EPA-600/9-76-Q14
July 1976
AREAWIDE ASSESSMENT
PROCEDURES MANUAL
VOLUME III
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
-------
APPENDIX G
PART I
URBAN STORMWATER MANAGEMENT TECHNIQUES:
PERFORMANCE AND COST
G.I Introduction
G.I.I Purpose of Appendix G and Its Relationship to Chapter 6
The Chapter 2 preliminary assessment presented a broad identification of
major pollutant sources within an urban area, together with a perspective on
the relative magnitude of pollutant loads generated in an urban setting by
intermittant sources from combined sewer overflows and storm drainage systems.
In Chapter 3, alternative technical approaches for the estimation of
stormwater-related waste flow and quality were discussed. Various methods
of analyses including steady-state and time-varying water quality modeling
were presented in Chapter 5 to determine the impact of storm related pollu-
tants on the quality of receiving waters. Chapter 6 presents a methodology
for the evaluation of stormwater runoff control alternatives. The Manual
user is guided through a worksheet approach to the development of a least
cost mix of structural and nonstructural pollution control alternatives to
meet previously identified water quality goals.
In support of Chapter 6, Appendixes G and H have been prepared. Appendix G
provides the estimated performance capability and pollutant removal unit cost
input to the alternatives methodology of Chapter 6 from the standpoint of
nonstructural control of urban stormwater runoff. This is in contrast to
Appendix H which presents performance and cost data for structural solutions
to point source and nonpoint source pollution control. In order to make
Appendix G responsive to the data input needs of the alternatives evaluation
methodology of Chapter 6, the discussions of nonstructural management
techniques have been formated into Land Management Control Alternatives and
Collection Systems Control Alternatives.
G-l
-------
G.I.2 Description of Appendix G, Parts I and II
Appendix G is presented in two parts. Part I has been specifically researched
and written to be in concert with other portions of the AAPM. The approach
taken in the development of nonstructural performance and cost data is at
the same level of detail and sophistication as has been used elsewhere in the
manual's development of the assessment methodology. For discussions and
example presentation pertinent literature data are used in conjunction with
assumed or site-specific constraints to arrive at reasonable estimates of
costs and generalized effectiveness of stormwater management alternatives.
When site-specific data are available in a planning area, they are to be used
to provide a more accurate analysis for the decision matrix. Those site
specific data which should be used include total annual precipitation, runoff
coefficient, land-use patterns and population density, miles of street, miles
of curb, sewer miles, number of combined sewer overflows, number and volume
of combined sewer overflows per year, and the like. Although the performance
and cost estimates developed in Part I are based on reliable literature
sources, the estimates should not be mechanistically applied to specific
planning areas without considering whether the expressed or implied assump-
tions are representative of existing conditions.
Part II of this appendix consists of EPA Report No. 600/2-77-083, "Storm
Water Management Model: Level I-Comparative Evaluation of Storage-Treatment
and other Management Practices." The report describes simplified procedures
for obtaining a preliminary estimate of the magnitude of stormwater discharges
and the associated costs of control. The approach is similar to that used in
Part I in that it is designed as a "desktop" procedure to compare selected
alternative control technologies. It has been included in its entirety as
Part II in order to provide an alternate approach to the evaluation of storm-
water management practices. Unlike -Part I which discusses a great number of
individually-treated control techniques, Part II discusses only street
sweeping, sewer flushing, catch/basin cleaning, and storage-treatment. How-
ever, it does present a graphical method for combining processes in series
or parallel, arriving at a least-cost optimal combination of storage-
treatment and other management practices using marginal cost analysis.
G-2
-------
Part I of this appendix considers (1) Sources and Gross Pollution Loads of
Urban Runoff, (2) Land Management Control Alternatives, and (3) Collection
Systems Control Alternatives. The gross pollution loading relationships
given in Chapter 3 are compared with quantitative measurements of individual
sources such as street pollution and the buildup of municipal wastewater
solids in combined sewers. The determination of the pollutional load
establishes the baseline from which the performance capability and effective-
ness of specific management techniques are calculated. The cost of various
control measures are then estimated based on available literature references.
As previously mentioned, the techniques discussed in Part I are classified
into two categories. The first category is Section G.3, Land Management
Control Alternatives. The measures discussed are street cleaning, erosion
control, storage in residential ponds, porous pavement, chemical use control,
and air pollution control. The second category is Section G.4, Collection
Systems Control Alternatives. The measures discussed are storage in existing
sewer system, reduction or elimination of excessive infiltration and inflow,
periodic sewer flushing and scraping, and catch basin cleaning.
Two additional management techniques, considered to be structural or semi-
structural control methods, are also discussed in the second category. The
first is sewer separations for which the conclusion is drawn that due to
cost considerations this technique is feasible only in a developing area.
The second semistructural control technique entails the installation of
swirl concentrators at combined sewer overflow points. The discussion in
this appendix considers swirl devices as flow regulators in combined sewer
systems which will maximize in-line storage while providing a BOD removal
capability not found in other flow regulating devices. On the other hand,
the discussion of swirl devices in Chapter 6, covered in 6.4.2.7, Storage/
Treatment Methodology, considers these overflow regulators (which may be
designed for solids removal) antecedent to off-line stormwater storage/
treatment systems.
For each stormwater management practice discussed, the same general approach
is followed. A brief review of previous studies is given to describe the
range of potential applicability and to point out the agreement or disparity
of the literature data and results. The potential applicability, performance
-------
capability and costs are presented in example format. In those instances
were assumptions are made; for example, population density, land use activi-
ties in relation to street miles or sewer miles, precipitation and runoff
coefficients; they are for illustrative use in the example. (For individual
planning areas, site specific data are to be used where available, or a
reasonable estimate in lieu thereof.) The costs which are given, therefore,
are reflective of the example assumptions made and must be viewed in that
light. Site-specific data applied to the example problem might substantially
change the load reduction potential and cost projections in any individual
planning area.
It is important to note that basic assumptions made or data used in Parts I
and II are not identical and therefore the costs developed through a Part I
approach may not be exactly comparable to the costs resulting from a Part II
approach. For example, the cost of street sweeping given in Part I is $10.40
per curb-mile including disposal of sweepings versus $7.00 per curb-mile as
given in Part II. The latter unit cost does not include disposal of the
sweepings, nor does the optimization analysis provide for its inclusion.
From the standpoint of the context in which Parts I and II have been prepared
and their relationship to the Chapter 6 methodology, the following comment
may be obvious to users of the Manual but it bears additional attention. The
Part I discussions of management alternatives have been prepared to furnish
performance and cost inputs to Chapter 6. It is then the function of
Chapter 6 to use the stormwater management practices performance and cost
alternatives data from Appendix G, Part I, and.the structural systems
performance and cost alternatives data from Appendix H, to arrive at an
optimal mix of structural and nonstructural pollution reduction alternatives
which satisfy the previously developed load-reduction imperatives.
Conversely, Part II is a self-contained nonstructural/semi-structural
alternatives evaluation methodology which provides a least-cost solution
based on a limited number of technical alternatives, and which does not
optimize among structural and nonstructural techniques. Again, it is being
included in this appendix to demonstrate that more than one evaluation
approach is available.
G-4
-------
G.I.3 Literature Sources and Data Reliability
The text which follows is designed to fill a need for specific and.illustra-
tive information on management alternatives to input a first-level decision
matrix. The process performance and cost data are not intended to be a
complete listing or compilation of all the available literature concerning
the sources, loadings, and alternative management practices for the control
of urban nonpoint source pollution. There are other assessment and state-of-
the-art documents available for an overview, and many of these have been used
as a reference source for the material presented in this appendix.
The first level source of information is the library of EPA reports generated
by the grant and contract activities of the Storm and Combined Sewer Section,
Municipal Environmental Research Laboratory, Cincinnati. As a result of
these and other EPA Research and Development projects, much information has
been generated in defining problems and in the application of management
techniques to the abatement of urban stormwater pollution. From some reports,
information has been extracted directly. However, other reports were useful
for their bibliographies which referred to original studies. In this case
the original source of data could be examined and analyzed more critically
for specific inclusion herein.
For much of the work presented in this appendix, data from the original,
recent, and not so recent studies were used. As input to the development
of the sources and gross pollution loads of urban stormwater runoff, data
from those studies were analyzed and, in the oft occurring instances of
irreconcilable data due to differences in experimental design or unrealistic
experimental conditions, those data most closely approximating real-world
experience were used. As a result of the evaluation of background data, the
AAPM user can utilize the analytical results and cost performance estimates
with confidence in a first-level planning exercise.
At this point, it should be restated, as it was stated originally in
Chapter 6, that from the universe of research, demonstration, and on-site
studies which have been carried out for the assessment of nonstructural
technology for control of urban stormwater runoff pollution, a welter of
data for performance capabilities and costs is available. Since the
G-5
-------
information presented in this appendix has been collected from available
literature and because it will be used in a preliminary way for the evaluation
of alternative pollution control options with respect to performance and
costs, it has been necessary to establish a quality measurement to relate
the data from all sources.
The concept of "relative reliability" represents a reasonable indication to
the user of this information regarding the nature and extent of the experience/
data base upon which the cost or performance information is based. Although
the judgement of the relative reliability of the information is subjective,
it establishes for the user a relative confidence level for his alternative
evaluation, indicating in the appropriate area of the alternative spectrum
where data are deficient or where data are sufficient for reasonable confi-
dence in definitive decision making. Using the relative reliability of the
data, the user is directed away from making a major decision among a number
of potentially usable techniques based on insufficient or unreliable
information.
The relative reliability concept is stressed in order to convey to the user
community that the information presented here, upon which decisions are
based, results from studies conducted with differing levels of sophistication.
Although the best available information has been used, further research and
experience in nonstructural management techniques will result in establishing
a greater confidence in the precision and accuracy of currently available data
and a greater confidence in the application of the data in a decision-making
process.
G.2 Sources of Gross Urban Runoff Pollutant Loads
G.2.1 Sources
Water pollutants from urban areas resulting from rainfall originate from a
number of sources. For example, separate storm sewer pollution is generally
recognized as pollution washed off the urban area by rainfall. Combined
sewers used for both stormwater and municipal sewage have an additional
pollutional component due to solids accumulation and escaping wastewater.
During dry weather periods municipal sewage solids settle out in the sewer
and are flushed into the receiving stream by the next rainfall of sufficient
G-6
-------
intensity to cause resuspension and overflows. Also, since a portion of the
combined sewage overflows upstream of the treatment plant during wet weather,
a portion of the municipal sewage generated by the population of the urban
area during a storm event goes directly to the receiving stream.
Stormwater loads may be reduced by employing various combinations of struc-
tural end-of-pipe control techniques and urban runoff management practices.
The objective of Part I of this appendix is to examine the potential effec-
tiveness and costs of the more prominent management practices available.
Structural alternatives; such as deliberate interception, storage and treat-
ment; will not be considered except for purposes of comparison. These are
analyzed in detail in Chapter 6 and in Part II of this appendix.
G.2.2 Determination of Source Loads
In order to assess the effectiveness and costs of each of the various urban
stormwater management practices the relative magnitude of pollutant loads
from combined sewer overflows and from separate stormwater runoff must be
estimated. Each of these loads is affected differently by the application
of the various management options. For example, street sweeping can reduce
the amount of urban dust-and-dirt which will be washed off the urban area
into the receiving stream during wet weather. Similarly, periodic combined
sewer flushing can reduce the amount of settled solids which are washed into
the receiving streem during rain storms.
A relationship between combined sewer and separate sewer BOD pollutant
loadings which is often used is that of Heaney et al. (1). Using actual
sewer effluent measurements from seven urban areas it was reported that for
equivalent area and precipitation, combined sewer BOD loadings averaged
4.12 times higher than separate sewer loadings. An independent survey of
available data conducted by Lager and Smith (2) found that average BOD con-
centrations in combined sewage are 3.83 times those found in separate sewers
(115 mg/1 vs. 30 mg/1).
Rather than merely employing these average values (which are calculated
independent of community size), it is necessary for the purpose of this
appendix to attempt to confirm these ratios through a quantitative analysis
of measurements of individual sources of urban stormwater pollutants, such
G-7
-------
as street pollutants and the accumulation of municipal wastewater solids in
sewers, and to compare these values with the gross loading relationships
developed in Chapter 3.
G.2.2.1 Separate Stormwater Loads
Many attempts have been made to relate stormwater loads to land use. One
general procedure for predicting runoff quality that was outlined in Chapter 3
is based upon research done by the University of Florida for the Environmental
Protection Agency. This procedure, which relates runoff quality to land use
and population density, estimates loads via the following relationships:
MS = a(i,j) . R . PI (PDd) . Y (G-l)
Mc = 3(i,j) . R . Pj (PDd) . Y (G-2)
where:
M = pound of pollutant (j) from land use (i) with separate and
unsewered conveyance (Ibs/acre-yr)
M = pound of pollutant (j) from land use (i) with combined sewer
conveyance (Ibs/acre-yr)
a(i,j) = constant for pollutant (j) and land use (i) with separate
and unsewered conveyance (Ibs/acre-in)
$(i,j) = constant for pollutant (j) and land use (i) with combined
sewer conveyance (Ibs/acre-in)
R = annual precipitation (in/yr)
p1 (PDj) = population function
PD, = population density (persons/acre)
Y = street sweeping effectiveness factor
Applying these relationships to a hypothetical urban area possessing the
average developed land use characteristics of 248 urbanized areas in the
United States (58.4% residential, 8.6% commercial, 14.8% industrial, and
18.2% other developed) Heaney et al. developed the following expression for
the average annual BOD load from separate storm sewers as a function of
population density (1):
C-8
-------
MS = 0.467 . R . (0.142 + 0.218PD0'54) + 0.457R (G-3)
where:
M = average annual BOD loading from separate storm sewers
(Ib BOD/acre-yr)
R = annual precipitation (in/yr)
PD = population density of urbanized drainage area (persons/acre)
It is important to emphasize that similar relationships may be developed for
other pollutant parameters of interest, e.g., suspended solids or nutrients.
Most evaluations of urban management practices, however, have been conducted
with BOD removal as the primary concern. For example purposes the estimations
and analyses in this appendix will also be developed on a BOD basis.
The average annual precipitation for the seven cities from which runoff data
was used to develop Equation (G-3) was 36 inches/year. Therefore, substi-
tuting this value for R, Equation (G-3) becomes:
M = 18.8 + 3.67 PD°'54 (G-4)
Population density, in turn, is known to increase with community size in a
fairly regular way, as described by the following relationship derived by
Smith (3) :
PD = 0.3 POP0'304 (G-5)
where:
POP = community population
Equation (G-5) is then substituted into Equation (G-4) to obtain the follow-
ing relationship for estimating BOD loading from separate storm sewers as a
function of community population.
M = 18.8 + 1.9 POP0'1642 (G-6)
This relationship is shown in Figure G-l (curve A). It can be seen that
separate sewer BOD loading (Ib BOD/acre-year) is relatively insensitive to
community size, ranging from about 25-35 Ib BOD/acre-year.
The validity of this loading relationship may be tested using published
values of BOD accumulation upon urban surfaces. A portion of the pollutional
G-9
-------
NOTE: CURVE A DEVELOPED USING
CHAPTER 3 METHODOLOGY
CURVE B DEVELOPED FROM STREET
SURFACE POLLUTANT ACCUMULATION
300
2"100
i
uj
of.
U
O
z
Q 10
a
O
CO
A SEPARATE STORM SEWERS
B STREET SURFACES
I ill 11 111
i i i i i 111
3 10 100 1000
COMMUNITY POPULATION (THOUSANDS)
FIGURE G-l
ESTIMATED BOD LOADING IN URBAN RUNOFF
AS A FUNCTION OF COMMUNITY SIZE
G-10
-------
load attributed to separate storm sewers is contributed by the dust-and-dirt
which accumulates on the streets of the urban area. This load can then be
reduced by means of street sweeping. During the summer of 1967, the American
Public Works Association (4) conducted street sweeping measurements over a
four-week period in the City of Chicago. The results of the study showed
that the amount of litter which accumulates on the streets ranged from
26-422 Ib/day/mile of curb. The dust-and-dirt fraction of the litter was
defined as that fraction passing a screen with 1/8-inch openings. The amount
of dust-and-dirt accumulated was measured as 21-275 Ib/day/mile of curb. It
was found that most of the BOD in street litter was contained in the dust-and-
dirt fraction. The dust-and-dirt fraction was pulverized in a blender and
dissolved in water. Without filtering, the BOD and COD of the water and
dust-and-dirt mixture was found using standard techniques. The concentration
of BOD in the dust-and-dirt fraction ranged from 3-7.7 mg/g. The amount of
BOD accumulated varied with the type of land use and tended to be greater in
high density residential areas. The weighted estimate for BOD accumulation
on the streets of Chicago was 0.4 Ib BOD/day/mile of curb or 0.8 Ib BOD/day/
mile of street. An interesting and, perhaps, significant result of the
study was that the amount of BOD collected from the street was not related to
the time since the last rainfall.
Using U.S. Department of Transportation data provided in the APWA report (4),
miles of streets can be related to community size. This relationship is
plotted as curve A in Figure G-2. Combining this with Equation (G-5) yields
a relationship between community size and miles of streets/acre (curve B in
Figure G-2), which when further multiplied by the APWA BOD accumulation rate
for streets (0.8 Ib BOD/day/mile x 365 days/year = 292 Ib BOD/year/mile of
street) yields curve B in Figure G-l. This provides a relationship for the
potential annual BOD available from street surfaces as a function of com-
munity size.
Further examination of Figure G-l reveals that the BOD loading values derived
from the street sweeping experiments (curve B) are about one-fourth the
loading when estimated from the BOD concentration found in separate storm
sewers (curve A). A possible explanation for this factor difference is that
the lower values of curve A are based upon dirt-and^dust available from street
G-ll
-------
3000
1000
UJ
100
ml i i 11 ill I I I I 11 ill I I I I I I Him
3000
1000
o
o
o
o
><
UJ
ce.
100
CO
UJ
3 10 100 1000
COMMUNITY POPULATION (THOUSANDS)
FIGURE G-2
RELATIONSHIP BETWE'EN COMMUNITY SIZE
AND (A) TOTAL MILES OF STREET;
(B) STREET (SEWER) MILES PER 10,000 ACRES;
AND (C) TOTAL MILES OF SEWER
G-12
-------
surfaces only. These materials, however, accumulate at varying rates on all
urban surfaces, including roof tops, parking lots, sidewalks, and pervious
areas and are available to be washed from all these surfaces into separate
storm sewers during rainfall events. This fact is reinforced by recalling
that one of the conclusions of the Chicago study was that the amount of
dust-and-dirt swept from the streets seemed to be independent of the time
since the previous rainfall, probably due to the fact that rainfall tended
to wash dust-and-dirt from the non-street areas onto the street.
As a rough approximation it might be assumed that the dust-and-dirt cover is,
on the average, the same for all urbanized surfaces. In a careful study of
urban land use for 53 central cities and 33 satellite cities Bartholomew (5)
found that roughly 56% of the land was urbanized and that streets occupied an
average of 28.1% of the urbanized area. Thus, it can be seen that the ratio
of street BOD loading as recorded by APWA (Figure G-l, curve A) to the gross
loading from the total urbanized area as estimated by Chapter 3 procedures
(Figure G-l, curve B) is roughly the same as the ratio of street area to
total urbanized area measured by Bartholomew, i.e., 25% vs. 28.1%. This
tends to lend credence to both sets of estimates. More importantly, it
leads to the further conclusion that the amount of BOD (in the form of
dust-and-dirt) which can be removed from the streets (using current street
sweeping practices) is not likely to exceed the amount actually on the
street surfaces which accounts for only about 25% of the total loading.
G.2.2.2 Combined Sewer Loads
The experiments on buildup of sanitary sewage solids in a pilot sewer con-
ducted by FMC Corporation (6) can be used in an attempt to account for the
additional loading observed from combined sewers. In this work, FMC allowed
raw sanitary sewage to flow through 12-inch diameter and 18-inch diameter
pilot sewers both 790 feet long. The amount of solids accumulation was
measures in terms of TOC (total organic carbon) as a function of time and
distance along the sewer. As might be expected, the measurements were
scattered but by averaging the accumulation per length of sewer per unit of
time over the first 267 feet and over the entire length for the times used
(1.75, 3.92, and 7.83 days) the average rate of accumulation was 2.09 Ib
TOC/mile/day. It was also found that the BOD of the accumulated solids
G-13
-------
equaled about 1.8 times the TOC measurement. The suspended solids concen-
tration of the raw sewage used by FMC was 133 mg/1 which is low compared to a
more normal value of 200 mg/1. If the measured accumulation is multiplied by
the ratio 200/133 the value for normal sanitary sewage is 5.66 Ib BOD/mile/day
or 2067 Ib BOD/mile/yr.
Thus, if the length of sewer can be stimated, the loading due to accumulation
of sanitary sewage solids can also be estimated. One relationship developed
by Smith (3) is shown below:
Feet of installed sewer/capita = 54 (PD)~ * " (G-7)
Combining this expression with Equation (G-5) the following relationship for
miles of sewer versus community size results:
Miles of sewer = 0.02237 POP0'8024 (G-8)
This relationship is shown plotted by the dashed line in Figure G-2 (curve C).
It can be seen that the miles of sewer is very similar to the miles of street.
The relationship for miles of street is probably more reliable as an estimate
of length of sewer. If one assumes that the miles of sewer is equal to the
miles of street, the expression for miles of sewer per acre as a function
of community size becomes the same as curve B in Figure G-2. Multiplying
miles of sewer/acre times 2067 Ib BOD/mile/yr. gives the loading in terms of
Ib BOD/acre-yr. caused by flushing of settled sanitary sewage solids from
combined sewers during the wet weather. This relationship is plotted as a
function of community size in Figure G-3 (curve A).
Some raw sanitary sewage will also escape into the receiving stream during
overflow periods and contribute to the difference between separate storm
sewer and combined sewer loadings. Assuming that the production of sanitary
sewage can be estimated as 0.17 Ib BOD per capita per day, the equivalent
loading is 62.05 (365 x 0.17) times the population density in persons/acre.
Combining this relationship with Equation (G-5) gives the following equation
for loading due to raw sewage escape:
Ib BOD/acre-yr. = 18-62 POP0'304 (G-9)
A survey of combined sewer problems conducted by APWA (7) in 1967 showed that
because of wet weather, treatment plants (197 plants surveyed) bypass an
G-14
-------
300
100
* A ACCUMULATED
SOLIDS FLUSHED
at
U
O
z
o 10
Q
o
CO
1
E CURVE(C)x3.2
D CURVE A+B+C
C SEPARATE SEWER
(EQ. G-4)
B ESCAPING WASTEWATER
I I I Mil I I I I I I III
3 10 100 1000
COMMUNITY POPULATION (THOUSANDS)
FIGURE G-3
ESTIMATED BOD LOADINGS
AS A FUNCTION OF COMMUNITY SIZE FOR:
(A) ACCUMULATED SOLIDS FLUSHED FROM
SANITARY SEWERS; (B) ESCAPING WASTEWATER;
AND (C) SEPARATE SEWERS.
G-15
-------
average of 350 hr/yr or about 4% of the time. The fraction of raw municipal
sewage which escapes during bypassing can be shown (8) to depend on the ratio
of treatment plant capacity (MGD) to actual dry weather flow (MGD). The
fraction escaping ranges from 48% when the ratio is ten, to 67% when the
ratio is one. If a nominal value of 60% corresponding to a ratio of three is
used, the loading caused by bypassed municipal sewage during wet weather can
be estimated as 2.4% of that given by Equation (G-9), which is plotted as a
function of community size in Figure G-3 (curve B).
Adding these two sources of BOD gives an incremental loading difference
between storm and combined sewer discharges of 57 to 180 Ib BOD/acre-yr. If
this increment is now added to that estimated for pollution for from separate
storm sewers using Equations (G-4), the overall estimate for combined sewer
loading may be found. This is accomplished graphically in Figure G-3 by
adding curves A, B, and C to derive curve D, the combined sewer loading
relationship.
The seven measurements used for deriving the factor 4.12 are shown in
Figure G-4. The dashed line (curve C) represents a factor of 4.12 times
curve A. It can be seen that all but one of the measurements fall below
the line. If the ratio of the loading for each point is divided by the
equivalent estimate for separate storm sewers from curve A the average ratio
becomes 3.2 instead of 4.12. The ratio of the loading for each point is
divided by the equivalent estimate for separate storm sewers from curve A
the average ratio becomes 3.2 instead of 4.12. The ratio of 3.2 is shown
as curve B in Figure G-4. Using a factor of 3.2 instead of 4.12, the
estimated loading relationship for combined sewers has been calculated and
is shown as curve E in Figure G-3. Comparing curves D and E, it is seen
that the two estimates agree well if the factor of 3.2 between loading of
separate storm sewers and combined sewers is used. Table G-l summarizes the
calculations employed in defining the curve relationships in Figures G-l,
G-2, and G-3.
From the analysis above, the relative loading functions for separate and
combined sewer discharges have been derived from reported measurements of
pollutant accumulation on streets and in sewers. Having arrived at this
point it is now possible to discuss the relative efficiency and potential
G-16
-------
I
u
z
Of.
U
Q
O
eo
Z
o
z
UJ
U
Z
o
u
o
O
co
NOTE: (1) CURVE (B) EQUALS 3.2 TIMES
CURVE (A)
(2) CURVE(C) EQUALS 4.12 TIMES
CURVE(A)
(3) CIRCLED DATA POINTS ARE
COMBINED SEWER EFFLUENT
MEASUREMENTS FROM HEANEY(l)
10
1.0
0.1
'A SEPARATE STORM
SEWERS
I I I I I I I I I
I I I I I I II
1 10 100
POPULATION DENSITY (PERSONS/ACRE)
FIGURE G-4
BOD CONCENTRATION FOR SEPARATE
STORM SEWERS AS A FUNCTION OF
POPULATION DENSITY
G-17
-------
TABLE G-l
URBAN AREA BOD LOADS (Ib BOD/ACRE-YR) COMPUTED FROM STREET SWEEPING
AND COMBINED SEWER SOLIDS BUILDUP MEASUREMENTS AS COMPARED TO
ESTIMATES DETERMINED USING THE CHAPTER 3 METHODOLOGY
Community
Population
3,000
10,000
30,000
100,000
300,000
1,000,000
Miles of
Street/Acre,
Figure G-2,
Curve (B)
0.0252
0.0195
0.0198
0.023
0.0285
0.038
BOD Loading (Ib BOD/Acre-yr)
Storm Sewers
Figure G-l
Curve (B)(A£WA)
26.2
20.3
20.6
23.9
29.6
39.5
Figure G-l,
Curve (A) (Ch. 3)
25.9
27.4
29.1
31.4
33.9
37.2
Solids Flushed,
Figure G-3
Curve (A)
52.1
40.3
40.9
47.5
58.9
78.5
Escaping Wastewater,
Figure G-3
Curve (B)
5.1
7.3
10.3
14.8
20.6
29.8
Combined Sewers
Figure G-3,
Curve (D)
83.1
75.0
80.3
93.7
113.4
145.5
Eq. G-4
X 3.2
82.9
87.7
93.1
100.5
108.5
119.0
en
i-"
00
-------
costs of management techniques for controlling these pollutants.
G.3 Land Management Control Alternatives
G.3.1 Street Cleaning
The primary objective of municipal street cleaning practices is to enhance the
aesthetic appearance of streets by periodically removing accumulated litter,
debris, dust, and dirt? Such practices, however, do have an impact upon the
amount and type of roadway pollutants which may be washed into receiving
waters during runoff events. Consequently street cleaning is widely
considered as a candidate management practice for reducing stormwater pollu-
tion loadings.
Streets are conventionally cleaned by manual or mechanically sweeping or by
periodic flushing with water. The cleanliness of streets is also affected
by the type and condition of pavementj the effectiveness of anti-litter
programs, and the degree of air pollution (particulate) control in the urban
area. The magnitude of the effect of these latter factors upon stormwater is
difficult to assess except in general terms, due to the paucity of quantita-
tive information. Litter control, primarily affecting large street debris
such as cans, paper, bottles, is programmed entirely for aesthetic purposes
and has little effect upon important water pollutants such as BOD, pesticides,
heavy metals and small particulates. Streets in good condition are generally
cleaner than those in poor condition; and concrete pavements tend to be
cleaner than asphalt.
The purpose of this section will be to develop cost and effectiveness
information for street cleaning techniques only. Because of the lack of good
information no attempt will be made to develop cost/effectiveness relation-
ships for litter control programs or pavement condition. Section G.3.6,
however, provides an estimate of the impact of particulate air pollution
control upon stormwater loads.
G.3.1.1. Street Sweeping
The most common methods of street sweeping include:
(1) mechanical (broom-type) sweepers
(2) manual
G-19
-------
(3) vacuum sweepers
(4) combined vacuum and mechanical broom-type sweepers
Mechanical sweepers are most commonly used and, understandably, the majority
of the currently available performance literature addresses this type of
sweeper. Mechanical sweepers basically consist of a gutter and main broom
which rotate at high speeds forcing the debris from the gutter and street
surface onto a conveyor belt and subsequently into a hopper. Water is
usually sprayed on the surface for dust control.
The effectiveness of mechanical sweepers is recognized to be a function of a
number of factors, including: (1) particle size distribution of accumulated
surface contaminants, (2) sweeping frequency, (3) number of passes, (4)
equipment speed, and (5) pavement conditions.
Table G-2 displays the distribution of street surface pollutant fractions
associated with various particle sizes (9). The interrelationship between
mechanical sweeper efficiency and particle size is shown in Table G-3.
The overall efficiency can be seen to be roughly 50 percent.
The effectiveness of street sweeping is also affected by the frequency of
sweeping and the number of sweeper passes during each sweeping interval.
As the sweeping frequency and number of passes increase the effectiveness of
contaminant removal increases. The effect of sweeping frequency is
described more fully in Part 2 of this appendix. For the purposes of the
analysis of cost/effectiveness of mechanical sweepers in this section,
however, the following relationship, developed by Sartor £ Boyd (9), will
be used:
_
Efficiency = 100 (1 - M*/MQ) (1 - e -) (G-10)
where M* = ultimate residual dust-and-dirt, gm/sq.ft.
MQ = initial dust-and-dirt loading, gm/sq.ft.
P = number of passes made by sweeper
This relationship was determined from actual mechanical sweeper efficiency
tests on naturally accumulated dust-and-dirt as well as a simulation developed
to represent natural dust-and-dirt. Efficiency tests performed by equipment
manufacturers and other research organizations were also cited in the
studies.
G-20
-------
TABLE G-2
STREET SURFACE POLLUTANTS ASSOCIATED
WITH VARIOUS PARTICLE SIZES (9)
Particle Size
Measured Pollutant
TS
BOD5
COD
VS
Phosphates
Nitrates
Kjeldahl nitrogen
All heavy metals
All pesticides
PCB
<43y
(-
5.9
24.3
22.7
25.6
56.2
31.9
18.7
51.2
73
34
43y-246y
6 by weight)
37.5
32.5
57.4
34.0
36.0
45.1
39.8
>246y '
56.5
43.2
19.9
40.4
7.8
23.0
41.5
48.7
27
66
TABLE G-3
INTERRELATIONSHIP BETWEEN MECHANICAL
SWEEPER EFFICIENCY AND PARTICLE SIZE (9)
Particle Size
(microns)
Sweeper Efficiency
(% removal)
2,000
840-2,000
246-840
104-246
43-104
<43
Overall
79
66
60
48
20
15
50
G-21
-------
It can be seen by Equation (G-10) that if the ratio of the ultimate residual
divided by the initial loading is 0.05 the sweeping efficiency for one pass
is 50%. Similarly, the efficiency of two-pass sweeping is 74% and the ef-
ficiency of three-pass sweeping is 85%.
The analysis of storm and combined sewer pollutant sources presented earlier
in this appendix showed that about 25% of the separate storm sewer BOD load
could be attributed to dust-and-dirt which can be swept from streets. This
conclusion was based on the APWA (4) street sweeping experiments made in
Chicago, which gave a weighted average street accumulation rate of 0.4 Ib BOD/
curb-mile/day. It should also be noted that the URS study by Sartor and Boyd
(9) which resulted in Equation (G-10) also performed similar accumulation
studies which produced significantly different values. The URS study
measured street pollution in each of twelve cities for more than five land-
use categories per city. The pollutant cover on a 40 ft. by 25 ft. section of
street was measured by hand sweeping and.flushing. The amount of BOD
removed from these small sections averaged 14 Ib BOD/curb-mile. Inquiries
were made to determine the number of days since the street section was last
swept. Based on this information, it was calculated that the street pollutant
load averaged 4.5 Ib BOD/curb-mile/day. This estimate is roughly ten times
the APWA estimate of 0.4 Ib BOD/curb-mile/day. Thus, the results of the two
measurement programs are incompatible and cannot be averaged.
Because some logical value for loading is needed, the following evaluation
must be made. The length of street swept by APWA.was about 38
times the length swept by URS. Because of the greater amount of street
sampled and the fact that URS did not sweep streets repeatedly but relied on
local information on the time between regular sweepings it would appear that
the APWA results form a more solid basis for estimating street pollutant
loads.
Therefore, using the separate storm sewer loading relationship developed in
Section G.2.2, and assuming that 25% of this load is on street surface and
is available for removal, the maximum amount of BOD available for removal by
street sweepers is 6-9 Ib BOD/acre-year (25-37 Ib BOD/acre-year times 0.25).
If single-pass sweeping with an efficiency of 50% is used the load removal
rate through sweeping will be 3-5 Ib BOD/acre-year, or 12-14% of the separate
G-22
-------
storm sewer load.
The cost of street sweeping has been reported by many sources and, according
to Morris et al.(ll), can vary from $2 to $14/curb-mile. Sartor and Boyd
(9) cite a survey made by American City magazine where it was found that
street sweeping costs varied from $2.18 to $8.42/curb-mile in 1970-71 dollars.
The APWA report of street sweeping experiments in Chicago estimated the cost
of single-pass mechanical street sweeping at about $10/curb-mile in 1968
dollars. The average cost of street sweeping in Cincinnati (1975) (12) was
$8.40/curb-mile for mechanical sweeping and $45.68/curb-mile for hand sweep-
ing. The cost of disposal of the sweepings was $3.36/cu.yd. The volume of
sweepings collected was 0.6 cu.yd./curb-mile in Cincinnati which compares to
a range of 0.18-0.56 cu.yd./curb-mile for the four cities surveyed by Sartor
and Boyd (9). In Chicago the average volume of sweepings was 1.5 cu.yd./curb-
mile. Since the amount collected in Cincinnati is about the average amount,
the cost of disposal can be estimated at about $2/curb-mile (0.6 cu.yd./curb-
mile x $3.36/cu.yd.) which, when added to the $8.40/curb-mile for sweeping,
gives a total of $10.40/curb-mile.
The survey made by Sartor and Boyd (9) showed that the frequency of street
sweeping computed by dividing the miles of street swept per year by the miles
of streets scheduled for sweeping ranged from a low of 36 times/year in
Baltimore to a high of 121 times/year in Phoenix. The average was 70 times/
year, or every 5.2 days. Since the miles of street per acre range from a
low of 0.019 to a high of 0.038, miles of street/acre can be multiplied by
$/mile of street (2 x $10.40/curb-mile) times the average number of sweepings
per year to find the cost in terms of dollars per acre per year. The cost of
street sweeping is $28-$55/acre-year and this divided by the average loading
removed (3-5 Ib BOD/acre-year) gives the cost in dollars per pound of BOD
removed as $7-$14/lb of BOD removed, for a single pass.
Vacuum street-sweepers may also be used. Three types of vacuum sweepers are
available on the market today. The first is the so-called conventional
vacuum sweeper which operates by sweeping the material from the path into
approximately a one-foot windrow. This windrow, and only this windrow, is
picked up by the vacuum. Dust problems are less evident than those created
by mechanical sweepers; however, removal of fine particles is still questionable.
-------
The second type features vacuum action over the entire path, assisted by a
gutter broom. Still, the particulates which are embedded in the road surface
do not receive sufficient agitation to become air-suspended and, therefore,
the vacuum is unable to draw them into the hopper.
A relatively new concept is the regenerative air system. Sweepers of this
type force air down onto the pavement, suspending the particles, which are
then picked up by the vacuum suction. These sweepers may be the most
efficient in removing fines.
The potential for overall debris control and, particularly, removal of dust-
and-dirt by vacuum sweepers has been rather superficially reported in
information currently available. An on-going EPA research investigation in
San Jose, California is conducting a field examination of a variety of
sweeper types, including vacuum sweepers (13).
Based on data from a pilot sweeping study, Field- et al. noted that it could
be feasible to improve removal efficiencies for various street surface
contaminants through the use of sweepers employing a combination of broom and
vacuum action (13). Under favorable conditions such equipment might be
capable of removing up to 90% of deposited solids and perhaps as much as
67% of street surface BOD due to a greater efficiency in the removal of
smaller particle sizes.
Costs of vacuum sweeping are reported to range widely from $2-$14/curb-mile.
Regenerative air sweepers may cost from $3 - $10/curb-mile.
G.3.1.2 Street Flushing
Street flushing is a practice which is employed in many cities as an
alternative to or in addition to street sweeping. Street flushers consist
of an 800 to 3500 gallon water supply tank mounted on a truck or trailer
which is equipped to allow water to be sprayed through three or more
directional nozzles onto the street surface. As currently practiced, street
flushing does not pick ,up contaminants but primarily serves to transport them
from the center of the street surface to the gutter. The volume of water
used is generally insufficient to transport the accumulated material to
the nearest drain.
G-24
-------
The relative surface cleaning efficiency of street flushing was compared
to that of mechanical brush sweeping in the previously mentioned URS study
(9). A mobile flushing unit with special high pressure, highly-effective,
spray nozzles was used. The results of the tests which were conducted for
similar mass loading, particle size, and surface type are shown in Figure G-5.
A comparison of the curves indicates that a street flusher of the type used
in that study was a superior method for moving street contaminants, especially
those in the dust-and-dirt fraction. Conventional street flushers, however,
are not likely to be as effective as that used in the study.
Overall, unless greater than conventional flush volumes are used, street
flushing will not on its own be an effective contaminant control practice.
Even if street contaminants can be effectively washed into sewers, the
practice will have impact only in areas which are served by combined sewers
and also employ a sewer flushing program. The mere relocation of pollutants
from street surfaces into sewers does not insure that they will not be
subsequently washed into receiving waters during the next runoff event either
in combined sewer overflows or direct discharge from separate storm sewer.
G.3.2. Sediment $ Erosion Control
Soil erosion in urban areas is associated with construction of buildings,
dams, sewerage facilities, roads, and new residential areas. Many adverse
effects are caused by uncontrolled soil erosion. For example, sediment
washed off denuded land can fill the pores of downstream land and destroy
grass and other forms of vegetation thus reducing the infiltration capacity
of the land and increasing the rate of runoff. Sediment will also clog
storm sewers causing downstream flooding which can result in property damage.
High sediment loads in natural streams make the water less fit for most
human needs and increase the cost of potable water treatment. High sediment
loads also can have a deleterious effect on aquatic life. The high runoff
velocities resulting from the effects of erosion can erode stream banks causing
further damage to the streams.
Although the acreage under construction is generally small compared to other
forms of erodable land, the rate of erosion can be severe. For example,
Ports (14) estimates that the rate of erosion from construction activity can
G-25
-------
O
Z
z
2 10'_
NOTE: SURFACE: ASPHALT
INITIAL MASS: 20gm/$q ft
SWEEPER
(WAYNE 450)
10 12 14
RELATIVE EFFORT ri200FT/MINUTE
FORWARD SPEED(FT/MIN)
SOURCE:(9)
FIGURE G-5
COMPARISON OF CLEANING
PERFORMANCES OF MOTORIZED
STREET SWEEPING AND
MOTORIZED STREET FLUSHING
G-26
-------
be as high as 200 tons/acre-year as compared to about 0.2 tons/acre-year from
forestland. Erosion from croplands is generally recognized as the single
greatest source of sediment in natural streams. Ports estimates the rate of
erosion from croplands to be in the range of 0.3 - 6 tons/acre-year.
In a study of nonpoint source pollution made by Midwest Research Institute
in cooperation with Hittman Associates (15) the average erosion rate for
construction was estimated as 75 tons/acre-year as compared to 0.4 tons per
acre-year for forest and 7.5 tons/acre-year for cropland. This report also
estimated the amount of land under construction at about 1.5 million acres
as compared to 412 million acres of cropland. The U.S. Department of
Agriculture (16) estimates that the total land area of the 50 states is about
2.3 billion acres and of this 1.1 billion acres is in farms and 333 million
acres are in active croplands. Thus, if the erosion from croplands is
assumed to be 6 tons per acre-year, the total sediment runoff for the U.S.
is about two billion tons per year. Similarly, assuming the erosion from
construction activities as 200 tons/acre-year, the total runoff for the U.S.
is about 300 million tons per year. Thus, uncontrolled erosion from small
land areas in urban construction activities might account for as much as
15% of the sediment runoff attributed to active croplands.
Other major sources of sediment are harvested forests and grassland. It has
been estimated that both of these sources contribute about twice the amount
estimated for construction activities (15). This report also estimated the
sediment from urban construction activities at about three percent of the
total runoff. ^
As much as 95 percent of the uncontrolled erosion which can occur at
construction sites may be prevented using various combinations of relatively
simple and inexpensive control techniques. These techniques were described
in an Environmental Protection Agency report prepared by Hittman Associates
(17), and range from the construction of sandbag and straw bale sediment
barriers to use of diversion dikes, filter berms, flexible erosion control
mats, gabions and chutes, flumes, and, check dams. Table G-4 summarizes the
calculated effectiveness of 10 erosion control systems (18).
G-27
-------
TABLE G-4
PROMISING CONTROL SYSTEM AND EFFECTIVENESS
(After Reference 18)
System Numbers Components Percent Effectiveness
1 Seed, fertilizer, straw mulch. 91
Erosion structures (normal). Sedi-
ment basins (0.04 ratio, and 70 per-
cent of area)
2 Same as (1) except chemical (12 90
months protection) replaces straw
3 Same as (1) except chemical straw 91
tack replaces asphalt
4 Seed, fertilizer, straw mulch. Diver- 90
sion berms. Sediment basins (0.04 ratio
and 100 percent area)
5 Seed, fertilizer, straw mulch. Down- 93
stream sediment basin (0.06 ratio)
6 Seed, fertilizer, chemical (12 months 92
protection). Downstream sediment basin
(0.06 ratio).
7 Seed, fertilizer, straw mulch. Down- 96
stream sediment basin using flocculants.
8 Same as (7) without straw mulch. 94
9 Chemical (12 months protection) sedi- 94
ment basin using flocculants.
10 Same as (9) with seed, fertilizer 96
G-28
-------
Detailed costs for 25 erosion control methods were estimated in a report
prepared for the Environmental Protection Agency by Engineering Science,
Incorporated (18). Table G-5 summarizes the unit cost estimates developed,
along with major assumptions used in preparing the estimates. The report
also provides a method for estimating the overall cost of sediment control
at specific sites as well as the damage costs which would result if no
control were exercised.
It is difficult to generalize what a typical construction site erosion
control system is and what its cost (e.g., $/acre) would be. The number,
type, and cost of control measures are highly variable and very site and
geographically specific because: (1) the erosion potential of sites vary
widely with climate, slope, soil type, existing ground cover and other site
conditions; (2) labor rates and material costs vary from region to region;
(3) costs and feasible techniques are a function of project size, site
terrain, and the type of construction activity (residential building, pipe-
lines, highways, etc.); (4) it is sometimes difficult to distribute costs
and benefits between sediment control objectives and aesthetic benefits
(e.g., sodding and seeding practices, on-site ponds as sediment traps);
and (5) techniques applied and their costs vary with the intended period of
effectiveness, project life, and maintenance cost requirements.
Some attempts to evaluate average sediment control requirements for
construction sites have been made. In 1972, for instance, Dow Chemical Co.
performed an economic analysis for sediment control methods for watersheds
undergoing urbanization (19). It utilized the Seneca watershed near
Washington, D.C. as a model. The control practices included sedimentation
basins, diversion berms, level spreaders, grade stabilization, sodded
ditches, seeding and straw mulch. The total watershed system cost $1,125
per acre and controlled 91 percent of the erosion. It claimed that control
systems with large sedimentation basins could boost control to 96 percent
at a lesser total cost. Engineering Science (18) also estimated the cost of
a "typical" erosion control program for a 2.95 acre commercial construction
project. The control system included straw bale sewer inlet protectors, an
earthen diversion dike, a straw bale diversion with a gravel weir, and a
sediment retention basin. Using the unit cost values in Table G-5 the cost
G-29
-------
TABLE G-5
COSTS FOR ON-SITE EROSION CONTROL MEASURES*
METHOD
UNIT COSTS
California Virginia
REMARKS
A) CONTROL STRUCTURES
Gravel and Earth Check Dam
Rock Riprap Check Dam
Concrete Check Dam
Concrete Chute
Diversion Dike (Interceptor
Dikes)
Erosion Check
Filter Berm (Filter Inlets)
Flexible Downdrain
Flexible Erosion Control Mats
Gabions
Level Spreader
Sandbag Barriers
Sectional Downdrain
Sediment Retention Basin
Straw Bale Inlet Protection
Straw Bale 'Barriers
$1.84-0.83/cf
$7.00-8.17/cf
$22.15-8.04/cf
$32.45/£t
5.40/ft2
$4.51/ft
0.48/cf
$3.43/£t
$5. SO/ ft
0.39/cf
$7.34/ft
$1.18/ft2
$3.34/ft2
1.72/ft2
1.41/ft2
$3.80/ft
1.91/ft
1.63/ft
$3.10/bag
12.40/ft
$14.55/ft
10.91/ft
$0.51-0.39/cf
$S5/inlet
$3.93/ft
-
$5.99-$6.96/cf
$20.03-$7.22/cf
$28.35/ft
4.72/ft2
$3.70/ft
0.39/cf
$2.65/ft
$5.11/ft
0.37/cf
$7.26/ft
$l.ll/ft2
$2.76/ft2
1.54/ft2
1.26/ft2
$3.16/ft
1.57/ft
1.36/ft
$2.44/bag
9.76/ft
$11.85/£t
9.13/ft
$0.42-0.33/cf
$46 /in let
$3.3;l/ft
19 cf - 225 cf
structures, resp.
56 cf - 300 cf
structures. resp.
51 cf - 891 cf
structures, resp.
40 ft chute, 3 ft wide
sides, 3 in thick
405 cf dike, 43 ft long
150 ft jute mesh
810 cf gravel berm
•;nn ft unit with end
connections
based on . 33,000 ft2
channel lining install.
10 ft2xl ft install.
100 ft2xl ft "
1000 ft2x 1 ft "
15 ft long
44 ft long
78 ft long
filling § placing 180
bags/dayMSW barrier
44 ft unit
234 ft unit
earth structures 30 to
40 ft long and 6-8ft h
2 ft bales x one high
B) GROUND COVERS
Excelsior Mat
Jute Mesh on One-Acre Plot
Straw or Hay (blower applied)
Woodchips
4" Square Plugs of Sod
Sodding
Chemical Soil Stabilizer
Hydromulch
$12,000/ac
$7,700/ac
$l,200/ac
$8,000/ac
$ll,300/ac
$14,800/ac
$l,300/ac
$858-434/ac
$10,200/ac
$6,700/ac
$l,100/ac .
$7,200/ac
$10,300/ac
$14,300/ac
$l,250/ac
$738-373/ac
includes seed 6
fertilizer
3" cover
includes seed §
fertilizer
1 acre - 30 acre job,
resp.
*A11 costs in 1972 dollars
G-30
-------
was estimated at $l,340/acre (California) and $l,110/acre (Virginia).
Engineering-Science also concluded that the technique which appears to be
the most cost-effective is hydromulching. Hydromulching is a technique where
wood chips are mixed with grass seed, fertilizer and water to form a slurry
which is then sprayed on the denuded land. The wood chips tend to hold the
soil and encourage the growth of the grass which then acts as an effective
erosion deterrent. The cost of hydromulching in 1973 dollars ranges from
about $850/acre when only one acre is treated to a low of about $344/acre
when the land area is 30 acres or greater. For the example commercial
construction site described above, the use of hydromulching would add
$720/acre (53.7%) and $680/acre (6.13%) to the erosion control program costs
in California and Virginia, respectively.
Cost estimates have also been made in various studies for determining the
economic, aesthetic, and environmental damages which may result from not
controlling erosion. The Dow Chemical Study estimated that miscellaneous
damages of erosion from construction sites could reach $1,500 per acre (19).
These damages included: a need for turbidity control in water treatment;
dredging costs downstream; flooding; adverse effects to commercial and
recreational fishing; boating and aesthetics. Engineering Science also made
cost estimates of removing silt from homes, streets, stream channels, and
in domestic water treatment (18). Estimated costs for sediment removal are
shown in Table G-6. The study concluded that the cost of controlling erosion
at construction sites is in most cases significantly less than the cost of
correcting the damage caused by uncontrolled erosion.
G.3.3 Site Runoff Control
On-site or upstream runoff control refers to storage for detention (short
term) or retention (long term) of runoff prior to its entry into a drainage
system. In urban areas, roofs of structures represent a large part of the
impervious surfaces which increase runoff. In many communities with .combined
sewers, the drainage from such roof areas is discharged into the sewer
system via the single property sewer connector. The pollution potential
of roof runoff consists of particulate air pollution dustfall, tree leaves,
and bird droppings. Other impervious surfaces such as paved parking lots,
G-31
-------
TABLE G-6
COSTS FOR SEDIMENT REMOVAL MEASURES
(Adapted from Reference 18)
Removal Measure
Unit Costs
California Virginia
Sediment Removal from Streets
Sediment Removal from Basements
Sediment Removal from Storm Sewers
Bucket Line Cleaning
Sediment Removed from Storm Sewers
Redding § Hydraulic Flushing of
Storm Sewer
$8/cy
$77/cy
$144/cy
$68/cy
$6.60/cy
$65/cy
$122/cy
$62/cy
G-32
-------
plazas, etc., having their own classes of pollutants, generally drain into
the municipal sewerage system, causing sudden increases in pollutional load
and wastewater volume during a storm event. In areas of lesser population
densities, although the absolute and relative magnitudes of impervious
surfaces decrease, similar effects of a storm event exist but to a lesser
degree. In the latter situation in addition to runoff from impervious areas,
surface runoff from pervious areas also contributes a pollutional load,
generally erosion solids; and results in a sudden incremental volume to
either the sewerage system or to the natural drainage network of the area.
Detention - In its simplest form, detention means capturing stormwater and
controlling its release rate in order to decrease downstream peak flow rates.
Oftentimes, on-site storage does or can be designed to provide for the dual
or multi-benefits of aesthetics, recreation, recharge, irrigation, or other
uses. For example, groundwater supplies are replenished by detention-recharge.
However, the potential for groundwater pollution must also be considered.
The design essentials include a contained area that allows the stormwater to
pond and a release structure to control the rate at which the runoff is
allowed into the drainage system. The release structure is usually a simple
construction, such as a small-diameter pipe draining the basin or an
orifice plate placed at a sewer inlet. The capacity of the pipe or orifice
limits the flowrate to a level acceptable to the downstream system. Where
the depth of ponding has to be limited, the release structure will have an
automatic overflow to prevent excessive ponding.
Successful variations of detention that take advantage of facilities
primarily used for other purposes are ponding on parking lots, plazas, and
recreation and park areas. The fundamental approach is the same as for other
forms of detention but low cost is implied.
Surface ponding is the most common form of detention being used by developers.
In most cases the facilities are carefully planned so that the ponding area is
a dual-use facility for recreation and athletics that enhances the value of
the site when dry. Variable level ponds have a permanent water level during
dry weather and increased holding capacity during storm conditions. The
permanent lakes have aesthetic and recreational appeal which increases
lot values. Basins that are dry between storms are often designed to be
G-33
-------
used as baseball fields, tennis courts, and general open space. Parking lots
can be made to serve as low-depth storage ponds by sloping the side and
constructing drain outlets. Side slopes are restricted to about 4 percent
for traction in the winter, and the pond depth is limited by the need for
people to reach their vehicles. Obviously, a truck terminal lot can be
allowed to pond to a. greater depth than a supermarket lot.
Other variations of detention that have proven successful for metropolitan
application are ponding on plaza areas and ponding on roof tops. The basic
approach is the same as for other forms of detention. The outlet from the
ponding area must be constructed to allow runoff to accumulate during peak
storm conditions. The depth that can accumulate on plazas must be limited to
approximately 3/4 inch because of pedestrians, .but it is possible to design
plazas so that portions can be flooded without inconvenience. Metropolitan
roof tops provide an excellent opportunity for stormwater detention. Most
are flat, watertight, and structurally designed to take loads greater than
that of ponded stormwater. It adds very little to the cost of a new
building to ensure structural conditions for ponding. The detention is
controlled by a simple drain ring set around the roof drains. As the roof
begins to pond, flow is controlled by orifices in the ring; extreme flows
overflow the ring to prevent structural damage to the roof.
Retention - The precipitation/infiltration process is the most important
method of replenishing the groundwater reservoirs that serve as potable
water supplies for many areas of the county. The decreased infiltration
and increased water demand caused by urbanization will stress groundwater
supplies unless recharge areas are set aside. Although large-scale urban
stormwater recharge programs have not been implemented because of potential
groundwater pollution, onsite retention and recharge has been developed for
small watersheds. Retention basins are usually variable-depth ponds
designed with no outlet or only a bypass for exceptional flow conditions.
They fill during storms and help maintain the groundwater during dry
intervals. If groundwater protection is important, heavily polluted runoff
is not used for recharge. The pollution control value is in the decreased
volume of runoff entering downstream systems, as was discussed in the
previous section.
G-34
-------
Retention is also practiced as controlled onsite storage where groundwater
recharge is not important. In a typical example, the California Division of
Highways has built retention basins to dispose of highway runoff in the
San Joaquin Valley. These basins were developed from 1- to 6-acre depressions
that had originally been excavated for embankment material. Infiltration
capacity is sometimes improved by excavating 6- to 10-foot deep trenches or
vertical drains and backfilling with porous material. Maintenance is
minimized by providing low-velocity channels ahead of the basins to help
settle suspended particles. The areas are scarified once a year to decrease
the surface clogging effects of organic solids. Advantages of the ponds
include total containment of the highway runoff pollutants and the
recreational asset to local cities that can result from an overall plan to
landscape the basins as additional park land. The alternative to retention
is to construct sewers to carry the runoff to receiving waters. Therefore,
the economic advantages depend on the size and length of sewer that would be
required.
Design Considerations - The acceptability of onsite storage as a pollution
control alternative depends on the mitigation of apparent adverse factors,
including the safety hazard to children, maintenance difficulties, mosquito
breeding, algae growth, the land area required, possible poor appearance of
dry ponds, and the responsibilities of ownership.
Safety - The safety features depend on the secondary use of the facility.
Obviously, a dual-purpose recreational lake cannot be fenced to prevent
access. Typical safety features include shallow bank slopes, fences,
and outlet guards.
Maintenance - Debris removal, care for the landscaping, and maintenance
of the outlet structure are all part of the routine operation of a
retention facility.
Mosquito breeding and algae growth - Both mosquito and algae problems can be
eliminated from dry basins by ensuring that the areas dry out completely
between uses. For permanent ponds, these problems are more difficult to
control. Mosquito breeding can be upset by controlling grass at the shoreline,
varying the water depth every few days, or stocking the ponds with larvae-
eating fish.
G-35
-------
Land area required - The best way to overcome objections to land set aside
as a detention pond is to recognize that the area can be an asset as open
space. Housing near greenbelts and pond areas usually has a higher market
value if the open space is aesthetically designed.
Poor appearance of dry ponds - Detention ponds are most presentable when
a grass cover is kept on the basin slopes and floor. Grasses can be grown
that will withstand periodic flooding. If retention basins contain water for
long periods of time or need to be vegetation-free for better infiltration,
appearance objections may be overcome by sight barriers such as trees.
Responsibility of ownership - In most cases the responsibilities of operation
and ownership should be assumed by a public agency. The equipment, manpower,
and expertise required for operation and maintenance is beyond the abilities
of homeowner associations and developers.
Effectiveness and cost - The effectiveness of storage ponds in reducing
pollutional loads can be estimated from the following exercise. In Chapter
t
16 of the Soil Conservation Service Hydrology Handbook (20) the following
relationship was developed based on the use of a triangular hydrograph and a
number of heuristic constraints:
q = 484 A Q/(D/2 +0.6 Tc) (G-ll)
qp = peak rate of runoff, CFS
A = catchment area, sq. miles
Q = amount of rainfall, inches
D = duration of rainfall, hrs
Tc = time of concentration, hrs
In the context of runoff storage it is seen in the equation that the peak
rate of runoff (qp) is directly proportional to the, amount of rainfall (Q)
and the size of the catchment area (A). If, for example, the runoff from
25% of the urban drainage area flows into storage ponds, the peak runoff
rate will be reduced by 25%.
In order to estimate the effect that residential storage ponds have on
reducing combined sewer overflows the following computations must be performed.
The fraction of the drainage area from which runoff flows into storage ponds
G-36
-------
is called Fa, and K is the ratio of treatment plant capacity (TPC) to dry
weather flow (DWF). When storage ponds are used, a corrected value for K
(called K*) can be computed as follows:
K* = (K - 1) / (1 - Fa) + 1 (G-12)
This procedure has been followed for the situation in which 25% and 40% of
the land area drains into ponds, and the results are shown in Figure G-6.
This figure shows that while the use of on-site storage does have a potential
for reducing the annual hours of overflow, the reduction is strongly
dependent on the K ratio. If, for example, the K ratio is 10 and 40% of the
land area drains into ponds, the number of hours that overflows occur per
year are reduced from 65 hours/year to 46 hours/year. This is a 29.2%
reduction in annual overflow hours and a 40% reduction in runoff volume.
However, a more representative raio (K) of TPC:DWF ratio is 4. At K = 4,
there is a 12% reduction in the number of hours overflow per year when
25% of the drainage area runoff is impounded, and a 21.4% reduction in hours
overflowing when 40% of the land area drains into ponds.
The feasibility of using neighborhood ponds for storage of runoff depends on
the topography of the community and on the availability and cost of land.
Although no general appraisal of the cost/effectiveness of ponds is
applicable to all situations, one economic aspect of surface ponding is
derived from the savings realized by eliminating the construction of a
conventional sewer project. As examples of the cost magnitude involved
several surface ponding sites are listed in Table G-7 showing the cost
comparison between estimates for drainage systems using ponds to decrease
peak flows and estimates for conventional strom sewer construction.
In the absence of technical feasibility and economic estimates to the
contrary, the following type of reasoning can be used when the characteristics
of the specific community are known. If the ponds are sized to contain the
runoff from a total of eight inches of rain, the range of water level for
the ponds is two feet, and the volumetric runoff coefficient is 0.25, the
ratio of drainage area to ponds area will be 12. Thus, if 25% of the
surface drains into the ponds, the pond area will be 2.1% of the drainage
area. The cost of ponds was estimated by Black and Veatch (22) as roughly
G-37
-------
NOTE: CURVES ARE FOR
0%,25%, AND 40% OF
DRAINAGE AREA DRAINING
INTO PONDS
I I I I I I III
1 10 100
TREATMENT PLANT CAPACITY/DRY WEATHER FLOW
FIGURE G-6
EFFECT OF UPSTREAM STORAGE ON ESTIMATED ANNUAL
HOURS OF OVERFLOW VERSUS TREATMENT PLANT
HYDRAULIC CAPACITY
G-38
-------
TABLE G-7
COST COMPARISON BETWEEN SURFACE PONDING TECHNIQUES
AND CONVENTIONAL SEWER INSTALLATION (21)
Site
Description
Cost estimate, $
With Surface
Ponding
With Conventional
Sewers
i
w
vo
Earth City,
Missouri
Consolidated
Freightways, St.
Louis, Missouri
Ft. Campbell,
Kentucky
Indian Lakes.
Estates, Blooming-
ton, Illinois
A planned community in-
cluding permanent re-
creational lakes with
additional capacity for
storm flow
A trucking terminal using
its parking lots to de-
tain storm flows
A military installation
using ponds to decrease
the required drainage
pipe sizes
A residential development
using ponds and an
existing small diameter
drain
2,000,000
115,000
2,000,000
200,000
5,000,000
150,000
3,370,000
600,000
-------
$15,000/acre in current dollars. If the land cost is taken as $5000/acre
the total cost of ponds will be $20,000/acre. In terms of dollars per acre
of total drainage area this is $500/acre. Amortizing the ponds at 6% over
a life of 50 years the cost of owning the ponds will be $31.72/acre-year.
If the pollutional load of the runoff is 30 Ib BOD/acre-year and the ponds
reduce the load by 12.5% to 25% the cost of BOD reduction will be in the
range $4.23 to $8.46 per Ib BOD removed. Thus, it appears that the use of
neighborhood ponds for storage of runoff may be a feasible pollution control
alternative.
As mentioned in the beginning of this section on on-site control of runoff,
another alternative for reducing the amount of combined sewer overflowing
is removal of roof downspout drainage from the combined sewer. If downspout
drainage is directed onto the lawn area a major fraction of the rainfall
runoff from roofs is likely to infiltrate into the ground. In the ten
acre area studied by APWA (4) and Tholin and Keifer (23) about 31% of the
area of the individual building lots was roof area. About 17.2 percent
of the ten acre area was covered by paved streets and alleys. The pervious
graction including roofs, streets, and alleys was 0.379. If the runoff
coefficient for lawn area is taken as 0.1 and the runoff coefficient for
streets and roofs is taken as 1.0 the composite runoff coefficient with
downspouts emptying into the combined sewer will be 0.44 as compared to
0.25 when the downspouts are directed onto the lawn area. This represents
a 43 percent reduction in the runoff coefficient. Since some of the roof
drainage will fail to infiltrate and perhaps flow ultimately into the
combined sewer this estimate is an upper limit. It might be expected that
removing downspouts might reduce the annual hours of overflow by about
15-25 hours/year and effect a reduction in total runoff volume between
25-40%. This simple and inexpensive method appears to have significant
potential for preventing combined sewer overflowing and thus reducing the
amount of pollution which reaches the stream. The cost will be primarily
measured in terms of inconvenience to homeowners.
G-40
-------
G.3.4 Porous Pavement
The use of porous asphalt paving to improve infiltration of precipitation
at the source prior to concentration is a technique which is still in the
developmental stages. Its purpose is to increase infiltration and to reduce
flood peaks. It is also used to reduce the need for separation of storm
sewers and sanitary sewers, especially in cases where the system is already
overloaded. The advantages of using this management technique are given as
follows:(24)
1. Reduces the total volume of runoff from paved areas.
2. Can reduce the peaking effect of local floods.
3. Enhances groundwater supply.
4. Its use can often result in savings resulting from the elimination
of the need for storm sewers and curbing.
5. An improvement in the quality of roadside vegetation may be seen due
to improved water availability in the soil.
6. As contrasted with conventional paving materials, there would be
some preservation of natural drainage patterns in the urban setting.
A number of potential disadvantages are given as follows: (24)
1. It has not been clearly established that the filtering effect of
the sub-base results in a significant improvement in the quality
of the runoff if that runoff is polluted. In those instances
where the runoff can be severely polluted by substances which could
reduce the quality of the groundwater, it is not recommended that
porous pavement be used.
2. Under certain circumstances the surface may become clogged and its
permeability reduced or eliminated. Examples of such conditions
are inadequate maintenance, rain on a frozen surface, and certain
conditions during snowmelt. These circumstances can all result
in runoff.
3. When the usual accessories of conventional paving are required
(curbs, etc.) the higher construction costs may affect other
economic considerations.
G-41
-------
4. A special maintenance program is required.
The feasibility of using proous pavement in urban areas to reduce the rate
and volume of runoff was examined by Thelen et al. (25) of the Franklin
Institute Research Laboratories, Philadelphia, Pennsylvania. They concluded
that an open-graded asphalt concrete would be the most suitable material for
porous pavement because of its superior physical characteristics, its low
cost, and its ability to be laid by conventional paving methods. Other
types of porous pavement such as bricks assembled on rods with spacers,
rubber sheeting over honeycomb, or bricks with lugs to control spacing have
been suggested and might be appropriate for parking lots or aircraft runways.
The potential advantage of using porous pavement appears to be good but
many problems have yet to be fully resolved. For example, water which
infiltrates into the surface and the base course must be able to slowly
infiltrate into the subgrade. Thelen et al. estimate that the coefficient
of permeability must be at least 0.01 ft/day; characteristic of a sand-clay
mixture. Freeze-thaw laboratory experiments were performed by Thelen et al.
and it was concluded that the asphaltic porous surface would be able to
hold its strength after 265 freeze-thaw cycles. However, a more realistic
way of testing the porous pavement would be to lay a test length of highway
in a. northern climate. The hope is that aerobic bacteria which should be
able to live in the surface and base courses of the pavement will help to rid
the open spaces of organic material which will tend to clog the interstices.
However, much of the dust-and-dirt which accumulates on streets is inorganic
and the possibility of gradual clogging has not been adequate investigated.
As compiled by Delaware University, Water Resources Center, the design
criteria and specifications are as follows: (24)
Porosity of Asphalt: Lab studies at the Franklin Institute (25)
revealed that a porous asphaltic concrete containing 55% asphalt
by weight and aggregate graded to allow water flow of 76 inches
per hour to be optimal porous road material.
Aggregates: The aggregates used for porous pavement construction should
satisfy ASTM-C-693-71 except in requiring the gradation to be the
"open-graded type", but also requiring a soundness test ASTM-694-62.
G-42
-------
As observed in Table G-8, the surface thickness and the thickness of the
aggregate base course depend on the load bearing capacity of the subgrade
soil and the traffic volume carried. The base thickness ranges from 6 inches
for light traffic to 22 inches for highway traffic. The surface thickness
ranges from 4-7 inches. The reservoir capacity of the pavement ranges from
2.4 inches of rain at a 6-inch base thickness to 7.65 inches of rain at a
base thickness of 22 inches. Thus, it can be seen that even with 6 inches
of base the reservoir capacity is sufficient to store a very large fraction
of the storms. Since streets and highways cover about 28% of the developed
urban area it is not unreasonable to visualize porous pavement as having an
effect similar to ponds holding the runoff from 28% of the drainage area.
Capacity of Subsurface Reservoir: For the Philadelphia area a sub-
surface reservoir depth of 16 inches is recommended, capable of
providing temporaty storage for a design storm of 5.4 inches per
hour. Maximum daily precipitation is the critical factor and base
courses of 7 inches are recommended for areas with 3 inches maximum
precipitation per rainy day, 14 inches thickness for 6 inches
maximum daily precipitation.
Soil Permeability: A soil capable of absorbing 5 inches of rainfall in
a 10-day period, having a permeability of over 0.042 ft/day is
adequate.
Maintenance: The surface of porous paving must be cleaned regularly
and after each storm using a vacuum-type road sweeper to keep
surface porosity as great as possible.
Additional design criteria and specifications are:
1. On slopes in excess of 5% porous paving should not be used.
On shallower slopes a gravel-filled swale takes runoff and
base flow.
2. Where soil is poorly drained, trench drains may be used at
edges of porous paving areas or in a lattice work to lead
excess water off-site.
G-43
-------
TABLE G-8
REQUIREMENTS FOR SURFACE AND BASE COURSE AND SUBSURFACE CAPACITY
Traffic
Load
Light
Medium
Heavy
CBR1!
2
2
2
2
2
2
2
DTN1
1
10
20
50
100
1000
5000
Surface
Thickness
(inches)
4
4
4-1/2
5
5
6
7
Base
Thickness
(inches)
6
12
13
14
16
20
22
Reservoir Capacity (in. of rainfall)
Surface Base Total
.60 1.80 2.40
.60 3.60 4.20
.66 3.90 4.56
.75 4.20 4.95
.75 4.80 5.55
.90 6.00 6.90
1.05 6.60 7.65
o
I
Notes: 1. DTN = Design Traffic Number; CBR = California Bearing Ratio
2. A minimum surface thickness of 4 inches is used regardless of DTN
3. The estimated volume of voids in the base aggregate is 40%.
4. Frost bearing: If the combined surface and base thickness is less than
anticipated frost penetration, additional base is required.
-------
3. A single "V" drain may be used to intercept longitudinal base
flow during exceptional storms or to divert base flow from fill.
4. In areas where grading puts exceptional pressure on areas of
subsurface reservoirs, excess water can be removed via a tile
drain system.
5. Additional informtion on specifications is found in the EPA
report "Investigations of Porous Pavements for Urban Runoff
Control" (25).
Cost Guidelines: Under contract, the University of Delaware built a
3100 sq. yd. porous parking lot in 1973. The cost of two inches
of asphalt topping was $5.50 per sq. yd. as compared to $3.33 per
sq. yd. of conventional asphalt.
An estimate of costs of conventional and porous pavements prepared by the
Franklin Institute in 1972 and updated to January, 1975 is shown in Table
G-9.
TABLE G-9
COSTS OF CONVENTIONAL AND POROUS PAVEMENTS
($ per sq. yd.) (26)
Type
Parking Lot
Residential Street
Low Capacity
High Capacity
Business Street
Suburban
City
Rural Road
Highway, 2 -lane
Porous
Range
8.43-8.53
8.44-8.49
8.25-8.75
8.87-9.29
9.32-11.09
8.01-11.09
9.07-10.56
Pavement
Average
8.48
8.47
8.51
9.04
10.21
8.59
9.81
Conventional
Range
4.87-7.75
6.40-12.80
11.13-16.13
9.20-13.20
18.93-29.60
9.65-17.60
11.39-27.27
Pavement
Average
6.31
9.60
13.64
11.20
24.27
12.27
19.33
To summarize, the use of porous pavement has many potential advantages such
as reducing the rate of runoff, replenishing the ground water supplies,
eliminating the need for curbs and storm sewers for highway drainage,
improving safety by eliminating the formation of puddles during heavy rains,
G-45
-------
and relief of flash flooding. On the other hand, questions such as the sus-
ceptability of the pavement to clogging, the durability of the pavement during
winter weather under heavy traffic loads, and the problem of adequate drainage
into the subgrade remain to be satisfactorily resolved.
Although there may be cost savings due to elimination of curbings and storm-
water drainage systems when porous pavement is used, the placement and sizing
of storm sewerage systems is generally determined by ordinance in most
municipalities. Porous paving is a relatively new development, and few
local regulations permit its use. Where it can be used, however, regulations
may not permit any reduction in the size of storm drains.
The cost of porous pavement is roughly equivalent to the cost of conventional
pavement but significantly less than conventional pavement equipped with storm
drains. The potential advantage of using porous pavement appears to be good
but many problems have yet to be fully resolved.
G.3.5 Chemical Use Control
Most surfaces in an urban setting are treated, altered, or otherwise exposed
to chemicals either applied by man or resulting directly from man's activi-
ties. The urban environment accumulates the refuse from man's activities
and the process of urbanization increases the accumulation. Contaminants
of many kinds accumulate on urban surfaces from dustfall, littering, leakage
from street vehicles, and many other sources. Particles discharged into the
air from industrial, commercial, or construction activities will either
settle to the ground if they are too heavy to remain airborne or will be
washed out in the next rainfall. On occasions these washouts can occur many
hundreds of miles distant from the original source of the air contamination.
Streets in industrial areas have been found to be particularly contaminated,
containing soluble compounds of heavy metals and organics. Concentrations of
metals in runoff have been found to be ten to one hundred times greater than
in sanitary sewage, and contain copper, cadmium, zinc, and lead in high enough
levels in street runoff to kill certain aquatic organisms (27).
Traffic residuals are another major source of chemicals in stormwater runoff.
Some pollutants such as lead compounds are released to the atmosphere and
then settle to the ground. Indicative of this is the high correlation
G-46
-------
between traffic density and lead fallout measured in dustfall. Quantita-
tively, less than 5 percent by weight of the traffic-related deposits
originate directly from motor vehicles, but these pollutants are among the
most important by virtue of their potential toxicity. Spills or leaks or
motor vehicles lubricants, antifreeze, and hydraulic fluids result in grease,
petroleum and n-paraffins in runoff. Lead and lead oxide stem from fuels
and the wear of tires. Zinc loadings may, in part, result from motor oils.
Wear of engine parts allows the deposition of copper, nickel, and chromium.
Finally, asbestos fibers are left from the wear of clutch and brake linings.
In addition to highly active industrial and commercial centers, urban
surfaces remote from these activity centers are also sinks and sources of
chemicals. Suburban sidewalks, planter strips, lawns and backyard garden
plots, driveways, and roadside green belts, etc. are contributory to the
total pollutional load of runoff. Deicing salts used on streets and high-
ways contribute not only salt contamination in acute and chronic doses, but
also are the source of ferric ferrocyanide, sodium ferrocyanide, chromate,
and phosphate which are used as special additives in much of the highway salt
in common use. High nutrient levels from fertilizer application on lawns
and garden plots, and specific pesticides resulting from tree spraying,
weed control, and insect control on public and private lands have been
noted.
Nutrients - Data on loading intensities of nutrients found on street
surfaces have been presented by Sartor and Boyd (9), and shown in Table G-10.
As noted in the report, the strength values vary somewhat from one land-use
category to another, but only over a moderate range. These data, which are
based on the analysis of samples from numerous cities, imply that all street
surface contaminants are similar in nutrient composition from site to site.
Pesticides - The widespread and often indiscriminate use of pesticides is a
cause for concern due to their toxicity and persistence in the environment.
Although it is difficult to identify specific sources of pesticides, par-
ticularly at a sublethal chronic level, reports of fish kills and subsequent
chemical analyses do substantiate the transport of this class of toxic com-
pounds to receiving waters. Sartor and Boyd (9) reported the loading
G-47
-------
TABLE G-10
NUTRIENTS IN STREET SURFACE CONTAMINANTS
VARIATION WITH.LAND-USE CATEGORY (9)
Phosphates
Residential
Industrial
Commercial
Kjeldahl Nitrogen
Residential
Industrial
Commercial
Nitrates
Residential
Industrial
Commercial
STRENGTH
(% by weight)
0.113
0.142
0.103
0.218
0.163
0.157
0.0064
0.0072
0.0600
LOADING
(Ib/curb-mi)
1.07
3.43
0.29
2.04
3.94
0.45
0.063
0.178
0.172
INTENSITY
(lb/1,000 sq ft)
12.3
39.4
3.41
23.8
67.1
5.17
0.70
2.00
1.96
Note: The term "strength," as used here, refers to the amount of
contaminant contained in the dry solids collected from the
street surface (on a weight basis), i.e., a phosphate value
of 0.1 percent would be equivalent to 1 Ib of phosphate per
1,000 Ib of sample.
intensities of pesticides found in street surface samples which they tested
(Table G-ll), and the pesticide concentration measured in the total solids
on the streets tested, distinguishing among residential, industrial, and
commercial land-use activities (Table G-12).
Additional clarification of the data indicated that ODD, DDT, and dieldrin
tended to be associated with the finer particles (DDD:60 wt %, < 246 y;
DDT § dieldrin:80 wt %, < :246 y). found on the streets.
Heavy Metals - As was the case in the discussion of pesticides, interest
in the occurrence of heavy metals in urban runoff is not so much in the BOD
implications of their presence but rather because of .their potential toxicity
in receiving streams. Data from Sartor and Boyd (9), presented in Table G-13
G-48
-------
TABLE G-ll
PESTICIDE LOADING INTENSITIES
(10~6 lb/curb-mi)
San Jose I
San Jose II
and Seattle
Phoenix II,
Atlanta
and Tulsa
Milwaukee
Bucyrus
Baltimore
p,pM)DD
67
120
34
0.5
83
100
p,pM)DT
110
170
13
1.0
60
30
DIELDRIN
11
27
24
10
17
3.0
ENDRIN
2
0
0
0
0
0
LINDANE
17
0
0
3.1
0
0
METHOXY-
CHLOR
0
0
0
8500
1600
170
METHYL
PARATHION
20
0
0
0
0
0
PCB's
1,200
1,100
65
3,400
650
1,000
TOTAL OF ALL
PESTICIDES
AND PCB's
1,427
1,417
136
12,000
2,451
1,300
en
i
-------
TABLE G-12
PESTICIDE CONCENTRATIONS IN TOTAL SOLIDS (ppm) (9)
Residential
San Jose I
Milwaukee
Baltimore
Industrial
San Jose I
Milwaukee
Baltimore
Commercial
San Jose I
Milwaukee
Baltimore
p,p-DDD
0.082
0
0.11
0.060
0
0.020
0.040
0.020
0.020
p,p-DDT
0.15
0
0.030
0.091
0
0.020
0.030
0.031
0.031
DIELDRIN
0
0.009
0
0.031
0
. 0.018
0
0
0
ENDRIN
0
0
0
0
0
0
0.058
0
0
LINDANE
0
0
0
0.031
0.001
0
0
0
0
METHOXY-
CHLOR
0
2.5
0.19
0
3.6
0
0
1.8
0
METHYL
PARATHION
0
0
0
0.037
0
0
0
0
0
PCB's
0.81
2.0
0.99
1.5
2.0
1.0
0.60
0.99
0.51
in
O
-------
shows the heavy metals loading intensities (in pounds per curb mile) as
distributed among the major land-use categories.
TABLE G-13
HEAVY-METALS LOADING INTENSITIES
(Ibs/curb-mile)
Land Use
Residential
Industrial
Commercial
Chromium
2.0
4.7
1.0
Nickel
0.5
2.2
0.3
Lead
15.7
14.8
3.5
Copper
4.8
7.7
1.8
Zinc
16.8
29.2
3.0
Mercury
4.8
0.8
1.5
The authors noted in their presentation that the samples collected from
street surfaces in the cities studied were composited in various ways to
reflect a particular trend of interest. This applies to the data shown in
Table G-13 and, therefore, should be treated accordingly when used in further
analysis.
For samples collected from five cities there was little trend for the indi-
vidual metals to be distributed in relation to particle size. An exception
to that was lead. There seemed to be a distinct tendency for lead to be
associated with fine particles (<246y). The assumption has been made that
the principal source of lead is antiknock gasoline additives, in which case
the results are as expected from particulate automobile exhaust emissions.
Deicing Compounds - The salting of streets and highways to control ice and
snow is beneficial in cutting down on highway deaths, injuries, and property
damage. Because of the large quantities of salt used annually in salting
streets, adverse environmental effects have been reported (28,29,30). Among
the many are high chloride levels in snow melt runoff, sewage, and surface
streams; high chloride levels and density stratification in lakes and
impoundments; ground and surface water supply contamination; widespread
damage of roadside soils, vegetation, and trees; high levels of chromium
and ferrocyanide compounds used as road ice additives; and roadway damage
and vehicle corrosion.
G-51
-------
Extensive use of salt for deicing of streets and highways started in the
early 1950"s when the total annual usage in the U.S. was about 500,000 tons
and has grown since then until the current usage is about 10 million tons/
year. Salt usage for deicing in the State of Massachusetts has risen from
about 25,000 tons/year in 1955 to about 225,000 tons/year in 1972. This
represents an annual increase of about 13.6%. Since the miles of streets and
highways also increased over that 18-year period the average annual applica-
tion rate increased from 4.3 tons/lane-mile in 1955 to 23.7 tons/lane-mile in
1972, a rate of increase of about 10% per year. The application rate needed
for deicing is very dependent on the climate. For example, Cincinnati, Ohio
and Ottawa, Canada both have a population of about 500,000 with about 900
miles of streets but the salt usage in Cincinnati averages about 11,000
tons/year or 6 tons per lane-mile per year while the salt usage in Ottawa is
72,000 tons/year or 39 tons/lane-mile per year.
Cost Considerations - In recent years many have questioned the advisability
of heavy use of salt for deicing, particularly, the use of the "bare pave-
ment" policy. In a study by Abt Associates (28), it was estimated that the
annual cost of adverse effects associated with the use of salt for deicing
was 2.9 billion dollars. The greatest single damaging effect was attributed
to corrosion of automotive vehicles at a cost of 2 billion dollars per year.
Other damage estimates made in this report were 500 million dollars per year
in damage to highway structures, 150 million dollars per year in damage to
health and water supplies, 50 million dollars per year in damage to vegeta-
tion, and finally 10 million dollars per year in damage to utilities.
On the other hand, the Abt report did not attempt to quantify the beneficial
effects of highway deicing through salt application. In order to establish
an order of magnitude, this aspect of the question was addressed in a report
(31) prepared by the Institute for Safety Analysis (TSIA) for the Salt
Institute of Alexandria, Virginia. The total annual benefits associated
with highway deicing was estimated at 18.4 billion dollars in the TSIA
report. About 80% of the total was associated with lost wages and lost
productive capacity caused by late arrival at work when no salt is used
for deicing of streets and highways. TSIA estimated that about 42 million
persons are employed in the snow belt at an average wage of $4.54/hour. Thus,
G-52
-------
if each worker is delayed by two hours on each of twenty inclement weather
days per year the total wages lost will be about 7.6 billion dollars per
year. Workers engaged in manufacturing were estimated as 13.9 million
within the snow belt. The value of lost productive capacity was estimated
as $9 per hour. Thus, if each manufacturing worker is late for work, by
two hours on each of 20 inclement days per year the total loss in productive
capacity is computed as 7 billion dollars annually. These two estimates
account for 14.6 billion dollars annually or about 80% of the grand total
for benefits.
Other categories of benefits estimated in the TSIA report were loss of
wages because of absenteeism, loss of revenue earned in shipment of goods
by truck, and increased use of automotive fuels. Wages lost as a result
of absenteeism was estimated by assuming that 10 percent of the 42 million
workers in the snow belt will be absent on each of 20 inclement days per
year. Assuming an 8-hour day and $4.54 per hour in wages this benefit
totals about 3 billion dollars annually. Potential losses to intercity
truck revenue was based on an estimate of 93 million vehicle-miles traveled
daily in the snow belt and an estimate that 70% of the vehicles-miles were
load-carrying or revenue-producing. The revenue produced per vehicle-mile
was estimated as $1.15 and a two-hour delay was assumed on each of 20
inclement days per year. Pick up and delivery trucks within the snow belt
travel an estimated 189 million vehicle-miles per day or 13.5 million
vehicle-miles per hour assuming a 14-hour work day. Of these vehicle-miles,
it was estimated that about 48% were loaded and generating revenue at the
rate of $2.20 per vehicle-miles. Using these assumptions the estimate for
revenue lost due to a two-hour delay on each of 20 inclement days per year
was computed as 600 million dollars annually.
The increased cost of automotive fuel was estimated from the additional
fuel consumption known to be required for travel on snow- and ice-covered
streets and highways. About 2,287 million vehicle-miles are traveled by
all automotive vehicles in the snow belt daily. At an average gasoline
mileage of 20.8 miles per gallon the total fuel consumption in the snow
belt is about 110 million gallons/day. Estimating the cost of fuel at
$0.60 per gallon the daily fuel cost is about 66 million dollars per
G-53
-------
day. The increase in fuel consumption caused by hard-packed snow and ice
cover on the streets was estimated at 15%. Thus, the daily cost for addi-
tional fuel was about 10 million dollars. Multiplying this by the estimated
20 inclement days per year gives a total annual additional fuel cost of 200
million dollars.
Although TSIA presented convincing evidence that time lost in responding to
traffic accidents and other forms of medical emergencies can result in loss
of life no attempt was made to place a monetary value on this aspect of the
problem.
TSIA also reevaluated the categories of salt damage presented by the Abt
Associates report. The TSIA estimate for total annual damage was one billion
dollars as compred to the Abt Associates estimate of 2.9 billion dollars.
Although additional work might profitably be done to more precisely estimate
the costs and benefits associated with the use of salt for deicing highways
and streets it is clear from these two reports that neither of the two
extremes of heavy salt use to implement the "bare pavement" policy or a
prohibition on the use of salt are likely to represent the best solution.
As presented by Field et al., (29) aside from chemical melting, various
methods for deicing are available or have been conceived which may become
more prominent in the future especially when communities realize that a
price must be paid to alleviate the pollutional effects of wintertime
salting. Some of these methods are:
1. External and in-slab thermal melting systems.
2. Stationary (or pit) and mobile thermal "snow melters".
3. Substitute deicing compounds.
4. Compressed air or high-speed fluid streams in conjunction with
snowplow blade or sweepers to loosen pavement bond and lift snow.
5. Snow adhesion reducing substances in pavement.
6. Pavement substances that store and release solar energy for
melting.
7. Electromagnetic energy to shatter ice.
G-54
-------
8. Road and drainage design modifications to enhance runoff, reduce
wintertime accidents, and capture snowmelt for treatment or control,
9. Salt retrieval or treatment possibly enhanced by the addition of
chelating agents.
10. Improved tire or vehicular design to reduce deicer requirements.
Although it is recognized that power, maintenance, and chemical
costs for the above systems are high when compared to rock salt,
municipalities, such as Burlington, Massachusetts have expressed a
deep willingness to explore and demonstrate new methods regardless
of cost. Burlington has recently suspended roadway salting prac-
tices when a study indicated that their well water chloride con-
centrations could exceed the recommended limit of 250 mg/1 if
salting was continued. It should also be pointed out that experi-
ence, operational data, and knowledge of environmental effects are
lacking for the substitute chemical deicers.
G.3.6 Control of Particulate Fallout
The provisions of Section 208 of the Federal Water Pollution Control Act
Amendments, as well as a variety of 208 planning guidance documents, mandate
coordination between air quality maintenance planning and areawide waste
treatment planning. Particulate material released into the atmosphere
precipitates by gravity or through entrainment with precipitation and may
contribute significantly to the dust-and-dirt cover on urban surfaces. This
material is then available for incorporation as pollutant load in urban
runoff.
Major sources of such materials are stacks and vents, construction and
excavation projects, agricultural operations, and exposed vacant land areas.
Automobile traffic and commercial air traffic are also sources of fine
airborne particulates. Materials may be generated from activities entirely
within the 208 area or through transport from other areas by prevailing
winds.
Many such forms of fallout are largely inert and would contribute only to
turbidity and suspended solids levels in runoff. Others, however, may be
G-55
-------
reactive and possibly impose BOD, nutrient, and toxics loadings upon
receiving waters. The extent to which each source contributes to the
accumulation of specific pollutants on urban surfaces is a complex issue,
and one that has not been adequately defined. Nonetheless, some coarse
estimates can be made, particularly with regard to nontransportation
related particulates, to provide a judgement regarding the potential
impact of point source air quality control upon runoff.
In the 1950's and 1960's contaminants falling to the surface by gravity or
as a result of being entrained in rainfall were routinely measured by means
of dustfall jars. Dustfall jars were partially filled with water and placed
in an elevated position, such as a rooftop, for a period of one month. The
contents of the jars were then analyzed for mass of particulate material,
composition, particle size distribution, etc. The use of dustfall jars has
been discontinued in most communities in recent years in favor of the high-
volume sampler. Johnson et al. (32) gives average values for dustfall in
seven U.S. cities which range from a low of 15.5 tons/sq mi/mo in Tacoma,
Washington, to a high of 63.8 tons/sq mi/mo in New York City. APWA (4)
reported that the average dustfall in Chicago was 36.9 tons/sq mi/mo in
1966 and 41 tons/sq mi/mo in 1965. APWA also showed that the amount of
dustfall depended on the month of the year, being least in August and
maximum in February.
The amount of dust-and-dirt swept from streets as reported by APWA (4)
was 79.2 Ib/day/curb-mile. This estimate can be converted as follows to
tons/sq mi/mo when the miles of street per acre is known and it is assumed
that the area of the streets is about 28% of the total urban land area.
tons/sq mi/mo = 5431 (miles of street/acre)
The miles of street per acre in the 10-acre test area used by APWA (4) was
0.037. Therefore, the amount of dust-and-dirt was equivalent to 201 tons/
sq mi/mo. Thus, it can be concluded that the measured dust-and-dirt
originating from dustfall was approximately 30% of the total surface
accumulation estimated from street sweeping experiments. Johnson (32)
gave percentages ranging from 16-33% of the total dust-and-dirt which might
originate from dustfall. These might well be over-estimates because there
G-56
-------
is evidence that conversion from coal to oil and gas for heating and the
imposition of air pollution regulations has reduced the amount of pollutants
in urban air.
Thus, it may be seen that control of particulate air pollution will benefit
pollution control. For illustrative purposes, the cost of particulate
control will be compared with that of street cleaning.
One of the major sources of atmospheric particulates is coal-fired power
generating stations. For this example a plant having the following charac-
teristics will be considered: capacity - 1000 megowatts; conversion rate -
0.85 Ib coal/kw-hr.; coal content - 15% ash; 85% of ash entrained in flue
gas (no control); volume of gas - 4 million actual cubic feet per minute
(acfm); electrostatic precipiator efficiency - 99%.
Using these assumed data the potential amount of flyash emitted from an
uncontrolled stack can be estimated at approximately 900 million pounds per
year. The cost of a 4-million acfm electrostatic precipitator installation
is about $21 million (33). This amount amortized at 17% per year, typical
of industrial depreciation rates, results in an annual cost of $3,570,000.
Operating and maintenance cost will be about $178,000 and the cost of power
at three cents per kw-hr is about $850,000 per year. The total cost of
removing over 99% of the particulate is about $4.6 million dollars/year.
Thus, the cost of removing particulate material at the source is about a
half cent per pound.
On the other hand, the cost of mechanical street sweeping to remove dust-and-
dirt from street surfaces is more expensive. Using the APWA accumulation
rate for Chicago (79.2 lb/day/curb-mile), a seven day sweeping frequency, 50%
sweeper efficiency, and the average sweeping cost developed in Section G.3.1
($10.40/curb-mi1e), the cost of removing dust-and-dirt may be estimated at
roughly four cents per pound of dust-and-dirt removed.
Thus, it appears that removing the particulate material at the source is less
expensive by a factor of nearly 8. In smaller sized power plants the cost
will be somewhat higher per pound of particulate removed but not likely to
equal the cost of removing dust-and-dirt from the street by sweeping. It
should also be remembered that particulate control would effect all urban
land area, including streets. However, on a BOD basis it is difficult to
estimate the impact of particulate source control. For the example above
G-57
-------
the effect upon potential BOD loadings from urban runoff would be negligible.
For other industrial or municipal sources which could contain oxygen demanding
materials the impact could be greater.
G.4 Collection Systems Control Alternatives
G.4.1 Introduction
The goal of management practices applied to collection systems is either
hydraulic control to minimize the volume of storm runoff and municipal
sewage which overflow into the receiving stream without treatment, or loading
controls to minimize the pollutants which are contained in urban stormwater
runoff and combined sewer overflows. During combined sewer flows in excess
of treatment plant capacities are a storm event diverted around the
treatment plant and are generally discharged directly into a receiving
stream without treatment. Since the overflowed excess is comprised of
untreated sanitary wastes and a wide variety of environmentally disruptive
substances, a potential public health hazard and an adverse stream quality
impact results.
It is the purpose of this section of this appendix to review the quantifi-
cation of combined sewer overflow events and volumes, and to review the
management alternatives for controlling the volume and/or pollutant loadings
attributable to combined sewer overflows.
G.4.2 Volume Control
G.4.2.1 Review of Available Analytical Techniques
A number of reports have attempted to estimate the annual number of hours
during which combined sewer overflows are likely to occur as a function of
interceptor capacity expressed as a multiple of DWF. One of the first was
by McKee (34) who estimated the number of times overflow occurred and the
fraction of sanitary sewage it contained based on the intensity distribution
of the hourly rainfall.
Assuming the population density and the rate of inflow both increase, as the
runoff coefficient increases, the calculated that the rainfall intensity
producing a runoff flow equal to dry weather flow approximates 0.01 inch/hour
for all communities. He also estimated that the first 0.03 inches of each
rainfall event would be used in wetting the land surface and would result
G-58
-------
in no runoff. While this correction made little difference in the rainfall
distribution pattern, rainfall time was essentially reduced from 6.64% to
5.56%. Implicit in this analysis was the assumption that the runoff coeffi-
cient was the same for all intensities. The result of McKee's analysis is
shown in Figure G-7 (curve A) as the number of hours per year combined sewer
overflows will occur as a function of interceptor capacity expressed as
multiples of the dry weather flow rate.
The results of a study of combined sewer overflows in Detroit were presented
by Palmer (35). His analysis was for a part of Detroit having a population
density of 40 persons/acre and an estimated dry weather flow of 162 gal/
capita/day. Following McKee's lead, Palmer estimated the equivalent dry
weather flow at 0.01 inch/hour, and also assumed that rainfall equal to or
less than 0.03 inch/hour would produce no runoff. The number of hours per
year in which the rainfall exceeded 0.03 inch per hour was 263 hours, or 3%
of the time. Palmer's estimate of annual hours of combined sewer overflow as
a function of interceptor capacity is shown as curve B in Figure G-7.
St. Louis was the site of a similar analysis of combined sewer overflows made
by Shifrin and Horner (36). The area studied had a population density of
27 persons/acre and the estimated dry weather flow of 166 gal/capita/day.
They estimated the rainfall equivalent of dry weather flow at 0.007 inch/hour
and assumed that 0.4 inch of depth is required to wet the land surface. In
this analysis only a very limited range of interceptor capacity waS con-
sidered. The results are shown as curve D in Figure G-7.
Johnson (37) made a study of the number and duration of overflow events at
eight overflow points in the Washington, D.C. combined sewer system. His
analysis was similar to those of McKee and Palmer. The results, shown as
curve C in Figure G-7, demonstrated that the measured annual hours of overflow
exceeded the calculated estimates for six out of the eight overflow sites
studied.
Benjes et al (38) made a study of expected combined sewer overflow hours/
year in Kansas City. Benjes estimated the dry weather sanitary flow as
equivalent to 0.0035 inch/hour, and assumed that 0.04 inch of rain was
required to wet the land surface. The results of this study are shown as
curve E in Figure G-7.
G-59
-------
NOTE: CURVE A, FROM Mc KEE(34]
CURVE B, FROM PALMER(35)
CURVE C, FROM JOHNSON (37)
CURVE D, FROM SHIFRIN & HORNER(36)
CURVE E, FROM BENJES, etal(38)
CURVE F, RELATIONSHIP DEVELOPED
FROM DES MOINES, IOWA DATA
_ 1000
a*
to
Of.
ID
O
o
z
o
_j
u_
OL
100 -
10
OL
O
z
<
1
i i i i i ml
II M I I I
1 10 100
TREATMENT PLANT CAPACITY/DRY WEATHER FLOW
FIGURE G-7
ESTIMATED ANNUAL HOURS OF OVERFLOW VERSUS
TREATMENT PLANT HYDRAULIC CAPACITY
G-60
-------
Each of the foregoing studies of combined sewer overflow frequency recognized
that a threshold rainfall exists, below which no measurable runoff occurs.
Palmer believed that the intensity must exceed 0.03 inch/hour before runoff
will occur and the other studies all eliminated some quantity (0.02-0.04
inches) from the initial hours of each event. Also, all five studies
incorporated an estimated runoff coefficient into the calculation of the
amount of rainfall which is equivalent to dry weather flow. The same runoff
coefficient was then implicitly assumed for all intensities above the
threshold value. All five investigators concluded that the capacity of the
interceptors must be very large in order to effect a significant reduction in
the annual hours of combined sewer overflows. As a result of the study made
by Johnson, a ratio of 30 between interceptor design flow and dry weather
flow was adopted for use in portions of the Washington, D.C. area. According
to Johnson at a WWF:DWF ratio of 3 the combined sewers would overflow 240
hours per year. When the WWF:DWF ratio was increased to 30 the overflow
hours per year would be reduced to 13 hours per year. This represents a
reduction in the time of overflow of about 95%. The principal weakness of
the analyses described above is the assumption that the runoff coefficient is
independent of the rainfall intensity. In order to avoid having to make this
assumption, Davis and Borchardt (39) made measurements of the runoff coeffi-
cient in Des Moines based on the rational method. Measurements were made for
two catchments: catchment 0-11 having a population density of 10.7 persons/
acre and catchment S-3 having a population density of 5.3 persons/acre.
Calculated runoff coefficients for each catchment as a function of rainfall
intensity are shown in Figure G-8. A regression line for catchment 0-11
data has been plotted in Figure G-8, and the equation relating the runoff
coefficient to rainfall intensity is shown below:
C = 0.3836 + ln(I)/9.48248 (G-13)
I = rainfall intensity, in/hr
I = runoff, in/hr
C = I /I
r
Extrapolating the regression line in Figure G-8 it is seen that the rainfall
intensity which produces no runoff would be about 0.026 inch/hour. This
G-61
-------
NOTE- • DRAINAGE AREA 0-11
* DRAINAGE AREA S-3
REGRESSION LINE AND
EQUATION FOR
DRAINAGE AREA 0-11
0 0.1 0.2 0.3 0.4
C,RATIONAL METHOD RUNOFF COEFFICIENT
SOURCE:(39)
FIGURE G-8
RATIONAL METHOD RUNOFF COEFFICIENT
VERSUS RAINFALL INTENSITY
G-62
-------
figure agrees well with the estimates of 0.03-0.04 inch per hour which had
been assumed by previous investigators.
The relationship between runoff coefficient and rainfall intensity is known
to depend on percent imperviousness which, in turn, is believed to be related
to population density. In their Des Moines study, Davis and Borchardt (39)
found that for an urban area with a population density of 10.7 persons/acre
the rate of runoff could be related to rainfall intensity as follows:
CFS/Ac = 1(0.380 + ln(I)/9.526) (G-14)
I = rainfall intensity, in/hr
Using the relationships of Chapter 3, the value for C at a population
density of 10.7 persons/acre is about 0.35 as compared to a value of 0.38 at
a population density of 13.1 persons/acre. Thus, for a rough estimate, the
runoff coefficient shown in Figure G-8 for catchment 0-11 would be increased
by 10% to find the expected runoff coefficient for a population density of
13.1 persons/acre.
To convert a distribution of hourly rainfall intensities to a distribution
of runoff rates, Equation (G-13) can be used. Using the data of Davis and
Borchardt (39), a distribution of hourly equivalent runoff is plotted in
Figure G-9.
However, runoff rates are more meaningful when expressed as multiples of the
dry weather flow of municipal sewage. If the production of municipal sewage
is estimated as 100 gal/capita/day, the flow will be 0.00131 mgd/acre at a
population density of 13.1 which is equivalent to a runoff rate of 0.00201
inches/hour.
If the rainfall intensity is less than 0.026 inch/hour no runoff will occur.
The distribution of rainfall intensities shown in Figure G-9 indicates that
about 46% of the rainfall hours have intensities greater than 0.026 inch/hour.
Therefore, since the total rainfall hours was 489 hours/year in Des Moines
over the 10-year period between 1950 and 1960, the combined sewer would
overflow 225 hours/year if the interceptor capacity is just equivalent to the
dry weather flow. If the runoff rate is equal to the dry weather flow, the
rainfall intensity will be 0.0403 inch/hour and this intensity of rainfall
G-63
-------
NOTE; A = HOURLY RAINFALL INTENSITY(39)
B = HOURLY EQUIVALENT RUNOFF USING RATIONAL METHOD
RUNOFF COEFFICIENTS(39)
C = CUMULATIVE RAINFALL INTENSITY
D = CUMULATIVE RUNOFF INTENSITY
en
i
3
O
co
Z
l.OF
10
-1
" 10-2
1C'
10
-4
N
X
N
\
s
B
N.
0.1 0.5 2 10 30 50 70 90 98 99.8
PROBABILITY %, EQUAL TO OR GREATER THAN
FIGURE G-9
PROBABILITY DISTRIBUTION OF RAINFALL AND RUNOFF INTENSITIES
-------
will be exceeded 196 hours per year. Using this reasoning, the relationship
N
between WWF:DWF ratio and annual hours of overflowing has been developed for
the Des Moins data, and is shown as curve F in Figure G-7. It can be seen
that the potential for limiting the number of hours during which overflowing
occurs is significant. If the capacity of the treatment plant is 3.5 times
the dry weather flow the total annual overflow will be reduced from 225 to
125 hours, which is a reduction of 44%. A 90% reduction in the number of
hours of overflow could be achieved but only if the plant capacity is 35
times the dry weather flow.
It is generally accepted that a large fraction of the total overflow volume
is contributed by a few high-intensity storms. As a result, the potential
for making a major reduction in the total amount of overflow by increasing
the capacity of the plant and sewerage system is considerably reduced. To
quantify this facet of the situation the first moment of the distribution of
runoff rates must be found.
Since both the distribution of rainfall intensities and the distribution of
runoff rates appear to be log-normally distributed the first moment of the
distribution functions can be computed as given in Smith (8). The mean rain-
fall intensity for Des Moines was computed as 0.0672 inch/hour and this value
when multiplied by the total number of rainfall hours (489) gives a total
accumulation of 32.86 inches per year. Similarly, the mean value for runoff
is 0.03546 inch/hour and this value times 225 hours/year of runoff gives an
accumulated runoff amount of 7.97 inches per year. Thus, the average runoff
coefficient for Des Moines at a population density of 13.1 is 7.97/32.86 or
0.243.
By using the first moment of the distribution of runoff rates, the fraction
of the total amount of runoff (7.97 inch/year) which will escape when the
capacity of the plant is some multiple of the dry weather flow can be found.
The results of this calculation are shown by the zero percent curve in
Figure G-10. It can be seen that to reduce the runoff volume which overflows
by 50% the capacity of the treatment plant must be 100 times the dry weather
flow rate.
G-65
-------
NOTE: CURVES ARE FOR
0%,25%, AND 40% OF
DRAINAGE AREA DRAINING
INTO PONDS
O
Z
£100
O
oc
IU
O
Z 10
*
**-
o
u
tx.
I I I I I Illl I I [ 1 I I III
10 100 300
TREATMENT PLANT CAPACITY/
DRY WEATHER FLOW
FIGURE G-10
EFFECT OF UPSTREAM STORAGE ON PERCENTAGE
OF TOTAL RUNOFF VOLUME OVERFLOWING VERSUS
TREATMENT PLANT HYDRAULIC CAPACITY
G-66
-------
If the concentration of pollutants in the runoff were the same in each volume
of runoff this estimate of the fraction of runoff escaping would lead to a
pessimistic view of the potential for limiting pollution by increasing the
capacity of the plant and sewerage system. However, since there is some
evidence that a larger fraction of the pollutants are present in runoff from
smaller storms, and especially in the first flush, the analysis based on
number of overflow hours may have more validity. If the concentration of BOD
is assumed to be the same for all runoff the concentration can be computed as
follows:
BOD, mg/1 = 4.422 (BOD loading, Ib BOD/acre-yr)/(annual (G-15)
runoff, in/yr)
Thus it can be seen that if the annual runoff is 7.97 in/yr and the storm
sewer loading is 30 Ib BOD/acre-yr the average BOD concentration will be
16.1 mg/1. Similarly, if the combined sewer loading is 100 Ib BOD/acre-yr
the average BOD concentration will be 55.5 mg/1.
G.4.2.2 Storage in the Sewerage System
The municipality of Metropolitan Seattle has installed and demonstrated (40)
a computer augmented treatment and disposal system (CATAD) which monitors and
controls storage of runoff in a combined sewer system serving an area of
13,120 acres. It was shown that storage of storm runoff in trunks and inter-
ceptors can reduce the volume of runoff escaping by about 74% when the
regulator gates are manually controlled from a central control panel, and
by about 90% when the gates are controlled automatically by computer
algorithms.
Although performance measurements made on the CATAD system were very
scattered there is little question that, in sufficiently large communities,
storage of runoff in the sewerage system is a viable strategy for reducing
or eliminating the volume of runoff which escapes into the receiving stream.
For example, by means of the following simple analysis the storage volume
available in the interceptors can be roughly estimated. If the interceptors
are designed to transmit K times the dry weather flow with a Manning rough-
ness coefficient of 0.013, the required interceptor diameter can be found
from the following relationship.
G-67
-------
1/70
D = 0.308 (K DWF/S '*) ' (G-16)
D = interceptor diameter, ft
K = multiple of DWF
DWF = dry weather flow, mgd
S = interceptor slope, ft/ft
In the 1967 APWA survey (7) of combined sewer problems it was found that of
the 109,000 miles of sewer installed about 7,600 miles or 7% were intercep-
tors. Thus, if the length of interceptor is taken as 7% of the total sewer
length shown in Figure G-2, and the interceptor diameter is found from
Equation (G-16), the volume of the interceptor can be calculated as follows:
V = 0.002171 D2 L (G-17)
V = interceptor volume, mg
L = interceptor length, miles
If dry weather flow is taken as 100 gpd/capita, the interceptor is sized to
transmit four times the dry weather flow, and the slope of the interceptor
is assumed to be 0.0003 ft/ft, the diameter of the interceptor will vary from
about 2 ft at a population of 10,000 to a diameter of 7.5 ft at a population
of about 220,000. Up to a population of 45,000 the slope must be increased
to provide the minimum velocity of 2 ft/sec necessary to provide adequate
scouring. Since 7.5 ft diameter is near the upper limit of current practice
it has been assumed that for populations above 220,000 multiple 7.5 ft
diameter interceptors will be provided.
Based on the assumptions itemized above, the interceptor volume can be
expressed by the following expressions as a function of the drainage area
in acres.
V = 0.078 (Acres/1000)2'3 (G-18)
V = 0.0217 (Acres/1000)2'76 (G-19)
Equation (G-18) applies from 10,000 to 17,500 acres or from 100,000 to
220,000 population and Equation (G-19) applies from 17,500 to 50,000 acres
or for a population greater than one million.
G-68
-------
The CATAD system served an area of 13,120 acres and had a design storage of
29.8 mg, however, it was found that the actual storage was only 17.83 mg or
about 60% of the design storage. Substituting an area of 13,120 acres into
Equation (G-18) gives an estimate of 29.1 mg which shows that the estimates
made agree reasonably well with the CATAD system.
The important conclusion to be drawn from Equations (G-18) and (G-19) is that
the available interceptor storage volume increases very rapidly with the area
drained. The volumetric runoff coefficient measured in the CATAD testing
program was 0.152. Using this value for C and the ratio of design storage
to actual storage of 0.6, Equations (G-18) and (G-19) can be used to express
the volume of rain (inches) which can be stored in the sewerage system for
any size drainage area.
Stored rainfall, inches = 0.01134 (Acres/1000)1'3 (G-20)
Stored rainfall, inches = 0.003155 (Acres/1000)1'76 (G-21)
Equation (G-20) is used with Equation (G-18), and Equation (G-21) is used
with Equation (G-19). Since the area of the metropolitan area is a function
of the population the inches of rainfall which might be stored can also be
expressed as a function of the population as follows.
Stored rainfall, inches = 3537 X 10~6 (POP/1000)0'905 (G-22)
Stored rainfall, inches = 637.8 X 10"6 (POP/1000)1'225 (G-23)
From Equation (G-20) it can be seen that for the Metro Seattle case where
the drainage area was 13,120 acres, a maximum of 0.322 inches of rain can be
stored in the collection system. Rainfall records for the Seattle area
showed that rainfall exceeded 0.1 in/day for 88 days/year, 0.25 in/day for
46.6 days/year, and 0.5 in/day for 17.6 days/year. These three points appear
to fit an exponential distribution expressed as follows:
F(I) = 1 - e~41 (G-24)
I = rainfall intensity, in/day
F(I) = fraction of rain days with intensities less then I
The total number of days/year in which some rain fell was 130 days. There-
fore, it can be seen that rain intensity will be less than 0.322 in/day for
G-69
-------
72.4% of the 130 days/year or 94 days/year. This is clearly a. significant
reduction in the number of days overflowing occurs.
It is also important to examine the volume of runoff which is contained. The
first derivative of Equation (G-24) is the probability density function.
Multiplying the probability density function by I, and integrating from zero
to infinity gives a total annual rainfall of 32.5 inches/year. The amount
of rain falling in days with intensities less then I can be expressed as
follows.
C = 32.5(1 - e"4I(l+4I)) (G-25)
C = cumulative rainfall, in/yr
From Equation (G-25) it can be seen that the total amount of rainfall con-
tained during days when the intensity was less than 0.322 in/day is 11.98
in/year or about 37% of the total annual amount. However, during days when
the intensity exceeds 0.322 in/day the first 0.322 in/day can also be stored.
Since it has already been shown that 94 days/year had intensities less than
0.322 in/day, it follows that 130 minus 94 or 36 days/year will have intensi-
ties greater than 0.322 in/day. Thus, of 0.322 inches stored during each of
the 36 days, an additional 11.59 inches of rain will be contained. Adding
11.59 to 11.98 gives a total of 23.6 in/year contained. Therefore, a total
of about 73% of the runoff can be contained. This estimate agrees well with
the findings of the CATAD system using manual control of the gates. This
analysis, however, implicitly assumed that the interval for storing and
releasing the runoff was one day. If the adjustment period is less than one
day greater fractions might be contained.
It can be seen from this simplistic analysis that storage in the collection
system offers a significant potential for reducing the amount of overflow.
In addition to overflow volume the potential for reducing pollution loading
is also impressive because of the potential for containing small storms and
the first flush of larger storms where a large fraction of the pollution is
believed to originate.
The total construction cost for the CATAD system was about 3.9 million dollars
in mid-1968 which would correspond to about 8.5 million current dollars. This
G-70
-------
corresponds to about $650/acre drained. Amortizing at 6% over 20 years
gives $56.67/acre/year. Operating cost was estimated at $5/acre in 1974 or
about $6/acre in current dollars. If 75% of the pollutional load or about
75 Ib BOD/acre-year is contained the cost in terms of pollution control is
about $0.84 per pound of BOD removed.
G.4.2.3 Use of Combined Sewer Regulators
Combined sewer regulators are designed to intercept all dry weather flows and
automatically bypass wet weather flows which are greater than the interceptor
and/or treatment plant capacity. Originally, a low dam or weir was construe^
ted across the combined sewer downstream from a vertical or horizontal
orifice. Flows dropping through the orifice were collected by the intercep-
tor and conveyed to the treatment plant. Although more sophisticated
mechanical regulators were developed to improve control over the diverted
volumes, no specific consideration was given to quality control. More
recently, several regulators have been developed which are capable of pro-
viding both quality and volume control through induced hydraulic flow
patterns that tend to separate and concentrate the solids from the main
stream (41,42,43).
Conventionally designed regulators can be subdivided into three major groups:
(1) static, (2) semiautomatic dynamic, and (3) automatic dynamic. The group-
ing reflects the general trend toward the increasing degree of control and
sophistication and, of course, the capital and operation and maintenance
costs. Conventional regulator design, use, advantages, and disadvantages
are well covered in the literature (41,44).
Recent emphasis has resulted in the development of several new and innovative
regulators both in the United States and in Europe (45) . Those showing the
greatest promise are undergoing prototype testing. Regulators included in
this group are fluidic devices, swirl concentrators, broad-crested inflatable
fabric dams, and automatic slide gates and tide gates. Improved regulators
developed in England include the vortex regulator, high side-spill weir,
stilling pond regulator, and the spiral flow regulator. The choice of a
regulator must be based on several factors including: (1) quantity control,
(2) quality control, (3) economics, (4) reliability, (5) ease of maintenance,
and (6) the desired mode of operation (automatic or semiautomatic).
G-71
-------
G.4.2.4 Use of Swirl Concentrators as Combined Sewer Regulators
The swirl regulator/concentrator has shown outstanding potential for providing
both quality and quantity control, and is believed to be practical for instal-
lation at overflow points along an interceptor. In the following illustrative
example the average number of combined sewer overflow points per 1000 acres of
catchment and per 1000 population was given in the 1967 APWA survey (7) of
combined sewer problems. These are shown in Figures (G-ll) and (G-12). Con-
struction cost for swirl concentrators was estimated by Benjes (46) and the
cost is expressed by the following relationship in December 1976 dollars.
Construction cost, dollars = 772.72 A0'7727 (G-26)
A = swirl concentrator surface area, sq. ft.
The following sizing relationship was developed by APWA (45) for 90% removal
of suspended solids.
A = 30(CFS)°'7588 (G-27)
CFS = peak flow rate, cfs
Assuming that the total overflow rate (cfs/acre) is equally divided among
the various overflow points, the following relationship for construction cost
in terms of dollars/acre can be derived by substituting Equation (G-27) into
Equation (G-26).
Construction cost, $/acre = 10,700(CFS/Ac)°'586(N/Ac)°'414 (G-28)
N/Ac = number of overflow points per acre
CFS/Ac = overflow rate, cfs/acre
Operating and maintenance cost given by Benjes (46) can be expressed as
follows in terms of annual man-hours. No power or chemicals are required.
The manpower consists of one inspection of each swirl concentrator every
two weeks (2 hr/inspection) and washing of the concentrator after every
overflow event. It is assumed that 30 overflows will occur each year.
Annual man-hours per concentrator = 52 + 78.16 A ' (G-29)
G-72
-------
Z
O
NOTE: NUMBER OF COMBINED SEWER OVERFLOW POINTS
SUM OF COMBINED SEWER AND
SEPARATE STORM SEWER OVERFLOW POINTS
O 30
o.
o
o
2 10
O
0.
1.0
u.
o
Z
.1
,1
till till
1 1 I 1 LL
11
1 10 100
COMMUNITY POPULATION (1000'S)
1000
FIGURE G-ll
NUMBER OF SEWER OVERFLOW POINTS PER 1000 POPULATION
VERSUS COMMUNITY POPULATION
-------
o
o
o
z
O
o_
£
O
U_ UJ
to
z<
NOTE: NUMBER OF COMBINED SEWER
OVERFLOW POINTS
SUM OF COMBINED SEWER AND
SEPARATE STORM SEWER OVERFLOW
POINTS
30
10
£ 1
Q
.1
i i 11 mil i i i mill \ i i Mini i i I mill i i i
.1
i 10 100 1000
COMMUNITY POPULATION (1000'S)
FIGURE G-12
NUMBER OF OVERFLOW POINTS PER 1000 ACRES OF DRAINAGE AREA
VERSUS COMMUNITY POPULATION
-------
Combining Equations (G-28) and (G-29) and assuming a manpower cost of
$10/hour the following relationship is derived for operating and maintenance
cost expressed as dollars/acre-year.
OW cost, $/acre-yr = $520 (N/Ac) + $2213 (N/Ac)0'768 (CFS/Ac)°'232 (G-30)
It can be seen that both the construction and the operating and maintenance
costs depend on the number of overflow points per acre (N/Ac) and the runoff
rate in CFS per acre.
If the production of municipal sewerage is assumed to be 100 gal/day/capita
the rate of flow for municipal sewerage can be expressed as 0.000155 CFS/acre
times the population density. If the population density is 10.7 and the
capacity of the interceptor is assumed to be 3.5 times the rate for municipal
sewage the interceptor capacity will be 0.0058 CFS/acre. Rates of flow
exceeding this amount will be assumed to overflow.
From Figure (G-9) it can be seen that in Des Moines (39), the intensity of
rainfall will exceed one inch/hour in only about 0.5% of the rainfall hours
or 2.5 hours/year. Using one inch/hour as the design point for the sizing of
swirl concentrators, and using Equation (G-14), it is calculated that the
runoff rate at 1 inch/hour will be 0.380 CFS/acre. By subtracting the
capacity of the interceptor (0.0058 CFS/acre) from the runoff rate the over-
flow rate is calculated to be 0.074 CFS/acre. In Figure G-12 it is seen
that the number of overflow points per acre of urban land varies with the
population. A representative value is about 0.0035 overflow points per acre.
An average construction cost per acre for swirl concentrators can now be
found by substituting a value of 0.374 CFS/acre and a value of 0.0035 for
number of overflow points per acre into Equation (G-28). For the 50,000
population community the construction cost is $586/acre, but in very small
communities the cost could be as much as $1000/acre. Taking the useful life
of the swirl concentrators as 20 years, the interest rate as 6%, and the
ratio of capital to construction cost as 1.35 the amortization cost will be
about $70/acre-year but this amount might be as high as $120/acre-year for
small communities. Operating and maintenance cost can be estimated by
substituting values for N/Ac and CFS/Ac into Equation (G-30). If 0.374 CFS/ac
G-75
-------
and 0.0035 overflow points per acre are used, the annual operating and
maintenance cost will be about $25/acre-year. This could be as high as
$78/acre-year for very small communities where the value for N/Ac is 0.015.
Thus, the total cost of owning and operating swirl concentrators in most
communities is likely to be about $95/acre-year, but could be as high as
$200/acre-year for very small communities.
The swirl concentrator is capable of removing about 50% of the BOD from the
overflow. Thus, if the annual load from combined sewers is 196 Ib BOD/acre-
year, 48 Ib BOD/acre-year might be removed by the swirl concentrators.
Dividing the previously calculated $95/acre-year by 48 Ib BOD/acre-year
gives an estimate of $1.98 per pound of BOD removed when swirl concentrators
are installed at all overflow points of a combined sewerage system. This is
two-thirds the cost of $2.94/lb BOD removed which is estimated later in
Section G.4.2.6 for installing separate sewers in undeveloped land.
G.4.2.5 Reduction in Infiltration/Inflow (I/I)
A serious problem results from both excessive infiltration and high inflow
rates into sewer systems: both limit the capacity of the sewerage system
and the treatment plant to handle runoff resulting in increased amounts of
overflows and treatment plant bypasses. Infiltration usually occurs from
groundwater sources seeping into sewer pipes from leaky joints, crushed or
collapsed pipe segments, leaky lateral connections, or other pipe failures.
Inflow usually occurs from surface runoff, from roof leaders, cellar and
yard drains, foundation drains, commercial and industrial "clean water"
discharges, drains from springs and swampy areas, depressed manhole covers,
cross-connections, and the like. The subject of I/I control strategies
and costs has been thoroughly reported by Lager and Smith (2). The informa-
tion presented in this section has been adopted from their report.
G.4.2.5.1 Inflow Control
Correction of inflow conditions is dependent on regulatory action on the
part of city officials, rather than on public construction measures. If
elimination of existing inflows is deemed necessary because of adverse
effects of these flows on sewer systems, puming stations, treatment plants,
G-76
-------
or combined sewer regulator-overflow installations, new or more restrictive
sewer-use regulations may have to be invoked.
The effects of inflows into sewers can be greatly reduced by a variety of
methods. Many authorities advocate the discharge of roof water into street
gutter areas—or onto on-lot areas in the hope that it will percolate into
the soil (47). Discharging roof or areaway drainage onto the land or into
street gutters reduces the immediate impact on the sewer system be allowing
reduction of the volume and attenuation.of the flow. The use of pervious
drainage swales and surface storage basins within urban areas allows the
stormwater to percolate into the ground.
Depressed manholes (those with vented covers in street areas where runoff
can pond over the cover) can be repaired or the covers replaced with unvented
covers.
The elimination of inflow sources is generally found to be cost effective.
Some of the most common sources of inflow are summarized in Table G-14.
Estimates for the flow contribution by each source and the cost of elimina-
ting that source are summarized in the following table.
TABLE G-14
COST ESTIMATES FOR INFLOW ELIMINATION
Flow rate, in Rehabilitation cost
Source elimination gallons per minute in 1974 'dollars.$
Leakage around manhole
covers 10-20 50-75
Holes in manhole covers 50-100 100-125
Foundation drain discon-
nection 10 300-1,200
Roof leaders disconnection 10 50-75
Cross-connection plugging 250-450 100-500
Catch basin 300 3,000-5,000
Ditch or storm sewer ,
infiltration sanitary sewer
(per manhole reach) 60-80 500-2,500
Area drain disconnection 50-200 50-350
G-77
-------
G.4.2.5.2 Control of Infiltration
The average rate of infiltration represents a minor fraction of the hydraulic
capacity but the peak infiltration rate can be several times the dry weather
flow. For example, the most commonly used allowance standard for infiltra-
tion is 500 gallons per inch of pipe diameter per mile per day. Santry (48)
itemized the length and diameter of sewer pipe in three communities and the
average pipe diameter ranged from 9.82 inches at a total sewer length of
2822 miles to a low of 6.51 inches at a length of 6.3 miles. The three data
points are well represented by the following relationship.
D = 5.75 L°'67348 (G-31)
3-
D = average pipe diameter, inches
3.
L = total length of sewer, miles
At a population of 50,000 the length of sewer will be about 128 miles, the
average pipe diameter will be about 8 inches, and the population density
will be about 8 persons/acre. Assuming the dry weather flow as 100 gal/
capita/day the flow of municipal sewage will be 800 gal/acre/day. The
infiltration rate allowed is 4000 gal/mile/day. Since the miles of sewer
per acre is about 0.021, the infiltration rate allowed is 84 gal/acre/day
or about 10.5% of the dry weather flow. In terms of dry weather flow the
infiltration allowances ranged from 10% of dry weather flow to as much as
four times dry weather flow. It can be seen from Figure G-7 that if the .
infiltration equals twice dry weather flow, the capacity of the treatment
plant, in multiples of dry weather flow, must be reduced by two. For
example, if the capacity of the treatment plant is four times dry weather
flow with no infiltration the annual hours of overflowing will be reduced
from 225 to 117. However, with infiltration at twice the dry weather flow
the reduction will be only to 165 hours/year representing an additional
48 hours/year of overflowing. In terms of the additional volume of runoff
escaping as a result of excessive infiltration the effect is much less.
The problem of infiltration involves two basic areas of concern: (1) pre-
vention in new sewers by adequate design, construction, inspection, and
testing practices, and (2) the elimination or cure of existing infiltration
by proper survey, investigation, and corrective measures. Control of
G-78
-------
infiltration in new sewer systems involves engineering decisions and
specification of the methods and materials of sewer construction, pipe,
joints, and laying procedures and techniques. Correction of existing
sewer infiltration can be accomplished by three basic approaches:
(1) replacing the defective component, (2) sealing the existing openings,
and (3) building within the existing component.
In order to conduct a sewer system evaluation or a system analysis, the
following approach is taken:
CD
(2)
(3)
(4)
Identify the scope and nature of the infiltration/inflow problem.
Establish an end objective. (The amount of infiltration/inflow
that can be economically eliminated).
Isolate those general sections of the sewer system where
infiltration/inflow is occurring.
Formulate a plan which can be economically justified for
investigating and locating specific areas from which the
major infiltration/inflow emanates.
(5) Formulate a plan which will assure correction of the infiltration/
inflow problem along with alternatives for rehabilitation and a
prediction of the end results that can be expected.
The costs for an evaluation survey for the determination of excessive
infiltration and inflow is summarized in the following table.
TABLE G-15
EVALUATION SURVEY COST ESTIMATES (49)
Phase
Estimated costs per foot for
specific areas of sewer system,
in 1974 dollars. $
Physical survey
Rainfall simulation
Preparatory cleaning
Internal inspection
0.15-0.25
0.25-0.50
0.30-0.90
0.40-0.70
G-79
-------
Based on the findings of survey and the engineers' reports, a decision is
made as to which sewers will not need any work, which sewers can be success-
fully grouted, relined, or replaced to eliminate the sources of infiltration/
inflow, and the amount of street repair that will be required.
The correction alternatives include (1) replacement of broken sections,
(2) insertion of various types of sleeves or liners, (3) internal sealing
of joints and cracks with gels or slurries, and (4) external sealing by
soil injection grouting. Additional detailed information is available in
recent EPA reports on jointing materials (47,50) and sealants (47,50,51,52).
G.4.2.5.3 Rehabilitation Costs
Rehabilitation costs for any one area is site specific. Generalized
estimates, however, may be calculated based on some unit costs for certain
classes of repair. The following cost information has been adopted from
EPA Report No. 430/9-75-021 (53).
G.4.2.5.3.1 Sewer Replacement Costs
The cost curve for replacing the existing gravity sewer with a new pipe of
the same size is shown in Figure G-13. Included in the costs are the costs
for site preparation, excavation, backfill, pavement, pipe materials,
removal of existing pipe, pipe installation, reconnection of one house
service connection for every 20 feet of pipe and field inspection. In
deriving the cost curve, it was assumed that the depth of cover over the
crown of the pipe is 9 feet, the pipe is laid in moderately wet soil condi-
tions, the excavations are limited to earth excavations and the cost
required to remove the existing pipe is 50% of that required to install the
new pipe. The cost required for sewage bypassing during construction is not
included.
For preliminary estimations, this curve should be sufficient in most
applications. For more detailed cost estimations, individual costs should
be developed based on the actual field conditions. Factors which may affect
the cost for sewer replacement are shown in Table G-16.
G-80
-------
600
500-
400
o
O200
^•100
<* 90
~ 80
£ 70
O 60
" 5°
2 40
30
u
20
10
I I I I I
1
6 8 10 20 40
PIPE DIAMETER (INCHES)
60 80 100
SOURCE(53)
FIGURE G-13
SEWER REPLACEMENT COST VERSUS PIPE DIAMETER
G-81
-------
TABLE G-16
SEWER REPLACEMENT COST CRITERIA (53)
Size of pipe
Depth of pipe
Type of service
Type of pipe
Removal of existing pipe
Number of service connections to be made
Groundwater elevation
Proximity to other utilities
Pipe transportation requirements
Infiltration allowance requirements
Access to site work
Availability of storage area for pipe materiald and equipment
Availability of storage area for excavated materials
Weather conditions
Availability and cost of labor
G-82
-------
G.4.2.5.3.2 Pipe Lining (Polyethylene) Costs
The cost curve for pipe lining with polyethylene pipe is shown in Figure G-14.
Included in the costs are the costs for site preparation, insertion pit, pipe
materials, pipe welding, pipe installation, connection of one house service
connection for every 20 feet of pipe, pipe sealing off in manholes and
mobilization. It was assumed that the depth of cover over the crown of the
sewer is 9 feet.
Factors which may affect the pipe lining cost are shown in Table G-17.
They should be considered in developing more refined cost data.
G.4.2.5.3.3 Grouting Costs
The costs for chemical grouting of sewer pipes are shown in Figure G-15.
The costs are developed based on the following assumptions (54):
(1) Length of manhole section: 300 feet
(2) Type of pipe: Vitrified clay
(3) Depth of flow: Less than 20% of pipe diameter
(4) Type of joint: Factory made
(5) Joint spacing: 4 feet
(6) Access to manholes: Readily accessible
(7) Manhole opening: 21 inches
(8) Manhole diameter: 4 feet
(9) Manhole condition: Structurally sound with steps for access
(10) Manhole depths: 6-8 feet
(11) Hazardous gas: None present
(12) Random vs. successive manhole sections: All sections requiring
grouting are successive
(13) Mobilization distance: Within 100 miles
(14) Weather conditions: Mild temperature and no storm
(15) Traffic control: None required
(16) Chemical grout used: Acrylamide gel or urethane foam
G-83
-------
o
o
600
500
400
300
_j 200
UJ
Z
vy
O
(J
O
Z
z
100
90
80
70
60
50
£ 40
30
20
10
I
I
I
8 10 20 40 60 80 100
PIPE DIAMETER (INCHES)
SOURCE(53)
FIGURE G-14
PIPE LINING(POLYETHYLENE) COST
VERSUS PIPE DIAMETER
G-84
-------
TABLE G-17
PIPE LINING COST CRITERIA (53)
Size of sewer
Length of sewer
Depth of sewer
Grade and direction change of sewer
Depth of flow in sewer
Size of liner pipe
Liner pipe wall thickness required
Annulus grouting requirements
Number of service connections to be made
Type of surface restoration required
Pipe transportation requirements
Type of manhole "seals" required
Extent of sewer cleaning required
Technique to "prove" or preinspect sewer lines
Excavation requirements
Groundwater elevation
Access to site of work
Availability of electrical power for fusing
Availability of storage area for pipe materials and equipment
Availability of storage area for excavated materials
Mobilization distance
Availability and cost of labor
G-85
-------
z
o
, 36-INCH PIPES
O
Q£
O
10 20 30 40 50 60 70 75
NUMBER OF JOINTS GROUTED
SOURCE(53)
FIGURE G-15
GROUTING COST VERSUS NUMBER OF
PIPE JOINTS GROUTED
G-86
-------
TABLE G-18
SEWER LINE GROUTING COST CRITERIA (53)
Mobilization distance
Weather condition
Terrain
Type of soil
Access to manholes
Manhole opening
Manhole size
Manhole cleanliness
Manhole depth
Hazardous gases in manhole
Type of pipe
Pipe size
Pipe alignment
Pipe grade
Pipe cleanliness
Depth of flow
Flow rate
Ability to plug
Type of joint
Joint spacing
Offset joints
Intruding service connections
Structurally damaged pipe
Random vs. successive manhole sections
Availability and cost of labor
G-87
-------
G.4.2.6 Sewer Separation
In the 1967 APWA (7) report the cost of sewer separation was shown to vary
enormously depending on whether partial or complete separation was being
considered. The cost given for partial sewer separation averaged about
$25-30 per foot of sewer in December 1976 dollars. Thus, the cost of
installing sewers initially based on sewer lengths given in Figure G-2 ranges
from about $2800-$5500/acre. Assuming the sewers have a life of 50 years
and the interest reat is 6% installed, they will cost from $177 to $394/year.
The cost to the homeowner for the house connection will be about one-third
of the sewer cost in terms of dollars/capita. Thus, the cost of owning the
sewerage system will range from $235/acre-year to $465/acre-year.
The cost of sewer separation in developed areas is much greater. For
example, the cost of sewer separation in developed areas was given for
several communities by Lager and Smith (2). The cost ranged from a low
of about $4800 per acre in Bucyrus, Ohio, to a high of $150,400 per acre
in Boston. Nationwide costs for sewer separation ranged from $9,250 to
$35,580 per acre. Thus, it appears that sewer separation in highly
developed urban areas is essentially impractical but installation of
separate sewers at the time the land is developed is a feasible alternative
for reducing pollution. At a population of 50,000 the annual cost of
owning separate storm sewers costing $27.5 per linear foot is about
$194/acre-year.
The pollution control potential for separate sewers can be estimated from
the analysis of BOD load sources. About 30% of the annual load is associated
with pollutants washed from urban areas and 70% of the load is caused by
solids which settle in combined sewers to be washed into the receiving stream
later by stormwater. If the load from separate storm sewers is 30 Ib
BOD/acre-year the corresponding load from combined sewers might be esti-
mated at about 96 Ib BOD/acre-year. Thus, by providing separate sewers
the reduction in pollution load will be about 66 Ib BOD/acre-year. Dividing
$194/acre-year by the pollution load removed from the receiving stream
(66 Ib BOD/acre-year) the cost of BOD removal is about $2.94 per Ib of BOD.
This analysis applies only if the sewers are constructed in undeveloped
land. In the developed area the cost could be greater by a factor of ten.
G-88
-------
G.4.3 Loading Control
The potential impact of wet weather pollution discharges from combined sewers
can also be limited through collection system management techniques aimed at
controlling the quantity of pollutant available for discharge from the sewers.
The analyses of stormwater pollution sources in Section G-2 estimated that
the annual BOD load from combined sewers ranges from 80-120 Ib BOD/acre-year.
Of this amount, 65% or 52-74 Ib BOD/acre-year is attributable to municipal
sewage solids which settle in sewers and are later flushed into receiving
waters by storms. Thus, it is apparent that reasonably effective measures
to limit the availability of this material for discharge with overflow will
have a significant impact upon the magnitude of stormwater loads.
Three methods of load control will be discussed in this section; sewer
flushing, sewer scraping, and catch basin cleaning. The cost effectiveness
of structural sewer separation will also be discussed here to provide a cost
contrast with the semistructural management approaches. Part II of this
appendix also considers sewer flushing in the level I SWMM analysis of best
combinations of storage/treatment, street sweeping and catch basin cleaning.
G.4.3.1 Sewer Flushing
Periodic sewer flushing has been proposed as one way of limiting the pollu-
tion from combined sewers. The goal of sewer flushing is to maintain the
inventory of BOD exerting solids in the combined sewer system at a low level,
so that, when storms of sufficient intensity to flush the solids from the
sewer occur, the pollutional impact will be minimized. A number of flushing
approaches are available, including flushing stations, in-line storage, and
portable tanker units.
A flushing station technique developed by FMC (6) involves installation of
a watertight bag in existing manholes with pump, valves, and controls to
draw screened raw sewage from the sewer for storage in the inflatable bag.
The screened sewage in the bag is released periodically with sufficient
energy to flush settled solids from the lateral sewer downstream of the
flushing station. In-line storage systems have been described by Pisano (55).
They involve a system of internal dams which are employed to block the flow
of sewage at critical upstream points for instantaneous release of sewage to
G-89
-------
scour downstream segments without creating an artificial overflow. The
tanker approach merely involves gravity or pressurized dumping of flush
water into strategic manholes to provide scouring action.
Because each flushing wave becomes attenuated by wall friction and other
internal pipe configuration flushing has limited usefulness beyond certain
distances. It has been estimated that up to 1200 feet of small- and medium-
diameter sewer can be flushed by a single flush station (56). FMC, in their
study, concluded that from two to four flush stations are needed for every
nine acres of urban land served by combined sewers. If the miles of sewer
per acre is 0.025 (corresponding to an average community size of 170,000,
Figure G-2) this would mean flush stations would have to be placed from 297
to 594 feet apart.
Recent studies in Boston, however, have developed a method for estimating
pollutant loadings associated with dry weather sewage solids deposition in
combined sewer systems (57). The predictive equations relate the total
daily mass of pollutant deposition accumulations within a collection system
to physical characteristics of collection systems such as per capita waste
rate, service area, total pipe length, average pipe slope, average diameter
and other more complicated parameters that derive from analysis of pipe
slope characteristics. A comparative error analysis of the model for a
test case collection system indicated a relative error in predicting solids
deposition ranging from 8 to 18%. Suspended solids were also found through
regression analyses to be a useful surrogate for BOD, COD, and nutrient
forms. An important outcome of the work was the determination of the rela-
tionship between the distribution of solids deposition and cumulative pipe
length in the system which is reproduced as Figure G-16. The curves reveal
that between 80 and 90% of the deposition of suspended solids (and by
association, BOD) occurs in only 50% of the system. These curves can be
used in a preliminary fashion to estimate the total length of sewer which
may have to be flushed.
The location of sewers which will likely benefit from flushing may then be
•
approximated knowing the location of lines with average slopes less than
those indicated. Obviously, other factors affect the location in severity
G-90
-------
NOTE:
CURVE
1
2
3
RANGES OF
AVERAGE SLOPE (FT/FT)
0.01—0.018
0.018—0.025
0.025—0.037
100
co
O
o.
CO
9
_i
O
CO
U
on
UJ
a.
100
PERCENT PIPE LENGTH
SOURCE:(57)
FIGURE G-16
CUMULATIVE DISTRIBUTION OF SOLIDS DEPOSITED
VERSUS PIPE LENGTH
G-91
-------
of deposits. The reader is referred to the study report to evaluate the
specifics of flushing system design (57).
By calculation of daily mass balance in a sewer system the inventory of
deposited solids after (n) days of daily flushing may be found to be
represented by the following:
Mn = L(Fr + Fr2 + V* + '' "V^ + MoFr (G'32)
where:
n = number of days
M = Ibs of solids remaining
M = initial Ibs of solids
o
F = fraction of solids remaining after each flush
L = daily solids accumulation (Ibs/day)
For large values of (n) the last term in Equation (G-32) will approach zero.
If the ratio M /L is then multiplied by F and subtracted from the expression
for M /L it can be seen that for large values of n Equation (G-32) will
approximate the following expression:
M = LF /(I - F ) (G-33)
a r v r'
M = mass of BOD stored in the sewers, Ib
3-
Flushing experiments conducted by FMC showed that the flushing efficiency
(1-F ) ranged from a minimum of 35% to a maximum of about 75% (6). The
volumes of water stored in the flushing station ranged from 300 gallons to
900 gallons. The recommended frequency for sewer flushing was once-per-day.
If one applies a cleaning efficiency of 35% (F = 0.65) to Equation (G-33)
the sewer solids inventory will stabilize (within 1%) at 1.86 times the daily
accumulation. When the cleaning efficiency is 50% (F =0.5) the inventory
will stabilize within seven days at the daily accumulation and when cleaning
efficiency is 75% the inventory will stabilize within four days at one-third
the daily accumulation. Therefore, Equation (G-33) can be used in most cases
to estimate solids inventory, but for short time intervals between storm
events Equation (G-32) can be used to estimate the inventory washed out by
G-92
-------
the stormwater. A key factor in estimating the efficacy of sewer flushing
is the average time interval between rainfall events of sufficient intensity
to cause overflow of the combined sewer. If the design capacity of the
treatment plant is based on a production rate of 100 gpd/capita at a popula-
tion density of 13.1 the size of the plant will be 0.00131 mgd/acre of urban
area served. In the interceptor is sized at 3.5 times the treatment plant
capacity the capacity of the interceptor 0.00459 mgd/acre. If the runoff
coefficient for rate of runoff, as used in the Rational Method, had a value
of 1.0 this threshold value of 0.00459 mgd per acre would be equivalent to a
rainfall intensity of 0.007 inches per hour. However, it is known that at
these low values of rainfall intensity the runoff coefficient is small and
the relationship (Equation (G-14)) developed by Davis and Borchardt (39)
between rainfall intensity and runoff coefficient shows that the rainfall
intensity which will result in a runoff of 0.007 in/hr is near 0.007 in/hr.
According to the distribution of hourly rainfall intensities given by Davis
and Borchardt (39) rainfall exceeding 0.07 in/hr will occur during about
22% of the rain hours or about 108 hours/year. Thus, the average interval
between rainfall intensities which are of sufficient intensity to cause
overflow of the combined sewer is about 3.4 days.
In.the FMC report (6) on sewer flushing the expected flushing efficiency was
estimated at 60-75%. However, to be conservative the once-a-day flushing
efficiency will be taken as 50% here. From Equation (G-32) the solids
inventory will be 88% of the daily accumulation if the interval between
storms is three days and 94% if the interval is four days. Thus, the inven-
tory at an interval of 3.4 days can be estimated at 90.4% of the daily
accumulation. The reduction in BOD reaching the stream can then be computed
as (3.4 - 0.904)/3.4 or 73.4%. Since the load computed from settled solids
was 52-79 Ib BOD/acre-year, the BOD reduction is 38-58 Ib BOD/acre-year.
A generalized cost of sewer flushing is difficult to estimate, because only
limited cost data are available and the number of flushing points per acre
is not known with a great degree of assurance. Based on the findings of
the Boston study (57) it is likely that the number of flushing points in the
system may be less than previously estimated, perhaps closer to the two
stations per nine acres reported by FMC (6) rather than four per nine acres.
G-93
-------
For the mechanized daily flushing system developed by FMC (6) the cost per
unit (or cost per manhole) was estimated at $5500 in 1972 dollars. Thus, the
capital cost per acre is about $1250 or approximately $2000 per acre in cur-
rent dollars. Amortization over 20 years at 6% gives a debt service of
$174/acre/year. FMC recommended an operation and maintenance allowance of
$102 per month for the two unit per nine acre installation which converted
to current dollars becomes roughly $217/acre/year. The total cost under
these conditions is then $391/acre/year (debt service plus operation and
maintenance). If the previously estimated BOD reduction with daily sewer
flushing is used (35-58 Ib BOD/acre-year) the cost of sewer flushing will
range from $5.75-$10.30/lb BOD/removed.
Sewer flushing can also be done with manual labor. APWA (4) reports that in
1960 all of the sewers in Chicago were flushed approximately 3.2 times/year.
The cost of flushing was estimated in 1960 dollars as $42 per mile of sewer
flushed. Assuming 0.025 miles of sewer per acre, the cost of manually
flushing all sewers once would be $1.05/acre in 1960 dollars or $2.65/acre
in current dollars. The annual cost of daily flushing in current dollars
would be $967/acre-year. This estimate is higher than the estimate for
automatic sewer flushing but if the flushing was done every two days, the
cost of manual flushing might be competitive with automatic flushing.
G.4.3.2 Catch Basin Cleaning
Catch basin cleaning is one of the most discussed nonstructural pollution
control measures. The potential for pollution abatement .by this method,
however, is likely to be small.
Historically, the role of catch basins was to minimize sewer-clogging by
trapping coarse debris and to reduce odor emanations from the sewers by
providing a water seal. In early sewer systems, catch basins were important
because of the number of impaired streets', the use of flat grades, ineffi-
cient means of sewer-cleaning, and low flows in the sewer systems. With
improvements in street surfacing, attention to design for self-cleaning
velocity in sewers, and the advent of street sweeping and improved sewer-
cleaning techniques, their benefits have been reported as being marginal.
G-94
-------
Despite the purported reduced need, catch basins remain very prevalent in
many sewer systems. The APWA report (4) on street accumulation reported that
Chicago had 3815 miles of sewer in 1960 with 200,000 catch basins. The AVCO
report on stormwater pollution in Tulsa reported 330 miles of installed
sewers with 22,000 catch basins (58). Thus, the average number of catch
basins in Chicago was 52.4/mile of sewer in Chicago and 66.7/mile of sewer
in Tulsa. Averaging these gives an estimate of 60 catch basins/mile.
The Metcalf and Eddy report on catch basin technology (59) quoted a 1928
survey of catch basin dimensions conducted by American City Magazine. Ninety-
six American cities, the District of Columbia, and four Canadian cities par-
ticipated in the survey. The average catch basin volume available for
storage of solids and water was 1.45 cu. yds. The APWA report of street
accumulation quoted catch basins cleaning statistics for the City of Chicago
in the period 1946-1960. The average amount of material removed from each
catch basin was 0.7 cu yd/yr. The cleaning frequency was once or twice per
year. Thus, it appears that when catch basins are cleaned about once a year,
the available volume is about 50% water and 50% solids. The solid material
is wet with a density of about 110 Ib per cu. ft.
The best data on the amount of pollution contained in uncleaned catch basins
is given by Sartor and Boyd (9). Twelve uncleaned catch basins in
San Francisco were completely stirred and the BOD concentration of the
slurry was measured. The BOD concentrations ranged from 5 mg/1 to 1500 mg/1
with an average of 241 mg/1. The amount of water in a single catch basin
just before annual cleaning is about 1 cu. yd. Using the average BOD con-
centration of 241 mg/1, the uncleaned catch basin will contain about 0.4 Ib
of BOD. Assuming 60 catch basins per mile of sewer and 0.025 miles of sewer
per acre, this is equivalent to 0.61 Ib BOD per acre. Assuming that the
catch basins are cleaned annually, the amount of pollution removed in the
cleaning process will be 0.61 Ib BOD/acre-year. This constitutes only
about 2% of the previously estimated 25-35 Ib BOD/acre/year for separate
storm sewers. Part II of this appendix also contains an analysis of catch
basin effectiveness based on an assessment by Lager and Smith (2). The
analysis reveals that for twice-per-year catch basin cleaning the expected
G-95
-------
level of BOD removal from stormwater discharges would be slightly greater
than 6%.
Sartor and Boyd (9) also flushed uncleaned catch basins with clean water at
rates corresponding to storms with intensities ranging from 0.07-0.7 in/hr.
The catch basins contained from 2000-3000 Ib of solids. It was found that
only about 1% of the solids were removed by the flushing effect. Thus, it
appears that solids which accumulate in catch basins which are primarily
inorganic are not readily flushed out by rainfall events.
The potential for reducing the amount of pollution which reaches the stream
from separate storm sewers by means of catch basin cleaning is apparently
small. The amount of inorganic solids which can be intercepted in catch
basins, however, is a much larger percentage of the total solids loading.
For example, the APWA report on street accumulation (4) estimated the amount
of dust-and-dirt on the streets as 1.5 lb/day/100 ft of curb. Assuming the
sewer length equals the street length and applying the factor of four men-
tioned previously, the amount of dust-and-dirt believed to be washed into
the storm sewer is about 231,000 1/yr per mile of sewer. Annual cleaning
catch basins in Chicago yielded about 0.7 cu. yd. of material which was
60% solids. Assuming 60 catch basins per mile, this is equivalent to a
removal of about 75,000 Ib. of solids per mile of sewer annually. This
represents about 32% of the estimated annual load of dust-and-dirt.
Some cost information is available for cleaning of catch basins. The cost
of catch basin cleaning in Chicago was given by APWA as $3.50 per catch basin
cleaned in 1960 dollars. Catch basin cleaning costs in Buffalo, New York
ranged from $4.59 in 1966-67 to $7.61 per catch basin in 1970-71 (60). The
Chicago costs adjusted to December, 1976 become $8.80 per catch basin, and
the Buffalo equivalent cost is $11.23. Sartor and Boyd (9) surveyed catch
basin cleaning practice in seven cities and found that the cost of catch
basin cleaning (1971) was $15.00 for hand-cleaning and about $7 per catch
basin for mechanical cleaning. An average cost of $10/catch basin will be
used here.
Lager and Smith (59) reported the results of an APWA survey of 299 cities
which showed an average cleaning frequency of 2.3 times/year. Of the seven
G-96
-------
cities surveyed by Sartor and Boyd (9) two reported a frequency of 2.3
times/year, twe at a frequency of once a year, one at six times/year, and the
remainder "as required".
Assuming a cleaning frequency of 2.3 times/year, 60 catch basins per mile,
0.025 miles of street/acre, and a cost of $10 per cleaning gives an overall
cost for catch basin cleaning of $34.50/care-year. Divising the cost per
acre-year by the estimated 0.61 Ib BOD/acre-year gives the cost of BOD
removal at $56.50 per Ib of BOD removed. Therefore, it would appear that
not only is the potential effectiveness of catch basin cleaning small but
the cost is high.
G-97
-------
REFERENCES
1. Heaney, Huber, Medina, Murphy, Nix, (University of Florida), "Nationwide
Evaluation of Combined Sewer Overflows and Urban Stormwater Discharges,
Volume II: Cost Assessment and Impacts", U.S. Environmentap Protection
Agency, EPA-600/2-77-064, March 1977.
2. Lager, J.A., and Smith, W.G., "Urban Stormwater Management and Technology:
An Assessment," U.S. EPA Report EPA-670/2-74-040, NTIS-PB 240 687,
December 1974.
3. Smith, Robert, "Cost to the Consumer for Collection and Treatment of
Wastewater:, U.S. Environmental Protection Agency, EPA 17090-07/70,
July 1970.
4. American Public Works Association, Federal Water Pollution Control
Administration, "Water Pollution Aspects of Urban Runoff", WP-20-15,
January 1969.
5. Bartholomew, Harland, "Land Uses in American Cities", Harvard University
Press, 1955.
6. Central Engineering Laboratories, FMC Corporation, U.S. Environmental
Protection Agency, "A Flushing System for Combined Sewer Cleaning",
EPA 11020 DNO 03/72, March 1972.
7. American Public Works Association, Federal Water Pollution Control
Administration, "Problems of Combined Sewer Facilities and Overflows
1967", WP-20-11, December 1967.
8. Smith, Robert, "The Use of the Log-Normal Distribution for Rainfall
Data, Internal EPA Memorandum to Record, February 10, 1977.
9. Sartor, J.D., and Boyd, G.B., "Water Pollution Aspects of Street
Surface Contaminants", U.S. Environmental Protection Agency, EPA-R2-
72-081, November 1972.
10. Sartor, J.D., Boyd, G.B., and Agardy, F.J., "Water Pollution Aspects of
Street Surface Contaminants", Presented at the 45th Annual Conference of
the Water Pollution Control Federation, Atlanta, Georgia, October 1972.
11. Morris, R.H., et al., "Water Pollution Abatement Technology-Capabilities
and Costs: Urban Runoff", National Commission on Water Quality, NTIS
Report PB-247-391, December 1975.
12. 1975 Annual Report, City of Cincinnati, Department of Public Works,
Highway Maintenance Division.
G-98
-------
13. Field, R., Tafuri, A.N., and Masters, H.E., "Urban Runoff Pollution
Control Technology Overview", U.S. EPA Report 600/2-77-047, March 1977.
14. Ports, M.A., Sediment and Erosion Control Design Criteria", APWA
Reporter, May 1975.
15. Midwest Research Institute and Hittman Associates, Inc., "Methods for
Identifying and Evaluating the Nature and Extent of Nonpoint Sources
of Pollutants", U.S. Environmental Protection Agency, EPA-430/9-73-014.
16. . Agricultural Statistics 1973, U.S. Department of Agriculture.
17. Hittmann Associates, Inc., "Processes, Procedures, and Methods to
Control Pollution Resulting from all Construction Activity", U.S.
Environmental Protection Agency, EPA 430/9-73-007.
18. Engineering Science, Inc., "Comparative Costs of Erosion and Sediment
Control, Construction Activities", U.S. Environmental Protection Agency,
EPA-490/9-73-016.
19. Dow Chemical Company, "An Economic Analysis of Erosion and Sediment
Control Methods for Watersheds Undergoing Urbanization", U.S. Department
of the Interior (C-1677), February 1972.
20. Soil Conservation Service National Engineering Handbook; Section 4,
Hydrology, August 1972.
21. Poertner, H.G., "Practices in Detention of Urban Stormwater Runoff, An
Investigation of Concepts, Techniques, Applications, Costs, Problems,
Legislation, Legal Aspects, and Opinions", APWA, Special Report No. 43,
1974.
22. Patterson, W.L., and Banker, R.F., "Estimating Cost and Manpower
Requirements for Conventional Wastewater Treatment Facilities", U.S.
Environmental Protection Agency, 17090 DAN 10/71, October 1971.
23. Tholin, A.L., and Kftifer, C.J,, "Hydrology of Urban Runoff", Trans.
American Society of Civil Engineering Paper No. 3061.
24. Toubler, J., and Westmacott, R., "Water Resources Protection Measures
in Land Development - A Handbook", Delaware University, Water Resources
Center, Newark, Delaware, NTIS #PB-236-049, April 1974.
25. Thelen, Edmund, et al., "Investigation of Porous Pavements for Urban
Runoff Control", Franklin Institute Research Labs., U.S. Environmental
Protection Agency, 11034 DUY, March 1972.
26. "208 Areawide Wastewater Management Plan - Fifth Planning District
Commission, Roanoke, Virginia, Moore, Gardner, and Associates, Inc.,
July 1976.
G-99
-------
27. U.S. EPA, "Water Quality Management Planning for Urban Runoff", Report
No. EPA 440/9-75-004, December 1974.
28. Murray, D.M., and Ernst, U.F.W., "An Economic Analysis of the Environ-
mental Impact of Highway Deicing", U.S. Environmental Protection Agency,
EPA-600/2-76-105, May 1976.
29. Field, R., Struzeski, E.J., Jr., Masters, H.E., and Tafuri, A.N., "Water
Pollution and Associated Effects from Street Salting", U.S. Environmental
Protection Agency, EPA-R2-73-257, May 1973.
30. Struzeski, E., "Environmental Impact of Highway Deicing", U.S. Environ-
mental Protection Agency, 11040 GKK, June 1971.
31. Brenner, R., and Moshman, J., "Benefits and Costs in the Use of Salt to
Deice Highways", The Institute for Safety Analysis, The Salt Institute,
November 1976.
32. Johnson, R.E., et al., "Dustfall as a Source of Water Quality Impairment",
Hour. Sanitary Engineering, Div. ASCE Vol 92 Sal p 245, February 1966.
33. Draft Report, EPA Contract No. 6802-1473, Industrial Gas Cleaning
Institute, Stamford, Connecticut, 1977.
34. McKee, J.E., "Loss of Sanitary Sewage through Storm Water Overflows",
Jour. Boston Soc. Civil Engineers, 34:2, April 1947.
35. Palmer, C.L., "The Pollutional Effects of Storm-Water Overflows from
Combined Sewers", Sewage and Industrial Wastes, 22:2, 154, 1950.
36. Shifrin, W.G., and Horner, W.W., "Effectiveness of the Interception of
Sewage-Storm Water Mixtures", JWPCF, 33:6, 650, 1961.
37. Johnson, F.C., "Equipment, Methods, and Results from Washington, D.C.
Combined Sewer Overflow Studies", JWPCE, 33:7, 721, 1961.
38. Benjes, H.H., et al., "Storm-Water Overflows from Combined Sewers",
JWPCF, 33:13, 1252, 1961.
39. Davis, P., and Borchardt, J., "Combined Sewer Overflow Abatement Plan,
Des Moines, Iowa, "U.S. EPA Report No. EPA-R2-73-170, April 1974.
40. Leiser, C.P., "Computer Management of a Combined Sewer System", U.S.
EPA, Report No. EPA-670/2-74-022, July 1974.
41. "Combined Sewer Regulation and Management: A Manual of Practice",
American .Public Works Association, 11022 DMU, Environmental Protection
Agency, July 1970.
42. "The Swirl Concentrator as a Combined Sewer Overflow Regulator Facility",
American Public Works Association, EPA-R2-72-008, Environmental Protec-
tion Agency, September 1972.
G-100
-------
43. Field, R., "The Dual Functioning Swirl Combined Sewer Overflow Regulator/
Concentrator", EPA-670/2-73-059, Edison Water Quality Research Labora-
tory, Environmental Protection Agency, September 1973.
44. Metcalf £ Eddy, Inc., "Wastewater Engineering : Collection, Treatment,
Disposal, New Yrok, McGraw-Hill Book Company, 1972.
45. American Public Works Association, U.S. Environmental Protection Agency,
"Relationship Between Diameter and Height for the Design of a Swirl
Concentrator as a Combined Sewer Overflow Regulator", EPA-670/2-74-039,
July 1974.
46. Benjes, H.H., "Cost Estimating Manual - Combined Sewer Overflow Storage
and Treatment", U.S. Environmental Protection Agency, Report No. EPA-
600/2-76-386, December 1976.
47. "Prevention and Correction of Excessive Infiltration and Inflow into
Sewer Systems: A Manual of Practice", American Public Works Association,
11022 EFF, Environmental Protection Agency, January 1971.
48. Santry, I.W., "Sewer Maintenance Costs", J. Water Pollution Control
Federation, 44:7, 1425, 1972.
49. Cesareo, D.J., and Field, R., "Infiltration-Inflow Analysis", Jour.
Env. Engineering Division, ASCE, 101:5, 775, October 1975.
50. "Heat Shrinkable Tubing as Sewer Pipe Joints", The Western Company,
11024 FLY, Environmental Protection Agency, June 1971.
51. "Improved Sealants for Infiltration Control", The Western Company,
11020 DIH, Environmental Protection Agency, June 1969.
52. "Ground Water Infiltration and Internal Sealing of Sanitary Sewers",
Montgomery County Sanitary Department, Montgomery, Ohio, 11020 DHQ,
Environmental Protection Agency, EPA-430/9-75-021, December 1975.
53. "Handbook for Sewer System Evaluation and Rehabilitation", U.S.
Environmental Protection Agency, EPA-430/9-75-021, December 1975.
54. "Preliminary Report for a Manual of Practice," The Sewer Rehabilitation
Subcommittee, Technical Advisory Committee, American Public Works
Association, 1975.
55. Pisano, W.C., in "Proceedings, Urban Stormwater Management Seminars",
EPA Report WPD 03-76-04, January 1976.
56. Metcalf and Eddy, "Best Management Practices for Nonstructural Solutions
to Stormwater Pollution Control", draft report EPA Contract No. 68-03-
2437, December 1976.
G-101
-------
57. Pisano, W.C., and Queiroz, C.S., "Procedures for Estimating Dry
Weather Pollutant Deposition in Sewerage Systems", draft report,
EPA Grant No. R804579, May 1977.
58. AVCO Economic Systems Corporation, Federal Water Quality Administration,
"Storm Water Pollution From Urban Land Activity", 11034 FKL 07/70,
July 1970.
59. Lager, J.A., and Smith, W.F., Metcalf and Eddy, Inc., "Catchbasin
Technology Overview and Assessment", Unpublished report on EPA Contract
68-03-0274.
60. Buffalo Sewer Authority Annual Report 1970-71.
G-102
-------
APPENDIX G, PART II
EPA-600/2-77-083
April 1977
STORM WATER MANAGEMENT MODEL:
LEVEL I—COMPARATIVE EVALUATION OF STORAGE-TREATMENT
AND OTHER MANAGEMENT PRACTICES
by
James P. Heaney
Stephan J. Nix
Department of Environmental Engineering Sciences
University of Florida
Gainesville, Florida 32611
Grant No. R-802A11
Project Officers
Richard Field Dennis Athayde
Storm and Combined Sewer Section Urban Runoff Program
Wastewater Research Division Non-Point Source Branch
Municipal Environmental Research Laboratory(Cinti.) Water Planning Division
Edison, New Jersey 08817 Washington, D.C. 20460
WATER PLANNING DIVISION
OFFICE OF WATER AND HAZARDOUS MATERIALS
US ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
and
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
US ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
-------
DISCLAIMER
This report has been reviewed by the Municipal Environmental Research Labora-
tory and the Water Planning Division, Office of Water and Hazardous Materi-
als, US Environmental Protection Agency, and approved for publication.
Approval does not signify that the contents necessarily reflect the views
and policies of the US Environmental Protection Agency, nor does any mention
of trade names or commercial products constitute endorsement or recommenda-
tion for use.
11
-------
FOREWORD
The US Environmental Protection Agency was created because of increasing
public and government concern about the dangers of pollution to the health
and welfare of the American people. Noxious air, foul water, and spoiled
land are tragic testimony to the deterioration of our natural environment.
The complexity of that environment and the interplay between its components
require a concentrated and integrated attack on the problem.
Research and development is that necessary first step in problem solving and
it involves defining the problem, measuring its impact, and searching for
solutions. The Municipal Environmental Research Laboratory develops new and
improved technology and systems for the prevention, treatment, and management
of wastewater and solid and hazardous waste pollutant discharges from munici-
pal and community sources, for the preservation and treatment of public
drinking water supplies and to minimize the adverse economic, social, health,
and aesthetic effects of pollution. This publication is one of the products
of that research; a most vital communication link between the researcher and
the user community.
Combined sewer overflows and urban stormwater discharges are a significant
pollution source. This report describes simplified procedures to enable
decision makers to obtain a preliminary estimate of the magnitude of this
pollution source and the associated costs of control.
Francis T. Mayo, Director
Municipal Environmental Research Laboratory
Ned Notzen, Acting Director
Water Planning Division
iii
-------
PREFACE
This report is part of a series of documents on urban stormwater management
which provides analysts with a wide variety of tools for evaluating alterna-
tives ranging from simple desktop procedures as outlined in this report
(Level I analysis) to sophisticated computer-based simulation using the
original Storm Water Management Model (Level IV analysis). The companion
document to this simplified procedure for comparing other management practices
with storage-treatment options would be very useful in supplementing this
report. The other report is titled:
Heaney, J.P., W.C. Huber, and S.J. Nix, Storm Water Management
Model: Level I—Preliminary Screening Procedures, EPA-600/2-76-
275, Environmental Protection Technology Series, USEPA, 1976.
iv
-------
ABSTRACT
The original USEPA Storm Water Management Model (SWMM) provides a detailed
simulation of the quantity and quality of stormwater during a specified
precipitation event lasting a few hours. This model is widely used. How-
ever, it is too detailed for many purposes. Indeed, a wide range of evalu-
ation techniques ranging from simple to complex procedures are needed. In
particular, the 208 planning effort needs simplified procedures to permit
preliminary screening of alternatives. In response to this need, four
levels of stormwater management models are being prepared. This volume
presents a "desktop" procedure to compare selected alternative control
technologies.
A graphical procedure is described which permits the analyst to examine a
wide variety of control options operating in series with one another or in
parallel. The final result is presented as a control cost function for
the entire study area which is the optimal (least costly) way of attaining
any desired level of control. Given a specification regarding the desired
overall level of control the user can determine the appropriate amount of
each control to apply.
This methodology is applied to Anytown, U.S.A., a hypothetical community
of 1,000,000 people. The results indicate the mix of treatment, storage,
street sweeping, and sewer flushing which attains the specified pollution
control level at a minimum cost.
This report is submitted as part of Grant No. R-802411 by the University of
Florida under sponsorship of the US Environmental Protection Agency. Work
was completed in December 1976.
v
-------
TABLE OF CONTENTS
FOREWORD ill
PREFACE iv
ABSTRACT v
LIST OF FIGURES . ix
LIST OF TABLES xi
LIST OF SYMBOLS xii
ACKNOWLEDGMENTS xv
SECTION
I SUMMARY 1
General Theory and Methodology 1
Control Technologies 2
Application to Anytown, U.S.A 2
II RECOMMENDATIONS 6
III INTRODUCTION 7
IV 208 PLANNING AREAS 9
V GENERAL THEORY AND METHODOLOGY 12
Theory 12
Marginal Analysis 12
Production Theory 13
Methodology 13
VI CONTROL TECHNOLOGIES 26
Street Sweeping 26
Combined Sewer Flushing 36
Catch-basin Cleaning 41
Storage-Treatment 41
vii
-------
TABLE OF CONTENTS (CONCLUDED)
SECTION
VII APPLICATION TO ANYTOWN, U.S.A 46
Problem Statement 46
Application 48
REFERENCES 65
GLOSSARY 67
APPENDICES
A. Quantity and Quality Analysis 69
B. Working Curves for Application to Anytown, U.S.A. 73
viii
-------
LIST OF FIGURES
FIGURE Page
1 PRODUCTION FUNCTIONS 14
2 GENERALIZED STORMWATER POLLUTION CONTROL NETWORK 16
3 GRAPHICAL PROCEDURE FOR DETERMINING OPTIMAL CONTROL
STRATEGIES, STEPS 1 AND 2 17
4 GRAPHICAL PROCEDURE FOR DETERMINING OPTIMAL CONTROL
STRATEGIES, STEP 3 20
5 GRAPHICAL PROCEDURE FOR DETERMINING OPTIMAL CONTROL
STRATEGIES, STEPS 4 AND 5 22
6 GRAPHICAL PROCEDURE FOR DETERMINING OPTIMAL CONTROL
STRATEGIES, STEPS 5 (CONCLUDED), 6 AND 7 24
7 STORMWATER POLLUTION CONTROL TECHNOLOGIES - AVAILABILITY
FACTORS EQUAL 1.0 27
8 IMPERVIOUSNESS AS A FUNCTION OF DEVELOPED POPULATION
DENSITY " 33
9 SWEEPING AVAILABILITY FACTOR AS A FUNCTION OF DEVELOPED
POPULATION DENSITY 33
10 PRODUCTION FUNCTIONS FOR STREET SWEEPING 34
11 PRODUCTION FUNCTION FOR COMBINED SEWER FLUSHING 38
12 PRODUCTION FUNCTION (ISOQUANTS) FOR STORAGE-TREATMENT,
ATLANTA, GEORGIA 44
13 TOTAL COST CURVE FOR STORAGE-TREATMENT, STORM SEWERED
AREAS, ATLANTA, GEORGIA 45
14 STORMWATER POLLUTION CONTROL NETWORK FOR ANYTOWN, U.S.A.-
AVAILABILITY FACTORS EQUAL 1.0 49
15 MARGINAL COST CURVES FOR THE PARALLEL OPTIONS, STORM
AREAS MEDIUM AVAILABILITY FACTORS 51
ix
-------
LIST OF FIGURES ( CONCLUDED )
FIGURE
16 TOTAL COST CURVES FOR THE PARALLEL OPTIONS, STORM AREAS ... 52
17 TOTAL COST CURVE FOR STORAGE-TREATMENT, STORM AREAS 54
18 ISOQUANTS OF THE OVERALL FRACTION OF BOD REMOVED, STORM
AREAS HIGH AVAILABILITY FACTORS 55
19 ISOQUANTS OF THE OVERALL FRACTION OF BOD REMOVED, STORM
AREAS MEDIUM AVAILABILITY FACTORS 56
20 ISOQUANTS OF THE OVERALL FRACTION OF BOD REMOVED, STORM
AREAS - - LOW AVAILABILITY FACTORS 57
21 TOTAL COST CURVE FOR ALL OPTIONS, STORM AREAS HIGH
AVAILABILITY FACTORS 58
22 TOTAL COST CURVE FOR ALL OPTIONS, STORM AREAS MEDIUM
AVAILABILITY FACTORS 59
23 TOTAL COST CURVE FOR ALL OPTIONS, STORM AREAS LOW
AVAILABILITY FACTORS 60
24 TOTAL COST CURVES FOR ALL DRAINAGE SYSTEM SERVICE AREAS . . 64
x
-------
LIST OF TABLES
TABLE Page
1 ANNUAL COST OF OPTIMAL STRATEGY FOR ANYTOWN, U.S.A.,PRESENTED
BY TYPE OF SEWERAGE SYSTEM - MEDIUM AVAILABILITY FACTORS . . 4
2 ANNUAL COST OF OPTIMAL CONTROL STRATEGY FOR ANYTOWN,
U.S.A., PRESENTED BY TYPE OF CONTROL TECHNOLOGY FOR DIFFERENT
ASSUMED AVAILABILITY FACTORS 5
3 COMPARISON OF ANNUAL COST OF OPTIMAL CONTROL STRATEGY FOR
ANYTOWN, U.S.A. USING STORAGE-TREATMENT ALONE AND IN
COMBINATION WITH OTHER MANAGEMENT PRACTICES 5
4 PERCENT OF STREET POLLUTANTS IN VARIOUS PARTICLE SIZE
RANGES 29
5 BRUSH-TYPE SWEEPER EFFICIENCY FOR VARIOUS PARTICLE SIZE
RANGES 30
6 AVERAGE VALUES OF GUTTER LENGTH. . . 37
7 UNIT COSTS OF STREET SWEEPING 37
8 EXAMPLE PROBLEM EVALUATING CATCH-BASIN PERFORMANCE .... 42
9 LAND USE AND POPULATION CHARACTERISTICS OF ANYTOWN, U.S.A. 47
10 ANNUAL WET- AND DRY-WEATHER FLOWS AND BOD LOADS FOR ANYTOWN,
U.S.A 50
11 OPTIMAL STRATEGY FOR 25, 50, 75, AND 85 PERCENT OVERALL BOD
REMOVAL, ANYTOWN, U.S.A. - HIGH AVAILABILITY FACTORS .... 61
12 OPTIMAL STRATEGY FOR 25, 50, 75, AND 85 PERCENT OVERALL BOD
REMOVAL, ANYTOWN, U.S.A. - MEDIUM AVAILABILITY FACTORS ... 62
13 OPTIMAL STRATEGY FOR 25, 50, 75, AND 85 PERCENT OVERALL BOD
REMOVAL, ANYTOWN, U.S.A. - LOW AVAILABILITY FACTORS .... 63
xi
-------
LIST OF SYMBOLS
Ap Area served by option p, ac
A.,,, Area served by combined sewers to be flushed, ac
or
A,, Area to be swept, ac
AR Annual runoff, in/yr
a(i,j) Coefficient for storm and unsewered areas for pollutant j on
land use i, Ib/ac-yr-in
3(i,j) Coefficient for combined areas for pollutant j on land use i,
Ib/ac-yr-in
C Cost per unit of effort, $/X -yr
C Cost per mile of sewer flushed, $/mile
or
CCTT Cost per curb mile swept, $/curb-mile
jVi
CF Total cost function for option p
DD Daily dust and dirt accumulation rate, Ib/day
DS Annual depression storage, in/yr
DWF Dry-weather flow, in/yr
£ "Pick-up" efficiency of the street sweeping equipment
F Pounds of pollutant per pound of dust and dirt
f.(PD,) Population density function for land use i
G Gutter density, curb-miles/ac
I Total imperviousness, percent
!„ Imperviousness due to streets only, percent
D
M^ Combined sewer deposition pollutant (BOD) load, Ib/yr
xii
-------
LIST OF SYMBOLS (CONTINUED)
M^ Pollutant load in area served by option p, Ib/yr
M' Pollutant load available to option p, Ib/yr
P
M T Pollutant load available to all parallel options , Ib/yr
M,, Wet-weather pollutant (BOD) load, Ib/yr
MC Marginal cost per pound of pollutant removed by option p, $/lb
MC Composite marginal cost per pound of pollutant removed by the
parallel options , $/lb
MF Marginal cost function for option p
MFTT Composite marginal cost function for the parallel options
IIL Annual dry-weather BOD load, Ib/ac-yr
HL BOD load of combined sewer deposition, Ib/ac-yr
m Unit pollutant load in area served by option p, Ib/acre-yr
m.^ Annual wet-weather pollutant (BOD) load, Ib/ac-yr
Nn Number of dry days since the last storm
N~ Number of days between street sweepings
J
n Number of times the streets were swept since the last storm
P Annual precipitation, in
PI Total pollutant at the beginning of the storm, Ib
P Pollutant remaining at the end of the last storm, Ib
PD, Population density in the developed area, persons/ac
PF Production function for option p
4> Fraction of pollutant load available to option p (0 <_ £ 1.0)
<£ „ Fraction of wet-weather BOD load available for flushing
(o < SF i i.o)
4> Fraction of wet-weather BOD load available for sweeping
(o 14>CW1 i.o)
rsw
xiii
-------
LIST OF SYMBOLS (CONCLUDED)
W^ Net pollutant (BOD) discharge, Ib/yr
E
w Pollutant removal by option p, Ib/yr
W Pollutant removal by the parallel options , Ib/yr
W01, BOD load in deposition removed by daily sewer flushing, Ib/yr
Sr
W Wet-weather BOD removed by sweeping, Ib/yr
L> -L '
X Input vector
X Level of effort for process p (0 < X < 1.0)
P ~ P ~
X Fraction of combined sewerage system components flushed daily
(o < XSF i i.o)
X Input vector to storage-treatment option (0 _< X _< 1.0)
O -L O J.
X Fraction of days per year an area is swept (0 £ X <_ 1.0)
o W o W ~
Y Output vector
Y Fraction of available pollutant load removed by option p
P (0 < Y < 1.0)
— p —-
Y Fraction of pollutant removed by the parallel options
(0 < YTT < 1.0)
— II —
Y. Fraction of pollutant removed by the serial operation
V (0 < Y, < 1.0)
— ty —
Y0_ Fraction of available BOD removed by flushing (0 < Y0_, < 1.0)
or — or —
YCT Fraction of BOD removed by storage-treatment (0 <_ Y £ 1.0)
O -L O J-
Y Fraction of available BOD removed by sweeping (0 _< Y £ 1.0)
o W ~~"~ o W
Z Total cost for process p, $/yr
Z Composite total cost of the parallel options , $/yr
7. , Composite total cost of the serial operation, $/yr
Z F Total cost of combined sewer flushing, $/yr
Z Total cost of storage-treatment, $/yr
o L
Z Total cost of sweeping, $/yr
oW
xiv
-------
ACKNOWLEDGMENTS
Numerous individuals were very helpful in formulating and conducting
specific phases of this study. Dennis Athayde, Richard Field, and Pat
Waldo of USEPA provided many valuable suggestions and overall review. Dr.
William Pisano of Energy and Environmental Analysis, Inc. provided informa-
tion regarding their sewer flushing studies in Boston. George Hinkle and
Richard Sullivan of the American Public Works Association provided data
on street sweeping. John Lager of Metcalf and Eddy, Inc. provided informa-
tion regarding catch-basin cleaning. Dr. Wayne C. Huber, University of
Florida, reviewed an earlier draft of this document.
xv
-------
SECTION I
SUMMARY
Analysis of wet-weather pollution control alternatives is much more compli-
cated than the traditional dry-weather sewage problem due to the highly
variable flow and the much broader range of options to be evaluated. The
highly variable nature of the flows requires statistical characterization
of the properties of the runoff hydrographs and pollutographs using averaging
times ranging from a single storm event to an annual series. The range of
control options has been extended from examining only storage and treatment
devices to inclusion of other management practices, e.g., street sweeping,
sewer flushing, catch-basin cleaning. These units operate in series and/or
in parallel with one another.
This report provides a simplified methodology for evaluating these other
management practices in conjunction with storage-treatment options. A
graphical solution technique is used to evaluate wet-weather control alter-
natives for Anytown, U.S.A., a typical U.S. city of 1,000,000 people. The
results demonstrate the technique and provide a preliminary indication
regarding the relative competitiveness of the various control options.
GENERAL THEORY AND METHODOLOGY
The optimal combination of storage-treatment devices and other management
practices for wet-weather pollution control can be determined using marginal
analysis from economic theory, and a graphical solution procedure. Marginal
analysis indicates that more intensive use should be made of control alter-
natives with lower marginal costs, measured in dollars per pound of pollu-
tant removed. As these activities are expanded, marginal costs increase to
the point where other options become competitive. The entire analysis can
be viewed as determining, at any specified marginal cost, the quantity of
pollution which the various control options, in parallel, would offer to
control. These results, for all options in parallel, are combined to yield
a composite control cost curve. Then this composite option is evaluated
with the downstream option(s) in series with it to yield the final result.
The solution is guaranteed to be optimal because every option produces a
diminishing marginal value of pollution control as its level of effort is
expanded. For example, if sewer flushing is to be used as a control alter-
native the initial monies will be spent where it is most effective, e.g.,
cleaning the pipes with the heaviest deposition rate. As more money is
spent, controls would be used on progressively cleaner sections of pipe.
Thus, the pollution control effectiveness, per dollar invested, would
-------
decrease. Also, constant unit control costs are assumed. As a consequence,
marginal costs increase thereby guaranteeing that the control cost functions
are convex and the resulting graphical solution is the optimal one.
CONTROL TECHNOLOGIES
For the purposes of this study, four technologies were considered: street
sweeping, combined sewer flushing, catch-basin cleaning, and storage-
treatment. Only combined sewered areas utilize all four technologies.
Storm sewered areas do not require sewer flushing. In addition to flush-
ing, unsewered areas do not use catch-basin cleaning or street sweeping
if it is assumed that there are no gutters.
For street sweeping, an overall BOD removal efficiency of 0.5 is assumed.
The assumed unit cost is $7.00/curb-mile swept ($4.35/curb-km). The per-
formance of sweepers was estimated, for varying sweeping intervals and
removal efficiencies, using a continuous simulation of one year of data
for Minneapolis. A modified version of the street sweeping procedure
described in SWMM was used.
Data on combined sewer flushing were obtained from studies in Boston, Mass.
The results of these efforts indicated that a relatively small percentage
of the pipes retain a substantial amount of the total deposition. The
assumed annual costs of flushing per unit length of sewer line is $11.78/ft
($38.64/m). .Daily flushing is assumed to remove 100 percent of the BOD
deposited in the affected pipes.
Catch basins were found to be relatively ineffective as a wet-weather pollu-
tion control device due to their relatively small size in relation to the
contributing drainage area. Thus, they were not investigated further.
The procedure for evaluating storage-treatment technologies was presented
in our earlier work. Thus, this control technology was not discussed in
detail.
APPLICATION TO ANYTOWN, USA
The methodology was applied to a hypothetical urbanized area, called Any-
town, which has characteristics typical of the 248 urbanized areas in the
US as listed below:
(1) Population Density (urbanized area): 5.14 persons/ac
(12.70 persons/ha)
(2) Mean Annual Precipitation: 33.4 in (84.8 cm)
(3) Land Use Percentage (urbanized area): residential, 31.4%;
commercial, 4.6%; industrial, 8.0%; other developed, 9.8%;
undeveloped, 46.2%.
2
-------
(4) Land Use Percentage (developed areas only): residential,
58.4%; commercial, 14.8%; industrial, 8.6%; other
developed, 18.2%.
(5) Percent of Developed Area Served by Type of Drainage
System; combined sewers, 14.4%; storm sewers, 38.3%;
unsewered, 47.3%.
(6) Population Density of the Developed Area by Type of
Drainage System—person/ac (persons/ha): combined,
16.7 (41.3); storm, 13.0 (32.1); unsewered, 4.6 (11.4);
all developed areas, 9.6 (23.7).
The results of this analysis, presented by type of sewerage system, are
shown in Table 1. Although the combined sewered area comprises less than
15 percent of the land area, about 40 percent of the total costs are
incurred for this area because the loadings are higher and it is more cost-
effective to control this portion of the total load.
A breakdown of total control costs, by type of technology and assumed
availablility factors, is presented in Table 2. For the medium availability
factors, storage-treatment is used for about 80 percent of total control.
As expected, sweeping and flushing gain in relative importance as the
availability factors increase. This effect is most pronounced for street
sweeping. This type of sensitivity analysis is quite helpful in providing
an indication of the importance of reliable estimates of the availability
factors.
Lastly, the significance of the savings resulting from using management
practices other than storage-treatment are evaluated in Table 3. The
results indicate savings (relative to using storage-treatment only) of 6
percent, 21 percent, or 37 percent for 50 percent control for low, medium,
and high availability factors, respectively. These results definitely
indicate the need to evaluate all available control options in area-wide
wastewater management planning.
-------
TABLE 1. ANNUAL COST OF OPTIMAL STRATEGY FOR ANYTOWN, U.S.A., PRESENTED
BY TYPE OF SEWERAGE SYSTEM - MEDIUM AVAILABILITY FACTORS
Type
of
System
Combined
Storm
Unsewered
Total
Acreage
ac (ha)
15,100
(6,110)
40,100
(16,230)
49,500
(20,030)
104,700
(42,370)
Total Annual
for
25%
0.48
0.12
0.56
1.16
Indicated
50%
1.65
0.82
1.42
3.89
Cost ($ x 10 /yr)
% BOD Control
75% 85%
4.50 7.86
3.56 7.43
2.82 2.82
10.88 18.11
a
Anytown has a population = 1,000,000
-------
TABLE 2. ANNUAL COST OF OPTIMAL CONTROL STRATEGY FOR ANYTOWN, U.S.A., PRESENTED BY TYPE OF
CONTROL TECHNOLOGY FOR DIFFERENT ASSUMED AVAILABILITY FACTORS.
Total Annual Cost ($ x 10 /yr) for Indicated % BOD Control and Assumed Availability Factors
Type of
Control
Technology Low
25%
Med
High
Low
50%
Med
High
Low
75%
Med
High
85%
Low Med High
Sweeping
Flushing
Storage-
Treatment
0 0.16 0.24
0.14 0.14 0.18
1.18 0.86 0.43
0.21 0.59 0.88
0.17 0.21 0.28
4.25 3.09 1.95
0.56 1.45 2.84
0.26 0.57 0.60
0.94 2.58 3.80
1.01 0.69 0.82
11.50 8.86 5.25 19.31 14.84 9.72
TOTAL
1.32 1.16 0.85
4.63 3.89 3.11
12.32 10.88 8.69
21.26 18.11 14.34
TABLE 3. COMPARISON OF ANNUAL COST OF OPTIMAL CONTROL STRATEGY FOR ANYTOWN, U.S.A., USING
STORAGE-TREATMENT ALONE AND IN COMBINATION WITH OTHER MANAGEMENT PRACTICES.
Annual Cost ($ x 10 /yr)
Storage-Treatment and
Other Options
%BOD Storage-
Control Treatment(S-T)Only Low
Medium
High
Savings Over Storage-
Treatment Only
Low
Medium
High
25
50
75
85
1.47
4.95
13.39
22.42
1.32
4.63
12.32
21.26
1.16
3.89
10.88
18.11
0.85
3.11
8.69
14.34
10
6
8
5
21
21
19
19
42
37
35
36
-------
SECTION II
RECOMMENDATIONS
This simplified methodology for evaluating urban stormwater pollution con-
trol alternatives is intended to serve as a preliminary screening device.
It requires neither a computer nor an understanding of more refined analyti-
cal solution procedures. After the user understands the concepts and pro-
cedures, he may wish to substitute the appropriate analytical procedures
using derived functions.
The results indicate significant savings if other management options are
combined with storage-treatment options. Further savings can be realized
by recognizing that a significant portion of the control costs can be
assigned to other purposes.
-------
SECTION III
INTRODUCTION
In recent years there has been the realization that stormwater from urban
areas is a serious water pollution source. Abatement of this source will
require a monumental effort in research, development, and implementation.
In this study, a simple methodology is developed which provides a "first-
cut" evaluation of the problem and the optimal control strategy.
Several technologies are available to control stormwater pollution. At
present, emphasis is placed on storage-treatment control techniques [1].
However, other techniques are available, e.g., street sweeping, sewer
flushing. These methods, used in conjunction with storage-treatment, may
provide a more cost-effective pollution management package [2, 3, 4, 5, 6].
The resultant optimal mix of all control options is often referred to as
"Best Management Practice" or BMP's.
With the potential control effectiveness of options other than storage-
treatment established, the need has arisen for a methodology capable of
determining, on a "first-cut" basis, the most cost-effective usage of
these other options in conjunction with (or exclusive of) storage-treatment
in the urbanized area. "First-cut" or preliminary analyses establish the
magnitude of the problem and rapidly evaluate alternatives. This study
derives a relatively simple methodology to obtain this "first-cut."
Several analytical techniques which can provide an optimal "mix" of control
alternatives are available. Many require the use of computerized algorithms
which defeat the need for simplicity. Nearly all require an accurate knowl-
edge of the functional form of empirically derived relationships. A simple
methodology was developed by Heaney, Huber, and Nix [7] but was limited to
storage-treatment as a control alternative.
A graphical technique is chosen to provide a preliminary estimate of an
optimal stormwater pollution control strategy. Graphical solution tech-
niques do have drawbacks. They are relatively time consuming and more
susceptible to human error. Nevertheless, there are definite advantages.
Computational aides are not necessary and complex analytical procedures are
avoided.
The next section presents a generalized description of a typical 208 plan-
ning area. Section V describes the procedure used to obtain an optimal
strategy along with the economic theories used to derive the methodology.
This procedure is applicable to a wide variety of storrawater pollution
-------
control networks. Section VI discusses the various control technologies and
develops the production functions and cost equations necessary for the
methodology of Section V. Section VII is an application of the methodology
to a hypothetical urban area known as Anytown, USA. Anytown is given the
characteristics found for urbanized areas around the nation [1]. The opti-
mal integrated control package is determined for this hypothetical situation.
Appendix A presents a simplified method for estimating wet-weather quantity
and quality. Equations to estimate dry-weather quantity and quality are
also given for comparative purposes. Lastly, working curves for the applica-
tion to Anytown are placed in Appendix B.
-------
SECTION IV
208 PLANNING AREAS
The Federal Water Pollution Control Act Amendments of 1972 (PL92-500) are a
comprehensive piece of legislation designed to implement a procedure by
which virtually all sources of pollution to the nation's waters are to be
eliminated and the purity of these waters restored [8]. The pollutants are
discharged from both urban and rural areas and from point and nonpoint
sources. Several goals were set forth by the Act:
(1) that the discharge of pollutants into navigable waters
be eliminated by 1985;
(2) that a level of water quality be attained by July 1,
1983, that provides for the protection of aquatic
life, wildlife, and recreation; and
(3) that areawide water quality management planning
processes be developed and utilized.
Other provisions include funding for the necessary research and to aid in
the implementation of management plans.
Section 208 of the Act sets overall guidelines for the development of area-
wide planning processes. The US Environmental Protection Agency, designated
to carry out the intent of the Act, has published specific guidelines to aid
local authorities in attaining the overall goals [9]. These guidelines
state that the 208 planning procedure should proceed along the following
lines:
(1) Identify the problems in meeting the 1983 goals of
the Act.
(2) Identify all constraints and priorities pertaining to
the 208 planning area.
(3) Identify all possible solutions to the problems.
(4) Develop alternative plans to meet the statutory
requirements.
(5) Analyze the alternative plans for technologic and
economic feasibility.
-------
(6) Select an areawide plan.
(7) Seek approval for the plan.
(8) Periodically update the plan.
The selection of a specific plan should be based on cost effectiveness,
feasibility, and public acceptance.
An important portion of the selected plan should be involved with the con-
trol of stortnwater pollutant discharges. EPA guidelines specifically state
the need for "an analysis of the magnitude of existing and anticipated urban
storrawater problems" [9]. Additionally, techniques to better manage the
existing drainage systems, thus preventing discharges at the source, and/or
improved methods for the storage and treatment of urban runoff, should be
developed.
Areawide management is conducted at the local level. In general, areawide
plans should be developed for a region relatively homogeneous in its waste-
water problems and ultimate discharge locations. Such an area will include
one or several urbanized areas which are of primary concern to this study.
In order to conduct an analysis of stormwater discharges from these areas
and potential control strategies, a comprehensive inventory of the charac-
teristics of each should be available. For the preliminary or "first-cut"
analysis conducted in this study, these characteristics should include
land use, sewerage system service areas and population served by each, and
the mean annual precipitation.
A definition of an urbanized area is needed to properly delineate the areas
of potential urban stormwater discharge. The U.S. Census describes an
urbanized area as follows [10]:
(1) A central city (or adjacent cities) of 50,000 or more
inhabitants.
(2) Settled areas in close proximity to the central city,
including the following:
a. Incorporated areas of 2,500 or more inhabitants
or less than 2,500 if the area includes 100 or
more closely settled housing units.
b. Small parcels of land with a population density
greater than 1,000 (386) inhabitants per square mile (km).
c. Other small parcels of unincorporated land with
less than the required population density that
eliminate enclaves.
With this definition, the local planner can divide the urbanized acreage
among five land use categories: residential, commercial, industrial, other
developed (parks, institutions, etc.), and undeveloped. The definition of
10
-------
an urbanized area allows for the inclusion of large areas of undeveloped
lands not likely to be developed in the planning future. These areas should
not be included in the following analysis. Additionally, the planner should
delineate the area and population served by combined and storm drainage
systems and unsewered areas within the remaining developed (or developing)
area. With these data, the following graphical procedures may be applied
to provide a "first-cut" evaluation of the urbanized area's stormwater
problem and optimal control strategy.
11
-------
SECTION V
GENERAL THEORY AND METHODOLOGY
This section presents the economic theories and general methodology neces-
sary to determine an optimal stormwater pollution control strategy. The
discussion is based heavily on production theory and marginal analysis from
economics.
THEORY
Marginal Analysis
In its simplest terirs, marginal may be defined as "extra." In economic
terms, for example, marginal cost is defined as the extra cost associated
with an additional unit of some commodity. In economic decision making
marginal analysis determines whether an action results in a sufficient
additional benefit to justify the additional cost.
Two
Lk..L^/Liu-i. Ly^,i.*^-.j-^*- ^.\s i v« h? k. .^ .*, jr h-ii^. u.uu-fc.b.-i.v-'iLt-t-*- ^~\j ±j ±- •
basic rules governing the concept of marginal analysis are [11]:
(1) The scale of an activity should, if possible, be
expanded so long as its marginal net yield (taking
into account both benefits and costs) is a positive
value; and the activity should therefore be carried
to a point where this marginal net yield is zero.
(2) For optimal results, activities should, whenever
possible, be carried to levels where they all yield
the same marginal returns per unit of effort
(cost).
As an example of rule (2), assume that product A, at a specific production
level, is yielding $1.50 per $1.00 spent and product B is returning $2.00
per $1.00 spent. In this situation the firm is missing the opportunity to
gain $0.50 by not transferring the $1.00 spent to manufacture product A to
product B. Therefore, to assure the maximum return, both products should
be manufactured at levels of equivalent marginal return or yield.
In stormwater pollution control these same concepts apply. Analysts should
seek, in such cases, to utilize various control procedures at levels yield-
ing an equivalent marginal cost.
12
-------
Production Theory
A production process seeks to increase the utility of a commodity or com-
modities. In any such process certain technological relationships restrict
the decision maker's options on input jind output levels [12]. Consider an
input vector to a production process, X, defined as
X = (X.., X_,. . • , X.,..., X ). (1)
Similarly, the output vector, Y, is defined as
Y = (Yr Y2,..., Y.J Ym). (2)
The technological relationship between the input and output vectors, known
as the production function, is
Y = PF (X) (3)
where Y is the maximum output attainable with input vector X. In other
words, any output YJ may not be increased without a reduction in some other
output Y, or an increase in some input X^. Examples of production functions
are shown in Figure 1. The single-input, single-output production function
shown may be viewed as a two-input, single-output function with one input
held constant.
The shape of the production function is governed by the "law" of diminishing
returns which states that, as an input to a production process is increased,
with all other inputs held constant, a point will be reached beyond which
any additional input will yield diminishing marginal output. For example,
if a treatment plant experiences increases in raw sewage flow and no al-
terations are made to the facility, a flow will be reached where an incre-
ment in flow will result in a diminishing increase of pollutant removed.
METHODOLOGY
In this study, a stormwater pollution control option is defined as a unique
set of conditions and control technologies. For example, although a par-
ticular control technology, such as street sweeping, may be used in several
different subareas within an urbanized area, those subareas may have varying
pollutant loading rates which affect the cost-effectiveness of the common
technology. Also, within a particular subarea there may be several distinct
pollutant sources requiring different control technologies.
Knowing the production function for each stormwater pollution control tech-
nology (production process) and with the control options defined, it is
possible to graphically determine an optimal strategy. In the discussion
that follows all production functions have been transformed into a single-
input, single-output form and expressed in terms of the fraction of available
pollutant removed, Y, as a function of the fraction of the level of effort,
X. The definition of level of effort is dependent on the particular tech-
nology. For example, the level of effort for street sweeping is defined
as the fraction of days during a year when sweeping occurs. All production
functions and later functions or graphs are derived on an annual basis.
13
-------
CM
X
c/f
CO
UJ
o
O
o:
o_
Q
o
tr
QL
i-
o
Q.
Two-input, single-output
production process
INPUT I TO PRODUCTION PROCESS, X.
CO
CO
UJ
o
o
tr
a.
Q
o
o:
Q.
Single-input, single-output
production process
Z)
Q.
INPUT TO PRODUCTION PROCESS, X,
Figure 1. Production Functions
14
-------
Before delving into the methodology a few more definitions are required.
In stormwater pollution control, options may operate in parallel, series,
or a combination of both. A parallel operation is defined as one in which
the effluent (untreated portion) of any one option does not act as the
influent to any other parallel option. A serial operation is defined as
one in which options are sequential with the effluent from one option acting
as the influent to the next.
A network of series/parallel pollution control options is shown in Figure 2.
In this example four options (p = 1, 2, 3, and 4) operate in parallel
followed by one option (p = 5) operating in series with the parallel group.
The pollutant flows through this network are shown in terms of the pollutant
load in the area served by the parallel options, >L, the fraction of the
pollutant load available to option p, ((>„, and the pounds removed by each
option p, W . The pollutant load available to each option, Mp, is the
product of (j)p and Mp. The pollutant load M^ is shown as the influent to
an imaginary option (p = 4) that has zero pollutant removal capacity. This
simply allows the residual pollutant loads to be routed to option 5 without
passing through the other parallel options. For example, street sweeping
does not reach the entire surface pollutant load of an area. Therefore,
some portion may be washed off by runoff events and routed to a storage-
treatment facility without having the opportunity to be removed by sweeping.
The influent to option 5 is the pollutant load not removed by the parallel
group. This network will serve as an example and reference throughout the
remainder of this section.
Once the production functions are established, the first step is to construct
the total cost curve for each option (see Step 1, Figure 3). Production
functions for several specific pollution control technologies and methods to
develop the total cost curves are discussed in Section VI. However, for
the purposes of generalization, a total cost curve is defined as a function
of the fraction of pollutant removed, i.e.,
Zp = CFp(Yp) (4)
where Z = total cost for option p, $/yr;
= fraction of available pollutant load removed by option p
P
P (0 < Y < 1.0); and
CF (Y ) = total cost function in terms of Y .
P P P
Recall that the fraction of available pollutant removed is the dependent
variable of the production function. Thus, to derive the total cost curve,
one only needs to reverse the axes of the production function and develop
the relationship between the level of effort for option p, and the total
cost. Mathematically, this may be stated as
xP = pFp1(y
15
-------
M,/=0,M
M4' =
- 0p)Mp+ M4
M+M-W-W-W -W
,, .
3 4 I 2 3 5
LEGEND
M
M
W
= CONTROL PROCESS
= AVAILABLE POLLUTANT LOAD, Ib/yr
= AVAILABILITY FACTOR
= POLLUTANT LOAD , Ib/yr
= POLLUTANT REMOVAL , Ib/yr
Figure 2. Generalized Stormwater Pollution Control Network
16
-------
STEP I : FIND TOTAL COST CURVE FOR EACH OPTION (p = 1,2, 3,4 ,ond 5)
PRODUCTION FUNCTION
TOTAL COST CURVE
LEVEL OF EFFORT, Xp
o.
Ml
O
o
2p- Cp-Xp
0 1.0
FRACTION OF AVAILABLE
POLLUTANT REMOVED , Yp
STEP 2 .- FIND MARGINAL COST CURVE FOR EACH PARALLEL
OPTION (p= 1,2,3, ond 4)
TOTAL COST CURVE MARGINAL COST CURVE
rti
OT
O
o
<
O
Wp=0p-Mp-Yp
MCp=Az
V)
O
o
o
cc
<
POLLUTANT REMOVED,Wp.lb
0 Wpmfl)t
POLLUTANT REMOVED,Wp, Ib/yr
Figure 3. Graphical Procedure for Determining Optimal Control
Strategies, Steps 1 and 2
17
-------
where X = level of effort for option p (0 < X < 1.0);
P — P —
Y = fraction of available pollutant load removed by option p
P (0 <_ Y £ 1.0); and
PF (Y ) = inverse of the production function for option p.
P P
If total cost is assumed to be a linear function of the level of effort,
then
Z = C • X (6)
P P P
where C = annual cost of option p per unit of effort, $/X .
Substituting equation (5) into equation (6) yields
Z = C • PF~1(Y ). (7)
P P P P
Equation (7) is the desired form of the total cost function (equation 4).
The next step is to generate the marginal cost curve for each parallel
option (see Step 2, Figure 3). This curve gives the relationship between
the marginal cost per pound of pollutant removed at any level of pollutant
removed. The marginal cost curve is the first derivative of the total cost
curve. However, the total cost curves for the parallel options must be
converted from the fraction of pollutant removed to pounds removed. This
is accomplished using the following equation,
W = M' • Y (8)
P P P
where W = pollutant removal by option p, Ib/yr;
M^ = pollutant load available to option p, Ib/yr; and
Y = fraction of available pollutant load removed by option p
P (0 < Y < 1.0).
p
The maximum value of W , W~ , depends on the maximum removal efficiency
of option p, Yn . The equation used to find M^ is
i^max P
M' = (J> • M (9)
P P P
where cj) = fraction of pollutant load (M ) available to option p
p (0 < <|>D < 1.); and p
M = pollutant load in area served by option p, Ib/yr, and
P M = m • A ;
P P P
18
-------
where m = unit pollutant load in area served by option p, Ib/ac-yr;
and
A = area contributing pollutants to option p, ac.
The pollutant load per acre, IIL, can be found using methods described in
Appendix A. The normalized version of the total cost curve (equation 4) may
now be written as
Z = CF (W ) (10)
P P P
since only the units of the abscissa of the total cost curve are being
changed. Utilizing equation (10), the marginal cost curve is described
by the following equation,
d(CFp(Wp))
where MC = marginal cost per pound of pollutant removed by
parallel option p, $/lb; and
MF (W ) = the marginal cost function in terms of W .
P P P
Graphically, the marginal cost curve is determined by finding the slope,
AZp/AWp, of the total cost curve at several values of W . These values,
plotted against the values of W , give an approximation of the marginal
cost curve. The marginal cost curves are increasing functions of pounds
of pollutant removed.. This result necessarily follows from the earlier
assumptions of a concave production function and constant unit costs.
Once the marginal cost curves are developed for the parallel options, a
composite marginal cost curve may be constructed (see Step 3, Figure 4).
This single curve summarizes the effect of the entire parallel group (p =
1, 2, 3, and 4). This is accomplished by adding the marginal cost curves
with respect to the ordinate of the marginal cost curves. In other words,
at several equivalent values of MCp for the parallel options, the corre-
sponding W 's are summed. The composite marginal cost curve is
mTI = MFII(WII) (12)
where ^TT = comPosite marginal cost per pound of pollutant
removed by the parallel options, $/lb;
W T = pollutant removal by the parallel options, Ib/yr,
(= W1 + W_ + W_, in the example network); and
MF (W ) = the composite marginal cost function in terms of W .
19
-------
STEP 3 : FIND COMPOSITE MARGINAL COST CURVE FOR ALL PARALLEL OPTIONS
(NOTE: OPTION 4 IS IMAGINARY)
MARGINAL COST CURVE ( p= I) MARGINAL COST CURVE (p = 2) MARGINAL COST CURVE (p=3)
o
s
W
O
O
<
z
o
W
'o
W,
'max
o
S
O
O
o
a:
MC
W
10
O
CO
o
o
a:
POLLUTANT REMOVED,W, ,lb/yr
POLLUTANT REMOVED, W2 , Ib/yr
POLLUTANT, REMOVED, W3, Ib/yr
COMPOSITE MARGINAL COST CURVE FOR ALL PARALLEL OPTIONS ( p= 1, 2,3 and 4 )
«IoiWlo+W2o+W3o
Figure
POLLUTANT REMOVED BY PARALLEL OPTIONS , W^ , Ib/yr
Graphical Procedure for Determining Optimal Control Strategies, Step 3
-------
The composite total cost curve for the parallel options is constructed
by integrating the composite marginal cost curve (see Step 4, Figure 5),
i.e. ,
max
o
where Z = composite total cost of the parallel options, $/yr;
and
W = maximum pollutant removal by the parallel options
max (W 4- W7 + W_ in the example network), Ib/yr.
max max max
At this point the economic behavior of the parallel group has been condensed
into a single equivalent "option." Therefore, the problem has been reduced
to one with two options in series. Next, the two-option serial operation
is aggregated into a single equivalent "option" representing the entire
example network. Although the procedure will be unique to a two-option
serial operation, this will not limit the number of options in series that
may be analyzed. Any number of options may be aggregated by simply working
with pairs until condensed to one equivalent "option." The previous pro-
cedure for the parallel case may be applied to any number of options.
A two-option serial operation may be viewed as a production "process" with
two inputs and one output. The production function can be described using
isoquants (see Figure 1), i.e., lines of input combinations capable of
producing a constant output and having the following characteristics [12]:
(1) Isoquants cannot intersect. Intersection would
imply that the same input levels are capable of
producing different output levels.
(2) Isoquants slope downward to the right because
increased use of one input requires the lessened
use of the other input.
(3) Isoquants are convex to the origin due to the
inability of one input to be substituted for
another at a specific level of output.
The inputs are the total costs of each option in series and the output is
the fraction of pollutant removed by the serial operation. In this par-
ticular case, the inputs are the composite total costs for the parallel
group, Z , and the total costs for the subsequent option, Z,..
Before constructing the isoquants of the fraction removed by the serial
operation, both total cost curves must be in terms of the fraction of
pollutant removed. The curve for option 5 was constructed earlier (see
21
-------
STEP 4 : INTEGRATE COMPOSITE MARGINAL COST CURVE TO OBTAIN
COMPOSITE TOTAL COST CURVE FOR ALL PARALLEL OPTIONS
COMPOSITE MARGINAL COST
CURVE FOR ALL PARALLEL OPTIONS
"lo WH max
POLLUTANT REMOVED, W,
Mn
, Ib/yr
COMPOSITE TOTAL COST CURVE
FOR ALL PARALLEL OPTIONS
tn
o
u
0 WIo WJTmax MH
POLLUTANT REMOVED,W... , Ib/yr
STEP 5 : FIND ISOQUANTS OF THE FRACTION OF POLLUTANT
REMOVED BY OPTIONS IN SERIES,
FOR ALL PARALLEL OPTIONS
TOTAL COST CURVE FOR OPTION 5
t=l
tu
to
o
u
55
o
1.0
FRACTION OF POLLUTANT REMOVED
BY ALL PARALLEL OPTIONS .Y,,.
in
til
tn
o
o
1.0
•'max
FRACTION OF POLLUTANT REMOVED
BY OPTION 5 , Yg
Figure 5. Graphical Procedure for Determining Optimal Control Strategies,
Steps 4 and 5
22
-------
Step 1, Figure 3) and is already in the proper form. The composite total
cost curve for the parallel group was left in terms of the pounds of
pollutant removed (equation 13). The following equation is used to con-
vert to the fraction removed:
where M T = pollutant load available to all parallel processes
(= M-L + M2 + M3 + M4), Ib/yr.
These curves must be in terms of the fraction removed due to the nature of
the serial operation. Essentially, one input is passing through two op-
tions, as opposed to a parallel operation where each input is independent.
Therefore, the action of one affects the other and it becomes necessary to
optimize the fraction removed by each option and then determine what
quantity of pollutant was removed by each, rather than the reverse.
Constructing the isoquants of the overall fraction of pollutant removed
requires several combinations of Y and Y,- capable of providing the desired
overall fraction. This is determined by the following equation,
where Y, = fraction of pollutant removed by the serial
operation.
Equation (15) states that the fraction of pollutants removed by the serial
operation is the sum of the removal from the first option, Y , and the
incremental removal due to the second option, Y5(l-Yjj). By noting the Z
and Z^ corresponding to the various combinations of YJJ and Y5 from each
of the total cost curves, the isoquants may be drawn (see Step 5, Figures 5
and 6).
The next step is to develop the optimal expansion path from the isoquants
by constructing points of tangency between the isoquants and isocost lines.
As the name suggests, isocost lines are lines of equal cost. The isocost
lines are given as
Z^ - Zn + Z, (16)
where Z. = composite total cost of the serial operation, $/yr.
The slope of this linear equation is -1. Therefore, to find the point of
tangency simply requires that the point on the isoquant tangent to a line
of a negative unit slope be located. These points determine the optimal
or least-cost combination of costs from each option. The optimal solution
may fall at a corner point. Connecting these points gives the optimal ex-
pansion path (see Step 6, Figure 6). The final step is to construct a com-
posite total cost curve for the serial operation. This may be done by
plotting the values of Z. against the corresponding values of Y,/, found on
the optimal expansion path (see Step 7, Figure 6). This curve, for the
23
-------
STEP 5
(CONTINUED )
ISOQUANTS OF
STEP 6
TOTAL COST, 2 g , $ /yr
FIND OPTIMAL EXPANSION PATH
ISOQUANTS OF
TOTAL COST, 2 , $/yr
STEP 7 : FIND TOTAL COST CURVE FOR ALL OPTIONS
(p= 1,2,3,4, and 5)
Figure 6.
ti)
V)
O
0
FRACTION OF POLLUTANT REMOVED
BY ALL OPTIONS, Y^
Graphical Procedure for Determining Optimal Control
Strategies, Steps 5 (concluded), 6 and 7
24
-------
example network shown in Figure 2, represents the final total cost for the
entire network as a function of the overall fraction of pollutant removed.
If there were subsequent options the curve would merely represent a com-
posite of two options in series that could next be combined with the
following process.
The methodology for establishing optimal strategies has been developed. At
this point, a planner could select an overall removal fraction and proceed,
in reverse, through the seven steps shown in Figures 3 through 6 and deter-
mine the optimal operating levels of each option. This is demonstrated by
the example application found in Section VII.
25
-------
SECTION VI
CONTROL TECHNOLOGIES
Section V set up a methodology by which engineers and planners could deter-
mine an optimal strategy with any number of control options. For the
purposes of this study, four technologies will be considered: street
sweeping, combined sewer flushing, catch-basin cleaning, and storage-
treatment. Typically, these technologies operate as shown in Figure 7.
Only combined sewered areas may utilize all four technologies. Storm
sewered areas do not require sewer flushing to remove sanitary sewage
deposition. In addition to flushing, unsewered areas do not have catch
basins or street sweeping since materials are transported to adjacent
pervious areas. (It is assumed that there are no gutters.) For combined
sewered areas the network operates in the following manner. A portion of
the street solids are removed by sweeping and a portion are washed off during
runoff events and partially captured by catch basins which are subsequently
cleaned by artificial means or flushed by a storm surge. The sanitary
sewage deposited in the sewer lines is also flushed artificially or by
storm surges. The pollutants flushed from the catch basins and sewer lines
during storm surges are sent to the wet-weather storage-treatment facility.
The material removed from the catch basins is normally sent to a sanitary
landfill. The material flushed from the sewers is sent to the dry-weather
treatment plant.
This section develops the production function for each technology. Addi-
tionally, the relationships to construct the total cost curves are given.
With this information, the methodology of Section III may be applied to any
urbanized area.
The term "pollutant" has been used almost exclusively up to this point.
However, the pollutant BOD will be the parameter of concern in this and
remaining sections. BOD is the most commonly used indicator of general
water pollution levels. The same method could be used for any other single
pollutant.
STREET SWEEPING
The sweeping of roadways is a long-established practice in American cities.
However, the primary purpose of this activity is the removal of unsightly
debris. Recent studies indicate that a portion of the material found on
the streets (and therefore a potential pollution source during runoff
events) may be removed by .a conscientious sweeping program [4, 5]. The
particle size and pollutant distribution of street contaminants are shown
26
-------
COMBINED SEWER AREAS
DEP
w,
WSW "WCB
CB
w,
ST
= MDEp * Mw
2. STORM SEWER AREAS
M
Mw" Wsw" wca
'ca
WE = Mw - W
sw
3. UNSEWERED AREAS
SYMBOL
LEGEND
ITEM
SOURCES
I ) WET-WEATHER POLLUTANT LOAD M w
2) DEPOSITION POLLUTANT LOAD M
CONTROLS
I ) STREET SWEEPING (SW)REMOVAL
2) CATCH BASIN (CB)
3) SEWER FLUSHING (SF)
4) STORAGE-TREATMENT (ST) "
EFFLUENT
NET POLLUTANT DISCHARGE
OEP
wsw
WCB
W
WE= MW-WST
ALL UNITS ARE IN POUNDS (Ibs).
Figure 7. Stormwater Pollution Control Technologies - Availability Factors Equal 1.0
-------
in Table 4.
Street sweeping may be performed manually or mechanically, with the latter
enjoying more widespread usage. Mechanical sweepers are divided into two
categories: brush-type and vacuum-type. Removal efficiencies with brush-
type sweepers for various particle sizes are shown in Table 5. The overall
efficiency is 0.50 with the coarser materials enjoying higher efficiencies
than fine particles. APWA reports that vacuum type sweepers have achieved
efficiencies of greater than 0.95 [5]. Of course, the increased efficiency
of vacuum sweepers results in a substantially higher cost over brush-types.
Street sweeping has several advantages and disadvantages as a pollution
control technique. Some favorable characteristics are the
(1) control of pollutants at the source; and
(2) dual purpose of sweeping for pollution control
and esthetics.
Unfavorable traits include
(1) relatively low efficiency as a pollution control
measure;
(2) sweeper's history as a traffic hazard;
(3) removal of only the portion of the load located near
the gutter; and
(4) problems of vehicular parking along the streets.
Although sweeping has a relatively low removal efficiency, in a coordinated
system of storage-treatment and other management practices, it may prove
to be a viable alternative.
Street sweeping may be considered a production process (as described
earlier). Indeed, all pollution control techniques may be described as
such. Therefore, it is possible to describe the technological relationship
between the input and output of street sweeping in terms of a production
function. In this case, the input is the fraction of the days on which
sweeping occurs during a year and the output is the fraction of BOD removed.
In order to generate the production function a model was developed to
simulate the conditions within an urbanized area and the effect of street
sweeping. Hourly rainfall is converted to runoff using a simple runoff
coefficient, and subsequently accumulated BOD is removed by scheduled
sweeping or a runoff event. The model makes use of the following assump-
tions :
(1) The average removal efficiency for BOD is equivalent
to that of all particle sizes. This is assumed because
of the apparent consistency of the portion of BOD
28
-------
TABLE 4. PERCENT OF STREET POLLUTANTS IN VARIOUS PARTICLE SIZE RANGES
to
VO
Pollutant
Total Solids
Volatile Solids
BOD5
COD
KjeldahL Nitrogen
Nitrates
Phosphates
Percent of Pollutant Associated with Each Particle Size Range
Particle Size (microns)
>2,000 840+2,000 246+840 104+246 43+104 < 43
24.4
11.0
7.4
2.4
9.9
8.6
0
7.6
17.4
20.1
4.5
11.6
6.5
0.9
24.6
12.0
15.7
13.0
20.0
7.9
6.9
27.8
16.1
15.2
12.4
20.2
16.7
6.4
9.7
17.9
17.3
45.0
19.6
28.4
29.6
5.9
25.6
24.3
22.7
18.7
31.9
56.2
Source: Sartor, J.D., and Boyd, G.B., "Water Pollution Aspects of Street Surface Contaminants,"
USEPA Report EPA-22-72-081, November 1972, p. 7.
-------
TABLE 5. BRUSH-TYPE SWEEPER EFFICIENCY FOR
VARIOUS PARTICLE SIZE RANGES
Particle Size
(microns)
2000
840+2000
246+ 840
104+ 246
43+ 104
<43
Overall
Sweeper Efficiency
(%)
79
66
60
48
20
15
50
Source: Sartor, J.D., and Boyd, G. B., "Water Pollution Aspects of Street
Surface Contaminants," USEPA Report EPA-22-72-081, November 1972,
p. 10.
30
-------
contained within the particle size ranges (see
Table 4).
(2) A runoff event encompasses consecutive hourly
runoff occurrences and intermittent dry periods
not to exceed twelve hours. For example, an
intermittent dry period of twelve hours will
start a new event; a period of eleven hours or less
will not [1].
(3) No sweeping occurs during an event. If an event
and a scheduled sweeping coincide the streets are
simply not swept until the next scheduled time.
(4) Only one pass is made per sweep.
The pollutant washoff functions incorporated in the model were identical
to the functions found in the SWMM and STORM models [13, 14]. However, the
methods of pollutant build-up and removal by street sweeping are somewhat
different. SWMM and STORM allow the linear build-up of pollutants as
long as the elapsed time from the previous runoff event is less than the
street sweeping interval. The relationship is
Pn = F • DD • 1SL + P (17)
1 D . o
where P.. = total pollutant load at the beginning of the storm, Ib;
F = pounds of pollutant per pound of dust and dirt;
DD = daily dust and dirt accumulation rate, Ib/day;
N = number of dry days since the last storm; and
P = pounds of pollutant remaining at the end of the last
storm (event).
If the number of days since the last runoff event is greater than the
sweeping interval, the following equation is employed by SWMM and STORM.
FT = P (l-e)n + N_ • DD • F • [(l-e)n + (l-e)11'1 + ... + (1-e)] (18)
1 O O
+ DD • F • (ND - nNg)
where N = number of days between street sweepings;
n = number of times the streets were swept since the
last storm; and
€ = "pick up" efficiency of the street sweeping equipment.
31
-------
The major flaw in this procedure is that the street sweeping "counter" is
set to zero at the end of every runoff event. In other words, after the end
of an event, N days must pass before sweeping occurs. Therefore, it is
conceivable that the streets will never be swept according to this procedure.
For example, assume that N is 20 days. If the longest dry period during
a year is 15 days, STORM and SWMM will fail to simulate any sweeping—even
though an interval of 20 days was specified.
To correct this deficiency, the model developed for this study merely
establishes a sweeping schedule from which no deviation is allowed except
in the case of a coincident runoff event. This is not an entirely accurate
assumption, for public works departments certainly have the flexibility to
alter their sweeping schedule. However, this is not considered to be a
serious error. When sweeping does occur, the amount of pollutant removed
is taken as the product of the accumulated pollutants available and the
"pick-up" efficiency.
Not all of the accumulated pollutants are available for removal by sweeping.
There are considerable amounts on parking lots, driveways, and other im-
pervious areas not subject to sweeping by municipal units. Total and
street imperviousness as a function of developed population density is
shown in Figure 8 [1]. If pollutants are assumed to be uniformly distributed
over the impervious area and that only the pollutants in the street are
sweepable, then
*sw = -y- * 0.6 PD~°'2 for PDd > 0.1 (19)
where (j) = sweeping availability factor, i.e., proportion of
pollutant load which is sweepable (0 <^ STJ <_ 1.0);
I = imperviousness due to streets only, percent; and
s
I = total imperviousness, percent.
A plot of equation (19) (Figure 9) shows that <(><,„ ranges from about 0.43
at PD^ = 5 persons/ac (12.4 persons/ha) to about .35 at PD^ = 15 persons/ac
(37.1 persons/ha). In actuality, a disproportionate amount of the pollu-
tion is located on the streets or is delivered to the streets prior to
entering the final drainage canals. To test the sensitivity of the result
to ^qij' evaluations will be made with <}>gy = 0.40 representing a lower bound
SW = 1-0 representing the upper bound, and $$^=0.70 representing an
average value.
Running the model with several different efficiencies (ranging from 0.1 to
0.9) and sweeping intervals (ranging from 1 to 42 days) generated the family
of production functions shown in Figure 10. The model was run using data
for the developed areas of Minneapolis, Minnesota (including hourly pre-
cipitation for 1971). The production function for a "pick-up" efficiency
of 0.50 is used to describe the typical mechanical sweeping operation.
This corresponds to the efficiency shown in Table 5 for brush-type sweepers.
The efficiency could be any value suitable to local conditions. For
32
-------
10
100
20
persons/ nectars
30 40
TOTAL IMPERVIOUSNESS
IMPERVIOUSNESS DUE TO STREETS ONLY
05 10 IS 2O
DEVELOPED POPULATION DENSITY , POd , persons /acre
Figure 8. Imperviousness as a Function of Developed Population
Density
(0
persons / hectare
30 40
so
6O
70
OS 10 IS 20
DEVELOPED POPULATION DENSITY , PDd, person*/acre
Figure 9. Sweeping Availability Factor as a Function of
Developed Population Density
33
-------
1.0
to
O
a 0.8
03
O
UJ
or
o
o
CD
UJ
_l
CD
2
O
O
<
(T
STREET SWEEPING SIMULATION,
MINNEAPOLIS, MINN. - 1971
6 = efficiency e=°-9
FRACTION OF DAYS STREETS ARE SWEPT, X
SW
Figure 10. Production Functions for Street Sweeping
34
-------
example, the use of vacuum sweepers would dictate the use of a higher
efficiency.
The production function generated by the model is in terms of the fraction
of BOD removed annually. In order to generate the total cost curve the
fraction removed must be converted to the pounds of BOD removed (as
described in Section V). Therefore,
WSW * (mW - mDEP) ' ASW ' *SW ' YSW (20)
where, W = wet-weather BOD removed by sweeping, Ib/yr;
oW
m^ = annual wet-weather BOD load, Ib/ac-yr;
SL = annual wet-weather BOD load due to combined sewer
deposition, Ib/ac-yr;
A = area to be swept, ac;
oW
= sweeping availability factor, i.e., proportion of
BOD load which is sweepable (0 5 (|> <_ 1.0); and
Or*
Y = fraction of available BOD removed by sweeping
(0
-------
Also, some average values for gutter length are shown in Table 6. The
sweeping cost per curb mile, Cg, is more difficult to determine. APWA
reports a wide range of values for several street sweeping cost parameters
from over 160 municipalities [16]. The median and mean for each
parameter are given in Table 7. The median value of $7.00/curb mile
($4.35/curb-km) swept will be used because of the large variance in the
data.
COMBINED SEWER FLUSHING
Combined sewers often experience dry-weather sewage deposition. These
solids accumulate in the sewers until removed by a storm surge or by
artificial flushing. The deposition carried away by runoff discharges
directly to the receiving water if the dry-weather treatment plant is
bypassed. Controlled flushing allows the sewers to be cleaned without
adding pollutants to the water body. Instead, these pollutants are routed
to the dry-weather plant for treatment.
As with street sweeping, sewer flushing is not a new idea; its primary
purpose has been to improve hydraulic capacity and self-scouring ability.
However, several reports indicate the ability of a flushing program to
remove a substantial portion of the pollutants associated with deposition
[2, 3, 6]. Several systems are available for sewer flushing, e.g., flush-
ing stations, in-line storage, and portable tankers. Flushing stations
are tanks placed at strategic locations that release the required flushing
volumes. Varying degrees of automation are utilized [3]. In-line storage
involves a system of internal dams used to block the sewage flow at upstream
points for rapid release to scour downstream elements [2]. The use of
tankers merely requires that the trucks be dispatched to the system com-
ponents requiring flushing.
Pisano has investigated the deposition problem in two Boston systems—
Dorchester and South Boston [2]. The two systems have a total of 2666
sewer elements with an average length between manholes of 191 ft (58.2m) per
segment. Through a simulation model it was estimated that 10.3 percent
of the daily dry-weather solids in the Dorchester system was deposited in
the lines. The South Boston system retained 6.6 percent. Also, the
Dorchester system retains 75 percent of the total deposition in only 18
percent of the system components. South Boston retains 63 percent in 22
percent of the components. Therefore, a relatively small portion of the
combined sewer elements retain a substantial amount of the total deposition.
As expected, pipe slope was reported to be the major factor in determining
potential deposition problems.
Pisano provided the data used to develop the sewer flushing production
function [2]. The input to this process is the fraction of the combined
sewer segments flushed daily. The output is the fraction of available BOD
removed annually by flushing. The production function is based on informa-
tion regarding the relative concentration of deposition within the two
systems of Boston (e.g., 75 percent of the deposition is found in 18 percent
of the Dorchester system elements). The function, shown in Figure 11,
36
-------
TABLE 6. AVERAGE VALUES OF GUTTER LENGTH
Curb or Gutter Length
Land Use
miles/ac
(km/ha)
ft/ac
(m/ha)
Residential
Commercial
Industrial
Other
0.059
(0.235)
0.070
(0.279)
0.034
(0.136)
0.023
(0.091)
312
(235)
370
(279)
180
(136)
121
(91)
Source: Heaney, J.P., Huber, W.C., Medina, M.A., Murphy, M.P., Nix, S.J.,
and Hasan, S.M., "Nationwide Evaluation of Combined Sewer Overflows
and Urban Stormwater Discharges, Volume II: Cost Assessment,"
USEPA Report EPA-600/2-77-064B, March 1977.
TABLE 7. UNIT COSTS OF STREET SWEEPING
Street Sweeping Costs
Mean
Median
$/curb-mile
($/curb-km)
86.61
(53.82)
7.00
( 4.35)
($/m3)
22.14
(28.96)
13.79
(18.04)
$/ton
($/metric ton)
31.31
(34.51)
14.28
(15.74)
$/capita/year
1.54
1.23
Source: Unpublished data from American Public Works Association, 1976.
37
-------
fe 0.2
s
o
CURVE BASED ON DATA FOR S. BOSTON
AND DORCHESTER, MASS. ( PISANO , [ 2 ] )
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
FRACTION OF SEWER COMPONENTS FLUSHED DAILY, X SF
Figure 11. Production Function for Combined Sewer Flushing
38
-------
is based on several assumptions:
(1) A flushing program cleanses a designated portion
of the system elements daily.
(2) Daily flushing will remove virtually 100 percent
of the available daily deposition. This assumes
that the sewers have been properly maintained and
do not contain beds of debris. Of course, not all
of the annual deposition will be available for
flushing, i.e., some portion will be removed
by runoff events.
(3) Pisano reports deposition in terms of suspended
solids. BOD, the pollutant of concern here,
is assumed to be deposited in a similar manner
[2].
(4) All components or pipe sections are ranked,
according to the severity of the deposition
problem, for flushing priority.
(5) The BOD flushed daily is routed to the dry-
weather treatment facility. The flushing
volumes are small enough to prevent an
artificial combined sewer overflow.
Inspection of the production function reveals that sewer flushing also ex-
hibits decreasing marginal output as the input is increased. In fact, the
effect is dramatic after approximately 10 or 20 percent of the sewers are
flushed daily.
To develop a total cost function for any urbanized area, it is necessary
to convert the production function in terms of the fraction of BOD removed
to the pounds of BOD removed annually. This is accomplished by the follow-
ing equation,
WSF - *SF "DBF ' ASF ' YSF (23)
where W = BOD in deposition removed by daily sewer flushing,
b* Ib/yr;
(j> F = sewer flushing availability factor, i.e. , proportion
of pollutant load that is flushable (0 < OT, < 1.0);
or
m___ = annual BOD load of combined sewer deposition,
\JLjL .. - i
lb/ac-yr;
A = area served by combined sewers to be flushed, ac; and
or
YSF = fraction of available BOD removed by flushing (0 <_ YSF < 1.0)
39
-------
A method of estimating the combined sewer deposition BOD load, m^p, is
found in Appendix A. A more refined procedure is being developed. Results
should be available later this year [17].
Assuming that the total annual costs of sewer flushing, Zgp, are a linear
function of the system footage to be flushed, the total cost curve for
any area is given by the following equation,
ZSF = CSF ' (°-AOG) ' ASF ' XSF (24)
where CCT, = cost per mile of sewer flushed, $/mile;
or
0.40G = sewer length in A-,.,, miles/ac = 40 percent of
gutter length;
X^p = fraction of combined sewerage system components
flushed daily (0 < X01, < 1.0); and
— or —
-1
X = PF (W ), the inverse sewer flushing production function
in terms of pounds of BOD removed.
This equation and the construction of the total cost curve require several
assumptions:
(1) Flushing will be performed by the in-line storage
and sudden release of dry-weather flow at upstream
locations [2].
(2) The redeposition of BOD at the trailing edge of the
resulting flush wave is assumed to be negligible [2].
(3) The cost per unit length of flushed sewer line is
constant; regardless of pipe size, type, slope, or
Manning's n.
(4) The length of combined sewers per acre is assumed to
be 40 percent of the gutter length. Equation 22 or
Table 6 may be used to estimate the gutter length, G.
Pisano indicates that the total present worth of the cost (capital and
operation/maintenance) per in-line flushing module (inflatable dam) and
the initial cleaning is $22,500. It is assumed that one module is needed
per segment requiring flushing. The annual cost per module is $2,250
(8% interest, 20 year service life). The Boston system segments have an
average length of 191 feet. Therefore, the annual cost of flushing per
unit length of sewer line is $11.78/ft ($38.64/m) or $62,200/mile
($38,600/km).
40
-------
CATCH-BASIN CLEANING
In a study dealing with overall catch-basin performance, Metcalf and Eddy,
Inc. define a catch basin as [18]:
a chamber or well, usually built at the curb line of
a street, for the admission of surface water to a
sewer or subdrain, having at its base a sediment sump
designed to retain grit and detritus below the point
of overflow.
This definition implies that catch-basins are not intended to remove BOD or
suspended solids, but act primarily as grit chambers designed to prevent
the clogging of sewer lines. However, the catch basin does act as a
sedimentation tank capable of removing some portion of the BOD. Unfor-
tunately, the small portion of BOD removed may be flushed from the sump
during runoff events. Catch basins act much as septic tanks, but are
subject to highly variable and, often, overwhelming flows. Lager and
Smith estimate the typical pollution control effectiveness in an example
shown in Table 8 [18]. The efficiency of BOD removal, calculated below using
data from Table 8, i.e.,
. removal -loss _ (345,800 -262,500) 100
ncy input ~ 25,000 basins (50 storms)(1.04 Ib)
= 6.4%
indicates that the expected removal level is not significant. For this
reason, catch-basin cleaning will not be analyzed further.
STORAGE-TREATMENT
The remaining method of controlling stormwater pollution involves storage
and/or treatment of the collected runoff. Storage-treatment facilities
operate in series with the management practices.
A variety of storage and treatment technologies are available. Examples of
storage include
(1) in-line storage,
(2) tanks,
(3) lagoons, and
(4) tunnels.
Treatment methods include
(1) sedimentation,
41
-------
TABLE 8. EXAMPLE PROBLEM EVALUATING CATCH-BASIN PERFORMANCE
EXAMPLE PROBLEM 7-3: ANNUAL POLLUTION ASSESSMENT OF CATCHBASIN PERFORMANCE
Given the conditions expressed in the preceding problems, determine the aggre-
gate effectiveness of the catchbasins over a period of years in terms of BOD,.
removed.
Specified Conditions
1. Total number of catchbasins = 25,000.
2. Curb length per catch basin = 0.10 curb mile (0.16 curb-km).
3. Annual precipitation = 35.1 in (89.2 cm).
4. Catchbasins are cleaned twice a year.
5. The pollution load displaced from each basin is 0.21 Ib (.10 kg)
BOD5 for each of 50 storms occurring in a year.
6. The runoff coefficient = 50%.
Assumptions
1. The annual rainfall can be characterized as 50 equal 5-h storms.
2. BOD5 removal by sedimentation will total 26.6% of the applied load.
Solution
1. Determine the annual loss of BOD,- by liquid volume displacement.
BOD5 loss = 25,000 basins x 50 storms x 0.21 Ib (.10 kg)
= 262,500 Ib/yr (125,000 kg/yr)
2. Compute the BOD5 entering a catchbasin each storm (following pro-
cedures of earlier example).
BOD- entering = 1.3 Ib (.59 kg) available x 0.80 removed from streets
= 1.04 Ib (.47 kg)
3. Determine the annual removal of BOD,- by sedimentation.
BODS removed = 25,000 basins x 50 storms x [1.04 Ib (.47 kg) x 0.266]
= 345,800 Ib/yr (156,800 kg/yr)
4. Compare the net benefit ratio
Benefit = 345,800 Ib (156,800 kg) removed * 262,500 Ib (119,000 kg)
lost
= 1.32:1.
Comment
The problem illustrates that from a pollution, abatement standpoint the bene-
fits of catchbasins are marginal at best. Of course, with the cleaning fre-
quency of twice per year, the liquid fraction pollution might average half the
specified value, thereby doubling the benefit ratio; however, the gross impact
is still small. This example is based on grossly synthesized data and real,
long-term removal data from a few catchbasins are required for an actual assess-
ment of catchbasins.
Reference: Lager, J.A., and Smith, W.G., "Catchbasin Technology Overview and
Assessment," USEPA Report (draft), 1977.
42
-------
(2) swirl concentrators,
(3) microstrainers,
(4) dissolved air flotation,
(5) contact stabilization, and
(6) physical-chemical treatment.
The operation of a storage-treatment facility is a production process
involving two inputs and one output. The inputs are the storage capacity
and the maximum treatment rate and represent the input vector to the
storage-treatment process, Xgx- The output is the fraction of available
BOD removed annually, Y .
O J.
A methodology to derive the production function and total cost curve for
storage-treatment in any urbanized area is discussed in an EPA publication
by Heaney, Huber, and Nix [7], Rather than summarize this methodology
here, the reader is referred to this report for details. With relatively
little data, the production function and total cost curve may be derived
for any city in the U.S. As an example, a production function (in the two-
dimensional isoquant form) for Atlanta, Georgia, is shown in Figure 12.
Additionally, a total cost curve for the storm sewered areas of that city
is shown in Figure 13.
43
-------
T, cm/hr
0.01 0.02 0
T, cm/hr
0,90
0.80
0.004 0.008 0.012 0.016 0.020
i
-0.40
0.002 0.004 0.006 0.008
T , in/hr
0.010 0.02O
TREATMENT , T, in. / hr
0.030
Figure 12. Production Function (Isoquants) for Storage-Treatment,
Atlanta, Georgia [Heaney, Huber and Nix, 1976]
44
-------
Ln
14.0
13.0
12.0
II.0 -
\ 10.0
-------
SECTION VII
APPLICATION TO ANYTOWN, U.S.A.
PROBLEM STATEMENT
In this section, the methodology presented in Section V is applied to a
hypothetical urbanized area. The characteristics of this area, called Any-
town, necessary to utilize this methodology are derived from average charac-
teristics of the 248 urbanized areas in the U.S. [1]. These averages are:
(1) Population Density (urbanized area): 5.14 persons/ac
(12.70 persons/ha).
(2) Mean Annual Precipitation; 33.4 in (84.8 cm).
(3) Land Use Percentage (urbanized area) : residential,
31.4%; commercial, 4.6%; industrial, 8.0%; other
developed, 9.8%; undeveloped, 46.2%.
(4) Land Use Percentage (developed areas only): residential,
58.4%; commercial, 14.8%; industrial, 8.6%; other
developed, 18.2%.
(5) Percent of Developed Area Served by Type of Drainage
System; combined sewers, 14.4%; storm sewers, 38.3%;
unsewered, 47.3%.
(6) Population Density of the Developed Area by Type of
Drainage System—persons/ac (persons/ha): combined,
16.7 (41.3); storm, 13.0 (32.1); unsewered, 4.6 (11.4);
all developed areas, 9.6 (23.7).
Assuming a population of 1,000,000 persons and using the above values, the
necessary land use, drainage system, and population characteristics for the
developed areas in Anytown are derived and shown in Table 9. The land use
percentages are assumed to be constant regardless of the drainage system
(e.g., combined, storm, and unsewered areas each have 58.4 percent of the
service area as residential). Additionally, it is assumed that the popula-
tion density for each drainage system service area is constant regardless
of the land use [e.g., residential, commercial, industrial, and other
developed areas in the combined sewered areas all have a population density
of 16.7 persons/ac (41.3 persons/ha)].
46
-------
TABLE 9. LAND USE AND POPULATION CHARACTERISTICS OF ANYTOWN, U.S.A.
Drainage
System
Land Use
Area,
ac
(ha)
Population Density,
persons/ac
(persons/ha)
Comb ined
Storm
Unsewered
Residential
Commercial
Industrial
Other
TOTAL or AVG.
Residential
Commercial
Industrial
Other
TOTAL or AVG.
Residential
Commercial
Industrial
Other
TOTAL or AVG.
TOTAL OR AVG.
8800
(3560)
1300
( 530)
2200
( 890)
2800
(1130)
15100
(6110)
23500
(9510)
3400
(1380)
5900
(2390)
7300
(2950)
40100
(16230)
29000
(11740)
4200
(1700)
7300
(2950)
9000
(3640)
49500
(20030)
104700
(42370)
16.7
(41.3)
16.7
(41.3)
16.7
(41.3)
16.7
(41.3)
16.7
(41.3)
13.0
(32.1)
13.0
(32.1)
13.0
(32.1)
13.0
(32.1)
13.0
(32.1)
4.6
(11.4)
4.6
(11.4)
4.6
(11.4)
4.6
(11.4)
4.6
(11.4)
9.6
(23.7)
47
-------
The methodology is applied to the control network shown in Figure 14. In
effect, the entire procedure is carried out for each drainage system area
as though it were a separate entity. Within each system area, a specific
control technique applied to one land use is regarded as a separate option.
This is primarily due to the fact that the wet-weather BOD load is differ-
ent for each land use. Therefore, in combined areas, the control network
consists of eight options (four for street sweeping and four for sewer
flushing) in parallel followed by storage-treatment in series. In the
storm sewered areas, the control network consists of the four street sweep-
ing options followed by storage-treatment in series. In the unsewered
areas, the only control option is storage-treatment. The notation repre-
senting the various land uses and drainage systems found in Figure 14 will
be used throughout the remainder of this section.
Before application of the methodology can begin, the wet-weather BOD loads
(the pollutant of interest here), for each land use within each drainage
system service area, must be estimated. Using the information provided
on Table 9 and the relationships found in Appendix A, these values are
computed and shown in Table 10. For comparative purposes, the annual wet-
weather and dry-weather flows and the dry-weather BOD loads are also shown.
APPLICATION
Following the seven steps discussed and shown in FiguresS, 4, 5 and 6 of
Section V for each drainage system service area will give an optimal
operating strategy applicable to that area. The production functions and
total cost curves for the individual parallel options are derived from
the information provided in Section VI and Table 9. The gutter length
necessary to develop total cost curves for sweeping and flushing was
computed from Equation 22 for residential areas and taken from Table 6 for
other land uses. The production function and total cost curve for storage-
treatment for each drainage system are found by applying the data found in
Table 9 and the mean annual precipitation to the simplified assessment pro-
cedure discussed by Heaney, Huber, and Nix [7]. Anytown is assumed to be
located in Region III [7], The total cost curves for the fifteen options
are presented in Appendix B.
Much uncertainty exists regarding the appropriate values to use for the
availability factors for street sweeping (^qij) and sewer flushing ($„„).
Thus, three different cases will be analyzed: (1) high availability
(<(>SF = gw = 1.0), medium availability (SF = 0.8, gW = 0.7), and low
availability Cj&gp = 0.6, <|>sw = 0.4).
Street sweeping in the storm sewered areas will be used to illustrate how
these four options shown in Figure 14 are combined into one equivalent
option. The marginal cost curves for these four options and the composite
marginal cost curve are shown in Figure 15. Recall that, for a given
marginal cost, the pollutant removal by the four options is simply the
sum of the individual removals. The removal by option SW4 is insignificant
because the pollutant loading per acre is so small. The derived total cost
curves for the three cases in the storm sewered area are shown in Figure 16.
48
-------
-p-
VJD
COMBINED SEWERED AREA
J_
STORM SEWERED AREA UNSEWERED AREA
II
STREET
SWEEPING
I
1
SEWER
r
FLUSHING
i
\
STREET SWEEPING
I
LEGEND
a = combined
b = storm
c = unsewered
I
2
3
4
= residential
= commercial
= industrial
= other developed
TOTAL EFFLUENT , W,
M
w
Figure 14. Stormwater Pollution Control Network for Anytown, U.S.A. - Availability Factors Equal 1.0
-------
TABLE 10. ANNUAL WET- AND DRY-WEATHER FLOWS AND BOD LOADS FOR ANYTOWN, U.S.A.
Ui
o
Drainage
System
Combined
Storm
Una ewe red
TOTAL
Land Use
Residential
Commercial
Industrial
Other
TOTAL
Residential
Commercial
Industrial
Other
TOTAL
Residential
Commercial
Industrial
Other
TOTAL
Wet-
Weather
Flow
In (cm)
13.7
(34.8)
13.7
(34.8)
13.7
(34.8)
13.7
(34.8)
_
12.5
(31.8)
12.5
(31.8)
12.5
(31.8)
12.5
(31.8)
_
8.5
(21.6)
8.5
(21.6)
8.5
(21.6)
8.5
(21.6)
-
Dry-
Weather
Flow
in (cm)
22.4
(56.9)
22.4
(56.9)
22.4
(56.9)
22.4
(56.9)
_
17.4
(44.2)
17.4
(44.2)
17.4
(44.2)
17.4
(44.2)
_
6.2
(15.7)
6.2
(15.7)
6.2
(15.7)
6.2
(15.7)
_
Dry-
Weather
BOD Load
Ib/ac
(kR/ha)
942
(1057)
703
(789)
910
(1021)
1035
(1161)
_
807
(905)
807
(905)
807
(905)
807
(905)
_
286
(321)
286
(321)
286
(321)
286
(321)
_
Street
Solids
Ib/ac
(kg/ha)
30
(34)
107
(120)
40
(45)
0.5
(0.6)
_
27
(30)
107
(120)
40
(45)
0.5
(0.6)
_
17
(19)
107
(120)
40
(45)
0.5
(0.6)
_
TOTAL (all
Wet-Weather BOD Loads
Sewer Street
Deposition Solids
Ib/ac 10&lb
(kg/ha) (106kg)
95 0.264
(107) (0.120)
334 0.139
(375) (0.063)
127 0.088
(142) (0.040)
1.7 0.001
(1.9) (0.0005)
0.492
(0.223)
0.634
(0.288)
0.364
(0.165)
0.236
(0.107)
0.004
(0.0,02)
1.238
(0.562)
0.493
(0.224)
0.449
(0.204)
0.292
(0.133)
0.004
(0.002)
1.238
(O.563)
2.968
(1.347)
wet-weather sources) 4
(2
Sewer
Deposition
106lb
(106kg)
0.836
(0.380)
0.434
(0.197)
0.279
(0.127)
0.005
(0.002)
1.554
(0.706)
_
_
_
_
_
_
_
.
1.554
(0.706)
.522
.053)
-------
MEDIUM AVAILABILITY
0.2 0.4 0.6
BOD REMOVED BY PARALLEL OPTIONS
1.0
, I06lb/yr
1.2 1.238
O.I 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
FRACTION OF BOD REMOVED BY PARALLEL OPTIONS , vi
1.0
Figure 15. Marginal Cost Curves for the Parallel Options, Storm Areas - Medium Availability Factors
-------
N>
AVAILABILITY
FACTOR, 0.w CURVE
BOD REMOVED BY PARALLEL OPTIONS , Wjj , I06lb/yr
i
0.2
r
0.5
O.I 0.2 0.3 0.4 0.5 0.6 0.7 0.8
FRACTION OF BOD REMOVED BY PARALLEL OPTIONS,.
i
0.9
1.236
1.0
Figure 16. Total Cost Curves for the Parallel Options, Storm Areas
-------
As expected, the total costs increase as the availability factor, 4>sw>
decreases .
For the storm sewer area, the problem is now reduced to evaluating the
optimal combination of the composite cost curve for the parallel options
and the downstream total cost curve for storage-treatment shown in Figure 17,
The resultant optimal solutions for the three assumed availability factors
are shown in Figure 18 (4>sw = 1.0), Figure 19 (SW = 0.7), and Figure 20
(4>gy =0.4). In each figure the ordinate and abscissa are scaled so that
the maximum cost is used as the upper bound. Thus, the maximum overall
pollutant removal is a point in the northwest corner of each figure, e.g.,
97 percent in Figure 18. Lastly, the final results for the storm sewered
area are shown in Figures 21 (gy =1.0), 22 (gw = 0.7), and 23 (
-------
Ln
14.0
12.0 -
u>
O
x 10.0 A
CO
O 6.0
Z 4.0 •
2.0 -
i
O.I
1
0.2
i
0.3
0.4 0.5 0.6 0.7 0.8
FRACTION OF BOD REMOVED BY STORAGE - TREATMENT , Y
0.9 1.0
ST
Figure 17. Total Cost Curve for Storage-Treatment, Storm Areas
-------
5.84
10.0 11.0 11.46
TOTAL ANNUAL COST , Z , $ X I06/yr
Figure 18. Isoquants of the Overall Fraction of BOD Removed, Storm Areas - High Availability Factors
-------
5.84
1.0
2.0 3.0 4.0 5.0 6.0 7.0 8.0
TOTAL ANNUAL COST , Z* $ X I06/yr
9.0 10.0 11.0 11.46
~ST
Figure 19. Isoquants of the Overall Fraction of BOD Removed, Storm Areas - Medium Availability Factors
-------
9.64
Ul
1.0
2.0 3.0 4.0 5.0
TOTAL ANNUAL COST ,
6.0 7.0
, $ X IO6/yr
9.0 10.0 11.0 11.46
Figure 20. Isoquants of the Overall Fraction of BOD Removed, Storm Areas - Low Availability Factors
-------
l/l
oo
HIGH AVAILABILITY
=1-0
02 0.4 0.6
BOD REMOVED BY ALL OPTIONS
, I0 Ib/yr
O.I 0.2 0.3 0.4 0.5 0.6 0.7 0.8
FRACTION OF BOD REMOVED BY ALL OPTIONS , Y*
.2 1.238
0.9
1.0
Figure 21. Total Cost Curve for All Options, Storm Areas - High Availability Factors
-------
Oi
ID
MEDIUM AVAILABILITY
02 0.4 0.6
BOD REMOVED BY ALL OPTIONS
0.8
, I0 Ib/yr
O.I 0.2 0.3 0.4 0.5 0.6 0.7
FRACTION OF BOD REMOVED BY ALL OPTIONS
0.8
1.2 1.238
0.9
1.0
Figure 22. Total Cost Curve for All Options, Storm Areas - Medium Availability Factors
-------
15.0 -
(C
O
Ml
10.0-
h-
tn
o
O
5.0 -i
<
(-
O
LOW AVAILABILITY
0SW= 0.40
02 0.4 0.6
BOD REMOVED BY ALL OPTIONS
, I0 Ib/yr
O.I
0.2
0.3
i
0.4
0.5
0.6
0.7
0.8
1.2 1.238
0.9
1.0
FRACTION OF BOD REMOVED BY ALL OPTIONS , Y^
Figure 23. Total Cost Curve for All Options, Storm Areas - Low Availability Factors
-------
TABLE 11. OPTIMAL STRATEGY FOR 25, 50, 75 AND 85 PERCENT OVERALL BOD REMOVAL, ANYTOWN, U.S.A., -
HIGH AVAILABILITY FACTORS
Drainage
System Alternatives
Combined Street
Sweeping
Sever
Flushing
Storage-
Treatment
TOTAL/AVG.
Stone Street
Sweeping
Storagc-
Tr eat merit
70TAL/AVC.
Uncovered TOTAL/A VG.
TOTAI /AUC.
BOD Removed By
Each Process
(105 Ib/yr)
Land Use 25Z
Residential 0
Commercial 0.07
Industrial 0.03
Other 0
Residential 0.22
Commercial 0.18
Industrial 0.10
Other 0
0
0.60
Residential 0
Commercial 0.14
Industrial 0.01
Other 0
0
0.15
0.36
1.11
502
0
0.08
0.04
0
0.25
0.19
0.12
0
0.40
1.08
0.09
0.23
0.14
0
0
0.46
0.70
2.24
75Z
0.06
0.09
0.05
0
0.30
0.24
0.14
0
0.65
1.53
0.35
0.29
0.18
0
0
0.82
1.05
3.40
85Z
0.11
0.09
0.06
0
G.32
0.25
0.16
0
0.78
1.73
0.41
0.2*
0.19
0
C.12
l.Oi.
1.05
3.84
Fraction of Influent
BOD Reooved By
Each Process
25Z
0
0.50
0.36
0
0.27
0.41
0.37
0
0
0.30
0
0.39
0.02
0
0
0.12
0.29
0.25
50Z
0
0.56
0.49
0
0.29
0.45
0.42
0
0.29
0.53
0.14
0.63
0.59
0
0
0.37
0.57
0.50
75Z
0.22
0.64
0.61
0
0.36
0.54
0.51
0
0.56
0.75
0.56
0.79
0.75
0
0
0.66
O.S5
0.75
85Z
0.43
0.68
0.65
0
0.38
0.59
0.56
0
0.75
0.87
0.64
0.30
0.80
0
0,33
0.82
0.85
0.85
25Z
0
0.07
0.04
0
0.08
0.06
0.04
0
0
0.29
0
0.12
0.01
0
0
0.13
0.43
0.85
Total Cost o£
Each Process
(S x 106/yr)
5CZ
0
0.08
0.05
0
0.13
0.09
0.06
0
0.85
1.26
0.28
0.27
0.20
0
0
0.75
1.10
3.11
75Z
0.18
0.11
O.OS
0
0.27
0.20
0.1?.
0
2.43
3.40
1.43
0.59
0.40
C
0
2.47
2.32
8.69
B5X
0.39
0.13
0.09
0
0.35
0.29
0.1S
0
5.35
6.78
2.07
0.61
0.51
0
1.55
4.74
2.82
14.34
-------
TABLE 12. OPTIMAL STRATEGY FOR 25, 50, 75 AND 85 PERCENT OVERALL BOD REMOVAL, ANYTOWN, U.S.A. -
MEDIUM AVAILABILITY FACTORS
Drainage
System
Combined
Storffi
Jo severed
BOD Removed By
Each Process
(106 Ib/yr)
Alternatives
Street
Sveeplng
-
Sewer
Flushing
Storage-
Treatment
TOTAL/AVG.
Stree:
Sweeping
Storage-
Treatment
TOTAL/AVG.
TOTAL/AVG.
Land Use 25Z
Residential o
Commercial 0,03
Industrial 0
Other o
Residential 0.16
Commercial 0.13
Industrial 0.03
Other 0
0.18
0.58
Residential 0
Commercial 0,08
Industrial 0,01
Other 0
0
0.09
0,45
SOX
0
0,05
0.02
0
0.18
0.15
0.09
0
0.65
1.14
0.01
0,16
0,10
0
0,07
0.34
0.80
75%
0
0,06
0.04
0
0.24
0.19
0.11
0
0.93
1.57
0,14
0.17
0.10
0
0.36
0,77
1.05
85Z
0.04
0,06
0.04
0
0.25
0.20
0.12
0
.1 . 08
1,79
0.24
0.19
0.12
0
0.45
1,00
1.05
Fraction of Influent
BOD Removed By
Each Process
25X
0
0.32
0
0
0,24
0.38
0.35
0
0.11
0.29
0
0,31
0.07
0
0
0.07
0.36
502
0
0.48
0,33
0
0,27
0.42
0.38
0
0.41
0.55
0.02
0.62
0.59
0
0.08
0,28
0.65
751
0
0.63
0.58
0
0.35
0.54
0,51
0
0.66
0.77
0.33
0.67
0,62
0
0,43
0,63
0.85
85*
0,22
0.65
0,60
0
0.37
0.57
0.52
0
0.80
0.87
0.54
0.76
0.71
0
0.65
0.81
0.85
25X
0
0.04
0
0
0,06
0.05
0.03
0
0.30
0,48
0
0,10
0.02
0
0
0,12
0.56
Total Cost of
Each Process
($ x 106/yr)
50*
0
0.06
0.03
0
0.09
0.08
0.04
0
1,35
1.65
0.04
0,26
0.20
0
0,32
0,82
1.42
75X
0
0.11
0.07
0
0.25
0.20
0.12
0
3.75
4.50
0.71
0.33
0.23
0
2.29
3.56
2.82
ss:
0.18
0.11
0.08
0
0.30
0,25
0.14
0
6.80
7.86
1.39
0.49
0,33
0
5.22
7.43
2.82
TOTAL/AVG.
1.12
2.28 3.39
3.84
0.25
0.50
0.75
0.85
1.16
3.89 10.88 18.11
-------
TABLE 13. OPTIMAL STRATEGY FOR 25, 50, 75 AND 85 PERCENT OVERALL BOD REMOVAL, ANYTOWN, U.S.A. -
LOW AVAILABILITY FACTORS
OJ
Drainage
System Alternatives
Combined Street
Sweeping
Sewer
Flushing
Storage-
Treatment
TOTAL /A VG.
Storr Street
Sweeping
Stora»e-
Treatnent
TCTAL/AVG.
Jnsewered TO~AL/AVG.
BOD Removed By
Each Process
(106 lb/yr)
Land toe
Residential
Corraercial
Industrial
Other
Residential
Coirnercial
Industrial
Other
Residential
Commercial
Industrial
Other
25Z
0
0
0
0
0.12
0.10
0.06
0
0.37
0.65
0
0
0
0
0
0
0.49
50%
0
0.01
0
C
0.13
0.11
0.06
0
0.82
1.13
0
'0.06
0.02
0
0.24
0.32
0.83
75Z
0
0.02
0.01
0
0.14
0.12
0.07
0
1.23
1.59
0
0.09
0.06
0
0.61
0.76
1.05
85S
0.02
0.04
0.02
0
0.20
0.16
0.09
0
1.29
1.82
0.02
0.09
0.06
0
0.82
0.99
1.05
Fraction of Influent
BOD Removed By
Each Process
25X
0
0
0
0
0.24
0.38
0.36
0
0.21
0.32
0
0
0
0
0
0
0.39
so;;
0
0.22
0
0
0.26
0.40
0.39
0
0.47
0.55
0
0.39
0.23
0
0.21
0.26
0.67
75X
0
0.43
0.23
0
0.28
0.45
0.42
0
0.73
0.78
0
0.64
0.59
0
0.56
0.61
0.85
85Z
0.16
0.65
0.57
0
0.40
0.61
0.57
0
0.85
0.89
0.06
0.65
0.60
0
0.77
0.80
0.85
251
0
0
0
0
0.06
0.05
0.03
0
0.57
0.71
0
0
0
0
0
0
0.61
Total Cost of
Each Process
(S x 106/yr)
SOS
0
0.02
0
0
0.07
0.06
0.04
0
1.80
1.99
0
0.13
0.06
0
0.89
1.08
1.56
75:
0
0.05
0.02
0
0.11
0.08
0.07
0
4.97
5.30
0
0.29
0.20
0
3.71
4.20
2.82
BS:
0.14
0.11
0.07
0
0.47
0.34
0.20
0
8.14
9.47
0.12
0.29
0.21
0
8.35
8.97
2.82
1.14
2.28
3.40
3.86
0.25
0.50
0.75
0.85
1.32
4.63 12.32 21.26
-------
HIGH AVAILABILITY
MEDIUM AVAILABILITY
LOW AVAILABILITY
STORAGE-TREATMENT
ONLY
0.5 1.0 1-5 2.0 2J5 3.0 3.5
BOD REMOVED BY TOTAL NETWORK, Wjbc , I06 Ib/yr
4.522
O.I
0.2
0.3
0.4
0.5
0.6
0.7
0.8
FRACTION OF BOD REMOVED BY TOTAL NETWORK, Y™
abc
0.9
1.0
Figure 24. Total Cost Curves for All Drainage System Service Areas
-------
REFERENCES
1. Heaney, J.P., Huber, W.C., Medina, M.A., Murphy, M.P., Nix, S.J., and
Hasan, S.M., "Nationwide Evaluation of Combined Sewer Overflows and
Urban Stormwater Discharges, Volume II: Cost Assessment," USEPA
Report EPA-600/2-77-064B, March 1977.
2. Pisano, W.A., "Cost Effective Approach for Combined and Storm Sewer
Cleanup," in Proc. Urban Stormwater Management Seminars, USEPA Report
WPD-03-76-04, Jan. 1976.
3. FMC Corporation, "A Flushing System for Combined Sewer Cleansing,"
USEPA Report 11020 DNO, March 1972.
4. Sartor, J.D. and Boyd, G.B., "Water Pollution Aspects of Street Surface
Contaminants," USEPA Report EPA-22-72-081, November 1972.
5. American Public Works Association, "Water Pollution Aspects of Urban
Runoff," USEPA Report 11030 DNS 01/69, January 1969.
6. Metcalf and Eddy, Inc., "Urban Stormwater Management and Technology:
An Assessment," USEPA Report EPA-670/2-74-040, December 1974.
7. Heaney, J.P., Huber, W.C., and Nix, S.J., "Stormwater Management Model:
Level I—Preliminary Screening Procedures," USEPA Report EPA-600/2-76-
275, October 1976.
8. Federal Water Pollution Control Act Amendments of 1972, PL 92-500.
9. Guidelines for Areawide Waste Treatment Management Planning, USEPA,
1975.
10. U.S. Bureau of the Census, County and City Data Book, 1972 (A Statisti-
cal Abstract Supplement), Social and Economic Statistic Administration,
U.S. Department of Commerce, 1973.
11. Baumol, W.J., Economic Theory and Operations Analysis, Prentice-Hall,
Inc., Englewood Clifs, New Jersey, 1965.
12. James, L.D., and Lee, R.R., Economics of Water Resources Planning,
McGraw-Hill, Inc., New York, 1971.
13. Huber, W.C., Heaney, J.P., Medina, M.A., Peltz, W.A. , Hasan, S.M., and
Smith, G.F., "Storm Water Management Model; User's Manual—Version II,"
USEPA Report EPA-670/2-75-017, March 1975.
65
-------
14. Hydrologic Engineering Center, Corps of Engineers, "Urban Storm Water
Runoff: STORM," Generalized Computer Program 723-58-L2520, May 1975.
15. Graham, R.H., Costello, L.S., and Mallon, H.J., "Estimation of Impervi-
ousness and Specific Curb Length for Forecasting Stormwater Quality and
Quantity," Journal of the Water Pollution Control Federation, Vol. 46,
No. 4, April 1974, pp. 717-725.
16. Unpublished data from American Public Works Association, 1976.
17. Northeastern U., "Characterization of Solids Behavior in and Variabil-
ity Testing of Selected Control Techniques for Combined Sewer Systems,"
EPA Grant No. R-804578, R. Field, Project Officer, Edison, N.J., 1977.
18. Metcalf and Eddy, Inc., "Catchbasin Technology: Overview and Assess-
ment," USEPA Contract No. 68-03-0274 (Draft), September 1976.
66
-------
GLOSSARY
Combined sewage: Sewage containing both domestic sewage and surface water or
stormwater, with or without industrial wastes. Includes flow in heavily
infiltrated sanitary sewer systems as well as combined sewer systems.
Combined sewer: A sewer receiving both intercepted surface runoff and muni-
cipal sewage.
Combined sewer overflow: Flow from a combined sewer in excess of the inter-
ceptor capacity that is discharged into a receiving water.
Depression storage: Amount of precipitation which can fall on an area with-
out causing runoff.
Detention: The slowing, dampening, or attenuating of flows either entering
the sewer system or within the sewer system by temporarily holding the water
on a surface area, in a storage basin, or within the sewer itself.
Domestic sewage: Sewage derived principally from dwellings, business build-
ings, institutions, and the like. It may or may not contain groundwater.
Isocost lines: Lines of equal cost.
Isoquants: Curves representing combinations of the inputs yielding the same
amount of output.
Marginal cost: The rate of change of total cost.
Precipitation event: A precipitation event terminates if zero rainfall has
been recorded for the previous specified time interval.
Production function: Locus of technologically efficient combinations of
inputs and outputs.
Runoff coefficient: Fraction of rainfall that appears as runoff after sub-
tracting depression storage and interception. Typically accounts for infil-
tration into ground and evaporation.
Storm flow: Overland flow, sewer flow, or receiving stream flow caused
totally or partially by surface runoff or snowmelt.
Storm sewer: A sewer that carries intercepted surface runoff, street wash
and other wash waters, or drainage, but excludes domestic sewage and indus-
trial wastes.
67
-------
Storm sewer discharge: Flow from a storm sewer that is discharged into a
receiving water.
Stormwater: Water resulting from precipitation which either percolates into
the soil, runs, off freely from the surface, or is captured by storm sewer,
combined sewer, and to a limited degree sanitary sewer facilities.
Surface runoff: Precipitation that falls onto the surfaces of roofs, streets,
ground, etc., and is not absorbed or retained by that surface, thereby col-
lecting and running off.
68
-------
APPENDIX A
QUANTITY AND QUALITY ANALYSIS
In order to develop an optimal stonnwater pollution control strategy, the
magnitude of the problem must be estimated. Several methods are available
to estimate the quantity and quality of urban runoff. A simplied method
to assess stormwater pollution loads and control costs by Heaney, Huber,
and Nix can be used to compute these parameters for any urbanized area
[Al], In addition to the runoff estimations, equations are presented to
determine the corresponding dry-weather (sanitary sewage) flows and quality.
This methodology is briefly described below. The following equations may
be applied to any land use or sewerage system service area.
Annual runoff may be estimated by the following equation:
AR = (0.15 + 0.75 (1/100)) P - 5.234 DS°'5957 (A1)
where AR = annual runoff, in;
I = total imperviousness, percent;
P = annual precipitation, in; and
DS = annual depression storage, in.
The annual depression storage is an index of the available areas capable
of retaining precipitation. This parameter is determined by the following
relationship,
DS = 0.25 - 0.1875 (1/100). (A2) ,
The equation used to estimate imperviousness is
(0.573-0.0391 log1()PDd)
1
where PD, = population density in the developed area, persons/ac.
I = 9.6 PDd iu u (A3)
Knowing the population density of the area allows the annual runoff to be
quickly determined.
The dry-weather flow may be estimated by the following equation,
69
-------
DWF = 1.34 PDd (A4)
where DWF = dry weather flow, in/hr.
This relationship is based on an assumed dry-weather flow of 100 gallons/
capita-day (378£/capita-day) .
Estimating the quality of urban runoff presents a more difficult task.
Available data indicate wide variation in estimated pollutant loads. If
annual pollutant loads are assumed to vary as a function of population
density, precipitation, land use and type of sewerage system, the following
relationships, may be used:
m^ = B(i, j) *P«f . (PD,) for combined sewered areas, (A5)
and
IIL, = a(i,j) *P*f . (PD,) for storm and unsewered areas, (A6)
where HL, = annual wet weather pollutant load, Ib/ac-yr;
P = annual precipitation, in/yr;
= population density function for land use i;
a(i,j) = coefficient for storm and unsewered areas for pollutant
j on land use i, Ib/ac-yr-in; and
3(i,j) = coefficient for combined sewered areas for pollutant
j on land use i, Ib/ac-yr-in.
Values of a(i,j), 0(i,j) and f.(PD) are shown in Table AI.
The equation used to estimate dry-weather quality, in terms of BOD,
is
= 62.1 PDd - m (A7)
where nL = annual dry-weather BOD load, Ib/ac-yr; and
IIL = annual BOD load of combined sewer deposition,
Ib/ac-yr.
This estimate assumes a per capita BOD discharge of 0.17 Ibs (77 gm)/day.
Combined sewer deposition is defined as that portion of the dry-weather
pollutant load that is deposited in the combined sewers, usually due to
inadequate carrying velocities. Often, this load is flushed from the sewers
during runoff periods and becomes part of the stormwater discharge. The
deposition may be estimated by computing the difference between combined and
storm sewered area BOD loadings derived for the combined area of concern.
70
-------
TABLE Al. POLLUTANT LOADING FACTORS
Land Uses: i = 1 Residential
i = 2 Commercial
i = 3 Industrial
i = 4 Other (assume PD,= 0)
Pollutants:
1
2
3
4
5
BOD5, Total
Suspended Solids (SS)
Volatile Solids, Total (VS)
Total PO, (as PO-)
Total N
Population Function:
i = 1
i = 2,3
i = 4
= 0.142 + 0.218
= 1.0
= 0.142
PD
0.54
a and 3 Factors for Equations: Storm factors, a, and combined factors, 3»
have units Ib/ac-yr-in.
Pollutant, j
1. BOD5 2. SS
3. VS 4. PO,
5. N
Storm
Areas, a
1.
2.
3.
4.
Residential
Commercial
Industrial
Other
0.799
3.20
1.21
0.113
16.3
22.2
29.1
2.70
9.45
14.0
14.3
2.6
0.0336
0.0757
0.0705
0.00994
0.131
0.296
0.277
0.0605
Combined
Areas, 3
1. Residential
2. Commercial
3. Industrial
4. Other
3.29
13.2
5.00
0.467
67.2
91.8
120.0
11.1
38.9
57.9
59.2
10.8
0.139
0.312
0.291
0.0411
0.540
1.22
1.14
0.250
Source: Heaney, J.P., Huber, W.C., and Nix, S.J., "Storm Water Management
Model: Level I—Preliminary Screening Procedures," USEPA Report
EPA-600/2-76-275, October 1976, p. 17.
71
-------
This assumes that the greater loads experienced by combined areas are due
to the deposition of dry-weather solids. Thus, combined sewer deposition
is estimated by the following equation:
= (B(i,j)-a(i,j))'P
f±(PDd).
(A8)
Of course, for storm sewered and unsewered areas, deposition from dry-
weather sources is not computed unless there are illicit connections of
sewage to the storm sewers.
REFERENCE
Al. Heaney, J. P., Huber, W. C., and S. J. Nix, "Storm-Water Management
Model: Level I—Preliminary Screening Procedures," EPA-600/2-76-
275, Cincinnati, Ohio, Oct. 1976.
72
-------
APPENDIX B
WORKING CURVES FOR GRAPHICAL SOLUTION
The basic curves for the analysis consist of one curve for each option
showing total cost as a function of pounds of pollutant removed, and level
of pollutant control. The scaling of each curve is set by the total cost as a
a function of the level of pollution control which ranges from 0 to 1. The
actual pounds removed differ as a function of the availability factor, ,
and the total load, M. Thus, the scaling on this abscissa is set up as a
function of . The curves are arranged as follows:
Figures
B1-B4 Total Cost Curves for Combined Sewered Areas, by Land
Use, Street Sweeping
B5-B8 Total Cost Curves for Combined Sewered Areas, by Land
Use, Sewer Flushing
B9-B12 Total Cost Curves for Storm Sewered Areas, by Land Use,
Street Sweeping
B13-B15 Total Cost Curves for Storage-Treatment, by Type of
Sewerage System
78-81
82-85
86-88
73
-------
u>
O
ni
3.5
3.0
2.5
2.0 .
o
O 1.5 -I
<
_l
<
i.o -I
05 ^
i
0
0.05
0.10
sw
0.150
sw
BOD REMOVED BY SWEEPING , V\LW ,!06lb/yr
SW,
O.I
0-2
0.3
r
0.4
0.20 08W 0.250SW0.264
0.5
0.6
0.7
0.8
0.9
1.0
FRACTION OF AVAILABLE BOD REMOVED BY SWEEPING , Y|W
Figure Bl. Total Cost Curve for Residential Portion of Combined Sewered Areas, Street Sweeping
-------
<0
O
0.35
0.30
0.25 -
ow 0.20 -
V)
O
O 0.15
_j
<
0.10
0.05 -
0.025
0.05
BOD REMOVED BY SWEEPING , W(
0.075 0SW 0.10
Qw , I06lb/yr
0.125 08W 0.139
0.6
O.I 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
FRACTION OF AVAILABLE BOD REMOVED BY SWEEPING , Y*
5W o
i
1.0
Figure B2. Total Cost Curve for Commercial Portion of Combined Sewered Areas, Street Sweeping
-------
0.35
• ,_ 0.30 -
>»
\
<0
O
X 0.25 •
0.20 -
MJ
*-"
V)
O
o
0.10 -
0.05 •
r
0
0.02
sv»
0.04
sw
d
0.06
'sw
BOD REMOVED BY SWEEPING , ww , I0 Ib/yr
O.I
0.2
0.3
0.4
05
0.6
0.7
i
0.8
0.08 0.088
0.9
1.0
FRACTION OF AVAILABLE BOD REMOVED BY SWEEPING , Y°
&YM
Figure B3. Total Cost Curve for Industrial Portion of Combined Sewered Areas, Street Sweeping
-------
0.35
,_ 0.30 •
>%
v.
-------
35.0
oo
BOD REMOVED BY FLUSHING, W° , I0b Ib/yr
SF,
i
O.I
I
0.2
0.3
I
0.4
0.5
0.6
0.7
0.8
0.80^0.836
0.9
1.0
FRACTION OF AVAILABLE BOD REMOVED BY FLUSHING . Y"
5r i
Figure B5. Total Cost Curve for Residential Portion of Combined Sewered Areas, Sewer Flushing
-------
VD
3.5
3.0 -
>.
"
ID
2
<
O
2.5
2.0 -
8
O 1.5
1.0
0.5
r
0
u>
SF
0.40^0.434^
SF
BOD REMOVED BY FLUSHING, W|F , I06 Ib/yr
O.I 0.2 0.3 0.4 05 0.6 0.7 0.8 0-9
a
1.0
FRACTION OF AVALABLE BOD REMOVED BY FLUSHING , Y
SF,
Figure B6. Total Cost Curve for Commercial Portion of Combined Sewered Areas, Sewer Flushing
-------
3.5
oo
o
o 4
0.279
BOD REMOVED BY FLUSHING , W|F
Ib/yr
O.I
i
0.2
0.3
0.4
0.5
I
0.6
0.7
0.8
0.9
1.0
FRACTION OF AVAILABLE BOD REMOVED BY FLUSHING , Y
SF.
Figure B7. Total Cost Curve for Industrial Portion of Combined Sewered Areas, Sewer Flushing
-------
oo
ow
3.5
3.0 -
2.5 -
2.0 -
V)
8 1.5
1.0 -
0.5 -
'SF
BOD REMOVED BY FLUSHING , W
0.003 0SF
, I06 Ib/yr
0.004
'SF
0.005
'ST
I
0
0.2
I
0.3
I
0.4
O.J 0.2 0.3 0.4 0.5 0.6 0.7 0.8
FRACTION OF AVAILABLE BOD REMOVED BY FLUSHING , '
0.9
1.0
5F4
Figure B8. Total Cost Curve for Other Portion of Combined Sewered Areas, Sewer Flushing
-------
oo
7.0
6.0 •
M
8
2.0 A
10 4
0.10 0SW 0.20 0SW 0.30 0SW
BOD REMOVED BY SWEEPING ,
sw.
0.40 0SW
, I06 Ib/yr
0.50
O.I
0.2
0.3
0.4
0.5
0.6
0.7
I
0.8
FRACTION OF AVAILABLE BOD REMOVED BY SWEEPING , Y
SW.
0.60
I
0.9
1.0
Figure B9. Total Cost Curve for Residential Portion of Storm Sewered Areas, Street Sweeping
-------
oo
Co
0.7
0.6 •
0.5 •
•$04-
a w n
tU
CO
8 0.3 -
0-2 J
0, J
0.05
0.10 0
SW
0.15
0.20
i 0-250sw
BOD REMOVED BY SWEEPING, w£w , I06 Ib/yr
0.30 ^ 0.35
r
0
O.I
0.2
I
0.3
0.4
0.5
0.6
0.7
0.8
0.9
FRACTION OF AVAILABLE BOD REMOVED BY SWEEPING , Y
SW,
1.0
Figure BIO. Total Cost Curve for Commercial Portion of Storm Sewered Areas, Street Sweeping
-------
oo
tw
BOD REMOVED BY SWEEPING , WgW JO6 Ib/yr
O
0.20
O.I 0.2 0.3 0.4 0.5 0.6 0.7 0.8
FRACTION OF AVAILABLE BOD REMOVED BY SWEEPING , Ycu
0.9
0.236
1.0
Figure Bll. Total Cost Curve for Industrial Portion of Storm Sewered Areas, Street Sweeping
-------
oo
Ul
0.7
0.6 -
sw
i
1.0
Figure B12. Total Cost Curve for Other Portion of Storm Sewered Areas, Street Sweeping
-------
14.0
00
O.I 0.2 0.3 0.4 0.5 0.6 0.7
FRACTION OF BOD REMOVED BY STORAGE - TREATMENT , Y
0.8 0.9
a
1.0
ST
Figure B13. Total Cost Curve for Storage-Treatment, Combined Areas
-------
oo
OT
8 60
4.0
2.0 -
O.I
0.2
0.3
0.4
0.5 0.6
0.7
0.8
FRACTION OF BOD REMOVED BY STORAGE - TREATMENT , Y
0.9
ST
1.0
Figure B14. Total Cost Curve for Storage-Treatment, Storm Areas
-------
oo
oo
14.0
12.0
_: io.o •
o tn
Ml
II
.rj a.o .
o
X
I
0
BOD REMOVED BY STORAGE- TREATMENT , w£ ( = W° ),IO Ib/yr
O.I 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
FRACTION OF BOD REMOVED BY STORAGE - TREATMENT , Y£ ( = Y£T )
Figure B15. Total Cost Curve for all Options (Storage-Treatment), Unsewered Areas
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing}
1. REPORT NO.
EPA-600/2-77-083
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
STORM WATER MANAGEMENT MODEL: LEVEL I - COMPARATIVE
EVALUATION OF STORAGE-TREATMENT AND OTHER MANAGEMENT
PRACTICES
5. REPORT DATE
April 1977 (Issuing Date)
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
James P. Heaney
8. PERFORMING ORGANIZATION REPORT NO.
Stephan J. Nix
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Department of Environmental Engineering Sciences
University of Florida
Gainesville, FL 32611
10. PROGRAM ELEMENT NO.
1BC611
11. CONTRACT/GRANT NO.
R-802411
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory—Cin.,OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA/600/14
15. SUPPLEMENTARY NOTES
Project Officer: Richard Field, Phone: 201/548-3347 x503 (8-342-7503)
See also EPA-600/2-76-275, Storm Water Management Model: Level I - Preliminary
Screening Procedures
^^^^AOOT^CIA"^^^^^^^^^^^^^^^^^^^^^^ ~™^^^^^^^^™^™^~ _.__.„ ^__^^^^_^_^^^^^ ^^_^_^^^^^^^_^^_^^_^^^^^^
16. ABSTRACT
The original USEPA Storm Water Management Model (SWMM) provides a detailed simulation
of the quantity and quality of stormwater during a specified precipitation event last-
ing a few hours. This model is widely used. However, it is too detailed for many
purposes. Indeed, a wide range of evaluation techniques ranging from simple to complex
procedures are needed. In particular, the 208 planning effort needs simplified proce-
dures to permit preliminary screening of alternatives. In response to this need, four
levels of stormwater management models are being prepared. This volume presents a
"desktop" procedure to compare selected alternative control technologies.
A graphical procedure is described which permits the analyst to examine a wide variety
of control options operating in series with one another or in parallel. The final
result is presented as a control cost function for the entire study area which is the
optimal (least costly) way of attaining any desired level of control. Given a speci-
fication regarding the desired overall level of control the user can determine the
appropriate amount of each control to apply.
This methodology is applied to Anytown, U.S.A. ,. a hypothetical community of 1,000,000
people. The results indicate the mix of treatment, storage, street sweeping, and
.-r fl
ushing uhirh
the secified ollution control level at minimum cost.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
*Storm sewers, *Water pollution, Control
simulation, *Cost effectiveness, *Waste
treatment, *Sewage treatment, *Surface
water runoff, *Runoff, *Combined sewers,
*Mathematical models, Storage tanks,
Methodology, Economics, Flushing,
latch basins
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Simplified evaluation,
Sewer flushing, Street
sweeping, Catch-basin
cleaning
13B
13. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report/
UNCLASSIFIED
21. NO. OF PAGES
105
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
89
-------
Areawide Assessment Procedures Manual
Appendix H
POINT SOURCE CONTROL ALTERNATIVES:
Performance and Cost
Prepared for
Municipal Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
-------
TABLE OF CONTENTS
Appendix Page
H POINT SOURCE CONTROL ALTERNATIVES:
PERFORMANCE AND COST H-l
H.I Introduction H-l
H.2 Relative Reliability of Performance
and Cost Information H-2
H.3 Cost Components H-4
H.3.1 Construction Costs H-5
H.3.2 Operation and Maintenance Costs H-9
H.3.2.1 Labor Costs H-ll
H.3.2.2 Material Costs H-ll
H.3.2.3 Energy Costs H-ll
H.3.2.4 Chemical Cost H-ll
H.4 Cost Format H-12
H.5 Treatment System Performance Matrix H-13
H.6 Municipal Wastewater Treatment Systems H-15
H.7 Wet-Weather Treatment Processes H-46
H.8 Municipal Wastewater Treatment Processes H-72
H.8.1 Support Personnel H-72
H.8.2 Miscellaneous Structures H-72
H.8.3 Wastewater Treatment Processes H-76
H.8.4 Sludge Treatment and Disposal Processes H-154
H.8.5 Wastewater Transportation Methods H-196
H.8.6 Sludge Transportation Methods H-200
H.9 References H-210
111
-------
LIST OF FIGURES
Figure No. Title Page
H-l Upgrading/Expansion Factor H-10
H-2 Treatment System 1 - Primary Treatment H-16
H-3 Treatment System 2 - Primary Treatment With
Metal-Salt Addition (FeCl_) H-18
H-4 Treatment System 3 - Trickling Filter H-20
H-5 Treatment System 4 - Trickling Filter With
Metal-Salt Addition (FeCl ) H-22
o
H-6 Treatment System 5 - Activated Sludge H-24
H-7 Treatment System 6 - Activated Sludge With
Metal-Salt Addition (Alum) H-26
H-8 Treatment System 7 - Activated Sludge/
Nitrification (Single Stage) H-28
H-9 Treatment System 8 - Activated Sludge/
Nitrification/Denitrification (Three Stages) H-30
H-10 Treatment System 9 - Activated Sludge/
Nitrification - Filtration (With Alum) H-32
H-ll Treatment System 10 - Physical/Chemical H-34
H-12 Treatment System 11 - Activated Sludge/
Nitrification/Denitrification with Alum
(Three Stages) H-36
H-13 Treatment System 12 - Activated Sludge/
Nitrification/Denitrification/Activated
Carbon (With Alum) H-38
H-14 Treatment System 13 - Small Flow Treatment
Systems H-40
H-15 Treatment System 14 - Oxidation Ditch (Designed
for Nitrification) H-42
H-16 Treatment System 15 - Land Application of
Wastewater (Non-Underdrained) H-44
H-17 Concrete Stormwater Storage Reservoir H-46
IV
-------
LIST OF FIGURES
(continued)
Figure No. Title Page
H-18 Earthen Storage Basin H-50
H-19 Stationary Screen H-52
H-20 Horizontal-Shaft Rotary Screen H-54
H-21 Vertical-Shaft Rotary Screen H-56
H-22 Chemical Coagulation (Ferric Chloride and
Polymer) H-60
H-23 Stormwater Sedimentation H-62
H-24 Dissolved Air Flotation H-64
H-25 Swirl Regulator/Concentrator H-66
H-26 High-Intensity Mixing/Chlorine Contact Basin H-68
H-27 High-Rate Filtration (Gravity) H-70
H-28 Support Personnel H-72
H-29 Miscellaneous Structures H-74
H-30 Low-Lift Pump Station H-76
H-31 Preliminary Treatment H-78
H-32 Flow Equalization H-80
H-33 Primary Clarifier With Sludge Pumps H-84
H-34 Conventional Activated Sludge Aeration With
Diffused Air H-86
H-35 Activated Sludge Aeration With Pure Oxygen H-88
H-36 High-Rate Trickling Filter H-90
H-37 Low-Rate Trickling Filter H-92
H-38 Aerated Lagoons H-94
H-39 Rotating Biological Contactors H-96
-------
LIST OF FIGURES
(continued)
Figure No. Title Page
•B^^BBM^BBBiMB^^BiB^BB ^MB^V^MVMB ^^m^E*^
H-40 Facultative Lagoons H-100
H-41 High-Rate Activated Sludge (Complete Mix) H-104
H-42 Final Clarifier (Flocculator Type) H-106
H-43 Clarifier for High-Rate Trickling Filter
(Includes Recycle Pumps) H-108
H-44 Activated Sludge/Nitrification (Single Stage) H-110
H-45 Separate Nitrification (With Clarifier) H-112
H-46 Separate Denitrification (With Clarifier) H-114
H-47 Breakpoint Chlorination H-116
H-48 Ammonia Stripping H-118
H-49 Ion Exchange (For Ammonia Removal) H-120
H-50 Phostrip H-122
H-51 Polymer Feed System H-124
H-52 Mineral Addition H-126
H-53 Two-Stage Tertiary Lime Treatment
(Without Recalcination) H-130
H-54 Lime Recalcination H-132
H-55 Microscreening H-134
H-56 Gravity Filtration (Dual-Media) H-136
H-57 Activated Carbon Adsorption H-138
H-58 Chlorination (Disinfection) H-142
H-59 Dechlorination Using Sulfur Dioxide H-144
H-60 Ozonation (Air- and 0--Generated) H-146
VI
-------
LIST OF FIGURES
(continued)
Figure No. Title Page
H-61 Post Aeration H-150
H-62 Groundwater Recharge (Infiltration) H-152
H-63 Sludge Pumping , H-154
H-64 Gravity Thickener H-156
H-65 Dissolved Air Flotation Thickener H-158
H-66 Centrifugation (Lime Sludge Dewatering) H-160
H-67 Centrifugation (Biological Sludge Dewatering) H-162
H-68 Vacuum Filtration (Biological Sludge) H-164
H-69 Vacuum Filtration (Lime Sludge) H-166
H-70 Filter Press (Lime Sludge) H-168
H-71 Filter Press (Biological Sludge) H-170
H-72 Sludge Drying Beds H-172
H-73 Two-Stage Anaerobic Digesters H-174
H-74 Aerobic Digesters H-176
H-75 Heat Treatment of Sludge H-178
H-76 Composting H-180
H-77 Incineration (Fluidized Bed) H-182
H-78 Incineration (Multiple Hearth) H-184
H-79 Lime Stabilization H-186
H-80 Sludge Storage H-188
H-81 Landfilling (Biological Sludge
Excluding Transportation) H-190
H-82 Landfilling (Lime Sludge
Excluding Transportation) H-192
VII
-------
LIST OF FIGURES
(continued)
Figure No, Title Page
H-83 Land Application of Sludge H-194
H-84 Gravity Sewers H-196
H-85 Transmission Force Main H-198
H-86 Liquid Sludge Transport (Rail) H-200
H-87 Dewatered Sludge Transport (Rail) H-202
H-88 Dewatered Sludge Transport (Truck) H-204
H-89 Liquid Sludge Transport (Truck) H-206
H-90 Sludge Transport (Pipeline) H-208
Vlll
-------
APPENDIX H
POINT SOURCE CONTROL ALTERNATIVES:
Performance and Cost
H.I Introduction
Estimation of the monetary cost of the various control alternatives requires
the ready availability of comprehensive construction and operating cost data.
To facilitate use in a 208 program, these data must be in a convenient for-
mat applicable to the wide range of situations that may be encountered. The
cost data should be useful to planners and engineers with varying degrees of
technical background, and should be useful both for developing and for re-
viewing the costs associated with structural control alternatives.
Cost data presented in this appendix are generalized rather than site-specific,
and are intended primarily for comparative analysis. Also, the data in this
appendix represent a technology which is by no means static. Therefore, this
information should be updated to reflect technological advances or other
factors affecting comparative costs.
The user of this appendix is cautioned against treating any cost estimates
based on the data contained- herein as absolute. The estimates are valid
only for comparative purposes, and even these comparisons must be performed
with caution because of the possible differences in the reliability of the
performance and cost information from various sources. There may be con-
siderable difference between cost estimates for comparative purposes and the
actual construction costs of facilities. Frequently, planners and engineers
err in not emphasizing this fact enough to the local communities involved
in the 208 program. The comparative numbers somehow become cast in stone
during the planning phase. Later, during the implementation phase of the
program, the communities express their concern when they find that the
actual costs of implementation are vastly different than those implied by
the comparative cost estimates.
H-l
-------
H.2 Relative Reliability of Performance and Cost Information
Monetary-cost comparisons should not be the sole basis for selecting control
alternatives, as discussed in Chapter 6; but, at some point in the selection
process, the relative costs of various alternatives must be considered.
Therefore, it is very important for the engineer or planner to understand the
reliability of the information upon which the cost figures are based.
the reliability of performance data must also be considered, because this type
of information frequently is the basis for determining the size of treatment
units or other control devices needed for a particular control alternative.
This section covers the use of the performance and cost information of Appen-»
dix G (Best Management Practices) and Appendix H (Point Source Control Al-
ternatives) , and provides a method for assuring adequate consideration of the
relative reliability of the various applicable performance and cost infor-
mation needed for comparison of applicable control alternatives.
The performance data and cost information in this and the Best Management
Practices Appendix are utilized to determine the monetary cost of feasible
control alternatives for addressing water quality problems in 208 planning
areas. Performance data for a particular control alternative are compared to
a required standard to assess the alternative's capability to meet the stand-
ard. Then the monetary costs of those alternatives which meet the performance
requirements are determined by utilizing the cost curves. Since performance
and cost information for one alternative may be based on much more extensive
data and experience than the information for another alternative, the re-
liability of both the cost information and the performance information
should be taken into account when considering relative cost and performance
capabilities.
The reliability of information is especially important in developing,
evaluating, and selecting control alternatives for areawide water quality
management, because there are highly varying degrees of experience with the
various control alternatives. For example, an abundance of cost figures and
estimates are available to substantiate performance and cost curves for an
activated sludge treatment plant. Less data and experience are available
to substantiate performance and cost relationships for street sweeping as
H-2
-------
an alternative in control of pollution from urban runoff. Even less data
and experience may be available for various land management alternatives
such as zoning. Although each of these three alternatives is known to be
effective in reducing pollutant levels, determination of the best combination
will require careful deliberation, good judgment, and full recognition of
the reliability of each type of information at the time the decision is made.
The concept of "relative reliability" is presented here to aid the user of
this manual in comparing the monetary cost of control alternatives. Five
levels of relative reliability are used to identify the nature and extent
of the experience and data upon which the cost and performance information
is based:
• Level A indicates estimates based on detailed breakdowns of all
pertinent cost elements and is supported by detailed engineering data.
This level of reliability is always based on site-specific information.
The relative reliability of information in this level is +_ 15%. For
example, facilities-planning estimates (Section 201 of P.L. 92-500)
represent Level A information reliability.
• Level B indicates that the data and experience on a particular
control alternative are sufficient only to establish a relationship,
as expressed by a table of data or a single curve or family of
curves. The relative reliability of information at this level
is +_ 30%. For example, general cost curves such as the wastewater
treatment systems curves and process curves presented in Appendix H
represent Level B information reliability.
* Level C indicates that the data and experience are sufficient only to
establish a range of values for cost or performance. The relative
reliability of information at this level is +_ 50%. For example, street
sweeping estimates, such as those in the Best Management Practices
Appendix, represent Level C information reliability.
• Level D indicates that the data and experience are sufficient only to
establish the relative order of magnitude of the cost and performance
characteristics.
H-3
-------
• Level E indicates that the data or experience is insufficient to
establish any level of cost or performance estimate, or that site-
specific factors are so critical to the performance and cost that a
general estimate should not be made.
This manual does not present guidelines on the application of the relative
reliability concept for particular situations. Rather, the application by
the user will be a function of the control alternatives that are being
compared, the closeness of the cost or performance estimates, the background
of the user, the consequences of error, and other factors.
The "relative reliability" concept is introduced to emphasize to the user
that comparisons of cost or performance estimates prepared using this manual
are only as reliable as the lowest level of reliability assigned to the con-
trol alternatives being considered. The concept is particularly well
suited to compare more traditional engineering approaches to load reduction
with "emerging" non-structural control techniques whose costs and relative
effectiveness have not been satisfactorily evaluated or sufficiently
documented.
H»3 Cost Components
Information in a convenient format has been developed to provide a concise,
yet complete, set of cost data that enable the user of the manual to produce
cost estimates of adequate quality for use in comparing strategies in Area-
wide Assessment Planning. Many sources were used in the development of the
cost data, but in all cases the cost data were converted to a uniform basis.
Where possible, these cost data were checked against actual construction
costs.
The method used in developing the cost curves was to plot all available cost
data uniformly, including actual construction costs. When differences in
cost occurred, every effort was made to determine the reasons; and usually the
significant differences were corrected, .such as inclusion of buildings and
pumps in some estimates and not in others. The curves included in this appen-
dix were then fitted to these representative data.
Some of the costs presented in this appendix will be more reliable than others.
Higher reliability costs generally occur where a large amount of historical
H-4
-------
data exists, such as clarifiers and activated sludge. However, all cost data
presented should be adequate to provide the user with the information needed
to make judgments necessary in Areawide Assessment Planning.
Table H-l provides the user with the general basis of all cost curves con-
tained in this appendix.
H.3.1 Construction Costs
Construction-cost curves have been developed both for process components and
for treatment systems. These construction-cost curves represent the cost of
unit processes or treatment systems for a wide capacity range. Specific items
not included in the construction cost are:
1. Land Costs (except land application and landfill).
2. Site Work.
3. Piping.
4. Electrical Work.
5. Engineering and Construction Supervision.
6. Project Contingencies.
7. Miscellaneous Structures.
The additional costs for Items 1 through 6 are generally represented as a
percentage of the installed construction cost of the components specific to
the unit or system being evaluated for comparative cost estimates of the type
generally developed by using these curves. Additional cost curves are in-
cluded for Item 7 (Miscellaneous Structures) and should be included where
appropriate. Note that the cost curves developed for municipal wastewater
treatment systems (Figures H-2 through H-16) already include the costs for
miscellaneous structures. Table H-2 presents a general format for identifying
the costs, with representative percentages for the items indicated. Land
costs depend on local conditions and should be developed for each individual
case. However, it should be noted that development of land costs, except in
land application and land disposal of sludge, may not be necessary for
comparison purposes. Most alternatives will have similar land requirements.
H-5
-------
TABLE H-l
GENERAL COST AND DESIGN BASIS FOR COST CURVES
Basis of Costs
1. ENR = 2475, September 1976
2.
Labor rate, including fringe benefits
Note:
$7.SO/hr
Labor costs are based on a man-year of 1,500 hours. This
represents: a 5-day work week; an average of 29 days for
holidays, vacations, and sick leave; and 63j hours of
productive work time per day.
3. Energy Costs
a. Electric Power
b. Fuel Oil
c. Gasoline
4. Land
5. Chemical Costs
a. Liquid Oxygen
b. Methanol
c. Chlorine 150-lb cylinder
1-ton cylinder
Tank Car
d. Quicklime
e. Hydrated Lime
f. Polymer (Dry)
g. Ferric Chloride
h. Alum
i. Activated carbon (granulated)
j Sulfuric Acid (66° Be)
k. Sodium hexametaphosphate
1. S0_ 150-lb cylinders
1-Ton cylinder
Tank Car
Design Basis
$0.02/kwh
$0.37/gallon
$0.60/gallon
$l,000/acre
$65/Ton
$0.50/gallon
$360/Ton
$260/Ton
$160/Ton
$25/Ton
$30/Ton (as CaO)
$1.50/lb
$100/Ton
$72/Ton
$0.50/lb
$50/Ton
$0.25/lb
$450/Ton
$215/Ton
$155/Ton
1. Construction costs and operation and maintenance costs are based on
design average flow unless otherwise noted.
2. Operation and maintenance costs include:
a. Labor costs for operation, preventive maintenance, and minor repairs.
b. Materials costs to include replacement parts and major repair work
(normally* performed by outside contractors) .
c. Chemical costs.
d. Fuel costs.
e. Electrical power costs.
3. Construction costs do not include external piping, electrical, instru-
mentation, site work, contingency, or engineering and fiscal'fees.
H-6
-------
TABLE H-2
DEVELOPMENT OF CAPITAL COSTS
Component Installed Construction Costs
(Unit processes specific to
each Cost Estimate) $_
Misc. Structures (Figure H-29)* $_
Subtotal 1
Avg. Range**
Piping ToT" 8-15% $
Electrical 8% 5-12% $"
Instrumentation 5% 3-10% $"
Site Preparation 5% 1-10% $"
Subtotal 2
Engineering and Construction
-Supervision @ 15% *** $_
Contingencies @ 15% *** $_
TOTAL CAPITAL COST
*Not to be included when municipal wastewater treatment system or wet
weather treatment process curves are used. These include miscellaneous
structures in their construction costs.
**Range due to level of complexity, degree of instrumentation, subsoil
conditions, configuration of site, etc.
***Percentage of Subtotal 2.
H-7
-------
All construction costs have been indexed to September, 1976. To adjust for
other time periods, appropriate cost indexes, such as those in the following
list, should be used where appropriate:
• ENR Building Cost Index - appears weekly in Engineering News Record,
McGraw-Hill, Inc.
• ENR Construction Cost Index - appears weekly in Engineering News
Record, McGraw-Hill, Inc.
• EPA Treatment Plant and Sewer Construction Cost Index - appears
monthly in the WPCF Journal.
• BLS Labor Cost Index - appears monthly in Employment and Earnings,
Bureau of Labor Statistics.
• BLS Wholesale Price Index - appears monthly in Wholesale Prices and
Prices Indexes, Bureau of Labor Statistics.
To facilitate use of the cost data presented in this appendix, each construc-
tion-cost curve includes a summary of the design basis, assumptions, and cost
basis. Representative assumptions were made for the cost-curve development,
but these can be easily modified to reflect site-specific conditions.
A generalized adjustment factor can be used to develop costs for mass or
hydraulic loading factors, detention times, periods of operation, or solids
concentrations other than those shown as the design basis. The cost curves
are entered at an effective flow (CO, where
QE = QDESIGN x Cumulative Adjustment Factor
where:
and
0- „„_.,.. = the flow shown on the curve
DESIGN
, „ ,. . - . Design Mass Loading
Cumulative Adjustment Factor = New gass Loading *
Design Solids Concentration Design Time Operation £
New Solids Concentration x New Time of Operation
H-8
-------
This generalized adjustment factor will permit development of costs for site
specific situations not identical to the design basis used for development
of the curves.
Ideally, the cost curves would have been developed to compare a design param-
eter such as Surface Area or Volume vs Cost rather than Plant Flow vs Cost.
For the purposes of this appendix, however, the latter approach was selected
to screen the many alternatives required in Areawide Assessment.
A common occurrence when developing comparative cost estimates for areawide
assessment plans is considering upgrading and/or expanding existing facilities.
Often there are many economies to be realized in this practice. However, there
are also economic disadvantages that should not be overlooked. Some of the
additional costs that are often associated with upgrading and/or expanding
an existing facility include interface costs associated with connecting pieces
of equipment together, additional costs incurred by the contractor due to
working in and around process equipment and yard piping, and problems of
interfacing with old or obsolete equipment. Obviously, the actual additional
costs associated with upgrading and/or expanding existing facilities will
vary considerably depending on plant layout, contractor experience, age of
existing plant, and relative size of the upgrade and/or expansion. However,
ft review of plant upgrade and expansions did provide a trend which can be
useful in developing construction costs. Figure H-l provides an Upgrade/
Expansion Factor. This factor represents a percentage increase .to be
applied to the construction cost of the Upgrade/Expansion Alternative. As
the size of the upgrade/expansion increases, the construction cost approaches
the cost of a new facility. However, as the size of the upgrade/expansion
decreases, the factor increases.
H.3.2 Operation and Maintenance Costs
Operation and maintenance costs consist of labor, material, energy, and
chemical components. Each is detailed below. For each construction-cost
curve, there is a corresponding 0 § M cost curve covering each of the 0 § M
cost components and a total 0 § M cost.
H-9
-------
FIGURE H-l
UPGRADING/EXPANSION FACTOR
FIGURE H-l UPGRADING/EXPANSION FACTOR
$
2
<3 g x
01 .5 uj
|2 M ^
•S o
I §2
I ° w
4,8%
100
UPGRADE / EXPAN SION FLOW , mgd
H-10
-------
H.3.2.1 Labor Costs
Labor costs include the manpower required to operate and maintain the facility
or system, plus such support tasks as supervision and administration, cleri-
cal work, laboratory work, and yard work. Labor costs are based on a labor
rate including fringe benefits of $7.50/hr; a man-year of 1,500 hours
incorporating a five-day work week; an average of 29 days for holidays,
vacations, and sick leave; and 6% hours productive work time per day.
H.3.2.2 Material Costs
Material costs include the various materials required for routine maintenance
of facilities. Examples are paint, grease, and replacement parts. Structural
equipment (buildings, roads, and basins) generally has lower material costs
than does mechanical equipment (pumps and aerators). Material costs have a
base date of September, 1976. The wholesale price index should be used to
adjust for other time periods.
H.3.2.3 Energy Costs
Each mechanical operation at a treatment facility, such as pumping, mixing,
and aeration, consumes energy. The horsepower requirements have been con-
verted into electrical units (KWH). A corresponding cost has been developed
using a unit price of 2$ per KWH. Adjustments to this unit cost for
site-specific applications can be made by direct ratio.
Energy other than electrical is required for some processes (such as incinera-
tion). In these cases, the amount of energy (fuel) required was computed and
a cost was determined on the basis of an assumed cost per unit; this assumed
unit cost appears with the cost curves. Adjustments to this unit cost again
may be made on a direct-ratio basis.
H.3.2.4 Chemical Cost
Various unit processes require chemicals. The quantities of chemicals re-
quired were based on assumed loading rates. The costs were then computed
using a unit price for each chemical. The assumed unit chemical costs are
included in Table H-l. Adjustments to the unit costs may be made by direct
ratio within the same bulk quantity ranges.
H-ll
-------
H.4 Cost Format
The cost data in this appendix are presented in a format designed to facilitate
use at the various levels of the planning process. The general presentation
of the cost data is as follows:
• Treatment System Performance Matrix
- Table H-3. Provides selected Municipal Wastewater
Treatment Systems that will achieve varying degrees of
treatment.
• Municipal Wastewater Treatment Systems: Performance and Costs
- Figures H-2 through H-16, Section H.6
• Wet-Weather Treatment Processes: Costs
T Figures H-17 through H-27, Section H.7
• Support Personnel: Costs
- Figure H-28, Section H.8.1
• Miscellaneous Structures: Costs
- Figure H-29, Section H.8.2
• Wastewater Treatment Processes: Costs
- Figures H-30 through H-62, Section H.8.3
• Sludge Treatment and Disposal Processes: Costs
- Figures H-63 through H-83, Section H.8.4
• Wastewater Transportation Methods: Costs
- Figures H-84 and H-85, Section H.8.5
• Sludge Transportation Methods: Costs
- Figures H-86 through H-90, Section H.8.6
The Treatment System curves will probably be most useful in the 208 process,
because they provide a relatively quick and efficient means of developing
comparative costs of various treatment facilities. If costs which are more
specific to the site or facility involved are desired, the process curves
in Sections H.7 and H.8 can be used to synthesize specific treatment systems
as appropriate.
H-12
-------
The process curves generally include individual unit processes, so that the
system configuration for both treatment and sludge handling can be more
flexible.
H.5 Treatment System Performance Matrix
The Treatment System Performance Matrix, Table H-3, links the point source
load allocations and the Municipal Wastewater Treatment System cost curves.
Water quality throughout the planning period is defined by applying 20-year
projected wastewater effluent characteristics from municipal wastewater treat-
ment plants. Should an impact analysis indicate unacceptable stream water
quality with these effluent characteristics, additional treatment would be
required. The wastewater allocation needed to meet the water quality objec-
tives establishes the effluent restrictions and, therefore, the required level
of treatment. The control level refers to the projected effluent character-
istics. Comparing these requirements to the Treatment System Performance
Matrix indicates the system curve that most closely approximates the desired
level of control. This should be done with caution because, when using the
matrix, the system selected will be controlled by a single parameter. For
example, System 11 may be required to meet the desired nitrogen level;
therefore, total nitrogen is the controlling parameter. In order to achieve
the required removal of this pollutant, System 11 might remove more BOD,, than
O
necessary. If this type of situation appears extreme, the user should
evaluate the configuration of the required system to determine if the imbalance
is unavoidable. If the manual user can conceive an alternative system that
will produce a more balanced effluent with respect to the required effluent
objective, then a new system curve should be developed from the component
curves (Sections H.7 and H.8). In the foregoing example, a treatment
system consisting of System 5 with the addition of breakpoint chlorination
may provide a more cost-effective alternative to System 11. Should this be
the case, the user of the manual can develop his own systems curves on the
forms provided. The component municipal treatment process cost curves will
provide the basis for the hybrid treatment system curves. The system
configuration should be developed and the cumulative costs developed from the
component municipal treatment process curves. The cumulative costs may be
plotted on the forms provided.
H-13
-------
TABLE H-3
TREATMENT SYSTEM PERFORMANCE MATRIX
EFFLUENT CHARACTERISTICS
System
Number
-
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Note:
Figure
No
-
H-2
H-3
H-4
H-5
H-6
H-7
H-8
H-9
H-10
H-ll
H-12
11-13
H-14
H-15
H-16
Total
BODs
210
130
100
45
25
20
15
10
10
10
5
5
3
20
15
-
TSS
230
100
50
60
30
20
15
20
20
10
5
5
5
20
15
-
COD
400
250
185
90
50
45
35
35
45
45
25
30
10
45
46
-
P
11
9
2
8
2
7
2
8
8
1
1
0.
0.
7
6
-
NH3-N
20
20
20
18
18
17
17
2
1
2
20
5 1
5 1
1
23
1.0
-
N03-N
0
0
0
0
0
0
0
18
1
18
0
1
1
0
8
-
•»
UOD
406
286
241
150
120
107
100
24
20
24
99
12
12
107
27
-
Description of System
Raw Waste Characteristics
Primary
Primary and Metal Salt Addition (FeCl3)
Primary and Trickling Filter
Primary and .Trickling Filter with Metal Salt (FeCl3)
Primary and Activated Sludge
Primary, Activated Sludge, Metal Salt (Alum)
Primary, Activated Sludge/Nitrification
Primary, Activated Sludge, Nitrification, Denitrification
Primary Metal Salt Addition (Alum) , Activated Sludge/Nitrification
Filtration
Preliminary, Two-Stage Lime, Filtration, Carbon Adsorption
Primary Metal Salt Addition (Alum), Activated Sludge, Nitrification,
Denitrification, Polymer, Filtration
Primary Metal Salt Addition (Alum), Activated Sludge, Nitrification-
Denitrification, Polymer, Filtration, Carbon Adsorption
Small-Flow Treatment Systems, i.e., Package Plants - Extended
Aeration Plant 0.01-0.1 mgd; contact stabilization plant 0.1-
1.0 mgd.
Oxidation Ditch; 0.05-10 mgd (designed for nitrogen removal)
Land Application
Treatment systems 1-12 include disinfection, sludge handling, miscellaneous structures, and support personnel. Treatment Systems
13-15 DO NOT include sludge dewatering, miscellaneous structures and support personnel.
UOD = Ultimate Oxygen
2Contact Stabilization.
Demand
= (1.
5 x
BOD5) + (4.
57 x NH3-N)
Extended Aeration.
-------
H.6 Municipal Wastewater Treatment Systems
Municipal wastewater treatment systems that will meet various effluent criteria
are presented in the Treatment System Performance Matrix (Table H-3). These
systems are not presented as a comprehensive list of the only technological
methods available to meet the effluent criteria, but rather to provide the
user of this manual with an expedient compilation of monetary costs for
selected systems. Construction and operation § maintenance cost curves have
been developed for each of these systems. The cost curves and related
effluent quality, sludge audit, process, service life, design, and other
data are presented in Figures H-2 through H-16.
Municipal Wastewater Treatment Systems:
Performance and Costs:
Figures H-2 through H-16
H-15
-------
FIGURE H-2
TREATMENT SYSTEM 1-
PRIMARY TREATMENT
Lift
Pumps
Preliminary
Treatment
Primary
Clarifier
Disinfection
4 - Ultimate
Disposal
Processes Included:
Gravity Vacuum
Thickener Digestion Filter
Lift Pumps, Preliminary Treatment, Primary Clarifiers,
Chlorination, Gravity Thickener, Sludge Digestion,
Vacuum Filters, Miscellaneous Structures, Support
Personnel.
Wastewater Characteristics;
BOD5, mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH3-N, mg/1
N03-N, mg/1
UOD, mg/l
Sludge Audit:
Point No.
1
2
3
4
Influent
210
400
230
11
20
0
406
Sludge Quantity
Ibs/mg
1,080
1,080
540
540
Effluent
130
265
100
9
20
0
286
Concentration
%
4
8
4.5
20
Notes: 1. Dashed line on construction cost curve indicates size range of
marginal applicability from a process and/or economic basis.
2. See individual treatment process curves for design basis of
specific unit processes. (Adjustment factors should be used
where applicable.)
3. Aerobic digestion at plant sizes less than 3 mgd; two-stage
anaerobic digestion at plant sizes greater than 3 mgd.
H-16
-------
o
a
c
o
FIGURE H-2 TREATMENT SYSTEM I
PRIMARY TREATMENT
inn
10
in
ni
^— •
^»
^
'
*> *
Tl 1 1 1 1 1 1 1 1 1 1 1
-cnN
" " "^^
ST
s
*uc
Tl
'
i ^
X"
K
Dr
X"
c
x
:o
'"
ST-
X
x"
,x
/
f
t
O.I
1.0
10
100
FLOW.mgd
IU
in
w
0
0
IJO
«^
o
1 1
3E
0
1 I
o
O.I
o
a
<
OOI
0
^^
,— =
^x
•*--
^
^^-
.^-^
x
OPERATION 8
,**•
,^-
^
.
^
«(
^
**
X
til
P
^,-
^Chemicals
ria
* -
* '
~ ~
•^ '
• -^r-
' X
x^
'
x^
^
-^
j,
MAINTENANCE
Xf '
\<
___
p""^
, *"
^
^-
x
^
fH*
>*
X
x
'
£
$ *
I
t
I
>wer
^x
1 /
X
rlX
abor
.
COST
x^,
f
s
s
^
X
/
^'
'
^
!#
^
L
//'
s
^
7
1.0 10
FLOW , mgd
• i.u
",
^^^
j «
: O.I |
' £
JS
«
o
2
if
^>
E
i 0.01 5
. 0.001
100
H-17
-------
FIGURE H-3 TREATMENT SYSTEM 2-
PRIMARY TREATMENT WITH METAL-SALT ADDITION (FeCl3)
Lift
Pumps
Preliminary
Treatment
-*r
FeCI,
1
Primary
Clarifier
Disinfection
Ultimate
Disposal
Gravity Vacuum
Thickener Digestion Filter
Processes Included:
Lift Pumps, Preliminary Treatment, Ferric Chloride
Addition, Primary Clarifiers, Chlorination, Gravity
Thickener, Sludge Digestion, Vacuum Filters,
Miscellaneous Structures, Support Personnel.
Wastewater Characteristics;
BODj., mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH3-N, mg/1
NO--N, mg/1
UOD, mg/1
Influent
210
400
230
11
20
0
406
Effluent
100
185
50
2
20
0
241
Sludge Audit;
Point No.
1
2
3
4
Sludge
itity
Ibs/mg
2,160
2,160
1,410
1,410
Concentration
2
4
3
20
Notes: 1. Dashed line on construction cost curve indicates size range of
marginal applicability from a process and/or economic basis.
2. See individual treatment process curves for design basis of
specific uitit processes. (Adjustment factors should be used where
applicable.)
3. Fed, dosage at 100 mg/1.
4. Aerooic digestion at plant sizes less than 3 mgd; two-stage
anaerobic digestion at plant sizes greater than 3 mgd.
H-18
-------
FIGURE H-3 TREATMENT SYSTEM 2-
PRIMARY TREATMENT WITH METAL-SALT
ADDITION (FeClj)
o>
w
_0
1
o
a
10
c
o
o
o
100
o
3
a
O
1
10
1.0
O.I
O.I
:CONSTRUCTION COST:
1.0
10
100
FLOW.mgd
10
10
O.I
0.01
0
^— *
1
, —
Ma
, •
OPERATION 8
terials
^
-^^
•*"r
^
,
^L
"p
>
^
^
a
^
x*
3or
i i
,Ji
o\
/
»er
4
«
^
^
'
^
J
y
•p/C
X
—
>
^*
^
fie
MAINTENANCE
X
X
X1
X
' 1
Total
X
X
ix"
-x
•x
/
/
Dice
Is
X1
/
x
/
x
X
/
^
'
/
**
^
/
X
s
s
s*
^
COST
X
s
s
/,
X
(*•
x1
x^ /-
x >
/
x
^
/P
'?
' 1
X
/
V
/
=01
^
/
/
/
*
Ml
/
/
/
>
JT
1 1.0 10
TllO
i"
('
t
01
n ni
0.001
100
a
FLOW., mgd
H-19
-------
FIGURE H-4
TREATMENT SYSTEM 3-
TRICKLING FILTER
Lift
Pumps
Preliminary
Treatment
-cm—
Primary
Clarifier
High Rate
Trickling Filter
Ultimate
Disposal
Gravity
Thickener Digestion
Vacuum
Filter
Processes Included:
Lift Pumps, Preliminary Treatment, Primary Clarifiers,
High Rate Trickling Filter, Secondary Clarifiers,
Chlorination, Gravity Thickener, Sludge Digestion,
Vacuum Filters, Miscellaneous Structures, Support
Personnel.
Wastewater Characteristics:
BOD , mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH -N, mg/1
NO^-N, mg/1
UOD, mg/1
Influent
210
400
230
11
20
0
406
Sludge Audit:
Point No.
Sludge_
itity
Effluent
45
90
60
8
18
0
150
Concentration
1
2
3
4
5
6
1,080
450
1,530
1,530
765
765
4
3
4
5
3
20
Notes: 1. Dashed line on construction cost curve indicates size range of
marginal applicability from a process and/or economic basis.
2. See individual treatment process curves for design basis of
specific unit processes. (Adjustment factors should be used where
applicable.)
3. Aerobic digestion at plant sizes less than 3 mgd; two-stage
anaerobic digestion at plant sizes greater than 3 mgd.
H-20
-------
FIGURE H-4 TREATMENT SYSTEM 3
TRICKLING FILTER
o
Q
O
O
_o
i
o
o
o
.a
o
IUU
10
IO
O.I
0
10
I.O
O.I
0.01
0
»*'"'
1
••••
Po
X
^
x"
.—
9^
^.
Ml
/
.*•
—a
s
'a
^
ICON
..^
STRUC
^
TIOK
^x
X" '
'
cc
X1
1.0
FLOW.mgd
OPERATION
^
yf
'—t
wii
M
^
*•
f
,
lie
iwrl
X
^ I*1
^ *"
^ '
/*
at
l1^
"'
^ '
^ r
^ •*
a
ji
^
iSI
jX
, X
jX
•^—-
x
10
MAINTENANCE
^
x
•^ /
^
f
n
-*
^
X
^
r
^
'
X
x'
!
.0
/
J
jUr
r
COST
>
X"
7s*
tfX"
\ -
/
Sx^-
s
Mm
j
X
•
^
—
r
X
/
X
^.
.
/'
t
, /
^/^
/
-------
FIGURE H-5 TREATMENT SYSTEM 4-
TRICKLING FILTER WITH METAL- SALT ADDITION (Fed3)
FeCI,
l_jff Preliminary
Pumps . Treatment
Primary
Clarifier
Ultimate
Disposal
Gravity Vacuum
Thickener Digestion Filter
Processes Included:
Lift Pumps, Preliminary Treatment, Ferric Chloride
Addition, Primary Clarifiers, High Rate Trickling
Filters, Secondary Clarifiers, Chlorination, Gravity
Thickener, Sludge Digestion, Vacuum Filters,
Miscellaneous Structures, Support Personnel.
Wastewater Characteristics:
BOD5, mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH3-N, mg/1
N03-N, mg/1
UOD, mg/1
Influent
210
400
230
11
20
0
406
Sludge Audit:
Point No.
1
2
3
4
5
6
Sludge Quantity
Ibs/mg
2,160
330
2,490
2,490
1,580
1,580;
Effluent
25
50
30
2
18
0
120
Concentration
%
2
3
2
4
3
20
Notes: 1. Dashed line on construction cost curve indicates size range of
marginal applicability from a process and/or economic basis.
2. See individual treatment process curves for design basis of
specific unit processes. (Adjustment factors should be used
where applicable.)
3. Fed3 dosage at 100 mg/1.
4. Aerobic digestion at plant sizes less than 3 mgd; two-stage
anaerobic digestion at plant sizes greater than 3 mgd.
H-22
-------
FIGURE H-5
100
10
1.0
OJ
O.I
TREATMENT SYSTEM 4-
TRICKLING FILTER WITH METAL-SALT
ADDITION (FeCI3)
•CONSTRUCTION COST:
1.0
10
FLOW.mgd
X
100
o
a
_o
i
o
o
IU
1.0
1
3
~a
£
O.I
0.01
1
— •*"
X
__ —
la
•7
v '
erii
qf
--—
OPERATION
Is
"^
s
t'
S
s
J
^
0 '
a
/
^i
-•
-7
MAINTENANCE
>
/
/
otal
,*
(
X1
/
K
'^^
Ih
,
^
f
-»
>r
^
^>
'
x
iic
//'
--•
x
•^
IS'
/
/
y
' /"
1 1 /
CO.ST
X
/
-••
^
/
p^
f
/
//
1 /
>
1 — .
/
/
'
JX1
/
^
^
L
/
/
al
*
>
L'
)0
S
I
>
^
f
'"
l.\J
a. 1
a.
en
o
6
^
0
Z
(0
o
u
0.01 2
o
0.001
O.I
1.0 10
FLOW , mgd
100
H-23
-------
FIGURE H-6
Lift
Pumps
TREATMENT SYSTEM 5-
ACTIVATED SLUDGE
Primary
Preliminary Clarifier
Treatment
Activated
Sludge
Secondary
Clarifier
Disinfection
Ultimate
Disposal
Gravity Vacuum
Thickener Digestion Filter
Processes Included:
Lift Pumps, Preliminary Treatment, Primary Clarifiers,
Activated Sludge, Secondary Clarifiers, Chlorination,
Gravity Thickener, Sludge Digestion, Vacuum Filters,
Miscellaneous Structures, Support Personnel.
Wastewater Characteristics:
BOD,., mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH--N, mg/1
NO^-N, mg/1
UOD, mg/1
Sludge Audit;
Point No.
Influent
210
400
230
11
20
0
406
Sludge
Effluent
20
45
20
7
17
0
107
itity
Concentration
1
2
3
4
5
6
1,080
820
1,900
1,900
950
950
4
0.8
2.6
8
5
20
Notes: 1. Dashed line on construction cost curve indicates size range of
marginal applicability from a process and/or economic basis.
2. See individual treatment process curves for design basis of
specific unit processes. (Adjustment factors should be used where
applicable.)
3. Aerobic digestion at plant sizes less than 3 mgd; two-stage
anaerobic digestion at plant sizes greater than 3 mgd.
H-24
-------
FIGURE H-6 TREATMENT SYSTEM 5-
ACTIVATED SLUDGE
100
o
Q
in
c
o
10
1.0
O.I
O.I
^^
*•**"
V*
_
1
„>
CONSTRUCTION CC
^
•
X
1
/s
s
'
s
'
\ \
ST-
l~~
-• —
s
...
i
x
X
f r i
1 j
^
/
f 1
M-k
| ;
; ! • • i
!
1
.
---
—
— ~-
'
I
— i-
i •
Ij,
/
'•
— |_t
| ,
_ _J_
_ _J-
I
j
1.0 10
FLOW.mgd
100
o
o
o
U
o
3
C
O
&
o
a>
g
'
O
2
,o
10
1.0
01
0.01
o
^
/
Tt
,••""*
•• '"
tar
<^
/
OPERATION 8
^ —
•?—
i
cols
X
^
MAINTENANCE
S
/
,/
^^
^
'
'
/j
'
x
X
^
X
'
^
/*
/
^J
^
^
_: -
l.O
f
' ^
^f
-+-?
*
p^
COST
/
r
1 (
y
M
Povi
/
>
s
S
ibor
'
iter
er
X
v
/
x'
Ql
(
/
'
\
'
/
4
,
*
r
'
s
in
'
01
0.01
OOOI
10 100
I
ID
6
FLOW , mgd
H-25
-------
FIGURE H-7 TREATMENT SYSTEM 6-
ACTIVATED SLUDGE WITH METAL-SALT ADDITION (ALUM)
Lift
Pumps
Primary
Preliminary Clarifier
Treatment
Alum
Activated
Sludge
Secondary
Clarifier
Disinfection
OOOisss
Gravity Vacuum
Thickener Digestion Filter
Processes Included:
Lift Pumps, Preliminary Treatment, Primary Clarifiers,
Alum Addition, Activated Sludge, Secondary Clarifiers,
Chlorination, Gravity Thickener, Sludge Digestion,
Vacuum Filters, Miscellaneous Structures, Support
Personnel.
Wastewater Characteristics:
BOD,-, mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH3-N, mg/1
NCL-N, mg/1
UOD, mg/1
Sludge Audit:
Point No.
1
2
3
4
5
6
Influent
210
400
230
11
20
0
406
Sludge Quantity
Ibs/mg
1,080
1,150
2,230
2,230
1,280
1,280
Effluent
15
35
15
2
17
0
100
Concentration
4
0.8
2.3
6
3.5
20
Notes: 1. Dashed line on construction cost curve indicates size range of
marginal applicability from a process and/or economic basis.
2. See individual treatment process curves for design basis of
specific unit processes. (Adjustment factors should be used
where applicable.)
3. Alum dosage at 100 mg/1.
4. Aerobic digestion at plant sizes less than 3 mgd; two-stage
anaerobic digestion at plant sizes greater than 3 mgd.
H-26
-------
FIGURE H-7 TREATMENT SYSTEM 6-
ACTIVATED SLUDGE WITH METAL-SALT
ADDITION (ALUM)
IUVJ
10
*>
w
O
"5
O
O
m
§
2 1.0
O.I
^^*"
„ '
-^*
*
*•*
~L4 1
CON*
X
•
i
3TRUC
s
TION
]
: .X
s
1
CO
S
s
, '
->
ST
-r
—j*-
— I—
X
i
,
;
/
X1
X
(
x
_j_
_L
|
I _j_
'
o
o
I
s
o
ate
o
ja
o
ota
O.I
1.0
10
FLOW.mgd
O.I
i.o
10
100
10
1.0
Ol
001
' — -^
^•^
^*-
/
<
P^-
•rf»
^ '
r
^
^P-**
-*
OPERATION 8
s"
X
^
^,
X
*£ '
, ** >
, •*
• *
s
'X
K'
/,
.
,?
^
MAINTENANCE
/
/S
IciMffl
X
f
^ota
owe
^
/
r ^
\
!>
V
^
X
•#•
^
ie«
2
/
'
111
-------
FIGURE H-8
Lift
Pumps
TREATMENT SYSTEM 7-
ACTIVATED SLUDGE/NITRIFICATION CSINGLE STAGE},
Primary Activated Secondary
Preliminary Clarifier Sludge/Nitrification "IT
T. ^-^ « x-^ Disinfection
Ultimate
Disposal
Gravity Vacuum
Thickener Digestion Filter
Processes Included; Lift Pumps, Preliminary Treatment, Primary Clarifiers,
Activated Sludge with Nitrification, Secondary
Clarifiers, Chlorination, Gravity Thickener, Sludge
Digestion, Vacuum Filters, Miscellaneous Structures,
Support Personnel.
Wastewater Characteristics;
BOD , mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH -N, mg/1
NO^-N, mg/1
UOD, mg/1
Sludge Audit:
Point No.
1
2
3
4
5
6
Influent
210
400
230
11
20
0
406
Sludge
tity
Ibs/mg
1,080
820
1,900
1,900
950
950
Effluent
10
35
20
8
2
18
24
Concentration
4
0.8
2.6
4
2.5
20
Notes: 1. Dashed line on construction cost curve indicates size range of
marginal applicability from a process and/or economic basis.
2. See individual treatment process curves for design basis of
specific unit processes. (Adjustment factors should be used
where applicable.)
3. Aerobic digestion at plant sizes less than 3 mgd; two-stage
anaerobic digestion at plant sizes greater than 3 mgd.
H-28
-------
o
o
FIGURE H-8
10
ID
O.I
O.I
TREATMENT SYSTEM 7-
ACTIVATED SLUDGE / NITRIFICATION
(SINGLE STAGE)
CONSTRUCTION COST:
1.0
10
FLOW.mgd
100
10
w
o
o
o
to
c
o
tn
o
O
o
J3
a
10
1.0
O 1
001
1
\-jr*
•*"~"
*s
/
M
iter
\'
"Total,
J^J'
1 -^i
•^
x
^
OPERATION 8
ial
'
~~z>
•js~
^^
'C
^
•*;
^X
he
^ 9
,
m\C(
1
j .X
«'i
y^>
f
---5^
-•/* —
f
is
X
x
,
MAINTENANCE
X
f
j
s
»m
s
/
^
*
it
s
/
—.
4
r,
r
^
£. -
?
/
/
' L
X
x"
^ >
- - ^ —
X"
^ X'y^
/
^x'
obor
COST
X1
/
— ^
>^
S
'
x^
I/
T
i^- — .
/
X
X
Bta
^X
X
/
1
f
Sf
/,
—
y f
7
^
,,'
31 1.0
01
-001
. , 0.001
O.I
1.0 10
FLOW , mgd
£
o
o
6
100
H-29
-------
FIGURE H-9 TREATMENT SYSTEM 8-
ACTIVATED SLUDGE/NITRIFICATION/DENITRIFICATION (THREE STAGES)
Preliminary
Treatment
Primary
Clarifier
Activated
Sludge
Secondary
Clarifier
Gravity
Digestion Thickener 4
Disinfection
Ultimate
Disposal
Denitrification
Clarifier
Processes Included; Lift Pumps, Preliminary Treatment, Primary Clarifiers,
Activated Sludge, Secondary Clarifiers, Nitrification,
Denitrification, Chlorination, Gravity Thickener, Sludge
Digestion, Vacuum Filters, Miscellaneous Structures,
Support Personnel.
Wastewater Characteristics: Influent Effluent
BOD5, mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH -N, mg/1
NO^-N, mg/1
UOD, mg/1
Sludge Audit:
Point No.
1
2
3
4
5
6
7
8
210
400
230
11
20
0
406
Sludge Quantity
Ibs/mg
1,080
720
100
280
2,180
2,180
1,090
1,090
10
45
20
8
1
1
20
Concentration
4
0.8
0.8
0.8
2.4
4
2.5
20
Notes: 1. Dashed line on construction cost curve indicates size range of
marginal applicability from a process and/or economic basis.
2. See.individual treatment process curves for design basis of
specific unit processes. (Adjustment factors should be used
where applicable.)
3. Aerobic digestion at plant sizes less than 3 mgd; two-stage an-
aerobic digestion at plant sizes greater than 3 mgd.
H-30
-------
FIGURE H-9 TREATMENT SYSTEM 8-
ACTIVATED SLUDGE /NITRIFICATION/DENITRIFICATION
(THREE STAGES)
IUU
10
in
w
a
1
0
«
c
o
:=
'i 1.0
O.I
0
10
Ilions Of Dollars
or , Chemicals)
b
. 3
m *•
2 0
,2 O.I
o ^^
c
c
0.01
0.
ttr-
1
^
^
,''
-CON
(
jix1
i
| ' !
STRUCTION C
^
: S
/^
j
1
^
[X1
J-i-4
nsT -
)
j
X
/
I ^^
1 i
1
I !
'
,
X
j
1 1.0 10
FLOW.mgd
Z?
S
• —
Utr OPERATION 8 MAINTENANCE CO
j | 1 1 1 if
i
1
J^
^
•-•
,^^
^F
p^-
^->
^
•^
o«
"^
4<
61
^
iteri
x#'
_^'-
x'
Q fl ^
','
'
t''
/
**
^
^
^
J
X
"^X
", 1''
r
"^
X
s
, i
:N<
|
j
j
y
X1 ^
- ,
X* I, '
iX
j
jQ
^
m
X
>or
/
cats
i
^
/ ' y
~ • ^ —
s
.
/~
,
x
/
/
ST
5^
X
^
^
' /
\ '
/
r
<
^
^
X^
^
/\
T(
/
, '
. f
f.
/
>tol
^
1
!
100
- i *V
J '
i
H
• ',
i 0 1
O
i w
°
T
03
4ooi —
. nnni
.0 10 100
FLOW , mgd
H-31
-------
FIGURE H-10
TREATMENT SYSTEM 9-
ACTIVATED SLUDGE/NITRIFICATION - FILTRATION (WITH ALUM)
Alum
Lift
Pumps
Activated
Sludge/
Nitrification
Secondary
Clarifier
Ultimate
Disposal
Vacuum
Filter
Processes Included; Lift Pumps, Preliminary Treatment, Alum Addition,
Primary Clarifiers, Activated Sludge with Nitrification,
Secondary Clarifiers, Filtration, Chlorination, Gravity
Thickener, Sludge Digestion, Vacuum Filters, Miscel-
laneous Structures, Support Personnel.
Wastewater Characteristics:
BOD5, mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH -N, mg/1
NO,-N, mg/1
UOD, mg/1
Sludge Audit:
Point No.
1
2
3
4
5
6
Influent
210
400
230
11
20
0
406
Sludge Quantity
Ibs/mg
1,800
600
2,430
2,430
1,380
1,380
Effluent
10
45
10
1
2
18
24
Concentration
3
0.8
2.5
4
2.5
20
Notes: 1. Dashed line on construction cost curve indicates size range of
marginal applicability from a process and/or economic basis.
2. See individual treatment process curves for design basis of
specific unit processes. (Adjustment factors should be used
where applicable.)
3. Aerobic digestion at plant sizes less than 3 mgd; two-stage an-
aerobic digestion at plant sizes greater than 3 mgd.
H-32
-------
FIGURE H- 10
100
10
o °
^ 0
« E
c •
O -c
= o
•
"05 A.
0 .
i 0-.I
1 "
< 0
«-
0.01
0
TREATMENT SYSTEM 9-
ACTIVATED SLUDGE/NITRIFICATION - FILTRATION
(WITH ALUM)
^X
j
S
<•
<
CON
! >
^
STRUCTION CC
X
s
/
i
i
i
X
i
— 1 —
ST
f
i s
X
1
=\
1
^
x
|
/
\
/
1 1.0 10
FLOW.mgd
•^f
j-—
/
^~
,*--
^
^--
OPERATION 8 MAINTENANCE COST
^
Moteri
x
'
ll
x
i
/
1
*
i" C
,
,'
I
/
ft
Labor
^s
X
*hiemi(
X,
' x
/
"'
— —
ai:
X
1
X
^
/
<£- — ! — 7
-X"
Xi
< X
.Xi
i
!
]
ix
/|
x
'-
/
,/
?
'
*'
'
~?4
>
1
1
I
1-
1 TX
J?
^
f *
1 ' / C
t A
/
taf
1 x
•r -
xJX
x
'0,
X
i
i
^
y-
'
t/
/
/
/f
^
^
2 j
:
t
100
Jj
'.
f
1 1.0 10 100
FLOW , mgd
H-33
-------
FIGURE H-ll
TREATMENT SYSTEM 10-
PHYSICAL/CHEMICAL
Lift
Pumps
Preliminary
Treatment
-CD
Two-Stage
Lime
Carbon
Adsorption
Regeneration
r-
)t
9
itratu
xi
h
Disi
fef
*l
o
Gravity
Thickener
Ultimate
Disposal
Vacuum
Filter
Processes Included; Lift Pumps, Preliminary Treatment, Two-Stage Lime,
Gravity Filtration, Interstage Pumping, Carbon
Adsorption, Chlorination, Gravity Thickener, Vacuum
Filters, Miscellaneous Structures, Support Personnel.
Wastewater Characteristics;
BOD mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH -N, mg/1
NO^-N, mg/1
UOD, mg/1
Sludge Audit:
Point No.
1
2
3
Influent
210
400
230
11
20
0
406
Sludge Quantity
Ibs/mg
7,500
7,500
7,500
Effluent
5
25
5
1
20
0
99
Concentration
5
10
30
Notes: 1. Dashed line on construction cost curve indicates size range of
marginal applicability froiii a process and/or economic basis.
2. See individual treatment process curves for design basis of
specific unit processes. -(Adjustment factors should be used
where applicable.)
3. Lime dosage at 400 mg/1 as CaO.
4. Carbon adsorption without regeneration at plant sizes less than
3 mgd; carbon adsorption with regeneration at plant size greater
than 3 mgd.
H-34
-------
M
^
O
c
o
FIGURE H-ll
TREATMENT SYSTEM 10-
PHYSICAL/CHEMICAL
100
10
O.I
O.I
CONSTRUCTION
I.O
10
FLOW.mgd
100
o
O
O
o
I
O.I
IOO
10
I.O
Ol
s
/
^
s
X
f
_.
aX
OPERATION a
^
x-1
r^
^
X
X
X
/
V
/
>
X
jx
jf*
-^
>
/
J>
^
/
MAINTENANCE
X
^x
x
K
1
X
j/
..r
^
^
we
,
^c
X
ate
X
y
g
'
.
s
^
-.!«
rial
/"
V
^
' ^1
al*9-
J^
4
/
COST
/
xj
.at
y
^^
/
*
* i
X
Of-
x>
X
/
*
i
,
/
-c
x
x_^
^
>
/
/
ht
/,
/
^
m
x
/
/
ICO
*
/
> if
P'
TjlO
ll
|
^
|
-id
-O.I
001
I.O 10
FLOW , mgd
1
a>
o
|
O
I
100
H-35
-------
FIGURE H-12
TREATMENT SYSTEM 11-ACTIVATED SLUDGE/
NITRIFICATION/DENITRIFICATION/WITH ALUM (THREE STAGES)
Al m
Lift
Primory
PreBminory Oarifier
Treatment
Activated
Sludge
Secondary
Clarifier
Nitrification
Nitrification
Clarifler
Disinfection
Gravity Vacuum
Thickener Digestion Filter
Filtration
L
lander
tion
Polymer
Denitrification
-Or
Processes Included:
Lift Pumps, Preliminary Treatment, Primary Clarifiers,
Alum Addition, Activated Sludge, Secondary Clarifiers,
Nitrification, Nitrification Clarifier, Denitrification,
Polymer Addition, Denitrification Clarifier, Filtration,
Chlorination, Gravity Thickener, Sludge Digestion,
Vacuum Filtration, Miscellaneous Structures, Support
Personnel.
Wastewater Characteristics:
BOD , mg/1
COD? mg/1
TSS, mg/1
Total-P, mg/1
NH--N, mg/1
NO^-N, mg/1
UOD, mg/1
Sludge Audit;
Point No.
1
2
3
4
5
6
7
8
Influent
210
400
230
11
20
0
406
Sludge Quantity
Qu£
70%
Ibs/mg
1,080
1,050
100
280
2,510
2,510
1,420
1,420
Effluent
5
30
5
0.5
1
1
12
Concentration
4
0.8
0.8
0.8
2.8
4
3
20
Notes:
Dashed line on construction cost curve indicates size range of
marginal applicability from a process and/or economic basis.
See individual treatment process curves for design basis of
specific unit processes. (Adjustment factors should be used
where applicable.)
Aerobic digestion at plant sizes less than 3 mgd; two-stage an-
aerobic digestion at plant sizes greater than 3 mgd.
H-36
-------
FIGURE H-12
o
Q
TREATMENT SYSTEM II-
ACTIVATED SLUDGE /NITRIFICATION/DENITRIFICATION
WITH ALUM (THREE STAGES)
100
10
1.0
O.I
O.I
CONSTRUCTION COST:
1.0
10
FLOW.mgd
100
10
in
w
O
O
o
at
c
O
a
3
c
<
E
5
o
a.
1.0
O.I
0.01
O.I
. — •
>
***
«=-
^
/
•^*"
Ch
*^
OPERATION 8
^
err
X
r
--
ic
'
x
"*^
--'
S
<
.^
^
'
jt
s /
' S
/
'
/
\
>
— ^
^
/
MAINTENANCE
X
.
ibo
T£-,
F^1
f
/
^X
x
/
ou
x
^
X
(
er
-;
x
/
•£-
••;,
/
x
/ .
Total
^
r
ater
s
•'
COST
/
-f
^
ali
^X
x
7^-
/
(/
X
^
s
x
X
r
x
^
x
'
--?'•
7
,
/
,
7
f'
- _ i.
2
1.0 10
FLOW , mgd
100
H-37
-------
FIGURE H-13
TREATMENT SYSTEM 12-ACTIVATED SLUDGE/NITRIFICATION/
DENITRIFICATION/ACTIVATED CARBON (WITH ALUM)
Nitrification
Ctarifltr
Processes Included:
Lift Pumps, Preliminary Treatment, Primary Clarifiers,
Alum Addition, Activated Sludge, Secondary Clarifier,
Nitrification, Nitrification Clarifier, Denitrification,
Polymer Addition, Denitrification Clarifier, Filtration,
Interstage Pumping, Carbon Adsorption, Chlorination,
Gravity Thickener, Digestion, Vacuum Filter,
Miscellaneous Structures, Support Personnel.
Wastewater Characteristics:
BOD,., mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH -N, mg/1
NO^-N, mg/1
UOD, mg/1
Sludge Audit:
Point No.
{
1
2
3
4
5
6
7
8
Influent
210
400
230
11
20
0
406
Sludge Quantity
Ibs/mg
1,080
1,050
100
280
2,510
2,510
1,420
1,420
Effluent
3
10
5
0.5
1
1
12
Concentration
4
1
0.8
0.8
2.8
4
3
20
Notes:
Dashed line on construction cost curve indicates size range of
marginal applicability from a process and/or economic basis.
See individual treatment process curves for design basis of
specific unit processes. CAdjustment factors should be used
where applicable.)
Carbon adsorption without regeneration at plant sizes less than
3 mgd; carbon adsorption with regeneration at plant sizes
greater than 3 mgd.
H-38
-------
FIGURE H-13
"5
Q
O
O
O
M
J
TREATMENT SYSTEM 12-
ACTIVATED SLUDGE /NITRIFICATION /DENITRIFICATION/
ACTIVATED CARBON WITH ALUM ADDITION
100
10
1.0
O.I
±
O.I
O.I
CONSTRUCTION COST:
1.0
10
100
FLOW.mgd
10
1.0
O.I
001
^
/
X
f^
/
s
^
*~^
uX
X
OPERATION 8
^
-C
/
X
^
h«
x1
+
x
^' '
mkx
^ _ _
/
Aaterid s
s
/
^
^
•'r
,^-
X"
l»-7
s
/
t
s
^
X
y
MAINTENANCE
jX'
Lai
x*
>or
y
/ <
/
'ow
/
>r
X
X'
/
^
T<
XI
X
>
rta
^ *•
/
^
/
>
/
^
/"
- • —5;
, ^/
'
_
s
s
/
t
COST
/
a—
S
/
/
/
xx
/
f
/
/
/
/
fx
X
/
X
^
„,
^
2
2
/
x
/
^ '^
,
'•
,
/
1.0 10
FLOW , mgd
100
H-39
-------
FIGURE H-14
TREATMENT SYSTEM 13
SMALL FLOW TREATMENT SYSTEMS
Service Life: 30 years
Relative Reliability: Level B -
Design Basis:
1. Construction costs include:
a. Comminutor
b. Aeration basin
c. Clarifier
d. Chlorine contact chamber
e. Aerobic digester
f. Chlorine feed facility
g. Building
h. Fencing
2. Extended aeration (E.A.) between 0.01 and 0.1 mgd.
Detention time: 24 hours.
3. Contact stabilization (C.S.) between 0.1 and 1.0 mgd.
Detention time: 3 hours contact; 6 hours stabilization.
4. Process Performance:
Wastewater Characteristics: Influent Effluent
i^> • O • • £1 • /
BOD., mg/1 210 25 20
COD, mg/1 400 50 45
TSS, mg/1 230 25 20
Total-P, mg/1 11 7 7
NH3-N, mg/1 20 17 2
References: 9, 43, 47
H-40
-------
FIGURE H-14
o
a
O
O
10
1.0
O.I
OOI
OOI
O.I
0.01
0.001
0.0001
TREATMENT SYSTEM 13-
SMALL FLOW TREATMENT SYSTEMS
-^
^
^E
s
ite
'
nc
ec
i
7
i*1-
i
: CONST
!
lontQ'
i **^
jf\
teroti
:t
^
30
RUCTION (
1 j
Stabil
^
•^
E.A.)
i !
—
!
zat
x-
X
Pac
H
-
Q
<(
- 1-
:o
1
n(
jg
ST-
C.S.)
Pi
— 1—
j Pla
nt
ickc
ge
F
>lc
n
O.I
1.0
FLOW.mgd
0.01
O.I 1.0
FLOW , mgd
10.0
x^
^
^
X
/
X*
^
V
/
X"
X
OPERATION
Total (E.A.);
1 IK
Jr\
1^1
^r 1 1 . *
X"
x^
Labor fE./
aterla
1 -^
X
1
Power i
-^L.
Che
y
X"
mil
/
il
s(E.A.)
I i
-
&-
;a
4
.
S(EJ
,«^
. ' -^--^
i 1
*•!
,<^i
,• r
I /
/'X
t
s
^)
a
X"
•L
^
•o»
J
/
C
/
/
MAINTENANCE
Tot
/
ibor
-*—
. —
erf
t
iem
/
al
x^
(C
— •
^-^
/
:.s
C.S
x-
s
/
f
';
,•
icals(
/
X
.
/
/
:.
) ^
*. -
/
.
s.)
: Ma
»
COST
er
als(
:.s
)
IOO
H-41
-------
FIGURE H-15
TREATMENT SYSTEM 14
OXIDATION DITCH (DESIGNED FOR NITRIFICATION)
Service Life; 30 years
Relative Reliability; Level B
Design Basis;
1. Construction costs include:
a. Comminuter
b. Aeration basin
c. Clarifier
d. Chlorine contact chamber
e. Chlorine feed facility
f. Building
g. Fencing
2. Detention time: 24 hours
3. Process Performance:
Wastewater Characteristics: Influent Effluent1
w/N Removal w/o N Removal
BOD5, mg/1 210 15 15
COD, mg/1 400 40 40
TSS, mg/1 230 15 15
Total-P, mg/1 11 6 6
NH3-N, mg/1 20 1 1
N03-N, mg/1 0 2 18
Note: 0 § M costs are w/o nitrogen removal. Add 5 - 10% annual 0 § M
costs to those shown w/ nitrogen removal.
Reference: 47
H-42
-------
FIGURE H-15
i
in
c
o
_o
~o
o
o
TREATMENT SYSTEM 14-
OXIDATION DITCH (DESIGNED FOR NITRIFICATION)
10
1.0
O.I
w
«
1
^
N
«* *
1
[_| 1 U- 1 1 — i— J — Ut-l
CONSTRUCTION CO
trog
!
,**
sn
^
Remo
L
!
i
!
j
ra
^
s*^
I
<
1
^
^w/
|
-
U
ST-
4?
r \
^
tf>
£
!/
^
7 J
{'
_j_
'0 Nitrogen Removal i
j
1
• '.
1
\
1
0.01
0
1.0
0.
|2
w
0
3
0.01
0.001
0
1
01 O.I 1.0
FLOW.mgd
OPERATION a MAINTENANCE COST
— |
To
H
!
1
ol
X
^
- } ^-Mainte
/
X
I/
x*
, y
X
>^x-
^ /
—Chen
lonce-
;
^
^
-^
i
I i
i
Powi
r
>
iica
s
-
<
,'
*
/
\/\
T X
Ix
,x
^ ^
\/
-*.
f
^
^
^r»i
i
1
i
^
/
x
/
^
,
)or H
.
/
^'
/ /
i
i
10
rnOI
7
7
,'
'', —
'' a
fe
nni 2*
c
V
"c
"5
2
; in
o
s.
-•0001 o
t 2
T S
Q.
. 0.0001
.01 O.I 1.0 10
FLOW , mgd
H-43
-------
FIGURE H-16
TREATMENT SYSTEM 15
LAND APPLICATION OF WASTEWATER (NON-UNDERDRAINED)
Service Life; 30 years (equipment only)
(Land assumed to have infinite service life)
Relative Reliability: Level B
Design Basis;
1. Costs are for spray irrigation of wastewater.
2. Construction costs include:
a. Storage - 60 days' retention (based on average flow of waste-
water), earthen construction, asphalt-lined with riprap.
b. Land - to include storage area; land required for 2"/wk
application rate; 200 ft buffer zone.
c. Field preparation - to include brush and tree removal and site
leveling at 500 cu yd/acre.
d. Distribution piping.
e. Distribution pumping.
f. Service roads and fencing.
g. Monitoring wells.
Adjustment Factor;
To adjust for application rate other than above, enter curve at
effective flow (Qg):
2" Wppk
Q = Q - 2 Week
DESIGN New Application Rate
Reference: 27
H-44
-------
FIGURE H-16
o
o
100
10
1.0
0.
TREATMENT SYSTEM IS-
LAND APPLICATION OF WASTEWATER
(NON-UNDERDRAINEO)
CONSTRUCTION
H
O.I
Construction
Cost
H—^
fi
2^04
mc~%
&
Land
7~7i
A
1.0
10
FLOW.mgd
i
100
10
O _
1
o
CO
C
o
m
o
O
o
3
C
C
4
J_
"o
1.0
O.I
0.01
O.I
1.0 10
FLOW , mgd
m^
^-
"^^
x*
^
f**
s
^
^
OPERATION 8
s
^
d-
x
x
1
/
-<-
<
>'
^
/
i
i>
^:
*~ ^
H*^
*\s
lif
1
I/
f
MAINTENANCE
i /
^
/
i^j
•'
Materials Y
/I
/
yfl?-
/
^ y/
V
^
La
i«
X
s
/
^" 1
>or
7^-
'
!
/
^
/
/
,
I 1 1
COST
/
i XT
/
/
/
/ /
/
f
T
./
Dtal
UP°
/
'
/
we
)t-
/
\
1
)
/
/
/
r-
|
^
/
/
/
-*-l
/
/
/
•• i.u
/
-O.I
i
i
0.01
'
. 0.001
100
I
H-45
-------
H.7 Wet-Weather Treatment Processes
Cost Curves:
Figures H-17 through H-27
FIGURE H-17
CONCRETE STORMWATER STORAGE RESERVOIR
Service Life; 50 years
Relative Reliability: Level B
Design Basis:
1. Construction costs based on actual projects and on comparison with
sludge aeration basins exclusive of aeration equipment ranging
from 400,000 to 5,000,000 gallons.
2. Operation and maintenance costs include automatic washdown of basins
after storms.
Reference: 36
H-46
-------
FIGURE H-171 CONCRETE STORMWATER STORAGE
RESERVOIR (WITHOUT COVER)
a>
^
o
o
a
at
c
o
o
a
o
O
too
10
I.O
O.I
I.O
I.O
O.I
O.OI
0.001
I.O
CONSTRUCTION COST:
10
IOO
IOOO
\ r— i i i i T 111 i i
OPERATION 8 MAINTENANCE COST!
9O Qmi/Yr of Op«olloii
60 Dan/It of Optroflon
30 Doyi/Yr of Operation
IS Oor«/Yr of Operation
10 100
Copority, «o
IOOO
H-47
-------
FIGURE H-17
CONCRETE STORMWATER STORAGE RESERVOIR
Service Life: 50 years
Relative Reliability; Level B
Design Basis:
1. Construction costs based on actual projects and on comparison with
sludge aeration basins exclusive of aeration equipment ranging
from 400,000 to 5,000,000 gallons.
2. Operation and maintenance costs include automatic washdown of basins
after storms.
Reference: 36
H-48
-------
o
a
w
c
o
in
^
o
o
o
a>
o
U
FIGURE H-172 CONCRETE STORMWATER STORAGE
RESERVOIR (WITH COVER)
100
10
1.0
O.I
1.0
1.0
O.I
0.01
0.001
1.0
:CONSTRUCTION COST:
10
100
1000
Capacity, mg
i I 1111—i—i—i—i—i i
OPERATION 8 MAINTENANCE COST!
M Ooyi/Yr of Opmtlon
•0 Doyt/Yr >f Optraltan
SO Do/i/Yr of Ootrallon
a Dop/Yr of Optrotion
10
100
1000
Capacity, mg
H-49
-------
FIGURE H-18
EARTHEN STORAGE BASIN
Service Life: 50 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include liner, paving and fencing, on-site soil
supply, and no groundwater problems or rock excavation.
2. Interior slope is 2.5 to 1.
Exterior slope is 3 to 1.
Compaction loss = 20%.
Levee top width = 16 feet.
Reservoir is 18 feet deep.
Length/width ratio is 2.
3. Manual cleanout twice a year based on 0.004 manhours/sq ft of basin
water surface area.
4. No electrical costs.
Reference: 36
H-50
-------
FIGURE H-18 EARTHEN STORAGE BASIN
a>
^
o
o
o
10
I.O
O.I
O.OI
Tl T 1 1
;CONSTRUCTION COST:
m
+-4-
X
1.0
10 100
Capacity , mg
1000
o
Q
O
i
o
o
1.0
10
100
1. 0
O.I
O.OI
0.001
1
i
[
1
(
/
f
OPERATION a MAINTENANCE
/
j
£
r
I
~s~
t
X
^
|
!
y
jf
X
!
j
i i
/
^
/
COST
!
l
|
yj
jf
t r
I
^—
/
j
j
; j
t
/
/
'
L,
t
\
1
— ~T
T
IOOO
Capacity , nig
H-51
-------
FIGURE H-19
STATIONARY SCREEN
Service Life: 15 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include collection flumes for sludge and
screened effluent, and housing for screens.
2. Screens are wedgewire (stainless steel).
3. Costs based on screens rated at 4 mgd each. Total capacities
range from 12 mgd (3 screens) to 192 mgd (48 screens).
4. Costs are related to hydraulic capacity.
5. Screen assembly requires 4 to 8 feet of head loss.
6. Costs include influent headers and metal weirs to distribute
flow to each unit.
7. Labor costs include 24 hours/year for routine checks. Also for
each overflow event: 1 hour startup/shutdown time, 1 hour wash
time, 1 hour travel time, and 2 hours twice a day for operation.
Process Performance: (Swirl Concentrator Followed By Stationary Screen)
Typical Pollutant Removals, %
BOD5 0-25
TSS 0-25
References: 36, 51
H-52
-------
o
Q
O
o
o
o
FIGURE H-19 STATIONARY SCREEN
10
1.0
O.I
0.01
CONSTRUCTION COST:
7
7
1.0
10
100
1000
FLOW , mgd
1.0
O.I
0.01
0.001
OPERATION 8 MAINTENANCE COST:
SODoyt/Yr of Operation
60Doyt/Yr of Operation
30 Ooyt/rr o( Opwollon
15 0
-------
FIGURE H-20
HORIZONTAL-SHAFT ROTARY SCREEN
Service Life: 15 years
Relative Reliability; Level B
Design Basis:
1. Construction costs include housing for gallery and screen chambers.
2. Loading rate = 14 sq ft screen/ragd.
3. Screen submergence varies from 74% to 83%.
4. Screen opening (Microns): Pretreatment 150-420; complete
treatment 23-35.
5. Screen material is stainless steel.
6. Drum speed =0-7 rpm.
7. Labor costs include 48 hours/yr for routine checks and 3 hr/yr/screen
for maintenance. Also, for each overflow event: 1 hour setup/
shutdown time, 1 hour travel time, 3 hours/screen for cleanup time,
and 4 hours/day for operation.
Process Performance:
Typical Pollutant Removals, %
BOD5 40 - 60
SS 50 - 70
References: 36, 42, 51
H-54
-------
FIGURE H-20
HORIZONTAL-SHAFT ROTARY SCREEN
10
1.0
CO
o
o
O
in
c
o
O.I
0.01
1.0
CONSTRUCTION COST:
10 100
FLOW.mgd
1000
o
o
M
C
O
O
o
3
•a
c
0.001
OPERATION 8 MAINTENANCE COST
0.01
900ay>/Yr of Operation
60 Oat* ' Y' of Opirotlon
30 Oajt I Yr of Op«rotlon
19 Oan/Yr of Oporotlon
10 100
FLOW , mgd
1000
H-55
-------
FIGURE H-21
VERTICAL-SHAFT ROTARY SCREEN
Service Life: 15 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include housing for equipment.
2. Cost data are developed for multiple use of 3-mgd, 60 inch screens.
3. Screen openings range from 74 to 230 microns.
4. Screen material is stainless steel.
5. Drum speed is 30-65 rpm.
6. Labor costs include 48 hours/yr for routine checks and 6 hours/yr/
screen for maintenance. Also, for each overflow event: 1 hour/
screen shutdown time for plant cleanup and 4 hours/day for operation.
Process Performance:
Typical Pollutant Removals, %
BOD5 ( )
TSS ( )
References: 36, 42, 51
H-56
-------
FIGURE H-21 VERTICAL -
lOOl 1 1 ' 1 1 Mill 1 1 1
10
CO
a
"5
o
O
CO
c
0
i i.o
O.I
1
1.0
0
O.I
o
CO
c
.0
2
o
O
0.01
o
3
C
C
0.001
1
::CON
i
: •
1
- -j-f
i
SHAFT ROTARY SCREEN
STRUCTION CC
)ST~
; 1 1
1 • ! '
i
\\\ • i 1
>
— L-
'•
--i4- —
(
. •
I /
/
-------
FIGURE H-22
CHEMICAL COAGULATION
(FERRIC CHLORIDE AND POLYMER)
Service Life: 35 years
Relative Reliability: Level B
Design Basis:
1. Velocity gradient, G = 20 to 70 sec" for flocculation, G = 300 sec"
for rapid mix.
2. Detention time is 20 minutes for flocculation, 1 minute for rapid
mix.
3. Reinforced concrete basins.
4. Turbine type mixers.
5. For ferric chloride:
a. Pump costs based on two 25 gallon/hour hydraulic pumps to
four 50 gallon/rain pumps.
b. Storage tanks range from two 3,000 gallon fiberglass re-
inforced plastic (FRP) tanks to ten 50,000 gallon under-
ground concrete tanks with rubber linings.
c. Ferric chloride dosage = 100 mg/1.
For polymer:
a. Feed costs range from manual feed to four volumetric dry
feeders, four mixing tanks and two holding tanks.
b. Polymer dosage = 0.5 mg/1.
6. Operation and maintenance costs include 0.004 manhours/sq ft/storm
1 overflow event and 0.7 hp/mgd.
Reference: 36
H-58
-------
FIGURE H-221
lOOi 1— i —
10
o
"o
o
o
CO
c
o
S I.O
O.I
I
I.O
(A
"5
O.I
o
CO
c
.2
in
0
O
O.OI
o
•a
c
c
0.00 1
„****
.-•
-"
,,
^
!
^
CHEMICAL COAGULATION
(FERRIC CHLORIDE AND POLYMER)
-CON
x^
*
3TRUC
/
TION CC
. .1.
1ST"
1 1
1
t
•
. : ; ! i i
i
i >
1
; Jx
^X
^X
1
.0 10
FLOW
^-
X
X
-'
g
I
1
-r-f
.
L/
! .X
'
1
!
! ;
y
f
-1 ' '
^
_i. .
, ; ;;
\\\ |
!
I
100
mgd
OPERATION 8 MAINTENANCE COST
„
x-
*
x*"
x*
^
"^
^
t
^''
x'
x
rf *"
•*"
x
^X"
^s
' ^
X1
X
^
X
^
^x
x
^
^
S
X
i*"
X"
x^
X
;.
X
i
~i
-X
X
>
^ *
s
/
! ,/
x"
M / \/
— ^
/^
S
x
'^4 —
JX
s*
;
!
x
x
^
r^-
^
'
X
,
/
^^
^'
'
X
4
>
t
j-
IOOO
- »O Doyt/Yr of Opvatlon
~i 60 Day»/Yr of Optrorton
t 16 Doyt/Yr of Op«rotlon
i
i
0 10 IOO IOOO
FLOW , mgd
H-59
-------
FIGURE H-22
CHEMICAL COAGULATION
(FERRIC CHLORIDE AND POLYMER)
Service Life: 35 years
Relative Reliability; Level B
Design Basis:
1. Velocity gradient, G = 20 to 70 sec" for flocculation, G = 300 sec"
for rapid mix.
2. Detention time is 20 minutes for flocculation, 1 minute for rapid
mix.
3. Reinforced concrete basins.
4. Turbine type mixers.
5. For ferric chloride:
a. Pump costs based on two 25 gallon/hour hydraulic pumps to
four 50 gallon/min pumps.
b. Storage tanks range from two 3,000 gallon fiberglass re-
inforced plastic (FRP) tanks to ten 50,000 gallon under-
ground concrete tanks with rubber linings.
c. Ferric chloride dosage = 100 mg/1.
For polymer:
a. Feed costs range from manual feed to four volumetric dry
feeders, four mixing tanks and two holding tanks.
b. Polymer dosage = 0.5 mg/1.
6. Operation and maintenance costs include 0.004 manhours/sq ft/storm
overflow event and 0.7 hp/mgd.
Reference: 36
H-60
-------
FIGURE H-222 CHEMICAL COAGULATION (POLYMER)
lOOi • — ' ' — ' — 1 — . ' — . — i 1 .
10
in
o
&
o
at
c
0
5 1.0
O.I
1.0
w>
_o
f °-'
o
at
c
o
at
0
O
0.01
O
•3
C
C
0.001
]
j
tCON
M
3TRUCTI
i ; '
i
• ~T~t
\
j ;
I -
DN
|
1 . i
1
i ^
' — ' 1 '"*"]
j
X
• |
i :
• : . 1
'
/^
/
^
]
,
^
cc
ST -
--•-I— i-
, , 1 —
j
n
;
i
j •
i * ^
/
X
,
;
^
~*-4-
- i .
A
4-
_^_
1 . . J/r '-) — ' * j • —— — . — 1 — ' — >- • - 1
s
ir~
vT
-------
FIGURE H-23
STORMWATER SEDIMENTATION
Service Life: 40 years
Relative Reliability: Level B
Design Basis:
1. Cost is based on recommended design flow of 3,000 gpd/sq ft of
surface area.
2. Basins have side water depth of 12 feet and freeboard of 1.5 feet.
3. Costs apply to circular sludge collection equipment in circular
basins and large rectangular basins (20,000 sq ft). Costs do not
apply to straight-line sludge collection equipment.
4. Costs do not include sludge removal or disposal.
5. Construction cost includes steel troughs and weirs.
Process Performance:
Typical Pollutant Removals, %
BOD5 25 - 40
SS 25 - 50
References: 36, 51
H-62
-------
FIGUF
10
1.0
0)
"5
o
O
M
C
0
I 0.
0.01
1.0
w
_0
0
O.I
o
(0
c
s
i
o
0.01
o
3
c
c
0.001
1
*E H-23
1
|
! i
STORMWATER SEDIMENTATION
-CON
! '
*-
!
1
STRUCTION
'
CO
H~-
ST -M — t— i-l
-f- ^
; ;
—
—
i_4--L - -
1 ' ' /
j j/
i/
/ 1
/
i 1 i f! i i i
K
> !
L/ ;
L/! ' '
/\ . • ,
h .: y
: I
s
f
1
'
y
y
y/
. . • s\
\s\ ' ! - !
. ' !
'
! ' '
j .
1 ;
—
.-i_
^_^..,
! : ,
i
,
i
! • i !
I
: 1 ; i i :
.0 10 100
FLOW.mgd
OPERATION a MAINTENANCE COST
I
^
^
^
,^--
•^
^^
^«-
^x-
^
^^
^
•^
^
f
^
i"**"
*-
P7
^•-^
X^"
i
i
^
c — ~^
^
^
, ^
^
i ! • i ; i ; ! i i i /
X
^_
J
*~
X
X
•^i
^ ^
jf^r
x*' .
0 10
FLOW
: i
!
i
j
j
/i
.
,
S
y
X
X
7
^
X
'
,•
f
! ' y
'/
' i
f >
/ /
c ^
/f 'X^
'' J/1 /
"T j^T
(//| !
;
i i
i i
j ;
/|
!/
/I
/
K
X
*—j
/
J/
x^T
100
, mgd
'y H
-------
FIGURE H-24
DISSOLVED AIR FLOTATION
Service Life: 40 years
Relative Reliability: Level B
Design Basis:
1. Costs are based on an overflow rate of 4,440 gpd/sq ft of surface
area.
2. Construction cost includes the basic unit, flow splitting device,
and an enclosed piping and equipment gallery for drive equipment,
pumps, air tanks and miscellaneous equipment.
3. Largest practical size for an individual unit is 20 ft X 100 ft.
4. Power cost is based on 0.10 kw hr/sq ft.
5. No chemical costs are included.
6. Operations and maintenance costs include 48 hours/yr for routine
checks, 0.009 hours/sq ft for maintenance. Also, for each overflow
event: 1 hour travel time, 1 hour setup/shutdown time, 0.004
hours/sq ft for washdown, and 4 hours/day operation.
Process Performance: (With Chemicals)
Typical Pollutant Removals, %
BOD5 40 - 60
SS 50 - 70
References: 36, 37, 51
H-64
-------
o
Q
M
c
o
0
o
u
0
3
C
FIGURE H-24 DISSOLVED AIR FLOTATION
1.0
0.
.01
1.0
1.0
0.1
0.01
0.001
n i ' t- i i i t -i n T
CONSTRUCTION COST:
I
10 100
FLOW.mgd
1000
OPERATION 8 MAINTENANCE COST
9O Dqtt/Yr of Operation
60 Do»/Yr of Operation
SO Dayi/Yr at Operation
IS Dajt/Yr of Operation
10 100
FLOW , mgd
1000
H-65
-------
FIGURE H-25
SWIRL REGULATOR/CONCENTRATOR
Service Life: 50 years
Relative Reliability: Level B
Design Basis;
1. Construction costs include basic chamber. Costs do not include
buildings, pumping stations, flow measurement, or basin dewatering
facilities.
2. Chamber diameters range from 12 ft to 48 ft.
3. Labor costs include 52 hours/yr for routine inspections, plus
process cleanup after storm overflow events.
4. Process cleanup based on following schedule/storm event:
Plow Manhours/Storm
mgd
5 12
15 14.4
30 15.9
50 20.4
80 22.9
150 25.4
250 27.9
Process Performance: (Swirl Concentrator Followed By Stationary Screen)
Typical Pollutant Removals, %
BOD5 0-25
SS 0-25
References: 36, 37, 51
H-66
-------
8
FIGURE H-25 SWIRL REGULATOR/CONCENTRATOR
l.0
0.
o.oi
0.001
1.0
CONSTRUCTION COST:
10
100
FLOW.mgd
1000
10
c
o
8
O
0.0001
0.001
10 100
FLOW , mgd
900oyt/Yr of Optrotlon
60Doy>/Yr of Optrotlon
~^*' 300oyt/Yrof Optratlon
11 Doyt lit of Optrotlon
1000
H-67
-------
FIGURE H-26
HIGH-INTENSITY MIXING/CHLORINE CONTACT BASIN
Service Life: 50 years
Design Basis:
1. Costs are based., on 2-minute detention time and on velocity gradient
(G) of 300 sec .
2. Construction costs include concrete mixing basin and stainless steel
mixers.
3. Miscellaneous costs such as chlorine storage area, hoist, and
evaporator are not included.
4. Labor costs include 8 hours/yr/unit for routine maintenance. Also,
for each overflow event: 8 hours for cleaning and 1 hour/day
operation.
5. Power requirement is 1.25 hp/mgd.
References: 36, 37
H-68
-------
FIGURE H-26 HIGH -INTENSITY MIXING / CHLORINE CONTACT BASIN
o
o
1.0
O.I
0.01
0.001
CONSTRUCTION COST:
If
*
10
100
FLOW.mgd
1000
o
o
JO
i
o
o
O.I
0.01
0.001
0.0001
1.0
^OPERATION a MAINTENANCE COST-
10 100
FLOW , mgd
9OOoyi/Yr of Optrotion
60Day»/Yr of Opiratlon
SO Days / Yr of Op«rotlon
IS Dam/Yr of Op.rotlon
1000
H-69
-------
FIGURE H-27
HIGH-RATE FILTRATION (GRAVITY)
Service Life; 40 years
Relative Reliability; Level B
Design Basis;
1. Construction cost includes the filters, dual non-proprietary filter
media, and housing for filters and filter galleries.
2. Application rate is 16 gpm/sq ft.
3. Maximum headless is 12 feet.
4. Pumping costs other than backwash and surface wash are not included.
5. Labor costs include 48 hours/yr for routine checks and 12 hours/yr/
filter for maintenance. Also, for each overflow event: 1 hour
startup and shutdown, 1 hour/filter cleanup, and 4 hours/day for
operation.
6. No chemical costs are included.
Process Performance: (When Used in Combination With Chemical Addition,
Flocculation/Sedimentation)
Typical Pollutant Removals, %
BOD5 60 - 80
SS 80-95
References; 36, 37, 51
H-70
-------
FIGURE H-27 HIGH-RATE FILTRATION (GRAVITY)
o
a
o
2
100
10
O.I
CONSTRUCTION COST:
I
i I ! !
10 100
FLOW.mgd
1000
o
O
o
i
o
O
~o
3
C
0.01
0.001
10 100
FLOW , mgd
•O Dqri/Yr of OpMtlon
•0 Dop/Yr of Optrtftal
50 Oayt/Yr of OoorMlM
l» Dojl/Yt of Operation
1000
H-71
-------
H.8 Municipal Wastewater Treatment Processes
H.8.1 Support Personnel:
Cost Curves, Figure H-28
H.8.2 Miscellaneous Structures:
Cost Curves, Figure H-29
FIGURE H-28
SUPPORT PERSONNEL
Relative Reliability: Level B
Design Basis:
1. Costs include the manpower required to support the operation of a
wastewater treatment facility. These support functions include
supervision and administration, clerical work, laboratory work, and
administrative costs.
2. The labor costs are based on 1500 hour man-year. This includes a
five-day work week; an average of 29 days for holidays, vacations
and sick leave; and 6 1/2 hours of productive work per 8 hour day.
Reference: 45
H-72
-------
FIGURE H-28
SUPPORT PERSONNEL
O.I
o
o
to
c
o
01
o
o
"5
c
0.01
o
o
0.001
0.0001
O.I
1.0 10
FLOW , mgd
\.
X*
*
f^ t
J
X-
.at
X
k-^i
^—
f
s
<4
^
>
S
s
,
OPERATION 8 MAINTENANCE COST
X
X
jX'
/
X
S
f
t
, '
3^
'
,
1
i
x>
'
i
Si
^
/O'
XY
'. W
X
H4X
otol
I
>
\ l/TT-
Clerlco
7
.
/
/
I
\
ipc
X,
Lxl
ird
or
7^-
r visor
j
i_x x
'X1
1 1 ^
"*
•X
X
/
/
/
^
/•
^
*1'
X
/
>
V
. I
t
I11
Ac
U
x"
v
"t
mink
1
i ^^
1 ^
jr
trativ
:x^
" /
'X
E?
x
'
i i
,
* i
!"
/
'
^
X
X
,*!
^
/
N
1
,
f ^
0
o
_l_
o
£
O
i
•o
OB
CO
I
100
H-73
-------
FIGURE H-29
MISCELLANEOUS STRUCTURES
Service Life; 50 years
Relative Reliability: Level B
Design Basis;
Construction cost includes:
a. Administrative offices.
b. Laboratories.
c. Shop and garage facilities. 0
Note: Full cost of miscellaneous structures might not be applicable for
small-flow systems.
Reference: 3
H-74
-------
FIGURE H-29 MISCELLANEOUS STRUCTURES
IU
1.0
C
2
&
O
IA
C
_o
i o.i
0.01
0
1.0
«
^
_o
'o
01
o
1 1
* 3
i £
o — •
o
0.01
o
•3
C.
C
0.001
0
^
ft* '
•X-1
^
^X '
-CON
|
|
;
^~
t*r
!
STRUCTION C(
1
1
X
/*!
;
I 1
L-U
1ST"
]
S
Y/
^ :
i
™
i _
1
j ;
.
«
1 1.0 10
FLOW.mgd
^—
1
— -
—
T<
. .
**
OPERATION 8 MAINTENANCE COST
)ta
^^
.--
„
^
=~;
^ -
i
!r^~ —
Mater
-*j —
i
-—
^~
C"
lal
^^^
•y^
; ,
^:
JS^
.
i
i
j
i
,
f^^
r''^
^*
^*?
^~
i
!
X
\
/
X
| f
y
» /
•-*£.*
^ y
ibor
_ „
100
rnO.I
^
'r
^0.01
1
1
-(- "°
._
-1 «
1—
O
*"*"
-L 0.001
1
.0.0001
1.0 10 100
FLOW , mgd
H-75
-------
H.8.3 Wastewater Treatment Processes
Cost Curves:
Figures H-30 through H-62
Raw Wastewater Characteristics;
BOD,. 210 mg/1
COD 400 mg/1
TSS 230 mg/1
NH,-N 20 mg/1
TKN 30 mg/1
NO^-N 0 mg/1
UOD 406 mg/1
Total-P 11 mg/1
. Alkalinity (as CaCO-) 300 mg/1
pH ^7.3
FIGURE H-30
LOW-LIFT PUMP STATION
Service Life: 15 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include:
a. Fully-enclosed wet well/dry well structure.
b. Pumping equipment capable of meeting peak pumping requirements
of 2 Q with largest unit out of service.
c. Standby pumping facilities.
d. Piping and valves within structure.
e. Bar screens - mechanically cleaned.
2. Package pumping stations are used in a flow range of 50 to 1,200 gpm
(0.072 to 1.73 mgd).
3. Curves developed for TDK = 10 feet.
Adjustment Factor;
To adjust operating power costs for TDH's other than 10 feet, enter
curves at effective flow, Qg
% = %ESIGN x
References: 3, 7, 9
H-76
-------
FIGURE H-30 LOW-LIFT PUMP STATION
o
o
c
0
o
o
1.0
O.I
0.01
0
44 1
"CON
Pockogt Stations'*-
_^
^
^^~
^
--
X
''
.1
X
3T
t
1 1
RUC
,.
S
i— I
Tl
^r
\ — 1
Dh
s
— U4
cc
^ '
1.0
44
ST
- -;X
^
X
X
^
^•'
/
10 10
1.0
01
0.01
0.001
O.I
FLOW, mgd
^
^"
^SJ»
^
OPERATION 8
/
>= ^ =
M
X
/
'
H • "~
ateriats
.s
.'-+
/
s_
/ '
x
/
^
Power
MAINTENANCE
x
/
<^f
L
•^
.c
"
boi
'
/
*••
-^
/
* ^
COST
X
/
•x
^
/
f
/Total
^
/
^
#*
^
^
^
•
-'•'
/
/'
O.I
0.01
-------
FIGURE H-31
PRELIMINARY TREATMENT
Service Life: 30 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include:
a. Flow channels and superstructures.
b. Bar screens (mechanical).
c. Grinders for screenings.
d. Gravity grit chamber with mechanical grit-handling equipment.
e. Parshall flume and flow-recording equipment.
2. Operation and maintenance costs do not include cost for grit
disposal.
3. Screenings 1-3 cu ft/mg.
4. Grit 2-5 cu ft/mg.
5. If low-lift pumping is used prior to preliminary treatment, the cost
for bar screens can be subtracted from the unit cost of preliminary
treatment, because they are included in the low-lift pumping station.
Process Performance;
Suspended material greater than 5/8 inch and grit coarser than 65 mesh
(0.208 mm) will be removed. However, removal of BOD and TSS by pre-
treatment is assumed negligible.
H-78
-------
FIGURE H-31
PRELIMINARY TREATMENT
o
o
0.001
pztfcftrti:-:
t^jXf+Uni
W/0 Bar Scrt»n«-i—j
0.01 7
FLOW.mgd
Annual Cost, Millions Of Dollars
(Total -Labor -Materials)
o
g p •-
0.001
— -•
«=
"
g^
OPERATION
— «=
,.-"
^
p.- e ""
= • -
^— -•
~* •
,-^-
:-^±
"T
a
— '
,
^
MAINTENANCE
'\^,
^ \"
\,
•** L?
Mater
x-
^
*
X1
ia
T<
x
*
S
itat
x '
^^
<^—
^
' ' v^l
Power
•^
COST
^,
s
.at
hr-
_/
^"x1
^
lor
^
^
^
x*
^
/
/'
, 'J
,
/
/'
O.I
1.0 10
FLOW , mgd
O.I
0.01
0.001
0.0001
100
H-79
-------
FIGURE H-32
FLOW EQUALIZATION
Service Life: 40 years
Relative Reliability: Level B
Design Basis:
1. Costs were derived for detention times of 0.5, 1.0, and 2.0 days
based on offline storage at average flow conditions.
2. Mixing requirements = 20 to 40 hp/mg of storage volume.
3. Construction costs include basin and mechanical mixing equipment
(pumping not included).
4. Construction costs are based on concrete basins for design flows
less than 1 mgd and 6-inch concrete-lined earthen basins for
design flows greater than 1 mgd.
References: 4, 5, 7
H-80
-------
o
o
at
c
o
o
o
10
c
o
o
o
a
3
c
c
FIGURE H-321 FLOW EQUALIZATION
(DETENTION TIME • 0.5 DAYS)
o
I
w
O
J3
O
10
I.O
O.I
O.OI
CONSTRUCTION COST:
H—(-
O.I
1.0
10
100
FLOW.mgd
1.0 I r— i 1 ,— , ,
O.I
0.01
O.OOI
0
1
j
OPERATION 8 MAINTENANCE
i
I
'
J
i
1
•^
/
\s
— •
'
•^
^
Y
/
^t*
—f
^x
4
V
i
i
.
£_
, :
i .
•
\
'. ,
| }
1 :
:
COST
j y'
r
1 s ' ! yf i
w
i
. ; '/*\*r i
i Power'
y
i ! JT
, S \ ',
l t
1
^
-*
^
r^
: / i Total .
A^
i 1 -X'
i Jf •
hJXf
x Labor
— •
l i •
•r! '
*—
"n
!
^
— i—
,
i/(
'
L
1
H-^
1 -T^
*
i
i
^.
^/
^
' ''
+~
1
^
'
,
! V
; .<
'
f
' ^X Materials'
^—
j.x' '
, ^
1 I.O
"
•-4
_.-
1
i
™f~—
10
!
1
, t
f
/
nOI
'
- r\ c\\
'
T
(: O.OOI
*-
O.OOOI
100
a>
I
FLOW , mgd
H-81
-------
o
o
to
c
o
in
^
O
o
O
10
c
o
o
"5
FIGURE H-322 FLOW EQUALIZATION
(DETENTION TIME = 1.0 DAYS)
10
1.0
O.I
0.01
I . 1 I M-TI 4 4-
ICONSTRUCTION COST;
O.I
1.0
o 0.01
o
K
0.001
Ml ^
1.0
10
100
FLOW, mgd
^
' f
^f
/
t
x"
/
/"
^
X
/
OPERATION 8
/
<•
^
_x
,x
,
^
'
t
y ^
/
"^*"
* ^
'
^ ^"^
/
x*
MAINTENANCE
^
>
r
S
—
Sr
^
J_
T
^
^
X
S
^
To
— 5
2
^^
s
/
'
t>^
' Labor ^
^
COST
/
^~
-/-
X
-*
^
^
s
7p
^^
^
^
/
QW
^
j
/
sr
^
.
^
/"
^
>
'
/
y •
2 . .
Materials
O.I
1.0 10
FLOW , mgd
100
H-82
-------
M
^
o
o
a
FIGURE H-323 FLOW EQUALIZATION
(DETENTION TIME » 2.0 DAYS)
10
1.0
O.I
0.01
O.I
CONSTRUCTION COST:
1.0
10
FLOW.mgd
100
1.0
to
w
O
O
O
a
c
O
M
O
o
c
c
o
a.
o
t-
O.I
0.01
0.001
O.I
s
s
^
/
_/
p»
/
s~
^
OPERATION
^
£>
'
^
^'
?
7
"^ ,
*•
X
/
^^
f * J*
f ^
a
/
f
MAINTENANCE
/
/
X
>
v^
f
>
T(
-p
f
L
^
^
>t
^
a
""
^
2
^
'ov,
XJT
'
/
'/"I
. ,
er
,
^W
COST
/
/
',
at
/
' /
^Ss
' •
aria
1 —
f
/
r j
J
'
^
* £.
/
/
1.0 10
FLOW , mgd
100
H-83
-------
FIGURE H-33
PRIMARY CLARIFIER WITH SLUDGE PUMPS
Service Life: 50 years
Relative Reliability: Level B
Design Basis:
1. Clarifier designed for surface overflow rate of 800 gpd/sq ft
(based on average Q).
2. Costs include primary sludge pumps. Sludge concentration of *
solids. Pump head assumed as 10 ft TDH.
3. Process performance:
Wastewater Characteristics
In Out
BODq, mg/1 210 130
COD, mg/1 400 265
TSS, mg/1 230 100
Total-P, mg/1 11 9
Adjustment Factor:
To adjust costs for alternative surface overflow rate, enter flow at
effective flow (Q )
I-*
= 0 _ 800 gpd/sq ft
^DESIGN New Design Surface Overflow Rate
References : 9, 24
H-84
-------
FIGURE H-33 PRIMARY CLARIFIER WITH SLUDGE PUMPS
M
k.
O
o
O
10
1.0
O.I
0.01
O.I
'CONSTRUCTION COST:
1.0
10
FLOW, mgd
100
Annual Cost, Millions Of Dollars
(Total -Labor -Material)
o
b o
o b o ^
,X"
--
»— ••
*^
^^
/
^
**•
X
OPERATION S
S
x"
^
,
^
^
^
<
,
^ 7
.'
s
--.
^
, '
/
tS^
f
^
41
x'
s
MAINTENANCE
^x
J
s
T
>
X^«
_X"
X
^
S'
3t
X1
^
X1
3l
X
^
/
x*
•
/
Powe
/
,'
COST
X
r
_/"]
X
X
S
S
s
/
' \ \ •/
' \- r
•:^
Ma
teri
X-
^
j
r
/
al
S
/
/
2
.'
?
.
/
'
/
^
i
; O.OOI
(
—
0
0.
• u.uoui
. 0.00001
O.I
1.0 10
FLOW , mgd
100
H-85
-------
FIGURE H-34
CONVENTIONAL ACTIVATED SLUDGE AERATION WITH DIFFUSED AIR
Service Life: 40 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include costs for basins, air supply equipment
and piping, and blower building. Clarifier and recycle pumps are
not included. Clarifier costs are found in Figure H-42.
2. Diffused aeration.
3. 1.2 Ibs 0 supplied per pound of BOD,, removed.
4. MLVSS = 2,000 mg/1.
5. F/M = 0.5.
6. Detention time = 6 hours.
7. Process performance:
Wastewater Characteristics
In_ Out*
BOD , mg/1 130 20
COD, mg/1 265 45
TSS, mg/1 100 20
Total-P, mg/1 9 7
NH -N, mg/1 20 17
TKN, mg/1 30 18
*Following clarification
References: 3, 7
H-86
-------
FIGURE H-34
CONVENTIONAL ACTIVATED SLUDGE
AERATION WITH DIFFUSED AIR
1.0
o
Q
O.I
0.01
CONSTRUCTION
X
O.I
1.0
10
100
FLOW.mgd
M
w
O
O
O
O
o
1.0
0
1 O.I
o
X
0.
o
.a
o
_l
2 0.01
,2
0.001
^x
'
^x
•^
X*
.X
X
x*
X"
/
OPERATION S
.
^
/
x
X*
,,
,
/
„'
•^
/
X
- ^ —
y
y' ,
x"
x
7*"
V
X
MAINTENANCE
^
/
r"
^
Power
«' i y
y
^X^*"
X*!
^ |
.
r
/
X
1
Te
"
!•
' /
lat
»tal/
±LS
/
./
erial
COST
^
^
/
X
/
•7^
^"
^
/*
^
x'
Li
^ '
7
> i
/
/
^
,.
^
abor '
O.I
1.0 10
FLOW , mgd
100
H-87
-------
FIGURE H-35
ACTIVATED SLUDGE AERATION WITH PURE OXYGEN
Service Life: 30 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include: dissolution equipment, oxygen
generators and liquid oxygen feed/storage facilities instrumentation
(where applicable), and licensing fees.
2. Oxygen was assumed to be delivered as liquid oxygen for plants from
0.1 to 1 mgd size. For plants from 1.0 to 100 mgd, oxygen was
assumed to be generated on-site.
3. 1.2 Ibs 02 supplied per pound of BOD5 removed.
4. MLVSS = 4,000 mg/1.
5. Detention time = 5 hours.
6. Process performance:
Wastewater Characteristics
In_ Out*
BOD,., mg/1 130 20
COD, mg/1 265 40
TSS, mg/1 100 25
Total-P, mg/1 9 7
NH -N, mg/1 20 17
TKN, mg/1 30 18
*Following clarification
References: 39, 40, 41
H-88
-------
o
Q
O
O
in
c
o
o
O
c
<
FIGURE H-35 ACTIVATED SLUDGE AERATION
WITH PURE OXYGEN
10
1.0
O.I
O.OI
O.I
0.01
;CONSTRUCTION COST:
1.0
10
FLOW.mgd
0.001
FLOW , mgd
100
H-89
-------
FIGURE H-36
HIGH-RATE TRICKLING FILTER
Service Life: 50 years
Relative Reliability; Level B
Design Basis:
1. Construction costs include: circular filter units with rotating
distributor arms, synthetic media (6 feet-deep), and underdrains.
Clarifiers and recycle equipment not included. (See Figure H-43.)
2. Organic loading rate: High Rate = 45 Ib BOD /day/1,000 cu ft.
O
3. Hydraulic loading rate: High Rate = 30.2 mgad (693 gpd/sq ft)
@ 3:1 recycle rate.
4. Electrical power not required (included in clarifier cost).
5. Process performance:
Wastewater Characteristics
BOD,., mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH--N, mg/1
TKN, mg/1
In
130
265
100
9
20
30
Out*
45
90
60
8
17
18
*Following clarification
References: 3, 5, 6, 7, 30
H-90
-------
o
a
M
C
O
in
w
o
o
o
I
i
*•
o
"o
C
C
FIGURE H-36 HIGH-RATE TRICKLING FILTER
10
1.0
O.I
0.01
XtCONSTRUCTION COST;
-h-
TTT
\ I
rr
O.I
1.0
10
100
FLOW.mgd
O.I
0.01
0.001
0.0001
s
^
t.s
s
— •
^
, ^
OPERATION 8
'
^
^
f •
S
U-
s
^ ^
£ ^
Tc
/ *^^
tal
.xH
-?*
MAINTENANCE
r^
L
Mater
1
^
.a
at
X
X
r^-
x
x'
r
"'
. ^
_, ^
COST
^
^~
^.
-------
FIGURE H-37
LOW-RATE TRICKLING FILTER
Service Life: 50 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include: circular filter units with rotating
distributor arms, rock media (6 feet-deep), and underdrains.
Clarifiers not included. (See Figure H-43.)
2. Organic loading rate: Low Rate = 15 Ib BOD /day/1,000 cu ft.
3. Hydraulic loading rate: Low Rate = 2.4 mgad (55 gpd/sq ft).
4. Electrical power not required (included in clarifier cost).
5. No pump station included.
6. Process performance:
Wastewater Characteristics
BOD , mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH -N, mg/1
NO,-N, mg/1
•J
In Out*
130 30
265 60
100 60
9 8
20 2
30 18
*Following clarification at temperature above
15°C.
References: 3, 5, 6, 7, 30
H-92
-------
to
k
o
o
o
FIGURE H-37 LOW-RATE TRICKLING FILTER
IU
1.0
o
"5
o
O
01
c
o
2 O.I
0.01
/
/
x
/
.'
-U f
"CON
s
jx
3T
/
RUC
X
_X
. 1
Tl
|
1 i— ]
DN
/
^
1 — U4-]
CO
^J
^
U
ST
/
/
/
/
^
/-
i
O.I
O.I
0.01
0.001
0.0001
1.0
10
FLOW.mgd
O.I
1.0
10
FLOW , mgd
too
•**"
^
^
"
^
^
^
,^^
••^
^
OPERATION 5
ft*
_^
^"
^*
^>
**
**•
-
•
^
|
|
,^
,+ *"
.<
!
i
1
|
|
^,
*^
X^
X
MAINTENANCE
^
f
x
•
\fS
^
Pol
j*
a
, Y
x
•f
,-
1
^
:'^
'''MO
i — i — i
COST
s
^
*'"
.abor
J*
/r
terial
j
P
'^
x
x'
x*
|±::
,;
^''
^ '
X
|
100
H-93
-------
FIGURE H-38
AERATED LAGOONS
Service Life: 30 years
Relative Reliability: Level B
Design Basis:
1. Average detention time = 7 days.
2. 15-ft water depth.
3. Horsepower required: 30 to 40 hp/mg.
4. Floating mechanical aerators.
5. Construction cost includes:
a. Excavation, embankment, and seeding of lagoon/slopes (3 cells),
b. Service road and fencing.
c. Riprap embankment protection.
d. Hydraulic control works.
e. Aeration equipment and electrical equipment.
6. Process performance:
Wastewater Characteristics
BOD,-, mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH3-N, mg/1
Is.
210
400
230
11
20
Out
25
50
40
8
18
Adjustment Factor:
To adjust construction cost for detention time other than above, enter
curve at effective flow (Q )
QE = QnpcTQM x New Design Detention Time
7 Days
References: 27, 43
H-94
-------
o
o
at
c
o
o
O
I
FIGURE H-38 AERATED LAGOONS
10
1.0
o.i
0.01
O.I
1.0
O.I
~ 0.01
OOOI
•CONSTRUCTION
1.0
10
100
FLOW.mgd
O.I
^^
_ — •
-^
'
^^
,
^
^
- ^
/
OPERATION
—
, —
S*
/
^
i^
<•
£ -
/
^^
^
T
,
>''~
-^
^^*
4?
^x
^ * "
I — 1
a
3tC
X*
-71
^-«
^
MAINTENANCE
**
/
^
'
>^*<
^
^
-?
j
f
^
,p
"^
-^
x
^
0
=
/
'
ier
r*
• T&-
f
COST
^
V
Labor^.
^P&
• Ma
ter
ials
Z
'
j
^'
^^
• ULI
•
' '
- 0.01
' '
• 0.001
. 0.0001
•>
o
o
1.0
10
100
FLOW , mgd
H-95
-------
FIGURE H-39
ROTATING BIOLOGICAL CONTACTORS
Service Life: 30 years
Relative Reliability: Level B
Design Basis:
1. Construction cost includes:
a. RBC shafts; standard media, 100,000 sq ft/shaft.
b. Motor drives - 5 hp/shaft.
c. Molded fiberglass covers.
d. Reinforced concrete basins.
2. Cost does not include final clarifiers. (See Figure H-42.)
3. Loading rate:
a. 1.0 gpd/sq ft, w/o nitrification.
b. 0.5 gpd/sq ft, w/nitrification.
4. Process performance:
Wastewater Characteristics
In Out
w/o Nitrification w/Nitrification
BOD,., mg/1 130 20 15
COD, mg/1 265 45 35
TSS, mg/1 100 25 25
Total-P, mg/1 97 8
NH -N, mg/1 20 17 2
Reference: 48
H-96
-------
FIGURE H-391 ROTATING BIOLOGICAL CONTACTOR (W/NITRIFICATION)
o
Q
in
c
O
uu
in
1.0
O.I
0
X"1
/
/
y
/"
i
! ' -
i i/
' !
i !
:CON
1
;
3TRUCTION C<
i < :
i
1 1
1 i
—U-L,
_/
t /
j
y
/
/
J •
i
1/0.5 gpd/ ft*
if
|
' |
1
! j
1
"T
1
3ST~
I |
]
1
' •
4t-
—
-
_L
-4-1-
j
1
j
1
4-
1 1.0 10 10
FLOW.mgd
1.0
o
o
o
i
o
o
O.I
o
£1
O
o
O.
"a
.o
C 0.01
0.001
O.I
M^=
•^
/
s
_^
•
/
^^
^
S
OPERATION
y>
s
/
s
S
L^. ~ t
£
* £_
S* *
.s
s
A
/ ^
— *^-
*
a
/
/
^
—y
MAINTENANCE COST
/
/
s
/
/I
/
/
S
^^
f
s
•*
!
; ,
u '
/
—.
•
f
r
/ •
m- 7
S
**
\ \
\ j
, Tot
7
• Row
. 1 nh
4Ma
ji .
•er
or
er
nls
i
t
\
I
—*--
_j_
I
'
i
i
1
1
1
O.I
0.01
o
0.001
0.0001
1.0 10
FLOW , mgd
100
H-97
-------
FIGURE H-39
ROTATING BIOLOGICAL CONTACTORS
Service Life: 30 years
Relative Reliability: Level B
Design Basis:
1. Construction cost incudes:
a. RBC shafts; standard media, 100,000 sq ft/shaft.
b. Motor drives - 5 hp/shaft.
c. Molded fiberglass covers.
d. Reinforced concrete basins.
2. Cost does not include final clarifiers. (See Figure H-42.)
3. Loading rate:
a. 1.0 gpd/sq ft, w/o nitrification.
b. 0.5 gpd/sq ft, w/nitrification.
4. Process performance:
Wastewater Characteristics
In Out
w/o Nitrification w/Nitrification
BOD,, mg/1 130 20 15
COD, mg/1 265 45 35
TSS, mg/1 100 25 25
Total-P, mg/1 9 7 8
NH -N, mg/1 20 17 2
Reference: 48
H-98
-------
FIGURE H-39Z ROTATING BIOLOGICAL CONTACTOR (W/0 NITRIFICATION)
IUU
10
0)
^
5
1
0
i»
g
3
2 1.0
O.I
((-
,
'
'
^
^
'
/ '
CON
"jT~
/
3T
,
^UC
Tl
^
/
1 — i — 1
DN
i
X1
^
/I.Oopd
,
CO
^
x
ST
/
/ff2
i i
i
O.I
1.0
10
100
FLOW.mgd
1.0
o
0
o
o
|
_.. O.I
I
a>
I
"a
~ 0.01
0.001
O.I
1.0 10
FLOW , mgd
1
^
J
— '
-=
s*
/
' • —
^^
/
f
OPERATION a
.— •"
L^
/
*•-
'
^ p
y
-'
,*
^/
• '
-^
. <
^«.
ff
/
;
.^
MAINTENANCE
/
,x
/
^
\
t
s
f
^
(
/
X
X-
/
/
x
e?
/
• ?
-4 »
U-
-------
FIGURE H-40
FACULTATIVE LAGOONS
Service Life: 50 years
Relative Reliability: Level B
Design Basis:
1. Warm climate - lagoon loading of 40 Ib BOD-/acre/day.
2. Cool climate (Northern U.S.) - lagoon loading of 20 Ib BOD5/
acre/day.
3. Water Depth = 4 ft.
4. Construction costs include:
a. Excavating, grading, and other earthwork required for normal
subgrade preparation.
b. Service roads.
c. Costs do not include land and pumping.
5. Process performance:
Wastewater Characteristics
BOD,., mg/L
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH3-N, mg/1
In_
210
400
230
11
20
Out
30
100
60
8
15
1
15 (cool climate)
1 (warm climate)
Adjustment Factor:
To adjust costs for loadings other than those above, enter curve at
effective flow (Q_)
Warm Climates:
40 Ib BOD /acre/day
Cool Climates:
„
Qp ~
E
References ; 3, 5, 28
Design Loading
20 Ib BOD- /acre/day
_ 5
. _ _ . _ -. -. • ' i
New Design Loading
H-100
-------
o
O
CO
c
o
FIGURE H-401 FACULATIVE LAGOON (Warm Climates)
I.O
O.I
0.01
O.I
O.I
•CONSTRUCTION
I.O
IO
FLOW.mgd
I.O
IO
FLOW , mgd
100
I.U
m
w
0
O
0.1
O
to
c
5
Z
«
o
O
O.OI
o
3
C
C
0.001
/
/
/
OPERATION
^
rf
^
7
^
3 '
1
a
X
1 1 — 1- M M M
MAINTENANCE
S
'
s
'
,
-X
COST
/*
_
jX'
^-
^
(
IOO
H-101
-------
FIGURE H-40
FACULTATIVE LAGOONS
Service Life: 50 years
Relative Reliability: Level B
Design Basis:
1. Warm climate - lagoon loading of 40 Ib BOD /acre/day.
2. Cool climate (Northern U.S.) - lagoon loading of 20 Ib BOD5/
acre/day.
3. Water Depth = 4 ft.
4. Construction costs include:
a. Excavating, grading, and other earthwork required for normal
subgrade preparation.
b. Service roads.
c. Costs do not include land and pumping.
5. Process performance:
Wastewater Characteristics
BOD mg/1
COD, mg/1
TSS, mg/1
Total -P, mg/1
NH3-N, mg/1
In
210
400
230
11
20
Out
30
100
60
8
15
1
(cool climate)
(warm climate)
Adjustment Factor:
To adjust costs for loadings other than those above, enter curve at
effective flow (Qp)
es:
40 Ib BOD /acre/day
Warm Climates:
=
Design Loading
Cool Climates:
20 Ib BOD /acre/day
^E " ^DESIGN X r: - K — r-=-t - -r: -
New Design Loading
References : 3, 5, 28
H-102
-------
FIGURE H-402 FACULATIVE LAGOON (Cool Climates)
IUU
10
CO
0
£
o
M
C
o
2 10
O.I
0
1.0
in
0
0
O.I
O
to
c
0
o
0 01
o
3
C
C
0.001
0
/
^
1
^
^
X
v
^
/
S
X"
s
>
- - J
£ H
U 1
CON
3T
X
*uc
1 1
Tl
i
Jx
X!
1
ON
/
cc
X
1.0
FLOW, mgd
OPERATION 8
'
X*
„.
''
X
x
-u
ST
jr
*
X
x
IO
MAINTENANCE
X
X]
i
*
s
^
1.0
FLOW , mgd
•-7-
^ ^
COST
X
'
^
x
/
'
x ^
10
100
100
H-103
-------
FIGURE H-41
HIGH-RATE ACTIVATED SLUDGE AERATION (COMPLETE MIX)
Service Life: 40 years
Relative Reliability: Level B
Design Basis:
1. Construction cost includes cost for basins, air supply equipment
and piping, and a blower building. Clarifier and recycle pumps
are not included. (See Figure H-42.)
2. Basins sized with 50 percent recycle flow.
3. Detention time = 3 hours.
4. F/M = 1.5.
5. 0.7 Ibs 02 applied per pound BOD_ removed.
6. MLVSS = 2,000 mg/1.
7. Process Performance:
Wastewater Characteristics
IB. Out
BOD-, mg/1 130 40
COD, mg/1 265 80
TSS, mg/1 100 35
Total-P, mg/1 9 8
NH3-N, mg/1 20 19
References: 3, 7
H-104
-------
FIGURE H-41 HIGH-RATE ACTIVATED SLUDGE-AERATION -COMPLETE MIX
(Two-Hour Detention Time)
IV
1.0
(A
w
O
"5
Q
O
m
c
o
I O.I
0.01
**""
L^^
-•»•
4J 1
-CON
1 1
ST
^
\ 1 1
*UCTI
S
{S
i — i — i
DN
/
s
L-
C
s
LL
:o
/
^
U-:
s"H
s1
s
/
/
J
/
y
/
O.I
1.0
10
100
FLOW.mgd
o
o
_o
i
o
o
O.I
0.01
0.001
^
'
^,
J,
X
^
^
"^
-"
OPERATION 8
^
S
4*>
—
-
t*
y
*•
i
>
•**
(
ab
/
f '
_ r
/
'.'•^
/
/
MAINTENANCE
Total
s
' •
^
^ *
'
**
i
'
^
x
^
^
*
^jx
..V
r
'
> '
ft
COST
/
lot
1
v'
r
/
^/
srla
/
x'
,
Is
^
-
^
X
^
**
i
(
^/
^
'
* rf '
j T
f
\
O.I
1.0 10
FLOW , mgd
100
H-105
-------
FIGURE H-42
FINAL CLARIFIER (FLOCCULATOR TYPE)
Service Life: 40 years
Relative Reliability: Level B
Design Basis;
1. Flocculator-type clarifier.
2. Overflow rate of 600 gpd/sq ft used for development of costs.
3. Costs include sludge return and waste pumps. Sludge concen-
tration of 1 percent solids. Pump TDH at 10 ft. Spare pumps
included as necessary. Pump capacity 350 gpm/mgd of plant
capacity. Nonclog centrifugal pumps.
4. Rectangular units when surface area is less than 500 sq ft.
Circular units when surface area is greater than 500 sq ft.
5. Maximum clarifier diameter = 200 ft.
6. Clarifier performance: See performance characteristics predicted
for processes that precede clarifiers.
Adjustment Factor:
To adjust capital cost for alternative overflow rates, enter the
curve at effective flow (QE)
Q = QnFqTrN x 600 gpd/sq ft
t ufcsibiN New Design overflow Rate
References: 6, 7, 9, 24
H-106
-------
o
"o
<0
c
O
o
O
FIGURE H-42 FINAL CLARIFIER (FLOCCULATOR TYPE)
\\J
1.0
CO
W
a
"5
a
o
(A
C
_o
I O.I
OOI
/
f
s
/
t.
/'
-CON
X
*
ST
x
we
/s
Tl
^
DN
y
n
cc
J '
4-1 1
1ST-
, ^__
X
X
^
x
f
/
_J_
I
h.
o
I
^
.O
O.I
O.I
0.01
0.001
1.0
10
100
FLOW, mgd
O.I
-*^
r-?
^
?*•
TJ?
^
^
^
fol^
•^
OPERATION
^
/
X
^
^
4 X
t!
57
u1
^
>
' Ma<
jf
^
• •
a
^
«ri
.t
r
MAINTENANCE
i
J'
'/
, /
' . J
alsxd
™,f
/ '
,
/
/
/
/
,/
j»
/
^?
f
/
j/
' X
' X
^ r
^»_
X
/v
'
COST
/
y
-/
/
/
' /
/
v
XV
Lab
1
Pi
/
/
/
f
r /
/
Ul
9W
/
/
/
ei
/
/
Hjjj
> < • i
/
, '
/ , '
/
0.1
0.01
O.OOI
0.0001
1.0
10
100
FLOW , mgd
H-107
-------
FIGURE H-43
CLARIFIER FOR HIGH-RATE TRICKLING FILTER
(INCLUDES RECYCLE PUMPS)
Service Life: 40 years
Relative Reliability: Level B
Design Basis;
1. Construction costs include: sludge pumps, effluent recycle
pumps, clarifier mechanisms and internal piping.
2. Overflow rate = 800 gpd/sq ft at average design flow.
3. Recycle pumping capacity = 3 times average wastewater flow.
4. Curve is to be used in conjunction with high-rate trickling
filter only.
5. Rectangular units when surface area is less than 500 sq. ft.
Circular units when surface area flow is greater than 500 sq ft.
6. Maximum clarifier diameter = 200 ft.
7. Clarifier performance: see predicted performance of high-rate
trickling filter.
Adjustment Factor:
To adjust construction cost for alternative loading rates, enter
curve at effective flow (Q )
= QDESIGN x 800 gpd/sq ft
New Design overflow Rate
References: 3, 6
H-108
-------
FIGURE H-43 CLARIFIER FOR HIGH RATE TRICKLING FILTER
(INCLUDES RECYCLE PUMPS)
o
o
o
o
o
o
c
<
IU
1.0
O.I
0.01
0
•^ —
, —
^
**
s*
44 1
-CON
X
i
|
STRUCTION CC
S
\s
/
,
'
1
+ --
-•
V
XT
I
1
RT-
X
X
/
|
X
!
/
s
1
/
1 1.0 10 10
1.0
O.I
0.01
0.001
FLOW.mgd
O.I
1.0
10
— ""
f^
**
, —
^
^
^*~
tJtl
M
— 1 — 1 HIM 1 — 1 1 — 1 — 1 1 1 1 1 1 \ 1 .
OPERATION 8 MAINTENANCE COST
ite
^
/
•ic
'
X*
Is
s
J
?
^
^
lf
I s
•r
V"
f
/
f '
"
1
X
/
/
/
!
!
j
1
>
•XI
X
>
x>
Power
X^ X
S-
,
',
JH
r
x
^
A-
^
/
h'
/i
i
-^
\
\
/
' X
Tjto!!
f
J
S
t
/
/
Sj
1/X
yf
/I ^
' X
/
/,
X
/
Labor
\ i
/
/
/
/
/
/
f
/
1
/
/
/
2
7
(
'/'
£
f\
100
FLOW , mgd
H-109
-------
FIGURE H-44
ACTIVATED SLUDGE/NITRIFICATION (SINGLE STAGE)
Service Life: 40 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include aeration tanks and aeration devices, but
not necessarily clarifiers and sludge pumps. (See Figure H-42.)
2. The activated sludge system is assumed to be a plug flow. The
nitrification takes place in the latter portions of the basin.
3. The detention time is assumed to be 10 hours.
4. The aeration and mixing are accomplished by diffused air.
5. Oxygen requirements: 1.5 Ibs 02/lb BODc removed plus 4.6 Ibs 09/lb
NH3 oxidized.
6. MLVSS = 1,500 mg/1.
7. SRT = 15 days.
8. Process performance:
Wastewater Characteristics
BOD-, mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH--N, mg/1
NOj-N, mg/1
In_
140
265
100
9
20
0
Out*
10
35
20
8
2
18
*Following clarification.
References: 3, 7, 9
H-110
-------
FIGURE H-44 ACTIVATED SLUDGE / NITRIFICATION
(SINGLE STAGE)
1.0
•>
w
0
^
Q
o
§
i o.i
0.01
^^
X
4
|X
/
t
-UI 1
-CON
/
'
ST
X
i 1
*uc
V
s
1— 1
Tl
x1^
1
1 1
3N
LJ
/
1 — M-
cc
/
)ST-
X
^
/
/
1
i
/
/
/
/
'
[2
O.I
O.I
10
FLOW.mgd
1.0
10
100
IU
0
o
1.0
*•-
O
08
C
.2 —
= 0
s i2
M
O
O
O.I
0
3
C
C
0.01
/
X
x^
/^
/
^
X
X
X
OPERATION 8
-»
/
S
ft
/
40
^
'
>w
t^
""
^
^
81
/
iri
••
^'
.
^
LX
8—
jT
„ ""X
,
; y
/
*
x
X"
MAINTENANCE COST
/
^
^
/
X
k-J°
L/
•
^
i
>
J
/
^
^
^
|
'
I
y
s
3b
L^H
s
' /
s
j
t
to>
-^
_^ ?
/'
• u.i
'
x*
tfl
-0.01 .2
^
O>
-i- 5
h_
+ §
4. Q-
1
i 0.001 3
I ^
-.0.0001
100
FLOW , mgd
H-lll
-------
FIGURE H-45
SEPARATE NITRIFICATION (WITH CLARIFIER)
Service Life: 40 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include nitrification tanks, aeration devices,
clarifiers, and sludge recycle and waste pumps, but not pH ad-
justment facilities.
2. System to follow high-rate activated sludge system.
3. Detention time = 3 hours.
4. CL requirements: 1.5 Ibs CL/lb BOD. removed plus 4.6 Ibs 0 /lb
NH3-N oxidized. * 2
5. Sludge return pumps sized for 100 percent recycle. Operated at
50 percent recycle.
6. Final clarifier overflow rate = 600 gpd/sq ft.
7. Process performance:
Wastewater Characteristics
BOD,., mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
NH -N, mg/1
NO^-N, mg/1
In
40
80
35
9
19
0
Out*
10
35
20
8
1
18
*Following clarification.
References: 2,7
H-112
-------
o
a
a>
^
o
o
o
at
c
o
o
O
15
a
c
FIGURE H-45 SEPARATE NITRIFICATION (WITH CLARIFIER)
I
"o
10
1.0
O.I
0.01
O.I
I.O
0.
0.01
0.001
•CONSTRUCTION COST:
1.0
10
FLOW.mgd
O.I
1.0
10
FLOW , mgd
100
/
/
.
/
/
/
/
OPERATION 8
/
/
/
/
\ - -
1
— '
z
/
/
jrtaK
-
X1
y/
„ '
^»
-/'
•^
MAINTENANCE
^jf
/"
Ma
,f
/
er
/
>
^
/•
al
^
^
-
5
^
^
ibc
/
/
* •
/
s
• s*
* ^
*^^*
r, X
COST
^
s
—^
/
/
»er
X
^x
s
/
— i
^
X?
^
»
/
^
— 2
f
/
/
^/
^
t
,'
-•
O.I
0.01
w
I
0.001
0.0001
100
H-113
-------
FIGURE H-46
SEPARATE DENITRIFICATION (WITH CLARIFIER)
Service Life: 40 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include denitrification tanks (uncovered), mixers,
methanol feed, clarifiers, sludge recycle and waste pumps, but do
not include reaeration facility. (See Figure H-61.)
2. Two hours detention time in denitrification tank.
3. MLVSS = 2,000 mg/1.
4. Denitrification recycle pumps sized for 100 percent recycle,
operated at 50 percent recycle.
5. Final clarifier overflow rate = 600 gpd/sq ft.
6. 3 Ibs methanol per Ib of nitrate nitrogen removed.
7. Methanol storage - 30 days supply with a minimum tank size of
500 gallons.
8. Process performance;
Wastewater Characteristics
In_ Out
BOD , mg/1 10 10
COD, mg/1 35 45
TSS, mg/1 20 20
Total-P, mg/1 8 8
NH -N, mg/1 1 1
\Tf\v VT «« /I
NO^-N, mg/1 19 1
References: 2, 19
H-114
-------
FIGURE H-46 SEPARATE OENITRIFICATION (WITH CLARIFIER)
o
o
5 I
— a>
100
10
1.0
O.I
O.I
10
1.0
O.I
0.01
CONSTRUCTION COST:
1.0
10
100
FLOW.mgd
J^*
^^~
/•
_^
/
s
\
_^^
/
/
OPERATION a
lot
/
^
er
f
/
-
a
.
^
/
_ab
s-
ff
/
^*
or
^x
• '•- /
s
s
/
— •
y
V
y^
/
MAINTENANCE
^
^
^
/
^
^
Total/
^" x'
/
A
^
^
x
w
_,
* .
?
7
J-
| ?
• ^
X*
x
7
^
. **
POM
' ~7~
, ^
/
'/
emlc<
COST
^
/
er
f
/
Is
•*"
_/
^
k^
— ^
S j
f/
S
,
fy
H
^
^
H
/
7
'
'
/,
'/
,
,
••
0.01
£
3
i
o.ooi S
O.I
1.0
10
0.0001
100
FUOW , mgd
H-115
-------
FIGURE H-47
BREAKPOINT CHLORINATION
Service Life: 15 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include:
a. Chlorine storage and feed system.
b. Lime storage and feed system (1 hp/800 gal mixing).
c. Chlorine contact tank (30 minutes detention) .
d. Costs do not include a dechlorination facility, but this
should generally be included whenever breakpoint chlorination
is used. (See Figure H-59.)
2. Chemical costs based on 10 Ibs Cl /lb NH -N in feed (1,500 Ibs/mg)
and 9 Ibs CaO/lb C12 (1,350 Ibs/mg). *
3. Process performance:
Wastewater Characteristics
In_ Out
NH3-N, mg/1 18 2
References : 4, 5, 7, 19
H-116
-------
FIGURE H-47 BREAKPOINT CHLORIN ATION
10
IX)
O.I
OOI
•CONSTRUCTION COST:
O.I
1.0
10
100
FLOW.mgd
o
a
o
o
o
o
-------
FIGURE H-48
AMMONIA STRIPPING
Service Life: 30 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include:
a. Ammonia stripping tower - 20' high packed with 1/2 inch diameter
schedule 80 PVC pipe at 3 inch centers horizontally with
alternate layers placed at right angles at 2 inch centers
vertically.
b. Pumps - 50 ft TDH.
c. Lime feed facilities to raise pH to 11-11.5 and sulfuric acid
facilities to subsequently neutralize the treated effluent.
2. Hydraulic loading: 1.0 gpm/sq ft.
3. Air/water ratio: 400 cu ft/gal.
4. Process performance:
Wastewater Characteristics
In_ Out
NH3, mg/1 18 3
References: 5, 11, 19, 26
H-118
-------
s
o
2
FIGURE H-48 AMMONIA STRIPPING
1.0
O.I
QOI
O.I
CONSTRUCTION COST:
1.0
10
FLOW.mgd
X
100
in
o
~o
.
. 0
O _|
o ^
o
3
C
QOI
O.
0.
o
0.
i
•n
o
v
o
0.001
1.0 10
FLOW , mgd
H-119
-------
FIGURE H-49
ION EXCHANGE (FOR AM40NIA REMOVAL)
Service Life: 30 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include:
a. Gravity feed clinoptilolite beds with loading rate of
5.25 gpm/sq ft at 4 ft depth.
b. Blackwash regeneration facilities at 8 gpm/sq ft.
c. Influent pumping at 15 ft TDH.
d. Sodium chloride regeneration facilities using 2 percent NaCl
solution, 40 bed volumes/regeneration, and 1 regeneration/
24 hours.
e. Closed-loop air stripping tower for regenerant recovery.
f. Clarification - softening facility for spent regenerant.
2. Chemical costs include: makeup clinoptilolite and makeup
regenerant.
3. Ammonia sulfate produced by this system may be sold to defer
0 § M costs; however, it was not included in this cost estimate.
4. Process performance:
Wastewater Characteristics
In Out
NH3-N, mg/1 18 1
References: 19, 49
H-120
-------
FIGURE H-49 ION EXCHANGE (FOR AMMONIA REMOVAL)
IUU
10
M
w
O
O
CA
C
O
S 1.0
O.I
**
^
s
'
,
.
'*
CON
,
j
S
3T
s
f
*UCTI
^
^^
)N
/
(
^
4-
:o
x
ST-
/
f
^/
1
S
S
]
: !
^-
/
/
/
O.I
1.0 10
FLOW.mgd
100
M
a
o
0 1.0
o -e
0
2 o
5 -1
s °
^- .5
CO
0
o
0 1
o
3
c
<
O.OI
p?
«- .
>
^^^
.
.
^J
.^
OPERATION 8
-j/1
jS
J,
f
s
y
— 2'
•^
/
x
c
"i /
^q
i\«S
MAINTENANCE
<^J-
••vC^yr
r^x :
^>
^
/!y
^r . :
\°
^A""
/
-•-"
,/
^ ,
1
|
/
/
4
^
,
1
/
/
/
• *. -
z —
,'
•'
/
-^
/;
^
.t
/
/5s
/
COST
/
£/
/
^
>
y-
yl
r
f
/
q
ot
xf
/•
V
f
,
~
' — '
M
^
^
^
y(
'
^
^
/
/
/
-• I.VI
1
J
/
(/}
-O.I o
e
S.
^ o
0>
£
w>
: !Z
±001 ®
o
-^- 5
*"^
.. O.OOI
O.I
1.0
10
100
FLOW , mgd
H-121
-------
FIGURE H-50
PHOSTRIP
Service Life: 40 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include:
a. Stripper (10 hours detention at 50 percent of return sludge)
b. Flash mixer.
c. Flocculator - clarifier.
d. Thickeners.
e. Lime feed and storage facilities.
2. Lime cost based on 225 Ibs/mg.
3. Process applies only to activated sludge.
4. Process performance:
Wastewater Characteristics
In_ Out
Total-P, mg/1 9 2
Reference: 20
H-122
-------
FIGURE H-50 PHOSTRIP
"o
o
O
o
g
O
O
°
0
i
1
100
10
in
O.I
0
i^^rf
=
p— —
.. •*•
.v
*-\
1
CON
\- —
ST
-^ •
^UC
Tl
^^***
^^~
DN
|
C
:o
i
ST-
^
H
-
|-
—
^
!
*•
x
^
O 10 1C
FLOW, mgd
;:O.OI
O
i
0.001
0.0001
FLOW , mgd
H-123
-------
FIGURE H-51
POLYMER FEED SYSTEM
Service Life: 20 years
Relative Reliability: Level B
Design Basis:
1. System includes chemical storage, chemical feeding, rapid mix;
flocculation and settling are included in a separate curve. The
system is not for sludge conditioning.
2. Polymer dosage at 1 mg/1 (8.34 Ibs/mg).
3. Construction costs include:
a. Use of dry polymer.
b. Feedstock solution - 0.25 percent.
c. Piping and building to house the feeding equipment and to
store bags are included.
d. Systems for 1 mgd plant size and smaller, use manual pro-
cedures. Two systems of tanks and feeders are included.
e. For the 10 mgd plant size, the cost includes two feeders and
mixing tanks, one day tank, and two solution feeders.
f. For the 100 mgd plant size, the cost includes four feeders
and mixing tanks, two holding tanks, and ten solution
feeders.
g. The rapid-mix tank is concrete, and is equipped with stain-
less steel mixer and handrails.
h. For the 0.1 mgd plant size, no separate building is required.
Cost includes manual operation with feeder, mix tank, solu-
tion feeder, and holding tank.
References: 6, 9, 18, 25
H-124
-------
a
o
O
5
|
i
FIGURE H-51 POLYMER FEED SYSTEM
1.0
O.I
0.01
0.001
O.I
'CONSTRUCTION COST:
1.0
10
FLOW.mgd
100
1.0
o
o
o
o
jo
o
o
'
o
I
O
.O
O.I
0.01
0.001
O.I
, — '
L<
^
ibor
-^-—
/
OPERATION 8
U
*f
r.--
/
/„,
.-^C
/
^
>•'
MAINTENANCE
TotolJ
.he
^
*'
• —
^
/
mi cols
X
•v
^
T'
•.
•*•
i-,
7-
7
"^
^
/
t~
j
>
' x
.
>
Powe
1IX
•H XI
Mate
COST
/
J
1.
s
rial
/
'/
r-f
f
K,
S
/
/
^_
/
•^
L/
.
/ ^'
(
/
r
rnOI
^
'
,
U.UI — .
:: co
o
w
O
1
w
_L *
1
- 0.001
. . 0.0001
1.0 10
FLOW , mgd
100
H-125
-------
FIGURE H-52
MINERAL ADDITION
Service Life: 20 years
Relative Reliability: Level B
Design Basis:
1. Alum dosage of 200 mg/1 and ferric chloride dosage of 100 mg/1.
Phosphorus removal - for other dosages see adjustments below.
2. The rapid-mix tank is constructed of concrete, and multiple
basins are used for volumes greater than 1,500 cubic feet.
3. Costs include:
a. Liquid chemicals (8.3 percent Al.O and 35 percent FeClj) .
b. Chemical feed equipment sized for twice the average feed
rate .
c. Storage of at least 15 days.
d. Price of building is included except for plants with a
capacity of less than 1 mgd.
e. Rapid-mix tank includes stainless steel mixer.
Adjustment Factor:
To adjust costs enter curve at effective flow (Q )
' "E ' %ESIGN x
3 ' «E ' DESIGN *
H-126
-------
c
o
FIGURE H-521 MINERAL ADDITION (ALUM)
10
I.O
O.I
OOI
1
=a
^^-
— —
--
„ - •
-CON
. . •*""
ST
^
*uc
Tl
I
^
s~
•^
DN
^
*^
CC
2
ST
/
/
/
/
/
2
2
V
O.I
1.0
10
100
FLOW.mgd
1.0
«
w
O
o
O
O.I
_
1
.o
0.01
O.OOI
O.I
y
/
.— •
^
.
—— •—
^
J
/
^— •
OPERATION
abor
- h
^
S
^
To
^
X1
tal <
/
/
«• *
,
. »
X
Ij-Ch
^
„ ,
^
• fPov
a
*&
/t
/
)m
^k
^^
/
rer
MAINTENANCE
— >
• ^
/
/
^L
*.r
cols
1
teri
y
/
^
als
4
/
t—
/
'/
t
A 4
V'
s
r
./
^;
»
»
/
/'
COST
/
y
/
f A
SS.
V
/
/
/ f
/
— ^
-^
'/
>
f.
/
t—
»
/
'
/
/
nOI
0.01
0.001
, 0.0001
1.0 10
FLOW , mgd
I
£
i
I
o
100
H-127
-------
FIGURE H-52
MINERAL ADDITION
Service Life: 20 years
Relative Reliability: Level B
Design Basis:
1. Alum dosage of 200 mg/1 and ferric chloride dosage of 100 mg/1,
Phosphorus removal - for other dosages see adjustments below.
2. The rapid-mix tank is constructed of concrete, and multiple
basins are used for volumes greater than 1,500 cubic feet.
3. Costs include:
a. Liquid chemicals (8.3 percent Al?0_ and 35 percent Fed,).
b. Chemical feed equipment sized for twice the average feed
rate.
c. Storage of at least 15 days.
d. Price of building is included except for plants with a
capacity of less than 1 mgd.
e. Rapid-mix tank includes stainless steel mixer.
Adjustment Factor:
To adjust costs enter curve at effective flow (QE)
Alum: Q = Q x Alum Dose
200 mg/1
FeCl3 = QE = QDESIGN x FeCl3 Dose
100 mg/1
H-128
-------
o
O
o
3
C
<
FIGURE H-522 MINERAL ADDITION (FERRIC CHLORIDE)
0)
.c
o
I
w
O
J3
O
a
,o
10
1.0
O.I
0.01
O.I
CONSTRUCTION
1.0
10
100
FLOW.mgd
1.0
O.I
o.6>
0.001
•&**
i —
/
t
„— •
,
- •*
E?
OPERATION
X
^
_^r*
X
7
.^
^?
'
• *
^--
a
..TotoL
^
X-
/
" n ^*. *i
•flote
^Xl
^
/
h
ric
MAINTENANCE
s
/ ,
s
V
/
;hemic
Z^—
h • >•
is^
^^H
'OK
fer
f
ol
?
-^
1
->
^
/ .
/
•/
,'/
'
COST
s
y
s
/
y
L/
I
/r
/
^
-^
f
t y
^
/
TlO.I
t
'•001
O.OOI
0.0001
£
o
I
1.0
10
100
FLOW , mgd
H-129
-------
FIGURE H-53
TWO-STAGE TERTIARY LIME TREATMENT
(WITHOUT RECALCINATION)
Service Life: 40 years
Relative Reliability: Level B
Design Basis;
1. Typical secondary effluent as feed to two-stage lime treatment.
2. Lime dosage rate = 400 mg/1 or 3,340 Ib/mg as CaO.
3. Clarifier overflow rate = 1,000 gpd/sq ft.
4. Construction cost includes: lime storage and feed facilities,
rapid-mix facilities, flocculator/clarifiers, flow and pH controls,
and recarbonization facilities.
5. Costs do not include recalcination facilities (see Figure H-54).
6. Process performance:
Wastewater Characteristics
In_ Out
BODr, mg/1 20 8
COD, mg/1 45 18
TSS, mg/1 20 20
Total-P, mg/1 8 0.5 (with filtration)
1.5 (without filtration)
Adjustment Factor;
To adjust costs, enter curves at effective flow (Q )
1000
Construction Cost: Qc = Q
DESIGN New Design Overflow Rate
Chemical Costs (OHQ: Q£ . Q x New
References: 4, 5, 7, 8, 11, 18, 26, 31
H-130
-------
o
«
e
=
FIGURE H-53 TWO STAGE TERTIARY LIME TREATMENT
(WITHOUT RECALCI NATION)
100
10
1.0
O.I
O.I
CONSTRUCTION COST:
1.0
10
100
FLOW.mgd
O
Q
M
C
o
o
O
o>
.c
O
I
5
o
IS
O.I
10
1.0
01
001
x
^-
—
T<
X
*-
X
)tOl
s
OPERATION 8
^
X
/*
1
^
s
^ *
2 ^
Row
-L
X"
,1 '
jS*
t'"1/
'••*•
• "f^
^x"
^^
-4
&
MAINTENANCE
Ma
.X"
er
^~
V
v
' ^
S
^^
al
^
^
^
8
^
,4
/
/
/
a ^
X
- • -^>
s4>
'//
( ^
. _^«
, ^
COST
X
'S
x
//
^
/
,
f
Chemica
^
L
.
,
-^
s
x
ib
^ '
s
s
'/'
,'
V
rnO.I
i
,
- 0.01
::OjOOI
..0.0001
1.0 10
FLOW , mgd
a>
•^
o
I
a.
100
H-131
-------
FIGURE H-54
LIME RECALCINATION
Service Life: 30 years
Relative Reliability: Level B
Design Basis;
1. Quantity of lime sludge: 4,500 Ib/mg; 30 percent solids (from
two-stage tertiary lime treatment).
Operations:
Flow Wet Solids
Ibs/hr
(24 hrs/day)
Days/Week Hours/Day Furnace Hearth
Operating Operat ing Loading Area
Ib/hr sq ft
0.1
1.0
10.0
100.0
62.5
625
6,250
62,500
1
6
7
7
20
16
20
20
525
1,095
7,500
75,000
112
256
2 at 760
3 at 5,070
3. Fuel requirements (No. 2 fuel oil): 129,000 gal/yr/mgd.
4. Construction costs included: recalcination furnace, sludge conveyors,
storage, hoppers, building.
Adjustment Factor:
When lime recalcination is used, reduce the chemical cost of two-stage
tertiary lime treatment (Figure H-53) by 70 percent.
References: 4, 7, 8, 11, 18
H-132
-------
FIGURE H-54 LIME RECALCINATION
o
o
o
o
M
c
o
o
o
wu
10
IO
O.I
0
--•
f •
1
t-l 1
CON
^
1 — 1
ST
^
F?UC
^
Tl
X^
Dr
X
cc
X
1.0
>ST-
^
^
^
^
^
s
10 10
10
1.0
O.I
0.01
FLOW, mgd
^-
x"'
•****
-
S*
— •
/
OPERATION 8
j j
"*/
^
-7
/
^
fff
+—
^
-. s
*'
^
Te
/
Fuel
X
s
}a
f
s
MAINTENANCE
.^
S
s
!/
A/
A
^
^
X
,/
,x
/
/
s
/
/
x
-p-
/
/
>
x
u «•
Lab
-i
/,
s /
' 7
,x
./
X"
1 — 1 1
COST
or
!/<•
.r
/
Me
X
P
>
^_
<±,
'/
ter
owe
/
^
CIS
/
r
>
y
^*
—
/
^
j>
^
/
/
^ j *
X?
, .
* ' f •
1.0
O.I
0.01
£
e
I
w
O
A
O
O.OOI
O.I
1.0
10
100
FLOW , mgd
H-133
-------
FIGURE H-55
MICROSCREENING
Service Life: 20 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include: tanks, drums, screens, backwash
equipment, drive motors, and building. Instrumentation for
automatic operation is included.
2. Hydraulic loading =2.5 gpm/sq ft at average flow.
3. Screen mesh: 25 microns.
4. Peripheral drum speed: 15 fpm at 3-in. head loss.
5. Backwash 3 percent of throughput at 25 psi.
6. Process performance:
Wastewater Characteristics
In_ Out
TSS, mg/1 20 12
Adjustment Factor:
To determine costs for hydraulic loadings different than that
above, enter curve at effective flow (Q)
0 = 0 x 2.5 gpm/sq ft
^E ^DESIGN New Design Hydraulic Loading
References; 5, 8, 11, 24, 26
H-134
-------
c
o
o
o
o
o
FIGURE H-55 MICROSCREENING
10
O.I
0.01
O.I
o
.a
o
CONSTRUCTION COST:
10
10
FLOW.mgd
FLOW , mgd
100
IX)
O.I
0.01
0.001
0
f4.
'
/
Y
M
/"
^
f
/
iter
s
_/" J
/ ,
^
OPERATION a
oh
s
fS
/
>
^
i
,
i* ^
«
>
',fy
•
<(
''L
^
MAINTENANCE
^
_/^
'/
T^
y
abor
^R
^
Wfl
,
w
r
<;
•^
'
7
.0
ate
/
^
^k—
•^
COST
/
r
xl
X
^^
''
X
'
V
A
{
^
^
/
10
TlOl
0.01
0001
0.0001
100
o
i
H-135
-------
FIGURE H-56
GRAVITY FILTRATION (DUAL-MEDIA)
Service Life: 30 years
Relative Reliability; Level B
Design Basis;
1. Feed rate = 4 gpm/sq ft at average flow.
2. Backwash rate = 15 gpm/sq ft with air scour.
3. Backwash holding tank = capacity of 2 backwash cycles.
4. Construction costs include facilities for backwash storage, all
feed and backwash pumps, piping, and building.
5. Process performance:
Wastewater Characteristics
BOD5, mg/1
COD, mg/1
TSS, mg/1
Total-P, mg/1
In
20
40
20
2
Out
15
30
5
1
Adjustment Factor:
To adjust for loading rates other than above, enter curve at
effective flow (Q ) .
_ 4 gpm/sq ft _
^DESIGN x New Design Filtration Rate
References : 4, 7, 24
H-136
-------
o
a
FIGURE H-56 GRAVITY FILTRATION (DUAL-MEDIA)
ID
O.I
0.01
O.I
1.0
Q>
O
5
I
o
J3
O
0.01
0.001
O.I
CONSTRUCTION COST:
10
10
100
FLOW.mgd
.s
r
s
*~
/
/
•y*
_x
^
'
f
s~
^
OPERATION 8
/
^
/^
{
^
Toto
x;
. '1
2 ,
•~p
,.'
^
t ' -
/
/
1—3
MAINTENANCE
^
x^
s/
^
•^L
jf
^
'
S
ab
-?
s
,
>r
^
.
.(
^
^
X
^
' *•
; i^
X
COST
Po
/^
/
f
'
wer
1^0
/
/i
^
^
tei
>^
^
*
X
ia
x
— 2
7"
^
^'
i
2 " "
• U.I
'
,
jlO.01
0.001
. 0.0001
I
1.0
10
100
FLOW , mgd
H-137
-------
FIGURE H-57
ACTIVATED CARBON ADSORPTION
Service Life: 35 years
Relative Reliability: Level B
Design Basis;
1. Contact time = 30 minutes (empty bed basin).
2. Regeneration furnace loading = 80 Ib/sq ft/day.
3. Construction costs include:
a. For flows above breakpoint:
1. Carbon columns (minimum of 3).
2. Virgin § spent carbon storage tanks.
3. Feed and backwash pumps and all necessary piping.
4. Operations building.
5. Regeneration furnace (Multiple Hearth Furnace).
6. Slurry tank and steam generator.
b. For flow below breakpoint:
1. Items a.l-a.4 - no regeneration.
4. Carbon Dosage
H-571 - Tertiary Effluent: for flow less than 3.0 mgd = 30 Ib/mg
(without regeneration); for flow greater than 3.0 mgd =
3 Ib/mg (10 percent make up) (with regeneration)
2
H-57 - Physical/Chemical: for flow less than 1.5 mgd = 1,650 Ib/mg
(without regeneration); for flow greater than 1.5 mgd =
165 Ib/mg (10 percent make up) (with regeneration).
5. Regeneration heat requirement: 7,000 Btu/lb of carbon regeneration.
6. Effluent from activated sludge, two-stage lime treatment, and gravity
dual-media filters as feed to carbon adsorbers.
7. Process performance:
Wastewater Characteristics
In Out
BOD,., mg/1
COD, mg/1
TSS, mg/1
15
30
5
3
10
5
References: 4, 5, 6, 7, 29
H-138
-------
o
O
S
o
FIGURE H-571 ACTIVATED CARBON ADSORPTION
CTERTIARY EFFLUENT)
10
1.0
O.I
X
O.I
10.0
1.0
o
J3
O
a
.o
O.I
0.01
O.I
CONSTRUCTION COST:
IO
10
100
FLOW.mgd
JX
^
X
^
^
**
/
J
s
*^
OPERATION a
f
4
*
^,
/
*
/
/
^ »
'
S
*
; 'Tot<
x*
" .
x
x
/
i
^*~
/
r I
MAINTENANCE
:hei
/*•
f
>/
X
^y*
/
C— ^
Iner
lie
— ^
lot
A
/
/
gy
ii
er
^
/,
X
,.
V
a
«4
^
^
Ib
^
^.'
ff
/
>
x
s
/ 1
./
^
COST
~«.
/
/
^
s
'
/
^
/
^
X
/
X
^
-u
^
^
•^
ab
X
fl
b
,x
jr
/
^
1'
al
x'
«/
nl.O
,
y/Fuel
O.I
0.01
0.001
o
i
tn
5
1
o
i
1.0
10
100
FLOW , mgd
H-139
-------
FIGURE H-57
ACTIVATED CARBON ADSORPTION
Service Life; 35 years
Relative Reliability: Level B
Design Basis:
1. Contact time = 30 minutes (empty bed basin).
2. Regeneration furnace loading = 80 Ib/sq ft/day.
3. Construction costs include:
a. For flows above breakpoint:
1. Carbon columns (minimum of 3).
2. Virgin 5 spent carbon storage tanks.
3. Feed and backwash pumps and all necessary piping.
4. Operations building.
5. Regeneration furnace (Multiple Hearth Furnace).
6. Slurry tank and steam generator.
b. For flow below breakpoint:
1. Items a.l-a.4 - no regeneration.
4. Carbon Dosage
H-57 - Tertiary Effluent: for flow less than 3.0 mgd = 30 Ib/mg
(without regeneration); for flow greater than 3.0 mgd =
3 Ib/mg (10 percent make up) (with regeneration)
2
H-57 - Physical/Chemical: for flow less than 1.5 mgd = 1,650 Ib/mg
(without regeneration); for flow greater than 1.5 mgd =
165 Ib/mg (10 percent make up) (with regeneration).
5. Regeneration heat requirement: 7,000 Btu/lb of carbon regeneration.
6. Effluent from activated sludge, two-stage lime treatment, and gravity
dual-media filters as feed to carbon adsorbers.
7. Process performance:
Wastewater Characteristics
BOD mg/1
COD, mg/1
TSS, mg/1
In
15
30
5
Out
3
10
5
References: 4, 5, 6, 7, 29
H-140
-------
o
Q
o
Q
o
o
FIGURE H-57 ACTIVATED CARBON ADSORPTION
C PHYSICAL/CHEMICAL")
10
1.0
O.I
0
s
/
/
,
x
\
-U 1
tCON
I X"1^
*
ST
>X-
RUC
Tl
X
DN
X
cc
Y"
1.0
ST-
^
^s
^
,X^
1
^X
,
^
10
,'
1C
10.0
o
.0
1.0
O.I
0.01
FLOW.mgd
s
s
t
/
/
^
(
f
f
s
s
:her
/
X
/
s
,
• **
OPERATION
nic
^
'
^
,
al
^
^
.X"1^
•^
/
ro al
iV"
/
^ _
,•
,
^
A
* ' T/
,' /
p
/
j , , IUln
x ^
^~
A
r*-E
a
/
X,
ter
^
y
r
ne
MAINTENANCE
/
'/
^
/
X" i
ols /
^ <,r
/^
gy
^
X
^
^
/
'
^
^ •
1 /
/
/
X
Xx
J ?Tn»n
COST
X
I
lOIOi^
f
/]
' La
^,
bo
X*
I
Fn
//
//
'
•jf
•-*-.
er<
/
f
,
he
9*
'/
/
'
ni
/•
/
:i
.
— • i
" ' <
/
i
t
it:
,
*'
1.0
O.I
0.01 S
0.001
O.I
1.0
10
100
FLOW , mgd
H-141
-------
FIGURE H-S8
CHLORINATION (DISINFECTION)
Service Life: 15 years
Relative Reliability; Level B
Design Basis:
1. Construction costs include:
a. Chlorination building.
b. Chlorine storage and handling facilities including hoists,
etc.
c. Chlorinators.
d. Plug flow contact chamber.
2. Average chlorine dosage, 10 mg/1.
3. Chlorination contact time, 30 min for average flow.
4. Chlorine residual, 1 mg/1.
Adjustment Factor:
To adjust costs, enter curves at effective flow (QE)
m^m-i^i r~o«. rnp»yn. n - n v- New Chlorine Dosage
Chemical Cost (0§M): Q£ - QDESIGN x IQ mg/1
References: 3, 7, 9
H-142
-------
FIGURE H-58 CHLORINATIOM (DISINFECTION)
«
§
« -~
o
Q
U
I
o
J3
O
_l
I
"5
IU
10
O.I
0.01
0
^
^
^
^
\
-14 1
-CON
^X^
' J
ST
X*
i— |
*uc
--^^
1— 1
Tl
DIS
x
X
cc
.
10
)ST~
X
x
X
^x
'"'
?
X
10
• 1
10
FLOW.mgd
1.0
O.I
0.01
0.001
-.
•*"
X^y
,^
•^
^
.^
^^
x1
OPERATION
•^
f
M
^
/>
iter
, '
,/
i^f
x "*
Olfl^*
,<:J
' Tol
X
f
f
,. — '
a
.^
»•
X
ol
•^
>
MAINTENANCE
[S
^
X
,-*
••
X
7
/
Chemic
7T
x
—
x*
*
m -
J^>
• ^
/
as t
s
• • —
1 — 1
COST
s
1 x
f
X
^
X
*
X
:R(
^
/
"I
X
^
x*
.a
werJ
_
%
^
x*
K
^
«
/
/
/•
' •
s
r
\
r
Tl01
(
.
- 001
- 0001
. 0.0001
O.I
1.0
10
100
FLOW , mgd
H-143
-------
FIGURE H-59
DECHLORINATION USING SULFUR DIOXIDE
Service Life; 15 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include SO™ feed facilities, reaction tank
(1 minute detention), mixer, and storage facilities; building space
not included.
2. S02 costs based on 20 Ib/mg (1 mg/1 SO required per mg/1 chlorine
residual.
Adjustment Factor;
To adjust costs, enter curve at effective flow (Q£)
Chemical Costs (OftM): QE = QDESJGN x New S02 Dosage
1 mg/1 S02
References: 1, 5
H-144
-------
FIGURE H-59 DECHLORINATION USING SULFUR DIOXIDE
I.U
O.I
o
o
0.
o i
I ?
= o
5 3
„_• i
S 5
0 £
t: o.oi
c
c
0.001
0
^
--
^
j^
CON
STRUCTION CO
.-•"'
•^
1
^.t
.
\
ST^
^s
if
f
—
-
— ^
**
i
'
1 1.0 10
FLOW.mgd
|
OPERATION 8 MAINTENANCE
!
/
-^
. —
^_
^/
^
_/
^
^
pX-
^
^
•?
,
i'
i i
1
• ;
.,*'
'
[_
1
|
f
|
j
j
i i
COST
; 1 •
: !
I
i Chemicals
i
K
ji/
11
1 ij^X-
*S\-
i
^
^
•i4^"
„ ,
'/
X
-^
.
'
^
u-
i v
pr
i
1 /
X
•
^ \
— i
• • \
[^
A
^
' \
S ,
' /
: )r\
-XT ' 1 ^
:-*pKTi ^ ^ • ^!^*
^^ ^R
_^j \s
^r ^
^
-i--r
or
i , ,
Vr-
^
—
^Material
: ' l
Power ;UIP-
•^4— ••[-•• ^
\
1.0 10
FLOW , mgd
,
i
f
!
_j.
j.
100
rnOI
(
_y
1
_
I .0
2
i
^ «
«
^ e
t; 0.001 o
F
=;
1 OOOOI
100
H-145
-------
FIGURE H-60
OZONATION (AIR- AND DEGENERATED)
Service Life; 30 years
Relative Reliability; Level B
Design Basis;
1. Construction costs include:
Air Systems:
a. Air blowers.
b. Air filters.
c. Air coolers.
d. Air dryers.
e. Ozonator.
f. Ozone injector.
g. Ozone-water contact chamber.
h. Aeration chamber.
Oxygen Systems:
a. Oxygen storage.
b. Ozonator.
c. Ozone injector.
d. Ozone-water contact chamber.
e. Aeration chamber.
2. Oxygen requirements = 3 Ib 0 /lb 0 .
& O
3. Ozone dosage = 8 mg/1.
Adjustment Factor:
To adjust costs, enter curve at effective flow (Q_)
„, . , _ fn^i\ n r, New Ozone Dosage
Chemical Costs (OSM): QE - QDESIGN x 5-5575 *-
References: 1, 7
H-146
-------
o
Q
tn
c
o
o
o
*>
c
o
S
o
o
I
10
I.O
O.I
O.OI
O.I
FIGURE H-601 OZONATION (AIR)
'CONSTRUCTION COST:
1.0
10
FLOW, mgd
FLOW , mgd
100
I.O
O.I
O.OI
0.001
0
s
. —
X
^
s
'
7
OPERATION 8
S
/»,
S
i/"1
^
/
f
Hj
^
/
^
/•
'
^
1
Tota
r^n
t-i-7
f
. '
xi
^
X
^
i^*'
MAINTENANCE
/
s
^ •
t^
^
/
^F
^
*f
p>
^
/I
"0
^
; '
tn
N.
.0
~~7^
. 'x^
^ ^-
r
X
COST
X
x
^
!
^J
^>**"
Lab<
/M
^v
^ — •
)r !
f
/
ate
^~
/
ri<
/
'
il
i
i~
i
. '
/ /
/
, '
\
"\
~ - •*•
10 1C
O.I
O.OI
o
•g
QOOI
0.0001
H-147
-------
FIGURE H-60
OZONATION (AIR- AND (^-GENERATED)
Service Life: 30 years
Relative Reliability; Level B
Design Basis:
1. Construction costs include:
Air Systems:
a. Air blowers.
b. Air filters.
c. Air coolers.
d. Air dryers.
e. Ozonator.
f. Ozone injector.
g. Ozone-water contact chamber.
h. Aeration chamber.
Oxygen Systems:
a. Oxygen storage.
b. Ozonator.
c. Ozone injector.
d. Ozone-water contact chamber.
e. Aeration chamber.
2. Oxygen requirements = 3 Ib 0?/lb Q_.
3. Ozone dosage = 8 mg/1.
Adjustment Factor:
To adjust costs, enter curve at effective flow CQp)
Chemical Costs (0§M): Q = O-CCTPM x New Ozone Dosage
Li Uco-LvjIN — / _
8 mg/1
References: 1, 7
H-148
-------
FIGURE H-602 OZONATION (OXYGEN)
CO
o
o
a
o
S
10
1.0
O.I
CONSTRUCTION
m-p
-?H—t+r
>r
*
tr
1.0 10
FLOW.mgd
100
Do
O
i
Co
o
3
C
0.01
0.001
O.I
1.0 10
FLOW , mgd
0.001
o
I
s.
0.0001
H-149
-------
FIGURE H-61
POST AERATION
Service Life; 20 years
Relative Reliability; Level B
Design Basis;
1. Construction costs include aeration equipment and post aeration
basin.
2. Designed to increase dissolved oxygen from 1 mg/1 to 5 mg/1.
3. Detention time = 20 minutes.
4. Power information based on transfer of 34 Ibs of 0_ per million
gallons of wastewater treated.
References: 1, 7
H-150
-------
FIGURE H-61 POST AERATION
10
1.0
O.I
0.01
O.I
O.I
CONSTRUCTION COST:
1.0
10
100
FLOW.mgd
I.U
M
w
^
O
O.I
o «—
« S
§ o
* "5
~ £
o — *
o
0.01
o
3
c
c
0.001
~f
/
**^
/
— —
/
X"
OPERATION 8
,*--
*—
^
^
/
^ ^
3 ••
>
1
" ?**
f * ~
t -—
- • "
« • —
/
•*•
«— •
MAINTENANCE
/
/ \
^
^^^~
• ••
^
^
X
••
^'
To
^il
..-
--
f
t
5J ^^
. -"i
^
COST
-
.ab
s
>
Power
^
^
/
**
or
x'
^
^
.
Ha
/
^<
/
ei
/
'
— ^ -
^
^
^'^
lal
• u.i
«
':O.OI
*«
a
*-
2
l
^
T i
4- 0001
«
. . 0.0001
1.0
10
100
FLOW , mgd
H-151
-------
FIGURE H-62
GROUNDWATER RECHARGE (INFILTRATION)
Service Life; 30 years (equipment only); land assumed to have infinite
life.
Relative Reliability; Level B
Design Basis;
1. Construction costs include site work, infiltration basin, gravel
service road (12 ft), fence (4 ft) and on-site disposal of debris.
Reference: 27
H-152
-------
o
o
FIGURE H-62 GROUNOWATER RECHARGE
(INFILTRATION)
10
1.0
OJ
0. I
O.I
O, 1—I 1—I—t—1.4-i-J
•CONSTRUCTION
1.0
10
FLOW.mgd
100
O.I
_o
"o
10
c
o
s
o
0.01
0.001
0.0001
O.I
^r
/
s
/
OPERATION 8
x1
/
/
x
X
!
!
/
r
MAINTENANCE
V
1 V
/•
' —
X
I/*
X
/
t
'
X
COST
/
/
^
!
/
s
^
\
\
1
1.0 10
FLOW , mgd
100
H-153
-------
H.8.4 Sludge Treatment and Disposal Processes:
Cost Curves, Figures H-63 through H-83
FIGURE H-63
SLUDGE PUMPING
Service Life: 10 years
Relative Reliability; Level B
Design Basis:
1. Costs are based on a sludge loading of 1,900 Ibs/mg at 4% solids,
i.e., 5,700 gal of sludge/mg for combined primary and secondary
sludge after thickening.
2. Non-clog centrifugal pumps.
3.' TDH.= 30 feet.
Adjustment Factor:
To adjust costs for alternative sludge quantities and characteristics,
enter curves at effective flow (Qg):
n n New Design Sludge Mass 4%
^E = ^DESIGN 1,900 Ib/mgX New Design Concentration (%)
References: 4, 7
H-154
-------
in
o
o
Q
o
2
FIGURE H-63 SLUDGE PUMPING
1.0
O.I
0.01
0.001
O.I
i
1
!
1 ;
X
1 _,
X
x
1 |
i X
L-X
x.
i !
I
1
I
i'
-CON
1
i
STRUCTION
CO
t
i
-
--L
i
1 '
i ;
i
j ,
i
i
i-k
j^X
i i x"
-rT
1
X
'•>'•
X^ ' '
' '.
. ..
i
.-
:
j
N
ST-
i i
i
• ^x
_xT
x1
JC
~L —
^
i
1
,
I
1
1
^
j
i
1
1
i
-t-l-
•
!
''i
t
I
_ _L
I
1.0
10
100
FLOW.mgd
O.I
0
i
10
5
^
O
0.01
0.001
0.0001
O.I
-i—i MMI—^
40PERATION a MAINTENANCE COST
1.0 10
FLOW , mgd
0.001
0.01
0.0001
0.00001
H-155
-------
FIGURE H-64
GRAVITY THICKENER
Service Life: 50 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include thickener and all related
mechanical equipment. Pumps are not included. (See Sludge
Pumping Figure H-63.)
2. Costs are based on thickening of secondary sludge (820 Ib/mg;
loading = 6 Ib/sq ft/day). See adjustment factors for other
sludge loadings.
3. 0 § M costs do not include polymer or metal addition.
Adjustment Factor:
To adjust costs for alternative sludge quantites, concentrations,
and thickening properties, enter curves at effective flow (QE)
n _ n 6 Ib/sq ft/day New Design Sludge Mass
^E ^DESIGN x New Design Mass Loading 820 Ibs/mg
References: 5, 6, 7, 13, 18
H-156
-------
FIGURE H-64 GRAVITY THICKENER
"o
O
-------
FIGURE H-65
DISSOLVED AIR FLOTATION THICKENER
Service Life: 40 years
Relative Reliability: Level B
Design Basis;
1. Construction costs include:
a. Flotation chamber (two-hour detention based on sludge flow).
b. Pressure tanks (60 psig).
c. Recycle pumps (100% recycle).
2. Costs for thickening of secondary sludge only: 820 Ib/mg.
3. Loading rate = 2 Ib/sq ft/hr.
4. Operating hours: 0.1 and 1 mgd = 40 hrs/wk; 10 mgd = 100 hrs/wk;
100 mgd = 168 hrs/wk.
Adjustment Factor:
To determine costs at loading rates or sludge quantities other than
above, enter curve at effective flow Qc.
Ct
n n 2 Ib/sq ft/hr New Design Sludge Mass
^E = ^DESIGN x New Design Mass Loading Rate 820 Ibs/day/mg
References: 5, 6, 8, 13, 18
H-158
-------
FIGURE H-65 DISSOLVED AIR FLOTATION THICKENER
o
Q
in
c
o
CONSTRUCTION COSTlJ
0.01
O.I
1.0 10
FLOW.mgd
O
o
o
•9
o
o
0.01
0.001
0.0001
OPERATION 8 MAINTENANCE COST!
A
Total
Labor
W
\ Power: j
ry
i Material
O.I
1.0 10
FLOW , mgd
^
100
H-159
-------
FIGURE H-66
CENTRIFUGATION (LIME SLUDGE DEWATERING)
Service Life: 20 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include: centrifuges (solid bowl), with
minimum of one spare; sludge pumps and piping; cake conveyors,
internal electrical and building cost.
2. Sludge quantity: 4,500 Ib/mg at 10% solids.
3. Operation = 8 hrs/day.
4. Costs do not include centrate handling.
Adjustment Factor:
Costs for sludge quantities and characteristics are different than
those for digested primary and secondary sludge. They are determined
by entering curves at effective flow (Qc).
C>
0 „ New Design Sludge Mass 10%
UE = ^DESIGN 4,500 Ibs/mgx New Design Feed Sludge
Concentration
References: 3, 5
H-160
-------
FIGURE H-66 CENTRIFUGATION ( LIME, SLUDGE DEWATERING )
o
a
in
c
o
o
o
c
o
M
O
O
o
J3
O
100
10
1.0
O.I
O.I
O.I
£ o.oi
0.001
CONSTRUCTION COST:
et
1.0
10
100
FLOW.mgd
J «•"•""
^
y
^
V
-"-
^
OPERATION
^
.
^
^
,
''
x*
-''
7
'
Tot<
r',^^
^
1 Po
/ .
1 ^^^
a
•^
we
~te
MAINTENANCE
^
/
^ i
fjf
/
r X
^*
^
^
^
^
•-
-7
A
^
/*
s
'U
COST
-^
s
)t«
X
KL
jX'
rial
#^
.at
^
01
v
^ '
7
/
^
/
'
-•
-.
O.OI
O.I
0.001
O.I
1.0
10
0.0001
100
FLOW , mgd
H-161
-------
FIGURE H-67
CENTRIFUGATION (BIOLOGICAL SLUDGE DEWATERING)
Service Life: 20 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include: centrifuges with minimum of one
spare unit; sludge pumps and piping; cake conveyors; and building
costs.
2. Construction costs shown are for digested and undigested
primary and secondary sludges.
3. 0 § M costs are for digested sludge.
4. Sludge quantity: digested primary and secondary sludge - 900
Ib/mg at 4%.
5. Operation = 8 hrs/day.
6. Cationic polymer cost based on 10 Ib/ton dry solids.
Adjustment Factor;
Costs for sludge quantities and characteristics are different than those
for digested primary and secondary sludges. They are determined by
entering curves at effective flow (QE) .
New Design Sludge Mass _ 4% _
900 Ibs/mg New Design Sludge
Concentration
0
DESIGN
References ; 3, 4, 5
H-162
-------
FIGURE H-67 CENTRIFUGATION (BIOLOGICAL SLUDGE DEWATERING)
v>
^
D
O
O
10
c
O
IU
1.0
O.I
0.01
0
J*—
*~
"
1
-CON
^**
ST
^-
RUC
Tl
^
!
3N
^
x
c
f*
LU
DO
,
Digests
U
SI
^
s
^x
d Biological SI
xi
ud
^
X
ge
,
1.0 10 10
FLOW.mgd
1.0
_o
"o
O _
o
O
o
J3
O.I
0.01
0.001
O.I
^^v
x*'
^
/
(1
pc
^<
dat«
X
— — *
y
X
OPERATION 8
rials
x3
3
/
^
^
^
' /
<'
x
^
x^
^ "" / "
' \S^
i
/
/
•—
X
*--
y
MAINTENANCE
/
ix1"
jX
^1
^x
•^
Power
s
^
X
^
al
x
/
C
^
M
.
^
x
'
m
/
.,
/
»
y
cats
x
/ ^
X
'
COST
/
/
j
/ \
/
/
'
s
•^
vi.
^
x
atx
/
X
e
s
'
/
/
j
/
x
nO.I
j
•
001
nnni
. 0.0001
1.0 10
FLOW , mgd
w
I
100
H-163
-------
FIGURE H-68
VACUUM FILTRATION (BIOLOGICAL SLUDGE)
Service Life: 20 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include: pumps, internal piping and electrical
controls; mechanical equipment, conveyors, and sludge cake storage
hopper; building, chemical-handling, and storage facilities.
2. Costs are for dewatering of combined primary and secondary digested
sludge - 900 Ib/mg. See adjustment factor for dewatering other
sludge.
3. Filter yield = 5 Ib/sq ft/hr.
4. Operation time (excluding downtime for maintenance):
6 hrs/day for 1-mgd plant or less.
12 hrs/day for 10-mgd plant.
18 hrs/day for 100-mgd plant.
Interpolate for other plant sizes.
5. Chemical dosage: FeCl- = 35 Ib/mg; CaO = 90 Ib/mg.
Adjustment Factor:
Costs for sludge quantities and dewatering characteristics are
different than those above. Enter curves at effective flow (Q ).
New Design Original Design Operation
5 Ibs/sq ftA
lew Design Ma<
Loading Rate
0 Sludge Mass 5 Ibs/sq ft/hr Time
^DESIGN X 900 Ibs/mg X New Design Mass X New Design Operating Time
References; 3, 4, 7
H-164
-------
FIGURE H-68 VACUUM FILTRATION (BIOLOGICAL SLUDGE)
• in
Annual Cost, Millions Of Dollars Millions Of Dollars
(Total -Labor-Chemicals-Materials)
o
b o
02 ° P 6 0E 5 <
-—
— —
p—
-CON
STRUCTION CO
,--
1
i
;
i
^j
^
.Je*
i
Ul
ST-
i
I • '
1
1 1
1 ^
^Xi |
^ ,
i
j
.
1
x^
/
/
^
'
1 1.0 10 100
FLOW.mgd
| r— i 1 i i , mi r— , 1 i , i in r— , 1 O.I
— . «•
OPERATION 8 MAINTENANCE COST
^
^
Materic
w
x^T>
f*
\
•
Is-
>
1
_jx"
.4--
X
~~ ^/
^
/
X
«•-
^
"
/
i
IX
i
!
i i
X
^T
^ Labpr^
S
^ '
/
/
x
f
f
/
^
/*
,•
/'
'
i ^
•
j
1
JotalX
^-7^-
•
^
—-7*\
/
f —
Power ^
I/
^X
T x
rf
X
-7
•J/
Chemicals
!
^
/
S
^
^
k#
i
1
i i
^
|
/
- ^
noi
L *-
£
t o.ooi
O.OOOI
1 1.0 10 100
FLOW , mgd
H-165
-------
FIGURE H-69
VACUUM FILTRATION (LIME SLUDGE)
Service Life; 20 years
Relative Reliability: Level B
Design Basis;
1. Construction costs include: pumps, internal piping and electrical,
controls; mechanical equipment, conveyors, sludge-cake storage
hopper; building.
2. Costs are for dewatering of lime sludge (4,500 Ib/mg @ 10%).
3. Filter yield = 8 Ib/sq ft/hr.
4. Operation time (excluding downtime for maintenance):
6 hrs/day for 1-mgd plant or less.
12 hrs/day for 10-mgd plant.
18 hrs/day for 100-mgd plant.
Interpolate for other plant sizes.
Adjustment Factor:
Costs for sludge quantities, concentrations, and dewatering
characteristics or operating times are different than those above.
Enter curves at effective flow (Q ).
New Design Original Design Oper-
Q = QrvESIGN * Sludge Mass x 8 Ibs/sq ft/hr x ation Time
4,500 Ibs/mg New Design Mass New Design Operation
Loading Rate Time
References; 3, 4, 7
H-166
-------
FIGURE H-69 VACUUM FILTRATION (LIME SLUDGE)
10
1.0
O.I
O.I
CONSTRUCTION COST:
10
10
FLOW.mgd
IOO
1.0
o
° ? O.I
5 1
o
\ I
3 i
5 0.01
o C
0.001
/
'
-*-
'
^
^
OPERATION
v
/
•"*
s
I
„,
^,'
aboi
^
^
-•'
s
• „ •
'
t .
S
, •
a
^
'
/
X
MAINTENANCE
s
S
/
/
-»>
^~
-X
^*
^
Po
^
•
"7
^
ro
IH
i.
^
al
Ti '
J^
^
dc
iter
xi
;<^
/
als
COST
^
/
S
/
'/?
'
s
_/
^
^x
^
[?'
/
- - t
jf. A 2
7
/
7
1
,
-
..
O.I
1.0 10
FLOW , mgd
O.I
0.01
V
I
0.00!
0.0001
100
H-167
-------
FIGURE H-70
FILTER PRESS (LIME SLUDGE)
Service Life; 15 years
Relative Reliability; Level B
Design Basis;
1. Construction costs include: filter presses, pressure pumps,
conveyor equipment, sludge storage tanks, and building.
2. Sludge loading: 4,500 Ib/mg at 10%.
3. Cake characteristics: density = 75 Ib/cu ft; solids content = 45%.
4. Operations: For 0.1 to 1 mgd plants - 20 cycles/week.
For 1 to 10 mgd plant - 48 cycles/week.
For 10 to 100 mgd plant - 84 cycles/week.
5. Cycle time: 2 hours/cycle.
Adjustment Factor;
To develop cost for sludge quantities, concentrations, characteristics
or cycles per week different than those used to develop these curves,
enter curve at effective flow (Qc).
b
New Design Original Design New Design Cycle
QE = QncoTQv x Sludge Mass x Cycles Per Week x Time
4,500 Ibs/mg New Design Cycles 2 hours
Per Week
References: 5, 18
H-168
-------
o
o
o
«
FIGURE H-70 FILTER PRESS (LIME SLUDGE)
100
10
1.0
O.I
O.I
CONSTRUCTION COST:
10
100
FLOW.mgd
1.0
5 -5
"5
o 1
1 \
= o
- |
I -5
o -x
O.I
OOI
0.001
^
^
-X
•**
/
^x1
•p
M(
/-
OPERATION 8
+*
**
ite
\
^* *
. «
.a bo
i
ri(
>
A
4
1
>'s -
2
7
'
we
, ^^
^*
r
^»-
"^
*y
^
MAINTENANCE
<*—
**~
^x
7
To
^»
!^
to
-L
/
1
^
'
x
' '
-'
-------
FIGURE H-71
FILTER PRESS (BIOLOGICAL SLUDGE)
Service Life; 15 years
Relative Reliability; Level B
Design Basis;
1. Construction costs include: filter presses, pressure pumps,
conveyor equipment, chemical feed and storage facilities,
conditioning tanks, sludge storage tanks, and building.
2. Sludge loading; digested primary + secondary » 900 Ib/mg @ 2.5%
3. Cake characteristics: density = 65 Ib/cu ft; solids content = 40%
4. Operations: For 0.1 to 1 mgd plants - 20 cycles/week
For 1 to 10 mgd plant - 48 cycles/week
For 10 to 100 mgd plant - 84 cycles/week
5. Conditioning chemicals: FeCl3 = 35 Ib/mg; CaO = 90 Ib/mg.
Adjustment Factor;
To develop cost for sludge quantities, concentrations, characteristics
or cycles per week different than those used to develop these curves,
enter curve at effective flow (Q ).
New Design Original Design New Design Cycle
QP = CLFqTrN x Sludge Mass x Cycles Per Week x Time
900 Ib/mg New Design Cycles 2 hours
Per Week
References; 5, 18
H-170
-------
FIGURE H-71 FILTER PRESS (BIOLOGICAL SLUDGE)
IUV
10
«
k.
o
£
o
«
c
_o
i i.o
0.1
0
LO
£ 5
5 o
f I o.
0 i
g s
5 E
1 s
- * »»
•» °
o -o
0 o
V o.oi
1 o
1 £
0.001
0
**•
.1
^
z
•*^
-
^
^
==
/
^
^
•^
r.
II - --)
"CON
..^
ST
^UC
Tl
^
^
1 — I— 1
)N
X
^
U4-I-
cc
K
J4
ST
l-xr^
•
/
i
Digested Biological
\
1.0
FLOW.mgd
OPERATION 3
^^
f*
»•
/
^
^
/
1
i
7
•*
>toL--
•f*T^
:r=
/
:: A,
H
X
! (
Z
«
^
r
Slud<
X
je
10
MAINTENANCE
^
S*~
aterial
^
Chemicals
/
/
/
X
^
/'
J-
^
/
'
X
.0
Lx
^^
501
x'
/
.0
FLOW , mgd
4
/
, ^^^
.^"
/
' X
/
COST
>
/
****
*•
/
i
L'
^_ ^
/
^^
^*
/
^
/
^
/
x
^
^
X1
/
* •
> -
,
10
,'
100
m 0.01
: 0.001
• i
•^
1
i £
i
-0.0001
.,0.00001
100
H-171
-------
FIGURE H-72
SLUDGE DRYING BEDS
Service Life; 20 years
Relative Reliability; Level B
Design Basis;
1. Construction costs include: sand beds, sludge inlets, underdrains,
cell dividers, sludge piping, underdrain return, and other structural
elements of the beds.
2. Bed loading: 900 Ib of sludge/mg; 20 Ib/sq ft/year.
Adjustment Factor;
To adjust costs for bed loading rates, sludge quantities, or charac-
teristics, enter curve at effective flow (Q ).
Ci
New Design
Q = QnT3t;TrM x Sludge Mass x 20 Ib/sq ft/yr
c ut&iWN 900 Ib/mgNew Design Bed Loading
References: 3, 5
H-172
-------
FIGURE H-72 SLUDGE DRYING BEDS
IU
1.0
«
o
~o
O
«»-
O
in
c
o
2 O.I
0.01
^^f
i — •
^
s
J
'
CON
^
ST
rf'
*UC
Tl
1
/
1 1
DN
^
1 — i
'
C<
/
DS
t
T~
0.1
IO
10
FLOW.mgd
O.I
1.0
10
100
I.U
M
^
O
0.1
O -~
S -
.1 3
= i
2 o
^- |S
in «^
O
00!
0
c
c
0.001
s^
^L
.ab(
/
— 1 1 Mill 1 —
OPERATION 8
^r
>r
'
**
* 7 '
*• '
/
Tote
* * ^
•* ^ >
x
y
;Mate
j^
x
•ia
1 1 — 1 — 1 1 INI
MAINTENANCE
- ,
j$
'/
\
s
^
x
j/
i
j^f
*
'
i — i
COST
*•• u.i
+ 0.01
en
o
; g
•*" 2
4- QOOi
'•
.. 0.0001
100
FLOW , mgd
H-173
-------
FIGURE H-73
TWO-STAGE ANAEROBIC DIGESTERS
Service Life: 50 years
Relative Reliability; Level B
Design Basis:
1. Capital costs include: digester, heat-exchanger, gas-collection
equipment, control building.
2. Feed to digesters is combined primary and is thickened.
3. Feed - 1,900 Ib/mg at 4% solids (75% volatile).
4. Effluent from digesters is 900 Ib/mg at 2.5% solids.
5. Loading rate - 0.16 Ib/cu ft/day.
6. Operating temperature - 85 to 110°F.
7. Digester gas is utilized for heating. Excess gas is not utilized.
Adjustment Factor;
To adjust costs for loading rates different than those presented here,
enter curve at effective flow (Q ) .
x New Design Sludge Mass
- 1,900 Ib/mg -
References : 7, 8, 10, 13
H-174
-------
FIGURE H-73 TWO STAGE ANAEROBIC DIGESTERS
IUU
10
Cft
w
0
"o
o
0
Iff
c
o
I 1.0
O.I
0
1.0
/ CA
o
o
° O.I
o 5
J3
£ 5
o _r
— o
i «
o
ift s
o _r
o o
jo .01
o C.
3
C
C
.001
0
=
««
-CON
]
STRUCTION CO
i
^
!
^s
— |
-
**
j.
^
14 1
ST~|
!
*—^
X
S^ •
*
X
; '
^
^
.1 1.0 10 ""•
FLOW.mgd
it
^
***^
^s
•^
^^«
^
OPERATION 8 MAINTENANCE COST
w»"
S*
^
=*!'
L^.
T —
, . .^
X
.-^
__.
— —
— i
1 —
1 —
—
X
-,>
--'i
, --^
- 'r
i
/
/
**
**
1
^
<•
b
/
'
Ql
J*
j i
+ -
^
*•
R
I
!
/
: S
/
;
i
:^
^
X
.x
j
-i ; 1
^
x
1*7
X
1
±— ^^
,X*W
XI
ateria
!
ow
/
/
X
er
^
L(
!
/
X
/.
i
^
y
bo
/'
i— i--
1
\
t
— J
/
100
T33».0\
' ~ -
/
'
H
/
..-
- 001
L 1
o
0.
t .000!
h
OOOOI
.0 10 100
FLOW , mgd
H-175
-------
FIGURE H-74
AEROBIC DIGESTERS
Service Life: 40 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include:
a. Basins (20 day detention time) - sludge flow = 5,700 gal/mg
(1900 Ib/mg
at 4%)
b. Floating mechanical aerators
2. Mixing requirements: 134 hp/ing.
3. Oxygen requirements: 1.6 Ibs 02/lb VSS destroyed.
Adjustment Factor;
To adjust costs for design factors different from those above, enter
curves at effective flow (Q_).
QE = QnpcTGN x 20 days x New Design Sludge Mass x
New Design Retention Time 1,900 Ib/mg
4%
New Design Sludge Concentration
References; 6, 13
H-176
-------
FIGURE H-74 AEROBIC DIGESTERS
o
Q
_o
"o
o -,
S
o
IU
1.0
O.I
0.01
0
X
-X*
^
^
ft
.1
-U 1
-CON
I
^jX
3T
j
•
UL
:o
M
Ul
ST-
y
S^
'
—*
*
,
'
\ \
! i i
\
i
X
i
.
/\
1
1
T
1.0 10 1C
FLOW.mgd
I.Oi— i — i— i — i i i i 1 1 1 1 — i 1— i — 1 — i 1 — i — 111.
O.I
0.01
0.001
0
-,
^
/
^
-u
^
s
ibor
OPERATION 8 MAINTENANCE COST
^
5«-
/
^
sf
-»
.
X
•1
«-
7
i
.
xT
^ ^
P
L
i
1
!•''
f
/
'
ower
Mat!
j
^
r*
S
^ •
f
TotaL
y^x
^/
1
j
i
1 i
Jri
-^
als
\
X
XUJ
'I
i
j
'
X
«
/
^
!>
i
!
i
j
j X
x^ :
-*'
-— 71
X
*
r
t
/
7 — *
X
^i
i
f
/
/
'
/
x
X
y1
'
^
—
— T
^
^
^'
^
1
i
\
\
i i
1
1
!
i
1
:
!
i
Q |
^
,
-0.01
J 0.00 1
. 0.0001
.0 10 100
FLOW , mgd
H-177
-------
FIGURE H-75
HEAT TREATMENT OF SLUDGE
Service Life: 25 years
Relative Reliability; Level B
Design Basis:
1. Construction costs include: sludge feed pumps, grinders, heat
exchangers, reactors, boilers, gas separators, and buildings.
2. Costs are related to average wastewater flow by the following:
a. Sludge quantity = 1900 Ibs/mg (undigested, combined thickened
primary plus secondary sludge).
b. Solids concentration =4.5%
c. Sludge flow =3.8 gpm/mgd based on 8,000 operating hrs per year
3. Fuel costs are for steam generation.
Adjustment Factor;
To adjust costs for design factors different than for those above, enter
curve at effective flow (Q_).
n „ New Design Sludge Mass
^E = ^DESIGN 1,900 Ib/mg
References; 4, 23
H-178
-------
o
o
FIGURE H-75 HEAT TREATMENT OF SLUDGE
100
10
1.0
O.I
O.I
CONSTRUCTION COST;
1.0
! I
10
FLOW.mgd
100
o
Q
o
O
OPERATION 3 MAINTENANCE COST
1.0 10
FLOW , mgd
H-179
-------
FIGURE H-76
COMPOSTING
Service Life: 17 years
Relative Reliability: Level B
Design Basis:
1. Construction costs include: asphalt pad, roads, sewer,
drainage pond, electrical work, engineering. Do not
apply cost multipliers shown in Table H-2.
2. Sludge production rate: 900 Ib/mg.
3. Land Requirement: 0.35 acres/ (ton/day) .
Assumed land cost = $10,500/acre.
4. Costs apply to composting of digested or raw biological
sludge.
Adjustment Factor:
To adjust cost for sludge composting rates different than
900 Ib/mg enter cost curves at effective flow (Q ) .
QE = QDESIGN X
New Design
900 Ib/mg
References: 53
H-180
-------
FIGURE H-76 COMPOSTING
IU
1.0
in
o
o
0
o
W»
C
0
2 O.I
O.OI
- -
:
. -^
\. i"
14 1 1
-CON
|
^^
^
3T
RUC
-^
^x
Tl(
DN
CC
1
1 .
!
f
ST-
j
i ^
^T'
* ;
\—
1
J
f
^
'
O.I
1.0 10
FLOW.mgd
100
o
o
O
O.I
|2
o
3
0.01
0.001
1
1
—
^^
•»
•^"
1 — i — i i i 1 1 r* — i — i 1
OPERATION a M/
a '
.--
1
•••
•*
^
**?"
:
>•
\
\ '
j
j ^
^f^.
^t'i'
1
i — 1 1 Mil 1
INTENANCE
uH
^l
X"' ^
i
\ i
-br
'•r
1 T
*l : i :
i
i . 1
:
'
1
\ .
i
COST
T(
>1o\
^^ .
1
; f
^
X
^
-xf
"Labor'—
1
' ,
1 i
j '
1 :
i
,
'
^
|
'
:
i
O.I
10 10
FLOW , mgd
100
H-181
-------
FIGURE H-77
INCINERATION (FLUIDIZED BED)
Service Life: 30 years
Relative Reliability; Level B
Design Basis;
1. Construction costs include: reactor, air blowers and accessories,
preheater, scrubbers, fuel pumps, building.
2. Costs are for undigested dewatered primary and secondary sludge
(1,900 Ib/mg at 20% solids; 75% volatile).
3. Operations: Flow Day/Week Operating Hrs/Day
mgd
0.1 1 20
1.0 7 20
10.0 7 20
100.0 7 20
4. Fuel requirements = 100 - 120 gal No. 2 fuel oil/dry ton sludge.
Adjustment Factor:
Fuel costs for conditions different than those given above may be
adjusted. However, the relationship of fuel requirements and
operating conditions are too complicated to allow for simple
adjustment here. Specific detailed study is suggested for each
case.
References: 9, 21, 22, 34
H-182
-------
FIGURE H-77 INCINERATION (FLUIDIZED BED)
IUU
10
M
O
"o
O
••-
O
c
0
i i.o
O.I
0
1.0
M
k_
O
0 ^-
0 1 O.I
»- u.
O 1
en o
C 0
5 -J
a= 2
£
«> "™*
o
u
0.01
o
c
c
0.001
0
•^
^
^
1
*
-CON
^^
5TRUCTION CO
, — '
t
^^'
|
^*
*f
i
ST-
-
j
^
^^
^
—
-
!
+ *
.
1 1.0 10 100
FLOW.mgd
— ••
^
/
/
i
I
j
.
-
,.-•
- —
. '
/
X"
/
£^
/
OPERATION S MAINTENANCE COST
^
^.w-
y
y
/
pt
^
^
>
je
To
Xl
i
1
:
1
i \ \\\ /-
fa
e
•lal
1 //,
XI >
./" ^/
v*1
x"
>
_^ i
/T •
'//
^y
1^
'
t^
A /
/
>
V
' ^.
\
\ — T—
J
i
r'llX/
V
^
tf S
^ y
//
/ ^
/
y
/
S
.Labor
•-]-]••
,
i
1 ;
.
y* /
'
/
^.
/
y'
\
\
i •
--_
j-
/
s
.
n r\\
r ^.^
(O
r o
r h.
4>
O
O
t o.ooi £
"""""*
0.0001
1 .0 10 100
FLOW , mgd
H-183
-------
FIGURE H-78
INCINERATION (MULTIPLE HEARTH)
Service Life; 30 years
Relative Reliability: Level B
Design Basis;
1. Construction costs include: incinerator, building, sludge conveyor,
ash-handling equipment, gas scrubbers.
2. Costs are for undigested dewatered primary and secondary sludge
(1,900 Ib/mg at 20% solids; 75% volatile).
3. Operations:
Flow
mgd
0.1
1.0
10.0
100.0
Day/Week Operating Hrs/Day
1 20
7 20
7 20
7 20
4. Fuel requirements for warm-up and incineration = 32,000 gal of No. 2
fuel oil/yr/mgd.
Adjustment Factor;
To adjust fuel costs of other than those listed, use graph below.
Btu Consumption per ton Wet Feed
76 77 78 79 80
Percent Moisture in Wet Feed
NOTES: 1. Curves are only applicable for continuous operation at
feed rates above 4 tons per hour.
2. Sludge heat content is 10,000 btu/lb volatile solids.
82
83
References: 3, 4, 5, 8, 9, 13
H-184
-------
o
a
o
S
o
Q
in
c
o
a>
O
O
o
c
<
FIGURE H-78 INCINERATION (MULTIPLE HEARTH)
10
1.0
0.1
O.I
1.0
O.I
0.0!
0.001
O.I
CONSTRUCTION COST:
1.0
10
100
FLOW, mgd
OPERATION 8 MAINTENANCE COST^
Labor
Total
Material
)iel
0.1
0.01
0.001
0.0001
1.0
10
100
FLOW , mgd
H-185
-------
FIGURE H-79
LIME STABILIZATION
Service Life: 20 years
Relative Reliability: Level B
Design Basis:
1. Construction cost includes:
a. Two volumetric feeder systems with manually loaded bins,
dissolving chambers, and accessories for plants less than
1.5 mgd.
b. For plants larger than 1.5 mgd, two gravimetric feeder-slaker
systems and steel bins to hold lh truckloads of quick lime each,
c. For plants larger than 25 mgd, four gravimetric feeder-slaker
systems with bin gates and accessories.
d. Sludge holding tank (3 days detention time).
2. Operations and maintenance costs include:
a. Slaker - 1 hour of operation/slaker/shift in use.
b. Feeder - 10 minutes of operation/hour/feeder.
c. Slurry Pot - feed line (for slake lime) - 4 hours/week.
d. Power requirements of 7.0 kwh/1,000 Ibs lime.
3. Use hydrated lime (Ca(OH)2) for plants less than 1.5 mgd.
4. Use quicklime (CaO) for plants larger than 1.5 mgd.
5. Sludge mass is 1900 Ibs dry solids/mg for thickened primary and
secondary sludge at 4% solids.
6. Lime dosage is 212 Ib (as CaO)/ton of dry solids.
References: 13, 18, 50
H-186
-------
o
Q
FIGURE H-79 LIME STABILIZATION
100
10
1.0
O.I
O.I
CONSTRUCTION COST:
1.0
10
FLOW.mgd
100
IO
o
o
o
w
a, o
c JD
°
o
1 I
1.0
.01
1.0 10
FLOW , mgd
_^*
7*
X
ft
/
rial
X"
OPERATION 8
(
/
en
/
/
^
a!
^
/
/
, ™
^«-
^ <•
x
x^
"Cher
/*
.-^
L
. .. —
~?
^
s
t
Powe
"
lie
^
,
ab
/
r
MAINTENANCE
Gls.
/
Tn
4
to
^ X
^^
yr*
T?
~/
x
' y
./
x .
/
-^
i^
^
/
/
/
^
/
/
^
«
, -
^
•
i — i 1
COST
.01 —
U)
.001 o
0)
I
100
.000"!
H-187
-------
FIGURE H-80
SLUDGE STORAGE
Service Life; 30 years
Relative Reliability; Level B
Design Basis;
1. Costs are for storage of thickened primary and secondary sludge
(1,900 Ib/mg; at 4% solids).
2. Mixing by diffused air (25 cfm/1,000 cu ft, or approximately 130
hp/mg).
3. Construction costs include: storage tank and air-supply system
for mixing and aeration.
Adjustment Factor;
To adjust costs for other sludge quantities and concentrations, enter
the curves at effective flow (QE).
0 = 0 Y New Design Sludge Mass 4%
^E ^DESIGN 1,900 Ibs/mgNew Design Sludge
Concentrations
References: 3, 7, 9, 13
H-188
-------
c
o
FIGURE H-80 SLUDGE STORAGE
10
1.0
O.I
0.01
O.I
CONSTRUCTION COST:
1.0
IO
100
FLOW.mgd
U.I
0
0
0 1 °01
O w
«
I 1
i 1
3 1
1- O.OOI
o
3
c
<
1 0.0001
•^
/
^
x
'
r~
^
' s
X,
x^
OPERATION 8
s
S
s
^~
s*
,
/
^fff
J '*
s*
/
/
Tot
* ^
t *
'^
^
\
ai
/
"
\ 1— 1 — 1 1 INI 1
MAINTENANCE
^
*
Power
«
^
"
x
X
X
^
\
}
X
^
1 — 1 ,
COST
"^"*
X1
K>r i
?»• Labor
x^
irt
^
X"
1 i
X
,
X
^
^ ^
" U.UI
"* ' nnni
s
*
o
j_ Q.
' *"^
.. 0.00001
O.I
1.0
10
100
FLOW , mgd
H-189
-------
FIGURE H-81
LANDFILLING (BIOLOGICAL SLUDGE EXCLUDING TRANSPORTATION)
Service Life: 20 years
Relative Reliability: Level B
Design Basis;
1. Construction costs do not include cost for land (1.1 acres/mgd
including allowance for 25% of volume for cover and 10% loss of
surface area for roads and buffer zone).
2. Construction costs include: site preparation, front end loaders,
monitoring wells, fencing, leachate collection and treatment.
3. Operation and maintenance costs include:
a. Labor costs for operation, preventive maintenance, and minor
repairs.
b. Material costs to include replacement parts, soil for mixing
with sludge (1 part soil to 3 parts sludge), fuel for bull-
dozer operation, and repair work performed by outside con-
tractors.
4. Costs are for landfilling of dewatered and digested biological
sludge. Costs for landfilling of other predominantly biological
sludges can be obtained by using the adjustment factor.
5. Sludge quantity = 900 Ib/mg at 20% solids; 2.7 cu yd/mg.
Note: at 20% concentration, may require blending with soil.
Adjustment Factor:
For sludge quantities and concentrations other than those listed above,
enter curve at effective flow (Q_).
0 _ 0 New Design Sludge Mass 20%
^E~ ^DESIGN 900 Ib/mg x New Design Sludge Concentration
References: 9, 32
H-190
-------
O
O
FIGURE H-81 LANDFILLING (BIOLOGICAL SLUDGE,
EXCLUDING TRANSPORTATION)
10
1.0
O.I
0.01
O.I
CONSTRUCTION COST;
1.0
10
100
FLOW.mgd
O.I
O
O
M
O
O
0.01
0.001
0.0001
O.I
x*^1
"~^
s
f
X
|jr-
^^
^ .
OPERATION 8
—pj
••• ""
X
^
M
^ •
,'
olnt*
..^
r*r**
X
'
inanca
-H
^
,E
MAINTENANCE
1
f^
-^s*t
>^
ieix
•ot
^
^
y
at
3k
^
^
h
^ **
^ e
lot<
,
X
>
.-^-
trials
COST
S
'
*r
_S
^
s
./^
.
^
L
x-
+
j
ibor
1.0 10
FLOW , mgd
100
H-191
-------
FIGURE H-82
LANDFILLING (LIME SLUDGE EXCLUDING TRANSPORTATION)
Service Life; 20 years
Relative Reliability; Level B
Design Basis;
1. Construction costs include: site preparation, bulldozers, monitor-
ing wells, fencing, and leachate collection and treatment.
2. Construction costs do not include cost for land (3.1 acres/mgd;
including allowance for 25% of volume for cover and 10% loss of
surface area for roads and buffer zone).
3. Operation and maintenance costs include:
a. Labor costs for operation, preventive maintenance, and minor
repairs.
b. Material costs to include replacement parts, soil for mixing
with sludge (1 part soil to 3 parts sludge), fuel for bull-
dozer operation, and repair work performed by outside con-
tractors.
4. Lime sludge quantity = 4,500 Ib/mg at 30%; 7.4 cu yd/mg.
Adjustment Factor:
To adjust costs for other sludge quantities and concentrations, enter
the curves at effective flow (Q ).
Q _ Q New Design Sludge Mass 50%
^E = ^DESIGN 4,500 Ib/mg New Design Concentration
References; 9, 32
H-192
-------
JO
is
o
Q
o
u
o
3
c
<
FIGURE H-82 LANDFILLING (LIME SLUDGE,
EXCLUDING TRANSPORTATION)
10
1.0
O.I
0.01
O.I
1.0
O.I
0.01
0.001
CONSTRUCTION COST:
1.0
10
FLOW.mgd
O.I
1.0
10
FLOW , mgd
100
^^
*^
s
s
__
**£\
»—
Mr
OPERATION
inf
^
/
jr
L''
^
ince
,S
\-,*-*
'
, Ene
a
^
/
^*~
gy
MAINTENANCE
/
j-
>
s~
/ ;
j -
a
Ma
x
X
.--
te
/
I*
•\
s
/
iifi
s
*
s
l_(
COST
T<
S
3tX
>tal
fc'V
S"
)f
^
s
/
>
s
/
/^
s
/
£_
. f
S
'
100
H-193
-------
FIGURE H-83
LAND APPLICATION OF SLUDGE
Service Life: 30 years
Relative Reliability; Level B
Design Basis;
1. Construction costs include: storage lagoon (6 weeks); land prepara-
tion, monitoring wells (3 at 0.1 mgd, 5 at 1 mgd, 8 at 10 mgd, 25
at 100 mgd, and services roads.
2. Costs are for application of digested biological sludge - 900 Ib/mg
at 4% solids.
3. Transport of sludge to site is included in the appropriate trans-
portation curve. (See Figures H-86 through H-90.)
4. Sludge application rate - 10 ton (dry)/acre/year.
5. Land costs are not included.
6. Sludge application is by subsurface injection - unit attached to
haul truck.
7. Operation and maintenance costs include:
a. Labor costs for sludge operation, preventive maintenance, and
minor repairs.
b. Material costs to include replacement of parts and repair per-
formance by outside contractors.
Adjustment Factor;
If costs are desired for different, application rates enter curve at
effective flow (QE).
QE = QDESIGN X 10 ton (dry)/acre/yr
New Design Application Rate
Reference: 9
H-194
-------
M
k.
O
O
a
10
c
o
o
O
FIGURE H-83 LAND APPLICATION OF SLUDGE
1.0
0.01
0.001
±tCONSTRUCT I ON COST:
-t-
-Totol
Construction Cost
^
±
I S^~ \ i
-i— Lond Preparation
X i Cott
J..-4-
O.I
1.0
10
100
FLOW.mgd
O ^
o
o
o
o
.0
1.0
O.I
0.01
0.001
0
OPERATION 8 MAINTENANCE COST
.
j
,
' I
1
^
/
1
,x
^
rtattrid
*fT
^
x
1 ,
x-
j
1
; L
^
^
Labor
***
\
\
-H — -
^s
'' S
1
j :
' 1 i
i i i i i !
:
i • 1
TotaJ^
•^
X
^
Xx
^^ —
xT
L
^'
i
j
t
j ^
s
x^
^
./P//'
i^XJ'^x^
^ ^
—
L 1 — i — ,
\
L
v
^
s\s
1
Y
-
.
j
1
— l"1
1
4
_.
,t
f~
I
nO.I
' nm
i-
.
0.001
.
. 0.0001
.0 10 100
o
FLOW , mgd
H-195
-------
H.8.5 Wastewater Transportation Methods:
Cost Curves, Figures H-84 and H-85
FIGURE H-84
GRAVITY SEWERS
Service Life; 50 years
Relative Reliability; Level B
Design Basis;
1. Peaking factor allowance ranges from 3 for flows of
1 mgd and less average flow, to 2 for flows with
greater than 10 mgd average flow.
2. Average slope of 0.002 to 0.005.
3. Velocity of not less than 2 fps when flowing full at peak flow;
minimum sewer size = 8 inches.
4. Repaving of road surface required for 10% of distance.
5. Does not include right-of-way or aerial crossing, etc.
References; 38, 52
H-196
-------
o
Q
—
i
X
10
w
O
'o
Q
c
o
10
1.0
O.I
O.OI
O.I
O.I
0.01
O.OOI
0.0001
O.I
FIGURE H-84 GRAVITY SEWERS
CONSTRUCTION COST:
1.0
10
IOO
FLOW.mgd
1111—r i i i i i 11 ii—ii i -
OPERATION a MAINTENANCE COST:
-I-
1.0
10
100
FLOW , mgd
H-197
-------
FIGURE H-85
TRANSMISSION FORCE MAIN
Service Life; 50 years
Relative Reliability; Level B
Design Basis;
1. Peaking factor allowance ranges from 3 for flows of
1 mgd and less average flow, to 2 for flows with
greater than 10 mgd average flow.
2. 5-ft. depth of cover over crown of pipe.
3. Average velocity of 5 fps.
4. Repaving of road surface required for 10% of distance.
5. Does not include pump stations, right-of-way,
aerial crossings, etc.
Reference: 38
H-198
-------
FIGURE H-85 TRANSMISSION FORCE MAIN
1 U
V
x 1.0
IA
W
O
75
O
O
(ft
2 O.I
2
O. 01
*-
,. ••
CON
. —
ST
^*
RUC
Tl
1
.^f*
1
1
DN
"*
^
cc
x'
>ST-
-------
4.8.6 Sludge Transportation Methods:
Cost Curves, Figures H-86 through H-90
FIGURE H-86
LIQUID SLUDGE TRANSPORT (RAIL)
Service Life: 15 years
Level of Reliability: Level B
Design Basis:
1. Construction cost includes loading facilities.
2. Storage at plant equals one day's production.
3. Pumping and piping are sized to fill 1, 10, 20, and 100
unit car trains in 1.5, 2, 3, and 15 hours, respectively.
4. Rail cars discharge by gravity into unloading storage.
5. Storage at unloading area not included in cost.
6. Travel distances of 40, 80, and 160 miles one way.
7. Costs based on 8 hours operation per day.
8. Operation and maintenance costs include car lease, labor,
electrical energy, supplies, and rail maintenance.
9. Assume a Full Car Maintenance Lease rate of $525/car.
10. Rail haul charges are based on the following:
Approximate Railroad
Area Rate Variation, Adjust Accordingly
North Central and Central Average rate as presented here
Northeast 25% higher than average
Southeast 25% lower than average
Southwest 10% lower than average
West Coast 10% higher than average
The railroads generally allow a rebate of $0.06 to $0.20 per mile
per car if the shipper provides the car.
11. Solids content of sludge = 4%.
12. Rail cars have 20,000 gallon capacity.
Reference: 46
H-200
-------
FIGURE H-86 LIQUID SLUDGE TRANSPORT (RAIL)
\\J
I.O
0)
k.
o
~o
o
O
-'
^-P^
i .
;
-1— -i
SI
1
_^^
"'
\
S
^^-^
•^\
x
X
i
I i
i
|
; i
' i • ! i '
• !
1 1
1 1
1
O 10 IOO
ANNUAL SLUDGE VOLUME,
OPERATION 8 MAINTENANCE
]
• i Li_
!
i
!
1
>
x
i
~r
!
i !
1
j i j
i
[T
(
i
IOOO
MG
COST
[
i
j ; ' : ; ; ||
1
1 ; •
I
|
i
j ,
! . I : I6O
i
i y
I
[ j i !
1 ;
1
Mile! : '
' i i \ i ]/'
\ \ '< 80 Mile
i
1
A
-U-i
j /
/ /
pv
^/
^
^
t r
Xi /
/ ]/.
— 7^
\y^ .
^^1 /^
//
s
f
PH^t
^n '
/t
1 j •
! /
/ /
jf
j/\
/ \ /
^
/
/A
K
r^K
f
% ^^
K
»0 Mile
U p-j ,
1 1 1 .
I i
i
: ' i < '
!
i
I j
i
0 10 IOO
ANNUAL SLUDGE VOLUME,
Y
\
:
i
,
IOOO
MG
H-201
-------
FIGURE H-87
DEWATERED SLUDGE TRANSPORT (RAIL)
Service Life: 15 years
Relative Reliability; Level B
Design Basis:
1. Construction cost includes construction of loading facilities.
2. Loading storage hopper is sized for one car load.
3. Cars are gravity loaded.
4. Rail cars dump by gravity into unloading storage.
5. Storage at unloading area is not included in the cost.
6. Operation and maintenance costs include rail haul charges, labor,
electrical power, and supplies for the loading facilities.
7. Assume the railroad provides the hopper cars.
8. Use 50 yd3 cars for 0-74,000 yd3 of sludge. Use 100 yd3 cars
for greater than 75,000 yd3 of sludge.
9. Rail haul charges are based on the following:
Approximate Railroad
Area Rate Variation, Adjust Accordingly
\
North Central and Central Average rate as presented here
Northeast 25% higher than average
Southeast 25% lower than average
Southwest 10% lower than average
West Coast 10% higher than average
10. Travel distances presented are 40, 80, or 160 miles one way.
11. Costs based on 8 hours operation per day.
Reference: 46
H-202
-------
o
Q
in
c
o
in
O
o
o
10
c
o
o
o
FIGURE H-87 DEWATERED SLUDGE TRANSPORT (RAIL)
10
:±CONSTRUCTION COST
O.OI
IO
1.0
O.I
O.OI
10 IOO
ANNUAL SLUDGE VOLUME, 1000 CU YD
IOOO
\ —
,
/
X
/
/
' /
/
OPERATION
t
/
/
/
!
a MAINTENANCE
i
1
COST
i
i /
160 Mile
i
:
.
1
1
/
80 Mile A
. *
f *
/-
\
.
.f
s /
s/
'\/
x
s^
/
/•/
//
f
f
/
/
^
• i.
1,
/
f
',
/
f
s
\s
' /
//
> /
W'
jr /
S\S
j\
s\
\j
\
y
./
v/
4O Mile
i
/
/
/
/
/
/
s
"?
7
/
/
/
-^
>
«
j
i
i
10 IOO
ANNUAL SLUDGE VOLUME, IOOO CU YD
IOOO
H-203
-------
FIGURE H-88
DEWATERED SLUDGE TRANSPORT (TRUCK)
Service Life: 15 years
Level of Reliability: Level B
Design Basis;
1. Construction cost includes truck purchase and load/unload
facilities.
2. Operation and maintenance costs include truck maintenance, truck
operation and fuel, labor for truck and loading facility
operation, electrical power, and supplies for the loading
facility.
3. Costs are based on use of most cost effective size trucks per
volume of sludge transported. Truck sizes are 10 yd-* and 30 yd^.
4. Loading hopper is sized for one truck.
5. Equipment is sized to fill truck in 20 minutes maximum.
6. Loading into truck is by gravity. Truck unloading at disposal
sites is also by gravity.
7. Storage at unloading site is not included in cost.
8. Costs are based on 8 hours operation per day for 360 days
per year.
9. Travel distances of 10, 20, or 40 miles one way to disposal site.
10. Dewatered sludge cake solid content: 25%
Reference: 46
H-204
-------
FIGURE H-88 DEWATERED SLUDGE TRANSPORT (TRUCK)
v>
o
o
o
o
2
o
0
o
o
rH-TCONSTRUCTION COST
10 100 1000
ANNUAL SLUDGE VOLUME, 1000 CU YD
OPERATION 8 MAINTENANCE COST -~
0.01
IO 100 IOOO
ANNUAL SLUDGE VOLUME, IOOO CU YD
H-205
-------
FIGURE H-89
LIQUID SLUDGE TRANSPORT (TRUCK)
Service Life; 15 years
Level of Reliability; Level B
Design Basis;
1. Construction costs include truck purchase and load/unload
facilities.
2. Operation and maintenance costs include truck maintenance, truck
operation and fuel, labor for truck and loading facility opera-
tion, electrical power, and supplies for the loading facility.
3. Costs are based on use of most cost effective size trucks per
volume of sludge transported. Truck sizes are 1200 gallon,
2500 gallon, and 5500 gallon.
4. Equipment is sized to fill truck in 20 minutes maximum.
5. Loading into truck is by gravity. Truck unloading at disposal
site is also by gravity.
6. Storage at unloading site is not included in cost.
7. Costs are based on 8 hours operation per day for 360 days
per year.
8. Travel distances of 10, 20, or 40 miles one way to disposal site.
9. Fuel cost (gasoline) = $0.60/gallon.
10. Liquid sludge = 4% solids.
Reference: 46
H-206
-------
FIGURE H-89 LIQUID SLUDGE TRANSPORT (TRUCK)
1 \J
1.0
w
o
0
to
c
o
2 O.I
0.01
1
10
tf)
o
o
1.0
«•-
O
(O
c
o
2
CO
0
O
0 1
o
=
c
c
0.01
1
i — i ' — 1 —
i— .^L
1 . i
i • '
'!
\
':
^
^
^^0
*—
!
i
I ;
ICONSTRUCTION CO
! !
-f"*-H
O Mil
\
\ 20
i
x^|
— -'^
x
si
^ — • —
r , ^
Miles/
w/
T>gx^
ST—^-H+LU
i • . • 1
: : : -i I/I
: i : X^ -
1 : \' \r i
1 : >A/\ 1
i iyir/1
1 /^ i/T"1
y i/^ >
/ | :
f ! i 'I''
S ,s ~j^\ -
SsS
• Xx y ' ••
'S^ i : . i 1
^1-^t
i : , ; !
i
0 Mile;
: j
. | ,
i ' i !
i i
• i
: ; i
.0
j t
1
; '. i
1 : i
_ . i — _H
, i - i '
'
i
1
|
f
j_
!
t [ !
j ; • 1 - . ;
i !
: i i
; ;
1
j
10 IOO IOOO
SLUDGE VOLUME, mg
OPERATION 8 MAINTENAhi
1 i
• i i
f
1 '
: , i
i
— "—. —
f-E COST""4""! ill-
' ' • '. ' -
j -
!
I i
1
1 !
; : : / | ,
: ' ! /. ' '< i
i /T/K i
1 j > j , J/T ,/ ; :
, X Xi ! X :
i : x xC>
/I/IH
N»^ / / y*
1 , 2O Miles^/; / '/ ]
i
.^-*
,
^^
"^T"
^
~
^
-\
\:/ y A
y\ ^y
x^i ijpr ,
' [>r^' Lx*^
IS >T
^X"! jX^ , •
\^tf\ j
'/ ; !
r
v° V,ile* i i
1 :
\
.0
^^ .
^
' i i r '
i ' :
-*-
i I ; ! ' ;
1 i i '
i I '
1 I
! — ' i | , • • i i p
'I'll 1 . •
' '
' ! • ;
i • ; ' ' '
j !
i
j •
10 IOO IOOO
SLUDGE VOLUME, mg
H-207
-------
FIGURE H-90
SLUDGE TRANSPORT (PIPELINE)
Service Life: 15 years
Relative Reliability; Level B
Design Basis:
1. Construction cost includes: pipeline and pumping stations. Cost
includes one major highway crossing per mile, one single rail
crossing per 5 miles, and a nominal number of driveways and minor
road crossings.
2. Flow velocity = 4.0 fps.
3. Pumping distances of 5, 10, and 20 miles.
4. No rock excavation or major unusual problems (for hard rock
add 70% to cost).
5. Pipeline is buried 3 to 6 feet. For 6-10 feet, add 15% to cost.
6. No elevation change in pipeline.
7. Minimum pipe size is 4 inches.
8. Pipeline is cement-lined cast iron or ductile iron.
9. Costs based on 12 hours pumping per day.
10. Operation and maintenance cost includes labor, supplies and
electrical power for pump stations.
11. Pumps are dry-pit, horizontal or vertical, non-clog centrifugal
pumps operating at 1780 rpm.
Reference: 46
H-208
-------
FIGURE H-90 SLUDGE TRANSPORT (PIPELINE)
O
"o
O
c
0
Q
0
10
c
0
O
O
O
3
C
IO
IOO IOOO
SLUDGE PUMPING RATE, GPM
IO,OOO
I.O
0.1
O.OI
0.001
OPERATION 8 MAINTENANCE COST!
20 Miles
10 Miles
5 Miles
IOO IOOO
SLUDGE PUMPING RATE, GPM
IO.OOO
H-209
-------
H.9 References
1. Smith,-R., et al., "Cost of Alternative Processes for Wastewater
Disinfection". U.S. EPA, Cincinnati, Ohio (October, 1974).
2. Smith, R., "The Cost of Dispersed Floe Nitrification and Dentrifica-
tion for Removal of Nitrogen from Wastewater". U.S. EPA, Cincinnati,
Ohio (November, 1970).
3. Patterson, W.L. and Banker, R.F., "Estimating Costs and Manpower
Requirements for Conventional Wastewater Treatment Facilities". U.S.
EPA Report No. 17090 DAN 10/71 (October, 1971).
4. Van Note, R.H., et al., "A Guide to the Selection of Cost-Effective
Wastewater Treatment Systems". U.S. EPA Report No. 430/9-75-002
(July, 1975).
5. Metcalf and Eddy, Inc., "Assessment of Technologies and Costs for
Publicly Owned Treatment Works". Report to the National Commission
on Water Quality (September, 1975).
6. Roy F. Weston, Inc., Cost Curves Developed for U.S. EPA Miscellaneous
Chemical Industry Effluent Guidelines Project (January, 1975).
7. Roy F. Weston, Inc., Internal Cost-Estimating Computer Program -
DYNAMO 1.
8. Smith, R., "Electrical Power Consumption for Municipal Wastewater
Treatment". U.S. EPA, Cincinnati, Ohio (August, 1972).
9. Roy F. Weston, Inc., Cost Projections Based on National Average Unit
Costs Obtained From: a) Literature References; b) Weston In-house
Cost Data; c) Manufacturers' Information.
10. Wyatt, J.M. and White, P.E. Jr., "Sludge Processing, Transportation
and Disposal/Resource Recovery: A Planning Perspective". U.S. EPA
Report No. WA-75-R024 (December, 1975).
11. Smith, R. and McMichael, W.F., "Cost and Performance Estimates for
Tertiary Wastewater Treating Processes". U.S. Department of the
Interior Report No. TWRC-9 (June, 1969).
12. Toftner, R.O., "Planner's Handbook for Residual Waste Management".
U.S. EPA Draft Report (March, 1976).
13. U.S. EPA Technology Transfer, "Process Design Manual for Sludge
Treatment and Disposal". Report No. 625/1-74-006 (October, 1974).
14. Hagerty, D.J., Pavoni, J.L., and Heer, J.E. Jr., "Solid Waste
Management". New York: Van Nostrand-Reinhold Company (1973).
H-210
-------
15. Pavoni, J.L., Heer, J.E. Jr., and Hagerty, D.J., "Handbook of Solid
Waste Disposal: Materials and Energy Recovery". New York: Van
Nostrand-Reinhold Company (1975).
16. Cruver, J.E., Beckman, J.E., and Bevege, E.E., "Water Renovation of
Municipal Effluents by Reverse Osmosis". U.S. EPA Report No. 17040
EOR (August, 1972).
17. Universal Oil Products Company, ROGA Division, "Reverse Osmosis
Principles and Applications". Training Manual (October, 1970).
18. Gulp, R.L., Wesner, W.J., and Gulp, G.L., "Costs of Chemical
Clarification of Wastewater". U.S. EPA Draft Report for Contract
No. 68-03-2186 (January, 1976).
19. U.S. EPA Technology Transfer, "Process Design Manual for Nitrogen
Control" (October, 1975).
20. "Relative Cost Study of Alternate Phosphorous Removal Processes for
Wastewater Application". Boyle Engineering (June, 1972).
21. Ducan, G.J. and Levin, P., "Mathematical Model of Sewage Sludge
Fluidized Bed Incinerator Capacities and Costs". FWPCA Report
No. TWRC-10 (September, 1969).
22. Mayrose, D.T., "Fluidized Bed Reactors Ease Problems", Water and
Wastes Engineering, 13, No. 10, pg. 56 (1976).
23. Weing, Lewis J., Almgran, H.H., and Gulp, R.L., "Effects of Thermal
Treatment of Sludge on Municipal Wastewater Treatment Costs". U.S.
EPA Contract No. 68-03-2186 (1976).
24. U.S. EPA Technology Transfer, "Process Design Manual for Suspended
Solids Removal". No. 625/l-75-003a (January, 1975).
25. U.S..EPA Technology Transfer, "Process Design Manual for Phosphorus
Removal" (October, 1974).
26. Eilers, R.G., "Condensed One-Page Cost Estimates for Wastewater
Treatment". U.S. EPA, Cincinnati, Ohio (November, 1970).
27. Pound, C.E., Crites, R.W., Griffes, D.A., "Costs of Wastewater
Treatment by Land Application". U.S. EPA Contract No. 68-01-0966
(June, 1975).
28. Smith, R., "Cost-Effective Analysis for Water Pollution Control".
U.S. EPA (1974).
29. U.S. EPA Technology Transfer, "Process Design Manual for Carbon
Adsorption" (October, 1973).
H-211
-------
30. Roesler, J.F., Smith, R., "A Mathematical Model for a Trickling
Filter". U.S. Department of the Interior, FWPCA, Taft Water Research
Center, 1969.
31. Environmental Quality Systems, Inc., "Technical and Economic Review of
Advanced Waste Treatment Process". Office of the Chief of Engineers,
U.S. Army Corp of Engineers (March, 1973).
32. Council on Environmental Quality and U.S. EPA "Evaluation of Municipal
Sewage Treatment Alternatives" (February, 1974).
33. Smith, R., "New Technology for Carbon and Nitrogen Removal - Single Stage
Activated Sludge, Bio-Disc, or Fluidized Bed". U.S. EPA, Cincinnati,
Ohio.
34. Burd, R.G., "A Study of Sludge Handling and Disposal". FWPCA (May, 1968).
35. Ehlich, W.F., "What's Best for Sludge Transport". Water and Wastes
Engineering (October, 1976).
36. Benjes, H.H., Jr., "Estimating Construction Costs and Operating and
Maintenance Requirements for Combined Sewer Overflow Storage and
Treatment Facilities". Prepared for Municipal Environmental Research
Laboratory, Cincinnati, Ohio (May, 1976).
37. Hydroscience, Inc., "Texas Stormwater Manual on Treatment", Draft
Report.
38. "Costs of Wastewater Treatment by Land Application". U.S. EPA Report
No. 430/9-75 (1975).
39. Kalinske, A.A., "Comparison of Air and Oxygen Activated Sludge Systems".
Journal Water Pollution Control Federation, pg. 2472 (November, 1976).
40. Chapman, T.D., Matsch, L.C., and Zander, H.H., "Effect of High Dissolved
Oxygen Concentration in Activated Sludge Systems". Journal Water
Pollution Control Federation, pg. 2486 (November, 1976).
41. Parker, D.S. and Merrill, S.L., "Oxygen and Air Activated Sludge:
Another View". Journal Water Pollution Control Federation, pg. 2511
(November, 1976).
42. "Urban Stormwater Management and Technology - An Assessment". U.S. EPA
Report No. 670/2-74-040 (1974).
43. Benjes, H.H., Jr., "Small Community Wastewater Treatment Facilities".
Presented at EPA Technology Transfer, National Conference on Small
Wastewater Treatment Systems, Portland, Oregon, March 8-10, 1977.
H-212
-------
44. "Energy Conservation in Municipal Wastewater Treatment". Draft Report,
U.S. EPA Contract No. 68-03-2186 (November, 1976).
45. "Estimating Staffing for Municipal Wastewater Treatment Facilities".
U.S. EPA Contract No. 68-01-0328.
46. Ettlich.W.F., "Transport of Sewage Sludge". EPA Contract No. 68-03-2186
(August, 1976).
47. Culp/Wesner/Culp, "A Comparison of Oxidation Ditch Plants to Competing
Processes for Secondary and Advanced Treatment of Municipal Wastewater".
U.S. EPA Contract No. 68-03-2186.
48. Benjes, H.H., Jr., "Evaluation of Biological Wastewater Treatment
Processes".
49. "Energy Conservation in Municipal Wastewater Treatment". U.S. EPA
Draft Report, Contract No. 68-03-2186, Task No. 9 (November, 1976).
50. Smith, R. and Eilers, R.G., "Computer Evaluation of Sludge Handling
and Disposal Costs". U.S. EPA, Cincinnati, Ohio.
51. "Cost Estimates for Construction of Publicly-Owned Wastewater Treatment
Facilities - Summaries of Technical Data for Combined Sewer Overflows
and Stormwater Discharge, 1976 Needs Survey". U.S. EPA Report No.
430/9-76-012, MCD Report No. 48C (February 10, 1977).
52. "Cost Estimates for Construction of Publicly-Owned Wastewater Treatment
Facilities - Summaries of Technical Data, Categories I-IV, 1976 Needs
Survey". U.S. EPA Report No. 430/9-76-011, MCD Report No. 48C
(February 10, 1977).
53. Colacicco, D. et al. "Costs of Sludge Composting." Agricultural
Research Service, U.S. Dept. of Agriculture ARS-NE-79, February 1977.
H-213
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/9-76-014
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
Areawide Assessment Procedures Manual
5. REPORT DATE
July 1976 (Issuing Date)
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Municipal Environmental Research Laboratory
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS ,
U.S.Environmental Protection Agency, MERL
Wastewater Research Division
26 West St. Clair Street
Cincinnati, Ohio 45268
10. PROGRAM ELEMENT NO.
1HC619
11. CONTRACT/GRANT NO.
68-03-2428 68-03-2445
68-03-2437 68-01-4158
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohi 45268
13. TYPE OF REPORT AND PERIOD COVERED
Planning Manual
14. SPONSORING AGENCY CODE
EPA/600/14
15. SUPPLEMENTARY NOTES The manual is prepared as an information document and users plannin
manual to support the Agency's 208 areawide waste treatment management and planning
effort. It is a joint effort of the Office of Research and Development and the Office
of Water Planning and Standards.
16. ABSTRACT pert^nent to ^e implementation of State and areawide planning under Section
208 of P.L. 92-500, this manual provides an environmental management statement of pro-
cedures available for water quality management with particular emphasis on urban storm-
water. The manual summarizes and presents in condensed form a range of available proced
ures and methodologies that are available for identifying and estimating pollutant load
generation and transport from major sources within water quality management planning
areas. Although an annotated chapter is provided for the assessment of non-urban pollut
ant loads, the major emphasis oFthe manual is directed toward the assessment of prob-
lems and selection of alternatives in urban areas, with particular concern for storm-
water related problems. Also included in the manual are methodologies for assessing th
present and future water quality impacts from major sources as well as summaries of
available information and techniques for analysis and selection of structural and non-
structual control alternatives.
This manual is structured to present problem assessment and impact analysis
approaches for several levels of planning sophistication. Simple procedures are recom-
mended for initial analysis to develop the insight and problem understanding to guide
the application of more complex techniques where required. Presented in three volumes
the specific sections are as follows: procedures for assessment of urban and non-urban
pollution sources and loadings, pollutional load stream impact analysis, methodology
for evaluation and selection of control alternatives, rainfall runoff and water qualit
model applicability, land use and rainfall data analysis, runoff and water quality moni
toring and parameter handbook, and cost and performance of structural and nonstructural
pollution control alternatives.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATl Field/Group
Water quality, Assessments, Mathemati-
cal models, Systems analysis, Urban
areas, Rural areas, Waste water--
water pollution, Waste treatment,
Rainfall, Runoff, Regional planning,
Cost effectiveness—management methods
Areawide planning, Statistical
analysis, Stream impact analy-
sis, Treatment alternative
evaluation, AAPM, Section 208,
P.L. 92-500, Monitoring, Point
source pollution, Nonpoint
source pollution
13B
18. DISTRIBUTION STATEMENT
Release Unlimited
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
2129
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
U.S. GOVERNMENT PRINTING OFFICE: 1977-757-056/61*1(3 Region No. 5-11
------- |