EPA/600/R-08/018
April 2008
Arsenic Removal from Drinking Water by Adsorptive Media
U.S. EPA Demonstration Project at Oak Manor Municipal Utility
District at Alvin, TX
Six-Month Evaluation Report
by
H. Tien Shiao
Lili Wang
Abraham S.C. Chen
Battelle
Columbus, OH 43201-2693
Contract No. 68-C-00-185
Task Order No. 0029
for
Thomas J. Sorg
Task Order Manager
Water Supply and Water Resources Division
National Risk Management Research Laboratory
Cincinnati, Ohio 45268
National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 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
subsurface resources; protection of water quality in public water systems; remediation of contaminated
sites, sediments and ground water; 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 environmental problems by: developing and promoting technologies that protect and improve
the environment; advancing scientific and engineering information to support regulatory and policy
decisions; and providing the technical support and information transfer to ensure implementation of
environmental regulations and strategies at the national, state, and community levels.
This publication has been produced as part of the Laboratory's strategic long-term research plan. It is
published and made available by EPA's Office of Research and Development to assist the user
community and to link researchers with their clients.
Sally Gutierrez, Director
National Risk Management Research Laboratory
in
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ABSTRACT
This report documents the activities performed and the results obtained from the first six months of the
EPA arsenic removal technology demonstration project at the Oak Manor Municipal Utility District
(MUD) facility at Alvin, TX. The main objective of the project is to evaluate the effectiveness of the
Severn Trent Services (STS) Arsenic Package Unit (APU)-30S in removing arsenic to meet the maximum
contaminant level (MCL) of 10 |o,g/L. Additionally, this project evaluates 1) the reliability of the
treatment system for use at small water facilities, 2) the required system operation and maintenance
(O&M) and operator skill levels, and 3) the capital and O&M cost of the technology. The project also
characterizes water in the distribution system and residuals generated by the treatment process. The types
of data collected include system operation, water quality, process residuals, and capital and O&M costs.
After approval of a pilot-study exception request and engineering plans by the Texas Commission of
Environmental Quality (TCEQ), the APU-30S system was installed and started up on April 25, 2006.
The system consisted of two 63-in-diameter and 86-in-tall adsorption vessels configured in series with
53.6 ft3 of SORB 33™ in the lead vessel and 70.3 ft3 in the lag vessel, gas prechlorination equipment,
sample taps, and associated instrumentation. At the design flowrate of 150 gal/min (gpm), the system had
a hydraulic loading rate of 6.9 gpm/ft2 and an empty bed contact time (EBCT) of 6.2 min. Based on the
actual flowrate of only 134 gpm, the system operated at ahydraulic loading of 6.2 gpm/ft2 and an EBCT
of 6.9 min.
Source water supplied by two wells (Well 1 and 2) had a combined average concentration of 43.8 |o,g/L
for total arsenic, with As(III) as the predominating soluble species at 35.2 (ig/L. Iron existed mostly in
the particulate form, with concentrations ranging from 34.2 to 100 |o,g/L and averaging 60.5 |og/L. Total
manganese concentrations averaged 54.4 |og/L, existing almost entirely in the soluble form. After
prechlorination, As(III) was affectively oxidized to As(V), with concentrations averaging 0.6 and
27.1 ng/L, respectively. Somewhat unexpectedly, Mn(II) also was effectively oxidized, presumably, to
MnO2, leaving only 2.8 |og/L (or 6.5%) in the chlorinated water.
By the end of the first six months of system operation after treating approximately 11,241,500 gal (12,170
bed volumes [BV]) of water (1 BV = 124 ft3 of media in both the lead and lag vessels), arsenic
concentration was 10.2 (ig/L after the lead vessel and 1.4 (ig/L following the lag vessel. Because the
arsenic concentration following the lag vessel did not reach 10 (ig/L, the media in the lead vessel was not
changed out during the first six months of system operation.
Comparison of the distribution system sampling results before and after the system startup showed a
considerable decrease in arsenic (38.2 to 2.0 ng/L), iron (115 to <25 ng/L), and manganese concentration
(41.8to 1.3 (ig/L). Alkalinity, pH, lead, and copper did not appear to be affected.
Backwash was manually initiated by the operator when differential pressure across Vessel A reached
10 lb/in2 (psi), which occurred four times during the six-month period. About 6,058 gal/vessel/event of
wastewater was discharged to the roadside ditch during each backwash event. Approximately 14.9 Ib of
solids were discharged from Vessel A, including 4.2 x 10"5 Ib of arsenic, 0.9 Ib of iron, and 0.08 Ib of
manganese. Approximately 2.9 Ib of solids were discharged from Vessel B, including 1.5 x io~4 Ib of
arsenic, 0.2 Ib of iron, and 0.03 Ib of manganese. The reasons for the large amount of solids produced are
being investigated and will be reported in the Final Performance Evaluation Report.
The capital investment for the system was $179,750 consisting of $124,103 for equipment, $14,000 for
site engineering, and $41,647 for installation, shakedown, and startup. Using the system's rated capacity
IV
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of 150 gpm (or 216,000 gal/day [gpd]), the capital cost was $l,198/gpm (or $0.83/gpd). This calculation
does not include the cost of the building to house the treatment system.
O&M cost, estimated at $0.21/1,000 gal, included only the incremental cost for labor. There was no
incremental electricity cost or chemical consumption cost since gas chlorination was already performed
prior to the demonstration study.
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CONTENTS
DISCLAIMER ii
FOREWORD iii
ABSTRACT iv
FIGURES vii
TABLES vii
ABBREVIATIONS AND ACRONYMS ix
ACKNOWLEDGMENTS xi
Section 1.0 INTRODUCTION 1
1.1 Background 1
1.2 Treatment Technologies for Arsenic Removal 2
1.3 Project Objectives 2
Section 2.0 SUMMARY AND CONCLUSIONS 5
Section 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 8
3.3.1 Source Water 9
3.3.2 Treatment Plant Water 9
3.3.3 Backwash Water 9
3.3.4 Distribution System Water 9
3.3.5 Residual Solids 9
3.4 Sampling Logistics 11
3.4.1 Preparation of Arsenic Speciation Kits 11
3.4.2 Preparation of Sampling Coolers 11
3.4.3 Sample Shipping and Handling 11
3.5 Analytical Procedures 11
Section 4.0 SITE BACKGROUND 13
4.1 Site Description 13
4.1.1 Existing Facility 13
4.1.2 Source Water Quality 15
4.1.3 Treated Water Quality 17
4.1.4 Distribution System and Regulatory Monitoring 17
4.2 Treatment Process Description 17
4.3 Treatment System Installation 24
4.3.1 System Permitting 24
4.3.2 Building Construction 24
4.3.3 System Installation, Shakedown, and Startup 26
4.3.4 Media Loading 28
4.3.5 Punch List Items 28
4.4 System Operation 31
4.4.1 Operational Parameters 31
4.4.2 Residual Management 32
4.4.3 Reliability and Simplicity of Operation 32
4.5 System Performance 35
4.5.1 Treatment Plant Sampling 35
VI
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4.5.2 Backwash Water Sampling 43
4.5.3 Distribution System Water Sampling 43
4.6 System Cost 45
4.6.1 Capital Cost 45
4.6.2 Operation and Maintenance Cost 45
Section 5.0 REFERENCES 48
FIGURES
Figure 3-1. Process Flow Diagram and Sampling Schedule and Locations 10
Figure 4-1. Preexisting Chlorine Addition Point and Wells 1 and 2 Blending Point 13
Figure 4-2. Preexisting Storage Tank and Hydropneumatic Tank 14
Figure 4-3. Preexisting Polyphosphate Addition Point 14
Figure 4-4. Booster Pumps and Entry Piping to Distribution System 15
Figure 4-5. Photograph of APU-30S Arsenic Removal System 19
Figure 4-6a. Process Flow Diagram for APU-30S System with Vessel A in Lead Position 20
Figure 4-6b. Process Flow Diagram for APU-30S System with Vessel B in Lead Position 21
Figure 4-7. Gas Chlorination System 23
Figure 4-8. APU-30S System Valve Tree and Piping Configuration 23
Figure 4-9. Valve MB-127 to Supply Additional Treated Water from Hydropneumatic Tank
During Backwash 25
Figure 4-10. Small Ditch 25
Figure 4-11. Construction of Concrete Pad with Storage Tank and Hydropneumatic Tank 27
Figure 4-12. Photograph of Piping, Sample Taps, and Chlorine Injection Point Prior to
Treatment System 30
Figure 4-13. System Pressure Readings 33
Figure 4-14. Concentrations of Various Arsenic Species at IN, AP, TA, and TB Sampling
Locations 39
Figure 4-15. Total Arsenic Breakthrough Curves 40
Figure 4-16. Chlorine Consumption Based on Chlorine Gas Usage 41
Figure 4-17. Media Replacement and Operation and Maintenance Cost 47
TABLES
Table 1-1. Summary of the Arsenic Removal Demonstration Sites 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 Schedule and Analyses 8
Table 4-1. Water Quality Data for Oak Manor MUD 16
Table 4-2. Physical and Chemical Properties of SORB 33™ Media 18
Table 4-3. Design Specifications for STS APU-30S System 22
Table 4-4. Freeboard Measurements and Media Volumes in Adsorption Vessels 28
Table 4-5. System Inspection Punch-List Items 29
Table 4-6. Summary of APU-30S System Operations 31
Table 4-7. System Instantaneous and Calculated Flowrates 32
Table 4-8. Time Lapse Since Last Backwash 33
Table 4-9. Summary of Analytical Results for Arsenic, Iron, and Manganese 36
Table 4-10. Summary of Other Water Quality Sampling Results 37
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Table 4-11. Amount of Mn(II) Precipitated After Chlorination at 11 Arsenic Removal
Demonstration Sites 42
Table 4-12. Backwash Water Sampling Results 43
Table 4-13. Distribution Water Sampling Results 44
Table 4-14. Capital Investment Cost for APU-30S System 46
Table 4-15. Operation and Maintenance Cost for APU-30S System 46
Vlll
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ABBREVIATIONS AND ACRONYMS
Ap differential pressure
AAL American Analytical Laboratories
Al aluminum
AM adsorptive media
APU arsenic package unit
As arsenic
ATS Aquatic Treatment Systems
BET Brunauer, Emmett, and Teller
BV bed volume(s)
Ca calcium
CCR Consumer Confidence Report
C/F coagulation/filtration
Cl chlorine
CRF capital recovery factor
Cu copper
DO dissolved oxygen
EBCT empty bed contact time
EPA U.S. Environmental Protection Agency
F fluoride
Fe iron
FedEx Federal Express
FRP fiberglass reinforced plastic
gpd gallons per day
gpm gallons per minute
HIX hybrid ion exchanger
hp horsepower
ICP-MS inductively coupled plasma-mass spectrometry
ID identification
IX ion exchange
LCR (EPA) Lead and Copper Rule
MCL maximum contaminant level
MDL method detection limit
MEI Magnesium Elektron, Inc.
Mg magnesium
jam micrometer
Mn manganese
MUD Municipal Utility District
IX
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mV millivolts
Na sodium
NA not analyzed
NS not sampled
NSF NSF International
NTU nephlemetric turbidity units
O&M operation and maintenance
OIT Oregon Institute of Technology
ORD Office of Research and Development
ORP oxidation-reduction potential
P phosphorus
P&ID piping and instrumentation diagram
Pb lead
pCi/L picocuries per liter
psi pounds per square inch
PLC programmable logic controller
PO4 phosphate
POU point-of-use
PVC polyvinyl chloride
QA quality assurance
QA/QC quality assurance/quality control
QAPP Quality Assurance Project Plan
RPD relative percent difference
RO reverse osmosis
Sb antimony
SDWA Safe Drinking Water Act
SiO2 silica
SMCL secondary maximum contaminant level
SO4 sulfate
STS Severn Trent Services
TBD to be determined
TCLP Toxicity Characteristic Leaching Procedure
TCEQ Texas Commission of Environmental Quality
TDS total dissolved solids
TOC total organic carbon
TSS total suspended solids
UPS United Parcel Service
V vanadium
VOC volatile organic compound(s)
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ACKNOWLEDGMENTS
The authors wish to extend their sincere appreciation to the system operator, Mr. Jose Chavez, of Oak
Manor Municipal Utility District (MUD) in Alvin, TX. Mr. Chavez monitored the treatment system and
collected samples from the treatment and distribution systems on a regular schedule throughout this study
period. This performance evaluation would not have been possible without his support and dedication.
XI
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Section 1.0 INTRODUCTION
1.1 Project Background
The Safe Drinking Water Act (SOWA) mandates that 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). In order to clarify the implementation of the original rule, EPA revised the rule on March
25, 2003 to express the MCL as 0.010 mg/L (10 (ig/L) (EPA, 2003). The final rule requires all
community and non-transient, non-community water systems to comply with the new standard by
January 23, 2006.
In October 2001, EPA announced an initiative for additional research and development of cost-effective
technologies to help small community water systems (<10,000 customers) meet the new arsenic standard
and to provide technical assistance to operators of small systems in order to reduce compliance costs. As
part of this Arsenic Rule Implementation Research Program, EPA's Office of Research and Development
(ORD) proposed a project to conduct a series of full-scale, on-site demonstrations of arsenic removal
technologies, process modifications, and engineering approaches applicable to small systems. Shortly
thereafter, an announcement was published in the Federal Register requesting water utilities interested in
participating in Round 1 of this EPA-sponsored demonstration program to provide information on their
water systems. In June 2002, EPA selected 17 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 provided its recommendations to EPA on the technologies that it determined
were acceptable for the demonstration at each site. Because of funding limitations and other technical
reasons, only 12 of the 17 sites were selected for the 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 and the Oak Manor Municipal Utility District (MUD) water system in Alvin, TX was one of those
selected.
In September 2003, EPA, again, solicited proposals from engineering firms and vendors for arsenic
removal technologies. EPA received 148 technical proposals for the 32 host sites, with each site
receiving from two to eight proposals. In April 2004, another technical panel was convened by EPA to
review the proposals and provide recommendations to EPA with the number of proposals per site ranging
from none (for two sites) to a maximum of four. The final selection of the treatment technology at the
sites that received at least one proposal was made, again, through a joint effort by EPA, the state
regulators, and the host site. Since then, four sites have withdrawn from the demonstration program,
reducing the number of sites to 28. Severn Trent Service's (STS) SORB 33™ Arsenic Removal
Technology was selected for demonstration at the Oak Manor MUD facility.
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As of January 2008, 37 of the 40 systems were operational and the performance evaluation of 26 systems
were completed.
1.2 Treatment Technologies for Arsenic Removal
The technologies selected for the Round 1 and Round 2 demonstration host sites include 25 adsorptive
media (AM) systems (the Oregon Institute of Technology [OIT] site has three AM systems), 13 coagula-
tion/filtration (C/F) systems, two ion exchange (IX) systems, and 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 system modification. Table 1-1 summarizes the locations, technologies, vendors,
system flowrates, and key source water quality parameters (including As, Fe, 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 costs is provided in two EPA reports (Wang et al., 2004;
Chen et al., 2004), which are posted on the EPA website at
http://www.epa.gov/ORD/NRMRL/wswrd/dw/arsenic/index.html.
1.3 Project Objectives
The objective of the arsenic demonstration program is to conduct 40 full-scale arsenic treatment
technology demonstration studies on the removal of arsenic from drinking water supplies. The specific
objectives are to:
• Evaluate the performance of the arsenic removal technologies for use on small
systems.
• Determine the required system operation and maintenance (O&M) and operator
skill levels.
• Characterize process residuals produced by the technologies.
• Determine the capital and O&M cost of the technologies.
This report summarizes the performance of STS's system at the Oak Manor MUD in Alvin, TX during
the first six months from April 25 through October 25, 2006. The types of data collected included system
operation, water quality (both across the treatment train and in the distribution system), residuals, and
capital and preliminary O&M cost.
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Table 1-1. Summary of Arsenic Removal Demonstration Sites
Demonstration
Location
Site Name
Technology (Media)
Vendor
Design
Flowrate
(gpm)
Source Water Quality
As
(HS/L)
Fe
riijr/T,)
PH
(S.U.)
Northeast/Ohio
Wales, ME
Bow,NH
Goffstown, NH
Rollinsford, NH
Dummerston, VT
Felton, DE
Stevensville, MD
Houghton,NY(d:i
Newark, 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
AMfA/TComplex^
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
250W
38W
39
33
36W
30
30W
19W
27W
15W
25W
<25
<25
<25
46
<25
48
270(c)
l,806(c)
l,312(c)
1,615W
8.6
7.7
6.9
8.2
7.9
8.2
7.3
7.6
7.6
7.3
Great Lakes/Interior Plains
Brown City, MI
Pentwater, MI
Sandusky, MI
Delavan, WI
Greenville, WI
Climax, MN
Sabin, MN
Sauk Centre, MN
Stewart, MN
Lidgerwood, ND
City of Brown City
Village of Pentwater
City of Sandusky
Vintage on the Ponds
Town of Greenville
City of Climax
City of Sabin
Big Sauk Lake Mobile Home Park
City of Stewart
City of Lidgerwood
AM(E33)
C/F (Macrolite)
C/F (Aeralater)
C/F (Macrolite)
C/F (Macrolite)
C/F (Macrolite)
C/F (Macrolite)
C/F (Macrolite)
C/F&AM (E33)
Process Modification
STS
Kinetico
Siemens
Kinetico
Kinetico
Kinetico
Kinetico
Kinetico
AdEdge
Kinetico
640
400
340(e)
40
375
140
250
20
250
250
14W
13w
16W
20W
17
39W
34
25W
42W
146W
127(c)
466(c)
l,387(c)
l,499(c)
7827W
546(c>
l,470(c)
3,078(c)
1,344W
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
90W
50
37
35W
19w
56(a)
45
23(a)
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 Arsenic Removal Demonstration Sites (Continued)
Demonstration
Location
Site Name
Technology (Media)
Vendor
Design
Flow rate
(gpm)
Source Water Quality
As
Oig/L)
Fe
riijr/T,)
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)fe)
IX (Arsenex II)
AM (GFH/Kemiron)
AM (A/I Complex)
AM (fflX)
AM (Isolux)
Kinetico
Kinetico
Kinetico
Filtronics
Kinetico
Kinetico
Siemens
ATS
VEETech
MEI
250
250
75gpd
750
60/60/30
525
350
12
50
150
64
44
52
18
33
17
39
37W
35
15
<25
<25
134
69w
<25
<25
<25
125
125
<25
7.5
7.4
7.5
8.0
7.9
7.5
7.4
7.5
7.5
6.9
AM = adsorptive media; C/F = coagulation/filtration; EHX = hybrid ion exchanger; IX = ion exchange; RO = reverse osmosis
ATS = Aquatic Treatment Systems; MEI = Magnesium Elektron, Inc.; STS = Severn Trent Services
(a) Arsenic existing mostly as As(III).
(b) Design flowrate reduced by 50% due to system reconfiguration from parallel to series operation.
(c) Iron existing mostly as Fe(II).
(d) Replaced Village of Lyman, NE site which withdrew from program in June 2006.
(e) Facilities upgraded systems in Springfield, OH from 150 to 250 gpm, Sandusky, MI from 210 to 340 gpm, and Amaudville, LA from 385 to 770 gpm.
(f) Including nine residential units.
(g) Including eight under-the-sink units.
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Section 2.0 SUMMARY AND CONCLUSIONS
Severn Trent Service's APU-30S treatment system has been operating at the Alvin, TX location since
April 25, 2006. Based on the information collected during the first six months of operation, the following
summary and preliminary conclusions were made relating to the overall project objectives.
Performance of the arsenic removal technology for use on small systems:
• Chlorination was highly effective in oxidizing As(III) to As(V), reducing As(III)
concentration from 35.2 |o,g/L (on average) in raw water to 0.6 |o,g/L after chlorination.
Chlorination also was effective in oxidizing Mn(II), reducing it from 54.0 to 2.8 |o,g/L.
• SORB 33™ media effectively removed arsenic to 1.4 |o,g/L after treating 11,241,500 gal, or
12,170 bed volumes (BV), of water. (BV was calculated based on the 124 ft3 of media in
both the lead and lag vessels).
• Backwash at an average loading rate of 12.0 gpm/ft2 was effective in restoring differential
pressure (Ap) across the media beds, reducing it from about 10 psi, a pre-determined
backwash trigger point, to an initial level of about 3.5 psi. Although equipped with required
automatic features, manually triggered backwashes were preferred by the operator and
performed during the six-month study period.
• Since system startup, changes to the water quality in the distribution system occurred, which
included significant decreases in arsenic, iron, and manganese concentrations from 38.2 to
2.0 |og/L, from 115 to <25 |o,g/L, and from 41.8 to 1.3 |o,g/L, respectively. pH, alkalinity, lead,
and copper remained unchanged.
Required system O&Mand operator skill levels:
• The daily demand on the operator's time was reasonable, typically about 40 min/day to
visually inspect the system and record operational parameters.
• The system was easy to operate and experienced no downtime although operational
irregularities were experienced with Vessel A's flowmeter/totalizer, an automatic valve, and
system's parallel default settings.
Characteristics of residuals produced by the technology:
• A relatively large quantity of solids was produced during each backwash event, including
14.9 Ib from Tank A and 2.9 Ib from Tank B based on averaged total suspended solids (TSS)
results. Arsenic constituted only a fraction of the solids, i.e., <1.5 x 10"4 Ib.
Capital and O&Mcost of the technology:
• The capital investment for the system was $179,750 consisting of $124,103 for equipment,
$14,000 for site engineering, and $41,647 for installation, shakedown, and startup. The
building was funded by the city and not included in this cost. The unit capital cost was
$l,198/gpm (or $0.83/gpd) based on a 150-gpm design capacity.
• The O&M cost, estimated at $0.21/1,000 gal, included only incremental cost for system
operation labor.
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Section 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 STS treatment system began on April 25, 2006. Table 3-2 summarizes the types of data collected and
considered as part of the technology evaluation process. The overall system performance was evaluated
based on its ability to consistently remove arsenic to below the target MCL of 10 |o,g/L through the
collection of water samples across the treatment train. The reliability of the system was evaluated by
tracking the unscheduled system downtime and frequency and extent of repair and replacement. The
unscheduled downtime and repair information were recorded by the plant operator on a Repair and
Maintenance Log Sheet.
The O&M and operator skill requirements were evaluated based on a combination of quantitative data
and qualitative considerations, including the need for pre- and/or post-treatment, level of system
automation, extent of preventative maintenance activities, frequency of chemical and/or media handling
and inventory, and general knowledge needed for relevant chemical processes and related health and
safety practices. The staffing requirements for the system operation were recorded on an Operator Labor
Hour Log Sheet.
The quantity of aqueous and solid residuals generated was estimated by tracking the volume of backwash
water produced during each backwash cycle. Backwash water was sampled and analyzed for chemical
characteristics.
Table 3-1. Predemonstration Study Activities and Completion Dates
Activity
Introductory Meeting Held
Draft Letter of Understanding Issued
Final Letter of Understanding Issued
Request for Quotation Issued to Vendor
Vendor Quotation Received
Purchase Order Established
Letter Report Issued
Exception Request Submitted to TCEQ
APU-30S System Shipped
Engineering Package Submitted to TCEQ
Building Construction Begun
Building Completed
Exception Request Granted by TCEQ
System Permit Granted by TCEQ
Study Plan Issued
System Installation Completed
System Shakedown Completed
Performance Evaluation Begun
Date
November 2, 2004
January 21, 2005
February 8, 2005
February 14, 2005
March 20, 2005
May 3, 2005
May 12, 2005
July 8, 2005
September 4, 2005
September 9, 2005
October 6, 2005
November 12, 2005
November 2 1,2005
December 16, 2005
January 13, 2006
March 9, 2006
March 10, 2006
April 25, 2006
TCEQ = Texas Department of Environmental Quality
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Table 3-2. Evaluation Objectives and Supporting Data Collection Activities
Evaluation Objective
Performance
Reliability
System O&M and Operator
Skill Requirements
Residual Management
System Cost
Data Collection
-Ability to consistently meet 10 ug/L 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 for relevant chemical processes and health and
safety practices
-Quantity and characteristics of aqueous and solid residuals generated by
system operation
-Capital cost for equipment, engineering, and installation
-O&M cost for chemical usage, electricity consumption, and labor
The cost of the system was evaluated based on the capital cost per gal/min (gpm) (or gal/day [gpd]) of
design capacity and the O&M cost per 1,000 gal of water treated. This task required tracking the capital
cost for equipment, engineering, and installation, as well as the O&M cost for media replacement and
disposal, 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 daily basis (except for most Saturdays and
Sundays), the plant operator recorded system operational data, such as pressure, flowrate, totalizer, and
hour meter readings on a Daily System Operation Log Sheet; checked weight of the chlorine gas cylinder;
and conducted visual inspections to ensure normal system operations. If any problem occurred, the plant
operator contacted the Battelle Study Lead, who determined if the vendor should be contacted for
troubleshooting. The plant operator recorded all relevant information, including the problems
encountered, course of actions taken, materials and supplies used, and associated cost and labor incurred,
on a Repair and Maintenance Log Sheet. On a weekly basis, the plant operator measured several water
quality parameters on-site, including temperature, pH, dissolved oxygen (DO), oxidation-reduction
potential (ORP), and residual chlorine, and recorded the data on an On-Site Water Quality Parameters
Log Sheet. Monthly (or as needed) backwash data also were recorded on a Backwash Log Sheet.
The capital cost for the arsenic removal system consisted of the cost for equipment, site engineering, and
system installation. The O&M cost consisted of the cost for electricity consumption and labor. The gas
chlorine consumption was tracked on the Daily System Operation Log Sheet. Because the chemical
addition system was preexisting, chlorine consumption was not counted towards the O&M cost.
Electricity consumption was determined from utility bills. Labor for various activities, such as routine
system O&M, troubleshooting and repairs, and demonstration-related work, were tracked using an
Operator Labor Hour Log Sheet. The routine system O&M included activities such as completing field
logs, replacing the chlorine gas cylinder, ordering supplies, performing system inspections, and others as
recommended by the vendor. The labor for demonstration-related work, including activities such as
performing field measurements, collecting and shipping samples, and communicating with the Battelle
Study Lead and the vendor, was recorded, but not used for the cost analysis.
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3.3
Sample Collection Procedures and Schedules
To evaluate system performance, samples were collected at the wellhead, across the treatment system,
during APU-3OS filter backwash, and from the distribution system. The sample types and locations,
number of samples taken, and analytes measured during each sampling event are listed in Table 3-3.
Table 3-3. Sampling Schedule and Analyses
Sample
Type
Source
Water
Treatment
Plant Water
Backwash
Water
Distribution
Water
Residual
Solids
Sample
Locations
IN
IN, AC, TA, TB
Backwash
Discharge Line
from Each Vessel
One LCR and
Two Non-LCR
Residences
Spent Media
No. of
Samples
1
4
2
3
TBD
Frequency
Once
(during
initial site
visit)
Monthly
(first week
of each
four-week
cycle)
Monthly
(third week
of each
four-week
cycle)
Monthly or
as needed
Monthly
TBD
Analytes
On-site: pH, temperature,
DO, and ORP
Off-site: As(III), As(V),
As (total and soluble),
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, andTOC
On-site: pH, temperature,
DO, ORP, and C12 (free
and total)(a)
Off-site: As(III), As(V),
As (total and soluble),
Fe (total and soluble),
Mn (total and soluble),
Ca, Mg, F, NO3, SO4,
SiO2, P, turbidity, and
alkalinity
On-site: pH, temperature,
DO, ORP, C12 (free and
total) (a)
Off-site: As (total),
Fe (total), Mn (total),
SiO2, P, turbidity, and
alkalinity
As(total and soluble),
Fe(total and soluble),
Mn(total and soluble),
pH, TDS, and TSS
As (total), Fe (total), Mn
(total), Cu (total), Pb
(total), pH, and alkalinity
TCLP and total Al, As,
Ca, Cd, Cu, Fe, Mg, Mn,
Ni, P, Pb, Si, and Zn
Collection
Date(s)
11/02/04;
additional
source water
samples taken
02/16/05 (see
Table 4-1)
See Appendix B
See Appendix B
See Table 4-12
See Table 4-13
TBD
AC = after chlorination, IN = wellhead, TA = after lead vessel,
TCLP = toxicity characteristic leaching procedure
(a) On-site chlorine measurements not collected at IN.
TB = after lag vessel, TBD = to be determined;
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In addition, Figure 3-1 presents a flow diagram of the treatment system along with the analytes and
schedules at each sampling location. Specific sampling requirements for analytical methods, sample
volumes, containers, preservation, and holding times are presented in Table 4-1 of the EPA-endorsed
Quality Assurance Project Plan (QAPP) (Battelle, 2004). The procedure for arsenic speciation is
described in Appendix A of the QAPP.
3.3.1 Source Water. During the initial visit to the site on November 2, 2004, one set of raw water
samples was collected from Well 2 and speciated using an arsenic speciation kit (see Section 3.4.1). The
sample tap was flushed for several minutes before sampling; special care was taken to avoid agitation,
which might cause unwanted oxidation. Analytes for the source water samples are listed in Table 3-3.
Additional source water samples were taken on February 16, 2005, for Wells 1 and 2.
3.3.2 Treatment Plant Water. During the system performance evaluation study, biweekly water
samples were collected across the treatment train by the plant operator for on- and off-site analyses.
During the first week of each four-week cycle, samples were collected at the wellhead (IN), after
chlorination (AC), after the lead adsorption vessel (TA), and after the lag adsorption vessel (TB) and
analyzed for the analytes listed on Table 3-3. During the third week of the four-week cycle, samples were
taken from the same four locations and analyzed for the analyte list shown on Table 3-3.
3.3.3 Backwash Water. Backwash water samples were collected from both vessels by the plant
operator when the pressure differential across the lead vessel had reached 10 psi. Tubing, connected to
the tap on the discharge line, directed a portion of backwash water at about 1 gpm into a clean, 32-gal
container over the duration of the backwash for each tank. After the content in the container was
thoroughly mixed, composite samples were collected and/or filtered on-site with 0.45-(im filters.
Analytes for the backwash samples are listed in Table 3-3.
3.3.4 Distribution System Water. 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. Prior to system startup from March to June 2005, four
sets of monthly baseline water samples were collected from three residences, designated as DS1, DS2,
and DS3, within the distribution system. The DS1 residence located originally on Oak Manor Drive was
sampled only twice in March and April before being changed to another location on Oak Trail. The DS2
residence located orginally on Shady Oak Drive was sampled only once in March. Because the home
owner was not available to take samples in April, another location on Shady Oak Drive was selected for
May and June baseline sampling. The DS3 residence located on Kenny Court was used for all four
baseline sampling events. Following system startup, distribution system sampling continued on a
monthly basis at the same three locations as discussed.
The homeowners collected samples following an instruction sheet developed according to the Lead and
Copper Monitoring and Reporting Guidance for Public Water Systems (EPA, 2002). The dates and times
of last water usage before sampling and sample collection were recorded for calculation of the stagnation
time. All first-draw 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 and monthly samples are listed in
Table 3-3.
3.3.5 Residual Solids. Since media replacement did not take place during the intial six months of
this demonstration, no spent media samples were collected.
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Monthly (1st Week)
pH<
AC 1 After Chlorination
Xv
TA ) After Vessel A
TB 1 After Vessel B
^S
'~\
BW J Backwash Sampling Location
Chlorine Disinfection
INFLUENT | Unit Process
Process Flow
Backwash Flow
pH
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3.4 Sampling Logistics
3.4.1 Preparation of Arsenic Speciation Kits. The arsenic field speciation method uses an anion
exchange resin column to separate the soluble arsenic species, As(V) and As(III) (Edwards et al., 1998).
Resin columns were prepared in batches at Battelle laboratories according to the procedures detailed in
Appendix A of the EPA-endorsed QAPP (Battelle, 2004).
3.4.2 Preparation of Sample 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 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 designating the arsenic speciation bottle (if necessary). The
sampling locations at the treatment plant were color-coded for easy identification. The labeled bottles for
each sampling location were placed in separate Ziplock® bags and packed in the cooler.
In addition, all sampling- and shipping-related materials, such as disposable gloves, sampling instructions,
chain-of-custody forms, prepaid/addressed UPS air bills, and bubble wrap, were included. The chain-of-
custody forms and air bills were complete except for the operator's signature and the sample dates and
times. After preparation, the sample cooler was sent to the site via FedEx for the following week's
sampling event.
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 Section 4.0 of the EPA-endorsed QAPP (Battelle, 2004) were
followed by Battelle ICP-MS, AAL, and Belmont Labs. Laboratory quality assurance/quality control
(QA/QC) of all methods followed the prescribed guidelines. Data quality in terms of precision, accuracy,
method detection limits (MDL), 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 quality
assurance (QA) data associated with each analyte will be presented and evaluated in a QA/QC Summary
Report to be prepared under separate cover upon completion of the Arsenic Demonstration Project.
Field measurements of pH, temperature, DO, and ORP were conducted by the plant operator using a
WTW Multi 340i handheld meter, 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
11
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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 WTW 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.
12
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Section 4.0 SITE BACKGROUND
4.1
Site Description
4.1.1 Existing Facility. Located at 603 Mohawk Drive, Alvin, Texas, Oak Manor MUD's water
system supplies drinking water to about 189 homes from two wells, i.e., Wells 1 and 2, with a combined
flowrate of approximately 150 gpm. Well 1, located one mile northeast of the treatment plant, has an
average flowrate of 50 gpm. Well 2, located onsite, has an average flowrate of 100 gpm. The average
flowrates from both wells were estimated from the facility's historical water usage data collected during
July through December 2004.
Prior to the demonstration study, the water system operated for 8 to 9 hr/day with an average and peak
daily demand of approximately 74,000 and 97,400 gpd, respectively. The preexisting treatment included
gas chlorination to maintain a target total chlorine residual of 1.5 to 2.0 mg/L (as C12) and polyphosphate
addition to reach atarget dosage of 2.0 mg/L (as P). As shown in Figure 4-1, chlorine was added after the
Wells 1 and 2 water combined, but prior to a 75,000-gal storage tank and a 5,000-gal hydropneumatic
pressure tank (Figure 4-2). Polyphosphate was added to the Well 1 water just prior to the blending point
(Figure 4-3). The well pumps were controlled automatically by a high- and a low-level sensor in the
storage tank. Two booster pumps located immediately after the storage tank supplied water to the
hydropneumatic tank and distribution system (Figure 4-4) based on a set of low/high pressure settings
established for the hydropneumatic tank.
Figure 4-1. Preexisting Chlorine Addition Point and Wells 1 and 2
Blending Point
13
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Figure 4-2. Preexisting Storage Tank (in Foreground) and
Hydropneumatic Tank (in Background)
Figure 4-3. Preexisting Polyphosphate Addition Point
14
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Figure 4-4. Booster Pumps and Entry Piping to Distribution System
4.1.2 Source Water Quality. Source water samples were collected and speciated from Well 2 on
November 2, 2004, for on- and off-site analyses of the analytes listed on Table 4-1. Additional source
water samples also were collected on February 16, 2005, from Well 1, Well 2, and after Wells 1 and 2
combined. The analytical results for all source water sampling events are presented in Table 4-1 and
compared to those taken by the facility and submitted to EPA for the demonstration site selection.
Arsenic. Total arsenic concentrations in Wells 1 and 2 source water ranged from 17.4 to 47.4 |o,g/L. The
February 16, 2005, sampling results revealed that Well 1 water contained more total arsenic than Well 2
water, with concentrations in Well 1 at 47.7 |o,g/L and in Well 2 at 17.4 |og/L. The sample collected after
the blending point had a combined concentration of 34.5 |og/L, which was consistent with the average
concentration of Wells 1 and 2 before blending, but slightly higher than the 29-(ig/L concentration
obtained by the facility (although not specified by the facility, it was assumed that this sample was taken
after the blending point). Based on the November 2, 2004, speciation results for Well 2, essentially all of
the arsenic was in the soluble form. As(III) was the predominating species at 17.6 |o,g/L (or 94% of total
arsenic), indicating the need for oxidation prior to adsorption. The presence of As(III) as the
predominating arsenic species was consistent with the low DO and ORP readings, which were measured
at 1.7 mg/L and 1 mV, respectively.
Iron and Manganese. Total iron concentrations were 95 and 73 |o,g/L for the Wells 2 and 1 samples
taken on November 2, 2004, and February 16, 2005, respectively. Results for the samples taken from
Well 2 and Wells 1 and 2 combined on February 16, 2005, showed elevated iron concentrations at 687
and 317 (ig/L, respectively. The reason for the high iron concentrations is unknown. Based on the
November 2, 2004, speciation results, <40% of total iron existed in the soluble form. The presence of
particulate iron in source water was carefully monitored during the demonstration study to determine if
the measurement of particulate iron on November 2, 2004, was simply due to inadvertent aeration of the
sample during sampling.
15
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Table 4-1. Water Quality Data for Oak Manor MUD
Parameter
Date
PH
Temperature
DO
ORP
Total Alkalinity (as CaCO3)
Hardness (as CaCO3)
Turbidity
TDS
TOC
Nitrate (as N)
Nitrite (as N)
Ammonia (as N)
Chloride
Fluoride
Sulfate
Silica (as SiO2)
Orthophosphate (as P)
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
S.U.
°c
mg/L
mV
mg/L
mg/L
NTU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
HB/L
W?/L
HB/L
W?/L
HB/L
W?/L
HB/L
^g/L
W?/L
HB/L
W?/L
HB/L
W?/L
mg/L
mg/L
mg/L
Utility
Raw
Water
Data(a)
NA
7.8
NS
NS
NS
359
42
NS
NS
NS
NS
NS
NS
91
NS
2
NS
NS
29
NS
NS
NS
NS
62
NS
58
NS
NS
NS
NS
NS
201
12
3
Battelle Raw Water Data
Well 2
11/02/04
7.8
23.3
1.7
1
377
43
0.3
492
0.7
0.04
0.04
0.2
68.0
0.8
<1.0
16.8
0.06
18.8
19.0
O.I
17.6
1.4
95
37
61.6
61.7
1.5
1.5
2.1
1.9
259
9.3
4.8
Welll
02/16/05
NS
NS
NS
NS
330
NS
0.3
526
NS
0.05
0.05
NS
120.0
1.4
<1.0
15.8
0.05
47.7
NS
NS
NS
NS
73
NS
48.0
NS
O.I
NS
1.4
NS
194
10.6
2.9
Well 2
02/16/05
NS
NS
NS
NS
410
NS
8.7
670
NS
0.05
0.05
NS
98.0
1.5
2.0
15.5
0.05
17.4
NS
NS
NS
NS
687(d)
NS
65.2
NS
1.5
NS
1.2
NS
273
12.9
3.8
Welll
and 2
Combined(b)
02/16/05
NS
NS
NS
NS
379
NS
2.0
540
NS
0.05
0.05
NS
110.0
1.4
1.0
16.7
0.05
34.5
NS
NS
NS
NS
317(d)
NS
55.4
NS
0.8
NS
1.3
NS
201
12.0
3.2
TCEQ
Treated
Water
Data(c)
1998-2003
7.7-8.0
NS
NS
NS
356-360
42.0^3.3
NS
526-546
NS
0.01
0.01
NS
89.0-93.0
1.5-1.6
2.0
NS
NS
28.2-30.7
NS
NS
NS
NS
55.0-77.0
NS
37.5-62.0
NS
NS
NS
NS
NS
191-210
11.7-13.0
2.0-3.6
TCEQ = Texas Commission of Environmental Quality; NA = not available; NS = not sampled
(a) Provided to EPA for demonstration site selection; well number(s) not specified.
(b) Samples collected before storage tank with no chlorine or polyphosphate addition.
(c) Samples collected at point of entry into distribution system.
(d) Samples reanalyzed with similar results.
In general, adsorptive media technologies are best suited for source waters with relatively low iron levels
(e.g., less than 300 |o,g/L of iron, which is the secondary maximum contaminant level [SMCL] for iron).
Above 300 |o,g/L, taste, odor, and color problems can occur in treated water, along with an increased
potential for fouling of the adsorption system components with iron particulates.
16
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Manganese concentrations in source water ranged from 48.0 to 65.2 (ig/L. Well 2 water appeared to
contain more manganese, with concentrations ranging from 61.6 to 65.2 (ig/L, compared to that of Well 1
water at 48.0 (ig/L. The average concentration of water from Wells 1 and 2 sampled on February 16,
2005, was consistent with that of the combined well water (i.e., 56.6 versus 55.4 (ig/L) and close to the
58.0 (ig/L concentration provided by the facility. Based on the November 2, 2004, speciation result,
manganese existed entirely in the soluble form.
Silica, Sulfate, and Orthophosphate. As shown in Table 4-1, silica levels ranged from 15.5 to
16.8 mg/L (as SiO2); sulfate levels ranged from less than the method reporting limit of 1.0 mg/L to
2 mg/L; and Orthophosphate levels were all less than the method reporting limit of 0.05 mg/L (as P).
Usually, arsenic adsorption can be influenced by the presence of competing anions such as silica, sulfate,
and phosphate, but due to the low levels of these constituents, they were not expected to affect arsenic
adsorption onto the SORB 33™media.
Other Water Quality Parameters. A pH value of 7.8 was measured for Well 2 water, which was within
the STS target range of 6.0 to 8.0 for arsenic removal via adsorption. Therefore, pH adjustment was not
recommended prior to arsenic adsorption. Nitrate and nitrite were not detected in either well. Ammonia
at 0.2 mg/L (as N) was measured in Well 2 water. Chloride and fluoride were below their respective
SMCLs. Alkalinity ranged from 330 to 410 mg/L. The only total organic carbon (TOC) sample was
collected from Well 2 on November 2, 2004, which was measured at 0.7 mg/L. Uranium concentrations
ranged from less than the method reporting limit of 0.1 |o,g/L to 1.5 |o,g/L, well below its MCL of 30 |o,g/L.
Vanadium concentrations ranged from 1.2 to 2.1 |o,g/L. Sodium concentrations ranged from 194 to 273
mg/L across both wells. Calcium, magnesium, and hardness were low, ranging from 9.3 to 12.9 mg/L,
2.9 to 4.8 mg/L, and 42 to 43 mg/L (as CaCO3), respectively. Total dissolved solids (TDS) exceeded its
SMCL of 500 mg/L for all February 16, 2005, water samples, ranging from 492 to 670 mg/L.
4.1.3 Treated Water Quality. Historic treated water quality data collected by TCEQ from 1998
to 2003 also are presented in Table 4-1. The treated water samples were collected at the entry point into
the distribution system and after polyphosphate and chlorine addition. As expected, the treated water
quality data were similar to the source water quality data obtained by Battelle and the facility. Total
arsenic concentrations in the treated water ranged from 28.2 to 30.7 |o,g/L. Total iron was the only
constituent that had slightly lower treated water quality results as compared to the source water quality
results.
4.1.4 Distribution System and Regulatory Monitoring. Among the three residences selected for
distribution system water sampling, only DS3 was part of the Oak Manor MUD's historic sampling
network for Lead and Copper Rule (LCR) and monthly bacteriological sampling. Under the LCR,
samples were collected from designated taps at 10 residences every three years. Additional regulatory
monitoring directed by TCEQ included monthly sampling for coliform and volatile organic compounds
(VOCs), and biyearly/quarterly for inorganics, nitrate, and radionuclides.
Based on the information provided by the facility, the distribution system was constructed primarily of 6-
in cast-iron pipe. Piping within individual service hookups consisted primarily of %- to 1-in polyvinyl
chloride (PVC) and %- to 1-in galvanized iron. The distribution system was supplied directly by the
75,000-gal storage tank.
4.2 Treatment Process Description
STS provided an Arsenic Package Unit (APU)-30S Arsenic Removal System for the Oak Manor MUD
site. The APU is a fixed-bed, down-flow adsorption system used for small water systems with
17
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flowrates ranging from 5 to 150 gpm. The APU uses Bayoxide® E33 media (branded as SORB 33™ by
STS), an iron-based adsorptive media developed by Bayer AG, for the removal of arsenic from drinking
water supplies. Table 4-2 summarizes vendor-provided physical and chemical properties of the media.
Table 4-2. Physical and Chemical Properties of SORB 3311V1 Media
Physical Properties
Parameter
Matrix
Physical Form
Color
Bulk Density (lb/ft3 or g/cm3)
BET Surface Area (m2/g)
Attrition (%)
Moisture Content (%,by weight )
Particle Size Distribution
(U.S. Standard Mesh)
Crystal size (A)
Crystal phase
Values
Iron oxide composite
Dry pellets
Amber
35 or 0.56
142
0.3
<15
10 x35
70
a -FeOOH
Chemical Analysis
Constituents
FeOOH
CaO
MgO
MnO
S03
Na2O
TiO2
Si02
A1203
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
BET = Brunauer, Emmett, and Teller
SORB 33™ media is delivered in a dry crystalline form and listed by NSF International (NSF) under
Standard 61 for use in drinking water applications. The media exist in both granular and pelletized forms,
which have similar physical and chemical properties, except that pellets are denser than granules (i.e., 35
vs. 28 lb/ft3). The pellet form of the media was used for the Oak Manor MUD facility.
The treatment train consists of prechlorination/oxidation and adsorption. The APU-30S Arsenic Removal
Treatment System consists of two adsorption vessels, Vessels A and B, arranged in series (Figure 4-5).
When the arsenic concentration in the effluent from the lag vessel approaches 10 (ig/L, the spent media in
the lead vessel is removed and disposed of. After rebedding, this vessel is switched to the lag position. In
general, the series operation better utilizes the media capacity when compared to the parallel operation
because the lead vessel may be allowed to exhaust completely prior to change-out.
The piping and valve configuration of the APU-30S system consists of electrically actuated butterfly
valves to divert raw water flow into either Vessels A or B depending on which is operating as the lead
vessel. The piping and instrumentation diagrams (P&IDs) presented in Figures 4-6a and 6b use bolded
lines to indicate the process flow for series configuration with Vessels A and B, respectively, in the lead
position. Table 4-3 presents key system design parameters.
18
-------
Figure 4-5. Photograph of APU-30S Arsenic Removal System
The major process components/steps of the APU-30S system include the following:
• Intake. Raw water was pumped from the two supply wells and fed to the treatment system
via 3-in steel pipe (Figure 4-1). The well pumps were interlocked with the high and low level
sensors in the storage tank (Figure 4-2).
• Prechlorination/Oxidation. The existing gas chlorination system manufactured by
Ecometrics in Silverdale, PA, was used to oxidize As(III), Fe(II), and Mn(II) prior to the
adsorption vessels and provide a target total chlorine residual level from 1.5 to 2.0 mg/L
(as C12) for disinfection purposes. The chemical feed system consisting of one 150-lb
cylinder, a chlorinator unit (sitting on top of the chlorine gas cylinder), and an ejector was
located in a secured shed in the close proximity of the treatment system in the fenced area.
Figure 4-7 presents composite of pictures of the gas chlorination system. Note that the
current chlorine injection point (not pictured) was relocated after the Wells 1 and 2 blending
point to >10 ft downstream of the raw water sample tap, after system startup on April 25,
2006 (see Table 4-5). Operation of the chlorine feed system was linked to the well pumps so
that gas chlorine was injected only when the wells were on. Chlorine consumption was
tracked daily by recording the weight of the chlorine gas cylinder.
• Adsorption. The APU-30S system consisted of two 63-in-diameter, 86-in-tall adsorption
vessels configured in series. The tanks were made of fiberglass reinforced plastic (FRP),
rated for 100-psi working pressure, and skid mounted for ease of shipment and installation.
According to the original system design, each vessel was to contain 62 ft3 of media, yielding
an empty bed contact time (EBCT) of 3.1 min/vessel at a flowrate of 150 gpm. However,
based on STS's onsite measurements on May 17, 2006, Vessels A and B were inadvertently
loaded with an uneven amount of media (i.e., 53.6 and 70.3 ft3 for Vessels A and B,
respectively). As such, Vessel A had a slightly shorter EBCT than Vessel B (i.e., 2.7 vs. 3.5
19
-------
O
I UPBMB ___
valve Configuration and Water
Flow for TA Lead and TB Lag
W70SD1002 MODEL (I).CDR
RELEASED FOR
CONSTRUCTION
ARSENIC REMOVAL SYSTEM
AUMTX
SORB WS ARSENIC PACKAGE UNIT
PSI DIAGRAM
APU-3US (STAND ALONE! SERIES FLOW
FILTRATION PRODUCTS
Figure 4-6a. Process Flow Diagram for APU-30S System with Vessel A in Lead Position
-------
M/IB/OS il!WW W7DCD1000
W705D1002 MODEL (1) COR
g^gffg- >
Valve Configuration and Water
Flow for TB Lead and TA Lag
RELEASED FOR
CONSTRUCTION
ARSENIC REMOVAL SYSTEM
ALVIN,TX
SORB 33® ARSENIC PACKAGE UNIT
Ptl DIAGRAM
APU-30S (STAND ALONE) SERIES FLOW
Figure 4-6b. Process Flow Diagram for APU-30S System with Vessel B in Lead Position
-------
Table 4-3. Design Specifications for STS APU-30S System
Parameter
Value
Remarks
Pre-treatment
Target Total Chlorine Residual
(mg/L [as C121)
1.5 to 2.0
Gas chlorine used
Adsorption Vessels
Vessel Size (in)
Cross-Sectional Area (ft2/vessel)
Number of Vessels
Configuration
63 D x 86 H
21.6
2
Series
—
—
—
—
SORB 33™ Adsorption Media
Media Type
Media Quantity (Ib)
Media Volume (ft3)
Media Bed Depth (in)
SORB 33™
4,340
124
32
In pelletized form
Density for pelletized media 35 lb/ft3
62 ft3/vessel
Service
Design Flowrate (gpm)
Hydraulic Loading Rate (gpm/ft2)
EBCT for System (min)
Throughput to Lead Vessel Change-out
(gal)
Estimated Working Capacity (BV)
Average Use Rate (gal/day)
Estimated Media Life (months)
150
6.9
6.2
47,500,000
51,240
74,000
21
—
—
Based on total media volume of 124 ft3 and
system flowrate of 150 gpm (3.1 min/vessel)
Based on vendor revised proposal (STS, March
2005); lead vessel change-out to occur when
total arsenic concentration following lead
vessel reaches 16 ug/L
1 B V = 927 gal (based on media in both lead
and lag vessels)
Provided by facility
Estimated frequency of lead vessel change-out
based on average throughput to system
Backwash
Ap Setpoint (psi)
Backwash Flowrate (gpm)
Hydraulic Loading Rate (gpm/ft2)
Backwash Frequency (month/backwash)
Backwash Duration (mm/vessel)
Forward Flush Flowrate
Forward Flush Duration (mm/vessel)
Wastewater Production (gal/vessel)
10
210
9.7
1
20
210
10
6,300
—
Minimal recommended flowrate
-
Based on vendor's recommendation
—
—
—
-
min). Nonetheless, the design EBCT across the system remained unchanged at 6.2 min. The
hydraulic loading rate to each adsorption vessel was 6.9 gpm/ft2. Each adsorption vessel was
interconnected with schedule 80 PVC piping and five electrically actuated butterfly valves,
which made up the valve tree as shown in Figure 4-8. In addition to the 10 butterfly valves,
the system had two manual diaphragm valves on the backwash line, and six isolation ball
valves to divert raw water flow into either vessel, which reversed the lead/lag vessel
configuration. Each valve operated independently and the butterfly valves were controlled by
a Square D Telemechanique programmable logic controller (PLC) with a Magelis G2220
color touch interface screen.
22
-------
Figure 4-7. Gas Chlorination System
(Clockwise from the Top: Shed Housing Gas Chlorination System, Gas Cylinder,
Chlorine Ejector, and Chlorinator Unit)
Figure 4-8. APU-30S System Valve Tree and Piping Configuration
23
-------
• Backwash. The vendor recommended that the APU-30S system be backwashed on a regular
basis to remove particulates and media fines that accumulated in the media beds. Automatic
backwash could be initiated by either a time or a Ap setpoint across each vessel. During a
backwash cycle, each vessel was backwashed individually, while the second vessel remained
off-line. The backwash flowrate, hydraulic loading, duration, and wastewater produced were
210 gpm, 9.7 gpm/ft2, 30 min (including 10 min for forward flush), and 6,300 gal (including
2,100 gal for forward flush), respectively. The backwash/forward flush flowrates and the
amount of wastewater generated were determined by the flowrate and totalizer readings
shown on the PLC. The backwash and forward flush duration was timed and confirmed by
the operator. Backwash and forward flush water was mostly supplied by the two supply
wells; however, due to their maximum flowrate of 150 gpm, supplemental water had to be
drawn from the hydropneumatic pressure tank (Figure 4-9) located just downstream from the
adsorption vessels. Backwash wastewater was sent to a small ditch (Figure 4-10) adjacent to
the treatment system and subsequently drained into a roadside ditch.
• Media Replacement. Replacement of the media in the lead vessel will be scheduled once
the arsenic concentration following the lag vessel is approaching 10 (ig/L. Once the media in
the lead vessel is replaced, flow through the vessels will be switched such that the lag vessel
is placed into the lead position and the former lead vessel loaded with virgin media is placed
in the lag position. A Toxicity Characteristic Leaching Procedure (TCLP) test will be
conducted on the spent media before disposal to determine whether the media can be
considered non-hazardous.
• Storage and Distribution. The treated water was stored in a 24-ft tall, 75,000-gal storage
tank located immediately downstream of the APU-30S treatment system. A low-/high-level
sensor pair at 13/19.5 ft controlled the on/off of the well pumps. The booster pumps
subsequently pressured and temporarily stored water in a 5,000-gal hydropneumatic tank
before water entered the distribution system. The booster pumps switched on and off based
on the high and low pressure settings at 40 and 60 psi, respectively. The distribution system
was constructed primarily of 6-in cast-iron pipe. Piping within individual service hookups
consisted primarily of %- 1-in PVC and %- 1-in galvanized iron.
4.3 Treatment System Installation
4.3.1 System Permitting. A submittal package was sent by Oak Manor MUD to TCEQ on July 8,
2005, requesting an exception from conducting an on-site pilot study as required under Title 30 Texas
Administrative Code (30TAC) 290.42(g). The exception request was required by TCEQ prior to the
submission of engineering plans for the installation of the arsenic treatment system. The exception
submittal included a written description of treatment technology along with a schematic of the system and
relevant pilot- and full-scale data. Subsequently, a permit application package including a process flow
diagram of the treatment system, mechanical drawings of the treatment equipment, a schematic of the
building footprint and equipment layout, was submitted to TCEQ on September 9, 2005. TCEQ granted
its approval for the exception request and system permit application on November 21 and December 16,
2005, respectively. A permit was not required to discharge backwash wastewater to a roadside ditch.
4.3.2 Building Construction. A canopy (Figure 4-5) was built to shield the treatment system from
direct sunlight exposure. Construction of the concrete pad (Figure 4-11) began on October 6, 2005, and
the canopy was completed on November 12, 2005.
24
-------
Figure 4-9. Valve MB-127 to Supply Additional Treated Water from
Hydropneumatic Tank During Backwash
Figure 4-10. Small Ditch
25
-------
4.3.3 System Installation, Shakedown, and Startup. The shipment of the APU-30S system
arrived at the Oak Manor MUD on September 4, 2005. Upon arrival, STS's subcontractor, Abundant
Engineering, off-loaded the system components to a temporary staging area adjacent to the existing
treatment facility while the MUD awaited the completion of the concrete pad and issuance of the permit
approval. The pelletized media arrived in three super sacks on October 7, 2005. Although each super
sack usually has 38 ft3 of media bringing the total media volume to 114 ft3, the actual volume of media
shipped to the site was 124 ft3 based on freeboard measurements of the vessels (Section 4.3.4).
Upon receipt of the permit approval on December 16, 2005, Abundant Engineering performed most of the
installation work, including connecting the system to the existing inlet and distribution piping. A field
engineer from the STS Houston office made three separate trips to the site from January 17 to 19, from
March 9 to 10, and on April 5, 2006, to complete system installation and perform system shakedown and
startup. System installation, shakedown, and startup were completed on March 9, March 10, and April
25, 2006, respectively.
During the first trip from January 17 to 19, 2006, STS wired the PLC, conducted hydraulic testing on the
empty vessels, tested pressure gauges and flowmeters, loaded underbedding gravel and media, measured
freeboard heights after backwash, and disinfected the media and the system components with bleach. The
hydraulic test was performed at 88 gpm, lower than the design flowrate of 150 gpm. At this flowrate, the
inlet and outlet pressure for the treatment system were 14.0 and 6.0 psi, respectively, and the Ap readings
across Vessels A and B were 1.2 and 2.0 psi, respectively.
STS recommended a minimum backwash flowrate of 210 gpm (or 9.7 gpm/ft2), which exceeded the
maximum well capacity of 150 gpm. The remedy was to modify the preexisting plumbing, including the
installation of an automatic valve (MB-127), to deliver the treated water from the hydropneumatic tank to
supplement the backwash flow. Also, in order to prevent polyphosphate from entering the adsorption
vessels to cause adverse effects on arsenic adsorption, the preexisting polyphosphate addition was
relocated downstream of the APU-30S system and, later as discussed below, discontinued due to concerns
that polyphosphate in treated water might come in contact with the media during backwash.
STS's field engineer returned to the site from March 9 to 10, 2006, to perform a thorough media
backwash with supplemental flow. The backwash flowrates were verified to range from 250 to 270 gpm.
Although the polyphosphate addition point had been relocated downstream of the treatment system,
concern existed that polyphosphate still could come in contact with the media during backwash. After
shutting off polyphosphate addition, backwash and forward flush were performed and system shakedown
was completed on March 10, 2006. After chlorinating both vessels, the facility took samples for the
bacteriological test. Verbal approval to discharge the treated water into the distribution system was
granted by TCEQ on March 14, 2006.
Thereafter, the facility attempted to place the system online, but could not due to the production of
red/cloudy treated water. After 80,000 to 100,000 gal (or 86 to 108 BV) of water was used for backwash
and forward flush through both vessels, the facility contacted STS for a return visit.
The STS field engineer returned to the site for the third time on April 5, 2006, to troubleshoot the APU-
30S system. Vessels A and B were backwashed at 150 gpm for 30 and 40 min, respectively, followed by
20 min of forward flush. Vessel A backwash water cleared after 5 min, and Vessel B soon after. Forward
flush for Vessels A and B both cleared after 3 min. Only raw water was used during backwash, although
polyphosphate addition was discontinued for over a week prior to STS's return visit. After backwash,
both adsorption vessels were opened for freeboard measurements and media observations. The results of
the measurements and observations are discussed in Section 4.3.4. The vessels were then resealed and the
forward flush through both vessels resumed for about one hour before discharge was directed to the
26
-------
Figure 4-11. Construction of Concrete Pad with Storage Tank and
Hydropneumatic Tank (in Background)
27
-------
storage tank for distribution. The exact reason as to why the facility was unable to achieve clear water
was never determined.
Once all of the activities were completed, polyphosphate addition was restarted downstream of the APU-
30S due to complaints of iron in the treated water. On April 17, 2006, the facility shut off the
polyphosphate addition again on a permanent basis. The average iron concentration in the treated water
remained below the detection limit of 25 (ig/L as discussed in Section 4.5.3.
4.3.4 Media Loading. Media loading was performed by STS on January 19, 2006. The media as
shipped in super sacks was hoisted to the top of the canopy using a boom truck and loaded through a 12-
in x 4-in rigid funnel and a roof hatch into the adsorption vessels partially filled with water. A garden
hose was used to completely submerge the media, which was allowed to soak for about 4 hr. After the
top hat distributor was reinstalled and top piping reconnected, each vessel was backwashed at 150 gpm
for approximately 30 min to remove fines. The freeboard over the top of each media bed was then
measured three times and the averages of each vessel along with the calculated media volume are
summarized in Table 4-4.
The freeboard measurements taken from the top of the underbedding gravel to the top of the flange
openings before media loading were 65.3 and 66.5 in for Vessels A and B, respectively. The freeboard
measurements taken from the top of media beds to the top of the flange openings were 36.5 and 37.5 in
for Vessels A and B, respectively. As such, 51.8 and 52.3 ft3 of media should have been loaded into the
vessels. However, the freeboard measurements taken on April 5, 2006 (when STS returned to the site to
troubleshoot a facility's complaint concerning red/cloudy water from the adsorption vessels), and on May
17, 2006 (when STS returned to the site to complete the punch-list items identified by Battelle during its
system inspections [see Section 4.3.5]), indicated 52.7 to 53.6 ft3 of media in Vessel A and 69.4 to 70.3 ft3
in Vessel B. The discrepancy in media volume noted in Vessel B was attributed by the vendor to an
uneven distribution of three super sack contents to Vessels A and B and an incorrect freeboard
measurement of Vessel B after initial media loading on January 19, 2006. To avoid any confusion, it was
decided that the media volumes determined on May 17, 2006 (i.e., 43 and 57% in Vessels A and B)
should be used for all bed volume calculations.
Table 4-4. Freeboard Measurements and Media Volumes
in Adsorption Vessels
Date
01/19/06
04/05/06
05/17/06
Vessel A
Depth
(in)
36.5
36.0
35.5
Volume
(ft3)
51.8
52.7
53.6
Vessel B
Depth
(in)
37.5
28.0
27.5
Volume
(ft3)
52.3
69.4
70.3
Total
Volume
(ft3)
104
122
124
It also was noted during STS's April 5, 2006, site visit that the multiple backwashes after media loading
did not appear to have affected media integrity. Fine media was observed accumulating at the top of
media both with a depth of approximately 1 in. Below this level, the media appeared to be near its
original size and shape.
4.3.5 Punch List Items. Battelle performed system inspections and operator training for sample
and data collection on April 24 to 25, 2006. The performance evaluation study officially started on April
25, 2006. Table 4-5 summarizes the punch-list items and corrective actions taken from May 22, 2006, to
28
-------
Table 4-5. System Inspection Punch-List Items
Item
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Punch-List Item
Broken Well 2 totalizer
Raw water sample tap incorrectly
located (so that only Well 2 water might
be sampled [Figure 4-11])
Broken Vessel A flow meter
Inconsistent Vessel B freeboard
measurements taken on 01/19/06 and
04/05/06 by vendor (Section 4.3.4)
Vessels A and B sample taps (i.e., TA
and TB) incorrectly located (so that
same water was sampled by both taps)
1/8-in tubing from backwash discharge
piping to backwash wastewater sample
tap
Broken actuator valve 125b (not open
for automatic backwash)
Broken actuator valve 123 A (not open
for automatic backwash)
Missing backwash flow meter/totalizer
Broken totalizer on treated water line to
storage tank
Parallel vs. series default settings on
PLC
Block vs. unblock mode
Missing as-built drawings for APU-30S
system
Missing as-built site piping and
electrical drawings
Corrective Action(s) Taken
• Replaced Well 2 totalizer
• Used existing chlorine injection point (Figure 4-
12) for raw water sampling(a) during first three
sampling events on 04/25/06, 05/09/06, and
05/23/06
• Relocated raw water sample tap about 0.5 ft
after blending point of Wells 1 and 2 (Figure 4-
12) and relocated chlorine injection point about
10 ft downstream of the new raw water sample
tap for chlorine injection
• Relocate raw water sample tap to existing
chlorine injection point and continued using
relocated chlorine injection point
• Fixed Vessel A flow meter by removing
particles jammed in paddle wheel
• Retook freeboard measurements for both
Vessels A and B
• Relocated Vessels A and B sample taps (but
still at wrong locations)
• Corrected sample tap locations
• Discontinued use of 1/8-in tubing and sample
tap and replaced them with a 10-ft garden hose
to direct side stream from vessel via a spigot to
sample container
• Replaced actuator valve 125b
• Replaced actuator valve 123 A
• Installed a backwash flow meter/totalizer
• Replaced totalizer on treated water line
• Investigated PLC default settings, which might
not be changed from parallel to series. Power
outage will revert system to default setting
when left in manual mode [Section 4.3])
• Held a teleconference with facility
representatives, who expressed preference to
maintain PLC in unblock mode (i.e., system
valves remained open at all times)
• Provided as-built drawings for APU-30S system
• Provided as-built site engineering drawings
Resolution
Date
05/22/06
05/24/06
05/02/07
05/17/06
05/17/06
05/17/06
08/09/06
01/07
05/17/06
08/09/06
05/17/06
07/10/06
05/17/06
05/19/06
09/21/06
09/21/06
(a) Raw water samples collected after other treatment plant samples at AC, TA, and TB locations had been taken,
chlorine injection had been temporarily discontinued, and chlorine injection point had been thoroughly flushed.
29
-------
OJ
o
Figure 4-12. Photograph of Piping, Sample Taps, and Chlorine Injection Point Prior to Treatment System
-------
September 21, 2006. All punch-list items were addressed by STS and/or the facility by September 21,
2006.
4.4
System Operation
4.4.1 Operational Parameters. The operational parameters for the first six months of system
operation were tabulated and are attached as Appendix A. Key parameters are summarized in Table 4-6.
From April 25 through October 25, 2006, the system operated for 1,322 hr. This cumulative operating
time represents a use rate of about 30% during the first six-month operational period. The system
typically operated for a period of 7.2 hr/day (as compared to 8 to 9 hr/day prior to installation of the
arsenic treatment system). The average daily demand was about 51,700 gal (versus 74,000 gal provided
by the facility prior to the demonstration study) and the peak daily demand occurred on May 14, 2006, at
118,500-gal (compared to 97,400 gpd provided by the facility). Note that the demand calculated over
more than one day was not used to determine the peak daily demand.
Because of the difference in media volume in Vessels A and B (i.e., 53.6 ft3 for Vessel A and 70.3 ft3 for
Vessel B), the number of bed volumes treated by the system was calculated based on the combined media
volume, i.e., 124 ft3, in both vessels.
Table 4-6. Summary of APU-30S System Operations
Operational Parameter
Duration
Cumulative Operating Time (hr)
Average (Range) Daily Operating Time (hr)
System Operation -Adsor
Total Throughput (gal)
Bed Volumes (B V)(a)
Average (Range of) Daily Demand (gpd)
Average (Range of) Flowrate (gpm)(b)
Average (Range of) Hydraulic Loading (gpm/ft2)
Average (Range of) EBCT for System (min)(a)
Average (Range of) Inlet Pressure (psi)
Average (Range of) Outlet Pressure (psi)
Average (Range of) Ap across System (psi)
Average (Range of) Ap across Vessel A (psi)
Average (Range of) Ap across Vessel B (psi)
Value/Condition
04/25/06-10/25/06
1,322
7.2 (14.8-2.7)
ntion
11,241,500
12,172
51,700(21,000-118,500)
134(117-151)
6.2 (5.4-7.0)
6.9(6.1-7.9)
22.4 (18.0-28.0)
5.8 (3.0-8.0)
17.0 (13.0-21.0)
5.9 (2.5-10.0)
3.2 (2.3^.0)
System Operation - Backwash
Average (Range of) Backwash Flowrate (gpm)
Average (Range of) Hydraulic Loading Rate
Average (Range of) Backwash Duration (min)
Average (Range of) Wastewater Generated (gal)
260 (225-280)
12.0 (10.4-13.0)
23.3 (20.0-30.0)
6,058 (4,500-8,400)
(a) Calculated based on 124 ft3 (or 927 gal) of media in both Vessels A and B.
(b) Instantaneous flowrate readings from Vessel A.
Flowrates through the arsenic treatment system were tracked four ways. Instantaneous flowrate readings
were taken from an electromagnetic flowmeter/totalizer installed prior to Vessel A (or lead vessel).
31
-------
Calculated flowrate values were obtained from hour meter and flow totalizer readings recorded from one
each hour meter interlocked to Wells 1 and 2 and four totalizers, including the electromagnetic
flowmeter/totalizer installed prior to Vessel A and three preexisting positive displacement type master
totalizers installed at two wellheads and on the treated water line.
As shown in Table 4-7, all instantaneous and calculated flowrate readings were similar, with average
values ranging from 127 to 134 gpm. The instantaneous readings, chosen to determine the system
flowrates and total volume throughput, ranged from 117 to 151 gpm and averaged 134 gpm, which was
10.7% lower than the 150-gpm design value (Table 4-6). Based on the flowrates to the system, the
hydraulic loading rates to the adsorption vessels averaged 6.2 gpm/ft2 and the EBCTs for the system
varied from 6.1 to 7.9 min and averaged 6.9 min. As a result, the actual EBCT was 11.3% higher than the
design value of 6.2 min.
Table 4-7. System Instantaneous and Calculated Flowrates
Flowmeter/Totalizer
Type and Location
Electromagnetic, Prior to Vessel A
Electromagnetic, Prior to Vessel A
Positive Displacement, at Wellheads(a)
Positive Displacement, on Treated Water Line
Instantaneous/
Calculated
Instantaneous
Calculated
Calculated
Calculated
Flowrate (gpm)
Range
117-147
78-157
86-150
65-137
Average
134
127
132
134
(a) Sum of Wells 1 and 2 readings.
During the first six months, the system treated approximately 11,241,500 gal of water, equivalent to
12,172 BV, based on the 124-ft3 of media in both vessels.
The APU-30S system pressures were monitored at the system inlet and outlet and across the media beds.
As shown in Figure 4-13, for the first three days from April 25 to 27, 2006 (or at throughput up to
1,440 BV), Ap readings across both vessels were low at 3.0 psi, as compared to 1.2 and 2.0 psi across
Vessels A and B, respectively, during the hydraulic testing performed without media in the vessels on
January 17, 2006. Starting on the fourth day, Ap reading across Vessel A began to rise and a backwash
was performed on May 16, 2006, when Ap reached 8.5 psi (or at approximately 2,900 BV of throughput).
After backwash, the Ap readings returned to the original level of around 3.5 psi. As shown in Figure 4-
13 and Table 4-8, during the first six-month study, four backwashes were performed on both vessels,
averaging one backwash every six weeks. Both vessels were backwashed when Ap reached about 10 psi
across Vessel A, although Ap readings for Vessel B remained low and rather constant, averaging 3.2 psi
for the first six months.
It is postulated that the Ap rise across Vessel A was caused by the accumulation of precipitated solids in
the media bed caused by the addition of chlorine before the adsorption vessels. In addition, based on
several trip reports provided by STS, sediments produced from the wells also might have accumulated in
Vessel A contributing to the observed Ap rise.
4.4.2 Residual Management. Because media replacement was not performed during the first six
months of system operation, no spent media was produced in this reporting period.
4.4.3 Reliability and Simplicity of Operation. There was no downtime for the treatment system
during the first six-month study period. However, there were operational irregularities related to the
APU-30S system's Vessel A flowmeter/totalizer, automatic valve 123A, and system default settings.
32
-------
30 -
25 -
-System Inlet Pressure
-System Outlet Pressure
-System Differential Pressure (Calculated)
-Vessel A (Lead) Differential Pressure (Readini
-Vessel B (Lag) Differential Pressure (Readini
04/25/06
05/25/06
06/25/06
07/25/06
Date (mm/dd/yy)
08/25/06
09/25/06
10/25/06
Figure 4-13. System Pressure Readings
Table 4-8. Time Lapse Since Last Backwash
No.
1
2
3
4
Backwash
Date
05/16/06
07/14/06
08/09/06
09/19/06
Duration Since
Last Backwash
NA
8 weeks
4 weeks
5 weeks
Total
BV
Treated
2,904
6.914
8,314
10,569
AP before
Backwash
TA/TB
(psi)
8.50/3.00
9.00/3.00
8.75/3.75
10.0/3.75
AP after
Backwash
TA/TB
(psi)
3.50/2.50
3.25/2.75
3.75/3.00
3.25/3.25
NA = not available
The Vessel A flowmeter/totalizer broke on three separate occasions from April 25 to May 28, June 6, and
from September 6 to October 3, 2006, due to wear by either precipitated solids after prechlorination or
natural sediments from the wells. The automatic valve 123A failed to open during automatic backwash
on July 14, 2006, due to water and humidity accumulating in the valve. The APU-30S system was
discovered to be in parallel mode instead of series mode during the vendor's visit from May 16 to 17,
2006. The vendor determined that the system was left in manual mode (for backwash as discussed
below), which reverted back to its default parallel mode after a power outage. This occurred three times
throughout the first six-month period on June 19, September 5, and September 24, 2006, with the lag
vessel treating a total of about 20 BV of raw water from the three events.
During the first three and a half months of system operation, each backwash was initiated/ended by
physically opening/closing relevant valves by the operator. This was done to (1) ensure thorough
33
-------
backwash (i.e., by manually controlling the backwash duration till the effluent water cleared out;
Section 4.3.3), (2) circumvent recurring problems with backwash actuator valves 125b and 123a (which
would not open in automatic mode), and (3) allow a right amount of water to flow from the
hydropneumatic tank to supplement backwash (by manually opening and adjusting an isolation valve on
the backwash supplemental line). While it might be necessary to backwash manually as discussed, the
automatic control of the system should be utilized to minimize manual operation.
In addition, leaving the system in manual mode would put the system at risk of being reverted back to its
default parallel mode after a power outage as discussed above. This, in conjunction with the need to
accommodate the operator's request for his physical presence during backwash, prompted the vendor to
extend the automatic backwash timer setting from 30 to 120 days in the PLC on August 9, 2006. In doing
so, the operator could initiate a backwash, as Ap readings were approaching 10 psi (that usually happened
within the 120-day setpoint), by pushing the manual backwash button on the PLC screen. To alleviate the
three concerns mentioned above, the following actions were taken: (1) set backwash duration for 20 min
and forward flush for 10 min, (2) made onsite observations to ensure correct valve positions, and (3) leave
the manual isolation valve open at all times and allow the electrically actuated valve, MB-127, to control
the supplemental flowrate. Upon completion of the backwash, the operator reset the system back to the
automatic mode.
Operational irregularities also were experienced with the master totalizers on Well 2 and the treated water
line. The totalizer on Well 2 was broken from April 25 to May 21, 2006, while the totalizer on the treated
water line was broken from April 25 to July 10, 2006, and from August 21 to September 17, 2006.
The system O&M and operator skill requirements are discussed below in relation to pretreatment
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. Chlorination with the preexisting gas chlorination system
(discussed in Section 4.2 and shown in Figure 4-7) was the only pre-treatment required at the Oak Manor
MUD. The operator monitored the weight of the chlorine gas cylinder and target residual levels the same
way as prior to the arsenic demonstration study.
System Automation. For automatic system operation, the APU-30S system was fitted with electronic
flow sensors, flow controllers/valves, pressure transmitters/controllers, and a Square D Telemechanique
PLC with a Magelis G2220 color touch interface screen. For example, each adsorption vessel was
equipped with a flow sensor and totalizer (i.e., magnetic flowmeter), five electrically actuated butterfly
valves, and a pressure transmitter, all of which were capable of transmitting and receiving electronic
signals to and from the PLC. Although the PLC was capable of being interlocked with the well pumps,
hydropneumatic pressure tank, and/or the storage tank, the Oak Manor MUD elected not to pursue this
option due to additional electrical work required for interlocking.
The APU-30S system was capable of automatic backwash triggered by either a timer or a Ap setting. It
also allowed the operator to override the automatic setpoint by pushing the manual backwash button on
the PLC screen. As described earlier, to ensure a proper backwash, the operator initially conducted
backwash manually by physically opening/closing the valves. This practice was replaced with "semi-
automatic" backwash via the PLC after August 9, 2006.
The system also had six isolation ball valves to reverse the tank positions from lead to lag and vise versa
after each media replacement. Since media replacement would happen rather infrequently, the tank
switching operation was not automated.
34
-------
In addition to regular O&M, operator's awareness and abilities to detect unusual system performance
were necessary when troubleshooting system automation failures. The equipment vendor provided
hands-on training and a supplemental operations manual to help increase operator's awareness and
abilities to detect and cope with any performance irregularities.
Operator Skill Requirements. Under normal operating conditions, the skill requirements to operate the
system were minimal. The operator was on-site typically five times a week and spent about 40 min each
day to perform visual inspections and record the system operating parameters on the daily log sheets.
Normal operation of the system did not require additional skills beyond those necessary to operate the
existing water supply equipment.
TCEQ requires that the operator for the treatment system hold at least a TCEQ waterworks operator
license. There are four water operator certificate levels, i.e., A, B, C, and D, with Class A being the
highest. The certificate levels are based on education, experience, and related training. The operator for
the Oak Manor MUD system has a Class C certificate, which requires a high school graduate or
equivalent, two years of work experience, and 60 hr of related training (TCEQ, 2007).
Preventive Maintenance Activities. Preventive maintenance tasks included periodic checks of
flowmeters and pressure gauges and inspection of system piping and valves. Typically, the operator
performed these duties when he was on-site for routine activities.
Chemical Handling and Inventory Requirements. Gas chlorine cylinders were used for
prechlorination; the operator ordered chemicals as had been done prior to the installation of the APU-30S
system. Typically, four 150-pound cylinders were used per month and the gas chlorine supplier, DXI
Industries, refilled the chlorine cylinder onsite.
4.5 System Performance
The performance of the system was evaluated based on analyses of water samples collected from the
treatment plant and distribution system.
4.5.1 Treatment Plant Sampling. Table 4-9 summarizes the analytical results of arsenic, iron,
and manganese concentrations measured at the four sampling locations across the treatment train.
Table 4-10 summarizes the results of other water quality parameters. Appendix B contains a complete set
of analytical results through the first six months of operation. The results of the water samples collected
throughout the treatment plant are discussed below.
Arsenic. Water samples were collected on 14 occasions (including one duplicate sampling event on
August 1, 2006), with field speciation performed during seven of the 14 occasions at IN, AC, TA, and TB
sampling locations. Figure 4-14 contains four bar charts showing the concentrations of particulate
arsenic, As(III), and As(V) at the four sampling locations for each of the seven speciation events.
Total arsenic concentrations in raw water ranged from 30.2 to 52.5 |o,g/L and averaged 43.8 |o,g/L.
Particulate As levels were low, ranging from <0.1 to 5.9 |o,g/L and averaging 3.6 |o,g/L. Of the soluble
fraction, As(III) was the predominating species, ranging from 21.9 to 44.1 |o,g/L and averaging 35.2 |o,g/L.
As(V) was present, but at lower levels, ranging from 0.2 to 14.2 |o,g/L and averaging 4.8 |og/L.
After three sets of water samples were collected at the existing chlorine injection point (see Table 4-5),
the raw water sample tap was relocated to immediately after the blending point of Wells 1 and 2 on
May 24, 2006 (Section 4.3.5). After relocation, the average total arsenic level in source water increased
35
-------
Table 4-9. Summary of Analytical Results for Arsenic, Iron, and Manganese
Parameter
As (total)
As (soluble)
As
(paniculate)
As (III)
As(V)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
Sample
Location
IN
AC
TA(a)
TB(a)
IN
AC
TA(a)
TB(a)
IN
AC
TA(a)
TB(a)
IN
AC
TA(a)
TB(a)
IN
AC
TA(a)
TB(a)
IN
AC
TA(a)
TB(a)
IN
AC
TA(a)
TB(a)
IN
AC
TA(a)
TB(a)
IN
AC
TA(a)
TB(a)
Unit
Mfi/L
Mfi/L
W?/L
HB/L
^g/L
W?/L
HB/L
W?/L
HB/L
W?/L
HB/L
W?/L
^g/L
HB/L
W?/L
HB/L
W?/L
HB/L
W?/L
^g/L
HB/L
W?/L
HB/L
W?/L
HB/L
W?/L
HB/L
^g/L
W?/L
HB/L
W?/L
HB/L
W?/L
HB/L
HB/L
Hg/L
Sample
Count
14
14
13
13
7
7
6
6
7
7
6
6
7
7
6
6
7
7
6
6
14
14
13
13
7
7
6
6
14
14
13
13
7
7
6
6
Concentration
Minimum
30.2
23.5
0.2
0.05
27.4
24.3
0.05
0.05
<0.1
3.4
0.05
0.05
21.9
<0.1
0.05
0.05
0.2
23.3
0.05
0.05
34
<25
<25
<25
<25
<25
<25
<25
50.0
45.4
1.0
<0.1
49.5
0.1
<0.1
<0.1
Maximum
52.5
38.1
10.9
4.3
45.1
30.5
9.8
1.5
5.9
7.6
0.9
0.2
44.1
1.0
1.1
0.8
14.2
30.0
8.7
0.8
100
95
<25
65
43
<25
<25
<25
61.3
57.1
4.0
0.9
61.0
14.5
1.2
0.4
Average
43.8
31.5
6.7
1.0
39.9
27.7
6.4
0.7
3.6
5.3
0.3
0.1
35.2
0.6
0.5
0.5
4.8
27.1
5.8
0.3
60
38
<25
<25
<25
<25
<25
<25
54.4
51.1
2.0
0.4
54.0
2.8
0.5
0.1
Standard
Deviation
7.0
4.1
3.2
1.0
7.1
2.3
3.7
0.5
2.1
1.5
0.3
0.1
9.0
0.3
0.4
0.2
4.6
2.4
3.4
0.3
20
25
-
14.6
13.6
-
-
-
3.1
3.5
0.8
0.2
3.7
5.2
0.5
0.1
One-half of detection limit used for samples with concentrations less than detection limit for
calculations.
(a) Sample results taken on May 23, 2006, not representative of actual water quality at Vessels A and B
due to incorrect relocation of both sample taps (Section 4.3.5).
36
-------
Table 4-10. Summary of Other Water Quality Sampling Results
Parameter
Alkalinity
(as CaCO3)
Fluoride
Sulfate
Nitrate (as N)
Total P (as P)
Silica (as SiO2)
Turbidity
pH
Temperature
Dissolved
Oxygen
ORP
Free Chlorine
(as C12)
Sample
Location
IN(a)
AC
TA(b)
TB(b)
IN
AC
TA(b)
TB(b)
IN
AC
TA(b)
TB(b)
IN
AC
TA(b)
TB(b)
IN
AC
TA(b)
TB(b)
IN
AC
TA(b)
TB(b)
IN
AC
TA(b)
TB(b)
IN(C)
AC(C)
TA(b,c)
•pB(b, c)
IN(C)
AC(C)
TA(b,c)
•pB(b, c)
IN(C)
AC(C)
TA(b,c)
•pB(b, c)
IN(C)
AC(C)
TA(b,c)
•pB(b, c)
AC(C)
TA(b,c)
•pB(b, c)
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
ug/L
ug/L
ug/L
ug/L
Mg/L
Mg/L
Mg/L
Mg/L
NTU
NTU
NTU
NTU
s.u.
s.u.
s.u.
s.u.
°c
°c
°c
°c
Mg/L
Mg/L
Mg/L
Mg/L
mV
mV
mV
mV
Mg/L
Mg/L
Mg/L
Sample
Count
13
14
13
13
7
7
6
6
7
7
6
6
7
7
6
6
14
14
13
13
14
14
13
13
14
14
13
13
13
13
12
12
13
13
12
12
11
11
10
10
13
13
12
12
13
12
12
Concentration
Minimum
318
342
331
331
1.2
1.2
1.3
1.3
<1
1
1
1
O.05
<0.05
O.05
<0.05
25.2
20.4
<10
<10
14.4
14.8
15.3
12.6
0.1
0.2
0.1
0.1
7.5
7.3
7.6
7.6
22.8
22.3
22.1
21.7
1.2
1.2
1.7
1.5
217
407
292
397
0.3
0.1
0.2
Maximum
371
390
399
392
1.4
1.4
1.7
1.9
2
2
2
2
O.05
O.05
O.05
0.20
86.7
95.0
95.0
58.7
17.0
16.6
17.0
16.8
0.8
0.8
1.2
0.5
8.0
7.7
8.0
7.9
32.8
33.8
32.1
30.7
3.0
2.3
4.9
4.0
437
675
665
672
3.3
1.8
1.8
Average
347
361
365
362
1.3
1.4
1.4
1.5
0.8
1.7
1.8
1.5
<0.05
O.05
<0.05
0.05
42.7
43.2
26.5
9.1
15.4
15.7
15.9
15.6
0.4
0.4
0.3
0.3
7.7
7.5
7.7
7.7
25.6
25.4
25.2
25.0
1.8
1.8
3.2
2.7
344
602
580
597
2.1
1.4
1.3
Standard
Deviation
12.9
15.8
17.8
14.9
0.1
0.1
0.2
0.2
0.6
0.5
0.4
0.5
-
-
-
0.07
15.1
17.0
26.7
14.9
0.6
0.6
0.5
1.1
0.2
0.2
0.3
0.2
0.1
0.1
0.1
0.1
2.6
3.0
2.8
2.5
0.6
0.3
1.1
0.8
67.4
85.9
111
94
1.0
0.5
0.6
37
-------
Table 4-10. Summary of Other Water Quality Sampling Results (Continued)
Parameter
Total Chlorine
(as C12)
Total Hardness
(as CaCO3)
Ca Hardness
(as CaCO3)
Mg Hardness
(as CaCO3)
Sample
Location
AC(C)
TA(b,c)
•pg(b, c)
IN
AC
TA(b)
TB(b)
IN
AC
TA(b)
TB(b)
IN
AC
TAW
TB(b)
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
Sample
Count
13
12
12
7
7
6
6
7
7
6
6
7
7
6
6
Concentration
Minimum
0.3
0.2
0.5
31.0
30.0
31.5
32.7
18.8
18.0
19.0
19.8
12.1
12.0
11.8
11.8
Maximum
3.1
2.0
2.0
44.9
45.9
45.4
46.6
32.7
32.2
32.0
32.3
13.8
15.6
15.6
16.2
Average
2.1
1.5
1.4
37.8
40.2
41.1
42.1
25.1
26.6
27.5
28.2
12.7
13.6
13.5
13.9
Standard
Deviation
1.0
0.5
0.5
5.3
6.5
5.1
4.9
5.0
5.7
4.5
4.4
0.6
1.4
1.4
1.5
One-half of detection limit used for samples with concentrations less than detection limit for calculations.
(a) Outlier on August 29, 2006.
(b) Sample results taken on May 23, 2006, not representative of actual water quality at Vessels A and B due to
incorrect relocation of both sample taps (Section 4.3.5).
(c) Onsite water quality parameters not taken on August 1, 2006.
by about 41%, i.e., from 33.2 to 46.8 (ig/L (see the complete set of arsenic data in Appendix B and two
sets of arsenic speciation data in Figure 4-14).
The increase in total arsenic was attributed to the different arsenic concentrations in Well 1 and Well 2
water (see Table 4-1). Due to its close proximity to the blending point, water samples taken from the
relocated sample tap might not have been well mixed and, therefore, were more representative of Well 1
water with higher total arsenic concentrations. In contrast, the raw water sampling location (at the
existing chlorine injection point) prior to relocation was located further downstream from the blending
point (Figure 4-12) and, therefore, yielded more representative samples of blended water from both wells.
The operator continued to sample at the relocated sample tap during the first six-month study period.
After chlorination at AC sampling location, the average As(III) and As(V) concentrations were 0.6 and
27.1 |og/L, respectively, indicating effective oxidation. Free and total chlorine levels at the AC location
both averaged 2.1 mg/L (as C12) (see Table 4-10) and their corresponding ORP readings averaged 602
mV, compared to 344 mV in source water. As expected, the relocation of the raw water sample tap on
May 24, 2006, did not affect the water samples taken at the AC location. The average total arsenic levels
remained unchanged, i.e., averaging 34.7 (ig/L before relocation and 30.7 (ig/L after relocation. These
concentrations were in the same range of the raw water sample results before the raw water sampling
location was relocated.
38
-------
Arsenic Speciation at the Wellhead (IN)
As Concentration (jig/L)
D O O O O O I
ioug/L
Raw
3
water SE
ated on
mpletap
May 24, 200£
u
br
f
DAs particu ate)
• As (III)
DAs(V)
Arsenic
eaktrhough
rVesse A
04/25/06 05/23/06 06/21/06 07/1 9/06 08/1 6/06 09/1 2/06
Date
-
10/11/06
Arsenic Speciation after Chlorination (AC)
50-
— 40-
c
1 „
ru
g
5 20-
Raw water sample tap
relocated on May 24, 2006
Arsenic
break! rhough
10uq/L
DAs (particu ate)
• As (III)
DAs(V)
—
04/25/06 05/23/06
06/21/06 07/19/06 08/16,
Date
09/12/06 10/11/C
Arsenic Speciation after Lead Vessel A (TA)
60-
50-
_ 40-
1
|-
1
U
5 20-
10-
n -
Raw water sample tap
relocated on May 24, 2006
DAs (particu ate)
•As (III)
DAs(V)
Arsenic
breaktrhough
10u*L for Vessel A
.
n n
04/25/06 05/23/06 06/21/C
07/19/06
Date
09/12/06 10/11/06
Arsenic Speciation after Lag Vessel B (TB)
Raw water sample tap
relocated on May 24, 2006
04/25/06 05/23/06
07/19/06
Date
DAs (participate)
• As (III)
DAs(V)
Arsenic
breaktrhough
for Vessel A
09/12/06 10/11/06
Figure 4-14. Concentrations of Various Arsenic Species at IN, AC, TA, and TB Sampling Locations
-------
Figure 4-15 presents total arsenic breakthrough curves from the lead and lag vessels, along with total
arsenic concentrations in raw water and after chlorine addition. The lead vessel, Vessel A, removed the
majority of arsenic, existing predominately as As(V) because of prechlorination. On September 12, 2006,
after treating approximately 10,240 BV of water, arsenic was 10.0 (ig/L following the lead vessel and 0.8
(ig/L following the lag vessel. Through the end of the first six months of system operation, the system
treated only 12,170 BV, or 11,241,500 gal, of water.
As shown in Figure 4-15, total arsenic concentrations following the lag vessel remained <1.1 (ig/L until
September 27, 2006, when a concentration spike up to 4.3 (ig/L was observed. Total arsenic
concentrations decreased back to 1.4 (ig/L during the following sampling event on October 11, 2006. The
spike might have been caused by a power outage on September 24, 2006, when the system was reverted
back to its default parallel configuration (Section 4.4.3).
60
50 -
-At the Wellhead (IN)
- After Chlorination (AC)
After Lead Vessel A (TA)
-After Lag Vessel B (TB)
Raw water sample tap
relocated on May 24, 2006
Arsenic breaktrhough
for Vessel A on September 12,
2006
Bed Volume (103)
Figure 4-15. Total Arsenic Breakthrough Curves
Total chlorine levels following Vessels A and B averaged 1.5 and 1.4 mg/L (as C12), respectively, with
free chlorine levels averaged similarly at 1.4 and 1.3 mg/L (as C12). The corresponding ORP readings
averaged 580 and 597 mV, respectively. Both total and free chlorine were lower than the levels measured
at the AC location (i.e., 2.1 mg/L [as C12], on average), suggesting some chorine demand (i.e., 0.6 mg/L
[as C12], on average) across the lead vessel. The total chlorine demand for source water included 0.2
mg/L (as C12) for As, Fe, and Mn and 1.4 mg/L (as C12) for ammonia (breakpoint chlorination of 0.2 mg/L
[as N] as shown in Table 4-1). As a result, the overall chlorine demand would have been 2.2 mg/L (as
C12). The average chlorine consumption calculated based on the chlorine gas usage was 4.5 mg/L
(Figure 4-16), which was about 25% higher than the sum of chlorine demand and residuals measured.
40
-------
Figure 4-16. Chlorine Consumption Based on Chlorine Gas Usage
Iron. Total iron concentrations in source water ranged from 34 to 100 |o,g/L and averaged 60 |o,g/L
(Table 4-9), existing mostly as participate iron. The source water sample taken during the November 2,
2004, site visit, also contained a similar amount of total iron (i.e., 95 |og/L) with over 60% existing as
particulate iron. Particulate iron might exist in source water as part of natural sediment or caused by
inadvertent aeration of the samples during sampling. The amounts of DO measured in source water,
however, were low, ranging from 1.2 to 3.0 mg/L and averaging 1.8 mg/L.
Total iron concentrations in source water were not significantly affected by the relocation of the sample
tap on May 24, 2006, with an average decrease of only 11% observed (i.e., 66.1 (ig/L before relocation
and 58.9 |og/L after relocation). Total iron concentrations following prechlorination were slightly less
than those at the wellhead, ranging from less than the method reporting limit of 25 (ig/L to 95 |o,g/L and
averaging 38 |o,g/L. Correspondingly, soluble iron levels (based upon 0.45-(im filters) were <25 |o,g/L.
Total iron concentrations were reduced to an average of <25 |o,g/L after both Vessels A and B.
Manganese. Total manganese concentrations in source water ranged from 50.0 to 61.3 |o,g/L and averaged
54.4 |og/L, existing almost entirely in the soluble form (which was consistent with that found in source
water samples collected during the November 2, 2004, site visit [Table 4-1]). The amounts of total
manganese were not affected by the relocation of the sample tap. After prechlorination, an average of
93.5% of soluble manganese precipitated and formed, presumably, MnO2 solids. The MnO2 solids formed
along with unoxidized Mn(II) were removed by the media, causing total manganese concentrations to
decrease to 2.0 and 0.4 (ig/L following the lead and lag vessels, respectively. Note that 0.45-(im disc
filters were used to separate solids from the soluble fraction.
The high Mn(II) precipitation rate after chlorination at the Oak Manor MUD reflected rapid oxidation
kinetics by chlorine, which was contrary to the findings by most researchers who investigated the
oxidation of Mn(II) even with some lengths of contact time (Knocke et al, 1987 and 1990; Condit and
Chen, 2006). Varying Mn(II) oxidation kinetics were observed at 11 EPA arsenic removal demonstration
sites (Table 4-11), with two sites averaging less than 10% (i.e., Delavan, WI and Bruni, TX), seven sites
averaging from 14.6 to 55.0%, and two sites averaging at 93.5 and 70% (i.e., Alvin, TX and Springfield,
OH). It is not clear why some source waters had slower oxidation kinetics than others. Based on existing
41
-------
literature for Mn(II) oxidation with chlorine, the variables affecting Mn(II) oxidization kinetics might
include pH, temperature, and contact time. Mn(II) oxidation rates increased at high pH (i.e., 8.0) and high
temperature (Knocke et al., 1987). Table 4-11 did not show clear correlation between pH, temperature,
and contact time with precipitation rates (McCall et al., 2007). Out of the 13 sites investigated, the Oak
Manor MUD had the highest precipitation rates, which might partially be explained by the relatively high
temperature readings (average 25.6°C) measured at the site.
Competing Anions. Silica and phosphate are known to influence arsenic adsorption with iron-based
media. Silica concentrations in source water ranged from 14.4 to 17.0 mg/L with no significant
reductions across the treatment train. Total phosphorous concentrations in source water were somewhat
higher, ranging from 25.2 to 86.7 |o,g/L and averaging 42.7 mg/L. Total phosphorous concentrations were
progressively reduced to an average of 26.5 and 9.1 |og/L following Vessels A and B, respectively;
suggesting that total phosphorus might compete with arsenic for available adsorptive sites.
Other Water Quality Parameters. All other water quality parameters measured during the first six-
month study period were comparable to source water results presented in Table 4-1. As shown in Table
4-10, pH values of raw water varied from 7.5 to 8.0 and averaged 7.7. Arsenic removal by iron-based
adsorption media, in general, have greater arsenic removal capacities at near or lower than neutral pH
values. Alkalinity, reported as CaCO3, ranged from 318 to 371 mg/L and averaged 347 mg/L, not
including an outlier for raw samples taken on August 29, 2006. The results indicated that the adsorptive
media did not affect the amount of alkalinity in the treated water. Sulfate concentrations were
consistently low, averaging 0.8 mg/L in source water and 1.5 to 1.8 mg/L across the treatment train.
Fluoride levels ranging from 1.2 to 1.9 mg/L in all samples did not appear to have been affected by the
SORB 33™ media. Total hardness, existing 66% as calcium hardness and 34% as magnesium hardness,
ranged from 31.0 to 44.9 mg/L (as CaCO3), and also remained unchanged throughout the treatment train.
DO levels averaged 1.8 mg/L in source water. Due to a lack of a proper raw sample tap prior to May 24,
2006 (Section 4.3.5), source water was taken at the existing chlorine addition point (see Figure 4-1). DO
levels were higher before a proper raw water sample tap was installed, averaging 2.4 mg/L (compared to
1.6 mg/L after installation). DO at the AC location averaged 1.8 mg/L.
Table 4-11. Amount of Mn(II) Precipitated After Chlorination at 11
Arsenic Removal Demonstration Sites
Demonstration
Location
Bruni, TX
Anthony, NM
Brown City, MI
Delavan, WI
Sandusky, MI
Pentwater, MI
Springfield, OH
Alvin, TX
Rollinsford, NH
Climax, MN
Sabin, MN
Approximate
Contact Time
min
None
None
None
2
41
6
None
None
None
5
7
pH
S.U.
8.2
7.7
8.0
7.5
7.2
8.0
7.3
7.7
7.9
7.6
7.3
Temperature
°C
25.6
30.0
11.6
13.9
12.1
12.6
16.2
25.6
14.2
9.1
13.0
Ammonia
mg/L
-------
and TB, respectively. Thereafter, the DO levels were lower, averaging 1.9 and 2.0 mg/L at TA and TB,
respectively.
4.5.2 Backwash Water Sampling. Table 4-12 presents the analytical results for three monthly
backwash water sampling events for both adsorption vessels. pH values ranged from 7.7 to 7.8, similar to
those measured for source and treated water. TDS levels ranged from 482 to 532 mg/L and TSS from 5
to 400 mg/L. As expected, TSS values were higher for Vessel A (i.e., 294 mg/L) than for Vessel B (i.e.,
57 mg/L). Concentrations of total arsenic, iron, and manganese ranged from 3.2 to 17.0 |o,g/L, from 0.7 to
25.2 mg/L, and from 79 to 3,570 |o,g/L, respectively, with the majority of iron and manganese existing as
particulate. Assuming that an average of 6,058 gal (as compared to design of 6,300 gal) backwash and
fast rinse wastewater was produced from each vessel, at an average flowrate of 260 gpm and duration of
23.3 min, Vessel A would generate about 14.9 Ib of solids (including 4.2 x 10"5 Ib of arsenic, 0.9 Ib of
iron, and 0.08 Ib of manganese) and Vessel B would generate 2.9 Ib of solids (including 1.5 x 10"4 Ib of
arsenic, 0.2 Ib of iron, and 0.03 Ib of manganese), for each backwash cycle. The reasons for the large
quantity of backwash solids produced are being investigated and will be discussed in the Final
Performance Evaluation Report. The quantity of backwash wastewater and backwash solids discharged
per vessel will be further monitored during the next six-month study period.
4.5.3 Distribution System Water Sampling. Table 4-13 summarizes the results of the
distribution system sampling. Arsenic, iron, and manganese concentrations improved significantly after
system startup. Arsenic concentrations decreased, on average, from 38.2 to 2.0 |o,g/L, iron from 115 to
<25 |o,g/L, and manganese from 41.8 to 1.3 |o,g/L at each of the three sampling locations. Alkalinity, pH,
lead, and copper remained rather unchanged at each location after system startup. Copper concentrations
at DS1, however, were much higher than those at DS2 and DS3 (i.e., 498 |o,g/L, on average, at DS1
compared to 29.7 |o,g/L at DS2 and 31.0 |o,g/L at DS3). The operator reported that DS1 had older
distribution piping.
Iron concentrations within the distribution system were comparable to those at the entry point (or after the
lag vessel), but average arsenic and manganese concentrations within the distribution system increased
slightly from 0.9 to 2.0 |o,g/L and from 0.5 to 1.3 |o,g/L, respectively.
Table 4-12. Backwash Water Sampling Results
No.
1
2
3
Date
07/14/06
08/09/06
09/19/06
Vessel A
Q.
s.u.
7.7
7.7
7.7
CO
i—
mg/L
508
526
482
CO
f-
mg/L
366
116
400
1
-------
Table 4-13. Distribution Water Sampling Results
Sampling
Date
No.
BL1
BL2
BL3
BL4
Date
03/16/05(a)
04/20/05(a)
05/18/05
06/14/05W
Average
1
2
3
4
5
6
05/17/06(c)
06/07/06(d)
07/19/06(e)
08/15/06(f)
09/13/06fe)
10/10/0600
Average
1
£
w
~w
«
X
<
ug/L
NA
NA
NA
NA
NA
0.8
0.6
0.8
1.1
0.8
1.4
0.9
S
1
£
w
«
>2
Hg/L
NA
NA
NA
NA
NA
Mn at Entry Point0
"g/L
NA
NA
NA
NA
NA
DS1
non-LCR
1st Draw
Stagnation
Time
hr
10.0
12.0
8.6
11.0
10.4
0.
s.u.
8.2
7.6
7.4
7.7
7.7
41kalinity
mg/L
379
369
379
361
372
4s (total)
ug/L
27.8
32.4
92.8
32.4
46.3
i"
|,
QJ
ug/L
<25
<25
815
<25
123
Mn (total)
ug/L
40.6
32.7
60.5
36.9
42.7
j=
CU
ug/L
0.6
0.8
0.5
0.4
0.6
*
Ug/L
32.2
18.4
435
862
337
Cold-Water Faucet Not Flushed Before Shutting Off
<25
<25
<25
<25
65
<25
0.9
0.5
0.4
<0.1
0.5
0.5
10.0
9.0
10.3
9.8
9.3
9.7
7.8
7.8
7.7
8.0
7.9
7.8
363
353
358
379
385
368
1.9
1.8
1.4
1.2
1.6
1.6
<25
<25
<25
<25
<25
<25
0.3
0.4
0.5
0.3
0.7
0.5
0.1
0.3
0.4
0.6
0.6
0.4
624
465
496
383
520
498
DS2
non-LCR
1st Draw
Stagnation
Time
hr
6.4
K
S.U.
8.1
41kalinity
mg/L
366
4s (total)
Ug/L
29.6
Fe (total)
Hg/L
49
Mn (total)
Hg/L
68.3
j=
CL
Hg/L
0.6
a
Ug/L
20.1
Homeowner Not Available
8.6
7.0
7.3
NA
6.9
8.0
6.0
7.0
8.2
7.2
7.7
7.7
7.8
8.0
7.9
7.9
7.9
7.9
7.9
7.9
379
365
370
363
355
361
350
388
387
367
33.0
29.6
30.7
3.0
2.4
2.0
1.6
1.3
2.0
2.1
26
25
33
<25
<25
<25
<25
<25
<25
<25
38.3
50.9
52.5
1.1
1.3
2.5
1.2
3.0
1.7
1.8
0.6
1.3
0.8
0.5
0.1
0.6
0.4
0.2
0.6
0.4
59.1
28.6
35.9
29.4
36.8
27.3
51.3
18.5
14.9
29.7
DS3
LCR
1st Draw
Stagnation
[Time
hr
12.0
11.8
8.0
12.0
10.9
NA
8.5
8.0
8.0
8.0
10.0
8.5
K
S.U.
7.9
7.7
7.5
7.8
7.7
7.9
7.8
7.8
7.8
7.9
7.8
7.8
41kalinity
mg/L
379
368
357
356
365
347
359
357
358
398
382
367
4s (total)
Hg/L
29.8
30.9
50.3
31.2
35.5
3.9
2.8
2.1
2.0
1.4
2.0
2.4
i"
|,
V
Hg/L
<25
<25
268
<25
77
<25
<25
<25
<25
<25
<25
<25
Mn (total)
Ug/L
34.9
19.7
34.7
42.2
32.9
1.4
3.8
1.5
1.7
0.2
0.4
1.5
j=
CU
ug/L
0.3
0.1
0.7
0.8
0.5
0.2
0.5
0.4
0.5
0.3
0.5
0.4
r^
ug/L
32.6
81.7
36.5
74.0
56.2
25.9
23.3
32.4
41.3
18.7
44.6
31.0
NS = not sampled
NA = not analyzed
BL = Baseline Sampling
(a) DS1 and DS2 sampled at different locations as discussed in Section 3.3.4.
(b) DS1 sampled on 06/13/05.
(c) DS3 sampled on 05/18/06. Metals at entry point taken on 05/09/06.
(d) Metals at the entry point taken on 06/06/06.
(e) DS2 sampled on 07/25/06.
(f) Metals at the entry point taken on 08/16/06.
(g) Metals at the entry point taken on 09/12/06.
(h) Metals at the entry point taken on 10/11/06.
(i) Metals at entry point (As, Fe, and Mn) taken after Vessel B (Appendix B).
-------
4.6 System Cost
The 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 and the O&M cost includes 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 $179,750 (see Table 4-14). The equipment cost was $124,103 (or 69% of the total
capital investment), which included $86,642 forthe skid-mounted APU-30S unit, $18,858 for the E33
media ($152/ft3 or $4.35/lb to fill two vessels), $8,393 for shipping, and $10,211 for labor.
The engineering cost included the cost for preparing a submittal package for the exception request to
system piloting and a follow-up permit application to TCEQ by Oak Manor MUD. The permit submittal
package was prepared by SCL Engineering, the District's Engineer (see Section 4.3.1). The engineering
cost was $14,000, or 8% of the total capital investment.
The installation cost included the equipment and labor to unload and install the skid-mounted unit,
perform piping tie-ins and electrical work, load, and backwash the media, perform system shakedown and
startup, and conduct operator training. The installation cost was $41,647, or 23% of the total capital
investment.
The total capital cost of $179,750 was normalized to the system's rated capacity of 150 gpm
(216,000 gpd), which resulted in $l,198/gpm (or $0.83/gpd) of design capacity. The capital cost also was
converted to an annualized cost of $16,967/yr using a capital recovery factor (CRF) of 0.09439 based on a
7% interest rate and a 20-year return period. Assumed that the system operated 24 hours a day, 7 days a
week at the system design flowrate of 150 gpm to produce 78,624,000 gal of water per year, the unit
capital cost would be $0.22/1,000 gal. Because the system operated an average of 7.2 hr/day at 134 gpm
(see Table 4-6), producing 11,241,500 gal of water during the six-month period, the unit capital cost
increased to $0.75/1,000 gal at this reduced rate of use.
4.6.2 Operation and Maintenance Cost. The O&M cost included the cost for such items as
media replacement and disposal, electricity, and labor (Table 4-15). Although media replacement did not
take place during the first six months of system operation, the media replacement cost would represent the
majority of the O&M cost and was estimated to be $23,568 to change out the lead and lag vessels. This
media change-out cost would include the cost for media for two vessels, freight, labor, travel, and media
disposal. This cost was used to estimate the media replacement cost per 1,000 gal of water treated as a
function of the projected system run length at the 10 |o,g/L arsenic breakthrough from the lag vessel
(Figure 4-17). Because the actual media change-out most likely will take place only for the lead vessel, a
revised cost estimate (or actual) for one vessel will be used for the preparation of the Final Performance
Evaluation Report.
Comparison of electrical bills supplied by the utility prior to system installation and since startup did not
indicate a noticeable increase in power consumption. Therefore, electrical cost associated with operation
of the system was assumed to be negligible.
Under normal operating conditions, routine labor activities to operate and maintain the system consumed
an average of 40.4 min/day over the six-month period from April 25 to October 25, 2006 (or 183 days).
Therefore, the estimated labor cost was $0.21/1,000 gal of water treated.
45
-------
Table 4-14. Capital Investment Cost for APU-30S System
Description
Quantity
Cost
% of Capital
Investment
Equipment Cost
APU-30S Skid Mounted System (Unit)
E33 adsorptive media ( ft3)
Shipping
Vendor Labor
Equipment Total
1
124
-
-
-
$86,642
$18,858
$8,393
$10,211
$124,103
-
-
-
-
69%
Engineering Cost
Subcontractor Labor/ Travel
Engineering Total
-
-
$14,000
$14,000
-
8%
Installation Cost
Vendor Labor
Vendor Travel
Subcontractor Labor
Installation Total
Total Capital Investment
-
-
-
-
-
$4,913
$7,984
$28,750
$41,647
$179,750
-
-
-
23%
100%
Table 4-15. Operation and Maintenance Cost for APU-30S System
Cost Category
Volume processed (gal)
Value
11,241,500
Assumptions
April 25 to October 25, 2006
Media Replacement and Disposal Cost
Media replacement ($)
Shipping ($)
Vendor Labor/Travel ($)
Media disposal ($)
Subtotal
Media replacement
and disposal ($71,000 gal)
$18,858
$570
$2,800
$1,040
$23,268
See Figure 4-17
Vendor quote for 124 ft3 for both vessels
Vendor quote
Vendor quote
Vendor quote
Vendor quote
Electricity Cost
Electricity ($71,000 gal)
$0.00
Electrical costs assumed negligible
Labor Cost
Average weekly labor (min)
Labor ($71,000 gal)
Total O&M Cost/1,000 gal
280
$0.21
See Figure 4-17
40 min/day; 183 days for first six months of
study
Labor rate = $19.50/hr
46
-------
$25.00
$20.00
— $15.00
ro
O)
o
8
5
s
o $10.00
$5.00
$0.00
O&M cost
Media replacement cost
15 20 25 30
Media Working Capacity, Bed Volumes (xlOOO)
Note: One bed volume equals 124 ft3 (or 927 gal) for both Vessel A and B
Figure 4-17. Media Replacement and Operation and Maintenance Cost
47
-------
Section 5.0 REFERENCES
Battelle. 2004. Quality Assurance Project Plan for Evaluation of Arsenic Removal Technology.
Prepared under Contract No. 68-C-00-185, Task Order No. 0029, for U.S. Environmental
Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH.
Battelle. 2005. System Performance Evaluation Study Plan: U.S. EPA Demonstration of Arsenic
Removal Technology Round 2 at Alvin, TX. 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.
Condit, W.E. and A.S.C. Chen. 2006. Arsenic Removal from Drinking Water by Iron Removal, U.S. EPA
Demonstration Project at Climax, MN, Final Performance Evaluation Report.
EPA/600/R-06/152. 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. 2003. Minor Clarification of the National Primary Drinking Water Regulation for Arsenic. Federal
Register, 40 CFRPart 141.
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, D.C.
EPA. 2001. National Primary Drinking Water Regulations: Arsenic and Clarifications to Compliance
and New Source Contaminants Monitoring. Federal Register, 40 CFR Parts 9, 141, and 142.
Knocke, W.R., R.C. Hoehn, and R.L. Sinsabaugh. 1987. "Using Alternative Oxidants to Remove
Dissolved Manganese from Waters Laden with Organics." J. AWWA, 79(3): 75.
Knocke, W.R., J.E. Van Benschoten, M. Kearney, A. Soborski, and D.A. Reckhow. 1990. Alternative
Oxidants for the Remove of Soluble Iron and Manganese. Final report prepared for the AWWA
Research Foundation, Denver, CO.
Knocke, W.R., R.C. Hoehn, and R.L. Sinsbaugh. 1992. "Kinetic Modeling of Manganese(II) Oxidation
by Chlorine Dioxide and Potassium Permanganate." Environmental Science and Technology,
26(7): 1327-1333.
McCall, S.E., A.S.C. Chen, and L. Wang. 2007. Arsenic Removal from Drinking Water by Adsorptive
Media, U.S. EPA Demonstration Project at Chateau Estates Mobile Home Park in Springfield,
OH, Final Evaluation Report. EPA/600/R-06/152. U.S. Environmental Protection Agency,
National Risk Management Research Laboratory, Cincinnati, OH. .
Sorg, T.J. 2002. "Iron Treatment for Arsenic Removal Neglected." Opflow, 28(11): 15.
48
-------
Severn Trent Services. 2006. SORB 33™ As Removal Systems with Bayoxide® E33 Media Operation and
Maintenance Manual APU-30S'- City ofAlvin, Texas.
Severn Trent Services. 2006. SORB 33™ As Removal Systems with Bayoxide® E33 Media Vendor
Proposal for the APU-30S in Alvin, Texas.
TCEQ. 2007. Operator Training and Certification, http://www.tceq.state.tx.us/
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.
49
-------
APPENDIX A
OPERATIONAL DATA
-------
US EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet
1
2
3
4
5
04/25/06
04/26/06
04/27/06
04/28/06
04/29/06
04/30/06
05/01/06
05/02/06
05/03/06
05/04/06
05/05/06
05/06/06
05/07/06
05/08/06
05/09/06
05/10/06
05/11/06
05/12/06
05/13/06
05/1 4/06
05/15/06
05/16/06
05/17/06
05/18/06
05/19/06
05/20/06
05/21/06
05/22/06
05/23/06
05/24/06
05/25/06
05/26/06
05/27/06
05/28/06
Well
OpHr
Op
Time
hr
7.6
8.5
6.5
8.4
NA
NA
21.7
4.5
8.6
7.4
11.2
5.9
6.9
9.8
7.7
7.5
10.0
9.3
8.4
15.8
23.4
14.8
9.2
10.0
7.0
NA
NA
31.1
10.6
8.2
12.6
7.7
NA
NA
Well 1
Usage
gal
21 ,000
24,000
15,000
26,000
NA
NA
60,000
12,000
24,000
20,000
30,000
14,000
22,000
27,000
21 ,000
20,000
28,000
25,000
27,000
39,000
62,000
39,000
24,000
27,000
20,000
NA
NA
85,000
29,000
22,000
36,000
20,000
NA
NA
Avg
Flow
gpm
46
47
38
52
NA
NA
46
44
47
45
45
NA
NA
46
45
44
47
45
NA
NA
44
44
43
45
48
NA
NA
46
46
45
48
43
NA
NA
Well 2
Usage131
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
NA
NA
NA
53,000
40,000
63,000
38,000
NA
NA
Avg
Flow
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
83
81
83
82
NA
NA
Vessel A
Flowrate(b)
gpm
NM
NM
NM
off
NM
NM
NM
NM
NM
off
NM
NM
NM
NM
off
NM
NM
NM
off
NM
NM
NM
NM
NM
NM
NM
NM
off
NM
NM
off
NM
NM
NM
Usage|b|
gal
57,041
63,750
48,750
63,000
NA
NA
162,750
33,750
64,500
55,500
84,000
44,250
51 ,750
73,500
57,750
56,250
75,000
69,750
63,000
118,500
175,500
1 1 1 ,000
63,500
75,000
52,500
NA
NA
233,250
NA
NA
NA
NA
NA
NA
Avg
Flow
gpm
NA
125
125
125
NA
NA
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
NA
NA
125
129
126
131
126
NA
NA
Vessel B c|
Flowrate
gpm
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
Usage
gal
31
0
3
7
NA
NA
29
17
7
9
19
12
13
35
18
137
13
5
7
6
30
10
3,595
2,226
4
NA
NA
17
93
15
5
11
NA
NA
Avg
Flow
gpm
NA
0
0
0
NA
NA
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
7
4
0
NA
NA
0
0
0
0
0
NA
NA
AP
psi
2.50
3.50
3.00
off
NM
NM
3.25
3.00
3.00
off
3.25
3.25
3.25
3.25
off
3.00
2.75
2.75
off
2.2b
3.00
3.00
2.50
2.50
3.00
NM
NM
off
2.75
3.00
off
3.00
NM
NM
Vessel A & B
Total Cum.
Bed Volume
Treated1"1
no.
1,315
1,384
1,437
1,505
NA
NA
1,680
1,717
1,786
1,846
1,937
1,985
2,040
2,120
2,182
2,243
2,324
2,399
2,467
2,554
2,784
2,904
2,976
3,060
3,116
NA
NA
3,368
3,456
3,523
3,630
3,693
NA
NA
Vessel/System Pressure
Vessel A
AP
psi
2.50
3.50
3.00
off
NM
NM
3.50
3.50
3.50
off
3.75
3.75
4.00
4.25
off
4.50
4.25
5.00
off
6.00
8.50
8.50
3.50
3.75
3.75
NM
NM
off
4.00
4.00
off
4.00
NM
NM
Vessel B
AP
psi
2.50
3.50
3.00
off
NM
NM
3.25
3.00
3.00
off
3.25
3.25
3.25
3.25
off
3.00
2.75
2.75
off
2.25
3.00
3.00
2.50
2.50
3.00
NM
NM
off
2.75
3.00
off
3.00
NM
NM
Sys
AP
psig
13
14
14
NA
NA
NA
13
14
13
NA
NA
NA
NA
15
NA
13
13
15
NA
17
16
18
14
13
14
NA
NA
NA
14
15
NA
14
NA
NA
NaOCI
Average
Dosage
mg/L
4.8
NA
NA
NA
4.3
3.9
4.8
NA
NA
4.4
NA
NA
-------
US EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)
6
7
8
9
10
05/29/06
05/30/06
05/31/06
06/01/06
06/02/06
06/03/06
06/04/06
06/05/06
06/06/06
06/07/06
06/08/06
06/09/06
06/1 0/06
06/11/06
Well
OpHr
Op
Time
hr
34.2
11.7
5.8
5.1
7.5
6.1
NA
13.8
8.5
8.9
9.7
7.0
9.7
Well 1
Usage
gal
95,000
28,000
17,000
16,000
20,000
15,000
NA
40,000
24,000
25,000
26,000
19,000
23,000
NA
Avg
Flow
gpm
46
40
49
52
44
41
NA
48
47
47
45
45
40
NA
Well 2
Usage131
gal
170,000
52,000
18,000
26,000
40,000
31 ,000
NA
72,000
44,000
45,000
49,000
38,000
47,000
NA
Avg
Flow
gpm
83
74
52
85
89
85
NA
87
86
84
84
90
81
NA
Vessel A
Flowrate(b)
gpm
138
139
147
0
139
141
NM
0
NM
141
0
147
141
NM
Usage|b|
gal
NA
83,433
48,580
43,228
53,133
40,635
NA
109,902
68,000
75,536
78,232
58,617
80,386
NA
Avg
Flow
gpm
123
119
140
141
118
111
NA
133
133
141
134
140
138
NA
Vessel B c|
Flowrate
gpm
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
Usage
gal
19
3
4
12
7
7
NA
15
10
11
46
9
6
NA
Avg
Flow
gpm
0
0
0
0
0
0
NA
0
0
0
0
0
0
NA
AP
psi
3.00
3.50
3.50
3.50
3.00
3.00
NM
3.25
3.50
3.00
off
3.25
3.00
NM
Vessel A & B
Total Cum.
Bed Volume
Treated1"1
no.
3,979
4,069
4,121
4,168
4,225
4,269
NA
4,387
4,461
4,536
4,621
4,684
4,771
NA
Vessel/System Pressure
Vessel A
AP
psi
4.75
5.00
3.75
4.00
3.50
3.75
NM
4.00
4.25
4.50
off
4.50
5.00
NM
Vessel B
AP
psi
3.00
3.50
3.50
3.50
3.00
3.00
NM
3.25
3.50
3.00
off
3.25
3.00
NM
Sys
AP
psig
16
15
16
16
13
14
NA
16
16
16
NA
16
16
NA
NaOCI
Average
Dosage
mg/L
4.1
NA
4.6
NA
06/12/06 to 06/19/06 Operator was on vacation and no operational data was taken during this period.
06/1 7/06
06/1 8/06
06/1 9/06
06/20/06
06/21/06
06/22/06
06/23/06
06/24/06
06/25/06
06/26/06
06/27/06
06/28/06
06/29/06
06/30/06
07/01/06
07/02/06
NA
NA
NA
85.3
6.8
5.9
7.2
5.4
NA
15.0
8.6
10.3
7.9
8.9
NA
NA
NA
NA
NA
236,000
20,000
13,000
22,000
15,000
NA
41 ,000
24,000
28,000
21 ,000
24,000
NA
NA
NA
NA
NA
46
49
37
51
46
NA
46
47
45
44
45
NA
NA
NA
NA
NA
397,000
40,000
27,000
40,000
26,000
NA
77,000
44,000
52,000
40,000
44,000
NA
NA
NA
NA
NA
78
98
76
93
80
NA
86
85
84
84
82
NA
NA
NM
NM
NM
147
139
141
0
137
NM
144
0
140
137
0
NM
NM
NA
NA
NA
633,000
64,221
43,202
60,645
45,415
NA
126,662
69,040
84,712
63,661
71,057
NA
NA
NA
NA
NA
124
157
122
140
140
NA
141
134
137
134
133
NA
NA
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NA
NA
NA
4,840
7
7
10
5
NA
16
7
13
14
7
NA
NA
NA
NA
NA
1
0
0
0
0
NA
0
0
0
0
0
NA
NA
NM
NM
NM
3.50
3.25
3.25
off
3.25
NM
3.00
off
3.25
3.00
off
NM
NM
NA
NA
NA
5,459
5,528
5,575
5,640
5,689
NA
5,826
5,900
5,992
6,060
6,137
NA
NA
NM
NM
NM
4.25
4.25
4.50
off
4.25
NM
5.50
off
5.75
7.00
off
NM
NM
NM
NM
NM
3.50
3.25
3.25
off
3.25
NM
3.00
off
3.25
3.00
off
NM
NM
NA
NA
NA
16
15
16
NA
NA
NA
15
NA
17
18
NA
NA
NA
NA
NA
NA
4.7
NA
NA
NA
3.5
NA
NA
NA
-------
US EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)
11
12
13
14
15
07/03/06
07/04/06
07/05/06
07/06/06
07/07/06
07/08/06
07/09/06
07/10/06
07/11/06
07/12/06
07/13/06
07/14/06
07/15/06
07/16/06
07/17/06
07/18/06
07/19/06
07/20/06
07/21/06
07/22/06
07/23/06
07/24/06
07/25/06
07/26/06
07/27/06
07/28/06
07/29/06
07/30/06
07/31/06
08/01/06
08/02/06
08/03/06
08/04/06
08/05/06
08/06/06
Well
OpHr
Op
Time
hr
NA
26.1
8.7
6.6
5.6
7.5
NA
14.4
4.4
7.3
8.2
7.1
6.9
NA
16.7
8.7
6.0
6.2
4.0
NA
13.5
5.7
6.2
5.7
4.2
6.5
5.6
NA
14.3
8.3
6.7
6.1
8.2
3.4
NA
WelM
Usage
gal
NA
66,000
23,000
19,000
15,000
18,000
NA
41 ,000
12,000
18,000
23,000
19,000
19,000
NA
46,000
24,000
14,000
18,000
12,000
NA
37,000
15,000
17,000
15,000
1 1 ,000
19,000
14,000
NA
38,000
23,000
18,000
16,000
23,000
9,000
NA
Avg
Flow
gpm
NA
42
44
48
45
40
NA
47
45
41
47
45
46
NA
46
46
39
48
50
NA
46
44
46
44
44
49
42
NA
44
46
45
44
47
44
NA
Well 2
Usage|a|
gal
NA
127,000
45,000
33,000
29,000
36,000
NA
76,000
22,000
37,000
42,000
38,000
33,000
NA
86,000
47,000
32,000
29,000
24,000
NA
70,000
29,000
33,000
29,000
22,000
35,000
31 ,000
NA
69,000
43,000
35,000
32,000
42,000
17,000
NA
Avg
Flow
gpm
NA
81
86
83
86
80
NA
88
83
84
85
89
80
NA
86
90
89
78
100
NA
86
85
89
85
87
90
92
NA
80
86
87
87
85
83
NA
Vessel A
Flowrate(b)
gpm
NM
134
136
140
139
139
NM
133
144
137
138
131
138
NM
138
0
141
0
134
NM
0
135
0
137
136
127
132
NM
130
132
0
141
0
122
NM
Usage1"1
gal
NA
179,913
71 ,932
54,231
45,670
57,431
NA
121,775
34,767
44,150
56,740
53,41 1
50,331
NA
133,384
71,494
48,385
45,780
36,538
NA
108,383
45,273
49,913
45,842
32,614
53,228
44,537
NA
103,736
59,525
48,433
44,273
59,292
24,121
NA
Avg
Flow
gpm
NA
115
138
137
136
128
NA
141
132
101
115
125
122
NA
133
137
134
123
152
NA
134
132
134
134
129
136
133
NA
121
120
120
121
121
118
NA
Vessel B c|
Flowrate
gpm
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
Usage
gal
NA
28
8
7
8
4
NA
11
5
5
9
2
0
NA
12
10
12
2
6
NA
10
4
5
8
5
4
4
NA
12
7
6
4
13
3
NA
Avg
Flow
gpm
NA
0
0
0
0
0
NA
0
0
0
0
0
0
NA
0
0
0
0
0
NA
0
0
0
0
0
0
0
NA
0
0
0
0
0
0
NA
AP
psi
NM
3.50
3.25
3.25
3.50
3.00
NM
3.75
3.00
3.00
3.00
3.00
2.75
NM
3.00
off
3.00
off
3.50
NM
oft
3.50
off
3.00
3.00
3.00
3.00
NM
3.00
3.25
off
3.50
off
3.50
NM
Vessel A & B
Total Cum.
Bed Volume
Treated™
no.
NA
6,331
6,409
6,467
6,517
6,578
NA
6,710
6,747
6,795
6,856
6,914
6,968
NA
7,112
7,189
7,241
7,291
7,330
NA
7,447
7,496
7,550
7,599
7,634
7,692
7,740
NA
7,852
7,916
7,968
8,016
8,080
8,106
NA
Vessel/System Pressure
Vessel A
AP
psi
NM
5.50
5.75
6.50
6.50
7.50
NM
8.00
8.50
9.00
9.50
9.00
3.25
NM
4.00
off
4.50
off
5.50
NM
off
7.50
off
8.00
8.00
8.00
8.50
NM
8.00
8.50
off
8.50
off
8.00
NM
Vessel B
AP
psi
NM
3.50
3.25
3.25
3.50
3.00
NM
3.75
3.00
3.00
3.00
3.00
2.75
NM
3.00
off
3.00
off
3.50
NM
off
3.50
off
3.00
3.00
3.00
3.00
NM
3.00
3.25
off
3.50
off
3.50
NM
Sys
AP
psig
NA
18
18
16
17
18
NA
17
18
19
19
18
16
NA
16
NA
18
NA
18
NA
NA
16
NA
19
20
18
18
NA
17
19
NA
20
NA
18
NA
NaOCI
Average
Dosage
mg/L
NA
3.8
NA
4.8
NA
4.7
NA
NA
4.2
NA
3.3
NA
-------
US EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)
16
17
18
19
20
08/07/06
08/08/06
08/09/06
08/10/06
08/11/06
08/12/06
08/13/06
08/14/06
08/15/06
08/16/06
08/17/06
08/18/06
08/19/06
08/20/06
08/21/06
08/22/06
08/23/06
08/24/06
08/25/06
08/26/06
08/27/06
08/28/06
08/29/06
08/30/06
08/31/06
09/01/06
09/02/06
09/03/06
09/04/06
09/05/06
09/06/06
09/07/06
09/08/06
09/09/06
09/1 0/06
Well
OpHr
Op
Time
hr
14.6
6.1
5.7
10.0
5.3
5.4
NA
17.8
7.4
7.3
6.9
10.1
6.3
NA
15.3
6.1
7.9
4.7
6.5
5.8
NA
9.5
4.9
7.9
5.3
6.9
NA
NA
NA
NA
40.1
11.1
7.6
NA
NA
WelM
Usage
gal
39,000
16,000
15,000
28,000
14,000
14,000
NA
50,000
20,000
18,000
20,000
28,000
18,000
NA
39,000
17,000
22,000
12,000
18,000
15,000
NA
26,000
13,000
22,000
14,000
18,000
NA
NA
NA
NA
108,000
29,000
20,000
NA
NA
Avg
Flow
gpm
45
44
44
47
44
43
NA
47
45
41
48
46
48
NA
42
46
46
43
46
43
NA
46
44
46
44
43
NA
NA
NA
NA
45
44
44
NA
NA
Well 2
Usage|a|
gal
76,000
31 ,000
30,000
52,000
29,000
29,000
NA
93,000
39,000
36,000
38,000
52,000
37,000
NA
76,000
32,000
41 ,000
25,000
34,000
31 ,000
NA
50,000
26,000
42,000
27,000
37,000
NA
NA
NA
NA
206,000
56,000
38,000
NA
NA
Avg
Flow
gpm
87
85
88
87
91
90
NA
87
88
82
92
86
98
NA
83
87
86
89
87
89
NA
88
88
89
85
89
NA
NA
NA
NA
86
84
83
NA
NA
Vessel A
Flowrate(b)
gpm
0
131
133
0
129
126
NM
126
0
125
129
0
130
NM
0
126
0
128
122
126
NM
124
133
0
117
128
NM
NM
NM
NM
NM
NM
NM
NM
NM
Usage1"1
gal
106,013
44,544
41,949
62,006
40,250
40,415
NA
132,570
55,846
52,297
53,956
75,778
45,720
NA
109,715
45,724
57,370
34,835
47,390
36,732
NA
70,580
33,781
57,537
38,774
50,496
NA
NA
NA
NA
314,000
85,000
58,000
NA
NA
Avg
Flow
gpm
121
122
123
103
127
125
NA
124
126
119
130
125
121
NA
120
125
121
124
122
106
NA
124
115
121
122
122
NA
NA
NA
NA
131
128
127
NA
NA
Vessel B c|
Flowrate
gpm
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
Usage
gal
10
9
5
439
1
2
NA
12
7
3
5
5
0
NA
13
4
4
4
5
0
NA
9
4
6
4
5
NA
NA
NA
NA
1,160
9
5
NA
NA
Avg
Flow
gpm
0
0
0
1
0
0
NA
0
0
0
0
0
0
NA
0
0
0
0
0
0
NA
0
0
0
0
0
NA
NA
NA
NA
0
0
0
NA
NA
AP
psi
off
3Vb
3.75
off
3.00
3.00
NM
3.25
off
3.00
3.25
off
3.24
NM
off
3.00
off
3.00
3.00
3.00
NM
3.25
3.25
off
3.00
3.00
NM
NM
NM
NM
3.00
off
3.25
NM
NM
Vessel A & B
Total Cum.
Bed Volume
Treated™
no.
8,220
8,269
8,314
8,381
8,425
8,468
NA
8,611
8,671
8,728
8,786
8,868
8,917
NA
9,036
9,085
9,147
9,184
9,235
9,275
NA
9,351
9,388
9,450
9,492
9,546
NA
NA
NA
NA
9,886
9,978
10,040
NA
NA
Vessel/System Pressure
Vessel A
AP
psi
off
8.75
8.75
off
3.75
4.00
NM
5.00
off
5.50
5.75
off
5.75
NM
off
6.00
off
6.25
6.50
6.25
NM
6.50
6.75
off
7.00
7.25
NM
NM
NM
NM
7.75
off
8.00
NM
NM
Vessel B
AP
psi
off
3.75
3.75
off
3.00
3.00
NM
3.25
off
3.00
3.25
off
3.24
NM
off
3.00
off
3.00
3.00
3.00
NM
3.25
3.25
off
3.00
3.00
NM
NM
NM
NM
3.00
off
3.25
NM
NM
Sys
AP
psig
NA
17
18
NA
15
16
NA
15
NA
16
17
NA
16
NA
NA
17
NA
17
16
16
NA
16
16
NA
17
18
NA
NA
NA
NA
16
NA
18
NA
NA
NaOCI
Average
Dosage
mg/L
NA
3.3
NA
3.5
NA
6.9
NA
3.6
NA
NA
NA
NA
4.2
NA
NA
-------
US EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)
21
22
23
24
25
09/11/06
09/12/06
09/13/06
09/14/06
09/15/06
09/16/06
09/1 7/06
09/18/06
09/1 9/06
09/20/06
09/21/06
09/22/06
09/23/06
09/24/06
09/25/06
09/26/06
09/27/06
09/28/06
09/29/06
09/30/06
10/01/06
1 0/02/06
1 0/03/06
1 0/04/06
1 0/05/06
1 0/06/06
1 0/07/06
1 0/08/06
1 0/09/06
10/10/06
10/11/06
10/12/06
10/13/06
1 0/1 4/06
10/15/06
Well
OpHr
Op
Time
hr
19.2
4.5
5.0
7.4
4.0
7.1
NA
10.6
4.7
7.3
4.5
5.7
7.0
NA
12.3
4.0
3.7
6.7
2.7
NA
NA
18.0
5.2
3.0
5.2
6.1
NA
NA
20.6
4.8
4.4
5.7
3.1
NA
NA
Well 1
Usage
gal
51 ,000
12,000
14,000
19,000
1 1 ,000
17,000
NA
29,000
13,000
20,000
13,000
15,000
19,000
NA
36,000
10,000
1 1 ,000
18,000
7,000
NA
NA
53,000
14,000
9,000
14,000
16,000
NA
NA
56,000
13,000
12,000
15,000
9,000
NA
NA
Avg
Flow
gpm
44
44
47
43
46
40
NA
46
46
46
48
44
45
NA
49
42
50
45
43
NA
NA
49
45
50
45
44
NA
NA
45
45
45
44
48
NA
NA
Well 2
Usage|a|
gal
100,000
23,000
26,000
39,000
22,000
35,000
NA
54,000
25,000
40,000
24,000
31 ,000
39,000
NA
65,000
23,000
19,000
37,000
14,000
NA
NA
105,000
30,000
17,000
28,000
32,000
NA
NA
110,000
27,000
24,000
30,000
17,000
NA
NA
Avg
Flow
gpm
87
85
87
88
92
82
NA
85
89
91
89
91
93
NA
88
96
86
92
86
NA
NA
97
96
94
90
87
NA
NA
89
94
91
88
91
NA
NA
Vessel A
Flowrate(b)
gpm
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
0
142
138
NM
NM
0
133
131
133
0
NM
NM
Usage1"1
gal
151,000
35,000
40,000
58,000
33,000
52,000
NA
83,000
38,000
56,000
37,000
46,000
58,000
NA
101,000
33,000
30,000
55,000
21,000
NA
NA
158,000
44,000
24,447
41 ,485
46,490
NA
NA
158,661
38,217
35,170
43,559
23,555
NA
NA
Avg
Flow
gpm
131
130
133
131
138
122
NA
131
135
128
137
135
138
NA
137
138
135
137
130
NA
NA
146
141
136
133
127
NA
NA
128
133
133
127
127
NA
NA
Vessel B c|
Flowrate
gpm
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
Usage
gal
15
4
5
6
5
5
NA
10
4
3,243
4
4
3
NA
4,665
0
0
0
0
NA
NA
0
187
2
6
3
NA
NA
13
6
6
5
2
NA
NA
Avg
Flow
gpm
0
0
0
0
0
0
NA
0
0
7
0
0
0
NA
6
0
0
0
0
NA
NA
0
1
0
0
0
NA
NA
0
0
0
0
0
NA
NA
AP
psi
off
3.00
3.25
off
3.00
3.00
NM
3.00
3.75
3.25
3.50
3.25
3.00
NM
off
3.00
3.50
4.00
off
off
NM
off
3.25
off
3.50
3.50
NM
NM
off
3.75
3.00
3.00
off
NM
NM
Vessel A & B
Total Cum.
Bed Volume
Treated™
no.
10,203
10,241
10,284
10,347
10,382
10,438
NA
10,528
10,569
10,633
10,673
10,722
10,785
NA
10,899
10,935
10,967
1 1 ,026
1 1 ,049
NA
NA
11,219
1 1 ,267
1 1 ,295
1 1 ,340
1 1 ,390
NA
NA
11,561
1 1 ,602
1 1 ,640
1 1 ,687
11,713
NA
NA
Vessel/System Pressure
Vessel A
AP
psi
off
9.50
9.50
off
9.75
9.75
NM
9.75
10.00
3.25
4.00
4.00
4.25
NM
off
4.50
5.00
5.00
off
off
NM
off
4.75
off
5.00
5.50
NM
NM
off
6.25
6.25
7.00
off
NM
NM
Vessel B
AP
psi
off
3.00
3.25
off
3.00
3.00
NM
3.00
3.75
3.25
3.50
3.25
3.00
NM
off
3.00
3.50
4.00
off
off
NM
off
3.25
off
3.50
3.50
NM
NM
off
3.75
3.00
3.00
off
NM
NM
Sys
AP
psig
NA
20
21
NA
20
21
NA
21
21
15
17
17
17
NA
NA
16
18
18
NA
NA
NA
NA
16
NA
16
16
NA
NA
NA
16
16
15
NA
NA
NA
NaOCI
Average
Dosage
mg/L
NA
4.4
NA
4.2
NA
NA
5.2
NA
NA
NA
NA
5.2
NA
NA
NA
5.7
NA
NA
-------
US EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)
26
27
10/16/06
1 0/1 7/06
1 0/1 8/06
1 0/1 9/06
1 0/20/06
10/21/06
1 0/22/06
1 0/23/06
1 0/24/06
1 0/25/06
Well
OpHr
Op
Time
hr
17.0
3.1
4.6
4.6
4.5
NA
NA
14.9
4.8
4.6
WelM
Usage
gal
45,000
8,000
13,000
12,000
12,000
NA
NA
39,000
13,000
12,000
Avg
Flow
gpm
44
43
47
43
44
NA
NA
44
45
43
Well 2
Usage131
gal
91 ,000
17,000
25,000
25,000
25,000
NA
NA
79,000
26,000
24,000
Avg
Flow
gpm
89
91
91
91
93
NA
NA
88
90
87
Vessel A
Flowrate(b)
gpm
121
0
128
0
133
NM
NM
123
0
126
Usage1"1
gal
128,887
23,134
34,386
33,868
33,448
NA
NA
106,917
32,111
32,857
Avg
Flow
gpm
126
124
125
123
124
NA
NA
120
111
119
Vessel B|c|
Flowrate
gpm
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
Usage
gal
11
5
6
3
6
NA
NA
13
4
5
Avg
Flow
gpm
0
0
0
0
0
NA
NA
0
0
0
AP
psi
2.75
off
3.00
off
3.25
NM
NM
3.75
off
3.50
Vessel A & B
Total Cum.
Bed Volume
Treated™
no.
1 1 ,852
1 1 ,877
11,914
1 1 ,950
1 1 ,986
NA
NA
12,102
12,136
12,172
Vessel/System Pressure
Vessel A
AP
psi
6.25
off
6.75
off
7.50
NM
NM
9.00
off
9.00
Vessel B
AP
psi
2.75
off
3.00
off
3.25
NM
NM
3.75
off
3.50
Sys
AP
psig
17
NA
17
NA
16
NA
NA
19
NA
20
NaOCI
Average
Dosage
mg/L
6.1
NA
NA
4.8
(a) Totalizer on Well 2 broken from 04/25 to 05/21/06.
(b) Vessel A flowmeter and totalizer broken from 04/25 to 05/28/06, 06/06/06, and from 09/06 to 10/03/06.
(c) Vessel B flow meter should not register flow when placed in lag position.
(d) BV for Vessel A and B are 53.6 ft3 (401 gal) and 70.3 ft3 (526 gal), respectively. Total BV is 124 ft3 or 927 gal.
NM = Not Measured; NA = Not Available; off = Well off.
Highlight indicates calculated value.
-------
APPENDIX B
ANALYTICAL DATA TABLES
-------
Analytical Results from Long Term Sampling at Alvin, TX
Sampling Date
Sampling Location
Parameter Unit
Bed Volume
Alkalinity
=luoride
Sulfate
Nitrate (as N)
Total P (as P)
Silica (as SiO2)
Turbidity
pH
Temperature
DO
ORP
=ree Chlorine
Total Chlorine
Total Hardness (as CaCO3)
Ca Hardness (as CaCO3)
Mg Hardness (as CaCO3)
As (total)
As (soluble)
As (particulate)
As (III)
As(V)
Fe (total)
=e (soluble)
Mn (total)
Mn (soluble)
10»3
mg/L|a)
mg/L
mg/L
mg/L
mg/L
mg/L
NTU
S.U.
°C
mg/L
mV
mg/L
mg/L
mg/L
mg/L
mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
04/25/06
IN
-
361
1.2
1
<0.05
48.5
15.2
0.6
7.9
27.7
3.0
217
-
-
44.9
32.7
12.3
30.2
27.4
2.9
21.9
5.5
72
43
61.3
61.0
AC
-
366
1.4
2
<0.05
42.6
15.7
0.3
7.6
28.1
1.9
605
1.8
1.8
44.4
32.2
12.2
32.1
26.2
5.9
<0.1
26.1
34
<25
57.1
14.5
TA
TB
1.4
370
1.3
2
<0.05
<10
15.4
0.5
7.7
28.3
2.8
619
1.5
1.5
43.8
32.0
11.8
0.2
<0.1
<0.1
<0.1
<0.1
<25
<25
2.5
1.2
370
1.3
2
<0.05
<10
15.3
0.4
7.6
27.9
2.0
628
1.5
1.6
44.1
32.3
11.8
<0.1
<0.1
<0.1
<0.1
<0.1
<25
<25
0.3
<0.1
05/09/06
IN
-
347
-
-
-
48.2
17.0
0.3
7.9
32.8
2.8
254
-
-
-
34.6
-
66
-
59.2
-
AC
-
372
-
-
-
46.0
14.8
0.4
7.7
33.8
1.8
548
0.3
0.3
-
34.0
-
42
-
53.8
-
TA
TB
2.2
363
-
-
-
10.0
16.4
0.2
8.0
32.1
3.5
292
0.5
0.7
-
2.4
-
<25
-
1.3
-
355
-
-
-
<10
12.6
0.2
7.9
30.7
2.8
464
0.2
0.5
-
0.8
-
<25
-
0.4
-
05/23/06|a|
IN
-
355
1.3
2
<0.05
34.4
15.6
0.8
8.0
25.0
1.5
321
-
-
31.0
18.8
12.3
34.7
32.6
2.1
29.5
3.1
60
<25
52.3
51.8
AC
-
347
1.3
2
<0.05
34.3
16.6
0.3
7.5
25.0
1.7
407
0.7
0.7
30.0
18.0
12.0
38.1
30.5
7.6
0.5
30.0
<25
<25
45.8
1.4
TA
TB
3.5
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
06/06/06|b|
IN
-
346
-
-
-
51.5
15.4
0.3
7.8
27.6
1.6
365
-
-
-
47.9
-
87
-
56.1
-
AC
-
342
-
-
-
43.4
16.2
0.5
7.3
27.2
1.2
556
0.5
0.6
-
26.9
-
69
-
45.4
-
TA
TB
4.5
367
-
-
-
18.9
16.4
1.2
7.7
27.0
4.2
510
0.1
0.2
-
3.8
-
<25
-
2.9
-
363
-
-
-
<10
16.5
0.5
7.6
27.2
3.5
397
0.4
0.5
-
0.6
-
<25
-
0.9
-
06/21/06|c|
IN
-
338
1.2
<1
<0.05
44.5
14.4
0.6
7.6
25.8
2.1
302
-
-
42.5
28.7
13.8
48.1
44.2
4.0
43.9
0.2
66
<25
53.6
52.2
AC
-
359
1.2
2
<0.05
45.9
14.8
0.6
7.6
25.6
2.0
622
3.0
2.9
45.9
30.8
15.1
32.4
27.3
5.0
0.5
26.9
44
<25
50.4
1.1
TA
TB
5.5
371
1.3
2
<0.05
13.6
15.3
0.5
7.7
24.6
3.9
568
1.1
1.3
44.1
29.6
14.5
4.8
4.6
0.2
0.4
4.2
<25
<25
2.0
0.9
359
1.4
1
<0.05
<10
15.2
0.5
7.8
24.5
3.2
477
1.1
1.2
44.5
29.9
14.6
0.4
0.4
<0.1
0.4
<0.1
<25
<25
0.4
0.4
(a) Onsite water quality parameters taken on 05/26/06. (b) Onsite water quality parameters taken on 06/07/06 except for total and free CI2 readings, (c) Onsite water quality parameters taken on 06/22/06 except for total and free CI2 readings.
IN = influent; AC = after chlorination; TA = after Tank A; TB = after Tank B; TT = combined effluent
Analytical Results from Long Term Sampling at Alvin, TX
-------
Analytical Results from Long Term Sampling at Alvin, TX (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 (as CaCO3)
Ca Hardness (as CaCO3)
Mg Hardness (as CaCO3)
As (total)
As (soluble)
As (particulate)
As (III)
As(V)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
10"3
mg/L|a|
mg/L
mg/L
mg/L
mg/L
mg/L
NTU
S.U.
°C
mg/L
mV
mg/L
mg/L
mg/L
mg/L
mg/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
M9/L
07/05/06|a|
IN
339
-
-
37.8
15.4
0.5
7.5
24.5
1.8
430
-
-
-
44.4
-
86
52.7
AC
352
-
-
40.2
16.3
0.5
7.4
24.5
1.7
667
3.2
2.5
-
-
30.5
-
95
53.5
TA
TB
6.4
352
-
-
12.4
16.0
0.2
7.8
24.3
3.3
461
1.8
1.7
-
-
6.2
-
<25
4.0
356
-
-
<10
15.8
0.1
7.7
24.4
3.1
621
1.8
1.7
-
-
0.7
-
<25
-
0.7
07/19/06
IN
340
1.4
<1
<0.05
25.2
15.1
0.1
7.6
24.7
1.7
437
-
31.1
19.1
12.1
46.3
40.7
5.5
26.5
14.2
100
<25
50.0
49.5
AC
353
1.4
1
<0.05
20.4
15.2
0.5
7.6
23.9
2.3
459
1.9
2.2
32.0
19.3
12.7
27.6
24.3
3.4
1.0
23.3
60
<25
46.0
<0.1
TA
TB
7.2
349
1.7
1
<0.05
<10
15.8
0.2
7.9
23.4
4.9
596
1.5
1.6
31.5
19.0
12.5
6.1
6.1
<0.1
0.6
5.5
<25
<25
2.0
0.3
353
1.9
1
<0.05
<10
15.6
0.1
7.7
23.8
4.0
631
1.8
1.9
32.7
19.8
13.0
0.8
0.7
0.1
0.6
0.1
<25
<25
0.5
0.1
08/01/06|b|
IN
344
341
-
-
35.5
31.9
15.5
15.9
0.2
0.2
7.8
26.0
1.4
345
-
-
-
50.4
52.5
-
40
40
-
56.2
53.5
AC
349
350
-
-
28.9
33.0
16.4
16.3
0.3
0.3
7.6
24.7
1.7
655
2.3
2.4
-
-
34.9
33.6
-
<25
<25
-
50.9
53.2
TA
TB
7.9
357
354
-
-
<10
<10
17.0
16.1
0.3
0.2
7.9
25.1
3.7
644
1.4
1.4
-
-
8.3
7.9
-
<25
<25
-
2.5
1.7
362
350
-
-
<10
<10
16.5
16.8
0.2
0.2
7.8
24.8
2.9
652
0.9
1.0
-
-
1.0
1.1
-
<25
<25
-
0.3
0.2
08/16/06
IN
318
1.4
<1
<0.05
36.2
15.4
0.2
7.8
24.3
1.2
369
-
37.4
25.1
12.3
51.0
45.1
5.9
44.1
1.0
52
38
52.3
54.9
AC
343
1.4
1
<0.05
39.2
15.7
0.3
7.6
23.9
1.5
655
2.5
2.6
42.5
29.0
13.5
35.9
30.5
5.4
0.7
29.8
37
<25
52.7
0.8
TA
TB
8.7
331
1.5
2
<0.05
15.9
15.6
0.2
7.6
24.1
1.8
651
1.8
1.9
40.5
27.8
12.7
8.8
8.6
0.1
0.7
8.0
<25
<25
1.5
0.2
331
1.4
1
0.2
<10
16.0
0.1
7.7
24.1
1.5
668
1.8
2.0
42.9
29.4
13.5
1.1
0.9
0.2
0.6
0.2
<25
<25
0.4
0.1
08/29/06
IN
NA
-
-
50.2
14.7
0.2
7.6
25.6
1.4
423
-
-
-
40.1
-
34
-
52.0
AC
384
-
-
53.9
15.2
0.3
7.5
25.2
1.7
660
2.2
2.1
-
-
23.5
-
42
-
50.5
TA
TB
9.4
381
-
-
33.0
15.6
0.1
7.6
25.0
2.2
655
1.7
1.5
-
-
7.6
-
<25
-
1.2
366
-
-
<10
15.2
0.3
7.7
24.8
2.9
655
1.5
1.6
-
-
0.6
-
<25
-
0.1
Cd
to
(a) Onsite water quality parameters taken on 07/07/06. (b) Onsite water quality parameters taken on 08/02/06 except for total and free CI2 readings.
IN = influent; AC = after chlorination; TA = after Tank A; TB = after Tank B; TT = combined effluent
Analytical Results from Long Term Sampling at Alvin, TX
-------
Analytical Results from Long Term Sampling at Alvin, TX (Continued)
Cd
OJ
Sampling Date
Sampling Location
Parameter Unit
Bed Volume
Alkalinity
=luoride
Sulfate
Mitrate (as N)
Total P (as P)
Silica (as SiO2)
Turbidity
M
Temperature
DO
ORP
=ree Chlorine
Total Chlorine
Total Hardness (as CaCO3)
Ca Hardness (as CaCO3)
Vlg Hardness (as CaCOj)
As (total)
As (soluble)
As (particulate)
As (III)
As(V)
=e (total)
=e (soluble)
Vln (total)
Vln (soluble)
10»3
mg/L|a|
mg/L
mg/L
mg/L
mg/L
mg/L
NTU
S.U.
°C
mg/L
mV
mg/L
mg/L
mg/L
mg/L
mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
09/12/06
IN
-
352
1.4
<1
<0.05
38.7
15.3
0.2
7.7
23.4
1.5
303
-
37.8
25.2
12.7
49.8
44.7
5.1
39.4
5.3
45
<25
53.2
52.8
AC
362
1.4
2
O.05
42.8
15.3
0.3
7.5
23.1
2.0
655
2.6
2.9
40.7
26.9
13.7
34.9
28.6
6.3
0.4
28.1
<25
<25
50.0
0.7
TA
TB
10.2
362
1.4
2
O.05
24.6
15.7
0.1
7.6
23.1
1.7
639
1.7
1.7
41.2
27.2
14.0
10.0
9.1
0.9
0.4
8.7
<25
<25
1.3
<0.1
362
1.4
2
O.05
<10
15.8
0.2
7.6
23.1
1.5
646
1.6
1.8
41.5
27.4
14.1
0.8
0.8
O.1
0.4
0.3
<25
<25
0.1
<0.1
09/27/06
IN
354
86.7
14.8
0.3
7.7
22.8
NAW
390
39.8
58
56.6
AC
382
95.0
15.7
0.2
7.5
22.3
NAW
660
2.9
3.1
26.7
43
54.2
TA
TB
11.0
388
76.3
16.1
0.2
7.6
22.1
NAW
659
1.7
2.0
10.9
<25
2.0
382
58.7
15.5
0.1
7.7
21.7
NA|cl
658
1.2
1.4
4.3
<25
0.6
10/11/06
IN
371
1.3
<1
<0.05
28.1
15.9
0.8
7.7
23.1
NA|b|
317
39.6
26.3
13.4
44.0
44.7
<0.1
40.7
4.1
39
<25
52.9
55.6
AC
390
1.4
2
<0.05
39.3
16.0
0.8
7.5
22.8
NA|bl
675
3.3
3.1
45.6
30.0
15.6
30.2
26.6
3.5
0.9
25.7
<25
<25
52.6
0.9
TA
TB
11.6
399
1.4
2
O.05
19.9
15.3
0.4
7.6
22.8
NA|b|
665
1.8
1.9
45.4
29.8
15.6
10.2
9.8
0.4
1.1
8.7
<25
<25
1.0
0.2
392
1.5
2
O.05
<10
16.5
0.4
7.6
22.5
NA|bl
672
1.7
2.0
46.6
30.4
16.2
1.4
1.5
<0.1
0.8
0.8
65
<25
0.5
0.2
IN = influent; AC = after chlorination; TA = after Tank A; TB = after Tank B; TT = combined effluent
Analytical Results from Long Term Sampling at Alvin, TX
------- |