United States
       Environmental Protection    Office of Water       EPA 811-D-93-001
       Agency           4603          April 1993


&EPA SMALL WATER SYSTEM         ~~


      BYPRODUCTS TREATMENT AND

      DISPOSAL COST DOCUMENT

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, -t

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                                                                         I
    SMALL 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
1.0   INTRODUCTION		.	......;.	1

      1.1    Background ,..'..	,...:...	.'.,..	1
      1.2    Purpose and Scope  .....'....			 1
      1.3    Water Treatment Processes	 . . . .	:	; . . 3
      1.4    Byproducts Generated ,	 7
      1.5    Byproducts Management Options Overview	 7

2.0   BYPRODUCT CHARACTERIZATION	. . 9
                                     A        "            '.            :
      2.1    Introduction	 9  .
      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	•. . .:	15
      2.7    References	 .	 .  15.

3.0   COST ASSUMPTIONS	....:............	17

      3.1    Introduction	; . .	....;....  17
      3.2    Capital Cost Assumptions .>	•	17
      3.3    Operation and Maintenance Assumptions	19
      3.4  '  Total Annual Cost Assumptions	 .  . . :	.21
      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 Components	  30
            4.3.3  Operation and Maintenance Components	  31 .
            4.3.4  Cost Components Excluded	31
                      .''•..•'
      4.4    Gravity Thickening Cost Equations	;  31

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                            TABLE OF CONTENTS    .
                                  (continued)                        ,

                                                                         Page

5.0   CHEMICAL PRECIPITATION'	34

      5.1    Technology Description	34
      5.2    Technology Applicability	•	- 35
      5.3   . Technology Limitations	,	35
      5.4    Cost Components	36
  •\                                                                   ,
            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	38

      5.5    Cost Equations	....'.......-	.' . V .  . . 38

6.0   MECHANICAL DEWATERING	 40

      6.1    Technology Description	40
      6.2    Technology Applicability	41.
      6.3    Technology Limitations  . . .	41
      6.4    Cost Components	 . . .	i	 43
                                         /      i,             *               •*
            6.4.1   Design Assumptions	43
            6.4.2   Capital Components	43
            6.4.3   Operation and Maintenance Components  	44
            6.4.4   Cost Components Excluded	•.  . . 45

      6.5    Cost Equations	;	:	 '. 45

7.0   NONMECHANICAL DEWATERING .		..'.	. . 47

      7.1    Sand Drying Bed Description  . . .  ''.	.47
      7.2    Technology Applicability	48
      7.3    Technology Limitations	48
      7.4    Sand Drying Bed Cost Components	 49

            7.4.1   Design Assumptions  ......<	 . 49
            7.4.2   Capital Components  .	51
            7.4.3   Operation and Maintenance Components  	:	51
            7.4.4   Cost Components Excluded	52

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                             TABLE OF CONTENTS
                                  (continued)
                                                                        Page
       7.5   Sand Drying Bed Cost Equations	  52
       7.6   Storage Lagoon Description  .	54
       7.7   Technology Applicability	55
       7.8   Technology Limitations	-..	56
      .7.9   Storage Lagoons Cost Components	. ,  56

             7.9.1   Design Assumptions	• • •  •	57
             7.9.2   Capital Components	,..:....  57
             7.9.3   Operation and Maintenance Components  	: . .  58
             7.9.4   Cost Components Excluded . . 1	  58
                                              V.             «     '   ,   ,      '
       7.10   Lime Softening Storage Lagoon Cost Equations . .  . -.	  59
                                  '             .        ,\     '
 8.0   EVAPORATION PONDS 	:	 .  .	'.. . .  61

      • 8.1    Technology Description	.61
       8.2    Technology Applicability	  62
       8.3    Technology Limitations  ..........	 .'	62
       8.4    Cost Components	;.........	63
                                                                     V
             8.4.1   Design Assumptions	  63
.,            8.4.2   Capital Components  ,	......",  64
             8.4.3 .  Operation and Maintenance Components	 .... ....  65
             8.4.4   Cost Components Excluded ...-.'	'.  65
                    ''    •     .
       8.5    Cost Equations	  66

' 9.0    POTW DISCHARGE		68

       9.1    Technology Description	....."	68
       9.2    Technology Applicability	69
       9.3    Technology Limitations	:	69
       9.4    Cost Components	.......;.	 . . . ;	70

             9.4.1   Design Assumptions  	-	70
             9.4.2   Capital Components	•. .	..."  71
             9.4.3  , Operation and Maintenance Components ........:	72
             9.4.4   Cost Components Excluded	 .  72

       9.5    Cost Equations	72

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                            TABLE OF CONTENTS
                                  (continued)
            9.5.1    500 Feet of Discharge Pipe	72
            9.5.2 •   1,000 Feet of Discharge Pipe	.	73

10.0  DIRECT DISCHARGE			 75

      10.1   Technology Description		75
      10.2   Technology Applicability	76
      10.3   Technology Limitations	.'	;....'.... 76
      10.4   Cost Components	;	.77

            10.4.1   Design Assumptions	•.	77
            10.4.2   Capital Components	77
            10.4.3   Operation and Maintenance Components	78
 •           10.4.4   Cost Components Excluded . .	 79

      10.5   Cost Equations	79

            10.5.1   500 Feet of Discharge Pipe	79
            10.5.2   1000 Feet of Discharge Pipe	 80
         '   10.5.3.  500 Feet of Discharge Pipe with a"
                    Holding Tank or Lagoon  ...'.:	81
            10.5.4   1,000 Feet of Discharge Pipe with a
                    Holding Tank or Lagoon	82

11.0  FRENCH DRAINS	. . 84

      11.1   Technology Description	84
      11.2   Technology Applicability . . .-	 . . '.'	  . . 84
      11.3   Technology Limitations . . . .	 85
      11.4   Cost Components	%	85

            11.4.1   Design Assumptions  . .	85
            11.4.2   Capital Components	85
            11.4.3   Operation and Maintenance Components  .	"... 86
            11.4.4   Cost Components Excluded	86

      11.5   Cost Equations	 .	.86

12.0  LAND APPLICATION .	88

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                            TABLE OF CONTENTS
                                 (continued)
                                                                        Page
      12.1   Technology Description .„„..,....	88
      12.2   Technology Applicability	v	89
      12.3   Technology Limitations	...;.....	90
      12.4   Liquid Sludge Land Application Cost Components-.	91

            12.4.1  Design Assumptions  .	....;.... 91
            12.4.2  Capital Components		 92
            12.4.3  Operation and Maintenance Components	'..'.. 92
            12.4.4  Cost Components Excluded	1	93

      12.5   Liquid Sludge Land Application Cost Equations	 93  .

            12.5.1Spfinkler System	 ...~	.-	93
            12.5.2  Trucking System	 94

      12.6   Dewatered Sludge Land Application Cost Components	95
                                     \
            12.6.1  Design Assumptions		95
            12.6.2  Capital Components	 95
            12.6.3  Operation and Maintenance Components  .	 96
            12.6.4  Cost Components Excluded	 96

      12.7   Dewatered Sludge Land Application Cost Equations	96
                                           v,             '             -

13.0   NONHAZARDOUS WASTE LANDFILL	1 .'	I . i  . 98

      13.1   Technology Description	,	.......>.	.98
      13.2   Technology Applicability and Limitations  . .,		98
      13.3   Cost Components	  100

            13.3.1  Design Assumptions	•..'..;	  100
            13.3.2  Cost Components.	'. . .	  100

      13.4   Total Annual Cost Equation ".	  101
         /
14.0   HAZARDOUS WASTE LANDFILL . . .		.  102

      14.1   Technology*Description	-. . .	  102
      14.2   Technology Applicability and Limitations  . •; .	  103
      14.3   Cost Components . .  .'	 . . ...  ...... ^ ................  104.

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                             TABLE OF CONTENTS
                                 .  (continued)
                                                                           P_age
            14.3.1   Design Assumptions 	;	  104
            14.3.2   Cost Components	  104
            14.3.3   Cost Components Excluded	  105
                          •            *
      14.4  Total Annual Cost Equation	  105

            14.4.1   Hazardous Waste Disposal	  105
            14.4.2   Stabilization and Hazardous Waste Disposal	  105

15.0  RADIOACTIVE WASTE DISPOSAL	 .	.  106
           • \              '                            'r           •
      15.1  Sources of Radioactivity in Drinking Water  .	  106
      15.2  Radium Removal  .	  107
      15.3  Low-Level Radioactive Waste Disposal	  108
      . 15.4  Cost Information  	.	'. .	  110

16.0  REFERENCES			 .  110
                                LIST OF TABLES

Table 1 - Water System Categories	...,./. 1
Table 2 - Chemical Coagulation Sludge Volumes  .  . , .	'.  .	10
Table 3 - Lime Softening Sludge Volumes	'.	12
Table 4 - Ion Exchange Brine Volume ..:...	 . .	13
Table 5 - Reverse Osmosis Brine Volumes	: .  . 14
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	30
Table 10 - Chemical Precipitation  ....'...	:	37
Table 11 - Pressure Filter Presses	44
Table 12 - Sand Drying Beds	'	....;...: 51
fable 13 - Storage Lagoons - Lime Softening  Sludge	 58
Table 14 - Evaporation Ponds	 65
Table 15 - POTW Discharge  	, :		'... 71
Table 1.6 - Direct Discharge  ...-..-.	. . . . .	 78
Table 17 - Liquid Sludge Land. Application	.'. .  .	'.  . 92

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                             TABLE OF CONTENTS
                                   (continued)
                               LIST OF FIGURES

Figure 1 - Sludge/Slurry Producing Water. Treatment Processes
Figure 2 - Brine Producing Water Treatment Processes ....'.
Figure 3 - Brine Treatment arid Disposal Options •>.  ..	
Figure 4 - Sludge/Slurry Treatment and Disposal Options  ."•...
                                                                           Page
. 4
. 5
25
26
APPENDIX A - POTW Charges

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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 water treatment systems under Section 1415 of the
SDWA.

The Office of Ground Water and Drinking Water ,(OGWDW) must assess the waste treatment
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.
Special problems associated with small community water treatment byproducts management
are addressed in this document. A separate document addresses the byproduct management
methods for large water treatment systems.       .                       .  ,

1.2    PURPOSE  AND SCOPE

The purpose of this document is to present methods to estimate water byproduct management •
costs applicable to small water systems.  Small water systems include  systems in Categories 1
through 4 identified in Table 1. These systems are designed for populations ranging from 25
to 3,300 people and have design flow rates ranging from 0.024 to 0.65 million gallons per day
(MOD).

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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
V
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 from small water systems. Selected waste treatment
and disposal options are included in this document.  These options are intended to provide a
general overview of the costs associated with the treatment and disposal of water treatment
plant byproducts. Cost equations in this document are for comparison purposes  only. Site
           •                       i       '              *        ,
specific factors will cause individual cases to vary considerably from these estimates.

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1.3    WATER TREATMENT PROCESSES

Four primary water treatment processes that produce byproducts are considered in this
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 and 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 for these
four water treatment processes. A brief description of each of these water treatment
technologies  is presented below.

       Coagulation and Filtration
 /
 x              •
Chemical coagulation and filtration, also referred to more generically as suspended solids
removal, are  processes used to remove a variety of substances including participate matter that
causes turbidity, microorganisms, color, disinfection byproduct precursors, and some
inorganic contaminants. This type of treatment typically is used for surface water. The
                                                                                      -1
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.

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        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 III, and arsenic V. Precipitation of these contaminants is
 performed by the addition of lime or lime with soda ash. Lime softening is often followed by
                                                       i
 a coagulation and sedimentation stage to improve removal of the paniculate matter. This
- treatment typically  is used for ground water; however, in some regions of the country, river
 water also may require softening;  The resultant waste byproduct is a sludge or slurry
 consisting of a high pH calcium hydroxide flpcculent.

        Ion 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 III 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 hi which dissolved ions
 undergo a phase transfer from a solution to a solid-surface phase. The resultant waste
                                                     \.r
 byproduct is a brine.                                 j     •   •  ,

        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
 under the SDWA.  Reverse osmosis is not used to remove mercury or arsenic IE. 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.

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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 particulates 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.  Backwash 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.

1.5   BYPRODUCTS MANAGEMENT OPTIONS OVERVIEW
                                                               r
                                                              .'
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 small system water treatment facilities include the following
options:
                    Chemical Precipitation;
                    Mechanical Dewatering;
                    Nonmechanical Dewatering;
                   - Evaporation Ponds;
                    POTW Discharge;
                    Direct Discharge;
             -      French Drain;
                    Land Application;
                    Nonhazardous Waste Landfill;
                    Hazardous Waste Landfill; and
                    Radioactive Waste Disposal.

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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) french drain, 4) direct discharge, arid 5) evaporation
ponds.

Radioactive wastes should be managed in accordance with EPA's guidance entitled "Suggested
Guidelines for the Disposal of Drinking Water Wastes Containing Naturally Occurring
Radionuclides."  The guidelines were originally issued in 1990  and will be revised when the
Agency issues regulations relating to radionuclides.

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                  2.0 BYPRODUCT CHARACTERIZATION

2.1   INTRODUCTION

Water byproducts, or the waste streams generated during the treatment of water to obtain
drinking water, consist of sludges, slurries, and brines.  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;
                                                            * t  •
variations are not unusual for different months of the year.  To estimate the byproducts
generated on a national basis, assumptions regarding these parameters are made and described
in the following paragraphs which address each water treatment technology.
                        i           . -
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 the range of flow categories for small systems are summarized in Table 2.
The solids concentration of this sludge ranges from 0.5 to 3 percent.

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                                      TABLE 2
                 CHEMICAL COAGULATION SLUDGE VOLUMES
Water Treatment Plant Flow
(gal/day)
5,600
24,000
87,000
270,000
• ' • • 650,000
Typical Volume Ranges
(gal/day)
0.06-21
0.25-90
1-300
3-1,000 :
7-2,400
Typcial Volumes
(gal/day)
10
30
100
300
700
From this analysis,' the volume of chemical coagulation sludge generated ranges from 0.06 to

2,400 gallons of sludge per day depending on the water treatment plant flow rate.


To estimate the amount of sludge produced in an alum coagulation plant for the removal of

turbidity, based on specific feed water characteristics, the following equation can be used (Ref

2).  -                         .


             S = 8.34 Q (0.44 Al + SS + A)

                    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:                                    '
                                       s    •                ,

             SS  = b Tu
                                          10

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                    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 backwash event. The volume generated ranges
from 0.5 to 5 percent of the treated water. In general, small treatment plants will generate a
higher percentage of filter backwash than large treatment plants because they tend to operate
less efficiently.                 '                    .

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. 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, hi some regions of
the country, river water also may require softening.

The  quantity of lime softening sludge ranges from 0.4 to 1.5 percent of the treated water flow
rate, with an average of 1.2 percent.  The lime sludge volumes for the range of flow
categories for small systems 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.
                                           11

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                                     TABLE 3
                      LIME SOFTENING SLUDGE VOLUMES
Water Treatment Plant Flow
(gal/day)
5,600
24,000
87,000
270,000
650,000
Typical Volume Ranges
(gal/day)
20-90
100-400
350-1,300
1,100-4,100
2,600-9,900
Typical Volumes
(gal/day)
70
300
1,100
3,300
7,900
The volume of sludge generated from lime treatment facilities ranges from 20 to 9,900 gallons
per day depending on the water treatment plant flow rate.
                                                             /'
The filter backwash volume from lime softening depends on the number of filters and
frequency and duration of each backwash event.  The volume generated ranges from 0.5 to 5
percent of the treated water. In general, small treatment plants will generate a higher
percentage of filter backwash than large treatment plants because they tend to operate less
efficiently.

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).
Brines are produced from rinsing, regenerating, and backwashing the ion exchange unit. Of
these three byproducts streams, the regeneration stream contains the highest levels of total
dissolved solids (TDS) ranging from 10 to 300 times the levels found hi 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
                                         12

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resin during regeneration as well as excess regeneration salts.  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 of water processed (Ref. 2). Brine volumes are calculated assuming  that these brine
generation rates are applicable to small treatment systems; the low end of this range is used as
the typical volume of brine generated.  The resultant brine generation rates are provided in
Table 4.
                                                   i
                                       TABLE 4
                         ION EXCHANGE BRINE VOLUME
Water Treatment Plant Flow
(gal/day)
5,600
24,000
87,000
270,000
650,000
Typical Volume Range
(gal/day)
100-500
400-2,200
1,500-7,900
4,700-24,400
11,200-58,800
Typical Volumes
(gal/day)
100
400
1,500
4,700
11,200
The volume of brine produced from small ion exchange facilities -ranges from approximately
100 to 58,800 gallons per day depending on the water treatment plant flow rate, the quality of
the untreated water, and the type of ion exchange system used.
                                          13

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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 small
facility sizes being considered in this analysis, the volume of reject water or brines produced
from backwashing the membrane are typically 25 to 50 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 25 to 50 percent
of the feed water.  The brine volumes are presented in Table 5.
                                      TABLE 5
                       REVERSE OSMOSIS BRINE VOLUMES
Water Treatment Plant Flow
(gal/day)
5,600 .
24,000
87,000
270,000
650,000
Typical Volume Range
(gal/day)
.y
1,900-5,600
8,000-24,000
29,000-87,000
90,000-270,000
216,700-650,000
Typical Volume
(gal/day)
5,600
24,000
46,850
90,000
216,700
The volume of brine produced from a reverse osmosis facility ranges from 1,900 to 650,000
gallons per day depending on the water treatment plant flow rate, the initial water quality, and
the efficiency of the membrane.
                                          14

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2.6    BYPRODUCT DENSITIES

The densities of the byproduct streams from the water treatment technologies considered in
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
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 =   	100    	
                    percent solids    +   100-percent solids
                    density solids          density water
This equation is applicable for sludge with a solids concentration of less than 50 percent.  A
typical value for the density of the solids in an alurn or iron sludge is 145 lb/ft3 (Ref.3).
Dewatered sludge densities also can 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
                                          15

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3.  American Water Works Association. Sh'b. Schlammr Slydge. KIWA Ltd.,  1990.

4.  American Water Works Association. Sludge:  Handling and Disposal.  Denver, CO:
      American Water Works Association, 1989.
                                        16

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                            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 cost document should be used for
relative comparisons and broad base estimation purposes only. Individual project costs have
been found.to be very different from those presented herein. This is primarily due to site-
specific factors such as physical and.chemical characteristics of the residuals, site constraints,  .
operational costs and differing state and local regulatory requirements. More accurate site
specific cost estimates should be developed for facility planning and budgeting purposes.
                               \
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, pumps) were calculated individually.

       Land                 .
                                                              <
Land prices vary substantially across the country. Land prices depend on the proximity to
metropolitan areas, state of land development (i.e., unproved or unimproved), current use, and
scarcity of land. A cost of $1,000 per acre is assumed for small water systems.  This land
cost represents an average cost for rural, unimproved land.  Costs for unimproved rural land
vary from approximately $150 per acre in states with large tracts  of undeveloped land to
$2,200 per acre in states with small tracts  of undeveloped land. Costs for suburban or
industrial unimproved land averages $10,000 per acre and ranges from approximately $4,000
per acre to $350,000 per acre depending on location.
                                              1-7

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                                   TABLE 6
          CAPITAL COST FACTORS AND SELECTED UNIT COSTS
                  Component
        Land
        Buildings
        Piping
        Pipe Fittings
        Electrical
        Instrumentation
        Engineering Fee
        Contractor's Overhead and Profit
      Factor/Unit Cost
$l,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
12% of Direct Capital
    *  Piping costs are calculated directly when piping is a significant cost (e.g., for direct
      'discharge).
    f  Factor is used when piping costs are calculated directly

Costs for purchasing land are included in the capital cost equation for all treatment and

disposal processes that use surface impoundments and for french drains.  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. When the above criteria are met, a minimum land purchase of Vz 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.


       Buildings

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 199% jVteans Building

Construction 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
                                          18

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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.

Costs.for constructing buildings are included in the capital cost equation for equipment
intensive byproduct treatment technologies. For example, building costs are included in the
capital cost for chemical precipitation and mechanical dewatering.  The building costs are
presented as a separate cost in the capital cost equation to allow the user to delete the cost for
land if construction of a building or addition to an existing building is unnecessary.  .

       Piping and Pipe Fittings
Piping costs are calculated in two separate manners 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 were calculated by
sizing individual pipe lengths and determining installation charges. For these management
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.

3.3 OPERATION AND MAINTENANCE ASSUMPTIONS
                           •   •     \                                      •
Table 7 presents cost factors and unit costs used to calculate the operation and maintenance
costs presented in this document.  The labor rate is discussed below.   ,
                                           19

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                                      TABLE 7
                        OPERATION AND MAINTENANCE
                        COST FACTORS AND UNIT COSTS
                 Component
          Factor/Unit Cost
  Labor
  Insurance and General and Administrative
   Expenses
  Maintenance
  Electricity	
$14.50/Hour
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 10-region average for nonunion scale laborers.  The hourly rate of
$14'.50 is based on an average salary of $8.65 per hour with a 12.2 percent fringe benefit and
a 50 percent labor overhead cost.  Average salaries by region range from $7.25 per hour in the
south central to $10.17 in the western United States.  Fringe rates range from approximately 8
to 15 percent depending on the region of the country.

       Insurance and General and Administrative Expenses
A factor of two percent of the direct capital cost excluding land and buildings is used to
estimate insurance and general and administrative expenses.  This cost is not included for
POTW discharge, direct discharge, trench drain, and lagoon-based technologies.

       Maintenance
A factor of two to three percent of the direct capital cost excluding land and buildings is used
to estimate maintenance expenses., It is assumed that no maintenance is required over the 20-
year operating life for POTW discharge, direct discharge, and french drain systems.
                                         20

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3.4  TOTAL ANNUAL COST ASSUMPTIONS

Total annual costs are equal to the sum of the operation and maintenance costs plus the
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
and  10 percent interest rate is 0.1175.  Alternate capital recovery factors can be calculated
using the formula presented below.

              Capital Recovery Factor = (1  + i)N (i)'

                    Where:              i = interest rate
                                        N  = number of years
                                    1
3.5  COST COMPONENTS EXCLUDED

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.

       Sample Collection and Laboratory Analysis

Costs for sample collection and analysis to determine solids content, free liquids, 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 can be minimal or extensive.

       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 french drains, direct discharge, 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).

       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 and
          . '                            i
retention times were selected based on published literature, vendor contacts, and best
engineering judgement. 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, French drains are
typically used for flow ratesi of less than 10,000 gallons per day.  The cost equations only
include brine flow rates of less than  10,000 gallons per day even though the highest  flow rate
expected is two orders of magnitude  higher than 10,000 gallons per day.

The limits of .the cost equations presented for each byproduct management method may be
extended somewhat beyond the limits presented in this document. The upper or lower end for
some equations, however, may represent the largest or smallest practical units.  Therefore, the
technology limitations and design assumptions should be carefully reviewed prior to  extending
the limit of the equations.  Best engineering judgement should be used when extending the
equations beyond their specified ranges.

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 1-4
water treatment plants.  The user may want to size the equipment (i.e., determine the capital
                                          22

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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.
Typically, the design flow rate for the water treatment system may be two to three tunes the
average operating 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 operating 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.

3.7    CALCULATING BYPRODUCT MANAGEMENT COSTS

Byproduct management costs, are calculated using the cost equations presented in 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,
respectively. These figures present complete management trains. That is, they depict
byproduct management methods, resulting residuals, and management options for those
residuals.  Individual cost chapters present residual factors to use to determine residual
volumes that require further treatment or disposal.  The overall byproduct management costs
are determined by summing the capital and operation and maintenance costs from the treatment
and disposal of all byproducts and residuals.                                  •
                                          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
NA
NA .
NA
Operation & Maintenance
Cost
Average
Average
Average
Average
.Average
Average
Average
' Average
Average
NA
NA -
NA
           24

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                         4.0 GRAVITY THICKENING

4.1    TECHNOLOGY DESCRIPTION

In this report, gravity thickening is a treatment technology considered for filter backwash and
sludges.  Gravity thickening serves to increase the solids concentration of the filter backwash
and sludge streams so they can be treated by one of the dewatering methods addressed in the
following sections.

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 upflow
backwash, downflow regeneration, and downflow rinse. In general, this volume ranges 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.                                ,

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 and mechanical dewatering are other treatment and
disposal options.
                                                                \
In cases where backwash byproducts cannot be recirculated to the head of the plant nor
discharged to a surface water or POTW, the backwash waters must be disposed as a water
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
                                         28

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0.08 percent, where chemical coagulation (alum) sludge have.a solids concentration ranging
from 0.5 to 2.0 percent.

Backwash water and sludges are gravity fed to a tank where gravity thickening is performed.
Gravity thickening occurs by allowing suspended solids to settle naturally.  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.
                                                        j
4.2    TECHNOLOGY APPLICABILITY AND LIMITATIONS

For this report, gravity thickening is applicable to the filter backwash streams and sludges
from chemical coagulation or lime softening byproducts streams. Because of the high volumes
and low solids concentrations characteristic of these byproduct waste streams, pretreatment is
necessary before the byproducts can be dewatered by the methods discussed in the remainder
of this report.  Pretreatment also is necessary to equalize the flow rates.

4.3    COST COMPONENTS
                                                              s '
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 and sludges from chemical
             coagulation and lime softening.
             The filter backwash and sludge flow by gravity from the treatment plant to the
              settling tank.
              Each treatment facility has 1 or 2 filters. Each filter is backwashed twice a
              week with a backwash volume ranging from 490 to 24,200 gallons per event.
             These backwash volumes are generated in 20 minutes.
             The total backwash volume is either 2 or 2.5 percent of treated water.

                                          29         -

-------
             The backwash and sludge is allowed to settle in a tank for 31/2 days.

             The volume of backwash and sludge is reduced by 90 percent.
                                                    V,
             The thickened sludges are discharged to another treatment for further
             dewatering.        "  ,


       4.3.2  Capital Components  -

                                                              i
The capital components for each filter backwash system consist of the following items:

             Holding tank;
             Piping and fittings;
             Pump;
             Trenching;
             Electrical; and
             Instrumentation.

Table 9 indicates the number of filters, the filter backwash volume,  and backwash settling tank
capacities used to develop the capital cost equation for filter backwash.
                                      TABLE 9
                                FILTER BACKWASH
Number of
Filters
1
1
1
1
2
Filter Backwash
Volume
(gal/event)
490
2,170
7,810
24,220
23,210
Number
of
Tanks
1 .
1
1
1
1
Backwash Settling
Tank Capacity
(gal)
500
2,500
10,000
30,000
50,000
                                         30

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       4.3.3  Operation and Maintenance Components

The operation and'maintenance components for each gravity thickening system include the
following items:
              Electricity;
              Labor;
              Maintenance labor and materials; and
              Insurance and general and administration.

       4.3.4  Cost Components Excluded

The following cost components are not included hi 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.
f                                                                         \
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
                                                        *   '                      i
The cost equations for the capital components and operation and maintenance were developed
by estimating the costs  for five different filterbackwash and sludge flow'rates. The filter
backwash and sludge flow rate (X) used in the equations below is the average daily volume
generated (e.g. 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.
                                          31

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Capital Costs
       Y = 1,500 + 0.01 X

             Where:      Y = $
                          X = gallons of filter backwash/sludge per day

             Range:      5,600 gpd <; X <; 87,000 gpd
       Y = 61.7 X050-6,200

             Where:      Y = $
                          X = gallons of filter backwash/sludge per day

             Range:       87,000 gpd < X <; 650,000 gpd
Operation and Maintenance
       Y = 300 + 3.82 x 103 X

             Where:      Y = $/year
                          X = gallons of filter backwash/sludge per day

             Range:    .   5,600 gpd s X <; 87,000 gpd
       Y = 3.60 X050-400

             Where:      Y = $/year
                          X = gallons of filter backwash/sludge per day

             Range:      87,000 gpd < X <; 650,000 gpd
                                   32

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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
s

 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 wastewaters.  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 can be 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 forni by a chemical reaction between the soluble metal ions and the
 precipitant. The resultant 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.
 Prior to disposal, the clarifier sludge may require additional dewatering by mechanical or
 nonmechanical means.
                                           34

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5.2    TECHNOLOGY APPLICABILITY
                                                                       ; ,
Chemical precipitation is used primarily for treatment of reverse osmosis and cation exchange
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. While technically feasible, chemical precipitation as a method to treat ion exchange
and reverse osmosis brines is an expensive waste treatment/disposal option relative to options
such as evaporation ponds, sanitary sewer discharge, french drain, 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 not be economically feasible water treatment options for small facilities.
        ,                                „                        r

5.3    TECHNOLOGY LIMITATIONS

Anion exchange  wastes cannot be treated by lime precipitation because 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 in the effluent.

As mentioned above, chemical precipitation may be a relatively expensive treatment option
compared with french drain disposal, 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.
            uiL.
                                           35

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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.


       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 hi 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 precipitation tank;
             Clarifier/settling tank;
             Agitators;
             Sludge pumps;
             Building;
             Piping;
             Electrical;vand
             Instrumentation.                        .
                                          36

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Table 10 indicates the brine volumes, tank capacities, and clarifier capacities used to develop
the capital cost equation for chemical precipitation.
                                     TABLE 10
                           CHEMICAL PRECIPITATION
Byproduct
Flow Rate
(gal/day)
3,930
12,200
29,300
67,500
162,500
274,000
350,000
500,000
1,000,000
Precipitation
Tank Size
(gallons)
200
400
650
2,000
5,000
6,000
8,000
12,000
23,000
Mix Tank
Capacity
(gallons)
30
40
50
75
100
-"200
300
600
1,200
Clarifier
Capacity
(gallons)
800
1,600
2,500
8^000
20,000
24,000
30,000
40,000
50,000
      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.
                                        37

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       5.4.4  Cost Components Excluded

 The following cost components are not included in the cost equations for chemical
 precipitation systems since they are accounted for elsewhere hi 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.
 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 were developed
 by estimating the costs  for seven 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 die 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 = [1,500 X °-36]  + [4,900 + 135.5 X °-50]
             Y = [Equipment Cost] + [Building Cost]
                    Where:      Y - $
                                 X = gallons of brine per day
                    Range:       3,000 gpd  <. X <. 162,500 gpd
                                          38

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       Y = [1,500 X °36] + [253 X 05° - 39,300]

       Y = [Equipment Cost] + [Building Cost]

             Where:      Y = $
                          X = gallons of brine per day

             Range:       162,500 gpd < X * 1,000,000 gpd


Operation and Maintenance

       Y = 366 X OM               .

            . Where:      Y = $/year
                          X = gallons of brine per day

             Range:       3,000 gpd * X *  = 162,500 gpd

       Y = 19,900 + 0.15 X

             Where:       Y = $/year       - -
                          X = gallons of brine per day

             Range:       162,500< Xi 1,000,000


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
                                  39

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                       6.0  MECHANICAL DEWATERING

 Mechanical dewatering processes include centrifuges, vacuum-assisted dewatering beds, belt
 filter presses, and plate and frame filter presses.  These 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.  Though this
 mechanical dewatering is more applicable to larger water plants, it is included here since
 equipment is available for byproduct flow rates addressed in this document. Pressure filter
 press technology, applicability, limitations, and costs are presented in this section.
                                                    r

 6.1    TECHNOLOGY 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 the 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 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.

Pressure filter presses consist of multiple filter plates on metal frames.  The capacity of a press
depends on the number and  size of the plates and on the depth of the chamber between the
plates. Plates are available  in a variety of sizes, shapes and materials.  The choice of filter
media adds additional variation to the performance of an individual press.  Filter media
                                          40

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 varies in its particle retaining size, permeability, durability, and its ease of cake release.
 Sludge type and the initial solid's concentration of a sludge affect the filter media choice.

 6.2    TECHNOLOGY APPLICABILITY

 With proper sludge conditioning, pressure filter presses can effectively dewater both lime and
 alum sludges.  Lime sludges attain final solid concentrations of 40 to 70 percent while alum
 sludges attain 35 to 50 percent final solid's 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 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 filter presses hi the water treatment industry has been increasing hi the
 last several years.  They are especially applicable for facilities that want to achieve a high
 sludge solids content.  The high solid's content achieved by pressure filter presses makes this a
 suitable technique to dewater sludges before 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
 more applicable to larger water systems.         ,                .

 6.3    TECHNOLOGY LIMITATIONS

Available, equipment sizes and equipment costs limit the applicability of this technology for
small water systems.  Sludge flow rates less than 100 gallons per day are not applicable to
filter press dewatering.  Even at 100 gallons per day, the filter press equipment is oversized.
                                           41

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Although the suspended solid's concentration of the filtrate is low, filtrate disposal may be a
problem. Proper preconditioning of alum sludges before filter press dewatering normally
requires the addition 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 weight), 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 ithe treatment plant.

Pumps that deliver sludge to the filter press must be capable of operating under a 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 and low flow rates.

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 creates disposal problems due to its low pH.
Precoating the press reduces blinding and required 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 preconditioning of alum sludges is
essential to ensure efficient sludge dewatering. Sufficient quantities of lime must be added and
a 20- to 30- minute contact tune is required to develop the necessary dewatering qualities.
                                           42

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 6.4    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.


        6.4.1  Design Assumptions


              Pressure filter presses are effective for sludge flow rates greater than 100
              gallons per day.

              Stainless steel filter presses with paper filter media are used for flow rates less
              than 500 gallons per day.

              Sludge flows by gravity to a polymer feed system.

              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.

              The filter press  operates on a batch basis.

              Filtrate collects  hi a filtrate holding tank before being pumped to the head of the
              treatment plant.                  .

              Filter cake collects in a small, wheeled container, which is emptied into a larger
              solid's  bin as necessary.

              Accumulated solids require disposal on a periodic basis.

              The dewatered sludge volume is 0.03 and 8 percent of the initial volume for
              lime and alum sludges, respectively.


       6.4.2  Capita! Components


The capital components for each pressure filter press system consist of the following items:

              Pressure filter press;


                                          43

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              Polymer feed system;            .  .,  .....       .  	
              Positive displacement pump;
              Steel filtrate tank and pump;
              Filter cake storage bin;
              Building;
              Piping;
              Electrical; and
              Instrumentation.

Table 11 shows the sludge volumes, settling tank/gravity thickener capacities, and filter press

capacities used to develop the capital cost equation for pressure filter presses.


                                      TABLE 11

                            PRESSURE FILTER PRESSES
Sludge Flow Rate
(gal/day)
100
500
2,000
5,000
10,000
Filter Press Capacity
(cu. ft.)
0.5
2.0
10
24
24
       6.4.3  Operation and Maintenance Components

The operation and maintenance components for each pressure filter press system include the
following items:

             Electricity;
             Polymer;
             Labor;
             Maintenance labor and materials; and
             Insurance and general and administration.
                                         44


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                     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; and
                            Filtrate disposal, if the filtrate 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
              filtrate disposal, if the overflow cannot be pumped to the head of the treatment works, can be
              determined using other sections of this document.

              6.5    COST EQUATIONS

              The cost equations for the capital components and operation and maintenance were developed
              by estimating the costs for five 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 - [11,500  + 1,155 X 05fr] + [3,500 +  143 X °-50]
                            Y = [Equipment Cost] + [Building Cost]
                                  Where:      Y = $
                                               X = gallons of sludge per day
                                  Range:       100 gpd <. X < 2,000 gpd
                                                        45
.

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       Y = [11,500 + 1,155 X050] + [10,000]

       Y = [Equipment Cost] + [Building Cost]

             Where:   .    Y = $
                          X = gallons of sludge per day

             Range:       2,000 gpd <: X <. 10,000 gpd


Operation and Maintenance                                        '

       Y = 578 X °50 - 400

             Where:       Y = $/year
                          X = gallons of sludge per day

            . Range:       100 gpd z X < 10,000 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
                                  46

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                    7.0  NONMECHANICAL DEWATERING             r

 Nonmechanical dewatering of sludges and slurries is performed in sand drying beds, storage
 lagoons, and permanent lagoons.  Nonmechanical dewatering processes are characterized by
 their simplicity to operate and maintain.  In sand drying beds and storage lagoons, dewatered
 sludge is removed for disposal via land application or in a landfill. A permanent lagoon
 dewaters the sludge and is the final disposal site for  the sludge. Costs were developed for two
 nonmechanical dewatering processes: sand drying beds and dewatering lagoons.

 7.1    SAND DRYING BED DESCRIPTION

 A sand drying bed is a nonmechanical means of dewatering sludges that utilizes drainage,
 decanting, and evaporation.  The technology involves spreading an even layer of thickened
 sludge (solid concentrations of 1 to 4 percent for coagulant sludges and 2 to 6 percent for
 softening sludges) over a draining sand bed. Free water in the sludge gravity drains through  .
 the sand to the underdrains or forms a supernatant layer that is decanted.  Most gravity and
 decant drainage occurs in the first few days after application. After this time, evaporation is
 the primary dewatering process and the sludge remains on the drying bed until the desired
 solids concentration is achieved.  The depth of initial sludge application and the time required
 for the sludge to dry on the sand bed are functions of several variables that need to be
 determined individually for each treatment unit.

Drying beds are frequently constructed of concrete walls and floor with slotted pipe
underdrains buried beneath 18 to 24 inches of graded sand and gravel. Sludge from a
thickener is batch applied to the sand through one or several inlet structures.  Free water
drains from the sludge through the sand bed to the underdrains. As they accumulate,
supernatant and rain water are drawn off by a variable height outlet structure. After drying,
sludge cake is removed manually by shovel and wheel barrow or mechanically with a small
                                          47


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 front end loader or tractor.  •
 The method of sludge removal and the requirements at the ultimate disposal site determine the
 desired sludge cake solid's concentration. Manual sludge removal, using a shovel and
 wheelbarrow, requires solids' concentration of approximately 25 percent to ensure proper
 sludge handling.  Mechanically removing sludge by a vacuum truck or a front end loader
 requires solids' concentrations in the range of 15 to 25 percent. Many landfills require sludge
 cakes to have a minimum of 20 percent dry solids to meet acceptance criteria.

 Sludge removal and disposal costs are a large percentage of the total operation and
 maintenance costs for drying beds. Disposal costs of the solids are not included hi this
 section, but can be determined by using the information presented hi other sections of this
 document. Sludge removal costs are directly related to the  number of sludge applications per
 drying bed per year. Less frequent, thicker,  sludge applications result hi a thicker sludge cake
 that has lower unit costs for removal but may require more  drying bed area.  Individual
 treatment plants must determine then: most cost effective drying tunes and disposal
 frequencies.      :                    .                                       .

 7.2    TECHNOLOGY APPLICABILITY

 Sand drying beds effectively dewater lime and alum sludges to solids concentrations of 50
 percent and 20 to 25 percent, respectively. At these solid's concentrations, both sludges are
 suitable for landfilling or land application.  Lime sludges have a smaller percentage of
chemically-bound water and dewater more quickly than coagulant sludges.

7.3    TECHNOLOGY LIMITATIONS

For alum sludge, which contains as much as 40 percent bound water, chemical conditioning by
polymers is frequently necessary to aid  in the rapid release of water from the sludges.
                                          48

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Chemical conditioning causes the sludge to set quickly.  Once the polymer is incorporated into
the sludge, rapid application of a uniform depth of sludge is necessary for effective dewatering
and uniform drying. Several sludge application points in a drying bed or smaller bed sizes
may be necessary to ensure even application and drying of alum sludges.  Consequently, due
to the increased labor and operating requirements associated with alum sludges, it is unlikely
that sand drying beds would be used for treating these sludges.

Seasonal weather conditions affect the tune sludge must remain on the drying beds. Treatment
plants located in northern or seasonally wet areas, must prepare for longer bed drying times in
cold or damp weather. Enclosing the drying beds reduces the variation in drying times by
shielding the sludge cake from rain and snow and increasing the ambient temperature around
the beds.  Other options are to lagoon sludge during bad weather for application at a later date
or to build extra beds.

Drying beds are not effective for sludges with very low  suspended solid's concentrations or
sludges with high percentages of dissolved solids. Low solids' sludges (less than 1 percent
solids) will move through and blind sand beds, reducing the beds' effectiveness.  These
sludges must be thickened before drying bed application. High dissolved solid sludges, such
as the waste brines generated by  reverse osmosis, are not effectively captured by drying beds
because the dissolved solids flow through sand beds into the underdrains.

7.4    SAND DRYING BED 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

             Sand drying beds are used to dewater lime or non-alum sludges.

                                          49

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 Sludges flow to the lagoons or tanks via 500 feet of 2- to 6-inch diameter PVC
 piping buried 4 feet below the ground surface.

 The tanks or lagoons are sized to hold 21 or 42 days of volume.  Typically 15
 or 30 days of volume are necessary; however, the additional lagoon capacity is
 provided for slower drying conditions.

 Sludge is concentrated to 3 percent solids by weight in a lagoon or tank through
 decanting and evaporation; the sludge volume is reduced by 67 percent.

 The lagoons are constructed with a synthetic membrane liner and a geotextile
 support fabric.

 The lagoon bottom slopes to a sump.

 No polymers are added to the sludge.

 An 18-inch layer of sludge containing 3 percent solids is applied 6 to 12 times
 per year to each sand bed.

 The sludge pump and the drying bed piping are sized  to deliver sludge to the
 drying bed from the lagoon in one to two hours.  Drying beds are located 100
 feet from the lagoon.

 Drying beds are sized to hold 33 percent of the initial sludge volume applied to
 the bed in an 18-inch layer. Increased sizing is used to offset slower drying
 tunes in bad weather.

 Underdrains consisting of 2- to 6-inch diameter PVC piping collect filtrate.

 Drying beds are constructed of reinforced concrete with a 6-ihch bottom slab
 and 8-inch walls. The bed contains  18 inches of sand. The underdrain piping
 rests in 6 inches of gravel underneath the sand.

The final solid's concentration is 20 percent by weight.  Five percent of the
 initial sludge volume (0.7 cubic feet of solids per 100 gallons of initial sludge
volume) requires final disposal.
uiiuai aiuugc vuiumc \\j. i ^UUIL.
volume) requires final disposal.
The sludge cake is removed from beds either removed manually or by using a
small front-end loader depending on the total surface area of the beds.
                             50

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       7.4.2  Capital Components-  . •


 The capital components for each sand drying bed system consist of the following items:

             Dewatering tank or lagoon;
             Piping and fittings;
             Pumps;
             Trenching;
             One, two, or four sand drying beds;
             Land clearing;
             Electrical; and
             Instrumentation.
Table 12 shows the sludge volumes, number of beds, and the total required surface area used

to develop the capital cost equation for sand drying beds.


                                     TABLE 12

                               SAND DRYING BEDS
Sludge Volume
(gal/day)
20
100
500
- 2,000
5,000
10,000
Number of
Beds
1
2
2
2
4
4
Total Surface Area
(ft2)
25
150
750
2,500
3,200
7,000
      7.4.3  Operation and Maintenance Components


The operation and maintenance components, for each sand drying bed system include the

following items:
                                        51

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              Electricity;                     .-  ..  ,        .
              Sand replacement;
              Labor;
              Maintenance labor and materials; and
              Drying bed cleaning.

       7.4.4  Cost Components Excluded


The following cost components are not included in the cost equations for sand drying bed

systems:

              Drying bed enclosures;
              Polymers and polymer feed system;
              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    SAND DRYING BED 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 from the

capital and operation and maintenance costs obtained using the equations presented below.


       Capital Costs

             Y = [8,670 X °-25] + [0.5 X]

             Y = [Equipment Cost] + [Land Cost]

                                          52

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              Where:       Y = $
                           X = gallons of sludge per day
                           Z = land cost in dollars per acre (e.g., $l,000/acre)

              Range:       20 gpd'<. X <: 1,000 gpd
       Y = [1,936 X 05° -18,900] + [(9.69 x 10'2 +  1.89 x 1Q-4 X) Z]

       Y = [Equipment Cost] + [Land Cost]

              Where:       Y = $
                           X = gallons of sludge per day
                           Z = land cost in dollars per acre (e.g., $l,000/acre)

                           Note: For systems less than 2,000 gallons of sludge per
                           day, 1/2 acre of land is required.

              Range:       1,000 gpd < X * 10,000 gpd
Operation and Maintenance

       Y = 3,000 + 64.5 X 05°

              Where:      Y = $/year
                          X = gallons of sludge per day

              Range:       20 gpd ^ X ^ 1,000 gpd

       Y= 190 X050-1,600

              Where:      Y = $/year
                          X = gallons of sludge per day

              Range:       1,000 gpd  < X <. 10,000 gpd


Total Annual Cost

       Y = [CAP x CRF] + O&M
                                   53

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-------
                     Where:       Y = $/year
                                  CAP = capital cost
<^/vr = capiiai cosi
CRF = capital recovery factor (e.g., 0.1175)
O&M = operation and maintenance cost
 7.6    STORAGE LAGOON DESCRIPTION

 Storage lagoons, although land intensive, have historically been the most common and the least
 expensive method to thicken or dewater water treatment sludge. The lagoons are lined ponds
 designed to collect and dewater sludge for a predetermined period of time.  Dewatering of the
 sludge occurs by decanting the supernatant and by evaporation. 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 longrterm disposal sites for sludges. As one lagoon fills,
 another one is excavated.
               ^
 Lagoons are usually earthen basins with gradual side slopes. Sizes range from less than one to
 15 acres and from four 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 reduce turbulence in 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
                                          54

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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 in lagoons 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 lagoon.

7.7    TECHNOLOGY APPLICABILITY

Storage lagoons are primarily used for the dewatering of lime softening sludge, although
coagulant (alum) sludge also can be dewatered in certain situations. Final solids'
concentrations reported for lime and alum sludges after lagooning are 20 to 60 percent and
seven 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 solid's concentrations suitable for land filling. 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 suitable for  land filling.
                                           55

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 7.8   TECHNOLOGY LIMITATIONS

 Lagoons frequently do not produce a dewatered sludge suitable for landfill disposal.  In
 particular, 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 storage, alum
 sludges may need further dewatering to meet the 20 percent solids concentration required by
 many landfills. Often, alum sludge is allowed to dry further after removal from the lagoon
 and prior to hauling from the site. Thickened alum sludges are difficult to remove from
 lagoons.  Removal requires specialized dredging or vacuum equipment and knowledgeable
 operators. Consequently, lagoons will not be considered for treatment/disposal of alum
 sludges.

 Lagoons are 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 results since a
 lagoon is 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 of sufficient size
 to accommodate the equipment used.

7.9    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.
                                          56

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       7.9.1  Design Assumptions


              Permanent lagoons are used to dewater lime sludges; each lagoon has a storage
              capacity of ten years.

              The lagoons, are earthen basins lined with a synthetic membrane and a geotextile
              support fabric. They have no underdrains, but have a variable height outlet
              structure to discharge supernatant.

              Sludge flow rates range from 100 to 10,000 gallons per day (gpd). Although
              small system lime softening units generate less than 100 gpd of sludge, the
              lagoons cannot be constructed to engineering specifications at sizes less than
              100 gpd.                             •      .   .

              Sludge is gravity fed to the lagoons from the treatment plant via 750 feet of 2-
              inch diameter PVC piping buried 4 feet below the ground surface.

              Decanted supernatant from the lagoon is collected and pumped to the head of
              the treatment plant.

              Treatment plants operate two permanent lagoons to provide 20 years of
              permanent storage. Each lagoon has a 12-month  storage capacity. Free liquid
              is continuously decanted from the lagoon while it is accepting sludge and
              returned to the head of the treatment plant. After the 12-month period, the
              other lagoon is used while free liquid from the idle lagoon is decanted and
              evaporated. The remaining sludge is allowed to dry before the next sludge
              application.
       7.9.2  Capital Components


The capital components for each storage lagoon consist of the following items:

             Earthen lagoons;
             Piping and fittings;
             Trenching;
             Decant collection tank and pump;
             Electrical;                                         .     .
             Instrumentation; and
             Land clearing.
                                          57

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Table 13 displays the sludge volumes, number of ponds, and total lagoon surface area used to

develop the capital cost equation for lime softening lagoons.


                                    TABLE 13

                STORAGE LAGOONS - LIME SOFTENING SLUDGE
Lime Softening
Sludge Volume
(gal/day)
100
500
1,000
2,000
4,000
10,000
Number of
Ponds
2
2
2
2
2
2
Total Surface
Area
(acres)
0.04
0.18
0.40 v
0.80
1.5
3.8
      7.9.3  Operation and Maintenance Components

The operation and maintenance components for each storage lagoon include the following

items:

             Labor;
             Maintenance labor and materials; and
             Electricity.


      7.9.4  Cost Components Excluded


The following cost components are not included in the cost equations for storage lagoons:

             Sludge dewatering equipment; and                                   : _
             Supernatant disposal, if the supernatant cannot be pumped to the head of the
             treatment plant.
                                       58

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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.


7.10   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.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.


       Capital Costs

             Y = [10,900 + 1,729 X050] + [(5.33 x 10^ X097) Z]

             Y = [Equipment Cost] + [Land Cost]

                    Where:       Y = $
                                 X = gallons of sludge per day
                                 Z = land cost in dollars per acre (e.g., $l,000/acre)

                    Range:       100 gpd <; X  <. 1,500 gpd

             Y = [6,100 X 05° -  148,300] + [(5.33 x 104 X 097) Z]

                    Where:       Y = $
                                 X = gallons of sludge per day  .
                                 Z  = land cost in dollars per acre (e.g., $l,000/acre)

                    Range:       1,500 <  X <. 10,000 gpd

      Operation and Maintenance

             Y = 2,100 + 0.30 X050

                                          59

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             Where:   '   Y = $/year
                         X = gallons of sludge per day

             Range:      100 gpd <. X * 10,000 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
                                 60

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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 ponds or lagoons for
storage and evaporation. The lagoons are designed with a large surface area to allow solar and
wind evaporation to dewater the brine. 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 lagoon.  Outlet piping from the pond may be needed
in situations where the sludge loading exceeds the design capacity of the pond or for handling
overflows 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
ranging from 15,000 to 35,000 milligrams per liter (mg/1), solids will accumulate within the
pond at a rate of 14 to IVi inches per year.  When these solids reach a predetermined depth,
inflow to the pond  is stopped and evaporation continues until a solid concentration suitable for
disposal is achieved.  The solids are then removed by a front-end loader  into trucks for
transport to a disposal site.
                                          61

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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 in ponds may be enacted in the  future.  Therefore,
 good engineering practice suggests that at a minimum a synthetic liner should be included hi
 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 used in 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
wastes with low TDS concentrations will operate for several years  before solids accumulation
necessitates removal.

8.3    TECHNOLOGY LIMITATIONS

Several factors limit the applicability of evaporation ponds as a sludge dewatering option.
Evaporation is a land intensive treatment requiring shallow basins with large surface areas.
                                         62

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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 reverse osmosis treatment plants.

There is also a limitation on how small a pond can be sized.  This limitation is due to that the
pond is an engineered excavation rather than simply a hole dug hi the ground.  To maintain
and construct the side slopes of the pond, the bottom surface area must be a minimum size to
accommodate the equipment used.

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

The following section presents the design assumptions, capital components, and the operation
and maintenance components used to prepare the costs for this technology.

       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.     .                                          .               •
              Waste brines flow from the treatment plant to the evaporation pond by gravity •
              or by the pressure from the treatment system via 750 to 7,500 feet of schedule
              40 PVC piping. Pipe diameters range from 2 to 8 inches.

                                          63

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              Waste brine flow rates range from 200 to 500,000 gallons per day (gpd).
              Although small system ion exchange units generate less than 200 gpd, the ponds
              cannot be constructed to engineering specifications at sizes less than 200 gpd.
              In addition, waste brine flow rates from some small system reverse.osmosis
              plants may exceed 500,000 gpd; however, the land requirements become
              prohibitive at sizes over 500,000 gpd.

              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 earthen berm has two and one-half to one (2.5:1) side slopes and two 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; one foot of sand is placed on top of the liner.

              Piping from the treatment process is sized to discharge  waste brines to the
              ponds as they are generated.

              The evaporation ponds are sized with sufficient surface area to evaporate the
              average daily flow. The pond depth is two feet to provide solids storage
              volume and to accommodate 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 14 indicates the brine volumes, number of ponds, and the total required surface area

used to develop the capital cost equation for evaporation ponds.
                                          64

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                                    TABLE 14
                             EVAPORATION PONDS
Brine Volume .
(gal/day)
200
400
1,000
10,000
50,000
100,000
. 200,000
400,000
500,000
Number of
Ponds
1
2
2
2
2
2
4
6
3
Total
Surface Area
(acres)
0.06
0.12
0.30
3
15
30
60
,120
150
      8.4.3 Operation and Maintenance Components

The operation and maintenance components for each evaporation pond include the following

items:

            Labor;
            Maintenance labor and materials; and
            Insurance and general and administration.


      8.4.4 Cost Components Excluded

The following cost components are not included in the cost equations for evaporation ponds:
            Solids removal from the pond; and
            Dewatered sludge disposal
                                       65

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Costs for sludge disposal are included in other sections of this document.


8.5    COST EQUATIONS


The cost equations for the capital components and for operation and maintenance were
developed by estimating the costs for seven 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 = [139 X °-B]  + [(7.52 x 104 X 093) ZJ

             Y = [Equipment Cost] -f [Land Cost]

                    Where:       Y = $               .
                                  X = gallons of brine per day
                                  Z = land cost in dollars per acre (e.g., $l,000/acre)

                                  Note:  For systems less than 1,000 gallons of brine per
                                  day, l& acre of land is required.
                    Range:
200 gpd ^ X s 50,000 gpd
             Y = [16 X1-05] + [(4.08 x 10^ X °98) Z]

             Y = [Equipment Cost] + [Land Cost]

                    Where:
                    Range:
Y = $
X = gallons of brine per day
Z = land cost in dollars per acre (e.g., $l,000/acre)

50,000 gpd < X z 500,000 gpd
                                          66

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Operation and Maintenance

       Y = 66 X °-61

             Where:


             Range:
Y = $/year
X = gallons of brine per day

200 gpd <: X <: 50,000 gpd
       Y = 0.71 X 104

             Where:


             Range:
Y = $/year    . •
X = gallons of brine per day

50,000 gpd < X <. 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
                                  67

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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 (POTW) 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 the sanitary sewer system if an adequate
 system is not already in place.  Installation of this system includes piping, pipe fittings, and
 trenching.

 The piping required to carry the byproduct stream to the outfall is the primary capital cost
 associated with this treatment method.  Poly vinyl chloride (PVC) 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 hi the event of a pipe burst. In areas of winter
 frost, the pipe must be laid sufficiently below grade to prevent whiter freezing.

 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.  Most small communities
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

                                         68

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treatment plants for wastes sent to the POTW facility since tKey are part of the same entity.

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.

In some cases, chemicals in the water treatment byproducts will actually aid in the treatment of
wastewaters at the POTW by acting as a settling agent.  In other cases, the solids content or
other constituents hi 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.

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 not 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
                                        - 69

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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 $4.50
per thousand gallons discharged.  Appendix A presents POTW charges used to determine a
typical POTW charge for this document.

In all cases, the water treatment plant must have or be able to gain access to a sanitary sewer
line or have convenient truck access. Many communities, especially with populations under
500, do not maintain POTW facilities. 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.

9.4    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.

       9.4.1  Design Assumptions

             The byproduct stream flows by gravity or under pressure from the treatment
             process via PVC piping to the sewer line.
             Byproduct flow rates range from 100 to' 1,000,000 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.
             Two-inch minimum diameter pipe is used to prevent clogging. Pipe diameters
             range from 2 to 6 inches.  Schedule 40 PVC pipe is used.
                                         70

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             Holding tanks and lagoons are not required for small water treatment systems.
             Costs are for discharge of brines and slurries and do not include TSS or BOD
             surcharges.
      9.4.2  Capita! Components


The capital components for each POTW discharge system consist of the following items:

             Piping and fittings;
             Trenching; and
             Land clearing.

Table 15 indicates the brine volumes and pipe diameters used to develop the capital cost

equation for the POTW systems.

                                    TABLE 15

                                POTW DISCHARGE
Byproduct
Flow Rate
(gal/day)
160
330
1,010
2,440
3,930
12,200
29,380
67,500
162,500
500,000
750,000
1,000,000
Pipe Diameter
(inches)
2
2
2
2
2
2
2
2
3
4
6
6
                                        71

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       9.4.3  Operation and Maintenance Components

The operation and maintenance components for each POTW discharge system include the
following items:
              Labor; and
              Basic POTW charges.
No maintenance requirements are assumed for this technology.

       9.4.4  Cost Components Excluded

The following cost components are not included in the cost equations for POTW discharge
systems:
              Any fees charged by the POTW for the initial connection; and
              Land cost.
It is assumed the water treatment facility would be able to'gain access for piping via an
easement.

9.5    COST  EQUATIONS

The cost equations for the capital components and operation and maintenance were developed
by estimating the costs for 12 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 = $3,500
                                         72

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             Where:       Y = $
                          X = gallons of brine per day

             Range:       100 gpd <; X <; 150,000 gpd
      Y = 2,700 +3.1 X
                         0.50
             Where:      . Y = $
                          X = gallons of brine per day

             Range:       150,000 gpd < X <; 1,000,000 gpd
Operation and Maintenance

      Y = [375] + [(1.83 x 10-3) 365 X]

      Y = [Operating Costs] + [POTW Charges]

             Where:       Y = $/year
                          X = gallons of brine per day
                          (1.83 x iO"3 = POTW volume charge)

             Range:       100 gpd <; X <  1,000,000 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


9.5.2 1,000 Feet of Discharge Pipe


      Capital Costs

      Y = 7,400

                                  73

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             Where:      Y = $
                          X = gallons of brine per day

             Range:       100 gpd <; X <; 150,000 gpd
       Y = 4,800 + 6.7 X
                         0.50
             Where:      Y = $
                          X =-ga!lons of brine per day

             Range:       150,000 gpd < X <: 1,000,000 gpd
Operation and Maintenance

       Y = [375] + [(1.83 x 10-3) 365 X]

       Y = [Operating Costs]  + [POTW Charges]

             Where:       Y = $/year           '
                      -    X = gallons of brine per day
                          (1.83 x lO'3 = POTW volume charge)

             Range:       100 gpd s X < 1,000,000 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
                                  74

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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.  No pretreatment or concentration of the
byproduct stream is necessary 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. Polyvuiyl chloride (PVC) 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.  In areas of winter
frost, the pipe must be laid sufficiently below grade to prevent winter freezing.

An equalization/holding tank is optional in instances where reverse osmosis is used as the
water treatment system.  It serves several purposes when disposing of treatment wastes by
direct discharge: First, the tank reduces the necessary discharge piping diameter by allowing
wastes to be continuously discharged at a lower flow rate.  Second, the tank reduces the
variations in the quality of the discharged wastes by mixing the wastes generated over a period
of time. Third, the tank provides emergency storage when discharge is not possible. The size
of the holding/equalization tank will depend on the byproduct volumes and the required
number of days of storage.
                                         - 75

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 10.2  TECHNOLOGY APPLICABILITY

 Direct discharge can be used for small water treatment systems where little oversight is
 available.  The level of operator experience and maintenance required is minimal. This
 method has been 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 hi
 sludge or brine prior to discharge. Direct discharge requires the lowest level of oversight and
 maintenance of all the treatment/disposal methods presented hi this document.

 10.3  TECHNOLOGY LIMITATIONS

 The primary limitations of direct discharge of water treatment plant byproducts are federal,
 state, and local regulations.  The discharge of waste into surface water is regulated by the
 Clean Water Act.  Water treatment plants are required to obtain a 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 should not be practiced.

 A second limitation is that the byproducts can potentially have a negative effect upon the
 quality of water in the receiving body.  In receiving waters with low velocities, discharged
 sludges will collect 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.

.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.
                                           76

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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 100 to 1,000,000 gallons per day depending
             on the water system technology.

             The point of discharge is 500 feet or 1,000 feet from the water treatment
             system.

             Two-inch minimum diameter pipe is used to prevent clogging. Pipe diameters
            ' range from 2 to 6 niches.

             Schedule 40 PVC pipe is used.

             A 1- to 2-day storage tank or lagoon is optional.


       10.4.2 Capital Components

The capital components for each direct discharge system consist of the following items:

             Piping and fittings;
             Trenching; and
             Land clearing.                          •         .
In addition, a pump, holding tank or lagoon, electrical, and instrumentation are added for the

direct discharge option with a holding tank or lagoon.


Table 16 indicates the brine volumes, pipe diameters, and tank/lagoon capacities used to

develop the capital cost equation for direct discharge.  •
                                          77

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                                     TABLE 16
                               DIRECT DISCHARGE
Byproduct
Flow Rate
(gal/day)
160
330
1,010
2,440
3,930
12,200
29,380
67,500
162,500
500,000
750,000
1,000,000
Pipe Diameter
(inches)
•2
2
2
2
2
2
2
2
3
4
6
6
Tank or Lagoon Capacity
500-gallon tank
1,000-gallontank
2,000-gallon tank
5,000-gallontank
8,000-gallon tank
25,000-gallon lagoon
50,000-gallon lagoon
115,000-gallon lagoon
330,000-gallon lagoon
750,000-gallon lagoon
1,1 25,000-gallon lagoon
1,500,000-gallon lagoon
       10.4.3 Operation and Maintenance Components

The operation and maintenance components for a direct discharge system with no holding tank
includes labor. No maintenance requirements are assumed for this technology. The operation
and maintenance components for direct discharge with a holding tank or lagoon include the
following items:
             Electricity;
             Labor;
             Maintenance labor and materials; and
             Insurance and general and administration.
                                        78

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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 cost.
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 12 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
              Y = 3,500
                    Where:      Y = $  .     •
                                 X = gallons of brine per day
                    Range:       100 gpd & X <  150,000 gpd
             Y = 2,700 + 3.1 X
                                 0.50
                    Where:      Y = $
                                 X = gallons of brine per day
                                          79

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             Range:       150,000 gpd <. X <. 1,000,000 gpd
Operation and Maintenance

       Y = 375

             Where:
               Y = $/year
               X = gallons of brine per day
             Range:       100 gpd s X < 1,000,000 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
10.5.2 1,000 Feet of Discharge Pipe
Capital Cost
      Y = 7,400

             Where:


             Range:
               Y = $
               X = gallons of brine per day
100 gpd
                            150,000 gpd
      Y =
4,800 + 6.7 X 05°

  Where:
                         Y = $
                         X = gallons of brine per day
             Range:       150,000 gpd < X <; 1,000,000 gpd
                                  80

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Operation and Maintenance

       Y = 375
             Where:       Y = $/year
                          X = gallons of brine per day

             Range:       100 gpd <; X <  1,000,000 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
10.5.3 500 Feet of Discharge Pipe with a Holding Tank or Lagoon


Capital Costs

      Y = 5,000+ 75.4 X050

      Y = Equipment Cost

             Where:      Y  = $
                          X  = gallons of brine per day.

             Range:       100 gpd ^ X 5 12,000 gpd


      Y = [14,400 + 9.46 x 10'2 X] + [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., $1000/acre)
                                   81

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             Range:        12,000 gpd < X < 1,000,000 gpd
 Operation and Maintenance

       Y = 1,000 +0.13 X

             Where:
Y = $/year
X = gallons of brine per day
             Range:       100 gpd $ X * 12,000 gpd


       Y = 2,600 + 1.44 x!0'2X

             Where:       Y = $/year
                          X = gallons of brine per day

             Range: ,      12,000 gpd < X <;  1,000,000 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
10.5.4 1,000 Feet of Discharge Pipe with a Holding Tank or Lagoon
Capital Cost
       Y = 8,600 + 75.4X050

             Where:
             Range:
Y = $
X = gallons of brine per day

100 gpd ^ X ^ 12,000 gpd

         82

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       Y  = [17,800 + 9.70 x 10'2 X] .+ [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., $1000/acre)

             Range:      12,000 gpd < X * 1,000,000 gpd
Operation and Maintenance

       Y = 1,000 4-0.13X

              Where: '     Y = $/year
                          X = gallons of brine per day

              Range:       100 gpd ^ X ^ 12,000 gpd
         = 2,600 + 1.44xlO-2X

             Where:      Y = $/year
                          X = gallons of brine per day

             Range:       12,000 gpd <  X <. 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
                                   83

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                                            11.0  FRENCH DRAINS

              11.1   TECHNOLOGY DESCRIPTION

              French drains are a type of drainfield similar to a residential septic system used for waste
              disposal. A distribution box discharges the effluent into a system of gravel-filled trenches,
              known as a drainfield.  French drains are constructed trenches or beds. A trench is typically
              18 inches to three feet wide and a bed is 3 to 25 feet wide.  Both trenches and beds have a
              maximum length of 100 feet and are 1 to 2 feet deep. The beds contain % -inch to 2%-inch
              gravel.  Effluent runs through the pore spaces in the gravel and eventually percolates  into the
              surrounding soil.  The size of the drainfield depends on the daily flow rates of wastewater, the
              percolation rate of surrounding soil, and the  depth to ground water.

              Drainfields are part of a septic-type system.  In this system, wastewater flows to a distribution
              box. The distribution box has up to nine outlets and each outlet leads to a gravel bed.
              Wastewater flows through the outlets and into the drainfield trenches.  As effluent percolates
              into the surrounding soil, the water quality of the effluent is improved by physical, chemical,
              and biological interactions with the soil.

              11.2  TECHNOLOGY APPLICABILITY

              French drains are a disposal option for water treatment brines. Although there  is theoretically
              no limit to the amount of byproducts that can be discharged into these systems,  drainfields are
              usually limited to flows of 10,000 gallons per day. Higher flows can overload a system
              causing drainfield failure and creating a ground water mound.  These failures allow untreated
              effluent into the surrounding soils and the ground water.  French drains are preferred  in some
              areas because the drainfield needs less square footage than a standard drainfield with
              perforated pipes. French drains are a versatile disposal option for
                                                       84
.

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small daily flows since they can be used in almost all climates and can be modified to be
effective with varying soil types,

11.3   TECHNOLOGY LIMITATIONS

Several factors limit the use of french drains. They are designed to handle the brines from
reverse osmosis or ion exchange; alum and lime sludges cannot be disposed via french drams.
Systems are generally limited to discharge flows of less than 10,000 gallons per day because of
the area needed for the drainfield.  Higher daily flows make the system an inefficient method
of byproduct treatment due to problems such as overloading the drainfield and elevated ground
water levels.  In addition, french drains are illegal in some states.

11.4   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.

       11.4.1  Design Assumptions

              The soil has a moderate percolation rate of 10 minutes per inch.     . -
            •  The system is gravity fed.
              The maximum bed size is 100 feet in length and 25 feet wide with 10 feet
              between beds.

       11.4.2  Capital Components

The capital components for each french drain system consist of the following items:
              Earthwork;
              Gravel drainfield beds;
              Piping; and
              Land.

                                         85

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        11.4.3  Operation and Maintenance Components

 The operation and maintenance components for each french drain system includes labor to
 inspect the french drain system. No maintenance requirements are assumed for this
 technology.

        11.4.4  Cost Components Excluded

 The following cost components are not included in the cost equations for french drain systems:
               Collection and laboratory analysis of drainfield soil samples;
               System maintenance, if necessary; and
               Cost of boreholes for percolation test.

 11.5   COST EQUATIONS

 The cost equations for the capital components and operation and maintenance were developed
 by estimating the costs for five different brine 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.

       Capital Cost
              Y = [2,600 + 2.92 X] + [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., $1,000 per acre)
                                          86


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             Range:   ,   100 gpd s X * 2,000 gpd


        Y = [100 + 3.96 X] + [0.75 Z]

        Y = [Equipment Cost]  + [Land Cost]

             Where:       Y  = $
                          X  = gallons of brine per day
                          Z  =  land cost in dollars per acre (e.g., $1,000 per acre)

             Range:       7,000 gpd < X s 10,000 gpd


Operation and Maintenance
                                                               \

        Y - 375

             Where:       Y  =  $/year     .        .

             Range:       100 gpd ^ X ^ 10,000 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
                                  87

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                             12.0  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.

 12.1  TECHNOLOGY DESCRIPTION

 Land application disposes water treatment byproducts by applying them directly to land
 surfaces. In general, liquid sludges contain less than 15 percent solids.  Liquid, pumpable,
 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.

 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
 and the sludge is applied with sprinklers.  Rapid infiltration is used with deep and highly
 permeable soils, such as sands. Liquid sludge is fed continually, into a shallow basin 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 buried pipes that captures effluent for reuse or discharge into a receiving body
of water; underdrainage minimizes ground water contamination  and subsurface flow of _• •

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 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, run 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.

 12.2   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 is increasing and it is gaining in
popularity as a disposal method due to increased regulatory controls associated with 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 sludge application.  Alum sludges do not benefit the soil matrix and
 should be used as fill  material.
                                           89

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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 is stockpiled until soil conditions are
 appropriate for land application.

 12.3  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 in 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
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.
                                           90

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12.4   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.
                                 ».

       12.4.1  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 plant is 500 feet from the storage lagoon; the sludge is gravity-fed to
              the lagoon.

              The lagoons are sized for 6-month storage except for the 130 gallons per day
              system, which has storage capacity for one year.

              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) except for the 130 gallons
              per day system.  Sludge  is applied once per year for 130 gallons per day
              system.

              The sludge application is 1 inch thick.


      Application By Sprinkler:

              The land application  rate is 14 inch per day.

              The sprinkler system is a portable system with all piping above ground.

              The sprinkler system has a radius of 50 feet.
                                         91

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       12.4.2 Capital Components

The capital components for each land application consist of the following items:

              Storage lagoon;
              Piping;
              Land;
              Electrical; and
              Sprinkler system, when appropriate.

Table 17 indicates the sludge volume and pond surface areas used to develop the capital cost,
equation for the land application systems.
                                     TABLE 17
                      LIQUID SLUDGE LAND APPLICATION
Sludge Volume
(gal/day)
130
1,000
5,000
10,000
Pond Surface Area
(acres)
0.05 •:
0.15
0.53
0.92
       12.4.3  Operation and Maintenance Components
The operation and maintenance components for land application include the following items:

              Electricity;
              Labor;
              Sludge removal from storage pond;
              Maintenance labor and materials;
              Insurance and general and administration; and
              Transportation and land application fees, when appropriate.
                                         92

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       12.4.4 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.

12.5   LIQUID SLUDGE LAND APPLICATION COST EQUATIONS

The cost equations for the capital components and operation and maintenance were developed
by estimating the costs for 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
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.

       12.5.1  Sprinkler System

              Capital Cost
                    Y =  [17,700  +  14.7 X] + [(0.2 + 7.0 x 103 X 05°) Z] + [(0.2  +
                          2.7 x 10-4 X) Z]
                    Y =  [Equipment Cost] +  [Pond Land Cost] + [Application Field
                       .   Cost]
                          Where:       Y = $
                                       X = gallons of sludge per day
                                       Z  = land cost in dollars per acre (e.g.,
                                       $l,000/acre)
                                       Note:  for sludge flow rates <. 1,000 gpd, the total
                                              land requirement is 0.5 acre
                          Range:              100 gpd ^ X ^ 10,000 gpd
                                          93

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        Operation and Maintenance

             Y = 1,200 + 0.85 X
                    Where:       Y = $/year
                                 X = gallons of sludge per day

                    Range:             100 gpd <; X <; 10,000 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
12.5.2 Trucking System


       Capital Cost

             Y = [15,200 + 13.9 X] + [0.2 + 7.0 x 10'3 X 05°) Z]

             Y = [Equipment Cost] 4-  [Land Cost]

                   Where:       Y =   $
                                X =   gallons of sludge per day
                                Z =   land cost in dollars per acre (e.g.,
                                       $l,000/acre)

                   Range:       100 gpd ^ X s 10,000 gpd


       Operation and Maintenance

             Y = 1,100 + 11.8 X

                   Where:       Y = $/year
                                X = gallons of sludge per day

                                  94
                                                                                    J

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                          Range:  ,     100 gpd $ X * 10,000 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
12.6   DEWATERED SLUDGE LAND APPLICATION COST COMPONENTS


       12.6.1  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 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 soil.

              The application rate is two dry tons of sludge per acre.


       12.6.2  Capital Components


The capital components for dewatered sludge land application consist of the following items:

              Land for sludge stockpile; and
              Land clearing.
                                         95

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       12.6.3  Operation and Maintenance Components

 The operation and maintenance components for each dewatered sludge land application include
 the following items:
               Labor;
               Sludge loading; and
               Transportation and land application fees.

       12.6.4  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.

 12.7   DEWATERED SLUDGE LAND APPLICATION COST EQUATIONS

 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
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.

              Capital Cost
                   Y = [1.45 X087] + [0.5 Z]
                   Y = [Equipment Cost] + [Land Cost]
                          Where:       Y = $
                                       X = gallons of sludge per day
                                       Z = land cost in dollars per day
                                         96

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        ...   Range:-   .   100 gpdsX s 1^000 gpd  •'

      Y = [1.45 X 087] + [(0.33 + 1.6 x 10^ X) Z]

      Y = [Equipment Cost] + [Land Cost]  *

            Where:      Y = $
                         X = gallons of sludge per day
                         Z = land cost in dollars per day

            Range:       1,000 gpd < X £ 10,000 gpd


Operation and Maintenance

      Y = 150 + 28.2 X                                 .

            Where:      Y = $/year
                         X = gallons of sludge per day

            Range:       100 gpd s X ^ 10,000 gpd


Total Annual Cost

      Y =  [CAP x CRFJ + O&M

            Where:      Y = $/year   •    ,       .
                         CAP = capital cost
                         CRF = capital recovery factor (e.g., 0.1175)
                         O&M = operation and maintenance cost
                           97

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                 13.0 NONHAZARDOUS WASTE LANDFILL

 13.1   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, corrective action
 requirements, closure and post-closure care requirements, and financial assurance.
 Implementation of these criteria may directly contribute to the early closure of many landfills
 and increase the tipping fees charged by other landfills.

 13.2  TECHNOLOGY APPLICABILITY AND LIMITATIONS

The percent solids and leaching characteristics of a sludge are the two most important
                                         98

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characteristics in determining the applicability of disposal hi 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 hi 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 hi a landfill.

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 hi 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),
the sludge can be disposed hi 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
and the overall stability of the disposal area.  In most cases, a solids  content of 15—20 percent
is required for landfilling, but in some cases wastes with less than  15 percent solids will be
accepted for disposal.

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.
                                           99

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 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.

 13.3  COST COMPONENTS

 The following section presents the design assumptions and cost components used to prepare
 the costs for this technology.

       13.3.1 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 toxicity.

       13.3.2 Cost Components

The cost components for non-hazardous waste landfill consist of the following items:
              Commercial nonhazardous waste landfill tipping fee; and
              Transportation fees.
                                          100

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13.4  TOTAL ANNUAL COST EQUATION


            Y = [35 X] -J- [2.48 + 0.16 Z] X

            Y = [Disposal] + [Transportation]
                  Where:      Y = $/year
                              X = Tons of sludge requiring disposal per year
                              Z = Transportation distance from 5 to 50 miles
                                      101

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                    14.0 HAZARDOUS WASTE LANDFILL         ....:.

 14.1  TECHNOLOGY DESCRIPTION

 Hazardous waste landfills are used for ultimate disposal of hazardous wastes (including listed
 and characteristic wastes). For water treatment byproduct sludges specifically, hazardous
 waste landfills are used for the disposal of 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 HOPE 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.
                                         102

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14.2   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 hi a hazardous waste landfill.
Water treatment byproducts that exhibit the characteristic of ignitability, corrosivity,
reactivity, or toxicity require disposal hi 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 H) 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 hi 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 liquid collects in the cylinder or beaker, the sludge contains free liquids and  is not
appropriate for landfilling. If no  liquid collects in 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 in 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 (i.e.,
ignitability, corrosivity, reactivity, and toxicity) that require wastes to meet specified
                                          103

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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 hi 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.


 14.3  COST COMPONENTS


 The following section presents the design assumptions and cost components used  to prepare

 the costs for this disposal technology.


       14.3.1 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,  diey 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 toxicity characteristic (TC)  wastes.


       14.3.2 Cost Components


The cost components for hazardous waste landfill consist of the following items:

             Hazardous waste landfill charges;
             Stabilization charges; and
             Transportation fees.

                                          104

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       14.3.3 Cost Components Excluded         .    •

The following cost components are not included in the cost equations for hazardous waste
landfills:
             Generator notification requirements;
             Manifest requirements; and
             OtherRCRArequirements, as applicable.                 .        . -.
14.4  TOTAL ANISfUAL COST EQUATION


      14.4.1 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


      14.4.2 Stabilization and Hazardous Waste Disposal


             Y = [400 X] + [(7.9 + 0.22 Z) X]

             Y = [Stabilization/Disposal] + [Transportation]

                   Where:      Y = $/year
                                X = Tons of sludge requiring disposal per year
                                Z = Transportation distance between 200 and 500 miles
                                        105

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                   15.0 RADIOACTIVE WASTE DISPOSAL

 15.1   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 in
 western states.

 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 picocurries per liter (pCi/L) was set by the U.S. EPA.  It was estimated
 that 1,000 community water supplies exceeded the radium standard in the U.S.; most of which
 were groundwater systems with capacities of 0.5 million gallons per day or less.  Federal
 MCLs have not yet been established for radon or for natural uranium, although regulations 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."  The guidance,
 which is currently being revised, is designed to provide water suppliers and state and local
 governing agencies with some assistance. The guidance provides recommendations and
 summarizes existing regulations and criteria used by EPA and other agencies in addressing the
disposal of fadionuclides 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 additional, state-
 specific information.
                                         106

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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.

15.2   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 treatment media and 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 or proposed state requirements that  pertain to Naturally
Occurring and Accelerator-Produced Materials (NARM) that limit the discharge of wastes
containing radionuclides into the environment.                          .
                                          107

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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.

15.3   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 will 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
                                          108

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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
minimized 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 which will accept the. waste is located. Second, all free standing liquids
are removed. Third, materials are packaged in 55-gallon drums with 4 mil liners.   Fourth, all
necessary permitting, shipping, and packaging paperwork is completed and finally,  the drams
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
                                          109

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 survey, complete the labelling and paperwork, and deliver the drums to the disposal sito-If a
 waste generator does not want to be involved in 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.

 15.4   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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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.
                                         110

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Armbrust, Andy, U.S. Ecology; contacted by Mary Rooney, DPRA.  Concerning low-level
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Brown, Denise, U.S. Ecology; contacted by Mary Rooney, DPRA. Concerning low-level
       waste disposal costs. 24 July 1992.

Camp, John, Rain 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.

Clingingsmith, Larry, C.P. Environmental; contacted by Mary Rooney, DPRA. Concerning
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Cornwell, Bishop, et al.  Handbook of Practice. Water Treatment Plant Waste Management.
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Crase, Arvil, U.S. Ecology; contacted by Mary Rooney, DPRA. Concerning low-level
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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
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       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.

Gumerman, Robert C., Bruce E. Burris, and Sigurd P. Hanser.  Small Water Treatment
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Hahn, Norman, Wisconsin Department of Natural Resources; contacted by Mary Rooney,
      DPRA." Concerning radioactive sludge disposal options.  22 July 1992.
                                       .111

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 Hahn, Norman.  "Disposal of Radium Removal from Drinking Water."  American Water
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 Haraldson, Gary, Lakewood Water Treatment Plant; contacted by Mary Rooney, DPRA.
       Concerning use of sand drying beds.  11 August 1992. .

 Harrison, Jack, Chem Nuclear; contacted by Mary Rooney, DPRA. Concerning low-level
       radioactive waste disposal costs. 27 July 1992.

 Higgins, Kirt, Envirocare; contacted by Mary Rooney, DPRA. Concerning NORM disposal
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 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
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 Koeckeritz, Om, Koeckeritz Excavating; contacted by Kristina Uhlig, DPRA. Concerning
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 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.
                                        112

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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
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Mohr, Bob, Chem Nuclear; contacted by Mary Rooney, DPRA.  Concerning low-level
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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.
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Ohio River Valley Water Sanitation Commission.  A Study of Wastewater Discharges
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Parrotta, Marc,  US EPA; contacted by Pat Martz Kessler, DPRA.  Concerning the
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Perez, Yvonne,  U.S. Ecology; contacted by Mary Rooney, DPRA. Concerning low-level
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Peterson, Bruce, Peterson Ag Service; contacted by Kristina Uhlig, DPRA.  Concerning
       liquid sludge land application costs.  18 August 1992.

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                                        113

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Sadowski, Greg,  Sharples/ALFA-LAVAL Company; contacted by Mary Rooney, DPRA.
       Concerning scroll centrifuge costs.  19 August 1992.

Seefert, Ken, Croixland Excavating; contacted by Kristina Uhlig, DPRA. Concerning French
       drains. 24 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.
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U.S. Environmental Protection Agency, Office of Research and Development. Innovative
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U.S. Environmental Protection Agency.  The Cost Digest:  Cost Summaries of Selected^
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U.S. Environmental Protection Agency, Office of Drinking Water.  Technologies for
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       EPA/625/4-89/023.  March 1990.

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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,
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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 Equipment; contacted by  Mary Rooney, DPRA.
       Concerning gravity thickeners.  24 August 1992.
                                        115

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  APPENDIX A
POTW CHARGES
     A-l  •

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                                  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.  Three of the cities contacted during the
telephone sample do not charge to accept wastes from water treatment plants and a fourth does
not have a wastewater treatment plant.  In addition, many of the POTWs contacted during the
telephone sample and by the League of Minnesota Cities charge a flat rate per month with no
additional charges for higher flow rates.                                              :
                                        A-2

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         TABLE 1
SEWER RATES - SMALL CITIES
    TELEPHONE SAMPLE
City
Gordb
Clarkdale
Westeliffe
Anthony
Bird City
Livermore Falls
Ada
Cannon Falls
Circle Pines
Deer River
Harlem
Crooksville
Agate Beach
State
Alabama
Arizona
Colorado
Florida
Kansas
Maine
Minnesota
Minnesota
Minnesota
Minnesota
Montana
Ohio
Oregon
Population
2,112
2,144
324
900
467
3,500
1,971
2,653
3,321
907
1,023
2,766
700
Sewage Fee Charged
Business: $7.50/month if < 12 employees;
$15/month if > 12 employees
Residential: $10/month
Residential: $15/month x unit (up to 6 "
units) 	
No sewer system - well & septic system . ., .
$8.50/month
$15 + $1.87/1 ,000 gallons
$3/month for sewer line + $3/unit if
apartment + $.67/1,000 gallons
Minimum: $9. 10/2 months + $1.48/1,000
gallon BOD: $44.57/100 pounds Suspended
solids: $28.93/100 pounds; Industrial
surcharge: $.47/1 ,000 gallons
$5.50/month + $1.10/1, 000 gallons
$9.00 base rate
Minimum: $7.84/month/meter Gallons used
during winter x 12 x .00325 + 1068
$10.80/2,000 gallons + $4.45/1,000
gallons (2K+)
$5.25/1,000 gallons +
$1/1 ,000 gallons (IK +) +
$.25 surcharge > 10,000 gallons +
$1.55/1,000 gallons for BOD over 600 mg.
          A-3

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            TABLE 2
          SEWER RATES
LEAGUE OF MINNESOTA CITIES SURVEY
City
Dent
Goodridge
Kettle River
Mapleview
Steen
Beaver Bay
Big Falls
Breezy Point
Center City
Hartland
Motley
Peterson
Plummer
Rose Creek
Rothsay
Round Lake
Wood Lake
Argyle
Battle Lake
Bigfork
Butterfield
Population
167
191
174
235
154
283
490
384
458
322
444
• 285
353 '
380
476
480
420
741
708
541
634
Sewage Fee Charged
$10 (commercial)
$5 (residential)
$25 (commercial)
$18/quarter + $.20/1,000 gallons (over 2.3K)
$18/quarter
$16/month (residential)
$16/month (commercial)
$100/year
$207 < 7,999 gallons
$26.08/8,000 gallons + $.76/1,000 gallons (8K+)
$12/quarter
$1.26/1,000 gallons + TSS + BOD (not
listed)
$7.50/month (June-Aug.)
or $20/month (other mos.)
$5 + $.35/1, 000 gallons (commercial)
$5 .+ $1/1, 000 gallons (1K+)
$1.24/1 ,000 gallons
$10/4,000 gallons + 1.50/1,000 gal. (4K+)
$5/month (Residential)
$.80/1, 000 gallons
$10.28 + $.723/1,000 gallons
$19.50/quarter
$12 (Residential)
              A-4

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             TABLE 2

           SEWER RATES
LEAGUE OF MINNESOTA CITIES SURVEY
            (continued)
City
Carver
Freeport
Goodhue
Rollingstone
Siver Lake
St. Clair
Adams
Richmond
: Walnut Grove
Birchwood
Maple Lake
Preston
Appleton
Blooming Prairie
Cold Spring
Lake Crystal
Lakefield
Lexington
Mapleton
Pine Island
Population
642
563
657
528
698
655
797
867
753
1,059
1,132
1,478
1,842-
1,969
2,294
2,078
1,845
2,150
1,576
1,977
Sewage Fee Charged
$3.50/1,000 gallons (Jan., Feb., March)
+ 2.70/1, 000 gallons
$7 (Residential)
Water usage x .50 + $24
$20/quarter
$2.57/1, 000 gallons .'•""'
$20 + $1.50/1, 000 gallons (6K+)
$4.80 (minimum)
$6.30 (0-5K) -f $1.26/1,000 gallons (5K+) .
$20
,$33/quarter .- _ •
$12.71 (0-3K) + $3 . 10/1 ,000 gallons (3K+)
$1.55/1, 000 gallons
$21.75 + $1.93/1, 000 gallons
$4.50 + $1.26/1, 000 gallons
$11 (0-6K)
+ $1.60/1 ,000 gallons (6K+)
$1. 25/1 ,000 gallons (0-20K) + $.50/1, 000 gallons
(20K+)
$1.97/1, 000 gallons + 1.13
$33
$15 - -
$1.63/1, 000 gallons
               A-5

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                                 TABLE 2

                              SEWER RATES
                 LEAGUE OF MINNESOTA CITIES SURVEY
                                 (continued)
     City
Population
             Sewage Fee Charged
Ely
 , 4,820
$2.00/1,000 gallons
Newport
  3,323
$8.58 (0-10,000 gallons)
$10.66 (10-15,000 gallons)
$16.12 (15-25,000 gallons)
$26.00 (25-40,000 gallons)
$36.40 (40-55,000 gallons)
$49.40 (55-75.000 gallons)
                                    A-6

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.... . TECHNICAL REPORT DATA , , *
(.. •„, (fleax read Instructions on, [he reverse before compleling) , ,
1. REPORT NO. ='» 2J. »-' •<"•<'# •"*!-.••{• iV **-'*•*' " •
£SW &//-?- 93-00 1 - .: '" ' • * ' • ' fc 1
4. TITLE AND SUBTITLE • ' ••'••'•
Small IWater System Byproducts
Treatment and Disposal Cost Document
7. AUTHOR(S)
DPRA Incorporated
9. PERFORMING ORGANIZATION NAME AND ADDRESS
DPRA Incorporated
IDUU First National Bank Building
332 Minnesota Street
St. Paul, MN 55101
12. SPONSORING AGENCY NAME AND ADDRESS
IS. SUPPLEMENTARY NOTES :.\:.
Ben Smith-Project Manager
1 ' • 3. RECIPIENT'S ACCESSION NO.
< • •
5. REPORT PAT;E^« _
April 1993
6. PERFORMING ORGANIZATION CODE
EPA/OGWDW .«/ ••:..- • • : .
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
.68-CQ-0020
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE

16. ABSTRACT ....... 	 -
This document provides a summary of techniques for projecting the
costs of frater treatment residuals treatment and disposal. It is a
generalized report developed for use in the evaluation of prospec-i '
tive drinking water regulatory alternatives.
17- KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS b.lDENTIFI!
drinking water treatment costs/
residuals management, cost
analysis ,
18. OlSTRIBUTtON STATEMENT 19. SECURH
20. SECURI1
!RS/OPEN ENDED TERMS C. COSATI Field/Croup

•Y CLASS (This Rfportl 21. NO. OF PAGES
131
V CLASS iTIiispafel 22. PRICE
6PA Form 2220-1 (Rev. 4-77)    PREVIOUS EDITION is OBSOLETE
                                                                                                                           J

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