EPA/600/R-07/049
June 2007
Arsenic Removal from Drinking Water by Adsorptive Media
U.S. EPA Demonstration Project at
Webb Consolidated Independent School District in Bruni, TX
Six-Month Evaluation Report
by
Shane Williams
Abraham S.C. Chen
Lili Wang
Battelle
Columbus, OH 43201-2693
Contract No. 68-C-00-185
Task Order No. 0029
for
Thomas J. Sorg
Task Order Manager
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
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DISCLAIMER
The work reported in this document was funded by the United States Environmental Protection Agency
(EPA) under Task Order 0029 of Contract 68-C-00-185 to Battelle. It has been subjected to the Agency's
peer and administrative reviews and has been approved for publication as an EPA document. Any
opinions expressed in this paper are those of the author(s) and do not, necessarily, reflect the official
positions and policies of the EPA. Any mention of products or trade names does not constitute
recommendation for use by the EPA.
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FOREWORD
The U.S. 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 actions 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 preventing and reducing risks from pollution that
threaten human health and the environment. The focus of the Laboratory's research program is on
methods and their cost-effectiveness for prevention and control of pollution to air, land, water, and sub-
surface resources; protection of water quality in public water systems; remediation of contaminated sites,
sediments and groundwater; prevention and control of indoor air pollution; and restoration of ecosystems.
NRMRL collaborates with both public and private sector partners to foster technologies that reduce the
cost of compliance and to anticipate emerging problems. NRMRL's research provides solutions to envi-
ronmental problems by developing and promoting technologies that protect and improve the environment;
advancing scientific and engineering information to support regulatory and policy decisions; and provid-
ing the technical support and information transfer to ensure implementation of environmental regulations
and strategies at the national, state, and community levels.
This publication has been produced as part of the Laboratory'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.
Sally Gutierrez, Director
National Risk Management Research Laboratory
in
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ABSTRACT
This report documents the activities performed and the results obtained from the first six months of the
arsenic removal treatment technology demonstration project at the Webb Consolidated Independent
School District (Webb CISD) site at Bruni, TX. The main objective of the project is to evaluate the
effectiveness of AdEdge Technologies' AD-33 media in removing arsenic to meet the new arsenic
maximum contaminant level (MCL) of 10 |o,g/L. Additionally, this project evaluates 1) the reliability of
the treatment system (Arsenic Package Unit [APU]-50LL-CS-S-2-AVH), 2) the required system
operation and maintenance (O&M) and operator skills, and 3) the capital and O&M cost of the
technology. The project also characterizes the water in the distribution system and residuals produced by
the treatment process. The types of data collected include system operation, water quality (both across
the treatment train and in the distribution system), process residuals, and capital and O&M cost.
The APU-50LL-CS-S-2-AVH treatment system consisted of two 42-in-diameter, 72-in-tall carbon steel
vessels in series configuration, each containing approximately 22 ft3 of AD-33 pelletized media, which is
an iron-based adsorptive media developed by Bayer AG and marketed under the name of AD-33 by
AdEdge. The treatment system was designed for a peak flowrate of 40 gal/min (gpm) and an empty bed
contact time (EBCT) of approximately 4.1 min per vessel. The actual average flowrate for the six-month
operational period was 44 gpm, based on readings of the hour meter interlocked to the well pump and the
electromagnetic flow meter/totalizer installed on each adsorption vessel.
As part of the water treatment system, a pH adjustment/control system was used to adjust the pH value of
raw water from as high as 8.2 to a target value of 7.0. A prechlorination system also was used to oxidize
As(III) to As(V) and maintain a target chlorine residual level of 1.2 mg/L (as C12) in the distribution
system. The pH adjustment/control system consisted of a carbon dioxide (CO2) supply assembly, an
automatic pH control panel, a CO2 membrane module (that injected CO2 into a CO2 loop), and an in-line
pH probe. The prechlorination system, which was upgraded from the preexisting system, included a
chemical feed pump, a sodium hypochlorite (NaOCl) feed tank, and an inject port located downstream of
the CO2 loop and in-line pH probe.
The AdEdge treatment system began regular operation on December 8, 2005. The data collected included
system operation, water quality (both across the treatment train and in the distribution system), process
residuals, and capital and O&M cost. Between December 8, 2005, and June 9, 2006, the system operated
an average of 4.3 hr/day, treating approximately 2,070,000 gal of water. This volume throughput was
equivalent to 12,600 bed volumes (BV) based on the 22 ft3 of media in one adsorption vessel or 6,300 BV
based on the 44 ft3 of media in the two adsorption vessels in series.
Since system start-up, the APU system has experienced component failures associated with the pH
control system and flow meters/totalizers. Leaks were detected in the CO2 supply line; the proportional
flow control valve malfunctioned; and the in-line pH probe failed. There were periods when the pH
control system was switched from automatic to manual mode until replacement of certain system
components were performed to address the problems encountered. In addition to the pH control system
problems, errors were encountered with the system flow meters/totalizers. On two occasions, the system
totalizers reset and began totalizing from zero, likely caused by a programming error. As of the end of
the first six months of the evaluation period, the issues with the pH control system appeared to have been
resolved and programming updates are being prepared to prevent future totalizer errors.
Total arsenic concentrations in raw water ranged from 46.2 to 62.9 |o,g/L. As(III) was the predominating
species, ranging from 35.8 to 40.8 |o,g/L. Chlorination effectively oxidized As(III) to As(V), reducing
IV
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As(III) concentrations to an average value of 1.7 |og/L. As of June 6, 2006, the total arsenic level in the
treated water following the lead adsorption vessel was 1.1 |o,g/L at approximately 12,100 BV. The arsenic
level from the lag vessel at the time was 0.8 |og/L. Concentrations of phosphorus and silica, which could
interfere with arsenic adsorption by competing with arsenate for adsorption sites, ranged from <0.01 to
0.03 mg/L (as PO4) and from 40.6 to 43.9 mg/L (as SiO2), respectively, in raw water. Concentrations of
iron, manganese, and other ions in raw water were not high enough to impact arsenic removal by the
media.
Comparison of the distribution system sampling results before and after operation of the system showed a
significant decrease in arsenic concentration (from an average of 68.7 (ig/L to an average of 2.4 (ig/L).
The arsenic concentrations in the distribution system were similar to those in the system effluent. Lead
and copper concentrations did not appear to have been affected by the operation of the treatment system.
The capital investment cost of $138,642 included $94,662 for equipment, $24,300 for site engineering,
and $19,680 for installation. Using the system's rated capacity of 40 gpm (or 57,600 gal/day [gpd]), the
capital cost was $3,466/gpm (or $2.41/gpd) of design capacity. The capital cost also was converted to an
annualized cost of $13,086/yr using a capital recovery factor (CRF) of 0.09439 based on a 7% interest
rate and a 20-year return period. Assumed that the system operated 24 hours a day, 7 days a week at the
system design flowrate of 40 gpm to produce 21,024,000 gal of water per year, the unit capital cost would
be $0.62/1,000 gal. Because the system operated an average of 4.3 hr/day at 44 gpm, producing
2,070,000 gal of water during the six-month period, the unit capital cost increased to $3.16/1,000 gal at
this reduced rate of use.
The O&M cost included only the cost associated with the adsorption system, such as media replacement
and disposal, CO2 and chlorine usage, electricity consumption, and labor. Although media replacement
did not occur during the first six months of system operation, the media replacement cost would represent
the majority of the O&M cost and was estimated to be $11,190 to change out one vessel (including 22 ft3
AD-33 media and associated labor for media change out and disposal). This cost was used to estimate the
media replacement cost per 1,000 gal of water treated as a function of the projected media run length to
the 10 |o,g/L arsenic breakthrough.
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CONTENTS
DISCLAIMER ii
FOREWORD iii
ABSTRACT iv
APPENDICES vii
FIGURES vii
TABLES vii
ABBREVIATIONS AND ACRONYMS ix
ACKNOWLEDGMENTS xi
1.0 INTRODUCTION 1
1.1 Background 1
1.2 Treatment Technologies for Arsenic Removal 2
1.3 Project Objectives 2
2.0 SUMMARY AND CONCLUSIONS 5
3.0 MATERIALS AND METHODS 7
3.1 General Project Approach 7
3.2 System O&M and Cost Data Collection 8
3.3 Sample Collection Procedures and Schedules 8
3.3.1 Source Water Sample Collection 10
3.3.2 Treatment Plant Water Sample Collection 10
3.3.3 Backwash Water/Solid Sample Collection 10
3.3.4 Distribution System Water Sample Collection 10
3.4 Sampling Logistics 10
3.4.1 Preparation of Arsenic Speciation Kits 10
3.4.2 Preparation of Sampling Coolers 10
3.4.3 Sample Shipping and Handling 11
3.5 Analytical Procedures 11
4.0 RESULTS AND DISCUSSION 12
4.1 Facility Description and Preexisting Treatment System Infrastructure 12
4.1.1 Source Water Quality 12
4.1.2 Treated Water Quality 15
4.1.3 Distribution System 16
4.2 Treatment Process Description 16
4.3 System Installation 25
4.3.1 Permitting 25
4.3.2 Building Preparation 25
4.3.3 Installation, Shakedown, and Startup 25
4.4 System Operation 27
4.4.1 Operational Parameters 27
4.4.2 Residual Management 28
4.4.3 System/Operation Reliability and Simplicity 30
4.5 System Performance 31
4.5.1 Treatment Plant Sampling 31
4.5.2 Backwash Water Sampling 39
4.5.3 Distribution System Water Sampling 39
4.6 System Cost 39
VI
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4.6.1 Capital Cost 39
4.6.2 Operation and Maintenance Cost 41
5.0 REFERENCES 44
APPENDICES
APPENDIX A: OPERATIONAL DATA A-l
APPENDIX B: ANALYTICAL DATA B-l
FIGURES
Figure 4-1. Existing Water Treatment Facility 12
Figure 4-2. Wellhead at Webb CISD 13
Figure 4-3. Existing Chlorine Addition System 13
Figure 4-4. Process Flow Diagram for the APU-50LL-CS-S-2-AVH system 18
Figure 4-5. Process Flow Diagram and Sampling Schedule and Locations 19
Figure 4-6. Process Diagram of (top) CO2 pH Adjustment System and (bottom) pH/PID
Control Panel 21
Figure 4-7. Carbon Dioxide Gas Flow Control System for pH Adjustment 22
Figure 4-8. Chlorination System 23
Figure 4-9. Adsorption System Valve Tree and Piping Configuration 24
Figure 4-10. Maintenance Shop Building 26
Figure 4-11. System Being Delivered to Site 26
Figure 4-12. System Instantaneous and Calculated Flowrates 29
Figure 4-13. System Operational Pressures 29
Figure 4-14. Concentrations of Various Arsenic Species at IN, AP, TA, and TB Sampling
Locations 35
Figure 4-15. Total Arsenic Breakthrough Curves 36
Figure 4-16. Silica (as SiO2) Breakthrough Curves 37
Figure 4-17. pH Values Measured Throughout Treatment Train 38
Figure 4-18. Media Replacement and Operation and Maintenance Cost 43
TABLES
Table 1-1. Summary of Round 1 and Round 2 Arsenic Removal Demonstration Locations,
Technologies, and Source Water Quality 3
Table 3-1. Predemonstration Study Activities and Completion Dates 7
Table 3-2. Evaluation Objectives and Supporting Data Collection Activities 8
Table 3-3. Sampling Schedule and Analytes 9
Table 4-1. Water Quality Data for Webb CISD, Bruni, TX 14
Table 4-2. TCEQ Treated Water Quality Data 15
Table 4-3. Physical and Chemical Properties of AD-33 Media 16
Table 4-4. Design Features of AdEdge APU-50LL-CS-S-2-AVH System 20
Table 4-5. Properties of Celgard, X50-215 Microporous Hollow Fiber Membrane 22
Table 4-6. System Punch-List/Operational Issues 27
Table 4-7. Summary of APU-50LL-CS-S-2-AVH System Operation 28
Table 4-8. Summary of Analytical Results for Arsenic, Iron, and Manganese 32
vn
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Table 4-9. Summary of Water Quality Parameter Sampling Results 33
Table 4-10. Distribution System Sampling Results 40
Table 4-11. Capital Investment Cost for the APU-50LL-CS-S-2-AVH System 41
Table 4-12. Operation and Maintenance Cost for the APU-50LL-CS-S-2-AVH System 42
Vlll
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ABBREVIATIONS AND ACRONYMS
Ap differential pressure
AAL American Analytical Laboratories
AM adsorptive media
APU arsenic package unit
As arsenic
ATS Aquatic Treatment Systems
ATSI Applied Technology Systems Inc.
BET Brunauer, Emmett, and Teller
BV bed volume
Ca calcium
C/F coagulation/filtration process
CISD Consolidated Independent School District
Cl chlorine
CRF capital recovery factor
Cu copper
DO dissolved oxygen
EBCT empty bed contact time
EPA U.S. Environmental Protection Agency
F fluorine
Fe iron
gpd gallons per day
gpm gallons per minute
HOPE high-density polyethylene
hp horse power
ICP-MS inductively coupled plasma-mass spectrometry
ID identification
ISFET Ion Sensitive Field Effect Transistor
IX ion exchange
LCR Lead and Copper Rule
MCL maximum contaminant level
MDL method detection limit
MEI Magnesium Elektron, Inc.
Mg magnesium
Mn manganese
mV millivolts
Na sodium
NA not analyzed
IX
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ABBREVIATIONS AND ACRONYMS (Continued)
ND not detectable
NRMRL National Risk Management Research Laboratory
NSF NSF International
O&M operation and maintenance
OIT Oregon Institute of Technology
ORD Office of Research and Development
ORP oxidation-reduction potential
PID Proportional Integral Derivative
PLC programmable logic controller
PO4 phosphate
POU point of use
psi pounds per square inch
PVC polyvinyl chloride
QA quality assurance
QAPP Quality Assurance Project Plan
QA/QC quality assurance/quality control
RO reverse osmosis
RPD relative percent difference
SDWA Safe Drinking Water Act
SiO2 silica
SMCL secondary maximum contaminant level
SO42" sulfate
STS Severn Trent Services
TCEQ
TCLP
TDS
U
V
voc
Texas Commission on Environmental Quality
toxicity characteristic leaching procedure
total dissolved solids
uranium
vanadium
volatile organic compound
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ACKNOWLEDGMENTS
The authors wish to extend their sincere appreciation to Webb Consolidated Independent School District
and Mr. George Gonzales, who monitored the treatment system and collected samples from the treatment
and distribution systems throughout this study period. This performance evaluation would not have been
possible without his efforts.
XI
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1.0 INTRODUCTION
1.1 Background
The Safe Drinking Water Act (SDWA) mandates that the United States Environmental Protection Agency
(EPA) identify and regulate drinking water contaminants that may have adverse human health effects and
are known or anticipated to occur in public water supply systems. In 1975 under the SDWA, EPA
established a maximum contaminant level (MCL) for arsenic at 0.05 mg/L. Amended in 1996, the
SDWA required that EPA develop an arsenic research strategy and publish a proposal to revise the
arsenic MCL by January 2000. On January 18, 2001, EPA finalized the arsenic MCL at 0.01 mg/L (EPA,
2001). In order to clarify the implementation of the original rule, EPA revised the rule text on March 25,
2003, to express the MCL as 0.010 mg/L (10 (ig/L) (EPA, 2003). The final rule requires all community
and non-transient, non-community water systems to comply with the new standard by January 23, 2006.
In October 2001, EPA announced an initiative for additional research and development of cost-effective
technologies to help small community water systems (<10,000 customers) meet the new arsenic standard,
and to provide technical assistance to operators of small systems in order to reduce compliance cost. As
part of this Arsenic Rule Implementation Research Program, EPA's Office of Research and Development
(ORD) proposed a project to conduct a series of full-scale, on-site demonstrations of arsenic removal
technologies, process modifications, and engineering approaches applicable to small systems. Shortly
thereafter, an announcement was published in the Federal Register requesting water utilities interested in
participating in Round 1 of this EPA-sponsored demonstration program to provide information on their
water systems. In June 2002, EPA selected 17 sites from a list of 115 sites to be the host sites for the
demonstration studies.
In September 2002, EPA solicited proposals from engineering firms and vendors for cost-effective arsenic
removal treatment technologies for the 17 host sites. EPA received 70 technical proposals for the 17 host
sites, with each site receiving from one to six proposals. In April 2003, an independent technical panel
reviewed the proposals and provided its recommendations to EPA on the technologies that it determined
were acceptable for the demonstration at each site. Because of funding limitations and other technical
reasons, only 12 of the 17 sites were selected for the Round 1 demonstration program. Using the
information provided by the review panel, EPA, in cooperation with the host sites and the drinking water
programs of the respective states, selected one technical proposal for each site. As of April 2007, 11 of
the 12 systems were operational and the performance evaluation of eight systems was completed.
In 2003, EPA initiated Round 2 arsenic technology demonstration projects that were partially funded with
Congressional add-on funding to the EPA budget. In June 2003, EPA selected 32 potential demonstration
sites and the Webb Consolidated Independent School District (CISD) in Bruni, TX was one of those
selected.
In September 2003, EPA again solicited proposals from engineering firms and vendors for arsenic
removal technologies. EPA received 148 technical proposals for the 32 host sites, with each site
receiving from two to eight proposals. In April 2004, another technical panel was convened by EPA to
review the proposals and provide recommendations to EPA with the number of proposals per site ranging
from none (for two sites) to a maximum of four. The final selection of the treatment technology at the
sites that received at least one proposal was made, again, through a joint effort by EPA, the state
regulators, and the host site. Since then, four sites have withdrawn from the demonstration program,
reducing the number of sites to 28. AdEdge Technologies (AdEdge), using the Bayoxide E33 (AD-33)
media developed by Bayer AG, was selected for demonstration at the Webb CISD site in April 2004.
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1.2 Treatment Technologies for Arsenic Removal
The technologies selected for the Round 1 and Round 2 demonstration host sites include 25 adsorptive
media (AM) systems (the Oregon Institute of Technology [OIT] site has three AM systems), 13
coagulation/filtration systems, two ion exchange (IX) systems, 17 point-of-use (POU) units (including
nine residential reverse osmosis [RO] units at the Sunset Ranch Development site and eight AM units at
the OIT site), and one process modification. Table 1-1 summarizes the locations, technologies, vendors,
system flowrates, and key source water quality parameters (including arsenic, iron, and pH) at the 40
demonstration sites. An overview of the technology selection and system design for the 12 Round 1
demonstration sites and the associated capital cost is provided in two EPA reports (Wang et al., 2004;
Chen et al., 2004), which are posted on the EPA Web site at
http://www.epa.gov/ORD/NRMRL/wswrd/dw/arsenic/index.html.
1.3 Project Objectives
The objective of the Round 1 and Round 2 arsenic demonstration program is to conduct 40 full-scale
arsenic treatment technology demonstration studies on the removal of arsenic from drinking water
supplies. The specific objectives are to:
Evaluate the performance of the arsenic removal technologies for use on small
systems.
Determine the required system operation and maintenance (O&M) and operator
skill levels.
Characterize process residuals produced by the technologies.
Determine the capital and O&M cost of the technologies.
This report summarizes the performance of the AdEdge system at the Webb CISD in Bruni, TX during
the first six months from December 8, 2005, through June 9, 2006. The data collected included system
operational data, water quality data (both across the treatment train and in the distribution system), and
capital and preliminary O&M cost data.
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Table 1-1. Summary of Round 1 and Round 2 Arsenic Removal Demonstration
Locations, Technologies, and Source Water Quality
Demonstration
Location
Site Name
Technology (Media)
Vendor
Design
Flowrate
(gpm)
Source Water Quality
As
(HS/L)
Fe
(HS/L)
PH
(S.U.)
Northeast/Ohio
Wales, ME
Bow,NH
Goffstown, NH
Rollinsford, NH
Dummerston, VT
Felton, DE
Stevensville, MD
Houghton, NYW
Buckeye Lake, OH
Springfield, OH
Springbrook Mobile Home Park
White Rock Water Company
Orchard Highlands Subdivision
Rollinsford Water and Sewer District
Charette Mobile Home Park
Town of Felton
Queen Anne's County
Town of Caneadea
Buckeye Lake Head Start Building
Chateau Estates Mobile Home Park
AM (A/I Complex)
AM (G2)
AM(E33)
AM (E33)
AM (A/I Complex)
C/F (Macrolite)
AM (E33)
C/F (Macrolite)
AM (ARM 200)
AM (E33)
ATS
ADI
AdEdge
AdEdge
ATS
Kinetico
STS
Kinetico
Kinetico
AdEdge
14
70W
10
100
22
375
300
550
10
250(e)
38W
39
33
36W
30
30W
19W
27W
15W
25W
<25
<25
<25
46
<25
48
270W
1,806W
1,312W
l,615(c)
8.6
7.7
6.9
8.2
7.9
8.2
7.3
7.6
7.6
7.3
Great Lakes/Interior Plains
Brown City, MI
Pentwater, MI
Sandusky, MI
Delavan, WI
Greenville, WI
Climax, MN
Sabin, MN
Sauk Centre, MN
Stewart, MN
Lidgerwood, ND
City of Brown City
Village of Pentwater
City of Sandusky
Vintage on the Ponds
Town of Greenville
City of Climax
City of Sabin
Big Sauk Lake Mobile Home Park
City of Stewart
City of Lidgerwood
AM (E33)
C/F (Macrolite)
C/F (Aeralater)
C/F (Macrolite)
C/F (Macrolite)
C/F (Macrolite)
C/F (Macrolite)
C/F (Macrolite)
C/F&AM (E33)
Process Modification
STS
Kinetico
Siemens
Kinetico
Kinetico
Kinetico
Kinetico
Kinetico
AdEdge
Kinetico
640
400
340(e)
40
375
140
250
20
250
250
14W
13W
16W
20W
17
39W
34
25W
42W
146W
127w
466W
l,387(c)
l,499(c)
7827(c)
546W
1,470W
3,078(c)
l,344(c)
1,325W
7.3
6.9
6.9
7.5
7.3
7.4
7.3
7.1
7.7
7.2
Midwest/Southwest
Arnaudville, LA
Alvin, TX
Bruni, TX
Wellman, TX
Anthony, NM
Nambe Pueblo, NM
Taos, NM
Rimrock, AZ
Tohono O'odham
Nation, AZ
Valley Vista, AZ
United Water Systems
Oak Manor Municipal Utility District
Webb Consolidated Independent School
District
City of Wellman
Desert Sands Mutual Domestic Water
Consumers Association
Nambe Pueblo Tribe
Town of Taos
Arizona Water Company
Tohono O'odham Utility Authority
Arizona Water Company
C/F (Macrolite)
AM (E33)
AM(E33)
AM (E33)
AM(E33)
AM (E33)
AM (E33)
AM (E33)
AM(E33)
AM (AAFS50/ARM 200)
Kinetico
STS
AdEdge
AdEdge
STS
AdEdge
STS
AdEdge
AdEdge
Kinetico
770(e)
150
40
100
320
145
450
90(b)
50
37
35W
19w
56(a)
45
23(a)
33
14
50
32
41
2,068W
95
<25
<25
39
<25
59
170
<25
<25
7.0
7.8
8.0
7.7
7.7
8.5
9.5
7.2
8.2
7.8
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Table 1-1. Summary of Round 1 and Round 2 Arsenic Removal Demonstration Locations, Technologies, and
Source Water Quality (Continued)
Demonstration
Location
Site Name
Technology (Media)
Vendor
Design
Flowrate
(gpm)
Source Water Quality
As
(HS/L)
Fe
(HS/L)
pH
Far West
Three Forks, MT
Fruitland, ID
Homedale, ID
Okanogan, WA
Klamath Falls, OR
Vale, OR
Reno, NV
Susanville, CA
Lake Isabella, CA
Tehachapi, CA
City of Three Forks
City of Fruitland
Sunset Ranch Development
City of Okanogan
Oregon Institute of Technology
City of Vale
South Truckee Meadows General
Improvement District
Richmond School District
Upper Bodfish Well Cffi-A
Golden Hills Community Service District
C/F (Macrolite)
IX (A300E)
POU RO(1)
C/F (Electromedia-I)
POE AM (Adsorbsia/ARM
200/ArsenXnp)
and POU AM (ARM 200)Ž
IX (Arsenex II)
AM (GFH)
AM (A/I Complex)
AM (FflX)
AM (Isolux)
Kinetico
Kinetico
Kinetico
Filtronics
Kinetico
Kinetico
Siemens
ATS
VEETech
MEI
250
250
75gpd
750
60/60/30
525
350
12
50
150
64
44
52
18
33
17
39
37W
35
15
<25
<25
134
69W
<25
<25
<25
125
125
<25
7.5
7.4
7.5
8.0
7.9
7.5
7.4
7.5
7.5
6.9
AM = adsorptive media process; C/F = coagulation/filtration; HIX = hybrid ion exchanger; IX = ion exchange process; RO = reverse osmosis
ATS = Aquatic Treatment Systems; MEI = Magnesium Elektron, Inc.; STS = Severn Trent Services
(a) Arsenic existing mostly as As(III).
(b) Design flowrate reduced by 50% due to system reconfiguration from parallel to series operation.
(c) Iron existing mostly as Fe(II).
(d) Replaced Village of Lyman, NE site which withdrew from program in June 2006.
(e) Facilities upgraded systems in Springfield, OH from 150 to 250 gpm, Sandusky, MI from 210 to 340 gpm, and Arnaudville, LA from 385 to 770 gpm.
(f) Including nine residential units.
(g) Including eight under-the-sink units.
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2.0 SUMMARY AND CONCLUSIONS
AdEdge's APU-50-LL-CS-S-AVH treatment system with AD-33 pelletized media was installed and has
operated at the Webb CISD site in Bruni, TX since December 8, 2005. Based on the information
collected during the first six months of system operation, the following conclusions were made relating to
the overall objectives of the treatment technology demonstration study.
Performance of the arsenic removal technology for use on small systems:
Chlorine was effective in oxidizing As(III) to As(V). Analytical data confirmed that
average As(III) concentrations decreased from 38.5 |o,g/L in raw water to 1.7 |o,g/L after
chlorination and that average As(V) concentrations increased correspondingly from
14.9 |o,g/L in raw water to 51.9 |o,g/L after chlorination. Because no iron was present in
raw water, little or no particulate As was produced upon chlorination.
AD-33 media effectively lowered arsenic concentrations to below the 10 |o,g/L MCL
during the first six months of system operation. The volume throughput recorded in this
study period was 12,600 bed volumes (BV) (based on 22 ft3 of media in one vessel) or
6,300 BV (based on 44 ft3 of media in both vessels), which was about 27% of the media
run length projected by the vendor.
The operation of the system significantly lowered arsenic concentrations in the
distribution system (i.e., from 68.7 to 2.4 (ig/L, on average); however, the system did not
appear to have impacted lead or copper concentrations in the distribution system.
Some operational problems related to the CO2 Gas Flow Control System were
encountered during the first six months of system operation. Primary problems included
a faulty proportioning valve and failure of the in-line pH probe. A reoccurring problem
unrelated to the pH adjustment system was associated with the electromagnetic water
flow meters/totalizers, which randomly reset to zero.
Required system O&M and operator skill levels:
The daily demand on the operator was typically 20 min to visually inspect the
system and record operational parameters, although additional time and effort
was required to troubleshoot the problems associated with the CO2 system.
Operation of the system did not appear to require additional skills beyond those
necessary to operate the existing water supply equipment, with the exception of
the CO2 and pH control portion of the system. The CO2 system required
additional operator training and safety awareness.
Texas Commission on Environmental Quality (TCEQ) requires that the operator
of the treatment system holds at least a Class D TCEQ waterworks operator
license.
Process residuals produced by the technology:
The pressure differential (Ap) measured across the media vessels, during the first
six months of operation, did not warrant a backwash. Therefore, no backwash
residuals were produced.
Cost-effectiveness of the technology:
Based on the system's rated capacity of 40 gpm (or 57,600 gpd), the capital cost
was $3,466/gpm (or $2.41/gpd) of design capacity.
-------
Media replacement and disposal did not occur during the first six months of system
operation, although the cost to change out one vessel (22 ft3 AD-33 media) was estimated
to be $11,190, which includes the replacement media, spent media disposal, shipping,
labor, and travel.
-------
3.0 MATERIALS AND METHODS
3.1
General Project Approach
Following the predemonstration activities summarized in Table 3-1, the performance evaluation study
of the AdEdge treatment system began on December 8, 2005. Table 3-2 summarizes the types of data
collected and considered as part of the technology evaluation process. The overall performance of the
system was determined based on its ability to consistently remove arsenic to below the arsenic MCL of 10
|o,g/L through the collection of water samples across the treatment plant, as described in the Study Plan
(Battelle, 2005). The reliability of the system was evaluated by tracking the unscheduled system
downtime and the frequency and extent of repair and replacement. The unscheduled downtime and repair
information were recorded by the plant operator on a Repair and Maintenance Log Sheet.
Table 3-1. Predemonstration Study Activities and Completion Dates
Activity
Introductory Meeting Held
Project Planning Meeting Held
Draft Letter of Understanding Issued
Final Letter of Understanding Issued
Request for Quotation Issued to Vendor
Vendor Quotation Received by Battelle
Purchase Order Completed and Signed
Engineering Plans Submitted to TCEQ
System Permit Issued by TCEQ
APU System Shipped and Arrived
System Installation Completed
System Shakedown Completed
Final Study Plan Issued
Performance Evaluation Begun
Date
November 15, 2004
February 17, 2005
February 23, 2005
March 24, 2005
March 14, 2005
April 1, 2005
April 18, 2005
June 8, 2005
August 3 1,2005
October 13, 2005
November 19, 2005
November 19, 2005
November 30, 2005
December 8, 2005
TCEQ = Texas Commission on Environmental Quality
The O&M and operator skill requirements were evaluated based on a combination of quantitative data
and qualitative considerations, including the need for pre- and/or post-treatment, level of system
automation, extent of preventive maintenance activities, frequency of chemical and/or media handling and
inventory, and general knowledge needed for relevant chemical processes and related health and safety
practices. The staffing requirements for the system operation were recorded on an Operator Labor Hour
Log Sheet.
The quantity of aqueous and solid residuals generated is estimated by tracking the amount of backwash
water produced during each backwash cycle. Backwash water is sampled and analyzed for chemical
characteristics.
The cost of the system was evaluated based on the capital cost per gal/min (gpm) (or gal/day [gpd]) of
design capacity and the O&M cost per 1,000 gal of water treated. This requires the tracking of the capital
cost for equipment, site engineering, and installation, as well as the O&M cost for media replacement and
disposal, CO2 and chlorine consumption, electrical power usage, and labor. Data on Webb CISD's O&M
cost were limited to CO2 and chlorine consumption, electricity usage, and labor because media
replacement did not take place during the first six months of system operation.
-------
Table 3-2. Evaluation Objectives and Supporting Data Collection Activities
Evaluation Objective
Performance
Reliability
System O&M and
Operator Skill
Requirements
Residual Management
Cost-Effectiveness
Data Collection
-Ability to produce treated water that consistently meets 10 ug/L of arsenic MCL
-Unscheduled system downtime
-Frequency and extent of repairs including a description of problems, materials and
supplies needed, and associated labor and cost
-Pre- and post-treatment requirements
-Level of automation for system operation and data collection
-Staffing requirements including number of operators and laborers
-Task analysis of preventive maintenance including number, frequency, and complexity of
tasks
-Chemical handling and inventory requirements
-General knowledge needed for relevant chemical processes and health and safety
practices
-Quantity and characteristics of aqueous and solid residuals generated by system operation
-Capital cost for equipment, engineering, and installation
-O&M cost for chemical usage, electricity consumption, and labor
3.2
System O&M and Cost Data Collection
The plant operator performed daily, biweekly, and monthly system O&M and data collection according to
instructions provided by the vendor and Battelle. On a daily basis, the plant operator recorded system
operational data, such as pressure, flowrate, totalizer, and hour meter readings on a Daily System
Operation Log Sheet and conducted visual inspections to ensure normal system operations. If any
problem occurred, the plant operator contact the Battelle Study Lead, who determined if the vendor
should be contacted for troubleshooting. The plant operator recorded all relevant information, including
the problem encountered, course of action taken, materials and supplies used, and associated cost and
labor, on the Repair and Maintenance Log Sheet. Every other week, the plant operator measured pH,
temperature, dissolved oxygen (DO), and oxidation-reduction potential (ORP), and recorded the data on a
Weekly Water Quality Parameters Log Sheet.
The capital cost for the arsenic removal system consisted of the cost for equipment, site engineering, and
system installation. The O&M cost consisted of the cost for chemical usage, electricity consumption, and
labor. CO2 and chlorine consumption was tracked through daily measurements and recorded on Daily
System Operation Log Sheets. Electricity consumption was tracked through the on-site electric meter.
Labor for various activities, such as routine system O&M, system troubleshooting and repair, and
demonstration-related work, were tracked using Operator Labor Hour Log Sheets. The routine O&M
included activities such as completing field logs, replenishing chemical solutions, ordering supplies,
performing system inspections, and others as recommended by the vendor. The demonstration-related
work, including activities such as performing field measurements, collecting and shipping samples, and
communicating with the Battelle Study Lead and vendor, was recorded, but not used for the cost analysis.
3.3
Sample Collection Procedures and Schedules
To evaluate the performance of the system, samples were collected from the wellhead, across the
treatment plant, from the backwash discharge line, and from the distribution system. Table 3-3 provides
the sampling schedule and analytes measured during each sampling event. Specific sampling
requirements for analytical methods, sample volumes, containers, preservation, and holding times are
presented in Table 4-1 of the EPA-endorsed Quality Assurance Project Plan (QAPP) (Battelle, 2004).
-------
Table 3-3. Sampling Schedule and Analytes
Sample
Type
Source
Water
Treatment
Plant Water
Distribution
Water
Backwash
Water
Sampling
Locations'3'
At Wellhead (IN)
At Wellhead (IN),
After pH
Adjustment (AP),
After Lead Vessel
(TA), and After
Lag Vessel (TO)
Three LCR
Locations within
School
Backwash
Discharge Line
from Each Vessel
No. of
Sampling
Locations
1
4
4
3
2
Frequency
Once during
initial site
visit
First week
of each four-
week cycle
Third week
of each four-
week cycle
Monthly(c)
Monthly or
as needed
Analytes
On-site: pH, temperature,
DO, and ORP
Off-site: As (total and
soluble), As(III), As(V),
Fe (total and soluble),
Mn (total and soluble),
U (total and soluble),
V (total and soluble),
Na, Ca, Mg, Cl, F, NO3,
NO2, NH3, SO4, SiO2,
PO4, turbidity, alkalinity,
TDS, and TOC.
On-site: pH, temperature,
DO, ORP, and C12 (free
andtotal)(b)
Off-site: As (total and
soluble), As(III), As(V),
Fe (total and soluble),
Mn (total and soluble),
Ca, Mg, F, NO3, SO4,
SiO2, P, turbidity, and
alkalinity.
On-site: pH, temperature,
DO, ORP, and C12 (free
andtotal)(b)
Off-site: As (total), Fe
(total), Mn (total), SiO2,
P, turbidity, and
alkalinity
pH, alkalinity, As, Fe,
Mn, Pb, and Cu
pH, TDS, TSS,
As (total and soluble),
Fe (total and soluble),
and
Mn (total and soluble)
Sampling
Date
11/15/04
12/08/05, 01/05/06,
02/01/06, 03/14/06,
04/11/06,05/09/06,
06/06/06
12/13/05, 01/17/06,
02/15/06, 02/28/06,
03/28/06, 04/25/06,
05/23/06
Baseline sampling:
06/15/05, 07/21/05,
08/24/05, 09/19/05
Monthly sampling:
01/05/06, 02/01/06,
03/14/06,04/11/06,
05/09/06, 06/06/06
To be determined
(a) Abbreviations in parentheses corresponding to sample locations shown in Figure 4-5.
(b) Except at IN location.
(c) Four baseline sampling events performed from June to September 2005 before system became operational.
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3.3.1 Source Water Sample Collection. During the initial visit to the site on November 15, 2004,
one set of source water samples was collected and speciated using an arsenic speciation kit (see Section
3.4.1). The sample tap was flushed for several minutes before sampling; special care was taken to avoid
agitation, which might cause unwanted oxidation. Analytes for the source water samples are listed in
Table 3-3.
3.3.2 Treatment Plant Water Sample Collection. During the system performance evaluation
study, biweekly water samples were collected across the treatment train by the plant operator for on- and
off-site analyses. During the first week of each four-week cycle, samples were collected at the wellhead
[IN], after pH adjustment and chlorination [AP], after the lead adsorption vessel [TA], and after the lag
adsorption vessel [TB] and analyzed for the analytes listed on Table 3-3. During the third week of the
four-week cycle, samples were taken from the same four locations and analyzed for the analyte list shown
on Table 3-3.
3.3.3 Backwash Water/Solid Sample Collection. Because the system did not require backwash
during the first six months of operation, no backwash residuals were produced. Further, because media
replacement did not take place, there were no spent media samples collected.
3.3.4 Distribution System Water Sample Collection. Samples were collected from the
distribution system by the plant operator to determine the impact of the arsenic treatment system on the
water chemistry in the distribution system, specifically, the arsenic, lead, and copper levels. From June to
September 2005, prior to the startup of the treatment system, four baseline distribution sampling events
were conducted at three locations within the distribution system. Following startup of the arsenic
adsorption system, distribution system sampling continued on a monthly basis at the same three locations.
The three locations selected were sample taps within the Webb CISD that had been included in the Lead
and Copper Rule (LCR) sampling in the past. The baseline and monthly distribution system samples
were collected following an instruction sheet developed according to the Lead and Copper Monitoring
and Reporting Guidance for Public Water Systems (EPA, 2002). The date and time of last water use
before sampling and the date and time of sample collection were recorded for calculation of the stagnation
time. All samples were collected from a cold water faucet that had not been used for at least 6 hr to
ensure that stagnant water was sampled. Analytes for the baseline samples coincided with the monthly
distribution system water samples as described in Table 3-3. Arsenic speciation was not performed for
the distribution system water samples.
3.4 Sampling Logistics
All sampling logistics including preparation of arsenic speciation kits and sample coolers, and sample
shipping and handling are discussed as follows:
3.4.1 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) (Edwards et al., 1998).
Resin columns were prepared in batches at Battelle laboratories according to the procedures detailed in
Appendix A of the EPA-endorsed QAPP (Battelle, 2004).
3.4.2 Preparation of Sampling Coolers. For each sampling event, a sample cooler was prepared
with the appropriate number and type of sample bottles, disc filters, and/or speciation kits. All sample
bottles were new and contained appropriate preservatives. Each sample bottle was affixed with a pre-
printed, color-coded, and waterproof label, consisting of the sample identification (ID), date and time of
sample collection, collector's name, site location, sample destination, analysis required, and preservative.
The sample ID consisted of a two-letter code for the specific water facility, sampling date, a two-letter
10
-------
code for a specific sampling location, and a one-letter code designating the arsenic speciation bottle (if
necessary). The sampling locations at the treatment plant were color-coded for easy identification. For
example, red, orange, yellow, and blue were used to designate sampling locations for IN, AP, TA, and
TB, respectively. The prelabeled bottles for each sampling location were placed in separate ziplock bags
and packed in the cooler.
When appropriate, the sample cooler was packed with bottles for the three distribution system sampling
locations. In addition, all sampling and shipping-related materials, such as latex gloves, sampling
instructions, chain-of-custody forms, prepaid FedEx air bills, and bubble wrap, were included. Except for
the operator's signature, the chain-of-custody forms and prepaid FedEx air bills had already been
completed with the required information. The sample coolers were shipped via FedEx to the facility
approximately 1 week prior to the scheduled sampling date.
3.4.3 Sample Shipping and Handling. After sample collection, samples for off-site analyses were
packed carefully in the original coolers with wet ice and shipped to Battelle. Upon receipt, the sample
custodian verified that all samples indicated on the chain-of-custody forms were included and intact.
Sample IDs were checked against the chain-of-custody forms and the samples were logged into the
laboratory sample receipt log. Discrepancies noted by the sample custodian were addressed with the plant
operator by the Battelle Study Lead.
Samples for metal analyses were stored at Battelle's inductively coupled plasma-mass spectrometry (ICP-
MS) Laboratory. Samples for other water quality analyses were packed in separate coolers and picked up
by couriers from American Analytical Laboratories (AAL) in Columbus, OH and TCCI Laboratories in
Lexington, OH, both of which were under contract with Battelle for this demonstration study. The chain-
of-custody forms remained with the samples from the time of preparation through analysis and final
disposition. All samples were archived by the appropriate laboratories for the respective duration of the
required hold time and disposed of properly thereafter.
3.5 Analytical Procedures
The analytical procedures described in detail in Section 4.0 of the EPA-endorsed QAPP (Battelle, 2004)
were followed by Battelle ICP-MS, AAL, and TCCI Laboratories. Laboratory quality assuarnce/quality
control (QA/QC) of all methods followed the prescribed guidelines. Data quality in terms of precision,
accuracy, method detection limits (MDLs), and completeness met the criteria established in the QAPP
(i.e., relative percent difference [RPD] of 20%, percent recovery of 80 to!20%, and completeness of
80%). The quality assurance (QA) data associated with each analyte will be presented and evaluated in a
QA/QC Summary Report to be prepared under separate cover upon completion of the Arsenic
Demonstration Project.
Field measurements of pH, temperature, DO, and ORP were conducted by the plant operator using a
VWR Symphony SP90M5 Handheld Multimeter, which was calibrated for pH and DO prior to use
following the procedures provided in the user's manual. The ORP probe also was checked for accuracy
by measuring the ORP of a standard solution and comparing it to the expected value. The plant operator
collected a water sample in a clean, plastic beaker and placed the Symphony SP90M5 probe in the beaker
until a stable value was obtained. The plant operator also performed free and total chlorine measurements
using Hach chlorine test kits following the user's manual.
11
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4.1
4.0 RESULTS AND DISCUSSION
Facility Description and Preexisting Treatment System Infrastructure
Located at 619 Avenue F in Bruni, Texas, the Webb CISD water system supplies water to approximately
230 students and staff members during the academic year. Figure 4-1 shows the preexisting water
treatment facility. The water system is served by a single well that is 7-in in diameter and approximately
345 ft deep. The supply well, shown in Figure 4-2, is equipped with a 5-horsepower (hp), 15-in
submersible pump rated for 40 gpm at 300 ft H2O or 130 lb/in2 (psi). The preexisting system typically
operated for 6 to 8 hr/day, with an average daily demand of 10,000 gpd and an estimated peak daily
demand of 15,000 gpd. The preexisting treatment included only chlorination with a 10% sodium
hypochlorite (NaOCl) solution to reach a target residual level of 1.2 mg/L (as C12). Figure 4-3 shows the
chlorine addition system at the site. Following chlorination, the treated water was stored in a 15,000-gal
storage tank located in a fenced area in the immediate vicinity of the well and chlorine addition system.
Figure 4-1. Existing Water Treatment Facility
(from Left to Right: Wellhead in front of White Storage Shed, Chlorine Addition
System in Black Rectangular Box, and White Storage Tank for Treated Water)
4.1.1 Source Water Quality. Source water samples were collected and speciated on November
15, 2004, for on- and off-site analyses with analytes listed on Table 4-1. The results are presented in
Table 4-1 and compared to those taken by the facility for the EPA demonstration site selection.
Arsenic. Total arsenic concentrations of source water ranged from 55.6 to 59 |og/L. Based on Battelle's
speciation results, out of 55.6 |o,g/L of total arsenic, 19.6 |o,g/L existed as As(V) and 35.6 |o,g/L as As(III).
Therefore, preoxidizing was needed to oxidize As(III) to As(V) prior to adsorption.
12
-------
Figure 4-2. Wellhead at Webb CISD
Figure 4-3. Existing Chlorine Addition System
13
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Table 4-1. Water Quality Data for Webb CISD, Bruni, TX
Parameter
Date
pH
Temperature
DO
ORP
Total Alkalinity (as CaCO3)
Hardness (as CaCO3)
Turbidity
TDS
TOC
Nitrate (as N)
Nitrite (as N)
Ammonia (as N)
Chloride
Fluoride
Sulfate
Silica (as SiO2)
Orthophosphate (as PO4)
As(total)
As (total soluble)
As (paniculate)
As(III)
As(V)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
U (total)
U (soluble)
V (total)
V (soluble)
Na (total)
Ca (total)
Total Mg
Unit
S.U.
°c
mg/L
mV
mg/L
mg/L
NTU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
^g/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
^g/L
pCi/L
pCi/L
Mfi/L
Mfi/L
mg/L
mg/L
mg/L
Raw Water
Facility
Data(a)
-
8.1
NA
NA
NA
323
24
NA
NA
NA
NA
NA
NA
188
NA
104
NA
NA
59
NA
NA
NA
NA
27
NA
8
NA
NA
NA
NA
NA
301
7
2
Battelle
Data
11/15/04
8.0
25.3
1.5
-122
325
23.5
0.7
1,060
0.9
O.04
<0.01
O.05
130
1.0
98.0
42.3
O.06
55.6
55.2
0.4
35.6
19.6
<25
<25
4.5
4.3
10.6
10.2
4.4
4.4
333
6.1
2.0
Treated Water
TCEQ
Data
01/12/98-10/26/04
6.8-8.2
NA
NA
NA
232-297
25-27.2
NA
781-795
NA
0.3-1.2
0.01
NA
180-229
0.7-0.8
97.4-113
NA
NA
75.9-104
NA
NA
NA
NA
10-51
NA
1-8
NA
<25
NA
NA
NA
272-293
7.1-8.0
1.0-2.3
(a) Provided by facility to EPA for demonstration site selection.
TCEQ = Texas Commission on Environmental Quality
NA = not analyzed
Iron. Iron concentrations in source water were low, typically less than its detection limit of 25 |o,g/L. In
general, adsorptive media technologies are best suited to sites with relatively low iron levels (e.g., less
than 300 |o,g/L of iron, which is the secondary maximum contaminant level [SMCL] for iron). Above 300
Hg/L, taste, odor, and color problems can occur in treated water, along with an increased potential for
fouling of the adsorption system components with iron particulates.
14
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pH. pH values of raw water were between 8.0 and 8.1. At pH values greater than 8.0 to 8.5, the
technology vendor recommends that the pH values be lowered to enhance the adsorptive capacity of the
media. The treatment process for the Webb CISD site included a CO2 injection and pH monitoring and
control module prior to arsenic adsorption. The target pH level after pH adjustment was 7.0.
Competing Anions. Arsenic adsorption can be influenced by the presence of competing anions such as
silica and phosphate. Analysis of source water indicated silica levels at 42.3 mg/L and orthophosphate
levels less than its detection limit (i.e., <0.06 mg/L). The effect of silica on arsenic adsorption was
monitored closely during the demonstration study.
Other Water Quality Parameters. Other water quality parameters in source water were below their
respective primary MCLs, including nitrate, nitrite, and ammonia. Also, chloride, fluoride, sulfate, and
manganese were below their respective SMCLs. Total dissolved solids (TDS) were measured at 1,060
mg/L, which is above the SMCL of 500 mg/L.
4.1.2 Treated Water Quality. In addition to the source water quality data, Table 4-1 also presents
historic treated water quality data collected by TCEQ from January 1998 through October 2004. These
treated water quality data were similar to the source water quality data provided by the facility and
collected by Battelle. Total arsenic concentrations of the treated water were slightly higher and ranged
from 75.9 to 104 |o,g/L. No arsenic speciation data were available for the water following chlorination.
pH values ranged from 6.8 to 8.2. Additional analytes including several metals and radionuclides are
summarized in Table 4-2.
Table 4-2. TCEQ Treated Water Quality Data
Parameter
Date
Aluminum
Antimony
Barium
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Gross Alpha
Gross Beta
Radium 226
Tritium
Unit
HB/L
HB/L
^g/L
HB/L
HB/L
HB/L
W?/L
HB/L
HB/L
^g/L
HB/L
HB/L
HB/L
W?/L
pCi/L
pCi/L
pCi/L
pCi/L
TCEQ Data
01/12/98-10/26/04
4-50
1-4
39.7^0
<1
0.2-1.2
<10
2.2-7.7
1-12
0.4
1-20
8.5-12.7
1-10
<1
<4-20
26.2-28.3(a)
11.8-12.5
<1
500
(a) over 15 pCi/L MCL
15
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4.1.3 Distribution System. Based on the information provided by the facility, the distribution
system is constructed primarily of polyvinyl chloride (PVC) piping and some galvanized piping. The
piping within the building is copper. The distribution system is supplied directly from the 15,000-gal
storage tank.
The three locations selected for distribution sampling include one location each in the middle school, high
school, and cafeteria. These locations represent the distribution system sampling and also are part of the
school's historic LCR sampling network. The site also samples for coliform once a month and volatile
organic compounds (VOCs), inorganics, nitrate, and radionuclides as directed by the TCEQ, typically
once every two to three years.
4.2
Treatment Process Description
The arsenic package unit (APU) marketed by AdEdge is a fixed-bed, down-flow adsorption system used
for small water systems in the flow range of 5 to 100 gpm. It uses Bayoxide E33 media (branded as AD-
33 by AdEdge), an iron-based adsorptive media developed by Bayer AG, for the removal of arsenic from
drinking water supplies. Table 4-3 presents physical and chemical properties of the media. AD-33 media
is delivered in a dry crystalline form and listed by NSF International (NSF) under Standard 61 for use in
drinking water applications. The media exist in both granular and pelletized forms, which have similar
physical and chemical properties, except that pellets are denser than granules (i.e., 35 lb/ft3 vs. 28 lb/ft3).
For the Webb CISD site, pellets were selected for use.
Table 4-3. Physical and Chemical Properties of AD-33 Media
(a)
Physical Properties
Parameter
Matrix
Physical form
Color
Bulk Density (lb/ft3)
BET Area (m2/g)
Attrition (%)
Moisture Content (%)
Particle size distribution (U.S. Standard mesh)
Crystal Size (A)
Crystal Phase
Value
Iron oxide composite
Dry pellets
Amber
35
142
0.3
<15 (by weight)
10 x35
70
a -FeOOH
Chemical Analysis
Constituents
FeOOH
CaO
MgO
MnO
S03
Na2O
TiO2
Si02
A12O3
P205
Cl
Weight (%)
90.1
0.27
1.00
0.11
0.13
0.12
0.11
0.06
0.05
0.02
0.01
(a) Provided by AdEdge
BET = Brunauer, Emmett, and Teller
16
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For series operation, when the media in the lead vessel completely exhausts its capacity and/or the
effluent from the lag vessel reaches 10 (ig/L of arsenic, the spent media in the lead vessel is removed and
disposed of. After rebedding, the lead vessel is switched to the lag position and the lag vessel is switched
to the lead position. In general, the series operation better utilizes the media capacity when compared to
the parallel operation because the media in the lead vessel may be allowed to exhaust completely prior to
change-out.
When comparing the performance of the lead vessel (series operation) with that of two smaller parallel
vessels of a similarly-sized system (parallel operation), the number of BV treated by the system is
calculated based on the media volume in the lead vessel for the series operation and in the two parallel
vessels for the parallel operation. The calculation does not use the media volume in the lead and lag
vessels because this approach considers the two vessels as one large vessel, which has twice as much
media than the in-parallel system. The media volume in the lead vessel is equal to the sum of the media
volume in each of the two vessels in parallel; the flow through the lead vessel is equal to the sum of the
flow through each of the two vessels in parallel; and the empty bed contact time (EBCT) in the lead
vessel is the same as EBCT in each of the two vessels in parallel.
The arsenic treatment system at the Webb CISD site (specifically referred to as the APU-50LL-CS-S-2-
AVH system) consists of two pressure vessels, Vessel A and Vessel B, operating in series. The piping
and valve configuration of the pressure vessels allow electrically actuated butterfly valves to divert raw
water flow into either Vessel A or Vessel B depending on which is operating as the lead vessel. A
simplified process flow diagram of the treatment system is shown in Figure 4-4. The system is located in
the maintenance building, which provides sufficient space available to house the system. Figure 4-5 is a
generalized process flow sampling diagram of the system that illustrates sampling locations and
parameters analyzed during the demonstration study. Table 4-4 presents key system design parameters.
The key process steps and major components of the water treatment system include:
Intake. Raw water is pumped from the supply well and fed to the treatment system.
pH adjustment. The pH of raw water is lowered to a target pH value of 7.0 using CO2,
which was selected for use for pH adjustment because 1) CO2 is less corrosive than
mineral acids, such as H2SO4, and 2) when the treated water is depressurized after exiting
the adsorption vessels, some CO2 may degas, thereby raising the pH of the treated water
and reducing its corrosivity to the distribution piping.
A Carbon Dioxide Gas Flow Control System manufactured by Applied Technology
Systems, Inc. (ATSI) in Souderton, PA is used for pH adjustment. Figure 4-6 presents a
process diagram of the system, which is designed to introduce gaseous CO2 into water in
a side-stream configuration, or a CO2 loop. The system, illustrated in Figure 4-7 as a
composite of photographs, consists of a liquid CO2 supply assembly, an automatic pH
control panel, a CO2 membrane assembly, and a pH probe located downstream of the
membrane module:
o Liquid CO2 in two 50-lb cylinders vaporizes into gaseous CO2 via a feed vaporizer
prior to entering the pH control panel.
o As the CO2 gas flows to the pH control panel, its gas flowrate is automatically
controlled and adjusted by a JUMO pH/Proportional Integral Derivative (PID)
controller and an Alicat mass flowmeter (Figure 4-6) to reach a desired pH setpoint.
The gas flowrate also may be regulated manually through the use of a three-way ball
17
-------
Process Flow Diagram
AdEdge Arsenic Reduction System
Model APU50LL-CS-2-AVH
Reversible Lead/Lag Configuration
Webb Consolidated School
Bruni, Texas
(Series Operation: Vessel A
shown as Lead Vessel)
Pre-chlorination and
CO2 pH adjustment
feed points
New tie in
from Well #3
Sample valve
Skid Battery
Limits
To temp
storage
and
recycle
Figure 4-4. Process Flow Diagram for APU-50LL-CS-S-2-AVH System
-------
Monthly
pH,
otal),
(HI),
Mg,
P04,
inity
--(B
v
w) /
^...L
f
MEDIA
VESSEL
B
STORAGE TANK
(15,000 GAL)
Footnote
(a) On-site analyses
DISTRIBUTION
SYSTEM
Bruni, TX
AD-33Ž Technology
Design Flow: 40 gpm
Biweekly
pH.>/ and Chlorination
( TA J Vessel A Effluent
CTB J Vessel B Effluent
f BW J Backwash Sampling Location
( SS ) Sludge Sampling Location
DA: C12 Chlorine Disinfection
INFLUENT Unit Process
fc^ -P, -p.
pH
-------
Table 4-4. Design Specifications for AdEdge APU-50LL-CS-S-2-AVH System
Parameter
Value
Remarks
Pre-treatment
Target pH Value after Adjustment (S.U.)
Target Chlorine Residual (as C12)
7.0
1.2
Using CO2
Using NaCIO
Adsorption Vessels
Vessel Size (in)
Cross-Sectional Area (ft2/vessel)
Number of Vessels
Configuration
42 D x 72 H
9.6
2
Series
AD-33 Adsorption Media
Media Bed Depth (in)
Media Quantity (Ib)
Media Volume (ft3)
Media Type
27.5
1,540
44
AD-33
770 Ib/vessel
22 ft3/vessel
In pelletized form
Service
Design Flowrate (gpm)
Hydraulic Loading Rate (gpm/ft2)
EBCT (mm/vessel)
Estimated Working Capacity (BV)
Throughput to Breakthrough (gal)
Average Use Rate (gal/day)
Estimated Media Life (months)
40
4.2
4.1
46,900
7,725,000
12,000
21.5
Based on flowrate of 40 gpm per vessel (8.2
min total EBCT for both lead and lag vessels)
Bed volumes to 10 ug/L total As breakthrough
from lag vessel based on vendor estimate
1 BV = 22 ft3 = 164 gal
Based on 5 hr/day operation at 40 gpm
Estimated frequency of media change-out from
lead vessel based on 12,000 gal/day use rate
Backwash
Pressure Differential Set Point (psi)
Backwash Flowrate (gpm)
Hydraulic Loading Rate (gpm/ft2)
Backwash Frequency (month/backwash)
Backwash Duration (mm/vessel)
Service-to-Waste Fast Rinse Flowrate (gpm)
Fast Rinse Duration (min/vessel)
Wastewater Production (gal/vessel)
10
90
9.4
3-4
20
90
1-4
1,890-2,160
Actual backwash frequency to be determined
-
-
-
-
valve and a rotameter. Further, a solenoid valve interlocked with the well pump
allows gas to flow only when the well pump is turned on.
After flowing out of the control panel, CO2 is injected into water through a CelgardŽ
microporous hollow fiber membrane module housed in a 1.5-in stainless steel
sanitary cross. Table 4-5 lists the properties and specifications of the hollow fiber
membrane module. The sanitary cross is located in a side stream from the main
water line to allow only a portion of water to flow through the membrane module to
minimize the pressure drop. The membrane introduces CO2 gas into water at a near
molecular level for rapid mixing/reaction with water to achieve a quick pH response/
change.
Located downstream from the sanitary cross, a Sentron Ion Sensitive Field Effect
Transistor (ISFET) type silicon chip sanitary pH probe with automatic temperature
compensation continuously monitors pH levels of the treated water and sends signals
back to the pFI/PID controller for pH control.
20
-------
ATSI CO, pH Control
Panel (ATSI)
Source: Applied Technology Systems, Inc. (ATSI)
1.5" Dia. PVC Housed
Membrane w/
1" MNPT Connection
on each end for water
20 Ib or 50lb
Cylinders for
Gas Supply
Ball Valve or Other
Flow Control Valve
Distance to pH probe
(Distance 10')
Horn
Power In
Wellpump
Contacts
C02 Gas
Inlet
4-20 rriAmp
Signal to
Control
Module
BV1
Figure 4-6. Process Diagram of (top) CO2 pH Adjustment System and (bottom)
pH/PID Control Panel
21
-------
Figure 4-7. Carbon Dioxide Gas Flow Control System for pH Adjustment
(Clockwise from Top Left: Liquid CO2 Supply Assembly;
Automatic pH Control Panel; CO 2 Membrane Module; Port for pH Probe)
Table 4-5. Properties of CelgardŽ, X50-215 Microporous
Hollow Fiber Membrane
Parameter
Porosity (%)
Pore Dimensions (urn)
Effective Pore Size (urn)
Minimum Burst Strength (psi)
Tensile Break Strength (g/filament)
Average Resistance to Air Flow (Gurley sec)
Axial Direction Shrinkage (%)
Fiber Internal Diameter, nominal (urn)
Fiber Wall Thickness, nominal (um)
Fiber Outer Diameter, nominal (um)
Module Dimensions (in)
Value
40
0.04x0.10
0.04
400
>300
50
<5
220
40
300
1.5 x3.0
Data Source: Celgard
22
-------
o Throughout the first six-month operational period, the CO2 pH control system
supplied CO2at approximately 14.2 ft3/hr, using about 7 Ib/day (based on a gas
density of 0.117 lb/ft3 and an average operating time of 4.3 hr/day). The CO2 gas
supplied from two 50-lb cylinders provided CO2 for about 14 days before requiring
change-out.
Prechlorination. The existing chlorination system, as shown in Figure 4-3, was upgraded
and installed inside the maintenance building along with the APU-50LL-CS-S-2-AVH
system. The chlorine addition system oxidizes As(III) to As(V) prior to the adsorption
vessels and provides a target chlorine residual of 1.2 mg/L (as C12) for disinfection in the
distribution system. The chlorine feed system, illustrated in Figure 4-8, includes a solenoid-
driven, diaphragm-type metering pump with a capacity range of 0.19 to 8.4 gal/hr (gph), a 50-
gal high-density polyethylene (HDPE) chemical feed tank to store the 10% NaCIO solution,
and a chlorine injection port. The chlorine is injected into raw water line following the CO2
injection and pH probe, but prior to the AP sampling location. Operation of the chlorine feed
system is linked to the well pump so that chlorine is injected only when the well is on.
Chlorine consumption is measured using volumetric markings on the outside of the feed tank.
Figure 4-8. Chlorination Feed System
(Clockwise from Top Left: Chlorine Metering Pump;
HDPE Chemical Feed Tank with Secondary Containment; Chlorine Injection Port)
23
-------
Adsorption. The AdEdge APU-50LL-CS-S-2-AVH system consists of two 42-in-diameter,
72-in-tall pressure vessels configured in series, each containing 22 ft3 of AD-33 media. The
tanks are carbon steel construction, skid mounted, and rated for 100-psi working pressure.
EBCT for the system is 4.1 min in each vessel. The hydraulic loading rate to each vessel is
approximately 4.2 gpm/ft2, based on the design flowrate of 40 gpm.
Each pressure vessel is interconnected with schedule 80 PVC piping and five electrically
actuated butterfly valves, which make up the valve tree as shown in Figure 4-9. In addition to
the ten butterfly valves, the system has two manual diaphragm valves on the backwash line
and six isolation ball valves to divert raw water flow into either vessel, which reverse the lead
lag vessel configuration. Each valve operates independently and the butterfly valves are
controlled by a Square D Telemechanique programmable logic controller (PLC) with a
Magelis G2220 color touch interface screen.
Figure 4-9. Adsorption System Valve Tree and Piping Configuration
Backwash. The vendor recommended that the APU-50LL-CS-S-2-AVH system be
backwashed, either manually or automatically, on a regular basis to remove particulates and
media fines that accumulate in the media beds. Automatic backwash can be initiated by
either timer or differential pressure (Ap) across the vessels. During the backwash cycle, each
vessel is backwashed individually, while the second vessel remains off-line. Backwash is
performed upflow at a flowrate of 90 gpm to achieve a hydraulic loading rate of about 9.3
gpm/ft2. Because the incoming flowrate from the supply well is insufficient to provide the
necessary flow for backwash, supplemental water is supplied from the treated water storage
tank to the head of the system. Each backwash cycle is set to last for about 20 min/vessel of
backwash followed by 1 to 4 min/vessel of service-to-waste fast rinse, generating a combined
total of approximately 1,890 to 2,160 gal/vessel of wastewater.
24
-------
The backwash water produced is pumped to a 12,000-gal fiberglass backwash storage tank
located adjacent to the treated water storage tank (see Figure 4-1). Water from the backwash
storage tank is sent to an on-site wastewater plant and then to a series of four stabilization
ponds, which provide approximately 120 days of storage capacity. If the storage capacity of
the stabilization ponds is exceeded, the discharge goes to a normally dry streambed, where it
ultimately evaporates or percolates into the ground. However, due to the minimal pressure
drop across the vessels throughout the first six months of system operation, system backwash
was not necessary. The pressure drop and the arsenic concentrations across the vessels will
continue to be monitored and a backwash will be scheduled, when needed, during the next six
months of system operation.
Media Replacement. The media in the lead vessel will be replaced once the arsenic
concentration from the lag vessel reaches 10 |o,g/L. After the media replacement in the lead
vessel, flow through the vessels will be switched such that the lag vessel is placed into the
lead position and the former lead vessel with the virgin media is placed in the lag position.
The spent media will be tested for EPA's toxicity characteristic leaching procedure TCLP
before disposal.
4.3 System Installation
The installation of the APU system was completed by AdEdge on November 19, 2005. The following
briefly summarizes some of the predemonstration activities, including permitting, building preparation,
and system offloading, installation, shakedown, and startup.
4.3.1 Permitting. An exception submittal package was submitted to TCEQ by Webb CISD on
April 18, 2005, requesting an exception to use data from an alternative site in lieu of conducting an on-
site pilot study as required under Title 30 Texas Administrative Code (30 TAC) §290.42(g). The
exception submittal included a written description of the treatment technology along with a schematic of
the system and relevant pilot- and full-scale data. In addition, a permit application submittal package
including a process flow diagram of the treatment system, mechanical drawings of the treatment
equipment, and a schematic of the building footprint and equipment layout also was submitted to TCEQ
for permit approval on April 18, 2005. TCEQ requested supplemental information, in a response letter
dated June 3, 2005, to complete their review of the request. In response, supplementary data were
provided by the vendor on July 14, 2005, Battelle on August 22, 2005, and Littlefield of Southwest
Engineers, Inc. on August 29, 2005. Based on a review of the submitted data (which included revised
engineering plans and specifications, dated August 19, 2005) and discussions with the vendor, Battelle,
and EPA, TCEQ granted an exception request and approval to construct the arsenic removal treatment
system on August 31, 2005.
4.3.2 Building Preparation. The existing maintenance shop building as shown in Figure 4-10 had
adequate space to house the planned arsenic treatment system. The maintenance building is a single-story
metal structure with concrete flooring. Additional preparation required the installation of a lockable wire
cage enclosure around the treatment system.
4.3.3 Installation, Shakedown, and Startup. The treatment system arrived on-site on October 13,
2005. Figure 4-11 shows a photograph of the system arriving at the site. AdEdge and ATSI were on-site
for the system installation during the week of November 14, 2005. ATSI performed the installation and
shakedown of the Carbon Dioxide Gas Flow Control System for pH adjustment. Meanwhile, AdEdge
and the local operator performed the arsenic treatment system installation and shakedown work, which
included hydraulic testing, media loading (by hand), and media backwash. The system officially went
online and was put into regular service on December 7, 2005. Battelle was on-site on December 8 and 9,
25
-------
Figure 4-10. Maintenance Shop Building
Figure 4-11. System Being Delivered to Site
26
-------
2005, to inspect the system and provide training to the operator for sampling and data collection. As a
result of the system inspections, a punch-list of items was identified, some of which were quickly
resolved and did not affect system operations or data collection, although several problems related to the
pH adjustment system and the media vessel flow meters surfaced throughout the six-month study period.
Table 4-6 summarizes the items identified and corrective actions taken. In addition, these problems are
discussed in detail in Section 4.4.3.
Table 4-6. System Punch-List/Operational Issues
Item
No.
1
2
3
4
5
6
7
Punch-List/
Operational Issues
Well pump hour meter not provided
Leak in CO2 supply system
Flow totalizer for Vessels A and B
reset to zero
In-line pH probe reporting pH >8
Malfunctioning proportioning valve
restricted CO2 injection
In-line pH probe not reporting pH
reading
Flow totalizer for Vessels A and B
reset to zero
Corrective Action(s) Taken
Installed hour meter for well pump
Checked and tightened all connections
and fittings
Vendor notified
No corrective action taken
Flushed pH probe by-pass line and
increased flowrate through by -pass line
Replaced proportioning valve
Replaced pH probe
Vendor notified
Problem likely due to a programming
error; a flash memory card with
necessary programming updates to be
provided by vendor
Resolution
Date
01/09/06
01/11/06
01/12/06
03/13/06
04/24/06
05/30/06
02/22/06
05/23/06
TBD
4.4
TBD = to be determined
System Operation
4.4.1 Operational Parameters. The operational parameters for the first six months of system
operation were tabulated and are attached as Appendix A. Key parameters are summarized in Table 4-7.
From December 8, 2005, through June 9, 2006, the system operated for approximately 787 hr. Because
the well pump hour-meter was not installed during the first 32 days of operation, the average daily
operational time and flowrate over the last 151 days of operation were used to estimate approximate
overall operational time. This cumulative operating time represents a use rate of approximately 18%
during the first six months of system operation. The system typically operated for a period of
approximately 4.3 hr/day.
Flowrates of the system were tracked by instantaneous flowrate readings from the electromagnetic flow
meter/totalizer on each adsorption vessel, and calculated flowrate values based on hour meter and flow
totalizer readings from the same electromagnetic flow meters/totalizers and a preexisting positive
displacement type master totalizer installed at the wellhead. As shown in Figure 4-12, the instantaneous
readings for Vessels A and B, denoted by "" and "A," respectively, were significantly higher than the
corresponding calculated values, denoted by "n" and "A," respectively, with an average value of 52 gpm
for the instantaneous readings and 44 gpm for the calculated values. In addition, the calculated values
based on the electromagnetic flow meters/totalizers were significantly higher than those based on the
master totalizer (denoted by "*" in the figure). Although the results produced by the master totalizer were
closer to the design flowrate of 40 gpm, the calculated values by the electromagnetic flow meters/
totalizers were used as system flowrates. This was based on the belief that readings from the
27
-------
Table 4-7. Summary of APU-50LL-CS-S-2-AVH System Operation
Operational Parameter
Duration
Cumulative Operating Time (hr)
Average Daily Operating Time (hr)
Throughput (gal)
Bed Volumes (BV)(a)
Average (Range) of Flowrate (gpm)
Average (Range) of EBCT per Vessel (min)(a)
Average (Range) of EBCT for System (min)(a)
Average (Range) of Inlet Pressure (psi)
Average (Range) of Outlet Pressure (psi)
Average (Range) of Ap across System (psi)
Average (Range) of Ap across Vessel A (psi)
Average (Range) of Ap across Vessel B (psi)
Value/Condition
12/08/05-06/09/06
787
4.3
2,070,000
12,625
44 (39-53)
3.7(3.1-4.2)
7.5 (6.2-8.4)
41.2 (34-60)
30.1(24-50)
11.2(8-14)
3.2 (1-6)
4.3 (0-6)
(a) Calculated based on 22 ft3 of media in one vessel.
factory-calibrated electromagnetic flow meters/totalizers were more reliable than those from the master
totalizer, for which little information was available regarding its accuracy and installation specifications.
Therefore, for performance evaluation purposes, the data produced by the electromagnetic flow
meter/totalizer on the lag vessel was used to determine system flowrates and total volume treated.
Figure 4-12 also identifies flowrate data that were not consistent with normal operations and caused by an
unintentional resetting of the electromagnetic flow meters/totalizers on two separate occasions. Detailed
discussions regarding the resetting of the totalizers are provided in Section 4.4.3.
During the first six months, the system treated approximately 2,070,000 gal of water based on the
totalizer readings from the lag vessel. The amount of water treated was equivalent to approximately
12,600 BV based on the 22 ft3 of media in one vessel or 6,300 BV based on the 44 ft3 of media in both
vessels. Flowrates to the system ranged from 39 to 53 gpm and averaged 44 gpm. The average system
flowrate was 10% higher than the 40-gpm design value (Table 4-4), which was derived from the 40-gpm
supply well flowrate based on the pump curve provided by the facility. Based on the flows to the system,
the EBCT for the lag vessel varied from 3.1 to 4.2 min and averaged 3.7 min, which was 11% lower than
the design EBCT of 4.1 min.
The APU system pressures were monitored at the system inlet and outlet and between the lead and lag
vessels. The average pressure differential (Ap) across the treatment train, lead vessel, and lag vessel for
the first month of system operation was 10, 3, and 4 psi, respectively. By the end of the first six months
of system operation, the average Ap across the treatment train, lead vessel, and lag vessel were 11,3, and
4 psi, respectively. As such, no pressure increase was observed after 787 hr of system operation or after
treating approximately 2,070,500 gal of water. Noticeable pressure spikes were observed during the last
four months of system operation; however, none of these spikes caused significant increase in Ap across
the treatment train or adsorption vessels. As a result, no media backwash was performed during the first
six months of system operation. Figures 4-13 shows total and differential pressures for each vessel and
the system.
4.4.2 Residual Management. Because neither backwash nor media replacement was performed
during the first six months of system operation, no residual was produced in this reporting period.
28
-------
55 -
50-
45-
S 35 -
2
1
"- 30 H
20 -
15-
-Totalizer Average Flowrate
-Vessel A (Lead) Instantaneous Flowrate
-Vessel A (Lead) Average Flowrate
Vessel B (Lag) Instantaneous Flowrate
Vessel B (Lag) Average Flowrate
10
12/09/05 12/29/05 01/18/06 02/07/06 02/27/06 03/19/06 04/08/06 04/28/06 05/18/06 06/07/06
Date
Figure 4-12. System Instantaneous and Calculated Flowrates
70
50 -
-System Inlet Pressure
-Vessel A (Lead) Inlet Pressure
Vessel B (Lag) Inlet Pressure
-System Outlet Pressure
-Vessel A (Lead) Outlet Pressure
Vessel B (Lag) Outlet Pressure
System Differential Pressure (calculated)
Vessel A (Lead) Differential Pressure (reading;
Vessel B (Lag) Differential Pressure (reading;
12/09/05 12/29/05 01/18/06 02/07/06 02/27/06 03/19/06 04/08/06 04/28/06 05/18/06 06/07/06
Date
Figure 4-13. System Operational Pressures
29
-------
4.4.3 System/Operation Reliability and Simplicity. Operational irregularities experienced during
the first six months of the demonstration study were related to the pH adjustment system and the media
vessel flow meters/totalizers.
As described in Section 4.2, pH adjustment using a CO2 injection module is a process component. On
January 11, 2006, leaks were detected in the CO2 system, resulting in an additional change-out of a CO2
gas cylinder during the sixth week of the system operations. The leaks were tracked to the supply line
where loose fittings were discovered. During the week of March 13, 2006 (the 15th week of operation),
the proportional flow control valve that regulates the CO2 injection rate began operating improperly. The
failure caused the pH levels to remain higher than desired. Based on in-line probe readings, the pH values
averaged 7.8 during that week of operation. The pH control system was switched to operate in the
manual mode until the control valve was replaced on April 24, 2006. On May 3, 2006, the digital screen
on the JUMO pH/PID controller was not displaying the pH measurement. A replacement in-line pH
probe was installed on May 30, 2006, which restored the digital display on the JUMO pFi/PID controller.
The CO2 system failed to consistently adjust the pH to the target value of 7.0, with the pH values
measured by the in-line pH probe varying between 6.5 and 8.2.
On two separate occasions, January 12, 2006, and May 23, 2006, both electromagnetic flow
meters/totalizers malfunctioned, causing the meters to reset and begin totalizing from zero. The failure
was thought to have been caused by a programming error. A flash memory card with the necessary
programming updates was provided by the vendor; and on June 15, 2006, the operator integrated the
upgrades to prevent future reoccurrences of the problems.
Due to the malfunction of the electromagnetic flow meters/totalizers, an effort was made to evaluate their
accuracy by comparing cumulative totalizer readings from each electromagnetic flow meter/totalizer.
The cumulative totalizer readings from the electromagnetic flow meters/totalizers on the lead and lag
vessels were 2,086,700 and 2,070,000, respectively. Based on those cumulative measurements, a
variation of less than 1% was measured through the first six-month operational period.
The system O&M and operator skill requirements are discussed below in relation to pre- and post-
treatment requirements, levels of system automation, operator skill requirements, preventive maintenance
activities, and frequency of chemical/media handling and inventory requirements.
Pre- and Post-Treatment Requirements. Two forms of pre-treatment were required at the Webb CISD
site, i.e., pH adjustment and prechlorination. CO2 was used to lower the pH value of raw water from as
high as 8.2 (Table 4-1) to a target value of 7.0 in order to maintain effective adsorption by the AD-33
media. The CO2 injection point and in-line pH probe used to monitor and control the adjusted pH level,
were installed upstream of the prechlorination injection point. O&M of the pH adjustment system
required routine system pressure checks and regular changesout of the CO2 supply bottles as pressure was
depleted. The operator also recorded a daily pH reading from the in-line probe and performed calibration
of the pH probe, as needed. The use of CO2 for pH adjustment also required additional safety training and
awareness for the operator, due to the added hazards.
For prechlorination, the existing chlorination system was upgraded and installed inside the maintenance
building, which housed the APU-50LL-CS-S-2-AVH system. The upgraded chlorination system, as
discussed in Section 4.2 and shown on Figure 4-8, utilized a 10%NaOCl solution to reach a target
residual level of 1.2 mg/L (as C12). The upgraded chlorination system did not require maintenance or
skills other than those required by the previous system. The operator monitored chlorine tank levels,
consumption rates, and residual chlorine levels.
30
-------
System Automation. The system was fitted with automated controls that would allow for the backwash
cycle to be controlled automatically. The system is also equipped with an automated Carbon Dioxide Gas
Flow Control System, which includes a liquid CO2 supply assembly, an automatic pH control panel, a
CO2 membrane module and an in-line pH probe located downstream of the membrane module. Each
media vessel is equipped with five electrically actuated butterfly valves which are controlled by a Square
D Telemechanique PLC with a Magelis G2220 color touch interface screen. Although not automated, the
system is also equipped with six isolation ball valves to allow for reversible lead lag configuration.
The automated portion of the system did not require regular O&M; however operator awareness and an
ability to detect unusual system measurements were necessary when troubleshooting system automation
failures. The equipment vendor provided hands-on training and a supplemental operations manual to the
operator.
Operator Skill Requirements. The skill requirements to operate the system demand a higher level of
awareness and attention than the previous system. The system offers increased operational flexibility,
which, in turn, requires increased monitoring of system parameters. The operator's knowledge of the
system limitations and typical operational parameters is key in achieving system performance objectives.
The operator was on-site typically five times a week and spent approximately 20 min each day to perform
visual inspections and record the system operating parameters on the daily log sheets. The basis for the
operator skills began with on-site training and a thorough review of the system operations manual;
however, increased knowledge and invaluable system troubleshooting skills are gained through hands on
operational experience.
TCEQ requires that the operator of the treatment system hold at least a Class D TCEQ waterworks
operator license. The TCEQ public water system operator certifications are classified by Class D through
A. Licensing eligibility requirements are based on education, experience, and related training. The
minimum requirements for a Class D license are high school graduate or GED and 20 hr of related
training. Licensing requirements incrementally increase with each licensing level, with Class A being the
highest requiring the most education, experience, and training.
Preventive Maintenance Activities. Preventive maintenance tasks included periodic checks of
flowmeters and pressure gauges and inspection of system piping and valves. Checking the CO2 cylinders
and supply lines for leaks and adequate pressure and calibrating the in-line pH probe also were
performed. Typically, the operator performed these duties while on-site for routine activities.
Chemical/Media Handling and Inventory Requirements. NaOCl was used for prechlorination; the
operator ordered chemicals as done prior to the installation of the APU-50LL-CS-S-2-AVH system. CO2
used for pH adjustment was ordered on an as needed basis. Typically, four 50-lb cylinders were used per
month. As the CO2 cylinders were delivered to the site by the CO2 supplier, empty cylinders were
returned for reuse.
4.5 System Performance
The performance of the system was evaluated based on analyses of water samples collected from raw and
treated water and distribution system.
4.5.1 Treatment Plant Sampling. Table 4-8 summarizes the analytical results of arsenic, iron,
and manganese concentrations measured at the four sampling locations across the treatment train.
Table 4-9 summarizes the results of other water quality parameters. Appendix B contains a complete set
of analytical results through the first six months of operation. The results of the water samples collected
throughout the treatment plant are discussed below.
31
-------
Table 4-8. Summary of Analytical Results for Arsenic, Iron, and Manganese
Parameter
As
(total)
As
(soluble)
As
(paniculate)
As (III)
As(V)
Fe
(total)
Fe
(soluble)
Mn
(total)
Mn
(soluble)
Sampling
Location
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
Unit
ug/L
ug/L
tig/L
ug/L
tig/L
ug/L
ug/L
tig/L
ug/L
tig/L
ug/L
ug/L
tig/L
ug/L
tig/L
ug/L
ug/L
tig/L
ug/L
ug/L
tig/L
ug/L
tig/L
ug/L
ug/L
tig/L
ug/L
tig/L
ug/L
ug/L
tig/L
ug/L
tig/L
ug/L
ug/L
ug/L
Sample
Count
15
15
15
15
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
15
15
15
15
7
7
7
7
15
15
15
15
7
7
7
7
Concentration
Minimum
46.2
50.2
Maximum
62.9
64.4
Average
56.9
58.6
Standard
Deviation
4.6
4.3
(a)
51.5
50.8
56.5
61.0
53.4
53.6
1.7
3.6
(a)
<0.1
1.2
8.6
8.9
4.9
6.3
3.7
2.7
(a)
35.8
0.5
40.8
3.3
38.5
1.7
2.1
1.1
(a)
13.2
47.7
17.3
57.7
14.9
51.9
1.4
3.3
(a)
<25
<25
<25
<25
<25
<25
<25
<25
2.6
2.9
0.1
<0.1
2.6
3.0
<0.1
<0.1
28.8
<25
<25
<25
<25
<25
<25
<25
5.4
4.6
1.8
5.0
4.2
3.5
1.6
5.1
<25
<25
<25
<25
<25
<25
<25
<25
3.9
3.5
0.3
0.5
3.6
3.2
0.3
0.8
6.0
2.4
0.0
0.0
0.0
0.0
0.0
0.0
0.8
0.6
0.5
1.3
0.5
0.2
0.6
1.9
One-half of detection limit used for samples with concentrations less than detection limit for calculations.
(a) Statistics not provided; see Figure 4-15 for arsenic breakthrough curves.
32
-------
Table 4-9. Summary of Water Quality Parameter Sampling Results
Parameter
Alkalinity
(as CaCO3)
Fluoride
Sulfate
Nitrate
(asN)
Phosphorus
(as PO4)
Silica
(as SiO2)
Turbidity
pH
Temperature
Dissolved
Oxygen
Sampling
Location
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
Unit
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
NTU
NTU
NTU
NTU
s.u.
s.u.
s.u.
s.u.
°c
°c
°c
°c
mg/L
mg/L
mg/L
mg/L
Sample
Count
15
15
15
15
7
7
7
7
7
7
7
7
7
7
7
7
14
14
14
14
15
15
15
15
15
15
15
15
12
12
12
12
12
12
12
12
12
12
12
12
Concentration
Minimum
305
306
294
312
0.5
0.6
0.5
0.4
104
104
98
100
0.05
O.05
0.05
O.05
O.01
0.01
O.01
0.01
40.6
40.2
13.5
1.7
0.1
0.1
O.I
0.1
8.0
7.1
7.1
7.1
21.3
21.2
21.4
21.4
1.1
1.4
0.9
1.3
Maximum
334
344
342
352
0.9
1.2
1.5
1.0
111
112
114
136
0.05
O.05
0.05
O.05
0.03
0.06
O.03
0.03
43.9
43.5
44.4
45.3
1.1
1.5
1.1
2.0
8.3
8.1
7.6
7.5
27.1
27.2
27.5
27.4
3.1
4.1
3.4
3.5
Average
320
322
321
325
0.6
0.8
0.8
0.7
106
107
108
111
0.05
O.05
0.05
O.05
0.01
0.01
0.01
0.01
41.9
41.9
38.4
35.4
0.5
0.4
0.4
0.5
8.2
7.4
7.3
7.3
25.6
25.7
25.6
25.4
1.7
2.0
1.8
2.0
Standard
Deviation
9
10
12
12
0.2
0.2
0.3
0.2
2.4
3.6
5.9
11.9
0.00
0.00
0.00
0.00
0.01
0.01
0.01
0.01
1.1
1.0
8.3
13.1
0.3
0.4
0.3
0.5
0.1
0.3
0.1
0.1
1.7
1.9
1.9
2.0
0.6
0.7
0.6
0.6
33
-------
Table 4-9. Summary of Water Quality Parameter Sampling Results (Continued)
Parameter
ORP
Free
Chlorine
(as C12)
Total
Chlorine
(as C12)
Total
Hardness
(as CaCO3)
Ca
Hardness
(as CaCO3)
Mg
Hardness
(as CaCO3)
Sampling
Location
IN
AP
TA
TB
AP
TA
TB
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
IN
AP
TA
TB
Unit
mV
mV
mV
mV
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Sample
Count
12
12
12
12
12
-
10
11
-
10
7
7
7
7
7
7
7
7
7
7
7
7
Concentration
Minimum
234
309
387
371
0.5
-
0.6
0.7
-
0.7
17.1
19.1
11.6
15.8
11.3
11.9
7.6
9.9
5.8
5.3
4.0
3.3
Maximum
378
679
690
700
2.0
-
1.7
2.1
-
2.1
30.1
30.0
33.0
47.2
22.7
22.8
25.1
29.4
9.0
9.1
10.7
17.9
Average
280
535
594
608
1.0
-
1.1
1.3
-
1.2
22.8
23.0
24.3
26.3
15.5
15.9
16.7
17.9
7.3
7.1
7.7
8.4
Standard
Deviation
44.1
89.0
85.1
104
0.5
-
0.4
0.4
-
0.5
4.9
4.7
6.9
10.7
4.4
4.2
5.7
6.8
1.0
1.2
2.0
4.5
One-half of detection limit used for samples with concentrations less than detection limit for
calculations.
Arsenic. Water samples were collected on 15 occasions (including one duplicate sampling event), with
field speciation performed during seven of the 15 occasions from IN, AP, TA, and TB sampling locations.
Figure 4-14 contains four bar charts showing the concentrations of particulate arsenic, As(III), and As(V)
at four locations for each of the seven speciation events.
Total arsenic concentrations in raw water ranged from 46.2 to 62.9 |o,g/L and averaged 56.9 |o,g/L. As(III)
was the predominating species, ranging from 35.8 to 40.8 (ig/L and averaging 38.5 |o,g/L. As(V) also was
present in source water, ranging from 13.2 to 17.3 |o,g/L and averaged 14.9 |o,g/L. Particulate As
concentrations were lower, ranging from <0.1 to 8.6 |o,g/L and averaging 4.9 (ig/L. The arsenic
concentrations measured were consistent with those collected previously during source water sampling
(Table 4-1).
Chlorination effectively oxidized As(III) to As(V) prior to the adsorption vessels. After chlorination the
average As(III) and As(V) concentrations were 1.7 and 51.9 |og/L, respectively. Free and total chlorine
were monitored at the AP and TB sampling locations to ensure that the target chlorine residual levels
were properly maintained for disinfection purposes. Free chlorine levels at the AP location ranged from
0.5 to 2.0 mg/L (as C12) and averaged 1.0 mg/L (as C12); total chlorine levels ranged from 0.7 to 2.1 mg/L
(as C12) and averaged 1.3 mg/L (as C12) (Table 4-9). The residual chlorine levels measured at the TB
34
-------
Arsenic Species at Wellhead (IN)
Arsenic Species after pH Adjustment and Chlorination (AP)
70
60
As Concentration (fig/L)
D O O O O O
As (participate)
As (III)
OAs(V)
-
-
_
70-
60-
As Concentration (^g/L)
D 0 0 0 0 0
As (paniculate)
As (III)
OAs(V)
12/8/2005 1/5/2006 2/1/2006 3/14/2006 4/11/2006 5/9/2006 6/6/2006 12/8/2005
Date
1/5/2006 2/1/2006 3/14/2006 4/11/2006 5/9/2006 6/6/2006
Date
Arsenic Species after Vessel A(TA)
Arsenic Speciation after Vessel B (TB)
12/8/2005 1/5/2001
4/11/2006 5/9/2006 6/6/2006
12/8/2005 115/2006 2/112006
3/14/2006
Date
4/1112006 5/9/2006 6/6/2006
Figure 4-14. Concentrations of Various Arsenic Species at IN, AP, TA, and TB Sampling Locations
-------
location were similar to those measured at the AP location, indicating little or no chlorine consumption
through the AD-33 vessels.
The total arsenic breakthrough curves shown in Figure 4-15 indicate that the lead vessel removed the
majority of arsenic, existing predominately as As(V), following chlorination. Through the end of the first
six months of system operation, the system has treated approximately 2,070,000 gal of water, equivalent
to 12,600 BV based on the 22 ft3 of media in one adsorption vessel or 6,300 BV based on the 44 ft3 of
media in both vessels. Arsenic breakthrough, based on laboratory analysis of samples collected on June
6, 2006 (approximately 12,100 BV) was 1.1 and 0.8 (ig/L for the lead and lag vessels, respectively. The
12,600 BV of throughput represents approximately 27% of the media capacity estimated to be 46,900 BV
by the vendor (Table 4-4).
The average total arsenic breakthrough was significantly higher in both the lead and lag vessels during the
first three months of system operation. For the eight samples collected from December 8, 2005, through
February 28, 2006, the average total arsenic concentrations following the lead and lag vessels were 3.4
and 3.3 |og/L, respectively. In contrast, for the seven samples collected from March 14, 2006 through
June 6, 2006, the average total arsenic concentrations following the lead and lag vessels were 1.3 and 0.9
Hg/L, respectively. Further, laboratory results from two of the first four sampling events (December 8,
2005 and January 17, 2006) showed higher total arsenic concentrations following the lag vessel than
following the lead vessel. System operations are ongoing and the media in the lead vessel will be
recharged once it is completely exhausted or the breakthrough of the lag vessel approaches 10 (ig/L,
whichever comes first.
80 i
70 -
60
50
40 -
30
20
10 -
-At Wellhead (IN)
-After pH Adjustment and Chlorination (AP)
-After Vessel A (TA)
-After Vessel B (TB)
6 8
Bed Volumes (103)
10
12
14
Figure 4-15. Total Arsenic Breakthrough Curves
(Based on 22ft3 of Media in Each Vessel)
36
-------
Competing Anions. Phosphate and silica, which can influence arsenic adsorption, were measured at the
four sampling locations across the treatment train throughout the first six months of the demonstration
study. Phosphorus concentrations were low ranging from <0.01 to 0.06 mg/L (as PO4). Silica
concentrations ranged from 1.7 to 45.3 mg/L. Significant silica concentration reductions (96%, 85%, and
24%, respectively) were noted in samples collected during the first three weeks of operation. Following
the third week of operation the maximum silica concentration reduction was less then 10%. Figure 4-16
represents the silica breakthrough curves from the treatment train.
50
45
40
35
25
o
0 20
ro
15
10
5
At the Wellhead (IN)
After pH Adjustment and Chlorination (AP)
After Lead Vessel A (TA)
After Lag Vessel (TB)
10
12
14
Bed Volume (10
Figure 4-16. Silica (as SiO2) Breakthrough Curves
(Based on 22ft3 of Media in Each Vessel)
Iron and Manganese. Total iron concentrations in raw water were below its detection limit of 25 Lig/L
(Table 4-8). Total iron concentrations across the treatment train also were below the detection limit,
except for two occasions. One total iron concentration was detected on January 17, 2006, at 28.8 Lig/L
and the second on May 23, 2006, at 28.4 Lig/L, both at the IN location. Total manganese levels ranged
from 2.6 to 5.4 Lig/L and averaged 3.9 Lig/L in raw water. Total manganese concentrations in the effluent
from the adsorption vessels showed a slight increasing trend, with <1.8 Lig/L measured after the lead
vessel and <5.0 Lig/L after the lag vessel. Soluble manganese concentrations were similar for the four
sample locations averaging 3.6 Lig/L, 3.2 Lig/L, 0.3 Lig/L and 0.8 Lig/L for IN, AP, TA, and TB,
respectively.
Other Water Quality Parameters. As shown in Table 4-9, pH values of raw water measured at the IN
sample location varied from 8.0 to 8.3 and averaged 8.2. The pH values, following CO2 injection for pH
adjustment, at the AP location, varied from 7.1 to 8.1 and averaging 7.4. The average adjusted pH value
37
-------
of 7.0, at the AP location prior to the adsorption media, is desirable for adsorptive media which, in
general, have a greater arsenic removal capacity when treating water at near neutral pH values. Figure 4-
17 presents the pH values measured throughout the treatment train.
On two separate occasions on January 5 and 17, 2006, the pH values were not reduced following CO2
injection, as indicated by the second and third sets of IN (denoted by "*") and AP data points (denoted by
"") shown in Figure 4-17. The pH values measured, with a portable VWR meter, at the IN sampling
location were 8.1 and 8.0, respectively and the pH values measured at the AP location also were 8.1 and
8.0, respectively. In contrast, the pH values (denoted by "*") measured at the AP location by the in-line
probe were approximately 1.0 unit less than those measured at the same location by the VWR meter. pH
measurements prior to and following these two isolated events suggest that pH values measured by the
VWR meter at the AP location on January 5 and 17, 2006, most likely were the result of instrument or
measurement errors.
8.5
8.0
7.5
7.0
6.5
6.0
,002 proportioning valve malfunctioned.
CO2 system operated in
manual mode until -
proportioning valve was
replaced.
In-line pH probe failure.
--At the Wellhead (IN)
After pH Adjustment and Chlorination (AP)
After Lead Vessel A (TA)
-K- After Lag Vessel B (TB)
IK In-line pH Probe After Adjustment
10
12
Bed Volume (103)
Figure 4-17. pH Values Measured throughout Treatment Train
(Based on 22ft3 of Media in Each Vessel)
Throughout the first six month operational period, pH values reported by the VWR meter were
approximately 0.4 pH units (on average) higher than those reported by the in-line pH probe; however a
common trend is obvious, as illustrated in Figure 4-17. A possible explanation for the variations might be
degassing of dissolved CO2 when the water samples were collected from the AP location, thus resulting in
elevated readings measured by the portable VWR meter.
38
-------
Alkalinity, reported as CaCO3, ranged from 294 to 352 mg/L. The results indicated that the adsorptive
media did not affect the amount of alkalinity in the water after treatment. The treatment plant samples
were analyzed for hardness only on speciation weeks. Total hardness ranged from 11.6 to 47.2 mg/L (as
CaCO3), and also remained constant throughout the treatment train. Sulfate concentrations ranged from
98 to 136 mg/L, and remained constant throughout the treatment train. Fluoride results ranged from 0.4
to 1.5 mg/L in all samples. The results indicated that the adsorptive media did not affect the amount of
fluoride in the water after treatment. DO levels ranged from 0.9 to 4.1 mg/L and averaged 1.9 mg/L.
ORP readings averaged 280 mV in raw water, but increased to an average of 579 mV after chlorination.
4.5.2 Backwash Water Sampling. Backwash was not performed during the first six-month
operational period; however, a backwash is anticipated to occur during the second six-month operation
period.
4.5.3 Distribution System Water Sampling. Prior to the installation/operation of the treatment
system, baseline distribution system water samples were collected from the middle school, high school,
and cafeteria on June 15, July 21, August 24, and September 19, 2005. Following the installation of the
treatment system, distribution system water sampling continued on a monthly basis at the same three
locations, with samples collected on January 5, February 1, March 14, April 11, May 9, and June 6, 2006.
The results of the distribution system sampling are summarized on Table 4-10.
The most noticeable change in the distribution system samples since the system began operation was a
decrease in arsenic concentration. Baseline arsenic concentrations ranged from 49.6 to 99.9 (ig/L and
averaged 68.7 (ig/L for all three locations. After the performance evaluation began, arsenic
concentrations were reduced to <5.0 (ig/L (or 2.4 (ig/L on average), which were similar to the arsenic
concentrations in the system effluent.
Lead concentrations ranged from 0.3 to 2.3 (ig/L, with none of the samples exceeding the action level of
15 (ig/L. Copper concentrations ranged from 6.5 to 565 (ig/L, with no samples exceeding the 1,300 (ig/L
action level. Measured pH values ranged from 7.6 to 8.1 and averaged 7.8, which were 1A of a pH unit
higher than the avearge pH value immediately after the adsorption vessels. Compared to an average value
of 8.2 before the treatment sytem became operational, the lowered pH values did not appear to have
affected the Pb or Cu concentrations in the distribution system.
Alkalinity levels ranged from 305 to 348 mg/L (as CaCO3). Iron was not detected in any of the samples;
manganese concentrations ranged from <0.1 to 2.4 (ig/L. The arsenic treatment system did not seem to
affect these water quality parameters in the distribution system.
4.6 System Cost
System cost is evaluated based on the capital cost per gpm (or gpd) of the design capacity and the O&M
cost per 1,000 gal of water treated. The capital cost includes the cost for equipment, site engineering, and
installation. The O&M cost includes the cost for media replacement and disposal, electrical power use,
and labor.
4.6.1 Capital Cost. The capital investment for equipment, site engineering, and installation of the
Bruni treatment system was $138,642 (see Table 4-11). The equipment cost was $94,662 (or 68% of the
total capital investment), which included $77,082 for the skid-mounted APU-50LL-CS-S-2-AVH unit,
$13,200 for the AD-33 media ($300/ft3 or $8.57/lb to fill two vessels), $2,580 for shipping, and $1,800
for labor.
39
-------
Table 4-10. Distribution System Sampling Results
BJ)
"e-1
a z
Ł H
BL1
BL2
BL3
BL4
1
2
3
4
5
6
Location
BJ)
i 'S
m Q
06/15/05
07/21/05
08/24/05
09/19/05
01/05/06
02/01/06
03/14/06
04/1 1/06
05/09/06
06/06/06
Middle School
1
H
S
"a
a.
3s G
14.5
15.0
15.6
13.0
14.8
15.0
15.0
15.3
10.8
14.7
S3
e.
8.3
8.1
8.2
8.1
7.7
7.9
7.6
7.9
7.6
7.8
^
'"§
^g
<<
334
330
317
330
343
312
310
323
326
305
52.0
54.4
83.1
49.6
2.1
3.4
1.4
3.1
1.3
1.0
'
<25
70.9
<25
<25
<25
<25
<25
<25
<25
<25
a
§
1.9
13.5
2.2
3.3
<0.1
0.4
0.8
0.3
0.3
0.1
1.9
1.2
0.3
1.9
0.8
0.3
0.9
1.0
0.4
1.0
a
O
114
7.3
23.9
40.1
209
119
278
113
86.3
234
High School
1
H
S
=
a
Ť sŤ
x G
14.8
15.3
15.7
13.3
14.5
15.2
15.2
15.0
14.8
14.8
S3
e.
8.3
8.2
8.2
8.1
7.7
8.1
7.8
7.9
7.7
7.7
^
a
^g
<<
330
330
321
330
348
312
314
311
331
309
53.0
79.2
85.8
51.4
3.5
4.4
2.0
5.0
2.0
2.0
'
<25
32.8
<25
<25
<25
<25
<25
<25
<25
<25
a
§
1.2
6.0
1.2
1.5
2.4
0.2
0.8
0.6
0.7
1.9
2.3
2.0
0.9
1.5
2.3
0.8
1.8
1.6
0.7
0.7
a
O
115
44.8
72.5
77.3
308
214
259
337
164
565
Cafeteria
1
H
S
=
a
3 ^
S G
15.0
15.5
15.8
13.5
15.0
15.0
15.3
15.2
14.7
14.6
S3
e.
8.3
8.1
8.2
8.1
7.6
8.1
7.8
7.9
7.7
8.0
^
a
^g
<<
330
330
321
326
334
312
318
315
322
322
77.7
53.3
84.7
99.9
1.4
3.8
1.3
3.6
1.2
0.7
'
<25
<25
<25
<25
<25
<25
<25
<25
<25
<25
a
§
5.9
6.8
2.1
2.4
<0.1
0.6
0.9
0.3
0.1
0.2
11.5
2.9
0.3
1.9
0.5
0.6
0.9
0.8
0.4
0.6
a
O
381
106
23.2
44.4
15.4
250
19.7
16.0
6.5
14.9
Lead action level =15 ng/L; copper action level =1.3 mg/L
Hg/L as unit for all analytes except for pH (S.U.) and alkalinity (mg/L [as CaCO3]).
BL = Baseline Sampling; NA = Not Available
-------
Table 4-11. Capital Investment Cost for APU-50LL-CS-S-2-AVH System
Description
Quantity
Cost
% of Capital
Investment
Equipment Cost
APU Skid-Mounted System (Unit)
AD-33Media(ft3)
Shipping
Vendor Labor
Equipment Total
1
44
$77,082
$13,200
$2,580
$1,800
$94,662
68
Engineering Cost
Vendor Labor/Travel
Subcontractor Labor/Travel
Engineering Total
$11,800
$12,500
$24,300
18
Installation Cost
Subcontractor Labor
Vendor Labor
Vendor/ Subcontractor Travel
Installation Total
Total Capital Investment
-
$12,574
$4,860
$2,246
$19,680
$138,642
14
100
The engineering cost included the cost for preparing three submittal packages for the exception request,
permit application, and supplemental information for the permit (see Section 4.3.1). The engineering cost
was $24,300, or 18% of the total capital investment.
The installation cost included the equipment and labor to unload and install the skid-mounted unit,
perform piping tie-ins and electrical work, load, and backwash the media, perform system shakedown and
startup, and conduct operator training. The installation cost was $19,680, or 14% of the total capital
investment.
The total capital cost of $138,642 was normalized to the system's rated capacity of 40 gpm (57,600 gpd),
which resulted in $3,466/gpm of design capacity ($2.41/gpd). The capital cost also was converted to an
annualized cost of $13,086/yr using a capital recovery factor (CRF) of 0.09439 based on a 7% interest
rate and a 20-year return period. Assuming that the system operated 24 hours a day, 7 days a week at the
system design flowrate of 40 gpm to produce 21,024,000 gal of water per year, the unit capital cost would
be $0.62/1,000 gal. Because the system operated an average of 4.3 hr/day at 44 gpm (see Table 4-7),
producing 2,070,000 gal of water during the six-month period, the unit capital cost increased to
$3.16/1,000 gal at this reduced rate of use.
4.6.2 Operation and Maintenance Cost. The O&M cost included the cost for such items as
media replacement and disposal, CO2 usage, electricity consumption, and labor (Table 4-12). Although
media replacement did not occur during the first six months of system operation, the media replacement
cost would represent the majority of the O&M cost and was estimated to be $11,190 to change out the
lead vessel. This media change-out cost would include the cost for media, underbedding, freight, labor,
travel, spent media analysis, and media disposal fee. This cost was used to estimate the media
replacement cost per 1,000 gal of water treated as a function of the projected lead vessel media run length
at the 10 |o,g/L arsenic breakthrough from the lag vessel (Figure 4-18).
The chemical cost associated with the operation of the treatment system included the cost for NaCIO for
prechlorination and CO2 gas for pH adjustment. NaCIO was already being used at the site prior to the
41
-------
installation of the APU unit for disinfection purposes prior to distribution. The presence of the APU
system did not affect the use rate of the sodium hypochlorite solution. Therefore, the incremental
chemical cost for chlorine was negligible. The 50-lb CO2 cylinder was replaced weekly during the first
six months of system operation. Each change-out costs $31.52 and includes the replacement and delivery
charges. The CO2 costs for the first six months of operation were calculated to be $828 or $0.40/1,000
gallons of water treated.
Comparison of electrical bills supplied by the utility prior to system installation and since startup did not
indicate a noticeable increase in power consumption. Therefore, electrical cost associated with operation
of the system was assumed to be negligible.
Under normal operating conditions, routine labor activities to operate and maintain the system consumed
20 min per day, 5 days per week, as noted in Section 4.4.3. Therefore, the estimated labor cost was
$0.41/1,000 gal of water treated.
Table 4-12. Operation and Maintenance Cost for APU-50LL-CS-S-2-AVH System
Cost Category
Volume Processed (gal)
Value
2,070,000
Assumptions
Through June 9, 2006
Media Replacement and Disposal Cost
Media Replacement ($)
Underbedding and Freight for
Media and Gravel Shipping ($)
Travel and per diem ($)
Vendor and Subcontractor Labor ($)
Media Disposal ($)
Subtotal
Media Replacement and Disposal
($/l,000 gal)
$6,600
$330
$1,000
$2,160
$1,100
$11,190
See Figure 4-18
$300/ft3 for 22 ft3 (one media
vessel)
Including spent media analysis
Based upon lead vessel media run
length at 10-|ag/L arsenic
breakthrough from lag vessel
CO 2 Usage
CO2 Gas ($/l,000 gal)
$0.40
Based on consumption of CO2 for
pH adjustment (50-lb bottles)
Electricity Cost
Electricity ($/l,000 gal)
$0.001
Electrical costs assumed negligible
Labor Cost
Average Weekly Labor (min)
Labor ($/l,000 gal)
Total O&M Cost/1,000 gal
100
$0.41
See Figure 4-18
20 mm/day
Labor rate = $19.50/hr
Based upon lead vessel media run
length at 10-|ag/L arsenic
breakthrough from lag vessel
42
-------
o
o
O&M cost
Media replacement cost
$0.50
$0.00
20
30 40 50 60 70
Media Working Capacity, Bed Volumes (xlOOO)
80
90
100
Note: One bed volume equals 22 ft (165 gal)
Figure 4-18. Media Replacement and Operation and Maintenance Cost
43
-------
5.0 REFERENCES
Battelle. 2004. Revised Quality Assurance Project Plan for Evaluation of Arsenic Removal Technology.
Prepared under Contract No. 68-C-00-185, Task Order No. 0029, for U.S. Environmental
Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH.
Battelle. 2005. Final System Performance Evaluation Study Plan: U.S. EPA Demonstration of Arsenic
Removal Technology at the Webb Consolidated Independent School District in Bruni, Texas.
Prepared under Contract No. 68-C-00-185, Task Order No. 0029 for U.S. Environmental
Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH.
Chen, A.S.C., L. Wang, J. Oxenham, and W. Condit. 2004. Capital Costs of Arsenic Removal
Technologies: U.S. EPA Arsenic Removal Technology Demonstration Program Round 1.
EPA/600/R-04/201. U.S. Environmental Protection Agency, National Risk Management
Research Laboratory, Cincinnati, OH.
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, 90(^:103-113.
EPA. 2001. National Primary Drinking Water Regulations: Arsenic and Clarifications to Compliance
and New Source Contaminants Monitoring. Fed. Register, 40 CFR Parts 9, 141, and 142.
EPA. 2002. Lead and Copper Monitoring and Reporting Guidance for Public Water Systems.
EPA/816/R-02/009. U.S. Environmental Protection Agency, Office of Water, Washington, DC.
EPA. 2003. Minor Clarification of the National Primary Drinking Water Regulation for Arsenic.
Federal Register, 40 CFR Part 141.
Wang, L., W. Condit, and A. Chen. 2004. Technology Selection and System Design: U.S. EPA Arsenic
Removal Technology Demonstration Program Round 1. EPA/600/R-05/001. U.S.
Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati,
OH.
44
-------
APPENDIX A
OPERATIONAL DATA
-------
Table A-l. EPA Arsenic Demonstration Project at Bruni, TX - Daily System Operation Log Sheet
Week No.
1
2
3
4
5
6
7
8
9
10
11
Day of
Week
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Date
12/08/05
12/09/05
12/12/05
12/13/05
12/14/05
12/15/05
12/16/05
12/19/05
12/20/05
12/21/05
12/22/05
12/23/05
12/26/05
12/27/05
12/28/05
12/29/05
12/30/05
01/02/06
01/03/06
01/04/06
01/05/06
01/06/06
01/09/06
01/10/06
01/11/06
01/12/06
01/13/06
01/16/06
01/17/06
01/18/06
01/19/06
01/20/06
01/23/06
01/24/06
01/25/06
01/26/06
01/27/06
01/30/06
01/31/06
02/01/06
02/02/06
02/03/06
02/06/06
02/07/06
02/08/06
02/09/06
02/10/06
02/13/06
02/14/06
02/15/06
02/16/06
02/17/06
Well
Operational
Hours
hr
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
4.2
2.4
4.5
NA
10.9
5.0
4.4
4.9
2.7
6.6
2.9
3.4
2.4
3.9
4.7
10.5
8.4
6.6
5.6
13.6
3.4
3.0
2.5
2.2
4.8
1.5
2.0
2.9
5.6
Vessel A
Flowrate
gpm
NA
53
50
50
50
50
49
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
50
50
50
50
50
50
52
50
NA
52
50
51
51
51
NA
NA
51
52
51
51
51
52
51
52
51
51
52
52
50
52
52
51
51
50
Cumulative
Totalizer
gal
NA
23,794
35,319
38,069
48,075
51,866
57,415
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
92,686
96,835
103,668
116,084
131,789
142,134
148,763
6,614
NA
35,434
48,544
60,350
73,080
79,955
98,481
106,034
114,427
121,235
131,558
143,267
172,144
194,479
213,083
227,540
262,989
271,073
279,832
286,120
292,035
304,459
308,325
313,473
321,089
335,365
Usage
gal
NA
23,794
11,525
2,750
10,006
3,791
5,549
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
35,271
4,149
6,833
12,416
15,705
10,345
6,629
6,614
NA
28,820
13,110
11,806
12,730
6,875
18,526
7,553
8,393
6,808
10,323
11,709
28,877
22,335
18,604
14,457
35,449
8,084
8,759
6,288
5,915
12,424
3,866
5,148
7,616
14,276
Average
Flowrate
gpm
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
41
46
24
NA
44
44
45
43
42
NA
NA
41
47
44
42
46
44
47
43
43
40
49
42
45
43
43
43
44
42
Pressure
Differential
psi
NA
3.0
3.0
3.0
3.0
3.0
3.0
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
1.0
2.0
1.0
1.0
3.0
4.0
4.0
5.0
NA
5.0
5.0
4.0
5.0
4.0
NA
NA
3.0
3.0
4.0
5.0
5.0
4.0
5.0
5.0
4.0
4.0
4.0
5.0
5.0
5.0
4.0
1.0
2.0
2.0
Vessel B
Flowrate
gpm
NA
51
48
48
48
49
48
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
48
49
48
48
48
49
50
52
NA
53
51
52
51
52
NA
NA
53
53
53
52
52
53
53
53
51
51
53
53
51
53
53
52
52
52
Cumulative
Totalizer
gal
NA
19,174
30,304
32,962
42,634
46,290
51,661
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
85,630
89,621
96,210
108,229
123,309
133,247
139,601
6,727
NA
36,043
49,412
61,429
74,407
81,422
100,350
108,614
116,547
123,472
133,918
145,866
175,129
197,638
216,459
231,048
266,801
274,942
283,796
290,139
296,107
308,620
312,504
317,684
325,362
339,775
Usage
gal
NA
19,174
11,130
2,658
9,672
3,656
5,371
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
33,969
3,991
6,589
12,019
15,080
9,938
6,354
6,727
NA
29,316
13,369
12,017
12,978
7,015
18,928
8,264
7,933
6,925
10,446
11,948
29,263
22,509
18,821
14,589
35,753
8,141
8,854
6,343
5,968
12,513
3,884
5,180
7,678
14,413
Average
Flowrate
gpm
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
39
44
25
NA
45
45
46
44
43
48
47
39
48
45
42
46
45
48
43
44
40
49
42
45
43
43
43
44
43
Pressure
Differential
psi
NA
5.0
4.0
4.0
4.0
4.0
4.0
NA
NA
NA
NA
5.0
NA
NA
NA
NA
5.0
NA
4.0
4.0
4.0
4.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
NA
NA
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
System
Inlet Pressure
psi
NA
40
40
38
38
38
39
NA
NA
NA
NA
40
NA
NA
NA
NA
40
NA
40
36
36
38
38
36
38
38
40
42
38
38
38
38
NA
NA
38
42
40
38
40
38
36
36
38
42
38
40
38
38
50
44
36
36
Outlet
Pressure
psi
NA
30
30
28
28
28
29
NA
NA
NA
NA
30
NA
NA
NA
NA
30
NA
32
28
26
28
28
26
28
28
30
32
28
28
28
28
NA
NA
26
30
38
26
28
26
26
26
26
30
26
28
26
26
38
32
26
26
Pressure
Differential
psi
NA
10
10
10
10
10
10
NA
NA
NA
NA
10
NA
NA
NA
NA
10
NA
8
8
10
10
10
10
10
10
10
10
10
10
10
10
NA
NA
12
12
2
12
12
12
10
10
12
12
12
12
12
12
12
12
10
10
Cumulative
Volume
Treated
gal
NA
19,174
30,304
32,962
42,634
46,290
51,661
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
85,630
89,621
96,210
108,229
123,309
133,247
139,601
146,328
NA
175,644
189,013
201,030
214,008
221,023
239,951
248,215
256,148
263,073
273,519
285,467
314,730
337,239
356,060
370,649
406,402
414,543
423,397
429,740
435,708
448,221
452,105
457,285
464,963
479,376
Cumulative
Bed Volumes
Treated ''"
BV
NA
117
185
201
260
282
315
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
522
546
587
660
752
812
851
892
NA
1,071
1,153
1,226
1,305
1,348
1,463
1,514
1,562
1,604
1,668
1,741
1,919
2,056
2,171
2,260
2,478
2,528
2,582
2,620
2,657
2,733
2,757
2,788
2,835
2,923
pH
NA
6.64
6.82
6.88
6.80
6.84
6.88
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
6.85
6.94
6.94
6.92
6.85
6.91
6.88
6.92
NA
6.94
6.95
6.91
NM
6.89
NA
NA
6.93
6.76
6.76
6.82
6.62
6.51
6.58
6.62
6.56
6.61
6.63
6.62
6.76
6.71
6.67
6.74
6.67
-------
Table A-l. EPA Arsenic Demonstration Project at Bruni, TX - Daily System Operation Log Sheet (Continued)
Week No.
12
13
14
15
16
17
18
19
20
21
Day of
Week
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Date
02/20/06
02/21/06
02/22/06
02/23/06
02/24/06
02/27/06
02/28/06
03/01/06
03/02/06
03/03/06
03/06/06
03/07/06
03/08/06
03/09/06
03/10/06
03/13/06
03/14/06
03/15/06
03/16/06
03/17/06
03/20/06
03/21/06
03/22/06
03/23/06
03/24/06
03/27/06
03/28/06
03/29/06
03/30/06
03/31/06
04/03/06
04/04/06
04/05/06
04/06/06
04/07/06
04/10/06
04/11/06
04/12/06
04/13/06
04/17/06
04/18/06
04/19/06
04/20/06
04/21/06
04/24/06
04/25/06
04/26/06
04/27/06
04/28/06
Well
Operational
Hours
hr
5.4
3.1
2.2
2.3
2.2
5.1
2.2
2.1
NA
1.3
1.9
0.7
0.9
1.6
1.9
3.0
5.4
4.8
5.0
5.4
5.7
7.8
10.1
11.0
5.2
6.5
5.2
7.7
3.8
6.3
14.7
8.5
6.1
10.1
7.3
5.8
7.9
12.0
18.5
15.4
9.4
8.1
8.5
9.0
7.2
12.4
15.8
8.8
5.7
Vessel A
Flowrate
gpm
52
51
52
52
52
53
52
52
NA
NA
49
52
50
52
52
50
51
51
52
52
52
49
52
51
52
52
51
52
53
46
51
52
51
48
52
52
53
51
52
52
49
52
53
51
49
52
52
49
53
Cumulative
Totalizer
gal
349,543
357,906
363,712
369,820
375,462
388,999
395,397
400,388
NA
403,939
408,768
410,597
412,952
417,448
422,421
430,465
447,253
460,094
473,291
487,179
501,498
522,266
550,641
582,679
596,177
612,520
625,670
647,997
657,686
674,693
714,575
738,606
754,237
780,646
798,657
813,257
834,182
867,024
915,364
953,590
980,223
1,003,256
1,026,074
1,052,191
1,069,814
1,104,268
1,151,908
1,175,787
1,189,735
Usage
gal
14,178
8,363
5,806
6,108
5,642
13,537
6,398
4,991
NA
3,551
4,829
1,829
2,355
4,496
4,973
8,044
16,788
12,841
13,197
13,888
14,319
20,768
28,375
32,038
13,498
16,343
13,150
22,327
9,689
17,007
39,882
24,031
15,631
26,409
18,011
14,600
20,925
32,842
48,340
38,226
26,633
23,033
22,818
26,117
17,623
34,454
47,640
23,879
13,948
Average
Flowrate
gpm
44
45
44
44
43
44
48
40
NA
46
42
44
44
47
44
45
52
45
44
43
42
44
47
49
43
42
42
48
42
45
45
47
43
44
41
42
44
46
44
41
47
47
45
48
41
46
50
45
41
Pressure
Differential
PSi
1.0
1.0
1.0
1.0
1.0
1.0
2.0
2.0
NA
NA
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
1.0
2.0
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
Vessel B
Flowrate
gpm
53
52
53
53
53
54
53
53
NA
NA
50
53
51
53
53
51
52
52
53
53
53
51
53
53
53
53
52
52
53
47
52
53
52
49
53
53
54
52
53
53
50
53
54
50
49
53
53
50
54
Cumulative
Totalizer
gal
354,107
362,573
368,442
374,611
380,319
393,999
400,371
405,522
NA
409,117
413,981
415,820
418,191
422,751
427,788
435,993
453,096
466,107
479,476
493,527
507,994
529,111
558,031
590,675
604,398
620,897
634,183
656,918
666,722
684,032
724,554
749,092
765,045
792,082
810,333
825,086
846,505
880,032
929,620
968,494
995,672
1,019,217
1,042,523
1,069,065
1,086,721
1,121,440
1,169,626
1,193,750
1,207,751
Usage
gal
14,332
8,466
5,869
6,169
5,708
13,680
6,372
5,151
NA
3,595
4,864
1,839
2,371
4,560
5,037
8,205
17,103
13,011
13,369
14,051
14,467
21,117
28,920
32,644
13,723
16,499
13,286
22,735
9,804
17,310
40,522
24,538
15,953
27,037
18,251
14,753
21,419
33,527
49,588
38,874
27,178
23,545
23,306
26,542
17,656
34,719
48,186
24,124
14,001
Average
Flowrate
gpm
44
46
44
45
43
45
48
41
NA
46
43
44
44
48
44
46
53
45
45
43
42
45
48
49
44
42
43
49
43
46
46
48
44
45
42
42
45
47
45
42
48
48
46
49
41
47
51
46
41
Pressure
Differential
PSi
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
NA
NA
4.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
4.0
2.0
0.0
1.0
1.0
0.0
2.0
0.0
0.0
2.5
0.0
2.5
2.5
2.5
2.5
4.0
4.0
4.0
5.0
5.0
4.0
4.0
5.0
4.0
4.0
5.0
5.0
5.0
5.0
System
Inlet Pressure
PSi
38
38
38
40
38
42
38
38
NA
NA
56
44
36
36
38
34
40
38
38
38
38
54
38
40
60
42
36
48
38
59
38
36
40
52
38
42
38
36
40
38
50
54
36
60
42
38
38
58
36
Outlet
Pressure
PSi
26
26
26
36
26
28
26
26
NA
NA
46
32
24
24
26
22
28
26
26
26
26
44
26
26
50
30
24
36
24
48
26
24
28
40
26
30
24
24
28
26
38
44
24
50
30
26
24
48
24
Pressure
Differential
PSi
12
12
12
4
12
14
12
12
NA
NA
10
12
12
12
12
12
12
12
12
12
12
10
12
14
10
12
12
12
14
11
12
12
12
12
12
12
14
12
12
12
12
10
12
10
12
12
14
10
12
Cumulative
Volume
Treated
gal
493,708
502,174
508,043
514,212
519,920
533,600
539,972
545,123
NA
548,718
553,582
555,421
557,792
562,352
567,389
575,594
592,697
605,708
619,077
633,128
647,595
668,712
697,632
730,276
743,999
760,498
773,784
796,519
806,323
823,633
864,155
888,693
904,646
931,683
949,934
964,687
986,106
1,019,633
1,069,221
1,108,095
1,135,273
1,158,818
1,182,124
1,208,666
1,226,322
1,261,041
1,309,227
1,333,351
1,347,352
Cumulative
Bed Volumes
Treated "'"
BV
3,010
3,062
3,098
3,135
3,170
3,254
3,293
3,324
NA
3,346
3,376
3,387
3,401
3,429
3,460
3,510
3,614
3,693
3,775
3,861
3,949
4,078
4,254
4,453
4,537
4,637
4,718
4,857
4,917
5,022
5,269
5,419
5,516
5,681
5,792
5,882
6,013
6,217
6,520
6,757
6,922
7,066
7,208
7,370
7,478
7,689
7,983
8,130
8,216
PH
6.78
6.86
6.78
6.88
6.80
6.84
6.88
6.86
NA
NA
6.99
6.93
7.02
6.96
7.68
7.53
7.73
8.12
8.22
7.56
7.42
7.33
7.38
7.61
7.64
7.60
7.70
NA
7.54
7.31
7.51
7.35
7.40
7.38
7.66
7.31
7.34
7.49
7.30
7.58
7.41
7.30
7.28
6.91
7.02
7.15
7.28
6.91
7.03
>
-------
Table A-l. EPA Arsenic Demonstration Project at Bruni, TX - Daily System Operation Log Sheet (Continued)
Week No.
22
23
24
25
26
27
Day of
Week
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Date
05/01/06
05/02/06
05/03/06
05/04/06
05/05/06
05/08/06
05/09/06
05/10/06
05/11/06
05/12/06
05/15/06
05/16/06
05/17/06
05/18/06
05/19/06
05/22/06
05/23/06
05/24/06
05/25/06
05/26/06'"'
05/30/06
05/31/06
06/01/06
06/02/06
06/05/06
06/06/06
06/07/06
06/08/06
06/09/06
Well
Operational
Hours
hr
10.3
7.4
11.3
9.6
10.4
16.6
9.4
11.5
10.1
10.1
21.4
2.8
2.5
7.6
8.9
13.9
7.5
9.3
20.5
6.7
14.3
10.9
5.7
7.3
5.7
4.2
10.6
11.2
10.2
Vessel A
Flowrate
gpm
53
52
50
50
44
51
52
50
50
52
52
49
52
51
46
52
49
51
52
50
50
45
52
53
52
44
52
52
52
Cumulative
Totalizer
gal
1,215,584
1,234,603
1,267,350
1,293,809
1,319,455
1,361,583
1,387,691
1,421,409
1,449,175
1,474,621
1,530,575
1,537,194
1,543,390
1,563,262
1,586,222
1,624,747
9,644
35,965
93,797
110,177
143,981
171,468
185,133
203,556
217,127
227,171
253,528
286,015
313,234
Usage
gal
25,849
19,019
32,747
26,459
25,646
42,128
26,108
33,718
27,766
25,446
55,954
6,619
6,196
19,872
22,960
38,525
9,644
26,321
57,832
16,380
33,804
27,487
13,665
18,423
13,571
10,044
26,357
32,487
27,219
Average
Flowrate
gpm
42
43
48
46
41
42
46
49
46
42
44
39
41
44
43
46
21
47
47
41
39
42
40
42
40
40
41
48
44
Pressure
Differential
psi
2.5
2.5
2.5
2.5
2.5
2.5
2.5
5.0
4.0
5.0
5.0
5.0
6.0
6.0
4.0
5.0
5.0
5.0
6.0
6.0
5.0
6.0
6.0
5.0
4.0
4.0
5.0
6.0
6.0
Vessel B
Flowrate
gpm
54
53
51
51
45
52
53
50
51
53
52
49
52
51
47
52
49
52
52
50
51
46
52
53
53
45
53
53
53
Cumulative
Totalizer
gal
1,233,777
1,252,930
1,286,025
1,312,756
1,338,555
1,380,917
1,407,248
1,441,360
1,469,389
1,495,067
1,551,451
1,558,049
1,564,205
1,584,309
1,607,542
1,646,303
1,665,455
1,691,932
14,918
31,398
65,035
92,786
106,485
125,055
138,591
148,595
175,113
207,864
235,373
Usage
gal
26,026
19,153
33,095
26,731
25,799
42,362
26,331
34,112
28,029
25,678
56,384
6,598
6,156
20,104
23,233
38,761
19,152
26,477
14,918
16,480
33,637
27,751
13,699
18,570
13,536
10,004
26,518
32,751
27,509
Average
Flowrate
gpm
42
43
49
46
41
43
47
49
46
42
44
39
41
44
44
46
43
47
12
41
39
42
40
42
40
40
42
49
45
Pressure
Differential
psi
5.0
5.0
5.0
5.0
2.5
5.0
5.0
5.0
5.0
5.0
5.0
4.0
6.0
5.0
4.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
6.0
5.0
3.0
3.0
5.0
5.0
5.0
System
Inlet Pressure
psi
42
38
48
60
58
36
38
40
44
38
44
52
40
38
56
38
38
34
36
58
36
40
38
46
50
52
44
36
48
Outlet
Pressure
psi
30
26
36
50
48
24
26
28
32
26
32
40
26
26
46
26
26
24
24
46
24
28
24
42
42
42
32
24
36
Pressure
Differential
psi
12
12
12
10
10
12
12
12
12
12
12
12
14
12
10
12
12
10
12
12
12
12
14
4
8
10
12
12
12
Cumulative
Volume
Treated
gal
1,373,378
1,392,531
1,425,626
1,452,357
1,478,156
1,520,518
1,546,849
1,580,961
1,608,990
1,634,668
1,691,052
1,697,650
1,703,806
1,723,910
1,747,143
1,785,904
1,805,056
1,831,533
1,846,451
1,862,931
1,896,568
1,924,319
1,938,018
1,956,588
1,970,124
1,980,128
2,006,646
2,039,397
2,066,906
Cumulative
Bed Volumes
Treated ''"
BV
8,374
8,491
8,693
8,856
9,013
9,271
9,432
9,640
9,811
9,967
10,311
10,352
10,389
10,512
10,653
10,890
11,006
1 1 , 1 68
11,259
11,359
11,564
11,734
11,817
11,930
12,013
12,074
12,236
12,435
12,603
pH
6.95
7.42
NA|e)
NA|el
NA'"
NA'"
NA|el
NA|el
NA|e)
NA'"
NA'e)
NA|el
NA|e)
NA|el
NA""
NA1"
NA'"
NA'"
NA'"
NA'"
7.01
NA|e)
NA|el
NA'"
6.78
7.01
6.89
6.85
6.86
>
1 ' Bed volume = 22 cu.ft. or 164 gallons (equivalent to the volume of media in one vessel)
(t>1 Bed volumes calculated based on Vessel B usage
(cl Totalizer for Vessel A re-set on 01/12/06 and 05/23/06.
(dl Totalizer for Vessel B re-set on 01/12/06 and 05/26/06.
(e| In-line pH probe not operational.
NA = not available
Highlighted cells indicate calculated values.
-------
APPENDIX B
ANALYTICAL DATA
-------
Table B-l. Analytical Results from Treatment Plant Sampling at Bruni, TX
Sampling Date
Sampling Location
Parameter Unit
Bed Volume
Alkalinity (CaCO3)
Fluoride
Sulfate
Nitrate (as N)
Total P (as PO4)
Silica (asSiO2)
Turbidity
pH
Temperature
DO
ORP
Free Chlorine (as
CI2)
Total Chlorine (as
CI2)
Total Hardness
(as CaCO3)
Ca Hardness (as
CaCO3)
Mg Hardness (as
CaCO3)
As (total)
As (soluble)
As (particulate)
As (III)
As(V)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
10A3
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
NTU
S.U.
°C
mg/L
mV
mg/L
mg/L
mg/L
mg/L
mg/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
12/08/05(a)
IN
-
317
0.5
104
<0.05
0.03
41.8
0.3
8.2
26.6
1.8
325
-
-
17.1
11.3
5.8
51.4
53.1
<0.1
35.8
17.3
<25
<25
4.3
4.2
AP
-
321
0.6
104
<0.05
0.1
41.5
<0.1
7.4
26.7
2.3
679
1.0
1.6
19.3
13.4
5.9
62.2
61.0
1.2
3.3
57.7
<25
<25
4.3
3.4
TA
NA
330
0.5
103
<0.05
<0.03
13.5
<0.1
7.1
24.8
0.9
387
0.1
0.3
27.9
17.2
10.7
3.9
3.4
0.5
2.9
0.6
<25
<25
1.8
1.6
TB
NA
352
0.4
100
<0.05
<0.03
1.7
<0.1
7.3
24.7
1.3
371
-
-
47.2
29.4
17.9
4.0
2.2
1.8
1.6
0.5
<25
<25
5.0
5.1
12/13/05(b)
IN
-
326
-
-
-
<0.03
43.3
<0.1
8.2
24.1
1.5
379
-
-
-
-
-
55.7
-
-
-
-
<25
-
3.7
-
AP
-
330
-
-
-
<0.03
43.5
0.1
7.2
24.0
1.5
592
0.6
-
-
-
-
55.8
-
-
-
-
<25
-
3.4
-
TA
0.2
330
-
-
-
<0.03
25.7
0.2
7.2
24.0
1.8
499
-
-
-
-
-
3.6
-
-
-
-
<25
-
1.1
-
TB
0.2
321
-
-
-
<0.03
6.4
0.2
7.2
23.0
2.0
425
-
-
-
-
-
3.5
-
-
-
-
<25
-
1.1
-
01/05/06
IN
-
334
0.5
104
<0.05
<0.03
41.7
0.2
8.1
23.5
2.1
234
-
-
19.4
12.0
7.4
51.5
56.5
<0.1
40.4
16.1
<25
<25
3.9
3.7
AP
-
334
0.6
104
<0.05
<0.03
42.3
0.4
8.1
23.5
2.2
533
2.0
2.1
19.1
11.9
7.2
60.1
51.3
8.7
1.5
49.8
<25
<25
3.3
3.3
TA
0.6
312
0.6
112
<0.05
<0.03
34.2
0.2
7.4
23.2
2.1
671
-
-
11.6
7.6
4.0
1.8
1.3
0.4
1.2
0.2
<25
<25
<0.1
<0.1
TB
0.6
312
0.7
114
<0.05
<0.03
31.8
0.2
7.3
23.1
2.0
686
1.5
2.1
15.8
9.9
5.9
1.5
1.3
0.2
1.2
<0.1
<25
<25
<0.1
0.2
01/17/06
IN
-
334
-
-
-
<0.03
43.8
1.1
8.0
25.7
2.4
257
-
-
-
-
-
58.8
-
-
-
-
28.8
-
4.5
-
AP
-
330
-
-
-
<0.03
42.8
0.4
8.0
25.9
1.6
538
1.5
1.8
-
-
-
60.4
-
-
-
-
<25
-
4.4
-
TA
1.2
321
-
-
-
<0.03
39.9
0.6
7.1
25.1
1.5
690
-
-
-
-
-
4.6
-
-
-
-
<25
-
0.5
-
TB
1.2
312
-
-
-
<0.03
39.6
0.3
7.1
24.2
1.4
700
1.7
1.7
-
-
-
6.3
-
-
-
-
<25
-
0.2
-
02/01/06
IN
-
320
0.5
105
<0.05
<0.03
41.7
0.7
8.1
26.7
1.3
239
-
-
23.7
17.0
6.7
61.4
54.3
7.1
40.8
13.5
<25
<25
3.2
3.6
AP
-
320
0.6
104
<0.05
<0.03
42.6
0.3
7.1
26.5
1.4
465
1.6
1.5
22.2
16.9
5.3
56.2
50.8
5.4
3.1
47.7
<25
<25
3.4
3.5
TA
2.0
342
0.5
98
<0.05
<0.03
41.6
0.2
7.3
26.2
1.5
605
-
-
33.0
25.1
7.9
3.4
3.0
0.4
2.9
0.1
<25
<25
<0.1
<0.1
TB
2.0
325
0.6
103
<0.05
<0.03
38.9
0.3
7.4
26.2
1.3
680
1.7
1.7
17.1
13.8
3.3
2.8
2.9
<0.1
2.4
0.5
<25
<25
<0.1
<0.1
(a) Chlorine measurements taken on 12/09/05.
(b) Water quality measurements taken on 12/15/05.
IN = at wellhead; AP = after pH adjustment; TA = after Tank A; TB = after Tank B.
NA = not available.
-------
Table B-l. Analytical Results from Treatment Plant Sampling at Bruni, TX (Continued)
Sampling Date
Sampling Location
Parameter Unit
Bed Volume
Alkalinity
(CaCO3)
Fluoride
Sulfate
Nitrate (as N)
Total P (as PO4)
Silica (asSiO2)
Turbidity
pH
Temperature
DO
ORP
Free Chlorine
(as CI2)
Total Chlorine
(as CI2)
Total Hardness
(as CaCO3)
Ca Hardness (as
CaCO3)
Mg Hardness (as
CaCO3)
As (total)
As (soluble)
As (particulate)
As (III)
As(V)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
10A3
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
NTU
S.U.
°C
mg/L
mV
mg/L
mg/L
mg/L
mg/L
mg/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
02/15/06
IN
-
324
-
-
-
<0.03
41.5
1.0
8.1
26.7
1.1
258
-
-
-
-
-
61.2
-
-
-
-
<25
-
3.2
-
AP
-
324
-
-
-
<0.03
42.3
1.5
7.2
26.9
1.6
546
0.6
0.7
-
-
-
64.4
-
-
-
-
<25
-
3.1
-
TA
2.8
316
-
-
-
<0.03
43.3
1.1
7.3
27.0
1.5
631
-
-
-
-
-
4.2
-
-
-
-
<25
-
0.6
-
TB
2.8
328
-
-
-
<0.03
40.2
2.0
7.2
27.1
2.1
663
0.9
1.0
-
-
-
3.9
-
-
-
-
<25
-
0.3
-
02/28/06(a)
IN
-
322
314
-
-
-
<0.03
<0.03
40.6
40.7
0.4
0.4
NA
NA
NA
NA
-
-
-
-
-
61.8
57.6
-
-
-
-
<25
<25
-
5.1
5.4
-
AP
-
314
318
-
-
-
<0.03
<0.03
41.6
41.0
0.2
0.2
NA
NA
NA
NA
NA
NA
-
-
-
61.9
57.4
-
-
-
-
<25
<25
-
3.2
4.6
-
TA
3.3
322
310
-
-
-
<0.03
<0.03
41.8
41.5
0.2
0.3
NA
NA
NA
NA
-
-
-
-
-
2.7
2.6
-
-
-
-
<25
<25
-
<0.1
<0.1
-
TB
3.3
335
327
-
-
-
<0.03
<0.03
41.3
41.2
0.2
0.2
NA
NA
NA
NA
NA
NA
-
-
-
2.2
2.4
-
-
-
-
<25
<25
-
<0.1
<0.1
-
03/14/06
IN
-
314
0.7
107
<0.05
<0.01
41.5
0.6
8.2
26.3
1.6
238
-
-
20.1
13.3
6.8
60.3
51.9
8.3
38.7
13.2
<25
<25
4.1
4.1
AP
-
310
0.8
107
<0.05
<0.01
40.6
0.4
7.3
26.7
1.7
569
0.8
1.1
21.2
13.9
7.3
62.3
53.5
8.9
1.9
51.6
<25
<25
3.2
3.1
TA
3.6
322
0.8
106
<0.05
<0.01
41.1
0.3
7.3
26.5
1.3
657
-
-
22.2
14.3
8.0
2.2
1.5
0.7
1.3
0.2
<25
<25
0.3
0.3
TB
3.6
327
0.8
106
<0.05
<0.01
38.7
0.7
7.3
26.6
2.3
662
1.0
1.2
24.2
15.6
8.5
1.7
1.5
0.2
1.3
0.2
<25
<25
0.2
0.2
03/28/06(b)
IN
-
325
-
-
-
;
41.7
0.9
8.2
26.5
1.5
259
-
-
-
-
-
46.2
-
-
-
-
<25
-
4.9
-
AP
-
321
-
-
-
-
42.1
0.9
7.5
27.2
1.8
309
0.5
1.2
-
-
-
50.2
-
-
-
-
<25
-
3.7
-
TA
4.7
325
-
-
-
;
42.6
0.9
7.6
27.4
1.8
532
-
-
-
-
-
1.4
-
-
-
-
<25
-
0.3
-
TB
4.7
325
-
-
-
;
42.1
0.8
7.5
27.4
1.9
587
0.9
1.0
-
-
-
1.1
-
-
-
-
<25
-
0.1
-
04/11/06(c)
IN
-
311
0.7
106
<0.05
<0.01
40.9
0.7
NA
NA
NA
NA
-
-
30.1
22.7
7.4
55.4
51.5
3.8
36.5
15.0
<25
<25
3.5
3.6
AP
-
307
0.8
106
<0.05
<0.01
40.2
0.5
NA
NA
NA
NA
NA
NA
30.0
22.8
7.2
57.2
51.6
5.6
0.5
51.1
<25
<25
3.5
3.4
TA
6.0
315
0.8
107
<0.05
<0.01
40.5
0.5
NA
NA
NA
NA
-
-
27.9
21.3
6.6
1.0
0.8
0.2
0.5
0.3
<25
<25
<0.1
<0.1
TB
6.0
315
0.8
108
<0.05
<0.01
42.7
0.6
NA
NA
NA
NA
NA
NA
29.6
22.6
6.9
0.6
0.6
<0.1
0.4
0.2
<25
<25
<0.1
<0.1
(a) Water quality parameters not measured.
(b) Water quality measurements taken on 04/05/06.
IN = at wellhead; AP = after pH adjustment; TA = after Tank A; TB = after Tank B.
NA = not available.
-------
Table B-l. Analytical Results from Treatment Plant Sampling at Bruni, TX (Continued)
Sampling Date
Sampling Location
Parameter Unit
Bed Volume
Alkalinity (CaCO3)
Fluoride
Sulfate
Nitrate (as N)
Total P (as PO4)
Silica (as SiO2)
Turbidity
pH
Temperature
DO
ORP
Free Chlorine (as CI2)
Total Chlorine (as CI2)
Total Hardness (as
CaCO3)
Ca Hardness (as
CaCO3)
Mg Hardness (as
CaCO3)
As (total)
As (soluble)
As (particulate)
As (III)
As(V)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
10A3
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
NTU
S.U.
°C
mg/L
mV
mg/L
mg/L
mg/L
mg/L
mg/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
04/25/06(a)
IN
-
331
-
-
-
<0.01
40.8
0.2
8.2
26.5
1.3
327
-
-
-
-
-
56.5
-
-
-
-
<25
-
3.1
-
AP
-
344
-
-
-
<0.01
40.8
0.2
7.4
26.3
1.6
603
0.8
1.1
-
-
-
59.5
-
-
-
-
<25
-
2.9
-
TA
7.7
331
-
-
-
<0.01
41.3
0.7
7.3
26.7
1.6
650
-
-
-
-
-
1.1
-
-
-
-
<25
-
<0.1
-
TB
7.7
344
-
-
-
<0.01
41.2
0.1
7.4
26.6
2.0
623
0.7
0.8
-
-
-
0.9
-
-
-
-
<25
-
<0.1
-
05/09/06(b)
IN
-
310
0.9
111
<0.05
<0.03
41.8
0.2
8.1
27.1
1.3
279
-
-
28.6
19.7
9.0
62.9
54.3
8.6
40.2
14.1
<25
<25
3.3
3.3
AP
-
306
1.2
112
<0.05
<0.03
42.3
0.2
7.2
27.2
1.8
499
1.1
1.2
29.3
20.2
9.1
63.8
55.4
8.4
0.7
54.6
<25
<25
3.1
3.1
TA
9.5
294
1.5
113
<0.05
<0.01
42.7
0.2
7.3
27.5
2.1
610
-
-
26.8
18.3
8.5
1.0
0.8
0.2
0.5
0.3
<25
<25
<0.1
<0.1
TB
9.5
314
1.0
113
<0.05
<0.01
42.1
0.3
7.3
27.3
2.4
643
1.5
1.5
29.8
21.1
8.8
0.6
0.6
<0.1
0.5
0.1
<25
<25
<0.1
<0.1
05/23/06(c)
IN
-
313
-
-
-
<0.01
42.8
0.3
8.3
21.3
3.1
271
-
-
-
-
-
54.8
-
-
-
-
28.4
-
3.9
-
AP
-
326
-
-
-
<0.01
41.6
0.5
7.6
21.2
4.1
546
0.5
0.8
-
-
-
50.4
-
-
-
-
<25
-
2.9
-
TA
11.0
338
-
-
-
<0.01
41.7
0.3
7.5
21.4
3.4
597
-
-
-
-
-
1.3
-
-
-
-
<25
-
<0.1
-
TB
11.0
318
-
-
-
<0.01
38.1
0.2
7.5
21.4
3.5
636
0.6
0.7
-
-
-
0.6
-
-
-
-
<25
-
<0.1
-
06/06/06(d)
IN
-
305
0.7
107
<0.05
<0.01
43.9
0.6
8.2
26.4
2.1
299
-
-
20.2
12.4
7.8
58.5
52.3
6.2
37.0
15.3
<25
<25
2.6
2.6
AP
-
318
0.8
112
<0.05
<0.01
43.2
0.5
7.3
26.6
2.6
537
0.9
0.9
19.8
12.2
7.6
57.6
51.6
6.1
0.8
50.8
<25
<25
3.0
3.0
TA
12.1
313
0.8
114
<0.05
<0.01
44.4
0.7
7.2
27.1
2.1
594
-
-
21.0
13.0
8.0
1.1
1.1
<0.1
0.7
0.5
<25
<25
<0.1
<0.1
TB
12.1
318
0.8
136
<0.05
<0.01
45.3
0.8
7.3
27.1
2.2
620
0.7
0.8
20.5
12.7
7.8
0.8
0.8
<0.1
0.6
0.2
<25
<25
0.1
<0.1
(a) Water quality measurements taken on 04/20/06.
(b) Water quality measurements taken on 05/04/06.
(c) Water quality measurements taken on 05/12/05.
(d) Water quality measurements taken on 06/01/06.
IN = at wellhead; AP = after pH adjustment; TA = after Tank A; TB = after Tank B.
NA = not available.
------- |