL MEDIA
TEMPERATURE EFFECTS
45
FIGURE 16
-------
100
80
c
0)
o
u
z
UJ
o
IL
li.
UJ
u
il
E
60
40
20
NO RECIRCULATION
RECIRCULATION
1 kg/m3/day 62.4 Ib Bobg/1,000 cu ft/day
10
20
30
40
50
60
BOD5 LOAD, lb/1,000 cu ft/day
EFFECT OF ORGANIC LOAD ON
NITRIFICATION EFFICIENCY OF
ROCK MEDIA TRICKLING FILTERS
46
FIGURE'17
-------
Organic nitrogen removals in rock media trickling filters are also
unpredictable. The organic nitrogen in biological waste treatment plant
effluents typically consists of 1-3 mg/1 of soluble refractory organic
nitrogen. Also, about 10 percent of the effluent suspended solids are
organic nitrogen. Raw waste organic nitrogen sources may cause an addi-
tional effluent organic nitrogen in attached growth processes. To attain
an organic nitrogen concentration of less than 3 mg/1, effluent filtration
is probably required.
Plastic media trickling filters have been proposed for nitrification.
Duddles, et al reported on a second stage plastic media trickling
filter with a loading rate of 0.5 gpm/sq ft treated waste flow. The
typical influent BOD was reported to be 20 mg/1. It can be calculated
that the BOD loading was 11 lb/1,000 cubic feet per day for the 0.5 gpm/
square foot loading. Ammonia removals of 90 percent were achieved. Tem-
perature effects at the,§e loadings were not influential as shown on Figure
18. Stenquist, et al reported that a single combined carbonaceous/
nitrification trickling filter at 14 lb/1,000 cubic feet per day, attained
average effluent ammonia concentrations of 1 mg/1 at a pilot plant in
Stockton. Raw waste flow application rates were 0.15 to 0.20 gpm/sq ft.
Temperatures were always in excess of 20C during the pilot work. Both
plants used a 21.5 feet deep medium. Current reports of the full scale
Stockton plant indicate that at 14 pounds of BOD /I,000 cubic feet, effluent
ammonia concentrations are 4-5 mg/1.
The above studies show effluent organic nitrogen concentrations to
be 0.9-2.7 mg/1 and 7.2-12.7 . Filtered effluents from these
studies.showed the soluble effluent organic nitrogen to be 0.8-2.0
mg/1 and 2.1-3.0 mg/1 . The Stockton plant receives canning wastes
containing higher than normal organic nitrogen concentrations; therefore,
it is likely that this organic nitrogen data are not typical.
It appears that to attain 90 percent, plus, nitrification efficiency,
BOD loadings must be maintained below 10 pounds per 1,000 cu ft in a
single stage plastic media trickling filter, or below 10 pounds per 1,000
cu ft and 0.5 gpm/sq ft in a second stage plastic media trickling filter.
At these low loading rates, temperatures above IOC do not appear to
influence the degree of nitrification.
Rotating biological media systems have also been proposed for nitri-
fication. The Gladstone, Michigan plant data indicate that flow applica-
tion rates of 1.0 to 2.0 gpd/sq ft and BOD loadings of from 24-76 pounds/
1,000 cubic feet resulted in ammonia removals of from 0-96 percent with an
average of 66 percent. Temperatures varied from 8C to 20C. Effluent pH
varied from 6.5-7.4 and is influenced by alum feed of about 60 mg/1 as well
as the nitrification effect.
/ O£- \
Pilot plant studies were conducted at Belmont, Indiana using the
RBM unit as a nitrification unit preceded by a carbonaceous waste treatment
process. With BOD loadings of 5-14 lb/day/1,000 cubic feet and hydraulic
loadings of 1.8-3.0 gpd/sq ft ammonia removals ranged from 60-94 percent.
47
-------
90
80
in
cc
u
o
u
n
70
60
SUMMER
WASTE TEMPERATURE
(~18.3*C)
WINTER
WASTE TEMPERATURE
(y 6.6*C)
0.5
1.0
RAW INFLUENT HYDRAULIC APPLICATION RATE, gpm/sq ft
PLASTIC MEDIA TRICKLING FILTER
LOADING - TEMPERATURE - PERFORMANCE RELATIONSHIP
OF A NITRIFYING TRICKLING FILTER (22)
48
FIGURE 18
-------
Date
3/23-3/27
3/28-4/30
5/1-5/13
5/17-5/26
5/27-6/17
T
14. 3C
16.4
19.1
20.0
21.8
V/Q
(cu ft/gpm)
17.5
15.1
23.9
25.2
15.6
g-gpd/
sq ft BOD
2.6
3.0
1.9
1.8
2.9
in-mg/1
8
17
18
16
18
NH -N in
mg/1
11
14
12
8
12
NH -N out
mg/1
1.4
5.7
1.9
0.5
1.9
At Saline, Michigan, pilot plant studies of disc type RBM have been
conducted to determine nitrification capabilities. These data are shown
on Figure 19. Also shown are the Belmont data. From these data, the
hydraulic loading must be below 35 cu ft/gpm or 24,300 cu,ft/million
gallons to obtain 90 percent nitrification. This corresponds to a unit
hydraulic loading of about 2.0 gpd/sq ft of effective surface area for
lattice type RBM media and about 3.0 gpd/sq ft of effective surface area
for disc type RBM media. The data from the disc media used at Saline,
Michigan, and the lattice media used at Gladstone, Michigan and Belmont,
Indiana indicate that unit surface area has a little effect on the nitri-
fication results. It appears that hydraulic loads, even with low influent
BOD concentrations influence the nitrification efficiency. Sufficient
data to assess the temperature effects are available only from Gladstone.
Figure 20 presents the relationship developed by Antonie to fit the data
available from Gladstone . The Saline data indicate that at lower
loadings than those experienced at Gladstone, temperature has less effect
on nitrification efficiency.
Solids Production
Field data for solids production are always subject to errors in
sampling, measurement and system storage complications. Solids production
is an important design consideration for all wastewater treatment schemes.
The wastewater applied to the attached growth biological system will be
composed of biodegradable organics which will be in the solid and soluble
form and non-biodegradable volatile and nonvolatile solids. The portion
of influent settled sewage non-biodegradable solids were presented pre-
viously and for the typical waste represent about 0.38 Ib/lb BOD .
The theoretical range of solids production from organic synthesis
is from 0.15-0.75 pound per pound of BOD . The "normal" value of bio-
logical cell production is about 0.3 pound per pound BOD . Therefore, a
typical total solids production (including solids lost in the effluent)
would be 0.68 pound per pound BOD . If the effluent solids were 30 mg/1,
the waste solids production would be about 0.45 pound per pound BOD for
a typical domestic waste.
Data are shown in the following tabulation for sludge production from
attached growth plants. The variability of the sludge production figures
are typical. However, note that three of the total solids production
values are near the typical solids production value. The waste sludge
production values are calculated based on reported solids production and
the solids leaving the system.
49
-------
z
o
o
IE
IT
I-
100
90
80
70
60
50
GLADSTONE
Ul
o
ct
in
a.
40
30
20
10
10
TEMPERATURE RANGE= 52-70*F
= 20-50 mg/l (except Gladstone)
20 30
40
50
60
FLOW, gpm/1,000 cu ft
70
80
RBM PROCESS
NITRIFICATION - HYDRAULIC LOAD RELATIONSHIP
50
FIGURE 19
-------
z
o
\±
DC
UJ
U
UJ
0.
100 i
90 H
80 4
70 J
60 -I
SO
40
30
20
10
B005 LOADING
HYDRAULIC LOADING
= 35-60 ppd/1,000 cu ft
-46 ppd/1,000 cu ft ave.
= 1.5 gpd/sq ft effective
surface area
s 30 cu ft/gpm
10
15
TEMPERATURE - C
20
RBM PROCESS
NITRIFICATION - TEMPERATURE RELATIONSHIP
51
FIGURE 20
-------
Process
Rock Media
Rock Media
RBM
ABF
ABF
Location
Total Waste
Solids Production Sludge Production
(Ib solids/lb (Ib solids/lb
BOD Applied
Dallas, Tx.
North Plant 0.42
Dallas, Tx.
South Plant 0.65
Pewaukee, Wise. 0.62
Corvallis, Ore. 0.67*
Rochester, Minn. 0.47*
BOD Applied
0.22
0.33
0.43
0.39
0.39
Effluent
Solids
(mg/1)
40
43
30
34
17
*Estimated from volatile solids data.
For nitrification, solids production values are very low. The theore-
tical solids production is 15 percent of the dry weight of ammonia nitrogen
nitrified. For example, a waste having an influent ammonia nitrogen con-
centration of 20 mg/1 will produce 3 mg/1 of solids. This is a small
quantity and is lost in the significance of the carbonaceous solids
production values.
PROCESS PERFORMANCE
The characteristic capability and reliability of various processes
is an important consideration in meeting effluent criteria. Not only is
the average effluent quality important, the extremes must be considered
to assure meeting the criteria imposed on most all plants. This section
will review reported data for the various processes discussed.
Extended Aeration and Conventional Activated Sludge
The activated sludge process has the capability of converting essen-
tially all influent soluble organic matter to solids, it is necessary to
efficiently remove the solids in order to attain high quality effluents
in terms of organics. Unfortunately, plain sedimentation of flocculant
solids is not easily predicted. When dealing with large input solids
quantities, density currents, and thickening considerations, careful
operational consideration of solids balances is necessary to attain good
effluent quality consistently.
The data from activated sludge processes reflect the problems in
attaining consistently good effluent quality. The Deeds and Data section
of the JWPCF reports data from 20 plants during the period from 1960 to
1965. Plant BOD loadings ranging from 18 to 74 pounds BOD /I,000 cubic
feet resulted in average effluent BOD values of 3 to 86 mg/1 with 8 of
the 20 plants reporting average BOD values of less than 20 mg/1.
52
-------
Data are shown/on Figure 21. Data has been selected to exemplify
representative experience and potential process capability. The data
in each case represent daily' data for an entire year. The plants selected
experience a range of loadings. Also, shown on Figure 21 are typical data
for oxidation ditch plants which will be discussed later. The conclusions
which may be made from these data are:
1. Two plants shown have significant industrial waste flows.
The High Point, North Carolina Eastside plant receives textile dye
wastes and the Grand Island, Nebraska plant received slaughter-house
wastes. Both plants perform as well as the domestic waste plants.
2. The loadings on the plants range from 20 to 80 pounds of BOD
per 1,000 cubic feet of aeration capacity. The performance of the plants
are not related to unit organic loading to the aeration basin.
3. The Grand Island plant data are presented for the best one
year of data (1968) and the worst one year of data (1965) from the same
plant. A long period of operator training by the consulting engineer and
continual data monitoring on this plant is part of .the reason for the
excellent improvement in effluent quality. :
4. Whereas all of the plants shown are considered to have good
operational control, and design, the Grand Island plant, for one year,
produced an effluent BOD significantly better than 10 mg/1, 70 percent
of the time. Four of the plants produced an effluent better than 35 mg/1,
90 percent of the time. This level of treatment is a fair representation
of current activated sludge process capability and reliability under
typical conditions.
Many extended aeration plants do not practice good sludge inventory
and wasting management and periodic discharges of high solids concentra-
tions are experienced. Extended aeration plants typically will "burp"
the solids upon.high flows to the plant. The results of a plant study
by Morris, et al are shown on Table 6 which emphasize poor solids
management.
The potential for the activated sludge process is better exemplified
by the Grand Island plant producing a quality better than 5 mg/1, 50
percent of the time and 20 mg/1, 90 percent of the time.
Biological nitrification of ammonia to nitrate is a well established
phenomenon and several bench scale processes and demonstration processes
have shown virtually complete conversion is possible if sufficient oxygen
transfer is available. Several activated sludge plants having excess
oxygen transfer capability do nitrify; however, until the past few years,
few plants routinely monitored effluent ammonia.
A source of good data suitable for probability analysis on activated
sludge nitrification is available from the Dallas demonstration pilot
plant.- The plant was a constant flow (150 gpm) plant receiving trickling
filter-effluent having an average BOD of 60 mg/1. The aeration basin was
loaded at 20 pounds/1,000 cubic feet and had an average hydraulic detention
53
-------
AUSTIN. TEXAS
PLAN T D
PLUG FLOW
20-25 IbAI.OOOcu. ft
GRAND ISLAND, NEBRASKA
CMAS PLANT 80 lb/1.000 cu. ft. -
AUSTIN. TEXAS
PLANTS A, B. C
DALLAS. TEXAS
CMAS 40 lb/1.000 cu. ft;
WORST OXIDATION
DITCH PLANT *
OXIDATION DITCH
PLANTS - AVERAGE
HIGH POINT. NC
EASTSIDE '
GRAND ISLAND, NEBRASKA
CMAS 80 lb/1,000 cu. ft.
CONTACT STABILIZATION
40-50 lb/1,000 cu. ft:^
^BEST OXIDATION
HIGH POINT, NC
WESTSIDE
DITCH PLANT
2 5 10 20 30 40 50 60 70 60 90
PERCENT OF TIME VALUE WAS LESS THAN
* OXIDATION DITCH PLANT DATA BASED ON 17 PLANTS.
98 99
ACTIVATED SLUDGE
EFFLUENT QUALITY
54
FIGURE 21
-------
TABLE 6
EXTENDED AERATION PERFORMA^gE
(Reference: Morris, et. al)
Date
Aug. '61
8
9
10
11
12
13
14
Dec. '61
12
13
14
15
16
17
18
Mar. '62
6
7
8
9
10
11
12
May '62
14
15
16
17
18
19
20
Flow,
qpd
20,400
18,400
18,000
18,900
22,800
26,600
21, .200
27,800
23,900
24,000
22,300
47,300
36,200
42 , 800
32,000
39,900
59 , 100
71,500
46,800
58,100
45,300
28,000.
23,900
21,300
22,000
22,400
23,600
22,300
MLSS,
mg/1
6,580
5,480
6,000
5,910
6,090
.6,440
6,380
6,580
7,240
6,260
6,220
6,600
6,480
4,640
4,440
5,360
5,340
5,180
5,180:
5,380
8,000
7,860
8,320
7,980
7,900
8,220
7,960
Effluent
BOD,
mg/1
10
9
9
10
6
8
11
14
10
8
8
>71
24
34
21
100
34
210
34
43
50
26
27
28
34
27
18
19
Effluent
Suspended
Solids ,
mg/1
17
30
20
12
12
14
14
15
69
20
1500
20
190
29
180
45
490
32
110
58
15
12
16
25
21
14
12
Effluent
NH3-N,
mg/1
0.48
0.46
0.42
0.48
0.62
0.44
0.44
0.54
0.42
0.54
0.48
3.00
1.06
0.54
1.06
2.72
1.30
1.74
2.04
1.16
2.48
7,06
6.70
5.96
6.00
3.20
2.50
2.70
55
-------
time of 4 hours. Sludge retention time (SRT) varied from 7 to 20 days.
. : The activated sludge effluent BOD and ammonia nitrogen are shown on
Fjigure 22.
The effluent BOD median value was less than 20 mg/1 and 50 percent
of the time a zero ammonia nitrogen value was obtained. Seventy percent
of the time an effluent ammonia value of less than 2 mg/1 was obtained.
Poorer results were obtained when SRT's in excess of 15 days occurred.
Clarifier solids buildup associated with attempting to thicken sludge
in the clarifier resulted in denitrification and poorer quality. The
pilot plant was monitored continually and the operators were highly
skilled individuals who reacted quickly to ill effects.
The data for this study show that the activated sludge process may
produce an effluent quality of 2 mg/1 NH -N seventy percent of the time.
Oxidation Ditch
The oxidation ditch extended aeration process has enjoyed consistently
good results insofar as reliability and performance are concerned. Table
7 shows results of performance from several plants. Data is presented on
Figure 21 representing a recent survey of operating data from 17 plants.
The results show consistently low average effluent values, with peak
values which are typical of other activated sludge plants, but lower than
the poorly managed extended aeration or conventional activated sludge
plants. The one Texas plant, on Table 7, shows peak effluent BOD and TSS
values indicating the need for good solids management, which if not
practiced, will result in poorer effluent quality.
Trickling Filters
Selected trickling filter plant effluent data are presented in Figure
23 to indicate process reliability. Process capability has been presented
in detail in earlier sections of this presentation. A guideline summary
is presented in Figure 24 relating approximate effluent quality to organic
loading. The data on Figure 23 indicate that the effluent quality varia-
tion is probably no more than the influent quality variation.
Rotating Biological Media
Rotating biological media, as a secondary treatment alternative, is
relatively new and only a few plants have been in operation for more than
one year.
Very few full scale data are available.
Recently, the data from the Gladstone, Michigan plant have become
available affording a detailed analysis of the RBM process capability
at one plant. Return frequency data for the Gladstone plant are shown
on Figure 25.
56
-------
TABLE 7
OXIDATION DITCH PERFORMANCE
Period
of
Ave. Effluent
Quality-mg/1
Peak Effluent
Values-mg/1
Glenwood, Minn.
Somerset, Ohio
W. Liberty, Ohio
Lucasville, Ohio
Sugar Creek, Ohio
Brookston, Ind.
Clayton Co., Ga.
Paris, Texas
Record
months
2
9
12
12
2
1
12
18
(mgd)
0.34
0.10
0.20
0.20
0.8
0.20
0.44
3.90
BOD
7
7
2
3
12
7
5
17
TSS NH3
13 8.2
15 0.1
2
8
8
6
10
14
Org N BOD5
2.3 18
19
3*
7*
14
12
15
60
TSS NH?
34 19
35 0.7
6*
10*
9
20
40
60
*Peak Month
57
-------
<
O
U.
U.
UJ
50
45
40
35
30
25
20
15
10
BOD-
NH3-N
2 5 10 20 30 40 50 60 70 80 90 95 98 B9
PERCENT OF TIME EQUAL TO OR LESS THAN
ACTIVATED SLUDGE EFFLUENT
QUALITY, DALLAS, TEXAS
NITRIFICATION PILOT PLANT
FIGURE 22
58
-------
80
70
^ 60
01
in
Q
Z
Ul
D
U.
U.
Ul
50
40
30
20
10
0 '
2 5
AVERAGE LOAD
500/1,000 CUBIC FEET
X
AVERAGE LOAD
- 200/1,000 CUBIC FEET
10 20 30 40 50 60 70 BO 90 95 98 99
PERCENT OF TIME VALUE WAS LESS THAN
TRICKLING FILTER
EFFLUENT QUALITY
TWO TEXAS PLANTS
FIGURE 23
59
-------
130
120
110 '
100 '
90 '
I
in
O
§
Z
111
3
UL
U.
UJ
80
70
60
50
40
30
20-
10-
10 20 30 40 50 60 70 80 90 100
pounds per 1,000 cu ft/day
EFFLUENT QUALITY
TRICKLING FILTERS
FIGURE 24
60
-------
U 2.0
UJ
1.0
u. >
1L
U.
UJ
50
40
o>
3 30
o
3 20
U.
U.
HI
10
SUSPENDED SOLIDS
BOD.
10 20 30 40 50 60 70 80 90 95 98 99
PERCENT OF TIME VALUE WAS LESS THAN
RBM EFFLUENT QUALITY
GLADSTONE,MICHIGAN
FIGURE 25
61
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The Gladstone, Michigan plant is a 1 mgd plant and consists of pri-
mary sedimentation, RBM's designed for 1.94 gpd/sq ft of effective surface
area, chemical addition, and final sedimentation. The plant started in
March of 1974 and reached stable operation by June of 1974. The manufac-
turer's literature would predict the following effluent quality based on
the operating data when chemicals were not added.
I
Predicted Removal Predicted Effl. Quality
BOD in Q BOD NH -N ' BOD NH -N
Month mg/1 gpd/sq ft % % mg/l mg/1
June, 1974 99 1.5 97.5 99 7(17)*
July, 1974 105 1.7 92 97 8(19) 0.6(<1.0)
Aug., 1974 102 1.5 92.5 99 8(12) 0.2(<1.0)
(*) Actual values
The actual results are shown in parenthesis. For the three months
of operation when chemicals were not added, the effluent BOD averaged 16,
whereas a BOD of 8 mg/1 would be predicted by the manufacturer's
literature.
The conclusions which may be reached based on the Gladstone, Michigan
data are as follows:
At low unit flow rates (1.0-2.0 gpd/sq ft) effluent BOD
values from the RBM, will be comparable to activated sludge
processes.
Ammonia nitrogen concentrations in the Gladstone, Michigan
effluent exceeded 2 mg/1 consistently; however, good nitri-
fication was experienced during the warmer summer months.
A review of effluent data fro various biological waste treatment pro-
cesses indicates that capability to achieve year around effluent BOD and
NH -N criteria for well designed and operated plants may generally be
assigned as follows. Specific plants designed for unusual temperature
and/or industrial wastes may be assessed differently.
Effluent BOD or
Suspended Solids Ammonia N*-mg/l
50% of 90% of
Time Time 50% of Time
Conventional Activated Sludge 20 40 1
Extended Aeration 10 30 1
Oxidation Ditch 10 30 1
Trickling Filter 30 40 3
RBM 20 40 3
' *If system is designed -for nitrification
62
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ESTIMATING PROJECT COSTS AND OPERATING & MAINTENANCE REQUIREMENTS
The key area of alternative comparison is equitable cost comparisons.
In the facility planning stage of a project, the cost estimation is
necessarily based on generally defined facility components.. To make
comparisons of costs of several alternatives, it is impractical to make
detailed lists of material and equipment components for each alternative;
therefore, the use of general cost estimating guides for the process
functional units are relied upon.
This section presents procedures which may be used to develop con-
struction costs and operating and maintenance requirements of the
alternative processes previously described. Estimates are presented for
construction costs as a function of appropriate capacity parameters for
the major plant components. The total initial investment, which includes
engineering, fiscal, administrative and land costs are not shown but may
be developed on the basis of these relationships.
To make planning cost estimates for a project, several techniques
are used. For conventional facilities, or often used unit processes,
the results of previously developed detailed cost estimates may be
extrapolated to the project at hand. Extrapolation of costs requires
consideration of different unit size, local variations in labor and
material costs, differences in site requirements, inflation, and added
or reduced ancillary systems. Although each consideration may be quanti-
fied, considerable judgement on the part of the estimator is required
offering potential error in the estimate.
Where extensive cost data are not available, other techniques must
be employed. Alternative procedures include a thorough takeoff of a
specific component and relating the cost of the facility to the component
by a factor. A procedure commonly used in chemical industry is to add
the costs of all major purchased equipment and multiply an appropriate
experience factor times the equipment purchase cost to determine the
overall facility cost; typically used factors range from 2.0 to 3.0,
depending on the equipment intensity. For example, experienced ratios
of equipment purchase cost to installed facility cost for vacuum filters
range from 2.2 to 2.7 based upon detailed estimates of cost of several
projects. Again this method is subject to considerable judgement and
may afford opportunity for significant error.
The most frequently used approach to estimate costs for facilities
which do not have significant historical cost background is to:
a. Define the facilities by dimensions, construction material,
equipment piping and valve requirements. A general plan of the facility
is drawn defining walls, overall dimensions, and structural requirements.
b. Estimate quantities of major cost components: Rules of thumb
are applied to derive quantities, e.g., concrete walls - 8 inch minimum,
or 1 inch per foot of height. Concrete footings - two thirds the quan-
tity of wall concrete.
63
-------
c. Estimate costs of major cost components including: concrete,
equipment, piping and valves, excavation, housing.
d. Add 10 to 20 percent of .sum of cost for miscellaneous minor
cost components, which are not detected in the major cost items.
i
The use of any method of cost estimating requires careful considera-
tion of inflation. This has been especially true for the last 5 years
since inflation of construction costs have averaged about 9 percent per
year. The rapid change in costs effects both the use of previous cost
estimates to predict project costs and the planning for project cost
which may be 6 months to one year away from time the planning estimate
is prepared.
Many planners and engineers are accustomed to using cost indices
which track costs of specific items and proportion these costs in a pre-
determined mixture. Unfortunately, there is all too much evidence that
these time honored cost indices are not understood by the user, and/or
are inadequate for many specific applications.
The basis for all cost indices used in the construction industry
is to monitor the costs of specific construction material and labor
costs, proportion these costs by a predetermined factor and thereby
derive an index. The most frequently used indices are probably the
Engineering News Record's (ENR) Construction Cost Index and Building
Cost Index.
The ENR indices were started in 1921 and intended for general con-
struction cost monitoring. The large amount of labor included in the
construction cost index was appropriate prior to World War II; however,
on most all contemporary construction, the labor component is far in
excess of current labor usage. In fact, there should be little, if
any, application of the construction cost index to water utility plant
projects. This index does not include mechanical equipment, pipes and
valves, which are normally associated with water utility plant construc-
ton, and the proportional mix of materials and labor are not specific
to water utility construction.
To provide a more specific index the Environmental Protection Agency
developed a Sewage Treatment Cost Index. This index was based on the cost
components of a hypothetical 1 mgd trickling filter plant. The quantities
of labor, materials, construction equipment and contractor's overhead and
profit remain constant and the unit prices and price changes as derived
from the U.S. Bureau of Labor Statistics and Engineering News Record are
applied to the constant quantities to derive the index. Because this
index was specific to a single process and because more activated sludge
plants are being constructed currently, the EPA has developed a new index
based on the components of a hypothetical 5 mgd activated sludge plant
and 50 mgd activated sludge plant followed by chemical clarification and
filtration.
Obviously, the more specific an index is, the more accurately it
64
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will track cost change. The variation in inflation of various cost com-
ponents cannot be monitored by a single component index. If an index
is based on an improper mixture of several single component indices, it
also will fail. It is necessary for the planner to recognize the short-
comings of cost inflation and use judgement and the best data at hand in
deriving budget comparative estimates.
The cost estimating techniques used for the various unit processes
involved in this study are varied. Where historical cost data are avail-
able, these have been used. Where little or no historical cost data are
available, costs are developed by identifying costs of major components
and adding experience factors for miscellaneous unaccounted for features.
The basis of estimating each functional unit is described in the follow-
ing paragraphs. The cost relationships are shown graphically in Appendix
A. The costs presented include electrical work associated with the unit
function and a 15 percent contingency.
Raw Wastewater Pumping (Figure A-l)
Raw wastewater pumping stations are often incorporated into other
structures at small community wastewater treatment plants. When in-
appropriate to incorporate the pumping station into other structures at
the plant site, the use of package pumping stations is common. The
construction costs for the raw wastewater pumping station reflect con-
struction costs of both prefabricated and custom designed pumping stations
with a separate concrete wetwell and the use of manually cleaned basket
screens for pump protection.
Preliminary Treatment (Figure A-2)
Preliminary treatment includes screening, grit removal and flow
measurement. The provisions for screening are based on comminutors
for flows less than 0.5 mgd, and mechanically cleaned screens without
shredders for flows in excess of 0.5 mgd. A manually cleaned screen in
a bypass channel is provided. Grit removal is based on an aerated grit
basin with grit pumping to a grit washer. Flow measurement is based
upon a Parshall flume.
The design basis for these facilities is peak flow rate.
Sedimentation Basins (Figure A-3)
Costs for construction of plain sedimentation basins with sludge
collection equipment have been presented in earlier cost studies by
Black & Veatch . These cost estimates were made on the basis of
plants larger than 1 mgd. For plants smaller than 1 mgd, estimates of
quantities have been prepared during this study for selected sedimenta-
tion basin sizes. To provide updating of the previous information, the
cost data from the Black & Veatch study were used as well as quantity
takeoff information from several selected sedimentation basin sizes.
The cost data are presented as a function of the surface area
65
-------
provided, as was.done in the earlier study. Costs are based on the use
of two basins. The basin depth will affect the cost of the 'sedimentation
basin; albeit, minor variations will not exceed the accuracy of the esti-
mate. The cost data presented have been based on a basin having 15 feet
side water depth and a 1.5 feet freeboard. Cost components are presented
on this basis of steel launders and weirs. The costs for basin surface
areas in excess of 1,500 sq ft are applicable to sedimentation basins
using circular sludge collection equipment in circular basins. Cost
data for basins less than 1,500 sq ft in surface area are "applicable to
straight line sludge collection equipment in rectangular basins.
Waste Sludge Pumping Stations (Figure A-4)
Waste sludge pumping equipment is selected based on the sludge con-
centration to be pumped and the operation intended. Sludge'pumping units
which operate continuously may be centrifugal pumps, so long as one avoids
high solids concentrations and large suction head losses. Normally better
control is established using intermittent sludge pumping and use of posi-
tive displacement pumps.
Positive displacement pumping units are more expensive than equal
capacity centrifugal pumping units.
The cost data presented in the earlier study by Black & Veatch were
based on positive displacement pumping units. This study updates those
costs. A practical limitation is imposed as to the minimum size of pump-
ing unit and sludge piping which can be used. This limitation is reflected
in the cost estimate by 10 gpm.
The station is based on an underground structure which houses pumping
units and piping, constructed adjacent to and having common walls with the
solids separation unit process. A superstructure is included to access the
station from the ground level and to house electrical control equipment.
< (
Prefabricated Extended Aeration Plants (Including Aeration) (Figure A-5)
; ' I
Prefabricated extended aeration plants are typically used for ex-
tremely small flows. Estimates for capacities from 10,000 to 90,000 gpd
were made. Costs are presented for shop fabricated units. At some point
the economics shift in favor of field fabricated units and the designer
should investigate this for each application. Air requirements are based
on 2,100 cubic feet per pound of BOD removed (2 Ibs BOD/1,000 gallons).
Aeratdon using positive displacement blowers with 100 percent standby are
provided. Prefabricated extended aeration plants include a sedimentation
zone, return sludge pumping, waste sludge storage, and chlorine contact
basin, but not chlorine feed equipment. The prefabricated plant is esti-
mated on the basis of an above ground unit installed on a concrete pad.
Freight costs are included at $15 per cwt. A contingency allowance of
15 percent was added to the manufacturer's estimate of the equipment
and erection costs. In addition, percentagesvof equipment costs were
used for electrical (15 percent) and contractor's overhead and profit
(25 percent).
66
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Prefabricated "Contact Stabilization" Plants (Including Aeration)
(Figure A-5)
Construction costs have been developed for prefabricated contact
stabilization plants although the,specific design approach has not been
presented. The prefabricated plant for contact stabilization is more
closely akin to conventional activated sludge and is normally used with-
out primary sedimentation. Single stage systems are not normally
adaptable to situations requiring nitrification for the same reasons
explained for typical conventional activated sludge systems.
The prefabricated contact stabilization plant normally has a 3
hour contact zone and a reaeration zone. Although the flow path is iden-
tical to the true contact stabilization process, the contact zone is about
6 times larger. True contact stabilization relies on adsorption/absorp-
tion of organics in the contact zone with little or no real stabilization.
A reaeration zone is provided to condition the return activated sludge to
provide a suitable SRT. The prefabricated plant provides relatively short
term stabilization in the contact zone and further stabilization in the
stabilization zone.
Prefabricated contact stabilization plants are normally provided
with return sludge and waste sludge pumping, aerobic digestion of waste
activated sludge and a chlorine contact basin. The estimated prices shown
include blowers.and blower housing.
Custom Designed Extended Aeration Basins (Figure A-6)
For plants larger than 100,000 pd, the use of prefabricated con-
struction becomes marginally economical. The use of either concrete
structures, steel basins, or concrete lined, earthen basins becomes
more desireable. The construction costs estimates presented for custom
designed aeration basins are based on construction with structural con-
crete and concrete lined earthen basins. Provisions are included for
walkways, supports, and handrails for the structural concrete basin.
The estimated costs reflect a square or circular geometry associated with
a completely mixed aeration basin in contrast to the long narrow basins
sometimes associated with plug flow.
Oxidation Ditch Aeration Basins (Figure A-7)
Oxidation ditch aeration basins have been estimated using vertical
structural walls and sloped concrete side walls. The costs for these
alternative construction systems are very close. The construction cost
estimates are shown for either construction system. Aeration equipment
is not included in the oxidation ditch basin costs.
Mechanical Aeration Equipment (Figure A-8)
Aeration equipment estimated construction costs include purchase
cost as quoted by manufacturers, installation, manufacturer's installa-
tion check, and contractor's overhead and profit. Costs are based on
67
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fixed platform mounted surface aerators and paddle wheel type aerators.
Diffused Aeration Equipment (Figure A-9)
Diffused aeration equipment is based on the use of centrifugal
blowers, wherein two blowers are provided, one serving as a standby.
The blowers having inlet filter silencers are housed in a superstructure.
Air piping and sparger type diffusers are included.
Recirculation Pumping Stations (Figure A-10)
Recirculation pumping stations include the facilities for return
activated sludge pumping stations and similar uncomplicated pumping sta-
tions. The basis of the cost estimates shown are of the type of station
employing vertical diffusion vane pumping units with attendent valves,
piping and control facilities. The pump is suspended in the wetwell
and motors and motor control centers are housed in a superstructure.
The cost data base for recycle pumping stations is limited because these
facilities are normally constructed as part of other facilities.
The Black & Veatch report, "Estimating Costs and Manpower Require-
ments for Conventional Wastewater Treatment Facilities", presents cost
relationships for recycle pumping stations. The few data for recent
recycle pumping station costs have been reviewed in relationship to the
earlier Black & Veatch cost data. The recent cost data indicate the
influences on costs have approximately doubled the cost of recycle pump-
ing stations. These influences include inflation, OSHA regulations, and
EPA regulations on reliability which have been instituted since the
earlier B & V work.
Trickling Filters (Figure A-ll)
Costs for trickling filters were estimated on the basis of rock at
$12/cubic yard, redwood media at $2.75/cubic foot, and plastic media at
$2.75/cubic foot of media. Rock media trickling filters are based upon
a filter depth of 6 to 8 feet and plastic and redwood media filters are
based on a depth of 21 feet. Rotating distribution equipment costs were
obtained from manufacturers. The cost curves include the facilities
within the confines of the biocell foundation and do not include piping
to and from other functional units.
Rotating Biological Disks (Figure A-12)
Cost development procedures and unit costs for rotating biological
disks have been derived from Autotrol and from limited quantity take-off
information provided from recent construction projects.
The manufacturer's estimating cost for 100,000 sq ft (effective
area) have been used plus the estimated time associated with installation
and tankage as provided by the manufacturer.
Sludge Treatment (Figures A-13 and A-14)
Estimated costs for sludge treatment facilities are presented for
68
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anaerobic digestion and sludge drying beds. Aerobic digestion costs,
where applicable, may be derived from the construction cost estimates
for aeration basins and aeration equipment. The aerobic digester costs
derived would represent continuous flow designs, or designs which incor-
porate decanting provisions but may not represent batch operated systems.
Construction costs for anaerobic digestion have been derived, in
part, from the costs presented by Black & Veatch . The costs have
been updated by using limited number of costs experienced for recently
bid construction projects and inflating the cost relationship based on
these more recent costs. Anaerobic digesters represent two stage diges-
tion volume and include provisions for heating to 95F and mixing of the
primary digester and include an unheated, unmixed secondary digester of
equal size as the primary digester.
Sludge drying beds are based on jobs constructed during the past
year (1976) and estimates of intermediate sized installations. The
estimated costs include influent distribution piping and valves and
perforated underdrains.
Disinfection (Figures A-15 S A-16)
Feed Equipment S Storage. The most prevalent form of disinfection
is chlorine gas. The equipment and storage facilities requirements are
well known and commercial equipment is readily available. Construction
costs for chlorine feed equipment have been presented previously
The previous work cites the difficulty in isolating costs for the chlorine
feed and storage facilities. Most often, the chlorine feed and storage
facilities are combined with other sturctures, making analysis difficult.
Ton cylinders are shown; however, for less than 1,000 pounds per day feed
rate, 150 pound cylinders were used as a basis of storage requirements.
Several quantity take-offs of similar chlorine feed and storage
facilities were reviewed. Of seven installations, the installed chlor-
ination system facility was estimated to cost from 2.5 to 3.5 times the
purchase price of the chlorinators. The average estimated installed cost
of the seven installations was 3.0 times the quoted purchase price of the
chlorinators above.
The total installed cost includes distribution panels, cylinder
chocks, installation, manufacturer's preparation of shop drawings, in-
stallation check and startup, and contractor's overhead and profit.
Chlorinator costs include one standby chlorinator.
Miscellaneous piping varies significantly depending on the layout.
Piping costs will vary from 5 to 10 percent of the installed chlorina-
tion equipment cost.
Hoist equipment will be essentially constant for electrically
operated, monorail trolley hoists. For large storage areas having long
rails and extensive duct-o-bar electrical systems, the costs will
approach 30,000 dollars for a 30 cylinder storage system or 1,000 dollars
69
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per cylinder. Manually operated hoists systems are less expensive (about
half) but require more labor for loading and unloading. For the purposes
of this analysis, hoisting equipment is estimated at 0.50 dollars per
pound of cylinder storage capacity.
Chlorine Contact Tanks. Contemporary chlorine contact tanks are
constructed to provide a serpentine flow path to enable maximum use of
the chlorine fed. The construction costs of these structures are much
more than single or double pass basins constructed in the past. The
costs for the multi-pass contact tanks are presented in this report to
reflect current practice. The cost estimates presented are based on 2
basins, and structural concrete construction.
OPERATION & MAINTENANCE REQUIREMENTS
Operation and maintenance requirements include:
Administration
Labor
Power Costs
Chemical Costs
Miscellaneous Supply Costs
For small plants the segregation of these total operation and
maintenance costs into the above categories is difficult. Small com-
munities often do not have detailed budgets and in many cases do not
maintain records of the total cost of wastewater treatment. Many large
utilities have extended their recordkeeping to the costs associated for
the above categories by each unit process. Therefore, there are available
data to reasonably predict operation and maintenance requirements for
larger plants, but any attempt to accurately predict operation and main-
tenance requirements for small plants is subject to potentially large
errors.
The information presented in this section is based on distributing
experienced requirements for small community plants on the basis of pub-
lished information for operation and maintenance requirements from in-
dividual process units for larger plants.
The labor requirements are presented on the basis of manhours re-
quired. Miscellaneous supply costs are presented on the basis of annual
cost.
Labor requirements represent both operation and maintenance labor.
Most of the plants are not operated full time, and the plants are un-
attended at night and on weekends. In these instances, it is necessary
to provide alarm monitoring to a continuously manned site, such as the
police dispatcher.
Power and chemical requirements are not shown since these may be
70
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readily calculated from the system connected and operating equipment and
on typical chemical dosage rates. Appropriate unit costs may be applied
to values determined.
Miscellaneous supply costs are variable and difficult to assign
to individual unit functions. These costs have been assigned in pro-
portion to the distribution found at larger utilities where more detailed
records are maintained.
Requirements for site work and laboratory work are a function of
plant site size and number of analysis made, respectively, and are pre-
sented as such in the following operating and maintenance requirement
relationships.
The numbers of samples and laboratory analyses presumed to be per-
formed are outlined below. The unit time required for each analysis and
sample are obtained from information derived from the laboratory director
of Metropolitan Denver Sewer District No. 1 and from information presen-
ted in EPA's Handbook for Analytical Quality Control in Water and Waste-
water Laboratories"
PARAMETER UNIT TIME* (Hours)
BOD 0.24
TSS 0.36
COD 0. 36
TKN 0. 36
NO-NO 0.18
NH^ 0.18
PO^ 0.18
Dissolved Oxygen 0.12
pH 0.07
Conductivity 0.07
Turbidity 0.10
Alkalinity 0.18
Color 0.12
Automatic Sample Obtained 0.24
Manual Sample Obtained 0.60
Coliform 0.40
Cl Residual 0.20
*Based on 10 percent nonproductive time plus 5 percent standardization
and reagent preparation time plus 5 percent reporting time.
The laboratory and sampling requirements for various numbers of
samples and assuming one sample per sampling point per day of operation
are summarized below based on automatic samplers and the following
analysis per sample:
BOD, TSS, NH , pH, Coliform, Cl Residual
71
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LABORATORY MANHOURS REQUIRED PER YEAR
No. of Days Analyses are Performed Per Year
40 60 80 100 200
130
260
387
520
650
194
387
580
774
970
260
520
774
1040
1300
324
648
970
1300
1630
648
1296
1940
2600
3240
Number of Sampling
Points
2
4
6
8
10
The. cost for laboratory supplies presented in the Black & Veatch
study were about 0.70 to 3.00 dollars per manhour required in the
laboratory per year. The larger plants required greater supply costs
than the smaller plants. The supply costs for small community plants
will likely be in the range of 1.00 dollar per manhour.
Yard Maintenance. If the land upon which the facilities are
located are landscaped and grassed, the labor and supplies associated
with maintenance and care of the yard may be a significant budget item.
The requirements for the care of the yardwork is dependent upon climate,
types of plantings and area of site. Therefore, the requirements for
yard maintenance are basically independent of the flow capacity of the
plant. Guidelines are presented in the Dodge Guide which relate
yard maintenance to area and these are repeated here to arrive at a
basis for estimating yard maintenance.
Mowing
Fertilization
Crabgrass Control
Average
Frequency/
Year
30
2
1/3
Area of Plantsite
50,000 sq ft
100,000 sq ft
150,000 sq ft
250,000 sq ft
500,000 sq ft
1,000,000 sq ft
Labor
(Hours /Year
1,000 sq ft)
0.5
0.1
0.05
0.65
Maintenance/
Labor (Hours)
Materials
(Dollars/Year
1,000 sq ft)
0.50
3.0
1.50
5
Equip-
ment*
(Dollars)
160
5
165
32,
65,
97,
162,
325,
650,
Material & Equipment
Costs (Dollars)
415
665
915
1415
2665
5165
^Amortized over 5 years at 8 percent and independent of area.
Comparison of Alternative Processes
The primary purpose of this evaluation is to show examples of the
use of the cost data and to generally determine the relative economics
of alternative processes most likely to be used for small community
wastewater treatment. For secondary levels of treatment, the costs of
72 .
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the following competitive processes were evaluated.
Capacity, mgd Process
0.01, 0.1 Prefabricated extended aeration plants
0.1, 0.5, 2.0 Custom built extended aeration plants,
conventional activated sludge, trick-
ling filters, rotating biological media
systems and prefabricated contact
stabilization plants.
The applicability of individual processes for specific design flows
is not fixed nor representated to imply typical applicability. These
examples are merely presented to guide the reader through examples of
the use of information in this presentation.
The design conditions for the processes are as follows:
Raw Wastewater;
Suspended Solids 200 mg/1
Volatile Content 75 percent
BOD . 200 mg/1
NH -N 30 mg/1
Temperature 20C
Peaking Factor (dry weather) 1.5
Peaking Factor (wet weather) 4.0
Effluent Quality Case I Case II
BOD 25 25
TSS 25 25
NH -N - 3
The secondary process design bases were developed as shown on
Table 8. The schematic process diagrams and unit processes are shown
on Figures 26 through 33. The examples shown may superficially appear
to represent conservative aeration capacities for the plant sizes shown.
The peaking capacity required for small plants and the author's opinion
that aeration capacity should be provided for peak hour conditions is
reflected in these values.
The Case II (nitrification requirement) requires increasing the
biological treatment capabilities of all processes except the extended
aeration alternatives. Detention and oxygen supply have been included
in the extended aeration alternatives (Case I) to assure adequate
dissolved oxygen concentrations at normal operating conditions. The
modifications which are required to Tables 9-15 to provide for nitri-
fication are as follows: (Go to page 93)
73
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TABLE 8
EXAMPLE PROCESS DESIGN BASIS SUMMARY
Activated Sludge
Unit Process
Primary Sedimentation
Average .Overflow Rate (gpd/sq ft)
Suspended Growth Biological Treatment
Detention (Hours)
SRT (Days)
Waste Sludge (#/#BOD)
Oxygen Supply (#/#BOD)
Trickling Filter Design
K Value
Recirculation Rate (°-R/Q. )
Final Sedimentation
Average Overflow Rate (gpd/sq.ft)
Chlorination
Contact Detention Time @
Peak Flow (Hours)
Dosage Rate @ Peak Flow (mg/1)
Dosage Rate @ Average (mg/1)
Aerobic Digestion
Detention Time, days
Sludge Concentration, percent
Anaerobic Digestion
Primary Detention Time, days
Secondary Detention Time, days
Sludge Drying Beds
Anaerobically Digested
sq ft/lb/day dry solids
Aerobically Digested
sq ft/lb/day dry solids
Extended
Aeration
24
20
0.6
2.0
600
0.5
10
3
Conventional
800
0.6
1.0
20
600
0.5
10
3
15
2
15
15
10
20
Attached Growth Systems
Rock Plastic Rot. Biological
Media Media Media
800
0.5
0.2
1.0
600
0.5
10
3
15
15
10
800
0.5
0.2
2.0
600
0.5
10
3
15
15
10
800
0.5
0.3
0
600
0.5
10
3
15
15
10
-------
PUMPING
STATION
RAW
WASTE
RAW
WASTE
DERATED
GRIT
CHAMBER
1
/SEDIMENTATION
( ZONE
FLOW
MEASUREMENT
AERATION | ^
ZONE 1
/ 1 ^
^CHLORINE CONTACT
V ZONE
' m TO RECEIVING
WATER
(SCREENINGS I GRIT TO
TO LANDFILLl LANDFILL
STORAGE.
ZONE-^
EXTENDED AERATION
PACKAGE PLANT
SLUDGE DRYING :
BEDS
i DRY SLUDGE
( STOCKPILE
FIGURE 26 - PROCESS SCHEMATIC - EXTENDED AERATION
PROCESS (0.01 to 0.1 mgd )
For cases requiring nitrification or not requiring
nitrification
PUMPING
STATION
AERATED
GRIT
CHAMBER
TO
RECEIVING'
WATER
'SCREENINGS ' GRIT TO
| TO LANDFILL f LANDFILL
PACKAGE CONTACT
STABILIZATION
PLANT
r
, DR
t s
1
t
1
Y SLUDGE
FOCKPILE
SLUDGE DRYING
BEDS
FIGURE 27 - PROCESS SCHEMATIC - PREFABRICATED
CONTACT STABILIZATION PLANTS (0.1 to 1.0 mgd)
For cases not requiring nitrification
75
-------
PUMPING /V REAERATION \
STATION FLOW / /\ ZONE \
MFAMfRP- ' ~ / NX "s. x
RAW/^Y AERATED J^T AERAT|ON / ^oJ^EDIMENVm
W ) * GRIT _»J><3_T* BAS|N ^] | J^J^TATION U
WASTE X^ / CHAMBER ^ * P _i ZONE^Z
1 \ ^i*1^ ^>»^^ ^-XJ^*\
1 V \
I | 1 Jf \ AEROBIC DIGESTER1
SCREENINGS 1 GRIT TO RETURN <;i nnrc V ZONE
\ TO LANDFILL 1 TO LANDFILL RETURN SLUDGE \^__ ^
PACKAGE CONTACT
STABILIZATION PLANT
^ \
.ORINEJ TO
vlTACTJ ^ RECEIVING
ONE / WATER
\ /
}
SLUDGE DRYING
BEDS
.4 DRY SLUDGE STOCKPILE
FIGURE 28-PROCESS SCHEMATIC - PREFABRICATED CONTACT
STABILIZATION PLANT (0.1 to 1.0 mgd)
For cases requiring nitrification
^ETiJRJLsjLUB£L
PUMPING V. "T ' T ' X1
STATION p. ..... \ I 1 / 1
rUL/Tf \ 1 IX ^f* *^^^
.MEASURE- \| 1 / / \
RAW /^ >. AEKATED MENr |fc ^ /SEDIMEN-\
^^^^^ ^^_^.^te PR IT ^^^kTrir^iH^to ^MM^^W T ft Tinr.i H^^^
WACTClV / "HAMRFP f -» «-r-^ \ D . r,.,
j i Xl i\ ^T^
CHLORINE
CONTACT
BASIN
TO
* ; * KbCEIVING
,..,,,, WAIfcR
SCREENINGS 1 GRIT 1
T TO LANDFILL ! TO LANDFILL AERATION BASIN WASTE SLUDGE
\
\ SLUD
| BEDS
1 .-., J ,
GE DRYING
1
'DRY SLUDGE
T STOCKPILE
FIGURE 29 - PROCESS SCHEMATIC - CUSTOM DESIGNED
EXTENDED AERATION PLANTS (0.1 to 2.0 mgd)
For cases requiring nitrification or not requiring
nitrification ......
76
-------
RETURN SLUDGE
PUMPING
STATION
AERATED
GRIT
CHAMBER
SCREENINGS
TO LANDFILL
FLOW
MEASURE-
MENT
-*CX}
GRIT TO
LANDFILL
CHLORINE
CONTACT
RECEIVING
WATER
SLUDGE DRYING
BEDS
DRY SLUDGE STOCKPILE
FIGURE 30 - PROCESS SCHEMATIC - OXIDATION DITCH
EXTENDED AERATION PLANT (0.1 to 2JO mgd)
For cases requiring nitrification or not requiring
nitrification
PUMPING
STATION
FLOW
MEASURE
CHLORINE
CONTACT
RECEIVING
STREAM
SCREENINGS
TO LANDFILL
J
f
SLUDGE DRYING
BEDS
-------
PUMPING
STATION
FLOW
MEASURE
MENT
TRICKLING
FILTER
CHLORINE
CONTACT
SCREENINGS
TO LANDFILL
1
1 GRIT TO
4 LANDFILL
L ^__
FIGURE 32 - PROCESS SCHEMATIC - STATIONARY
MEDIA TRICKLING FILTERS (0.1 to 2.0 mgd)
For cases requiring nitrification or not requiring
nitrification
nprANT
DECANT
DRY SLUDGE
STOCKPILE
(SLUDGE
'DRYING
BED<.
PUMPING
STATION
FLOW
MEASURE
MENT
CHLORINE
CONTACT
RAW
1 SCREENINGS
TO LANDFILL
RECEIVING
WATER
DECANT ^_
SLUDGE DRYING
BEDS
f DRY SLUDGE STOCKPILE
FIGURE 33 - PROCESS SCHEMATIC - ROTATING BIOLOGICAL
MEDIA SYSTEM (0.1 to 2.0 mgd)
For cases requiring nitrification or not requiring
nitrification
18
-------
TABLE 9
PREFABRICATED EXTENDED AERATION PLANT
Plant Design Capacity - MGD
Unit Process/Function
Raw Sewage Pumping Station
Chlorine Contact
Chlorination
Drying Beds
Site Area
Lab Analysis
Unit
.on mgd
capacity
cu ft
volume
ppd
capacity
ppd
feed ave.
(sq ft)
acres
sampling points
days per year
0.01
0.04
120
10
1
400
0.5
2
40
0.05
0.20
560
25
1
1000
0.7
2
40
0.10
0.40
1200
50
3
2000
1.0
2
80
79
-------
TABLE 10
PREFABRICATED CONTACT STABILIZATION PLANTS
Plant Design Capacity - MGD
Unit Process/Function
Raw Sewage Pumping Station
Preliminary Treatment
Chlorination
Drying Beds
Site Area
Lab Analysis
Unit
mgd
capacity
mgd
capacity
ppd
capacity
ppd
feed ave.
(sq ft)
acres
sampling points
days per year
0.10
0.40
0.40
50
3
2000
1.0
2
80
0.5
2.0
2.0
250
15
10,000
2.0
2
80
1.0
4.0
4.0
500
30
20,000
3.0
2
120
80
-------
TABLE 11
CONVENTIONAL ACTIVATED SLUDGE
Unit Process/Function
Raw Sewage Pumping Sta.
Preliminary Treatment
Primary Sedimentation
Sludge Pumping
Aeration Basin
Unit
mgd
capacity
mgd
capacity
sq ft
area
gpm
capacity
cu ft
volume
Aeration Basin CFM AIR
Aeration Basin
(Alternative)
HP
aerators
Secondary Sedimentation sq ft
area
Sludge Pumping
Recirculation Pumping
Chlorine Contact
Chlorination
Aerobic Digester
gpm
capacity
mgd
capacity
cu ft
volume
ppd
capacity
ppd
feed ave.
cu ft
volume
CFM AIR
(Alternative) HP
Anaerobic Digester
(Primary) cu ft
(Secondary) cu ft
Drying Beds
aerators
volume
volume
sq ft
Site Area acres
Lab Analysis sampling points
day
s per year
Plant
0.10
0.40
0.40
170
10
3000
180
10
170
15
0.05
1200
50
3
800
20
1
400
400
1800
1.0
3
80
Design
0.50
2.0
2.0
850
15
Capacity
1.0
4.0
4.0
1700
25
16,700 33,300
900
30
850
25
0.25
5600
250
15
4000
90
5
2000
2000
9000
2.5
3
80
1800
60
1700
50
0.5
11,000
500
25
8000
180
10
4000
4000
18,000
4.0
3
120
- MGD
2.0
8.0
8.0
3400
50
66,700
3600
120
3400
100
1.0
22,000
1000
50
16,000
360
20
8000
8000
36,000
6.0
3
200
81
-------
TABLE 12
CUSTOM BUILT EXTENDED AERATION
Unit Process/Function
Raw Sewage Pumping Sta.
Preliminary Treatment
Aeration Basin
Aeration Basin
Aeration Basin
(Alternative)
Secondary Sedimentation
Sludge Pumping
Recirculation Pumping
Chlorine Contact
Chlorination
Drying Beds
Site Area
Lab Analysis
Unit
mgd
capacity
mgd
capacity
cu ft
volume
CFM AIR
HP
aerators
sq ft
area
gpm
capacity
mgd
capacity
cu ft
volume
ppd
capacity
ppd
feed ave.
sq ft
acres
ing points
per year
Plant
0.10
0.40
0.40
13,300
600
20
170
10
0.05
1200
50
3
2000
1.0
2
80
Design
0.50
2.0
2.0
66,700
3000
100
850
30
0.25
5600
250
15
Capacity
1.0
4.0
4.0
133,300
5700
200
1700
60
0.5
11,100
500
25
10,000 20,000
2.5
2
80
4.0
2
120
- MGD
2.0
8.0
8.0
266,700
11,400
400
3400
120
1.0
22,200
1000
50
40,000
6.0
2
200
82
-------
TABLE 13"
EXTENDED AERATION,OXIDATION DITCH "PLANT
Plant Design Capacity, - MGD
Unit Process/Function
Raw Sewage Pumping Sta.
Preliminary Treatment
Aeration Basin
Aeration Basin
Secondary Sedimentation
Sludge Pumping
Recirculation Pumping
Chlorine Contact
Chlorination
Drying Beds
Site Area
Lab Analysis
Unit
mgd
capacity
mgd
capacity
cu ft
volume
HP
aerators
sq ft
area
gpm
capacity
mgd
capacity
cu ft
volume
ppd
capacity
ppd
feed ave.
sq ft
acres
sampling points
days per year
0.10
0.40
0.40
13,300
20
170
10
0.05
1200
50
3
2000
1.0
2
80
0.50
2.0
2.0
66,700
100
850
30
0.25
5600
250
15
10,000
2.5
2
80
1.0
4.0
4.0
133,300
200
1700
60
0.50
11,100
500
25
20,000
4.0
2
120
2.0
8.0
8.0
266,700
400
3400
120
1.0
22,200
1000
50
40,000
6.0
2
200
83
-------
TABLE 14
ROCK MEDIA TRICKLING FILTERS
Unit Process/Function
Raw Sewage Pimping Sta.
Preliminary Treatment
Primary Sedimentation
Sludge Pumping
Secondary Sedimentation
Sludge Pumping
Recirculation Pumping
Trickling Filter
Chlorine Contact
Chlorination
Anaerobic Digester
(Primary)
(Secondary)
Drying Beds
Site Area Rock Media
Plastic Media
Lab Analysis
Plant Design Capacity
Unit
mgd
capacity
mgd
capacity
sq ft
area
gpm
capacity
sq ft
area
gpm
capacity
mgd
capacity
cu ft
volume
cu ft
volume
ppd
capacity
ppd
feed ave.
cu ft
volume
cu ft
volume
sq ft
acres
acres
'ling points
s per year
0.10
0.40
0.40
170
10
170
10
0.10
7150
1200
50
3
700
700
1400 .
1.5
1.0
3
80
0.50
2.0
2.0
850
15
850
25
0.50
35,750
5600
250
15
3400
3400
7000
3
2.5
3
80
1.0
4.0
4.0
1700
25
1700
50
1.0
71,500
11,100
500
25
6700
6700
14,000
5
4
3
120
- MGD
.-2.0
8.0
8.0
3400
50
3400
100
2.0
143,000
22,200
1000
50
13,400
13,400
28,000
7
6
3
200
84
-------
TABLE 15
ROTATING BIOLOGICAL MEDIA
Unit Process/Function
Unit
Plant Design Capacity - MGD
0.10 0.50 . 1.0 2.0
Raw Sewage Pumping Sta
Preliminary Treatment
Primary Sedimentation
Sludge Pumping
mgd
capacity
mgd
capacity
sq ft
area
gpm
capacity
Secondary Sedimentation sq ft
Sludge Pumping
RBM System
Chlorine Contact
Chlorination
Anaerobic Digester
(Primary)
(Secondary)
Drying Beds
Site Area
Lab Analysis
area
gpm
capacity
cu ft
volume
cu ft
volume
PPd
capacity
ppd
feed ave.
cu ft
volume
cu ft
volume
sq ft
acres
sampling points
days per year
0.40
0.40
170
10
170
10
3700
1200
50
3
700
700
1400
1.5
3
80
2.0
2.0
850
15
850
30
18,000
5600
250
15
3400
3400
7000
3
3
80
4.0
4.0
1700
35
1700
60
32,000
11,000
500
25
6700
6700
14,000
5
3
120
"8.0
8.0
3400
50
3400
120
74,000
22,200
1000
50
13,400
13,400
28,000
7
3
200
85
-------
CHANGES TO CASE I CONDITIONS FOR NITRIFICATION
PLANT DESIGN CAPACITY - MGD
ALTERNATIVE
Prefabricated Extended Aeration
Prefabricated Contact Stabilization
Add: Preceding Aeration Basin
(cu ft)
Surface Aerators (hp)
Recycle Pumping
Station mgd
Conventional Activated Sludge
Increase: Aeration Basin Size
to (cu ft)
Aeration Capacity
to (CFM)
or (HP)
Custom Built Extended Aeration
Oxidation Ditch .
Rock Media Trickling Filters,
Increase Media Volume To
Rotating Biological Media
Increase Media Volume To :
0.1
0.5
1.0
NO CHANGE
3,000 15,000 30,000
10 40 80
0.05 0.25
0.5
380
15
3,750
120
2.0
5,700 28,500 57,000 114,000
7,500
240
1,900
60
NO CHANGE
NO CHANGE
11,300 56,500 113,000 226,000
7,400 37,000 74,000 148,000
Other factors, besides economics, which affect the selection of
alternative processes include the ease, of operation, process reliability,
process and mechanical reliability and the effect of sludge treatment
process alternatives on the overall process. Table 16 presents general
advantages and disadvantages of the alternative secondary treatment processes
which may or may not be reflected in the economic analysis.
Construction 'Costs and .operating and maintenance requirements were
developed from the relationships shown in Appendix A. In addition to
the construction costs for the unit processes for which the cost curves
include electrical work and contingencies, costs are provided for the
following:
Site Improvements
Engineering, Legal, Administrative
Interest During Construction
15 percent of subtotal of
unit process costs
25 percent of construction costs
5 percent of subtotal of
projections
86
-------
TABLE 16
PROCESS ADVANTAGES AND DISADVANTAGES OF BIOLOGICAL
TREATMENT ALTERNATIVES FOR SMALL COMMUNITY APPLICATIONS
Prefabricated Extended
Aeration Plants:
Prefabricated Contact
Stabilization Plants:
Custom Designed
Extended Aeration Using
Low Speed Surface
Aerators:
Advantages
1. Stable process when
proper sludge
management is
performed.
2. Standardized design
and components
readily available.
3. Package design per-
mits relocation, if
necessary, for grow-
ing metro areas.
4. High quality
effluent.
5. Predictable process.
Disadvantages
1. Small air lift
pumps clog often,
at specific plants.
2. Requires good
operator skills
and routine monitoring
to assure continuing
high quality effluents.
3. Sufficient oxygen
supply should be
provided for nitri-
fication and pH may
need to be controlled.
1. Two basins of active 1.
sludge provide
opportunity for
fast recovery after 2.
upsets caused by
hydraulic peak
loads or toxic
loads.
2. Standardized design
and components
readily available.
3. Can be re-erected
at other sites,
with difficulty for
growing metro areas.
4. High quality effluent.
5. Predictable process.
1. Stable process when 1.
proper sludge manage-
ment is performed.
2. High quality effluent 2.
3. Many types of al-
ternative aeration
devices may be 3.
considered.
4. Predictable process.
Small air lift pumps
clog often, at
specific plants.
Requires good
operator skills and
routing monitoring.
Icing in cold weather
climates must be
considered.
Major maintenance
requires crane to
remove equipment.
Drive units afford
higher mechanical
maintenance.
Requires good opera-
tor skills and routine
monitoring.
Sufficient oxygen
supply should be
provided for nitrifi-
cation and pH may need
to be controlled.
87
-------
TABLE 16
(continued)
Oxidation Ditches:
Conventional Activated
Sludge:
Trickling Filter:
Advantages
1. Stable process
when proper sludge
management is
performed.
2. High quality
effluent.
3. Predictable process,
1. High quality
effluent.
2. Predictable
process.
3. Many types of
aeration devices
may be considered.
1. Stable process.
2. Operator skills
and monitoring
requirements less
than suspended
growth systems.
3. Energy requirements
less than suspended
growth systems.
Disadvantages
1. Icing of aerator
supports and nearby
area must be considered.
2. Major maintenance
requires crane to
remove equipment.
3. Drive units require
higher maintenance
frequency.
4. Requires good operator
skills and routine
monitoring.
5. Sufficient oxygen
supply should be pro-
vided for nitrification
and pH may need to be
controlled.
6. Only one type of
aeration device is
applicable.
1. Requires good operator
skills.
2. Requires frequent
monitoring.
3. Daily variation in
flows cause significant
shift in sludge
inventory.
4. Mechanical aeration
may cause spray and
mist problems.
5. More subprocesses
complicate overall plant.
1. Effluent quality is
not as predictable as
suspended growth
processes.
2. Filter flys, snails
are problem at some
locations.
3. High quality effluents
are difficult to
achieve.
4. More space required
than suspended growth
systems.
88
-------
TABLE 16
(continued)
Advantages Disadvantages
Rotating Biological Media 1. Stable process. 1. Effluent quality is
2. Good quality not as predictable as
effluent. suspended growth
3. Simple operation. process.
4. Low maintenance, 2. Heavy load on first
as a general rule. cell may cause odors.
3. Multiple drives at
larger plants affords
proportionally higher
maintenance requirements.
4. Shaft and drive failures
have been experienced
and require major
maintenance.
5. Oil leaks from drive
units are common.
6. Larger plants require
more space than equal
size suspended growth
systems.
89
-------
Inflation Allowance 8 percent of subtotal of project
costs
Land - Not included
Based on the unit process sizes, cost relationships, and operating
and maintenance requirements shown, the construction and operating costs
for Case I and Case II conditions are developed on Figures 34 and 35.
The project costs have been amortized at 6.5 percent interest and 25
years to develop a total annual cost which has been converted to a unit
cost on the basis of cost/1,000 gallons treated at the design flow con-
dition. The relationships comparing unit costs for the various processes
are shown on Figures 36 and 37. Labor has been charged at $9/hour, power
at $0.03/kwh, and chlorine at $250/ton.
A summary of capital costs and operating costs are tabulated in
Appendix B.
The cost comparison of the various alternatives as mentioned, are
not the "bottom line". When cost estimates for facility planning purposes
are within 10 percent, the accuracy of the estimate may not permit a clear
cut advantage. It may be necessary to eliminate costs of common functions
and reflect upon the costs of dissimilar functions.
For situations where dissimilar functions for alternative processes
are estimated to cause less than 10 percent difference in costs (during
the facility planning stage), the best answer might be more reasonably
chosen from considerations other than the cost analysis.
The cost value is not absolute. The methods used in arriving at the
costs are general. They are not intended for precision but are intended
to fairly and conservatively arrive at a project cost. The estimated costs
derived in the manner presented should not arbitrarily be reduced unless
detailed layout, quantity and unit price tabulation and more rigorous
analysis indicate reduction in cost is appropriate.
Operating and maintenance requirements for small community plants
developed in the example cost analysis, are typical but the unit costs
used for the labor ($9/hour) are not typical. For instance, in a recent
survey by the author's firm, principal labor costs (including fringe
benefits) were found to be $3.50-$5.00 per hour at small communities and
$8.00-$11.00 for larger communities. Because small community plants have
a higher proportionate cost associated with labor costs, the unit cost
used will heavily influence the total operation and maintenance costs.
The relationship of equivalent unit costs shown on Figures 36 and
37 emphasises that for small community wastewater treatment plants, less
complex and fewer unit processes provide a facility that is not only less
difficult to operate, they generally provide a higher reliability in
effluent quality and are more economical.
90
-------
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0.1
3 4
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1.0
3456 789
10
PLANT CAPACITY, mgd
CASE II - ESTIMATED COST COMPARISON
NITRIFICATION REQUIRED
FIGURE 35
92
-------
I
a
£
0)
c
o
o
o
100
9
8
7
6
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4
3
2
10
9
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0.1
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3456 789
10
PLANT CAPACITY, mgd
CASE I - ALTERNATIVE COMPARISON
NITRIFICATION NOT REQUIRED
FIGURE 36
93
-------
100
M
C
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0.1
8
7
6
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2
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9
8
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4
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456 789
10
PLANT CAPACITY, mgd
CASE II - ALTERNATIVE COMPARISON
NITRIFICATION REQUIRED
94
FIGURE 37
-------
APPENDIX A
CONSTRUCTION COST RELATIONSHIPS
OPERATING & MAINTENANCE REQUIREMENTS
-------
CONSTRUCTION COST, 1,000 dollors
_ 0 C
o «=» N oJ * w <» -Moxo0 ro CM * <* O>HO>
-------
12
a
o
o
o
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1,000
9
8
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6
5
4
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2
100
7
6
5
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3
2
10
i
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x
^
w 2 3 4 5678S
^
^
^
x^
X
X"
-X
x^
x
X
^
.0 2 3 4 56789,0
PEAK DESIGN FLOW RATE, mgd
ESTIMATED CONSTRUCTION COSTS
PRELIMINARY TREATMENT
(Screening, Grit removal & Flow measurement)
FIGURE A-2
-------
ESTIMATED CONSTRUCTION COST, 1,000 dollars
3 ° "'
ro w * w <» -4.0X0 ^ ro w . * uio>^ja><0'
....
^
^x
X
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s
^s~
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s
/
0.1
3 456789
1.0
SURFACE AREA, 1,000 sq ft
3 4 5 6 7 89
10
ESTIMATED CONSTRUCTION COST
SEDIMENTATION BASINS
FIGURE A-3
-------
^
w en ^j a>
ars
o
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8
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2 3 4 5 6789
10
2 3 4 5 6 789
100
FIRM PUMPING CAPACITY, gpm
ESTIMATED CONSTRUCTION COSTS
SLUDGE PUMPING STATIONS
FIGURE A-4
-------
M
k.
o
o
U
z
g
t-
u
O
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III
9
8
7
6
5
4
3
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100
9
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2
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0.01
3 4 5 67 89
0.1
3 4 5 6 789
1.0
PLANT CAPACITY, mgd
ESTIMATED CONSTRUCTION COSTS
PREFABRICATED ACTIVATED SLUDGE PLANTS
FIGURE A-S
-------
_o
~o
-a
o
o
o
O
U
U
ra
8
Q
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1,000
9
8
7
6
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4
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2
100
7
6
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3
2
10
STRUCTU
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X
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BAS
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0.1
345 6789
1.0
3 456789
10
VOLUME, mg
ESTIMATED CONSTUCTION COSTS
CUSTOM BUILT AERATION BASINS
FIGURE A-6
-------
1,000
_5
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o
o
o
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U
z
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u
8
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u .
9
8
7
6
5
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3
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7
6
5
4
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x
xx'
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f
SIDE
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0.1
3 4 5 6789
1.0
VOLUME, mg
3 4 56789
10
ESTIMATED CONSTRUCTION COSTS
OXIDATION DITCH AERATION BASINS
FIGURE A-7
-------
LOGO:
VI
a
O
U
O
8
UJ
<
wo
Ul
9
8
7
6
5
4
3
2
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7
6
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1
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x
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/
HORIZONTAL SHAFT AERATORS
2 3 456785
D
2 3 4 5 6 789
00 I,
INSTALLED HORSEPOWER, hp
ESTIMATED CONSTRUCTION COSTS
MECHANICAL AERATION
FIGURE A-8
-------
1,000
i2
^
S
o
8
«/>
8
O
a:
i/>
§
a
ui
<
S
ro CM
0.1
3 4 5 6789
1,0
3 4 5 6 789.
10
FIRM BLOWER CAPACITY, 1,000 cfm
ESTIMATED CONSTRUCTION COSTS
DIFFUSED AERATION
FIGURE A-9
-------
ESTIMATED CONSTRUCTION COSTS, 1,000 dollars
*
g !
o 01 * ui o> ^4co<0 ro a* * oicn^jcoto'
10
^
x^
^x
x^
^
s
s
S
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^~ '.
^
-
/
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,
'
0.1
3 4 5 67 89
1.0
FIRM CAPACITY, mgd
3 4 5 6 789
10
ESTIMATED CONSTRUCTION COSTS
RECIRCULATION PUMPING
FIGURE A-10
-------
ESTIMATED CONSTRUCTION COSTS, 1,000 dollars
i ' 't
« . 0 .... . C
0 INJ 01 * 01 0>-JOMO° W W * Ol O)-lt0C
-REDWOOI
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C
/
f
f /
/ /
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IA
10
3 4 5 67 89
100
3 4 5 6 789
1,000
VOLUME, 1,000 cu ft
ESTIMATED CONSTRUCTION COSTS
TRICKLING FILTERS
FIGURE A-11
-------
ESTIMATED CONSTRUCTION COSTS, 1,000 dollars
_, o
£ § 8
_. <=» N OJ * oi 0)^40X00 r\) OJ * O! 0)^40X0 <=>
/
/
y
/
/
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/
^
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jt
s
j
/
/
/
/
/
/
/
/
/
2 3456789 2 345678«
) 100 1
',000
MEDIA VOLUME, 1,000 cu ft
ESTIMATED CONSTRUCTION COSTS
ROTATING BIOLOGICAL MEDIA
FIGURE A-12
-------
"o
0
ars
o
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O
U
O
H
U
ID
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Z
O
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wt
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ro 01
<
a><0 °
ro c*J
1.0
3 4 5 6789
10
VOLUME, 1,000 cu ft
3 4 5 6 789
100
ESTIMATED CONSTRUCTION COSTS
ANAEROBIC DIGESTION
FIGURE A-13
-------
100
w 4
o
"o »
-o 3
0
o
O
9
£
H
i/>
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U
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L_ Q
u 8
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1-
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x
/
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/
/
/
/
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s
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3 456789
10
AREA, 1,000 sq ft
3 456789.
100
ESTIMATED CONSTRUCTION COSTS
SLUDGE DRYING BEDS
FIGURE A-14
-------
100
_0
~o
O
U
z
o
U
t/o
8
01
<
p
UJ
9
8
7
6
5
3
2
10
7
6
5
4
10
3 4 5 67 89
100
DESIGN FEED RATE, IBs per day
3 4 5 6 789
1,000
ESTIMATED CONSTRUCTION COSTS
CHLORINE FEED EQUIPMENT
FIGURE A-15
-------
i,ooo:
ars
o
a
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IS)
8
o
Q£
oo
8
a
1LI
K-
uo
HI
S
0
10
X
2 3 4 5 6789
10
2 3 4 5 6 7 89
100
VOLUME, 1,000 cuff
ESTIMATED CONSTRUCTION COSTS
CHLORINE CONTACT BASINS
FIGURE A-16
-------
1,000
9
8
7
6
5
S
>
O.
100
7
6
5
4
10
0.1
3 4 5 6789
1.0
FIRM PUMPING CAPACITY, mgd
3 4 5 6 789
10
LABOR
OPERATION & MAINTENANCE REQUIREMENTS
WASTEWATER PUMPING
FIGURE A-17
-------
10,000
9
8
7
6
5
M
o
o
-o
O
U
1,000
4
3
100
0.1
3 4 5 67 89
1.0
FIRM PUMPING CAPACITY, mgd
345 6 789
10
MISCELLANEOUS SUPPLY COSTS
OPERATION & MAINTENANCE REQUIREMENTS
WASTEWATER PUMPING
FIGURE A-18
-------
1,000
9
8
7.
6
5
4
3
2
"I
O
DC.
a.
_j
<
100
7
6
5
4
10
0.1
X
3 4 5 6789
1.0
3 4 5 6 7 89
10
AVERAGE PLANT FLOW RATE, mgd
LABOR
OPERATION & MAINTENANCE REQUIREMENTS
PRELIMINARY TREATMENT
FIGURE A-19
-------
10,000
9
8
7
6
5
4
3
£ 2
(/>
^
0
~o
-a
H 1,000
8 I
1 I
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4
3
2
100
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^
0.1
3 4 5 67 89 2
1.0
AVERAGE PLANT FLOW RATE, mgd
3 4 5 6 789
10
MISCELLANEOUS SUPPLY COSTS
OPERATION & MAINTENANCE REQUIREMENTS
PRELIMINARY TREATMENT
FIGURE A-20
-------
10,000
9
8
7
6
5
4
3
1 2
~i
_f
_j
>: 1,000
2 I
^ 7
i e
Z R
< 5
4
3
2
100
^
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^^
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^^
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X'
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X
X
X
0.1
2 3 4 5 6789
1.0
2 3 4 5 6 789
10
SURFACE AREA, sq ft
LABOR
OPERATION & MAINTENANCE REQUIREMENTS
SEDIMENTATION
FIGURE A-21
-------
v>
IH
o
o
-o
O
U
10,000
9
8
7
6
5
4
3
2
1,000
7
6
5
4
3
2
100
^
^
X
X
X
X
X
X
/
X
/
/
f
s
/
s
/
X
X
X
X1
/
/
0.1
2 3456789
1.0
3 456789
10
SURFACE AREA, 1,000 sq ft
MISCELLANEOUS SUPPLY COSTS
OPERATION & MAINTENANCE REQUIREMENTS
SEDIMENTATION
FIGURE A-22
-------
1,000
9
8
7
6
5
4
3
X.
t 2
_j
_j
o
oc.
>
°- 100
3 8
I 7
< 6
5
4
3
2
10
.*
^^
^
^
^
^+
^~
^
^
^
^
^
3 4 5 67 89
10
FIRM PUMPING CAPACITY, gpm
3 4 5 6 789
100
LABOR
OPERATION & MAINTENANCE REQUIREMENTS
SLUDGE PUMPING
FIGURE A-23
-------
10,000
9
8
7
6
5
S2
o
§
2
Z
7
6
»
4
3
100
X
345 6789
10
FIRM PUMPING CAPACITY, gpm
3 4 5 6 789
100
MISCELLANEOUS SUPPLY COSTS
OPERATION & MAINTENANCE REQUIREMENTS
SLUDGE PUMPING
FIGURE A-24
-------
10,000
9
8
7
6
5
E
%
S
3
Z
Z
1,000
CONTACT STABILIZATION
3 4 5 6789
3 4 5 6 789
PLANT CAPACITY, mgd
Note: Extended Aeration
Includes labor for sedimentation zone and aeration equipment.
Contact Stabilization
Includes labor for sedimentation basin, aeration equipment, aerobic
digester
LABOR
OPERATION & MAINTENANCE REQUIREMENTS
PREFABRICATED ACTIVATED SLUDGE PLANTS
FIGURE A-25
-------
M
a
O
U
9
8
7
6
5
4
3
2
1,000
7
6
5
4
3
2
TOO
^"~
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X
EX1
-X
x'
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^^
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Al
1C
^
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3 4 5 67 89
0.1
2 3 4 5 6 789
1.0
PLANT CAPACITY, mgd
MISCELLANEOUS SUPPLY COSTS
OPERATION & MAINTENANCE REQUIREMENTS
PREFABRICATED ACTIVATED SLUDGE PLANTS
FIGURE A-ze
-------
E
_f
O
Q£
10,000
9
8
7
6
5
1,000
7
6
5
4
100
10
3 4 5 6789
100
2 3 4 5 6 789
1,000
INSTALLED HORSEPOWER, hp
LABOR
OPERATION & MAINTENANCE REQUIREMENTS
CUSTOM BUILT AERATION BASINS USING
MECHANICAL AERATION
FIGURE A-27
-------
10,000
9
8
7
6
5
s
>-
a.
z
z
1,000
6
5
100
0.1
X
3 4 5 67 89
1.0
3 4 5 6 789
10
FIRM BLOWER CAPACITY , 1,000 cfm
LABOR
OPERATION & MAINTENANCE REQUIREMENTS
CUSTOM BUILT AERATION BASINS USING
DIFFUSED AERATION
FIGURE A-28
-------
V)
k_
o
o
-o
O
U
z
z
10,000
9
8
7
6
5
4
3
2
1,000
7
6
5
4
3
2
100
0
_^
JXX*'
.X1*"
^
""
x^
-
x^
X
X
X
^
^x
X"
x^
.s
^
X"
x^
x
X
^
2 34567 89 2 3456789
.1 1.0 1C
VOLUME, mg
MISCELLANEOUS SUPPLY COSTS
OPERATION & MAINTENANCE REQUIREMENTS
CUSTOM BUILT AERATION BASINS
FIGURE A-29
-------
10,000
< 1,000
Q_
9
8
7
6
5
4
3
2
0
7
6
5
4
3
2
)0
/
/
'
RC
/
X
-^
TAT
X
^
^~
ING
>
X
X
ME
/
^
X
Dl
/*
x'
A-
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/
\
/
/
/
/
/
/
_/
/
XV r«
^- i 1 A
/
/
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/
f
,TION^
X
/
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s
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X
r
/
lED
X
X
1 A .
IA
/
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/
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^
10
3 456789
100
3 4 5678U
VOLUME, 1^)00 cuft
LABOR
OPERATION & MAINTENANCE .REQUIREMENTS
TRICKLING FILTERS
FIGURE A-30
-------
10,000
9
8
7
6
5
M
O
O
u
1,000
7
6
5
4
100
10
ROTATING MEDIA
STATIONARY MEDIA
4 5 67 89
4 5 6 789
100
VOLUME, 1,000 cuff
1,000
MISCELLANEOUS SUPPLY COSTS
OPERATION & MAINTENANCE REQUIREMENTS
TRICKLING FILTERS
FIGURE A-31
-------
O
ID
9
8
7
6
5
4
3
2
1,000.
i
6
5
4
3
2
100
X
X
x
x
'
X
X
X
yX
/
.
X
^
*
/
-
-
'
2 3456789
2 3456789
10
VOLUME, 1,000 cu ft
100
LABOR
OPERATION & MAINTENANCE REQUIREMENTS
ANAEROBIC DIGESTION
FIGURE A-32
-------
10,000
9
8
7
6
5
8 i,ooo
<
i 7
5 6
5
4
100
3 4 5 67 89
10
VO LUME, 1,000 cu ft
3 4 5 6 7 89
100
MISCELLANEOUS SUPPLY COSTS
OPERATION & MAINTENANCE REQUIREMENTS
ANAEROBIC DIGESTION
FIGURE A-33
-------
10,000
9
8
7
6
5
<
13
Z
1,000
i
o
7
6
5
4
3
100
100
/
3 4 5 67 89
1,000
3 456789
10,000
DRIED SOLIDS APPLIED, Ibs/day
LABOR
OPERATION & MAINTENANCE REQUIREMENTS
SLUDGE DRYING BEDS
FIGURE A-34
-------
8
1 V, UV/U
9
8
7
6
5
4
3
2
1,000
7
6
5
4
3
2
100
X
X
/
.
/
/
'
^
'
y
x
s
/
/
f
/
s
2 345 6789 2 3 4 5 6 7 89
100
1,000
DRIED SOLIDS APPLlED> Ibs/day
10,000
MISCELLANEOUS SUPPLY COSTS
OPERATION & MAINTENANCE REQUIREMENTS
SLUDGE DRYING BEDS
FIGURE A-35
-------
. 1,000
9
8
7
6
5
4
3
t_
>s
1 2
h
_i
o
i .»
i
5
: 4
3
2
10
^
^
.s^
.s
^
-X
^~
-X
X
X
X
x
-""'
/
/
X
X
X
^
X
X
3 4 5 6789
3 4 5 6 789
10
CHLORINE USE, IBs day
100
LABOR
OPERATION & MAINTENANCE REQUIREMENTS
CHLORINATION
FIGURE A-36
-------
10,000
_
~o
-o
S
u
z
z
9
8
7
6
5
1,000
7
6
5
4
3
100
3 4 5 67 89
10
CHLORINE USE,lbs/day
3 4 5 6 789
100
MISCELLANEOUS SUPPLY COSTS
OPERATION & MAINTENANCE REQIUREMENTS
CHLORINATION
FIGURE A-37
-------
10,000
9
8
7
6
5
i,ooo:
7
6
5
4
100
0.1
X
X
2 3 4 5 6789
1.0
PLANT SIZE, mgd
2 3 4 5 6 789
10
LABOR
OPERATION & MAINTENANCE REQUIREMENTS
ADMINISTRATION
FIGURE A-38
-------
9
8
7
6
5
4
3
h.
X
"a 2
o
"o
-o
§ 1,000
_l Q
I \
4
3
2
100
.x"
^^
s^
^
y
^
^
S*
S
S
^
^
^^
^
S*
t
0.1
3 4 5 6789
1.0
PLANT SIZE, mgd
3 4 5 6 789
10
MISCELLANEOUS SUPPLY COSTS
OPERATION & MAINTENANCE REQUIREMENTS
ADMINISTRATION
FIGURE
-------
NUMBER OF SAMPLING
POINTS
I
O
<
I
0.
4200 1
3800
3400
3000
2600
2200
1800
z
< 1400 '
1000
600
200 '
40
60
80
100
120
140
160
180
200
NUMBER OF DAYS SAMPLES COLLECTED PER YEAR
LABORATORY MAN-HOUR REQUIREMENTS
FIGURE A-40
-------
1,000
NUMBER OF SAMPLING
POINTS
40
60
80
100
140
160
180
200
NUMBER OF DAYS OF SAMPLES COLLECTED PER YEAR
LABORATORY, MISCELLANEOUS SUPPLY COSTS
FIGURE A-41
-------
1,000
9
8
7
6
5
4
3
>x
_c
E
o
Of.
O.
_I
<
100
1
7
6
5
4
10
3 4 5 6789
10
PLANT SITE SIZE, acres
3 4 5 6 789
100
OPERATION & MAINTENANCE LABOR REQUIREMENTS
YARDWORK
FIGURE A-42
-------
o
-o
O
U
.10,000
9
8
7
6
5
1,000
6
5
4
3
.100,
3 4 5 6789
10
PLANT SITE SIZE, acres
3 4 5 6 789
100
MISCELLANEOUS SUPPLY COSTS
OPERATION & MAINTENANCE REQUIREMENTS
YARDWORK
FIGURE A-43
-------
APPENDIX B
COST COMPARISON SUMMARY
PREFABRICATED EXTENDED AERATION - CASES I & II
Capital Cost $
Operating Cost - $/Year
Labor @ $9/MH
Power @ 3C/KWH
Chlorine @ $250/TON
Misc. Supply
Annual O s M $/YEAR
Amortised Capital
(6*5% - 25 YRS)
Equivalent Annual Cost
Unit Cost ($/1000 GAL)
Plant
0.01
144,400
7,281
531
47
2,400
10,259
11,838
22,097
6.05
PREFABRICATED CONTACT STABILIZATION - CASE
Capital Cost $
Operating Cost - $/Year
Labor @ $9/MH
Power @ 3C/KWH
Chlorine @ $250/TON
Misc. Supply
Annual 0 & M $/YEAR
Amortised Capital
(6*j% - 25 YRS)
Equivalent Annual Cost
Plant
0.10
463,700
20,160
2,850
143
7,720
30,873
38,015
68,887
Capacity
0.05
277,400
10,845
1,005
47
3,880
15,777
22,741
38,518
2.11
I
Capacity
0.50
988,500
36,360
13,410
712
14,720
65,202
81,039
146,511
- mgd
0.10
422,500
17,550
4,170
143
6,170
28,033
34,637
62,670
1.72
- mgd
1.0
1,578,300
53,280
26,580
1,186
18,970
100,016
129,391
229,407
Unit Cost ($/1000 GAL)
1.89
0.80
0.63
B-l
-------
PREFABRICATED CONTACT STABILIZATION - CASE II
Capital Cost $
Operating Cost - $/Year
Labor @ $9/MH
Power @ 3C/KWH
Chlorine @ $250/TON
Misc. Supply
Annual 0 & M $AEAR
Amortised Capital
(6% - 25 YRS)
Equivalent Annual Cost
Unit Cost ($/1000 GAL)
CONVENTIONAL ACTIVATED SLUDGE -
Capital Cost $
Operating Cost - $/Year
Labor @ $9/MH
Power @ 3C/KWH
Chlorine @ $250/TON
Misc. Supply
Annual O & M $/YEAR
Amortised Capital
(6^% - 25 YRS)
Equivalent Annual Cost
Unit Cost ($/1000 GAL)
CONVENTIONAL ACTIVATED SLUDGE -
Capital Cost $
Operating Cost - $/Year
Labor @ $9/MH
Power @ 3C/KWH
Chlorine @ $250/TON
Misc. Supply
Annual O & M $/YEAR
Amortised Capital
(6% - 25 YRS)
Equivalent Annual Cost
Plant
0.10
596,450 1
23,310
5,910
143
8,440
37,803
48,900
86,703
2.38
CASE I
Plant
0.10
695,500 1
23,400
3,570
143
6,500
33,613
57,018
90,631
2.48
CASE II
Plant
0.10
753,740 1
23,760
7,530
143
6,550
37,983
61,800
99,783
Capacity
0.50
,343,100
42,300
25,710
712
16,040
84,672
110,110
194,872
1.07
Capacity
0.50
,472,900
37,935
11,610
712
10,690
60,947
120,750
181,697
1.00
Capacity
0.50
,611,200
40,365
19,500
712
10,890
71,467
132,100
203,567
- mgd
1.0
2,107,500
62,550
57,030
1,186
20,770
141,536
172,780
314,316
0.86
- mgd
1.0
2,355,000
55,305
22,920
1,186
15,150
94,561
193,066
287,627
0.79
- mgd
1.0
2,537,000
70,305
27,654
1.186
15,350
114,495
208,000
322,495
Unit Cost ($/1000 GAL)
2.73
1.12
0.89
2.0
3,835,100
93,870
45,750
2,373
25,720
167,713
314,407
482,120
0.66
2.0
4,162,700
101,970
77,280
2,373
26,120
207,743
341,300
549,043
0.75
B-2
-------
CUSTOM BUILT EXTENDED AERATION - CASES I & II
Plant Capacity - mgd
Capital Cost $
Operating Cost - $/Year
Labor @ $9/MH
Power @ 3C/KWH
Chlorine @ $250/TON
Misc. Supply
Annual O &'M $AEAR
Amortised Capital
(6^% - 25 YRS)
Equivalent Annual Cost
Unit Cost ($/1000 GAL)
OXIDATION DITCH - CASES I & II
Capital Cost $
Operating Cost - $/Year
Labor @ $9/MH
Power @ 3C/KWH
Chlorine @ $250/TON
Misc. Supply
Annual O & M $/YEAR
Amortised Capital
(6*5% - 25 YRS)
Equivalent Annual Cost
Unit Cost ($/1000 GAL)
ROCK MEDIA TRICKLING FILTERS -
Capital Cost $
Operating Cost - $/Year
Labor @ $9/MH
Power @ 3C/KWH
Chlorine @ $250/TON
Misc. Supply
Annual 0 & M $/YEAR
Amortised Capital
(6*5% - 25 YRS)
Equivalent. Annual Cost
0.10
424,300 1,
15,660
4,020
143
5,290
25,113
34,784
59,897
1.64
Plant
0.10
432,400 1,
15,660
4,020
143
5,290
25,113
34,784
59,897
1.64
CASE. I
Plant
0.10
768,600 1,
18,450
930
143
6,120
25,643
63,011
88,654
0.50
008,800
32,445
19,410
712
9,770
62,337
82,702
145,039
0.79
Capacity
0.50
029,900
32,445
19,410
712
9,770
62,337
82,702
145,039
0.79
Capacity
0.50
583,600
26,955
3,780
712
10,300
41,747
129,826
171,573
1.0
1,696,800
52,110
38,640
1,186
13,480
105,416
'139,106
244,522
0.67
- mgd
1.0
1,732,500
52,110
38,640
1,186
13,480
105,416
139,106
244,522
0.67
- mgd
1.0
2,570,900
45,855
7,380
1,186
14,300
68,721
210,766
279,487
2.0
2,898,600
92,160
77,130
2,373
20,900
192,563
237,632
430,195
0.59
2.0
2,816,100
92,160
77,130
2,373
20,900
192,563
237,632
430,195
0.59
2.0
4,375,500
79,560
14,550
2,373
22,270
1.18,753
358,710
477,463
Unit Cost ($/1000 GAL)
2.43
0.94
0.77
0.65
B-.3
-------
ROCK MEDIA TRICKLING FILTER - CASE II
Capital Cost $
Operating Cost - $/Year
Labor @ $9/MH
Power @ 3C/KWH
Chlorine @ $250/TON
Misc. Supply
Annual 0 & M $/YEAR
Amortised Capital
(6% - 25 YRS)
Equivalent Annual Cost
Unit Cost ($/1000 GAL)
ROTATING BIOLOGICAL MEDIA -
Capital Cost $
Operating Cost - $Aear
Labor @ $9/MH
Power @ 3C/KWH
Chlorine @ $250/TON
Misc. Supply
Annual O & M $AEAR
Amortised Capital
(6*5% - 25 YRS)
Equivalent Annual Cost
Unit Cost ($/1000 GAL)
ROTATING BIOLOGICAL MEDIA -
Capital Cost $
Operating Cost - $/Year
Labor @ $9/MH
Power @ 3C/KWH
Chlorine @ $250/TON
Misc. Supply
Annual O & M $AEAR
Amortised Capital
(6% - 25 YRS)
Equivalent Annual Cost
Plant
0.10
790,440 1
18,540
930
143
6,200
25,813
64,800
90,613
2.48
CASE I
Plant
0.10
596,900 1
17,280
1,950
143
5,870
25,243
48,900
74,143
2.03
CASE II
Plant
0.10
678,900 1
18,000
3,390
143
6,080
27,613
55,700
83,313
Capacity
0.50
,747,400
27,585
3,780
712
10,390
42,467
143,250
185,717
1.02
Capacity
0.50
,501,900
26,505
8,280
712
9,740
45,237
123,100
168,337
0.92
Capacity
0.50
,941,900
29,115
14,880
712
9,840
54,547
159,200
213,747
- mgd
1.0
2,989,500
47,025
7,380
1,186
14,300
69,891
245,100
314,991
0.86
- mgd
1.0
2,531,000
46,755
16,980
1,186
13,410
78,331
207,500
285,831
0.78
- mgd
1.0
3,265,000
52,245
30,780
1,186
13,580
97,791
267,700
365,491
2.0
5,194,500
81,360
14,550
2,373
30,190
128,473
425,850
554,323
0.76
2.0
4,325,000
83,700
33,150
2,373
20,770
139,993
354,600
454,593
0.62
2.0
5,629,000
90,000
60,150
2,373
21,020
173,543
461,500
635,043
Unit Cost ($/1000 GAL)
2.28
1.17
1.00
0.87
B-4
-------
APPENDIX C
BIBLIOGRAPHY
1. Benjes, H. H., "Aerobic Digestion", Presented at the Culp-Wesner-
Culp Seminar, South Lake Tahoe, 1975.
2. Monod, J., "Research on Crossing of Bacteria Cultures", Herman
et Cie, Paris, (1942).
3. McKinney, R. E., "Mathematics of Complete Mixing Activated Sludge",
Trans. Amer. Soc. Civil Eng., 128, Paper No. 3516 (1963).
4. Eckenfelder, W. W., Jr., and O'Connor, D. J., "Biological Waste
Treatment", Pergamon Press, Oxford, England, (1961).
5. Goodman, B. L., and Englande, A. J., "A Unified Model of the Acti-
vated Sludge Process", JWPCF, 46, 2, p. 312, February, 1974.
6. Goodman, B. L., "Monod Type Relationships Applied to Complete
Mixing Activated Sludge", Unpublished, January 25, 1973.
7. Process Design Manual for Upgrading Wastewater Treatment Plants,
U.S. EPA, Environmental Research Information Center, Cincinnati,
Ohio, October, 1974.
8. Baker, J. M. and Graves, Q. B., "Recent Approaches for Trickling
Filter Design", Journal of the Sanitary Engineering Division,
ASCE, 94, SA1, p. 65, February, 1968.
9. Gotaas, H. B., and Galler, W. S., "Design Optimization for Biologi-
cal Filter Models", Journal of the Environmental Engineering Division,
ASCE, 99, EE6, p. 831.
10. Gulp, Gordon, "Direct Recirculation of High Rate Trickling Filter
Effluent", JWPCF, 35, 6, p. 742 (1963).
11. 1971 Pilot Plant at the Willow Lake Sewage Treatment Plant, Salem,
Oregon, CH2M/Hill Engineers (March, 1972).
12. Williamson, K., McCarty, P. L., "A Model of Substrate Utilization
by Bacterial Films", JWPCF, 48. No. 1, p. 9, January, 1976.
13. Harremoes, Poul, "Biofilm Kinetics", Submitted to Water Pollution
Microbiology for Publication, 1976.
C-l
-------
14. Atkinson, Bernard and Howell, J. A., "Slime Holdup, Influent BOD,
and Mass Transfer in Trickling Filters", Journal of the Environ-
mental Engineering Division, ASCE, 101, EE4, p. 585, August, 1975.
15. Eckenfelder, W. W., "Trickling Filter Design and Performance".
Transactions of the American Society of Civil Engineers, 128,
pp. 371-398 (1963).
16. Caller, W. S., and Gotaas, H. B., "Analysis of Biological Filter
Variables". Journal, of the Sanitary Engineering Division, ASCE,
90, No. 6, pp. 59-79 (1964).
17. Germain, James E., "Economical Treatment of Domestic Waste by
Plaster-Medium Trickling Filters", JWPCF, 38, 2, p. 192, (Feb. 1966).
18. Chipperfield, P. N. J., "Performance of Plastic Media in Industrial
and Domestic Waste Treatment", JWPCF, 39, 11, p. 1860, November, 1967.
19. Unpublished data from University of Michigan at Saline, Michigan
plant.
20. Hartmann, H., "The Biodisk Filter", Oesterreichische Wasserwirtschaft,
11/12, 1965.
21. Benzie, W., "Effects of Climatic and Loading Factors on Trickling
Filter Performance", JWPCF, 35, No. 4, pp. 445-455 (1963).
22. Process Design Manual for Nitrogen Control, U.S. EPA, Environmental
Research Information Center, Cincinnati, Ohio, October, 1975.
23. Duddles, G. A., and Stevens, E. R., "Application of Plastic Media
Trickling Filters for Biological Nitrification Systems", Environ-
mental Protection Technology Series, U. S. EPA Contract No. 14-12-
900 (June, 1973).
24. Stenquist, R. J., Parker, D. S., and Dosh, T. J., "Carbon Oxidation-
Nitrification in Synthetic Media Trickling Filters", JWPCF, 46, 10,
p. 2327 (October, 1974).
25. Antonie, R. L., "Nitrification and Denitrification With the Bio-
Surf Process", presented at the Annual Meeting of the New England
W.P.C. Association in Kennebunkport, Maine, June 10-12, 1974.
26. Reid, Ouebe, Allison, Wilcox, and Associates, "Advanced Wastewater
Treatment Studies for the Consolidated City of Indianapolis,
Indiana, January, 1975.
27. Antonie, R. L., "Rotating Biological Contacts for Secondary Waste-
water Treatment", Presented at Culp-Wesner-Culp Seminar, South
Lake Tahoe, October, 1976.
C-2
-------
28. Morris, G. L., et al., "Extended Aeration Plants and Intermittent
Watercourses" Environmental Health Series Publication, U. S. Dept.
of HEW, July, 1963.
29. Black & Veatch, "Estimating Costs and Manpower Requirements for
Conventional Wastewater Treatment Plants", EPA Project 17090DAN,
October, 1971.
30. "Handbook for Analytical Quality Control in Water and Wastewater
Laboratories", U. S. EPA, Environmental Research Information Center,
Cincinnati, Ohio, 1972.
31. 1975 Dodge Guide, 7th Edition, McGraw Hill, 1975.
C-3
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