v United States
v Environmental Protection Office of Water EPA 811-D-93-002
' Agency 4603 April 1993
&EPA LARGE WATER SYSTEM
BYPRODUCTS TREATMENT AND
DISPOSAL COST DOCUMENT
00 2Q
U.S. EPA Headquarters Li
Mail code3S
1200 Pennsylvania Avenue NW
. Washington DC 20460
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LARGE WATER SYSTEM BYPRODUCTS
TREATMENT AND DISPOSAL COST DOCUMENT
Prepared for:
U.S. Environmental Protection Agency
Office of Ground Water and Drinking Water
Drinking Water Standards Division
401 M Street S.W.
Washington, D.C. 20460
Prepared by:
DPRA Incorporated
E-1500 First National Bank Building
332 Minnesota Street
St. Paul, Minnesota 55101
April 1993
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Notice
This document has been reviewed in accordance with U.S. Environmental Protection Agency
policy and approved for publication. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
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TABLE OF CONTENTS
Page
1.0 INTRODUCTION 1
1.1 BACKGROUND . 1
1.2 PURPOSE AND SCOPE 1
1.3 WATER TREATMENT PROCESSES 2
1.4 BYPRODUCTS GENERATED 6
1.5 BYPRODUCTS MANAGEMENT OPTIONS OVERVIEW 7
2.0 BYPRODUCT CHARACTERIZATION 8
2.1 INTRODUCTION 8
2.2 CHEMICAL COAGULATION AND FILTRATION 9
2.3 LIME SOFTENING 11
2.4 ION EXCHANGE 12
2.5 REVERSE OSMOSIS . 14
2.6 BYPRODUCT DENSITIES 14
2.7 REFERENCES ' 16
3.0 COST ASSUMPTIONS 17
3.1 INTRODUCTION 17
3.2 CAPITAL COST ASSUMPTIONS 17
3.3 OPERATION AND MAINTENANCE ASSUMPTIONS 19
3.4 ANNUAL CAPITAL COST ASSUMPTIONS . 20
3.5 COST COMPONENTS EXCLUDED 21
3.6 COST EQUATIONS 22
3.7 CALCULATING BYPRODUCT MANAGEMENT COSTS 23
4.0 GRAVITY THICKENING 28
4.1 TECHNOLOGY DESCRIPTION 28
4.2 TECHNOLOGY APPLICABILITY AND LIMITATIONS 29
4.3 COST COMPONENTS 29
4.3.1 Design Assumptions 29
4.3.2 Capital Cost Components 30
4.3.3 Operation and Maintenance Components 30
4.3.4 Cost Components Excluded 31
4.4 GRAVITY THICKENING COST EQUATIONS 32
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TABLE OF CONTENTS
(continued)
Page
5.0 CHEMICAL PRECIPITATION ! 34
5.1 TECHNOLOGY DESCRIPTION 34
5.2 TECHNOLOGY APPLICABILITY 34
5.3 TECHNOLOGY LIMITATIONS 35
5.4 COST COMPONENTS 35
5.4.1 Design Assumptions 36
5.4.2 Capital Components 36
5.4.3 Operation and Maintenance Components 37
5.4.4 Cost Components Excluded 37
5.5 COST EQUATIONS 38
6.0 MECHANICAL DEWATERING .'. 40
6.1 PRESSURE FILTER PRESS DESCRIPTION 40
6.2 TECHNOLOGY APPLICABILITY 41
6.3 TECHNOLOGY LIMITATIONS 41
6.4 PRESSURE FILTER PRESS COST COMPONENTS 42
6.4.1 Design Assumptions 42
6.4.2 Capital Components 42
6.4.3 Operation and Maintenance Components 43
6.4.4 Cost Components Excluded 45
6.5 PRESSURE FILTER PRESS COST EQUATIONS 45
6.6 SCROLL CENTRIFUGE DESCRIPTION 46
6.7 TECHNOLOGY APPLICABILITY 47
6.8 TECHNOLOGY LIMITATIONS 48
6.9 SCROLL CENTRIFUGE COST COMPONENTS 48
6.9.1 Design Assumptions 48
6.9.2 Capital Components 49
6.9.3 Operation and Maintenance Components 49
6.9.4 Cost Components Excluded . . . ., 50
6.10 SCROLL CENTRIFUGE COST EQUATIONS 51
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TABLE OF CONTENTS
(continued)
Page
7.0 NONMECHANICAL DEWATERING 53
7.1 LAGOON DESCRIPTION 53
7.2 TECHNOLOGY APPLICABILITY 54
7.3 TECHNOLOGY LIMITATIONS 55
7.4 STORAGE LAGOONS COST COMPONENTS 56
7.4.1 Design Assumptions 56
7.4.2 Capital Components 57
7.4.3 Operation and Maintenance Components 59
7.4.4 Cost Components Excluded . 59
7.5 LIME SOFTENING STORAGE LAGOON COST EQUATIONS 59
7.6 ALUM SLUDGE STORAGE LAGOONS COST EQUATIONS 61
s*"
8.0 EVAPORATION PONDS 63
8.1 TECHNOLOGY DESCRIPTION *. 63
8.2 TECHNOLOGY APPLICABILITY . 64
8.3 TECHNOLOGY LIMITATIONS 64
8.4 COST COMPONENTS 65
8.4.1 Design Assumptions 65
8.4.2 Capital Components 66
8.4.3 Operation and Maintenance Components 66
8.4.4 Cost Components Excluded 67
8.5 COST EQUATIONS 67
9.0 POTW DISCHARGE 70
9:1 TECHNOLOGY DESCRIPTION 70
9.2 TECHNOLOGY APPLICABILITY . 71
9.3 TECHNOLOGY LIMITATIONS 72
9.4 COST COMPONENTS 72
, 9.4.1 Design Assumptions 73
9.4.2 Capital Components 73
9.4.3 Operation and Maintenance Components 73
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TABLE OF CONTENTS
(continued)
Page
9.4.4 Cost Components Excluded 74
9.5 COST EQUATIONS 75
9.5.1 500 Feet of Discharge Pipe 75
9.5.2 1000 Feet of Discharge Pipe 76
9.5.3 500 Feet of Discharge Pipe with a
Holding Tank or Lagoon . 77
9.5.4 1000 Feet of Discharge Pipe with a
Holding Tank or Lagoon 79
10.0 DIRECT DISCHARGE 81
10.1 TECHNOLOGY DESCRIPTION 81
10.2 TECHNOLOGY APPLICABILITY . . -^ 82
10.3 TECHNOLOGY LIMITATIONS 82
10.4 COST COMPONENTS 83
10.4.1 Design Assumptions 83
10.4.2 Capital Components 83
10.4.3 Operation and Maintenance Components 84
10.4.4 Cost Components Excluded 85
10.5 COST EQUATIONS 85
10.5.1 500 Feet of Discharge Pipe 85
10.5.2 1000 Feet of Discharge Pipe 86
10.5.3 500 Feet of Discharge Pipe with a
Holding Tank or Lagoon 87
10.5.4 1000 Feet of Discharge Pipe with a
Holding Tank or Lagoon 88
11.0 LAND APPLICATION 90
11.1 TECHNOLOGY DESCRIPTION 90
11.2 TECHNOLOGY APPLICABILITY 91
11.3 TECHNOLOGY LIMITATIONS 92
11.4 LIQUID SLUDGE LAND APPLICATION COST COMPONENTS . . 93
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TABLE OF CONTENTS
(continued)
Page
11.4.1 Design Assumptions 93
11.4.2 Capital Components 94
11.4.3 Operation and Maintenance Components 94
11.4.4 Cost Components Excluded 95
11.5 LIQUID SLUDGE LAND APPLICATION COST EQUATIONS 95
11.5.1 Sprinkler System 95
11.5.2 Trucking System 96
11.6 DEWATERED SLUDGE LAND APPLICATION COST
COMPONENTS 97
11.6.1 Design Assumptions 97
11.6.2 Capital Components 97
11.6.3 Operation and Maintenance Components 98
11.6.4 Cost Components Excluded 98
11.7 DEWATERED SLUDGE LAND APPLICATION COST
EQUATIONS 98
12.0 NONHAZARDOUS WASTE LANDFILL 101
12.1 TECHNOLOGY DESCRIPTION 101
12.2 TECHNOLOGY APPLICABILITY AND LIMITATIONS 102
12.3 OFF-SITE NONHAZARDOUS WASTE LANDFILL
COST COMPONENTS 103
12.3.1 Cost Assumptions 103
12.3.2 Cost Components 103
12.4 OFF-SITE NONHAZARDOUS WASTE LANDFILL
COST EQUATION 104
12.5 ON-SITE NONHAZARDOUS WASTE LANDFILL
COST COMPONENTS 104
12.5.1 Design Assumptions 104
12.5.2 Capital Components 105
12.5.3 Operation and Maintenance Components 105
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TABLE OF CONTENTS
(continued)
Page
12.5.4 Closure Components ; 105
12.5.5 Post-Closure Components 105
12.5.6 Cost Components Excluded 106
12.6 ON-SITE NONHAZARDOUS WASTE LANDFILL COST
EQUATIONS 106
13.0 HAZARDOUS WASTE LANDFILL ; 108
13.1 TECHNOLOGY DESCRIPTION 108
13.2 TECHNOLOGY APPLICABILITY AND LIMITATIONS 109
13.3 COST COMPONENTS 110
13.3.1 Cost Assumptions 110
13.3.2 Cost Components 110
13.3.3 Cost Components Excluded .111
13.4 TOTAL ANNUAL COST EQUATION Ill
13.4.1 Hazardous Waste Disposal Ill
13.4.2 Stabilization and Hazardous Waste Disposal Ill
14.0 RADIOACTIVE WASTE DISPOSAL 112
14.1 SOURCES OF RADIOACTIVITY IN DRINKING WATER 112
14.2 RADIUM REMOVAL 113
14.3 LOW-LEVEL RADIOACTIVE WASTE DISPOSAL 114
14.4 COST INFORMATION 116
15.0 REFERENCES 117
Appendix A - POTW Charges
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TABLE OF CONTENTS
(continued)
LIST OF TABLES
Table 1 - Water System Categories 2
Table 2 - Chemical Coagulation Sludge Volumes 9
Table 3 - Lime Softening Sludge Volumes . 12
Table 4 - Ion Exchange Brine Volumes 13
Table 5 - Reverse Osmosis Brine Volumes 15
Table 6 - Capital Cost Factors And Selected Unit Costs 18
Table 7 - Operation and Maintenance Cost Factors And Unit Costs 20
Table 8 - Treatment System Sizing 24
Table 9 - Gravity Thickening 31
Table 10 - Chemical Precipitation 37
Table 11 - Pressure Filter Presses 44
Table 12 - Scroll Centrifuge .50
Table 13 - Storage Lagoons - Lime Softening Sludge . . 58
Table 14 - Storage Lagoons - Alum Sludge . 58
Table 15 - Evaporation Ponds 67
Table 16 - POTW Discharge 74
Table 17 - Direct Discharge 84
Table 18 - Liquid Sludge Land Application 94
Table 19 - Dewatered Sludge Land Application 98
LIST OF FIGURES
Figure 1 - Sludge/Slurry Producing Water Treatment Processes ,. 4
Figure 2 - Brine Producing Water Treatment Processes 5
Figure 3 - Brine Treatment and Disposal Options 25
Figure 4 - Sludge/Slurry Treatment and Disposal Options 26
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1.0 INTRODUCTION
1.1 BACKGROUND
The Safe Drinking Water Act (SDWA) Amendments of 1986 require the United States
Environmental Protection Agency (EPA) to list the best available technologies (BAT) capable
of meeting maximum contaminant level regulations. BAT is developed to assist EPA in
setting drinking water standards, particularly for taking into consideration the capabilities of
various treatment technologies for removing contaminants from water, to assist water utilities
in selecting appropriate treatment methods to meet the regulations, and to identify treatment
technologies that are appropriate for small systems under Section 1415 of the SDWA.
The Office of Ground Water and Drinking Water (OGWDW) must assess the waste treatment
i '
and disposal practices likely to be used by the regulated community as part of its
responsibilities to determine the costs of the National Primary Drinking Water Regulations. A
separate document addresses the byproduct management methods for small water treatment
systems.1
j
1.2 PURPOSE AND SCOPE
The purpose of this document is to present methods to estimate water byproduct management
costs for public water systems. Water systems addressed in this document include systems in
Categories 5 through 12 identified hi Table 1. These systems are designed for populations
' -v; C" ^.-,L , ' ,-. i.' ,'ซ i?te'
ranging from 3;301 people to more than one million people and have design flow rates ranging
from 1.8 to 430 million gallons per day (MOD).
1 Small Water System Byproducts Treatment and Disposal Cost Document, Draft Final,
DPRA Incorporated, April 1993.
1 ' ' ' .
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TABLE 1
WATER SYSTEM CATEGORIES
Category
1
2 '
3
4
5
6
7
8
9
10
11
12
Population Range
25-100
101-500
501-1,000
1,001-3,300
*. :
3,301-10,000
10,001-25,000
25',001-50,000
50,001-75,000
75,001-100,000
100,001-500,000
500,001-1,000,000
Greater than 1,000,000
Median
Population
57
225
750
1,910
5,500
15,500
35,500
60,000
88,100
175,000
730,000
1,550,000
Average
Flow
(MOD)
0.0056
0,024
0.086
0.23 .
0.7
2.1
5
8.8
13
27 ;
120
270
Design Flow
(MGD)
* 0.024
0.087
0.27
0.65
1.8
4.8
11
18
26
51
210
430
Source: U.S. EPA, OGWDW.
This document contains technology descriptions and the estimated costs for the treatment and
disposal of water treatment byproducts. Selected waste treatment and disposal options are .
' .till, .&ฃ,itb. _l. I. .. ' ซ
included in this document. These options are intended to provide a general overview of costs
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associated with the treatment and disposal of water treatment byproducts.
1.3 WATER TREATMENT PROCESSES
Four primary water treatment, processes that produce byproducts are considered in this
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document: 1) coagulation and filtration, 2) lime softening, 3) ion exchange, and 4) reverse
osmosis. Although this cost analysis focuses on byproducts from these four water treatment
processes, the costs presented in this document are applicable to byproducts from other water
treatment processes that produce similar residuals. The byproducts result from the material in
the unprocessed water (i.e., suspended and dissolved materials) and/or from the chemicals
used to,remove this material. Coagulation, filtration, and lime softening generate byproducts
classified as sludges and slurries. Ion exchange and reverse osmosis generate byproducts
classified as brines. Figures 1 and 2 present simplified flow diagrams of these four water
treatment processes. A brief description of each of these water treatment technologies is
presented below.
Coagulation and Filtration
Coagulation and filtration, also referred to more generically as suspended solids removal, are
processes used to remove a variety of substances including particulate matter that causes
turbidity, microorganisms, color, disinfection byproduct precursors, and some inorganic
contaminants. This type of treatment typically is used for surface water. The treatment
process consists of three phases: 1) addition of a coagulant which is vigorously mixed
" ' ""' '
throughout the water being treated, 2) light agitation of the water for a period of time to
promote particle growth and agglomeration, and 3) settling and/or filtration of the flocculent.
The resultant waste byproduct is a sludge or slurry.
Lime Softening '
Lime softening, also referred to as precipitative softening, can remove a wide range of
contaminants including turbidity, microorganisms, calcium, magnesium, barium, radium,
cadmium, lead, zinc, chromium ffi, and
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Fon Exchange
Historically, ion exchange was,used to remove hardness-causing cations, such as calcium and
magnesium; however, currently it also is used to remove radium, barium, iron, manganese,
cadmium, lead, chromium in and VI, nitrates, uranium, selenium, and arsenic V. This
treatment typically works best on ground waters, since surface waters frequently require
pretreatment to remove turbidity. Ion exchange is a separation process in which dissolved ions
undergo a phase transfer from a solution to a solid-surface phase. The resultant waste
byproduct is a brine. .
Reverse Osmosis
Reverse osmosis is used to treat water to remove a wide variety of contaminants including ions
in brackish water, ions that cause hardness, uranium, radium, and most inorganics regulated
i
under the SDWA. Reverse osmosis is not used to remove mercury or arsenic ffl. It is a
membrane-separation technique in which a semipermeable membrane allows water to permeate
through it while acting as a barrier to the passage of dissolved, colloidal, and paniculate
matter. The resultant waste byproduct is a brine.
1.4 BYPRODUCTS GENERATED
\
The byproducts generated are classified as either sludges and slurries or brines. The sludges
and slurries are water-solid mixtures where the solids or participates comprise at least 0.5
percent of the 'mixture and the solids are suspended rather than dissolved. Brines are solutions
/
with a dissolved salt concentration rather than an undissolved phase as with sludges and
slurries;ซBackwash water, whose composition depends on the water treatment technology.
employed; is assumed to.be routed into-the byproducts stream. In general, the backwash
stream has a composition similar enough to the primary byproduct for this to be practical.
The backwash volume is included in the~volumes considered for byproducts
treatment/disposal;
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1.5 BYPRODUCTS MANAGEMENT OPTIONS OVERVIEW
There are several management methods for water treatment byproducts. The management
method selected depends upon the water treatment practices and the byproduct characteristics.
Management methods should be thoroughly evaluated to minimize the possibility of generating
hazardous or low-level radioactive residuals. Hazardous and low-level, radioactive wastes.
must be managed in accordance. with existing regulations. Methods for management of the
byproducts produced from water treatment facilities include the following options:
Gravity Thickening
Chemical Precipitation
- . Mechanical Dewatering
Nonmechanical Dewatering
Evaporation Ponds ' -
POTW Discharge
Direct Discharge
Land Application , '
Nonhazardous Waste Landfill
Hazardous Waste Landfill
Radioactive Waste Disposal
Management options applicable to sludges and slurries include 1) mechanical dewatering, 2)
nonmechanical dewatering, 3) land application, 4) hazardous waste landfill, and 5)
nonhazardous waste landfill. Management options applicable to brines include 1) POTW
discharge, 2) chemical precipitation, 3) direct discharge, and 4) evaporation ponds.
In addition to the waste management options discussed above, deep well injection is a viable
disposal method for slurries and brines. Cost estimates for deep well injection are not
included in this document, however.?: uie y'~- .- i. .mu.
issu i..' ...^ariiiBg'&ese f, ararr-eter a
Radioactive waste management receives only limited discussion in this document. EPA has
developed draft guidance relating to these wastes entitled "Suggested Guidelines for the
Disposal of Drinking Water Wastes Containing Naturally Occurring Radionuclides." The
guidelines will be finalized when drinking water regulations for radionuclides are promulgated.
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2.0 BYPRODUCT CHARACTERIZATION
2.1 INTRODUCTION
^ j
r .
Water byproducts, or the waste streams generated.during the treatment of water to obtain
drinking water, consist of sludges, slurries, brines, and filter backwash. Whereas the sludges,
slurries, and brines are, for this study, considered treated directly^by one or more of the .
technologies presented in Sections 5.0 through 14.0, filter backwash may require pretreatment.
For these cases, it is assumed that filter backwash is pretreated by gravity thickening, which is
presented in Section 4.0. Following this pretreatment, the sludge from the thickener is then
treated by one of the technologies presented in Sections 5.0 through 14.0 and the decant is
either recycled to the head of the water treatment plant or is direct discharged.
- i
For this study, these byproducts are assumed to be generated from four water treatment
technologies: chemical coagulation and filtration, lime softening, ion exchange, and reverse
osmosis. Although this cost analysis focuses on byproduct volumes and characteristics
generated by these four technologies, the costs presented in this document are applicable to
byproducts from other water treatment processes that produce similar residuals.
In general, the volume of byproducts generated is dependent on the quality of feed water, the
efficiency of the treatment system, the water usage rate, the amount of chemicals used, and the
water treatment technology employed. The volume also can vary seasonally or monthly;
variations are not unusual for different months of the-year: To estimate the byproducts
generated on-a national basis, assumptions Tegardmg^ffiesฃparajneters are made and described
ii " (0' ! '1 "*'''.."
in the following paragraphs which address each-water-treatment technology.
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2.2 CHEMICAL COAGULATION AND FILTRATION
Chemical coagulation and filtration is frequently applied to surface waters to remove organic
matter and to pretreat hard-to-remove substances such as taste and odor compounds and color.
The most common chemical coagulant used is alum.
\
Based on actual facility data, alum sludge generation quantities range from 0.001 to 0.37
percent of the treated water flow rate with an average of 0.11 percent (Ref. 1). The alum
sludge volumes for each design flow category are summarized in Table 2. The solids
concentration of this sludge ranges from 0.5 to 3 percent. '
TABLE 2
CHEMICAL COAGULATION SLUDGE VOLUMES
Water Treatment
Plant Flow
, (mgd)
0.7
1.8
4.8
11
18
. ,26
i wratiorsyl *
210
, 430
' Typical Flow
Range
(gal/day)
7-2,600
18-6,700
48-17,800
110-^0,900
180-66,800
260-^96,600 ,
,51prl89,400^hl,
2,100-779,900 n
4,300-1,596,900
Typical
Volume
(gal/day)
770
2,000
5,300
12,100
19,800
.28,600 .
nf. S&MjOU, r:
231,300
473,500
From this analysis, the volume of chemical coagulation sludge generated ranges from 7 to
1,600,000 gallons of sludge per day depending on the water treatment plant capacity.
9
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The following equation can be used to estimate the amount of sludge produced in an alum
coagulation plant to remove turbidity based on specific feed water characteristics (Ref 2).
"^
S = 8.34 Q (0.44 Al + SS + A)
i
Where: S = sludge produced in pounds per day
Q = plant flow in million gallons per day
Al = Alum dose in milligrams per liter
SS = raw water suspended solids in milligrams per liter
A = .additional chemicals added such as polymer, clay,
or activated carbon in milligrams per liter
Since most water treatment plants do not routinely measure suspended solids, turbidity is often
used to estimate suspended solids. The relationship between turbidity and suspended solids
can be represented by the following equation:
i ,
* ซ .
i ' "
SS = b Tu ' .
Where: SS = raw water suspended solids in milligrams per liter
b = factor determined based on characteristics of raw
water, typically 0.7 to 2.2
Tu = turbidity
This correlation should be determined for a specific water treatment plant over a period of
time since turbidity can vary seasonally for the same water supply.
,'
The filter backwash volume from chemical coagulation and filtration depends upon the number
of filters and frequency and; duration of each backwashveyent^'The volume generated ranges
from 0.5 to 5 percent of the treated water. In general? large treatment plants will generate a
lower percentage of filter backwash than small treatme'ntiplants because they tend to operate
more efficiently. . .
10
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2.3 LIME SOFTENING
Lime softening is the precipitation of calcium, magnesium, and other cations from water using
lime and soda ash. Calcium and magnesium are the primary ions which contribute to water
hardness and for the purposes of this document, it is assumed that lime softening is used
specifically to remove calcium carbonate and magnesium bicarbonate hardness: It is also .
assumed that lime softening is performed only on ground water; however, in some regions of
the country, river water also may require softening.
The costs for treating/disposing of lime softening sludges, in general, do not include the two
largest design flow categories (210 and 430 MGD). It was assumed that a municipality with
these water demands may utilize a ground water source for a portion of their demand;
however, it is unlikely that its entire demand would be supplied by ground water.
t
The quantity of lime softening sludge ranges from 0.4 to 1.5 percent of the design flow rate,
with an average of 1.2 percent. The lime sludge volumes for each treated water design flow
are summarized in Table 3. The initial solids concentration of this sludge ranges from 2.4 to
greater than 25 percent with the majority of facilities having a solids concentration of 2.4
percent.
The volume of sludge generated from lime treatment facilities ranges from 2,800 to 6,600,000
gallons per day depending on the water treatment plant capacity.
. -IU t.-.ift5! iU! , ' will'. - '
The filter backwash volume from lime softening.depends oh the number of filters and
ii j i.u-i L/ciWiti*' *rJi^i_* . " i * '". ifiinii,
frequency and duration of each backwash event. The volume generated ranges from 0.5 to 5
percent of the treated water. In generalr large treatment plants willgenerate a lower
percentage of filter backwash than small treatment plants because they tend to operate more
efficiently.
11
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TABLE 3,
LIME SOFTENING SLUDGE VOLUMES
Water Treatment
Plant Flow
(mgd)
0.7
1,8
-4.8
11
18 ,
26
51
210 ;
430
Typical Volume
Range
(gal/day)
2,800-10,700
7,200-27,400
19,300-73,100
44,200-167,500
72,300-274,100
104,400-395,900
204,800-776,600
843,400-3,198,000
1,726,900-6,548,200
Typical
Volume
(gal/day)
8,500
21,900
58,300
133,600
218,600
315,800
619,400
2,550,600
5,222,700 ,
2.4 ION EXCHANGE
Ion exchange processes are used to soften water and remove impurities. Ion exchange systems
can be used to remove cations (e.g., calcium and magnesium) or anions (e.g., chloride).
ซ i :' ! ''..'
Brines-are produced from-rinsihg, regenerating, and bacfcwashing~the ion exchange unit. Of-
tt
these three byproducts streams, the regeneration stream contains the highest levels of total
dissolved solids (IDS) ranging from 10 to 300 tunes the levels found in the feed water. The
range of the average TDS from ion exchange brines is 15,000 to 35,000 milligrams per liter
(mg/1) (Ref. 2). -This high TDS content is the result of the salts removed from the exchange
resin during regeneration as well as excess regeneration salts.
12 '':'..
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By mixing the regeneration stream with the rinse and backwash streams, dilution>by
approximately an order of magnitude can be achieved.
The byproduct quantities (brines) from ion exchange range from 1.5 to 10 percent of the
treated water depending on the hardness of the feed water and the type of ion exchange unit
used. In general, for every kilogram of hardness removed, approximately 3 to 15 gallons of
brine are produced (Ref. 2). Operating data from six operating ion exchange water treatment
plants indicate that the volume of brine generated ranges from 17 to 83' gallons per 1000
gallons water processed (Ref. 2). Brine volumes are calculated assuming that these brine
generation rates are applicable to large treatment systems. The resultant brine generation rates
are provided in Table 4. ,
TABLE 4
ION EXCHANGE BRINE VOLUMES
Water Treatment
Plant Flow
(mgd)
0.7
1.8
4.8
11
18
1 26 .
51
210
430
Typical Volume Range
(gal/day)
12,300-63,200
31,500-162,500
84,000-^33,300
192,500-993,000
315,000-1,624,900
455,000-2,347,100
892,600-^,604,000
3,675,200-18,957,700 ,
7,525,400-38,818,100
Typical Volume
(gal/day)
12,300
. 31,500
84,000
192,500
315,000
455,000
892,600
3,675,200
7,525,400
13
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The volume of brine produced from ion exchange facilities ranges from approximately 12,000
\
to 38,900,000 gallons per day depending on the water treatment capacity, the quality of the
untreated water, and the type of ion exchange system used.
ป
(
2.5 REVERSE OSMOSIS
Reverse osmosis processes use a semi-permeable membrane that allows water to pass through
it while restricting the passage of dissolved, colloidal, and paniculate matter. The byproducts
stream contains the salts and other materials rejected by the membrane. The byproduct stream ,
has a high TDS concentration. Concentrations of specific contaminants in the byproducts
stream may range from 2 to 9 times the concentration in the feed water (Ref. 3). For the
facility sizes being considered in this analysis, the volume of reject water or brines produced
from backwashing the membrane are typically 15 to 20 percent of the feed flow with TDS
concentrations 3 to 4 times higher than the concentration of the feed water (Ref. 3). The
percentage of reject water produced decreases as the size of the water systems increase due to
increased efficiencies. For the purposes of estimating brine generation from reverse osmosis
water treatment plants, the volume of reject water is assumed to range from 15 to 20 percent
' *,
of the feed water. The brine volumes are presented hi Table 5.
The volume of brine produced from a reverse osmosis facility ranges from 123,500 to
107,500,000 gallons per day depending on the water treatment-plant capacity, initial water
quality, and efficiency of the membrane.
2.6 BYPRODUCT DENSITIES
The densities of the byproduct streams from the water treatment technologies considered hi
this analysis are, in general, dependent on the solids concentration. In general, the brines
resulting from reverse osmosis and ion exchange, although high in total dissolved solids, have
14
-------
TABLES
REVERSE OSMOSIS BRINE VOLUMES
Water Treatment
Plant Flow
(mgd)
0.7
1.8
4.8
11
18
26
51
210
430
Typical Flow Range
(gal/day)
123,500-175,000
317,600-450,000
847,100-1,200,000
1,941,200-2,750,000
3,176,500-4,500,000
4,588,200-6,500,000
9,000,000-12,750,000
37,058,800-52,500,000
75,882,400-107,500,000
Typical Volume
(gal/day)
175,000
1 450,000
1,200,000
1,941,200
3,176,500
4,588,200
9,000,000
37,058,800
75,882,400
a solids concentration of less'than one percent. Therefore, the brine density is assumed to be
that of water or 62.43 pounds per cubic feet (lb/ft3).
The density of the sludges generated from lime softening and chemical coagulation are more
variable and are dependent primarily on the solids concentration or moisture content. The
, \
sludge density is assumed to range from 64 to 74 lb/ft3 (Ref. 4). If the solids content of a
specific byproducts stream is known, the sludge density can be calculated from the following
equation (Ref. 3):
Density -
10Q
percent solids
density solids
+ 100-percent solids
density water
This equation is applicable for sludge with a solids concentration of less than 50 percent. A
15 -
-------
typical value for the density of the solids in an alurn or iron sludge is 145 lb/ft3 (Ref. 3).
Dewatered sludge densities can also be calculated using the equation provided as long as the
solids concentration remains below 50 percent. A typical density of a dewatered sludge is
assumed to be 100 lb/ft3 (Ref. 3).
2.7 REFERENCES
1. Robertson, R.F. and Y.T. Lin. "Filter Washwater and Alum Sludge Disposal: A Case
Study." Proceedings AWWA Seminar on Water Treatment Waste Disposal Seminar.
(June 25, 1978), 4, 1-8.
2. American Water Works Association. Handbook: Water Treatment Plant Waste
Management. 1987
3. American Water Works Association. Slih. Schlamm. Sludge KIWA Ltd., 1990.
4. American Water Works Association. Sludge: Handling and Disposal. Denver, CO:
American Water Works Association, 1989.
so fo/ rhe ccs'i ซ,.-ur- 'neiudet.
(
16
-------
3.0 COST ASSUMPTIONS
3.1 INTRODUCTION
The costs included in this document are based on a variety of sources including computer cost
models, published cost information, and vendor quotes. All costs presented in this document
are in 1992 dollars. The cost equations presented in this document should be used for relative
comparison purposes only. More accurate site specific cost estimates should be developed for
individual facility planning and budgeting purposes. Site specific factors and treatment ,
requirements like physical and qhemical characteristics of the residuals, site constraints,
operational costs and varying state or local regulatory requirements can all drive up final
project costs.
3.2 CAPITAL COST ASSUMPTIONS
Table 6 presents cost factors and unit costs used to calculate the capital costs presented in this
document. The land, buildings, and piping components are discussed in detail below. Other
capital cost items (e.g., tanks, lagoons, and pumps) were calculated individually.
Land - .
Land prices vary substantially across the country. Land prices depend on proximity to
metropolitan areas, state of land development (i.e., improved or unimproved), current use, and
scarcity of land. .An cost of $10,000 per acre is assumed for the cost.estimates included in this
document. Costs for suburban or industrial unimproved land averages $10,000 per acre and
ranges from approximately $4,000 to $350,000 per acre depending on location. Costs for
unimproved rural land vary from approximately $150 per acre in states with large tracts of
17 .
-------
TABLE 6
CAPITAL COST FACTORS AND SELECTED UNIT COSTS
Component
Factor/Unit Cost
Land
Buildings '
Piping
Pipe Fittings
Electrical
Instrumentation
Engineering Fee
Contingency, Bonding, & Mobilization
Contractor's Overhead and Profit
$10,000/Acre
$33.00/Ft2
5% of Installed Equipment*
20% of Piping Costsf
1 % of Installed Equipment
1-2% of Installed Equipment
15% of Direct Capital
20% of Direct Capital
12% of Direct Capital
* Piping costs are calculated directly when piping is a significant cost (e.g., for direct
discharge).
t Factor is used when piping costs are calculated directly.
undeveloped land to $2,200 per acre in states with small tracts of undeveloped land. An
average cost for rural, unimproved land is $1,000 per acre.
Costs for purchasing land are included in the capital cost equation for all treatment and
disposal processes that use surface impoundments. .For example, an impoundment is used for
storage prior to land application. The land costs are presented as a separate cost in the capital
cost equation to allow the user to delete the cost for land if no purchase is required or to vary
the cost of the land if the unit cost of land for a given area is available. A minimum land
purchase of '/z acre is used in developing land costs.
/
Land costs are not included for direct discharge and POTW discharge. It is assumed that the
water treatment authority is able to obtain an easement for placement of a sewer or discharge
line.
18
-------
Bujldings
Similar to land costs, building costs vary substantially based on geographic location. The
building cost of $33.00 per square-foot, listed in Table 6, is taken from 1992 Means Building
Constructipn Cost Data. This cost is for a basic warehouse or storage building and includes
electrical, foundations, heating, ventilation, air conditioning, and plumbing. It includes a 10
percent surcharge for structures of less than 25,000 square feet. This cost is the median cost
for basic warehouse and storage buildings. The lower quartile cost.is $21.30 per square foot .
- and the upper quartile cost is $45.65 per square foot. Different warehouse or building
configurations will change this unit cost.
\
Piping and Pipe Fittings . '
' Piping costs are calculated using two different methodologies depending on the magnitude of
the piping costs. For management systems in which the piping constitutes a significant portion
of the capital cost (e.g., direct discharge and POTW discharge), piping costs are calculated by
sizing individual pipe lengths and determining installation charges. For these management
r
systems, pipe fittings are assumed to be 20 percent of the installed piping costs. For
management systems where piping is not a significant cost (e.g., chemical precipitation and
mechanical dewatering), piping and pipe fittings are assumed to be 5 percent of the installed
equipment costs. .
t
s , ,
3.3 OPERATION AND MAINTENANCE ASSUMPTIONS
ipe . s .;
"W /
Table 7 presents cost factors and unit costs used to calculate the operation and maintenance
costs presented in this document. -The labor and supervision rates are discussed below.
19
-------
TABLET
OPERATION AND MAINTENANCE COST
FACTORS AND UNIT COSTS
Component
Factor/Unit Cost
Labor
Supervision
Supervision Factor
Insurance and General and
Administrative Expenses
Maintenance
Electricity
$28.00/Hour
$42.00/Hour
10% of Labor Hours
2% of Direct Capital, Excluding
Land and Buildings
2-3% of Direct Capital, Excluding
Land and Buildings
$0.086/Kilowatt-Hour
Labor
The labor rate is based on a 20-city average for union scale laborers. The hourly rate of
$28.00 is based on an average salary of $18.74 per hour including fringe benefits and a 50
percent labor overhead cost. Average salaries, including fringe benefits, by region range from
$1 1 . 17 per hour in the southeast to $26.23 in the western United States.
i
Suervision .
The supervision rate is based on an estimated salary of $45,000 per year for a water system
treatment manager. The $42.00 per hour assumes a 30 percent fringe benefit and a 50 percent
* '
labor overhead cost. The supervisor's salary is based on recent job postings in Public Works
''.
magazine.
3.4 ANNUAL COST ASSUMPTIONS
Total annual costs are equal to the sum of the yearly operation and maintenance costs plus the
20
-------
annualized capital costs. Annualized capital costs are calculated based on a 20-year operating
life and an interest rate of 10 percent. The capital recovery factor for a 20-year operating life
at a 10 percent interest rate is 0.1175. Alternate capital recovery factors can be calculated
using the formula presented below.
Capital Recovery Factor = fl + ft N (ft
Where: i = interest rate
N = number of years
3.5 COST COMPONENTS EXCLUDED
i p
The following,cost components are not included in the cost estimates presented in this
document. Other excluded costs, specific to each management option, are highlighted under
their respective technology cost sections.
i
Sample Collection and Laboratory Analysis
Costs for sample collection and analysis to determine solids content, free liquids, and toxicity
characteristics, and other parameters are not included in the costs presented in this document.
Sampling frequency is highly variable. Depending on the byproducts management method
selected, sampling requirements could be minimal or extensive.
't th.c '' '**' -I'-'cJc T ,'
Permits and Other Regulatory Requirements
Costs for permits and other regulatory requirements are not included in this analysis.
Requirements vary from state to state for a given management option. Permitting costs will
vary based on the size and complexity of a unit and the local governing jurisdiction.
21
-------
Management methods that may require permits include landfills, land application, evaporation
ponds, and storage lagoons. In addition, generators of hazardous waste are required to comply
with RCRA generator requirements (40 CFR Part 262).
i
Mechanical Backup
Costs for equipment backup, or redundancy, are not included in these cost estimates.
3.6 COST EQUATIONS
The cost equations for the capital components and for operation and maintenance were
developed by estimating the costs for different byproduct flow rates. Equipment sizes,
retention times, installed equipment costs, operational maintenance expenses, commercial
disposal fees, component cost factors, and unit costs were developed using published
literature, supplemented with vendor contacts and application of best engineering judgement.
A list of references and vendor contacts used to compile technical and cost-related information
is'presented in Section 15.0. Capacities for major equipment components are presented in
each cost chapter. Each cost equation encompasses the range of expected byproduct flow rates
unless a specific technology is not applicable to the entire range. For example, some
technologies are not feasible for very high flow rates due to excessive land requirements or
equipment limitations.
The limits of the cost equations presented for each byproduct management method may be
extended slightly oey6hcfcthe limits presented in this'fdbcument. The upper or lower end for
some equations, however, may represent the largest or smallest practical limit of a specific
technology. Therefore, the technology limitations and design assumptions should be carefully
reviewed prior to extending the range of the equations. Best engineering judgement should be
used when extending the equations beyond their specified limits.
22
-------
The capital and operation and maintenance equations encompass the water byproduct volumes
generated by both the design flow rates and the average operating flow rates for Category 5
through 12 water treatment plants. The user may want to size the equipment (i.e., determine
the capital cost) for the byproducts produced from the water treatment system design flow rate,
while calculating the operating cost using the average byproduct flow rate. Thus, the
equipment is sized for peak flow periods, but the actual operating costs may be more closely
estimated using an average daily flow rate. Typically, the design flow rate for the water
treatment system may be two to three times the average flow rate for the water treatment
facility. When calculating the costs for capital intensive management technologies such as
\
chemical precipitation and mechanical dewatering, the user may want to calculate both the
capital and operation and maintenance costs using the average flow rate. Table 8 indicates
whether the water treatment design flow rate or average flow rate should be used to calculate
the capital and operation and maintenance costs. The user of this document may always use.
the design flow rate to calculate costs, but this may result in substantial over estimation of the
cost to treat water byproducts generated by an actual facility.
All costs presented in this chapter are hi 1992 dollars. To update cost results obtained from
the cost equations specified hi the following sections, Builders' Construction Cost Indexes may
be used and are available hi quarterly, "cost report" issues,of Engineering News Record
(ENR). The ENR 20-city construction cost index or the Means Construction Cost Index are
useful general-purpose cost updating indexes. Their January 1992 values are 455.08 and
97.90, respectively.
/
3.7 CALCULATING BYPRODUCT MANAGEMENT G0STS
&
Byproduct management costs are calculated using the cost equations presented hi the following
chapters. Known byproduct flow rates from an operating facility may be used or approximate
byproduct volumes can be estimated using the information presented in Sections 2.3 through
2.6. Figures 3 and 4 present management options applicable to brines and sludges/slurries,
23
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TABLES
TREATMENT SYSTEM SIZING
Technology
Gravity Thickening
Chemical Precipitation
Mechanical Dewatering
Non-mechanical Dewatering
Evaporation Ponds
POTW Discharge
Direct Discharge
\
French Drain
Land Application
Non-Hazardous Waste Disposal
Hazardous Waste Disposal
Radioactive Waste Disposal
Capital Cost
Average
Average
Average
Design
Design
Design
Design
Design
Design
Average
NA
NA
Operation & Maintenance
Cost
Average
Average
Average
Average
Average
Average
Average .
Average
Average
Average
NA .
NA
respectively. These figures present complete management trains. That is, they depict
byproduct management methods, resulting residuals, and management options for the
residuals. Individual cost chapters present residual factors to use to determine residual
c
S
volumes that require further treatment or disposal; The annual byproduct management costs
; , f --4 - ' & " ' '
can be determined by calculating a total annual'cost (i.e. annualized capital plus operating and
maintenance) for each required treatment or disposal technology and then summing die costs
associated with all water treatment byproduct and residual management processes at the
facility. .
24
-------
9
SAL OPTIONS
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Nonhazardous Waste Landfill - (Chapt
Low-Level Radioactive Waste Disposa
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4.0 GRAVITY THICKENING
4.1 TECHNOLOGY DESCRIPTION
t
In this report, gravity thickening is a treatment technology considered for filter backwash and
sludge. Gravity thickening serves to increase the solids concentration of these waste streams
.'
so they are treatable by one of the technologies addressed in the following sections. Even
though both filter backwash and sludges are applicable to gravity thickening, filter backwash is
presented in more detail in this section.
Filter backwash byproducts are high volume, low solids slurries generated during the cleaning
of water treatment plant filters. The volume of backwash waters generated varies for
individual treatment plants and depends upon the number of filters and the frequency and
duration of each backwash event. The total backwash volume is comprised of upfiow
backwash, downflow regeneration, and downflow rinse. In general, backwash volumes range
from 0.5 to 5.0 percent of the treated water with the larger treatment plants producing less
backwash per million gallons of treated water than smaller treatment plants due to increased
plant efficiency. , '
T
Where practical, backwash waters are recycled to the head of the treatment works for
management. Recycling serves two purposes: it reduces the quantity of treated water lost to
,backwashing and it reduces the total volume of sludge generated. In cases where backwash
recycling is not possible, discharge to a surface water, publicly-owned treatment works
(POTW), or treatment by nonmechanical arid mechanical dewatering are other treatment and
disposal options. .
In cases where backwash byproducts cannot be recirculated to the head of the plant or
discharged to a surface water or POTW, the backwash waters must be disposed as a water
28
-------
treatment slurry. Backwash waters are chemically similar, to sludges produced by chemical
coagulation, but are more dilute. Backwash waters have an average solids concentration of
\
0.08 percent, where chemical coagulation (alum) sludge have a solids concentration ranging
from 0.5 to 2.0 percent.
Backwash water and sludges is gravity-fed to a tank where gravity thickening is performed.
Gravity thickening occurs by allowing suspended solids to naturally settle. The sludge
discharged from the tank is routed for further treatment and the decant is either direct
discharged or recycled to the head of the treatment plant.
. . ('
4.2 TECHNOLOGY APPLICABILITY AND LIMITATIONS
Gravity thickening is applicable to the filter backwash streams and chemical coagulation or
lime softening byproducts streams and/or their sludge waste streams. Because of the high
volumes and low solids concentrations characteristic of the backwash stream, pretreatment is
necessary before the byproducts can be dewatered by the methods discussed hi the remainder
of this report. Often sludges can be managed either with or without pretreatment depending
on the initial sludge characteristics (e.g. solids concentration), however, pretreatment may
also be necessary to equalize flow rates.
4.3 COST COMPONENTS
The following section presents the design assumptions, capital components, and the operation
and maintenance components used to prepare the costs for this technology.
4.3.1 Design Assumptions
Gravity thickening is used to pretreat filter backwash or sludges from chemical
coagulation and lime softening.
29
-------
- , The waste streams flow by gravity from the treatment plant to settling tank.
The backwash volume ranges from 7,000 to 2,500,000 gallons per day.
The total backwash volume is 0.5 to 2 percent of the design flow rate.
The initial solids concentration of the backwash is 0.1 percent and the discharge
concentration is equal to 1 percent.
The backwash is thickened in a tank.
The volume of backwash is reduced by 90 percent.
The supernatant is pumped to the head of the treatment plant.
- The thickened sludges are discharged to another treatment for further
dewatering. ,
4.3.2 Capital Cost Components
The capital components for each gravity thickening system consist of the following items:
Holding tank;
Piping and fittings; .
Pump; ,
Trenching;
Electrical; and
Instrumentation.
Table 9 indicates die holding tank capacities used to develop the capital cost equation for
gravity thickening.
4.3.3 Operation and Maintenance Components
The operation and maintenance components for each gravity thickening system include the
following items: .
30
-------
Electricity;
Labor and supervision;
Maintenance labor and materials; and <
Insurance and general and administration.
TABLE 9
GRAVITY THICKENING
Waste Stream
Volume
(gal/day)
7,000
. 13,300
36,000
96,000
165,000
270,000
510,000
1,050,000
2,150,000
Number
of
Tanks
1
1
1
1
1
1 /
1
2
2
Waste Stream
Settling Tank
Capacity (gal)
30,000
50,000
30,000
30,000
50,000
50,000
50,000
50,000
50,000
4.3.4 Cost Components Excluded
The following cost component is not included in the cost equations for gravity thickening
systems:
Supernatant disposal, if the supernatant cannot be pumped to the head of the
treatment plant; and '
Thickened sludge disposal.
31
-------
Costs for supernatant disposal, if the supernatant cannot be pumped to the head of the
treatment plant, and treatment of the thickened sludge can be determined using other sections
of this document.
4.4 GRAVITY THICKENING COST EQUATIONS
The cost equations for the capital components and operation and maintenance components
were developed by estimating the costs for nine different filter backwash flow rates. The filter
i
backwash and sludge flow rates (X) used in the equations below are the average daily volumes
generated (e.g. for filter backwash, 2.5 percent of the daily treated water flow rate). The
capital cost equation calculates the total capital cost (i.e., installed capital plus indirect capital
costs). The total annual cost is calculated based on the capital and operation and maintenance
costs obtained using the equations presented below.
(
CaoitaLCosts
Y= 32,400+ 41.7 X
0.50
Where: Y = $ '
X = gallons of filter backwash/sludge per day
Range: 7,000 gpd s X * 270,000 gpd
Y = 21,700 + 66.5 X
0.50
Where: Y = $
X = gallons of filter backwash/sludge per day
Range: 270,000 gpd < X <; 2,500,000 gpd
32
-------
Operation and Maintenance
Y = 5,800 + 8.04 X
0.50
Where: Y = $/year
X = gallons of filter backwash/sludge per day
Range: 7,000 gpd <; X <. 2,500,000 gpd
Total Annual Cost
Y = [CAP x CRF] + O&M
Where: Y - $/year
^ - CAP = capital cost
CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
33
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5.0 CHEMICAL PRECIPITATION
5.1 TECHNOLOGY DESCRIPTION
Chemical precipitation is applicable to aqueous byproduct streams such as ion exchange
backwash and reverse osmosis brines. Chemical precipitation is frequently used to remove
dissolved metals from aqueous solutions. It can be used to remove metal ions such as
aluminum, antimony, arsenic, cadmium, chromium, copper, iron, lead, mercury, selenium,
silver, thallium, and zinc. Hydroxide precipitation is the most widely used technology for
removing trace metals from waste waters. Lime, quicklime, soda ash, or caustic soda are
commonly used as sources of hydroxide ions. Under suitable conditions, metals form
insoluble metal hydroxides which can be separated from solution by clarification and filtration.
Sulfide precipitation and ferrous salt precipitation also are used depending on the metals
present in solution. ' , ' . -
/
The precipitation process involves adding a precipitant, such as hydroxide ions, to ion
exchange or reverse osmosis brines in a stirred reactor vessel. The dissolved metals are
converted to an insoluble form by a chemical reaction between the soluble metal ions and the
precipitant. The resulting suspended solids are separated from the aqueous phase in a
clarifier. Flocculation with or without a chemical coagulant or settling aid may be used to
enhance the removal of suspended solids. The supernatant from the clarifier is either
discharged to the sanitary sewer, to surface water or to the head of the treatment plant
depending on the'pH. Tftriortb'disposal,' the'clarifier sludge may require additional dewateririg
i * ซanon of rh.
by mechanical or nonmechanical means.
5.2 TECHNOLOGY APPLICABILITY
f
Chemical precipitation is used primarily for treatment of reverse osmosis and cation exchange
34 . '
-------
waste brines. Chemical precipitation is used to remove the high levels of dissolved solids
found in these waste streams where less expensive treatment and disposal options are not
available. .
The chemical precipitation method of treating ion exchange and reverse osmosis brines is an
expensive waste treatment/disposal option relative to options such as evaporation ponds,
sanitary sewer discharge, and direct discharge. Chemical precipitation is economically more
feasible for large systems treating more than 1 million gallons of water byproducts per day. If
chemical precipitation is the only method available for ion exchange and reverse osmosis
byproduct treatment, then ion exchange or reverse osmosis may require consideration of off-
site disposal options.
5.3 TECHNOLOGY LIMITATIONS
Anion exchange wastes cannot be treated by lime precipitation because the sodium, chloride
and sulfate dissolved ions are not readily precipitated by lime. In addition, the effluent from
the chemical precipitation process may still pose a disposal concern due to elevated levels of
dissolved solids such as sodium, chloride, and sulfate remaining hi die effluent.
As mentioned above, chemical precipitation may be a relatively expensive treatment option
compared to direct discharge, sanitary sewer discharge, and evaporation ponds. Chemical
precipitation has higher capital costs and higher labor costs than many other byproduct
treatment and disposal options. The higher labor costs are associated with the oversight
necessary for proper operation of the system.
v f . ' '
5.4 COST COMPONENTS
The following section presents the design assumptions, capital components, and the operation
and maintenance components used to prepare the costs for this technology.
35
-------
5.4.1 Design Assumptions
The chemical precipitation system consists of mixing and. holding tanks for the
lime solution, a precipitation tank, a clarifier, agitators, and pumps.
The precipitation tank has a Vi-hour retention time and a 5 percent overdesign.
The clarifier (settling tank) has a 1- to 2-hour retention time.
Waste brines flow to the treatment system under pressure from the ion exchange
-or reverse osmosis system.
The chemical precipitation equipment is located in the water treatment building.
Sludge from the clarifier may require additional dewatering prior to disposal.
The sludge volumes generated by chemical precipitation are 5 and 2 percent of
the influent volumes for reverse osmosis and ion exchange brines, respectively.
5.4.2 Capital Components ,
The capital components for each chemical precipitation system consist of the following items:
Carbon steel mixing tank;
Carbon steel holding tank;
Carbon steel precipitation tank;
Clarifier;
Agitators; .
Sludge pumps;
Building;
Piping;
Electrical; and ^
Instrumentation! .
10 ' - me ct. liquatK..., ; > ii:-~.tca'
Table 10 indicates the brine volumes, tank^capacities, and clarifier capacities used to develop
the capital cost equation for chemical precipitation.
36
-------
TABLE 10
CHEMICAL PRECIPITATION
Byproduct
Flow Rate
(gal/day)
27,400
67,500
274,000
500,000
1,000,000
2,740,000 .
Precipitation
Tank Size
(gallons)
650
2,000
6,000
12,000
23,000
60,000
Mix Tank
Capacity
(gallons)
50
75
200
600
1,200
1,500
Clarifier
Capacity
(gallons)
2,500
8,000
24,000
40,000
50,000
40,000 x 2
5.4.3 Operation and Maintenance Components
The operation and maintenance components for each chemical precipitation system
include the following items:
Lime;
Electricity;
Labor; .
Maintenance labor and materials;
Insurance and general and administration; and
Water.
5.4.4 .Cost Components Excluded
\ ..,
The following1 rosfcompohents^are not included hi the cost equations for chemical
precipitation systems since they are accounted for elsewhere in the document:
Sludge dewatering (if needed for the selected disposal option);
Sludge disposal; and
Clarifier overflow disposal, if the overflow cannot be pumped to the head of the
treatment works.
37
-------
Costs for sludge dewatering and sludge disposal techniques are included in other sections of
this document. Costs for clarifier overflow disposal, if the overflow cannot be pumped to the
head of the treatment works, can be determined using other sections of this document.
5.5 COST EQUATIONS
The cost equations for the capital components and operation and maintenance components
were developed by estimating the costs for six different brine flow rates. The capital cost
equation calculates the total capital cost (i.e., installed capital plus indirect capital costs).
Equipment costs and building costs are separate components in the capital cost equation to
enable the user to exclude the cost for a building addition if it is not necessary. The total
annual cost is calculated based on the capital and operation and maintenance costs obtained
using the equations presented below.
Capital Costs .
Y = [34,600 + 206 X oso] + [110 X ฐ55]
Y = [Equipment Cost] + [Building Cost]
Where: Y = $
X = gallons of brine per day
Range: 25,000 gpd s X s 500,000 gpd
;Y. = ., [34,600 -h 206.X ฐ50] + [65,000 + 160 X ฐf]
Y--=- [Equipment Cb:st] + [Building Cost]
Where: Y = $
X = gallons of brine per day v
* x '
Range: 500,000 gpd < X <; 3,000,000 gpd
38
-------
Ooeration and Maintenance
Y= 37,300 +0.17.X
Where: Y = $/year
X = gallons of brine per day
Range: 25,000 gpd <; X <; 500,000 gpd
Y= 57,500 + 0.13 X
Where: Y = $/year
X = gallons of brine per day
Range: 500,000 gpd < X <; 3,000,000 gpd
Total Annual Cost
Y = [GAP x CRF] + O&M
Where: Y = $/year
CAP = capital cost
CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
-1 - aple-1'iHer piate^ on >frfuปi .-ซunc;. ui a press
and toe :tf 'he pla'te& a'hd'Bp die^epJ*' i-f1[tfip c T the
39
-------
6.0 MECHANICAL DEWATERING
Mechanical dewatering processes include centrifuges, vacuum-assisted dewatering beds, belt
filter presses, and plate and frame filter presses. Mechanical dewatering processes have
relatively high capital and operation and maintenance costs compared to similarly sized
nonmechanical processes. Mechanical dewatering is not applicable to very small water plants
due to the high capital costs associated with .these technologies and limited equipment sizes
available. Two mechanical dewatering processes are included in this section: a pressure filter
press and a scroll centrifuge.
6.1 PRESSURE FILTER PRESS DESCRIPTION
\
A pressure filter, or plate and frame, press is a mechanical sludge dewatering method using a
positive pressure differential to separate free liquid from the sludge. Pressure filter presses
operate as batch processes, The press consists of adjacent plates that form a leak-proof seal
\. '
when electrically or hydraulically brought together! A positive displacement pump moves
sludge into chambers between the two plates. . Initially a pump supplies a high volume of
sludge to the chamber at a low pressure. As the chamber fills, the pump creates positive
pressure on the sludge which forces the liquid from the sludge. The pressure increases until
the desired solids concentration is achieved. After pumping ceases, the plates are separated
and the sludge cake is dropped into a container or onto a conveyor.
ป ^Pressure filter presses consist of multiple' filter plates on'metal-frames. The capacity of a press
'?* Pdependr6rilhe number 'and1 sizes6f ttiesplales and'o^tBe^deplrof-ffie^chamber between the
'plates. Plates are available in a variery'of'sizes^shapes, and?materials. The choice of filter
media adds additional variation to the performance of an individual press. Filter media varies
d in its particle retaining 'size, permeability, "'durability, and its ease of cake release. Sludge type
and the initial solids concentration of a sludge affect the filter media choice.
40
-------
6.2 TECHNOLOGY APPLICABILITY
With proper sludge conditioning, pressure filter presses can effectively dewater both lime and
alum sludges. Lime sludges attain final solids concentrations of 40 to 70 percent while alum
sludges attain 35 to 50 percent final solids concentrations. Dewatering with a filter press is a
batch process; each batch remains under pressure until the desired solids concentration is
achieved. This produces a consistent end product. Filter presses produce a filtrate that has a
lower suspended solids concentration than filtrates from other mechanical dewatering methods.
Pressure filter presses have been used in water treatment and industrial processes for many
years. Use of pressure filters presses in the water treatment industry has been increasing in
the last several years. They are especially applicable for facilities that want to achieve a high
sludge solids content. The high solids content achieved by pressure filter presses makes this a
suitable technique to dewater sludges prior to landfill.
Plate and frame filter presses have low land requirements, high capital costs, and are labor
intensive. They typically have higher capital and operating costs than comparable
nonmechanical dewatering alternatives. The high labor and capital requirements make them
S t '
more applicable to larger water systems.
6.3 TECHNOLOGY LIMITATIONS
i
Although the suspended solids concentration of the filtrate is low, filtrate disposal may be a
problemri.B^opep.ipre^conditioning of alum sludges prior to filter press dewatering normally
requiresithefaddition of lime. Lime-is used to lower the,alum-sludge's resistance to filtration.
A lime mixture is added to the alum sludge until a pH of approximately 11 is achieved. The
lime conditioning not only increases the total sludge volume (by as much as 20 to 30 percent
by weigh?), but also increases the pH of the resulting filtrate. The final filtrate pH may be too
high for sanitary sewer disposal or for recirculation to the head of the treatment plant.
41 " . '
-------
Pumps that deliver the sludge to the filter press must be capable of operating under a wide
variety of conditions. During initial pumping, sludge flow rates are high and pressures are
low. Toward the end of the cycle, the sludge flow rate is almost zero while pressures range
/
from 100 to 200 psi. A positive displacement pump such as a progressive cavity pump must
be used to achieve required flow rates and pressures. A second alternative is to use two
pumps: one to deliver high flow rates at low pressure and a second to deliver high pressure
with low flow rates.
f
Filter media must be cleaned every eight to ten cycles to ensure proper operation. Filter
cleaning is a time consuming process requiring an acid wash to dissolve built up calcium
carbonate from press plates. The acid wash presents disposal problems due to its low pH.
Pre-coating the press reduces blinding and frequency of cleaning, but adds to operation and
maintenance costs and potentially adds trace metals to the filtrate.
As with all mechanical dewatering methods, proper pre-conditioning of alum sludges is
essential to ensure efficient sludge dewatering. Sufficient quantities of lime must be added and
a 20 to 30-minute contact time is required to develop the necessary dewatering qualities.
6.4 PRESSURE FILTER PRESS COST COMPONENTS
The following section presents the design assumptions, capital components, and the operation
and maintenance components used to prepare the costs for this technology.
ฃ -ซ-, .-.a . .1 .'. .2.
6.4.1 Design Assumptions
^siintenaifr*' - -* nr
Pressure filter presses are effective for sludge flow rates greater than 100
gallons per day. - t
The polymer feed system consists of a polymer storage tank, a polymer pump, a
polymer/sludge contact tank, and a 20- to 30-minute holding tank.
A positive displacement pump delivers sludge to the filter press.
42
-------
The filter press operates on a batch basis.
Filtrate collects in a filtrate holding tank before being pumped to the head of the
treatment plant.
In the smaller systems, filter cake collects in a small, wheeled container, which
is emptied into a larger solids bin as necessary.
In the larger systems, the filter cake drops into roll-off bins located beneath the
filter press.
Accumulated solids require disposal on a periodic basis.
The dewatered sludge volume is 0.03 and 10 percent of the initial volume for
alum and lime sludges, respectively.
6.4.2 Capital Components
The capital components for each pressure filter press system consist of the following items:
Schedule 40 steel piping;
Polymer feed system;
Positive displacement pump(s);
Pressure filter press(es);
Steel filtrate tank and pump;
Filter cake storage bin;
Building;
Piping;
Electrical; and
Instrumentation.
Table 1 1 indicates the sludge volumes, settling tank/gravity thickener capacities, and filter
press capacities used to develop the capital cost equation for pressure filter presses.
A evil.
. .dvv'1 ed ".' '"'.'
6.4.3 Operation and Maintenance Components
The operation and maintenance components for each pressure ^Iter press system include the
following items:
Electricity;
Polymer;
43
-------
TABLE 11
PRESSURE FILTER PRESSES
Sludge Flow Rate
(gal/day)
500
2,000
5,000
50,000
.250,000
600,000
Filter Press Capacity
(cu. ft.)
2.0
10
24
50
130 x 2
160x3
Labor;
Maintenance labor and materials; and
Insurance and general and administration.
6.4.4 Cost Components Excluded
The following cost components are not included in the cost equations for pressure filter press
systems:
Dewatered sludge disposal;
Filtrate disposal, if the filtrate cannot be pumped to the head of die treatment
plant; and , . ,OI1. r ' .
Acid wash system,- if required^OQTOttO g^-o
Costs for sludge disposal techniques are included in other sections of this document. Costs for
filtrate disposal, if the overflow cannot be pumped to the head of the treatment works, can be
determined using other sections of this document. "
44
-------
6.5 PRESSURE FILTER PRESS COST EQUATIONS
The cost equations for the capital components and .operation and maintenance were developed
by estimating the costs for six different sludge flow rates. The capital cost equation calculates
the total capital cost (i.e., installed capital plus indirect capital costs). Equipment costs and
building costs are separate components in the capital cost equation to enable the user to
exclude the cost for a building addition if it is not necessary. The total annual cost is .
calculated based on the capital and operation and maintenance costs obtained using the
equations presented below.
Capital Cost
Y = [15,600 + 1,520 X 05ฐ] + [4,600 + 3.0 X]
Y = [Equipment Cost] + [Building Cost]
>
Where: Y = $
X = gallons of sludge per day
Range: 500 gpd <. X <. 50,000 gpd
f
Y = [4,181 X 05ฐ - 579,900] + [22,300 + 9.8 x 10'2 X]
Y = [Equipment Cost] + [Building Cost]
Where: Y = $
X = gallons of sludge per day
ss liL bab Rangei ls a ba'5
~ a; ' Tnซni'Kป" ' * ซ* n^sipr I*"- -T "* "ซ-' ->sf estmates
Operation and Nf^jntenance
Y = 13,400 + 0.92 X
1'i.i ' 'I.
Where: Y = $/year ' t.r ;
X = gallons of sludge per day
t - \
45
-------
Range: 500 gpd s X s 50,000 gpd
Y = 32,900 + 0.67 X
Where: Y = $/year
X = gallons of sludge per day
f ,
Range: 50,000 gpd < X <; 600,000 gpd
Total Annual Cost
Y = [CAP x CRF] + O&M
Where: Y = $/year
' CAP = capital cost
CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
6.6 SCROLL CENTRIFUGE DESCRIPTION
' ^
Centrifuges are a mechanical means of thickening sludges using centrifugal force to enhance
the settling process. The radial forces developed in the centrifuge are 500 to 4,000 times more
powerful than the gravitational force used in nonmechanical de watering. There are two basic
types of centrifuges: a solid bowl (scroll) centrifuge and a basket centrifuge. The scroll
centrifuge, which is a continuous feed unit, is more widely used for dewatering water
. .. . . . ,. . dge ?
treatment sludges. The basket centrifuge is a batch process with larger' units that require
greater operator and monitoring time. Design assumptions and cost estimates provided in this
section are for scroll centrifuges.
*' of- ' . -
-------
the rapid rotation of the bowl causes the sludge to accumulate on the inside of the cylindrical
bowl. A screw conveyor rotating at a slightly different speed inside the spinning bowl pushes
the accumulating sludge toward the narrow end of the centrifuge to a discharge point. Below
the sludge cake discharge point, a container collects the dewatered sludge for disposal.
Normally, the centrifuge is placed on a stand four to five feet above the floor to provide room
for a solids container below the discharge point. In large treatment works, a conveyor collects
and transports the sludge cake to a sludge storage container. Centrate, the liquid separated
from the sludge, flows along the bowl wall to the wide end of the centrifuge where it is
discharged.
6.7 TECHNOLOGY APPLICABILITY
Scroll centrifuges are used to dewater alum and lime sludges. With influent solids
concentrations of 1 to 10 percent solids, an alum sludge with 15 to 30 percent solids and a
lime sludge cake with 65 to 70 percent solids are produced. Because of the forces created by
the centrifugal motion, scroll centrifuges require minimal time to achieve optimal sludge solids
concentrations. A solid residence time of 8 to 12 minutes is typical for a scroll centrifuge.
. i
Daily operation of a scroll centrifuge requires little operator attention. After start-up and
initial sludge cake monitoring, periodic checking and a thorough cleaning are all that is
./
required. Most scroll centrifuges are equipped with a hydraulic backdrive. This senses the
back pressure on the scroll and varies the residence time of the solids to accommodate
differences hi influent solids-concentrations. The backdrive insures consistent>siudge solids
concentrations. .
..... ,, _ '-'.
Centrifuges have low land requirements and high capital costs. They typically have higher
capital and operating costs than comparable nonmechanical dewatering alternatives, but are
typically less labor intensive than filter presses. The high labor and capital requirements of
centrifuges make them more applicable to larger water systems.
47 -'''
-------
6.8 TECHNOLOGY LIMITATIONS
The dewatering performance of the scroll centrifuge is dependent upon obtaining a good
quality flocculent with the polymers. The treated flocculent needs to have a "globular"
consistency which allows the water to escape and the sludge to be scrolled to the discharge
point. Flocculents that are not firm will not be effectively conveyed through the centrifuge to
the discharge point.
s
A gravity thickener is necessary to increase the concentration of solids in the sludge prior to
being pumped into the centrifuge. The additional equipment and operating costs limit the
applicability of this technology to smaller systems. ,
6.9 SCROLL CENTRIFUGE COST COMPONENTS
The following section presents the design assumptions, capital components, and the operation
and maintenance components used to prepare the costs for this technology.
6.9.1 Design Assumptions .
The polymer feed system consists of polymer storage tank, a polymer pump,
and a polymer/sludge contact tank, and a 20 to 30-minute holding tank.
A positive displacement pump feeds conditioned sludge to the scroll centrifuge.
/
The scroll centrifuge operates 8 to 24 hours per day depending on the size of
the water system.
Centrate collects in a cehtrate holding tank before being pumped to the head of
the treatment works. '"
Dewatered sludge collects in a small, wheeled container, which is emptied into
a larger solids bin as necessary.
48
-------
The large systems are located on the second floor and the dewatered sludge
drops into sludge containers located below the centrifuge.
Accumulated solids require disposal on a periodic basis\
The dewatered sludge volume is 0.04 of the initial sludge volume.
6.9.2 Capital Components
The capital .components for each scroll centrifuge system consist of the following items:
Schedule 40 steel piping;
Polymer feed system;
Positive displacement pump;
Scroll centrifuge with backdrive;
Steel centrate tank and pump; .
Dewatered sludge storage bin;
Building;
Piping;
Electrical; and - *
Instrumentation.
Table 12 indicates the sludge flow rates and centrifuge motor sizes used to develop the capital
i
cost equation for the scroll centrifuge system.
6.9.3 Operation and Maintenance Components
The operation and maintenance components for each scroll centrifuge system include the
following items: .
Electricity;
^duli> Polymer; ;
y.r 'uer . . . . . , "' t'onf ">t this it ' '''tjsts *ni
Maintenance labor and matenals; and
Insurance and general and administration, h.
49
-------
TABLE 12
SCROLL CENTRIFUGE
Sludge Flow Rate
(gal/day)
2,000
5,000
50,000
250,000
600,000
2,500,000
5,200,000
Centrifuge
Capacity
,7^hp
7'Ahp
10 hp
25 hp
40 hp
8P hp x 2
80 hp x 4
6.9.4 Cost Components Excluded
The following cost components are not included in the cost equations for scroll centrifuge
systems:
Scroll cleaning apparatus;
Dewatered sludge disposal; and
Centrifuge overflow disposal, if the overflow cannot be pumped to the head of
(the treatmentjpjant.^
Costs for sludge disposal techniques are included in other sections of this document. Costs for
centrifuge overflow disposal, if the overflow cannot be pumped to the head of the treatment
works, can be determined using other sections of this document.
50
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6.10 SCROLL CENTRIFUGE COST EQUATIONS
The cost equations for the capital components and operation and maintenance were developed
by estimating the costs for seven different sludge flow, rates r The capital cost equation
calculates the total capital cost (i.e., installed capital plus indirect capital costs). Equipment
costs and building costs are separate components in the capital cost equation to enable the user
to exclude the cost for a building addition if it is not necessary. The total annual cost"is
calculated based on the capital and operation,and maintenance costs obtained using the
equations presented below.
Capital Cost
Y = ' [138,400 + 666 X ฐso] + [15,400 + 59 X OJO\
Y = [Equipment Cost] '+ [Building Cost]
Where: Y = $
X = gallons of sludge per day
Range: 2,000 gpd <: X < 250,000 gpd
Y = [287,000 + 0.63 X] + [40,400 + 2.26 x IQr2 X]
Y = [Equipment Cost] + [Building Cost]
.Where: Y = $
X = gallons of sludge per day
Range: '" '250,000 gpd * X * 5,500,000 gpd
51
-------
Operation and Maintenance
Y= 17,500 + 311 X0-50
Where: Y = $/year
X = gallons of sludge per day
Range: . 2,000 gpd <> X < 250,000 gpd
Y = 72,000 + 0.43 X
Where: Y = $/year
X = gallons of sludge per day
Range: 250,000 gpd * X <: 5,500,000 gpd
Total Annual Cost
Y = [CAP x CRF] + O&M
Where: Y =ป $/year
CAP = capital cost
CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
ge ' . iu >~'pdH peribanen lag- .*as> >,.* -..v
;s an. storage lagoons are use
-------
7.0 NONMECHANICAL DEWATERING
Nonmechanicai dewatering of sludges and slurries is performed in storage lagoons and
permanent lagoons. Nonmechanicai dewatering processes are characterized by their simplicity
to operate and maintain. In a storage lagoon, dewatered sludge is removed for disposal via
land application or in a landfill. In a permanent lagoon, dewatered sludge remains in the
lagoon and the lagoon is the final disposal site for the sludge.
7.1 LAGOON DESCRIPTION
Lagoons historically are the most common, and often the least expensive, method to thicken or
dewater water treatment sludge; however, they are land intensive. The lagoons are lined
ponds designed to collect and dewater sludge for a predetermined period of time. Dewatering
of the sludge occurs by decanting and by evaporation of the supernatant. Additional
dewatering can also be achieved if the lagoons have a sand bottom. Storage lagoons are sized
according to the sludge volumes generated and storage time required for an individual
\
treatment facility. When a storage lagoon has reached its designed capacity, the remaining
solids are typically removed from the lagoon using a front-end loader and hauled off site for
final disposal. Some treatment works use permanent lagoons as long-term disposal sites for
sludges. As one lagoon fills, another one is excavated.
\
Lagooning is a low technology method of sludge treatment and disposal. There are two types
of lagoonst:icpermanent and storage} In this reportV permanent lagoons' are used for the final
disp6salf6friime'softening sludges and storage lagoons'arerused for dewatering chemical
~v,t . ,. 1
coagulation (alum) sludges. Typically, lime sludges enter the lagoon at three percent solids
and can be dewatered to 50 to 60 percent solids, whereas, alum sludges enter the lagoon at one
percent solids and can be^dewatered to 7 to 15 percent solids. In general, a sludge needs to be
at leasf 20 percent solids before it can be laridfilled.
53
-------
Lagoons are lined ponds designed to collect and dewater sludge for a predetermined period of
time. Liquid is removed from the sludge by both decanting and evaporating the supernatant.
Storage lagoons are sized according to the sludge volumes generated and storage time required
for an individual treatment facility. When a storage lagoon has reached its designed capacity,
the remaining solids are dredged or vacuumed from the lagoon and prepared for final disposal.
Some treatment works use permanent lagoons as long-term disposal sites for sludges and as
one lagoon fills another one is excavated.
Lagoons are usually earthen basins with gradual side slopes. Sizes range from less than one to
56 acres and from 4- to 20-feet deep. Clay or synthetic liners cover the bottom and sidewalls
to prevent ground water infiltration of sludge leachate. Sludge flows from the treatment plant
by gravity or is pumped to the lagoon through an underground pipe. The lagoon inlet
structure is designed to minimize turbulence hi the lagoon caused by the incoming sludge.
The .outlet structure usually provides for decanting of the supernatant at various draw-off
depths. '
If the water byproduct residuals managed in the lagoons are determined to be hazardous waste,
these lagoons are subject to compliance with hazardous waste regulations for surface
impoundments. These regulations specify that the impoundments must be triple-lined with a
synthetic flexible membrane liner and a composite double liner. Although there are no federal
requirements specifying the design for lagoons containing nonhazardous waste at this time,
regulations regarding nonhazardous waste hi lagoons may be enacted in the future. Therefore,
good engineeringLpractice suggests that at a minimum a synthetic lirierahould be included in
'-. . "i > ' T- '' ' i<
the design of the,-lagpon> the 20 nป-. < -Is c<. ncentrat^n required by mam
*-ป_ 'Hi: -r ftei ""m ^ ta^m - .-
7.2 TECHNOLOGY APPLICABILITY^:
.. .! .
Storage lagoons are primarily used for the dewatering of lime softening sludge, although
coagulant (alum) sludge can also be dewatered in certain situations. Final solids
54 . " .'
-------
concentrations reported for lime and alum sludges after lagooning are 50 to 60 percent and 7
to 15 percent, respectively. The higher solid concentrations (greater than 50 percent) are
achieved through decanting of the supernatant layer and allowing the sludge to air dry.
Lagoons can operate under a variety of sludge flows and solids concentrations. Lagoons with
low-turbulence inlet structures and outlet structures designed to minimize suspended solids
carryover can accept backwash waters directly from the filters. This eliminates the need for
backwash holding tanks and sludge thickeners. Lagoons can withstand large variances in
sludge quality and do not require chemical conditioning of alum sludges:
Lagoons in areas with beneficial climates can achieve greater sludge dewatering. In areas with
hot, dry climates, storage lagoons function as evaporation ponds and can dewater both alum
and lime sludges to solids concentrations suitable for landfilling. In northern climates, natural
winter freezing dehydrates alum sludges and releases chemically bound water in the,sludge.
When the frozen sludge thaws, it retains a granular composition and precipitates to the lagoon
bottom. After the supernatant is decanted, solids with the consistency of coffee grounds
remain and are also suitable for landfilling.
7.3 TECHNOLOGY LIMITATIONS
i
Lagooning frequently does not produce a dewatered sludge suitable for landfill disposal.
Alum sludges do not dewater well in lagoons. The top layer of sludge dries, hardens, and
seals the moisture in the layers-below. Even after several years of lagooning, alum sludges
I- a, 'ja&ias Uu^c ^ta . mer> i^at
-------
Lagooning is a land intensive dewatering process. Water treatment facilities with limited land
availability will need to consider the costs of regular lagoon cleaning and sludge disposal or
the cost of acquiring land for additional lagoons when evaluating the feasibility of this
technology. In addition, permanent lagoons that act as final disposal sites for sludges may be
considered solid waste landfills in some states. As such, the lagoons would need to meet the
design, ground water monitoring, and permitting requirements of the state's environmental
regulatory agency.
There is also a limitation on how small a lagoon can be sized. This limitation is the result of
constructing an engineered excavation rather than simply a hole dug in the ground. To
maintain and construct the side slopes of the lagoon, the bottom surface area must be a
minimum size to accommodate the equipment used.
7.4 STORAGE LAGOONS COST COMPONENTS
The following section presents the design assumptions, capital components, and the operation
and maintenance components used to prepare the costs for this technology.
7.4.1 Design Assumptions
Storage lagoons are used to dewater alum sludges and are periodically dredged.
Permanent lagoons are used to dewater lime sludges; each storage lagoon has a
10-year capacity.
The lagoons are earthen basins lined with a synthetic membrane and a geotextUe
support fabric. They have.no-.underdrains, but have a,,variable height outlet
,'|f* * <;ฃ \ปX fj. "tr, . ii.i*-.11 i ปfl sr --.i ฐ^
structure to discharge supernatant. Permanent lagoons are 6- to 12-feet deep
and storage lagoons rangecfroin:3-to 5-feet deep. ''<-
- Decanted supernatant from the lagoon is collected and pumped to the head of
the treatment plant.
- Sludge flows from the treatment plant to the lagoon by gravity via 1,250 to
' - . . 56
-------
4,000 feet of 2- to 6-inch diameter PVC piping. Pipes are laid 4 feet below
grade.
Alum treatment plants operate two lagoons. Each lagoon has a six month
storage capacity. After six months, the second lagoon is used while free liquid
from the idle lagoon is allowed to evaporate. The remaining free liquid is
decanted and returned to the head of the treatment plant. Sludge is dredged
fronrthe lagoon on^an annual basis. .
Lime treatment plants operate 2 or 4 lagoons to provide a total of 20 years of
permanent storage. Each lagoon has a 6 or 12 month storage capacity prior to
drying and decanting. Free liquid is continuously decanted from the lagoon
while it is accepting sludge and returned to the head of the treatment plant.
After the 6 or 12 month period, another lagoon is used while free liquid from
the idle lagoon is decanted and evaporated. The remaining sludge is allowed to
dry prior to .the next sludge application.
Approximately 1.5 cubic feet of solids per 1,000 gallons of initial alum sludge
volume will require final disposal from the storage lagoons.
7.4.2 Capital Components
The capital components for each storage lagoon consist of the following items:
Two or four lined earthen lagoons;
Piping and fittings;
Trenching; -
Decant collection pump;
Electrical;
Instrumentation; and
Land clearingr , 1
JC -> I > j - Ifc- . . L
Tables 13 and 14 indicate the sludge volumes^ number~of ponds?. and total lagoon surface area
I ' i /L
used to develop the capital cost equation for lime softeningand alum storage lagoons,
respectively. " .
57
-------
TABLE 13
STORAGE LAGOONS - LIME SOFTENING SLUDGE
Lime Softening
Sludge Volume
(gal/day)
7,000
20,000
50,000
100,000
500,000
1,000,000
Number of
Ponds
2
2 .
2
2
4
4
Total Lagoon
Surface Area
(acres)
5
7
18
37
112
224
TABLE 14
STORAGE LAGOONS - ALUM SLUDGE
Alum Sludge
-Volume
(gal/day)
250
1,000
5,000
10,000
ifeo atฃ.t,50,OOOaKiir
entii 100,000 '<ป
1f-' * 200,000
k 500,000
Number of
Ponds
.2
2
. 2
2 '
x- ea. .-2 '>'
;,-ai 2 ,
2
2
Total Surface
Area
(acres)
0.1
0.4
2 ,-
t: 4ljOi -ซ>
t iipml-9.t costs .
Ui-22 ^ ซ-xcl-
45 '
112
58
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7.4.3 Operation and Maintenance Components
The operation and maintenance components for each storage lagoon include the following
items: -
Labor and supervision; , '
Maintenance labor and materials;
Electricity;
Insurance and general and administration; and '
Annual sludge removal, alum sludge only.
7.4.4 Cost Components Excluded
The following cost components are not included in the cost equations for storage lagoons:
Sludge dewatering equipment; . ,
T Dewatered sludge disposal; and
Supernatant disposal, if the supernatant cannot be pumped to the head of the
treatment plant.
Costs for sludge disposal techniques are included in other sections of this document. Costs for
supernatant disposal, if the supernatant cannot be pumped to the head of the treatment plant,
can be determined using other sections of this document.
7.5 LIME SOFTENING STORAGE LAGOON COST EQUATIONS
The cost equations for the capital components and operation and maintenance were developed
by estimating the costs for six different sludge flow rates. The capital cost equation calculates
the total capital cost (i.ei, install^! capital plus indirect capital costs). Equipment costs and
land costs are separate components in the capital cost equation to enable the user to exclude the
cost for purchasing land if it is not necessary. The total annual cost is calculated from the
capital and operation and maintenance costs obtained using the equations presented below.
59
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Lime Softening Capital Costs '
Y = [144 X ฐ91] + [{(1.57 x 10-3) X ฐ.87} Z]
Y = [Equipment Cost] + [Land Cost]
Where: Y = $ .
X = gallons of sludge per day
Z = land cost in $/acre (e.g., $10,000/acre)
Range: 2,800 gpd <; X <> 1,000,000 gpd
Operation and Maintenance
1 . /
Y= 7,700 + 1.69 X
Where: Y = $
X = gallons of sludge per day
Range: 2,800 gpd <: X * 50,000 gpd
Y = 33,100 + 1.33 X ,
Where: 'Y = $/year
X = gallons of sludge per day
Range: 50,000 gpd < X <; 1,000,000 gpd
Total Annual Cost
" 'ns of
Y=
Where: Y = $/year
CAP = capital cost
CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
60
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7.6 ALUM SLUDGE STORAGE LAGOONS COST EQUATIONS
The cost equations for the capital components and operation and maintenance were developed
by estimating the costs for eight different sludge flow rates. The capital cost equation
calculates the total capital cost (i.e., installed capital plus indirect capital costs). Equipment
costs and land costs are separate components in the capital cost equation to enable the user to
exclude the cost for purchasing land if it is not necessary. The total annual cost is .calculated
from the capital and operation and maintenance costs obtained using the equations presented
below.
Alum'Capital Costs
Y = [13,700 + 60.8 X] -I- [(0.5 + 3.44 x 10"4 X) Z]
Y = [Equipment Cost] + [Land Cost]
Where: Y = $
X = gallons of sludge per day
Z = land cost in $/acre (e.g., $10,000/acre)
Range: 250 gpd <: X <; 10,000 gpd
, Y = [326,500 + 28.6 X] + [(4.2 + 2.35 x 104 X) Z]
Y = [Equipment Cost] + [Land Cost]
Where: 'ฅ-$.-
X = gallons,of sludge per day
Z = land cost in $/acre (e.g., $10,000/acre)
ฃC " " '1 rt '. -
Range: 10,000 gpd s X * 500,000 gpd
61
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Alum Operation and Maintenance
Y= 6,100 +2.56 X
-Where:. Y = $/year.
X = gallons of sludge per day
Range: 250 gpd z X <; 10,000 gpd
28,500 + 1.02 X
Where:
Range:
Y = $/year
X = gallons of sludge per day
10,000 gpd * X s 500,000 gpd
Total Annual Cost
Y= [CAP x CKF] + O&M
Where: Y = $/year
CAP = capital cost
-J CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
OOu
t a
u aceutriuiate \\>' .
or reacnes a predefe--- .ie-<
62
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8.0 EVAPORATION PONDS
8.1 TECHNOLOGY DESCRIPTION
Evaporation ponds are a nonmechanical means by which favorable climatic conditions are used
to dewater waste brines generated by treatment processes such as reverse osmosis and ion
exchange. The technology involves discharging the waste brines to a pond for storage and
evaporation. The lagoons are designed with a large surface area to allow solar and wind
evaporation to dewater the brines. Pond sizes are determined by the surface area required to
evaporate the waste flows and by the desired storage capacity.
" . *
Evaporation ponds normally have an earthen construction with gradually sloping berms. Inlet
piping transfers the wastes by gravity flow, or in the case of reverse osmosis, by the operating
pressure from the treatment plant, to the pond. Outlet piping from the pond may be needed in
situations where sludge loading exceeds the design capacity of the pond or for handling
overflow in emergency conditions; otherwise, no outlet is necessary. Synthetic or clay liners
may be necessary to prevent leaching of brine solutions into subsurface soil and ground water.
Site-specific soil and hydrogeologic information will determine if lining of the pond bottom
and sidewalls is required.
Depending on the total dissolved solids (TDS) concentration of the brine, solids removal may
be required from the pond on an intermittent basis. For brines with a TDS concentration
ranginglfrom 15,OOOUo;3550QO!milligrams per liter (mg/1), solids will'accumulatei(within the
pond at/a-rate of 'A torl^rinches per year. When solids accumulation reaches a predetermined
depth, inflow to the pond is stopped and evaporation continues until a solids concentration
suitable for disposal is achieved. Front-end loaders and dozers remove the solids to trucks for
transport to the disposal site.
63
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If the water byproduct residuals managed in the ponds are determined to be hazardous waste,
these ponds are subject to compliance with the hazardous waste regulations for surface
impoundments. These regulations specify that the impoundments must be triple-lined with a
synthetic flexible membrane liner and a composite double liner. Although there are no federal
requirements specifying the design for ponds containing nonhazardous waste at this time,
regulations regarding nonhazardous waste hi ponds may be enacted in the future. Therefore,
good engineering practice suggests that at a minimum a synthetic liner should be included in
the design of the pond.
8.2 TECHNOLOGY APPLICABILITY
Evaporation ponds are used primarily for treatment of waste brines generated by ion exchange
and reverse osmosis processes. These treatment methods produce large volume waste streams
with high dissolved solids concentrations that make other nonmechanical and all mechanical
treatment methods impractical.
Evaporation ponds dewater brine solutions quickly with few operation and maintenance
requirements; however, evaporation ponds can only be utilized hi areas of the country, with
favorable climatic conditions, such as high temperatures, low humidity and low precipitation.
Waste brines from ion exchange and reverse osmosis require no pretreatment and are piped
directly from the treatment plant. Evaporation ponds accommodate batch or continuous
loadings and eliminate the need for equalization/holding tanks. In addition, ponds treating
wastesjwith low TDS concentrations will operateafqr several years beforcLSOlids accumulation
** '"ver 1 50 acres .ซ rx
8.3 TECHNOLOGY
tne-
Several factors limit the applicability of evaporation ponds as a sludge dewatering option.
i
Evaporation is a laud intensive treatment requiring shallow basins with large surface areas.
64 ,
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' The high volumes of waste brines generated by membrane treatment processes make land
availability an important consideration. Since reverse osmosis generates large reject volumes,
the land requirements increase, which in turn, increase the cost. Consequently, evaporation
becomes impractical for most large system reverse osmosis treatment plants.
Local climatic conditions are also important factors in determining the applicability of
evaporation. Climatic conditions primarily affect evaporation rates. A regional comparison of
the mean annual evaporation and mean annual precipitation indicates that the northeast,
southeast, Great Lakes, and coastal northwest regions of the United States have low, net
annual evaporations and are unsuitable for evaporation ponds. In addition, evaporation ponds
are generally considered unsuitable for alum and lime softening sludges.
8.4 COST COMPONENTS
^ - i
The following section presents the design assumptions, capital components, and the operation
and maintenance components used to prepare the costs for this technology.
i . .
8.4.1 Design Assumptions
The evaporation pond is used for treatment of ion exchange or reverse osmosis
brines. The influent solids concentration ranges from 1.5 to 3.5 percent by
weight. .
Reverse osmosis systems with flow rates of 4.8 MGD and greater and ion
exchange systems with flow rates of 51 MGE>"and greater are not considered
rai applicable for evaporationiponds since over 150 acres is required to evaporate
the daily generation volumes.
/ i *
Waste brines flow from the; treatment plant to the evaporation pond by gravity
or by the pressure from the treatment system via 1,250 to 4,000 feet of 4- to 8-
inch diameter PVC piping. Pipes are laid 4 feet below grade.
%
- Waste brine flow rates range from 31,000 to 500,000 gallons per day:
-------
The pond is designed for a geographical region with a net annual evaporation
rate of at least 45 inches per year.
The pond has no outlet.
The pond sides and earthen berm are engineered to have two and one-half to
one (2.5:1) side slopes and 2 feet of free board.
Soils cut from the excavation of the basin are used to construct the berm.
The pond is constructed with a synthetic membrane liner and a geotextile
support fabric; 1 foot of sand is placed on top of the liner.
Piping from the treatment process is sized to discharge the waste brines to the
ponds as they are generated. The treatment process is assumed to run 8 to 16
hours per day.
The evaporation ponds are sized with sufficient surface area to evaporate the
average daily flow. The pond depth is 2 feet; this depth provides solids storage
volume and accommodates peak flows.
8.4.2 Capital Components
The capital components for each evaporation pond consist of the following items:
Evaporation ponds;
Piping and fittings;
Pumps;
Land clearing; and
Instrumentation.
Table 15 indicates the brine volumes, number of ponds, and the total required surface area
- Ot mciuaed . ijjs " - .a^i* -.ortds '
used to develop the capital cost equation for evaporation ponds.
n "5 isposal
'' "r '
8.4.3 Operation and Maintenance Components
The operation and maintenance components for each evaporation pond include die following
items:
66
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TABLE 15
EVAPORATION PONDS
Brine Volume
(gal/day)
31,000
50,000
100,000
200,000
400,000
500,000
Number of
Ponds
2
2
2
4
6
3
Total
Surface Area
(acres)
10
15
30
60
120
150 .
Mowing;
Labor and supervision;
Maintenance labor and materials; and
Insurance and general and administration.
8.4.4 Cost Components Excluded
lv ,
The following cost component is not included in the cost equations for evaporation ponds:
Dewatered sludge disposal '
Costs for sludge disposal are included in other sections of this document.
67
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8.5 COST EQUATIONS
' V
The cost equations for the capital components and for operation and maintenance were
developed by estimating the costs for six different brine flow rates. The capital cost equation
calculates the total capital cost (i.e., installed capital plus indirect capital cost). The.total
annual cost is calculated from the capital and operation and maintenance costs obtained using
the equations presented below. .
Capital Cost
Y = [193,600 + 28.8 X] + [(4.08 X ฐ98) Z]
Y = [Equipment Cost] -I- [Land Cost]
Where: Y = $
X = gallons of brine per day
Z = land cost in $/acre (e.g., $10,000/acre)
Range:
30,000 gpd * X i 150,000 gpd
Y = [44,820 X ฐ5 - 1.43 x 107] + [(4.08 X ฐ98) Z]
Y = [Equipment Cost] + [Land Cost]
Where: Y = $
r
X = gallons of brine per day
. Z = land cost in $/acre (e.g., $10,000/acre)
68
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Range: 150,000 gpd < X s 500,000 gpd
Operation and Maintenance
Y,= 11,600 +0.96 X
Where: Y = $/year
X gallons of brine per day
Range: 30,000 gpd * X <; 150,000 gpd
Y = 1,500 X050-476,000
Where: Y = $/year
X = gallons of brine per day
Range: 150,000 gpd < X * 500,000 gpd
ToJaLAnnual Cost
-L> I _ 'V'0,1
T :ซ di
** [CAP x'-CREf ^ O&M
;. -. it'
nen
-.- .ami*
oon'redt^at. .
Where: Y = $/year
CAP = capital cost
CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
69
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9.0 POTW DISCHARGE
9.1 TECHNOLOGY DESCRIPTION
Sludges, slurries, and brines generated from the treatment of drinking water are, in some
cases, discharged directly to publicly owned treatment works (POTWs) for treatment and
disposal. This byproduct disposal technique is used most often where the water treatment
facility and the POTW are under the same management authority. The water treatment
byproducts are most often discharged to the POTW via the sewer system, but small volumes
may be stored on site and delivered to the POTW in a tanker truck. For each water treatment
facility a conveyance system is required to access into the sanitary sewer system if an adequate
system is not already in place. Installation of this system would include piping, pipe fittings
and trenching. .
The discharge piping is the primary capital cost associated with this treatment method.
Poly vinyl chloride (PVC) or reinforced concrete piping is normally chosen for its low cost and
corrosion resistance. Pipe diameter is determined based on the maximum expected flow and
acceptable head losses. Washout points are necessary at all low points in the discharge line to
prevent clogging by accumulated sediments. Gate valves are necessary at regular intervals to
control waste stream flow in the event of a pipe burst. The pipe must be laid sufficiently
r
below grade to prevent winter freezing.
i
An equalization tank/lagoon is optional and serves several purposes when disposing of
^ .lie wafer treatm.: .jrcaucts wm v *r\ *c ie treatment tff
treatment wastes by POTW discharge. First,, the equalization tank/lagoon reduces the
icn. da ~ se e [n ^ ฐ :t,ntem'
necessary discharge piping diameter by allowing filter backwash waters to be. continuously
if ' , ity ' ' !
discharged at a lower flow rate. Second, the equalization tank/lagoon reduces the variations in
the quality of the discharged wastes by mixing the wastes generated over a period of time.
Third, the equalization tank/lagoon provides an emergency waste storage area when discharge
70
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is not possible. The size of the equalization tank/lagoon will depend on the byproduct
volumes and the required number of days of storage.
Additional costs for treating waste in a POTW include any charges imposed by the
municipality for use of the sewer system (e.g., lift stations, piping network), basic fees
charged by the POTW,'and any strength surcharges based on excessive total suspended solids
(TSS) and chemical oxygen demand (COD) in the waste stream. Many small communities
(i.e., less than 50,000 residents) have not developed charges for excess TSS and COD in
wastewater since there is not significant industry in many of these towns. Many communities
charge flat rate fees instead of charges based on waste volumes. In addition, some
communities do not charge water treatment plants for wastes sent to the POTW facility since
they are part of the same entity (i.e., municipal public works).
9.2 TECHNOLOGY APPLICABILITY
Discharge into sanitary sewers is a common method of disposing water treatment byproducts
including brines and filter backwash. Alum coagulant and lime sludges also may be
discharged to a POTW under certain conditions. The ability of the wastewater treatment plant
to accept the increased hydraulic and solids loading must be considered when determining if
POTW discharge is an appropriate disposal method. In addition, the capacity of the sewer to
handle the flow rates and solids content of the waste must be considered. The sewer must
maintain a sufficient flow velocity to prevent solids deposition. .
' ซ. peunu
In some cases, chemicals hi the water treatment byproducts will actually aid in the treatment of
i
wastewaters at the POTW by acting as a settling agent. In other cases, the solids content or
other constituents in the byproducts may hinder the wastewater treatment process and add to
the sludge disposal problem at the POTW. A thorough analysis of byproduct constituents and
volumes is required prior to selection of a POTW as a treatment and disposal option.
71
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9.3 TECHNOLOGY LIMITATIONS
Discharging lime softening sludges to a POTW is normally not recommended due to the
dramatic increase in loading to the sludge handling system at the POTW. The disposal.of
waste brines from the ion exchange and reverse osmosis process is a viable option if the
concentrated waste does hot adversely affect the sewage treatment process and if the volumes
are not excessive in comparison to the POTW capacity.
Disposal of alum sludges via a sewer is not used frequently. The high solids content of alum
sludges and the elevated concentrations of aluminum interfere with the wastewater treatment
processes. Some POTW refuse to accept alum sludges due to high solids content of the
sludge, high aluminum concentrations, and intermittent flows. The POTWs that accept alum
sludges often charge higher rates to accept these wastes.
POTW surcharges for disposal to the sewer system substantially increase the cost of this
disposal method. POTW charges vary from a flat rate of several dollars per month to $3.65
per thousand gallons discharged. Appendix A presents POTW charges used to determine a
i
typical POTW charge for this document.
'' ' > '
In all cases, the water treatment plant must have or be able to gam access to a sanitary sewer
line or have convenient truck access, the POTW must be designed with adequate capacity to
manage the water treatment waste and specific contaminant levels must not exceed
concentration levels specified in the POTW use permit.
-a* .<- ' ' .
9.4 COST COMPONENTS
f
The following section presents the design assumptions, capital components, and the operation
and maintenance components used to prepare the costs for this technology.
72
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9.4.1 Design Assumptions
Byproduct flow rates range from 2,000 to 25,000,000 gallons per day
depending on the water treatment technology.
The sewer line connection is 500 feet or 1,000 feet from the water treatment
system.
- The byproduct stream flows by gravity or under pressure from the treatment
process to the sewer line. ,
- Two-inch minimum diameter pipe is used to prevent clogging. Pipe diameter
ranges from 2 to 24 inches.
PVC or reinforced concrete piping is used.
A 1- to 2-day storage lagoon is optional.
9.4.2 Capital Components
The capital components for each POTW discharge system consist of the following items:
Piping and fittings;
Trenching; and <
Land clearing. '
In addition, a pump, storage lagoon, electrical, and instrumentation are added for those
facilities electing to store byproducts prior to discharge to a POTW.
Table 16 indicates the brine volumes, pipe diameters and lagoon capacities used to develop the
capital cost equation for the POTW systems.
nv1- '? ' " "tior -w!
"9.4.3 Operation and Maintenance Components
The operation and maintenance components for each POTW discharge system include the
following items: '
Labor and supervision;
73 '--'
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TABLE 16
POTW DISCHARGE
Byproduct
Flow Rate
(gal/day)
30,000
67,500
162,500
500,000
750,000
1,000,000
10,000,000
25,000,000
Pipe Diameter
(inches)
2
2
3
4
6
6
' 24
36
i
Lagoon Capacity
50,000-gaIlon lagoon
115,000-gallon lagoon
330,000-galloh lagoon
750,000-gallon lagoon
1,125,000-galloh lagoon
1,500,000-galIon lagoon
15,000,000-gallon lagoon
37,500,000-gallon lagoon
Maintenance labor and materials;
Basic POTW charges;
- Total suspended solids (TSS) surcharges;
Electricity; and
Insurance and general and administration.
9.4.4 Cost Components Excluded
The following cost components are not included in the cost equations for POTW. discharge
systems:'-
**,-ซ/ป
Ariy"feesvcharged by the POTW for die initial connection; and
Land cost.
It is assumed the water treatment facility would be able to gain access for piping via an
easement.
74
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9.5 COST EQUATIONS
i
The cost equations for the capital components and operation and maintenance were developed
by estimating the costs for eight different brine flow rates. The capital cost equation calculates
the total capital cost (i.e. , installed capital plus indirect capital costs). The total annual cost is
calculated from the capital and operation and maintenance costs obtained using the equations
presented below. ( '.
9.5.1 500 Feet of Discharge Pipe . . ,
' Capital Costs . -
Y = 4,500
. Where: Y = $
X = gallons of brine per day
'
Range: 2,000 gpd <; X < 150,000 gpd
Y= 4,600 + 1.9xlO-J.X ,
-Where: Y = $
X = gallons of brine per day
Range: 150,000 gpd * X s 25,000,000 gpd
Operation and Maintenance
iฃe-- f> 000 and < ? , ' '% ' ' * .
-,Y = [1,000] + [(1.83 x 10ฐ) 365 X] + [(0.12) 365 Z]
Y = [Operating Cost] + [POTW Volume Charge] + [POTW Strength
Charge] .
Where: Y = $/year
X = gallons of brine per day
75
-------
Z = pounds per day of TSS in excess of 300 ppm
(1.83 x 10-3 = POTW volume charge)
(0.12 = TSS Surcharge)
Range: 2,000 gpd <; X * 25,000,000 gpd
Total Annual Cost
Y= [CAPxCRF] + O&M
Where: Y = $/year .
' CAP = capital cost v ,
CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
9.5.2 1000 Feet of Discharge Pipe
Capital Costs
Y ซ 8,700
Where: Y = $
X = gallons of brine per day
Range: 2,000 gpd * X < 150,000 gpd
Y = 9,000 + 3.9 x 10-3 X
Where: Y = $
*tj X =sgallons of brine per day
Ranger < 150,000 gpd * X * 25,000,000 gpd
X' ' bn,
76
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Operation and
Y = [1,000] + [(1.83 x 10-3) 365 X] + [(0.12) 365 Z]
Y = [Operating Cost] +' [POTW Volume Charge] + [POTW Strength
Charge],
Where: Y = $/year
X = gallons of brine per day
Z = pounds per day of TSS in excess of,300 ppm
(1.83 x 10ฐ = POTW volume charge)
(0.12 = TSS Surcharge)
Range: 2,000 gpd <; X z 25,000,000 gpd
Total
Y= [CAP x CRF] + O&M
Where: Y = $/year - .
CAP = capital cost
CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
9.5.3 500 Feet of Discharge Pipe with a Storage Lagoon
Capital Costs
Y= [44.3 X056] + [0.5 Z]
Y = [Equipment Cost] +., [Land Cost] charge
S.-SL- -hark.-.
! Where: Y = $ ,
X<^= gallons of brine per day
Z = land cost in dollars per acre (e.g^, $10,000/acre)
Range: 25,000 gpd i X * 750,000 gpd
Y= [1.13X084] + [{(2.47xlO-5)X074}Z]
77 ' , '
-------
Y = [Equipment Cost] + [Land Cost]
Where: Y = $
X = gallons of brine per day
Z = land cost in dollars per acre (e.g., $10,000/acre)
Range: 750,000 gpd < X <; 25,000,000 gpd
Operation and Maintenance
j .
Y = [3,500 + 2.25 x 10'2 X] + [(1.83 x 10'3) 365 X] + [(0.12) 365 Z]
Y = [Operating Cost] + [POTW Volume Charge] -I- [POTW Strength
Charge]
Where: Y = $/year
X = gallons of brine per day
v Z = TSS pounds per day in excess of 300 ppm
(1.83 x.lO-3 = POTW volume charge)
(0.12 = TSS Surcharge)
Range: 25,000 gpd s X s 500,000 gpd
Y = [0.30 X ฐ81] + [(1.83 x 10-3) 365 X] + [(0.12) 365 Z]
Y = [Operating Cost] + [POTW Volume Charge] + [POTW Strength
Charge] -
Where: Y = $/year
X = gallons of brine per day
Z = TSS pounds per day in excess of 300 ppm
(1.83 x 10ฐ = POTW volume charge)
J.- j; (0.12 = TSS)Surcharge)
Range: 500,000 gpd < X <> 25,000,000 gpd
78
-------
Total Annual Cost
Y = [CAP x CRF] + O&M
Where: Y = $/year
CAP = capital cost
CRF = capital recovery factor (e.g., 6.1175)
O&M = operation and maintenance cost
9.5.4 1000 Feet of Discharge Pipe with a Storage Lagoon
Capital Cost
Y = [19,500+ 0.1 IX] + [0.5 Z]
Y = [Equipment Cost] + [Land Cost]
Where: Y - $
X = gallons of brine per day
Z = land cost in dollars per acre (e.g., $10,000/acre)
Range: 25,000 gpd * X <; 750,000 gpd
Y = ,[60,200 + 6.97 x 10'2 X] + [{(2.47 x 10'5) X ฐ74} Z]
t
Y = [Equipment Cost] + [Land Cost]
Where: . Y = $
X = gallons of brine per day
Z = land cost in dollars per acre (e.g., $10,000/acre)
Range: >=* 750,000 gpd < X i 25,000,000 gpd
'' ' -
79
-------
Operation and Maintenance
Y =. [3,500 + 2.25 x 10'2 X] .+ [(1.83 x 10-3)365 X] + [(0.12) 365 Z]
Y = [Operating Cost] + [POTW Volume Charge] + [POTW Strength
Charge]
Where: Y = $/year '
X = gallons of brine per day
Z = TSS ponds in excess of 300 ppm
(1.83 x 10:3 = POTW volume charge)
(0.12 = TSS Surcharge)
Range: 25,000 gpd s X <; 500,000 gpd
Y = [0.30.X ฐ81] + [(1.83 x 10ฐ) 365 X] + [(0.12) 365 Z]
Y = [Operating Cost] + [POTW Volume Charge] + [POTW Strength
Charge]
Where: Y = $/year
X = gallons of brine per day
Z - TSS pounds in excess of 300 ppm
(1.83 x 10 3 = POTW volume charge)
(0.12 = TSS Surcharge)
Range: 500,000 gpd < X * 25,000,000 gpd
i . --
Total Annual Cost
Y = [CAP x CRF] + O&M
. waters1 to be coatt- jCha^tec ,
"
^
,- '' Y " ^- ,.a
wer n^ rate Tiee^fat f CiAf'=^capiSi-;cost; vari^tior tie qualif
f.. ^. ? ' CRF = .capital recovery factor (e.g., tO. 1175)
O&M = operation and maintenance cost
80
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10.0 DIRECT DISCHARGE
10.1 TECHNOLOGY DESCRIPTION
Directly discharging water treatment byproducts into surface water is a common sludge, slurry
and brine disposal method. The technology involves piping the waste stream from the water
plant to a receiving body of water such as a river, lake or ocean. Pumping, gravity or, in the
case of reverse osmosis, pressure from the treatment plant provides the force necessary to
carry the byproduct to the receiving waters^ Generally, no pretreatment or concentration of
the byproduct stream is practiced prior to discharge. The receiving waters dilute the waste
concentration and gradually incorporate the sludge or brine.
The piping required to carry the byproduct stream to the outfall is the primary capital cost
associated with this treatment method. Polyvinyl chloride (PVC) or reinforced concrete piping
is normally chosen for its low cost and corrosion resistance. Pipe diameter is determined
based on the maximum expected flow and acceptable head losses. Washout points are
necessary at all low points hi the discharge line to prevent clogging by accumulated sediments.
Gate valves are necessary at regular intervals to control waste stream flow hi the event of a
pipe burst. The pipe must be laid sufficiently below grade to prevent winter freezing.
An equalization tank/lagoon is optional and serves several purposes when disposing of
treatment wastes by direct discharge. First, the equalization tank/lagoon reduces the necessary
discharge-piping diameter by allowing filter backwash%aterstocbe'continuously discharged at
tohvi IvAthf C"if -.- v, ป-;r War... ./. * r. .71, ,rt are-rpnittT-cri tr\ .-J-.j-.ii . . ,. - _
a'lower flow, rater Second, the equalization tank/lagoon reduces the variations in the quality of
t
the discharged-wastes by mixing the wastes generated ovef'a'period of time. Third, the
equalization'tank/lagoon provides an emergency waste storage area when discharge is not
possible. The size of the equalization tank/lagoon will depend on the byproduct volumes and
the required number of days of storage. .
81
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10.2 TECHNOLOGY APPLICABILITY
>'".'
Direct discharge can be used for water treatment systems where little.oversight is available.
The level of operator experience and maintenance required is minimal. This method has been
i
used to dispose of alum and lime sludges and brines generated by reverse osmosis and ion
exchange treatment methods. Generally, there is no treatment of the solids in the sludge or
brine prior to discharge. Direct discharge requires the lowest level of oversight and
maintenance of all the treatment/disposal methods presented in this document.
10.3 TECHNOLOGY LIMITATIONS
Careful consideration needs to be given to qualitative impacts on receiving streams prior to
application of this disposal approach. Byproducts can potentially have a negative effect upon
the quality of water in the receiving body. Beyond the direct qualitative effects, low
velocities can contribute to accumulation of discharged sludges around the outfall. The
accumulation of sludges and sediments can greatly alter the local water quality and create an
area of anaerobic activity with lower water pH and odor problems. In addition, sudden
increases in water volume and velocity can resuspend settled solids and shock load the
receiving waters. .
An additional consideration is that there may be Federal, state, or local regulatory limits on
direct discharge.of water treatment plant byproducts. The discharge of waste into surface
'.GiET'jnent? r r
water is regulated by-the Clean Water Act. Water treatment plants are required to obtain a
ฐ r-eact- direct .-eio IK ueroS
National Pollutant Discharge Elimination System (NPDES) permit. Some states require
toxicity testing of wastewaters as part of their NPDES programs. Reverse osmosis brines may
be acutely or chronically toxic to aquatic life. In these cases, direct discharge of untreated
wastewater may be prohibited.
82
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Alum sludges can be of special concern. Several studies have investigated the toxicity of
aluminum release by alum sludges in receiving waters. The studies indicate a trend of higher
trout mortality rates in waters with higher aluminum concentrations and a negative impact on
phytoplankton productivity.
} ,
10.4 COST COMPONENTS
The following section presents the design assumptions, capital components, and the operation
and maintenance components used to prepare the costs for this technology.
10.4.1 Design Assumptions
Byproduct flow rates range from 2,000 to 25,000,000 gallons per day
depending on the water treatment technology.
The discharge point is 500 feet or 1,000 feet from the water treatment system.
The byproduct stream flows by gravity or under pressure from the treatment
process to the discharge point. .
Two-inch minimum diameter pipe is used to prevent clogging. Pipe diameter
. ranges from 2 to 24 inches.
PVC or reinforced concrete piping is used.
A 1- to 2-day lagoon is optional.
10.4.2 Capital Components -
The capital components^feach^irecf discharge sysifiefif consist of the following items:
s
Piping and fittings;'
Trenching; and
Land clearing.
83
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In addition, a pump, storage lagoon, electrical, and instrumentation are added for those
N
facilities electing to store byproducts prior to direct discharge.
,'
Table 17 indicates the brine volumes, pipe diameters, and storage lagoon capacities used to
develop the capital cost equation for direct discharge.
TABLE 17
DIRECT DISCHARGE
Byproduct
Flow Rate
(gal/day)
30,000
67,500
162,500
500,000
750,000
1,000,000
10,000,000
.' 25,000,000
Pipe Diameter
(inches)
2
2 .
3
4
6
6
24
36
Lagoon Capacity
50,000-gallon lagoon
115 ,000-gallon lagoon
330,000-gallon lagoon
750,000-gallon lagoon '
1,125,000-gallon lagoon
1,500,000-gallon lagoon
15,000,000-galIon lagoon
37,500,000-gallon lagoon
10.4.3 Operation and Maintenance Components
The operation and maintenance components for each direct discharge system include the
following items: 0' ."
Labor and supervision;
Maintenance labor and materials;
Electricity; and
- Insurance and general and administration.
.84
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10.4.4 Cost Components Excluded
The following cost components are not included in the cost equations for direct discharge
systems:
NPDES permit application and monitoring costs; and
Land costs.
It is assumed the water treatment facility would be able to gain access for piping via an
easement.
10.5 COST EQUATIONS
The cost equations for the capital components and operation and maintenance were developed
by estimating the costs for eight different brine flow rates. The capital cost equation calculates
the total capital cost (i.e., installed capital plus indirect capital costs). The total annual cost is ,
calculated from the capital and operation and maintenance costs obtained using the equations
presented below.
10.5.1 500 Feet of Discharge Pipe
Capital Costs
k (
Y = 4,500
Where: Y = $ &
X = gallons of brine per day
Range: 2,000 gpd <: X < 150,000 gpd
Y = 4,600 + 1.9 x 10-3 X
Where: Y = $
X = gallons of brine per day
85
-------
Range: 150,000 gpd s X <; 25,000,000 gpd
Operation and Maintenance
Y = 1,000
Where: Y = $/year
X = gallons of brine per day
Range: 2,000 gpd * X s 25,000,000 gpd
To{aj Annual Cost
Y = [CAP x CRF] + O&M
Where: Y = $/year
CAP = capital cost
CRF = capital recovery factor (e.g., 0.1175)
O&M operation and maintenance cost
10.5.2 1000 Feet of Discharge Pipe
Capital Cost
Y= 8,700
Where: Y = $
X = gallons of brine per day
Range: 2,000 gpd <: X < 150,000 gpd
Y = 9,000 -t-3.9xlO-3X
Where: Y = $
X ~ gallons of brine per day
Range: 150,000 gpd s X i 25,000,000 gpd
86
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Operation and Maintenance
Y= 1,000
Where: Y = $/year . .
X = gallons of brine per day
Range: .. 2,000 gpd <; X < 25,000,000 gpd
Total Annual Cost
j
Y = [CAP x CRF] + O&M
Where: Y - $/year
CAP = capital cost
CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
10.5.3 500 Feet of Discharge Pipe with a Storage Lagoon
Capital Costs
Y = [44.3 X ฐ56] + [0.5 Z]
s
Y = [Equipment Cost] + [Land Cost]
Where: Y = $
X = gallons of brine per day
Z = land cost in dollars per acre (e.g., $10,000/acre)
Range: 25,000 gpd <; X z 750,000 gpd
Y = [1.13 X 084] + [{(2.47 x lO'5) X ฐ74} Z]
Y = [Equipment Cost] + [Land Cost}
Where: Y = $
X - gallons of brine per day
Z = land cost in dollars per acre (e.g., $10,000/acre)
87
-------
Range:
750,000 gpd < X s 25,000,000 gpd
Operation and Maintenance
Y = 3,500 + 2.25 x 10'2 X
Where: . Y = $/year
X = gallons of brine per day
Range:
25,000 gpd * X s 500,000 gpd
0.81
Y = 0.30 X ฐ81
Where:
Range:
Y = $/year
X = gallons of brine per day
500,000 gpd < X * 25,000,000 gpd
Total Annual Cost
Y = [CAPxCRF] + O&M '.
Where: Y = $/year
CAP = capital cost
CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
10.5.4 1000 Feet of Discharge Pipe with a Storage Lagoon
Capital Cost .
1 Y= [19,500 + 0.11X3 + [0.5 Z]
Y = [Equipment Cost] + [Land Cost}
Where:
Y = $
X = gallons of brine per day
-------
Z = land cost in dollars per acre (e.g., $10,000/acre)
Range: 25,000 gpd <. X <> 750,000 gpd
Y = [60,200 -1- 6.97 x 1Q-2 X] + [{(2.47 x 10'5) X ฐ74} Z] .
Y = [Equipment Cost] + [Land Cost]
Where: . Y = $
X = gallons of brine per day
Z = land cost in dollars per acre (e.g., $10,000/acre)
Range: 750,000 gpd < X ฑ 25,000,000 gpd
i
Operation and Maintenance '.
Y= 3,500 + 2.25 x 10"2 X
' s ,
Where: Y - $/year
X = gallons of brine per day
Range: 25,000 gpd si X 5 500,000 gpd
Y = 0.30 X
0.81
Where: Y = $/year . .
X = gallons of brine per day
Range: 500,000 gpd < X <. 25,000,000 gpd
rs " ifu Rraiion is useci viit leep ;?*ฃ
1 ' . M'lfc*- '* t'; * J * ' i -i*/,iH ป.' " i
fTotals-Annual Cost -la'Sl^'^e ; *"d.continual!v in!?" a
Y= [CAP x CRF]"+ O&M ":''' / ,
Where: , Y = $/year
, CAP = capital cost .
4 CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
89
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11.0 LAND APPLICATION
Land application can be used to dispose of liquid and sludge/slurry wastes, two land
application systems are included in this analysis: a sprinkler system for liquid waste and
transport off site for application via a specially equipped tanker truck. A general description
of land application, its applicability, and limitations is presented below. Separate cost
information is presented for land application of liquid and sludge byproducts.
11.1 TECHNOLOGY DESCRIPTION
Land application disposes water treatment byproducts by applying them directly to land
surfaces. In general, the liquid sludges contain less than 15 percent solids. Liquid, pumpabie,
sludge can be applied to land surfaces via spraying from a truck or sprinkler system, injected
into the subsurface, or discharged directly to a selected land application field. Dewatered
sludge is applied by spreading the solid material over the land surface. Sludge application is
dependent on several variables, such as the crop planted in the application field and the
chemistry of the soil and sludge.
% ' V
Liquid sludge can be applied to a selected land application field using various methods. Once
on the field, the sludge is treated by infiltration or overland flow, improving water quality by.
physical, chemical, and biological interactions with the soil. During infiltration, liquid sludge
is allowed to percolate into the soils. Slow infiltration is used with moderately permeable soils
j ,. 1- -j i -j *1. . ., . ,, . ,._-... _ . H..U, gas. . *< ' . ,
and the liquid sludge is applied with sprinklers. Rapid infiltration is used with deep and
.... 1_,'iฉ0-4ueซtt>1U>cxeas . _. >sy.i*^iroh- ^,ซoeiated with, other ,. . .
highly permeable soils, such as sands. Liquid sludge is fed continually into a shallow basin
"i?"j car' to *M' ri~ ' LP r""c
during an application period, which may vary between several hours to "several weeks,
depending on the volume of liquid sludge. Both infiltration systems also can use
underdrainage. Underdrainage is a system of bVied pipes that captures effluent for reuse or
gi , .
discharge into a receiving body of water; underdrainage minimizes ground water
90
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contamination and subsurface flow of leachate to adjacent properties. Overland flow is used in
areas with low permeability soils. Sludge is applied at the top of a slope and runs overland;
runoff ditches collect the effluent for reuse or discharge.
Liquid sludge can be applied by surface spraying or subsurface injection. If the application
. field is near the waste-generating plant or storage lagoon, a sprinkler system can be used to
spray liquid sludge from the lagoon. If a remote application field is used, sludge must be
transported to the disposal site in a truck. The transport truck or a tanker truck may be'used
to apply the sludge or may be used strictly for transport. If a tanker truck is used, the sludge
must be transferred to another specialized vehicle for application. Depending on the type of
vehicle, the sludge can be applied by spraying or subsurface injection.
Dewatered sludges are stored on site until they are transported to a disposal site. At the land
application field, the sludge is spread by a truck and tilled into the soil by a tractor.
Monitoring of .soils, rim off from land application, and potentially affected water resources
may be advisable to protect open land that may become cropland and to protect local water
quality. Monitoring soils for metals and/or radionuclides may be required by state and other
agencies.
11.2 TECHNOLOGY APPLICABILITY
Land application of liquid and dewatered sludges provides final disposal for lime and, to some
degree, alum sludges. The acceptability, of land application^ increasing)and tit is gaining in
popularity, as a disposalimethodiduejtoiincreased regulatoryccontrols assoctatedjwith other
disposal methods. Lime sludges can be used in farmland to neutralize soil pH in place of
commercial products. Non-food chain crops, mine reclamation areas, and forests are
preferred vegetation for sludgdapplication. Alum sludges do not benefit the soil matrix and
- should only be used as fill material. .*-..'
91
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Farmers may be reluctant to allow spreading of sludges on their fields. If farmers are willing
to use sludge, the application of sludge is seasonal, usually in the spring; however, sludges are
produced year round. Seasonal weather conditions also affect sludge application. In northern
areas, sludge application is limited to warmer months when applications can infiltrate soils or
the sludge can be injected into soils. Where the ground is frozen or covered with snow for
part of the year or applied to farmland, sludge would require stockpiling until soil conditions
are appropriate for land application.
11.3 TECHNOLOGY LIMITATIONS
There are numerous limitations to land application of sludges including chemical alteration of
the soil, seasonal conditions, and proximity of available land: Land application is not
appropriate for brines and is limited for sludges. If radionuclides are present, land application
may not be appropriate. Regulated levels of radionuclides vary from state to state and water
suppliers should contact their radiation and drinking water authorities to obtain state-specific
information.
Land application for,alum sludge is limited. Alum sludge contributes little to soil
conditioning, and may actually harm soil nutrient balances. Studies indicate that alum sludges
fix phosphorous in the soil, preventing uptake of phosphorous hi plants.
Application of any sludge to the land may introduce trace metals to the soil. The application
lifetime of a site is limited to when one of the trace metals reaches the'maximum allowable
concentration. Due,to the possibility of trace'metal absorption by vegetation, non-food chain
'.'' - ,*: r /J tixiti Vysri1 -ti >r . J <:g. .
crop fields are preferred for land application.
Land application also is limited to areas where agricultural land, grassland, or forested land is
available nearby, since transportation costs to remote disposal areas increase substantially with
distance.
1 92
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11.4 LIQUID SLUDGE LAND APPLICATION COST COMPONENTS
The following section presents the design assumptions, capital components, and the operation
and maintenance components used to prepare the costs for this technology.
11.4.1 Design Assumptions
The storage lagoon is constructed with a synthetic membrane liner, overlain by
12 inches of sand.
The applied sludge consists of lime or alum sludge.
The water treatment plant is 500 feet from the storage lagoon; the sludge is
gravity-fed to the lagoon.
The lagoons are sized for 6-month storage.
The application field is cultivated farmland. The farmer uses a personally-
owned tractor and fuel to till the land following the sludge application.
Application By Truck: .
The sludge is applied twice per year (spring and fall).
The sludge application is 1 inch thick.
\ .
Application By Sprinkler:
/
The land application rate is % inch per day.
, 1 mts-Snt. .flee.-' - .iude uit . .
The sprinkler system is a portable system with above-ground piping.
T '> '
- ,.. The sprinkler system has ji radius of 50 feet.
93
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11.4.2 Capital Components , . .
The capital components for land application consist of the following items:
Storage lagoon;
Piping;
Land; ,
Electrical; and . .
Sprinkler system, when appropriate.
Table 18 indicates the sludge volume and pond surface areas used to develop the capital cost
equation for the land application systems.
TABLE 18
LIQUID SLUDGE LAND APPLICATION
Sludge Volume
(gal/day) .
.. . 2,000
10,000
20,000
60,000 '
100,000
500,000
Pond Surface Area
(acres)
0.27
0.92
1.26
2.64
3.72
10.97
11.4.3 Operation and Maintenance Components
The operation and'maintenance components for land application include the following items:
Electricity; . ,
Labor and supervision; - ., .'
Sludge removal from storage pond;
Maintenance labor and materials;
Insurance and general and administration; and
Transportation and land application fees, when appropriate.
94
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..
11.4.4 Cost Components Excluded
Costs for incorporation of the liquid sludge into the soil, if necessary, are not included in the
cost equations for liquid sludge.
11.5 LIQUID SLUDGE LAND APPLICATION COST EQUATIONS
The cost equations for the capital components and operation and maintenance were developed
by estimating the costs for six different sludge flow rates. The capital cost equation calculates
the total capital cost (i.e., installed capital plus indirect capital costs). Equipment costs and
land costs are separate components in the capital cost equation to enable the user to exclude the
cost for purchasing land if it is not necessary. The total annual cost is calculated based on the
capital and operation and maintenance costs obtained using the equations presented below.
- 11.5.1 Sprinkler System .
Capital Cost
Y = [120 X ฐ-78] + [{(2.06 x 10:3) X 066} Z] + [(2.87 x 10 X) Z]
Y = [Equipment Cost] + [Pond Land Cost] + [Application Field
Cost]
Where: Y = $
X = gallons of sludge per day
Z = land cost in $/acres(e.g:,$10,000/acre)
t i
Range: 2,000 gpd * X * 500,000 gpd
Operation and Maintenance
Y= 81.7 X056
Where: Y = $/year
' X = gallons of sludge per day
95
-------
Range: 2,000 gpd s X i 60,000 gpd
Y = 8.63 X
0.76
Where: Y = $/year
X = gallons of sludge per day
Range: 60,000 gpd < X * 500,000 gpd
Total Annual Cost
Y = [CAPxCRF] + 0&M
Where: Y = $/year
CAP = capital cost
CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
11.5.2 Trucking System
Capital Co$|
Y = [104 X ฐ78] + [{(2.06 x lO'3) XOM} Z] x
Y = [Equipment Cost] + [Land Cost]
Where: Y = $
X = gallons of sludge per day
Z = land cost in $/acre (e.g., $10,000/acre)
Range: 2,000 gpd i X ^ 100,000 gpd
Operation and Maintenance
Y= 18.9 X0-*
Where: Y = $/year - ' '
X = gallons of sludge per day
96
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Range: 2,000 gpd * X s 100,000 gpd
Y = [CAP x CRF] + O&M
Where: Y = $/year
CAP = capital cost
CRF = capital recovery factor (e.g. , 0. 1 175)
O&M = operation and maintenance cost
l
11.6 DEWATERED SLUDGE LAND APPLICATION COST COMPONENTS
11.6.1 Design Assumptions
The sludge is stockpiled on site.
The sludge is transported off site for land application.
A front-end loader is used to load the sludge for transport. The front-end
loader is owned by the water treatment plant.
The application field is within 25 miles of the plant.
The application field is agricultural. The fanner growing crops on the field
uses a personally-owned tractor and fuel to till the sludge into the soil.
The application rate is two dry tons of sludge per acre.
<;u CU.6.2 Capital Components . *;6&r EQU,r
,' - * . '
The capital components for dewatered sludge land application consist of the following items:
-i . ."
Land for sludge stockpile; and - .
Land clearing. ^
c. >ii
Table 19 indicates the sludge volume and storage pile surface area used to develop the cost
equations for the land application of dewatered sludge.
97
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TABLE 19
DEWATERED SLUDGE LAND APPLICATION
Sludge Volume
(gal/day)
2,000 '
10,000
20,000
60,000
Storage Pile
Surface Area
(acres)
0.34
2.2
4.5
9.2
11.6.3 Operation and Maintenance Components
\
The operation and maintenance components for each dewatered sludge land application include
the following items:
Labor and supervision; .
Sludge loading; and
Transportation and land application fees.
11.6.4 Cost Components Excluded
Costs for incorporation of the dewatered sludge into the soil, if necessary, are not included in
the cost equations for dewatered sludge.
i ,
11.7 DEWATERED SLUDGE LAND APPLICATION COST EQUATIONS
-v fr '* er lay
The cost equations for the capital components and operation and maintenance were developed
by estimating the costs for four different sludge flow rates. The capital cost equation
calculates the total capital cost (i.e., installed capital plus indirect capital costs). Equipment
costs and land costs are separate components in the capital cost equation to enable the user to
98
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exclude the cost for purchasing land if it is not necessary. The total annual cost is calculated
based on the capital and operation and maintenance costs obtained using the equations
presented below. t
Capital Cost
Y= [111 X050-4,700] + [0.5 Z]
Y = [Equipment Cost] + [Land Cost]
V,
Where: Y = $
X = gallons of sludge per day
Z = land cost in $/acre (e.g., $10,000/acre)
Range: 2,000 gpd * X < 2,500 gpd
/ . . .
. Y. = (111 X aso - 4,700] + [{(4.9 x 10'2) X ฐ50 - 2} Z]
Y = [Equipment Cost] + [Land Cost]
Where: Y = $
X = gallons of sludge per day
Z - land cost in $/acre (e.g., $10,000/acre)
Range: 2,500 gpd s X < 60,000 gpd
Operation and Maintenance .
Y = 800 + 28.2 X
Where: Y = $/year . ,
; ...(_> .''- X =gallons of sludge per day
Range: 2,000 gpd * X $ 60,000 gpd
99
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Total Annual
Y= [CAP x CRF] + O&M
Where: Y = $/year
CAP = capital cost
CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
:cii
100
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12.0 NONHAZARDOUS WASTE LANDFILL
12.1 TECHNOLOGY DESCRIPTION
Nonhazardous waste landfills are used for ultimate disposal of dewatered byproduct sludges.
A landfill is an area of land or an excavation in which wastes are placed for permanent
disposal, and that is not a land application unit, surface impoundment, injection well, or waste
pile (40 CFR Part 257.2). Two forms of nonhazardous waste landfills are commonly used to
dispose of byproduct sludges: monofills and commercial nonhazardous waste landfills.
Monofills are landfills that only accept one type of waste (e.g., water treatment byproducts
sludges or incinerator ash). Commercial nonhazardous waste landfills accept a mix of
residential and industrial wastes.
Nonhazardous waste landfills are regulated by individual states and under the Resource
Conservation and Recovery Act (RCRA). Each state has specific guidelines on what types of
waste can and cannot be disposed in nonhazardous waste landfills and also determines
construction and operation criteria. In many cases, the state requirements are more stringent
than the Federal requirements under RCRA.
On October 9, 1991, the U.S. EPA promulgated new criteria for^existing and future municipal
solid waste landfills (56 FR 50978), a major subset of nonhazardous waste landfills. These
criteria include location restrictions, operating criteria, design criteria, ground water
monitoring requirements j corrective action requirements ^closure and post-closure care
requirements, and financial assurance! Implement&ibtfof'^ impact
the use of this disposal option and increase theHippihg fees charged by some landfills beyond
the levels estimated by inflatioif factors..
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12.2 TECHNOLOGY APPLICABILITY AND LIMITATIONS
The percent solids and leaching characteristics of a sludge are the two most important
characteristics in determining the applicability of disposal in a nonhazardous waste landfill.
The sludge cannot contain free liquids as defined by the Paint Filter Liquids Test (SW-846,
Method 9095). In this test, a representative 100 ml or 100 gram sample-is placed in a conical
paint filter (60 mesh) and placed on a ring stand above a graduated cylinder or beaker. If any
liquid collects in the cylinder or beaker, the sludge contains free liquids and is not appropriate
for landfilling. If liquid does not collect in the cylinder or beaker, the waste does not contain
free liquids and can be disposed in a landfill.
, f
In addition to passing the Paint Filter Liquids Test, the waste cannot exhibit the characteristic
of toxicity as determined by the toxicity characteristic leaching procedure (TCLP) test (40
CFR Part 261, Appendix II). In the TCLP test, an extraction is performed to determine if any
constituent is present in the waste leachate above the regulated concentration. If any
constituents are present at concentrations greater than or equal to the TCLP limits (40 CFR
Part 261.24), the waste cannot be disposed in a nonhazardous waste landfill. If constituents
are not present above the toxicity characteristic (TC) regulatory level and the waste does not
exhibit other characteristics of hazardous waste (i.e., ignitability, reactivity, and corrosivity),
i
the sludge can be disposed in a nonhazardous waste landfill.
Additional sludge characteristics such as sludge specific gravity, compaction analysis, and
shear properties also are important when determining the applicability of a sludge for disposal
in a nonhazardous waste landfill. These characteristics determine the ease of sludge handling
1 zi
and the overall stability of the disposal area. In most cases, a solids content of 1520 percent
is required for landfilling, but in some cases wastes with less than 15 percent solids will be
accepted for disposal.
102
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Many water treatment facilities currently dispose of their waste in commercial or publicly-
owned landfills. Landfilling tends to be the most economical option for disposal of water
byproduct residues. Rising landfill costs, decreasing landfill availability, and increasing
environmental regulations governing waste disposal may make this option less economical.
Because the availability of landfills is decreasing and environmental regulations are increasing,
there is increased emphasis on the benefits of monofills within the water industry. Generally,
the costs associated with the development of a monofill are less than those associated with a
municipal or industrial waste landfill. In addition, the water treatment facility limits potential
liability by controlling the type of wastes disposed at a monofill.
1 \
12.3 OFF-SITE NONHAZARDOUS WASTE LANDFILL COST COMPONENTS
The following section presents the design assumptions and components used to prepare the
costs for this technology.
12.3.1 Design Assumptions
- A commercial nonhazardous waste landfill is used for sludge disposal.
Transportation distance varies from 5,to 50 miles.
There is no economy of scale for large waste volumes.
All wastes pass the Paint Filter Liquids Test.
The waste does not exhibit the characteristics of ignitability, corrosivity,
reactivity, or tpjucity, ,i,
;a> 5Vi>:. 1 ฃ St. Mai .
12.3.2 Cost Components -
> : - -!1
The cost components for non-hazardous waste landfill consist of the following items:
. i
Commercial nonhazardous waste landfill tipping fee; and
Transportation fees.
103 ' ,
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12.4 OFF-SITE NONHAZARDOUS WASTE LANDFILL COST EQUATION
Total Annual Cosj
Y= [35 X] + [(2.48 + 0.16Z)X]
Y = [Disposal] + [Transportation]
1 Where: ' Y = $/year
X = tons of sludge requiring disposal/year
Z = transportation distance from 5 to 50 miles
12.5 ON-SITE NONHAZARDOUS WASTE LANDFILL COST COMPONENTS
The following section presents the design assumptions used to prepare the costs for on-site
nonhazardous waste landfills, including capital, operation and maintenance, and the closure
i
and post-closure care components..
12.5.1 Design Assumptions .
The landfill has a 20-year operating life.
- The landfill is a combination fill (i.e., a design combining below and above
grade fills). ,
The landfill containment system consists of two feet of clay, a 30 mil HDPE
liner, one foot of sand with a leachate collection system, a geotextile filter
fabric, and one foot of native soil fill.
The intermediate cover consists of slope and earthfill soils.
;. : mes; . . .
' ' f' - "4
A groundwater monitoring system is installed and is sampled biannually.
The final cover consists of one foot of native soil fill, a geotextile support
fabric, a 30 mil PVC liner, one foot of sand with drain tiles, a geotextile filter
fabric, and l.S feet of topsoil.
The post-closure care period is 30 years.
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12.5.2 Capital Components
, ' \ i t
The capital components for each landfill consist of the following items:
Land;
Land clearing;
Landfill excavation;
Composite (clay and synthetic) liner;
Leachate collection system;
Groundwater monitoring system;
Equipment storage and maintenance buildings;
Visual screening berm;
Bulldozer;
Track; and . ' ' ;
Inspection,*testing, and quality assurance.
12.5.3 Operation and Maintenance Components
The operation and maintenance components for each landfill include the following items:
Labor and supervision;
Maintenance labor and materials;
Intermediate cover;
Groundwater monitoring;
Leachate collection and treatment; and
Utilities including electricity and water.
12.5.4 Closure Components
The closure components for each landfill include the following items:
Final cover system including drain tilesV
Revegetation; and
Inspection, testing, and quality assurance. .
12.5.5 Post-Closure Components
The post-closure components for each landfill include the following items:
Groundwater monitoring;
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.Leachate collection and treatment;
Landscape maintenance;
Slope maintenance; and
Annual inspection. , ,
12.5.6 Cost Components Excluded .
Siting and permitting costs are not included in the cost estimates. Regulatory requirements for
Subtitle D landfills vary from state to state. Permitting costs will vary based on the size of the
landfill and the local governing jurisdiction. ,
12.6 ON-SITE NONHAZARDOUS WASTE LANDFILL COST EQUATIONS
Capital Cpsts
Y= [8,079 X067] + [(20.4 + 0.33X050)Z]
Y = [Landfill Cost] + [Land Cost]
Where: Y - $ '
X = tons of sludge requiring disposal/year.
Z = land cost in $/acre (e.g., $10,000/acre)
Range: 2,500 TPY s X <; 100,000 TPY
Operation and Maintenance
Y.= 2,411X^)900,
Where: Y = $/year
X = tons of sludge requiring disposal/year
Range: 2,500 TPY <; X < 30,000 TPY
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246 X ฐป + 300,900
Where: Y = $/year
X = tons of sludge requiring disposal/year
Range: 30,000 * X s 100,000 TPY
Closure
Y = 506 X
0.80
Where:
Range:
Y - $ . -
X = tons of sludge requiring disposal/year
2,500 TPY * X & 100,000 TPY
Post-Closure
600 +58.2 XOJ :
Where: Y $/year
X =* tons of sludge requiring disposal/year
Range: 2,500 TPY s X s 100,000 TPY
Total Annual Cost
[8,483 X ฐ* - 250,300] + [(2.4 + 0.04 X ฐ *) Z] '.
Where: Y = $/year
^ ,(.' X = tons of sludge requiring disposal/year
* land Z = land cost in $/acfe (e.g., $10,000/acre)
Range:' ^ 2,500TPY ฃX.x 100,000 TPY
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Y = 246 X ฐ-50 -h 300,900
Where: Y = $/year
X = tons of sludge requiring disposal/year
Range: 30,000 <: X s 100,000 TPY
Closure
Y= 506 X
0.80
Where:
Range:
Y = $
X = tons of sludge requiring disposal/year
2,500 TPY * X * 100,000 TPY
Post-Closure
600 + 58.2 X M .
Where: Y = $/year
X = tons of sludge requiring disposal/year
Range: 2,500 TPY * X s 100,000 TPY
Total Annual Cost
[8,483 X OJO - 250,300] + [(2.4 + 0.04 X **) Z]
Where: Y * $/year
, X = tons of sludge requiring disposal/year
* Z = land cost in $/acre (e.g., $10,000/acre)
Range:
2,500 TPY s X s 100,000 TPY
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13.0 HAZARDOUS WASTE LANDFILL
13.1 TECHNOLOGY DESCRIPTION
Hazardous waste landfills are used for ultimate disposal of hazardous wastes (including listed
and characteristic wastes). Hazardous waste landfills are used for the disposal of water
treatment byproduct sludges exhibiting one or more characteristics of hazardous waste
(ignitability, corrosivity, reactivity, and toxicity). A hazardous waste landfill is a disposal
facility where hazardous waste is placed in or on land and which is not a waste pile, a land
treatment facility, a surface impoundment, an underground injection well, a salt dome
formation, a salt bed formation, an underground mine, or a cave (40 CFR Part 260.10).
Hazardous waste landfills are regulated by the Federal government under RCRA or by
individual states where the state has received RCRA authorization.
Hazardous waste landfills must be permitted in accordance with the hazardous waste permit
regulations (40 CFR Part 270). The hazardous waste landfill regulations specify that landfills
must be designed with a synthetic flexible membrane liner and composite double liner. In
addition, the landfill must have a leachate collection system above the top liner and a leachate
detection system between the top liner and bottom composite liner. The containment system
for a hazardous waste landfill, in descending order starting with the component closest to the
waste, consists of a 1-foot protective soil layer, a geotextile filter fabric, a leachate collection
system (a 1-foot sand layer with drainage pipes), a 30-mil HDPE liner, a leachate detection
system (a 1-foot sand layer with drainage pipes), a 30 mil-HDPE liner, and a 3-foot layer of
compacted clay, which has a hydraulic conductivity < 1 x 10~7 cm/sec. Leachate collected
from the landfill must be tested to determine if it is a hazardous waste. If the leachate is
determined to be a hazardous waste, it must be managed as a hazardous waste.
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13.2 TECHNOLOGY APPLICABILITY AND LIMITATIONS
The leaching characteristics and the presence of free liquids are the two most important
characteristics in determining the applicability of sludge disposal in a hazardous waste landfill..
Water treatment byproducts that exhibit the characteristic of ignitability, corrosivity,
reactivity, or toxicity require disposal in a hazardous waste landfill. Typically, water
treatment byproducts are not ignitable, reactive, or corrosive, but may exhibit the
characteristic of toxicity. The TCLP test (40 CFR Part 261, Appendix n) is used to determine
if wastes are toxic. In the TCLP test, the extraction is performed to determine if any
constituent is present in the waste leachate above the regulated concentration. If any
constituents are present at concentrations greater than or equal to the TC limits (40 CFR Part
261.24), the waste is hazardous and requires disposal in a hazardous waste landfill. If no
constituents are present above the regulatory level and the waste does not exhibit other
characteristics (i.e., ignitability, reactivity, and corrosivity), the sludge can be disposed in a
nonhazardous waste landfill.
In addition, the sludge cannot contain free liquids as defined by the Paint Filter Liquids Test
(SW-846, Method 9095). In this test, a representative 100 ml or 110 gram sample is placed in
a conical paint filter (60 mesh) and placed on a ring stand above a graduated cylinder or
beaker. If any liquid collects hi the cylinder or beaker, the sludge contains free liquids and is
not appropriate for landfilling. If no liquid collects hi the cylinder or beaker, the waste does
not contain free liquids and can be disposed in a landfill without further dewatering. If the
waste contains free liquids, it must be stabilized or treated by another method to remove free
liquids prior to disposal hi a landfill.
The Hazardous and Solid Waste Amendments of 1984 restrict the land disposal of untreated
hazardous wastes. The land disposal restrictions for Third Third Wastes (55 FR 22520)
promulgated treatment standards for wastes exhibiting characteristics of hazardous waste
(ignitability, corrosivity, reactivity, and toxicity) that require wastes to meet specified
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concentration standards prior to land disposal. In general, for sludges exhibiting the TC
characteristic, the sludges must be stabilized prior to land disposal to meet the concentration
standard. Other treatment methods are acceptable as long as the waste contains TC
concentrations at or below the level specified in the Third Third Final Rule prior to land
disposal. The additional treatment required by the Land Disposal Restrictions Rule
significantly increases the cost of hazardous waste disposal.
13.3 COST COMPONENTS
The following section presents the design assumptions and cost components used to prepare
the costs for this disposal technology.
13.3.1 Design Assumptions
- A commercial hazardous waste landfill is used for sludge disposal.
Transportation distance varies from 200 to 500 miles.
There is no economy of scale for large waste volumes.
All wastes pass the Paint Filter Liquids Test or if they fail the Paint Filter
Liquids Test, they are stabilized prior to disposal.
The waste fails the TCLP test.
Some wastes require stabilization prior to disposal to meet the Land Disposal
Restrictions Treatment Standards for TC wastes.
13.3.2 Cost Components
The cost components for hazardous waste landfill consist of the following items:
Hazardous waste landfill charges;
Stabilization charges; and
Transportation fees.
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13.3.3 Cost Components Excluded
The following cost components are not included in the cost equations for hazardous waste
landfills:
Generator notification requirements;
Manifest requirements; and
Other RCRA requirements, as applicable.
13.4 TOTAL ANNUAL COST EQUATION
13.4.1 Hazardous Waste Disposal
Y = [200 X] + [(7.9 + 0.22 Z) X]
Y = [Disposal] + [Transportation]
Where: Y = $/year
X = tons of sludge requiring disposal per year
Z = transportation distance between 200 and 500 miles
13.4.2 Stabilization and Hazardous Waste Disposal
Y = [400 X] + [(7.9 + 0.22Z) X]
Y = [Stabilization/Disposal] + [Transportation]
Where: Y = $/year
X = tons of sludge requiring disposal per year.
Z = transportation distance between 200 and 500 miles
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14.0 RADIOACTIVE WASTE DISPOSAL
14.1 SOURCES OF RADIOACTIVITY IN DRINKING WATER
Radionuclides, such as radium, uranium, and radon, naturally occur in drinking water sources
in the United States. Radium is found in ground waters and is most common in the Midwest
and Florida. Uranium is found in sandstone and phosphate rock ground waters primarily hi
western states. Radon occurs much more frequently hi drinking waters and has been found hi
most regions of the country.
Presently, Federal regulations have established maximum contaminant levels (MCLs) only for
radium, gross alpha radiation and beta/photon emitters. In 1976, a drinking water standard for
combined radium of 5 picocuries per liter (pCi/L) was set by the U.S. EPA. It was estimated
that 1,000 community water supplies would exceed the radium standard hi the U.S.; most of
which were groundwater systems with capacities of 0.5 million gallons per day or less. No
Federal MCLs have been promulgated for radon or for natural uranium, although standards
are under development. In addition, waste containing more than 0.05 percent of natural
uranium may be regulated as a "source material" under the Atomic Energy Act. Because of
existing regulations, radium contamination will be the focus of this section.
In 1990, the EPA issued guidance entitled "Suggested Guidelines for the Disposal of Drinking
Water Treatment Wastes Containing Naturally Occurring Radionuclides." That guidance was
designed to provide water suppliers and state and local governing agencies with some
assistance. The guidance provided recommendations and summarized existing regulations and
criteria used by EPA and other agencies in addressing the disposal of radionuclides generated
by industries other than the water treatment industry. Because this guidance is not regulation
and regulations vary from state to state, water suppliers should contact radiation and drinking
water authorities within their state for more specific information.
112
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A water supply system with radium levels that exceed regulations has several options to bring
the radium levels below the Federal MCLs. The supply can develop a new water source,
dilute the radium rich water with less rich water from another source, or treat the water to
reduce radium levels. A water treatment plant should carefully study the cost and feasibility of
radium removal and disposal of radium-contaminated sludges before choosing to install a
radium removal treatment technology.
14.2 RADIUM REMOVAL
Treatment processes that remove radium from drinking water include lime softening, ion
exchange, reverse osmosis, manganese green sand filters, and radium selective resins. These
processes have 80 to 98 percent removal efficiencies and concentrate the radium removed from
the treated water in the backwash, brine, and sludge wastes.
,'-''
Radium wastes generated by drinking water treatment are identified as naturally occurring
radioactive material (NORM). The United States does not have Federal regulations governing
the disposal of NORM. The United States Nuclear Regulatory Commission (NRC) is
mandated to regulate the disposal of high-level and low-level radioactive wastes generated in
the United States. The disposal of NORM is not licensed by the NRC because it is not a
manmade radioactive waste and does not fall under NRC jurisdiction. The EPA has proposed
standards to control the disposal of NORM wastes with radionuclide concentrations greater
than 2000 pCi/g (dry weight). Individual states also have proposed regulating the handling
and disposal of NORM. Presently, there are no state or Federal regulations governing the
disposal of radioactive water treatment wastes and it may be several years before proposed
regulations are adopted. However some states, including Texas, Louisiana, Wisconsin, and
Colorado, have disposal regulations that pertain to Naturally Occurring and Accelerator-
Produced Materials (NARM) that limit the discharge of wastes containing radionuclides into
the environment.
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The radium content in wastes generated by water treatment processes will depend upon the
type of wastes, removal efficiency of the process, and the volume of waste generated. Filter
backwash water will have little or no elevated radium concentrations. Brines generated from
reverse osmosis and ion exchange methods will have a wide variety of radium concentrations.
Sludge and solid wastes will have the greatest radium concentrations.
14.3 LOW-LEVEL RADIOACTIVE WASTE DISPOSAL
There are several disposal options for NORM wastes generated by water treatment plants.
Most of these disposal methods, including direct discharge to surface waters, discharge to
sanitary sewers, land application, and landfilling have been discussed in detail in previous
sections. When state and local regulations permit disposal of water treatment plant NORM by
these methods, the costs of disposal should be similar to non-NORM sludge disposal costs.
One additional disposal option, sending wastes to a low-level radioactive disposal site, has not
been mentioned previously and will be discussed in detail here. It should be noted that this
will usually be a final option for a water treatment plant that cannot develop a new water
source or dilute the radium-rich water with less rich water from another source.
For plants that do not have alternative water sources or cannot reduce the radium in their
source by dilution, radium containing waste will require disposal. It is assumed that the final
disposal product will consist of a resin or filter media used specifically to capture the radium
in the feed water rather than the brine or sludge resulting from more general water treatment.
The brines and sludges should not require this special disposal since the radium concentration
in these wastes is typically below regulated levels. Consequently, the waste volumes will be
significantly lower than those specified for general water treatment.
There are currently three low-level radioactive waste disposal sites operating in Nevada, South
Carolina, and Washington, and one NORM disposal site operating in Utah. Each low-level
site bases waste disposal costs on several factors including state of origin of the waste, type of
114
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waste, and measured radioactivity at the container surface. All disposal facilities are located
in a regional pricing compact. The Low-Level Radioactive Waste Policy Amendments Act
(LLRWPAA) of 1985 authorized the formation of regional compacts and a system of
incentives and penalties to ensure that states and compacts will be responsible for their own
waste after January 1, 1993. States located in a compact with an operational waste disposal
facility pay the lowest disposal costs while states located outside of the compacts with disposal
facilities pay a disposal surcharge of $40 or $120 per cubic foot (approximately $300 to $900
per 55-gallon drum). The NORM disposal site is not part of a pricing compact and does not
add surcharges.
Most water byproduct treatment processes do not generate wastes with radiation levels high
enough to be classified as a low-level radioactive waste and that possibility should be
mmimized through proper treatment design. In some instances, a treatment process may
concentrate the radionuclides in activated carbon or in a highly selective resin to levels
necessitating disposal at a low-level or NORM site. The choice of a disposal location for
NORM is made by the waste generator or by a state regulatory agency.
Several steps must be taken when disposing of a radioactive waste solid to meet the
requirements of the disposal facility and the various regulating agencies. First, a low-level or
NORM disposal site that will accept the waste is located. Second, all free standing liquids are
removed. Third, materials are packaged hi 55-gallon drums with 4 mil liners. Fourth, all
necessary permitting, shipping, and packaging paperwork is completed and finally, the drums
are sent to the disposal site by a Department of Transportation (DOT)-approved carrier with
proper care and instructions.
There are several ways a small volume waste generator can arrange for the disposal of wastes
at a low-level or NORM site. A small volume waste generator can package the waste
materials themselves. After packaging, a collection service (such as those that pick up
radioactive wastes from hospitals) can be contracted to pick up the drums, perform a radiation
115
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survey, complete the labelling and paperwork, and deliver the drums to the disposal site. If a
waste generator does hot want to be involved hi the waste packaging and disposal, a broker
can be hired to complete the process. Brokers will send trained personnel to solidify or absorb
and package all materials. The broker will arrange for transportation and disposal and
complete all necessary paperwork. The broker's charges cover all costs including
mobilization, transportation of packaged drums, and disposal. Brokers also can be hired to
provide oversight and permitting expertise while the waste generators supply the labor and
materials necessary for packaging.
14.4 COST INFORMATION
Radioactive waste disposal costs are not included within this report. These costs may be
obtained from EPA's guidance entitled "Suggested Guidelines for the Disposal of Drinking
Water Treatment Wastes Containing Naturally Occurring Radionuclides" that is scheduled for
release in 1993. This revision of the Guidelines, which originally were issued in 1990, will
provide cost-related information, recommendations, and a summary of existing regulations and
criteria used by EPA and other agencies in addressing the disposal of radionuclides.
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15.0 REFERENCES
Ag-Chem Equipment; contacted by Allan Timm and Mary Rooney, DPRA. Concerning
terragators. 29 July 1992.
American Water Works Association. Sludge: Handling and Disposal. Denver, CO:
American Water Works Association, 1989.
American Water Works Association. Handbook: Water Treatment Plant Waste
Management. 1987
American Water Works Association. Slib. Schlamm. Sludge. KIWA Ltd., 1990.
Aquino, John T. "NSWMA Releases Expanded Tipping Fee Survey." Waste Age.
December 1991, pp. 24-28.
Camp, John, Rani for Rent; contacted by Kristina Uhlig, DPRA. Concerning sprinkler
systems. 21 August 1992.
Clark, Viessman, Hammer. Water Supply and Pollution Control. Harper and Row. 1977.
Clinging smith, Larry, C.P. Environmental; contacted by Mary Rooney, DPRA. Concerning
lagoon dredging costs. 19 August 1992.
Fraigh, Al, American Materials Corporation; contacted by Mary Rooney, DPRA.
Concerning sand and gravel costs. 23 August 1992.
Gavzonetti, Gary, Centrisys Corporation; contacted by Mary Rooney, DPRA. 13 August
1992. Contacted by Allan Timm, DPRA. 28 August 1992. Concerning centrifuge
applications and cost.
Gregory, Sue, Biogro; contacted by Kristina Uhlig, DPRA. Concerning liquid and
dewatered sludge land application costs. 18 August 1992.
Gross, Rod, Envirex, Inc.; contacted by Mary Rooney, DPRA. Concerning gravity thickener
application and costs. 24 August 1992.
Gruidi, Dan, Robert D. Hill; contacted by Mary Rooney, DPRA. Concerning density of
granular salt. 30 July 1991.
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Gumerman, Robert C., Bruce E. Burris, and Sigurd P. Hanser. Small Water Treatment
System Costs. Park Ridge, NJ: Noyes Data Corporation, 1986.
Hahn, Norman, Wisconsin Department of Natural Resources; contacted by Mary Rooney,
DPRA. Concerning radioactive sludge disposal options. 22 July 1992.
Hahn, Norman. "Disposal of Radium Removal from Drinking Water." American Water
Works Association Journal. 1986, pp. 137-144.
Haraldson, Gary, Lakewood Water Treatment Plant; contacted by Mary Rooney, DPRA.
Concerning use of sand drying beds. 11 August 1992.
Hill Reference Library; contacted by Greg Kvaal, DPRA. Concerning bulk and bagged lime
costs. 19 August 1992.
Hoeft, Mark, J&M Custom Waste; contacted by Kristina Uhlig, DPRA. Concerning liquid
sludge land application costs. 17 August 1992.
Huffman, Tom, Hydro Engineering Inc.; contacted by Kristina Uhlig, DPRA. 19 August
1992. Contacted by Allan Tim, DPRA. 31 July 1992. Concerning sprinkler systems.
Koeckeritz, Orn, Koeckeritz Excavating; contacted by Kristina Uhlig, DPRA. Concerning
septic field design and cost. 21 August 1992.
Krall, Tom, Mobile Dredging and Pumping; contacted by Mary Rooney, DPRA.
Concerning lagoon dredging costs. 26 August 1992.
Kramer, Brian, Metro Ag Inc.; contacted by Kristina Uhlig, DPRA. Concerning liquid and
dewatered sludge land application costs. 20 August 1992.
Krizan, William. "Second Quarterly Cost Report." Engineering News-Record. 29 June
1992, p. 33.
Kuehne, Susan, Star Systems Filtration Division; contacted by Mary Rooney, DPRA.
Concerning filter press costs. 17 August 1992.
Lowry, Jerry, Lowry Engineering; contacted by Mary Rooney, DPRA. Concerning low-
level radioactive water disposal options. 21 July 1992.
Meltzer, Jim, Northern Gravel Co.; contacted by Mary Rooney, DPRA. Concerning sand
and gravel costs. 4 August 1992.
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Metcalf & Eddy, Inc. Wastewater Engineering: Treatment,. Disposal. Reuse. 2nd ed.
Boston, MA: McGraw-Hill, 1972.
Minnesota Pollution Control Agency, Water Quality Division. Individual Sewage Treatment
Systems Standards - Chapter 7080. July 1989.
Mueller, Donald, LWT Inc.; contacted by Mary Rooney, DPRA. Concerning lagoon
dredging costs. 26 August 1992.
Nidetz, Jeff, Cyrigan; contacted by Mary Rooney, DPRA. Concerning reverse osmosis and
ion exchange treatment processes. 12 August 1992.
Nuclear Regulatory Commission Information Digest. 1992 Edition. NUREG-1350, Volume
4. March 1992.
Ohio River Valley Water Sanitation Commission. A Study of Wastewater Discharges from
Water Treatment Plants. April 1981.
Parrotta, Marc. "Radioactivity in Water Treatment Wastes: A USEPA Perspective."
American Water Works Association Journal. April 1991, p. 134
Parrotta, Marc, US EPA; contacted by Pat Martz Kessler, DPRA. Concerning the Suggested
Guidelines for the Disposal of Drinking Water Treatment Wastes Containing Naturally
Occurring Radionuclides. March 3, 1993.
Peterson, Bruce, Peterson Ag Service; contacted by Kristina Uhlig, DPRA. Concerning
liquid sludge land application costs. 18 August 1992.
Pinkey's; contacted by Mary Rooney, DPRA. Concerning septic tank cleaning.
28 August 1992.
R.S. Means Company, Inc. 1992 Means Site Work and Landscape Cost Data, llth ed.
Kingston, MA: Construction Consultants and Publishers, 1991.
R.S. Means Company, Inc. 1992 Means Mechanical Cost Data. 15th ed. Kingston, MA:
Construction Consultants and Publishers, 1991.
R.S. Means Company, Inc. 1992 Means Building Construction Cost Data. 50th ed.
Kingston, MA: Construction Consultants and Publishers, 1991.
Richardson Engineering Services, Inc. Process Plant Construction Estimating Standards.
Mechanical and Electrical. Vol. 4. Mesa, AZ. 1990.
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Richardson Engineering Services, Inc. Process Plant Construction Estimating Standards.
Process Equipment. Vol. 4. Mesa, AZ. 1990.
Robertson, R.F. and Y.T. Lin. "Filter Washwater and Alum Sludge Disposal: A Case
Study." Proceedings AWWA Seminar on Water TreatmentJWaste Disposal Seminar.
(June 25, 1978), 4, 1-8.
Sadowski, Greg, Sharpies/ALFA-LAVAL Company; contacted by Mary Rooney, DPRA.
Concerning scroll centrifuge costs. 19 August 1992.
Tabor, Paul, Simpson Filtration Inc., contacted by Allan Timm, DPRA. Concerning filter
press costs. 29 July 1992.
U.S. Environmental Protection Agency, Center for Environmental Research Information.
Process Design Manual - Land Treatment of Municipal...Wastegater.. EPA-625/1-81-
013. October 1981.
U.S. Environmental Protection Agency, Office of Drinking Water. Radionuclide Removal
for Small Public Water Systems. EPA 570/9-83-010. June 1983.
U.S. Environmental Protection Agency, Office of Research and Development. Design
Manual - Onsite Wastewater Treatment and Disposal Systems; EPA-625/1-80-012.
October 1980.
U.S. Environmental Protection Agency, Office of Research and Development. Innovative
and Alternative Technology Assessment Manual. EPA^130/9-78-009. February 1980.
U.S. Environmental Protection Agency, Office of Research and Development. Process
Design Manual - Land Application of Municipal Sludge. EPA-625/1-83-016. October
1983.
U.S. Environmental Protection Agency. The Cost Digest: Cost Summaries of Selected
Environmental Control Technologies. Prepared by Radian Corporation for the Office
of Research and Development. EPA-600/8-84-010. October 1984.
U.S. Environmental Protection Agency. Waste By Products Document in Support of Drinking
Water Treatment BAT Cost Analyses. Prepared by Malcolm Pirnie, Inc. for the Office
of Drinking Water. April 1990.
U.S. Environmental Protection Agency, Office of Drinking Water. Technologies for
Upgrading Existing or Designing New Drinking Water Treatment Facilities.
EPA/625/4-89/023. March 1990.
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U. S. Nuclear Regulatory Commission. Regulating the Disposal of Low-Level Radioactive
Waste. A Guide to the Nuclear Regulatory Commission's 10 CFR Part 61. Office of
Nuclear Material and Safeguards.
Vetter, Gerry, Carylon Company; contacted by Kristina Uhlig, DPRA. Concerning dewatered
sludge land application costs. 26 August 1992.
Viessman, Warren, Jr., et al. Introduction to Hydrology. 2nd Ed., New York, NY:
Harper & Row, 1977.
"Wage Rates for Key Construction Trades." Engineering News - Record. 29 June 1992,
p. 57.
Webber, Mike, Farmers Union Co-Op; contacted by Kristina Uhlig, DPRA. Concerning
liquid sludge land application costs. 17 August 1992.
Wilcox, Terry, Walder Pump and JfJquipment; contacted by Mary Rooney, DPRA.
Concerning application of gravity thickeners. 24 August 1992.
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APPENDIX A
POTW CHARGES
-------
APPENDIX A
POTW CHARGES
The POTW charges presented in Chapter 9 of this document are based on a limited sampling
of POTW rates conducted for this analysis and a survey published by the League of Minnesota
Cities. Table 1 presents the results of the telephone sample and Table 2 presents selected
results from the League of Minnesota Cities Survey. -Ten of the cities contacted during the
telephone sample do not charge to accept wastes from water treatment plants; three were not
certain. In addition, some of the POTWs contacted during the telephone sample and by the
League of Minnesota Cities charge a fiat rate per month with no additional charges for higher
flow rates.
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-------
TABLE 2
SEWER RATES - LARGE CITIES
LEAGUE OF MINNESOTA CITIES SURVEY
City
Benson
Wadena
Ely
Chisholm
Arden Hills
Andover
Bemidji
Owatonna
Albert Lea
Mankato
Burnsville
Duluth
State
Minnesota
Minnesota
Minnesota
Minnesota
Minnesota
Minnesota
Minnesota
Minnesota
Minnesota
Minnesota
Minnesota
Minnesota
Population
3,656
4,699
4,820
5,930
8,012
9,387
10,949
18,632
19,200
28,651
35,674
92,811
Sewage Fee Charged
$2.47/1 ,000 gallons
$1.55/1,000 gallons
$2.62/1,000 gallons
$.90/1 ,000 gallons
$1.64/1, 000 gallons
Varies for "area"; ranges
between $4.50 and
$8.50/month
Flat rate ranges between
$4.45 and $44.00
$2.50/month +
$1.78/1, 000 gallons
$3.65/month
$.86/unit
Commercial: 90% of
winter water usage or
metered water
$3.75/month + $1.72 to
$2. 99/1, 000 gallons
Misc.
Minimum: $6.23
Minimum: $7.84
Connection charge:
$75 digging fee
Minimum: $2.50
$14 connection
charge if turned off
Connection charge:
$168/unit
A-5
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1.
4.
7.
9.
REPORT NO. 2.
EPA 811-D-93-002
TITLE AND SUBTITLED _ _ , . :
Large water System Byproducts
Treatment and Disposal Cost Document
AUTHOR(S)
DPRA Incorporated
...' . :.'-;-. . "... ;'.'
PERFORMING ORGANIZATION NAME AND ADDRESS
DPRA Incorporated.
E-1500 First National Bank Building" ;';' ;
332 Minnesota Street
St. Paul, MN 55101
12. SPONSORING AGENCY NAME AND ADDRESS
15. SUPPLEMENTARY NOTES
Ben Smith-Project Manager
. ; :' . i <,. .
... .. ......
:.v:r I-'".'-'.-!.-.-/.
3. RECIPIENT'S ACCESSION NO.
5. REPORT DATE
April 1993
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
1 1. CONTRACT/GRANT NO. .
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
' " ' ._-. -
...-^.--.r.v:..'^-:--.-,-:
- s.-. ?;.*;;.. ;
^5' ;: ;
This document provides a summary of techniques for projecting
the costs of drinking water treatment residuals .tr,eaitttient and; disposal
It is a generalized report developed for use in the evaluation of
prospective drinking water regulatory aTterriati'ves.' 'Its fodus Is. on
systems serving water to over 3300 people.
17
a.
-'.:.-...: . .-'
" ':'-;' ;'V: u'::-':-v'-
KEY WORDS AND DOCUMENT ANALYSIS' -"'"
DESCRIPTORS
drinking water treatment costs/
residuals management costs,
regulatory impact costing
18
. DISTRIBUTION STATEMENT
b.lDENTIFIERS/OPEN ENDED TERMS
19. SECURITY CLASS (This Report/
20. SECURITY CLASS (This page)
c. COSATi Field/Group
21. NO. OF PAGES
'38
22. PRICE
,
EPA Foim 2220-1 (Rซv. 4-77) PREVIOUS EDITION is OBSOLETE
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