EPA/600/R-00/088

October 2000

Arsenic Removal from Drinking Water 

by Ion Exchange and 

Activated Alumina Plants

by

Lili Wang

Abraham Chen

Keith Fields

Battelle

Columbus, OH 43201-2693

Contract No. 68-C7-0008

Work Assignment No. 3-09

for

Work Assignment Manager

Thomas J. Sorg

Water Supply and Water Resources Division

National Risk Management Research Laboratory

Cincinnati, OH 45268

National Risk Management Research Laboratory

Office of Research and Development

U.S. Environmental Protection Agency

Cincinnati, OH 45268
ii

Disclaimer

The information in this document has been funded by the United States Environmental Protection Agency (EPA) under Work Assignment (WA) No. 2-09 of Contract 

No. 68-C7-0008 to Battelle. It has been subjected to the Agency’s peer and administrative reviews and has been approved for publication as an EPA document. Mention of trade names or commercial products does not constitute an endorsement or 

recommendation for use.
iii

Foreword

The United States Environmental Protection Agency (EPA) is charged by Congress 

with protecting the Nation’s land, air, and water resources. Under a mandate of

national environmental laws, the Agency strives to formulate and implement action

leading to a compatible balance between human activities and the ability of natural 

systems to support and nurture life. To meet this mandate, EPA’s research program 

is providing data and technical support for solving environmental problems today and 

building a science knowledge base necessary to manage our ecological resources 

wisely, understand how pollutants affect our health, and prevent or reduce environmental risks in the future.

The National Risk Management Research Laboratory (NRMRL) is the Agency’s

center for investigation of technological and management approaches for reducing

risks from threats to human health and the environment. The focus of the

Laboratory’s research program is on methods for prevention and control of pollution 

to air, land, water, and subsurface resources: protection of water quality in public 

water systems; remediation of contaminated sites and groundwater; and prevention 

and control of indoor air. The goal of this research effort is to evaluate the

performance on a full-scale level of five processes, including coagulation/filtration,

lime softening, iron oxidation/filtration, ion exchange, and activated alumina, to

consistently remove arsenic over a sustained period of time (1 year).

This publication has been produced as part of NRMRL’s strategic long-term research 

plan. It is published and made available by EPA’s Office of Research and Development to assist the user community and to link researchers with their clients.

E. Timothy Oppelt, Director

National Risk Management Research Laboratory
iv

Abstract

This report documents treatment plant information as well as results of year-long sampling and analysis at two ion exchange (IX) plants (referred to as Plants A and B) and 

two activated alumina (AA) plants (referred to as Plants C and D), with capacities varying from 800 to 3,000 gallons per day (gpd). The objective of sampling and analysis 

was to evaluate the performance of the full-scale water treatment plants to consistently 

remove arsenic from source water. Additionally, data were collected to evaluate the 

chemical characteristics of residuals produced by these treatment processes.

The study was divided into three phases: source water sampling, preliminary sampling, and long-term evaluation. Source water sampling was conducted to evaluate

source water characteristics at each plant. Preliminary sampling was initiated in

August 1998 and consisted of four sampling events conducted at each facility on

either a weekly or biweekly basis to refine procedures for subsequent events during 

the third phase. Long-term evaluation consisted of weekly or biweekly sampling at

each facility from September 1998 to September 1999. Samples from resin regeneration were collected at Plant A from March to June 1999. Spent AA samples were 

collected at Plants C and D during the media change-out events in December 1998 

and May 1999, respectively.

Results from the long-term evaluation demonstrated that both the IX and AA systems 

are capable of achieving arsenic levels of less than 5 μg/L in the treated water, provided that the IX resin was regenerated or the AA medium was changed out before 

arsenic breakthrough occurred. The two IX systems had inlet arsenic concentrations 

between 45 and 65 μg/L [primarily As(V)]. When Plant A was operated beyond 3,000 

to 3,200 bed volumes (BV) of water, arsenic chromatographic peaking occurred.

Arsenic breakthrough was not observed at Plant B where an average 97% of removal 

efficiency was achieved, leaving only 0.8 to 4.5 μg/L arsenic in the finished water.

Both AA systems consisted of two parallel treatment trains with a roughing AA column followed by a polishing column in each train. The systems operated on a media 

throwaway basis. The average arsenic removal efficiencies achieved at Plants C and 

D were 87% and 98%, respectively. The raw water at Plant C (34 to 76 μg/L total

arsenic) contained approximately 0.3 to 28.8 μg/L As(III), which was nearly completely removed, even though no oxidation treatment was provided. The water at

Plant D contained slightly higher total arsenic concentrations (53.3 to 87 μg/L) but no 

As(III), which was consistently removed to less than 5 μg/L in the finished water. The 

AA media in the roughing tanks were exhausted and disposed of about every 1 to

1.5 years after treating approximately 9,600 BV at Plant C and 5,260 BV at Plant D.

The regeneration process at Plant A recovered from 67 to 86% of arsenic from the 

spent brine. The spent AA at Plants C and D passed the Toxicity Characteristic

Leaching Procedure (TCLP) test for metals including arsenic, and therefore was

disposed of as nonhazardous waste.
v

Contents

Foreword .................................................................................................................iii

Abstract ...................................................................................................................iv

Appendices..............................................................................................................vi

Figures .................................................................................................................. viii

Tables......................................................................................................................ix

Acronyms and Abbreviations....................................................................................xi

1.0 Introduction....................................................................................................... 1

1.1 Background................................................................................................. 1

1.1.1 General Chemistry of Arsenic ............................................................ 1

1.1.2 Determination of Arsenic Species ...................................................... 3

1.1.3 Treatment Technologies for Arsenic Removal.................................... 3

1.1.3.1 Ion Exchange........................................................................ 3

1.1.3.2 Activated Alumina................................................................. 4

1.1.4 Data Gaps......................................................................................... 5

1.2 Objectives................................................................................................... 5

1.3 Report Organization.................................................................................... 6

2.0 Conclusions ...................................................................................................... 7

3.0 Materials and Methods ...................................................................................... 8

3.1 General Project Approach........................................................................... 8

3.2 Preparation of Sampling Kits and Sample Coolers....................................... 9

3.2.1 Preparation of Arsenic Speciation Kits ............................................... 9

3.2.2 Preparation of Sample Coolers ........................................................ 10

3.3 Sampling Procedures................................................................................ 11

3.3.1 General Approach and Sampling Schedules .................................... 11

3.3.2 Arsenic Field Speciation Procedure ................................................. 11

3.3.3 Backwash, Spent Brine, and Spent AA Sampling Procedure............ 13

3.3.4 Sampling Procedure for Other Water Quality Parameters................. 14

3.4 Technical Approaches for Special Studies................................................. 14

3.4.1 Short-Term Special Study at Plant A................................................ 14

3.4.2 Short-Term Special Study at Plant D................................................ 16

3.5 Analytical Procedures ............................................................................... 17

4.0 Results and Discussion................................................................................... 19

4.1 Plant Selection.......................................................................................... 19

4.2 Plant A...................................................................................................... 19
vi

4.2.1 Plant A Description.......................................................................... 19

4.2.2 Initial Source Water Sampling.......................................................... 21

4.2.3 Preliminary Sampling....................................................................... 21

4.2.4 Long-Term Sampling....................................................................... 25

4.2.4.1 Arsenic ............................................................................... 25

4.2.4.2 Other Water Quality Parameters ......................................... 27

4.2.4.3 Backwash/Regeneration Wastewater.................................. 27

4.2.5 Special Study at Plant A .................................................................. 29

4.3 Plant B...................................................................................................... 31

4.3.1 Plant B Description.......................................................................... 31

4.3.2 Initial Source Water Sampling.......................................................... 32

4.3.3 Preliminary Sampling....................................................................... 32

4.3.4 Long-Term Sampling....................................................................... 35

4.3.4.1 Arsenic ............................................................................... 36

4.3.4.2 Other Water Quality Parameters ......................................... 36

4.4 Plant C...................................................................................................... 39

4.4.1 Plant C Description.......................................................................... 39

4.4.2 Initial Source Water Sampling.......................................................... 42

4.4.3 Preliminary Sampling....................................................................... 42

4.4.4 Long-Term Sampling....................................................................... 43

4.4.4.1 Arsenic ............................................................................... 43

4.4.4.2 Other Water Quality Parameters ......................................... 46

4.4.4.3 Spent AA Samples.............................................................. 50

4.5 Plant D...................................................................................................... 51

4.5.1 Plant D Description.......................................................................... 51

4.5.2 Initial Source Water Sampling.......................................................... 53

4.5.3 Preliminary Sampling....................................................................... 53

4.5.4 Long-Term Sampling....................................................................... 55

4.5.4.1 Arsenic ............................................................................... 55

4.5.4.2 Other Water Quality Parameters ......................................... 57

4.5.4.3 Spent AA Samples.............................................................. 57

4.5.5 Special Study at Plant D .................................................................. 61

4.5.5.1 Regeneration of Spent AA Using Caustic Solution............... 61

4.5.5.2 Adsorption of Arsenic onto AA............................................. 61

5.0 Quality Assurance/Quality Control................................................................... 64

5.1 Quality Assurance Objectives.................................................................... 64

5.2 Overall Assessment of Data Quality .......................................................... 64

5.2.1 Total Arsenic, Aluminum, Iron, and Manganese................................ 64

5.2.2 Water Quality Parameters ................................................................ 65

5.2.3 TCLP Metals .................................................................................... 65

6.0 References...................................................................................................... 66

Appendices

APPENDIX A: Plant A Data................................................................................... 69

A.1 Complete Analytical Results from Long-Term Sampling at Plant A............ 70

A.2 Technical Data on Purolite® A-300 ............................................................ 82

A.3 Water Usage Report................................................................................. 87

APPENDIX B: Plant B Data................................................................................... 89

B.1 Complete Analytical Results from Long-Term Sampling at Plant B............ 90
vii

APPENDIX C: Plant C Data .................................................................................101

C.1 Complete Analytical Results from Long-Term Sampling at Plant C...........102

C.2 Technical Data on DD-2 AA.....................................................................108

C.3 Water Usage Report................................................................................116

APPENDIX D: Plant D Data .................................................................................121

D.1 Complete Analytical Results from Long-Term Sampling at Plant D...........122

D.2 System Plumbing Diagram ......................................................................130

D.3 Water Usage Report................................................................................132
viii

Figures

Figure 1-1. Concentration–pH Diagrams for As(III) and As(V) ................................ 2

Figure 3-1. Example of Sample Bottle Label ........................................................ 11

Figure 3-2. Photographs of a Typical Sample Cooler (with Four Sample 

Compartments) and a Color-Coded Instruction Sheet ........................ 12

Figure 3-3. Instruction Sheet for Arsenic Field Speciation .................................... 15

Figure 4-1. Process Flow Diagram and Sampling Locations at Plant A................. 20

Figure 4-2. Cross Section of FiloxTM Filter and A300X IX Filter at Plant A.............. 22

Figure 4-3. Total Arsenic Analytical Results during Long-Term Sampling at 

Plant A............................................................................................... 26

Figure 4-4. Water Treated between Regenerations of the IX System at 

Plant A............................................................................................... 26

Figure 4-5. Inlet and Outlet Sulfate Concentrations and Percent Removal at 

Plant A............................................................................................... 28

Figure 4-6. Inlet and Outlet pH and Alkalinity Analytical Results at Plant A........... 28

Figure 4-7. TDS, Total Arsenic, and Sulfate during the IX System 

Regeneration at Plant A (June 13, 1999)............................................ 30

Figure 4-8. TDS, TSS, pH, and Flowrate during the IX System Regeneration 

at Plant A (June 13, 1999) ................................................................. 30

Figure 4-9. Process Flow Diagrams and Sampling Locations at Plant B............... 33

Figure 4-10. Photograph of the IX System at Plant B ............................................. 34

Figure 4-11. Total Arsenic Analytical Results during Long-Term Sampling at 

Plant B............................................................................................... 37

Figure 4-12. Inlet and Outlet Sulfate Analytical Results and Percent Removal 

at Plant B........................................................................................... 38

Figure 4-13. Inlet and Outlet Alkalinity and pH Analytical Results at Plant B........... 38

Figure 4-14. Process Flow Diagrams and Sampling Locations at Plant C............... 40

Figure 4-15. Cross Section of AA Tank at Plant C (Source: Aqua Specialties, 

1999)................................................................................................. 41

Figure 4-16. Arsenic Form and Species Analytical Results during Long-Term 

Sampling at Plant C........................................................................... 46

Figure 4-17. Total Arsenic Analytical Results during Long-Term Sampling at 

Plant C .............................................................................................. 47

Figure 4-18. Inlet and Outlet Alkalinity, pH, Fluoride, and Sulfate Analytical 

Results at Plant C.............................................................................. 49

Figure 4-19. Process Flow Diagrams and Sampling Locations at Plant D............... 52

Figure 4-20. Total Arsenic Analytical Results during Long-Term Sampling at 

Plant D .............................................................................................. 58

Figure 4-21. Inlet and Outlet Alkalinity, pH, Fluoride, and Sulfate Analytical 

Results at Plant D.............................................................................. 60

Figure 4-22. Kinetics of Arsenic Adsorption on AA Media....................................... 62

Figure 4-23. Arsenic Adsorption Isotherm on AA Media ......................................... 62
ix

Tables

Table 3-1. Sample Containers and Preservation Methods................................... 10

Table 3-2. Summary of Sampling Activities at Plants A, B, C, and D ................... 13

Table 3-3. Summary of Sampling Schedule for Plants A and B ........................... 13

Table 3-4. Summary of Sampling Schedule for Plants C and D........................... 14

Table 3-5. Sampling Schedule for the Special Study at Plant A........................... 16

Table 3-6. Summary of Analytical Methods for Arsenic Treatment Study............. 18

Table 4-1. Initial List of Treatment Facilities Identified for the Study .................... 19

Table 4-2. Typical Chemical and Physical Characteristics of Purolite A-300 

Anion Exchange Resin....................................................................... 23

Table 4-3. Regeneration Schedule of the A300X Resin Column at Plant A.......... 23

Table 4-4. Source Water Analytical Results at Plant A (June 9, 1998)................. 23

Table 4-5. Analytical Results from Preliminary Sampling at Plant A (August 

6, 1998 to August 26, 1998)............................................................... 24

Table 4-6. Summary of Arsenic Analytical Results at Plant A (September 1, 

1998 to June 17, 1999)...................................................................... 25

Table 4-7. Summary of Water Quality Parameter Analytical Results at 

Plant A (September 1, 1998 to June 17, 1999)................................... 27

Table 4-8. Summary of Analytical Results from Backwash/Regeneration 

Samples at Plant A (August 6, 1998 to June 13, 1999)....................... 29

Table 4-9. Percent Recoveries of Arsenic during the Resin Regeneration at 

Plant A............................................................................................... 31

Table 4-10. Typical Source Water Quality Data at Plant B (November 12, 

1995)................................................................................................. 32

Table 4-11. Source Water Analytical Results at Plant B (June 9,1998).................. 34

Table 4-12. Analytical Results from Preliminary Sampling at Plant B (August 6 

through 25, 1998) .............................................................................. 35

Table 4-13. Summary of Arsenic Analytical Results at Plant B (September 1, 

1998 to May 25, 1999)....................................................................... 36

Table 4-14. Summary of Water Quality Parameter Analytical Results at 

Plant B (September 1, 1998 to May 25, 1999).................................... 37

Table 4-15. Typical Characteristics of DD-2 Activated Alumina............................. 42

Table 4-16. Arsenic Concentrations (μg/L) from Quarterly Water Sampling at 

Plant C .............................................................................................. 42

Table 4-17. Source Water Quality Measurements at Plant C (December 30, 

1994)................................................................................................. 42

Table 4-18. Source Water Sampling Analytical Results at Plant C (June 10, 

1998)................................................................................................. 43

Table 4-19. Analytical Results from Preliminary Sampling at Plant C (August 5 

through September 16, 1998) ............................................................ 44

Table 4-20. Summary of Arsenic Analytical Results at Plant C (September 30, 

1998 to June 9, 1999)........................................................................ 45

Table 4-21. Summary of Water Quality Parameter Analytical Results at 

Plant C (September 30, 1998 to June 9, 1999)................................... 48
x

Table 4-22. Analytical Results of Spent AA Samples at Plant C............................ 50

Table 4-23. Typical Characteristics of CPN Activated Alumina.............................. 53

Table 4-24. Arsenic Concentrations (μg/L) from Monthly Water Sampling at 

Plant D (March 6, 1992 to December 29, 1999).................................. 54

Table 4-25. Typical Source Water Quality Measurements at Plant D..................... 55

Table 4-26. Source Water Sampling Analytical Results at Plant D (June 10, 

1998)................................................................................................. 55

Table 4-27. Analytical Results from Preliminary Sampling at Plant D (August 5 

through September 16, 1998) ............................................................ 56

Table 4-28. Summary of Arsenic Analytical Results at Plant D (September 30, 

1998 to September 1, 1999) .............................................................. 57

Table 4-29. Summary of Water Quality Parameter Analytical Results at 

Plant D (September 30, 1998 to September 1, 1999) ......................... 59

Table 4-30. Analytical Results of Spent AA Samples at Plant D............................ 61

Table 4-31. Analytical Results of Caustic Wash and Acid Digestion of Spent 

AA Samples at Plant D ...................................................................... 61
xi

Acronyms and Abbreviations

AA activated alumina

ADD average daily demand

As arsenic

AWWA American Water Works Association

BV bed volumes

DA disinfectant addition

DI distilled

DL detection limit

EBCT empty bed contact time

EDR electrodialysis reversal

EPA United States Environmental Protection Agency

GAC granular activated carbon

GFAAS graphite-furnace atomic-absorption spectrophotometer

GI gastrointestinal

gpd gallons per day

gpm gallons per minute

GW groundwater

HCl hydrochloric acid

HDPE high-density polyethylene

hp horsepower

ICP-MS inductively coupled plasma-mass spectrometry

ID identification

IN inlet sampling location

IOCS iron oxide-coated sand

IX ion exchange

MCL maximum contaminant level

MDL method detection limit

MS matrix spike

MSD matrix spike duplicate

MSDS material safety data sheet

NA not available

ND not detected

NOM natural organic matter

NS not sampled

NTU nephelometric turbidity units
xii

O&M operations and maintenance

OU outlet sampling location

pCi picocuries

POC point of contact

POE point of entry

ppm parts per million

psi pounds per square inch

PVC polyvinyl chloride

QA quality assurance

QAPP quality assurance project plan

QA/QC quality assurance/quality control

RPD relative percent difference

SBA strong-base anion

SDWA Safe Drinking Water Act

TCLP Toxicity Characteristic Leaching Procedure

TDS total dissolved solids

TOC total organic carbon

TSS total suspended solids

WA work assignment

WAM Work Assignment Manager

WBA weak-base anion

XRD x-ray diffraction

ZPC zero point charge

%R percent recovery
xiii

Acknowledgments

We wish to thank Paul Kempt and Jeffrey Folger of the Drinking Water Program,

Department of Human Services, the State of Maine, and Bernie Lucey of the Department of Environmental Services, the State of New Hampshire, for their assistance in 

system selection and participation in the studies. Sincere appreciation also is extended

to all facility personnel who assisted in collecting samples weekly or biweekly for up 

to 12 months. Their work on this project was uncompensated, making their superb

efforts even more remarkable. Personnel from all facilities are thanked for their hard 

work and dedication throughout the duration of this project. 

1

1.0 Introduction

This project consists, in part, of a field study in which two 

water treatment processes were evaluated for their ability and effectiveness at reducing arsenic (As) levels in

source water. The first part of the study involved collecting water samples from various locations at two ion exchange (IX) and two activated alumina (AA) plants. The 

second part of the study involved sampling and analysis 

of spent brine and spent AA media to determine the

quantities and chemical characteristics of residuals produced by the IX and AA treatment processes, respectively. This report describes the design and operation of 

four treatment plants and presents the analytical results 

of the samples collected from the plants during 1 year of 

operation.

1.1 Background

The Safe Drinking Water Act (SDWA) of 1974 mandates 

that the United States Environmental Protection Agency 

(EPA) identify and regulate drinking water contaminants 

that may have an adverse human health effect and that 

are known or anticipated to occur in public water supply 

systems. Arsenic is a naturally occurring contaminant

that has known adverse human health effects. Excessive 

amounts of arsenic can cause acute gastrointestinal (GI) 

and cardiac damage. Chronic doses can cause vascular 

disorders such as blackfoot disease (Chen et al., 1994a),

and epidemiological studies have linked arsenic to skin

and lung cancer (Tate and Arnold, 1990). In 1975, under 

the SDWA, the EPA established a maximum contaminant level (MCL) for arsenic at 0.05 mg/L. Since that

time, revision of the MCL has been considered a number 

of times, but no change has been made. The SDWA was 

amended in 1996 and these amendments require that

the EPA develop an arsenic research strategy and publish a proposal to revise the arsenic MCL by January

2000.

A draft arsenic research plan was prepared by the EPA 

in December 1996 and was finalized in February 1998

based upon a technical review by the EPA’s Board of

Scientific Counselors (EPA, 1998). The plan identifies

the research needed by the EPA to support a proposed 

revision of the arsenic MCL. The plan also identifies a

number of treatment technologies available for arsenic

removal, and recognizes the need to determine the

capability of these technologies to remove arsenic to a

level significantly lower than the current MCL.

This field study was conducted as part of an EPA Work 

Assignment (WA) to evaluate the performance of nine

full-scale water treatment plants to remove arsenic from 

drinking water. These nine plants represent five arsenic 

removal unit processes: conventional coagulation/filtration, lime softening, iron/manganese removal, IX, and

AA. Long-term operational data were developed in these 

studies to support the ability and effectiveness of these

treatment processes to consistently remove arsenic from 

drinking water.

1.1.1 General Chemistry of Arsenic

Arsenic is a common, naturally occurring drinking water 

contaminant that originates from arsenic-containing rocks

and soil and is transported to natural waters through

erosion and dissolution. Arsenic occurs in natural waters 

in both organic and inorganic forms. However, inorganic 

arsenic is predominant in natural waters and is the most 

likely form of arsenic to exist at concentrations that cause

regulatory concern (Edwards et al., 1998).

The valence and species of inorganic arsenic are dependent on the oxidation-reduction conditions and the

pH of the water. As a general rule of thumb, the reduced, 

trivalent form [As(III)] normally is found in groundwater 

(assuming anaerobic conditions) and the oxidized, pentavalent form [As(V)] is found in surface water (assuming

aerobic conditions); this rule does not always hold true for 

groundwater, where both forms have been found together 

in the same water source. Arsenate exists in four forms in 

aqueous solution, depending on pH: H3AsO4, H2AsO4

–

, 

HAsO4

2–

, and AsO4

3–

. Similarly, arsenite exists in five

forms: H4AsO3

+

, H3AsO3, H2AsO3

–

, HAsO3

2–

, and AsO3

3–

. 

As shown in Figure 1-1, which contains solubility diagrams for As(III) and As(V), ionic forms of arsenate dominate at pH>3, while arsenite is neutral at pH<9 and ionic
2

Figure 1-1. Concentration–pH Diagrams for As(III) and As(V)
3

at pH>9. Ion exchange and AA treatment technologies, 

often used by small drinking water systems for arsenic

removal, function by exchanging arsenate with counter

ions of an anionic resin (e.g., Cl–) and by adsorbing arsenate onto alumina granules, respectively. Therefore, the 

valence and species of soluble arsenic are very important in evaluating arsenic removal.

1.1.2 Determination of Arsenic Species

Although total arsenic can be effectively preserved in

field samples, presently no method exists to consistently 

preserve inorganic arsenic species in field samples.

Preservation of total arsenic is accomplished by acidifying the sample to pH<2 in the field. However, a high

level of uncertainty over exact levels of As(III) and As(V) 

exists when acids such as nitric acid (HNO3) or hydrochloric acid (HCl) are used to preserve inorganic species 

of arsenic. Interconversion of As(III) and As(V) in samples preserved with 0.05 N HCl have been reported to

occur within 1 day (Andreae, 1977). Another laboratory 

study conducted by Eaton et al. (1997) examined the

preservation of arsenic using humic acid, ascorbic acid, 

and HCl; the study concluded that no effective methods 

exist for preserving As(III) and As(V) in water samples. 

Some researchers have frozen samples to preserve the 

inorganic species of arsenic. However, freezing is neither 

a cost-effective nor a practical method for field sampling.

In response to the lack of techniques available for adequately preserving arsenic species, field speciation protocols have been developed by Ficklin (1983), Clifford et 

al. (1983), and Edwards et al. (1998). In each of these

studies, an anion exchange resin column was used for

field speciation of arsenic. Ficklin (1983) used a strong

anion exchange resin (Dowex 1 × 8, 100-200 mesh,

acetate form) in a 10 cm × 7 mm glass column to separate As(III) from As(V) in water samples that had been

filtered through a 0.45-μm membrane filter and acidified 

with 1% HCl. The resin was supplied in chloride form

and was converted to the acetate form. However, in the

protocol by Clifford et al. (1983), a chloride-form strong 

base anion resin (ASB-2, 30-60 mesh) was used to separate As(III) from As(V). In this method, the sample was not 

filtered or preserved with acid. Both Ficklin and Clifford

used a graphite-furnace atomic-absorption spectrophotometer (GFAAS) to determine the arsenic concentration.

More recently, Edwards et al. (1998) made the following 

modifications to Ficklin’s method: (1) Substituted 50-100 

mesh resin for the 100-200 mesh resin to allow faster

sample flow. (2) Used 12 cm × 15 mm polypropylene columns to improve safety and speed of sample treatment. 

(3) Used 0.05% H2SO4 instead of 1% HCl to acidify 

samples prior to resin treatment. Edwards et al.’s use of 

H2SO4 helped to prevent potential problems associated 

with overacidification of the sample, and also helped to

prevent Cl– from interfering with the inductively coupled

plasma-mass spectrometry (ICP-MS) analysis. The reported recoveries of As(III) and As(V) ranged from 80 to 

120% by Ficklin (1983), 95 to 117% by Clifford et al.

(1983), and 100 to 105% by Edwards et al. (1998). For 

this study, the decision was made to use a field speciation 

technique similar to that used by Edwards et al. (1998).

1.1.3 Treatment Technologies for 

Arsenic Removal

Several common treatment technologies are used for removal of inorganic contaminants, including arsenic, from 

drinking water supplies. Large-scale treatment facilities 

often use conventional coagulation with alum or iron salts 

followed by filtration to remove arsenic (Chen et al.,

1994b; Hering et al., 1996; Scott et al., 1995; and Sorg, 

1993). Lime softening and iron removal also are common, conventional treatment processes that can potentially remove arsenic from source waters (McNeill and

Edwards, 1997). Small-scale systems and point-of-entry 

(POE) systems often use IX and AA adsorption because 

of their ease of handling and sludge-free operations. Recently, iron-based adsorption media, such as granular

ferric hydroxide, have been developed and shown high

arsenic removal capacities in laboratory and pilot tests

(Joshi and Chaudhuri, 1996; Driehaus, et al. 1998). Their

full-scale applications, however, are still limited. Other

technologies that also have been used for arsenic removal include manganese greensand, reverse osmosis, 

electrodialysis reversal (EDR), nanofiltration, and adsorption on activated carbon.

This report focuses on the IX and AA treatment processes used primarily by small drinking water systems. 

Two additional reports also have been developed to

cover conventional treatment processes, including coagulation/filtration and lime softening (Battelle, 1999) and 

iron removal (Battelle, 2000a).

1.1.3.1 Ion Exchange

Ion exchange is a physical/chemical process in which

ions held electrostatically on the surface of a solid phase 

are exchanged for ions of similar charge in a solution (i.e., 

drinking water). The solid is typically a synthetic anion

exchange resin which is used to preferentially remove

particular contaminants of concern. Ion exchange is commonly used in drinking water treatment for softening (i.e., 

removal of calcium, magnesium, and other cations in exchange of sodium), as well as removing nitrate, arsenate,

chromate, and selenate from municipal water (Clifford,

1999). Due to its higher treatment cost compared to conventional treatment technologies, IX application is limited 

primarily to small/medium-scale and POE systems.
4

Anion exchange resins come in two classes, strong-base 

anion (SBA) and weak-base anion (WBA). The quarternary ammonium functional groups (−R3

 ́N

+

 where R ́

represents organic radicals such as CH3) on the SBA

resins are strongly basic and ionized to act as ion

exchangers over the pH range of 0 to 13. The WBA

resins are useful only in the acidic pH region where the 

primary, secondary, and tertiary amine functional groups 

are protonated to form positively charged exchange sites 

for anions. Both SBA and WBA resins may be present in 

the hydroxide or chloride form. Typically, SBA resins are 

used for arsenic removal because they tend to be more 

effective over a larger pH range than WBA resins.

Ion exchange does not remove As(III) because As(III)

occurs predominantly as an uncharged ion (H3AsO3) in

water with a pH value of less than 9.0 (Ficklin, 1983;

Clifford, 1999). The predominant species of As(V),

H2AsO4

−

 and HAsO4

2−

, are negatively charged, and thus 

are removable by IX. If As(III) is present, it is necessary 

to oxidize As(III) to As(V) before removal by IX (Fox,

1989; Clifford and Lin, 1986).

To remove arsenic from drinking water, water is passed 

through one or more IX resin beds. Arsenate ions

(H2AsO4

−

and HAsO4

2 −

) and several other anions (most

notably sulfate) are preferentially removed according to

the order of preference for exchange. When all available 

sites on the resin have been exhausted, the bed is regenerated with a brine solution (chloride exchange).

The efficiency of the IX process for arsenic removal is

strongly affected by competing ions, such as total dissolved solids (TDS) and sulfate (Clifford 1999). Other

factors affecting the use of the IX process include empty 

bed contact time (EBCT) and spent regenerant disposal. 

Competition from background ions for available IX sites

can greatly affect the efficiency and economics of IX systems. The level of these background ions often determines the applicability of the IX process at a particular

site. The following selectivity sequence was established 

for SBA resins (Clifford, 1999):

SO4

2−

 > NO3

−

 > HASO4

2−

 > NO2

−

, Cl− > H2ASO4

−

, HCO3

− 

>> 

Si(OH)4, H3ASO4

Therefore, high sulfate and TDS levels can significantly

reduce arsenic removal efficiency (Clifford and Lin, 1986, 

1991). In general, the IX process is not economically 

attractive if source water contains high TDS (>500 mg/L) 

and sulfate (>150 mg/L) (Clifford, 1999). Also, the presence of Fe(III) in feed water can affect arsenic removal

by forming Fe(III)-arsenic complexes, which cannot be

removed by IX resins (Clifford et al., 1998).

When the sulfate concentration is high, sulfate may displace previously sorbed ions (such as arsenate) from a

resin bed, thereby causing higher arsenic concentrations 

in the effluent than in the influent. This phenomenon is

called chromatographic peaking (dumping), and is a potentially risky situation when toxic ions such as arsenic 

are involved. To avoid peaking, the resin bed must be

monitored and regenerated well in advance of the onset 

of the peaking.

For chloride-form resins, concentrated NaCl solution commonly is used as a regenerant. Arsenic elutes readily 

from IX columns mainly because it is subject to selectivity reversal in a high ionic strength (>1 M) solution 

(Clifford and Lin, 1995). The regenerated resin then is

ready for another exhaustion cycle.

Clifford et al. (1998) found that dilute regenerants at 0.5-

1.0 M were more efficient than concentrated ones at

2.0-4.0 M for eluting arsenic (in terms of the ratio of regenerant equivalent to resin equivalent). However, dilute 

regenerants could require longer regeneration time and

produce larger volumes of spent regenerant.

1.1.3.2 Activated Alumina

AA adsorption is a physical/chemical process by which

ions in solution (i.e., drinking water) are removed by the 

available adsorption sites on an oxide surface. AA is

usually prepared through dehydration of Al(OH)3 at high 

temperatures and consists of amorphous and gamma

alumina oxide (Chen and Snoeyink, 1987). AA is used

primarily in packed beds to remove contaminants such

as fluoride, arsenic, selenium, silica, and natural organic 

matter (NOM). To remove contaminants, feed water is

passed continuously through one or more AA beds. When

all available adsorption sites are occupied, the AA media 

may be regenerated with a strong base, NaOH, or simply disposed of.

Many studies have shown that AA is an effective treatment 

technique for arsenic removal. Factors such as arsenic

oxidation state, pH, competing ions, and EBCT significantly affect arsenic removal. Other factors affecting the 

use of the AA process include regeneration practice, 

spent regenerant disposal, and alumina disposal. The following subsections briefly discuss some of these factors.

Effects of Arsenic Oxidation State. Like all other treatment technologies, the AA process is more effective in

removing As(V) than As(III). In a study by Frank and

Clifford (1986), an AA column treating water containing

0.1 mg/L As(V) was able to treat about 23,400 BV before 

the effluent arsenic levels reached 0.05 mg/L. A similar

column treating water containing 0.1 mg/L As(III), however, began to break through after treating only 300 BV 
5

of water. Therefore, preoxidation of As(III) to As(V) often 

is recommended when treating water containing As(III).

Effect of pH. The AA process is sensitive to pH. Anions 

(including arsenic) are best adsorbed below pH 8.2, a

typical zero point charge (ZPC) for AA. Below this pH,

the AA surface has a net positive charge that can be

balanced by adsorbing anions, such as hydroxide, fluoride, and arsenate. Several studies have shown that the 

optimum pH for arsenic removal ranges from 5.5 to 6.0 

(Singh and Clifford, 1981; Rosenblum and Clifford, 1984).

The arsenic capacity of AA deteriorates as the pH increases from 6.0 to 9.0 (Hathaway and Rubel, 1987).

Column studies conducted by Clifford and Lin (1991)

also showed a similar trend. For a target arsenic effluent 

concentration of 0.05 mg/L, a column operating at pH

6.0 was able to treat 8,760 BV of water, but a column

operating at pH 7.3 treated only 1,944 BV. 

Some small AA systems are operated on a media throwaway basis without pH adjustments for an optimal run

length. These systems save costs for pH adjustments 

and for operations and maintenance (O&M) related to

media regeneration. Upon breakthrough, however, AA

must be replaced and the spent AA must pass the Toxicity Characteristic Leaching Procedure (TCLP) to be

disposed of as a nonhazardous waste.

Effect of Competing Ions. Like IX resins, AA exhibits

preferences for certain ions. The order of preference,

however, can be quite different from those of IX resins. 

Activated alumina appears to have a higher preference

for arsenic than for most competing ions in water (including sulfate) (Clifford, 1999; Vagliasindi et al., 1996). Further, as indicated by the general selectivity sequence

shown below (Clifford, 1999), AA preferentially adsorbs

H2AsO4

−

 over H3AsO3 [As(III)]:

OH−

 > H2AsO4

−

> Si(OH)3O

−

 > F−> HSeO3

−

 > TOC > 

SO4

2 −

> H3AsO3

Several studies have examined the effects of some of

these competing ions. Vagliasindi et al. (1996) found that 

increasing sulfate from 0 to 100 mg/L had only a small

impact on the sorption of As(V), and the presence of 

chloride did not affect As(V) removal at all. The addition 

of 4 mg/L dissolved organic matter, however, reduced

As(V) sorption about 50%. Also, the addition of 360 mg/L 

of sulfate and almost 1,000 mg/L TDS reduced the

sorption of As(V) by approximately 50%, compared to

sorption from deionized (DI) water (Clifford and Lin,

1986). Rosenblum and Clifford (1984) also reported that 

sulfate and chloride significantly reduced AA’s ability to

remove arsenic from water. For water containing approximately 530 mg/L of chloride, the arsenic removal was

16% lower than that for a nonchloride-containing water. 

And for water containing 720 mg/L sulfate, the arsenic

removal was 50% lower than that for a nonsulfatecontaining water.

Effect of Empty Bed Contact Time. Simms and Azizian 

(1997) conducted AA column tests using 3-, 6-, and 12-

minute EBCTs and found a linear relationship between

EBCT and arsenic adsorption. However, Vagliasindi and 

Benjamin (1997) found that arsenic adsorption increased 

only slightly with increasing EBCTs.

1.1.4 Data Gaps

The removal of arsenic from drinking water by IX and AA 

has been studied extensively at laboratory- and pilotscale levels. Although some short-term full-scale evaluations have been performed for both treatment processes, 

few data exist on the capability of these processes to

reduce arsenic on a sustained basis. Thus, a need exists 

to determine the effectiveness of IX and AA to produce 

drinking water containing low levels of arsenic on a longterm basis and under varying operational and seasonal 

conditions.

Another data gap that exists is the production and disposal of spent regenerants and spent media. Due to high 

arsenic concentrations in the spent regenerants, direct

discharge to a sanitary sewer may not be always possible depending on the local regulations. Therefore, the

spent regenerants may need to be treated prior to disposal. Arsenic can be removed from regenerants by

coprecipitation with ferric iron or aluminum salts, and the 

arsenic-laden sludge can be subsequently dried and

landfilled if toxicity limits are not exceeded. Brine reuse

has recently been studied to examine its potential in

reducing the brine consumption and the discharge volume (Clifford et al., 1998). Also, the spent AA media

from throwaway systems may be landfilled as a nonhazardous waste if they pass the TCLP tests.

Few data currently exist on the amounts and the chemical compositions of residuals generated by the IX and

AA processes and on the methods that are environmentally acceptable for their disposal. Therefore, information 

needs to be collected on the chemical characteristics of 

the wastes produced by these processes.

1.2 Objectives

The primary objective of this study was to evaluate the

effectiveness of IX and AA systems to consistently

reduce arsenic concentrations in source water to low

levels. This report presents the results of weekly and

biweekly monitoring for approximately 1 year at two IX

plants and two AA plants.
6

The second objective of this study was to examine residuals produced during IX and AA treatment processes. 

Information was collected on the quantities and chemical 

characteristics of the wastes produced by these two

treatment processes.

The third objective of this study was to conduct two shortterm special studies to collect more definitive data to help 

explain unusual performance conditions or variations observed during long-term sampling at the IX and AA plants.

1.3 Report Organization

Section 1.0 provides background information for this field 

study and project objectives. Section 2.0 of this report

presents the conclusions from the study of the two IX

plants and two AA plants. Section 3.0 describes the

materials and methods used to conduct this study.

Section 4.0 discusses the results of the study and Section 5.0 provides specific information on quality assurance/quality control (QA/QC) procedures. Section 6.0 is 

a list of references cited in the text. Appendices A, B, C, 

and D present the complete set of analytical data and

miscellaneous information collected at Plants A, B, C,

and D, respectively, during long-term sampling.
7

2.0 Conclusions

The EPA currently is in the process of revising the arsenic MCL. A proposed arsenic MCL of 0.005 mg/L was

published in the Federal Register on June 22, 2000,

which is significantly lower than the current MCL of

0.05 mg/L. The low arsenic standard will inevitably affect 

many water treatment facilities with high arsenic concentrations in water supplies. Therefore, there is a need 

to evaluate the ability of existing treatment processes to 

consistently remove arsenic to low levels. The primary

objectives of this project were to document arsenic removal at two IX plants (Plants A and B) and two AA

plants (Plants C and D), and to assess chemical characteristics of residuals (spent brine and spent AA) at these 

treatment plants.

The primary focus of this study was the long-term evaluation of arsenic removal at the IX and AA plants. The

two IX plants demonstrated the ability to consistently 

achieve low levels of arsenic in the treated water (i.e.,

<5 μg/L) when the resin was properly regenerated. During the long-term study, Plants A and B achieved an

average of 53% and 97% arsenic removal, respectively. 

Initially, Plant A was regenerated once every 3 months; 

however, early arsenic breakthrough (50 μg/L) was detected in the treated water before the scheduled regeneration of the system. Also, chromatographic effect was 

observed, which likely was caused by sulfate in the

source water, resulting in effluent arsenic concentrations 

exceeding the influent levels. After a run length to arsenic breakthrough (50 μg/L) of approximately 3,000-3,200 

BV was determined, a monthly regeneration schedule 

was recommended and implemented at Plant A. As

such, early arsenic breakthrough did not happen again.

During the Plant A study, up to 23.4 μg/L of arsenic was 

detected immediately after the regeneration. Further

study revealed that this “leakage” actually was due to an 

artifact caused by the arsenic already present in the

2,400-gal storage tank located just upstream from the

sampling point. At Plant B, noticeable arsenic breakthrough was not detected throughout the course of the

study because of the frequent column regeneration (i.e., 

once every 6 days). As(III) removal was not observed at 

either plant because source water contained primarily

As(V).

The two AA plants evaluated also were capable of

achieving arsenic levels of 5 μg/L or less in the treated 

water, provided that the AA was changed out at the

proper time before arsenic breakthrough. Both AA plants 

are operated on a media throwaway basis under raw pH 

conditions (i.e., pH 8.0 to 8.6). Arsenic removal efficiencies achieved at Plants C and D during the long-term 

study were 87% and 98%, respectively. The AA medium 

in the roughing tanks was exhausted and disposed of

about every 1 to 1.5 years after treating 9,600 BV at

Plant C and 5,260 BV at Plant D. Near complete As(III) 

removal by AA was observed at Plant C, as the source 

water contained 0.3 to 28.8 μg/L As(III), and the finished 

water contained less-than-detect levels of As(III).

The secondary focus of this study was on residual production and the chemical characteristics of the residuals.

Data from resin regeneration at Plant A demonstrated that 

the regeneration efficiency at Plant A ranged from 67% to 

86%, comparable with literature data. None of the spent

AA sampled at Plants C and D qualified as a hazardous

waste based on TCLP testing for metals including arsenic. 

Therefore, the spent AA was disposed of as nonhazardous 

waste. Using caustic wash, it was possible to recover

approximately 50% of the arsenic from the spent AA at

Plant D. The AA capacity obtained from the column operation at Plant D (0.25 g/kg) was less than that obtained

from the batch adsorption isotherm (1.09 g/kg).
8

3.0 Materials and Methods

This section discusses the materials and methods used 

for performing the source water, preliminary, and longterm sampling and data collection at two IX plants and

two AA plants. Section 3.1 describes the general project 

approach. Section 3.2 describes the preparation of arsenic speciation kits and sample coolers. Section 3.3 provides detailed sampling procedures. Section 3.4 discusses

the technical approach for the short-term special studies. 

Section 3.5 discusses pertinent analytical procedures.

3.1 General Project Approach

Several consecutive tasks were performed to accomplish

the project objectives described in Section 1.2. These

tasks involved the following activities:

• Select treatment plants and conduct an initial site 

visit to collect source water samples at each 

selected plant

• Prepare a preliminary sampling and data collection 

plan for each plant

• Finalize the sampling and data collection plan after 

completion of four weekly (Plants A and B) or 

biweekly (Plants C and D) preliminary sampling 

events at each plant 

• Implement the final sampling and data collection 

plan with weekly or biweekly sampling events at 

each plant for 9 months up to one full year

• Select treatment plants with unusual performance 

conditions or variations and conduct two short-term 

special studies.

For initial plant selection, the EPA Work Assignment

Manager (WAM) initiated contacts with representatives

of the states of Maine and New Hampshire for smallscale IX and AA systems currently in operation. Two IX 

plants (designated as Plants A and B) and three AA

plants (designated as Plants C, D, and E) were selected 

for initial site visits and source water sampling. The information collected during the site visits, including the concentration and speciation of arsenic in each source water,

was tabulated and used as the basis for the final plant

selection.

Following the final plant selection (Plants A, B, C, and D 

were selected), a preliminary sampling and data collection 

plan was prepared for each plant to document the plant’s 

operation and performance for arsenic removal and the

critical parameters that would impact the removal. Each 

preliminary plan also described the data collection effort to 

characterize the residuals produced by the treatment

process. The approved preliminary plans were implemented at Plants A and B during a 4-week trial period,

and Plants C and D during an 8-week trial period. Two

Battelle staff members revisited the plants during the first 

week of the trial period to perform sampling, conduct

training of plant support personnel, and establish/coordinate all required logistics (such as receiving/shipping of 

sample coolers, chain-of-custody coordination, communication methods, and emergency/contingency plans). The

remaining three sampling events during the preliminary 

sampling were performed by a designated point of contact (POC) or an alternate at each plant. The experience 

gained during the trial period was used to finalize the

long-term sampling and data collection plans.

All water and residual samples were collected and analyzed in accordance with the Category III Quality Assurance Project Plan (QAPP) prepared by Battelle (1998)

for this project. Water samples (source water and treated 

water) were collected weekly from Plants A and B. Water 

samples were collected biweekly from Plants C and D at 

the following four locations: (1) inlet; (2) after the first AA 

tank of train 1; (3) after the second AA tank of train 1;

and, (4) after treatment through both trains. During the

preliminary and long-term sampling phases, field arsenic 

speciation was conducted once every 4 weeks for Plants 

A and B and once every 8 weeks for Plants C and D.

Starting from March 1999, backwash and spent brine

samples were collected from Plant A when regeneration 

was performed once every 4 weeks. Spent AA samples 

also were collected during the media change-out at

Plant C in December 1998 and at Plant D on May 25,

1999.
9

All sample containers and arsenic speciation kits were

prepared and sent in coolers on a weekly or biweekly

basis from Battelle to each plant via Federal Express.

The coolers were returned to Battelle immediately after

the sample collection had been completed. Analyses of

arsenic, aluminum, iron, and manganese in water were

conducted by Battelle’s ICP-MS laboratory. Wilson Environmental Laboratories of Westerville, OH, was subcontracted to perform all other chemical analyses. Battelle

coordinated all sampling logistics.

3.2 Preparation of Sampling Kits 

and Sample Coolers

All arsenic speciation kits and sample coolers were

prepared at Battelle. The following sections describe the 

relevant preparation procedures.

3.2.1 Preparation of Arsenic 

Speciation Kits

The arsenic field speciation method used an anion

exchange resin column to separate the soluble arsenic

species, As(V) and As(III). A 250-mL bottle (identified as 

bottle A) was used to contain an unfiltered sample,

which was analyzed to determine the total arsenic concentration (both soluble and particulate). The soluble

portion of the sample was obtained by passing the unfiltered sample through a 0.45-μm screw-on disc filter to

remove any particulate arsenic and collecting the filtrate 

in a 125-mL bottle (identified as bottle B). Bottle B contained 0.05% (volume/volume) ultra-pure sulfuric acid to 

acidify the sample to about pH 2. At this pH, As(III) was 

completely protonated as H3AsO3, and As(V) was present in both ionic (i.e., H2AsO4

–

) and protonated forms (i.e.,

H3AsO4) (see Figure 1-1). A portion of the acidified sample in bottle B was run through the resin column. The

resin retained As(V) and allowed As(III) (i.e., H3AsO3) to 

pass through the column. (Note that the resin will retain 

only H2AsO4

–

 and that H3AsO4, when passing though the 

column, will be ionized to H2AsO4

–

 due to elevated pH

values in the column caused by the buffer capacity of

acetate exchanged from the resin.) The eluate from the 

column was collected in another 125-mL bottle (identified as bottle C). Samples in bottles A, B, and C were

analyzed for total arsenic using ICP-MS. As(III) concentration was the total arsenic concentration of the resintreated sample in bottle C. The As(V) concentration was 

calculated by subtracting As(III) from the total soluble

arsenic concentration of the sample in bottle B.

Arsenic speciation kits were prepared in batch at Battelle 

based on a method modified from Edwards et al. (1998). 

Each arsenic speciation kit contained the following:

• One anion exchange resin column

• Primary and duplicate A, B, and C bottles

• One 400-mL disposable beaker

• Two 60-mL disposable syringes

• Several 0.45-μm syringe-adapted disc filters.

Each speciation kit was packed in a plastic zip-lock bag 

along with latex gloves and a step-by-step speciation

sampling instruction sheet. All chemicals used for preparing the kits were of analytical grade or higher. The

arsenic speciation kits were prepared according to the

following procedures:

• Resin Preparation. Before packing into columns, 

the anion exchange resin (Dowex 1-X8, 50-100 

mesh) was converted from the chloride form (as 

supplied by Supelco) to the acetate form according 

to the method used by Edwards et al. (1998). First, 

1 kg of the resin was placed in a 3-L beaker. One 

liter of 1 N NaOH was then added to the resin, 

stirred for an hour using an overhead stirrer, and 

drained. This NaOH rinse was repeated sequentially for three times. The NaOH-treated resin then 

was rinsed with two 1-L batches of reagent-grade 

water, followed by three acetic acid rinses. Each 

acetic acid rinse consisted of adding 1 L of 1 N 

reagent grade acetic acid to the resin, stirring for 

5 minutes, and draining the spent acid. The acetic 

acid-treated resin was subsequently rinsed with 

3-L batches of reagent-grade water. The resin 

slurry was stored in a 2-L bottle and kept moist 

until use.

• Anion Exchange Column Preparation. The resin 

columns used were 12 cm × 15 mm in size and 

made of polypropylene (Bio-Rad Laboratories, 

CA). Each column was slurry packed with about 

20 g (drained weight) of the prepared resin, yielding a resin depth of approximately 10.5 cm. The 

column was sealed with two plastic caps (one each 

on top and bottom) to prevent contamination and 

retain moisture prior to use.

• Sample Bottles. VWRbrandTM TraceCleanTM highdensity polyethylene (HDPE) sample bottles (250 

and 125 mL) were used to prepare bottles A, B, 

and C. Bottles A and C were spiked with 500 and 

250 μL of concentrated ultra-pure nitric acid 

(HNO3), respectively; and bottle B was spiked with 

1.25 mL of 5% (volume/volume) ultra-pure sulfuric 

acid (H2SO4). H2SO4 was used to acidify the sample 

in bottle B because chloride (Cl–) in HCl could interfere with the ICP-MS arsenic detection and HNO3

(an oxidizing agent) could damage the resin or 

form nitric acid-arsenic redox couples (Edwards et 

al., 1998).
10

• Beaker, Syringes, and Filters. One 400-mL 

disposable plastic beaker was used to collect a 

water sample. Samples were filtered using 60-mL 

disposable plastic syringes with 0.45-μm screw-on 

disc filters. All disposable beakers, syringes, and 

filters were rinsed with DI water and air-dried 

before being packed into the sampling kits.

3.2.2 Preparation of Sample Coolers

Sample containers for analysis of all water quality

parameters except for total As, Al, Fe, and Mn were provided by Wilson Environmental Laboratories. These containers were new, rinsed with DI water, allowed to air dry, 

and contained appropriate preservatives before being

delivered to Battelle. These bottles were labeled with the 

letter D, E, F, or G, designating the specific analysis to

be performed. Table 3-1 lists the sample container size 

and type (for water and solid samples), sample preservation used, analysis to be performed, and holding time. 

All sample containers were labeled prior to shipment.

Figure 3-1 presents an example sample bottle label. The 

sample identification (ID) consisted of five parts, including a two-letter code for a water treatment plant, the

sampling date (mm/dd/yy), a two-letter code for a specific sampling location (e.g., IN for inlet water, TA for

after the first tank, TB for after the second tank, and OU 

for outlet water), a one-letter code (A through G) designating the analyses to be performed (see Table 3-1), 

and a code indicating whether the sample was a primary 

sample or a field duplicate sample. A field duplicate was 

identified by adding a “dup” to the label and a primary

sample used no additional coding.

After the sample bottles were labeled, they were placed in 

coolers subdivided into two or four compartments, each 

corresponding to a specific sampling location at each

plant. Color coding was used to identify sampling locations and all associated sample bottles. For example, red, 

blue, green, and yellow were used to designate sample

locations for inlet, TA, TB, and outlet locations, respectively. Other sampling and shipping-related materials, including latex gloves, chain-of-custody forms, prepaid Federal 

Express air bills, sampling instructions, ice packs, and

bubble wrap, also were packed into coolers. When arsenic speciation or residual samples were to be collected, 

arsenic speciation kits or bottles for residual samples also 

were included in the cooler. After preparation, sample

coolers were sent to all plants every Thursday via Federal

Table 3-1. Sample Containers and Preservation Methods

Container Size Container Type Preservation Method Analyte Hold Time

Arsenic Speciation Samples

250 mL (A) certified clean HDPE 

bottles

4°C 

HNO3

 for pH <2 Total As, Al, Fe, Mn 6 months

125 mL (B) certified clean HDPE 

bottles

4°C

0.05 % H2SO4 

Dissolved As, Al, Fe, Mn 6 months

125 mL (C) certified clean HDPE 

bottles

4°C 

HNO3

 for pH <2 Dissolved As, Al, Fe, Mn 6 months

Backwash/Spent Brine Samples

pH immediate 250 mL (D) plastic 4°C TSS 7 days

250 mL (A) certified clean HDPE 

bottles

4°C 

HNO3

 for pH <2 Total As, Al, Fe, Mn 6 months

Water Quality Parameter Samples

Alkalinity 14 days 250 mL (D) plastic 4°C pH immediate

Turbidity 48 hours

250 mL (D) plastic 4°C Sulfate 28 days

Fluoride 28 days

250 mL (E) plastic 4°C 

HNO3

 for pH<2 Hardness 6 months

250 mL (F) plastic 4°C

H2

 SO4 for pH <2 NO3

–

/NO2

–

28 days

500 mL (G) glass 4°C

H2SO4

 for pH<2 TOC 14 days

Spent AA Samples

8 oz (AA1) glass jar 4°C Total As, Al, Fe, Mn 6 months

4 oz (AA2) glass jar 4°C Water content, pH,

TCLP metals 14 days

4 oz (AA2) glass jar 4°C Water content, pH,

TCLP metals 14 days

TOC = total organic carbon.

TSS = total suspended solids.
11

Figure 3-1. Example of Sample Bottle Label

Express for the following week’s sampling activity. Figure 3-2 shows photographs of a sample cooler with four 

sample compartments and a color-coded instruction 

sheet placed under the lid of the cooler.

3.3 Sampling Procedures

3.3.1 General Approach and 

Sampling Schedules

One Battelle staff member and the EPA WAM traveled to 

each plant to collect source water samples, meet plant

operators, solicit interest in participating in this year-long 

sampling program, and obtain system design and operating information and historical water quality data. After

the plant selection, two Battelle staff members returned

to each plant to collect samples at selected sampling 

locations and train the plant operator or a designated 

POC to perform sampling and field arsenic speciation. 

The remaining three preliminary sampling events and

long-term sampling events then were conducted by the

trained plant personnel. Residuals sampling, including 

monthly collection of backwash and spent brine samples 

during the resin regeneration at Plant A and a single

spent AA sampling event at Plants C and D also were collected by the designated plant employees with detailed 

instructions provided by Battelle over the telephone.

Table 3-2 summarizes the sampling activities conducted 

at each plant.

During the preliminary and long-term sampling, sample

collection was conducted on a 4- or 8-week cycle, with

each week having unique sampling requirements. 

Tables 3-3 (for Plants A and B) and 3-4 (for Plants C and 

D) summarize the schedules for the initial source water, 

the preliminary, the long-term, and the residual sampling.

After receipt of the weekly sample coolers, plant personnel began sampling activities at the selected locations on 

the scheduled dates. Upon completion, all sample bottles were sealed with tape and placed in the same coolers for return shipment to Battelle by Federal Express.

Upon receipt of the samples, the designated Battelle

sample custodian immediately examined and compared

the conditions of all sample bottles with those indicated

in the chain-of-custody forms. Samples then were distributed to Battelle’s ICP-MS laboratory and Wilson Environmental Laboratories for chemical analyses.

Throughout the duration of the study, Battelle staff maintained frequent telephone contact with each plant to

ensure that all sampling activities were carried out as

planned. For example, after the scheduled arrival of

sample coolers, one Battelle staff member would call to 

confirm the receipt of the coolers, answer any questions, 

discuss irregular plant operations and unusual observations, and propose/suggest corrective actions. When

available, results of the chemical analyses also were discussed over the telephone and data sheets were sent

quarterly to the plants for review. Also, water usage and 

historic water quality data were sent along with sample

coolers or transmitted via facsimile to Battelle for information/evaluation.

3.3.2 Arsenic Field Speciation Procedure

The procedures for performing the field arsenic speciation are shown in Figure 3-3 and are described as follows (“steps” refer to Figure 3-3):

• Bottle A: A 400-mL disposable plastic beaker was 

rinsed thoroughly with the water to be sampled. 

The beaker then was used to collect a water sample and to fill bottle A with an aliquot of that sample 

(step 3). If necessary, additional sample water was 

added to the beaker after bottle A was filled to 

complete arsenic speciation sampling.

Bottle B: A 60-mL disposable plastic syringe was 

rinsed thoroughly with the water in the plastic 

beaker by completely filling and emptying the 

syringe (step 4). After attaching a 0.45-μm disc 

filter and wasting about 10 drops of the filtrate, the 

syringe was used to filter the water sample from 

the beaker and fill bottle B. Bottle B then was 

tightly capped and vigorously shaken for about 

15 seconds to allow thorough mixing of the filtered 

water and sulfuric acid (step 5).

• Bottle C: The protective caps on the top and bottom of a resin column were removed and approximately 40 mL of the water in bottle B was wasted 

through the column. This initial 40 mL was used to 

displace the water in the resin column and to 

ensure attainability of a representative sample from 

the column. The resin column then was positioned 

AP-09/15/98-IN-B-DUP

Date: 09/15/98 Time: 11a.m.

Collector’s Name: Sample Collector

Location: Any Plant

Sample ID: AP-02/15/98-PF-B-DUP

Send to: Battelle

Analysis Required: Total As, Al, Fe, and Mn 

Preservative: 0.05% sulfuric acid
12

Figure 3-2. Photographs of a Typical Sample Cooler (with Four Sample Compartments) and a 

Color-Coded Instruction Sheet

over bottle C, and the water from bottle B was 

passed through the column until approximately 

20 mL of the resin-treated sample had been 

collected in bottle C (step 6).

• The procedures described under the above three 

bullets were repeated to obtain duplicate bottles A, 

B, and C.

• Upon completion, the individual performing the 

speciation signed a chain-of-custody form (step 7). 

All sample bottles (for arsenic speciation and other 

water quality parameters), along with the signed 

chain-of-custody form, were placed in the original 

cooler with ice packs and shipped via Federal 

Express to Battelle (step 8).
13

Table 3-2. Summary of Sampling Activities at Plants A, B, C, and D

Sampling Activities

Sampling 

Frequency Plants A and B Plant C Plant D

Initial source water sampling Once 06/10/98 06/11/98 06/11/98

Preliminary sampling Weekly or 

biweekly

08/06/98 through 08/26/98 08/05/98 through 09/16/98 08/05/98 through 09/16/98

Long-term sampling Weekly(a) or 

biweekly

09/01/98 through 06/17/99 09/30/98 through 06/09/99 09/30/98 through 09/01/99

Spent AA sampling Once Not applicable 12/29/98 05/25/99

Backwash and spent brine 

sampling

4-week 03/21/99 through 06/13/99 

(Plant A only)

Not applicable Not applicable

(a) Except for the holiday weeks of 11/23/98, 12/21/98, and 12/28/98.

3.3.3 Backwash, Spent Brine, and 

Spent AA Sampling Procedure

Backwash and spent brine samples were collected at

Plant A on a monthly basis starting on March 21, 1999. 

When the IX tank was regenerated, eluate from each of 

the four regeneration steps (i.e., backwash, brine regeneration, slow rinse, and fast rinse) was collected alternately in two 32-gal buckets through a garden hose. A

stopwatch was used to measure the time elapsed to

assist in determining the start and end points of each

regeneration step. At the end of each regeneration step, 

the content in the bucket was thoroughly mixed, and a

portion of the water was transferred to sample bottles for 

pH, TSS, total As, Al, Fe, and Mn analyses.

Spent AA samples were collected from Plants C and D

during the medium replacement. At Plant C, AA samples 

were collected from roughing tanks, TA1 and TA2. At

Plant D, AA samples were collected from the top, middle, and bottom sections of the roughing tank in train 1

(TB1). With a bed depth of 3.2 ft, the top, middle, and

bottom sections were defined as 0-0.5, 1.1-1.6, and 2.2-

2.7 ft from the top of the bed. The AA was vacuumed 

from each section, placed in a container, and mixed thoroughly before a representative sample was collected. 

The sample collection was performed by the plant POC 

with assistance from a certified operator. When the samples arrived at Battelle, subsamples were sent to Wilson 

Environmental Laboratories for TCLP testing. Another

portion of the AA samples were regenerated with caustic

Table 3-3. Summary of Sampling Schedule for Plants A and B

Water Sampling

Initial Source 

Water Sampling Preliminary Sampling Cycle Long-Term Sampling Cycle

Analyte (Once) Week 1 Week 2 Week 3 Week 4 Week 1 Week 2 Week 3 Week 4

As (total) W* W* W W W W* W W, RG W

As (total soluble) W* W* W*

As (particulate) W* W* W*

As(III) W* W* W*

As(V) W* W* W*

Al (total) W* W* W W W W* W W, RG W

Fe (total) W* W* W W W W* W W, RG W

Mn (total) W* W* W W W W* W W, RG W

Al (dissolved) W* W*

Fe (dissolved) W* W*

Mn (dissolved) W* W*

Alkalinity W* W W* W W W W* W W

Sulfate W* W W* W W W W* W W

NO3-NO2 (N) W* W W* W

TOC W*

Turbidity W* W W* W W

Hardness W* W W* W

Ca Hardness W* W W* W

Mg Hardness W* W W* W

pH W* W W* W W W W* W, RG W

TSS W* RG

* = Duplicate samples collected and analyzed.

W = Water samples collected from the inlet and outlet locations.

RG = Regeneration wastewater samples collected at Plant A.

Empty cells indicate no samples taken.
14

Table 3-4. Summary of Sampling Schedule for Plants C and D

Water Sampling

Initial Source 

Water Sampling Preliminary Sampling Cycle Long-Term Sampling Cycle

Spent AA 

Sampling

Analyte (Once) Week 1 Week 3 Week 5 Week 7 Week 1 Week 3 Week 5 Week 7 (Once)

As (total) W* W* W W W W* W W W

As (total soluble) W* W* W*

As (particulate) W* W* W*

As (III) W* W* W*

As (V) W* W* W*

Al (total) W* W* W W W W* W W W

Fe (total) W* W* W W W W* W W W

Mn (total) W* W* W W W W* W W W

Al (dissolved) W* W*

Fe (dissolved) W* W*

Mn (dissolved) W* W*

Alkalinity W* W W* W W W W* W W

Fluoride W* W W* W W W W* W W

Sulfate W* W W* W W W W* W W

NO3-NO2 (N) W* W W

TOC W*

Turbidity W* W W* W

pH W* W W* W W W W* W W

Hardness W* W W

Ca Hardness W* W W

Mg Hardness W* W W

TCLP Metals AA

Percent moisture AA

As (total) AA

* = Duplicate samples collected and analyzed.

W = Water samples collected from the inlet, after Tank A, after Tank B, and outlet locations.

AA = Spent AA samples collected at Plants C and D.

Empty cells indicate no samples taken.

solutions to remove the adsorbed arsenic from AA.

Detailed experimental procedures are described in Section 3.4.2.

3.3.4 Sampling Procedure for Other Water 

Quality Parameters

All other water quality parameters identified in Tables

3-3 and 3-4 were analyzed using samples either in bottles A, B, and C or in bottles provided by Wilson Environmental Laboratories (i.e., bottles D, E, F, and G). All bottles D, E, F, and G were filled directly from sample taps 

and preserved according to the respective analytical 

methods. These sample bottles along with bottles A, B, 

and C were placed in the original coolers with ice packs 

and shipped via Federal Express to Battelle.

3.4 Technical Approaches for 

Special Studies

During the long-term evaluation studies, several observations were made on the performance of the treatment 

processes at Plants A and D that suggested a need for 

short-term special studies. At Plant A, arsenic breakthrough was detected in the effluent before the IX resin 

was regenerated; therefore, a revisit of the system,

especially its regeneration process, was made to enhance the understanding of the IX system performance. 

At Plant D, a laboratory study using the spent and virgin 

AA was designed to assist in evaluating the performance 

of the AA system.

The following sections discuss the technical approaches 

used for the special studies at Plants A and D, respectively, including experimental setup, test procedures, and 

sampling procedures.

3.4.1 Short-Term Special Study at Plant A

During June 12 to 14, 1999, Battelle staff performed a

resin regeneration study to evaluate the effectiveness of 

the renegeration process and determine the quantities and 

chemical characteristics of the regeneration residuals.

The flowrate and duration of each regeneration step

were measured by continuously monitoring the eluate’s

flowrate and TDS levels using an Omega ACCUM-UFLO totalizer and a Hanna HI 9635 conductivity/TDS

meter (Hanna Instruments, Inc., Woonsockett, RI), respectively. The pH of the eluate also was monitored

using a VWR Model 2000 pH meter and a nonrefillable 

combination pH electrode. All meters and probes were
15

Figure 3-3. Instruction Sheet for Arsenic Field Speciation
16

calibrated prior to use according to the manufacturers’ 

instruction manuals.

The test apparatus was set up as follows: (a) The eluate 

from the resin column was directed through a garden

hose and the totalizer to a 250-mL plastic beaker holding 

the TDS and pH probes. (b) The beaker was placed just 

inside the rim of a 32-gal plastic bucket, allowing the

eluate to overflow, after measurements, into the bucket. 

(c) Two 32-gal plastic buckets were used alternately during the sampling. (d) A stopwatch was used to measure 

the time elapsed.

The following test procedures were used for sampling

during the regeneration: 

• Collect one influent and one effluent sample.

• Turn on the power and start the stopwatch after 

water had entered the resin column.

• Record the time elapsed, TDS, pH, temperature, 

volume, and flowrate on a datalogger every 30 to 

60 seconds.

• Collect grab samples once every 4 to 6 minutes by 

filling up sample bottles with the overflow from the 

beaker. 

• Collect a composite sample from the bucket at the 

end of each regeneration step.

• Collect two influent and two effluent samples after 

regeneration was complete and the system 

returned to service.

• Collect two influent and two effluent samples each 

day on Day 2 and Day 3.

• Place sample bottles in a cooler with ice packs and 

have the cooler shipped via Federal Express to 

Battelle at the end of the test.

The number of samples collected at each step is listed in 

Table 3-5. All samples were analyzed for total As and

sulfate. Because the IX resins prefer sulfate ions to arsenic ions, and because sulfate was present in the water

(up to 25 mg/L), the sulfate content in the influent, effluent, spent regenerant, and rinse water was determined.

The percent recovery of arsenic from the regeneration 

was calculated using Equation 3-1:

%R = Mrecovered/Mremoved × 100% (3-1)

where: %R = percent recovery

Mrecovered = the amount of arsenic recovered from 

the resin column, g

Mremoved = the amount of arsenic removed from 

the source water, g.

Table 3-5. Sampling Schedule for the Special Study 

at Plant A

Tank Sampling Number of Samples 

Activities Time Grab Composite

Preregeneration Service Day 1 2 0

Regeneration Backwash Day 1: 

0-18 min

3 1

Brine 

regeneration

Day 1: 

18-42 min

6 1

Slow rinse Day 1: 

42-68 min

5 1

Fast Rinse Day 1: 

68-78 min

2 1

Service Day 1 4 0

Service Day 2 4 0

Postregeneration

Service Day 3(a) 2 0

Total 28 4

(a) The Day 3 samples were collected by the plant POC.

Mrecovered was calculated using the arsenic concentration

and the volume of the eluate from each regeneration step;

Mremoved was estimated based on the water usage data

and arsenic concentrations in the inlet and outlet water.

3.4.2 Short-Term Special Study at Plant D

A special study was conducted on the AA system at

Plant D to determine AA’s capacity for arsenic removal

under the field and laboratory conditions. The spent AA 

sampling has been described in Section 3.3.3. A virgin

AA sample and five gallons of raw water were collected 

and shipped to Battelle. Upon receiving these samples,

the following tests were performed by Battelle:

Test 1: Characteristics of the Spent AA

A subsample of each spent AA sample was sent to

Wilson Environmental Laboratories for TCLP testing.

Another subsample was digested with nitric acid and

analyzed for total arsenic. The resulting concentration

was compared with the concentration desorbed from the 

spent AA using caustic solutions. 

Prior to use, the spent AA samples were air-dried in

clean glass trays for several days and stored and

homogenized in glass bottles. A subsample of each airdried sample was analyzed for moisture content according to Standard Method ASTM D2216.

Three subsamples of each air-dried AA sample (from the 

top, middle, and bottom of the column) were weighed

(approximately 2.00 g) and digested using 100 mL each 

of concentrated nitric acid according to EPA Method

3051. The digestate was analyzed for total arsenic. The 

amount of arsenic recovered per unit dry weight from

each AA sample was calculated using Equation3-2:
17

qe = CAs × V/Wdry (3-2)

where: qe = Arsenic recovered, mg/g dry AA

CAs = arsenic concentration in digestate, mg/L

V = digestive fluid volume, L

Wdry = dry weight of AA, g.

Test 2: Regeneration of Spent AA Using 

Caustic Solutions

Caustic solutions of 1-2% (by weight) NaOH have been 

reported to be effective in stripping inorganic ions such

as fluoride, arsenic, and phosphate from spent AA (Chen 

and Snoeyink, 1987). Higher NaOH concentrations (i.e., 

4%) have also been suggested for stripping arsenic

because arsenic is much more difficult to remove from

AA than fluoride (Clifford, 1999), thus a 4% NaOH solution was used in this study. Studies have also showed

that comparable regeneration results have been obtained with 30 minutes to 3 days of contact time (Chen et 

al., 1989). Therefore, the regeneration test was run for

approximately 16 hours. 

Spent AA samples collected from the top, middle, and

bottom sections of the column were stripped with a 4%

NaOH solution to determine the amount of arsenic that

might be desorbed from each sample. The experiment

was conducted in duplicate at room temperature (about

22°C) according to the following procedures:

• Weigh approximately 70 g of a wet spent AA 

sample into one of six 250-mL plastic bottles 

containing 150 mL of 4% NaOH solution.

• Cap the bottles and place them on a tumbler for 

overnight mixing (approximately 16 hrs).

• Remove the contents from each bottle and filter 

them through a ZAPCAP-S 0.45-μm disposable 

cellulose acetate membrane filter (Schleicher & 

Schuell, Keene, NH).

• Rinse the residual AA three times with a total of 

200 mL Millipore DI water and filter the rinsate.

• Combine and mix the filtrate from each bottle and 

analyze the sample for total arsenic (preserved with 

nitric acid) and fluoride and sulfate (unpreserved).

The amount of arsenic, fluoride, and sulfate recovered

from the caustic wash was calculated using Equation 3-2 

except that the digestive fluid volume was replaced by

the total volume of the NaOH solution and the rinse

water used in the experiment.

Test 3: Adsorption Isotherm Experiment 

Isotherm tests were conducted to determine the capacity 

of the virgin AA (Alcoa CPN type granular AA, 28 × 48 

mesh) used at Plant D. To increase the initial As(V) concentration in the raw water from 50 μg/L to approximately 500 μg/L, 450 μL of 1.0-μg/μL As(V) standard 

solution was spiked to 1 L of raw water. A kinetic study 

was performed to determine the time required to reach

equilibrium. A series of 250 mg of virgin AA was accurately weighed, placed in a 250-mL plastic bottle containing 200 mL of the spiked raw water, and adjusted to 

the raw water pH of 7.7 ± 0.2. The bottles were placed 

on a tumbler for 7 days at room temperature (~22 °C). 

During the test period, the pH values of all test solutions 

were periodically checked and adjusted to 7.7 ±0.2. After 

1, 2, 5, 6, and 7 days, one bottle each was removed

from the tumbler and its content was decanted and

filtered through a ZAPCAP-S 0.45-μm disposable cellulose acetate membrane filter. The filtrate was collected

in a plastic bottle preserved with nitric acid for total arsenic analysis.

For the isotherm experiment, identical volumes of an

arsenic solution were exposed to different quantities of

AA. The control contained only arsenic solution, without 

alumina. During the test period, the pH values of all test 

solutions were periodically checked and adjusted to 7.7

±0.2. Final arsenic concentrations were determined, and 

the difference between test and control final concentrations was attributed to adsorption onto AA. The procedure for batch tests is as follows:

• Pour 200-mL aliquots of arsenic-spiked raw water 

into 250-mL plastic bottles with measured 

quantities (100 to 1,000 mg) of granular AA.

• Adjust the pH of solution in each bottle to 7.7 ±0.2.

• Cap bottles and place them on the tumbler.

• Remove bottles from the tumbler after 6 days and 

filter their contents as described above. 

• Analyze filtrate samples for total arsenic 

concentration.

3.5 Analytical Procedures

The analytical procedures used for this project were

described in Section 4.0 of the QAPP prepared by

Battelle (1998). Table 3-6 presents a summary of all

analytical methods used. All of the methods used are

standard EPA methods. Analyses of As, Al, Fe, and Mn 

in water samples were accomplished by ICP-MS using

EPA Method 200.8. ICP-MS was chosen as the method 

for As, Al, Fe, and Mn analyses because it has a low

method detection limit (MDL) and was a relatively lowcost method (about $35/sample). ICP-MS analyses were 

conducted on a Perkin Elmer Sciex Model 6000 equipped

with a crossflow pneumatic nebulizer and an automatic
18

Table 3-6. Summary of Analytical Methods for Arsenic Treatment Study

Sample Matrix Analyte Method Analytical Laboratory

As (total) EPA 200.8 Battelle ICP-MS 

Total Al EPA 200.8 Battelle ICP-MS 

Total Fe EPA 200.8 Battelle ICP-MS 

Total Mn EPA 200.8 Battelle ICP-MS 

Alkalinity EPA 310.1 Wilson Environmental

pH EPA 150.1 Wilson Environmental

Turbidity(a) EPA 180.1 Wilson Environmental

Hardness EPA 215.1/242.1 Wilson Environmental

SO4

2–

EPA 375.4 Wilson Environmental

F

− EPA 340.2 Wilson Environmental

TOC EPA 415.1 Wilson Environmental

Aqueous

NO3

–

/NO2

–

EPA 353.2 Wilson Environmental

Moisture content ASTM D 2216 Wilson Environmental

pH SW-846 9045 Wilson Environmental

TCLP metals SW-846 1311 Wilson Environmental

Total As SW-846 3051, 6020 Wilson Environmental

Spent AA

Total Fe SW-846 3051, 6020 Wilson Environmental

 (a) Turbidity was analyzed in the laboratory, not on site.

sampler. Yttrium (88.9Y) was added to all samples as an 

internal standard to correct for instrument drift. Because 

arsenic is monoisotopic, all measurements were made at 

a mass/charge ratio of 75. To eliminate an appreciable

interference from a chloride molecular species (40Ar35Cl), 

all ion current data at m/e 75 were corrected using

chloride measurements in all samples, and the MDL

was 0.1 μg/L As. All the unfiltered water samples (i.e., in 

bottle A) were digested using EPA Method 200.8 prior to 

analysis. Filtered water samples (i.e., in bottles B and C) 

were analyzed directly without digestion. Wilson Environmental Laboratories was subcontracted to perform all

other chemical analyses. QA/QC of all methods followed 

the guidelines provided in the QAPP (Battelle, 1998) and 

the data quality in terms of precision, accuracy, MDL, and 

completeness is discussed in Section 5.0 of this report.
19

4.0 Results and Discussion

This section presents the results of the treatment plant

selection process, which resulted in the selection of two 

IX plants, referred to as Plants A and B, and two AA

plants, referred to as Plants C and D. In addition, results 

from water and residuals sampling and analysis at

Plants A, B, C, and D are summarized and discussed.

Complete analytical results from long-term water sampling at Plants A, B, C, and D are presented in Appendices A.1, B.1, C.1, and D.1, respectively.

4.1 Plant Selection

The plant selection process consisted of identifying potential treatment facilities, contacting these facilities via

telephone, and conducting initial site visits during which

source water samples were collected and analyzed. Initially, a list was prepared consisting of two potential IX

treatment facilities and three AA facilities (Plants A, B, C, 

D, and E; see Table 4-1 for plant details). Staff at these 

potential candidate facilities were contacted to discuss 

the study and determine details of plant operation.

All plants except Plant E were selected for the subsequent phases of the study. Results from source water 

sampling at each of these four facilities are presented in 

the following subsections.

4.2 Plant A

Water and residual samples were collected and analyzed at Plant A, an IX plant, during three phases of the 

study.

The first phase consisted of source water sampling used 

to help determine if the plant should be considered for

subsequent phases. Source water sampling at Plant A 

was performed in June 1998. Following source water

sampling, the second phase of the study was initiated.

This second phase consisted of weekly water sampling

over a 4-week period in August 1998 and was designed 

to determine if the sampling locations and proposed 

water quality analyses were appropriate for the third

phase, long-term evaluation. The third phase was initiated in September 1998 and continued through June

1999. This long-term evaluation consisted of weekly 

sampling and analysis of raw and finished water. Also,

arsenic speciation sampling was conducted every fourth 

week. The third phase of the study also included sampling and analysis of residuals. Backwash and spent

brine samples were collected monthly beginning in March

1999.

4.2.1 Plant A Description

The IX system in Plant A supplies treated water to a

school and is used by approximately 350 students and

teachers. The IX system was installed by Lowry Engineering at Unity, ME in August 1990 and was designed 

based on an average daily demand (ADD) of 1,200

gallons per day (gpd) of water. The system is operated 

intermittently and the treated water is stored in a storage 

tank to supply daily demand. This system consists of a

FiloxTM oxidizing filter followed by an A300X IX resin

system. Figure 4-1 is a schematic diagram of the treatment process, which consists of the following major

components:

Table 4-1. Initial List of Treatment Facilities Identified for the Study

Plant ID Process

Source Water Arsenic 

Concentration (μg/L)

Sampling

Date

Population 

Served Historical Data

Source 

Water Type

A IX 23-34 (effluent) July 1995 ~ March 1997 350 Limited GW

B IX 52 November 12,1995 35 NA GW

C AA 42 December 30, 1994 600 Yes GW

D AA 40-80 NA 200 Yes GW

E AA 51-63 1988 97 families Yes GW

NA = not available; GW = groundwater.
20

1

STORAGE TANK

(2,400 GAL)

FILOX FILTER

IX System

2

PRESSURE TANK

MONTHLY WEEKLY

Plant A

Anion Exchange

Design Flow: 4 gpm

LEGEND

FILOX FILTER Unit Process

RG/

BW

Regeneration/Backwash 

Sampling Location

1 Water Sampling 

Location

RG/

BW

As (total), pH, TSS

SEPTIC TANK

BRINE TANK

BW

As (total), As (III), As (V), 

Hardness, Turbidity, NO3/NO2

As (total), As (III), As (V), 

Hardness, Turbidity, NO3/NO2

As (total), Alkalinity, pH,

Total Al,Total Fe, Total Mn, SO4

As (total), Alkalinity, pH,

Total Al,Total Fe, Total Mn, SO4

Backwash

To the distribution system 

DA: Cl2

DA: Cl2

Disinfectant Addition

Point

Flow Totalizer

From well

Regeneration

2

Note:

The outlet samples were planned to be 

collected at the IX system outlet, however, 

were actually collected after the storage tank. 

Proposed sampling location

Actual sampling location

Figure 4-1. Process Flow Diagram and Sampling Locations at Plant A
21

• Intake. The raw water is pumped from an 800-ftdeep bedrock well located in the eastern vicinity of 

the school building (Well 1) and flows directly into 

the FiloxTM filter. Well 1 was drilled in 1987-88 and 

has a 6-inch steel casing. Another well, Well 2, is 

located about 125-150 ft northeast of Well 1. Well 2 

was drilled in 1957 with a depth of 250 ft and an 

8-inch steel casing, but is not currently in use.

• Oxidizing Filter. The FiloxTM filter was installed to 

oxidize possible arsenite [As(III)] in water to arsenate [As(V)]. As shown in Figure 4-2, the FiloxTM 

filter is a 65-inch-long by 14-inch-diameter Polyglass

 vessel filled with a 22.5-inch-deep MnO2-

based medium. Because the source water contains 

primarily As(V) and almost no As(III), the oxidizing 

filter has functioned only as a prefiltration unit to 

remove particulate from the raw water. The FiloxTM 

filter is backwashed every 3 days with treated 

water from the storage tank. The backwash lasts 

for 15 to 20 minutes at a flowrate of 11 gallons per 

minute (gpm).

• Anion Exchange System. After passing through 

the FiloxTM filter, water flows into the A300X resin 

column. The A300X column has the same dimensions and configuration as the FiloxTM column 

except that it is filled with a 22.5-inch-deep Purolite 

A-300 anionic resin bed (Figure 4-2). The Purolite 

A-300 anionic resin (The Purolite Company, Bala 

Cynwyd, PA) is a strongly basic gel IX resin in 

chloride form. Typical physical and chemical 

properties of this resin are presented in Table 4-2. 

Detailed technical data on the resin can be found 

in Appendix A.2. At a design flowrate of 4 gpm, the 

hydraulic loading rate to the filter is 4 gpm/ft2 and 

the EBCT is 3.7 minutes.

• Resin Regeneration. The original design called 

for a regeneration frequency of every 3 months 

using a brine solution at 10 lb salt/ft3 resin. Because 

early arsenic breakthrough was detected during this 

study, a more frequent (once every 4 weeks) regeneration schedule was recommended to the plant 

personnel and has been implemented since March 

1999. Discussion on the resin regeneration is provided in Section 4.2.4.4. The brine solution is stored 

in a 35-inch-tall by 18-inch-diameter tank. The 

regeneration of the A300X resin column consists of 

four steps: upflow backwash, downflow brine, 

downflow slow rinse, and downflow fast rinse. The 

approximate flowrate and duration of each regeneration step are listed in Table 4-3 and were verified 

during the special study at Plant A.

• Chlorination. To disinfect the water, chlorine is 

added to the treated water through a conventional 

chemical feed pump.

• Storage Tank. The treated, chlorinated water is 

stored in a 2,400-gallon steel tank, and is pressurized through two booster pumps and two pressure 

tanks before it enters the school distribution 

system.

The cost of the system at the time of installation was

$6,886 with an additional $2,000 installation fee.

4.2.2 Initial Source Water Sampling

Source water sampling was conducted during the initial

site visit on June 9, 1998. Table 4-4 presents the analytical results from the source water sampling. The average 

total arsenic concentration was 23.1 μg/L. Particulate 

arsenic was less than detection; thus, soluble arsenic,

primarily As(V), accounted for the majority of the total

arsenic. The average As(III) concentration was 0.5 μg/L.

4.2.3 Preliminary Sampling

During the preliminary sampling phase of this study, 

water samples were collected only at the inlet and the

outlet of the system because of the lack of a sampling

tap after the oxidizing filter. The inlet samples were collected from a tap located on the pipe connecting to the

well. The outlet samples, originally planned to be collected between the resin tank and the storage tank, were 

actually collected after the storage tank. The outlet sampling location was changed because it was difficult to

draw water samples from the resin tank outlet when the 

system was turned off. The sampling locations and the

associated sample analyses performed at each location 

are shown on Figure 4-1.

Alkalinity, sulfate, turbidity, pH, total hardness, nitratenitrite, total Al, total Fe, total Mn, and total arsenic were 

analyzed on samples collected every week at both sampling locations. Arsenic speciation was conducted once

during the preliminary study on samples collected from

both sampling locations. Soluble and particulate arsenic 

were determined as part of the arsenic speciation, as

were the species (arsenite and arsenate) making up the 

soluble fraction of the total arsenic. Dissolved Al, Fe, and 

Mn concentrations at each sampling location were determined using a sample from bottle B of the arsenic speciation kits. Table 4-5 presents the results of the 4-week 

preliminary sampling period.

As shown on Table 4-5, inlet total arsenic concentrations 

ranged from 17.8 to 26.6 μg/L. Arsenic in the source

water was primarily As(V) and contained almost no As(III) 

and particulate arsenic, consistent with the results of the 

initial source water sampling (Table 4-4). On August 6,

1998, the total arsenic concentration in the finished water
22

Figure 4-2. Cross Section of FiloxTM Filter and A300X IX Filter at Plant A (Source: Lowry Engineering, 

Inc., 1990)
23

Table 4-2. Typical Chemical and Physical 

Characteristics of Purolite A-300 

Anion Exchange Resin

Polymer Structure Polystyrene crosslinked with 

divinylbenzene

Functional Groups R(CH3)2(C2H4OH)N+

Physical Appearance Clear spherical beads

Ionic Form Chloride

Screen Size, U.S. Std.Mesh 

(Wet)

16-50

Particle Size Range +16 mesh < 5%; -50 mesh < 1%

Uniformity Coefficient 1.7 maximum

Water Retention 40-45%

Swelling Salt –OH, 10%

pH Limitations None

Temperature Limitations 185oF maximum

Chemical Resistance Unaffected by dilute acids, alkalis, 

and most solvents

Whole Clear Beads 92% minimum

Shipping Weight 44 lb/ft3

 (705 g/L)

Total Capacity 1.45-1.6 meq/mL min. Volumetric;

3.5-3.7 meq/gm min. Weight

Table 4-3. Regeneration Schedule of the A300X 

Resin Column at Plant A

Regeneration 

Step

Flow 

Direction

Duration 

(min)

Flowrate 

(gpm)

Backwash Upflow 18 5.0

Brine Downflow 24 1.0

Slow Rinse Downflow 18 1.0

Fast Rinse Downflow 10 3.2

exceeded the concentration in the raw water, indicating arsenic breakthrough. Therefore, the IX column was 

regenerated immediately after the samples had been collected. Over the following 3 weeks, the arsenic concentrations in the finished water decreased slowly from 7.2 to

0.6 μg/L, corresponding to 62% to 98% arsenic removal. 

At the time, it was not clear why the IX column continued 

to leak even about 2 weeks after the resin regeneration. 

Further study revealed that this “leakage” actually was

due to an artifact caused by the arsenic already present 

in the 2,400-gal storage tank located just upstream from 

the sampling point. The storage tank contained relatively 

high arsenic water before the regeneration and was

replenished by the low arsenic water produced after the 

regeneration. Therefore, the arsenic concentrations in the 

effluent samples gradually decreased to low levels depending on how quickly the storage tank was replenished. 

It is expected that the water at the resin tank outlet immediately after the resin regeneration contained even lower 

arsenic concentrations (i.e., <1.0 μg/L). This hypothesis is 

being verified by a short-term special study.

During the preliminary sampling period, the inlet alkalinity concentrations ranged from 69 to 92 mg/L (as

CaCO3), and the inlet sulfate concentrations ranged from 

23 to 25 mg/L. According to the selectivity sequence discussed in Section 1.1.3.1, an SBA resin prefers sulfate

over HAsO4

2 −

 and H2AsO4

−

; HCO3

−

 is less preferred than 

HAsO4

2 −

 but has a similar affinity to the resin as H2AsO4

−

. 

Clifford and Rosenblum (1982) found that the presence 

of 720 mg/L sulfate reduced arsenic removal by more

than 50%. When arsenic broke through the IX column on 

August 6, 1998, both sulfate and alkalinity (mainly HCO3

−

at a neutral pH) showed little removal (20-25%). After

resin regeneration, sulfate was consistently reduced to

Table 4-4. Source Water Analytical Results at Plant A (June 9, 1998)

Parameter Unit

Primary

Sample

Duplicate

Sample Average 

Alkalinity mg/L(a) 84 84 84

Sulfate mg/L 20 20 20

Turbidity NTU 0.06 0.06 0.06

pH — 7.6 7.6 7.6

Total Hardness mg/L(a) 100 98 99

Ca Hardness mg/L(a) 88.9 87.4 88.2

Mg Hardness mg/L(a) 10.9 10.7 10.8

Total Al μg/L <400 <400 <400

Total Fe μg/L <30 40 30

Total Mn μg/L <20 30 20

NO3−NO2

 (N) mg/L(b) 0.75 0.78 0.77

TOC mg/L 1.1 1.1 1.1

As (total) μg/L 22.5 23.6 23.1

As (total soluble) μg/L 24.6 24.4 24.5

As (particulate) μg/L <0.1 <0.1 <0.1

As(III) μg/L 0.4 0.6 0.5

As(V) μg/L 24.2 23.8 24.0

(a) As CaCO3.

(b) Combined NO3−N and NO2−N.

NTU = nephelometric turbidity units.
24

Table 4-5. Analytical Results from Preliminary Sampling at Plant A (August 6, 1998 to August 26, 1998).

Sampling Date/Location

8/6/98(a) 8/11/98 8/18/98 8/26/98

Parameter Units IN OU IN OU IN OU IN OU

Alkalinity mg/L(b) 92 71 69

69

23

23 72 41 76 67

Sulfate mg/L 25 20 24

22

<5

<5 23 <5 24 <5

Turbidity NTU 0.3 <0.1 <0.1

<0.1

<0.1

<0.1 <0.1 <0.1 NS NS

pH 7.7 7.5 7.3

7.3

7.0

6.9 7.5 7.4 7.3 7.4

Total Hardness mg/L(b) 82.1 62.2 68.0

68.0

69.0

71.0 NS NS NS NS

Ca Hardness mg/L(b) 72.7 54.4 60.4

60.4

61.7

62.9 NS NS NS NS

Mg Hardness mg/L(b) 9.5 7.7 7.5

7.3

7.5

7.6 NS NS NS NS

Nitrate-Nitrite mg/L 0.5 0.8 0.7

0.7

0.5

0.6 NS NS NS NS

As (total) μg/L 17.8

20.0

23.2

21.3 19.0 7.2 26.0 1.9 26.6 0.6

As (total soluble) μg/L 18.8

19.1

22.1

22.7 NS NS NS NS NS NS

As (particulate) μg/L ND

0.9

1.1

ND NS NS NS NS NS NS

As (III) μg/L ND

ND

ND

ND NS NS NS NS NS NS

As (V) μg/L 18.8

19.1

22.1

22.7 NS NS NS NS NS NS

Total Al μg/L 9.7

13.9

9.8

16.6 30.8 18.2 158 19.7 64.5 25.0

Total Fe μg/L 42.8

68.1

0.3

4.8 31.8 1.0 37.0 16.0 47.0 ND

Total Mn μg/L 2.9

2.7

0.3

0.4 1.5 1.6 2.6 1.3 6.0 0.4

Dissolved Al μg/L 1.7

0.7

2.6

2.4 NS NS NS NS NS NS

Dissolved Fe μg/L ND

ND

ND

ND NS NS NS NS NS NS

Dissolved Mn μg/L 3.0

2.5

0.2

0.2 NS NS NS NS NS NS

(a) Samples were taken prior to resin regeneration. IN = inlet. NS = not sampled.

(b) As CaCO3

. OU = outlet. ND = not detected.

<5 mg/L throughout the subsequent 3 weeks. However, 

the alkalinity was reduced by 67%, 43%, and 12%, respectively, showing a decreasing trend with time. This

decreasing trend probably was caused by the fact that

the less-preferred bicarbonate was replaced from the

resin by the more preferred sulfate and arsenic ions. The 

pH values ranged from 7.3 to 7.7 in the inlet and 7.0 to 

7.5 in the outlet. Because the IX process is not pH

sensitive in the range of pH 6.5 to 9.0 (Section 1.1.3.1), 

the effect of inlet pH on the IX process is insignificant.

The slightly lower pH value at the outlet presumably was 

caused by the removal of alkalinity.

Iron compounds can clog and foul IX resins, thereby

lowering the arsenic removal capacities and reducing the 

water throughput. However, at Plant A, both total and

dissolved Fe and Mn concentrations were very low.

Therefore, the effects of Fe and Mn on the process were 

insignificant.

Based on the results of the preliminary sampling effort,

no changes were made to the approach for the long-term 

evaluation. Sampling locations and primary analytes remained unchanged.
25

4.2.4 Long-Term Sampling

Long-term sampling and analysis consisted of a total of 

37 weeks of sampling and included 10 arsenic speciation 

sampling events. During the long-term sampling phase,

water samples were collected at the same two locations 

that were used during the preliminary sampling phase:

inlet and outlet (Figure 4-1). Alkalinity, sulfate, turbidity, 

pH, total aluminum, total iron, total manganese, and total 

arsenic analyses were performed on samples collected

each week. Arsenic speciation sampling was conducted 

10 times during the long-term sampling phase on samples 

collected from each sampling location. Dissolved aluminum, iron, and manganese concentrations at each sampling location were determined monthly using a sample 

from bottle B of the arsenic speciation kits. Additionally, 

residual sampling was performed during this phase and 

consisted of collection and analysis of backwash wastewater and spent brine from the regeneration of the A300X

column. The following subsections summarize the analytical results for arsenic, other water quality parameters, 

and backwash/regeneration wastewater.

4.2.4.1 Arsenic

Table 4-6 provides a summary of the arsenic analytical results collected from the inlet and outlet locations at Plant A. 

Total arsenic concentrations at the inlet varied widely from

23.3 μg/L to 59.2 μg/L and averaged 40.6 μg/L. Consistent 

with previous phases of the study, particulate arsenic concentrations were low, averaging 0.4 μg/L and 0.5 μg/L at

the inlet and outlet sampling locations, respectively. As(III)

concentrations averaged 0.7 μg/L at the inlet and 0.2 μg/L 

at the outlet, indicating that As(V) made up the majority of

the soluble arsenic.

The effluent arsenic concentration ranged from 0.7 to as 

high as 82 μg/L, which exceeded the corresponding inlet 

arsenic concentration and the current 0.050 mg/L MCL

level. This chromatographic peaking, most likely was

caused by the sulfate in the source water. After two

3-month regeneration cycles and one 6-week regeneration cycle, it was determined that the system should be 

regenerated more frequently. The effluent data collected 

since April 18, 1999 indicated that if the system was

regenerated every 4 weeks or less, the system would be 

able to achieve arsenic effluent levels of less than 5 μg/L. 

Again, the column leak, which was observed during the 

preliminary sampling, still existed, as indicated by the data

collected on March 23, May 18, and June 14 through 17, 

1999. Because the effluent sampling location did not

change throughout the study, the reason for the column 

leak was again attributed to the storage tank (see Section 4.2.3). Figure 4-3 is a graph showing the total arsenic concentrations at the inlet and outlet of the IX column 

and removal percentages during the long-term sampling.

Based on the water usage data recorded at each regeneration event since 1994 (see Appendix A.4), the run

length of each regeneration cycle is calculated and plotted

in Figure 4-4 both in gallons and in BV. Bed volume was 

calculated by dividing the volume of water processed by 

the volume of the resin bed (2 ft3 or 14.96 gal). With the 

3-month regeneration schedule (before March 1999), the 

run length varied from 5,760 to 9,670 BV with an average 

of 7,890 BV. With the 4-week regeneration schedule, the 

run length was significantly shortened, ranging from 2,220

to 3,780 BV with an average of approximately 3,000 BV. 

This run length is reasonable compared with the 4,200

BV and 2,800 BV reported by Clifford and Lin (1986) and 

Hathaway and Rubel (1987), respectively.

Assuming an average daily demand of 1,200 gpd, a

3000-BV cycle (equivalent to 44,880 gal) would last for

37 days. However, due to variations in water demand

with the school schedule (e.g., low water demand during 

summer when school is dismissed), the regeneration 

frequency based on total flow rather than time of operation was recommended in place of a time schedule.

Table 4-6. Summary of Arsenic Analytical Results at Plant A (September 1, 1998 to June 17, 1999)

Parameter Sampling Location Units

Number of 

Samples

Minimum 

Concentration

Maximum 

Concentration

Average 

Concentration

Standard 

Deviation

As (total) Inlet μg/L 47 23.3 55.4 40.6 8.0

Outlet μg/L 47 0.7 81.5 19.0 20.3

As (total soluble) Inlet μg/L 20 30.8 60.9 45.9 9.0

Outlet μg/L 20 0.9 97 18.0 29.1

As (particulate) Inlet μg/L 20 0 3.4 0.4 1.0

Outlet μg/L 20 0 5.9 0.5 1.5

As (III) Inlet μg/L 20 0.1 1.4 0.7 0.3

Outlet μg/L 20 0 0.5 0.2 0.2

As (V) Inlet μg/L 20 30.2 60.2 45.2 9.1

Outlet μg/L 20 0.8 96.7 17.8 29.1

One-half of the detection limit was used for nondetect samples for calculations.

Primary and duplicate samples were averaged for calculations.
26

0

20

40

60

80

100

120

140

160

08/01/98 08/31/98 09/30/98 10/30/98 11/29/98 12/29/98 01/28/99 02/27/99 03/29/99 04/28/99 05/28/99 06/27/99 07/27/99

Date

Arsenic concentration (μg/L)

-200%

-150%

-100%

-50%

0%

50%

100%

% Removal

Inlet As Outlet As Reg 8/20/98 Reg 11/10/98 Reg 2/6/99

Reg 3/21/99 Reg 4/18/99 Reg 5/16/99 Reg 6/13/99 % Removal

Inlet

Outlet

% Removal

Figure 4-3. Total Arsenic Analytical Results during Long-Term Sampling at Plant A

0

20

40

60

80

100

120

140

160

09/23/94 09/23/95 09/22/96 09/22/97 09/22/98 09/22/99

Regeneration Date

Volume of water treated (x1000 gal)

0

2,000

4,000

6,000

8,000

10,000

Bed volume of water treated (BV)

Anion exchange resin regenerated every three months 

before March 1999 and every 4-6 weeks afterwards

Figure 4-4. Water Treated between Regenerations of the IX System at Plant A
27

4.2.4.2 Other Water Quality Parameters

In addition to arsenic analysis, other water quality parameters were analyzed to provide possible insight into the 

chemical processes occurring at the treatment facility.

Table 4-7 summarizes the analytical results for several

water quality parameters obtained during the long-term 

sampling.

Inlet sulfate concentrations ranged from 19 to 28 mg/L

with an average of 23.7 mg/L. As shown on Figure 4-5, 

sulfate concentrations were reduced to <5 mg/L at the

outlet after the column was properly regenerated. Just

after the arsenic breakthrough, the effluent sulfate concentrations increased rapidly, approaching but never

exceeding their influent levels. This sharp breakthrough

is typical for a most preferred species like sulfate (Clifford,

1999). Because sulfate is more preferred than arsenate 

by the resin, it can elute arsenate from the resin, causing 

chromatographic peaking, as observed during the longterm sampling.

Figure 4-6 plots the inlet and outlet alkalinity concentrations and pH throughout the long-term sampling. Alkalinity concentrations ranged from 61 to 93 mg/L (as CaCO3

) 

in the inlet with an average of 84.7 mg/L. The alkalinity 

was partially removed by the treatment, resulting in its

outlet concentrations ranging from 21 to 92 mg/L with an

average of 74.6 mg/L. Because bicarbonate is a lesspreferred ion, it broke through earlier than sulfate and

arsenic. The pH values ranged from 7.2 to 7.8 in the inlet 

with an average of 7.5. After the treatment, the pH values were slightly reduced, ranging from 7.0 to 7.7, presumably due to the removal of some alkalinity.

During the long-term sampling, the turbidity was low,

averaging 0.1 NTU at both the inlet and the outlet. Total 

hardness also was low, ranging from 64 to 83.9 mg/L (as 

CaCO3). As expected, the hardness was not removed by 

the IX column and remained constant at the inlet and the 

outlet. Nitrate-nitrite concentrations of the inlet water were 

very low and thus did not have any significant impact on 

arsenic removal.

The maximum total Al, Fe, and Mn concentrations were 

105, 80.2, and 3.1 μg/L, respectively, at the inlet, and 60, 

117, and 1.4 μg/L, respectively, at the outlet. As expected, the low metal concentrations of these cations did 

not have any effects on arsenic removal.

4.2.4.3 Backwash/Regeneration Wastewater 

Backwash wastewater and spent brine were sampled on 

August 6, 1998 and on March 21, April 18, May 16, and 

June 13, 1999. Composite samples were collected from 

each of the four regeneration steps (i.e., backwash, brine

Table 4-7. Summary of Water Quality Parameter Analytical Results at Plant A (September 1, 1998 to June 17, 1999)

Parameter

Sampling 

Location Units

Number of 

Samples

Minimum 

Concentration

Maximum 

Concentration

Average 

Concentration

Standard 

Deviation

Alkalinity Inlet mg/L 47 61 93 84.7 7.4

Outlet mg/L 47 21 92 74.6 16.9

Sulfate Inlet mg/L 47 19 28 23.7 1.8

Outlet mg/L 47 2.5 25 9.5 9.0

Turbidity Inlet NTU 20 0.05 0.3 0.1 0.1

Outlet NTU 20 0.1 0.1 0.1 0

pH Inlet — 47 7.2 7.8 7.5 0.1

Outlet — 47 7.0 7.7 7.5 0.2

Total Hardness Inlet mg/L 20 64 83.9 69.5 6.7

Outlet mg/L 20 61 79.0 67.3 5.0

Nitrate-Nitrite Inlet mg/L 20 0.3 0.8 0.5 0.1

Outlet mg/L 20 0.1 3.3 0.7 0.9

Total Al Inlet μg/L 47 5.5 105 16.7 15.7

Outlet μg/L 47 5.5 60 10.5 8.4

Total Fe Inlet μg/L 47 15 80.2 21.3 14.2

Outlet μg/L 47 15 117 19.4 15.9

Total Mn Inlet μg/L 47 0.3 3.1 0.9 0.7

Outlet μg/L 47 0.3 1.4 0.5 0.3

Dissolved Al Inlet μg/L 20 3.9 12.9 5.8 1.7

Outlet μg/L 20 5.5 19.5 6.2 3.1

Dissolved Fe Inlet μg/L 20 11.5 15.6 14.9 0.8

Outlet μg/L 20 15 15 15 0

Dissolved Mn Inlet μg/L 20 0.3 1.2 0.5 0.3

Outlet μg/L 20 0.3 2.7 0.5 0.6

One-half of the detection limit was used for calculating concentrations of nondetect samples.

Primary and duplicate samples were averaged for calculations.
28

0

10

20

30

40

50

60

08/01/98 08/31/98 09/30/98 10/30/98 11/29/98 12/29/98 01/28/99 02/27/99 03/29/99 04/28/99 05/28/99 06/27/99 07/27/99

Date

Sulfate concentration (mg/L)

-100%

-80%

-60%

-40%

-20%

0%

20%

40%

60%

80%

100%

% Removal

Inlet Sulfate Outlet Sulfate Reg 8/6/98 Reg 11/10/98 Reg 2/6/99

Reg 3/21/99 Reg 4/18/99 Reg 5/16/99 Reg 6/13/99 % Removal

Inlet

Outlet

% Removal

Figure 4-5. Inlet and Outlet Sulfate Concentrations and Percent Removal at Plant A

0

40

80

120

160

200

08/01/98 08/31/98 09/30/98 10/30/98 11/29/98 12/29/98 01/28/99 02/27/99 03/29/99 04/28/99 05/28/99 06/27/99 07/27/99

Date

Alkalinity (mg/Las CaCO3)

6.0

6.5

7.0

7.5

8.0

pH

Inlet alkalinity Outlet alkalinity Reg 8/6/98 Reg 11/10/98

Reg 2/6/99 Reg 3/21/99 Reg 4/18/99 Reg 5/16/99

Reg 6/13/99 Inlet pH Outlet pH

Inlet alkalinity

Outlet alkalinity

Inlet pH

Outlet pH

Figure 4-6. Inlet and Outlet pH and Alkalinity Analytical Results at Plant A
29

regeneration, slow rinse, and fast rinse). Analytical results 

of these sampling events are summarized in Table 4-8. 

As expected, the majority of arsenic was eluted from the 

column during the brine regeneration; the arsenic concentrations ranged from 1.83 to 38.5 mg/L with an average of 

15.6 mg/L. The arsenic concentrations in the elutes from 

the backwash, slow rinse, and fast rinse averaged 59.4, 

1,332, and 108 μg/L, respectively. The arsenic concentrations along with the respective volumes were used to

calculate the mass of arsenic recovered from the regeneration to determine the regeneration efficiency (to be

discussed in Section 4.2.4.4). The elevated pH value observed during the brine regeneration is presumably due 

to the elution of bicarbonate ions from the resin column.

4.2.5 Special Study at Plant A

During June 12 to 14, 1999, a special study was performed to evaluate the regeneration efficiency and to

determine the quantity and chemical characteristics of

the regeneration residuals.

Figure 4-7 plots total arsenic, TDS, and sulfate concentrations vs. time during the regeneration process. For the 

first 24 minutes during backwash and the initial stage of 

brining, all three parameters stayed at low levels. Afterwards, TDS concentrations increased sharply and reached

a maximum level of 26.1 mg/L. Meanwhile, sulfate concentrations jumped from about 20 mg/L to as high as

24 g/L. Arsenic also was eluted with sulfate; arsenic

concentrations increased sharply from less than 1 mg/L 

to more than 77 mg/L. Figure 4-7 also seems to indicate 

that arsenic was easier to elute than sulfate, most likely 

due to the selectivity reversal in the high-ionic strength

(>1 M) environment (Clifford, 1999). The ease of regeneration is a strong point in favor of IX as compared to

AA.

Figure 4-8 indicates that a flowrate of 3.0 gpm was applied to the backwash and fast rinse, which is lower than 

the 5 gpm specified in the service manual, and that

approximately 1 gpm was maintained during the brine

regeneration and slow rinse. The pH of the eluate was

close to neutral (~7.5) during backwash, increased to up 

to pH 9.0 after the introduction of the brine solution, and 

returned to neutral by the end of the process. Again, the 

change in the pH value is probably related to bicarbonate desorption from the column.

Table 4-8. Summary of Analytical Results from Backwash/Regeneration Samples at Plant A

(August 6, 1998 to June 13, 1999)

Parameter Units

Number of 

Sample Events

Minimum 

Concentration

Maximum 

Concentration

Average 

Concentration

Standard 

Deviation

Backwash

pH — 5 7.2 7.6 7.4 0.1

TSS mg/L 5 6.0 24.0 14.0 8.5

Total As μg/L 5 28.9 74.4 59.4 18.5

Total Al μg/L 5 86.4 847 432 325

Total Fe μg/L 5 264 1,982 1,102 733

Total Mn μg/L 5 15.3 59.8 40.2 19.4

Brine Rinse

pH — 5 8.1 8.9 8.5 0.3

TSS mg/L 5 6.0 13.0 9.0 2.9

Total As μg/L 5 1,830 38,522 15,623 15,109

Total Al μg/L 5 5.5 28.0 20.5 8.9

Total Fe μg/L 5 43.5 445 207 153

Total Mn μg/L 5 2.3 3.4 3.0 0.5

Slow Rinse

pH — 5 7.6 8.7 8.1 0.4

TSS mg/L 4 0.5 22.0 9.6 10.2

Total As μg/L 5 253 3,060 1,332 1,084

Total Al μg/L 5 13.5 236 65.2 96.3

Total Fe μg/L 5 15.0 1,567 336 688

Total Mn μg/L 5 1.6 42.0 12.6 16.6

Fast Rinse

pH — 5 7.0 8.4 7.7 0.5

TSS mg/L 5 0.5 4.0 1.2 1.6

Total As μg/L 5 6.9 356 108 141

Total Al μg/L 5 5.5 30.3 13.5 10.0

Total Fe μg/L 5 3.7 15.0 11.8 5.0

Total Mn μg/L 5 1.3 9.5 4.7 3.8
30

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0 10 20 30 40 50 60 70 80 90

Time elapsed, minutes

Arsenic (mg/L)

TDS (g/L)

0.00

5.00

10.00

15.00

20.00

25.00

30.00

Sulfate (g/L)

As

TDS

SO4

Backwash Brine and slow rinse Fast rinse

Figure 4-7. TDS, Total Arsenic, and Sulfate during the IX System Regeneration at Plant A (June 13, 1999)

0.00

10.00

20.00

30.00

40.00

50.00

0 10 20 30 40 50 60 70 80 90

Time elapsed, minutes

TDS, TSS (g/L)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

pH

Flowrate (gpm)

TDS

TSS

pH

Flowrate

Backwash Brine and slow rinse Fast rinse

Figure 4-8. TDS, TSS, pH, and Flowrate during the IX System Regeneration at Plant A (June 13, 1999)
31

Based on the water usage data and arsenic concentrations in the inlet and outlet, the mass of arsenic removed 

from the raw water was estimated and is presented in

Table 4-9 (see data listed under June 13, 1999). Furthermore, the amount of arsenic recovered from the regeneration also was calculated using the arsenic concentrations 

and the volume of the eluate from each regeneration step. 

The percent recoveries of arsenic calculated by Equation 

3-1 were 71.9-78.5%. Substituting the arsenic for sulfate, 

the percent recovery of sulfate was 78.7%.

Table 4-9 also presents the percent recoveries of arsenic from previous regeneration events. Excluding the data

of March 21, 1999, the percent recoveries ranged from

66.5% to 85.5% with an average of approximately 75%. 

This average value is somehow lower than the reported 

values (85-100%) (Clifford, 1999), which could be due to 

aged resin or the grab sampling.

4.3 Plant B

Water samples were collected and analyzed at Plant B, 

an IX plant, during the following three phases of the

study: source water sampling, preliminary sampling, and 

long-term evaluation. Source water sampling at Plant B 

was performed in June 1998. Preliminary sampling consisted of weekly water sampling for a 4-week period in

August 1998 and was designed to determine if the sampling locations and proposed water quality analysis were 

appropriate for the third phase, long-term evaluation. 

The third phase was initiated in September 1998 and continued through June 1999. Arsenic speciation sampling 

was conducted every fourth week. Backwash/regeneration sample collection and analysis were not performed 

at Plant B due to lack of information on the automatic

regeneration schedule.

4.3.1 Plant B Description

Plant B supplies water to approximately 35 employees of 

a medical facility. The water source is a 260-ft-deep bedrock well drilled in October 1995. The capacity of this

well is 2 gpm based on a 48-hr pump test. The water

treatment system treats approximately 800 gpd.

During this test, arsenic and gross alpha radiation levels 

in the well water were found to exceed maximum regulatory levels required by the EPA (Table 4-10). Gross

alpha in source water was remeasured at 31.00 pCi/L on 

December 28, 1995, and the concentration of total uranium (U-234 and U-238) was measured at 27.72 pCi/L.

Subtracting the concentration of total uranium from the

concentration of gross alpha leaves a level of 3.28 pCi/L, 

which falls under the 5 pCi/L MCL for gross alpha radiation. Although treatment for gross alpha radiation was

determined to be unnecessary, a system capable of treating both the arsenic and gross alpha was installed by

Norlen’s Water Treatment Service at Orrington, ME, in

March 1996.

Plant B uses an oxidizing filter followed by a cation-anion 

mixed-bed filtration system. Figure 4-9 is a schematic

diagram of the treatment process used, which consists

of the following major elements:

• Intake. Raw water is pumped from a 260-ft-deep 

bedrock well and flows through a pressure tank.

• Oxidizing Filter. An MN1054AF oxidizing filter 

tank was installed after the pressure tank to oxidize 

possible As(III) to As(V). The oxidizing filter tank is 

a 54-inch-long and 10-inch-diameter fiberglass 

tank with automatic control valves. An MnO2-based 

material is used as the oxidizing medium and is 

regenerated by potassium permanganate solution.

• Ion Exchange System. After passing through the 

oxidizing filter, water flows into an LAT-32 IX tank 

filled with both cation and anion exchange resins. 

The IX tank has the same size as the oxidizing 

filter and the resin bed is 1.5 ft3 (containing both 

cation and anion resins). At a design flow of 2 gpm, 

the hydraulic loading rate to the filter is 3.7 gpm/ft2

Table 4-9. Percent Recoveries of Arsenic during the Resin Regeneration at Plant A

Date

Volume of Water 

Treated

(gal)

Volume of Water 

Treated

(BV)

As Removed from 

Raw Water(a)

(mg)

As Recovered from 

Regeneration(b)

(mg)

Percent Recovery

(%)

3/21/99 49,000 3,275 6,200 1,091 17.6

4/18/99 42,600 2,848 5,260 3,496 66.5

5/16/99 49,500 3,309 6,099 5,212 85.5

4,262 71.9

6/13/99 53,500 3,576 5,931 4,654(c) 78.5

Average 48,650 3,250 — — 74.6(d)

(a) Expressed as Mremoved in Equation 3-1. (c) Calculation was based on grab sample data.

(b) Expressed as Mrecovered in Equation 3-1. (d) Excluded data of 3/21/99.
32

Table 4-10. Typical Source Water Quality Data 

at Plant B (November 12, 1995)

Parameter Unit Concentration

Turbidity NTU 0.85

Fluoride mg/L 1.77

pH — 8.2

Hardness mg/L(a) 39.9

Sodium mg/L 13.9

Iron mg/L 0.16

Arsenic μg/L 52

Gross alpha pCi/L 36.02

(a) Measured as CaCO3.

and the EBCT is 5.6 min. Information on the type 

and volume of anionic resin was not available at 

the time of study. Figure 4-10 shows a photograph 

of the IX system.

• Regeneration/Backwash. The oxidizing filter is 

regenerated with potassium permanganate stored 

in a 1.5-ft3 canister. The IX filter is regenerated with 

SoftouchTM, a potassium chloride-based regenerant, stored in a brine tank. Regeneration and backwash of both filters take place automatically once 

every 6 days. Detailed information on flowrates 

and durations of regeneration and backwash were 

unavailable. The spent regenerant and backwash 

wastewater are disposed of to the facility’s septic 

tank.

The arsenic removal system (shown in Figure 4-10) is

fully automatic. The total cost of the system, including installation, piping and fittings, 1-year supply of SoftouchTM

, 

and 1-year service warranty, was $2,975.80 at the time 

of installation.

4.3.2 Initial Source Water Sampling

Plant B influent water is supplied by a 260-ft-deep bedrock well drilled in October 1995. Table 4-10 presents

the source water quality data on samples collected after 

the well installation. As can be seen, the arsenic concentration in the source water exceeded the 0.05 mg/L arsenic MCL. The source water arsenic was not speciated.

A site visit to Plant B was conducted on June 9, 1998 to 

collect source water samples. During this sampling event,

samples were collected for arsenic [total, particulate, soluble, As(III), As(V)] and various other water quality parameters that may affect arsenic removal. Table 4-11 

presents the analytical results from the source water

sampling. These results are similar to those of the previous sampling events shown in Table 4-10. The total 

arsenic concentration in the source water averaged 

55.0 μg/L; of this, approximately 0.8 μg/L was particulate 

arsenic and 0.8 μg/L was As(III). The majority of the soluble arsenic was As(V). This speciation information suggests that the oxidizing step of the Plant B treatment

system is unnecessary. The inlet total iron concentrations averaged 150 μg/L. Aluminum concentrations were 

less than the detection limit, and manganese concentrations averaged 20 μg/L.

Alkalinity concentrations averaged 62.5 mg/L (as CaCO3)

and total hardness concentrations averaged 36 mg/L (as 

CaCO3). This low hardness concentration suggests that

the softening function of the cation resin seems unnecessary. Turbidity concentration was relatively low, averaging 0.45 NTU and the pH averaged 8.3. Sulfate concentrations averaged 45.5 mg/L, which was higher than 

the sulfate level in the raw water at Plant A.

4.3.3 Preliminary Sampling

During the preliminary sampling phase, only the inlet and 

outlet samples were collected because of the lack of a

sampling tap between the oxidizing filter and the IX filter. 

The inlet sample was collected from a tubing connecting 

to the inlet piping to the system. A sink faucet was used 

for the outlet sampling. The sampling locations and the 

associated sample analyses are shown on Figure 4-9.

Alkalinity, sulfate, turbidity, pH, total hardness, nitratenitrite, total Al, total Fe, total Mn, and total arsenic analyses were performed on all water samples collected.

Arsenic speciation sampling was conducted at the two

sampling locations once during the preliminary study.

Arsenic form (soluble and particulate) and species

(arsenate and arsenite) were determined as part of the

arsenic speciation. Table 4-12 presents the results of the 

4-week preliminary sampling period.

Results from the preliminary sampling events indicated

that inlet total arsenic concentrations ranged from 53.2

to 57.1 μg/L, and were consistently higher than the arsenic MCL. As found during the source water sampling, the 

total arsenic in the source water was primarily As(V),

and contained only little or no As(III) or particulate arsenic. Except for the week of August 11, 1998, the average 

total arsenic removal was more than 95%, leaving less

than 1.0 μg/L arsenic in the finished water. The finished 

water in August 11, 1998 had an abnormally high total

arsenic concentration (16.8 μg/L), hardness concentration (24 mg/L as CaCO3

), pH (10.1), and turbidity

(1.9 mg/L). The reason for these abnormal results was 

not clear. It was suspected that the samples might have 

been contaminated. 
33

INFLUENT

1

PRESSURE TANK

OXIDIZING FILTER 

IX FILTER

2

DISTRIBUTION 

SYSTEM

MONTHLY WEEKLY

Plant B

Ion Exchange

Design Flow: 2 gpm

LEGEND

IX TANK Unit Process

RG/

BW

Regeneration/Backwash 

Sampling Location

1 Water Sampling 

Location

RG/

BW

SEPTIC TANK

RG: KCl

RG: KCl Regeneration

RG: KMnO4

RG/

BW

As (total), As (III), As (V), 

Hardness, Turbidity, NO3/NO2

As (total), As (III), As (V), 

Hardness, Turbidity, NO3/NO2

As (total), Alkalinity, pH,

Total Al,Total Fe, Total Mn, SO4

As (total), Alkalinity, pH,

Total Al,Total Fe, Total Mn, SO4

Backwash

Figure 4-9. Process Flow Diagrams and Sampling Locations at Plant B
34

Figure 4-10. Photograph of the IX System at Plant B

Table 4-11. Source Water Analytical Results at Plant B (June 9,1998)

Parameter Unit

Primary

Sample

Duplicate

Sample

Average 

Concentration

Alkalinity mg/L(a) 63 62 62.5

Sulfate mg/L 46 45 45.5

Turbidity NTU 0.45 0.44 0.45

pH — 8.3 8.3 8.3

Hardness mg/L(a) 36 36 36

Ca Hardness mg/L(a) 29.7 30 29.9

Mg Hardness mg/L(a) 5.9 5.8 5.9

Total Al μg/L <400 <400 <400

Total Fe μg/L 200 100 150

Total Mn μg/L 30 <20 20

NO3−NO2

 (N) mg/L(b) <0.02 <0.02 <0.02

TOC mg/L <1.0 <1.0 <1.0

As(total) μg/L 53.8 56.2 55.0

As(total soluble) μg/L 53.5 54.9 54.2

As(particulate) μg/L 0.3 1.3 0.8

As(III) μg/L 0.8 0.8 0.8

As(V) μg/L 52.7 54.1 53.4

(a) As CaCO3.

(b) Combined NO3−N and NO2−N.
35

Table 4-12. Analytical Results from Preliminary Sampling at Plant B (August 6 through 25, 1998)

Sampling Date/Location

8/6/98 8/11/98 8/18/98 8/25/98

Parameter Units IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 63 27 64

64

34

34 65 12 64 17

Sulfate mg/L 44 <5 47

48

<5

<5 44 <5 47 <5

Turbidity NTU 0.3 <0.1 0.2

0.2

1.8

1.9 0.5 <0.1 − −

pH − 8.4 7.2 8.2

8.4

10.1

10.1 8.2 8.5 8.4 7.9

Total Hardness mg/L(a) 33.8 <2.0 32.0

32.0

28.0

20.0 NS NS NS NS

Ca Hardness mg/L(a) 28.0 0.5 26.2

26.2

26.7

18.7 NS NS NS NS

Mg Hardness mg/L(a) 5.8 0.8 5.6

5.6

<0.8

<0.8 NS NS NS NS

Nitrate-Nitrite mg/L <0.02 <0.02 0.02

0.02

0.04

0.02 NS NS NS NS

As (total) μg/L 53.2

56.6

0.8

1.1 57.1 16.8 54.7 0.8 54.1 0.9

As (total soluble) μg/L 59.6

59.1

1.0

0.7 NS NS NS NS NS NS

As (particulate) μg/L ND

ND

ND

0.4 NS NS NS NS NS NS

As (III) μg/L 0.7

0.8

ND

ND NS NS NS NS NS NS

As (V) μg/L 58.9

58.3

0.9

0.7 NS NS NS NS NS NS

Total Al mg/L 23.1

14.6

3.2

9.1 31.2 28.2 17.8 25.1 24.2 21.9

Total Fe μg/L 120

100

ND

2.5 88.2 78.8 105 9.4 98.6 2.4

Total Mn μg/L 2.1

1.8

0.1

0.2 3.9 0.7 2.5 0.3 2.7 0.2

Dissolved Al μg/L 1.7

2.7

1.5

1.7 NS NS NS NS NS NS

Dissolved Fe μg/L ND

ND

ND

ND NS NS NS NS NS NS

Dissolved Mn μg/L 1.2

1.2

0.1

0.1 NS NS NS NS NS NS

(a) As CaCO3.

Because Plant B uses a mixed resin bed, it removes

both cations and anions from the source water. Total

hardness was reduced to nondetect level. Alkalinity

decreased from approximately 64 mg/L (as CaCO3) at

the inlet to 12-27 mg/L at the outlet, concurrent with the 

decreased pH values of the outlet samples. The inlet

sulfate concentrations, ranging from 44 to 48 mg/L, were 

significantly reduced to less than the detection limit

(5 mg/L) after treatment. Turbidity and nitrate-nitrite concentrations were extremely low in the raw water, so no

significant changes were observed after the treatment.

Total and dissolved Al, Fe, and Mn concentrations also 

were low in the raw water, and therefore, their effects on 

the process were insignificant.

4.3.4 Long-Term Sampling

Long-term sampling and analysis consisted of 36 weeks 

of water sampling at the same two locations used during 

the preliminary sampling phase (see Figure 4-9). All

weekly samples were analyzed for alkalinity, sulfate, pH, 

total aluminum, total iron, total manganese, and total
36

arsenic. Arsenic speciation sampling was conducted at

each sampling location nine times during the long-term 

sampling phase on samples collected from each sampling location. Analysis included determination of hardness, nitrate-nitrite, and dissolved aluminum, iron, and

manganese concentrations. Backwash and regeneration 

wastewater was not sampled due to lack of information 

on the automatic regeneration schedule. The following

subsections summarize the analytical results of arsenic

and other water quality parameters.

4.3.4.1 Arsenic

Table 4-13 provides a summary of the arsenic analytical 

results collected at the inlet and outlet sampling locations. Total arsenic concentrations at the inlet ranged

from 40.8 to 64.5 μg/L with an average of 56.7 μg/L, 

which are comparable with the data collected during the 

previous phases of the study. Total arsenic concentrations at the outlet ranged from 0.8 to 4.5 μg/L with an

average of 1.6 μg/L. Therefore, an average removal rate 

of 97% was achieved, corresponding well with the removal rates observed during the preliminary sampling 

phase. Figure 4-11 is a graph showing the total arsenic 

concentrations at both sampling locations throughout the 

study.

Particulate arsenic concentrations averaged 0.5 μg/L at

the inlet and 0.3 μg/L at the outlet. As(III) concentrations 

averaged 0.8 μg/L in the raw water and 0.2 μg/L in the

finished water. These results were consistent with those 

of the source water and preliminary sampling. As(V) concentrations averaged 56.7 μg/L in the raw water and

1.4 μg/L in the finished water. Therefore, As(V) made up

the majority of the soluble arsenic, which suggests that the 

oxidizing filter may not be necessary; however, the filter 

can act as a safeguard against any occurrence of As(III).

Throughout the study, the IX system was able to consistently remove arsenic to <5 μg/L (or <2 μg/L at 90% of

the time). The satisfactory performance of this treatment 

process is likely due to the frequent regeneration of the 

system. The maximum run length of the system (in terms 

of BV), however, might not have been reached before

each regeneration cycle. The maximum run length was

not estimated because of lack of information on the

anion resin bed volume and water usage data.

4.3.4.2 Other Water Quality Parameters

Several other water quality parameters also were analyzed to provide information on the performance of the

treatment plant. Table 4-14 summarizes the analytical 

results for the other water quality parameters obtained

during the long-term sampling.

The inlet sulfate concentrations, ranging from 36 to 49

mg/L with an average of 44.5 mg/L, were consistently 

reduced to <5 mg/L after the treatment process. Figure 

4-12 shows the inlet and outlet sulfate concentrations as 

well as removal percentages. Due to the frequent regeneration of the IX filter, the sulfate in the inlet water did

not seem to impact the system performance for arsenic 

removal.

Figure 4-13 plots the inlet and outlet alkalinity and pH

values throughout the study. Inlet alkalinity concentrations remained constant at levels of 62 to 65 mg/L (as

CaCO3). The alkalinity was removed through exchange

of bicarbonate ions with the chloride ions on the resin.

Inlet pH values were relatively constant throughout the

duration of the study. The outlet pH values varied from

6.1 to 8.8 and were below the inlet pH values most of the 

time, presumably due to the removal of alkalinity. The

elevated outlet pH did not seem to impact arsenic

removal.

Turbidity and nitrate-nitrite concentrations were very low 

in the raw and finished water, and no significant changes 

were found after the treatment. Total and dissolved Al,

Table 4-13. Summary of Arsenic Analytical Results at Plant B (September 1, 1998 to May 25, 1999)

Parameter Sampling Location Units

Number of 

Samples

Minimum 

Concentration

Maximum 

Concentration

Average 

Concentration

Standard 

Deviation

As (total) Inlet μg/L 45 40.8 64.5 56.7 4.6

Outlet μg/L 45 0.8 4.5 1.6 0.7

As (total soluble) Inlet μg/L 18 43.9 62.7 57.4 5.5

Outlet μg/L 18 0.9 2.9 1.7 0.7

As (particulate) Inlet μg/L 18 0.1 1.6 0.5 0.6

Outlet μg/L 18 0.1 1.2 0.3 0.4

As(III) Inlet μg/L 18 0.4 1.3 0.8 0.3

Outlet μg/L 18 0.1 0.6 0.2 0.2

As(V) Inlet μg/L 18 43.2 62.0 56.7 5.6

Outlet μg/L 18 0.8 2.6 1.4 0.6

One-half of the detection limit was used for nondetect samples for calculations.

Primary and duplicate samples were averaged for calculation.
37

0

20

40

60

80

100

08/06/98 10/05/98 12/04/98 02/02/99 04/03/99 06/02/99 08/01/99

Date

50%

60%

70%

80%

90%

100%

Inlet As

Outlet As

% Removal

Inlet

Outlet

% Removal

Figure 4-11. Total Arsenic Analytical Results during Long-Term Sampling at Plant B

Table 4-14. Summary of Water Quality Parameter Analytical Results at Plant B (September 1, 1998 to May 25, 1999)

Parameter Sampling Location Units

Number of 

Samples

Minimum 

Concentration

Maximum 

Concentration

Average 

Concentration

Standard 

Deviation

Alkalinity Inlet mg/L 45 62 65 63.8 0.7

Outlet mg/L 45 3 17 8.2 3.8

Sulfate Inlet mg/L 45 36 49 44.5 2.4

Outlet mg/L 45 <5 <5 <5 0

Turbidity Inlet NTU 18 <0.1 0.6 0.4 0.2

Outlet NTU 18 <0.1 0.2 0.1 0.1

pH Inlet — 45 7.8 8.6 8.3 0.1

Outlet — 45 6.1 8.8 7.3 0.9

Total Hardness Inlet mg/L 18 33.0 46.7 38.4 4.3

Outlet mg/L 18 <2.0 8.3 2.1 2.5

Nitrate-Nitrite Inlet mg/L 18 <0.02 0.06 0.03 0.02

Outlet mg/L 18 <0.02 0.03 0.01 0.01

Total Al Inlet μg/L 45 <11 68.3 15.2 13.3

Outlet μg/L 45 <11 131 12.9 21.1

Total Fe Inlet μg/L 45 <30 139 69.5 39.7

Outlet μg/L 45 <30 72.7 21.5 14.0

Total Mn Inlet μg/L 45 <0.5 3.6 2.1 0.8

Outlet μg/L 45 <0.5 5.5 0.5 0.9

Dissolved Al Inlet μg/L 18 <11 21.8 7.3 5.4

Outlet μg/L 18 <11 10.4 6.0 1.6

Dissolved Fe Inlet μg/L 18 <30 113.5 35.1 35.9

Outlet μg/L 18 <30 31.2 16.8 5.4

Dissolved Mn Inlet μg/L 18 1.4 2.8 2.0 0.5

Outlet μg/L 18 <0.5 <0.5 <0.5 0

One-half of the detection limit was used for nondetect samples for calculations.

Primary and duplicate samples were averaged for calculations.
38

0

20

40

60

80

100

08/06/98 10/05/98 12/04/98 02/02/99 04/03/99 06/02/99 08/01/99

Date

Sulfate concentration (mg/L)

0%

20%

40%

60%

80%

100%

% Removal

Inlet Sulfate

Outlet Sulfate

% Removal

Inlet

Outlet

% Removal

Detection limit of 5 mg/L

Figure 4-12. Inlet and Outlet Sulfate Analytical Results and Percent Removal at Plant B

0

40

80

120

160

200

08/06/98 10/05/98 12/04/98 02/02/99 04/03/99 06/02/99 08/01/99

Date

Alkalinity (mg/L as CaCO3)

2.0

4.0

6.0

8.0

10.0

12.0

Inlet alkalinity

Outlet alkalinity

Inlet pH

Outlet pH

Inlet alkalinity

Outlet alkalinity

Inlet pH

Outlet pH

Figure 4-13. Inlet and Outlet Alkalinity and pH Analytical Results at Plant B
39

Fe, and Mn concentrations were low in the raw water, so 

their effects on the arsenic removal process were minimal.

4.4 Plant C

Water samples were collected and analyzed at Plant C, 

an AA plant, during the following three phases of the

study: initial source water sampling (June 10, 1998), preliminary sampling (August 5 through September 16, 1998),

and long-term sampling (September 30, 1998 through

June 9, 1999). Water sampling was performed biweekly 

during the preliminary and long-term sampling. Arsenic

speciation sampling was conducted during the initial 

source water sampling, once during preliminary sampling, and once every 8 weeks during the long-term sampling. Spent AA samples were collected once from two

roughing tanks during AA change-out on December 29, 

1998.

4.4.1 Plant C Description

Plant C supplies water to a school used by approximately 600 students and teachers. The ADD of the school is 

approximately 2,000-2,500 gpd. The AA system was

installed by Aqua Specialties of Northwood, NH, in August 

27, 1997 with a design flowrate of 14 gpm. Figure 4-14 is 

a schematic of the AA system.

As shown on Figure 4-14, Plant C consists of four AA

tanks that are arranged as two parallel sets of two tanks 

in series. Figure 4-15 shows a cross section of an AA

tank. The first set of the tanks (TA1 and TA2) are used 

as roughing filters and the second set (TB1 and TB2) are 

used as polishing filters. The major elements of the treatment process are described as follows:

• Intake. Raw water is supplied by a 700-ft-deep 

well and flows through the water system control 

room. A water flowmeter was installed to measure 

the volume of water entering the treatment system.

• Cartridge Filters. Two Ametek “Big Blue” 

cartridge filters were installed in parallel on the raw 

water header to remove particles from the well 

water. The cartridge filters are approximately 

93⁄4 inches tall and 5 inches in diameter. The 

nominal rating of the cartridge is 30 μm.

• Activated Alumina Tanks. After passing through 

the cartridge filters, the filtered water splits into the 

two AA treatment trains. Gate valves exist to 

isolate each train and control the split ratio; however, no water meter is available on either train to 

confirm the exact split ratio. Each fiberglass mineral tank (52 inches tall by 16 inches in diameter) 

contains approximately 4 ft3

 of Alcoa DD-2 AA. The 

depth of the AA bed is approximately 33 inches, 

leaving a free board distance of approximately 

9 inches between the top header and the top of the 

medium. The AA medium/gravel support interface 

material is approximately 6 inches above the floor. 

The influent flows downward through the AA bed 

and the treated water returns to the top of the tank 

through a 1-inch polyvinyl chloride (PVC) riser 

tube. The differential pressure across the medium 

was approximately 3 psi.

Alcoa DD-2 (14 × 28 mesh) is a successor of F-1 

AA. Typical physical and chemical properties of 

this medium are presented in Table 4-15, and the 

material safety data sheet (MSDS) is attached in 

Appendix C.2. At a design flowrate of 7 gpm 

(assuming water is split evenly into each train), the 

hydraulic loading rate to each tank is 5.0 gpm/ft2

and the EBCT is 4.3 minutes.

• Media Replacement. The AA system at Plant C is 

operated on a media-throwaway basis. When the 

AA medium in the roughing filters reaches its arsenic removal capacity, the spent AA is removed and 

replaced with virgin medium. The polishing filters 

are moved to the roughing filter position by physically repositioning the filters. The tanks with the 

new virgin medium then are placed in the polishing 

position. The AA in all four tanks was virgin in 

September 1997. The AA in the two roughing tanks 

(TA1 and TA2) was replaced with virgin AA on 

December 29, 1998 due to arsenic breakthrough. 

Also on that date, tanks TB1 and TB2 were moved 

to the roughing positions and the recharged TA1 

and TA2 were moved to the polishing positions.

• Backwash. Backwash is not performed on a 

routine basis. Since their installation, the AA tanks 

have been backwashed only twice with the pressurized treated water. Backwash of TA1 was performed during Battelle’s visit on August 5, 1998 

and lasted for approximately 5 minutes at a flowrate of 3 gpm. Backwash wastewater was disposed 

of to the school’s leach field.

• Storage Tank. The treated water from each train is 

combined and flows to a 15,000-gal steel storage 

tank buried outside the school building. The storage tank invert is at an elevation of approximately 

20 ft above the school’s floor grade. Water in the 

storage tank also serves the school’s fire sprinkler 

system. Before distribution, the treated water is 

pressurized by two Flint & Walling 2-horsepower 

(hp) centrifugal booster pumps buffered by four 

119-gal pressure tanks.

Quarterly sampling for arsenic has been conducted by a 

plant staff since March 1996 on raw water, between the
40

1

4

Storage Tank

(15,000 gal)

BIWEEKLY BIMONTHLY

As (total), As (III), As (V), 

Hardness, Turbidity, NO3/NO2

-

Plant C

Activated Alumina

Design Flow: 14 gpm

LEGEND

Cartridge Filter

BW

Backwash Sampling 

Location

1 Water Sampling 

Location

As (total), Alkalinity, 

pH, Total Al, Total Fe, 

Total Mn, F, SO4

BW

As (total), pH, TSS

Leach Field

As (total), Alkalinity, 

pH, Total Al, Total Fe, 

Total Mn, F, SO4

BW

AA

 Water Content, Total As

 pH, TCLP metals

AA

Spent AA Sampling 

Location

As (total), As (III), As (V), 

Hardness, Turbidity, NO3/NO2

 To the distribution system

Tank A1 Tank A2

Tank B1

2

Flowmeter

CF

Tank B2

CF

As (total), As (III), As (V), 

Hardness, Turbidity, NO3

-

/NO2

-

As (total), Alkalinity, 

pH, Total Al, Total Fe, 

Total Mn, F, SO4

CF

Tank AA tank

3

From well

Figure 4-14. Process Flow Diagrams and Sampling Locations at Plant C
41

Figure 4-15. Cross Section of AA Tank at Plant C (Source: Aqua Specialties, 1999)
42

Table 4-15. Typical Characteristics of DD-2 

Activated Alumina

Physical Characteristics DD-2 AA (14x28 mesh)

Appearance (color, shape) White, granule

Surface area, m2/g 250

Total pore volume, cc/g 0.395

Total porosity, % 56.2

Bulk density, kg/m3

620-830

Abrasion loss, wt% 1.6

Chemical Composition (wt%)

Al2O3 92.2

Na2O 0.90

Fe2O3 0.08

SiO2 0.09

Loss on ignition (Water) 6.5

Alumina XRD phase Amorphors, boehmite, and gamma

Price, $/lb 1.01

roughing and the polishing tanks in each train, and from 

treated water. The arsenic concentration data are summarized in Table 4-16. The data show that the arsenic

concentrations in samples collected between TA2 and

TB2 on October 13, 1998 reached the 0.05 mg/L arsenic 

MCL, indicating arsenic breakthrough in TA2. Water

usage data have been recorded since the AA system

installation and are attached in Appendix C.3.

Table 4-16. Arsenic Concentrations (μg/L) from 

Quarterly Water Sampling at Plant C

Date Raw Water A1B1(a) A2B2(b) Treated Water

03/11/96 37 — — —

06/13/96 46 — — —

9/18/96 47 — — —

11/12/96 50 — — —

02/11/97 50 — — —

06/11/97 42 — — —

08/12/97 37 — — —

08/14/97 — — — <5

08/27/97(c) — — — 13

10/23/97 78 — — <5

1/15/98 — 12 20 <10

04/23/98 — 16 17 <10

08/04/98 — 33 36 7

10/13/98 — — 50 17

01/08/99 43 37 29 5

(a) Water collected from a tap between TA1 and TB1.

(b) Water collected from a tap between TA2 and TB2.

(c) The AA system was installed.

— = No data collected.

4.4.2 Initial Source Water Sampling

Source water for Plant C is supplied by a 700-ft-deep 

bedrock well (drilled in 1994) through a submersible

pump (Model No. 13GS20). The capacity of this well is

12-14 gpm based on a 48-hr continuous pump test.

Source water quality measurements on samples collected on December 30, 1994 are presented in Table 4-

17. The historic quarterly sampling data shown in Table 

4-16 indicate significant variation in raw water arsenic

concentrations, which ranged from 37 to 78 μg/L. These 

concentrations were close to or exceeded the arsenic

MCL. Information on arsenic speciation was unknown

prior to this study.

Table 4-17. Source Water Quality Measurements at 

Plant C (December 30, 1994)

Parameter Unit Concentration

Alkalinity mg/L(a) 105

Turbidity NTU <1.0

Fluoride mg/L 1.91

Chloride mg/L 4.0

Sulfate mg/L 23

pH — 8.3

Hardness mg/L(a) 52.2

Sodium mg/L 38.4

Specific Conductance μmhos/cm 259

Arsenic μg/L 42

(a) Measured as CaCO3.

On June 10, 1998, an initial site visit to Plant C was conducted and source water samples were collected. The

analytical results as presented in Table 4-18 are consistent with previous plant sampling data shown in Table 4-

17. The total soluble arsenic concentration was relatively 

high, averaging 61.9 μg/L. Approximately 30% of the soluble arsenic existed as As(III) (18.1 μg/L) and the rest was

As(V) (43.8 μg/L). Particulate arsenic was not detected

in the raw water.

4.4.3 Preliminary Sampling

During the preliminary sampling phase of this study,

water samples were collected at four locations: (1) at the 

inlet; (2) after the roughing tank of train 1 (TA1); (3) after 

the polishing tank of train 1 (TB1); and (4) at the combined effluent of trains 1 and 2. Sampling taps were available at all four sampling locations. Sampling locations and 

sample analyses are indicated on Figure 4-14.

Preliminary sampling consisted of biweekly sample collection and analysis of various parameters (alkalinity, turbidity, pH, hardness, fluoride, sulfate, total arsenic, total
43

Table 4-18. Source Water Sampling Analytical Results 

at Plant C (June 10, 1998)

Parameter Units

Primary 

Sample

Duplicate 

Sample Average 

Alkalinity mg/L(a) 86 82 84

Fluoride mg/L 1.5 1.5 1.5

Sulfate mg/L 26 26 26

Turbidity NTU 1.27 0.28 0.78

pH — 8.1 8.1 8.1

Hardness mg/L(a) 50.2 53.7 52.0

Ca Hardness mg/L(a) 31.7 35.2 33.5

Mg Hardness mg/L(a) 18.5 18.5 18.5

Total Al μg/L ND ND ND

Total Fe μg/L 110 100 105

Total Mn μg/L 100 90 95

NO3–NO2

 (N) mg/L(b) 0.06 0.04 0.05

TOC mg/L 1.3 1.1 1.2

As (total) μg/L 60.0 58.0 59.0

As (total soluble) μg/L 61.4 62.5 61.9

As (particulate) μg/L ND ND ND

As (III) μg/L 18.1 18.2 18.1

As (V) μg/L 43.3 44.3 43.8

(a) As CaCO3.

(b) Combined NO3–N and NO2–N.

Al, total Fe, and total Mn analyses). Arsenic speciation

sampling was conducted once on samples collected 

from inlet and TA1 locations. Table 4-19 presents the

results of the biweekly preliminary sampling events.

Similar to the results of historic quarterly sampling, inlet 

total arsenic concentrations varied significantly, ranging 

from 21.3 to 56.1 μg/L. During the arsenic speciation

sampling on August 5, 1998, the inlet water contained an 

average of 5.9 μg/L As(III), which is lower than the concentration measured during the source water sampling

(18.1 μg/L). Most As(III) was removed by the roughing

filter, as indicated by the As(III) concentrations (1.1 μg/L) 

measured after the roughing filter. Particulate arsenic

was not measured at significant levels in any of the samples collected during preliminary sampling.

During the first sampling event on August 5, 1998, the

roughing filter removed close to 50% of the total arsenic 

from the raw water. However, the total arsenic concentrations after the roughing filter approached or was over 

the influent levels during two subsequent sampling events 

(i.e., August 19 and September 16, 1998), which indicated 

the exhaustion of the AA medium in the roughing filter. 

Regardless of the arsenic breakthrough from the roughing filter, the polishing filter still was able to reduce arsenic concentrations to low levels (e.g., 1.6 to 9.3 μg/L).

The combined treated water from both trains had total

arsenic concentrations ranging from 2.8 to 11.6 μg/L.

Fluoride concentrations ranged from 1.1 to 1.6 mg/L in

the raw water and 1.3 to 1.6 mg/L in the finished water. 

Therefore, fluoride was not removed by the AA tanks.

Similarly, sulfate concentrations remained relatively constant at 22 to 27 mg/L throughout the treatment process. 

Fluoride is known to be a major competing ion with arsenate for adsorption sites on AA surface, especially in an 

optimal pH range of 5.5-6.0. Sulfate also has some affinity for the AA surface (see Section 1.1.3.2). Removal of 

sulfate and fluoride by AA was not observed during these 

sampling events, thus confirming AA’s higher order of

preference for arsenate. Other factors such as high pH

values of the inlet water and near-exhaustion AA capacity, also might have contributed to the low reduction of

sulfate and fluoride. Clifford et al. (1986) reported that

the addition of 360 mg/L sulfate and 1,000 mg/L TDS

decreased the As(V) adsorption on AA by almost 50%.

Vagliasindi et al. (1996) found that arsenate adsorption

was insensitive to sulfate concentrations in the range of 

0 to 100 mg/L. Therefore, sulfate concentrations in raw 

water were not high enough to significantly affect the

As(V) removal. Alkalinity, total hardness, and nitrate/

nitrite remained relatively constant after the treatment.

Total aluminum concentrations slightly increased after the 

roughing and polishing tanks. The increase in aluminum 

concentration might have resulted from the dissolution of 

AA medium. Total iron and manganese concentrations in 

the raw water were rather low and did not appear to

impact arsenic removal.

Based on the results of the preliminary sampling, only

minor changes were made to the approach for the longterm evaluation. Sampling locations and analytes remained unchanged. However, arsenic speciation was

performed at all four locations during the long-term evaluation instead of just at the inlet and TA1 locations.

4.4.4 Long-Term Sampling

Biweekly long-term sampling and analysis was performed for 36 weeks (18 events) for alkalinity, fluoride, 

sulfate, turbidity, pH, hardness, nitrate-nitrite, total aluminum, total iron, total manganese, and total arsenic.

Long-term sampling also included five arsenic speciation 

sampling events at each sampling location. The four

sampling locations used during the preliminary sampling 

also were used during long-term sampling. Additionally,

spent AA samples were collected once during AA replacement.

4.4.4.1 Arsenic

Table 4-20 summarizes the arsenic analytical results collected at the four sampling locations. Total arsenic concentrations at the inlet ranged from 34.4 to 76.0 μg/L 

with an average of 53.5 μg/L. These concentrations were 

consistent with the historic arsenic data (Table 4-16).
4

4

Table 4-19. Analytical Results from Preliminary Sampling at Plant C (August 5 through September 16, 1998)

Sampling Date and Location

8/5/98 8/19/98 9/2/98 9/16/98

IN TA1 TB1 OU IN TA1 TB1 OU IN TA1 TB1 OU IN TA1 TB1 OU

Alkalinity mg/L(a) 72 69 77 67 69

66

72

70

75

84

65

66 71 81 82 80 87 88 88 87

Fluoride mg/L 1.4 2.0 1.5 1.5 1.1

1.2

1.3

1.3

1.4

1.4

1.3

1.3 1.2 1.3 1.4 1.4 1.6 1.6 1.6 1.6

Sulfate mg/L 22 23 23 22 23

24

24

23

23

24

23

23 23 23 23 23 27 28 27 27

Turbidity NTU 0.2 <0.1 <0.1 <0.1 0.3

0.3

<0.1

<0.1

<0.1

<0.1

<0.1

<0.1 − − − − − − − −

pH − 7.9 7.9 7.7 7.9 8.0

8.0

8.0

8.0

7.9

7.9

7.9

7.9 8.5 8.3 8.0 8.2 8.2 8.1 7.8 7.4

Total Hardness mg/L(a) 54 51 54 50 − − − − − − − − − − − −

Ca Hardness mg/L(a) 35.5 33.5 35.7 31.7 − − − − − − − − − − − −

Mg Hardness mg/L(a) 18.3 17.9 18.3 17.8 − − − − − − − − − − − −

NO3-NO2 (N) mg/L(b) 0.1 0.1 <0.1 0.1 − − − − − − − − − − − −

As (total) μg/L 38.8

37.3

17.8

19.5

2.3

2.5

2.8

2.8 21.3 22.8 2.9 4.0 38.5 18.6 1.6 3.0 56.1 41.4 9.3 11.6

As (total soluble) μg/L 37.1

35.4

19.7

21.2 − − − − − − − − − − − − − −

As (particulate) μg/L 1.7

1.9

<0.1

<0.1 − − − − − − − − − − − − − −

As (III) μg/L 7.0

4.8

0.2

2.0 − − − − − − − − − − − − − −

As (V) μg/L 30.1

30.6

19.5

19.2 − − − − − − − − − − − − − −

Total Al μg/L <11

14.8

33.0

29.7

48.6

45.2

30.5

29.4 19.0 34.4 41.6 32.8 18.6 38.5 41.8 39.2 29.5 36.9 33.2 37.9

Total Fe μg/L 73.2

48.5

<30

30.1

49.8

59.9

<30

<30 70.0 <30 <30 <30 64.3 <30 <30 <30 50.6 <30 <30 <30

Total Mn μg/L 95.1

88.1

77.2

78.8

71.9

75.0

76.3

75.0 112 83.1 88 77.2 88.8 90.8 85.3 93.3 67.6 78.1 76.9 78.6

Dissolved Al μg/L <11

<11

14.3

12.1 − − − − − − − − − − − − − −

Dissolved Fe μg/L <30

<30

<30

<30 − − − − − − − − − − − − − −

Dissolved Mn μg/L 88.2

89.4

81.8

81.8 − − − − − − − − − − − − − −

(a) Measured as CaCO3.

(b) Combined NO3-NO2 as N.

IN = inlet; TA1 = after Tank A1; TB1 = after Tank B1; OU = effluent.

− = No analysis performed.
45

Table 4-20. Summary of Arsenic Analytical Results at Plant C (September 30, 1998 to June 9, 1999)

Parameter Sampling Location Units

Number of 

Samples

Minimum 

Concentration

Maximum 

Concentration

Average 

Concentration

Standard 

Deviation

As (total) Inlet μg/L 23 34.4 76.0 53.5 9.4

After 1st tank μg/L 22 14.2 50.4 39.3 8.7

After 2nd tank

Outlet

μg/L

μg/L

23

23

0.4

1.3

26.7

21.8

6.8

7.2

9.2

6.8

As Inlet μg/L 10 42.3 63.6 54.9 8.1

(total soluble) After 1st tank μg/L 10 33.9 50.1 43.0 6.1

After 2nd tank

Outlet

μg/L

μg/L

10

10

0.4

1.8

26.0

18.6

7.1

6.8

9.9

6.5

As Inlet μg/L 10 <0.1 13.4 5.1 6.2

(particulate) After 1st tank μg/L 9 <0.1 <0.1 <0.1 0

After 2nd tank

Outlet

μg/L

μg/L

10

10

<0.1

<0.1

0.6

6.9

0.2

0.8

0.2

2.2

As (III) Inlet μg/L 10 <0.1 28.8 7.9 11.2

After 1st tank μg/L 10 0.3 9.1 3.0 3.3

After 2nd tank

Outlet

μg/L

μg/L

10

10

0.1

<0.1

2.6

1.9

0.6

0.7

0.8

0.7

As (V) Inlet μg/L 10 34.4 55.4 45.2 6.9

After 1st tank μg/L 10 33.6 48.3 39.9 6.4

After 2nd tank

Outlet

μg/L

μg/L

10

10

<0.1

<0.1

25.6

17.6

6.6

6.0

10.0

6.6

One-half of the detection limit was used for nondetect samples for calculations.

Primary and duplicate samples were averaged for calculations.

The first tank was TA1 before the medium change-out on December 29, 1998 and TB1 after the medium change-out.

The second tank was TB1 before the medium change-out on December 29, 1998 and TA1 after the medium change-out.

Samples collected after the roughing tank contained total 

arsenic of 14.2 to 50.4 μg/L with an average of 39.3

μg/L. Samples collected after the polishing tank contained total arsenic of 0.4 to 26.7 μg/L with an average of 

6.8 μg/L. The combined treated water (i.e., outlet) had

total arsenic concentrations ranging from 1.3 to 21.8

μg/L with an average of 7.2 μg/L. The average removal 

percentages were 26.5% and 87.3% by the roughing

and polishing tanks, respectively. The average overall

arsenic removal efficiency was 86.5% during the longterm sampling.

Figure 4-16 provides charts showing the fractions of the 

total arsenic concentration made up by particulate arsenic, As(III), and As(V) at each sampling location. The

inlet water contained primarily the oxidized species of

arsenic [i.e., As(V)] with various amounts of As(III) (0 to 

45%) and particulate arsenic (0 to 22%). Particulate arsenic was only detected in the inlet water on September 30, 

1998 and May 26, 1999 with concentrations averaging 

12.8 and 11.8 μg/L, respectively. Because total iron concentrations in the inlet samples also were abnormally 

high, it was suspected that some arsenate might have

clung to some iron particles, resulting in high particulate 

arsenic concentrations. Except for September 30, 1998, 

most particulate arsenic was removed by the system.

As(III) concentrations averaged 7.9 μg/L at the inlet,

3.0 μg/L after the roughing tank, 0.6 μg/L after the polishing tank, and 0.7 μg/L at the outlet location. Therefore, As(III) was almost completely removed by AA.

Because no oxidative treatments were performed ahead 

of the AA columns, conversion of As(III) to As(V) was

rather unlikely. The removal of As(III) would occur either 

through a direct sorption of As(III) or via some unexplained conversions of As(III) to As(V) prior to adsorption. Clifford and Lin (1984; 1991) had observed some

unplanned oxidation of As (III) to As(V) within alumina

columns, which resulted in better-than-expected performance for arsenic removal. Nonetheless, the adsorption of As(III) onto AA has been reportedly far less than 

that of As(V) (Vagliasindi, and Benjamin, 1997; Clifford, 

1999). Therefore, arsenite should be oxidized to arsenate prior to AA treatment.

The average As(V) concentrations were 45.2 μg/L at the 

inlet, 39.9 μg/L after the roughing tank, 6.6 μg/L after the 

polishing tank, and 6.0 μg/L at the outlet location. The

arsenic in the finished water consists almost entirely of

As(V).

Figure 4-17 presents the total arsenic concentrations at 

each sampling location and the overall removal percentages for each sampling event. The data were plotted 

twice, with one graph showing the sampling date and the 

other showing the BV of the water treated. BV was

calculated using the amount of water treated divided by 

the AA volume in each tank (4 ft3 or 29.92 gallons).
46

 Inlet

0

10

20

30

40

50

60

70

09/30/98 12/02/98 02/03/99 03/31/99 05/26/99

As (particulate)

As (III)

As (V) TA1

0

10

20

30

40

50

60

70

09/30/98 12/02/98 02/03/99 03/31/99 05/26/99

As (particulate)

As (III)

As (V)

TB1

0

10

20

30

40

50

60

70

09/30/98 12/02/98 02/03/99 03/31/99 05/26/99

As (particulate)

As (III)

As (V) Outlet

0

10

20

30

40

50

60

70

09/30/98 12/02/98 02/03/99 03/31/99 05/26/99

As (particulate)

As (III)

As (V)

Figure 4-16. Arsenic Form and Species Analytical Results during Long-Term Sampling at Plant C

As shown in Figure 4-17, the AA capacity of TA1 (the

roughing tank of train 1) was nearly exhausted after treating 10,050 BV of water. The plant record also indicated 

that arsenic breakthrough occurred in TA2 (the roughing 

tank of train 2) on October 13, 1998 after treating 9,156 

BV of water (see Table 4-16). Therefore, both TA1 and 

TA2 were recharged with virgin AA and repositioned to

become polishing tanks. TB1 and TB2 then were moved 

to the first position and used as roughing tanks. Within 1 

to 2 weeks after the medium replacement and tank

rearrangement, the total arsenic concentrations dropped 

to <20 μg/L after the roughing tank and <5 μg/L in the

system effluent. Afterwards, the arsenic concentrations 

after the roughing tank gradually increased to inlet levels 

again, indicating arsenic breakthrough from the roughing 

tank (TB1). Nonetheless, the arsenic concentrations 

measured after the polishing tank were consistently 

below 5 μg/L.

To estimate the AA capacity for arsenic in TA1 and TA2, 

the following assumptions were made: (1) 9,600 BV of

water were treated before arsenic breakthrough from

TA1 and TA2; (2) 53.5 μg/L total arsenic were in the raw 

water (see Table 4-20); (3) 30.7 μg/L total arsenic were 

in TA1 and TA2 effluent (calculated based on available

data from the plant record, preliminary sampling events, 

and long-term evaluation); and (4) the density of the AA 

was 730 kg/m3 (see Table 4-15). Using the above assumptions, 49.6 g of total arsenic was removed from the raw 

water by the two roughing tanks prior to 50-μg/L arsenic 

breakthrough, equivalent to an AA capacity of 0.30 g/kg 

(219 g/m3). This value is comparable to the AA capacity 

of 0.26 g/kg (to 50 μg/L arsenic breakthrough) reported 

by Fox (1989) in his study with a source water of pH 8.3 

and containing 50 to 350 μg/L As(V). Clifford (1999) estimated the practically achievable column capacity based 

on pH 6.0 operation with a source water containing 100 

μg/L As(V) to be 1,400 g As(V)/m3 of alumina, which was 

much higher than the capacity obtained for Plant C. Because Plant C operated under less ideal conditions (i.e., 

higher pH), it would not be expected to achieve the

same level of arsenic removal.

4.4.4.2 Other Water Quality Parameters

Sampling and analysis of other water quality parameters 

were performed to provide insight into the arsenic removal efficiency at the plant. Table 4-21 summarizes the 

analytical results for several water quality parameters 

obtained during long-term sampling at Plant C. Figure 4-18
47

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0

09/12/98 11/01/98 12/21/98 02/09/99 03/31/99 05/20/99 07/09/99

Date

0

20

40

60

80

100

Arsenic removal (%)

Inlet

TA1

TB1

Outlet

% Removal

TA1 was used as the roughing tank and TB1 was used as

the polishing tank before medium change-out on December

29, 1998; since then, TB1 was used as the roughing tank

and the recharged TA1 was used as the polishing tank.

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0

8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0

BV of water treated (x1000)

0

20

40

60

80

100

Arsenic removal (%)

Inlet

TA1

TB1

Outlet

% Removal

Roughing tanks replaced with virgin AA

after treating 11,071 BV of water

Arsenic broke through TA1

after treating 10,050 BV of water

Figure 4-17. Total Arsenic Analytical Results during Long-Term Sampling at Plant C
48

Table 4-21. Summary of Water Quality Parameter Analytical Results at Plant C (September 30, 1998 to 

June 9, 1999)

Parameter

Sampling 

Location Units

Number of 

Samples

Minimum 

Concentration

Maximum 

Concentration

Average 

Concentration

Standard 

Deviation

Alkalinity Inlet mg/L 23 67 90 81.1 6.3

After 1st tank mg/L 23 73 89 83.3 4.1

After 2nd tank

Outlet

mg/L

mg/L

23

23

73

72

89

87

80.9

78.3

4.4

4.6

Fluoride Inlet mg/L 23 1.2 1.6 1.4 0.11

After 1st tank mg/L 23 0.9 1.7 1.4 0.17

After 2nd tank

Outlet

mg/L

mg/L

23

23

0.3

0.2

1.6

1.6

1.3

1.2

0.33

0.36

Sulfate Inlet mg/L 23 22 27 25.2 1.2

After 1st tank mg/L 23 23 27 25.3 1.0

After 2nd tank

Outlet

mg/L

mg/L

23

23

18

19

35

29

25.9

25.2

3.5

2.1

Turbidity Inlet NTU 5 <0.1 0.3 0.14 0.11

After 1st tank NTU 5 <0.1 <0.1 <0.1 0

After 2nd tank

Outlet

NTU

NTU

5

5

<0.1

<0.1

<0.1

0.15

<0.1

0.07

0

0.04

pH Inlet — 23 7.8 8.1 8.0 0.1

After 1st tank — 23 7.8 8.1 7.9 0.07

After 2nd tank

Outlet

—

—

23

23

7.6

7.6

8.6

8.7

8.0

8.0

0.2

0.3

Total Hardness Inlet mg/L 5 47 57 52.4 4.6

After 1st tank mg/L 5 49 53 50.9 1.7

After 2nd tank

Outlet

mg/L

mg/L

5

5

48

48

52

53

49.2

50.3

1.8

1.8

NO3

-NO2 (N) Inlet mg/L 5 0.01 0.1 0.04 0.03

After 1st tank mg/L 5 0.01 0.3 0.14 0.11

After 2nd tank

Outlet

mg/L

mg/L

5

5

0.05

0.02

0.6

1.3

0.25

0.31

0.22

0.55

Total Al Inlet μg/L 23 <11 97.4 18.3 21.1

After 1st tank μg/L 23 12.7 59 27.5 12.3

After 2nd tank

Outlet

μg/L

μg/L

23

23

<11

12.6

109

112

29.4

32.5

24.2

23.2

Total Fe Inlet μg/L 23 <30 178 53.4 49.0

After 1st tank μg/L 23 <30 60.5 20.0 12.4

After 2nd tank

Outlet

μg/L

μg/L

23

23

<30

<30

25.6

125

15.6

36.3

2.5

36.4

Total Mn Inlet μg/L 23 48.9 90.7 67.2 11.9

After 1st tank μg/L 23 30.4 88.7 69.2 17.9

After 2nd tank

Outlet

μg/L

μg/L

23

23

1.9

6.4

87.9

86

55.2

46.5

25.9

28.6

Dissolved Al Inlet μg/L 10 <11 <11 <11 0

After 1st tank μg/L 10 <11 15.1 10.5 3.6

After 2nd tank

Outlet

μg/L

μg/L

10

10

<11

<11

23.3

23.3

12.6

13.4

7.7

7.7

Dissolved Fe Inlet μg/L 10 <30 <30 15 0

After 1st tank μg/L 10 <30 <30 15 0

After 2nd tank

Outlet

μg/L

μg/L

10

10

<30

<30

<30

<30

15

22.6

0

17.1

Dissolved Mn Inlet μg/L 10 52.2 68.1 63.1 6.3

After 1st tank μg/L 10 30.2 81.3 67.2 21.4

After 2nd tank

Outlet

μg/L

μg/L

10

10

16.0

10.3

76.3

75.8

56.2

45.7

24.6

25.2

One-half of the detection limit was used for nondetect samples for calculations.

Primary and duplicate samples were averaged for calculations.

The 1st tank was TA1 before the medium change-out on December 29, 1998 and TB1 after the medium change-out.

The 2nd tank was TB1 before the medium change-out on December 29, 1998 and TA1 after the medium change-out.
49

0.0

20.0

40.0

60.0

80.0

100.0

09/12/98 11/01/98 12/21/98 02/09/99 03/31/99 05/20/99 07/09/99

Date

Alkalinity (mg/L as CaCO3)

6

7

8

9

10

11

12

pH

Inlet alkalinity

Outlet alkalinity

Inlet pH

Outlet pH

AA change-out

Inlet pH

Inlet alkalinity

Outlet alkalinity

Outlet pH

AA change-out on December 29, 1998

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

09/12/98 11/01/98 12/21/98 02/09/99 03/31/99 05/20/99 07/09/99

Date

Sulfate concentration (mg/L)

0

2

4

6

8

10

Fluoride concentration (mg/L)

Inlet sulfate

Outlet sulfate

Inlet fluoride

Outlet fluoride

AA change-out

Inlet fluoride

Inlet sulfate

Outlet sulfate

Outlet fluoride

AA change-out on December 29, 1998

Figure 4-18. Inlet and Outlet Alkalinity, pH, Fluoride, and Sulfate Analytical Results at Plant C
50

plots the inlet and outlet water alkalinity, pH, fluoride,

and sulfate at Plant C.

Inlet alkalinity concentrations were relatively constant,

ranging from 67 to 90 mg/L (as CaCO3) with an average 

of 81.1 mg/L. Alkalinity remained relatively constant

across all four sampling locations. Inlet pH values

ranged from 7.8 to 8.1 with an average of 8.0. This pH

was higher than the optimal pH for the AA process,

which ranges from 5.5 to 6.0. Because pH adjustment

was not applied, the AA system was not operated for an 

optimal run length (or an AA adsorption capacity). Therefore, the run length of 9,600 BV (219 g/m3

) achieved at 

Plant C was shorter than the 15,536 BV (1,242 g/m3) 

reported by Hathaway and Rubel (1987) who operated the 

AA columns at pH 5.5. Nonetheless, the performance of 

the AA system demonstrated that a throwaway AA treatment system operating without pH adjustments is able to

consistently remove arsenic to low levels (i.e., <5 μg/L). 

The ease of operation and low O&M cost of such a throwaway system make this AA system an appealing option 

for small water treatment plants and POE systems.

Fluoride and sulfate in the raw water are the major competing ions for adsorption on AA. As shown on Figure 4-

18, inlet fluoride and sulfate concentrations were relatively constant, ranging from 1.2 to 1.6 mg/L for fluoride 

and 22 to 27 mg/L for sulfate. Removal of either ion

through the treatment process was insignificant most of 

the time, except for several weeks immediately after the 

medium replacement. For example, during the first week 

after medium replacement, fluoride concentrations decreased from 1.2 to 0.9, 0.3, and 0.2 mg/L across the

treatment process. The same trend lasted for subsequent sampling events until the fluoride removal capacity 

was reached. Sulfate removal appeared to be less significant than that of fluoride.

Turbidity, hardness, NO3-NO2 (N), total Al, Fe, and Mn

contents in the inlet water were relatively low. Therefore, 

their effects on the arsenic removal efficiency were insignificant. In some cases, turbid source water, which can be 

caused by iron precipitates if iron concentration is high,

may clog the AA filter and reduce the treatment efficiency.

Therefore, a cartridge filter often is installed prior to the 

AA bed to prevent medium clogging and fouling.

After the media replacement, total Al concentrations increased significantly in the tank effluent and combined

finished water, indicating alumina dissolution. An example can be found from the data of January 6, 1999, when 

total Al concentrations increased from nondetect levels

to 42, 109 and 112 μg/L at the TA1, TB1, and outlet

locations, respectively.

4.4.4.3 Spent AA Samples

Spent AA samples were collected from two roughing tanks

(TA1 and TA2) during AA replacement on December 29, 

1998. Subsamples were analyzed for TCLP metals

(arsenic, barium, cadmium, chromium, lead, mercury,

selenium, and silver) and percent moisture. As shown in 

Table 4-22, arsenic was not detected in leachate of the 

spent AA sample from TA1, and slightly above the

detection limit in leachate of the spent AA sample from

TA2. None of the results from analyses of spent AA from 

Plant C indicate exceedances of TCLP limits.

Table 4-22. Analytical Results of Spent AA Samples at Plant C

Parameter Unit MDL Tank A1 Tank A2

TCLP Metals

As-TCLP mg/L 0.05 <0.05 0.066

Ba-TCLP mg/L 1.0 1.2 1.2

Cd-TCLP mg/L 0.020 <0.02 <0.02

Cr-TCLP mg/L 0.030 <0.03 <0.03

Pb-TCLP mg/L 0.20 <0.2 <0.2

Hg-TCLP mg/L 0.0002 <0.0002 <0.0002

Se-TCLP mg/L 0.05 <0.05 <0.05

Ag-TCLP mg/L 0.020 <0.02 <0.02

TCLP extraction NA NA Complete Complete

Percent moisture % 0.1 36 24

NaOH Rinse Time (min)

Parameter Unit MDL 30 minutes 120 minutes 30 minutes 120 minutes

Caustic Wash(b)

Total As g/kg, dry 0.1(a) 0.09 0.11 0.07 0.10

Total Al g/kg, dry 11(a) 0.20 0.23 0.35 0.40

Fluoride g/kg, dry 0.1(a) 0.27 0.31 0.39 0.47

Sulfate g/kg, dry 5

(a) 3.16 3.17 NA NA

(a) MDL is in units of μg/L for digestate.

(b) Spent AA was washed with 1% NaOH solution for 30 and 120 minutes, respectively.
51

Spent AA subsamples were rinsed with 1% NaOH solution for 30 and 120 minutes, respectively, to strip arsenic, fluoride, and sulfate from the AA surface. The waste 

solution was analyzed for total arsenic, total aluminum,

fluoride, and sulfate. As shown in Table 4-22, the contact 

time of 120 minutes yielded higher arsenic concentrations than the contact time of 30 minutes, suggesting

that it might take longer than 30 minutes to reach desorption equilibrium. For the contact time of 120 minutes, 

the arsenic loading was 0.11 and 0.10 g/kg dry AA for

TA1 and TA2, respectively. Compared with the 0.30 g/kg 

adsorption capacity estimated in Section 4.4.4.1, only

one-third of the arsenic was recovered by the caustic

wash. Clifford and Lin (1986) found that 50 to 70% of

arsenic could be recovered from the AA columns during 

regeneration. Hathway and Rubel (1987) recovered 80-

82% of the arsenic during their pilot studies. In both

studies, a 4% NaOH solution was used to regenerate the 

AA media. Therefore, a 4% NaOH solution and a 16-hr 

contact time were used in a similar test performed on

spent AA samples collected from Plant D.

4.5 Plant D

Water samples were collected and analyzed at Plant D, 

an AA plant, during the following three phases of the

study: initial source water sampling (June 10, 1998), preliminary sampling (August 5 through September 16,

1998), and long-term sampling (September 30, 1998

through September 1, 1999). Similar to Plant C, water 

sampling was performed biweekly during the preliminary 

and long-term sampling. Arsenic speciation sampling

was conducted during the initial source water sampling, 

once during preliminary sampling, and every 8 weeks

during the long-term sampling. Spent AA samples were 

collected once from one roughing tank in Plant D during 

medium replacement on May 25, 1999.

4.5.1 Plant D Description

Plant D serves approximately 200 employees in a manufacturer’s warehouse. The ADD is approximately 3,000

gpd. The AA system was installed by Secondwind Environmental of Manchester, NH, in February 1996 with a

design flowrate of 20 gpm. The plant consists of four AA 

tanks, which are positioned as two parallel sets of two

tanks in series. The first set of tanks are used as roughing filters and the second set of tanks as polishing filters 

(Figure 4-19).

The treatment process at Plant D consists of the following major elements:

• Intake. Raw water is supplied from a 500-ft-deep 

well by a submersible pump at a flowrate of 

20 gpm. Influent water is pressurized in a WX 205 

captive-air hydropneumatic tank.

• Chlorination. Approximately 1 mg/L chlorine is 

added to the water through a single conventional 

LMI chemical feed pump. The purposes of 

chlorination are to convert all arsenite [As(III)] to 

arsenate [As(V)] and to disinfect the water.

• Cartridge Filter. One Harmsco cartridge filter was 

installed on the raw water header to remove particles from the well water. The filter is approximately 

21 inches long and 13 inches in diameter, and is 

reusable. The nominal rating of the cartridge is 

20 μm.

• Activated Alumina Tanks. The effluent from the 

cartridge filter splits into two AA treatment trains of 

two tanks in series. Gate valves exist to isolate 

each train and control the split ratio. A flowmeter is 

available on each train to confirm the exact split 

ratio. Each fiberglass mineral tank (6-ft-tall by 2-ftdiameter) contains approximately 10 ft3

 of Alcoa 

CPN AA (28 by 48 mesh). Table 4-23 lists typical 

physical and chemical properties of this medium. 

The influent flows downward through the AA bed 

and the effluent is collected at the bottom of the 

tank. At a design flowrate of 10 gpm (assuming 

water is split evenly into each train), the hydraulic 

loading rate to each tank is 3.18 gpm/ft

2

 and the 

EBCT is 7.5 min. The differential pressure across 

the medium was approximately 3 psi.

• Medium Replacement. Same as Plant C, the AA 

system at Plant D is operated on a throwaway basis 

without pH adjustments. When the AA medium in 

the roughing filters reaches its total arsenic removal 

capacity, the spent AA is removed and replaced 

with a virgin medium. The polishing filters are 

moved to the roughing filter position, and the tanks 

with the new virgin medium then are placed in the 

polishing position. The tank rearrangement is 

accomplished by changing the water flow through 

valving, which is different from Plant C where the 

medium tanks need to be physically repositioned. 

A diagram of the system plumbing is provided in 

Appendix D.2.

All four tanks contained virgin AA in February 1996 

when the system was installed. The roughing 

tanks, TA1 and TA2, were replaced with virgin AA 

in November 1997 due to arsenic breakthrough.

Approximately 1 month later, TB1 and TB2 were 

recharged with virgin AA because the medium had 

cemented. The spent AA passed the TCLP test 

and was disposed of as a nonhazardous waste. 

From November 11, 1997 to May 25, 1999, TB1 
52

1

4

Storage Tank

(3,000 gal)

BIWEEKLY BIMONTHLY

As (total), As (III), As (V), 

Hardness, Turbidity, NO3/NO2

Plant D

Activated Alumina

Design Flow: 20 gpm

LEGEND

AA tank

BW

Backwash Sampling 

Location

1 Water Sampling 

Location

As (total), Alkalinity, 

pH, Total Al, Total Fe, 

Total Mn, F, SO4

BW

Septic Tank

As (total), Alkalinity, 

pH, Total Al, Total Fe, 

Total Mn, F, SO4

BW

AA

 Water Content, Total As

 pH, TCLP metals

AA

Spent AA Sampling 

Location

As (total), As (III), As (V), 

Hardness, Turbidity, NO3/NO2

 To the distribution system

Tank B1* Tank B2*

Tank A1*

2

captive-air

hydropneumatic

tank

From well

Tank

Tank A2*

Cartridge

Filter

As (total), As (III), As (V), 

Hardness, Turbidity, NO3/NO2

As (total), Alkalinity, 

pH, Total Al, Total Fe, 

Total Mn, F, SO4

DA:Cl2

GAC Tank

DA:Cl2

Disinfectant

Addition Point

3

Note:

* The system plumbing can be reconfigured to place 

Tanks A1 and A2 into the lead positions and Tanks 

B1 and B2 into the polishing positions.

Figure 4-19. Process Flow Diagrams and Sampling Locations at Plant D
53

Table 4-23. Typical Characteristics of CPN 

Activated Alumina

Physical Characteristics CPN AA (28x48 mesh)

Appearance (color, shape) White, granule

Surface area, m2/g 300 -340

Total pore volume, cc/g 0.5

Total porosity, % 60.6

Bulk density, lb/ft3

 (kg/m3) 47 (752)

Abrasion loss, wt% 0.2

Chemical Composition (wt%)

Al2O3 94.1

Na2O 0.3

Fe2O3 0.03

SiO2 0.02

Loss on ignition (Water) 5.5

Alumina XRD phase Amorphors, chi, and gamma

Price, $/lb 1.98

and TB2 were operated in the roughing position 

and TA1 and TA2 operated in the polishing position. TB1 and TB2 were recharged again on May 

25, 1999 due to arsenic breakthrough. TA1 was 

recharged on July 23, 1999. Since May 25, 1999, 

TA1 and TA2 have been used as roughing filters 

and TB1 and TB2 used as polishing filters.

• Backwash. Backwash of each AA filter was originally scheduled every 4 months using untreated 

water. The last two backwashes occurred in 

January and May 1998. Backwash wastewater was 

disposed of to a septic tank. Currently, backwash 

is not performed on a routine basis.

• Granular Activated Carbon Tank. Water from the 

two AA treatment trains combines and flows into a 

granular activated carbon (GAC) tank to be 

dechlorinated. The GAC tank is 66 inches tall and 

18 inches in diameter, and is rebedded every 

2 years. Based on the plant record, residual Cl2

was not detected in effluent after dechlorination.

• Storage Tank. The treated water from the GAC 

tank is stored in a 3,000-gal atmosphere tank 

located inside the building. The water is pressurized through two booster pumps buffered by two 

pressure tanks before release to the distribution 

system.

Water samples are collected monthly by a certified operator from the raw water, between the roughing and the

polishing tanks in each train, and from treated water.

Table 4-24 summarizes arsenic concentration results

from the monthly sampling events. The data show that

the arsenic concentrations in water samples collected at 

A2B2 and A1B1 locations (i.e., after tanks TA2 and TA1, 

respectively, which both serve as roughing tanks)

approached the 0.05 mg/L arsenic MCL on June 12 and 

August 15, 1997, again respectively, which indicated 

arsenic breakthrough. Therefore, both tanks were rebedded with virgin AA in November 1997. Water meter

readings were recorded during monthly sampling at

Plant D and are attached in Appendix D.3.

4.5.2 Initial Source Water Sampling

Source water for Plant D is supplied by a 500-ft-deep 

bedrock well drilled in 1975 through a submersible pump.

The historic sampling data listed in Table 4-24 show that 

the raw water arsenic concentrations ranged from 39 to 

81 μg/L since March 1992. Arsenic speciation was not

conducted prior to this study. Typical source water quality measurements made at Plant D are presented in

Table 4-25.

On June 10, 1998, an initial site visit to Plant D was conducted during which time source water samples were

collected. Table 4-26 presents the analytical results from 

the source water sampling. Consistent with plant records 

(Table 4-25), the total soluble arsenic concentration was 

relatively high, averaging 61.1 μg/L. Almost all of the

soluble arsenic existed as As(V) (60.6 μg/L). Particulate 

arsenic was not detected in the raw water.

4.5.3 Preliminary Sampling

During the preliminary sampling phase of this study, water 

samples were collected at four locations: (1) at the inlet; 

(2) after the roughing tank TB1; (3) after the polishing tank 

TA1; and (4) after the GAC tank. Sampling taps were

available at all four sampling locations. Sampling locations 

and sample analyses are indicated on Figure 4-19.

Preliminary sampling consisted of biweekly sample collection and analysis of various parameters (alkalinity, turbidity, pH, hardness, fluoride, sulfate, total arsenic, total 

Al, total Fe, and total Mn analysis). Arsenic speciation

sampling was conducted once on samples collected from 

the inlet and after TB1. Speciation was not performed on 

samples collected after TA1 and GAC tank because 

As(V) is the dominant species in the source water based 

on source-water sampling results. Table 4-27 presents 

the results of the biweekly preliminary sampling.

As shown on Table 4-27, the inlet total arsenic concentrations were relatively constant, ranging from 56.0 to 

62.1 μg/L. During the first week of speciation sampling, 

the raw water contained an average of 61.6 μg/L As(V), 

0.2 μg/L As(III), and no particulate arsenic, which is consistent with the source water sampling results.

The roughing AA filter removed 55 to 70% of the total

arsenic from the raw water. The polishing filter further
54

Table 4-24. Arsenic Concentrations (μg/L) from Monthly Water Sampling at Plant D 

(March 6, 1992 to December 29, 1999)

Date Raw water A1B1(a) A2B2(b) B1A1(c) B2A2(d)

Treated 

Water Remarks

03/06/92 54 − − − − −

03/16/95 62 − − − − −

03/21/96 45 <5 <5 − − <5 AA system installed in 2/96;

04/16/96 40 <5 <5 − − <5 TA1 and TA2 were roughing 

05/08/96 46 <5 <5 − − <5 tanks; TB1 and TB2 were 

06/19/96 39 <5 <5 − − <5 polishing tanks

07/22/96 51 <5 <5 − − <5

08/20/96 50 <5 <5 − − <5

09/06/96 52 <5 <5 − − <5

10/15/96 45 <5 <5 − − <5

11/13/96 48 <5 <5 − − <5

12/20/96 77 <5 <5 − − <5

01/09/97 58 − <5 − − <5

02/21/97 60 36 <5 − − <5

03/21/97 70 <5 <5 − − <5

04/17/97 61 24 42 − − <5

05/15/97 77 32 43 − − <5

06/12/97 61 38 50 − − <5 Arsenic breakthrough TA2 (50 μg/L)

07/14/97 60 36 65 − − <5

08/15/97 81 47 57 − − <5 Arsenic breakthrough TA1 (50 μg/L)

09/12/97 60 42 48 − − <5

10/15/97 58 45 44 − − <5 TA1and TA2 rebedded and moved 

to polishing positions in 11/97; 

TB1and TB2 moved to roughing 

positions

11/18/97 62 − − <5 7 <5

12/23/97 54 − − 26 13 <5 TB1and TB2 rebedded in 12/97 and 

stayed in roughing positions 

01/19/98 71 − − <5 <5 <5

02/24/98 57 − − <5 <5 <5

03/25/98 63 − − <5 <5 <5

04/15/98 62 − − <5 <5 <5

05/19/98 61 − − <5 <5 <5

06/15/98 61 − − 15 <5 <5

07/23/98 72 − − 17 <5 <5

08/27/98 60 − − 23 <5 <5

09/16/98 68 − − 39 <5 <5

10/15/98 67 − − 34 <5 <5

11/12/98 54 − − 39 <5 <5

01/19/99 47 − − 41 <5 <5

02/16/99 46 − − 30 6 <5

03/18/99 50 − − 40 17 <5

04/28/99 66 − − 48 23 <5 TB1 and TB2 rebedded and moved 

to polishing positions on 5/25/99; 

TA1and TA2 moved to roughing 

positions

06/22/99 61 <5 <5 − − <5

07/14/99 61 <5 <5 − − <5 TA1 rebedded on 7/23/99, remained 

at roughing position

08/25/99 68 <5 5 − − <5

09/17/99 66 <5 7 − − <5

10/29/99 57 <5 12 − − <5

11/22/99 47 <5 11 − − <5

12/29/99 54 <5 17 − − 5

(a) Water collected from a tap between the roughing tank TA1 and the polishing tank TB1.

(b) Water collected from a tap between the roughing tank TA2 and the polishing tank TB2. 

(c) Water collected from a tap between the roughing tank TB1 and the polishing tank TA1. 

(d) Water collected from a tap between the roughing tank TB2 and the polishing tank TA2. 

– = Not sampled.
55

Table 4-25. Typical Source Water Quality 

Measurements at Plant D

Parameter Unit Concentration

Alkalinity mg/L(a) 56.8

Fluoride mg/L 1.15

Chloride mg/L 8.0

Sulfate mg/L 10

pH — 8.3

Hardness mg/L(a) 55

Sodium mg/L 13.9

Specific Conductance μmhos/cm 166

Arsenic μg/L 40-80

(a) Measured as CaCO3

Table 4-26. Source Water Sampling Analytical Results 

at Plant D (June 10, 1998)

Parameter Units

Primary 

Sample

Duplicate 

Sample Average 

Alkalinity mg/L(a) 56 55 55.5

Fluoride mg/L 1.13 1.13 1.13

Sulfate mg/L 15 15 15

Turbidity NTU 0.31 0.3 0.31

pH — 8.3 8.3 8.3

Hardness mg/L(a) 49 46 47.5

Ca Hardness mg/L(a) 42.2 39 40.6

Mg Hardness mg/L(a) 7.1 7.1 7.1

Total Al μg/L <400 <400 <400

Total Fe μg/L 50 60 55

Total Mn μg/L <20 <20 <20

NO3–NO2 (N) mg/L(b) 0.36 0.37 0.37

TOC mg/L 1.0 ND ND

As (total) μg/L 60.0 58.1 59.0

As (total soluble) μg/L 60.8 61.4 61.1

As (particulate) μg/L ND ND ND

As (III) μg/L 0.5 0.5 0.5

As (V) μg/L 60.3 60.9 60.6

(a) As CaCO3.

(b) Combined NO3–N and NO2–N.

reduced the total arsenic concentrations to 0.6-1.1 μg/L. 

The combined treated water after the GAC tank contained concentrations of total arsenic ranging from 0.7 to 

1.1 μg/L, corresponding to an overall removal efficiency

of greater than 98%.

Fluoride concentrations were constant throughout the

treatment process, with 1.1 mg/L in the raw water and

1.2 mg/L in the finished water. Therefore, fluoride was

not removed by the AA filters. Similarly, sulfate concentrations remained at constant levels of 11 to 14 mg/L

throughout the treatment process, except for one sample 

collected on August 5, 1998 with 30 mg/L of sulfate detected after TB1. The reason for this anomaly is unknown. Although both fluoride and sulfate have certain 

affinities for the AA surface, their removal by AA was not 

observed here; this result is most likely due to the nearly 

exhausted AA arsenic removal capacity (similar results

observed at Plant C, as discussed in Section 4.4.3).

Alkalinity, total hardness, and nitrate/nitrite remained

relatively constant after the AA tanks because these ions 

hardly reacted with the AA surface. Total aluminum concentrations in the water slightly increased after the treatment, presumably due to the dissolution of AA medium. 

Total iron and manganese concentrations in the raw 

water were less than detection limit.

The preliminary sampling effort at Plant D resulted in no 

changes to the long-term sampling approach.

4.5.4 Long-Term Sampling

Long-term sampling and analysis consisted of 24 biweekly sampling events, including six arsenic speciation 

sampling events. The four sampling locations used during the preliminary sampling also were used during longterm sampling. Additionally, spent AA samples were

collected once during medium replacement on May 25,

1999. A special short-term study was conducted using

the spent and a virgin medium. The following subsections summarize the analytical results for arsenic,

other water quality parameters, spent AA, and the special study.

4.5.4.1 Arsenic

Table 4-28 provides a summary of the arsenic analytical 

results at different sampling locations. Total arsenic concentrations at the inlet ranged from 53.3 to 87.0 μg/L 

with an average of 63.0 μg/L, exceeding the 0.05 mg/L

arsenic MCL. The inlet water contained primarily As(V)

with only minor concentrations of As(III) and particulate

arsenic. Particulate arsenic was detected at the inlet only 

on September 30, 1998 with a highest concentration of

12.7 μg/L. An abnormally high total Fe concentration

also was detected in the same samples. The maximum 

As(III) concentrations were 0.5 μg/L at the inlet and 0.4 

μg/L after the first tank. Should the As(III) concentration 

in the source water increase, As(III) would be oxidized to 

As(V) by chlorination before the AA adsorption.

Figure 4-20 presents the total arsenic concentrations at 

each sampling location and the corresponding overall

removal percentages throughout the long-term sampling. 

The figures were plotted against both sampling date and 

BV of treated water, respectively. As shown on these 

plots, the total arsenic concentrations after the roughing 

tank (TB1) gradually approached influent levels, indicating breakthrough. Based on the water usage data,

roughing tank TB1 treated approximately 4,350 BV of

water before arsenic breakthrough occurred on March 3, 

1999. The medium was replaced with virgin AA on May
5

6

Table 4-27. Analytical Results from Preliminary Sampling at Plant D (August 5 through September 16, 1998)

Sampling Date and Location

8/5/98 8/19/98 9/2/98 9/16/98

IN TB1 TA1 AC IN TB1 TA1 AC IN TB1 TA1 AC IN TB1 TA1 AC

Alkalinity mg/L(a) 59 48 61 59 58

58

59

59

55

55

53

53 57 58 57 56 58 56 55 56

Fluoride mg/L 1.1 1.3 1.4 1.2 1.0

1.0

1.2

1.2

1.3

1.4

1.2

1.2 1.1 1.2 1.3 1.1 − − − −

Sulfate mg/L 11 30 15 14 13

13

14

14

14

14

14

14 14 14 14 14 14 14 14 14

Turbidity NTU <0.1 <0.1 <0.1 <0.1 <0.1

<0.1

<0.1

<0.1

<0.1

<0.1

<0.1

<0.1 − − − − − − − −

pH − 8.5 8.3 7.9 8.0 8.2

8.2

8.0

8.1

8.0

7.9

7.9

7.9 7.9 7.9 7.8 7.7 8.2 8.1 7.8 7.8

Total Hardness mg/L(a) 53.0 51.0 52.0 54.0 − − − − − − − − − − − −

Ca Hardness mg/L(a) 45.4 43.9 45.2 46.2 − − − − − − − − − − − −

Mg Hardness mg/L(a) 7.2 7.2 7.2 7.5 − − − − − − − − − − − −

NO3-NO2 (N) mg/L(b) 0.6 0.4 0.4 0.4 − − − − − − − − − − − −

As (total) μg/L 59.7

57.8

18.1

21.1

1.1

0.9

1.0

1.1 62.1 26.3 0.6 0.7 56.0 19.6 0.8 0.7 61.0 27.6 0.9 0.9

As (total soluble) μg/L 61.4

62.1

21.4

21.4 − − − − − − − − − − − − − −

As (particulate) μg/L <0.1

<0.1

<0.1

<0.1 − − − − − − − − − − − − − −

As (III) μg/L 0.2

0.1

0.2

0.2 − − − − − − − − − − − − − −

As (V) μg/L 61.2

62.0

21.2

21.2 − − − − − − − − − − − − − −

Total Al μg/L 12.6

14.4

32.0

39.4

37.7

44.2

49.3

45.2 44.0 34.9 29.9 46.7 16.2 23.1 31.5 36.1 22.8 36.6 41.0 44.4

Total Fe μg/L <30

<30

<30

51.2

<30

<30

<30

37.2 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30

Total Mn μg/L <0.5

<0.5

<0.5

1.4

<0.5

<0.5

<0.5

<0.5 0.6 <0.5 <0.5 <0.5 0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

Dissolved Al μg/L <11

<11

14.5

14.0 − − − − − − − − − − − − − −

Dissolved Fe μg/L <30

<30

<30

<30 − − − − − − − − − − − − − −

Dissolved Mn μg/L <0.5

<0.5

<0.5

<0.5 − − − − − − − − − − − − − −

(a) Measured as CaCO3.

(b) Combined NO3-NO2 as N.

IN = inlet; TB1 = after Tank B1; TA1 = after Tank A1; AC = after the GAC tank.

− = No analysis performed.
57

Table 4-28. Summary of Arsenic Analytical Results at Plant D (September 30, 1998 to September 1, 1999)

Parameter Sampling Location Units

Number of 

Samples

Minimum 

Concentration

Maximum 

Concentration

Average 

Concentration

Standard 

Deviation

As (total) Inlet μg/L 30 53.3 87.0 63.0 6.8

After 1st Tank μg/L 30 1.3 60.8 31.6 21.8

After 2nd Tank

Effluent

μg/L

μg/L

30

30

0.6

0.4

3.2

9.6

1.3

1.2

0.7

1.8

As (total soluble) Inlet μg/L 10 61.1 70.4 66.3 2.8

After 1st Tank μg/L 10 1.4 60.6 38.2 21.5

As (particulate) Inlet μg/L 10 <0.1 12.7 2.1 4.2

After 1st Tank μg/L 9 <0.1 0.7 0.1 0.2

As (III) Inlet μg/L 10 <0.1 0.5 0.2 0.1

After 1st Tank μg/L 10 0.1 0.4 0.2 2.8

As (V) Inlet μg/L 10 61.1 70.1 66.1 21.4

After 1st Tank μg/L 10 1.3 60.4 37.9 0.0

One-half of the detection limit was used for nondetect samples for calculations.

Primary and duplicate samples were averaged for calculations.

The 1st tank was TB1 before the medium change-out on May 25, 1999 and TA1 after the medium change-out.

The 2nd tank was TA1 before the medium change-out on May 25, 1999 and TB1 after the medium change-out.

medium change-out) consistently contained <5 μg/L

arsenic. Except for one spike (9.6 μg/L) on May 26,

1999, the combined treated water had total arsenic concentrations similar to those in samples collected after the 

second tank, indicating that the other treatment train performed in similarly effective fashion. During the entire

study, the system arsenic effluent was consistently below

5 μg/L, corresponding to an average arsenic removal of 

greater than 98%.

Using an average 5,260 BV of water treated prior to 50-

μg/L arsenic breakthrough, an inlet arsenic concentration 

of 62.1 μg/L, an arsenic concentration of 26.5 μg/L after 

the roughing tanks, and a density of 752 kg/m3, it was 

estimated that approximately 106 g of arsenic was

removed from the raw water by the roughing filters,

corresponding to an arsenic loading of 0.25 g/kg (155

g/m3

). This value is comparable to that obtained from

Plant C (0.30 g/kg or 219 g/m3) and to reported values

(Fox, 1989).

4.5.4.2 Other Water Quality Parameters

As with Plant C, sampling and analysis of other water

quality parameters were performed to provide insight

into the arsenic removal efficiency at the plant. Table 4-

29 summarizes the analytical results of the water quality 

parameters measured during long-term sampling at

Plant D. Figure 4-21 plots the inlet and outlet alkalinity,

pH, fluoride, and sulfate concentrations.

Inlet alkalinity concentrations were relatively constant,

ranging from 44 to 59 mg/L (as CaCO3) with an average 

of 56.9 mg/L. Alkalinity also remained constant throughout all four sampling locations. Inlet pH values ranged

from 7.8 to 8.4 with an average of 8.2. This pH was

higher than the reported optimal pH for the AA process. 

Even though the pH of the inlet water was not adjusted to 

the optimal value, the system consistently removed arsenic to below 5 μg/L before the medium was exhausted.

Fluoride and sulfate in the raw water are the major competing ions for adsorption on AA. As shown on Table 4-29

and Figure 4-21, inlet fluoride and sulfate concentrations 

were relatively constant, ranging from 0.9 to 1.4 mg/L

and 11 to 15 mg/L, respectively. Removal of either ion

through the treatment process was not significant before 

the medium replacement on May 25, 1999. However, 

both fluoride and sulfate were removed to nondetect 

levels by the freshly recharged tank on June 6, 1999.

Afterwards, the removal of fluoride lasted until the end of 

this study; however, the sulfate removal capacity was

quickly exhausted.

Turbidity, hardness, NO3-NO2 (N), total Al, Fe, and Mn

contents in the inlet water were relatively low, so their

effects on the arsenic removal efficiency were determined insignificant. Similar to Plant C, after the medium 

replacement, total Al concentrations increased significantly at the second tank and effluent sampling locations, indicating medium dissolution. For example, total

Al concentration was as high as 7.5 mg/L at the second 

tank and effluent sampling locations.

4.5.4.3 Spent AA Samples

Spent AA samples were collected from the roughing tank 

TB1 during the medium replacement on May 25, 1999.

Subsamples were analyzed for TCLP metals and percent moisture. Analytical results are presented in Table

4-30. All three samples had arsenic TCLP testing results 

of less than 0.05 mg/L, far below the arsenic TCLP limit 

of 5.0 mg/L. Only minor concentrations of barium were

detected in the leachates of samples from the middle
58

0.0

20.0

40.0

60.0

80.0

100.0

09/02/98 10/22/98 12/11/98 01/30/99 03/21/99 05/10/99 06/29/99 08/18/99 10/07/99 11/26/99

Date

50.0

60.0

70.0

80.0

90.0

100.0

Inlet

After TB1

After TA1

Outlet

% Removal

Arsenic MCL

TB1 was used as the roughing tank and TA1

was used as the polishing tank before medium

change-out on May 25, 1999; since then, TA1

was used as the roughing tank and the recharged

TB1 was used as the polishing tank.

0.0

20.0

40.0

60.0

80.0

100.0

3,000 3,500 4,000 4,500 5,000 5,500 6,000 6,500

BV of water treated

50.0

60.0

70.0

80.0

90.0

100.0

Inlet

After TB1

After TA1

Outlet

% Removal

AA replacement and

tank switch on May 25, 1999

Arsenic MCL

Figure 4-20. Total Arsenic Analytical Results during Long-Term Sampling at Plant D
59

Table 4-29. Summary of Water Quality Parameter Analytical Results at Plant D (September 30, 1998 to 

September 1, 1999)

Parameter Sampling Location Units

Number of 

Samples

Minimum 

Concentration

Maximum 

Concentration

Average 

Concentration

Standard 

Deviation

Alkalinity Inlet mg/L 30 44 59 56.9 2.9

After 1st Tank mg/L 30 47.5 63 56.8 2.6

After 2nd Tank mg/L 30 52 65 56.8 2.6

Effluent mg/L 30 40 62 55.2 4.1

Fluoride Inlet mg/L 30 0.9 1.4 1.1 0.1

After 1st Tank mg/L 30 <0.1 1.4 1.1 0.3

After 2nd Tank mg/L 30 <0.1 1.5 1.0 0.5

Effluent mg/L 30 <0.1 1.6 1.0 0.5

Sulfate Inlet mg/L 30 11 15 13.5 1.0

After 1st Tank mg/L 30 7.5 17 13.5 1.8

After 2nd Tank mg/L 30 <5 16 12.3 3.9

Effluent mg/L 30 <5 15 12.2 3.9

Turbidity Inlet NTU 6 0.2 0.4 0.3 0.1

After 1st Tank NTU 6 <0.1 0.2 0.1 0.1

After 2nd Tank NTU 6 <0.1 <0.1 0.05 0.0

Effluent NTU 6 <0.1 <0.1 0.05 0.0

pH Inlet — 30 7.8 8.4 8.2 0.2

After 1st Tank — 30 7.8 8.4 8.1 0.1

After 2nd Tank — 30 7.0 9.9 8.1 0.5

Effluent — 30 7.7 9.5 8.0 0.4

Total Hardness Inlet mg/L 6 46 51 48.8 1.8

After 1st Tank mg/L 6 47 51 49.7 1.5

After 2nd Tank mg/L 6 <2 50 39.8 19.1

Effluent mg/L 6 <2 50 40.2 19.2

NO3

-NO2 (N) Inlet mg/L 6 0.3 0.8 0.4 0.2

After 1st Tank mg/L 6 0.3 1.3 0.6 0.4

After 2nd Tank mg/L 6 0.3 1.4 0.6 0.4

Effluent mg/L 6 0.3 0.5 0.4 0.1

Total Al Inlet μg/L 30 <11 44.7 14.1 10.2

After 1st Tank μg/L 30 <11 471 55.1 103

After 2nd Tank μg/L 30 <11 148(a) 54.9(a) 47.5(a)

Effluent μg/L 30 <11 190(a) 55.5(a) 51.7(a)

Total Fe Inlet μg/L 30 <30 483 44.4 97.7

After 1st Tank μg/L 30 <30 127 21.1 23.1

After 2nd Tank μg/L 30 <30 53.7 18.1 9.5

Effluent μg/L 30 <30 54.3 17.1 8.2

Total Mn Inlet μg/L 30 <0.5 11.2 0.9 2.3

After 1st Tank μg/L 30 <0.5 0.7 0.3 0.1

After 2nd Tank μg/L 30 <0.5 <0.5 0.3 0.0

Effluent μg/L 30 <0.5 <0.5 0.3 0.1

Dissolved Al Inlet μg/L 10 <11 <11 <11 0.0

After 1st Tank μg/L 9 13.3 19.2 15.5 2.1

Dissolved Fe Inlet μg/L 10 <30 <30 <30 0.0

After 1st Tank μg/L 10 <30 <30 <30 0.0

Dissolved Mn Inlet μg/L 10 <0.5 <0.5 <0.5 0.0

After 1st Tank μg/L 10 <0.5 1.5 0.4 0.4

One-half of the detection limit was used for nondetect samples for calculations.

Primary and duplicate samples were averaged for calculations.

The 1st tank was TB1 before the medium change-out on May 25, 1999 and TA1 after the medium change-out.

The 2nd tank was TA1 before the medium change-out on May 25, 1999 and TB1 after the medium change-out.

(a) High total Al concentrations measured on May 26, 1999 after the polishing tank and at the outlet due to medium dissolution were not included 

for calculations.
60

0.0

20.0

40.0

60.0

80.0

09/12/98 11/01/98 12/21/98 02/09/99 03/31/99 05/20/99 07/09/99 08/28/99 10/17/99

Date

Alkalinity (mg/L as CaCO3)

6.0

7.0

8.0

9.0

10.0

11.0

12.0

pH

Inlet alkalinity

Outlet alkalinity

AA change-out

Inlet pH

Outlet pH

Inlet pH

Inlet alkalinity

Outlet pH

Outlet alkalinity

AA change-out on May 25, 1999

0.0

5.0

10.0

15.0

20.0

09/12/98 11/01/98 12/21/98 02/09/99 03/31/99 05/20/99 07/09/99 08/28/99 10/17/99

Date

Sulfate concentration (mg/L)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

Fluoride concentration (mg/L)

Inlet sulfate

Outlet sulfate

AA change-out

Inlet fluoride

Outlet fluoride

Inlet fluoride

Inlet sulfate

Outlet fluoride

Outlet sulfate

AA change-out on May 25, 1999

Figure 4-21. Inlet and Outlet Alkalinity, pH, Fluoride, and Sulfate Analytical Results at Plant D
61

Table 4-30. Analytical Results of Spent AA Samples at Plant D

Parameter Unit MDL TB1-Top TB1-Middle TB1-Bottom

TCLP Metals

As-TCLP mg/L 0.05 <0.05 <0.05 <0.05

Ba-TCLP mg/L 1.0 <1.0 1.1 1.4

Cd-TCLP mg/L 0.020 <0.02 <0.02 <0.02

Cr-TCLP mg/L 0.030 <0.03 <0.03 <0.03

Pb-TCLP mg/L 0.20 <0.2 <0.2 <0.2

Hg-TCLP mg/L 0.0002 <0.0002 <0.0002 <0.0002

Se-TCLP mg/L 0.05 <0.05 <0.05 <0.05

Ag-TCLP mg/L 0.020 <0.02 <0.02 <0.02

TCLP extraction NA NA Complete Complete Complete

Percent moisture % 0.1 31.6 31.3 32.0

and bottom sections of TB1. None of the spent AA analytical results indicate exceedances of regulatory levels. 

Therefore, the spent alumina could be disposed of as a 

nonhazardous waste material.

4.5.5 Special Study at Plant D

4.5.5.1 Regeneration of Spent AA Using 

Caustic Solution

Spent AA samples collected from the top, middle, and

bottom sections of TB1 were mixed with caustic solution 

(4% NaOH) overnight to strip arsenic, fluoride, and sulfate from the AA surface. The rinsates were analyzed for 

total arsenic, fluoride and sulfate. The amounts of arsenic, fluoride, and sulfate desorbed from the AA medium 

were calculated as described in Section 3.4.2, and the

results are presented in Table 4-31. The same samples 

also were digested with concentrated nitric acid and the 

digestates were analyzed for total arsenic. As shown on 

Table 4-31, the amounts of arsenic and fluoride recovered from the spent AA showed a slightly increasing

trend from the top to the bottom sections of the tank. The 

data based on the acid digestion are higher, but showing 

a similar increasing trend. The average arsenic removal 

capacity based on acid digestion is 0.41 g/kg, higher than

the one estimated based on column operation (0.25 g/kg 

AA) (Section 4.5.4.1). Therefore, the arsenic removal 

capacity based on column operation might have been

underestimated. The arsenic removal capacities can be

placed in the following order:

caustic wash (0.21 g/kg) 

< column operation (0.25 g/kg)

< acid digestion (0.41 g/kg)

Based on the capacities from the column operation and 

acid digestion, approximately 84% and 50% of arsenic

were recovered by the caustic wash respectively, which 

fell in the ranges reported by Hathway and Rubel (1987) 

and Clifford and Lin (1986).

Table 4-31. Analytical Results of Caustic Wash 

and Acid Digestion of Spent AA Samples 

at Plant D

Parameter Unit

TB1-

Top

TB1-

Middle

TB1-

Bottom Average

Caustic Wash with 4% NaOH

Total As g/kg 0.19

0.19

0.21

0.21

0.23

0.23 0.21

Fluoride g/kg 0.36

0.40

0.42

0.42

0.43

0.43 0.41

Sulfate g/kg 0.40

0.48

0.56

0.59

0.39

0.36 0.46

Acid Digestion with HNO3

Total As g/kg 0.38 0.39 0.50 0.41

4.5.5.2 Adsorption of Arsenic onto AA

The results of the kinetic study as shown on Figure 4-22 

indicated that arsenic adsorption on AA had reached equilibrium within 2 days, consistent with previous studies by 

Rosenblum and Clifford (1984). As a result, all subsequent isotherm batch tests were maintained for 6 days to 

ensure equilibrium had been reached.

The As(V) adsorption isotherm on AA at pH 7.7 ±0.2 is 

presented in Figure 4-23. The following data were fitted 

with both Freundlich and Langmuir models and the

resulting equations are shown:

Freundlich model:

qe = 0.1679 × Ce

(0.452), r2

= 0.9632 (4-1)

Langmuir model:

(4-2)

where qe and Ce are the solid (mg/g AA) and liquid phase 

(μg/L) equilibrium As(V) concentrations, respectively.

qe = 0.6778 × 0.2957 ×

Ce

/(1+0.2957 × Ce), r2= 0.9677
62

0.0

100.0

200.0

300.0

400.0

500.0

600.0

0 1 2 3 4 5 6 7 8

Time elapsed (days)

As(V) equilibrium concentration (

μg/L)

Figure 4-22. Kinetics of Arsenic Adsorption on AA Media

0.10

1.00

0.1 1 10 100

Ce (μg/L)

qe (mg As[V]/g AA)

Batch

Freundlich

Freundlich model:

K = 0.1679

1/n = 0.452

Figure 4-23. Arsenic Adsorption Isotherm on AA Media
63

Because qe did not reach plateau under the experimental 

conditions, the Freundlich model seemed to fit the data

better than the Langmuir model. The significance of the 

Freundlich model with respect to As(V) adsorption onto

AA lies primarily in the assumption of heterogeneous adsorption site energies and multilayer adsorption. In batch 

tests performed by Rosenblum and Clifford (1984), a

similar relation between the solid and liquid phase arsenic concentrations was established; however, at much

higher aqueous equilibrium As(V) concentrations (i.e., up 

to 4 mg/L).

Based on the Freundlich model, at an inlet arsenic concentration of 63.0 μg/L, the AA adsorption capacity is

predicted to be 1.09 g As(V)/kg AA. This value is higher 

than the capacities obtained from the column operation

(0.25 g/kg), caustic wash (average of 0.21 g/kg), or acid 

digestion (0.41 g/kg). Because the column operated at

an average pH of 8.3, higher than the pH of the isotherm 

study (pH 7.7), the pH most likely affected the adsorption 

capacity. In actual column operation, the arsenic capacity

obtainable should be far less than the equilibrium values 

obtained from the adsorption isotherm. The competing 

anions and the nonequilibrium mass transfer limitations 

are some of the reasons for the low column capacities. 

An additional reason for the low capacity is the possible 

fouling of the porous alumina by particulate and colloidal 

constituents such as colloidal silica and mica (Clifford

and Lin, 1986), which were not monitored during this

study.
64

5.0 Quality Assurance/Quality Control

5.1 Quality Assurance Objectives

The precision, accuracy, MDL, and completeness for

each of the analytical measurements required for this

study were established in the QAPP (Battelle, 1998) and 

are listed in Table 1 of the QA/QC Summary Report

(Battelle, 2000b), which was prepared under separate

cover. These terms serve as indicators of data quality

and were calculated in accordance with the formulas

provided in the QAPP. The precision, accuracy, and

MDL of each of the measurements performed during the 

present study are presented in the summary report.

These quality assurance (QA) data are organized according to the date of sample receipt or sample analysis 

and are not site-specific. Therefore, the QA/QC section 

of this report shares the same QA data with other water 

treatment plants that have been included in the study.

5.2 Overall Assessment of Data Quality

Quantitative QA objectives listed in the QA/QC Summary 

Report include precision as relative percent difference 

(RPD), accuracy as percent recovery (%R), MDL, and

completeness. The precision, accuracy, and MDL or reporting limit of each of the measurements performed

during this study are presented in the QA/QC Summary 

Report. Total arsenic, aluminum, iron, and manganese

analyses on water samples were conducted in Battelle’s 

ICP-MS laboratory. The QA data associated with these

metal analyses also are presented in the QA/QC Summary Report. Other water quality parameters including 

alkalinity, pH, turbidity, hardness, nitrate-nitrite, sulfate,

fluoride, TDS, and TSS were analyzed by Wilson Environmental Laboratories, and their QA data were summarized in the QA/QC Summary Report. QA data for TOC 

analysis performed by CT&E Environmental Laboratory 

are presented in the QA/QC Summary Report. The

TCLP metal analysis on sludge samples also was conducted by Wilson Environmental Laboratories and its

associated QA data are summarized in the QA/QC 

Summary Report. Overall, the QA objectives of precision, accuracy, MDL, and completeness were achieved

by all laboratories. Therefore, all the valid data were

used to evaluate the effectiveness of the treatment processes and support conclusions.

5.2.1 Total Arsenic, Aluminum, Iron, 

and Manganese

At the early phase of the study, total As analysis was

performed by Battelle’s ICP-MS laboratory, and total Al, 

Fe, and Mn were analyzed by Wilson Environmental

Laboratories. Starting from June 1998, all four metals

were analyzed by Battelle’s ICP-MS laboratory. Therefore, QA data for only the total arsenic analysis before

June 16, 1998 and QA data for all four metals afterwards 

are presented.

The laboratory duplicate and matrix spike (MS) analyses 

were performed every 10 samples (instead of 20 samples as required by the QAPP [Battelle, 1998]). All the

samples were analyzed for four metals although metals

other than arsenic may not be required for every sample. 

Therefore, Battelle’s ICP-MS laboratory performed more 

QA/QC analyses than what were specified in the QAPP.

Greater than 99% of the precision results for all metals

met the QA objective of ±25% (with only two Fe outliers: 

27% on August 8, 1998 and 74% on December 22,

1998; three As outliers: 27% on August 18, 1998, 182% 

on October 1, 1998, and 27% on July 30, 1999; and four 

Al outliers: 26% and 33% on August 18, 1998, 48% on

December 15, 1998, and 48% on January 25, 1999).

The majority of the accuracy data associated with matrix 

spike analysis on August 31, 1998 exceeded the QA

limits of 75 to 125%. It is suspected that MS analyses 

were not performed correctly on that day. After this

problem had been identified, Battelle’s Work Assignment 

Leader, laboratory QA officer, and Battelle’s task leaders 

met to discuss the cause of the deviation. Corrective 
65

actions were taken including re-analyzing samples and

adjusting the amount of spike added to samples (i.e., the 

Fe spike was increased from 50 to 100, 200, 225, or

even as high as 2,000 μg/L because most of samples

contain much more than 50 μg/L of Fe). As indicated in 

the QA/QC Summary Report, the MS data quality was

significantly improved since November 3, 1998. Excluding the data on August 31, 1998, only five arsenic data

were outside the acceptable range for accuracy. However, 15 Al, 26 Fe, and 14 Mn accuracy data did not

meet the QA objective. With exceptions of one 23% and 

one 38% of accuracy, the Al accuracy data range from

65 to 125%. The Mn accuracy data range from 67 to

106% with the exception of one 37%. The Fe accuracy 

data range from 55 to 142% with exceptions of one 14%, 

one 23%, and one 38%.

All laboratory control samples showed %R within the

acceptable QA limit of 75 to 125% except for six outliers 

for total Fe with %R ranging from 73 to 143%. Al was not 

spiked to laboratory control samples until November 3,

1998 after corrective actions were taken. The MDL of Fe 

is the same as target MDL; however, MDLs of other

three metals were far below the target levels as specified 

in the QAPP (Battelle, 1998).

5.2.2 Water Quality Parameters

Water quality parameters include alkalinity, pH, turbidity, 

hardness (Ca and Mg), nitrate-nitrite, sulfate, fluoride, 

TDS, TSS and TOC. As shown in Table 3 of the QA/QC 

Summary Report, all the precision data were within the

acceptable QA limit of ±25% except for two Mn analyses 

with a 29% RPD (April 10 and 17, 1998) and three

nitrate-nitrite analyses with 40% RPD (August 6, 1998,

January 13, 1999, and February 11, 1999). The high

RPDs of these analyses might have been caused by the 

low measured concentrations in the samples that were

close to the detection limits for Mn and nitrate-nitrite. The 

accuracy data indicate that only one Al (70% on March 2,

1998), two Mn (66% and 64% on May 12, 1998), and

one Mg (126% on August 7, 1998) %R slightly exceeded 

the QA objectives of 75 to 125%. Although the matrix

spike duplicate (MSD) analysis was not required by the

QAPP, the accuracy and the precision data relating to

MSD also were presented. The MS/MSD analyses are not 

applicable to pH and turbidity measurements, though. The 

laboratory did not perform MS/MSD analyses on Ca and 

Mg hardness analyses until October 15, 1998 upon

Battelle’s request. All laboratory control samples showed 

%R within the acceptable QA limit of 75 to 125%. Reporting limits were below the required levels for all the

analytes except for sulfate. The reporting limits of sulfate 

was 5 mg/L, exceeding the required MDL of 3.66 mg/L. 

All precision, accuracy, and %R values for the TOC

analysis were within acceptable QA limits with the exception of one accuracy value, which was slightly below 

the 75 to 125% range at 72% (February 21, 1999).

5.2.3 TCLP Metals

The TCLP metals analyzed in the spent AA samples included As, Se, Hg, Ba, Cd, Cr, Pb, and Ag. The precision data were within QA limits of ±25%. The accuracy 

of matrix spikes and percent recovery of laboratory control samples were all within QA limits of 75 to 125%

except for one slightly elevated RPD for TCLP Se MS/

MSD at 26% (November 17, 1998).
66

6.0 References

Andreae, M. 1977. “Determination of Arsenic Species in 

Natural Waters.” Anal. Chem., 49: 820-823.

Aqua Specialties. 1999. Personal communication with

Chris Kofer, Owner, by Battelle.

Battelle. 1998. Quality Assurance Project Plan for Evaluation of Treatment Technologies for the Removal of

Arsenic from Drinking Water. Prepared for EPA’s

NRMRL, Cincinnati, OH.

Battelle. 1999. Evaluation of Treatment Technologies for 

the Removal of Arsenic from Drinking Water: Conventional Coagulation/Filtration and Lime Softening. Prepared for EPA’s NRMRL, Cincinnati, OH. September.

Battelle. 2000a. Evaluation of Treatment Technologies

for the Removal of Arsenic from Drinking Water: Conventional Iron Removal. Being prepared for EPA’s

NRMRL, Cincinnati, OH.

Chen, A.S.C., and V.L. Snoeyink. 1987. “Activated Alumina Adsorption of Dissolved Organic Compounds before and after Ozonation.” ES&T, 21 (January): 83-90.

Chen, A.S.C., V.L. Snoeyink, J. Mallevialle, and F.

Fiessinger. 1989. “Activated Alumina for Removing 

Dissolved Organic Compounds.” J. AWWA: 53-60.

Chen, S.L., S.R. Dzeng, M. Yang, K. Chiu, G. Shieh, and 

C.M. Wai. 1994a. “Arsenic Species in Groundwaters of 

the Blackfoot Disease Area, Taiwan.” ES&T: 877-881.

Chen, R.C., S. Liang, H.C. Wang, and M.D. Beuhler.

1994b. “Enhanced Coagulation for Arsenic Removal.”

J. AWWA (September): 79-90.

Clifford, D. 1999. “Ion Exchange and Inorganic Adsorption.” In American Water Works Association (Eds.),

Water Quality and Treatment: A Handbook of Community Water Supplies. 5th ed. New York: McGraw-Hill.

Clifford, D., and C. C. Lin. 1986. “Arsenic Removal from 

Groundwater in Hanford, California–A Preliminary Report.” University of Houston, Department of Civil/Environmental Engineering.

Clifford, D., and C. C. Lin, 1991. “Arsenic III and Arsenic V

Removal from Drinking Water in San Ysidro, New

Mexico.” EPA/600/2-91/011. U.S. EPA, Cincinnati, OH.

Clifford, D., and E. Rosenblum. 1982. “The Equilibrium

Arsenic Capacity of Activated Alumina.” U.S. EPA,

Cincinnati, Cooperative Agreement CR-807939-02.

Clifford, D., L. Ceber, and S. Chow. 1983. “Arsenic(III)/

Arsenic(V) Separation by Chloride-Form Ion-Exchange 

Resins.” Proceedings of the XI AWWA WQTC.

Clifford, D., G. Ghurye, and A. Tripp. 1998. “Arsenic

Removal by Ion Exchange with and without Brine

Reuse.” Proceedings of AWWA Inorganic Contaminants Workshop, San Antonio, TX.

Driehaus, W., M. Jekel, and U. Hildebrand. 1998.

“Granular Ferric Hydroxide–A New Adsorbent for the

Removal of Arsenic from Natural Water. J. Water SRT–

Aqua 47(1): 30-35.

Eaton, A.D., H.C. Wang, and J. Northington. 1997.

“Analytical Chemistry of Arsenic in Drinking Water.”

AWWARF Project 914.

Edwards, M., S. Patel, L. McNeill, H. Chen, M. Frey,

A.D. Eaton, R.C. Antweiler, and H.E. Taylor. 1998. 

“Considerations in As Analysis and Speciation.”

J. AWWA (March): 103-113.

EPA, see United States Environmental Protection Agency.

Ficklin, W.H. 1983. “Separation of Arsenic (III) and Arsenic(V) in Groundwaters by Ion Exchange.” Talanta, 

30(5): 371-373.
67

Fox, K. 1989. “Field Experience with Point-of-Use Treatment Systems for Arsenic Removal.” J. AWWA: 94-

101.

Frank, P., and D. Clifford. 1986. “Arsenic (III) Oxidation 

and Removal from Drinking Water.” EPA-600-52-

86/021.

Hathaway, S.W., and F. Rubel. 1987. “Removing Arsenic from Drinking Water.” J. AWWA, 79(8), 61-5.

Hering, J.G., P.Y. Chen, J.A. Wilkie, M. Elimelech, and

S. Lung. 1996. “Arsenic Removal by Ferric Chloride.”

J. AWWA (April): 155-167.

Joshi, A., and Chaudhuri, M. 1996. “Removal of Arsenic 

from Groundwater by Iron Oxide-Coated Sand.” J. 

Env. Eng., Am. Soc. Civ. Engrs., 122: 769-771.

Lowry Engineering, Inc. 1990. Personal communication

with Battelle.

McNeill, L.S., and M. Edwards. 1997. “Arsenic Removal 

During Precipitative Softening.” Journal of Environmental Engineering (May): 453-460.

Rosenblum, E., and D. Clifford. 1984. “The Equilibrium

Arsenic Capacity of Activated Alumina.” EPA-600/52-

83-107. U.S. EPA, Cincinnati, OH.

Scott, K.N., J.F. Green, H.D. Do, and S.J. McLean.

1995. “Arsenic Removal by Coagulation.” J. AWWA 

(April): 114-126.

Secondwind Environmental. 1999. Personal communication with Jodie Pepin, Commercial/Public Water Manager, by Battelle.

Simms, J., and F. Azizian. 1997. “Pilot-Plant Trials on

the Removal of Arsenic from Potable Water Using

Activated Alumina.” Proc. Water. Qual. Technol. Conf.: 

P6I/1-P6I/14.

Singh, G., and D. Clifford. 1981. “The Equilibrium Fluoride Capacity of Activated Alumina.” EPA- 600/52-81-

082. U.S. EPA, Cincinnati, OH.

Sorg, T.J. 1993. “Removal of Arsenic From Drinking

Water by Conventional Treatment Methods.” Proceedings of the 1993 AWWA WQTC.

Tate, C.H., and K.F. Arnold. 1990. “Health and Aesthetic 

Aspects of Water Quality.” In American Water Works

Association (Eds.), Water Quality and Treatment: A

Handbook of Community Water Supplies. New York:

McGraw-Hill.

United States Environmental Protection Agency. 1998.

Research Plan for Arsenic in Drinking Water. EPA/

600/4-98/042. Office of Research and Development, 

Washington, D.C. February.

Vagliasindi, F.G.A., M. Henley, N. Schulz, and M.M.

Benjamin. 1996. “Adsorption of Arsenic by Ion Exchange Resins, Activated Alumina, and Iron-Oxide 

Coated Sands.” Proc. Water Qual. Technol. Conf., 

1829-1853.

Vagliasindi, F.G.A., and M.M. Benjamin. 1997. “Arsenic 

Behavior in Packed Bed Adsorption Reactors: Media

Performance vs. Water Quality Composition.” Proc. 

Water Works Assoc. Conf., 443-456.

69

APPENDIX A

Plant A Data

A.1 Complete Analytical Results from Long-Term Sampling at Plant A

A.2 Technical Data on Purolite®

 A-300

A.3 Water Usage Report
70

A.1 Complete Analytical Results from Long-Term Sampling at Plant A
71

Table A-1. Analytical Results from Long-Term Sampling, Plant A (September 1 to 22, 1998)

Sampling Date 9/1/98 9/8/98 9/15/98 9/22/98

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 89 68 85

84

83

83 85 92 89 88

Sulfate mg/L 28 <5 25

24

<5

<5 25 <5 24 <5 (c)

Turbidity NTU <0.1 <0.1

pH 7.6 7.3 7.5

7.5

7.5

7.5 7.6 7.7 7.6 7.6

Total Hardness mg/L(a) 64.7 63.7

Ca Hardness mg/L(a) 57.4 56.7

Mg Hardness mg/L(a) 7.3 7.0

Nitrate-Nitrite mg/L(b) 0.3 0.2

As (total) μg/L 43.9

39.1

0.7

0.7 41.9 0.9 44.9 3.2 49.3 54.0

As (total soluble) μg/L 45.4

47.9

1.2

1.2

As (particulate) μg/L <0.1

<0.1

<0.1

<0.1

As (III) μg/L 0.4

0.4

<0.1

<0.1

As (V) μg/L 45.0

47.5

1.2

1.2

Total Al μg/L 16.4

21.5

<11

13.4 23.9 13.4 32.2 21.7 23.8 19.4

Total Fe μg/L <30

<30

<30

<30 <30 <30 <30 <30 <30 <30

Total Mn μg/L 2.1

1.8

<0.5

<0.5 0.9 <0.5 2.8 <0.5 0.8 <0.5

Dissolved Al μg/L <11

<11

<11

<11

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L 1.2

1.0

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3−N and NO2−N.

(c) Confirmed by sample re-analysis.

IN = inlet; OU = outlet.
72

Table A-2. Analytical Results from Long-Term Sampling, Plant A (September 29 to October 20, 1998)

Sampling Date 9/29/98 10/6/98 10/13/98 10/20/98

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 92 85 89

89

89

88 86 72 92 78

Sulfate mg/L 26 20 25

25

25

24 24 16 26 22

Turbidity NTU 0.1 <0.1

pH 7.6 7.5 7.7

7.7

7.6

7.6 7.6 7.5 7.6 7.4

Total Hardness mg/L(a) 83.9 79.0

Ca Hardness mg/L(a) 75.4 70.4

Mg Hardness mg/L(a) 8.4 8.6

Nitrate-Nitrite mg/L(b) 0.5 0.8

As (total) μg/L 51.6

59.2

81.0(c)

82.0 52.5 43.4 35.1 27.2 50.4 28.9

As (total soluble) μg/L 60.9

59.9

95.5

97.0

As (particulate) μg/L <0.1

<0.1

<0.1

<0.1

As (III) μg/L 0.7

0.6

0.3

0.3

As (V) μg/L 60.2

59.3

95.2

96.7

Total Al μg/L 14.4

15.8

15.6

16.0 24.3 <11 26.4 13.9 15.7 11.7

Total Fe μg/L <30

<30

<30

<30 <30 <30 <30 <30 <30 <30

Total Mn μg/L 0.6

0.5

<0.5

<0.5 1.0 <0.5 1.3 <0.5 0.7 <0.5

Dissolved Al μg/L <11

<11

<11

<11

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L <0.5

<0.5

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3−N and NO2−N.

(c) Confirmed by sample re-analysis.

IN = inlet; OU = outlet.
73

Table A-3. Analytical Results from Long-Term Sampling, Plant A (October 27 to November 17, 1998)

Sampling Date 10/27/98 11/3/98 11/10/98(c) 11/17/98

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 92 79 90

90

82

82 91 49 86 70

Sulfate mg/L 26 21 27

25

23

22 24 14 23 <5

Turbidity NTU <0.1 <0.1

pH 7.5 7.4 7.5

7.5

7.5

7.5 7.5 7.3 7.6 7.4

Total Hardness mg/L(a) 75.6 70.7

Ca Hardness mg/L(a) 67.7 62.9

Mg Hardness mg/L(a) 7.9 7.8

Nitrate-Nitrite mg/L(b) 0.6 0.8

As (total) μg/L 48.9

47.2

27.9

27.0 49.7 34.4 48.6 20.5 37.6 1.2

As (total soluble) μg/L 59.8

59.5

32.3

32.5

As (particulate) μg/L <0.1

<0.1

<0.1

<0.1

As (III) μg/L 0.2

0.1

<0.1

<0.1

As (V) μg/L 59.6

59.4

32.3

32.5

Total Al μg/L 19.0

<11

<11

11.9 <11 <11 12.0 <11 <11 <11

Total Fe μg/L <30

<30

<30

<30 <30 <30 <30 <30 <30 <30

Total Mn μg/L 0.6

0.5

<0.5

<0.5 0.8 <0.5 0.6 <0.5 0.5 <0.5

Dissolved Al μg/L <11

<11

<11

<11

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L 0.5

<0.5

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3−N and NO2−N.

(c) Samples were collected after the AX300 tank was regenerated on 11/10/98.

IN = inlet; OU = outlet.
74

Table A-4. Analytical Results from Long-Term Sampling, Plant A (Nov. 24 to Dec. 15, 1998)

Sampling Date 11/24/98(c) 12/01/98 12/08/98 12/15/98

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 90 90 87

88

90

90 78 87

Sulfate mg/L 23 <5 26

26

<5

<5 22 <5

Turbidity NTU <0.1 <0.1

pH 7.2 7.3 7.6

7.6

7.6

7.6 7.4 7.6

Total Hardness mg/L(a) 70 67

Ca Hardness mg/L(a) 61.7 59.7

Mg Hardness mg/L(a) 7.9 7.7

Nitrate-Nitrite mg/L(b) 0.5 0.1

As (total) μg/L 37.3

38.7

0.9

0.9 42.5 3.8 28.6 33.6

As (total soluble) μg/L 42.0

43.6

0.9

1.0

As (particulate) μg/L <0.1

<0.1

<0.1

<0.1

As (III) μg/L 0.7

0.7

0.1

0.1

As (V) μg/L 41.3

42.9

0.8

0.9

Total Al μg/L 14.4

17.3

11.6

11.1 13.6 11.5 <11 <11

Total Fe μg/L 32.1

31.2

34.8

33.4 <30 <30 <30 <30

Total Mn μg/L 0.8

0.9

<0.5

<0.5 1.4 <0.5 <0.5 <0.5

Dissolved Al μg/L 2.9

3.9

<11

<11

Dissolved Fe μg/L 15.6

11.5

<30

<30

Dissolved Mn μg/L 0.8

0.6

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3−N and NO2−N.

(c) No sampling due to Thanksgiving holiday.

IN = inlet; OU = outlet.
75

Table A-5. Analytical Results from Long-Term Sampling, Plant A (Dec. 22,1998 to Jan. 12, 1999)

Sampling Date 12/22/98(c) 12/29/98(c) 01/05/99 01/12/99

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 89 82 91 81

Sulfate mg/L 23 21 23 21

Turbidity NTU <0.1 <0.1

pH 7.6 7.5 7.6 7.5

Total Hardness mg/L(a) 70 67

Ca Hardness mg/L(a) 62.4 59.4

Mg Hardness mg/L(a) 7.6 7.2

Nitrate-Nitrite mg/L(b) 0.5 0.7

As (total) μg/L 37.7 45.1 39.4

38.7

34.9

32.2

As (total soluble) μg/L 41.5

42.1

29.0

28.7

As (particulate) μg/L <0.1

<0.1

5.9

3.5

As (III) μg/L 0.8

0.7

0.3

0.4

As (V) μg/L 40.7

41.4

28.7

28.3

Total Al μg/L <11 <11 22.1

20.3

13.6

12.2

Total Fe μg/L 40.1 40.3 80.2

74.1

<30

<30

Total Mn μg/L <0.5 <0.5 <0.5

0.8

0.8

1.4

Dissolved Al μg/L <11

<11

<11

<11

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L 1.0

0.7

2.7

<0.5

(a) Measured as CaCO3.

(b) Combined NO3−N and NO2−N.

(c) No sampling due to Christmas holiday.

IN = inlet; OU = outlet.
76

Table A-6. Analytical Results from Long-Term Sampling, Plant A (Jan 19 to Feb 9, 1999)

Sampling Date 01/19/99 01/26/99 02/02/99 02/09/99(c)

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 86

85

73

73 77 70 88 74 83 41

Sulfate mg/L 23

23

22

21 20 20 23 20 23 <5

Turbidity NTU <0.1 <0.1

pH 7.4

7.4

7.4

7.4 7.5 7.5 7.6 7.4 7.5 7.2

Total Hardness mg/L(a) 74 69

Ca Hardness mg/L(a) 65.7 61.9

Mg Hardness mg/L(a) 8.0 7.2

Nitrate-Nitrite mg/L(b) 0.5 0.4

As (total) μg/L 34.7 28.1 31.9 22.8 42.1 22.2 39.1

39.3

3.7

3.4

As (total soluble) μg/L 39.7

41.9

3.6

3.5

As (particulate) μg/L <0.1

<0.1

0.1

<0.1

As (III) μg/L 0.7

0.8

<0.1

<0.1

As (V) μg/L 39.0

41.1

3.6

3.5

Total Al μg/L 14.0 <11 <11 <11 34.1 60.0 27.4

19.9

<11

11.8

Total Fe μg/L <30 <30 41.3 48.3 <30 <30 41.9

<30

<30

<30

Total Mn μg/L 1.2 0.7 0.6 <0.5 <0.5 <0.5 3.1

2.0

<0.5

<0.5

Dissolved Al μg/L <11

<11

<11

<11

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L <0.5

<0.5

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3−N and NO2−N.

(c) The AX300 tank was regenerated on 2/6/99.

IN = inlet; OU = outlet.
77

Table A-7. Analytical Results from Long-Term Sampling, Plant A (Feb 16 to Mar 9, 1999)

Sampling Date 02/16/99(c) 02/23/99 03/2/99(d) 03/9/99

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 77

77

82

82 79 73

Sulfate mg/L 23

23

<5

<5 25 <5

Turbidity NTU <0.1 <0.1

pH 7.5

7.5

7.5

7.5 7.6 7.5

Total Hardness mg/L(a) 64 61

Ca Hardness mg/L(a) 56.2 53.9

Mg Hardness mg/L(a) 7.5 7.2

Nitrate-Nitrite mg/L(b) 0.8 0.9

As (total) μg/L 33.3 1.2 42.5

41.5

9.3

9.6

As (total soluble) μg/L 39.4

38.1

11.3

11.4

As (particulate) μg/L 3.1

3.4

<0.1

<0.1

As (III) μg/L 0.6

0.5

0.3

0.2

As (V) μg/L 38.8

37.6

11.0

11.2

Total Al μg/L <11 <11 <11

<11

15.0

<11

Total Fe μg/L 36.6 36.5 <30

<30

<30

<30

Total Mn μg/L 0.6 0.5 <0.5

<0.5

0.6

0.6

Dissolved Al μg/L <11

<11

<11

<11

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L <0.5

<0.5

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3−N and NO2−N.

(c) No sampling due to sampler’s vacation.

(d) No sampling due to FedEx mis-delivery of sample cooler.

IN = inlet; OU = outlet.
78

Table A-8. Analytical Results from Long-Term Sampling, Plant A (Mar 16 to Apr 6, 1999)

Sampling Date 03/16/99(c) 03/23/99 03/30/99 04/06/99

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 63

61

65

64 93 21 66 71 73 82

Sulfate mg/L 21

20

18

18 26 <5 21 <5 19 <5

Turbidity NTU 0.3 <0.1

pH 7.2

7.2

7.4

7.4 7.7 7.0 7.5 7.6 7.5 7.7

Total Hardness mg/L(a) 65 63

Ca Hardness mg/L(a) 57.9 55.7

Mg Hardness mg/L(a) 7.4 7.2

Nitrate-Nitrite mg/L(b) 0.6 0.1

As (total) μg/L 23.3 47.6 46.4 7.8 25.3 1.2 31.1

31.9

1.2

1.2

As (total soluble) μg/L 31.4

30.8

1.2

1.2

As (particulate) μg/L <0.1

1.1

<0.1

<0.1

As (III) μg/L 0.6

0.6

0.2

0.1

As (V) μg/L 30.8

30.2

1.0

1.1

Total Al μg/L 14.2 <11 18.0 <11 19.4 <11 <11

<11

<11

<11

Total Fe μg/L <30 <30 <30 <30 <30 <30 <30

<30

<30

<30

Total Mn μg/L 1.3 0.8 1.5 1.4 <0.5 <0.5 <0.5

<0.5

<0.5

<0.5

Dissolved Al μg/L <11

<11

<11

<11

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L <0.5

<0.5

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3−N and NO2−N.

(c) The AX300 tank was regenerated on 3/21/99 after samples were collected.

IN = inlet; OU = outlet.
79

Table A-9. Analytical Results from Long-Term Sampling, Plant A (Apr 13 to May 4, 1999)

Sampling Date 04/13/99 04/20/99(C) 04/27/99 05/04/99

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 87

87

84

85 73 29 87 73 88 89

Sulfate mg/L 25

24

<5

<5 22 <5 23 <5 23 <5

Turbidity NTU 0.2 <0.1

pH 7.7

7.6

7.7

7.7 7.4 7.1 7.6 7.4 7.8 7.7

Total Hardness mg/L(a) 64 68

Ca Hardness mg/L(a) 56.7 60.2

Mg Hardness mg/L(a) 7.3 7.5

Nitrate-Nitrite mg/L(b) 0.4 3.3

As (total) μg/L 43.9 6.4 26.0 23.4 39.8 2.6 53.8

48.2

2.6

2.6

As (total soluble) μg/L 52.7

52.9

2.5

2.3

As (particulate) μg/L 1.1

<0.1

0.1

0.3

As (III) μg/L 1.4

1.2

0.5

0.4

As (V) μg/L 51.3

51.7

2.0

1.9

Total Al μg/L 13.2 <11 <11 <11 49.4 12.1 14.0

13.1

<11

<11

Total Fe μg/L <30 <30 <30 <30 <30 <30 <30

<30

<30

<30

Total Mn μg/L 0.6 0.6 0.5 1.0 1.4 0.8 0.8

0.8

0.7

0.7

Dissolved Al μg/L <11

12.9

19.5

<11

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L 0.5

0.6

0.8

0.8

(a) Measured as CaCO3.

(b) Combined NO3−N and NO2−N.

(c) The AX300 tank was regenerated on 4/18/99.

IN = inlet; OU = outlet.
80

Table A-10. Analytical Results from Long-Term Sampling, Plant A (May 11, to Jun 1, 1999)

Sampling Date 05/11/99 05/18/99(C) 05/25/99 06/01/99

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 83

84

87

86 83 44 92 82 88 62

Sulfate mg/L 24

23

<5

<5 23 <5 24 <5 24 25

Turbidity NTU <0.1 <0.1

pH 7.5

7.5

7.6

7.6 7.6 7.3 7.7 7.5 7.6 7.6

Total Hardness mg/L(a) 64 65

Ca Hardness mg/L(a) 56.7 58.2

Mg Hardness mg/L(a) 7.0 7.1

Nitrate-Nitrite mg/L(b) 0.3 0.2

As (total) μg/L 43.9 1.9 42.7 10.1 45.9 1.7 44.1

43.9

1.6

1.5

As (total soluble) μg/L 44.9

44.7

1.5

1.5

As (particulate) μg/L <0.1

<0.1

0.1

<0.1

As (III) μg/L 1.1

1.1

0.4

0.2

As (V) μg/L 43.7

43.6

1.0

1.3

Total Al μg/L 18.3 13.4 12.0 <11 16.3 13.5 <11

<11

<11

<11

Total Fe μg/L <30 <30 <30 <30 31.7 <30 <30

<30

<30

<30

Total Mn μg/L 1.1 0.5 3.1 0.8 0.6 0.8 0.7

0.8

0.7

0.7

Dissolved Al μg/L <11

<11

<11

<11

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L 0.5

0.5

0.7

0.8

(a) Measured as CaCO3.

(b) Combined NO3−N and NO2−N.

(c) The AX300 tank was regenerated on 5/16/99.

IN = inlet; OU = outlet.
81

Table A-11. Analytical Results from Long-Term Sampling, Plant A (June 8, to Jun 17, 1999)

Sampling Date 06/08/99 06/13/99(c) 06/14/99 06/15/99 06/17/99

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 90

91

91

92 77 89 92 40 86 48 86 69

Sulfate mg/L 23

23

<5

<5 21 <5 25 16 24 13 23 <5

Turbidity NTU

pH 7.5

7.6

7.7

7.7 7.4 7.7 7.6 7.2 7.6 7.2 7.7 7.5

Total Hardness mg/L(a)

Ca Hardness mg/L(a)

Mg Hardness mg/L(a)

Nitrate-Nitrite mg/L(b)

As (total) μg/L 26.6 4.7 28.4 23.1 31.7 45.5 43.3 24.2 43.9 12.6

As (total soluble) μg/L

As (particulate) μg/L

As (III) μg/L

As (V) μg/L

Total Al μg/L 11.3 13.8 12.6 11.3 <11 12.5 105 13.8 <11 11.3

Total Fe μg/L <30 <30 37.1 <30 <30 <30 <30 <30 33.6 117

Total Mn μg/L 0.6 0.8 0.7 0.5 0.8 0.7 1.2 0.8 0.9 1.0

Dissolved Al μg/L

Dissolved Fe μg/L

Dissolved Mn μg/L

(a) Measured as CaCO3.

(b) Combined NO3−N and NO2−N.

(c) The AX300 tank was regenerated on 6/13/99 after samples were collected.

IN = inlet; OU = outlet.
82

A.2 Technical Data on Purolite® A-300
83
84
85
86
87

A.3 Water Usage Report
88

Plant A Water Usage Report

Water Treated per 

Date of Regeneration

Regeneration

Cumulative 

Usage

(gal) (gal) (BVs)

02/01/1995 1,886,500

05/01/1995 2,031,200 144,700 9,672

08/01/1995 2,167,400 136,200 9,104

11/03/1995 2,300,000 132,600 8,864

02/01/1996 2,393,900 93,900 6,277

05/01/1996 2,502,800 108,900 7,279

08/09/1996 2,589,300 86,500 5,782

11/01/1996 2,707,800 118,500 7,921

02/01/1997 2,810,400 102,600 6,858

05/10/1997 2,948,500 138,100 9,231

08/08/1997 3,034,600 86,100 5,755

11/05/1997 3,136,100 101,500 6,785

02/20/1998 3,279,000 142,900 9,552

05/06/1998 3,406,200 127,200 8,503

08/20/1998 3,517,500 111,300 7,440

11/10/1998 3,658,500 141,000 9,425

02/06/1999 3,775,700 117,200 7,834

03/21/1999 3,834,500 58,800 3,930

04/18/1999 3,877,100 42,600 2,848

05/16/1999 3,926,600 49,500 3,309

06/13/1999 3,980,100 53,500 3,576

07/16/1999 4,013,300 33,200 2,219

Bed volume = 2 cu ft = 14.96 gal.

* Regeneration performed on a quarterly basis prior to 2/6/99 and 

on a monthly basis after March 21, 1999.
89

APPENDIX B

Plant B Data
90

B.1 Complete Analytical Results from Long-Term Sampling at Plant B
91

Table B-1. Analytical Results from Long-Term Sampling, Plant B (September 3 to 22, 1998)

Sampling Date 9/3/98 9/8/98 9/16/98 9/22/98

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a)65 6

63

63

12

16 65 5 65 6

Sulfate mg/L 47 <5 47

46

<5

<5 45 <5 45 <5

Turbidity NTU 0.5 <0.1 − − − − − −

pH 8.1 6.7 8.0

8.0

7.5

7.5 8.5 8.5 8.3 8.8

Total Hardness mg/L(a) 37 4.0 − − − − − −

Ca Hardness mg/L(a) 31.2 3.2 − − − − − −

Mg Hardness mg/L(a) 5.4 0.8 − − − − − −

NO3−NO2 (N) mg/L(b) 0.04 0.03 − − − − − −

As (total) μg/L 52.7

47.1

1.7

1.7 60.5 0.8 57.6 4.5 63.4 2.6

As (soluble) μg/L 57.7

−

2.8

3.0 − − − − − −

As (particulate) μg/L <0.1

−

<0.1

<0.1 − − − − − −

As (III) μg/L 0.9

−

0.3

0.3 − − − − − −

As (V) μg/L 56.8

−

2.5

2.7 − − − − − −

Total Al μg/L 24.0

20.7

20.0

14.3 17.3 17.1 26.8 20.1 28.1 27.5

Total Fe μg/L 142

134

<30

<30 87.2 <30 <30 <30 126 <30

Total Mn μg/L 3.0

2.7

<0.5

<0.5 2.3 <0.5 <0.5 <0.5 2.5 <0.5

Dissolved Al μg/L <11

−

<11

<11 − − − − − −

Dissolved Fe μg/L <30

−

<30

<30 − − − − − −

Dissolved Mn μg/L 2.0

−

<0.5

<0.5 − − − − − −

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

IN = inlet; OU = outlet.
92

Table B-2. Analytical Results from Long-Term Sampling, Plant B (September 30 to October 20, 1998)

Sampling Date 9/30/98 10/6/98 10/13/98 10/20/98

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 63 6

63

63

17

17 64 10 64 6

Sulfate mg/L 46 <5 46

46

<5

<5 45 <5 43 <5

Turbidity NTU 0.6 0.1

pH 8.2 7.2 8.5

8.5

8.5

8.4 8.1 7.6 8.2 7.0

Total Hardness mg/L(a) 46.7 8.3

Ca Hardness mg/L(a) 40.7 7.5

Mg Hardness mg/L(a) 6.0 0.8

NO3−NO2 (N) mg/L(b) 0.04 <0.02

As (total) μg/L 58.0

34.0(c)

2.4

3.8 58.2 1.1 58.6 1.0 53.7 1.6

As (soluble) μg/L 57.1

56.2

2.0

1.9

As (particulate) μg/L 0.9

<0.1

0.4

1.9

As (III) μg/L 1.3

1.3

0.2

0.3

As (V) μg/L 55.8

54.9

1.8

1.6

Total Al μg/L 23.6

21.6

19.0

16.8 15.2 <11 <11 <11 12.0 12.3

Total Fe μg/L 116

89.6

<30

<30 82.3 <30 49.6 <30 56.2 <30

Total Mn μg/L 3.4

3.3

<0.5

<0.5 2.3 <0.5 2.2 0.5 2.2 <0.5

Dissolved Al μg/L <11

<11

15.2

<11

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L 2.8

2.9

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3

 and NO2 as N.

(c) Confirmed by sample reanalysis.

IN = inlet; OU = outlet.
93

Table B-3. Analytical Results from Long-Term Sampling, Plant B (October 29 to November 17, 1998)

Sampling Date 10/29/98 11/5/98 11/10/98 11/17/98

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 63 10 63

64

6

6

64 16 65 9

Sulfate mg/L 43 <5 44

44

<5

<5 44 <5 44 <5

Turbidity NTU 0.5 <0.1

pH 8.4 7.4 8.2

8.3

8.0

8.0 8.6 8.6 8.2 7.2

Total Hardness mg/L(a) 40 <2.0

Ca Hardness mg/L(a) 34.5 <0.5

Mg Hardness mg/L(a) 5.8 <0.8

NO3−NO2 (N) mg/L(b) 0.03 <0.02

As (total) μg/L 57.7

57.7

1.1

1.0 64.5 1.3 61.7 1.0 55.8 1.2

As (soluble) μg/L 56.7

55.9

0.9

0.9

As (particulate) μg/L 1.0

1.8

0.2

0.1

As (III) μg/L 0.8

0.7

0.2

0.1

As (V) μg/L 55.9

55.2

0.7

0.8

Total Al μg/L <11

12.6

<11

<11 14.0 16.9 11.0 <11 19.7 15.0

Total Fe μg/L 137

88.4

<30

<30 50.5 <30 91.4 <30 <30 <30

Total Mn μg/L 3.5

2.5

<0.5

<0.5 2.1 <0.5 3.0 <0.5 1.4 <0.5

Dissolved Al μg/L <11

<11

<11

<11

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L 2.5

2.6

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

IN = inlet; OU = outlet.
94

Table B-4. Analytical Results from Long-Term Sampling, Plant B (November 24 to December 15, 1998)

Sampling Date 11/24/98(c) 12/01/98 12/08/98 12/15/98

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 63 8.0 63

64

5

5

64 12

Sulfate mg/L 44 <5 46

45

<5

<5 47 <5

Turbidity NTU <0.1 <0.1

pH 8.1 7.2 8.2

8.2

7.1

7.1 8.4 8.3

Total Hardness mg/L(a) 37 <2.0

Ca Hardness mg/L(a) 31.5 <1.0

Mg Hardness mg/L(a) 5.8 <1.0

NO3−NO2 (N) mg/L(b) 0.02 <0.02

As (total) μg/L 54.4

54.3

1.5

1.6 57.0 1.7 58.5 2.1

As (soluble) μg/L 43.7

44.0

1.6

1.6

As (particulate) μg/L 10.7

10.3

<0.1

<0.1

As (III) μg/L 0.8

0.6

0.1

0.1

As (V) μg/L 42.9

43.4

1.5

1.5

Total Al μg/L 22.0

23.3

18.5

12.3 <11 13.5 <11 <11

Total Fe μg/L 104

85.4

51.2

42.4 <30 <30 <30 <30

Total Mn μg/L 2.2

2.1

<0.5

<0.5 1.8 <0.5 1.0 <0.5

Dissolved Al μg/L <11

<11

<11

<11

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L 1.7

1.7

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

(c) No sampling due to Thanksgiving holiday.

IN = inlet; OU = outlet.
95

Table B-5. Analytical Results from Long-Term Sampling, Plant B (Dec 22, 1998 to Jan 12, 1999)

Sampling Date 12/22/98(c) 12/29/98(c) 01/05/99 01/12/99

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 65 6 63 5

Sulfate mg/L 45 <5 49 <5

Turbidity NTU 0.1 <0.1

pH 8.3 6.5 8.2 6.4

Total Hardness mg/L(a) 35 <2.0

Ca Hardness mg/L(a) 29.7 <0.5

Mg Hardness mg/L(a) 5.3 <0.8

NO3−NO2 (N) mg/L(b) <0.02 <0.02

As (total) μg/L 40.8 1.6 51.9

52.7

1.5

1.0

As (soluble) μg/L 60.5(d)

60.3(d)

1.5

1.5

As (particulate) μg/L <0.1

<0.1

<0.1

<0.1

As (III) μg/L 0.2

0.6

<0.1

<0.1

As (V) μg/L 60.3

59.7

1.5

1.5

Total Al μg/L <11 <11 26.0

26.3

13.0

13.3

Total Fe μg/L 90.7 51.7 124

118

<30

<30

Total Mn μg/L <0.5 <0.5 2.2

2.1

<0.5

<0.5

Dissolved Al μg/L <11

38.0

<11

<11

Dissolved Fe μg/L <30

212

<30

<30

Dissolved Mn μg/L 3.0

1.4

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

(c) No sampling due to Christmas holiday.

(d) Confirmed by sample re-run.

IN = inlet; OU = outlet.
96

Table B-6. Analytical Results from Long-Term Sampling, Plant B (Jan 19 to Feb 9, 1999)

Sampling Date 01/19/99 01/26/99 02/02/99 02/09/99

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 63

64

10

9

64 8 64 8 64 10

Sulfate mg/L 46

45

<5

<5 46 <5 44 <5 42 <5

Turbidity NTU 0.6 0.2

pH 8.4

8.4

6.9

6.9 7.8 8.3 8.3 6.8 8.3 6.7

Total Hardness mg/L(a) 39 <2.0

Ca Hardness mg/L(a) 33.7 <1.0

Mg Hardness mg/L(a) 5.6 <1.0

NO3−NO2 (N) mg/L(b) 0.02 <0.02

As (total) μg/L 51.3 1.4 53.4 1.3 57.9 1.0 57.1

57.6

1.3

1.3

As (soluble) μg/L 63.7

61.7

1.3

1.3

As (particulate) μg/L <0.1

<0.1

<0.1

<0.1

As (III) μg/L 0.8

0.6

0.1

0.1

As (V) μg/L 62.9

61.1

1.2

1.2

Total Al μg/L 21.4 <11 <11 <11 68.3 131 66.4

35.0

<11

<11

Total Fe μg/L 139 <30 51.3 <30 123 48.9 111

114

<30

<30

Total Mn μg/L 3.0 1.1 0.6 0.7 1.6 <0.5 1.3

1.5

<0.5

<0.5

Dissolved Al μg/L <11

<11

<11

<11

Dissolved Fe μg/L 79.0

74.3

<30

<30

Dissolved Mn μg/L 1.4

1.4

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

IN = inlet; OU = outlet.
97

Table B-7. Analytical Results from Long-Term Sampling, Plant B (Feb 16 to Mar 9, 1999)

Sampling Date 02/16/99 02/23/99 03/02/99 03/9/99

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 63

63

7

7

63 4 62 5 64 10

Sulfate mg/L

44

46

<5

<5 36 <5 46 <5 48 <5

Turbidity NTU 0.3 0.2

pH 8.4

8.4

8.6

8.5 8.3 8.6 8.3 6.3 8.3 8.6

Total Hardness mg/L(a) 35 <2.0

Ca Hardness mg/L(a) 29.2 <1.0

Mg Hardness mg/L(a) 5.7 <1.0

NO3−NO2 (N) mg/L(b) 0.06 <0.02

As (total) μg/L 53.4 1.0 55.6 1.7 58.8 1.8 59.8

61.4

1.1

1.8

As (soluble) μg/L 60.8

60.1

1.0

1.0

As (particulate) μg/L <0.1

1.3

0.1

0.8

As (III) μg/L 0.6

0.6

0.3

0.2

As (V) μg/L 60.2

59.5

0.7

0.8

Total Al μg/L <11 <11 11.2 14.6 12.9 <11 <11

<11

<11

<11

Total Fe μg/L 132 30.7 79.2 43.6 74.6 <30 40.1

51.8

<30

<30

Total Mn μg/L 3.5 1.0 1.6 <0.5 1.9 0.6 1.5

1.6

<0.5

<0.5

Dissolved Al μg/L <11

<11

<11

<11

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L 2.1

1.4

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

IN = inlet; OU = outlet.
98

Table B-8. Analytical Results from Long-Term Sampling, Plant B (Mar 16 to Apr 6, 1999)

Sampling Date 03/16/99 03/23/99 03/30/99 04/06/99

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 63

63

15

15 64 15 64 7 64 9

Sulfate mg/L 43

44

<5

<5 45 <5 43 <5 46 <5

Turbidity NTU 0.4 0.2

pH 8.3

8.3

7.9

7.9 8.3 8.0 8.3 6.5 8.5 6.9

Total Hardness mg/L(a) 43 <2.0

Ca Hardness mg/L(a) 37.2 <1.0

Mg Hardness mg/L(a) 5.9 <1.0

NO3−NO2 (N) mg/L(b) <0.02 0.02

As (total) μg/L 57.8 1.4 58.7 1.7 58.9 1.8 63.0

62.0

1.3

1.3

As (soluble) μg/L 60.6

61.2

1.3

1.2

As (particulate) μg/L 2.4

0.8

<0.1

0.1

As (III) μg/L 0.7

0.4

0.3

0.2

As (V) μg/L 59.9

60.8

1.0

1.0

Total Al μg/L <11 <11 11.2 <11 <11 <11 <11

<11

<11

<11

Total Fe μg/L 48.7 30.2 48.7 <30 52.4 <30 53.0

65.8

72.2

73.2

Total Mn μg/L 3.6 5.5 2.0 <0.5 1.7 <0.5 2.2

2.1

<0.5

<0.5

Dissolved Al μg/L <11

<11

<11

<11

Dissolved Fe μg/L 36.0

35.6

30.7

31.7

Dissolved Mn μg/L 2.3

2.3

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

IN = inlet; OU = outlet.
99

Table B-9. Analytical Results from Long-Term Sampling, Plant B (Apr 13 to May 4, 1999)

Sampling Date 04/13/99 04/20/99 04/27/99 05/04/99

Sampling Location

Parameter Unit

IN OU IN OU IN OU IN OU

Alkalinity mg/L(a) 65

64

3

4

64 3 64 6 67 6

Sulfate mg/L 38

37

<5

<5 44 <5 44 <5 44 <5

Turbidity NTU 0.3 <0.1

pH 8.3

8.3

6.4

6.3 8.3 6.1 8.3 6.4 8.3 6.6

Total Hardness mg/L(a) 33 <2.0

Ca Hardness mg/L(a) 28.0 <1.0

Mg Hardness mg/L(a) 5.4 <1.0

NO3−NO2 (N) mg/L(b) 0.02 <0.02

As (total) μg/L 55.7 1.5 59.5 1.6 56.8 1.7 57.7

57.6

2.8

2.7

As (soluble) μg/L 57.7

57.6

2.4

2.5

As (particulate) μg/L <0.1

<0.1

0.3

0.2

As (III) μg/L 1.1

0.9

0.6

0.6

As (V) μg/L 57.0

56.8

1.8

1.8

Total Al μg/L <11 <11 20.3 <11 <11 13.9 <11

11.6

<11

<11

Total Fe μg/L 73.6 <30 37.3 <30 <30 <30 <30

<30

<30

<30

Total Mn μg/L 2.8 <0.5 2.0 <0.5 2.2 <0.5 1.7

1.6

<0.5

<0.5

Dissolved Al μg/L <11

<11

<11

<11

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L 1.5

1.5

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

IN = inlet; OU = outlet.
100

Table B-10. Analytical Results from Long-Term Sampling, Plant B (May 11 to May 25, 1999)

Sampling Date 05/11/99 05/18/99 05/25/99

Sampling Location

Parameter Unit

IN OU IN OU IN OU

Alkalinity mg/L(a) 65

65

13

13 64 4 64 4

Sulfate mg/L 44

44

<5

<5 46 <5 45 <5

Turbidity NTU

pH 8.3

8.3

7.0

6.8 8.3 6.4 8.3 6.2

Total Hardness mg/L(a)

Ca Hardness mg/L(a)

Mg Hardness mg/L(a)

NO3−NO2 (N) mg/L(b)

As (total) μg/L 60.1 1.5 58.4 1.8 55.0 1.9

As (soluble) μg/L

As (particulate) μg/L

As (III) μg/L

As (V) μg/L

Total Al μg/L 12.6 <11 <11 <11 <11 11.6

Total Fe μg/L 39.3 <30 <30 <30 76.1 30.1

Total Mn μg/L 2.4 <0.5 1.6 <0.5 2.5 1.1

Dissolved Al μg/L

Dissolved Fe μg/L

Dissolved Mn μg/L

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

IN = inlet; OU = outlet.
101

APPENDIX C

Plant C Data

C.1 Complete Analytical Results from Long-Term Sampling at Plant C

C.2 Technical Data on DD-2 AA

C.3 Water Usage Report
102

C.1 Complete Analytical Results from Long-Term Sampling at Plant C
10

3

Table C-1. Analytical Results from Long-Term Sampling, Plant C (September 30 to November 11, 1998)

Sampling Date 9/30/98 10/14/98 10/28/98 11/11/98

Sampling Location

Parameter Unit IN TA1 TB1 OU IN TA1 TB1 OU IN TA1 TB1 OU IN TA1 TB1 OU

Alkalinity mg/L(a) 67 88 85 87 73

74

73

73

74

74

72

76 87 84 89 86 90 89 84 86

Fluoride mg/L 1.2 1.4 1.5 1.5 1.3

1.3

1.3

1.4

1.5

1.4

1.4

1.3 1.5 1.5 1.5 1.5 1.5 1.6 1.5 1.5

Sulfate mg/L 22 26 33 27 26

24

24

23

24

24

23

24 27 27 27 27 27 26 26 27

Turbidity NTU 0.3 <0.1 <0.1 <0.1

pH 7.9 7.9 7.6 7.6 7.9

7.9

7.9

7.9

7.9

7.9

7.8

7.8 8.0 7.9 7.9 7.9 8.1 8.1 8.1 8.0

Total Hardness mg/L(a) 57 52 48 53

Ca Hardness mg/L(a) 38.7 34.5 30 35

Mg Hardness mg/L(a) 18.2 17.5 17.7 18.2

NO3-NO2 (N) mg/L(b) 0.1 0.2 0.2 0.2

As (total) μg/L 62.8

63.3

33.8

–

7.3

7.1

14.5

8.0 53.7 40.5 7.9 13.1 55.6 45.9 15.1 16.8 50.1 50.4 26.7 21.8

As (total soluble) μg/L 50.6

49.9

33.9

34.0

6.7

6.6

7.6

7.6

As (particulate) μg/L 12.2

13.4

<0.1

–

0.6

0.5

6.9

0.4

As (III) μg/L 6.7

6.7

0.3

0.3

0.4

0.3

0.3

0.3

As (V) μg/L 43.9

43.2

33.6

33.7

6.3

6.3

7.3

7.3

Total Al μg/L 16.3

21.5

31.3

30.0

33.8

34.6

31.3

26.8 21.3 28.2 14.8 27.0 12.5 48.2 22.6 33.0 30.4 39.0 30.6 34.9

Total Fe μg/L 114

131

<30

<30

<30

<30

<30

<30 <30 <30 <30 <30 <30 38.1 <30 <30 43.9 <30 <30 <30

Total Mn μg/L 70.8

70.4

75.7

72.7

78.5

78.5

73.8

77.1 85.7 86.2 83.4 79.7 80.6 81.6 82.1 85.0 70.3 78.7 87.9 86.0

Dissolved Al μg/L <11

<11

16.6

13.5

17.5

17.5

16.5

16.1

Dissolved Fe μg/L <30

<30

<30

<30

<30

<30

<30

<30

Dissolved Mn μg/L 65.4

66.4

76.3

75.7

76.4

76.2

75.9

75.7

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

IN = inlet; TA1 = after the roughing tank; TB1 = after the polishing tank; OU = outlet.
10

4

Table C-2. Analytical Results from Long-Term Sampling, Plant C (December 2, 1998 to January 6, 1999)

Sampling Date 12/2/98 12/9/98 12/23/98(c)(d) 1/6/99

Sampling Location

Parameter Unit IN TA1 TB1 OU IN TA1 TB1 OU IN TA1 TB1 OU IN TB1 TA1 OU

Alkalinity mg/L(a) 85 87 84 78 80

80

84

84

80

80

75

76 77 79 73 73

Fluoride mg/L 1.5 1.5 1.5 1.5 1.3

1.4

1.3

1.4

1.3

1.3

1.3

1.3 1.3 0.9 0.3 0.2

Sulfate mg/L 26 25 35 29 25

24

26

26

25

26

26

26 24 23 18 19

Turbidity NTU <0.1 <0.1 0.1 0.1

pH 7.8 7.8 7.8 7.6 7.9

8.0

7.9

7.9

7.9

7.9

7.8

7.8 8.0 8.0 8.6 8.7

Total Hardness mg/L(a) 57 53 50 50

Ca Hardness mg/L(a) 37.7 34.7 32.2 32.5

Mg Hardness mg/L(a) 19.4 18.1 17.9 18.0

NO3-NO2 (N) mg/L(b) 0.02 0.1 0.1 0.1

As (total) μg/L 54.8

54.4

46.9

46.8

24.0

24.1

17.8

17.5 76.0 47.5 25.1 16.2 52.5 14.2 0.5 2.6

As (total soluble) μg/L 57.6

57.6

50.1

49.8

26.0

24.8

18.6

18.3

As (particulate) μg/L <0.1

<0.1

<0.1

<0.1

<0.1

<0.1

<0.1

<0.1

As (III) μg/L 2.5

2.2

1.8

1.8

0.4

0.3

1.0

0.9

As (V) μg/L 55.1

55.4

48.3

48.0

25.6

24.5

17.6

17.4

Total Al μg/L 18.9

16.2

27.7

24.1

28.3

24.8

26.6

26.3 <11 22.7 19.4 16.4 <11 41.7 109 112

Total Fe μg/L 41.0

31.2

53.0

68.0

<30

<30

78.1

119 <30 <30 <30 <30 56.9 36.9 <30 68.2

Total Mn μg/L 69.8

69.9

82.9

81.9

76.7

76.2

61.6

62.0 73.9 88.7 78.4 45.1 90.7 67.2 1.9 6.4

Dissolved Al μg/L <11

<11

11.2

11.2

11.1

11.6

<11

<11

Dissolved Fe μg/L <30

<30

<30

<30

<30

<30

<30

<30

Dissolved Mn μg/L 68.1

68.1

80.8

80.7

75.2

74.0

58.5

59.2

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

(c) No sampling during the Christmas week.

(d) Tanks A1 and A2 were recharged with virgin activated alumina on 12/29/98; they were moved to polishing positions and Tanks B1 and B2 were moved to roughing positions 

afterwards.

IN = inlet; TA1 = after the roughing tank; TB1 = after the polishing tank; OU = outlet.
10

5

Table C-3. Analytical Results from Long-Term Sampling, Plant C (January 27, 1999 to March 3, 1999)

Sampling Date 01/27/99 02/03/99 02/17/99 03/03/99

Sampling Location

Parameter Unit IN TB1 TA1 OU IN TB1 TA1 OU IN TB1 TA1 OU IN TB1 TA1 OU

Alkalinity mg/L(a) 81 87 81 76 82 83 82 81 90

89

82

82

83

80

81

80 74 81 73 72

Fluoride mg/L 1.5 1.4 0.8 0.6 1.5 1.5 0.9 0.9 1.3

1.3

1.3

1.3

1.0

1.0

1.0

1.0 1.5 1.6 1.2 1.2

Sulfate mg/L 25 25 24 23 25 25 25 25 26

25

25

25

26

26

26

25 24 25 25 24

Turbidity NTU 0.2 <0.1 0.1 <0.1

pH 8.0 7.9 8.3 8.2 8.1 8.0 8.1 8.2 8.0

8.0

7.9

7.9

8.0

8.0

8.1

8.0 8.0 7.9 8.0 8.0

Total Hardness mg/L(a) 52 51 52 51

Ca Hardness mg/L(a) 34.5 33.7 34.2 32.7

Mg Hardness mg/L(a) 17.8 17.7 18.2 18.0

NO3-NO2 (N) mg/L(b) <0.02 0.02 0.3 0.05

As (total) μg/L 41.3 23.3 0.4 3.5 59.1

62.4

37.3

39.4

1.3

1.3

1.5

1.5 49.2 34.5 0.7 1.3 58.4 31.0 1.5 2.2

As (total soluble) μg/L 63.2

63.6

43.7

43.7

1.5

1.4

1.8

1.8

As (particulate) μg/L <0.1

<0.1

<0.1

<0.1

<0.1

<0.1

<0.1

<0.1

As (III) μg/L 28.8

28.8

9.1

9.1

2.6

1.2

1.9

1.9

As (V) μg/L 34.4

38.8

34.6

34.6

<0.1

<0.1

<0.1

<0.1

Total Al μg/L 11.4 15.8 30.4 52.7 98.2

96.5

67.0

52.0

88.4

53.7

26.1

89.5 <11 23.9 23.7 24.3 <11 25.3 31.8 33.5

Total Fe μg/L 35.9 <30 <30 125 86.8

75.8

<30

<30

36.1

<30

<30

<30 41.8 <30 <30 <30 <30 <30 <30 <30

Total Mn μg/L 55.8 78.8 35.1 9.8 64.9

67.5

79.8

80.2

50.3

49.4

49.9

49.9 57.6 68.1 59.3 60.0 76.9 80.8 69.9 66.6

Dissolved Al μg/L <11

<11

11.9

<11

22.5

24.0

22.8

23.8

Dissolved Fe μg/L <30

<30

<30

<30

<30

<30

<30

<30

Dissolved Mn μg/L 65.4

65.8

80.7

81.9

50.8

51.8

50.3

51.2

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

IN = inlet; TB1 = after the roughing tank; TA1 = after the polishing tank; OU = outlet.
10

6

Table C-4. Analytical Results from Long-Term Sampling, Plant C (Mar 17, 1999 to April 28, 1999)

Sampling Date 03/17/99 03/31/99 04/14/99 04/28/99

Sampling Location

Parameter Unit IN TB1 TA1 OU IN TB1 TA1 OU IN TB1 TA1 OU IN TB1 TA1 OU

Alkalinity mg/L(a) 73 79 77 73 80 83 79 74 86

86

87

88

85

85

78

78 85 88 85 80

Fluoride mg/L 1.5 1.7 1.6 1.5 1.5 1.5 1.4 1.3 1.4

1.4

1.4

1.4

1.4

1.4

1.3

1.3 1.4 1.4 1.4 1.4

Sulfate mg/L 25 25 25 24 26 26 26 26 26

26

27

27

26

27

26

26 26 25 25 26

Turbidity NTU 0.4 <0.1 <0.1 0.3

pH 7.9 8.0 7.9 7.9 8.0 7.9 7.9 7.6 8.1

8.1

8.0

8.0

8.0

8.0

7.9

7.9 8.0 7.9 7.8 8.0

Total Hardness mg/L(a) 47 49 48 48

Ca Hardness mg/L(a) 30.5 31.5 30.2 30.2

Mg Hardness mg/L(a) 16.9 17.1 17.4 17.3

NO3-NO2 (N) mg/L(b) 0.05 0.3 0.6 0.1

As (total) μg/L 34.4 33.1 2.4 2.0 61.7

59.8

37.0

36.7

0.5

0.4

1.8

1.9 42.6 42.5 1.0 2.4 46.1 41.4 4.3 2.8

As (total soluble) μg/L 60.3

61.4

39.6

39.5

0.4

0.4

2.0

1.9

As (particulate) μg/L 1.4

<0.1

<0.1

<0.1

0.1

<0.1

<0.1

<0.1

As (III) μg/L 11.8

11.4

2.6

2.5

0.1

0.1

0.5

0.4

As (V) μg/L 48.5

50.0

37.0

37.0

0.3

0.3

1.5

1.5

Total Al μg/L 25.2 21.8 20.2 30.8 <11

<11

29.0

16.7

16.7

13.3

21.4

18.1 19.9 15.3 16.6 21.7 13.0 22.4 30.8 13.7

Total Fe μg/L 131 <30 <30 45.6 <30

<30

<30

<30

<30

<30

<30

<30 98.1 <30 <30 <30 <30 <30 <30 34.2

Total Mn μg/L 76.7 81.4 67.3 79.7 62.2

59.2

68.0

66.8

63.7

64.9

34.2

34.3 59.6 71.2 52.2 28.6 55.6 46.9 40.4 25.5

Dissolved Al μg/L <11

<11

<11

<11

<11

<11

<11

<11

Dissolved Fe μg/L <30

<30

<30

<30

<30

<30

<30

<30

Dissolved Mn μg/L 63.9

64.0

68.0

67.2

62.8

62.9

32.1

32.0

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

IN = inlet; TB1 = after the roughing tank; TA1 = after the polishing tank; OU = outlet.
10

7

Table C-5. Analytical Results from Long-Term Sampling, Plant C (May 12, 1999 to Jun 9, 1999)

Sampling Date 05/12/99 05/26/99 06/09/99

Sampling Location

Parameter Unit IN TB1 TA1 OU IN TB1 TA1 OU IN TB1 TA1 OU

Alkalinity mg/L(a) 84 84 82 80 86.0 82 82 79 80

80

81

80

79

80

77

78

Fluoride mg/L 1.4 1.4 1.3 1.3 1.6 1.5 1.6 1.6 1.4

1.4

1.4

1.4

1.4

1.4

1.4

1.4

Sulfate mg/L 25 25 26 26 26 26 25 25 25

25

25

25

26

25

25

25

Turbidity NTU <0.1 <0.1 <0.1 <0.1

pH 8.1 8.0 8.0 8.1 8.1 8.0 8.0 8.0 8.0

8.0

7.9

8.0

8.0

8.0

7.9

7.9

Total Hardness mg/L(a) 49.0 49.3 48.0 49.7

Ca Hardness mg/L(a) 32.0 32.7 31.5 32.2

Mg Hardness mg/L(a) 16.6 16.6 16.5 16.5

NO3-NO2 (N) mg/L(b) 0.04 0.1 0.05 1.3

As (total) μg/L 39.5 45.6 0.9 2.9 54.5

54.0

47.2

47.1

1.7

1.6

4.3

4.3 43.6 43.0 1.7 4.6

As (total soluble) μg/L 42.3

42.6

47.7

48.0

1.5

1.4

4.3

4.3

As (particulate) μg/L 12.2

11.4

<0.1

<0.1

0.2

0.2

0.1

0.1

As (III) μg/L 1.1

1.1

1.5

1.4

0.2

0.2

0.4

0.4

As (V) μg/L 41.2

41.6

46.2

46.6

1.3

1.2

3.8

3.9

Total Al μg/L 16.3 15.1 <11 18.1 <11

<11

11.5

13.9

15.4

14.8

20.7

20.3 12.8 22.7 14.7 12.6

Total Fe μg/L <30 <30 <30 <30 178

177

<30

<30

<30

<30

101

101 30.5 <30 <30 <30

Total Mn μg/L 48.9 49.8 28.6 23.2 58.7

58.5

30.4

30.5

17.1

16.4

12.0

11.9 52.2 31.0 21.0 8.9

Dissolved Al μg/L <11

<11

12.0

11.9

<11

<11

20.2

12.4

Dissolved Fe μg/L <30

<30

<30

<30

<30

<30

91.4

<30

Dissolved Mn μg/L 51.8

52.6

30.3

30.2

16.0

16.0

10.4

10.2

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

IN = inlet; TB1 = after the roughing tank; TA1 = after the polishing tank; OU = outlet.
108

C.2 Technical Data on DD-2 AA
109
110
111
112
113
114
115
116

C.3 Water Usage Report
117

Plant C Water Usage Report

Water Treated Since AA 

Installed

Date

Cumulative 

Water Usage

(gal) (gal) (BVs) Remarks

08/28/1997 1,357,900 0 0 AA System Installed

06/11/1998 1,753,200 395,300 6,606

07/13/1998 1,796,200 438,300 7,325

08/19/1998 1,801,900 444,000 7,420

09/03/1998 1,806,200 448,300 7,492

09/08/1998 1,830,300 472,400 7,894

09/11/1998 1,840,700 482,800 8,068

09/14/1998 1,843,600 485,700 8,117

09/15/1998 1,847,300 489,400 8,178

09/16/1998 1,851,700 493,800 8,252

09/17/1998 1,854,800 496,900 8,304

09/18/1998 1,860,100 502,200 8,392

09/21/1998 1,863,300 505,400 8,446

09/22/1998 1,865,100 507,200 8,476

09/23/1998 1,866,800 508,900 8,504

09/24/1998 1,868,700 510,800 8,536

09/25/1998 1,870,800 512,900 8,571

09/28/1998 1,872,700 514,800 8,603

09/29/1998 1,874,700 516,800 8,636

09/30/1998 1,876,900 519,000 8,673

10/01/1998 1,880,100 522,200 8,727

10/02/1998 1,884,800 526,900 8,805

10/05/1998 1,888,000 530,100 8,859

10/06/1998 1,890,300 532,400 8,897

10/07/1998 1,892,800 534,900 8,939

10/08/1998 1,895,100 537,200 8,977

10/12/1998 1,899,600 541,700 9,052

10/13/1998 1,902,800 544,900 9,106

10/14/1998 1,905,800 547,900 9,156 Arsenic breakthrough in TA2 (50-μg/L)

10/15/1998 1,909,100 551,200 9,211

10/16/1998 1,912,400 554,500 9,266

10/19/1998 1,919,700 561,800 9,388

10/20/1998 1,922,200 564,300 9,430

10/21/1998 1,924,100 566,200 9,462

10/22/1998 1,926,500 568,600 9,502

10/23/1998 1,929,400 571,500 9,550

10/26/1998 1,932,300 574,400 9,599

10/27/1998 1,935,300 577,400 9,649

10/28/1998 1,938,600 580,700 9,704

10/30/1998 1,942,800 584,900 9,774

11/02/1998 1,944,700 586,800 9,806

11/03/1998 1,947,300 589,400 9,850

11/06/1998 1,955,100 597,200 9,980

11/09/1998 1,957,300 599,400 10,017

11/10/1998 1,959,300 601,400 10,050 Arsenic breakthrough in TA1 (50-μg/L)

11/12/1998 1,959,700 601,800 10,057

11/16/1998 1,963,000 605,100 10,112

11/17/1998 1,964,900 607,000 10,144

11/18/1998 1,966,700 608,800 10,174

11/19/1998 1,968,800 610,900 10,209

11/20/1998 1,970,900 613,000 10,244

11/23/1998 1,973,400 615,500 10,286

11/24/1998 1,976,400 618,500 10,336

11/25/1998 1,979,100 621,200 10,381

11/30/1998 1,981,000 623,100 10,413

12/01/1998 1,985,200 627,300 10,483

12/02/1998 1,987,000 629,100 10,513

12/03/1998 1,988,300 630,400 10,535

12/04/1998 1,990,200 632,300 10,567

12/07/1998 1,992,200 634,300 10,600

12/08/1998 1,994,500 636,600 10,638

12/09/1998 1,996,600 638,700 10,673

12/10/1998 1,998,500 640,600 10,705

12/11/1998 2,000,600 642,700 10,740

12/14/1998 2,002,700 644,800 10,775
118

Plant C Water Usage Report (continued)

Water Treated Since AA 

Installed

Date

Cumulative 

Water Usage

(gal) (gal) (BVs) Remarks

12/16/1998 2,007,000 649,100 10,847

12/17/1998 2,009,200 651,300 10,884

12/18/1998 2,011,300 653,400 10,919

12/21/1998 2,013,700 655,800 10,959

12/22/1998 2,015,900 658,000 10,996

12/23/1998 2,019,100 661,200 11,049

12/28/1998 2,020,400 662,500 11,071 AA changeout in TA1 and TA2

01/04/1999 2,020,800 662,900 11,078

01/05/1999 2,024,100 666,200 11,133

01/06/1999 2,026,500 668,600 11,173

01/07/1999 2,028,000 670,100 11,198

01/08/1999 2,031,300 673,400 11,253

01/11/1999 2,033,900 676,000 11,297

01/12/1999 2,035,900 678,000 11,330

01/13/1999 2,039,000 681,100 11,382

01/14/1999 2,041,300 683,400 11,420

01/19/1999 2,043,400 685,500 11,456

01/20/1999 2,043,600 685,700 11,459

01/21/1999 2,045,800 687,900 11,496

01/22/1999 2,048,000 690,100 11,532

01/25/1999 2,055,200 697,300 11,653

01/26/1999 2,057,600 699,700 11,693

01/27/1999 2,059,700 701,800 11,728

01/28/1999 2,062,200 704,300 11,770

02/02/1999 2,067,800 709,900 11,863

02/03/1999 2,071,700 713,800 11,928

02/04/1999 2,073,300 715,400 11,955

02/05/1999 2,077,200 719,300 12,020

02/08/1999 2,084,100 726,200 12,136

02/09/1999 2,087,700 729,800 12,196

02/10/1999 2,090,700 732,800 12,246

02/11/1999 2,092,500 734,600 12,276

02/12/1999 2,094,500 736,600 12,309

02/15/1999 2,096,600 738,700 12,345

02/16/1999 2,098,500 740,600 12,376

02/17/1999 2,101,000 743,100 12,418

02/18/1999 2,102,700 744,800 12,447

02/19/1999 2,104,800 746,900 12,482

02/23/1999 2,107,100 749,200 12,520

03/01/1999 2,108,300 750,400 12,540

03/02/1999 2,110,000 752,100 12,569

03/03/1999 2,112,100 754,200 12,604

03/04/1999 2,116,000 758,100 12,669

03/05/1999 2,119,700 761,800 12,731

03/08/1999 2,122,300 764,400 12,774

03/10/1999 2,130,700 772,800 12,914

03/11/1999 2,133,200 775,300 12,956

03/16/1999 2,137,200 779,300 13,023

03/17/1999 2,138,800 780,900 13,050

03/18/1999 2,140,900 783,000 13,085

03/19/1999 2,143,800 785,900 13,133

03/22/1999 2,149,800 791,900 13,234

03/23/1999 2,152,100 794,200 13,272

03/24/1999 2,154,200 796,300 13,307

03/25/1999 2,156,300 798,400 13,342

03/26/1999 2,158,200 800,300 13,374

03/29/1999 2,160,800 802,900 13,417

03/30/1999 2,162,800 804,900 13,451

03/31/1999 2,166,100 808,200 13,506

04/02/1999 2,175,000 817,100 13,655

04/05/1999 2,177,100 819,200 13,690

04/06/1999 2,179,500 821,600 13,730

04/08/1999 2,186,800 828,900 13,852

04/14/1999 2,191,100 833,200 13,924
119

Plant C Water Usage Report (continued)

Water Treated Since AA 

Installed

Date

Cumulative 

Water Usage

(gal) (gal) (BVs) Remarks

04/15/1999 2,199,200 841,300 14,059

04/16/1999 2,201,400 843,500 14,096

04/19/1999 2,200,000 842,100 14,073

04/20/1999 2,208,300 850,400 14,211

04/21/1999 2,210,400 852,500 14,246

04/22/1999 2,213,800 855,900 14,303

04/23/1999 2,216,000 858,100 14,340

04/29/1999 2,219,800 861,900 14,403

05/03/1999 2,220,100 862,200 14,408

05/04/1999 2,223,000 865,100 14,457

05/05/1999 2,225,600 867,700 14,500

05/06/1999 2,230,900 873,000 14,589

05/07/1999 2,233,500 875,600 14,632

05/10/1999 2,236,600 878,700 14,684

05/11/1999 2,239,200 881,300 14,728

05/12/1999 2,241,200 883,300 14,761

05/15/1999 2,246,500 888,600 14,850

05/17/1999 2,253,100 895,200 14,960

05/18/1999 2,258,400 900,500 15,048

05/19/1999 2,261,500 903,600 15,100

05/20/1999 2,263,600 905,700 15,135

05/21/1999 2,267,800 909,900 15,206

05/25/1999 2,273,200 915,300 15,296

05/26/1999 2,275,700 917,800 15,338

05/27/1999 2,279,800 921,900 15,406

06/01/1999 2,288,900 931,000 15,558

06/02/1999 2,291,700 933,800 15,605

06/04/1999 2,290,600 932,700 15,587

06/09/1999 2,303,500 945,600 15,802

06/10/1999 2,308,100 950,200 15,879

06/11/1999 2,310,100 952,200 15,912

06/14/1999 2,327,700 969,800 16,207

06/15/1999 2,334,200 976,300 16,315

06/17/1999 2,337,600 979,700 16,372

06/18/1999 2,339,800 981,900 16,409

07/16/1999 2,358,200 1,000,300 16,716

Bed volume = 4 cu ft per tank = 29.92 gal.

121

APPENDIX D

Plant D Data

D.1 Complete Analytical Results from Long-Term Sampling at Plant D

D.2 Technical Data on CPN AA

D.3 System Plumbing Diagram

D.4 Water Usage Report
122

D.1 Complete Analytical Results from Long-Term Sampling at Plant D
12

3

Table D-1. Analytical Results from Long-Term Sampling, Plant D (September 30 to November 11, 1998)

Sampling Date 9/30/98 10/14/98 10/28/98 11/11/98

Sampling Location

Parameter Unit IN TB1 TA1 AC IN TB1 TA1 AC IN TB1 TA1 AC IN TB1 TA1 AC

Alkalinity mg/L(a) 44 55 58 55 57

57

58

58

56

56

54

55 57 60 59 56 58 56 56 55

Fluoride mg/L 1.0 1.1 1.2 1.3 1.2

1.1

1.1

1.1

1.3

1.3

1.2

1.2 1.2 1.2 1.3 1.3 1.2 1.3 1.4 1.4

Sulfate mg/L 13 13 13 14 15

15

15

15

15

14

15

15 14 14 15 15 14 14 14 14

Turbidity NTU 0.4 0.2 <0.1 <0.1

pH − 8.1 8.1 7.9 7.8 8.4

8.4

8.2

8.2

7.9

7.8

7.8

7.8 8.3 8.1 7.9 7.7 8.0 7.8 7.8 7.8

Total Hardness mg/L(a) 50 51 48 48

Ca Hardness mg/L(a) 42.9 43.9 41.7 41.7

Mg Hardness mg/L(a) 6.9 6.8 6.7 6.8

NO3-NO2 (N) mg/L(b)0.4 1.3 0.4 0.4

As (total) μg/L 77.7

70.5

–

31.6 0.7 0.4 64.6 33.1 0.9 0.9 63.0 38.6 1.0 0.8 68.1 44.4 0.8 0.5

As (total soluble) μg/L 65.0

64.0

32.4

31.5

As (particulate) μg/L 12.7

6.5

–

0.1

As (III) μg/L 0.3

0.2

0.2

0.2

As (V) μg/L 64.7

63.8

32.2

31.3

Total Al μg/L 30.1

34.7

35.6

31.9 40.0 40.1 28.6 22.5 27.0 38.2 <11 23.3 20.6 31.6 14.4 36.5 36.9 31.5

Total Fe μg/L 626

340

<30

<30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30

Total Mn μg/L 4.4

3.8

<0.5

<0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

Dissolved Al μg/L <11

<11

18.2

17.1

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L <0.5

<0.5

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

IN = inlet; TB1 = after the roughing tank; TA1 = after the polishing tank; AC = after the GAC tank.
12

4

Table D-2. Analytical Results from Long-Term Sampling, Plant D (December 2, 1998 to January 6, 1999)

Sampling Date 12/2/98 12/9/98 12/23/98(c) 01/06/99

Sampling Location

Parameter Unit IN TB1 TA1 AC IN TB1 TA1 AC IN TB1 TA1 AC IN TB1 TA1 AC

Alkalinity mg/L(a) 58 57 54 55 57

58

57

58

55

55

56

56 58 63 58 57

Fluoride mg/L 1.2 1.2 1.4 1.4 1.1

1.1

1.1

1.1

1.2

1.2

1.2

1.2 1.1 1.2 1.3 1.3

Sulfate mg/L 14 17 14 14 14

14

14

14

14

14

14

14 14 14 14 14

Turbidity NTU 0.2 0.2 <0.1 <0.1

pH − 8.1 8.1 7.9 7.8 8.3

8.3

8.2

8.2

8.0

8.0

7.9

7.9 8.3 8.1 7.4 7.7

Total Hardness mg/L(a) 50 49 48 49

Ca Hardness mg/L(a) 43.2 42.4 41.5 41.7

Mg Hardness mg/L(a) 7.0 7.0 6.9 6.8

NO3-NO2 (N) mg/L(b) 0.3 0.4 0.8 0.3

As (total) μg/L 58.3

59.9

41.6

42.3

0.9

0.8

0.7

0.7 63.7 44.4 1.2 0.8 58.9 36.4 1.2 0.8

As (total soluble) μg/L 68.9

65.7

45.8

44.4

As (particulate) μg/L <0.1

<0.1

<0.1

<0.1

As (III) μg/L <0.1

<0.1

0.3

0.2

As (V) μg/L 68.9

65.7

45.5

44.2

Total Al μg/L 13.0

14.0

24.7

29.4

29.6

34.0

27.4

39.9 <11 21.0 38.4 25.0 44.7 17.2 30.0 16.1

Total Fe μg/L <30

<30

<30

<30

<30

32.6

31.0

77.5 <30 <30 <30 <30 150 34.7 53.7 25.4

Total Mn μg/L <0.5

<0.5

<0.5

<0.5

<0.5

<0.5

<0.5

<0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

Dissolved Al μg/L <11

<11

14.4

14.5

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L <0.5

<0.5

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

(c) No sampling during the Christmas week.

IN = inlet; TB1 = after the roughing tank; TA1 = after the polishing tank; AC = after the GAC tank.
12

5

Table D-3. Analytical Results from Long-Term Sampling, Plant D (January 20, 1999 to March 3, 1999)

Sampling Date 01/20/99 02/03/99 2/17/99 03/03/99

Sampling Location

Parameter Unit IN TB1 TA1 AC IN TB1 TA1 AC IN TB1 TA1 AC IN TB1 TA1 AC

Alkalinity mg/L(a) 57 55 55 56 58 56 56 54 56

57

57

56

56

56

55

55 56 57 55 53

Fluoride mg/L 1.1 1.1 1.2 1.3 1.2 1.2 1.3 1.4 1.0

1.0

1.1

1.1

1.1

1.1

1.2

1.2 1.2 1.2 1.4 1.4

Sulfate mg/L 14 14 14 14 13 13 13 13 12

13

12

13

13

13

12

13 13 11 12 11

Turbidity NTU 0.2 0.1 <0.1 <0.1

pH − 8.3 7.8 7.7 8.0 8.3 8.2 7.0 7.8 8.3

8.3

8.1

8.1

7.9

7.9

7.8

7.8 8.3 8.2 8.0 7.8

Total Hardness mg/L(a) 51 51 50 48

Ca Hardness mg/L(a) 44.2 43.7 43.2 41.0

Mg Hardness mg/L(a) 7.0 7.0 6.8 6.8

NO3-NO2 (N) mg/L(b) 0.3 0.5 1.4 0.5

As (total) μg/L 53.0 46.2 0.9 0.7 56.5

61.1

47.5

49.0

0.6

0.5

0.5

0.4 54.6 47.0 1.0 0.8 62.6 50.3 1.2 0.9

As (total soluble) μg/L 65.3

66.9

52.3

50.7

As (particulate) μg/L <0.1

<0.1

<0.1

<0.1

As (III) μg/L <0.1

<0.1

0.2

0.2

As (V) μg/L 65.3

66.9

52.1

50.5

Total Al μg/L <11 24.1 21.2 30.2 14.6

27.2

23.5

27.3

16.5

23.9

22.3

40.1 11.3 22.1 21.6 19.1 <11 41.0 24.4 22.3

Total Fe μg/L <30 <30 <30 <30 62.0

40.6

<30

44.6

<30

<30

<30

<30 <30 <30 <30 <30 36.3 <30 42.1 <30

Total Mn μg/L 0.5 <0.5 <0.5 <0.5 <0.5

<0.5

<0.5

<0.5

<0.5

<0.5

<0.5

<0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

Dissolved Al μg/L <11

<11

14.9

14.2

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L <0.5

<0.5

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

IN = inlet; TB1 = after the roughing tank; TA1 = after the polishing tank; AC = after the GAC tank.
12

6

Table D-4. Analytical Results from Long-Term Sampling, Plant D (Mar 17 to April 28, 1999)

Sampling Date 03/17/99 03/31/99 04/14/99 04/28/99

Sampling Location

Parameter Unit IN TB1 TA1 AC IN TB1 TA1 AC IN TB1 TA1 AC IN TB1 TA1 AC

Alkalinity mg/L(a) 54 55 55 54 58 57 57 56 58

58

57

57

57

56

55

56 58 58 57 56

Fluoride mg/L 1.4 1.4 1.5 1.6 1.2 1.2 1.3 1.4 1.1

1.1

1.1

1.1

1.2

1.2

1.3

1.3 1.1 1.1 1.2 1.3

Sulfate mg/L 11 12 12 11 15 14 14 14 15

14

14

14

14

14

14

14 14 14 14 14

Turbidity NTU 0.3 0.2 <0.1 <0.1

pH − 8.2 8.1 8.0 7.9 8.3 8.2 7.9 7.9 8.3

8.3

8.3

8.3

8.0

8.0

7.9

7.9 8.3 8.2 8.0 7.9

Total Hardness mg/L(a) 46 50 45 45

Ca Hardness mg/L(a) 39.5 42.9 38.0 38.7

Mg Hardness mg/L(a) 6.6 6.9 6.5 6.5

NO3-NO2 (N) mg/L(b) 0.4 0.4 0.4 0.3

As (total) μg/L 61.6 52.5 1.1 0.8 71.2

69.5

60.8

60.7

0.9

0.9

0.8

0.7 63.0 53.3 1.1 0.9 61.1 54.9 1.3 1.1

As (total soluble) μg/L 69.9

70.4

60.1

60.6

As (particulate) μg/L 1.3

<0.1

0.7

0.1

As (III) μg/L 0.5

0.3

0.4

0.2

As (V) μg/L 69.4

70.1

59.7

60.4

Total Al μg/L 13.5 18.2 16.7 18.8 <11

<11

24.4

24.7

22.6

18.7

27.4

24.8 <11 17.3 29.1 18.7 <11 18.5 33.5 24.4

Total Fe μg/L <30 <30 <30 <30 <30

<30

<30

<30

<30

<30

<30

<30 <30 <30 <30 <30 <30 <30 <30 <30

Total Mn μg/L 11.2 <0.5 <0.5 <0.5 <0.5

<0.5

<0.5

<0.5

<0.5

<0.5

<0.5

<0.5 <0.5 0.8 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

Dissolved Al μg/L <11

<11

13.6

13.3

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L <0.5

<0.5

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3 and NO2 as N.

IN = inlet; TB1 = after the roughing tank; TA1 = after the polishing tank; AC = after the GAC tank.
12

7

Table D-5. Analytical Results from Long-Term Sampling, Plant D (May 12 to June 23, 1999)

Sampling Date 05/12/99 05/26/99(C) 06/09/99 06/23/99

Sampling Location

Parameter Unit IN TB1 TA1 AC IN TA1 TB1 AC IN TA1 TB1 AC IN TA1 TB1 AC

Alkalinity mg/L(a) 57 58 58 55 58 57 55 54 58

58

56

56

52

52

50

50 58 57 59 60

Fluoride mg/L 1.1 1.1 1.1 1.2 1.3 1.4 0.6 0.6 1.1

1.1

1.2

1.2

<0.1

<0.1

<0.1

<0.1 1.0 1.1 <0.1 <0.1

Sulfate mg/L 14.0 14.0 14.0 14.0 13.0 14.0 <5 <5 13.0

13.0

14.0

14.0

<5

<5

<5

<5 14.0 15.0 15.0 15.0

Turbidity NTU 0.3 <0.1 <0.1 <0.1

pH − 8.4 8.3 8.0 7.8 8.3 8.1 9.9 9.5 8.3

8.3

8.1

8.1

8.4

8.4

8.7

8.7 8.3 8.0 8.3 8.4

Total Hardness mg/L(a) 48 47 <2.0 <2.0

Ca Hardness mg/L(a) 42.2 41.0 0.7 0.8

Mg Hardness mg/L(a) 6.3 6.4 0.8 0.8

NO3-NO2 (N) mg/L(b) 0.8 0.3 0.3 0.5

As (total) μg/L 62.4 56.8 1.4 1.0 65.9

66.4

1.4

1.4

2.1

2.1

9.5

9.6 60.2 1.7 2.9 2.3 61.1 2.3 1.8 1.1

As (total soluble) μg/L 66.6

66.0

1.4

2.3

As (particulate) μg/L <0.1

<0.1

<0.1

<0.1

As (III) μg/L 0.5

0.4

0.1

0.1

As (V) μg/L 66.1

65.7

1.3

2.1

Total Al μg/L <11 17.6 17.6 21.5 <11

<11

14.6

19.0

7,457 7,566 <11 21.5 121 190 12.1 22.4 108 115

Total Fe μg/L <30 <30 <30 <30 40.1

40.9

<30

<30

<30

<30

<30

<30 33.3 <30 <30 <30 <30 <30 <30 <30

Total Mn μg/L <0.5 <0.5 <0.5 <0.5 <0.5

<0.5

0.8

<0.5

<0.5

<0.5

<0.5

<0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

Dissolved Al μg/L 1.5

2.7

19.2

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L <0.5

<0.5

1.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3

 and NO2 as N.

(c) Tanks B1 and B2 were replaced with virgin activated alumnia on 5/25/99; they were used as polishing tanks and Tanks A1 and A2 used as roughing tanks afterwards.

IN = inlet; TB1 = after the roughing tank; TA1 = after the polishing tank; AC = after the GAC tank.
12

8

Table D-6. Analytical Results from Long-Term Sampling, Plant D (July 7 to August 18, 1999)

Sampling Date 07/07/99 7/21/99 8/04/99 8/18/99

Sampling Location

Parameter Unit IN TA1 TB1 AC IN TA1 TB1 AC IN TA1 TB1 AC IN TA1 TB1 AC

Alkalinity mg/L(a) 58 59 65 62 59 58 60 60 58

58

47

48

55

55

40

40 57 56 56 58

Fluoride mg/L 0.9 1.1 0.2 0.2 1.2 1.2 0.3 0.3 0.9

0.9

<0.1

<0.1

0.7

0.7

0.5

0.5 1.0 0.5 0.5 0.1

Sulfate mg/L 15 16 16 15 13 14 13 13 13

13

7

8

<5

<5

<5

<5 12 12 10 11

Turbidity NTU 0.30 0.10 <0.10 <0.10

pH − 8.2 8.0 8.3 8.0 7.8 8.0 8.3 8.4 8.2

8.2

8.3

8.4

8.4

8.5

8.4

8.4 8.2 8.3 8.4 8.3

Total Hardness mg/L(a) 48 50 47 50

Ca Hardness mg/L(a) 41.7 42.9 40.5 42.9

Mg Hardness mg/L(a) 6.5 6.6 6.6 6.8

NO3-NO2 (N) mg/L(b) 0.3 0.4 0.5 0.4

As (total) μg/L 60.3 3.4 3.2 1.0 87.9

86.0

10.9

10.4

1.2

1.2

0.7

0.6 59.8 5.4 1.6 0.8 58.8 6.5 1.1 0.6

As (total soluble) μg/L 100

68.8

9.5

10.0

As (particulate) μg/L <0.1

17.2

1.4

0.4

As (III) μg/L * *

As (V) μg/L <0.1

<0.1

6.1

10.0

Total Al μg/L 20.5 23.7 133 124 16.0

18.8

28.1

29.4

128

132

155

139 16.9 471 148 143 22.4 80.4 111 107

Total Fe μg/L <30 <30 <30 <30 <30

<30

<30

<30

<30

<30

<30

<30 <30 <30 <30 <30 <30 127 <30 <30

Total Mn μg/L <0.5 <0.5 <0.5 <0.5 <0.5

<0.5

<0.5

<0.5

<0.5

<0.5

<0.5

<0.5 <0.5 0.7 <0.5 <0.5 <0.5 0.7 <0.5 <0.5

Dissolved Al μg/L <11

<11

13.1

14.6

Dissolved Fe μg/L <30

<30

<30

<30

Dissolved Mn μg/L <0.5

<0.5

<0.5

<0.5

(a) Measured as CaCO3.

(b) Combined NO3

 and NO2 as N.

IN = inlet; TA1 = after the roughing tank; TB1 = after the polishing tank; AC = after the GAC tank.

* Abnormal results due to contaminated resin column.
12

9

Table D-7. Analytical Results from Long-Term Sampling, Plant D (September 1, 1999)

Sampling Date 9/1/99

Sampling Location

Parameter Unit IN TA1 TB1 AC

Alkalinity mg/L(a) 58 57 59 57

Fluoride mg/L 1.1 0.5 0.2 0.5

Sulfate mg/L 12 13 14 14

Turbidity NTU

pH − 7.8 8.2 8.1 8.0

Total Hardness mg/L(a)

Ca Hardness mg/L(a)

Mg Hardness mg/L(a)

NO3-NO2 (N) mg/L(b)

As (total) μg/L 60.3 1.3 0.8 0.7

As (total soluble) μg/L

As (particulate) μg/L

As (III) μg/L

As (V) μg/L

Total Al μg/L 14.9 277 129 68.8

Total Fe μg/L <30 <30 <30 <30

Total Mn μg/L <0.5 <0.5 <0.5 <0.5

Dissolved Al μg/L

Dissolved Fe μg/L

Dissolved Mn μg/L

(a) Measured as CaCO3.

(b) Combined NO3

 and NO2 as N.

IN = inlet; TA1 = after the roughing tank; TB1 = after the polishing

tank; AC = after the GAC tank.
130

D.2 System Plumbing Diagram
131
132

D.3 Water Usage Report
133

Plant D Water Usage Report

Water Meter Readings (gal) Cumulative Water Treated (BV)

Date Entrance A1B1 A2B2 B1A1 B2A2 A1B1 A2B2 B1A1 B2A2 Remarks

04/16/96 2,295,800 400 42,900 200 300 0 0 0 0 AA system installed in 2/96

05/08/96 2,333,260 18,800 61,600 200 300 246 250 0 0

06/19/96 2,409,900 56,200 100,200 200 300 746 766 0 0

07/22/96 2,466,374 83,800 128,600 200 300 1,115 1,146 0 0

08/20/96 2,523,670 111,900 157,300 200 300 1,491 1,529 0 0

09/06/96 2,553,380 126,400 172,300 200 300 1,684 1,730 0 0

10/15/96 2,631,240 164,700 211,400 200 300 2,197 2,253 0 0

11/13/96 2,703,750 200,300 247,800 200 300 2,672 2,739 0 0

12/20/96 2,770,410 233,000 281,200 200 300 3,110 3,186 0 0

01/09/97 2,800,240 247,700 296,100 200 300 3,306 3,385 0 0

02/21/97 2,888,940 291,900 339,900 200 300 3,897 3,971 0 0

03/21/97 2,948,004 321,000 369,400 200 300 4,286 4,365 0 0

04/17/97 3,000,610 346,900 395,700 200 300 4,632 4,717 0 0

05/15/97 3,059,700 376,000 425,200 200 300 5,021 5,111 0 0

06/12/97 3,108,910 400,300 449,800 200 300 5,346 5,440 0 0 Arsenic breakthrough in 

TA2 (50-μg/L)

07/14/97 3,157,310 424,500 473,900 200 300 5,670 5,762 0 0

08/15/97 3,208,400 449,300 499,400 200 300 6,001 6,103 0 0 Arsenic breakthrough in 

TA1 (50-μg/L)

09/12/97 3,250,280 469,900 520,300 200 300 6,277 6,382 0 0

10/15/97 3,295,576 492,200 543,000 200 300 6,575 6,686 0 0

11/18/97 3,357,040 504,800 557,100 17,200 17,600 6,743 6,874 - - TA1, TA2 rebedded in 

11/97

12/23/97 3,411,900 504,800 557,100 43,200 45,100 0 0 0 0 TB1, TB2 rebedded in 

12/97

01/19/98 3,447,000 504,800 557,100 60,500 62,200 0 0 231 254

02/24/98 3,509,210 504,800 557,100 91,200 93,100 0 0 642 667

03/25/98 3,560,110 504,800 557,100 116,400 118,400 0 0 979 1,005

04/15/98 3,594,940 504,800 557,100 133,600 135,700 0 0 1,209 1,237

05/19/98 3,661,900 504,800 557,100 167,100 168,600 0 0 1,656 1,676

06/15/98 3,720,820 504,800 557,100 196,200 197,600 0 0 2,045 2,064

07/23/98 3,778,580 504,800 557,100 224,800 226,200 0 0 2,428 2,447

08/27/98 3,830,990 504,800 557,100 250,800 252,100 0 0 2,775 2,793

09/16/98 3,856,690 504,800 557,100 263,600 264,900 0 0 2,947 2,964

10/15/98 3,897,300 504,800 557,100 283,800 285,000 0 0 3,217 3,233

11/12/98 3,936,270 504,800 557,100 303,000 304,300 0 0 3,473 3,491

12/21/98 3,982,560 504,800 557,100 326,000 327,200 0 0 3,781 3,797

01/19/99 4,015,700 504,800 557,100 342,500 343,600 0 0 4,001 4,016

02/16/99 4,055,600 504,800 557,100 362,300 363,400 0 0 4,266 4,281

03/18/99 4,095,300 504,800 557,100 382,000 383,100 0 0 4,529 4,544 *

04/28/99 4,147,400 504,800 557,100 407,900 408,900 0 0 4,876 4,889

05/25/99 4,181,200 504,800 557,100 424,600 425,600 0 0 5,099 5,112 Rebedded TB1, TB2 on 

5/25/99

06/22/99 4,218,500 522,800 575,800 424,600 425,600 241 250 0 0

07/14/99 4,269,800 548,000 601,700 424,600 425,600 578 596 0 0 Rebedded TA1 on 7/23/99

08/25/99 4,346,800 585,200 641,300 424,600 425,600 1,075 1,126 0 0

09/17/99 4,376,700 599,600 656,700 424,600 425,600 1,267 1,332 0 0

10/29/99 4,438,700 629,600 688,600 424,600 425,600 1,668 1,758 0 0

11/22/99 4,470,300 644,800 704,800 424,600 425,600 1,872 1,975 0 0

12/29/99 4,517,500 667,500 729,100 424,600 425,600 2,175 2,299 0 0

Bed volume = 10 cu ft per tank = 74.8 gal.

* Arsenic breakthrough was detected in TB1 based on Battelle's sampling results of 3/3/99.