EPA/600/R-11/027
March 2011
Arsenic Removal from Drinking Water by Adsorptive Media
U.S. EPA Demonstration Project at
Covered Wells in Tohono O'odham Nation, AZ
Final Performance Evaluation Report
by
Ryan J. Stowe*
Abraham S.C. Chen"
Lili Wang"
'Battelle, Columbus, OH 43201-2693
*ALSA Tech, LLC, Columbus, OH 43219-0693
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 arsenic removal
treatment technology demonstration project at Covered Wells in Tohono O'odham Nation, AZ. The main
objective of the project was to evaluate the effectiveness of AdEdge Technologies' (AdEdge) AD-33
media in removing arsenic to meet the new arsenic maximum contaminant level (MCL) of 10 |o,g/L.
Additionally, this project evaluated 1) the reliability of the treatment system (Arsenic Package Unit
[APU]), 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 characterized the water in the distribution system and
residuals produced by the treatment process. The types of 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.
The treatment system consisted of two 36-in x 72-in composite vessels in parallel configuration, each
containing approximately 19 ft3 of AD-33 pelletized media. AD-33 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 flowrate of 63 gal/min (gpm) (31.5 gpm per vessel) and an empty bed contact time (EBCT)
of 4.5 min. Over the performance evaluation period, the actual average flowrate was 29.5 gpm for Vessel
A and 30.6 gpm for Vessel B, based on readings from the flow meter/totalizer installed on each
adsorption vessel. The average EBCT was 4.8 min for Vessel A and 4.7 min for Vessel B.
Each of the two wells had its own chlorination system that consisted of a storage tank, a chemical feed
pump, and an injector. The chemical feed pumps were tied to the well pumps, which operated on an
alternating basis, and would start injecting sodium hypochlorite (NaOCl) solutions only when the well
pumps turned on. The pre-existing chlorine addition systems were configured for prechlorination and
could not be feasibly converted to post-chlorination as called for in the design since the predominate
arsenic species was As(V) (>90%) and oxidation of As(III) (average concentration of 0.5 (ig/L) was not
needed. The prechlorination system was used to maintain a target free chlorine residual of 1.0 mg/L (as
C12) or less in the distribution system for disinfection.
As part of the water treatment system, a Destin North Bay carbon dioxide (CO2) pH adjustment/control
system was used to adjust pH values of raw water from as high as 8.4 to a target value of 7.0. Due to
several operational issues, the Destin North Bay system was replaced with an AdEdge CO2 pH
adjustment/control system approximately five months into the study. The AdEdge system consisted of a
control panel/cabinet and a "Venturi style" injector. The control panel/cabinet contained components
such as an "Inlet" solenoid valve, a non-venting single stage pressure regulator, a manual loop controlled
by a needle valve, an automatic loop controlled by a Burkert pH controller and solid-state SensorX in-line
pH probe, a rotameter, an "Outlet" solenoid valve, and a check valve. CO2 was injected downstream of
the chlorination injection point.
The treatment system began regular operation on February 13, 2008. From February 13, 2008, through
the end of the performance evaluation study on March 19, 2010, the treatment system operated for a total
of 3,353 hr, treating approximately 11,686,000 gal (or 41,148 bed volume [BV]) of water. The average
daily operation time was 4.38 hr/day and the average daily demand was 15,276 gal/day (gpd).
Total arsenic concentrations in raw water ranged from 29.0 to 38.6 ug/L and averaged 34.9 ug/L. Soluble
As(V) was the predominating species, ranging from 33.3 to 36.4 ug/L and averaging 32.4 ug/L, based on
the results from six speciation sampling events. At the end of the performance evaluation study on March
19, 2010, total arsenic levels in the treated water were 0.6 and 0.4 ug/L following Vessels A and B,
respectively. (Note that treatment plant water sampling continued on June 15, September 29, and
IV
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November 3, 2010, with arsenic concentrations increasing from 1.2 to 4.2 and then to 3.3 (ig/L following
Vessels A and from 0.7 to 3.2 and then 3.0 (ig/L following Vessel B. By November 3, 2010, the
treatment system had treated approximately 60,000 BV of water.) Concentrations of silica and
phosphorus, which could interfere with arsenic adsorption by competing for adsorption sites, averaged
26.2 mg/L (as SiO2) and were less than the method detection limit (MDL) of 10.0 (ig/L (as P),
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 36.5 to an average of 0.9 (ig/L). Arsenic
concentrations in the distribution system were somewhat higher than those in the system effluent,
probably caused by redissolution and resuspension of arsenic particles. Lead and copper concentrations
appeared to have elevated somewhat after operation of the system; however, the elevated levels were
significantly under their respective action levels.
The capital investment cost of $115,306 included $86,018 for equipment, $12,897 for site engineering,
and $16,391 for installation. Using the system's rated capacity of 63 gpm (or 90,720 gpd), the capital
cost was $l,832/gpm (or $1.27/gpd) of design capacity. The capital cost also was converted to an
annualized cost of $10,884/yr using a capital recovery factor (CRF) of 0.09439 based on a 7% interest
rate and a 20-year return period. At a 100% use rate, the unit capital cost would be $0.33/1,000 gal. At
the actual use rate, the unit capital cost increased to $1.89/1,000 gal.
The O&M cost included only the cost associated with the media replacement and disposal, CO2 and
chlorine usage, electricity consumption, and labor. Although media replacement did not occur during the
performance evaluation study, the media replacement cost would have represented the majority of the
O&M cost. Media replacement and O&M cost per 1,000 gal of water treated was estimated and plotted
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 6
3.1 General Project Approach 6
3.2 System O&M and Cost Data Collection 7
3.3 Sample Collection Procedures and Schedules 7
3.3.1 Source Water 9
3.3.2 Treatment Plant Water 9
3.3.3 Backwash Wastewater/Solids and Spent Media 9
3.3.4 Distribution System Water 9
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 10
3.5 Analytical Procedures 10
4.0 RESULTS AND DISCUSSION 12
4.1 Facility Description and Pre-existing Treatment System Infrastructure 12
4.1.1 Source Water Quality 13
4.1.2 Distribution System 15
4.2 Treatment Process Description 15
4.3 System Installation 26
4.3.1 Permitting 26
4.3.2 Building Preparation 26
4.3.3 Installation, Shakedown, and Startup 26
4.4 System Operation 27
4.4.1 Operational Parameters 27
4.4.2 Residual Management 29
4.4.3 CO2pH Adjustment System 29
4.4.4 System/Operation Reliability and Simplicity 31
4.5 System Performance 33
4.5.1 Treatment Plant Sampling 33
4.5.2 Backwash Wastewater Sampling 41
4.5.3 Distribution System Water Sampling 41
4.6 System Cost 44
VI
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4.6.1 Capital Cost 44
4.6.2 Operation and Maintenance Cost 45
5.0 REFERENCES 47
APPENDICES
Appendix A: OPERATIONAL DATA
Appendix B: ANALYTICAL DATA
FIGURES
Figure 4-1. Fenced-In Area Around Well No. 1 and Pressure Reducing Valve Vault 12
Figure 4-2. Future Location of Arsenic Treatment System 13
Figure 4-3. Process Flow Diagram for APU System at TOUA 17
Figure 4-4. Process Flow Diagram with Sampling Schedules and Locations 18
Figure 4-5. Chlorine Addition System at TOUA 20
Figure 4-6. Overview of Destin North Bay CO2 pH Adjustment System 21
Figure 4-7. Destin North Bay CO2 Gas Flow Control System for pH Adjustment 22
Figure 4-8. Process and Instrument Diagram of AdEdge CO2 pH Adj ustment System 23
Figure 4-9. AdEdge CO2 pH Adjustment System Control Panel 24
Figure 4-10. AdEdge APU Arsenic Adsorption System 25
Figure 4-11. New Treatment Building with 15,000 gal Storage Tank (left) 27
Figure 4-12. System Instantaneous and Calculated Flowrates 29
Figure 4-13. System Pressure Readings 30
Figure 4-14. Differential Pressures Across Vessels A and B 30
Figure 4-15. Concentrations of Various Arsenic Species at IN, AP, TA, and TB Sampling
Locations 37
Figure 4-16. Total Arsenic Breakthrough Curves 39
Figure 4-17. pH Values Before and After Adjustment 41
Figure 4-18. Comparison of Arsenic Concentrations in System Effluent and Distribution System 43
Figure 4-19. Media Replacement and Other Operation and Maintenance Cost 46
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 6
Table 3-2. Evaluation Objectives and Supporting Data Collection Activities 7
Table 3-3. Sampling Schedules and Analytes 8
Table 4-1. Water Quality Data for Tohono O'odham Nation, AZ 14
Table 4-2. Physical and Chemical Properties of AD-33 Media(a) 15
Table 4-3. Design Specifications of AdEdge APU System 19
Table 4-4. System Punch-List/Operational Issues 27
Table 4-5. Summary of APU System Operation 28
Table 4-6. Summary of Analytical Results for Arsenic, Iron, Manganese, Uranium, and
Vanadium 33
Table 4-7. Summary of Water Quality Parameter Sampling Results 35
vn
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Table 4-8. Distribution System Sampling Results 42
Table 4-9. Capital Investment Cost for APU Arsenic Adsorption System 44
Table 4-10. Operation and Maintenance Cost for APU Arsenic Adsorption System 45
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
BET Brunauer, Emmett, and Teller
bgs below ground surface
BV bed volume
Ca calcium
C/F coagulation/filtration process
Cl chlorine
CO2 carbon dioxide
CRF capital recovery factor
Cu copper
CWRWS Covered Wells Regional Water System
DO dissolved oxygen
EBCT empty bed contact time
EPA U.S. Environmental Protection Agency
F fluorine
Fe iron
gpd gallons per day
gph gallons per hour
gpm gallons per minute
HOPE high-density polyethylene
HIX hybrid ion exchanger
hp horsepower
ICP-MS inductively coupled plasma-mass spectrometry
ID identification
IHS Indian Health Services
ISFET Ion Sensitive Field Effect Transistor
IX ion exchange
LCR Lead and Copper Rule
Iph liter per hour
MCL maximum contaminant level
MDL method detection limit
MEI Magnesium Elektron, Inc.
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ABBREVIATIONS AND ACRONYMS (Continued)
Mg magnesium
Mn manganese
mV millivolts
Na sodium
NaOCl sodium hypochlorite
NSF NSF International
O&M operation and maintenance
OIT Oregon Institute of Technology
ORD Office of Research and Development
ORP oxidation-reduction potential
P phosphorus
PID Proportional Integral Derivative
PO4 phosphate
POU point of use
psi pounds per square inch
PVC polyvinyl chloride
QAPP Quality Assurance Project Plan
QA/QC quality assurance/quality control
RO reverse osmosis
RPD relative percent difference
scfh standard cubic foot (feet) per hour
SDWA Safe Drinking Water Act
SiO2 silica
SMCL secondary maximum contaminant level
SO42" sulfate
SS stainless steel
STS Severn Trent Services
TCLP toxicity characteristic leaching procedure
TDS total dissolved solids
TOC total organic carbon
TOUA Tohono O'odham Utility Authority
U uranium
V vanadium
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ACKNOWLEDGMENTS
The authors wish to extend their sincere appreciation to the Tohono O'odham Utility Authority (TOUA)
for its support to this demonstration project. Mr. David Saddler, Water Manager, and his staff provided
logistical support before and during the performance evaluation study. Ms. Myrt Mclntyre of TOUA's
Water Quality Control Laboratory monitored the treatment system and collected samples from the
treatment and distribution systems throughout this study period. This performance evaluation study
would not have been possible without their efforts.
XI
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1.0 INTRODUCTION
1.1 Background
The Safe Drinking Water Act (SDWA) mandates that the U.S. Environmental Protection Agency (EPA)
identify and regulate drinking water contaminants that may have adverse human health effects and that
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). 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 required 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 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, onsite demonstrations of arsenic removal
technologies, process modifications, and engineering approaches applicable to small systems. Shortly
thereafter, an announcement published in the Federal Register requested 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 out of 115 sites to host 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 one to six proposals. In April 2003, an independent technical panel
reviewed the proposals and recommended to EPA the technologies they determined to be 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 demonstration project. 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.
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, including the Covered Wells site in the Gu Achi District of the Tohono O'odham Nation in Arizona.
The Covered Wells site is operated by the Tohono O'odham Utility Authority (TOUA), which is charged
by the Nation to provide services, including water/wastewater, electric, telephone, cellular, propane, and
internet to customers in the Nation.
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, EPA convened another technical panel to review
the proposals and provide recommendations to EPA; the number of proposals per site ranged from none
(for two sites) to four. At the site receiving at least one proposal, the final selection of the treatment
technology was made 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) AD33 Arsenic Removal Technology was selected for demonstration at the
TOUA site in April 2004.
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As of July 2010, 39 of the 40 systems were operational, and the performance evaluation of all 39 systems
was completed.
1.2 Treatment Technologies for Arsenic Removal
The technologies selected for the Rounds 1 and 2 demonstration host sites include 25 adsorptive media
(AM) systems (the Oregon Institute of Technology [OIT] site has three AM systems), 13 coagulation/
filtration (C/F) systems, two ion exchange (IX) systems, 17 point-of-use (POU) units (including nine
under-the-sink 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 overall objective of the arsenic demonstration program is to conduct 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 AM system at the Covered Wells site in Tohono
O'odham Nation, AZ, from February 13, 2008 to March 19, 2010. The data collected included system
operation, water quality (both across the treatment train and in the distribution system), and capital and
preliminary O&M cost.
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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
Flow rate
fepm)
Source Water Quality
As
(ug/L)
Fe
(ug/L)
PH
(S.U.)
Northeast/Ohio
Wales, ME
Bow,NH
Goffstown, NH
Rollinsford, NH
Dummerston, VT
Felton, DE
Stevensville, MD
Houghton, NY(d)
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
70(b)
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
l,806(c)
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
340W
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
l,470(c)
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
Amaudville, 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
56W
45
23W
33
14
50
32
41
2,068(c)
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
Flow rate
fepm)
Source Water Quality
As
(ug/L)
Fe
(ug/L)
PH
(S.U.)
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)(g)
IX(ArsenexII)
AM (GFH/Kemiron)
AM (A/I Complex)
AM(HIX)
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; HTX = hybrid ion exchange; 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) Withdrew from program in 2007. Selected originally to replace Village of Lyman, NE site, which withdrew from program in June 2006.
(e) Facilities upgraded systems in Springfield, OH from 150 to 250 gal/min (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 treatment system with AD-33 pelletized media was installed and has operated at the
Covered Wells site in Tohono O'odham Nation, AZ since February 13, 2008. Based on the information
collected during the system evaluation period, the following summary and conclusion statements are
provided.
Performance of the arsenic removal technology for use on small systems:
• AD-33 media effectively lowered arsenic concentrations to 0.6 and 0.4 (ig/L following
Vessels A and B, respectively, after treating 11,686,000 gal (or 41,148 bed volumes [BV]) of
water, based on a total media volume of 3 8 ft3 (19 ft3 per vessel).
• The operation of the treatment system significantly lowered arsenic concentrations from 36.5
to 0.9 (ig/L (on average) in the distribution system. Although lead and copper levels in the
distribution system were slightly elevated after the system was put into service, the
concentrations were significantly below their respective action levels.
Required system O&Mand operator skill levels:
• The operator typically spent over an hour to visually inspect the system, record operational
parameters, and change out carbon dioxide (CO2) cylinders. Additional time and effort were
required to troubleshoot the problems associated with the CO2 system.
• Some operational issues were encountered during operation of the Destin North Bay
and AdEdge CO2 pH adjustment systems. Primary issues involved a leaking
manifold, a malfunctioning pneumatic flow control valve, a faulty pH meter display,
a faulty solenoid, and a faulty check valve.
• 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.
Process residuals produced by the technology:
• The pressure differential (Ap) measured across the media vessels remained low during
system operation. Therefore, no backwash was required or performed throughout the
performance evaluation study.
Cost-effectiveness of the technology:
• Based on the system's rated capacity of 63 gpm (or 90,720 gal/day [gpd]), the capital cost
was $l,830/gpm (or $1.27/gpd) of design capacity.
• Media replacement and disposal did not occur during the performance evaluation
study; however, the cost to change out both vessels (38 ft3 AD-33 media) was
estimated to be $18,405, which included 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 arsenic removal system began on February 13, 2008, and ended on March 19, 2010 (note
that treatment samples continued to be collected and analyzed on a quarterly basis after the study had
been ended). 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 (ig/L through the collection of water samples
across the treatment plant, as described in the Study Plan (Battelle, 2006). The reliability of the system
was evaluated by tracking the unscheduled system downtime and the frequency and extent of repair and
replacement. Unscheduled downtime and repair information was 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
Letter Report Issued
Final Study Plan Issued
Building Construction Completed
Treatment System Shipped and Arrived
System Installation Completed
System Shakedown Completed
Performance Evaluation Begun
Date
December 7, 2004
February 18, 2005
February 25, 2005
March 11, 2005
March 11, 2005
September 7, 2005
October 5, 2005
February 16, 2006
May 5, 2006
March 2007
March 2007
January 7, 2008
January 7, 2008
February 13, 2008
O&M and operator skill requirements were assessed through quantitative data and qualitative
considerations, including needs 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.
Staffing requirements for the system operation were recorded on an Operator Labor Hour Log Sheet.
The cost of the system was evaluated based on the capital cost per gpm (or gpd) of design capacity and
the O&M cost per 1,000 gal of water treated. This task requires tracking 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 O&M cost were limited to CO2
consumption, electricity usage, and labor because media replacement did not take place during the
performance evaluation study.
-------
Table 3-2. Evaluation Objectives and Supporting Data Collection Activities
Evaluation Objectives
Performance
Reliability
System O&M and
Operator Skill
Requirements
Residual Management
System Cost
Data Collection
-Ability to consistently meet 10 ug/L of arsenic MCL in treated water
-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 preventative maintenance including number, frequency, and
complexity of tasks
-Chemical handling and inventory requirements
-General knowledge needed of relevant chemical processes and health and
safety practices
-Quantity and characteristics of aqueous and solid residuals generated by
system process
-Capital cost for equipment, engineering, and installation
-O&M cost for media replacement, electricity usage, 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 regular 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 would contact the Battelle Study Lead, who determined if the vendor
should be contacted for troubleshooting. The plant operator recorded all relevant information, including
problem encountered, course of action taken, materials and supplies used, and cost and labor incurred on
the Repair and Maintenance Log Sheet. Every other week, while collecting samples, the plant operator
measured pH, temperature, dissolved oxygen (DO), and oxidation-reduction potential (ORP), and
recorded the data on an Onsite Water Quality Parameters Log Sheet. Approximately three months after
the start of the study, DO and ORP measurements were discontinued due to difficulties with the
equipment encountered by the operator.
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 consumption was tracked by the number of CO2 cylinder change-outs. Electricity
consumption was tracked through an onsite electric meter. Labor for various activities, such as routine
system O&M, system troubleshooting and repair, and demonstration-related work, were tracked using an
Operator Labor Hour Log Sheet. The routine O&M included activities such as completing field logs,
replacing empty CO2 cylinders, 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 wellheads, 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
-------
Table 3-3. Sampling Schedules and Analytes
Sample
Type
Source
Water
Treatment
Plant Water
(Speciation)
Treatment
Plant Water
(Regular)
Distribution
System
Water
Sampling
Locations'3'
Well No. 1 and
Well No. 2
IN, AP, and TT
IN, AP, TA, and
TB
Three LCR
residences within
distribution
system
No. of
Samples
2
3
4
3
Frequency
Once during
initial site
visit
Before
05/28/08:
once every 8
weeks;
After
05/28/08:
once every 3
to 4 months
Before
05/28/08:
3 times in
one 8-week
cycle;
After
05/28/08:
monthly
Monthly(g'h)
Analytes
Onsite: 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
Onsite: pH, temperature,
DO(b), ORP03', and total
and free C12(C)
Off site:
As (total and soluble),
As(III), As(V),
Fe (total and soluble),
Mn (total and soluble),
U (total)(dx V (total)(e),
Ca, Mg, F, NO3, SO4,
SiO2, P, turbidity, and
alkalinity
Onsite: pH, temperature,
D0(b), ORP0^, and total
and free C12(C)
As (total), Fe (total)®,
Mn (total)®, U (total)(d®,
V (total)(e), Si02®, P®,
turbidity®, and
alkalinity®
pH, alkalinity, As (total),
Fe (total), Mn (total), Pb,
and Cu
Sampling
Date
12/07/04
04/01/08, 05/28/08,
10/07/08, 03/17/09,
07/14/09, 11/17/09
02/13/08, 04/15/08,
04/29/08, 05/12/08,
07/08/08, 07/30/08,
09/02/08, 11/18/08,
12/16/08, 01/20/09,
02/17/09, 04/15/09,
05/20/09, 06/16/09,
08/18/09, 09/15/09,
10/20/09, 12/15/09,
01/19/10, 02/16/10,
03/16/10
Baseline and
monthly sampling:
see Table 4-8
(a) Abbreviations in parentheses corresponding to sample locations shown in Figure 4-4.
(b) Measurement discontinued after 05/28/08.
(c) Except IN location.
(d) Measurement discontinued after 09/02/08.
(e) Measurement added on 09/02/08.
(f) Measurements discontinued after 1 1/17/09.
(g) Four baseline sampling events performed from October 2005 to January 2006 before system startup.
(h) Sampling frequency reduced to quarterly after system startup in February 2008.
DO = dissolved oxygen; LCR = Lead and Copper Rule; NA = not applicable; ORP = oxidation-reduction
potential; TDS = total dissolved solids; TOC = total organic carbon
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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).
3.3.1 Source Water. During the initial site visit on December 7, 2004, one set of source water
samples was collected from each of the two supply wells (i.e., Wells No. 1 and No. 2) and speciated using
an arsenic speciation kit (see Section 3.4.1). Sample taps were 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. During the performance evaluation study, the plant operator
collected water samples across the treatment train for onsite and offsite analyses. Battelle's Study Plan
(Battelle, 2006) called for biweekly sampling at the wellhead (IN), after chlorination and pH adjustment
(AP), after Vessels A and B (TA/TB), and/or after effluent from Vessels A and B combined (TT).
Speciation was performed once every 8 weeks, with samples taken at IN, AP, and TT and analyzed for
the analytes listed under "speciation" in Table 3-3. The other three sampling events collected samples at
IN, AP, TA, and TB and analyzed for analytes listed under "regular" in Table 3-3. This sampling
schedule was followed only briefly from April 1 through May 28, 2008. Since then, treatement plant
water samples were collected monthly for a total of 21 times, including four speciation events collected
once every 3 to 4 months.
Over the course of the performance evaluation study, the sampling schedule was changed several times as
presented below:
• After May 28, 2008, onsite measurements were modified to include only pH, temperature,
and total and free chlorine; DO and ORP measurement were discontinued.
• On September 2, 2008, uranium (total) was deleted from the list of analytes due to low levels
present in raw water. Meanwhile, vanadium (total) was added to the list of analytes.
• After the November 17, 2009, sampling event, speciation sampling was discontinued and
regular, non-speciation sampling was modified to include only arsenic (total), vanadium
(total), and the aforementioned water quality measurements.
3.3.3 Backwash Wastewater/Solids and Spent Media. Because the system did not require
backwashing during the performance evaluation study, no backwash residuals were produced. Further,
because media replacement did not take place, media samples were not collected.
3.3.4 Distribution System Water. Samples were collected from the distribution system 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 October 2005 to January 2006, prior to the startup
of the treatment system, four monthly baseline distribution sampling events were conducted at three
residences located within the distribution system. Following the startup of the arsenic adsorption system,
distribution system sampling continued on a quarterly basis at the same three residences until October 20,
2009, when it was discontinued.
The three residences selected were included in the Lead and Copper Rule (LCR) sampling in the past.
The baseline and quarterly 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 the 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 quarterly 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 in accordance with 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
code for a specific sampling location, and a one-letter code for 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, blue, and green were used to designate sampling locations for IN, AP, TA,
TB, and TT, respectively. The prelabeled bottles for each sampling location were placed in separate zip-
lock 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 UPS air bills, and bubble wrap, were included. Except for
the operator's signature, the chain-of-custody forms and prepaid UPS 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 Belmont Labs in
Englewood, 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 Belmont Labs. Laboratory quality assuarnce/quality
10
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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 120%, and completeness of
80%). The 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 Pre-existing Treatment System Infrastructure
The Tohono O'odham Nation's Covered Wells Regional Water System (CWRWS) serves the
communities of Lower Covered Wells and Upper Covered Wells (Covered Wells), located approximately
20 miles northwest of Sells, Arizona in the Gu Achi District of the Tohono O'odham Reservation. The
CWRWS has a total 64 of connections, serving a population of 310. The facility operates approximately
10 hr/day with an estimated daily demand of 36,000 gpd. The water system is supplied by two 8-in
diameter wells (Wells No. 1 and No. 2), which operate on an alternating basis at approximately 60 gpm.
Wells No. 1 and No. 2 are installed to a depth of 755 ft below ground surface (bgs) and screened from
605 to 745 ft bgs. The static water level is approximately 610 ft bgs. The pump is set at 692 ft bgs in
each well. Figures 4-1 and 4-2 are photographs of the fenced-in area surrounding Wells No. 1 and No. 2,
respectively.
The existing water facility was comprised of the following: two 8-in diameter wells each equipped with a
30-horsepower (hp) submersible pump and a pressure reducing valve in a vault, one 88,000-gal above
groundwater storage tank located approximately 9 miles from the well site, and 45,589 ft of 6-in water
line. Chlorination with a sodium hypochlorite (NaOCl) solution was the only pre-existing treatment,
which was accomplished by injecting the solution at the point of entry using a chemical metering pump
for a target free chlorine residual level of 1 mg/L (as C12) or less. The metering pump was set based on
the system flowrate. The proposed arsenic removal system was placed in between Wells No.l and No.2
(Figure 4-2).
Figure 4-1. Fenced-In Area Around Well No. 1 and Pressure Reducing Valve Vault
12
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Figure 4-2. Future Location of Arsenic Treatment System
(Well No. 2 in a Fenced-in Area in the Background)
4.1.1 Source Water Quality. Source water samples from Wells No. 1 and No. 2 were collected and
speciated on December 7, 2004. The results are presented in Table 4-1 and compared to those taken by
the facility and Indian Health Services (IHS) for the EPA demonstration site selection.
Arsenic. Total arsenic concentrations in source water ranged from 26.0 to 37.0 ug/L. Based on the
December 7, 2004 sampling results, of the 31.8 to 33.1 ug/L of total arsenic, 30.1 to 32.7 ug/L existed as
As(V) and up to 0.7 and 1.2 ug/L existed as particulate arsenic and As(III), respectively. Therefore,
As(V) was the predominating arsenic species in source water.
Iron. Iron concentrations in source water ranged from less than its detection limit of 25 |ag/L to 240 |ag/L.
In general, adsorptive media technologies are best suited to sites with relatively low iron levels (e.g., less
than 300 |ag/L of iron, which is the secondary maximum contaminant level [SMCL] for iron). With
concentrations greater than 300 |ag/L, taste, odor, and color problems can occur in the treated water, along
with an increased potential for fouling of the adsorption system components with iron particulate s.
pH. The source water pH was relatively high, with values ranging from 7.7 to 8.4. The pH of the water
was adjusted to a target value of 7.0 using CO2 prior to adsorptive media to increase its adsorptive
capacity and prolong its run length. CO2 was also less corrosive than mineral acids, such as H2SO4,
13
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Table 4-1. Water Quality Data for Covered Wells Site in Tohono O'odham Nation, AZ
Parameter
Date
Well
pH
Temperature
DO
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 (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)
Mg (total)
Unit
—
—
—
°C
mg/L
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
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
mg/L
mg/L
mg/L
Facility
Data(a)
NA
NA
7.7
NA
NA
150, 140*
27
NA
NA
NA
NA
NA
NA
17,21*
NA
23,23*
24*
0.065*
26, 34*
NA
NA
NA
NA
228*, 29*
NA
4*
NA
NA
NA
NA
NA
76, 72*
11, 10*
2*
fflS
Data(b)
12/08/03
NA
8.4
NA
NA
150
32.0
NA
NA
0.5
NA
NA
NA
6.9
NA
33.0
22.7
ND
37.0
NA
NA
ND
37.0
240
NA
ND
NA
NA
NA
NA
NA
78.9
9.1
2.2
Battelle
Data
12/07/04
Well No. 1
8.2
21.5
4.3
150
39.1
0.2
214
0.7
1.1
0.01
0.05
20.0
0.6
23.0
25.7
0.06
31.8
31.1
0.7
1.0
30.1
<25
<25
0.6
0.3
8.0
8.1
32.2
34.2
77.5
11.7
2.4
Well No. 2
8.2
21.5
4.3
150
39.6
0.5
248
1.0
1.2
0.01
0.05
21.0
0.6
23.0
27.1
0.06
33.1
33.9
0.1
1.2
32.7
<25
<25
1.1
0.5
7.4
7.6
30.7
31.2
75.0
11.4
2.7
(a) Data provided by Facility unless otherwise noted.
(b) After Farley, 2004.
*EPA analytical results
DO = dissolved oxygen; NA = not available; ND = not detected; TDS = total dissolved
solids; TOC = total organic carbon
and when the treated water depressurized after exiting the adsorption vessels, some CO2 may degas,
thereby raising pH values of the treated water and reducing its corrosivity to the distribution piping.
Competing Anions. Arsenic adsorption can be influenced by the presence of competing anions such as
silica and phosphate. Analysis of source water indicated that silica levels ranged from 22.7 to 27.1 mg/L
and that Orthophosphate levels were less than the detection limit (i.e., <0.06 mg/L). The effect of silica on
arsenic adsorption was monitored closely during the demonstration study.
14
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Other Water Quality Parameters. Nitrate levels in source water ranged from 1.1 to 1.2 mg/L (as N),
which were far below the MCL of 10 mg/L (as N). Nitrite levels were below the MDL of 0.01 mg/L (as
N). Chloride, fluoride, sulfate, manganese, and TDS were below their respective SMCLs. TOC levels
were <0.7 mg/L for Well No. 1 and 1.0 mg/L for Well No. 2.
4.1.2 Distribution System. The distribution system at Covered Wells is supplied by two wells
(Wells No. 1 and No. 2) that operate on an alternating basis. Water from each well is stored in a 88,000-
gallon aboveground storage tank, which is located approximately 9 miles from the well site. The mains
for the water distribution system are constructed primarily of 6-in C900 polyvinyl chloride (PVC).
Copper piping is used in some of the connections to the distribution system. Three locations, which are
part of the historic LCR sampling network, were selected to provide a good representation of the
distribution system for both baseline sampling and quarterly sampling after the system startup.
4.2
Treatment Process Description
The AdEdge arsenic package unit (APU) is a fixed-bed, down-flow adsorption system used for small
water systems with flowrates up to 75 gpm. The system uses Bayoxide® E33 media, an iron-based
adsorptive media developed by Bayer AG, for the removal of arsenic from drinking water supplies. Table
4-2 presents physical and chemical properties of the media. The Bayoxide® E33 media is delivered in a
dry granular form and is listed by NSF under Standard 61 for use in drinking water application. For this
site, Bayoxide® E33 was supplied in pelletized form, which has a density of 35 lb/ft3.
Table 4-2. Physical and Chemical Properties of AD-33 Media0
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)
10x35
70
a -FeOOH
Chemical Analysis
Constituents
FeOOH
CaO
MgO
MnO
S03
Na2O
Ti02
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
15
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As groundwater is pumped through fixed-bed pressure vessels, dissolved arsenic is adsorbed onto the
media, reducing its concentration to below the 10 (ig/L MCL. When the effluent arsenic concentration
reaches 10 (ig/L, the spent media is removed and can be disposed of as non-hazardous waste if it
successfully passes the EPA's toxicity characteristic leaching procedure (TCLP) test. The media capacity
is dependent upon arsenic species and its concentration in influent water, empty bed contact time (EBCT),
influent pH, and concentrations of interfering ions in the water. During the performance evaluation study,
the need for media replacement was never required. At the end of the study, arsenic concentrations in
Vessels A and B effluent were 0.6 and 0.4 (ig/L, respectively.
The APU system at TOUA consisted of two pressure vessels (i.e., Vessels A and B) operating in parallel.
Figure 4-3 shows a simplified process flow diagram of the treatment system. The system sat on a covered
concrete pad, which provided sufficient space for the modular treatment system and booster system
consisting of one 5,000-gal intermediate storage tank and three booster pumps. Figure 4-4 is a
generalized process flow sampling diagram of the system that illustrates sampling locations and
parameters analyzed during the demonstration study. Table 4-3 presents key system design parameters.
The key process steps and major components of the water treatment system include:
(a) Intake. Raw water was pumped from Wells No. 1 and No. 2 to the APU treatment system
via 6-in PVC pipe.
(b) Prechlorination. The original design called for post-chlorination since As(V) was the
predominant species. Due to the location of the chlorine injection point (i.e., at each
wellhead) and the associated cost required to relocate the injection point to the end of the
treatment train, a decision was made to keep the pre-existing chlorination setup. The chlorine
addition system was used to oxidize any As(III) in source water to As(V), while providing the
needed chlorine residuals for disinfection. Each well had its own NaOCl addition system (see
Figure 4-5), which consisted of a ProMinent Concept Plus Model 704 pump with a maximum
capacity of 1.03 gal/hr (gph) or 3.9 L/hr (Iph), a chlorine injection tap, a 30-gal chemical feed
tank (containing a 2% NaOCl solution, which was diluted down from 12.5%), and a control
relay box for chlorine pump control. Chlorine addition was synchronized with the well
pumps and consumption was monitored by measuring the solution level in each feed tank.
The metering pumps were set for a target free chlorine residual level of 1 mg/L (as C12) or
less.
(c) pH Adjustment. The raw water had high pH values (i.e., 8.4) that had to be lowered to a
target value of 7.0 to enhance arsenic adsorption. A CO2 automatic pH adjustment/control
system manufactured by Destin North Bay in Niceville, FL was initially used for pH
adjustment, but was later replaced with a system produced by AdEdge. Figure 4-6 presents a
schematic diagram of the original system, which was designed to introduce gaseous CO2 into
water using an in-line CO2 injector. The four major components of the system, as shown in
Figure 4-7, included a non-glass pH probe, a pH controller, a gas flow control panel, and a
CO2 injector, all of which are further explained below:
o The non-glass pH probe was a Honeywell Durafet III Electrode mounted inline with an
integral 50-ft cable, which was connected to a Honeywell pH controller. This probe was
more durable than its glass counterpart and utilized an ion sensitive field effect transistor
(ISFET), a miniaturized semiconductor chemical sensor, for a fast response.
o The pH controller was a Honeywell controller with dual 4 to 20 milliamp outputs, two
alarm relays, NEMA-4X enclosure, panel-mounting hardware, and an infrared
communications port. The pH controller required 110 V power.
16
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Process Flow Diagram
AdEdge E33 Arsenic Reduction System
To Storage
or Distribution
Flow Quality Indicator
Flow Instrument
^29' Pressure Differential Gauge
(«i) Pressure Gauge
Figure 4-3. Process Flow Diagram for APU System at TOUA
-------
INFLUENT
(WELL lor 2)
Once Every 8 Weeks (Before 05/28/08^
Once Every 3 to 4 Months (After 05/28/081
pH, tempera ture,
As(total and soluble), As(III),
As(V), Fe (total and soluble), Mn
(totaland soluble), U (total),
V(total), Ca,Mg, F, NO3, SO4,
SiO2, P, turbidity, alkalinity
pH, tempera tureOO,
Cl2(free and total/1), As(total
and soluble), As(lII), As(V), Fe
(totaland soluble), Mn (totaland
soluble), U (total), V(total), Ca,
Mg, F, NO3, SO4, SiO2, P,
turbidity, alkalinity
Sells, AZ
AdEdge APU w/ Bayoxide® E33
Design Flow: 63 gpm
1
r
Pre-Chlorination
pH ADJUSTMENT -
C02 INJECTION
3 Times in One 8-Week Cycle
(Before 05/28/081
Monthly (After 05/28/081
pH^, tempera ture®,
». As (total), Fe (total), Mn (total),
U (total), V(total), SiO2, P,
turbidity, alkalinity
INFILTRATION GALLERY
MEDIA
VESSEL
A
pH(a\ temperature'3),
C12 (free and total)**, As(total
and soluble), As(III),As(V), Fe
(totaland soluble), Mn (totaland
soluble), U (total), V(total), Ca,
Mg, F, NO3, SO4, SiO2, P,
turbidity, alkalinity
^, tempera ture®,
Cl2(free andtotal)0>, As (total),
Fe (total), Mn (total), U (total),
V(total), SiO2, P, turbidity,
alkalinity
LEGEND
At Wellhead
After p H Adj ustment
After Vessel A
After VesselB
Total Combined Effluent
Backwash SamplingLocation
Solid SamplingLocation
Unit Process
Process Flow
Backwash Flow
pH^, tempera tureW,
Cl2(free andtotal)W, As (total),
Fe (total), Mn (total), U (total),
V(total), SiO2, P, turbidity,
alkalinity
BOOSTER PUMP STATION WITH
5,000-GAL INTERMEDIATE STORAGE TANK
Footnote
(a) On-site analyses
DISTRIBUTION SYSTEM
Figure 4-4. Process Flow Diagram with Sampling Schedules and Locations
18
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Table 4-3. Design Specifications of AdEdge APU System
Parameter
Value
Remarks
Prechlorination (Pre-existing)
Target Free Chlorine Residual Level (mg/L [as C12])
<1.0
Using NaOCl solution
CO2 pH Adjustment
Total Usage (Ib CO2/day)
Injection Rate (scfh)
No. of 50 Ib Cylinders Used per Month
5.6
6.1
3 to 4
Reducing pH from 8.2 to 7
0
-
-
Adsorption Vessels
Vessel Size (in)
Cross-Sectional Area (ft2/vessel)
No. of Vessels
Configuration
Underlying Gravel Bulk Density (lb/ft3)
Underlying Gravel Quantity (Ib/vessel)
Media Quantity (Ib)
Media Volume (ft3/vessel)
Media Bed Depth (in)
Pressure Drop (psi)
36 D x 72 H
7.1
2
Parallel
100
450
1,330
19
32
4
-
-
-
-
Gravel composed of '/4-in >
1/8-in quartz
900 Ib in both vessels
Media bulk density 35 lb/ft
3
38ft3 in both vessels
-
Across a clean bed
Service
Design Flowrate (gpm)
Hydraulic Loading (gpni/ft2)
EBCT (min)
Estimated Working Capacity (BV)
Throughput To Breakthrough at 10 ug/L (gal)
Average Use Rate (gal/day)
Estimated Media Life (months)
63
4.4
4.5
51,000
14,484,000
22,500
21
System maximum flowrate
75 gpm
-
Based on design flowrate
-
1 BV = 284 gal
Based on 7 to 8 hr of daily
50 gpm
operation at
-
Backwash
Pressure Differential Setpoint (psi)
Backwash Flowrate (gpm)
Backwash Hydraulic Loading (gpm/ft2)
Backwash Frequency (per month)
Backwash Duration (min/vessel)
Filter-to -Waste Flowrate (gpm)
Filter-to -Waste Duration (min/vessel)
Wastewater Production (gal/event)
10-15
64
9.0
1
15
64
5
2,560
-
-
-
On as needed basis
-
-
-
Both vessels combined
o The CO2 gas flow control panel adjusted the CO2 gas injection rate in response to the pH
controller signal to maintain the setpoint of 7.0. The pressure regulator inside the panel
was set at 100 psig and the instrument regulator was set at 20 psig. The CO2 pH control
system was designed to feed 6.1 standard ft3/hr (scfh). The average CO2 use rate was
estimated to be 5.6 Ib/day based on a 63 gpm flowrate and the source water quality. The
gas supply included up to four 50-lb cylinders to provide a one-month supply of CO2.
o The in-line CO2 injector used the "Venturi effect" to provide CO2 gas mixing with the
water stream. The assembly included the injector, a check valve, a metering valve, and a
5-ft long stainless steel (SS) flexible hose. The CO2 injector was installed on the well
pump discharge piping where the piping comes onto the treatment system slab.
19
-------
Figure 4-5. Chlorine Addition System at TOUA
Several issues, such as malfunctioning components and leaks in the manifold, were
encountered immediately after installation of the Destin North Bay system in January 2008.
By early July 2008, AdEdge replaced the original system, at no additional cost, with one that
was designed and built by AdEdge. The problems associated with the Destin North Bay
System are further discussed in Section 4.4.3. Figure 4-8 shows a process and instrument
diagram of the AdEdge pH adjustment system and photographs of the control panel are
presented in Figure 4-9. Details concerning operation and components of the replacement
AdEdge CO2 pH adjustment system are described below:
o Gas supplied by the two 50-lb CO2 cylinders entered the control panel through an inlet
solenoid valve, which was controlled by a logic circuit that allowed CO2 gas to enter the
panel only if a signal was received by the control panel when the well pump was on.
o From the inlet solenoid valve, CO2 gas flowed to a non-venting single stage pressure
regulator mounted inside the control panel, by which gas pressure supplied to the
remainder of the panel components and ultimately to the injector was further reduced and
controlled. An "Inlet Pressure" gauge mounted on the control panel indicated the gas
pressure supplied to the upstream side of the pressure regulator.
o After the panel-mounted pressure regulator, the CO2 gas flow path was split into a
manual adjustment loop and an automatic adjustment loop depending on which mode,
automatic or manual, was selected. When the manual valve was opened, CO2 gas flowed
through the valve to a needle valve, by which the operator could control the gas flow
delivered to the injector. When the automatic valve was opened, CO2gas proceeded
20
-------
Noil-Glass pH Probe •*•
HOY Power
pH Controller
o o
4-20 ma
Gas Flow
Control
Panel
•25'
CO; Supply
300 psig
CO; Injector)
Water Pump
HOY Power
Customer
installed relay
allows power
to controller
only if pump
on and water
flowing
Figure 4-6. Overview of Destin North Bay CO2 pH Adjustment System
-------
Figure 4-7. Destin North Bay CO2 Gas Flow Control System for pH Adjustment
(Clockwise from top left: non-glass inline pH probe;
Honeywell pH controller; gas flow control panel; Venturi injector)
through the valve to a proportional solenoid valve. The valve was automatically
controlled via the proportional integral derivative (PID) functionality of the Burkert 8205
pH controller, which was connected to a solid state SensorX in-line pH probe mounted
approximately 25 ft downstream of the injection point. The manual and automatic flow
paths were brought back together and CO2 gas flow proceeded through a panel mounted
rotameter, by which the operator could gauge and record relative gas flow to the injector.
The rotameter reading was a relative reading only, since the meter was calibrated for air
and not CO2.
o An "Outlet Pressure" gauge mounted on the control panel measured the delivery pressure
of CO2 gas at the outlet of the panel. CO2 gas flowed to an outlet solenoid valve, which
was controlled by the same logic circuit as the inlet solenoid valve, allowing CO2 gas to
flow only when the well pump was on. CO2 gas then flowed from the outlet solenoid
away from the panel through a check valve and a submicron filter to the injector. The
injector from the original system, which employs the "Venturi effect", was used with the
new pH adjustment system. Failure of the outlet solenoid valve and check valve occurred
during the performance evaluation period leading to problems with the pH adjustment
system. The problems experienced and the corrective actions taken are explained in
further detail in Section 4.4.3.
22
-------
1 1 2 1 3 1 4 5161718
TO ADEDGE ADSORPTION
-------
'111. -== ••
1 I •:
Figure 4-9. AdEdge CO2 pH Adjustment System Control Panel
(d) Adsorption. The APU system consisted of two 36-in x 72-in composite vessels configured
in parallel, each containing 18.5 ft3 of pelletized E33 media supported by a gravel underbed.
The vessels had a 6-in flange opening on the top of the vessel for loading media and assessing
vessel contents. A 2-in Fleck control valve (Fleck Model 3150) was used on each vessel to
allow the vessel to operate independently. Each valve had a 3200NT timer for electronic
programming, which allowed for setting custom parameters such as backwashing frequency,
external notifications for alarm conditions, and accommodating other inputs and outputs.
Water entered the system through 2-in piping and flowed in parallel through the vessels.
Water in each vessel flowed from the upper distributor downward though the media where
treated water was collected at the bottom through a slotted hub and lateral assembly. The
treated water then traveled up through the riser piping in the vessel before it exited at the
outlet of the Fleck control valve.
All piping on the APU system was Schedule 80 PVC. The inlet line to each control valve
contained a diaphragm valve for isolation followed by a Y-strainer to prevent particulates
24
-------
from entering the controller. Ball valves were located on each outlet line from the controllers
also for isolation. Based on a design flowrate of 63 gpm, the EBCT for each vessel was 4.5
min and the hydraulic loading to each vessel was 4.4 gpm/ft2. Figure 4-10 shows the APU
system along with the booster station (left) and CO2 pH adjustment system (center
background).
Figure 4-10. AdEdge APU Arsenic Adsorption System
• Backwash. Backwashing was performed with raw water and initiated in one of three ways:
(1) automatically based on the number of days since the last backwash (once every 30 to 45
days as recommended by the vendor); (2) automatically based on reaching a high pressure
differential (typical setpoint of 10 to 15 psi); and (3) manually by depressing the backwashing
selector switch. The system was designed to backwash one vessel at a time while the second
vessel remained in service. During a backwash, each vessel underwent 15 min of an upflow
wash followed by 5 min of a downflow rapid rinse, both at a flowrate of 64 gpm. Each
backwash event (both vessels combined) would produce 2,560 gal of wastewater, which was
directed to a modified evaporation/transpiration bed consisting of four infiltration chambers
covered with gravel.
The differential pressure and timer triggers were disabled during the entire performance
evaluation period allowing backwash to only occur manually. Due to minimal pressure drop
across the vessels and low levels of arsenic in the treated effluent, routine system
backwashing was not performed. Pressure drop and arsenic concentrations across the vessels
were monitored regularly.
25
-------
On August 18, 2009, during sample collection by the operator, Vessel A went into backwash.
The operator noticed an unfamiliar value on the display screen of the control valve during the
backwash and made note of it. Battelle contacted the vendor the following day to determine
what triggered the vessel to automatically engage into a backwash. The vendor informed
Battelle that the value the operator recorded indicated the valve programming had been reset,
possibly by a power surge. The vendor walked the operator through the valve re-
programming steps on September 2, 2009, making certain to disable the timer and differential
pressure triggers for backwash. To engage a backwash, the operator would have to do it
manually by depressing the selector switch on the control valve.
• Media Replacement. Based on the analytical results from the final sampling event on March
16, 2010, total arsenic concentrations in the treated water were 0.6 and 0.4 (ig/L for Vessels
A and B, respectively. The total arsenic concentration in the combined effluent did not
exceed the MCL of 10 (ig/L; therefore, the media was not replaced during the study period.
Based on the estimate provided by the vendor, breakthrough of arsenic at 10 (ig/L was
expected to occur after treating approximately 14,484,000 gal (51,000 BV) or 21 months of
system operation assuming an estimated daily throughput of 22,500 gal.
4.3 System Installation
The installation of the APU system was completed by AdEdge on January 7, 2008. The following briefly
summarizes some of the predemonstration activities, including permitting, building preparation, and,
installation, shakedown, and startup.
4.3.1 Permitting. Because the Tohono O'odham Nation is governed by Tribal Sovereignty and
IHS performed the work related to site engineering and system/building tie-ins, the issuing of permits was
not required. Instead, the vendor provided IHS and TOUA with the system layout, footprint, and
electrical requirement for all system components to facilitate the facility's building design and
construction.
4.3.2 Building Preparation. A new structure was designed and funded by IHS and constructed by
TOUA to house the treatment system and other necessary components (i.e., pH adjustment system and
booster system). The new structure consisted ofalOftx 12ft concrete slab covered by a 20 ft * 20 ft
ramada shelter enclosed on the sides with corrugated metal panels. A fence was constructed around the
building and 5,000 gal storage tank for the booster system for additional security. Figure 4-11 shows the
new building and storage tank.
4.3.3 Installation, Shakedown, and Startup. The treatment system arrived onsite in March 2007,
but installation was delayed due to construction upgrades being made to the well site, which were not
completed until December 2007. The vendor was onsite for the system installation and shakedown during
the week of January 7, 2008. Onsite activities included hydraulic testing, media loading, freeboard
measurements, and media backwash along with the installation and shakedown of the CO2 pH adjustment
system. The vendor returned to the site the week of February 4, 2008 to train the operator and put the
system online. Battelle was onsite on March 31 and April 1, 2008, to inspect the system and provide
training to the operator for sampling and data collection. As a result of the system inspection, a punch-list
of items was identified. Table 4-4 summarizes the items identified and corrective actions taken. In
addition, these problems are discussed in detail in Section 4.4.3.
26
-------
Figure 4-11. New Treatment Building with 5,000 gal Storage Tank (left)
Table 4-4. System Punch-List/Operational Issues
Item
No.
1
2
3
4
5
6
Punch-List/
Operational Issues
Well pump hour meter not
provided for each well
CO2 regulators not functioning
properly
Sample tap not installed at
combined effluent location (TT)
pH controller display not
working
Pneumatic flow control valve
malfunctioning
CO2 manifold leaking
Corrective Action(s) Taken
Not in request for quotation (RFQ)
to vendor; two hours meters
purchased from AdEdge and
installed by TOUA
Two new CO2 regulators sent to site
by AdEdge
Sample tap supplied by AdEdge and
installed by TOUA
Destin North Bay CO2 pH
adjustment unit replaced with new
unit designed and installed by
AdEdge.
Resolution Date
07/07/08
05/15/08
06/08
07/10/08
4.4
System Operation
4.4.1 Operational Parameters. The operational parameters for the system performance
evaluation were tabulated and are attached as Appendix A. Key parameters are summarized in Table 4-5.
From February 13, 2008, through March 19, 2010, the system operated for atotal of 3,353 hr. Due to a
27
-------
Table 4-5. Summary of APU System Operation
Operational Parameter
Performance Evaluation Study Duration
Number of Days System Operating (day)
Cumulative Operating Time (hr)
Average Daily Operating Time (hr)
Throughput (gal)
Throughput (BV)(a)
Average (Range) of Instantaneous Flowrate (gpm)
Average (Range) of EBCT per Vessel (min)(d)
Average (Range) of System Inlet Pressure (psi)
Average (Range) of System 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
02/13/08 to 03/19/10
765
3,353
4.38
11,686,000
41,148
Vessel A
29.5 (9.4-52.8)(b'c)
Vessel B
30.6(20.1-54.2)
Vessel A
4.8 (2.7-15. l)(b'c)
Vessel B
4.7(2.6-7.1)
9.0 (5.0-18.0)
5.1 (2.0-10.0)
4.0 (0.0-14.0)
2.4 (0.0-10.0)
2.7 (0.0-9.0)
(a) Calculated based on 38 ft3 of media; 1 BV = 284 gal.
(b) Not including two outliers on November 23, 2009.
(c) Not including values from April 30 to May 20, 2009; flowmeter not functioning.
lack of hour meters on the well pumps since system startup until July 8, 2008, the system operating time
during this period was estimated based on the average daily operating time of 4.38 hr/day from July 8,
2008, through the end of the performance evaluation study.
Figure 4-12 compares calculated flowrates at each wellhead with instantaneous and calculated flowrates
through each vessel. Calculated flowrates were obtained by dividing incremental volumes recorded by a
totalizer by respective incremental operating times recorded from the well pump hour meter.
Instantaneous flowrates were recorded by the operator from a flow meter. Because the wellheads did not
have flowmeters, no instantaneous flowrates were recorded. Calculated flowrates for Wells No. 1 and
No. 2 averaged 59.9 and 60.3 gpm, respectively. The flowrate through each vessel was consistent at
approximately 30 gpm with slight fluctuations being observed periodically. The exceptions occurred
during the period when the vessel totalizers were not operating correctly, such as from April 30, 2009,
through May 20, 2009, for Vessel A. Excluding the data collected during this period and an outlier
recorded on November 23, 2009, also for Vessel A, an average instantaneous flowrate of 29.5 gpm was
calculated for Vessel A and 30.6 gpm for Vessel B. Since the vessels were configured in parallel, the
flow through each vessel should have been one-half (i.e., 30 gpm) of the total flow from the wellhead.
At the end of the study, the system had treated 11,686,000 gal of water based on the totalizers installed on
the vessels. This amount is comparable to the 11,627,700 gal recorded from the well head totalizers. The
amount of water treated was equivalent to 41,148 BV based on the 38 ft3 of media in both vessels (19 ft3
per vessel). Based on the instantaneous flowrates to the vessels, the average EBCT was 4.8 min for
Vessel A and 4.7 min for Vessel B, which were very close to the design value of 4.5 min as presented in
Table 4-3.
28
-------
160
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
-Well No. 1 Calculated Flow/rate
-Well No. 2 Calculated Flow/rate
-Vessel A Instantaneous Flow/rate
Vessel A Calculated Flow/rate
Vessel B Instantaneous Flow/rate
-Vessel B Calculated Flow/rate
2/2/2008 4/22/2008 7/11/2008 9/29/2008 12/18/2008 3/8/2009 5/27/2009 8/15/2009 11/3/2009 1/22/2010 4/12/2010
Date
Figure 4-12. System Instantaneous and Calculated Flowrates
Pressure readings of the APU system were monitored at the system inlet and outlet, while only
differential pressures (Ap) were monitored across the vessels. Throughout the duration of the
performance evaluation period, system inlet and outlet pressure readings averaged 9.0 and 5.1 psi,
respectively. The average Ap across the system was 4.0 psi. Ap readings ranged from 0 to 10 psi and
averaged 2.4 psi across Vessel A and from 0 to 9 psi and averaged 2.7 psi across Vessel B. Due to low
differential pressures across the system and vessels, no media backwash was performed during the
performance evaluation study. Figure 4-13 presents system pressure readings at the inlet and outlet along
with calculated differential pressures. Figure 4-14 presents differential pressures across Vessels A and B.
4.4.2 Residual Management. No residuals were produced because neither backwash nor media
replacement was required during the evaluation period.
4.4.3 CO2 pH Adjustment System. As described in Section 4.2, pH adjustment using a CO2 gas
flow control system was a process component. During system startup in early February 2008, problems
with regulators on the CO2 gas cylinders were observed. Leaks were detected in the SS hoses that
connected the regulators on the CO2 cylinders to the pH adjustment system. In addition, the low pressure
side (delivery pressure) of one of the regulators continually read 150 psi. The problems with the
regulators persisted until the vendor sent a new set of regulators to the site on May 15, 2008. Since then,
TOUA had to have one of the regulators rebuilt twice and the other once. Rebuilding the regulators has
kept them functioning properly throughout the evaluation period.
29
-------
-System Inlet Pressure
-System Outlet Pressure
System Differential Pressure
0
03/18/08 06/06/08 08/25/08 11/13/08 02/01/09 04/22/09 07/11/09 09/29/09 12/18/09 03/08/10
Figure 4-13. System Pressure Readings
Vessel A Differential Pressure D Vessel B Differential Pressure
01/13/08 04/02/08 06/21/08 09/09/08 11/28/08 02/16/09 05/07/09 07/26/09 10/14/09 01/02/10 03/23/10
Date
Figure 4-14. Differential Pressures Across Vessels A and B
30
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A number of operational issues arose during the use of the Destin North Bay CO2 pH adjustment/control
system. On May 2, 2008, the operator reported that the display on the Honeywell pH controller was no
longer working. After contacting the manufacturer, it was confirmed that there was a batch of pH
displays malfunctioning and that they would replace the display free of charge. Also on May 2, 2008, a
leak from the connection between the stainless steel piping and pneumatic flow control valve was
observed. On May 9, 2008, the CO2 manifold was found to not be functioning properly. Because of
concerns over the operational issues, the vendor proposed on May 30, 2008, to replace the Destin North
Bay system with a new CO2 pH adjustment system designed and assembled by AdEdge. The new system
was installed by the vendor on July 10, 2008.
On September 16, 2008, the operator noticed water in tubing in the system control panel, which,
according to the vendor, was caused by a malfunctioning check valve and a malfunctioning solenoid
valve on the outlet line to the injector. The operator reported again on October 28, 2008, the presence of
water in the same tubing and that the system was no longer able to adjust the pH to below 7.1 based on
the display on the pH control panel. After checking with the vendor for the status of replacement part
shipment, it confirmed that one three-way solenoid valve and two check valves had been shipped on
November 7, 2008. The replacement parts were apparently lost during shipping and had to be resent. On
December 10, 2008, the operator received one shipment with one three-way solenoid valve, but no check
valves. On December 11, 2008, the operator reported continuing presence of water in the tubing even
after the installation of the new three-way solenoid. By January 15, 2009, the rotameter on the system
control panel stopped working and water had leaked out of the tubing connections into the control panel.
In addition, the pH would not go below 7.6 based on the display on the pH control panel. It must be
noted, however, that pH measurements by a field pH meter during this period continued to show
acceptable pH values as presented in Appendix B (e.g., 7.2 and 7.0 following Vessels A and B,
respectively, on November 18, 2008, and 6.9 and 7.0 on December 16, 2008 [see Figure 4-17 in Section
4.5.1]). The differences observed between the field and inline pH measurements are further discussed in
Section 4.5.1.
On February 16, 2009, an engineer was dispatched by the vendor to the site to fix the pH adjustment
system. An additional solenoid valve was installed on the outlet line and the malfunctioning check valve
was replaced. Water was drained from the system control panel and the delivery pressure was increased
to approximately 80 psi. When the vendor left the site, the pH display was reading 7.0. No additional
issues with the pH adjustment unit were experienced after the onsite visit.
4.4.4 System/Operation Reliability and Simplicity. Operational irregularities experienced during
the demonstration study were almost entirely related to the pH adjustment system (as discussed in Section
4.4.3), vessel flow meters/totalizers, Y-strainers, and chlorination addition system.
On April 30, 2009, the paddlewheel in the Vessel A flowmeter/totalizer stopped rotating due to solids
buildup, which was cleaned off by the operator on May 27, 2009. Quarterly checking and cleaning of
paddlewheels were incorporated into the routine maintenance schedule. Problems also were experienced
with the Well No. 2 flowmeter, which stopped working on September 1, 2009. After troubleshooting and
cleaning by the Water Department, the meter was placed back into service approximately two weeks later.
Starting on September 30, 2009, higher-than-usual differential pressures (i.e., > 4 psi) were observed
across both vessels and had continued to increase to approximately 10 psi within three weeks. The cause
of the pressure increase was determined to be accumulation of sediment in the Y-strainers located on the
inlet lines to the valve controller on each vessel. Four new strainers were therefore purchased to allow the
operator to rotate the strainers on a quarterly basis. The dirty strainers were removed and cleaned for the
next changeout.
31
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On October 20, 2009, the operator noticed that chlorine residuals across the system were uncharacteristic-
ally low. Upon further inspection, the operator found that there was a hole in the line leading to the
injector. The line was repaired and the NaOCl solution was replenished. No further difficulties were
encountered with the chlorine addition systems during the study.
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 pre-treatment processes were required at the Covered
Wells site, i.e., pH adjustment and prechlorination. CO2 was used to lower pH values of raw water from
as high as 8.4 to a target value of 7.0 to maintain effective arsenic adsorption by AD-33 media. The CO2
injection point and inline pH probe used to monitor and control pH were installed downstream of the
chlorine injection point. O&M of the pH adjustment system required routine system pressure checks and
regular changeout of 50-lb CO2 cylinders. The operator also recorded daily pH readings from the inline
probe and CO2 gas flowrates from the rotameter on the control panel. The use of CO2 for pH adjustment
also required safety training for and awareness by the operator, due to potential hazards.
For prechlorination, the existing chlorination system at each well was utilized to maintain a target free
residual level of 1.0 mg/L (as C12) or less. Since the original chlorine system was used, no additional
maintenance or skills were required for its operation. The operator monitored chlorine tank levels and
measured residual chlorine levels at different locations across the treatment train.
System Automation. The system was fitted with a valve controller on each vessel, which was capable of
performing automatic backwash when triggered. All backwash triggers, however, were disabled to allow
for better management of backwash events. The system also was equipped with an automated CO2 gas
flow control system, which included a liquid CO2 supply assembly, a pH control panel with automatic
and manual models, a CO2 "Venturi style" injector, and an inline pH probe located downstream of the
injection point.
Operator Skill Requirements. The skill requirements to operate the system demanded a higher level of
awareness and attention than the previous system. The system offered increased operational flexibility,
which, in turn, required increased monitoring of system parameters. The operator's knowledge of the
system limitations and typical operational parameters were key to achieve system performance objectives.
The operator was onsite typically one to two days a week and spent approximately 1.5 hr/day to perform
visual inspections and record system operating parameters. The basis for the operator skills began with
onsite training and a thorough review of the system operations manual; however, increased knowledge
and system troubleshooting skills were gained through hands-on operational experience.
Preventive Maintenance Activities. Preventive maintenance tasks included periodic checks of flow
meters and pressure gauges and inspection of system piping and valves. Checking the CO2 cylinders and
supply lines for leaks and adequate pressure also were performed. Typically, the operator performed
these duties while onsite 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 system. CO2 used for pH
adjustment was ordered on an as-needed basis. Typically, four 50-lb cylinders were used per month. The
CO2 cylinders were delivered to TOUA by the CO2 supplier and then transported to the site
approximately 20 miles by the operator. Empty cylinders were returned to the CO2 supplier for reuse.
32
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4.5
System Performance
The system performance was evaluated based on analyses of water samples collected from the treatment
plant, backwash, and distribution system.
4.5.1 Treatment Plant Sampling. Table 4-6 summarizes the analytical results of arsenic, iron,
manganese, uranium, and vanadium concentrations measured at the five sampling locations across the
treatment train. Table 4-7 summarizes the results of other water quality parameters. Appendix B
contains a complete set of analytical results through the performance evaluation study. Treatment plant
water samples were collected on 28 occasions (including one set of duplicate samples collected during
the November 18, 2008 sampling event), with field speciation performed during six of the 28 occasions at
IN, AP, TA,TB, and TT sampling locations. Sampling at the TT location occurred only four times due to
the absence of a TT tap until June 2008. The results of the water samples collected throughout the
treatment plant are discussed below.
Table 4-6. Summary of Analytical Results for Arsenic, Iron, Manganese, Uranium,
and Vanadium
Parameter
As (total)
As (soluble)
As
(paniculate)
As (III)
As(V)
Fe (total)
Sampling
Location
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
Sample
Count
28
28
27(a)
28
4
5(b)
6
6
6
4
5w
6
6
6
4
6
6
6
6
4
5(d)
6
6
6
4
24
24
24
24
4
Concentration (jig/L)
Minimum
29.0
26.6
<0.1
<0.1
<0.1
33.7
34.2
<0.1
0.2
0.2
0.3
<0.1
<0.1
<0.1
<0.1
0.1
0.1
<0.1
<0.1
0.3
33.3
34.0
<0.1
<0.1
<0.1
<25
<25
<25
<25
<25
Maximum
38.6
39.4
1.2
1.3
1.1
36.8
36.2
1.1
1.0
1.1
2.0
2.9
0.5
0.3
0.3
.0
.1
.1
.0
.0
36.4
35.9
<0.1
<0.1
<0.1
60
32
77
<25
<25
Average
34.9
34.9
0.5
0.5
0.5
35.0
35.4
0.5
0.4
0.5
1.2
1.5
0.1
0.1
0.1
0.5
0.5
0.5
0.4
0.5
34.5
35.0
<0.1
<0.1
<0.1
<25
<25
<25
<25
<25
Standard
Deviation
2.2
2.9
0.3
0.3
0.4
1.2
0.9
0.4
0.3
0.4
0.8
0.9
0.2
0.1
0.1
0.3
0.3
0.3
0.3
0.3
1.2
0.8
-
-
-
12.5
6.3
13.8
-
-
33
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Table 4-6. Summary of Analytical Results for Arsenic, Iron, Manganese, Uranium,
and Vanadium (Continued)
Parameter
Fe (soluble)
Mn (total)
Mn (soluble)
U (total)
V (total)
Sampling
Location
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
Sample
Count
6
6
5(e)
6
4
24
24
24
24
4
6
6
6
6
4
7
7
7
7
0
20
20
19(f)
20
4
Concentration (jig/L)
Minimum
<25
<25
<25
<25
<25
0.1
<0.
<0.
<0.
<0.
<0.
<0.
<0.
<0.
<0.
7.0
7.0
<0.1
<0.1
-
23.5
25.2
<0.1
<0.1
0.1
Maximum
<25
<25
<25
<25
<25
2.8
3.0
2.1
1.3
<0.1
3.2
0.4
2.7
<0.1
0.1
8.3
8.4
<0.1
<0.1
-
38.1
39.7
6.2
3.7
3.7
Average
<25
<25
<25
<25
<25
0.7
0.7
0.3
0.1
<0.1
0.7
0.2
0.5
<0.1
<0.1
7.7
7.7
<0.1
<0.1
-
32.2
32.5
1.6
1.4
1.2
Standard
Deviation
-
-
-
-
-
0.9
0.7
0.5
0.2
-
1.2
0.1
1.1
-
0.0
0.4
0.4
-
-
-
3.4
3.6
2.0
1.5
1.4
One-half of detection limit used for samples with concentrations less than detection limit for
calculations.
(a) One outlier (i.e., 31.8 ug/L) from 08/18/09 omitted.
(b) One outlier (i.e., 22.0 ug/L) from 04/01/08 omitted.
(c) One outlier (i.e., 14.6 ug/L) from 04/01/08 omitted.
(d) One outlier (i.e., 21.9 ug/L) from 04/01/08 omitted.
(e) One outlier (i.e., 78 ug/L) from 05/28/08 omitted.
(f) One outlier (i.e., 31.8 ug/L) from 08/18/09 omitted.
Arsenic. Figure 4-15 contains three bar charts showing concentrations of participate arsenic, soluble
As(III), and soluble As(V) at the IN, AP, TA, and TB sampling locations. Speciation results at the TT
location were not presented in the figure because they were very similar to those at the TA and TB
locations. Speciation results at the IN location from the April 1, 2008 sampling event contained outliers
and were omitted from Figure 4-15.
Total arsenic concentrations in raw water ranged from 29.0 to 38.6 (ig/L and averaged 34.9 (ig/L. Soluble
As(V) was the predominating species, ranging from 33.3 to 36.4 (ig/L and averaging 32.4 (ig/L. Soluble
As(III) also was present in source water, although very low, ranging from 0.1 to 1.0 (ig/L and averaging
0.5 (ig/L. Particulate arsenic concentrations also were low, ranging from 0.3 to 2.0 (ig/L and averaging 1.2
(ig/L. The arsenic concentrations measured were consistent with those collected previously during source
water sampling (Table 4-1).
34
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Table 4-7. Summary of Water Quality Parameter Sampling Results
Parameter
Alkalinity
(as CaCO3)
Fluoride
Sulfate
Nitrate
(asN)
P
(asP)
Silica
(as SiO2)
Turbidity
pH
Temperature
Sampling
Location
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
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
Hg/L
Hg/L
Hg/L
Hg/L
Hg/L
mg/L
mg/L
mg/L
mg/L
mg/L
NTU
NTU
NTU
NTU
NTU
s.u.
s.u.
s.u.
s.u.
s.u.
°c
°c
°c
°c
°c
Sample
Count
24
24
24
24
4
6
6
6
6
4
6
6
6
6
4
6
6
6
6
4
24
24
24
24
4
23
23
23
23
4
24
24
24
24
4
20
20
20
20
3
llw
llw
n(b>
n(b>
2(c)
Concentration
Minimum
144
140
134
139
146
1.1
1.0
1.0
1.0
1.0
22.2
21.6
21.4
20.5
21.3
1.2
1.1
1.2
1.2
1.2
<10
<10
<10
<10
<10
24.4
24.5
18.7
20.7
26.6
0.1
0.1
0.1
0.1
0.1
7.8
6.5
6.4
6.2
6.6
26.2
27.4
26.8
27.2
30.6
Maximum
156
156
201
196
192
.2
.4
.2
.2
.1
24.8
24.6
27.1
28.1
23.8
.3
.8
.2
.2
.2
<10
<10
<10
<10
<10
27.8
27.5
32.6
33.8
34.7
1.9
2.2
2.3
2.0
0.3
8.4
7.9
7.5
7.6
7.1
34.1
33.7
34.0
34.4
34.7
Average
150
148
155
159
174
1.1
1.1
1.1
1.1
1.0
23.8
23.6
23.7
24.0
22.4
1.2
1.3
1.2
1.2
1.2
<10
<10
<10
<10
<10
26.2
26.2
26.9
27.3
31.5
0.5
0.6
0.5
0.5
0.1
8.0
6.9
6.9
6.9
6.9
30.6
31.8
31.9
32.3
32.7
Standard
Deviation
4.1
3.9
15.1
15.9
21.4
0.0
0.2
0.1
0.1
0.1
1.0
1.1
2.2
2.9
1.1
0.0
0.2
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
1.1
0.9
3.0
2.9
3.8
0.5
0.7
0.7
0.6
0.1
0.2
0.3
0.3
0.3
0.3
3.0
2.0
2.3
2.1
2.9
-------
Table 4-7. Summary of Water Quality Parameter Sampling Results (Continued)
Parameter
Dissolved
Oxygen (DO)
Oxidation-
Reduction
Potential
(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
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
IN
AP
TA
TB
TT
Unit
mg/L
mg/L
mg/L
mg/L
mg/L
mV
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
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Sample
Count
1
1
1
1
0
2
2
2
2
0
9
15
15
15
3
9
16
15
15
3
7
7
7
7
4
7
7
7
7
4
7
7
7
7
4
Concentration
Minimum
3.7
3.1
3.0
3.4
-
225
287
289
320
-
0.0
0.1
0.0
0.0
1.1
0.0
0.0
0.0
0.0
1.1
29.7
32.9
33.4
30.9
37.5
21.3
23.5
23.2
21.2
27.2
8.4
9.4
9.2
9.5
10.3
Maximum
3.7
3.1
3.0
3.4
-
243
303
321
351
-
0.1
2.2
2.1
2.2
2.1
0.1
2.1
2.1
2.2
1.9
47.3
48.8
94.5
93.0
86.7
36.2
37.3
67.8
66.1
60.0
11.1
11.4
27.4
26.8
26.7
Average
-
-
-
-
-
234
295
305
336
-
0.0
.5
.5
.4
.7
0.0
.4
.5
.4
.6
37.5
38.7
52.2
50.5
61.0
27.4
28.3
37.3
35.6
42.5
10.1
10.4
14.8
14.9
18.5
Standard
Deviation
-
-
-
-
-
12.3
11.5
23.1
21.5
-
0.0
0.5
0.5
0.6
0.5
0.0
0.6
0.5
0.5
0.4
5.7
5.2
28.6
27.2
25.8
4.9
4.6
20.6
19.4
17.5
1.0
0.7
8.1
7.9
8.4
i less than detection
11/18/08, 12/16/08,
One-half of detection limit used for samples with concentrations
(a) Nine outliers all at 25.0°C on 05/28/08, 07/08/08, 10/07/08,
04/15/09, 09/15/09, 01/19/10 omitted.
(b) Eight outliers all at 25.0°C on 07/08/08, 10/07/08, 11/18/08, 12/16/08,02/17/09,04/15/09,
09/15/09, 01/19/10 omitted.
(c) One outlier at 25.0°C on 10/07/08 omitted.
limit for calculations.
02/17/09,
Because most arsenic was present as soluble As(V), oxidation with chlorine was not required. After
chlorination, As(III) concentrations exhibited little change. Free and total chlorine residuals were
monitored at the IN, AP, TA, TB, and TT locations to ensure that the target chlorine residual level was
properly maintained for disinfection purposes. Measurements at the IN location were discontinued after
the September 15, 2009 sampling event. Total chlorine levels at the AP location ranged from 0.0 to
2.1 mg/L (as C12) and averaged 1.4 mg/L (as C12); free chlorine levels ranged from 0.1 to 2.2 mg/L (as
C12) and averaged 1.5 mg/L (as C12) (Table 4-7). The total and free chlorine measurements from
-------
Arsenic Species at the Inlet (IN)
• As(Particulate) •As(lll) DAs(V) |
Arsenic Species after Chlorination and pH Adjustment (AP)
I
I
£ 20
1
5
15
Figure 4-15. Concentrations of Various Arsenic Species at IN, AP, TA, and TB Sampling Locations
37
-------
Arsenic Species after Tank A (TA)
i
i
• As(Particulate) DAs(lll) DAs(V)
Arsenic Species after Tank B (TB)
• As(Particulate) •As(lll) DAs(V)^
Figure 4-15. Concentrations of Various Arsenic Species at IN, AP, TA, and TB
Sampling Locations (Continued)
38
-------
July 30, 2008, were omitted from all sampling locations due to the uncharacteristically high levels
measured. The total and free residual chlorine levels measured at the TA,TB, and TT locations were very
similar to those at the AP location, indicating little or no chlorine demand through the AD-33 vessels.
As shown by the samples taken during the last sampling event on March 16, 2010, after treating
approximately 41,000 BV of water, total arsenic concentrations following Vessels A and B were still as
low as 0.6 and 0.4 (ig/L, respectively. Based on the vendor's estimate, total arsenic breakthrough at
10 (ig/L would occur at 51,000 BV (or 14,484,000 gal). Figure 4-16 presents total arsenic concentrations
at the IN, AP, TA, and TB locations plotted against bed volumes.
Total As vs. Bed Volume
-AtWellheadflN) Afterchorination & pH Adjustment {AP) —*— After Tank A {TA) —•—AfterTank B{TB)
5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 45,000
Figure 4-16. Total Arsenic Breakthrough Curves (1BV = 284 gal)
Iron and Manganese. Iron and manganese were analyzed through November 17, 2009. The average
total iron concentration in raw water was less than the MDL of 25 (ig/L (Table 4-6). Average total iron
concentrations across the treatment train also were below the MDL. Total manganese levels in raw water
were low, ranging from 0.1 to 2.8 (ig/L and averaging 0.7 (ig/L. Manganese existed primarily in the
soluble form prior to chlorination, after which manganese existed mostly as particulate. Total manganese
levels were reduced to an average of 0.3 and 0.1 (ig/L following Vessels A and B, respectively.
Uranium and Vanadium. Uranium was detected in the initial source water samples collected by Battelle
on December 7, 2004 (Table 4-1) and its levels were monitored through September 2, 2008. Total
uranium concentrations in the raw water ranged from 7.0 to 8.3 (ig/L and averaged 7.7 (ig/L. Total
uranium levels were reduced to below the MDL of 0.1 (ig/L following each adsorption vessel. Since
uranium levels in the raw water were always below their MCL of 30 (ig/L and levels in the treated water
39
-------
were continually below the MDL, uranium analysis was discontinued in favor of vanadium analysis.
Total vanadium levels in raw ranged from 23.5 to 38.1 (ig/L and averaged 32.2 (ig/L. Total vanadium
concentrations averaged 1.6 and 1.4 (ig/L after Vessels A and B, respectively. Currently, there is no
MCL for vanadium.
Competing Anions. Phosphorus and silica, which might influence arsenic adsorption, were measured at
the five sampling locations across the treatment train through November 17, 2009, when the list of
analytes was reduced to only include arsenic and vanadium. Phosphorus was below its MDL of 10 (ig/L
for all sampling events during the evaluation period. Silica concentrations in the raw water ranged from
24.4 to 27.8 mg/L and averaged 26.2 mg/L. Little silica removal by the adsorption vessels was observed
during the study.
Other Water Quality Parameters. As shown in Table 4-7, pH values of the raw water varied from 7.8 to
8.4 and averaged 8.0. pH values following CO2 injection for pH adjustment at the AP location varied
from 6.5 to 7.9 and averaged 6.9, which is just below the target value of 7.0. Figure 4-17 shows the pH
of the well water before and after pH adjustment by CO2 as measured by the operator with a field pH
probe during sampling events. For comparison, pH readings recorded from the inline pH probe, which
was connected to the pH controller on the control panel, were plotted alongside the measurements made
by the operator. pH values of the adjusted water, as measured by the inline probe, ranged from 5.5 to 8.5
S.U. and averaged 7.1 S.U., which is somewhat higher than that measured with a field pH probe. The
discrepancies observed might have been caused by instrumentation errors, being that the field pH probe
used by the operator was calibrated before each use and that the inline pH probe connected to the pH
controller was calibrated twice during the entire study period. Nonetheless, the higher pH values
measured with the field pH probe were to the contrary of those observed at two other arsenic
demonstration sites where CO2 also was used for pH adjustments (Cumming et al., 2009; Williams et al.,
2010). Lower pH values measured at these sites were thought to be caused by CO2 degassing during
sample collection and analysis.
Alkalinity, reported as CaCO3, ranged from 144 to 156 mg/L and averaged 150 mg/L in raw water. As
expected, alkalinity after pH adjustment and adsorption remained relatively unchanged at 148 to 159
mg/L (on average), since CO2, instead of mineral acids, was used for pH adjustment.
Hardness. The treatment plant water samples were analyzed for hardness only on speciation events.
Total hardness, reported as CaCO3, ranged from 29.7 to 47.3 mg/L and averaged 37.5 mg/L in raw water.
Total hardness existed primarily as calcium hardness. Total hardness levels remained relatively
unchanged from IN to the AP sampling location. On March 17, 2009 and July 14, 2009, significantly
elevated total hardness levels (approximately 2-3 times the average concentration at IN and AP) were
observed at TA, TB, and TT for unknown reasons. Slightly elevated total hardness levels at TA, TB, and
TT also were also seen on November 17, 2009. Due to the elevated levels on the aforementioned
sampling dates, the average total hardness increased to 52.2, 50.5, and 61.0 mg/L following Tank A,
Tank B, and TT, respectively. The hardness levels at TA, TB, and TT from the remaining four sampling
events were somewhat lower or similar to the concentrations at IN and AP.
Sulfate concentrations in raw water ranged from 22.2 to 24.8 mg/L and averaged 23.8 mg/L. After pH
adjustment and adsorption, sulfate levels remained unchanged at 23.6 to 24.0 mg/L (on average).
Fluoride results ranged from 1.0 to 1.2 mg/L and averaged 1.1 mg/L following both treatment vessels.
The results indicated that the adsorptive media did not affect the amount of fluoride in water after
treatment.
40
-------
-Raw Water —•—pH Adjusted Water - By Field pH Probe —*—pH Adjusted Water - By Inline pH Probe
in 7.0 -
01/28/08 04/17/08 07/06/08 09/24/08 12/13/08 03/03/09 05/22/09 08/10/09 10/29/09 01/17/10 04/07/10
Date
Figure 4-17. pH Values Before and After Adjustment
Due to difficulties experienced by the operator with the equipment, DO was measured only once while
ORP was measured twice. On May 28, 2008, both measurements were discontinued. DO levels ranged
from 3.0 to 3.7 mg/L throughout the treatment train. ORP readings averaged 234 mV in raw water, but
increased to an average of 295 mV after chlorination.
4.5.2 Backwash Wastewater Sampling. Backwash was not performed during the performance
evaluation study.
4.5.3 Distribution System Water Sampling. Prior to the installation/operation of the treatment
system, four baseline distribution system water samples were collected from three residences, previously
used for LCR sampling, on October 19, 2005, November 22, 2005, December 14, 2005, and January 24,
2006. Following startup of the treatment system, distribution system water sampling continued on a
quarterly basis at the same three locations, with samples collected from July 2008 through October 2009.
Table 4-8 summarizes the results of the distribution system sampling.
The most noticeable change in the distribution system samples since the system began operation was a
decrease in arsenic concentration. Baseline arsenic concentrations averaged 35.6, 37.3, and 36.6 (ig/L for
the first draw samples at the DS1, DS2, and DS3 sampling locations, respectively. After the performance
evaluation study began, arsenic concentrations at DS1, DS2, and DS3 averaged 0.5, 1.5, and 0.7 (ig/L,
respectively. Although arsenic concentrations in the distribution system were low, there were three
sampling events (i.e., July 8, 2008, April 15, 2009, and October 20, 2009) when the arsenic levels in the
distribution water were higher than those in the system effluent. It is surmised that some redissolution
41
-------
Table 4-8. Distribution System Sampling Results
Sampling
Event
No.
BL1
BL2
BL3
BL4
1
2
3
4
5
6
Date
10/19/05
11/22/05(a)
12/14/05
01/24/06
07/08/08
10/16/08(b)
01/20/09
04/15/09(c)
07/14/09(d)
10/20/09(e)
DS1
Tautolo #0020-409-52600
LCR
1st draw
Stagnation Time
hrs
7.0
13.3
NA
10.3
7.2
NA
9.0
9.5
7.3
NA
Q.
s.u.
8.1
8.0
8.3
8.2
7.0
NA
8.2
7.0
6.8
NA
Alkalinity
mg/L
158
154
154
154
163
NA
142
152
158
NA
3.
M9/L
30.6
36.5
34.2
41.0
1.2
NA
0.3
0.3
0.2
NA
o
1L.
M9/L
<25
<25
<25
<25
<25
NA
<25
<25
<25
NA
c
S
M9/L
1.5
1.3
0.9
0.6
1.1
NA
<0.1
0.2
0.1
NA
.a
a.
M9/L
<0.1
0.1
<0.1
<0.1
0.3
NA
0.7
2.4
2.0
NA
5
M9/L
36.6
22.2
9.0
8.2
260
NA
34
99.6
74.8
NA
DS2
Saraficio #0020-409-51 200
LCR
1 st draw
Stagnation Time
hrs
8.9
12.5
NA
8.0
9.0
8.3
7.5
7.8
NA
7.3
Q.
S.U.
7.9
8.1
8.2
8.1
7.0
7.3
7.5
7.1
NA
7.5
Alkalinity
mg/L
158
145
150
154
160
157
158
161
NA
148
3.
M9/L
31.7
39.5
36.3
41.6
1.4
0.5
0.4
4.0
NA
1.3
o
1L.
M9/L
<25
<25
<25
<25
<25
<25
<25
<25
NA
<25
c
S
M9/L
2.3
1.1
2.0
0.3
0.7
0.2
<0.1
0.2
NA
0.7
.a
a.
M9/L
<0.1
0.1
0.3
<0.1
0.7
0.5
0.3
0.4
NA
0.5
5
M9/L
4.3
12.8
4.0
9.1
220
166
156
145
NA
169
DS3
Johnson #0020-409-50200
LCR
1st Draw
Stagnation Time
hrs
8.2
8.0
NA
7.0
9.5
7.0
7.0
NA
7.0
7.0
Q.
S.U.
7.9
8.1
8.2
8.3
6.8
7.2
8.0
NA
6.8
7.3
Alkalinity
mg/L
158
150
145
154
147
155
158
NA
162
154
3
M9/L
30.4
40.3
34.2
41.3
0.5
0.4
0.6
NA
0.5
1.3
o
1L.
M9/L
<25
<25
<25
<25
<25
<25
<25
NA
<25
<25
c
S
M9/L
1.9
0.9
0.8
0.1
0.4
0.2
0.2
NA
<0.1
0.5
.a
a.
M9/L
0.1
0.2
<0.1
<0.1
2.9
1.8
0.5
NA
1.8
1.1
5
M9/L
81.8
1.6
10.6
1.2
283
39.5
138
NA
124
78.2
(a) DS2 sampled on 021/21/05.
(b) DS1 not available for sampling on 10/16/08.
(c) DS3 not available for sampling on 04/15/09.
(d) DS2 not available for sampling on 07/14/09.
(e) DS 1 not available for sampling on 10/20/09.
BL = baseline sampling; NA = not available.
Lead action level =15 ug/L; Copper action level = 1,300 ug/L
Alkalinity measured in mg/L as CaCO3.
-------
—*—AfterVessel A (TA)
~4" AfterVessel B (TB)
«• DS1
D DS2
O DS3
20,000 25,000
Bed Volume (BV)
Figure 4-18. Comparison of Arsenic Concentrations in System Effluent and Distribution System
and/or resuspension of arsenic particles might have occurred in the distribution system. Figure 4-18
shows arsenic levels in the system effluent and distribution system plotted against BV.
Lead concentrations ranged from less than the detection limit of 0.1 to 2.9 (ig/L, with none of the samples
exceeding the action level of 15 (ig/L. Copper concentrations ranged from 34.1 to 283 (ig/L, with no
samples exceeding the 1,300 (ig/L action level. Measured pH values ranged from 6.8 to 8.2 and averaged
7.2, which were 0.3 units higher than the average pH value immediately after the adsorption vessels.
Higher pH values in the distribution system might be due to CO2 degassing. Compared to an average
value of 8.1 before the treatment sytem became operational, the lowered pH values appeared to have
some effects on the lead and copper concentrations in the distribution system. Lead and copper
concentrations were observed to increase slightly after the system was put into service. Before the system
was put into service, lead levels averaged <0.1, 0.1, and 0.1 (ig/L at DS1, DS2, and DS3, respectively,
while copper levels averaged 19.0, 7.6, and 23.8 (ig/L, respectively. After the system was put into
service, lead levels averaged 1.4, 0.5, and 1.6 (ig/L, respectively, and copper levels averaged 117, 171,
and 133 (ig/L, respectively.
Alkalinity levels exhibited no change, with concentrations ranging from 142 to 163 mg/L (as CaCO3).
Total iron concentrations were always less than the MDL of 25 (ig/L for all distribution sampling events,
including baseline sampling. Total Mn concentrations in the distribution system samples were typically
low, ranging from <0.1 to 1.1 (ig/L.
43
-------
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
treatment system was $115,306 (see Table 4-9). The equipment cost was $86,018 (or 75% of the total
capital investment), which included $48,715 for the skid-mounted unit, $18,402 for the CO2 pH control
system, $13,861 for the AD-33 media ($365/ft3 or $10.42/lb to fill two vessels), $992 for the gravel
underbedding, $1,339 for additional sample taps and totalizer/meters, and $2,709 for shipping.
The site engineering cost was $12,897, or 11% of the total capital investment. Because an engineering
plan or a permit submittal package was not required for the Covered Wells site, the engineering cost
represents a small fraction of total capital cost.
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, and perform system shakedown
and startup. The installation cost was $16,391, or 14% of the total capital investment.
Table 4-9. Capital Investment Cost for APU Arsenic Adsorption System
Description
Quantity
Cost
%of
Capital
Investment
Equipment Cost
APU Skid-Mounted System
CO2 pH Control System
AD-33 Media
Gravel Underbedding
Sample Taps & Totalizer/Meters(a)
Shipping
Equipment Total
1
1
38 ft3
-
-
-
-
$48,715
$18,402
$13,861
$992
$1,339
$2,709
86,018
-
-
-
-
-
-
75
Engineering Cost
Vendor Labor
Vendor Travel
Subcontractor Labor
Subcontractor Travel
Engineering Total
73 hr
2 day
-
-
-
$6,967
$1,008
$4,594
$329
$12,897
-
-
-
-
11
Installation Cost
Vendor Labor
Subcontractor Labor
Installation Total
Total Capital Investment
60 hr
-
-
-
$7,256
$9,135
$16,391
$115,306
-
-
14
100
(a) Additional taps and totalizer/meters for study purposes.
The total capital cost of $115,306 was normalized to the system's design capacity of 63 gpm (90,720
gpd), which resulted in $l,830/gpm of design capacity ($1.27/gpd). The capital cost also was converted
to an annualized cost of $10,884/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
44
-------
week at the system design flowrate of 63 gpm to produce 33,112,800 gal of water per year, the unit
capital cost would be $0.33/1,000 gal. Because the system operated only 4.38 hr/day at approximately 60
gpm on average (see Table 4-5), producing an estimated 5,755,320 gal of water annually, the unit capital
cost increased to $1.89/1,000 gal at this reduced rate of use.
4.6.2 Operation and Maintenance Cost. The O&M cost included the cost for items such as
media replacement and disposal, CO2 usage, electricity consumption, and labor (Table 4-10). Although
media replacement did not occur during the performance evaluation study, the media replacement cost
would have represented the majority of the O&M cost and was estimated to be $18,405 to change out the
media in both vessels. This media changeout cost would include the cost for media, the gravel
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 media
run length to the 10 |o,g/L arsenic breakthrough (Figure 4-19).
The chemical cost associated with system operation included the cost for NaOCl for prechlorination and
CO2 gas for pH adjustment. NaOCl had already been used at the site prior to the installation of the APU
unit for disinfection purposes. The presence of the APU system did not affect the use rate of the NaOCl
solution. Therefore, the incremental chemical cost for chlorine was negligible. During the performance
evaluation period the 50-lb CO2 cylinders were replaced a total of 91 times, or once every eight days.
Each changeout cost $38.74, which included the replacement and delivery charges. The CO2 cost for the
study period was $3,525 or $0.30/1,000 gal of water treated.
Table 4-10. Operation and Maintenance Cost for APU Arsenic Adsorption System
Cost Category Value Assumptions
Estimated Volume Processed (gal)
11,686,000
During 765-day study period; equivalent to
5,576,000 gal annually
Media Replacement and Disposal Cost
Media Replacement ($)
Labor, Travel, Freight, & Disposal ($)
Media Replacement and Disposal
($/l,000 gal)
$13,861
$4,544
See Figure 4-19
$365/ftJfor38ftj
Based upon media run length at 10-|j,g/L
arsenic breakthrough
CO 2 Cost
CO2 Cost ($)
Unit CO2 Cost ($/l,000 gal)
$3,525
$0.30
Based on cost of CO2 cylinders (50-lb) for pH
adjustment
Electricity Cost
Electricity ($/l,000 gal)
$0.05
Includes power used by the booster pumps
Labor Cost
Average Weekly Labor (hr)
Labor through Study (hr)
Labor Cost ($)
Unit Labor Cost ($/l,000 gal)
Total O&M Cost/1,000 gal
2.3
251
$5,522
$0.47
See Figure 4-19
1.5 hr/visit, 1.5 visit/week (on average)
109 week through study
Labor rate = $22.00/hr
Media replacement cost (based upon media
run length at 10-|ag/L arsenic breakthrough) +
$0.30 (CO2 cost) + $0.05 (electrical cost)+
$0.47 (labor cost)
Comparison of electrical bills supplied by TOUA prior to system installation and since startup indicated
an additional 3,304 kWh per year was required to run the system. The cost of the additional electricity
45
-------
was $299.75, which included the power necessary to run the three booster pumps. The electrical cost
associated with the operation of the system was calculated to be $0.05/1,000 gal of water treated.
Under normal operating conditions, routine labor activities to operate and maintain the system consumed
1.5 hr/day, 1 to 2 days per week, or 2.3 hr/week (on average). The labor cost incurred during the
performance evaluation study was $5,522 or $0.47/1,000 gal of water treated. This estimation assumed
that maintenance and operational procedures were consistently performed through the completion of the
performance evaluation study.
$3.50
$3.00
$2.50 -
$2.00 -
$1.50 -
$1.00
$0.50
$0.00
10
20
30 40 50 60 70
Media Working Capacity, Bed Volumes (xlOOO)
90
100
Note: One bed volume equals 38 ft3 (284 gal)
Figure 4-19. Media Replacement and Other Operation and Maintenance Cost
46
-------
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. 2006. Final System Performance Evaluation Study Plan: U.S. EPA Demonstration of Arsenic
Removal Technology at Covered Wells, Tohono O 'odham Nation, Arizona. 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.L. Oxenham, and W.E. 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(3): 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.
Farley, D. 2004. Preliminary Arsenic Feasibility Study: A Study to Evaluate and Recommend Options
for Reducing Arsenic Levels in Drinking Water on the Tohono O 'odham Nation, Indian Health
Services, Sells, AZ.
Cumming, L.J., A.S.C. Chen, and L. Wang. 2009. Arsenic Removal from Drinking Water by Adsorptive
Media, U.S. EPA Demonstration Project at Rollinsford, NH, Final Performance Evaluation
Report. EPA/600/R-09/017. U.S. Environmental Protection Agency, National Risk Management
Research Laboratory, Cincinnati, OH.
Wang, L., W.E. Condit, and A.S.C 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.
Williams, S., A.S.C. Chen, and L. Wang. 2010. Arsenic Removal from Drinking Water by Adsorptive
Media, U.S. EPA Demonstration Project at Webb Consolidated Independent School District in
Bruni, TX, Final Performance Evaluation Report. EPA/600/R-10/040. U.S. Environmental
Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH.
47
-------
APPENDIX A
OPERATIONAL DATA
-------
Table A-l. EPA Arsenic Demonstration Project at Covered Wells in Tohono O'odham Nation, AZ - Daily System Operation Log Sheet
Week No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Date
02/13/08
02/20/08
02/21/08
02/22/08
02/25/08
02/27/08
02/28/08
03/03/08
03/07/08
03/10/08
03/12/08
03/13/08
03/14/08
03/17/08
03/18/08
03/19/08
03/20/08
03/24/08
03/27/08
03/31/08
04/01/08
04/04/08
04/07/08
04/11/08
04/15/08
04/17/08
04/21/08
04/23/08
04/28/08
04/29/08
05/02/08
05/05/08
05/06/08
05/08/08
05/12/08
05/16/08
05/19/08
05/22/08
05/27/08
05/28/08
06/02/08
06/04/08
06/09/08
06/13/08
06/16/08
06/20/08
06/25/08
06/26/08
07/01/08
07/07/08
07/08/08
07/14/08
07/16/08
07/18/08
07/25/08
07/28/08
07/30/08
08/06/08
08/11/08
08/13/08
08/15/08
08/18/08
08/22/08
Time
NA
13:31
11:18
12:47
15:00
10:00
13:00
15:35
14:32
13:53
14:20
10:31
11:02
9:45
10:22
9:42
14:38
10:15
13:05
9:26
10:25
10:25
9:03
11:36
10:35
15:27
10:58
11:44
15:15
10:15
12:16
9:45
15:02
10:50
12:40
14:20
14:36
10:30
11:00
13:05
9:04
10:50
15:30
11:52
14:00
15:03
15:00
12:20
13:53
12:20
12:08
14:47
16:00
11:45
11:50
11:10
NA
9:42
14:35
16:00
9:05
13:15
15:00
Well
Running
Well#1
or 2
NA
NR
2
NR
2
NR
2
2
2
NR
2
NR
NR
NR
NR
NR
1
NR
1
NR
2
NR
NR
NR
1
1
2
1
1
2
1
2
1
1
2
1
2
1
2
1
1
2
1
2
2
2
1
2
2
2
1
2
1
2
1
2
2
1
2
2
1
1
1
Well No. 1
Cum.
Hours
Well
hr
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
7.0
9.8
10.9
17.5
20.0
24.9
32.3
36.2
38.5
40.8
55.0
63.5
Cum.
Volume
gal
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
1,320
25,070
42,240
95,770
98,990
116,110
134,390
134,520
152,960
174,770
196,040
227,840
249,540
272,060
277,550
325,240
340,740
371,280
402,610
421,540
445,450
477,400
480,920
510,040
556,950
556,990
583,750
594,780
598,910
624,380
633,730
653,050
681,710
696,520
704,490
717,100
769,630
798,360
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
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
63.7
65.7
62.6
64.3
62.3
65.7
64.5
63.3
57.8
91.4
61.7
56.3
Well No. 2
Cum.
Hours
Well
hr
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
17.0
22.3
25.2
44.5
52.7
59.9
83.0
98.9
104.2
107.1
107.1
116.0
Cum.
Volume
gal
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
53,210
79,450
91,490
115,180
116,390
140,540
157,300
171,620
180,000
219,380
232,150
271,210
282,290
315,300
337,140
356,230
375,030
427,630
457,990
492,170
535,650
593,160
595,940
665,130
711,700
729,330
791,340
810,290
820,990
891,650
921,860
947,730
1,032,480
1,090,530
1,109,990
1,120,540
1,120,540
1,153,310
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
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
60.8
59.6
61.5
61.0
61.4
59.9
61.1
60.8
61.2
60.6
0.0
61.4
Instrument Panel
Vessel A
Inst.
Flowrate
gpm
NA
NA
30.3
NA
30.0
NA
29.3
27.2
29.3
NA
30.3
NA
NA
NA
NA
NA
36.4
NA
NA
NA
29.3
NA
NA
NA
35.5
32.3
30.2
30.9
32.2
31.6
32.2
30.6
31.2
35.7
33.3
31.4
31.9
36.0
31.0
33.9
33.1
29.0
33.0
27.3
30.0
29.9
35.0
31.0
30.7
28.1
30.7
31.1
52.8
30.1
31.4
27.7
29.0
34.7
28.4
27.8
28.1
33.2
28.5
Incremental
Volume
gal
0
35,920
6,848
7,046
13,444
11,926
9,798
24,162
31,496
20,122
21,931
1,577
6,453
20,274
6,978
2,354
8,636
26,196
20,815
26,914
7,248
19,874
17,185
26,330
14,924
27,467
25,444
14,987
40,104
2,090
21,686
18,374
8,137
14,532
30,676
17,365
35,648
17,736
28,592
14,025
34,344
18,521
45,040
28,971
27,549
34,938
47,183
2,081
49,946
48,692
9,602
44,530
16,296
7,221
49,507
19,887
22,701
57,903
36,954
14,360
11,175
26,895
31,779
Bed
Volume
no.
0
253
301
351
445
529
598
769
990
,132
,287
,298
,343
,486
,535
,552
,612
,797
,943
2,133
2,184
2,324
2,445
2,630
2,736
2,929
3,108
3,214
3,496
3,511
3,664
3,793
3,850
3,953
,169
,291
,542
,667
,868
,967
5,209
5,339
5,656
5,860
6,055
6,301
6,633
6,647
6,999
7,342
7,410
7,723
7,838
7,889
8,238
8,378
8,537
8,945
9,205
9,307
9,385
9,575
9,799
Average
Flowrate
gpm
0.0
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
30.9
33.5
30.1
31.9
31.0
31.3
31.6
31.1
31.5
35.8
31.6
30.4
VesselB
Inst.
Flowrate
gpm
NA
NA
28.4
NA
31.2
NA
31.0
31.2
31.2
NA
31.6
NA
NA
NA
NA
NA
30.7
NA
NA
NA
31.4
NA
NA
NA
31.6
34.1
32.1
32.9
32.7
27.0
34.4
30.5
30.5
34.7
31.5
30.2
29.0
31.0
30.8
30.2
33.8
30.4
31.0
30.3
29.5
28.4
31.0
29.0
27.5
31.1
29.9
31.5
54.2
31.3
30.9
29.5
28.2
33.6
27.6
29.8
29.8
30.8
30.6
Incremental
Volume
gal
0
35,098
6,837
6,991
13,103
1 1 ,542
9,584
23,474
30,514
19,721
21,707
1,532
6,389
19,947
6,937
3,296
8,542
26,082
20,035
25,972
7,447
21,480
13,841
26,146
14,579
26,725
24,891
14,352
40,351
1,969
20,637
17,761
7,675
14,117
29,496
16,733
34,219
17,177
27,256
13,502
32,940
17,689
43,622
27,974
26,482
33,558
45,585
1,981
47,898
46,734
9,275
42,747
15,634
6,933
47,550
19,090
21,743
55,557
35,317
13,718
10,669
25,746
30,539
Bed
Volume
no.
0
247
295
345
437
518
586
751
966
1,105
1,258
1,268
1,313
1,454
1,503
1,526
1,586
1,770
1,911
2,094
2,146
2,297
2,395
2,579
2,682
2,870
3,045
3,146
3,430
3,444
3,590
3,715
3,769
3,868
4,076
4,194
4,435
4,556
4,748
4,843
5,075
5,199
5,506
5,703
5,890
6,126
6,447
6,461
6,798
7,128
7,193
7,494
7,604
7,653
7,988
8,122
8,275
8,667
8,915
9,012
9,087
9,268
9,483
Average
Flowrate
gpm
0.0
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
29.7
32.2
28.9
30.6
29.7
29.9
30.4
29.7
30.1
34.2
30.2
29.3
System Pressure
(psi)
Inlet
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
9
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
13
13
12
12
12
9
12
12
12
12
10
9
8
14
10
11
12
11
10
10
15
8
8
9
9
5
10
10
NA
9
10
10
9
12
9
10
9
10
9
Outlet
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
8
9
8
8
7
9
8
8
8
8
5
4
4
10
6
7
8
7
5
5
5
5
4
6
6
3
6
5
NA
5
8
8
5
8
5
4
5
5
5
Pressure
Differential for
Vessel (psi)
A
NA
NA
1.3
NA
0.0
NA
0.0
NA
NA
NA
5.0
NA
NA
NA
NA
NA
NA
NA
NA
NA
3.0
NA
NA
NA
2.5
2.5
2.5
2.5
3.0
2.5
2.5
6.0
7.0
2.0
0.0
1.0
2.5
2.5
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
10.0
9.5
5.0
4.0
4.0
2.0
9.0
9.0
2.5
0.0
1.0
2.0
0.0
0.0
2.5
3.0
2.5
B
NA
NA
2.0
NA
1.5
NA
0.0
NA
NA
NA
5.0
NA
NA
NA
NA
NA
NA
NA
NA
NA
5.0
NA
NA
NA
2.5
4.0
2.5
2.5
5.0
2.0
4.0
4.0
4.0
2.5
1.0
2.5
3.0
2.5
2.5
5.0
5.0
3.0
5.0
0.0
2.0
2.5
7.0
2.0
2.5
2.5
3.0
2.0
8.0
2.5
2.5
2.0
2.5
2.5
1.0
1.0
1.0
4.0
2.5
-------
Table A-l. EPA Arsenic Demonstration Project at Covered Wells in Tohono O'odham Nation, AZ - Daily System Operation Log Sheet
Week No.
29
30
31
32
33
34
35
36
37
38
39
40
41
43
44
45
46
47
48
48
49
50
51
53
55
56
57
58
59
60
61
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
Date
08/26/08
08/29/08
09/02/08
09/04/08
09/10/08
09/15/08
09/22/08
09/25/08
10/01/08
10/06/08
10/07/08
10/15/08
10/22/08
10/24/08
10/28/08
11/05/08
11/14/08
11/18/08
12/02/08
12/10/08
12/16/08
12/26/08
12/31/08
01/07/09
01/13/09
01/16/09
01/20/09
01/26/09
01/30/09
02/04/09
02/17/09
03/03/09
03/06/09
03/10/09
03/17/09
03/25/09
03/27/09
03/31/09
04/03/09
04/08/09
04/15/09
04/17/09
04/27/09
04/30/09
05/06/09
05/08/09
05/15/09
05/20/09
05/29/09
06/01/09
06/05/09
06/10/09
06/16/09
06/24/09
06/26/09
07/01/09
07/10/09
07/14/09
07/20/09
07/24/09
07/29/09
08/07/09
Time
14:25
12:15
10:32
14:50
15:15
12:30
10:00
10:15
12:40
10:47
11:00
14:37
9:21
15:00
13:49
15:24
9:27
9:46
14:31
13:53
9:33
14:50
9:15
14:05
11:35
13:05
8:54
15:25
16:00
12:15
8:48
11:05
13:22
11:12
9:35
15:30
14:40
11:50
12:40
9:44
12:10
14:50
15:45
14:21
14:45
14:42
14:00
11:42
12:20
14:04
15:40
15:30
10:03
10:10
15:15
15:10
10:30
9:33
12:00
15:00
10:45
14:45
Well
Running
Well#1
or 2
1
NA
2
1
1
1
2
1
1
1
2
1
2
2
2
1
2
1
1
1
1
2
2
1
1
2
2
1
1
1
2
1
NA
1
2
1
2
2
1
NA
1
2
1
1
2
2
1 8, 2
1
2
1
1
1
1
1
1
2
1
1
2
1
2
2
Well No. 1
Cum.
Hours
Well
hr
70.4
NA
85.2
89.1
98.7
107.9
115.2
119.5
137.7
144.5
145.3
156.5
167.7
171.6
179.6
193.3
210.1
215.6
235.8
247.3
256.6
274.4
286.6
295.1
304.0
314.1
320.1
330.7
335.8
344.7
361.6
382.0
NA
389.3
399.5
409.5
413.0
419.5
424.5
431.6
442.3
446.3
465.6
475.0
488.4
496.3
510.6
522.1
538.7
545.4
552.1
560.1
570.3
593.5
599.3
612.1
644.1
662.1
NA
686.1
696.1
722.1
Cum.
Volume
gal
823,450
NA
877,370
891,860
926,760
960,140
986,300
1,001,820
1,068,040
1,092,500
1,095,140
1,135,090
1,174,710
1,188,610
1,216,850
1,265,620
1,326,340
1,345,370
1,417,120
1,458,240
1,490,860
1,555,830
1,593,650
1,631,470
1,661,860
1,697,880
1,722,340
1,758,240
1,776,480
1,809,160
1,868,860
1,945,620
NA
1,959,750
1,992,250
2,025,260
2,037,470
2,060,490
2,076,940
2,103,650
2,141,950
2,155,780
2,223,690
2,258,180
2,304,510
2,319,690
2,386,040
2,429,060
2,485,080
2,507,590
2,531,040
2,560,140
2,596,230
2,681,800
2,700,630
2,745,910
2,861,840
2,923,750
2,987,720
3,014,270
3,048,460
3,141,180
Average
Flow/rate
gpm
60.6
NA
60.7
61.9
60.6
60.5
59.7
60.2
60.6
60.0
55.0
59.4
59.0
59.4
58.8
59.3
60.2
57.7
59.2
59.6
58.5
60.8
51.7
74.2
56.9
59.4
67.9
56.4
59.6
61.2
58.9
62.7
NA
32.3
53.1
55.0
58.1
59.0
54.8
62.7
59.7
57.6
58.6
61.2
57.6
32.0
77.3
62.3
56.2
56.0
58.3
60.6
59.0
61.5
54.1
59.0
60.4
57.3
NA
18.4
57.0
59.4
Well No. 2
Cum.
Hours
Well
hr
122.2
NA
135.7
138.2
145.9
154.6
169.5
176.3
183.7
191.8
199.3
218.4
232.5
236.9
241.5
257.4
268.5
278.0
307.5
320.1
327.0
339.2
347.2
358.0
371.9
372.9
377.9
384.9
390.9
397.9
416.9
436.9
NA
446.9
NA
472.9
476.9
480.9
484.9
490.9
502.9
505.9
518.9
522.9
533.9
538.9
548.9
554.9
569.9
577.9
581.9
591.9
600.9
611.9
619.9
633.9
660.9
672.9
NA
713.9
733.9
774.9
Cum.
Volume
gal
1,175,720
NA
,224,150
,234,170
,270,070
,294,270
' ,348,560
,373,380
,400,240
' ,429,890
,457,100
,526,840
' ,578,470
,594,630
,611,410
,671,140
,710,270
,744,730
,852,180
,898,280
,923,440
,966,920
2,001,500
2,036,100
2,087,330
2,093,600
2,110,150
2,136,140
2,159,670
2,182,040
2,251,340
2,324,110
NA
2,364,550
2,401,840
2,456,970
2,468,790
2,485,070
NA
2,523,020
2,565,390
2,576,260
2,622,890
2,639,250
2,677,790
2,682,570
2,732,020
2,753,120
2,809,130
2,837,600
2,851,990
2,888,560
2,922,230
2,961,950
2,993,310
3,041,900
3,142,420
3,185,300
3,276,230
3,337,620
3,409,340
3,561,350
Average
Flowrate
gpm
60.2
NA
59.8
66.8
77.7
46.4
60.7
60.8
60.5
61.0
60.5
60.9
61.0
61.2
60.8
62.6
58.8
60.5
60.7
61.0
60.8
59.4
72.0
53.4
61.4
104.5
55.2
61.9
65.4
53.3
60.8
60.6
NA
67.4
NA
35.3
49.3
67.8
NA
63.3
58.8
60.4
59.8
68.2
58.4
15.9
82.4
58.6
62.2
59.3
60.0
61.0
62.4
60.2
65.3
57.8
62.0
59.6
NA
25.0
59.8
61.8
Instrument Panel
Vessel A
Inst.
Flowrate
gpm
32.5
30.8
27.9
30.0
29.7
30.9
30.3
31.2
30.6
31.2
31.1
30.8
28.7
31.3
29.7
31.2
29.9
29.5
30.6
30.1
31.9
30.7
31.7
32.1
30.6
30.0
29.9
32.1
27.5
31.0
29.1
29.7
30.7
29.8
30.7
31.0
29.9
28.9
31.6
29.0
31.0
31.0
29.4
0.0
0.0
NA
0.0
0.0
26.1
28.7
30.5
30.5
29.0
31.2
29.8
28.9
29.0
26.3
29.8
31.4
31.8
30.0
Incremental
Volume
gal
24,423
16,509
35,387
12,140
33,866
32,223
40,837
19,800
48,473
27,743
15,610
55,395
47,133
15,048
23,294
55,911
50,220
28,308
91,524
43,984
30,197
55,153
36,984
37,088
41,441
21,762
20,775
31,504
21,074
27,922
65,833
71,654
12,635
20,407
36,613
44,624
12,765
20,021
16,516
25,372
42,696
10,886
59,584
20,426
0
NA
0
0
17,238
26,566
18,776
31,768
33,955
60,908
24,162
46,497
108,190
51,610
79,227
44,503
56,252
126,416
Bed
Volume
no.
9,971
10,087
10,336
10,421
10,660
10,887
1M74
1 ,314
1 ,655
1-.851
1 ,961
12,351
12,683
12,789
12,953
13,346
13,700
13,899
14,544
14,854
15,066
15,455
15,715
15,976
16,268
16,421
16,568
16,790
16,938
17,135
17,598
18,103
18,192
18,336
18,593
18,908
18,998
19,139
19,255
19,434
19,734
19,811
20,230
20,374
20,374
NA
20,374
20,374
20,496
20,683
20,815
21,039
21,278
21,707
21,877
22,204
22,966
23,330
23,888
24,201
24,597
25,487
Average
Flowrate
gpm
31.1
NA
20.8
31.6
32.6
30.0
30.7
29.7
31.6
31.0
31.3
30.5
31.0
30.2
30.8
31.5
30.0
31.5
30.7
30.4
31.1
30.6
30.5
32.0
30.3
32.7
31.5
29.8
31.6
29.3
30.6
29.6
NA
19.7
NA
20.7
28.4
31.8
30.6
32.3
31.3
25.9
30.7
25.4
0.0
NA
0.0
0.0
9.1
30.1
29.2
29.4
29.5
29.7
29.2
28.9
30.6
28.7
NA
11.4
31.3
31.4
Vessel B
Inst.
Flowrate
gpm
30.8
33.3
29.7
31.1
30.4
29.0
29.8
29.4
27.1
31.8
25.9
31.1
29.5
29.3
29.8
31.4
26.6
28.7
29.2
29.3
29.8
28.6
30.1
31.7
31.8
29.0
28.9
30.0
33.6
30.1
27.1
28.6
28.7
26.7
27.2
32.0
30.0
29.5
29.0
26.8
30.9
29.6
29.0
30.2
30.6
NA
29.8
31.9
28.2
30.5
29.7
27.2
31.6
30.0
30.9
29.3
28.9
30.1
30.2
28.1
29.2
30.4
Incremental
Volume
gal
23,374
15,784
33,755
1,599
42,316
30,730
39,165
19,053
46,620
26,853
15,113
53,108
45,211
14,406
22,420
53,758
48,191
27,190
88,256
42,417
29,858
52,687
35,870
35,667
39,888
20,884
19,966
30,204
20,152
27,729
63,277
69,244
12,193
19,594
35,269
43,068
12,338
19,323
16,048
24,603
41,131
10,561
57,560
24,883
42,268
NA
66,530
29,776
58,098
34,644
12,023
32,738
35,193
62,901
24,876
47,904
107,545
50,326
74,964
42,381
53,501
120,484
Bed
Volume
no.
9,648
9,759
9,997
10,008
10,306
10,523
10,798
10,932
11,261
11,450
11,556
11,930
12,249
12,350
12,508
12,887
13,226
13,417
14,039
14,338
14,548
14,919
15,172
15,423
15,704
15,851
15,991
16,204
16,346
16,541
16,987
17,475
17,560
17,698
17,947
18,250
18,337
18,473
18,586
18,759
19,049
19,123
19,529
19,704
20,002
NA
20,470
20,680
21,089
21,333
21,418
21,648
21,896
22,339
22,514
22,851
23,609
23,963
24,491
24,790
25,166
26,015
Average
Flowrate
gpm
29.7
NA
19.9
4.2
40.8
28.6
29.4
28.6
30.4
30.0
30.3
29.2
29.8
28.9
29.7
30.3
28.8
30.2
29.6
29.3
30.7
29.3
29.6
30.8
29.2
31.4
30.3
28.6
30.3
29.1
29.4
28.6
NA
18.9
NA
19.9
27.4
30.7
29.7
31.3
30.2
25.1
29.7
30.9
28.9
NA
45.6
28.4
30.6
39.3
18.7
30.3
30.5
30.7
30.0
29.8
30.4
28.0
NA
10.9
29.7
30.0
System Pressure
(PSi)
Inlet
11
10
10
10
10
8
8
8
10
12
9
10
9
9
8
18
8
10
10
11
10
10
10
10
14
10
10
12
8
10
13
8
8
11
11
10
10
8
8
10
12
8
10
8
8
NA
8
10
8
7
8
9
8
9
8
8
8
11
6
6
7
7
Outlet
5
4
4
5
5
4
4
4
5
8
5
7
5
4
4
5
4
7
5
5
5
5
5
6
10
6
8
8
4
6
10
4
5
8
7
4
5
4
5
6
9
4
6
4
2
NA
4
6
4
4
6
5
4
5
4
4
5
8
4
4
4
4
Pressure
Differential for
Vessel (psi)
A
2.0
2.0
1.0
2.0
1.0
2.0
2.0
2.0
2.0
1.5
1.0
2.0
2.0
0.0
2.0
1.0
0.0
1.0
1.0
1.5
1.0
1.5
1.0
2.5
2.5
2.0
1.0
2.0
5.0
2.0
0.5
2.0
2.5
2.0
2.0
2.5
2.0
2.0
2.5
2.5
2.5
2.5
2.5
2.5
2.5
NA
2.5
5.5
2.0
2.0
2.5
2.5
2.5
2.5
2.5
2.5
2.0
2.0
2.0
0.0
0.0
2.0
B
2.5
2.5
2.0
2.5
2.5
4.0
1.0
2.5
2.5
2.5
1.5
2.5
2.5
2.0
2.0
2.5
0.0
1.0
2.5
2.5
2.5
2.5
2.0
3.0
2.5
2.5
2.0
2.5
3.0
3.0
2.0
2.0
2.5
2.5
2.5
2.5
2.5
2.5
3.0
2.5
3.0
3.0
3.0
2.5
2.5
NA
2.5
5.5
2.0
2.0
3.0
2.0
2.5
2.5
2.5
2.5
2.5
2.5
2.0
0.0
1.0
2.0
-------
Table A-l. EPA Arsenic Demonstration Project at Covered Wells in Tohono O'odham Nation, AZ - Daily System Operation Log Sheet
Week No.
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
Date
08/13/09
08/17/09
08/18/09
08/21/09
08/26/09
09/01/09
09/08/09
09/10/09
09/15/09
09/18/09
09/21/09
09/24/09
09/30/09
10/05/09
10/07/09
10/14/09
10/16/09
10/19/09
10/20/09
10/26/09
11/04/09
11/09/09
11/12/09
11/16/09
11/17/09
11/19/09
11/23/09
11/25/09
11/30/09
12/04/09
12/08/09
12/11/09
12/14/09
12/15/09
12/21/09
12/24/09
12/28/09
12/31/09
01/06/10
01/08/10
01/11/10
01/15/10
01/18/10
01/19/10
01/22/10
01/25/10
01/29/10
02/01/10
02/03/10
02/05/10
02/09/10
02/16/10
02/19/10
02/23/10
03/02/10
03/05/10
03/08/10
03/12/10
03/19/10
Time
14:45
14:50
10:25
10:02
9:45
15:13
11:45
10:39
9:30
9:55
9:52
13:10
10:00
15:00
11:00
11:00
11:10
9:30
10:32
13:48
9:45
10:35
15:28
10:30
9:12
15:05
13:15
12:20
9:50
11:25
9:26
10:10
14:15
8:52
10:45
12:00
10:00
12:04
12:01
9:05
11:10
15:10
11:10
9:10
11:00
10:30
13:30
14:00
10:30
12:40
14:30
9:45
9:45
14:20
10:25
11:00
13:00
10:00
15:20
Well
Running
Well#1
or 2
1
2
1
1
2
1
2
2
1
2
1
NA
2
2
1
1
2
2
2
1
2
2
1
1
1
2
2
1
2
1
2
1
2
1
1
2
1
1
1
2
1
2
1
1
1
1
1
1
1
1
2
2
1
1
2
2
2
1
1
Well No. 1
Cum.
Hours
Well
hr
739.
749.
750.
758.
770.
790.
808.
814.
829.1
836.1
845.1
NA
875.1
891.1
898.1
917.1
921.1
931.1
936.1
950.1
974.1
985.1
995.1
1005.1
1007.1
1014.1
1018.1
1021.1
1035.1
1044.1
1055.1
1064.1
1077.1
1080.1
1099.1
1109.1
1126.1
1135.1
1159.1
1162.1
1172.1
1185.1
1192.'
1193.'
1200.
1206.
1213.
1223.
1227.
1232.
1246.
1261.
1267.
1275.
1290.
1290.
1300.
1306.1
1330.1
Cum.
Volume
gal
3,201,820
3,237,550
3,241,750
3,271,410
3,315,340
3,384,910
3,450,680
3,472,230
3,524,770
3,549,980
3,583,380
NA
3,694,100
3,749,490
3,775,150
3,843,400
3,856,490
3,892,180
3,908,360
3,961,280
4,048,590
4,087,620
,123,480
,162,690
',166,950
,173,210
' ,208,650
,226,370
' ,267,520
,302,160
,341,080
,374,550
,420,850
,432,280
,501,290
,540,340
,603,770
,639,310
,722,520
,734,300
' ,769,500
,817,990
' ,843,800
' ,845,400
,873,380
,893,040
,918,680
,957,880
,969,930
,988,450
5,039,940
5,095,530
5,118,600
5,144,480
5,198,800
5,199,160
5,231,970
5,255,270
5,340,610
Average
Flowrate
gpm
59.5
59.6
70.0
61.8
61.0
58.0
60.9
59.9
58.4
60.0
61.9
NA
61.5
57.7
61.1
59.9
54.5
59.5
53.9
63.0
60.6
59.1
59.8
65.4
35.5
14.9
147.7
98.4
49.0
64.1
59.0
62.0
59.4
63.5
60.5
65.1
62.2
65.8
57.8
65.4
58.7
62.2
61.5
26.7
66.6
54.6
61.0
65.3
50.2
61.7
61.3
61.8
64.1
53.9
60.4
NA
54.7
64.7
59.3
Well No. 2
Cum.
Hours
Well
hr
798.9
819.9
822.9
834.9
853.9
874.9
902.9
909.9
923.9
931.9
942.9
NA
968.9
985.9
994.9
1015.9
1023.9
1032.9
1036.9
1058.9
1086.9
1105.9
1114.9
1127.9
NA
1135.9
1150.9
1158.9
1167.9
1179.9
1187.9
1193.9
1196.9
1197.9
1208.9
1213.9
1217.9
1223.9
1231.9
1237.9
1242.9
1248.9
1252.9
1256.9
1263.9
1270.9
1279.9
1280.9
1286.9
1291.9
1294.9
1308.9
1315.9
1325.9
1342.9
1356.9
1361.9
1370.9
1382.9
Cum.
Volume
gal
3,647,560
3,726,500
3,738,650
3,780,990
3,833,140
3,833,180
3,833,640
3,833,140
3,833,140
3,833,640
3,833,680
NA
3,841,740
3,904,700
3,938,680
4,016,050
4,045,750
4,074,470
4,089,010
4,172,410
4,274,680
4,345,590
4,377,360
4,426,370
NA
4,499,880
4,508,610
4,513,070
4,570,030
4,616,770
4,644,540
4,667,040
4,677,880
4,679,790
4,720,090
4,740,310
4,754,820
4,776,990
4,804,120
4,826,900
4,845,970
4,866,570
4,883,160
4,897,180
4,921,620
4,950,360
4,981,220
4,985,110
5,006,090
5,026,220
5,038,010
5,090,230
5,114,590
5,152,680
5,213,340
5,265,170
5,284,870
5,316,910
5,361,790
Average
Flowrate
gpm
59.9
62.7
67.5
58.8
45.7
0.0
0.3
-1.2
0.0
1.0
0.1
NA
5.2
61.7
62.9
61.4
61.9
53.2
60.6
63.2
60.9
62.2
58.8
62.8
NA
153.1
9.7
9.3
105.5
64.9
57.9
62.5
60.2
31.8
61.1
67.4
60.5
61.6
56.5
63.3
63.6
57.2
69.1
58.4
58.2
68.4
57.1
64.8
58.3
67.1
65.5
62.2
58.0
63.5
59.5
61.7
65.7
59.3
62.3
Instrument Panel
Vessel A
Inst.
Flowrate
gpm
32.5
29.5
29.2
31.7
30.4
30.9
30.8
31.1
31.5
30.3
31.3
32.9
26.9
28.4
24.2
18.1
9.5
9.4
11.0
33.8
34.3
29.0
32.2
31.2
31.5
32.2
0.0
31.2
30.4
31.4
31.2
30.9
28.9
27.5
31.7
29.6
32.1
31.4
33.2
31.9
33.1
31.3
29.8
33.0
32.0
29.4
31.5
31.8
31.1
32.1
30.1
33.0
30.3
32.0
31.0
31.2
30.6
31.4
30.9
Incremental
Volume
gal
74,813
57,378
8,593
36,538
58,651
74,656
84,960
24,093
55,099
28,097
37,616
40,279
63,970
49,339
23,728
47,058
8,889
10,229
32,599
67,234
97,271
55,672
34,733
43,532
8,366
24,206
3,579
8,335
43,514
39,267
32,116
27,558
26,544
7,077
52,494
28,265
36,399
28,507
55,173
17,194
27,727
34,442
20,730
7,820
24,765
23,236
27,781
21,967
16,937
19,658
32,676
52,832
23,680
32,476
56,710
25,184
26,336
27,970
65,246
Bed
Volume
no.
26,014
26,418
26,479
26,736
27,149
27,675
28,273
28,443
28,831
29,029
29,294
29,577
30,028
30,375
30,542
30,874
30,936
31,008
31,238
31,712
32,397
32,789
33,033
33,340
33,399
33,569
33,594
33,653
33,959
34,236
34,462
34,656
34,843
34,893
35,263
35,462
35,718
35,919
36,307
36,428
36,624
36,866
37,012
37,067
37,242
37,405
37,601
37,756
37,875
38,013
38,244
38,616
38,782
39,011
39,410
39,588
39,773
39,970
40,430
Average
Flowrate
gpm
30.4
30.8
35.8
30.4
31.5
30.3
30.8
30.9
31.7
31.2
31.3
NA
19.0
24.9
24.7
19.6
12.3
9.0
60.4
31.1
31.2
30.9
30.5
31.5
NA
26.9
3.1
12.6
31.5
31.2
28.2
30.6
27.7
29.5
29.2
31.4
28.9
31.7
28.7
31.8
30.8
30.2
31.4
26.1
29.5
29.8
28.9
33.3
28.2
32.8
32.0
30.4
30.4
30.1
29.5
30.0
29.3
31.1
30.2
Vessel B
Inst.
Flowrate
gpm
30.0
31.1
30.8
32.2
29.8
31.9
27.4
30.0
29.6
29.3
31.4
29.8
32.3
34.8
34.1
44.1
44.9
46.9
40.2
32.9
29.5
28.5
30.8
31.0
32.7
28.9
30.9
28.5
29.1
29.3
29.7
29.9
20.1
31.5
30.4
29.1
29.4
29.7
30.8
29.2
30.0
28.9
28.9
28.5
29.5
32.6
30.3
28.9
31.0
29.9
31.2
29.0
31.1
30.6
27.0
30.5
31.7
31.3
30.3
Incremental
Volume
gal
71,185
55,823
8,286
17,450
74,761
71,975
81,126
23,134
52,164
26,550
35,529
37,702
62,619
69,111
36,343
97,247
33,031
51,011
29,982
65,845
92,446
51,829
33,328
41,625
8,014
22,960
33,078
15,214
43,016
39,064
32,214
27,925
26,918
7,188
52,596
28,361
36,531
28,821
54,735
16,825
27,067
33,692
20,695
9,794
22,608
22,835
27,143
21,736
15,993
18,758
31,445
52,108
23,165
32,378
55,504
24,977
26,121
27,444
63,903
Bed
Volume
no.
26,516
26,909
26,968
27,090
27,617
28,124
28,695
28,858
29,225
29,412
29,663
29,928
30,369
30,856
31,112
31,797
32,029
32,388
32,600
33,063
33,714
34,079
34,314
34,607
34,664
34,825
35,058
35,165
35,468
35,743
35,970
36,167
36,356
36,407
36,777
36,977
37,234
37,437
37,823
37,941
38,132
38,369
38,515
38,584
38,743
38,904
39,095
39,248
39,361
39,493
39,714
40,081
40,244
40,472
40,863
41,039
41,223
41,416
41,866
Average
Flowrate
gpm
28.9
30.0
34.5
14.5
40.2
29.3
29.4
29.7
30.0
29.5
29.6
NA
18.6
34.9
37.9
40.5
45.9
44.7
55.5
30.5
29.6
28.8
29.2
30.2
NA
25.5
29.0
23.1
31.2
31.0
28.3
31.0
28.0
30.0
29.2
31.5
29.0
32.0
28.5
31.2
30.1
29.6
31.4
32.6
26.9
29.3
28.3
32.9
26.7
31.3
30.8
29.9
29.7
30.0
28.9
29.7
29.0
30.5
29.6
System Pressure
(pa)
Inlet
8
6
5
8
7
8
7
10
9
9
8
10
8
8
8
10
12
18
17
7
6
7
8
8
10
8
6
6
6
7
7
6
6
10
9
6
7
7
8
10
8
9
6
6
6
7
6
6
8
6
9
6
7
7
6
6
7
7
6
Outlet
5
4
4
4
5
4
4
5
4
4
7
4
4
4
4
4
4
4
4
4
4
3
4
4
5
4
4
4
4
4
4
4
4
5
4
4
4
4
4
4
4
4
4
5
4
4
2
3
4
4
6
4
4
4
4
4
4
4
5
Pressure
Differential for
Vessel (psi|
A
2.0
0.0
0.0
2.0
0.0
2.0
0.0
0.0
2.5
0.0
2.5
2.0
4.0
5.0
5.0
6.0
9.0
9.0
8.5
2.0
2.0
2.5
2.0
2.0
2.5
2.0
2.0
2.0
2.5
2.0
2.5
2.0
2.0
2.5
2.5
2.0
2.5
2.5
2.5
2.5
2.0
2.5
2.5
2.5
2.5
2.5
2.0
2.0
3.0
2.5
2.0
2.0
2.5
2.5
2.5
2.0
1.5
2.5
2.5
B
2.5
2.0
0.0
2.5
2.5
2.5
2.0
2.0
3.0
2.0
2.5
2.5
4.0
5.0
5.0
7.0
9.0
9.0
8.0
2.5
2.5
2.5
2.5
2.0
2.5
2.5
2.0
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
3.0
3.0
2.5
2.5
2.5
3.5
3.0
3.0
3.0
2.5
2.5
2.5
2.5
2.5
2.5
2.5
3.0
2.5
2.0
2.0
2.5
2.5
NOTE:
(a) Bed volume = 19 cu.ft. (142 gal) for Vessel A, 19 cu.ft. (142 gal) for Vessel B, or 38 cu.ft. (284 gal) tola for two vessels.
NR = Not Running; NA = Not Availble.
Flowrate readings on each vessel are instantaneous.
-------
APPENDIX B
ANALYTICAL DATA
-------
Table B-l. Analytical Results from Treatment Plant Sampling at Covered Wells in Tohono O'odham Nation, AZ
Sampling Date
Sampling Location
Parameter Unit
Bed Volume
Alkalinity
Fluoride
Sulfate
Nitrate (as N)
Total P (as P )
Silica (as SiO2)
Turbidity
PH
Temperature
DO
ORP
Free Chlorine
Total Chlorine
Total Hardness
Ca Hardness
Mg Hardness
As (total)
As (soluble)
As (particulate)
As (III)
As(V)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
U (total)
V (total)
itf
mg/L|s|
mg/L
mg/L
mg/L
ng/L
mg/L
NTU
S.U.
•c
mg/L
mV
mg/L
mg/L
mg/L|a|
mg/L1"
mg/L1"
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
02/13/08
IN
145
-
-
<10
NA|b)
1.4
8.1
NA
NA
NA
NA
NA
-
-
35.6
-
-
49
1.3
-
7.0
_
AP
146
-
-
<10
NA|b)
1.9
6.8
NA
NA
NA
NA
NA
-
-
35.1
-
-
<25
0.7
-
7.0
_
TA
0.0
158
-
-
<10
NA'b>
1.9
6.4
NA
NA
NA
NA
NA
-
-
1.0
-
-
<25
0.5
-
<0.1
_
TB
0.0
172
-
-
<10
NA'b>
2.0
6.2
NA
NA
NA
NA
NA
-
-
0.9
-
-
<25
0.3
-
<0.1
_
04/01/08
IN
149
1.2
23.3
1.3
<10
27.7
1.9
NA
NA
NA
NA
NA
NA
39.0
28.0
11.1
36.6
22.0
14.6
0.1
21.9
<25
<25
0.3
0.3
7.9
_
AP
147
1.0
24.0
1.2
<10
27.5
0.6
NA
NA
NA
NA
NA
NA
38.3
27.3
10.9
35.3
34.2
1.1
0.1
34.0
<25
<25
0.2
<0.1
7.7
_
TA
2.2
143
1.2
27.1
1.2
<10
25.0
0.4
NA
NA
NA
NA
NA
NA
35.2
25.2
10.0
0.1
<0.1
<0.1
<0.1
<0.1
<25
<25
0.2
<0.1
<0.1
_
TB
2.1
139
1.2
26.8
1.2
<10
20.7
0.5
NA
NA
NA
NA
NA
NA
33.8
23.9
9.8
0.1
0.2
<0.1
<0.1
<0.1
<25
<25
<0.1
<0.1
<0.1
_
04/15/08
IN
155
-
-
<10
24.7
1.0
NA
NA
NA
NA
NA
NA
-
-
33.4
-
-
60
2.8
-
8.3
_
AP
151
-
-
<10
25.1
0.9
NA
NA
NA
NA
NA
NA
-
-
34.8
-
-
<25
0.3
-
8.4
_
TA
2.7
151
-
-
<10
25.0
0.8
NA
NA
NA
NA
NA
NA
-
-
<0.1
-
-
<25
<0.1
-
<0.1
_
TB
2.7
153
-
-
<10
24.6
0.8
NA
NA
NA
NA
NA
NA
-
-
0.2
-
-
<25
<0.1
-
<0.1
_
04/29/08
IN
145
-
-
<10
24.7
0.6
NA
NA
NA
NA
NA
NA
-
-
36.4
-
-
<25
0.5
-
7.9
_
AP
147
-
-
<10
24.7
1.0
NA
NA
NA
NA
NA
NA
-
-
36.7
-
-
32
1.2
-
7.9
_
TA
3.5
165
-
-
<10
26.9
1.4
NA
NA
NA
NA
NA
NA
-
-
0.2
-
-
37
0.7
-
<0.1
_
TB
3.4
165
-
-
<10
26.7
2.0
NA
NA
NA
NA
NA
NA
-
-
0.2
-
-
<25
0.2
-
<0.1
_
05/12/08
IN
151
-
-
<10
26.6
0.5
8.1
31.1
3.7
243
NA
NA
-
-
37.3
-
-
<25
0.2
-
7.8
_
AP
151
-
-
<10
26.0
0.6
7.2
32.6
3.1
287
NA
NA
-
-
36.0
-
-
<25
1.1
-
7.5
_
TA
4.2
147
-
-
<10
26.2
0.9
7.1
32.9
3.0
321
NA
NA
-
-
1.0
-
-
<25
<0.1
-
<0.1
_
TB
4.1
147
-
-
<10
26.1
0.8
7.0
33.0
3.4
351
NA
NA
-
-
0.8
-
-
<25
<0.1
-
<0.1
_
(a) As CaCO 3
(b) Silica not measured on 02/13/08.
-------
Table B-l. Analytical Results from Treatment Plant Sampling at Covered Wells in Tohono O'odham Nation, AZ (Continued)
Sampling Date
Sampling Location
Parameter Unit
Bed Volume
Alkalinity
Fluoride
Sulfate
Nitrate (as N)
Total P (as P )
Silica (as SiO2)
Turbidity
pH
Temperature
DO
ORP
Free Chlorine
Total Chlorine
Total Hardness
Ca Hardness
Mg Hardness
As (total)
As (soluble)
As (particulate)
As (III)
As(V)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
U (total)
V (total)
1
6.7'c'
36.0
-
-
<25
0.4
NA
-
TA
8.5
149
-
27.1
0.1
7.1
32.9
NA
NA
7.6 (c|
6.7 (c)
1.1
<25
0.1
NA
TB
8.3
151
27.2
0.1
7.1
33.1
NA
NA
7.8 |c)
7.2 (c)
-
-
0.7
<25
0.1
NA
09/02/08
IN
148
-
26.7
0.1
NA
NA
NA
NA
-
-
-
35.0
-
-
<25
0.2
7.5
30.2
AP
146
-
-
26.7
0.2
NA
NA
NA
NA
NA
NA
36.8
-
-
-
<25
0.2
7.5
30.2
TA
10.3
151
-
-
-
27.0
0.1
NA
NA
NA
NA
NA
NA
0.5
-
-
<25
0.1
0.1
0.1
TB
10.0
146
-
26.9
0.1
NA
NA
NA
NA
NA
NA
0.3
<25
0.1
0.1
0.1
10/07/08
IN
146
1.1
23.7
1.2
27.0
0.2
8.2
25.0
NA
NA
0.0
0.0
34.6
25.1
9.5
35.7
33.7
2.0
0.4
33.3
<25
<25
0.2
0.2
-
29.4
AP
144
1.1
24.3
1.2
26.8
0.3
7.1
25.0
NA
NA
1.8
1.7
37.3
27.1
10.2
36.5
34.5
2.1
0.4
34.0
<25
<25
0.4
0.2
-
30.4
TA
12.0
144
1.0
24.2
1.2
-
26.8
0.1
7.1
25.0
NA
NA
2.0
1.9
36.9
26.9
10.0
0.9
0.4
0.5
0.4
0.1
<25
<25
0.1
0.1
0.7
TB
11.6
146
1.1
23.1
1.2
-
26.5
0.1
7.1
25.0
NA
NA
2.1
2.0
36.4
26.4
10.0
0.6
0.3
0.3
0.4
0.1
<25
<25
0.1
0.1
0.4
TT
11.8
146
1.1
23.8
1.2
-
26.6
0.3
7.0
25.0
NA
NA
2.1
1.8
37.5
27.2
10.3
0.6
0.2
0.3
0.4
0.1
<25
<25
0.1
0.1
0.4
(a) As CaCO 3
(b) All metals re-analyzed on 08/28/08 from TB
(c) Uncharacteristically high levels
-------
Table B-l. Analytical Results from Treatment Plant Sampling at Covered Wells in Tohono O'odham Nation, AZ (Continued)
Sampling Date
Sampling Location
Parameter Unit
Bed Volume
Alkalinity
Fluoride
Sulfate
Nitrate (as N)
Total P (as P )
Silica (as SiO2)
Turbidity
PH
Temperature
DO
ORP
Free Chlorine
Total Chlorine
Total Hardness
Ca Hardness
Mg Hardness
As (total)
As (soluble)
As (particulate)
As (III)
As(V)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
U (total)
V (total)
10*
mg/L|a|
mg/L
mg/L
mg/L
ng/L
mg/L
NTU
S.U.
'C
mg/L
mV
mg/L
mg/L
mg/L|a|
mg/L1"
mg/L|a)
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
11/18/08
IN
-
145
145
-
<10
<10
25.1
25.6
0.1
0.1
8.0
25.0
NA
NA
0.0
0.0
-
37.9
38.6
-
-
<25
<25
-
0.3
0.3
35.5
34.2
AP
-
145
148
-
<10
<10
25.7
25.9
0.2
0.1
6.9
25.0
NA
NA
2.2
2.1
-
38.2
37.6
-
-
<25
<25
-
<0.1
0.2
36.6
36.6
TA
13.9
156
156
-
<10
<10
26.9
25.9
<0.1
<0.1
7.2
25.0
NA
NA
2.1
2.0
-
0.5
0.5
-
-
<25
<25
-
<0.1
<0.1
0.5
0.5
TB
13.4
156
159
-
<10
<10
27.3
27.7
0.2
<0.1
7.0
25.0
NA
NA
1.9
1.8
-
0.5
0.4
-
-
<25
<25
-
0.1
<0.1
0.5
0.5
12/16/08
IN
-
147
-
<10
25.0
0.2
7.9
25.0
NA
NA
0.0
0.0
-
36.3
-
-
30
-
2.6
33.2
AP
-
147
-
<10
25.2
0.2
6.9
25.0
NA
NA
1.7
1.6
-
35.1
-
-
28
-
1.3
32.5
TA
15.1
145
-
<10
25.1
0.1
6.9
25.0
NA
NA
1.8
1.7
-
0.7
-
-
77
-
2.1
0.7
TB
14.5
145
-
<10
25.4
0.1
7.0
25.0
NA
NA
1.9
1.8
-
0.5
-
-
<25
-
0.2
0.5
01/20/09
IN
-
144
-
<10
24.4
0.2
NA|d|
NA|d|
NA
NA
NA|d|
NA|d|
-
37.7
-
-
<25
-
1.0
31.9
AP
-
140
-
<10
25.5
0.3
NA|dl
NA|d)
NA
NA
NA|dl
NA|d)
-
35.6
-
-
<25
-
<0.1
30.5
TA
16.6
140
-
<10
23.0
<0.1
NA|dl
NA(d|
NA
NA
NA|dl
NA(d|
-
0.4
-
-
<25
-
<0.1
0.5
TB
16.0
142
-
<10
23.3
0.1
NA|d|
NA|d|
NA
NA
NA|dl
NA|d|
-
0.4
-
-
<25
-
<0.1
0.5
02/17/09
IN
-
149
-
<10
26.0
0.2
8.1
25.0
NA
NA
0.0
0.0
-
32.3
-
-
<25
-
0.2
27.5
AP
-
147
-
<10
25.9
0.2
7.0
25.0
NA
NA
2.1
2.1
-
33.0
-
-
<25
-
0.5
28.6
TA
17.6
151
-
<10
28.6
0.2
7.1
25.0
NA
NA
2.0
2.1
-
0.7
-
-
<25
-
<0.1
0.8
TB
17.0
158
-
<10
27.1
0.2
7.1
25.0
NA
NA
2.2
2.2
-
0.9
-
-
<25
-
0.1
0.9
03/17/09
IN
-
148
1.2
23.7
1.3
<10
25.2
0.2
8.4
26.6
NA
NA
0.1
0.1
47.3
36.2
11.1
37.1
36.8
0.3
0.4
36.4
31
<25
1.8
3.2
33.2
AP
-
146
1.1
23.5
1.1
<10
25.2
0.1
6.9
28.9
NA
NA
1.6
1.6
48.8
37.3
11.4
39.1
36.2
2.9
0.3
35.9
<25
<25
0.8
0.4
31.8
TA
18.6
195
1.0
21.4
1.2
<10
31.4
<0.1
7.5
30.3
NA
NA
1.6
1.6
93.6
67.8
25.8
0.2
0.3
<0.1
0.4
<0.1
<25
<25
<0.1
<0.1
0.5
TB
17.9
193
1.0
20.5
1.2
<10
32.0
<0.1
7.4
31.4
NA
NA
1.5
1.3
93.0
66.1
26.8
0.2
0.3
<0.1
0.3
<0.1
<25
<25
<0.1
<0.1
0.5
TT
18.3
189
1.0
21.3
1.2
<10
34.7
<0.1
NM
NM
NA
NA
NM
NM
86.7
60.0
26.7
<0.1
0.2
<0.1
0.3
<0.1
<25
<25
<0.1
<0.1
0.3
(a) As CaCO 3
(d) pH, temperature, free chlorine & total chlorine not measured
-------
Table B-l. Analytical Results from Treatment Plant Sampling at Covered Wells in Tohono O'odham Nation, AZ (Continued)
Sampling Date
Sampling Location
Parameter Unit
Bed Volume
Alkalinity
Fluoride
Sulfate
Nitrate (as N)
Total P (as P )
Silica (as SiO2)
Turbidity
pH
Temperature
DO
ORP
Free Chlorine
Total Chlorine
Total Hardness
Ca Hardness
Mg Hardness
As (total)
As (soluble)
As (particulate)
As (III)
As(V)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
U (total)
V (total)
itf
mg/L|a|
mg/L
mg/L
mg/L
M/L
mg/L
NTU
S.U.
•c
mg/L
mV
mg/L
mg/L
mg/L|a|
mg/L1"
mg/L1"
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
04/15/09
IN
148
-
-
<10
27.4
0.5
8.3
25.0
NA
NA
0.0
0.0
-
31.4
-
-
-
<25
-
0.3
27.9
AP
150
-
-
<10
27.0
0.3
6.9
25.0
NA
NA
2.1
2.1
-
31.7
-
-
-
<25
-
0.3
27.6
TA
19.7
161
-
-
<10
32.6
0.3
7.2
25.0
NA
NA
2.0
2.1
-
0.6
-
-
-
<25
-
<0.1
<0.1
TB
19.0
161
-
-
<10
31.7
0.6
7.2
25.0
NA
NA
2.2
2.2
-
0.4
-
-
-
<25
-
<0.1
<0.1
05/20/09
IN
155
-
-
<10
27.3
0.3
8.2
31.4
NA
NA
0.0
0.0
-
35.6
-
-
-
<25
-
0.3
33.6
AP
150
-
-
<10
26.7
1.4
6.9
33.3
NA
NA
1.5
1.5
-
39.4
-
-
-
<25
-
0.8
34.8
TA
20.4
155
-
-
<10
28.9
0.1
6.8
33.5
NA
NA
1.6
1.6
-
0.5
-
-
-
<25
-
0.1
0.5
TB
20.7
155
-
-
<10
28.8
0.2
6.8
33.8
NA
NA
1.5
1.5
-
0.5
-
-
-
<25
-
0.2
0.5
06/16/09
IN
154
-
-
<10
26.5
0.7
7.8
32.0
NA
NA
0.0
0.0
-
33.8
-
-
-
<25
-
0.2
35.1
AP
156
-
-
<10
27.1
2.2
6.8
32.1
NA
NA
0.8
1.0
-
26.6
-
-
-
<25
-
0.2
35.2
TA
21.3
156
-
-
<10
26.1
2.3
6.8
33.3
NA
NA
1.0
1.0
-
<0.1
-
-
-
<25
-
<0.1
0.6
TB
21.9
158
-
-
<10
25.8
0.8
6.8
33.2
NA
NA
0.8
1.0
-
<0.1
-
-
-
<25
-
0.2
<0.1
07/14/09
IN
151
1.2
24.8
1.2
<10
26.7
0.2
7.9
33.7
NA
NA
NA
NA
39.1
29.3
9.8
35.7
34.0
1.8
0.4
33.6
<25
<25
0.2
0.2
34.4
AP
151
1.2
24.6
1.2
<10
27.2
0.1
7.9
33.7
NA
NA
1.7
1.8
40.4
30.2
10.2
37.2
35.7
1.5
0.4
35.3
28
<25
3.0
0.2
35.2
TA
23.3
201
1.0
22.3
1.2
<10
32.1
0.1
7.1
34.0
NA
NA
1.7
1.8
94.5
67.1
27.4
0.6
0.5
<0.1
0.5
<0.1
<25
<25
<0.1
<0.1
0.1
TB
24.0
196
1.1
23.5
1.2
<10
33.8
0.4
7.1
34.4
NA
NA
1.8
1.9
87.0
61.1
25.8
0.5
0.4
<0.1
0.5
<0.1
<25
<25
<0.1
<0.1
<0.1
TT
23.6
192
1.0
22.7
1.2
<10
34.3
<0.1
7.1
34.7
NA
NA
1.9
1.9
79.8
55.1
24.6
0.4
0.3
<0.1
0.5
<0.1
<25
<25
<0.1
0.1
<0.1
08/1 8/09
IN
154
-
-
<10
26.3
0.7
8.1
34.1
NA
NA
NA
NA
-
32.2
-
-
-
<25
-
2.6
33.3
AP
154
-
-
<10
25.9
0.2
6.9
32.4
NA
NA
NA|e|
NA|e|
-
32.6
-
-
-
<25
-
1.9
32.9
TA
26.5
152
-
-
<10
25.9
0.4
6.9
30.9
NA
NA
NA|8>
NA|8>
-
31.8
-
-
-
<25
-
1.7
31.8
TB
27.0
154
-
-
<10
25.8
0.4
7.0
32.1
NA
NA
NA|e|
NA|e|
-
1.3
-
-
-
<25
-
1.3
0.2
(a) As CaCO 3
(e) Operator did not have chlorine kit at time of sampling
-------
Table B-l. Analytical Results from Treatment Plant Sampling at Covered Wells in Tohono O'odham Nation, AZ (Continued)
Sampling Date
Sampling Location
Parameter Unit
Bed Volume
Alkalinity
Fluoride
Sulfate
Nitrate (as N)
Total P (as P )
Silica (as SiO2)
Turbidity
PH
Temperature
DO
ORP
Free Chlorine
Total Chlorine
Total Hardness
Ca Hardness
Mg Hardness
As (total)
As (soluble)
As (particulate)
As (III)
As(V)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
U (total)
V (total)
10*
mg/L|a|
mg/L
mg/L
mg/L
ng/L
mg/L
NTU
S.U.
'C
mg/L
mV
mg/L
mg/L
mg/L|a|
mg/L1"
mg/L|a)
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
09/15/09
IN
-
156
-
-
<10
26.1
0.6
7.9
25.0
NA
NA
0.0
0.0
33.1
23.3
9.8
29.0
-
<25
-
0.1
-
23.5
AP
-
156
-
-
<10
26.2
2.1
7.0
25.0
NA
NA
1.0
1.1
34.0
24.1
9.9
31.0
-
<25
-
0.4
-
25.2
TA
28.8
154
-
-
<10
26.2
2.1
7.0
25.0
NA
NA
0.9
1.0
33.4
23.2
10.2
0.1
-
<25
-
<0.1
-
<0.1
TB
29.2
152
-
-
<10
26.2
1.1
6.9
25.0
NA
NA
1.0
1.0
30.9
21.2
9.7
0.2
-
<25
-
<0.1
-
<0.1
1 0/20/09
IN
-
148
-
-
<10
24.6
1.3
8.0
32.5
NA
NA
NA
NA
-
-
34.2
-
<25
-
0.3
-
28.5
AP
-
142
-
-
<10
24.5
0.8
6.6
32.5
NA
NA
0.1
0.0
-
-
35.2
-
27
-
2.0
-
28.8
TA
31.2
134
-
-
<10
18.7
0.7
7.2
34.0
NA
NA
0.0
NA
-
-
0.1
-
<25
-
<0.1
-
1.3
TB
32.6
190
-
-
<10
29.3
0.2
7.6
34.4
NA
NA
0.0
NA
-
-
0.8
-
<25
-
0.1
-
3.6
11/17/09
IN
-
156
1.1
22.2
1.2
<10
27.7
0.1
7.9
26.5
NA
NA
NA
NA
29.7
21.3
8.4
35.8
35.4
0.4
1.0
34.4
<25
<25
0.3
<0.1
38.1
AP
-
147
1.1
21.6
1.2
<10
27.1
0.5
6.6
30.5
NA
NA
1.1
1.1
32.9
23.5
9.4
35.5
36.0
<0.1
1.1
34.9
<25
<25
<0.1
0.1
39.7
TA
33.4
159
1.1
21.9
1.2
<10
29.5
0.3
6.8
29.0
NA
NA
1.1
1.1
36.9
25.9
11.0
1.2
1.1
0.1
1.1
<0.1
<25
<25
<0.1
<0.1
4.2
TB
34.7
174
1.0
21.7
1.2
<10
30.9
0.2
6.8
30.7
NA
NA
1.1
1.1
41.5
28.8
12.7
1.2
1.0
0.2
1.0
<0.1
<25
<25
<0.1
<0.1
3.0
TT
34.0
168
1.1
21.9
1.2
<10
30.3
<0.1
6.6
30.6
NA
NA
1.1
1.1
40.2
27.8
12.4
1.1
1.1
<0.1
1.0
<0.1
<25
<25
<0.1
<0.1
3.7
12/15/09
IN
-
-
-
8.0
29.4
NA
NA
NA
NA
-
-
33.2
-
-
-
34.6
AP
-
-
-
6.6
27.4
NA
NA
1.7
1.6
-
-
33.9
-
-
-
34.6
TA
34.9
-
-
6.6
26.8
NA
NA
1.4
1.3
-
-
0.4
-
-
-
3.1
TB
36.4
-
-
6.6
27.2
NA
NA
1.4
1.4
-
-
0.3
-
-
-
2.0
01/19/10
IN
-
-
-
8.0
25.0
NA
NA
NA
NA
-
-
33.8
-
-
-
35.0
AP
-
-
-
6.5
25.0
NA
NA
1.8
1.8
-
-
31.7
-
-
-
35.6
TA
37.1
-
-
6.5
25.0
NA
NA
1.8
1.8
-
-
0.5
-
-
-
4.7
TB
38.5
-
-
6.5
25.0
NA
NA
1.7
1.8
-
-
0.4
-
-
-
3.0
(a) As Ca CO 3
-------
Table B-l. Analytical Results from Treatment Plant Sampling at Covered Wells in Tohono O'odham Nation, AZ (Continued)
Sampling Date
Sampling Location
Parameter Unit
Bed Volume
Alkalinity
Fluoride
Sulfate
Nitrate (as N)
Total P (as P )
Silica (as SiO2)
Turbidity
PH
Temperature
DO
ORP
Free Chlorine
Total Chlorine
Total Hardness
Ca Hardness
Mg Hardness
As (total)
As (soluble)
As (particulate)
As (III)
As(V)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
U (total)
V (total)
101
mg/L|a|
mg/L
mg/L
mg/L
ng/L
mg/L
NTU
S.U.
C
mg/L
mV
mg/L
mg/L
mg/L|a)
mg/L|a|
mg/L(a|
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
02/16/10
IN
-
-
-
7.9
26.2
NA
NA
NA
NA
-
-
33.1
-
-
-
32.0
AP
-
-
-
6.6
33.5
NA
NA
1.5
1.5
-
-
29.7
-
-
-
31.2
TA
39.0
-
-
6.9
32.9
NA
NA
1.5
1.6
-
-
0.6
-
-
-
6.2
TB
40.5
-
-
6.9
32.5
NA
NA
1.5
1.6
-
-
0.3
-
-
-
3.7
03/1 6/1 df'
IN
-
-
-
NA
NA
NA
NA
NA
NA
-
-
34.4
-
-
-
33.4
AP
-
-
-
NA
NA
NA
NA
1.1
1.3
-
-
34.6
-
-
-
32.6
TA
40.0
-
-
NA
NA
NA
NA
0.6
0.7
-
-
0.6
-
-
-
5.2
TB
41.4
-
-
NA
NA
NA
NA
1.2
1.3
-
-
0.4
-
-
-
3.3
(a)AsCaCO3
(f) bed volume from 03/12/10
------- |