EPA/600/R-10/045

May 2010

Arsenic Removal from Drinking Water by Adsorptive Media

U.S. EPA Demonstration Project at 

Oak Manor Municipal Utility District at Alvin, TX

Final Performance Evaluation Report

by

Lili Wang§

Abraham S.C. Chen§

Anbo Wang‡ 

‡

Battelle, Columbus, OH 43201-2693

§

ALSA Tech, LLC, Columbus, OH 43219-0693

Contract No. 68-C-00-185

Task Order No. 0029

for 

Thomas J. Sorg

Task Order Manager

Water Supply and Water Resources Division

National Risk Management Research Laboratory 

Cincinnati, Ohio 45268

National Risk Management Research Laboratory

Office of Research and Development

U.S. Environmental Protection Agency

Cincinnati, Ohio 45268
ii

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. 
iii

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
iv

ABSTRACT

This report documents the activities performed and the results obtained for the EPA arsenic removal 

technology demonstration project at the Oak Manor Municipal Utility District (MUD) facility in Alvin, 

TX. The objectives of the project were to evaluate 1) the effectiveness of a Severn Trent Services (STS) 

Adsorptive Media System – Arsenic Package Unit (APU)-30S – with the use of SORB 33TM media in 

removing arsenic to meet the new arsenic maximum contaminant level (MCL) of 10 μg/L, 2) the 

reliability of the treatment system, 3) the simplicity of required system operation and maintenance 

(O&M) and operator skills, and 4) the cost-effectiveness of the technology. The project also

characterized water in the distribution system and process residuals produced by the treatment system.

The STS APU-30S system consisted of two 63-in × 86-in adsorption vessels configured in series with 

53.6 ft3 of SORB 33TM media loaded in the lead vessel and 70.3 ft3 in the lag vessel. The SORB 33TM

media is an iron-based adsorptive media developed by Bayer AG and packaged under the name SORB 

33TM by STS. The system was designed for a flowrate of 150 gal/min (gpm), corresponding to a design 

empty bed contact time (EBCT) of about 6.2 min (or 3.1 min/vessel) and a hydraulic loading rate of 6.9

gpm/ft2

. Actual flowrate through the system averaged 129 gpm during the performance evaluation study, 

yielding an EBCT of 7.2 min.

During the two-year performance evaluation study that began on April 25, 2006, and ended on April 8, 

2008, the treatment system operated for a total of 4,628 hr (or 6.7 hr/day), treating approximately 

35,358,250 gal or 38,140 bed volumes (BV) of water. (Bed volumes were calculated based on 124 ft3

 of 

media in both vessels.) The system continued to operate throughout the two-year study duration with 

only a few minor repairs and adjustments. The flowrate, pressure data, and other operational parameters 

were within the vendor specifications. 

Source water from Wells 1 and 2 contained 40.2 μg/L (on average) of total arsenic, which existed 

primarily as soluble As(III) (i.e., 31.5 μg/L). Prechlorination was effective at oxidizing As(III) to As(V), 

converting 98% of soluble arsenic to As(V). Arsenic breakthrough at 10 μg/L occurred after treating

9,527,220 gal (or 10,277 BV) of water following the lead vessel and 26,638,090 gal (or 28,736 BV) 

following the lag vessel. At the conclusion of the performance evaluation study, the system treated 

approximately 35,358,250 gal (or 38,140 BV) of water with 23.2 and 10.5 μg/L of total arsenic present in

the effluent of the lead and lag vessels, respectively. Bed volumes were calculated based on 124 ft3 of 

media in both lead and lag vessels.

Prechlorination also was effective in oxidizing soluble iron and manganese in source water, reducing their 

concentrations to below the method detection limit (MDL) of 25 μg/L for iron and 1.9 μg/L for 

manganese. 

Backwash was manually initiated by the operator when differential pressure across the adsorption vessels 

was approaching or exceeded 10 psi. During the first year of system operation, backwash was effective in 

restoring differential pressure (Δp) across the lead vessel, reducing it from above 10 psi to the initial level 

of <4.0 psi. Since then, backwash became less effective. Gradual accumulation of precipitated solids or 

well sediments was thought to have contributed to the progressively less effective backwash observed. 

Δp across the lag vessel remained low and constant around 3.1 psi throughout the performance evaluation 

study, indicating that precipitated solids and well sediments were removed mostly by the lead vessel. 

During each backwash event, approximately 7.2 kg of solids were discharged along with 10,800 gal of 

backwash wastewater. The discharged solids comprised 2.8 g of arsenic, 804 g of iron, and 71.8 g of 

manganese. 
v

Comparison of the distribution system sampling results before and after system startup showed noticeable 

decreases in arsenic (from 38.2 to 2.6 μg/L [on average]) and manganese concentrations (from 41.8 to 1.5 

μg/L [on average]) at all three distribution system sampling locations. Initially, arsenic concentrations in 

the distribution system water were higher than those in the plant effluent, probably due to redissolution 

and/or resuspension of arsenic previously accumulated in the distribution system. The concentrations 

then decreased and essentially mirrored those in the plant effluent. Lead and copper concentrations did 

not appear to have been affected by the operation of the treatment system. 

The capital investment cost for the treatment system was $179,750, including $124,103 for equipment, 

$14,000 for site engineering, and $41,647 for installation. Using the system’s rated capacity of 150 gpm, 

the capital cost was $1,198/gpm (or $0.83/gpd). This calculation did not include the cost for a building 

addition to house the treatment system. The unit annualized capital cost was $0.22/1,000 gal, assuming 

the system operated 24 hours a day, 7 days a week, at the system design flowrate of 150 gpm. The system 

operated only 6.7 hr/day on average, producing 18,928,170 gal of water per year. At this reduced usage 

rate, the unit annualized capital cost increased to $0.90/1,000 gal. O&M cost included only incremental 

cost associated with media replacement and disposal, and labor. There was no incremental electricity or 

chemical consumption cost. The unit O&M cost is presented in graphical form as a function of projected

media run length in this report. 
vi

CONTENTS 

DISCLAIMER ..............................................................................................................................................ii

FOREWORD...............................................................................................................................................iii

ABSTRACT ................................................................................................................................................. iv

FIGURES....................................................................................................................................................vii

TABLES .....................................................................................................................................................vii

ABBREVIATIONS AND ACRONYMS ....................................................................................................ix

ACKNOWLEDGMENTS ........................................................................................................................... xi

1.0 INTRODUCTION ................................................................................................................................. 1

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

1.2 Treatment Technologies for Arsenic Removal............................................................................. 2

1.3 Project Objectives......................................................................................................................... 2

2.0 SUMMARY AND CONCLUSIONS .................................................................................................... 5

3.0 MATERIALS AND METHODS........................................................................................................... 6

3.1 General Project Approach............................................................................................................. 6

3.2 System O&M and Cost Data Collection....................................................................................... 7

3.3 Sample Collection Procedures and Schedules.............................................................................. 8

3.3.1 Source Water....................................................................................................................... 8

3.3.2 Treatment Plant Water........................................................................................................ 8

3.3.3 Backwash Wastewater ........................................................................................................ 8

3.3.4 Residual Solids ................................................................................................................. 10

3.3.5 Distribution System Water................................................................................................ 10

3.4 Sampling Logistics..................................................................................................................... 12

3.4.1 Preparation of Arsenic Speciation Kits............................................................................. 12

3.4.2 Preparation of Sampling Coolers...................................................................................... 12

3.4.3 Sample Shipping and Handling ........................................................................................ 12

3.5 Analytical Procedures................................................................................................................. 12

4.0 RESULTS AND DISCUSSION .......................................................................................................... 14

4.1 Site Description .......................................................................................................................... 14

4.1.1 Pre-existing System .......................................................................................................... 14

4.1.2 Source Water Quality........................................................................................................ 16

4.1.3 Historic Distribution Water Quality.................................................................................. 18

4.1.4 Distribution System and Regulatory Monitoring.............................................................. 18

4.2 Treatment Process Description................................................................................................... 18

4.3 Treatment System Installation .................................................................................................... 26

4.3.1 System Permitting............................................................................................................. 26

4.3.2 Building Construction....................................................................................................... 26

4.3.3 System Installation, Shakedown, and Startup................................................................... 27

4.3.4 Media Loading.................................................................................................................. 29

4.3.5 Punch List Items ............................................................................................................... 29

4.4 System Operation ....................................................................................................................... 29

4.4.1 Operational Parameters..................................................................................................... 29

4.4.2 Residual Management....................................................................................................... 35

4.4.3 Media Rebedding.............................................................................................................. 35

4.4.4 Reliability and Simplicity of Operation............................................................................ 35
vii

4.5 System Performance ................................................................................................................... 37

4.5.1 Treatment Plant Sampling ................................................................................................ 37

4.5.2 Backwash Wastewater Sampling...................................................................................... 46

4.5.3 Spent Media Sampling...................................................................................................... 47

4.5.4 Distribution System Water Sampling ............................................................................... 48

4.6 System Cost ................................................................................................................................ 50

4.6.1 Capital Cost....................................................................................................................... 50

4.6.2 Operation and Maintenance Cost...................................................................................... 51

5.0 REFERENCES .................................................................................................................................... 53

APPENDICES

Appendix A: OPERATIONAL DATA

Appendix B: ANALYTICAL DATA

FIGURES

Figure 3-1. Process Flow Diagram and Sampling Schedule and Locations........................................... 11

Figure 4-1. Chlorine Addition Point and Wells 1 and 2 Blending Point ................................................ 14

Figure 4-2. Pre-existing Storage Tank and Hydropneumatic Tank ........................................................ 15

Figure 4-3. Pre-existing Polyphosphate Addition Point ......................................................................... 15

Figure 4-4. Booster Pumps and Entry Piping to Distribution System .................................................... 16

Figure 4-5. APU-30S Arsenic Removal System..................................................................................... 20

Figure 4-6a. Process Flow Diagram for APU-30S System with Vessel A in Lead Position.................... 21

Figure 4-6b. Process Flow Diagram for APU-30S System with Vessel B in Lead Position................... 22

Figure 4-7. Gas Chlorination System...................................................................................................... 24

Figure 4-8. APU-30S System Valve Tree and Piping Configuration ..................................................... 25

Figure 4-9. Valve MB-127 to Supply Additional Treated Water from Hydropneumatic Tank 

During Backwash................................................................................................................. 25

Figure 4-10. Small Ditch for Backwash Wastewater................................................................................ 26

Figure 4-11. Construction of Concrete Pad with Storage Tank and Hydropneumatic Tank .................... 27

Figure 4-12. Piping, Sample Taps, and Chlorine Injection Point Prior to Treatment System.................. 31

Figure 4-13. Δp Across Treatment System, and Lead and Lag Vessels................................................... 33

Figure 4-14. Concentrations of Arsenic Species at Influent, After Chlorination, after Lead 

Vessel, and after Lag Vessel ................................................................................................ 41

Figure 4-15. Total Arsenic Breakthrough Curves..................................................................................... 42

Figure 4-16. Total Iron Concentrations Versus Bed Volumes.................................................................. 44

Figure 4-17. Total Manganese Concentrations Versus Bed Volumes...................................................... 44

Figure 4-18. Comparsion of Total Arsenic Concentrations in Distribution System Water and 

Treatment System Effluent .................................................................................................. 50

Figure 4-19. Media Replacement and O&M Cost for APU-30S System ................................................. 52

TABLES 

Table 1-1. Summary of Round 1 and Round 2 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
viii

Table 3-3. Sampling Schedule and Analyses .......................................................................................... 9

Table 4-1. Water Quality Data for Oak Manor MUD ........................................................................... 17

Table 4-2. Physical and Chemical Properties of SORB 33TM Media .................................................... 19

Table 4-3. Design Specifications of APU-30S System ......................................................................... 23

Table 4-4. Freeboard Measurements and Media Volumes in Adsorption Vessels................................ 29

Table 4-5. System Inspection Punch-List Items.................................................................................... 30

Table 4-6. Summary of APU-30S System Operations.......................................................................... 32

Table 4-7. System Instantaneous and Calculated Flowrates ................................................................. 33

Table 4-8. Δp Across Vessels A and B Before and After a Backwash Event ....................................... 34

Table 4-9. Summary of Arsenic, Iron, and Manganese Analytical Results........................................... 38

Table 4-10. Summary of Other Water Quality Sampling Results........................................................... 39

Table 4-11. Amount of Mn(II) Precipitated After Chlorination at 11 Arsenic Removal 

Demonstration Sites............................................................................................................. 45

Table 4-12. Backwash Wastewater Sampling Results ............................................................................ 46

Table 4-13. Backwash Solids Total Metal Results.................................................................................. 47

Table 4-14. Spent Media Total Metal Analysis....................................................................................... 48

Table 4-15. Distribution Water Sampling Results................................................................................... 49

Table 4-16. Capital Investment for Treatment System............................................................................ 51

Table 4-17. O&M Cost for APU-30S System......................................................................................... 52
ix

ABBREVIATIONS AND ACRONYMS

∆p 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

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

HDPE high-density polyethylene

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

μm micrometer

Mn manganese

MUD Municipal Utility District
x

mV millivolts

Na sodium

NA not analyzed

NS not sampled

NSF NSF International

NTU nephelometric 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

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

SDWA Safe Drinking Water Act

SiO2 silica

SMCL secondary maximum contaminant level

SO4 sulfate

STS Severn Trent Services

TCLP Toxicity Characteristic Leaching Procedure

TCEQ Texas Commission of Environmental Quality

TDS total dissolved solids

TOC total organic carbon

TSS total suspended solids

V vanadium

VOC volatile organic compound(s)
xi

ACKNOWLEDGMENTS

The authors wish to extend their sincere appreciation to the system operators, Mr. Jose Chavez and Keith 

Swallers, of Oak Manor Municipal Utility District (MUD) in Alvin, TX. Mr. Chavez and Mr. Swallers 

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 their support and dedication. 

Ms. Tien Shiao, who is currently pursuing a Master's degree at Yale University, was the Battelle study 

lead for this demonstration project. 
1

1.0 INTRODUCTION

1.1 Project Background

The Safe Drinking Water Act (SDWA) 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 μg/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 33TM Arsenic Removal 

Technology was selected for demonstration at the Oak Manor MUD facility. 

As of May 2010, 39 of the 40 systems were operational and the performance evaluation of 36 systems 

was completed.
2

1.2 Treatment Technologies for Arsenic Removal

The technologies selected for the Round 1 and Round 2 demonstration host sites include 25 adsorptive 

media (AM) systems (the Oregon Institute of Technology [OIT] site has three AM systems), 13 

coagulation/filtration (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 Web site 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 full-scale arsenic treatment technology 

demonstration studies on the removal of arsenic from drinking water supplies. The specific objectives are 

to:

• Evaluate the performance of the arsenic removal technologies for use on small 

systems.

• Determine the required system operation and maintenance (O&M) and operator skill 

levels.

• Characterize process residuals produced by the technologies.

• Determine the capital and O&M cost of the technologies.

This report summarizes the performance of the STS’s system at the Oak Manor MUD in Alvin, TX from 

April 25, 2006 through April 8, 2008. The types of data collected included system operation, water 

quality (both across the treatment train and in the distribution system), residuals, and capital and O&M 

cost. 
3

Table 1-1. Summary of Round 1 and Round 2 Arsenic Removal Demonstration Sites

Demonstration 

Location Site Name Technology (Media) Vendor

Design 

Flowrate 

(gpm)

Source Water Quality

As 

(μg/L)

Fe

(μg/L)

pH

(S.U.)

Northeast/Ohio

Wales, ME Springbrook Mobile Home Park AM (A/I Complex) ATS 14 38(a) <25 8.6

Bow, NH White Rock Water Company AM (G2) ADI 70(b) 39 <25 7.7

Goffstown, NH Orchard Highlands Subdivision AM (E33) AdEdge 10 33 <25 6.9

Rollinsford, NH Rollinsford Water and Sewer District AM (E33) AdEdge 100 36(a) 46 8.2

Dummerston, VT Charette Mobile Home Park AM (A/I Complex) ATS 22 30 <25 7.9

Felton, DE Town of Felton C/F (Macrolite) Kinetico 375 30(a) 48 8.2 

Stevensville, MD Queen Anne’s County AM (E33) STS 300 19(a) 270(c) 7.3

Houghton, NY(d) Town of Caneadea C/F (Macrolite) Kinetico 550 27(a) 1,806(c) 7.6

Newark, OH Buckeye Lake Head Start Building AM (ARM 200) Kinetico 10 15(a) 1,312(c) 7.6

Springfield, OH Chateau Estates Mobile Home Park AM (E33) AdEdge 250(e) 25(a) 1,615(c) 7.3

Great Lakes/Interior Plains

Brown City, MI City of Brown City AM (E33) STS 640 14(a) 127(c) 7.3 

Pentwater, MI Village of Pentwater C/F (Macrolite) Kinetico 400 13(a) 466(c) 6.9

Sandusky, MI City of Sandusky C/F (Aeralater) Siemens 340(e) 16(a) 1,387(c) 6.9

Delavan, WI Vintage on the Ponds C/F (Macrolite) Kinetico 40 20(a) 1,499(c) 7.5

Greenville, WI Town of Greenville C/F (Macrolite) Kinetico 375 17 7827(c) 7.3

Climax, MN City of Climax C/F (Macrolite) Kinetico 140 39(a) 546(c) 7.4

Sabin, MN City of Sabin C/F (Macrolite) Kinetico 250 34 1,470(c) 7.3

Sauk Centre, MN Big Sauk Lake Mobile Home Park C/F (Macrolite) Kinetico 20 25(a) 3,078(c) 7.1 

Stewart, MN City of Stewart C/F&AM (E33) AdEdge 250 42(a) 1,344(c) 7.7

Lidgerwood, ND City of Lidgerwood Process Modification Kinetico 250 146(a) 1,325(c) 7.2

Midwest/Southwest

Arnaudville, LA United Water Systems C/F (Macrolite) Kinetico 770(e) 35(a) 2,068(c) 7.0

Alvin, TX Oak Manor Municipal Utility District AM (E33) STS 150 19(a) 95 7.8

Bruni, TX

Webb Consolidated Independent School 

District AM (E33) AdEdge 40 56(a) <25 8.0

Wellman, TX City of Wellman AM (E33) AdEdge 100 45 <25 7.7

Anthony, NM

Desert Sands Mutual Domestic Water 

Consumers Association AM (E33) STS 320 23(a) 39 7.7

Nambe Pueblo, NM Nambe Pueblo Tribe AM (E33) AdEdge 145 33 <25 8.5

Taos, NM Town of Taos AM (E33) STS 450 14 59 9.5

Rimrock, AZ Arizona Water Company AM (E33) AdEdge 90(b) 50 170 7.2 

Tohono O'odham 

Nation, AZ Tohono O’odham Utility Authority AM (E33) AdEdge 50 32 <25 8.2

Valley Vista, AZ Arizona Water Company AM (AAFS50/ARM 200) Kinetico 37 41 <25 7.8
4

Table 1-1. Summary of Arsenic Removal Demonstration Sites (Continued)

Demonstration 

Location Site Name Technology (Media) Vendor

Design 

Flowrate 

(gpm)

Source Water Quality

As 

(μg/L)

Fe

(μg/L)

pH

(S.U.)

Far West

Three Forks, MT City of Three Forks C/F (Macrolite) Kinetico 250 64 <25 7.5

Fruitland, ID City of Fruitland IX (A300E) Kinetico 250 44 <25 7.4

Homedale, ID Sunset Ranch Development POU RO(f) Kinetico 75 gpd 52 134 7.5

Okanogan, WA City of Okanogan C/F (Electromedia-I) Filtronics 750 18 69(c) 8.0

Klamath Falls, OR Oregon Institute of Technology

POE AM (Adsorbsia/ARM 200/ArsenXnp) 

and POU AM (ARM 200)(g) Kinetico 60/60/30 33 <25 7.9

Vale, OR City of Vale IX (Arsenex II) Kinetico 525 17 <25 7.5

Reno, NV

South Truckee Meadows General 

Improvement District AM (GFH/Kemiron) Siemens 350 39 <25 7.4

Susanville, CA Richmond School District AM (A/I Complex) ATS 12 37(a) 125 7.5

Lake Isabella, CA Upper Bodfish Well CH2-A AM (HIX) VEETech 50 35 125 7.5 

Tehachapi, CA Golden Hills Community Service District AM (Isolux) MEI 150 15 <25 6.9

AM = adsorptive media process; C/F = coagulation/filtration; HIX = hybrid ion exchanger; IX = ion exchange process; RO = reverse osmosis

ATS = Aquatic Treatment Systems; MEI = Magnesium Elektron, Inc.; STS = Severn Trent Services

(a) Arsenic existing mostly as As(III).

(b) Design flowrate reduced by 50% due to system reconfiguration from parallel to series operation. 

(c) Iron existing mostly as Fe(II).

(d) Withdrew from program in 2007. Selected originally to replace Village of Lyman, NE site, which withdrew from program in June 2006.

(e) Facilities upgraded systems in Springfield, OH from 150 to 250 gpm, Sandusky, MI from 210 to 340 gpm, and Arnaudville, LA from 385 to 770 gpm. 

(f) Including nine residential units.

(g) Including eight under-the-sink units.
5

2.0 SUMMARY AND CONCLUSIONS

Based on the information collected during the two-year performance evaluation study (from April 25, 

2006 to April 8, 2008), the following conclusions were made relating to the overall objectives of the 

treatment technology demonstration study. 

Performance of the arsenic removal technology for use on small systems:

• Prechlorination was effective in oxidizing As(III) to As(V), reducing As(III) concentrations 

from 31.5 μg/L (on average) in raw water to 0.7 μg/L (on average) after chlorination. 

• SORB 33TM media effectively removed arsenic in source water. Breakthrough at 10 μg/L, 

however, occurred relatively early, after treating only 10,277 BV of water following the lead 

vessel and 28,736 BV following the lag vessel (bed volumes were calculated based on 124 ft3

of media in both vessels). 

• During the first half of the performance evaluation study, backwash was effective in restoring 

differential pressure (Δp) across the lead vessel, reducing it from above 10 psi to the initial 

level of less than 4.0 psi. Afterwards, backwash became progressively less effective, 

presumably caused by gradual accumulation of precipitated solids and well sediments. 

• The treatment system significantly reduced arsenic concentrations in the distribution system

from a background level of 38.2 μg/L (on average) to 2.6 μg/L. Initially, arsenic 

concentrations in the distribution system were higher than those in the plant effluent, 

presumably caused by redissolution and/or resuspension of arsenic previously accumulated in 

the distribution system. The arsenic concentrations then decreased to mirror those of the 

plant effluent. Lead and copper concentrations did not appear to have been affected by the 

operation of the system. 

Required system O&M and operator skill levels:

• Under normal operating conditions, the skills required to operate the system were minimal, 

with a typical daily demand on the operator of only 40 min. Normal operation of the system 

did not appear to require additional skills beyond those necessary to operate the existing 

water supply equipment. A Class C state-certified operator was required for operation of the 

Oak Manor MUD water treatment system. 

Characteristics of residuals produced by the technology:

• Each backwash event produced approximately 10,800 gal of wastewater and 7.2 kg of solids 

(including 6.3 kg from the lead vessel and 0.9 kg from the lag vessel). Arsenic constituted

only 0.04% by weight of the solids. 

Capital and O&M cost of the technology:

• The unit annualized capital cost was $0.22/1,000 gal if the system operated at a 100% 

utilization rate. The system’s actual unit annualized capital cost was $0.90/1,000 gal, based 

on 6.7 hr/day of system operation and 18,928,170 gal/year of water production. 

• O&M cost included only incremental cost associated with media replacement and disposal, 

and labor. There was no incremental electricity cost or chemical consumption cost. 
6

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, and ended on April 8, 2008. 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 μg/L through the collection of water samples across the treatment train, as described in the 

Study Plan (Battelle, 2006). 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 assessed through quantitative data and qualitative 

considerations, including the need for any 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 amount of backwash 

wastewater produced during each backwash cycle and the need to replace the media upon arsenic 

breakthrough. Backwash wastewater and spent media were sampled and analyzed for chemical 

characteristics. 

Table 3-1. Predemonstration Study Activities and Completion Dates 

Activity Date

Introductory Meeting Held November 2, 2004

Draft Letter of Understanding Issued January 21, 2005

Final Letter of Understanding Issued February 8, 2005

Request for Quotation Issued to Vendor February 14, 2005

Vendor Quotation Received March 20, 2005

Purchase Order Established May 3, 2005

Letter Report Issued May 12, 2005

Exception Request Submitted to TCEQ July 8, 2005

APU-30S System Shipped September 4, 2005

Engineering Package Submitted to TCEQ September 9, 2005

Building Construction Begun October 6, 2005

Building Completed November 12, 2005

Exception Request Granted by TCEQ November 21, 2005

System Permit Granted by TCEQ December 16, 2005

Study Plan Issued January 13, 2006

System Installation Completed March 9, 2006

System Shakedown Completed March 10, 2006

Performance Evaluation Begun April 25, 2006

TCEQ = Texas Commission of Environmental Quality
7

Table 3-2. Evaluation Objectives and Supporting Data Collection Activities

Evaluation Objective Data Collection

Performance -Ability to consistently meet 10 μg/L of arsenic in treated water

Reliability -Unscheduled system downtime 

-Frequency and extent of repairs including a description of problems, materials 

and supplies needed, and associated labor and cost

System O&M and Operator 

Skill Requirements

-Pre- and post-treatment requirements

-Level of system 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

Residual Management -Quantity and characteristics of aqueous and solid residuals generated by 

system operation

System Cost -Capital cost for equipment, site engineering, and installation

-O&M cost for media, chemical consumption, electricity usage, 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 of the

capital cost for equipment, engineering, and installation, as well as the O&M cost for media replacement 

and disposal, chemical supply, 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 chlorine gas cylinders for 

chlorine consumption; 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 bi-weekly to monthly basis, the plant 

operator measured temperature, pH, dissolved oxygen (DO), oxidation-reduction potential (ORP), and 

residual chlorine, and recorded the data on an Onsite 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 media replacement and spent media disposal, 

electricity, and labor. The gas chlorine consumption was tracked on the Daily System Operation Log 

Sheet. Because the chemical addition system was pre-existing, chlorine consumption was not counted 

towards the O&M cost. Electricity consumption was determined from utility bills. Labor for 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 chlorine gas cylinders, 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.
8

3.3 Sample Collection Procedures and Schedules

To evaluate the system performance, samples were collected at the wellhead and across the treatment 

plant, during adsorption vessel backwash, and from the distribution system. Table 3-3 provides the 

planned sampling schedules and analytes measured during each sampling event. 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. Source water samples were collected from Well 2 during the initial visit to 

the site on November 2, 2004, and from Well 1 and Well 2 and after Wells 1 and 2 were combined on 

February 16, 2005. Before sampling, the sample tap was flushed for several minutes; special care was 

taken to avoid agitation, which could cause unwanted oxidation. The samples were analyzed for the 

analytes listed in Table 3-3. Onsite speciation was performed for the sample collected on November 2, 

2004, using an arsenic speciation kit described in Section 3.4.1. No speciation was performed for the 

samples collected on February 16, 2005.

3.3.2 Treatment Plant Water. Treatment plant water samples were collected by the plant 

operator biweekly, on a four-week cycle, for on- and off-site analyses. For the first week of each fourweek 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 speciated and analyzed for the analytes listed

under speciation sampling in Table 3-3. During the third week of each four-week cycle, samples were 

collected from the same four locations and analyzed for the analytes listed under non-speciation sampling 

in Table 3-3. 

Over the course of the demonstration study, several changes were made to the orginally planned sampling 

schedule:

• During November 15, 2006, through August 22, 2007, the sampling frequency was reduced 

from once every two weeks to once every four weeks, except for the May 30, 2007, event that 

did not take place until two weeks later. 

• Starting from September 12, 2007, the sampling frequency was increased again to once every 

two to four weeks to better monitor the arsenic breakthrough (except for the January 2 and 

March 13, 2008, events that took place five and six weeks, respectively, after the previous 

sampling events.) 

• Measurements for SiO2, turbidity, and alkalinity were discontinued from July 25, 2007. 

Measurements for Ca, Mg, F, NO3, and SO4 were discontinued from August 22, 2007. 

Measurements for P were discontinued on March 13, 2008. 

• NH3 was analyzed at all four sampling locations during October 3, 2007, through April 8, 

2008. 

3.3.3 Backwash Wastewater. Backwash wastewater samples were collected from both vessels by 

the plant operator during backwash events. Tubing, connected to the tap on the discharge line of each 

vessel, directed a portion of backwash wastewater at about 1 gpm into a clean, 32-gal container over the 

entire backwash duration from each vessel. After the content in the container was thoroughly mixed, 

composite samples were collected and/or filtered onsite with 0.45-μm disc filters. Analytes for the 

backwash samples are listed in Table 3-3.
9

Table 3-3. Sampling Schedule and Analyses

Sample 

Type

Sample 

Locations(a)

No. of

Samples Frequency Analytes

Collection 

Date(s)

Source 

Water

IN 1 From Well 2 

during initial 

site visit on 

11/02/04 and

from Well 1, 

Well 2, and

after Wells 1 

and 2 

combined on 

02/16/05

On-site: pH, 

temperature, DO, and/or

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, and/or TOC

11/02/04 and 

02/16/05 

Treatment 

Plant Water 

IN, AC, TA, 

TB 

4 Speciation 

Sampling:

Once every 

four weeks 

(from 04/25/06 

to 10/11/06)

Once every six 

to eight weeks

(from 11/15/06 

to 10/03/07) 

On-site: pH, 

temperature, DO, ORP, 

and/or Cl2 (free and 

total)(b)

Off-site: As(III), As(V),

As (total and soluble), 

Fe (total and soluble), 

Mn (total and soluble), 

Ca, Mg, F, NO3, NH3, 

SO4, SiO2, P, turbidity, 

and/or alkalinity

04/25/06, 05/23/06,

06/21/06, 07/19/06,

08/16/06, 09/12/06, 

10/11/06, 11/15/06,

01/10/07, 03/07/07, 

05/02/07, 06/27/07, 

08/22/07, 10/03/07

Non-speciation 

sampling:

Once every 

four weeks 

(from 05/09/06 

to 09/27/06) 

Once every 

two to ten 

weeks (from 

12/13/06 to 

04/08/08)

On-site: pH, 

temperature, DO, ORP,

and/or Cl2 (free and 

total)(b)

Off-site: As (total), 

Fe (total), Mn (total), 

NH3, SiO2, P, turbidity, 

and/or alkalinity

05/09/06, 06/06/06,

07/05/06, 08/01/06,

08/29/06, 09/27/06,

12/13/06, 02/06/07, 

04/04/07, 06/12//07, 

07/25/07, 09/12/07, 

11/06/07, 11/27/07, 

01/02/08, 01/29/08, 

03/13/08, 03/25/08, 

04/08/08 

Backwash 

Wastewater

BW 2 Monthly or as 

needed

As(total and soluble), 

Fe(total and soluble), 

Mn(total and soluble), 

pH, TDS, and TSS

07/14/06, 08/09/06,

09/19/06, 10/31/06,

12/05/06, 01/30/07,

03/13/07, 04/10/07,

05/09/07, 06/26/07,

08/29/07

Backwash 

Solids

BW 1 per 

vessel

Once Total Al, As, Ca, Cd, 

Cu, Fe, Mg, Mn, Ni, P, 

Pb, Si, and Zn

11/01/06

Distribution

Water

Three homes 

(with only 

one LCR 

sampling 

location) 

3 Monthly

(from 05/17/06 

to 04/04/07)

As (total), Fe (total), Mn

(total), Cu (total), Pb

(total), pH, and alkalinity

Baseline sampling: 

03/16/05, 04/20/05, 

05/18/05, 06/14/05 
Table 3-3. Sampling Schedule and Analyses (Continued)

10

Sample 

Type

Sample 

Locations(a)

No. of

Samples Frequency Analytes

Collection 

Date(s)

Monthly sampling:

05/17/06, 06/07/06,

07/19/06, 08/15/06,

09/13/06, 10/10/06,

11/21/06, 12/13/06,

01/10/07, 02/07/07,

03/07/07, 04/04/07

Spent Media From spent 

media in 

vessels

3 Once

(after end of 

study)

TCLP and total As, Ba, 

Ca, Fe, Mg, Mn, P, and 

Si

10/14/08

(a) Abbreviations corresponding to sample locations in Figure 3-1: IN = at wellhead; AC = after chlorination; 

TA = after lead Vessel A; TB = after lag Vessel B; BW = at backwash wastewater discharge line

(b) Onsite chlorine measurements not performed at IN location. 

(c) NH3 measured from 09/12/07 through 04/08/08.

(d) Measurements for alkalinity, SiO2, and turbidity discontinued on 07/25/07.

(e) Measurement for P discontinued on 03/13/08.

3.3.4 Residual Solids. Residual solids consisted of backwash solids and spent media samples. 

Backwash solids/water mixtures were collected after solids settled in the 32-gal backwash containers and 

the supernatant carefully decanted. The samples were air-dried, acid-digested, and analyzed for the 

analytes listed in Table 3-3. 

Three spent media samples were collected from the top, middle, and bottom of the exhausted lead vessel 

during the media changeout conducted on October 14, 2008, approximately 6 months after the end of the 

performance evaluation study. Spent media were removed from the vessel using a vacuum truck. 

Representative samples were collected at each level and stored in an unpreserved 1-gal wide-mouth highdensity polyethylene (HDPE) bottle. One aliquot of each sample was air-dried and acid-digested for the 

analytes listed in Table 3-3. 

3.3.5 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 on the levels of arsenic, lead, and copper. 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 224 Oak Manor 

Drive was sampled only twice on March 16 and April 20, 2005, before being changed to the final location 

on 95 Oak Trail. The DS2 residence located orginally on 98 Shady Oak Drive was sampled only once on 

March 16, 2005, before being changed to the final location of 61 Shady Oak Drive. The DS3 residence 

located on 7 Kenny Court was used for all baseline sampling events. Following system startup, 

distribution system sampling continued on a monthly basis through April 2007, at the same three 

locations as discussed. The distribution system sampling was discontinued after April 4, 2007.

The distribution system water samples were taken following an instruction sheet developed by Battelle 

according to the Lead and Copper Rule Reporting Guidance for Public Water Systems (EPA, 2002). First 

draw samples were collected from cold-water faucets that had not been used for at least six hours to 

ensure that stagnant water was sampled. The sampler recorded the date and time of last water use before 

sampling and the date and time of sample collection for calculation of the stagnation time. The samples 

were analyzed for the analytes listed in Table 3-3. Arsenic speciation was not performed for the 

distribution water samples.
11

LEGEND

LEGEND

At Wellhead

After Chlorination

After Vessel A

Cl2

INFLUENT

Chlorine Disinfection

Unit Process

Process Flow

Backwash Flow

AC

BW

Water Sampling Locations

IN

TB

TA

After Vessel B

Backwash Sampling Location

INFLUENT Oak Manor MUD

Alvin, TX

SORB 33TM Technology

Design Flow: 150 gpm

Cl2

BW

IN

AC

TA

TB

MEDIA 

VESSEL 

B

MEDIA 

VESSEL 

A

ROADSIDE

DITCH

Footnote DISTRIBUTION SYSTEM

(a) On-site analyses

STORAGE TANK

(75,000 GAL)

TWO BOOSTER 

PUMPS

See Table 3-3 for sample 

schedule and analytes.

See Table 3-3 for sample 

schedule and analytes.

See Table 3-3 for sample 

schedule and analytes.

See Table 3-3 for sample 

schedule and analytes.

See Table 3-3 for sample 

schedule and analytes.

HYDROPNEUMATIC

PRESSURE TANK (5,000 GAL)

LEGEND

LEGEND

At Wellhead

After Chlorination

After Vessel A

Cl2

INFLUENT

Chlorine Disinfection

Unit Process

Process Flow

Backwash Flow

AC

BW

Water Sampling Locations

IN

TB

TA

After Vessel B

Backwash Sampling Location

LEGEND

LEGEND

At Wellhead

After Chlorination

After Vessel A

Cl2

INFLUENT

Chlorine Disinfection

Unit Process

Process Flow

Backwash Flow

AC

BW

Water Sampling Locations

IN

TB

TA

After Vessel B

Backwash Sampling Location

INFLUENT Oak Manor MUD

Alvin, TX

SORB 33TM Technology

Design Flow: 150 gpm

Cl2

BW

IN

AC

TA

TB

MEDIA 

VESSEL 

B

MEDIA 

VESSEL 

A

ROADSIDE

DITCH

Footnote DISTRIBUTION SYSTEM

(a) On-site analyses

STORAGE TANK

(75,000 GAL)

TWO BOOSTER 

PUMPS

See Table 3-3 for sample 

schedule and analytes.

See Table 3-3 for sample 

schedule and analytes.

See Table 3-3 for sample 

schedule and analytes.

See Table 3-3 for sample 

schedule and analytes.

See Table 3-3 for sample 

schedule and analytes.

HYDROPNEUMATIC

PRESSURE TANK (5,000 GAL)

Figure 3-1. Process Flow Diagram and Sampling Schedule and Locations
12

3.4 Sampling Logistics

All sampling logistics including arsenic speciation kits preparation, sample cooler preparation, and 

sampling shipping and handling are discussed as follows:

3.4.1 Preparation of Arsenic Speciation Kits. The arsenic field speciation method used an anion 

exchange resin column to separate the soluble arsenic species, As(V) and As(III) (Edwards et al., 1998). 

Resin columns were prepared in batches at Battelle laboratories according to the procedures detailed in 

Appendix A of the EPA-endorsed QAPP (Battelle, 2004). 

3.4.2 Preparation of Sampling Coolers. For each sampling event, a sample cooler was prepared 

with the appropriate number and type of sample bottles, disc filters, and/or speciation kits. All sample 

bottles were new and contained appropriate preservatives. Each sample bottle was affixed with a preprinted, colored-coded, waterproof label consisting of the sample identification (ID), date and time of 

sample collection, collector’s name, site location, sample destination, analysis required, and preservative. 

The sample ID consisted of a two-letter code for the specific water facility, sampling date, a two-letter 

code for a specific sampling location, and a one-letter code 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. 

When needed, the sample cooler also included bottles for the distribution system water sampling.

In addition, all sampling and shipping-related materials, such as disposable gloves, sampling instructions, 

chain-of-custody forms, prepaid/pre-addressed FedEx air bills, and bubble wrap, were placed in each 

cooler. The chain-of-custody forms and air bills were completed except for the operator’s signature and 

the sample dates and times. After preparation, the sample coolers were 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 checked sample IDs against the chain-of-custody forms and verified that all samples indicated 

on the forms were included and intact. Discrepancies noted by the sample custodian were addressed with 

the plant operator by the Battelle Study Lead. The shipment and receipt of all coolers by Battelle were 

recorded on a cooler tracking log. 

Samples for metal analyses were stored at Battelle’s inductively coupled plasma-mass spectrometry (ICPMS) 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 Laboratories. Laboratory quality assurance/quality 

control (QA/QC) of all methods followed the prescribed guidelines. Data quality in terms of precision, 

accuracy, method detection limit (MDL), and completeness met the criteria established in the QAPP (i.e., 

20% relative percent difference [RPD], 80 to 120% percent recovery, and 80% completeness). 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 
13

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 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.
14

4.0 RESULTS AND DISCUSSION

4.1 Site Description

Located at 603 Mohawk Drive, Alvin, Texas, Oak Manor MUD’s water system supplies drinking water to 

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. 

4.1.1 Pre-existing System. 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 pre-existing treatment included gas chlorination to maintain a target total chlorine residual of 1.5 to 

2.0 mg/L (as Cl2) and polyphosphate addition to reach a target 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. Chlorine Addition Point and Wells 1 and 2 Blending Point

(Pre-existing) 

Chlorine 

Addition Point

Wells 1 and 2 

Blending Point 

Wells 2 

Wellhead 

Well 1 Inlet Piping 

from Offsite
15

Figure 4-2. Pre-existing Storage Tank (in Foreground) and 

Hydropneumatic Tank (in Background) 

Figure 4-3. Pre-existing Polyphosphate Addition Point 

Wells 1 Inlet Piping
16

Figure 4-4. Booster Pumps and Entry Piping to Distribution System

4.1.2 Source Water Quality. Source water samples were collected from Well 2 on November 2, 

2004, and analyzed for the analytes shown in Table 3-3. Additional source water samples were collected 

on February 16, 2005, from Well 1, Well 2, and after Wells 1 and 2 combined. The results of the source 

water analyses, along with those provided by the facility to EPA for the demonstration site selection, are 

presented in Table 4-1.

Arsenic. Total arsenic concentrations in source water from Wells 1 and 2 ranged from 17.4 to 47.4 μg/L. 

The results of February 16, 2005, sampling revealed that Well 1 water contained more total arsenic than 

Well 2 water, with the concentration in Well 1 at 47.7 μg/L and in Well 2 at 17.4 μg/L. The sample 

collected after the blending point had a combined concentration of 34.5 μg/L, which was consistent with 

the average concentration of Wells 1 and 2 water before blending, but slightly higher than the 29 μg/L

obtained by the facility (although not specified, it was assumed that this sample was taken after the 

blending point). Based on the speciation results for the water sample collected on November 2, 2004, 

essentially all of the total arsenic was in the soluble form. As(III) was the predominating species at 

17.6 μg/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 concentration was 95 μg/L in the sample collected on November 2, 

2004 from Well 2. Total iron concentration in the samples collected from Well 1, Well 2, and Wells 1 

and 2 combined on February 16, 2005 were 73, 687, and 317 μg/L, respectively. 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.
17

Table 4-1. Water Quality Data for Oak Manor MUD

Parameter Unit

Raw Water Historic 

Utility

Distribution 

Water Data(c)

Utility 

Data(a)

Battelle Data

Well 2 Well 1 Well 2

Wells 1 & 2

Combined(b)

Sampling Date NA 11/02/04 02/16/05 02/16/05 02/16/05 1998–2003

pH S.U. 7.8 7.8 NS NS NS 7.7–8.0

Temperature °C NS 23.3 NS NS NS NS

DO mg/L NS 1.7 NS NS NS NS

ORP mV NS 1 NS NS NS NS

Total Alkalinity (as CaCO3) mg/L 359 377 330 410 379 356–360

Hardness (as CaCO3) mg/L 42 43 NS NS NS 42.0–43.3

Turbidity NTU NS 0.3 0.3 8.7 2.0 NS

TDS mg/L NS 492 526 670 540 526–546

TOC mg/L NS 0.7 NS NS NS NS

Nitrate (as N) mg/L NS <0.04 <0.05 <0.05 <0.05 <0.01

Nitrite (as N) mg/L NS <0.04 <0.05 <0.05 <0.05 <0.01

Ammonia (as N) mg/L NS 0.2 NS NS NS NS

Chloride mg/L 91 68.0 120.0 98.0 110.0 89.0–93.0

Fluoride mg/L NS 0.8 1.4 1.5 1.4 1.5–1.6

Sulfate mg/L 2 <1.0 <1.0 2.0 1.0 2.0

Silica (as SiO2) mg/L NS 16.8 15.8 15.5 16.7 NS

Orthophosphate (as P) mg/L NS <0.06 <0.05 <0.05 <0.05 NS

As (total) μg/L 29 18.8 47.7 17.4 34.5 28.2–30.7

As (soluble) μg/L NS 19.0 NS NS NS NS

As (particulate) μg/L NS <0.1 NS NS NS NS

As (III) μg/L NS 17.6 NS NS NS NS

As (V) μg/L NS 1.4 NS NS NS NS

Fe (total) μg/L 62 95 73 687(d) 317(d) 55.0–77.0

Fe (soluble) μg/L NS 37 NS NS NS NS

Mn (total) μg/L 58 61.6 48.0 65.2 55.4 37.5–62.0

Mn (soluble) μg/L NS 61.7 NS NS NS NS

U (total) μg/L NS 1.5 <0.1 1.5 0.8 NS

U (soluble) μg/L NS 1.5 NS NS NS NS

V (total) μg/L NS 2.1 1.4 1.2 1.3 NS

V (soluble) μg/L NS 1.9 NS NS NS NS

Na mg/L 201 259 194 273 201 191–210

Ca mg/L 12 9.3 10.6 12.9 12.0 11.7–13.0

Mg mg/L 3 4.8 2.9 3.8 3.2 2.0–3.6

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 μg/L of iron, which is the secondary maximum contaminant level [SMCL] for iron). 

Above 300 μg/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. 
18

Manganese concentrations in source water ranged from 48.0 to 65.2 μg/L. Well 2 water appeared to 

contain more manganese, with concentrations ranging from 61.6 to 65.2 μg/L, compared to that of Well 1 

water at 48.0 μg/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 μg/L) and close to the 

58.0 μg/L concentration provided by the facility. Based on the speciation result on November 2, 2004, 

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 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 and 

phosphate, but due to the low levels of these constituents, they were not expected to affect arsenic 

adsorption onto the SORB 33TM media. 

Other Water Quality Parameters. A pH 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 (as CaCO3). 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 μg/L to 1.5 μg/L, well below its

MCL of 30 μg/L. Vanadium concentrations ranged from 1.2 to 2.1 μg/L. Sodium concentrations ranged 

from 194 to 273 mg/L for 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) 

ranged from 492 to 670 mg/L. 

4.1.3 Historic Distribution Water Quality. Historic distribution water quality data collected by

TCEQ from 1998 to 2003 also are presented in Table 4-1. The distribution water samples were collected 

at the entry point prior to entering into the distribution system and after polyphosphate and chlorine 

addition. As expected, the distribution water quality data were similar to the source water quality data 

obtained by Battelle and the facility. Total arsenic concentrations ranged from 28.2 to 30.7 μg/L. Total 

iron was the only constituent that had slightly lower distribution water quality results as compared to the 

source water quality results. 

4.1.4 Distribution System and Regulatory Monitoring. Of 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 3⁄4- to 1-in polyvinyl

chloride (PVC) and 3⁄4- to 1-in galvanized iron. The distribution system was supplied directly by the 

75,000-gal storage tank. 

4.2 Treatment Process Description

STS’ Arsenic Package Unit (APU)-30S is a fixed-bed, down-flow adsorption system designed for arsenic 

removal for small systems with flowrates ranging from 5 to150 gpm. The unit uses Bayoxide® E33 

(branded as SORB 33TM by STS), an iron-based adsorptive media developed by Bayer AG, for arsenic 
19

removal from drinking water supplies. Table 4-2 presents vendor-provided physical and chemical 

properties of the media. The SORB 33TM 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 are provided in 

both granular and pelletized forms, which have similar physical and chemical properties, except that 

pellets are 25% denser than granules (i.e., 35 vs. 28 lb/ft3

). The pellet form of the media was used for the 

Oak Manor MUD facility. 

Table 4-2. Physical and Chemical Properties of SORB 33TM Media

Physical Properties

Parameter Values

Matrix Iron oxide composite

Physical Form Dry pellets

Color Amber

Bulk Density (lb/ft3) 35

BET Surface Area (m2/g) 142

Attrition (%) 0.3

Moisture Content (%) <15 % (by wt.)

Particle Size Distribution 

(U.S. Standard Mesh) 10 × 35

Crystal Size (Å) 70

Crystal Phase α – FeOOH

Chemical Analysis

Constituents Weight %

FeOOH 90.1

CaO 0.27

MgO 1.00

MnO 0.11

SO3 0.13

Na2O 0.12

TiO2 0.11

SiO2 0.06

Al2O3 0.05

P2O5 0.02

Cl 0.01

BET = Brunauer, Emmett, and Teller Method

Source: STS 

The APU-30S 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 μg/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 changeout. 

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 in the lead 

position. 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 or B, respectively, in the lead 

position. Table 4-3 presents key system design parameters.
20

Figure 4-5. APU-30S Arsenic Removal System

The major process components/steps of the APU-30S system are discussed as follows: 

• Intake. Raw water pumped from the two supply wells (No. 1 and 2) was chlorinated 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). 

• Chlorination. 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 Cl2) 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. 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 × 86-in adsorption vessels 

configured in series. The vessels 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 min). 
21

Figure 4-6a. Process Flow Diagram for APU-30S System with Vessel A in Lead Position
22

Figure 4-6b. Process Flow Diagram for APU-30S System with Vessel B in Lead Position
23

Table 4-3. Design Specifications of APU-30S System

Parameter Value Remarks

Pretreatment

Target Total Chlorine Residual 

(mg/L [as Cl2]) 

1.5 to 2.0 Gas chlorine used

Adsorption Vessels

Vessel Size (in) 63 D × 86 H –

Cross-Sectional Area (ft2/vessel) 21.6 –

Number of Vessels 2 –

Configuration Series –

Adsorptive Media Bed

Type of Media SORB 33TM In pelletized form 

Media Quantity (lb) 4,340

Media Volume (ft3/vessel) 62 124 ft3 total

Media Bed Depth (in/vessel) 34

Service

Design Flowrate (gpm) 150 –

Hydraulic Loading (gpm/ft2) 6.9 Based on design flow rate and vessel crosssectional area of 21.6 ft2

EBCT (min/vessel) 3.1 6.2 min for both lead and lag vessels

Estimated Throughput to Lead 

Vessel Changeout (gal)

47,500,000 Based on an influent arsenic concentration of 

29 μg/L, a system media volume of 124 ft3, and 

an arsenic changeout concentration of 16 μg/L

following lead vessel 

Estimated Working Capacity (BV) 51,240 Based on total media volume of 124 ft3

Average Use Rate (gal/day) 74,000 Provided by facility 

Estimated Media Life (months) 21 Based on average use rate

Backwash

Δp Setpoint (psi) 10 –

Flowrate (gpm) 210

Hydraulic Loading (gpm/ft2) 9.7 Based on backwash design flow rate and vessel 

cross-sectional area of 21.6 ft2 

Backwash Frequency 

(month/backwash)

1

Backwash Duration (min/vessel) 20

Downflow rinse Flowrate 210

Downflow rinse Duration 

(min/vessel)

10

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.
24

Figure 4-7. Gas Chlorination System 

(Clockwise from the Top: Shed Housing Gas Chlorination System, Gas Cylinder, 

Chlorine Ejector, and Chlorinator Unit)

• 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 Δp setpoint across each vessel. During a 

backwash cycle, each vessel was backwashed individually, while the second vessel remained 

off-line. The vendor recommended backwash flowrate, hydraulic loading, and duration, were 

210 gpm, 9.7 gpm/ft2

, and 30 min (including 10 min for downflow rinse), respectively. 

The backwash/downflow rinse flowrates and the amount of wastewater generated were 

determined by the flowrate and totalizer readings shown on the PLC. The backwash and 

downflow rinse duration was timed and confirmed by the operator. Backwash and downflow 

rinse 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 and 

downflow rinse 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 was scheduled once the 

arsenic concentration following the lag vessel exceeding 10 μg/L. Once the media in the lead 

vessel was replaced, flow through the vessels was switched such that the lag vessel was 

placed into the lead position and the former lead vessel loaded with virgin media was placed 

in the lag position. A Toxicity Characteristic Leaching Procedure (TCLP) test was conducted 

on the spent media before disposal to determine whether the media could be considered nonhazardous.
25

Figure 4-8. APU-30S System Valve Tree and Piping Configuration

Figure 4-9. Valve MB-127 to Supply Additional Treated Water from 

Hydropneumatic Tank During Backwash
26

 

Figure 4-10. Small Ditch for Backwash Wastewater 

• 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 3⁄4- 1-in PVC and 3⁄4- 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 onsite 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. 
27

 

Figure 4-11. Construction of Concrete Pad with Storage Tank and 

Hydropneumatic Tank (in Background) 

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). 
28

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 Δp 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 pre-existing 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 pre-existing 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 downflow rinse were performed and system 

shakedown was completed on March 10, 2006. After chlorinating both vessels, the facility took samples 

for bacteriological testing. 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 of water was used for backwash and downflow 

rinse 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 APU30S system. Vessels A and B were backwashed at 150 gpm for 30 and 40 min, respectively, followed by 

20 min of downflow rinse. Vessel A backwash water cleared after 5 min, and Vessel B soon after. 

Downflow rinse 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 fast rinse through both vessels resumed for about one hour before 

discharge was directed to the 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 APU30S 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 μg/L as discussed in Section 4.5.1. 
29

4.3.4 Media Loading. Media loading was performed by STS on January 19, 2006. The super 

sacks of media were hoisted to the top of the canopy using a boom truck and loaded through a 12-in × 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 average 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) were 

to be used for all bed volume calculations. 

Table 4-4. Freeboard Measurements and Media Volumes 

in Adsorption Vessels

Date

Vessel A Vessel B Total 

Volume 

(ft3

)

Depth 

(in)

Volume 

(ft3)

Depth 

(in)

Volume 

(ft3)

01/19/06 36.5 51.8 37.5 52.3 104

04/05/06 36.0 52.7 28.0 69.4 122

05/17/06 35.5 53.6 27.5 70.3 124

4.3.5 Punch List Items. Battelle performed system inspection 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 

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 recorded during the performance 

evaluation study were tabulated and are attached as Appendix A. Key parameters are summarized in 

Table 4-6. From April 25, 2006, through April 8, 2008, the system operated daily except for two time 

periods, i.e., from November 30 through December 16, 2007, and from March 1 to 9, 2008, when the 

system was shut down for storage tank maintenance and valve repair, respectively. The system operated

for a total of 4,628 hr, or an average of 6.7 hr/day (as compared to 8 to 9 hr/day prior to installation of the 

arsenic treatment system). The 6.7 hr/day operating time represents a daily use rate of about 28%. 
30

Table 4-5. System Inspection Punch-List Items

Item 

No. Punch-List Item Corrective Action(s) Taken

Resolution 

Date

1 Broken Well 2 totalizer • Replaced Well 2 totalizer 05/22/06

2 Raw water sample tap incorrectly 

located (so that only Well 2 water might 

be sampled [Figure 4-12]) 

• 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 

• Relocated raw water sample tap to existing 

chlorine injection point and continued using 

relocated chlorine injection point 

05/24/06

05/02/07

3 Broken Vessel A flow meter • Fixed Vessel A flow meter by removing 

particles jammed in paddle wheel 

05/17/06

4 Inconsistent Vessel B freeboard 

measurements taken on 01/19/06 and 

04/05/06 by vendor (Section 4.3.4)

• Retook freeboard measurements for both 

Vessels A and B 

05/17/06

5 Vessels A and B sample taps (i.e., TA 

and TB) incorrectly located (so that 

same water was sampled by both taps). 

• Relocated Vessels A and B sample taps (but 

still at incorrect locations) 

• Corrected sample tap locations

05/17/06

08/09/06

7 Broken actuator valve 125b (not open 

for automatic backwash) 

• Replaced actuator valve 125b 05/17/06

8 Broken actuator valve 123A (not open 

for automatic backwash)

• Replaced actuator valve 123A 08/09/06

9 Missing backwash flow meter/totalizer • Installed a backwash flow meter/totalizer 05/17/06

10 Broken totalizer on treated water line to 

storage tank

• Replaced totalizer on treated water line 07/10/06

11 Parallel vs. series default settings on 

PLC 

• 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])

05/17/06

12 Block vs. unblock mode • Held a teleconference with facility

representatives, who expressed preference to 

maintain PLC in unblock mode (i.e., system 

valves remained open at all times)

05/19/06

13 Missing as-built drawings for APU-30S 

system 

• Provided as-built drawings for APU-30S system 09/21/06

14 Missing as-built site piping and 

electrical drawings

• Provided as-built site engineering drawings 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.
31

Figure 4-12. Piping, Sample Taps, and Chlorine Injection Point Prior to Treatment System
32

Table 4-6. Summary of APU-30S System Operation

Operational Parameter Value/Condition

Duration 04/25/06–04/08/08

Cumulative Operating Time (hr) 4,628

Average Daily Operating Time (hr) 6.7

System Operation – Adsorption

Total Throughput (gal)(a) 35,358,250

Bed Volumes (BV)(b) 38,140

Average Daily Demand (gpd)(c) 51,393

Average (Range of) Instantaneous Flowrate (gpm)(d) 129 (84–151)

Average (Range of) Hydraulic Loading (gpm/ft2) 6.0 (3.9–7.0)

Average (Range of) System EBCT (min)(c) 7.2 (6.1–11.0)

Average (Range of) System Inlet Pressure (psi) 27.9 (18.0–63.0)

Average (Range of) System Outlet Pressure (psi) 7.4 (3.0–27.0)

Average (Range of) Δp across System (psi) 20.8 (12.0-55.0)

Average (Range of) Δp across Vessel A (psi) 7.9 (1.3–15.0)

Average (Range of) Δp across Vessel B (psi) 3.1 (1.0–4.0)

System Operation – Backwash

Average (Range of) Backwash Flowrate (gpm)(e) 207 (173–275)

Average (Range of) Hydraulic Loading (gpm/ft2) 9.6 (8.0–12.7)

Average (Range of) Backwash Duration (min) 26.0 (20.0–30.0)

Average (Range of) Wastewater Generated 

(gal/vessel) 5,400 (4,000–6,800)

(a) Based on Vessel A totalizer. 

(b) Based on 124 ft3 of media in both Vessels A and B. 

(c) Calculated by dividing total throughput by number of system operating days.

(d) Based on instantaneous readings of Vessel A flow meter/totalizer. 

(e) Based on readings of Vessel A totalizer and respective operating time (see 

Section 4.4.4).

(f) Based on ten backwash events conducted from 07/14/06 to 08/29/07. 

During the entire period of the performance evaluation study, the system treated approximately 

35,358,250 gal of water, including the 1,223,042 gal already registered by the Vessel A totalizer during 

system startup. The amount of water treated was equivalent to 38,140 BV, based on 124 ft3 of media in 

both vessels. The average daily demand was 51,393 gal, versus 74,000 gal provided by the facility prior 

to the demonstration study. 

The total throughput and flowrates presented in Table 4-6 are based on the electromagnetic flow 

meter/totalizer installed at the inlet to Vessel A (i.e., lead vessel). Instantaneous flowrate readings from 

this flow meter ranged from 84 to 151 gpm and averaged 129 gpm, which was 14% lower than the 150 

gpm design value. Based on these flowrates, hydraulic loading rates to the adsorption vessels ranged 

from 3.9 to 7.0 gpm/ft2 and system EBCTs ranged from 6.1 to 11.0 min. As a result, the average system 

EBCT was 16 % higher than the design value of 6.2 min.

Flowrates through the treatment system also were tracked by a pre-existing positive displacement totalizer 

installed on the treated water line, and two pre-existing positive displacement totalizers installed at Wells 

1 and 2. Average flowrates were calculated based on readings of the well hour meter and the one 

electromagnetic and three positive displacement totalizers. As compared in Table 4-7, all calculated 

average flowrates were consistent with the instantaneous readings of the Vessel A flow meter with a 

relative difference within 5.4%. 
33

The system throughputs in this report are based on the electromagnetic flow meter/totalizer installed at 

the inlet to the Vessel A. This flow meter/totalizer was out of order on several occasions and had to be 

repaired as discussed in Section 4.4.4. Before the flow meter/totalizer was fixed, the system throughput 

was estimated based on the readings of the two positive displacement totalizers installed at the wellheads. 

There were two occasions (from April 25 to May 21, 2006, and from November 6 to 18, 2007) when both

Vessel A and Well 2 totalizers were not functioning; the system throughput values were estimated for the 

former occasion based on the average flowrate during the first six months of system operation (i.e., 125 

gpm) and respective system operating time, and for the latter occasion based on readings of the effluent 

totalizer. 

Table 4-7. System Instantaneous and Calculated Flowrates

Flowmeter/Totalizer

Type and Location

Instantaneous/

Calculated

Flowrate (gpm)

Range Average % Diff

Electromagnetic Flowmeter, Vessel A Inlet Instantaneous 84–151 129 -

Electromagnetic Totalizer, Vessel A Inlet Calculated 66–177 122 -5.4 %

Positive Displacement Totalizers, at Wellheads(a) Calculated 67–172 128 -0.8 %

Positive Displacement Totalizer, on Treated Water Line Calculated 101–172 131 +1.6 %

(a) Sum of Wells 1 and 2 readings.

The treatment system pressures were monitored at the system inlet and outlet and across the adsorption 

vessels. Differential pressure (Δp) readings across the system and Vessels A and B are presented in 

Figure 4-13. Table 4-8 summarizes Δp across Vessels A and B immediately before and after a backwash. 

0

10

20

30

40

50

60

04/25/06 06/25/06 08/25/06 10/25/06 12/25/06 02/25/07 04/25/07 06/25/07 08/25/07 10/25/07 12/25/07 02/25/08

Differential Pressure (psi)

System 

Vessel A (Lead) 

Vessel B (Lag) 

05/16/06 07/14/06

08/09/06

09/19/06 10/31/06 12/05/06 01/30/07

03/13/07 04/10/07 06/26/07

08/28/07 07/31/07

08/20/07

09/20/07

10/12/07

11/09/07

02/07/08

03/21/08

05/09/07

12/31/07

10/02/07

Figure 4-13. Δp Across Treatment System, and Lead and Lag Vessels
34

As shown in Figure 4-13, Δp readings across the lead vessel (Vessel A) increased steadily after 

backwashing, indicating accumulation of iron particles and/or media fines. Another backwash was 

performed when the Δp across Vessel A approached or exceeded 10 psi. During the first year of system 

operation from April 25, 2006, to April 10, 2007, backwashing was effective in reducing the Δp across 

the lead vessel to less than 4 psi (Table 4-8). Starting from May 9, 2007, at a throughput around 21,727 

BV, backwashing became less and less effective in reducing the Δp. Since then, Vessel A Δp readings 

after a backwash increased from 6.8 to 15.0 psi.

Table 4-8. Δp Across Vessels A and B Before and After a Backwash Event

No.

Backwash

Date

Duration Since 

Last Backwash

(week)

Amount of 

Water

Treated

Since Last 

Backwash

(BV)

ΔP across

Vessel A

before/after 

Backwash

(psi)

ΔP across

Vessel B 

before/after 

Backwash

(psi)

1 05/16/06 NA NA 8.5/3.5 3.0/2.5

2 07/14/06 8 4,070 9.0/3.3 3.0/2.8

3 08/09/06 4 1,400 8.8/3.8 3.8/3.0

4 09/19/06 6 2,253 10.0/3.3 3.8/3.3

5 10/31/06 6 1,813 11.0/3.8 3.0/3.0

6 12/05/06 5 1,441 11.0/4.0 3.5/3.5

7 01/30/07 8 2,551 13.0/4.3 4.0/3.0

8 03/13/07 6 2,242 15.0/4.0 3.0/3.3

9 04/10/07 4 1,537 11.0/3.8 3.3/3.0

10 05/09/07 4 1,538 10.0/6.8 3.3/3.3

11 06/26/07 7 2,987 NA/NA 2.8/3.8

12 07/31/07 5 1,618 NA/NA 2.0/3.3

13 08/20/07 3 1,253 NA/NA 1.0/3.3

14 08/28/07 1 437 12.0/1.3 2.8/3.3

15 09/20/07 3 1,117 15.0/15.0 3.3/2.8

16 10/02/07 2 636 15.0/10.0 3.0/3.5

17 10/12/07 1 519 7.0/NA 3.5/NA

18 11/09/07 4 1,415 15.0/9.0 2.0/4.0

19 12/31/07 7 1,820 14.0/7.5 2.5/2.0

20 02/07/08 5 1,834 15.0/7.0 3.5/3.8

21 03/21/08 6 1,770 15.0/11.0 3.5/3.0

NA = not available

Gradual accumulation of iron and manganese solids formed after prechlorination and, possibly, media 

fines were attributed to the less effective backwashing observed during the second year of system 

operation. In addition, based on trip reports provided by STS, sediments produced from the wells also 

might have contributed to the observed Δp rise. As shown in Figure 4-13, Δp readings across Vessel B 

remained low (averaging 3.1 psi) and constant throughout the two-year study period, indicating little or 

no accumulation of precipitated iron solids or media fines. The data seem to suggest that media fines may 

not have been the primary contributing factor to less effective backwashing, since both vessels were 

backwashed when the Δp across the lead vessel approached or exceeded 10 psi.

During the two-year performance evaluation study, 21 backwashes were performed on both vessels, 

averaging one backwash every five weeks. Both vessels were backwashed even although the Δp across 

Vessel B remained low. Based on the backwash logs, backwash flowrates ranged from 175 to 275 gpm
35

and averaged 207 gpm, which was very close to the design value of 210 gpm. Each backwash event 

lasted for approximately 26 min, including backwash and downflow rinse, thereby producing 

approximately 5,400 gal of wastewater per vessel. Based on the backwash logs, the amount of backwash 

water produced ranged from 4,000 to 6,800 gal/vessel. 

4.4.2 Residual Management. Residuals produced by the operation of the APU-30S system 

included backwash wastewater and spent media. Backwash wastewater was sent to a small ditch (Figure 

4-10) adjacent to the treatment system and subsequently drained into a roadside ditch. 

4.4.3 Media Rebedding. As described in Section 4.5.1, arsenic concentrations following the lag 

vessel first exceeded the MCL on September 12, 2007, after treated approximately 28,700 BV of water

(based on 124 ft3 of media). Since then through the end of the performance study on April 8, 2008, 

arsenic concentrations measured after the lag vessel fluctuated around 10.0 μg/L, indicating the need for 

rebedding of the lead vessel. 

In April 2008, Battelle contacted STS for media rebedding. An STS technician went to the site to 

perform media changeout on May 6, 2008, but had to abort the mission due to lack of proper vacuuming 

equipment to remove the spent media from the lead vessel. During the trip, the STS technician measured 

the Vessel A freeboard height (i.e., from the flange at the top of the vessel to the media surface) at 49 in, 

which was 13.5 in more than that measured on May 17, 2006 (Table 4-4), indicating significant media 

loss over the two year system operation. A spent media sample was collected from the lead vessel and 

submitted for TCLP analysis. 

In July 2008, instead of making a return trip to the site as planned, STS decided not to rebed Vessel A

citing the small size of the job. Soon afterwards, Battelle contacted SouthWest Water Company (SWC, 

Oak Manor MUD’s contractor for operating the water utility) to conduct the changeout. A quote for the 

changeout was received from SWC on July 23, 2008, and the paperwork needed to establish a purchase 

order for the rebedding service was received from SWC on October 3, 2008. 

The media rebedding of Vessel A was conducted by SWC on October 14, 2008, after the system treated 

approximately 52,400 BV of water (based on 124 ft3 of media). A vacuum truck was used to remove the 

spent media and the top portion of the gravel underbedding. Spent media samples were collected at the 

top (0 to 5 in from the top of the media bed), middle (11 to 15 in from the top of the media bed), and 

bottom (23 to 27 from the top of the media bed) of the media bed. Vacuum removal of the media was 

paused at each level to allow for the collection of spent media samples. After the spent media was 

completely removed, the top 6 in of the gravel underbedding also was removed. Subsequently, 6 in of 

fresh gravel was loaded on top of the remaining gravel underbedding, followed by virgin media. The 

freeboard height measured after the media changeout was at the target value of 39 in, based on the design 

bed volume. Following media changeout, the vessels were switched such that the lag vessel was placed 

into the lead position and the former lead vessel with the new media was placed in the lag position. 

Water samples were collected across the treatment system before and after the media changeout and the 

results are discussed in Section 4.5.1.

4.4.4 Reliability and Simplicity of Operation. There was no downtime for the treatment system 

during the performance study. However, there were operational irregularities related to the system’s 

Vessel A flowmeter/totalizer, automatic valve 123A, and system default settings. 

The Vessel A flowmeter/totalizer stopped functioning on seven separate occasions from April 26 to May 

26, 2006; on June 6, 2006; from September 6 to October 3, 2006; from January 15 to March 21, 2007; on 

April 2 and September 20, 2007, and from October 31 to April 8, 2008; due to wear by either precipitated 
36

solids 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 treatment 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, which reverted back to its default parallel mode after a power outage. This occurred three 

times 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. Therefore, leaving the system in manual mode put the system at 

risk of returning back to its default parallel mode after a power outage. 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 Δp readings were approaching 10 psi, by pushing the 

manual backwash button on the PLC screen. To alleviate the concerns mentioned above, the following 

actions were taken: (1) set backwash duration for 20 min and downflow rinse for 10 min, (2) made onsite 

observations to ensure correct valve positions, and (3) left the manual isolation valve open at all times and 

allowed 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, and from November 6 to 18, 

2007; while the totalizer on the treated water line was broken from April 25 to July 10, 2006; from 

August 21 to September 17, 2006; and from February 19 to March 7, 2008. 

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 pre-existing gas chlorination system 

(discussed in Section 4.2 and shown in Figure 4-7) was the only pre-treatment required. 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 treatment system was installed 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., electromagnetic 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 treatment system was capable of automatic backwash triggered by either a timer or a Δp 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 “semiautomatic” backwash via the PLC after August 9, 2006. 

The system also had six isolation ball valves to reverse the vessel positions from lead to lag and vice 

versa after each media replacement. Because media replacement occurred rather infrequently, the vessel

switching operation was not automated. 
37

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. 

The State of Texas requires that an operator for water treatment systems 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 diploma 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 APU30S 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 APU-30S system was evaluated based on analyses of water samples collected 

from the treatment plant, system backwash, and distribution system.

4.5.1 Treatment Plant Sampling. Water samples were collected at four locations through the 

treatment process: including IN, AC, TA, and TB (Table 3-3). The treatment plant water was sampled on 

36 occasions (including the three duplicate sampling events on August 1, 2006; April 4, 2007; and March 

13, 2008), with field speciation performed during 14 of the 36 occasions. Field-speciation samples were 

collected monthly from system startup to October 11, 2006; and switched to bimonthly from November 

15, 2006 to October 3, 2007. Field-speciation was discontinued after October 3, 2007. 

Table 4-9 provides a summary of analytical results for arsenic, iron, and manganese during the 

performance evaluation study from May 25, 2006, through April 8, 2008. Table 4-10 summarizes the 

results of the other water quality parameters. Because the sample tap for the system influent water was 

installed incorrectly before May 24, 2006 (see Item No. 2 in Table 4-5), the results of the first three sets 

of “IN” samples were not included in Tables 4-9 and 4-10. In addition, because the “TA” and “TB” 

samples on May 23, 2006, were collected from wrong sample taps, those results were not included in

Tables 4-9 and 4-10, either. Appendix B contains a complete set of analytical results. The results of the 

water samples collected throughout the treatment plant are discussed below. 

Arsenic. Figure 4-14 contains four bar charts showing the concentrations of total As, particulate As, and 

soluble As(III) and As(V) at the IN, AC, TA, and TB sampling locations for each speciation sampling 

event. Total arsenic concentrations in raw water ranged from 27.5 to 52.5 μg/L and averaged 40.2 μg/L, 

with over 94% existing as soluble arsenic. Of the soluble arsenic, As(III) was the predominating species
38

Table 4-9. Summary of Arsenic, Iron, and Manganese Analytical Results

Parameter

Sample 

Location Unit

Sample 

Count

Concentration Standard 

Minimum Maximum Average Deviation

As 

(total)

IN μg/L 33(a) 27.5 52.5 40.2 7.2

AC μg/L 36 22.5 41.2 31.6 4.7

TA μg/L 35(b) 0.2 28.5 -

(c) -(c)

TB μg/L 35(b) <0.1 10.6 -

(c) -(c)

As 

(soluble)

IN μg/L 12(a) 25.3 45.1 37.9 6.9

AC μg/L 14 19.6 30.5 25.7 3.5

TA μg/L 13(b) <0.1 22.1 -

(c) -(c)

TB μg/L 13(b) <0.1 10.8 -

(c) -(c)

As 

(particulate)

IN μg/L 12(a) <0.1 6.9 4.1 2.1

AC μg/L 14 2.7 11.6 5.6 2.4

TA μg/L 13(b) <0.1 4.8 -

(c) -(c)

TB μg/L 13(b) <0.1 0.6 -

(c) -(c)

As(III)

IN μg/L 12(a) 17.7 44.1 31.5 8.5

AC μg/L 14 <0.1 1.3 0.7 0.4

TA μg/L 13(b) <0.1 1.6 -

(c) -(c)

TB μg/L 13(b) <0.1 1.8 -

(c) -(c)

As(V)

IN μg/L 12(a) 0.2 21.5 6.4 6.6

AC μg/L 14 18.2 30.0 25.1 3.6

TA μg/L 13(b) <0.1 21.3 -

(c) -(c)

TB μg/L 13(b) <0.1 10.3 -

(c) -(c)

Fe 

(total)

IN μg/L 33(a) <25 145 62.7 36.8

AC μg/L 36 <25 169 42.8 33.1

TA μg/L 35(b) <25 29 <25 2.8 

TB μg/L 35(b) 12.5 31 13.0 3.1

Fe 

(soluble)

IN μg/L 12(a) <25 44 19.0 11.9

AC μg/L 14 <25 <25 <25 NA

TA μg/L 13(b) <25 <25 <25 NA

TB μg/L 13(b) <25 <25 <25 NA

Mn 

(total)

IN μg/L 33(a) 47.3 66.6 55.1 4.6

AC μg/L 36 42.6 57.1 50.6 3.8

TA μg/L 35(b) <0.1 9.6 2.2 2.0

TB μg/L 35(b) <0.1 0.9 0.3 0.2

Mn 

(soluble)

IN μg/L 12(a) 48.9 63.4 54.1 4.5

AC μg/L 14 <0.1 14.5 1.9 3.7

TA μg/L 13(b) <0.1 1.2 0.3 0.4

TB μg/L 13(b) <0.1 0.6 0.2 0.2

One-half of detection limit used for samples with concentrations less than detection limit for 

calculations. 

NA = not applicable

(a) Results of “IN” samples collected before May 24, 2006, not included because of use of 

incorrectly installed sample tap. 

(b) Results of “TA” and “TB” samples collected on May 23, 2006, not included because of use of 

wrong sample taps.

(c) Not meaningful for data related to breakthrough curves; see Figure 4-15. 
39

Table 4-10. Summary of Other Water Quality Sampling Results

Parameter Sample 

Location Unit Sample Count

Concentration Standard 

Minimum Maximum Average Deviation

Alkalinity 

(as CaCO3) 

IN mg/L 21(a) 318 696 375 76.0

AC mg/L 24 342 390 366 15.2

TA mg/L 23(b) 331 404 370 16.2

TB mg/L 23(b) 331 398 366 15.3

Ammonia 

(as N)

IN mg/L 10 0.1 0.2 0.2 0.1

AC mg/L 10 <0.05 0.20 0.07 0.06

TA mg/L 9 <0.05 0.10 0.03 0.03

TB mg/L 9 <0.05 0.10 0.03 0.02

Fluoride

IN mg/L 10(a) 1.1 1.5 1.4 0.1

AC mg/L 12 1.2 1.7 1.5 0.1

TA mg/L 11(b) 1.3 1.7 1.5 0.1

TB mg/L 11(b) 1.3 1.9 1.5 0.2

Sulfate

IN mg/L 10(a) 0.5 2.0 0.9 0.6

AC mg/L 12 1.0 3.0 1.9 0.5

TA mg/L 11(b) 1.0 2.0 1.8 0.4

TB mg/L 11(b) 1.0 2.0 1.5 0.5

Nitrate 

(as N)

IN mg/L 10(a) <0.05 <0.05 <0.05 NA

AC mg/L 12 <0.05 <0.05 <0.05 NA

TA mg/L 11(b) <0.05 <0.05 <0.05 NA

TB mg/L 11(b) <0.05 <0.05 <0.05 NA

Total P 

(as P)

IN μg/L 29(a) 25.2 86.7 40.7 11.2

AC μg/L 32 20.4 95.0 42.2 11.9

TA μg/L 31(b) 5.0 76.3 29.1 16.2

TB μg/L 31(b) 5.0 58.7 17.6 17.0

Silica 

(as SiO2) 

IN mg/L 21(a) 14.4 16.8 15.3 0.6

AC mg/L 24 14.8 16.7 15.7 0.6

TA mg/L 23(b) 15.2 17.0 15.8 0.5

TB mg/L 23(b) 12.6 16.8 15.6 0.8

Turbidity

IN NTU 21(a) 0.1 0.9 0.5 0.3

AC NTU 24 0.2 1.1 0.5 0.3

TA NTU 23(b) 0.1 1.3 0.5 0.3

TB NTU 23(b) 0.1 0.8 0.3 0.2

pH

IN S.U. 22(a) 7.4 8.1 7.8 0.2

AC S.U. 25 7.3 7.9 7.6 0.2

TA S.U. 24(b) 7.5 8.0 7.7 0.1

TB S.U. 24(b) 7.6 7.9 7.7 0.1

Temperature

IN °C 22(a) 21.5 27.6 23.9 1.7

AC °C 25 21.4 33.8 24.3 2.6

TA °C 24(b) 21.3 32.1 24.2 2.4

TB °C 24(b) 21.1 30.7 24.1 2.3

Dissolved 

Oxygen

IN mg/L 19(a) 1.2 2.9 2.0 0.6

AC mg/L 22 1.2 2.9 1.8 0.4

TA mg/L 21(b) 1.3 4.9 2.9 0.9

TB mg/L 21(b) 1.4 4.3 2.6 0.8

ORP

IN mV 25(a) 189 448 337 76.7

AC mV 28 189 687 592 123

TA mV 27(b) 190 708 576 134

TB mV 27(b) 190 687 577 137
Table 4-10. Summary of Other Water Quality Sampling Results (Continued)

40

Parameter Sample 

Location Unit Sample Count

Concentration Standard 

Minimum Maximum Average Deviation

Free Chlorine

(as Cl2) 

AC mg/L 27 0.3 3.3 2.1 0.8

TA mg/L 26(b) 0.1 3.2 1.4 0.7

TB mg/L 26(b) 0.2 2.7 1.3 0.6

Total Chlorine

(as Cl2) 

AC mg/L 27 0.3 3.3 2.2 0.8

TA mg/L 26(b) 0.2 3.4 1.4 0.7

TB mg/L 26(b) 0.4 2.8 1.4 0.6

Total Hardness 

(as CaCO3) 

IN mg/L 10(a) 31.0 45.8 39.9 4.7

AC mg/L 12 30.0 50.3 42.3 6.1

TA mg/L 11(b) 31.5 48.7 41.9 4.4

TB mg/L 11(b) 32.7 47.7 42.9 4.0

Ca Hardness 

(as CaCO3) 

IN mg/L 10(a) 19.1 33.0 27.2 4.0

AC mg/L 12 18.0 35.3 28.5 5.3

TA mg/L 11(b) 19.0 34.2 28.5 3.9

TB mg/L 11(b) 19.8 33.4 29.1 3.6

Mg Hardness 

(as CaCO3) 

IN mg/L 10(a) 10.4 14.5 12.7 1.1

AC mg/L 12 11.9 15.6 13.8 1.3

TA mg/L 11(b) 11.7 15.6 13.4 1.3

TB mg/L 11(b) 11.8 16.2 13.8 1.2

One-half of detection limit used for samples with concentrations less than detection limit for 

calculations. 

NA = not applicable 

(a) Results of “IN” samples collected before May 24, 2006, not included because of use of incorrectly 

installed sample tap.

(b) Results of “TA” and “TB” samples collected on May 23, 2006, not included because of use of wrong 

sample taps. 

with its concentrations ranging from 17.7 to 44.1 μg/L and averaging 31.5 μg/L. The remainder of 

soluble arsenic was As(V) with its concentrations ranging from 0.2 to 21.5 μg/L and averaging 6.4 μg/L. 

Some particulate arsenic also existed, with its concentrations ranging from <0.1 to 6.9 μg/L and averaging

4.1 μg/L. The average total arsenic concentration (i.e. 40.2 μg/L) measured during the two-year 

performance evaluation study was approximately 16.5% higher than that measured during the initial site 

visit on February 16, 2005 (i.e., 34.5 μg/L, Table 4-1). 

The presence of As(III) as the predominating soluble arsenic species in raw water is consistent with the 

low DO levels (i.e., 1.2 to 2.9 mg/L Table 4-10) measured during the performance evaluation study and 

that (i.e., 1.7 mg/L) measured during the November 2, 2004 site visit. ORP readings measured during the 

performance evaluation study, however, were much higher (i.e., from 189 to 448 mV and averaging 337 

mV) than that (i.e., 1 mV) measured during the November 2, 2004 site visit. These high ORP readings

were attributed primarily to the use of the handheld meter, which often gave erratic and drifting results at 

the arsenic removal technology demonstration sites. After prechlorination and adsorption, DO levels 

remained rather unchanged, averaging 1.8 to 2.9 mg/L. ORP readings increased significantly, as 

expected, to an average of 576 to 592 mV, due to the presence of chlorine residuals as discussed below. 

Prechlorination effectively oxidized As(III) to As(V) and provided required chlorine residuals to the 

distribution system. As shown in Figure 4-14, all samples collected at the AC location contained mostly 

As(V) and particulate arsenic. The average As(III) and As(V) concentrations of the AC samples were 0.7 

and 25.1 μg/L, respectively (Table 4-9). After chlorination, 98% of the soluble arsenic was present as 

As(V), compared to only 17% in raw water. The trace levels of As(III) measured were believed to have 

been caused primarily by the speciation method.
41

Arsenic Speciation at the Wellhead (IN)

0

10

20

30

40

50

60

04/25/06

05/23/0606/21/0607/19/0608/16/0609/12/0610/11/0611/15/0601/10/0703/07/0705/02/0706/27/0708/22/0710/03/07

As Concentration (μg/L)

As (particulate)

As (III)

As (V)

Arsenic Speciation after Chlorination (AC)

0

10

20

30

40

50

60

04/25/0605/23/0606/21/0607/19/0608/16/0609/12/0610/11/0611/15/0601/10/0703/07/0705/02/0706/27/0708/22/0710/03/07

As Concentration (μg/L)

As (particulate)

As (III)

As (V)

Arsenic Speciation after Lead Vessel A (TA)

0

10

20

30

40

50

60

04/25/0605/23/0606/21/0607/19/0608/16/0609/12/0610/11/0611/15/0601/10/0703/07/0705/02/0706/27/0708/22/0710/03/07

As Concentration (μg/L)

As (particulate)

As (III)

As (V)

As MCL = 10 μg/L

Arsenic Speciation after Lag Vessel B (TB)

0

10

20

30

40

50

60

04/25/0605/23/0606/21/0607/19/0608/16/0609/12/0610/11/0611/15/0601/10/0703/07/0705/02/0706/27/0708/22/0710/03/07

As Concentration (μg/L)

As (particulate)

As (III)

As (V)

As MCL = 10 μg/L

Figure 4-14. Concentrations of Arsenic Species at Influent, After Chlorination, 

after Lead Vessel, and after Lag Vessel
42

Free chlorine residuals measured at the AC location ranged from 0.3 to 3.3 mg/L (as Cl2) and averaged 

2.1 mg/L (as Cl2), which were similar to total chlorine residuals measured in the same samples (Table 4-

10). The total chlorine residual levels measured were very close to the target levels of 1.5 to 2.0 mg/L (as 

Cl2) set by the facility. The similar levels of total and free chlorine residuals measured suggest the 

absence of ammonia in raw water, which was confirmed by the low level of ammonia (i.e., 0.1 to 0.2 

mg/L [as N]) measured during the later part of the performance evaluation study. Total and free chlorine 

residuals measured after the lead and lag vessels averaged 1.3 to 1.4 mg/L (as Cl2), which were lower 

than those measured at the AC location (i.e., 2.1 mg/L [as Cl2]). Lower levels of total and free chlorine 

residuals suggest some chorine demand (i.e., 0.7 mg/L [as Cl2]) across the lead vessel. 

Figure 4-15 presents total arsenic breakthrough curves from the lead and lag vessels, along with total 

arsenic concentrations in raw water and after prechlorination. The lead vessel removed the majority of 

arsenic, existing predominately as As(V) because of prechlorination. On September 12, 2006, after 

treating 9,527,220 gal, or 10,277 BV, of water, arsenic concentrations reached 10.0 μg/L following the 

lead vessel and 0.8 μg/L following the lag vessel. Arsenic concentrations after the adsorption vessels 

continued to increase afterwards and reached 10.0 μg/L following the lag vessel the first time on 

September 12, 2007 after treating 28,736 BV (or 26,638,090 gal) of water. Since then through the end of 

the performance evaluation study on April 8, 2008, arsenic concentrations measured after the lag vessel 

fluctuated around 10.0 μg/L, indicating arsenic breakthrough at 10.0 μg/L occurred at the lag vessel after 

treating approximately 28,700 BV of water. Calculations of bed volumes were based on 124 ft3 of media 

in both vessels. 

0

10

20

30

40

50

60

0 5 10 15 20 25 30 35 40

Bed Volumes of Treated Water (x1000)

Total As Concentration (μg/L)

IN

AC

TA

TB

As MCL = 10 

/L

As Breakthrough at 

the Lead Vessel 

09/12/06

As Breakthrough at 

the Lag Vessel 

09/12/07

Figure 4-15. Total Arsenic Breakthrough Curves

(BV calculated based on 124 ft3 of media)
43

At the end of performance evaluation study after treating approximately 38,140 BV (35,358,250 gal) of 

water, total arsenic concentrations were 23.2 and 10.5 μg/L after the lead and lag vessels, respectively. 

The concentration after the lead vessel was close to that in the system influent (i.e., 28 μg/L after 

chlorination), indicating the lead vessel was approaching exhaustion.

The vendor-estimated working capacity for the treatment system was 51,240 BV (Table 4-3), which was 

based on 29 μg/L of arsenic in the system influent, 124 ft3 of media in both the lead and lag vessels, and 

16 μg/L of arsenic following the lead vessel. As shown in Figure 4-15, the 16- μg/L throughput 

following the lead vessel occurred at 16,900 BV, which is only one third of the value estimated by the 

vendor. The lower amount of media in the lead vessel (i.e. 53 ft3 vs. 62 ft3

) and the higher arsenic

concentration in raw water (i.e., 40.3 vs. 29 μg/L) might have contributed, in part, to the lower-thanexpected run length observed. 

As described in Section 4.4.3, approximately six months after the end of the performance evaluation 

study, the lead vessel was rebeddede on October 14, 2008. Before the media changeout, water samples 

were collected across the treatment train. Arsenic concentrations at the system inlet and after the lead and 

lag vessels were 26.8, 33.4, and 17.5 μg/L, respectively. One week after the media changeout on October 

21, 2008, water samples were collected again across the treatment train, with arsenic concentrations 

measured at 26.2, 15.2, and 2.6 μg/L at the three respective locations. The arsenic concentration in 

system effluent was reduced significantly from 17.5 to 2.6 μg/L, indicating that media changeout was 

conducted properly.

Iron. Total iron concentrations in source water ranged from <25 to 145 μg/L and averaged 62.7 μg/L 

(Table 4-9). Over 70% of iron in source water existed as particulate iron. The source water sample taken 

during the November 2, 2004, site visit also contained a similar amount of total iron (i.e., 95 μg/L) with 

over 60% existing as particulate iron. Particulate iron might exist in source water as part of natural 

sediment or as precipitates caused by inadvertent aeration during sampling. The amounts of DO 

measured in source water, however, were low, ranging from 1.2 to 2.9 mg/L and averaging 2.0 mg/L as 

discussed above. 

Total iron concentrations following prechlorination were slightly less than those at the IN sampling 

location, ranging from <25 μg/L to 169 μg/L and averaging 42.8 μg/L. Soluble iron levels at the AC 

location (based upon the use of 0.45-μm disc filters) were reduced significantly to below the method 

detection limit of 25 μg/L for all samples, indicating effective oxidation of soluble iron by chlorine. As 

shown in Figure 4-16, except for one sampling event on January 29, 2008, total iron was removed to 

below the method detection limit of 25 μg/L by the lead vessel throughout the performance evaluation 

study. Figure 4-16 shows total iron concentrations versus the amount of water treated across the 

treatment train. 

Manganese. Figure 4-17 shows total manganese concentrations versus the amount of water treated across 

the treatment train. Total manganese concentrations in source water ranged from 47.3 to 66.6 μg/L and 

averaged 55.1 μg/L. Manganese existed almost entirely in the soluble form, which was consistent with 

that found in the source water sample collected during the initial site visit on November 2, 2004 (Table 4-

1). After prechlorination, an average of 96.4% of soluble manganese precipitated and formed, presumably, 

MnO2 solids. The MnO2 solids along with unoxidized Mn(II) were removed by the media, causing total 

manganese concentrations to decrease to 2.2 and 0.3 μg/L following the lead and lag vessels, respectively. 

 
44

0

20

40

60

80

100

120

140

160

180

0 5 10 15 20 25 30 35 40

Bed Volumes of Treated Water (x1000)

Total Fe Concentration (μg/L)

IN

AC

TA

TB

Figure 4-16. Total Iron Concentrations Versus Bed Volumes

(BV calculated based on 124 ft3 of media)

0

10

20

30

40

50

60

70

0 5 10 15 20 25 30 35 40

Bed Volumes of Treated Water (1x1000)

Total Mn Concentration (μg/L)

IN

AC

TA

TB

Figure 4-17. Total Manganese Concentrations Versus Bed Volumes

(BV calculated based on 124 ft3 of media)
45

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) precipitation rates 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 70 and 93.5% (i.e., Alvin, TX and Springfield, 

OH). It is not clear why some source waters had slower oxidation kinetics than others. Based on existing

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.

Table 4-11. Amount of Mn(II) Precipitated after Chlorination at 11 

Arsenic Removal Demonstration Sites

Demonstration 

Location

Contact 

Time

(min)

Raw Water

After 

Chlorination Avg 

Mn(II) 

Precipi

-tated

(%)

pH

(S.U.)

Temperature

(°C)

NH3

(mg/L)

TOC

(mg/L)

Avg Mn 

(Total/

Soluble)

(μg/L)

Avg Mn 

(Total/

Soluble)

(μg/L)

Bruni, TX None 8.2 25.6 <detect 0.9 5.0/4.7 3.9/3.5 5.8

Anthony, NM None 7.7 30.0 None 1.6 9.6/8.9 9.8/6.8 23.5

Brown City, MI None 8 11.6 None <detect 16.1/15.7 15.0/9.8 31.9

Delavan, WI 2 7.5 13.9 2.9 1.6 19.2/20.1 18.1/17.7 2.7

Sandusky, MI 41 7.2 12.1 0.3 1.5 25.3/26.7 26.0/11.7 55.0

Pentwater, MI 6 8 12.6 0.3 2.0 27.3/28.8 30.1/14.3 52.4

Springfield, OH None 7.3 16.2 0.2 <detect 35.6/36.3 29.5/8.3 70.0

Alvin, TX None 7.7 25.6 0.2 0.7 54.4/54.0 51.1/2.8 93.5

Rollinsford, NH None 7.9 14.2 None <detect 110/124 101/86.5 14.6

Climax, MN 5 7.6 9.1 None 12.0 135/126 130/73.7 35.9

Sabin, MN 7 7.3 13.0 0.2 1.6 346/378 338/228 32.6

Other Water Quality Parameters. In addition to arsenic, iron, and manganese, other water quality 

parameters were analyzed and the results are included in Appendix B and summarized in Table 4-10. 

 

Silica and phosphate are known to influence arsenic adsorption with iron-based media. Silica 

concentrations in source water ranged from 14.4 to 16.8 mg/L with no significant reductions across the 

treatment train. Total phosphorous concentrations in source water ranged from 25.2 to 86.7 μg/L and 

averaged 40.7 mg/L. Total phosphorous concentrations were progressively reduced to an average of 29.1 

and 17.6 μg/L following the lead and lag vessels, respectively; suggesting that total phosphorus might 

compete with arsenic for available adsorptive sites.

As shown in Table 4-10, pH values of raw water varied from 7.4 to 8.1 and averaged 7.8. In general, 

iron-based adsorption media have greater arsenic removal capacities at near or lower than neutral pH 

values. Alkalinity, reported as CaCO3, ranged from 318 to 389 mg/L and averaged 359 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 0.9 mg/L in source water and 1.5 to 1.9 mg/L across the treatment train. 
46

Fluoride levels ranged from 1.1 to 1.9 mg/L in all samples and did not appear to have been affected by the 

SORB 33TM media. Total hardness, existing 68% as calcium hardness and 32% as magnesium hardness, 

ranged from 31.0 to 45.8 mg/L (as CaCO3), and also remained unchanged throughout the treatment train. 

4.5.2 Backwash Wastewater Sampling. Backwash was performed one vessel at a time using a 

mix of raw water (non-chlorinated) and treated water. Backwash wastewater was sampled 11 times from 

the sample ports located in the backwash effluent discharge lines from each vessel. The unfiltered 

samples were analyzed for pH, TDS, TSS, and total arsenic, iron, and manganese. Filtered samples using 

0.45-μm disc filters were analyzed for soluble arsenic, iron, and manganese. The analytical results are 

summarized in Table 4-12. pH values ranged from 7.5 to 8.0, similar to those of source and treated water. 

TDS levels ranged from 482 to 532 mg/L and averaged 513 mg/L. TSS levels ranged from 80 to 500

mg/L and averaged 307 mg/L for Vessel A, not including an outlier on June 26, 2007. As expected, TSS 

values were lower for Vessel B, ranging from 5.0 to 150 mg/L and averaging 44 mg/L. 

Concentrations of total arsenic in backwash wastewater varied widely from 10.1 to 888 μg/L and 

averaged 144 μg/L for the lead vessel and from 3.2 to 120 μg/L and averaged 23.7 μg/L for the lag vessel. 

Concentrations of soluble arsenic were lower, ranging from 13.9 to 37.0 μg/L and averaging 20.3 μg/L

for the lead vessel and from 1.5 to 29.1 μg/L and averaging 9.0 μg/L for the lag vessel. Particulate 

arsenic averaging at 69.6 μg/L might be associated with either iron particles filtered out by the media 

beds during the service cycles or media fines. As expected, total arsenic concentration was higher 

(approximately 6 times) in the backwash wastewater from the lead vessel than that from the lag vessel. 

Concentrations of total iron and manganese ranged from 0.7 to 161.3 mg/L (averaged 19.7 mg/L), and 

from 0.08 to 15.2 mg/L (averaged 1.8 mg/L), respectively, with over 99.8% existed as particulates. 

Table 4-12. Backwash Wastewater Sampling Results

pHTDSTSSAs (total)As (soluble)As (particulate) Fe (total) Fe (soluble) Mn (total) Mn (soluble) pHTDSTSSAs (total)As (soluble)As( particulate) Fe (total) Fe (soluble) Mn (total) Mn (soluble) 

No. Date S.U. mg/L mg/L μg/L μg/L μg/L μg/L μg/L μg/L μg/L S.U. mg/L mg/L μg/L μg/L μg/L μg/L μg/L μg/L μg/L

1 07/14/06 7.7 508 366 17.0 15.9 1.1 25,214 <25 3,570 0.2 7.8 532 150 7.7 1.5 6.2 10,739 <25 1,705 0.4

2 08/09/06 7.7 526 116 16.1 14.7 1.4 3,910 <25 162 1.8 7.7 508 5 3.2 2.6 0.6 662 <25 79 0.4

3 09/19/06 7.7 482 400 10.1 13.9 <0.1 22,591 <25 893 0.6 7.7 500 15 5.1 3.0 2.1 1,437 <25 341 0.2

4 10/31/06 7.5 498 225 15.3 15.2 0.1 17,085 <25 737 0.5 7.6 518 25 8.3 4.5 3.9 700 <25 197 0.5

5 12/05/06 7.5 524 80 20.3 16.7 3.6 4,820 <25 311 1.2 7.6 500 30 8.2 5.2 3.0 2,085 <25 131 1.2

6 01/30/07 7.8 488 370 341 37.0 304 38,134 34 2,425 4.9 7.9 532 10 59.0 29.1 29.9 5,982 41 1,101 5.6

7 03/13/07 7.8 522 490 23.6 21.5 2.1 19,881 <25 992 0.7 7.8 516 24 12.8 9.4 3.4 1,450 <25 358 0.8

8 04/10/07 7.9 524 265 22.4 23.0 <0.1 15,412 <25 983 0.7 7.8 498 25 14.1 11.3 2.8 1,352 <25 352 0.3

9 05/09/07 7.7 532 260 25.8 19.2 6.5 13,000 <25 1,158 0.8 7.7 518 30 14.1 3.5 10.6 1,755 451 402 0.6

10 06/26/07 7.8 518 1,130 205 20.2 185 59,138 <25 2,687 1.0 7.8 520 55 8.6 11.5 <0.1 1,631 <25 360 0.8

11 08/29/07 8.0 514 500 888 26.0 862 161,305 <25 15,258 0.4 8.0 518 115 120 17.3 103 25,305 <25 4,482 0.1

TDS = Total Dissolved Solids; TSS = Total Suspended Solids; NA = Not Analyzed

Sampling 

Event

Vessel B

BW1 BW2

Vessel A

Assuming that 5,400 gal (Table 4-6) of backwash wastewater would be generated from each vessel during 

each backwash event and that 307 and 44 mg/L of TSS would be produced from Vessels A and B, 

respectively, approximately 13.8 and 2.0 lb (or 6.3 and 0.9 kg) of solids, respectively, would be 

discharged every time when Vessels A and B were backwashed. Based on the average particulate metal 
47

data in Table 4-12, approximately 2.8 g of arsenic (i.e. 0.04% by weight), 804 g of iron (i.e. 11.2 % by 

weight), and 71.8 g of manganese (i.e. 1.0 % by weight) were generated from both the lead and lag 

vessels during each backwash event.

Backwash solid samples were collected on November 1, 2006, from Vessels A and B and analyzed for 

total metals; the results are presented in Table 4-13. Arsenic, iron, and manganese levels in the solids 

were averaged 2.0 mg/g (or 0.2% by weight), 291 mg/g (or 29% by weight), and 80.2 mg/g (or 8 % by 

weight), respectively. These amounts were significantly higher than those based on backwash wastewater 

metal analysis (i.e. 0.04%, 11.2%, and 1.0%, respectively). Challenges associated with sampling and 

sample digestion were believed to have contributed to the discrepancies observed. As expected, 

backwash solids from the lead vessel contained significantly higher percentages of metals, including As, 

Fe, Mn, Cu, and Zn, indicating removal of metal particulates by the lead vessel.

The particulate iron present in the backwash wastewater might have come from at least two separate 

sources, i.e., the iron from raw water or media fines. The amount of iron attributable to both sources was 

estimated using the data of the eleven backwash sampling events conducted from July 14, 2006, to 

August 29, 2007 (Table 4-12). The amount of iron attributable to the iron removed from raw water was 

estimated based on the average throughput between backwash events (i.e., 1,588,424 gal based on the

throughput data in Table 4-8) and the average total iron concentration (i.e., 62.7 μg/L) in source water 

during the same period. Assuming complete removal of iron solids by the media beds and complete 

discharge of iron solids during the backwash events, there would have been 377 g of iron solids, as part of 

TSS discharged per backwash event, originating from the iron in source water. As discussed above,

based on the average TSS measured in backwash wastewater, approximately 7,200 g of solids would be 

discharged from both Vessels A and B during each backwash event. Therefore, the natural iron level in 

backwash solids should be approximately 5.2%, which is 17.9% of that calculated based on backwash 

solids metal analysis (i.e., 29%), indicating that the backwash solids contained a significant amount of 

media fines. 

Table 4-13. Backwash Solids Total Metal Results (μg/g)

Analyte Mg Al Si P Ca Fe Mn Ni Cu Zn As Cd Pb

Vessel A 2,563 1,422 295 5,746 22,747 437,784 108,632 99 331 5,275 3,266 <0.1 46

Vessel B 6,219 1,551 728 1,964 31,798 144,335 51,676 53 197 1,095 825 1 50

Note: Average compositions calculated from triplicate analyses.

4.5.3 Spent Media Sampling. Spent media samples were collected from the lead vessel on May 6, 

2008, for TCLP analysis and on October 14, 2008, for metals analysis (Section 3.3.4). The results from 

TCLP analysis indicated that the media was non-hazardous and could be disposed of at a sanitary landfill. 

The ICP-MS results of the spent media samples are presented in Table 4-14. The average arsenic loading 

on the spent media was 3.5 mg/g of dry media. The adsorptive capacity also was calculated by dividing 

the arsenic mass represented by the area between the influent (IN) and the lead vessel effluent (TA) 

curves, as shown in Figure 4-15 by the amount of dry media in each vessel. Assuming no media loss, the 

dry weight of the media, i.e., 1,595 lb/vessel, was calculated based on a wet weight of 1,876 lb (i.e., 53,6

ft3 of media at 35 lb/ft3

) and a maximum moisture content of 15% (Table 4-2). Using this approach, the 

arsenic loading on the media would be 4.7 mg/g of dry media. Assuming that arsenic loading measured at 

the top of the media bed was representative of the media throughout the bed (because the lead vessel was 

approaching saturation as shown in Figure 4-15), ICP-MS analysis would have recovered approximately

74.5% of the arsenic removed during the adsorption run. 
48

Table 4-14. Spent Media Total Metal Analysis

Analyte (μg/g) Mg Si P Ca Fe Mn As Ba

Vessel 

A (Top) 

Run 1 1,920 6,907 2,143 5,418 526,004 11,047 3,451 783

Run 2 1,992 6,845 2,215 5,557 548,413 11,073 3,478 782

Ave. 1,956 6,875 2,179 5,487 537,208 11,059 3,464 783

As shown in Table 4-14, the spent media contained mostly iron at 537 mg/g (as Fe) or 854 mg/g (as 

FeOOH) on the media, which is close to the 90.1% (by weight) value specified by the STS for the virgin 

media (Table 4-3).

4.5.4 Distribution System Water Sampling. Distribution system water samples were collected to 

determine if water treated by the arsenic removal system would impact the lead, copper, and arsenic 

levels and other water chemistry in the distribution system. Prior to system startup, baseline distribution

system water samples were collected on March 16, April 20, May 18, and June 14, 2005. Since system 

startup, distribution system water sampling continued monthly at the same three locations until April 4, 

2007. The results are presented in Table 4-15. 

The main differences observed between the baseline samples and samples collected after system startup 

were decreases in arsenic and manganese concentrations at each of the three sampling locations. Arsenic 

concentrations were reduced from a pre-startup level of 38.2 μg/L (on average) to 2.6 μg/L after startup. 

Manganese concentrations were reduced from a pre-startup level of 41.8 μg/L (on average) to 1.5 

μg/L after startup. Iron concentrations measured in the distribution system were low both before and after 

system startup (except for two outliers at DS1 and DS3 on May 18, 2005 during the baseline sampling), 

with the majority of the samples being <25 μg/L. In general, the iron levels measured in the distribution 

system water mirrored those in the system effluent. Manganese levels measured in the distribution 

system water were slightly higher than those in the system effluent results (i.e., 1.5 vs. 0.3 μg/L [on 

average]). 

Arsenic concentrations measured in the distribution system water were compared to those measured in the 

plant effluent. As shown in Figure 4-18, prior to reaching 10,000 BV of throughput, arsenic 

concentrations in the distribution system water were higher than those in the plant effluent. Afterwards,

arsenic concentrations were at levels similar to those of the plant effluent. These results suggest initial 

redissolution and/or resuspendsion of arsenic previously accumulated in the distribution system. After

that, arsenic concentrations in the distribution system water essentially mirrored those of the plant

effluent. 

Measured pH values ranged from 7.6 to 8.2, and alkalinity levels ranged from 347 to 410 mg/L (as 

CaCO3); no discernable trends were observed after system startup. Lead levels ranged from <0.1 to 2 

μg/L (exclusing one data point at 7.9 μg/L for DS1 on May 17, 2006), which were less than the action 

level of 15 μg/L. The average lead level was 0.6 μg/L both in the baseline samples and the samples taken 

after system startup. Copper concentrations ranged from 14.9 to 862 μg/L, with no samples exceeding the 

1,300 μg/L action level. The average copper level was 153 μg/L in the baseline samples and 157 μg/L in

the samples taken after system startup. Copper concentrations at DS1 were much higher than those at 

DS2 and DS3 (i.e., 400 μg/L, on average, at DS1 compared to 29.5 μg/L at DS2 and 42.4 μg/L at DS3). 

The operator reported that DS1 had older distribution piping. Both lead and copper concentrations in the 

distribution system appeared to have not been affected by the operation of the arsenic treatment system. 
49

Table 4-15. Distribution Water Sampling Results

Address

Sample Type

Flushed / 1st Draw

Sampling Date

Stagnation Time pHAlkalinityAsFeMnPbCuStagnation Time pHAlkalinityAsFeMnPbCuStagnation Time pHAlkalinityAsFeMnPbCu

No. Date hr S.U. mg/L μg/L μg/L μg/L μg/L μg/L hr S.U. mg/L μg/L μg/L μg/L μg/L μg/L hr S.U. mg/L μg/L μg/L μg/L μg/L μg/L

BL1 03/16/05(a) 10.0 8.2 379 27.8 <25 40.6 0.6 32.2 6.4 8.1 366 29.6 49 68.3 0.6 20.1 12.0 7.9 379 29.8 <25 34.9 0.3 32.6

BL2 04/20/05(a) 12.0 7.6 369 32.4 <25 32.7 0.8 18.4 11.8 7.7 368 30.9 <25 19.7 0.1 81.7

BL3 05/18/05 8.6 7.4 379 92.8 815 60.5 0.5 435 8.6 7.7 379 33.0 26 38.3 0.6 59.1 8.0 7.5 357 50.3 268 34.7 0.7 36.5

BL4 06/14/05(b) 11.0 7.7 361 32.4 <25 36.9 0.4 862 7.0 7.7 365 29.6 25 50.9 1.3 28.6 12.0 7.8 356 31.2 <25 42.2 0.8 74.0

1 05/17/06(c) 11.0 7.9 363 16.5 <25 17.4 7.9 187 NA 8.0 363 3.0 <25 1.1 0.5 29.4 NA 7.9 347 3.9 <25 1.4 0.2 25.9

2 06/07/06 10.0 7.8 363 1.9 <25 0.3 0.1 624 6.9 7.9 355 2.4 <25 1.3 0.1 36.8 8.5 7.8 359 2.8 <25 3.8 0.5 23.3

3 07/19/06(d) 9.0 7.8 353 1.8 <25 0.4 0.3 465 8.0 7.9 361 2.0 <25 2.5 0.6 27.3 8.0 7.8 357 2.1 <25 1.5 0.4 32.4

4 08/15/06 10.3 7.7 358 1.4 <25 0.5 0.4 496 6.0 7.9 350 1.6 <25 1.2 0.4 51.3 8.0 7.8 358 2.0 <25 1.7 0.5 41.3

5 09/13/06 9.8 8.0 379 1.2 <25 0.3 0.6 383 7.0 7.9 388 1.3 <25 3.0 0.2 18.5 8.0 7.9 398 1.4 <25 0.2 0.3 18.7

6 10/10/06 9.3 7.9 385 1.6 <25 0.7 0.6 520 8.2 7.9 387 2.0 <25 1.7 0.6 14.9 10.0 7.8 382 2.0 <25 0.4 0.5 44.6

7 11/21/06 9.0 7.8 387 1.6 <25 0.3 0.5 500 5.5 7.7 391 1.7 <25 1.2 1.7 24.3 7.8 7.7 396 2.3 <25 0.6 0.8 104

8 12/13/06 9.0 7.8 368 1.8 <25 0.5 <0.1 369 8.0 7.8 368 1.7 <25 1.3 2.0 23.0 >6.0 7.8 368 1.8 <25 1.1 <0.1 61.2

9 01/10/07 9.0 8.0 402 1.4 <25 0.1 0.3 280 6.3 8.0 396 1.4 <25 0.3 0.1 16.0 11.0 8.0 410 1.5 <25 0.5 1.0 37.5

10 02/07/07(e) 10.0 8.1 376 2.4 <25 0.7 0.6 366 6.5 8.1 386 2.3 <25 0.7 0.8 49.8 7.8 8.0 386 2.7 <25 1.2 0.3 28.3

11 03/07/07 9.0 8.1 378 3.0 <25 <0.1 0.6 292 7.3 8.1 373 2.5 <25 0.2 0.6 39.7 7.8 8.0 373 2.6 <25 0.1 0.9 47.0

12 04/04/07 NA 8.0 366 3.6 <25 0.6 0.7 320 NA 8.1 368 3.6 <25 0.6 1.3 23.1 NA 8.0 371 3.3 <25 0.5 1.4 44.1

Average 9.6 7.9 373 3.2 <25 2.0 1.1 400 7.0 7.9 374 2.1 <25 1.3 0.7 29.5 8.5 7.9 375 2.4 <25 1.1 0.6 42.4

DS3

7 Kenny Court

LCR

1st Draw

61 Shady Oak Drive

Non-LCR

1st Draw

Homeowner Not Available

No. of 

Sampling 

Events

DS1

95 Oak Trail

Non-LCR

1st Draw

DS2

NS = not sampled; NA = not analyzed; BL = Baseline Sampling 

(a) DS1 and DS2 sampled at different locations as discussed in Section 3.3.5. 

(b) DS1 sampled on 06/13/05. 

(c) DS3 sampled on 05/18/06. 

(d) DS2 sampled on 07/25/06.

(e) DS2 Sampled on 02/08/07.
50

0

2

4

6

8

10

12

14

16

18

0 5 10 15 20 25 30 35 40

Bed Volumes of Treated Water (x1000)

Total As Concentration (μg/L)

TB

DS1

DS2

DS3

As MCL = 10 

/L

As Breakthrough at 

the Lag Vessel 

09/12/07

Figure 4-18. Comparsion of Total Arsenic Concentrations in Distribution System 

Water and Treatment System Effluent

(BV based on 124 ft3 of media)

4.6 System Cost

The cost of the system was evaluated based on the capital cost per gpm (or gpd) of design capacity and 

the O&M cost per 1,000 gal of water treated. This task required tracking capital cost for the equipment, 

site engineering, and installation and the O&M cost for media replacement and disposal, replacement 

parts, chemical supply, electricity consumption, 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 4-16). The equipment cost was $124,103 (or 69% of the total 

capital investment), which included $86,642 for the skid-mounted APU-30S unit, $18,858 for the SORB 

33TM 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. 
51

The total capital cost of $179,750 was normalized to the system’s rated capacity of 150 gpm 

(216,000 gpd), which resulted in $1,198/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 (Chen et al., 2004). Assuming 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 6.7 

hr/day at 129 gpm (see Table 4-6), producing 18,928,170 gal of water per year, the unit capital cost 

increased to $0.90/1,000 gal at this reduced rate of use. 

Table 4-16. Capital Investment for Treatment System

Description Quantity Cost

% of Capital 

Investment Cost

Equipment

APU-30S Skid Mounted System 1 $86,642 –

SORB 33TM Media 124 ft3 $18,858 –

Shipping – $8,393 –

Vendor Labor – $10,211 –

Equipment Total – $124,103 69%

Engineering

Subcontractor Labor/Travel – $14,000 –

Engineering Total – $14,000 8%

Installation

Subcontractor Labor – $28,750 –

Vendor Labor – $4,913 –

Vendor Travel – $7,984 –

Installation Total – $41,647 23%

Total Capital Investment – $179,750 100%

4.6.2 Operation and Maintenance Cost. The O&M cost included the cost for such items as 

media replacement and disposal, electricity, chemical, and labor (Table 4-17). The media replacement 

and disposal cost was $12,680, including cost for the replacement media for the lead vessel, freight, labor, 

equipment, and media disposal. This cost was used to calculate the media replacement cost per 1,000 gal 

of water treated as a function of total throughput at10-μg/L arsenic breakthrough from the lag vessel. 

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.

The chemical cost associated with the operation of the treatment system included chlorine addition prior 

to the adsorption vessels. This treatment step was in use at the site prior to installation of the treatment 

system. The treatment system did not have a significant effect on the chlorine gas usage based on the data 

collected during the performance evaluation study. Therefore, the incremental chemical cost for the 

treatment system was negligible. 

Under normal operating conditions, routine labor activities to operate and maintain the system consumed 

an average of 40.0 min/day. Therefore, the estimated labor cost was $0.25/1,000 gal of water treated

based on this time commitment and a labor rate of $19.50/hr. 
52

Table 4-17. O&M Cost for APU-30S System

Cost Category Value Remarks

Media Replacement and Disposal

Media Replacement ($) $7,940 48 ft3 (in lead vessel)

Shipping ($) $240 –

Subcontractor Labor ($) $1,000 –

Media Disposal ($) $1,500 –

Equipment $2,000 –

Subtotal $12,680 –

Media Replacement 

and Disposal ($/1,000 gal)

See Figure 

4-19

Based upon media run length at 10 μg/L 

arsenic breakthrough at lag vessel

Chemical Usage

Chemical Cost ($) $0.00 No additional chemicals required

Electricity

Electricity ($/1,000 gal) $0.00 Electrical costs assumed negligible

Labor Cost

Average Weekly Labor (hr/year) 243 40 min/day

Labor ($/1,000 gal) $0.25 

- Labor rate of $19.50/hr 

- Annual throughput of 18,928,170 gal 

Total O&M Cost/1,000 gal See Figure 

4-19

–

$0.00

$2.00

$4.00

$6.00

$8.00

$10.00

$12.00

$14.00

0 4 8 12 16 20 24 28 32 36 40 44 48 52

Media Working Capacity (x1000 BV)

Cost ($/1,000 gal)

Total O&M cost

Media replacement cost

Note: One bed volume equals to 124 ft3 (or 927 gal) for both Vessels A and B

Figure 4-19. Media Replacement and O&M Cost for APU-30S System
53

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. 2006. 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. 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.

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. 2003. Minor Clarification of the National Primary Drinking Water Regulation for Arsenic. Federal 

Register, 40 CFR Part 141.

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): 75-79. 

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 Mn.” 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.
54

Severn Trent Services. 2006. SORB 33TM As Removal Systems with Bayoxide® E33 Media Operation and 

Maintenance Manual APU-30S – City of Alvin, Texas.

Severn Trent Services. 2006. SORB 33TM 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.
APPENDIX A

OPERATIONAL DATA
A-1 

Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet

Op 

Time

Well 1 

Totalizer

Well 1 

Average 

Flow

Well 2 

Totalizer 

Well 2 

Average 

Flow 

Vessel A 

Instant 

Flowrate

Vessel A 

Totalizer

Vessel A 

Calculated 

Flowrate

Cum total 

Throughput

Cum total 

Bed Volume

Vessel A 

ΔP

Vessel B 

ΔP

System 

ΔP

Effluent 

Totalizer

Effluent 

Calculated 

Flowrate

hr kgal gpm kgal gpm gpm gal gpm gal BV psi psi psig gal gpm

04/25/06(a,c) NA 1,244 47 NM NA off 1,223,042 NA 1,199,097 1,294 2.50 2.50 13.0 NM NA

04/26/06(b) 8.5 1,268 47 NM NA NM NM NA 1,262,847 1,362 3.50 3.50 14.0 NM NA

04/27/06 6.5 1,283 38 NM NA NM NM NA 1,311,597 1,415 3.00 3.00 14.0 NM NA

04/28/06 8.4 1,309 52 NM NA off NM NA 1,374,597 1,483 off off NA NM NA

04/29/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

04/30/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/01/06 21.7 1,369 46 NM NA NM NM NA 1,537,346 1,658 3.50 3.25 13.0 NM NA

05/02/06 4.5 1,381 44 NM NA NM NM NA 1,571,096 1,695 3.50 3.00 14.0 NM NA

05/03/06 8.6 1,405 47 NM NA NM NM NA 1,635,596 1,764 3.50 3.00 13.0 NM NA

05/04/06 7.4 1,425 45 NM NA off NM NA 1,691,096 1,824 off off NA NM NA

05/05/06 11.2 1,455 45 NM NA NM NM NA 1,775,097 1,915 3.75 3.25 15.0 NM NA

05/06/06 5.9 1,469 NA NM NA NM NM NA 1,819,347 1,963 3.75 3.25 15.0 NM NA

05/07/06 6.9 1,491 NA NM NA NM NM NA 1,871,097 2,018 4.00 3.25 14.0 NM NA

05/08/06 9.8 1,518 46 NM NA NM NM NA 1,944,597 2,098 4.25 3.25 15.0 NM NA

05/09/06 7.7 1,539 45 NM NA off NM NA 2,002,347 2,160 off off NA NM NA

05/10/06 7.5 1,559 44 NM NA NM NM NA 2,058,597 2,221 4.50 3.00 13.0 NM NA

05/11/06 10.0 1,587 47 NM NA NM NM NA 2,133,597 2,302 4.25 2.75 13.0 NM NA

05/12/06 9.3 1,612 45 NM NA NM NM NA 2,203,347 2,377 5.00 2.75 15.0 NM NA

05/13/06 8.4 1,639 NA NM NA off NM NA 2,266,347 2,445 off off NA NM NA

05/14/06 10.8 1,678 NA NM NA NM NM NA 2,347,347 2,532 6.00 2.25 17.0 NM NA

05/15/06 28.4 1,740 36 NM NA NM NM NA 2,560,347 2,762 8.50 3.00 16.0 NM NA

05/16/06 14.8 1,779 44 NM NA NM NM NA 2,671,347 2,882 8.50 3.00 18.0 NM NA

05/17/06 9.2 1,803 43 NM NA NM NM NA 2,734,847 2,950 3.50 2.50 14.0 NM NA

05/18/06 10.0 1,830 45 NM NA NM NM NA 2,809,847 3,031 3.75 2.50 13.0 NM NA

05/19/06 7.0 1,850 48 NM NA NM NM NA 2,862,347 3,088 3.75 3.00 14.0 NM NA

05/20/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/21/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/22/06 31.1 1,935 46 858 NA off NM NA 3,095,597 3,339 off off NA NM NA

05/23/06 10.6 1,964 46 911 83 NM NM NA 3,177,597 3,428 4.00 2.75 14.0 NM NA

05/24/06 8.2 1,986 45 951 81 NM NM NA 3,239,597 3,495 4.00 3.00 15.0 NM NA

05/25/06 12.6 2,022 48 1,014 83 off NM NA 3,338,597 3,602 off off NA NM NA

05/26/06 7.7 2,042 43 1,052 82 NM NM NA 3,396,597 3,664 4.00 3.00 14.0 NM NA

05/27/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/28/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/29/06 34.2 2,137 46 1,222 83 138 1,931,776 129 3,661,597 3,950 4.75 3.00 16.0 NM NA

05/30/06 10.7 2,165 44 1,274 81 139 2,015,209 130 3,745,030 4,040 5.00 3.50 15.0 NM NA

05/31/06 6.8 2,182 42 1,292 44 147 2,063,789 119 3,793,610 4,092 3.75 3.50 16.0 NM NA

06/01/06 5.1 2,198 52 1,318 85 NM 2,107,017 141 3,836,838 4,139 4.00 3.50 16.0 NM NA

06/02/06 7.5 2,218 44 1,358 89 139 2,150,150 96 3,879,971 4,186 3.50 3.00 13.0 NM NA

06/03/06 6.1 2,233 41 1,389 85 141 2,200,785 138 3,930,606 4,240 3.75 3.00 14.0 NM NA

06/04/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/05/06 13.8 2,273 48 1,461 87 NM 2,310,687 133 4,040,508 4,359 4.00 3.25 16.0 NM NA

06/06/06(b) 8.5 2,297 47 1,505 86 NM NM 133 4,108,508 4,432 4.25 3.50 16.0 NM NA

06/07/06 8.9 2,322 47 1,550 84 141 2,386,445 131 4,178,508 4,508 4.50 3.00 16.0 NM NA

06/08/06 9.7 2,348 45 1,599 84 off 2,464,677 134 4,256,740 4,592 off off NA NM NA

06/09/06 7.0 2,367 45 1,637 90 147 2,523,294 140 4,315,357 4,655 4.50 3.25 16.0 NM NA

06/10/06 9.7 2,390 40 1,684 81 141 2,603,680 138 4,395,743 4,742 5.00 3.00 16.0 NM NA

06/11/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/12/06(d) NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/13/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/14/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/15/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/16/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/17/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/18/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/19/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/20/06 85.3 2,626 46 2,081 78 147 3,304,162 137 5,096,225 5,498 4.25 3.50 16.0 NM NA

06/21/06 6.8 2,646 49 2,121 98 139 3,368,383 157 5,160,446 5,567 4.25 3.25 15.0 NM NA

06/22/06 5.9 2,659 37 2,148 76 141 3,411,585 122 5,203,648 5,613 4.50 3.25 16.0 NM NA

06/23/06 7.2 2,681 51 2,188 93 off 3,472,230 140 5,264,293 5,679 off off NA NM NA

06/24/06 5.4 2,696 46 2,214 80 137 3,517,645 140 5,309,708 5,728 4.25 3.25 NA NM NA

06/25/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

Date

1

6

Week

9

7

8

5

4

3

2
Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)

A-2

Op 

Time

Well 1 

Totalizer

Well 1 

Average 

Flow

Well 2 

Totalizer 

Well 2 

Average 

Flow 

Vessel A 

Instant 

Flowrate

Vessel A 

Totalizer

Vessel A 

Calculated 

Flowrate

Cum total 

Throughput

Cum total 

Bed Volume

Vessel A 

ΔP

Vessel B 

ΔP

System 

ΔP

Effluent 

Totalizer

Effluent 

Calculated 

Flowrate

hr kgal gpm kgal gpm gpm gal gpm gal BV psi psi psig gal gpm

06/26/06 15.0 2,737 46 2,291 86 144 3,644,307 141 5,436,370 5,864 5.50 3.00 15.0 NM NA

06/27/06 8.6 2,761 47 2,335 85 off 3,713,347 134 5,505,410 5,939 off off NA NM NA

06/28/06 10.3 2,789 45 2,387 84 140 3,798,059 137 5,590,122 6,030 5.75 3.25 17.0 NM NA

06/29/06 7.9 2,810 44 2,427 84 137 3,861,720 134 5,653,783 6,099 7.00 3.00 18.0 NM NA

06/30/06 8.9 2,834 45 2,471 82 off 3,932,777 133 5,724,840 6,176 off off NA NM NA

07/01/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/02/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/03/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/04/06 26.1 2,900 42 2,598 81 134 4,112,690 115 5,904,753 6,370 5.50 3.50 18.0 NM NA

07/05/06 8.7 2,923 44 2,643 86 136 4,184,622 138 5,976,685 6,447 5.75 3.25 18.0 NM NA

07/06/06 6.6 2,942 48 2,676 83 140 4,238,853 137 6,030,916 6,506 6.50 3.25 16.0 NM NA

07/07/06 5.6 2,957 45 2,705 86 139 4,284,523 136 6,076,586 6,555 6.50 3.50 17.0 NM NA

07/08/06 7.5 2,975 40 2,741 80 139 4,341,954 128 6,134,017 6,617 7.50 3.00 18.0 NM NA

07/09/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/10/06 14.4 3,016 47 2,817 88 133 4,463,729 141 6,255,792 6,748 8.00 3.75 17.0 NM NA

07/11/06 4.4 3,028 45 2,839 83 144 4,498,496 132 6,290,559 6,786 8.50 3.00 18.0 429,000 NA

07/12/06 7.3 3,046 41 2,876 84 137 4,532,646 78 6,324,709 6,823 9.00 3.00 19.0 489,000 137

07/13/06 8.2 3,069 47 2,918 85 138 4,599,386 136 6,391,449 6,895 9.50 3.00 19.0 557,000 138

07/14/06 7.1 3,088 45 2,956 89 131 4,652,797 125 6,444,860 6,952 9.00 3.00 18.0 617,000 141

07/15/06 6.9 3,107 46 2,989 80 138 4,708,628 122 6,495,191 7,007 3.25 2.75 16.0 663,000 111

07/16/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/17/06 16.7 3,153 46 3,075 86 138 4,842,012 133 6,628,575 7,151 4.00 3.00 16.0 811,000 148

07/18/06 8.7 3,177 46 3,122 90 off 4,913,506 137 6,700,069 7,228 off off NA 878,000 128

07/19/06 6.0 3,191 39 3,154 89 141 4,961,891 134 6,748,454 7,280 4.50 3.00 18.0 929,000 142

07/20/06 6.2 3,209 48 3,183 78 off 5,007,671 123 6,794,234 7,329 off off NA 977,000 129

07/21/06 4.0 3,221 50 3,207 100 134 5,044,209 152 6,830,772 7,369 5.50 3.50 18.0 1,016,000 163

07/22/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/23/06 13.5 3,258 46 3,277 86 off 5,152,592 134 6,939,155 7,486 off off NA 1,129,000 140

07/24/06 5.7 3,273 44 3,306 85 135 5,197,865 132 6,984,428 7,534 7.50 3.50 16.0 1,177,000 140

07/25/06 6.2 3,290 46 3,339 89 off 5,247,778 134 7,034,341 7,588 off off NA 1,229,000 140

07/26/06 5.7 3,305 44 3,368 85 137 5,293,620 134 7,080,183 7,638 8.00 3.00 19.0 1,277,000 140

07/27/06 4.2 3,316 44 3,390 87 136 5,326,234 129 7,112,797 7,673 8.00 3.00 20.0 1,312,000 139

07/28/06 6.5 3,335 49 3,425 90 127 5,379,462 136 7,166,025 7,730 8.00 3.00 18.0 1,369,000 146

07/29/06 5.6 3,349 42 3,456 92 132 5,423,999 133 7,210,562 7,778 8.50 3.00 18.0 1,419,000 149

07/30/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/31/06 14.3 3,387 44 3,525 80 130 5,527,735 121 7,314,298 7,890 8.00 3.00 17.0 1,530,000 129

08/01/06 8.3 3,410 46 3,568 86 132 5,587,260 120 7,373,823 7,955 8.50 3.25 19.0 1,599,000 139

08/02/06 6.7 3,428 45 3,603 87 off 5,635,693 120 7,422,256 8,007 off off NA 1,656,000 142

08/03/06 6.1 3,444 44 3,635 87 141 5,679,966 121 7,466,529 8,055 8.50 3.50 20.0 1,707,000 139

08/04/06 8.2 3,467 47 3,677 85 off 5,739,258 121 7,525,821 8,118 off off NA 1,776,000 140

08/05/06 3.4 3,476 44 3,694 83 122 5,763,379 118 7,549,942 8,144 8.00 3.50 18.0 1,804,000 137

08/06/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

08/07/06 14.6 3,515 45 3,770 87 off 5,869,392 121 7,655,955 8,259 off off NA 1,926,000 139

08/08/06 6.1 3,531 44 3,801 85 131 5,913,936 122 7,700,499 8,307 8.75 3.75 17.0 1,977,000 139

08/09/06 5.7 3,546 44 3,831 88 133 5,955,885 123 7,742,448 8,352 8.75 3.75 18.0 2,025,000 140

08/10/06 10.0 3,574 47 3,883 87 off 6,028,701 103 7,804,454 8,419 off off NA 2,100,000 125

08/11/06 5.3 3,588 44 3,912 91 129 6,068,951 127 7,844,704 8,462 3.75 3.00 15.0 2,146,000 145

08/12/06 5.4 3,602 43 3,941 90 126 6,109,366 125 7,885,119 8,506 4.00 3.00 16.0 2,192,000 142

08/13/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

08/14/06 17.8 3,652 47 4,034 87 126 6,241,936 124 8,017,689 8,649 5.00 3.25 15.0 2,343,000 141

08/15/06 7.4 3,672 45 4,073 88 off 6,297,782 126 8,073,535 8,709 off off NA 2,406,000 142

08/16/06 7.3 3,690 41 4,109 82 125 6,350,079 119 8,125,832 8,766 5.50 3.00 16.0 2,464,000 132

08/17/06 6.9 3,710 48 4,147 92 129 6,404,035 130 8,179,788 8,824 5.75 3.25 17.0 2,522,000 140

08/18/06 10.1 3,738 46 4,199 86 off 6,479,813 125 8,255,566 8,906 off off NA 2,610,000 145

08/19/06 6.3 3,756 48 4,236 98 130 6,531,033 121 8,301,286 8,955 5.75 3.24 16.0 2,672,000 164

08/20/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

08/21/06(c) 15.3 3,795 42 4,312 83 off 6,640,748 120 8,411,001 9,073 off off NA NM NA

08/22/06 6.1 3,812 46 4,344 87 126 6,686,472 125 8,456,725 9,123 6.00 3.00 17.0 NM NA

08/23/06 7.9 3,834 46 4,385 86 off 6,743,842 121 8,514,095 9,185 off off NA NM NA

08/24/06 4.7 3,846 43 4,410 89 128 6,778,677 124 8,548,930 9,222 6.25 3.00 17.0 NM NA

08/25/06 6.5 3,864 46 4,444 87 122 6,826,067 122 8,596,320 9,273 6.50 3.00 16.0 NM NA

08/26/06 5.8 3,879 43 4,475 89 126 6,868,299 106 8,633,052 9,313 6.25 3.00 NA NM NA

08/27/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10

15

18

13

12

11

Date

16

14

17

Week
Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)

A-3

Op 

Time

Well 1 

Totalizer

Well 1 

Average 

Flow

Well 2 

Totalizer 

Well 2 

Average 

Flow 

Vessel A 

Instant 

Flowrate

Vessel A 

Totalizer

Vessel A 

Calculated 

Flowrate

Cum total 

Throughput

Cum total 

Bed Volume

Vessel A 

ΔP

Vessel B 

ΔP

System 

ΔP

Effluent 

Totalizer

Effluent 

Calculated 

Flowrate

hr kgal gpm kgal gpm gpm gal gpm gal BV psi psi psig gal gpm

08/28/06 9.5 3,905 46 4,525 88 124 6,938,879 124 8,703,632 9,389 6.50 3.25 16.0 NM NA

08/29/06 4.9 3,918 44 4,551 88 133 6,972,660 115 8,737,413 9,425 6.75 3.25 16.0 NM NA

08/30/06 7.9 3,940 46 4,593 89 off 7,030,197 121 8,794,950 9,488 off off NA NM NA

08/31/06 5.3 3,954 44 4,620 85 117 7,068,971 122 8,833,724 9,529 7.00 3.00 17.0 NM NA

09/01/06 6.9 3,972 43 4,657 89 128 7,119,467 122 8,884,220 9,584 7.25 3.00 18.0 NM NA

09/02/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/03/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/04/06(d) NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/05/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/06/06(b) 40.1 4,080 45 4,863 86 NM NM NA 9,198,220 9,923 7.75 3.00 16.0 NM NA

09/07/06 11.1 4,109 44 4,919 84 off NM NA 9,283,220 10,014 off off NA NM NA

09/08/06 7.6 4,129 44 4,957 83 NM NM NA 9,341,220 10,077 8.00 3.25 18.0 NM NA

09/09/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/10/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/11/06 19.2 4,180 44 5,057 87 off NM NA 9,492,220 10,240 off off NA NM NA

09/12/06 4.5 4,192 44 5,080 85 NM NM NA 9,527,220 10,277 9.50 3.00 20.0 NM NA

09/13/06 5.0 4,206 47 5,106 87 NM NM NA 9,567,220 10,321 9.50 3.25 21.0 NM NA

09/14/06 7.4 4,225 43 5,145 88 off NM NA 9,625,220 10,383 off off NA NM NA

09/15/06 4.0 4,236 46 5,167 92 NM NM NA 9,658,220 10,419 9.75 3.00 20.0 NM NA

09/16/06 7.1 4,253 40 5,202 82 NM NM NA 9,710,220 10,475 9.75 3.00 21.0 NM NA

09/17/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/18/06 10.6 4,282 46 5,256 85 NM NM NA 9,793,220 10,564 9.75 3.00 21.0 3,074,000 NA

09/19/06 4.7 4,295 46 5,281 89 NM NM NA 9,831,220 10,605 10.00 3.75 21.0 3,109,000 124

09/20/06 7.3 4,315 46 5,321 91 NM NM NA 9,891,220 10,670 3.25 3.25 15.0 3,166,000 130

09/21/06 4.5 4,328 48 5,345 89 NM NM NA 9,928,220 10,710 4.00 3.50 17.0 3,205,000 144

09/22/06 5.7 4,343 44 5,376 91 NM NM NA 9,974,220 10,760 4.00 3.25 17.0 3,252,000 137

09/23/06 7.0 4,362 45 5,415 93 NM NM NA 10,032,220 10,822 4.25 3.00 17.0 3,308,000 133

09/24/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/25/06 12.3 4,398 49 5,480 88 off NM NA 10,133,220 10,931 off off NA 3,418,000 149

09/26/06 4.0 4,408 42 5,503 96 NM NM NA 10,166,220 10,967 4.50 3.00 16.0 3,454,000 150

09/27/06 3.7 4,419 50 5,522 86 NM NM NA 10,196,220 10,999 5.00 3.50 18.0 3,483,000 131

09/28/06 6.7 4,437 45 5,559 92 NM NM NA 10,251,220 11,058 5.00 4.00 18.0 3,539,000 139

09/29/06 2.7 4,444 43 5,573 86 off NM NA 10,272,220 11,081 off off NA 3,562,000 142

09/30/06 NA NM NA NM NA off NM NA NA NA off off NA NM NA

10/01/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/02/06 18.0 4,497 49 5,678 97 off NM NA 10,430,220 11,252 off off NA 3,724,000 150

10/03/06 5.2 4,511 45 5,708 96 NM NM NA 10,474,220 11,299 4.75 3.25 16.0 3,770,000 147

10/04/06 3.0 4,520 50 5,725 94 off 7,793,016 NA 10,500,220 11,327 off off NA 3,796,000 144

10/05/06 5.2 4,534 45 5,753 90 142 7,834,501 133 10,541,705 11,372 5.00 3.50 16.0 3,840,000 141

10/06/06 6.1 4,550 44 5,785 87 138 7,880,991 127 10,588,195 11,422 5.50 3.50 16.0 3,891,000 139

10/07/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/08/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/09/06 20.6 4,606 45 5,895 89 off 8,039,652 128 10,746,856 11,593 off off NA 4,064,000 140

10/10/06 4.8 4,619 45 5,922 94 133 8,077,869 133 10,785,073 11,634 6.25 3.75 16.0 4,105,000 142

10/11/06 4.4 4,631 45 5,946 91 131 8,113,039 133 10,820,243 11,672 6.25 3.00 16.0 4,142,000 140

10/12/06 5.7 4,646 44 5,976 88 133 8,156,598 127 10,863,802 11,719 7.00 3.00 15.0 4,189,000 137

10/13/06 3.1 4,655 48 5,993 91 off 8,180,153 127 10,887,357 11,745 off off NA 4,215,000 140

10/14/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/15/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/16/06 17.0 4,700 44 6,084 89 121 8,309,040 126 11,016,244 11,884 6.25 2.75 17.0 4,362,000 144

10/17/06 3.1 4,708 43 6,101 91 off 8,332,174 124 11,039,378 11,909 off off NA 4,377,000 NA

10/18/06 4.6 4,721 47 6,126 91 128 8,366,560 125 11,073,764 11,946 6.75 3.00 17.0 4,395,000 NA

10/19/06 4.6 4,733 43 6,151 91 off 8,400,428 123 11,107,632 11,982 off off NA 4,428,000 120

10/20/06 4.5 4,745 44 6,176 93 133 8,433,876 124 11,141,080 12,018 7.50 3.25 16.0 4,460,000 119

10/21/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/22/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/23/06 14.9 4,784 44 6,255 88 123 8,540,793 120 11,247,997 12,134 9.00 3.75 19.0 4,573,000 126

10/24/06 4.8 4,797 45 6,281 90 off 8,572,904 111 11,280,108 12,168 off off NA 4,611,000 132

10/25/06 4.6 4,809 43 6,305 87 126 8,605,761 119 11,312,965 12,204 9.00 3.50 20.0 4,650,000 141

10/26/06 4.5 4,821 44 6,330 93 off 8,636,099 112 11,343,303 12,237 off off NA 4,688,000 141

10/27/06 4.9 4,834 44 6,355 85 118 8,669,044 112 11,376,248 12,272 9.25 3.50 20.0 4,728,000 136

10/28/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/29/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

19

Date

26

25

21

22

23

24

27

20

Week
Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)

A-4

Op 

Time

Well 1 

Totalizer

Well 1 

Average 

Flow

Well 2 

Totalizer 

Well 2 

Average 

Flow 

Vessel A 

Instant 

Flowrate

Vessel A 

Totalizer

Vessel A 

Calculated 

Flowrate

Cum total 

Throughput

Cum total 

Bed Volume

Vessel A 

ΔP

Vessel B 

ΔP

System 

ΔP

Effluent 

Totalizer

Effluent 

Calculated 

Flowrate

hr kgal gpm kgal gpm gpm gal gpm gal BV psi psi psig gal gpm

10/30/06 16.5 4,877 43 6,443 89 113 8,777,005 109 11,484,209 12,389 10.25 3.25 NM 4,867,000 140

10/31/06 6.0 4,893 44 6,474 86 off 8,804,665 77 11,511,869 12,418 10.50 3.00 off 4,915,000 133

11/01/06 5.5 4,908 45 6,505 94 123 8,831,308 68 11,534,293 12,443 3.75 3.00 NM 4,955,000 121

11/02/06 2.8 4,916 48 6,521 95 off 8,861,118 177 11,564,103 12,475 off off off 4,978,000 137

11/03/06 5.9 4,932 45 6,554 93 131 8,906,557 128 11,609,542 12,524 4.25 3.25 NM 5,028,000 141

11/04/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/05/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/06/06 13.8 4,969 45 6,629 91 127 9,011,500 127 11,714,485 12,637 5.50 3.75 15.0 5,146,000 143

11/07/06 5.0 4,983 47 6,656 90 off 9,048,578 124 11,751,563 12,677 off off NA 5,189,000 143

11/08/06 4.7 4,996 46 6,682 92 off 9,084,251 126 11,787,236 12,715 off off NA 5,229,000 142

11/09/06 4.5 5,008 44 6,707 93 130 9,126,133 155 11,829,118 12,761 5.50 3.25 15.0 5,269,000 148

11/10/06 5.4 5,022 43 6,745 117 123 9,160,760 107 11,863,745 12,798 5.50 3.25 14.0 5,315,000 142

11/11/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/12/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/13/06 14.9 5,062 45 6,818 82 130 9,274,788 128 11,977,773 12,921 6.00 3.50 16.0 5,445,000 145

11/14/06 4.5 5,075 48 6,842 89 129 9,307,581 121 12,010,566 12,956 6.00 3.50 15.0 5,481,000 133

11/15/06 4.8 5,087 42 6,868 90 131 9,344,528 128 12,047,513 12,996 6.50 3.50 16.0 5,522,000 142

11/16/06 4.9 5,099 41 6,892 82 off 9,377,930 114 12,080,915 13,032 off off NA 5,567,000 153

11/17/06 4.5 5,113 52 6,919 100 off 9,414,780 136 12,117,765 13,072 off off NA 5,602,000 130

11/18/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/19/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/20/06 16.8 5,157 44 7,010 90 129 9,541,056 125 12,244,041 13,208 7.25 3.75 16.0 5,747,000 144

11/21/06 5.1 5,171 46 7,037 88 132 9,579,089 124 12,282,074 13,249 7.25 3.50 18.0 5,788,000 134

11/22/06 5.4 5,185 43 7,065 86 134 9,617,440 118 12,320,425 13,291 7.50 3.50 17.0 5,831,000 133

11/23/06 8.8 5,208 44 7,112 89 off 9,683,133 124 12,386,118 13,362 off off NA 5,907,000 144

11/24/06 10.0 5,236 47 7,164 87 off 9,755,880 121 12,458,865 13,440 off off NA 5,990,000 138

11/25/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/26/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/27/06 17.5 5,282 44 7,257 89 off 9,879,410 118 12,582,395 13,573 off off NA 6,137,000 140

11/28/06 3.3 5,290 40 7,276 96 128 9,909,334 151 12,612,319 13,606 9.75 3.50 18.0 6,169,000 162

11/29/06 4.5 5,302 44 7,298 81 off 9,940,895 117 12,643,880 13,640 off off NA 6,202,000 122

11/30/06 4.9 5,315 44 7,324 88 127 9,980,119 133 12,683,104 13,682 10.00 3.50 19.0 6,243,000 139

12/01/06 8.4 5,336 42 7,368 87 121 10,037,765 114 12,740,750 13,744 10.00 3.00 18.0 6,313,000 139

12/02/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/03/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/04/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/05/06 19.6 5,388 44 7,471 88 139 10,143,913 90 12,846,898 13,859 11.00 3.50 19.0 6,475,000 138

12/06/06 8.0 5,410 46 7,516 94 off 10,202,219 111 12,900,304 13,916 off off NA 6,537,000 129

12/07/06 2.6 5,417 45 7,530 90 129 10,221,707 125 12,919,792 13,937 4.00 3.50 14.0 6,560,000 147

12/08/06 4.8 5,430 45 7,556 90 135 10,240,607 66 12,938,692 13,958 4.50 4.00 15.0 6,601,000 142

12/09/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/10/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/11/06 15.6 5,473 46 7,642 92 off 10,356,802 124 13,054,887 14,083 off off NA 6,736,000 144

12/12/06 5.6 5,487 42 7,673 92 129 10,399,393 127 13,097,478 14,129 5.50 3.50 15.0 6,785,000 146

12/13/06 6.9 5,506 46 7,710 89 133 10,450,383 123 13,148,468 14,184 5.50 3.25 15.0 6,844,000 143

12/14/06 2.5 5,512 40 7,724 93 off 10,469,096 125 13,167,181 14,204 off off NA 6,865,000 140

12/15/06 5.6 5,528 48 7,755 92 125 10,512,331 129 13,210,416 14,251 6.00 3.00 18.0 6,914,000 146

12/16/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/17/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/18/06(d) NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/19/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/20/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/21/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/22/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/23/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/24/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/25/06 55.9 5,677 44 8,027 81 118 10,905,508 117 13,603,593 14,675 8.00 3.00 15.0 7,386,000 141

12/26/06 3.7 5,687 45 8,047 90 126 10,931,651 118 13,629,736 14,703 8.25 3.50 16.0 7,421,000 158

12/27/06 7.9 5,708 44 8,089 89 113 10,988,360 120 13,686,445 14,764 8.00 3.00 16.0 7,487,000 139

12/28/06 3.0 5,716 44 8,105 89 123 11,009,551 118 13,707,636 14,787 8.00 3.00 17.0 7,512,000 139

12/29/06 5.1 5,730 46 8,132 88 off 11,045,572 118 13,743,657 14,826 off off NA 7,555,000 141

12/30/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/31/06 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

33

34

28

31

32

35

36

29

Date

30

Week
Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)

A-5

Op 

Time

Well 1 

Totalizer

Well 1 

Average 

Flow

Well 2 

Totalizer 

Well 2 

Average 

Flow 

Vessel A 

Instant 

Flowrate

Vessel A 

Totalizer

Vessel A 

Calculated 

Flowrate

Cum total 

Throughput

Cum total 

Bed Volume

Vessel A 

ΔP

Vessel B 

ΔP

System 

ΔP

Effluent 

Totalizer

Effluent 

Calculated 

Flowrate

hr kgal gpm kgal gpm gpm gal gpm gal BV psi psi psig gal gpm

01/01/07 17.5 5,775 43 8,226 90 115 11,171,274 120 13,869,359 14,962 10.00 3.00 20.0 7,703,000 141

01/02/07 4.7 5,787 43 8,250 85 116 11,203,438 114 13,901,523 14,996 10.00 3.00 20.0 7,741,000 135

01/03/07 4.5 5,799 44 8,274 89 off 11,216,062 NA 13,937,523 15,035 off off NA 7,779,000 141

01/04/07 5.3 5,813 44 8,301 85 off 11,252,654 115 13,974,115 15,075 off off NA 7,822,000 135

01/05/07 5.1 5,827 46 8,329 92 off 11,288,819 118 14,010,280 15,114 off off NA 7,865,000 141

01/06/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/07/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/08/07 17.8 5,873 43 8,423 88 122 11,412,750 116 14,134,211 15,247 11.00 3.00 18.0 8,014,000 140

01/09/07 5.9 5,888 42 8,454 88 114 11,452,700 113 14,174,161 15,290 11.00 3.00 19.0 8,061,000 133

01/10/07 6.6 5,905 43 8,487 83 off 11,495,550 108 14,217,011 15,337 off off NA 8,114,000 134

01/11/07 2.6 5,912 45 8,502 96 117 11,513,999 118 14,235,460 15,356 7.00 3.75 17.0 8,137,000 147

01/12/07 8.2 5,933 43 8,546 89 off 11,568,711 111 14,290,172 15,416 off off NA 8,205,000 138

01/13/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/14/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/15/07(b) 18.5 5,982 44 8,614 61 NM NM NA 14,407,172 15,542 9.00 3.00 16.0 8,361,000 141

01/16/07 8.1 6,003 43 8,656 86 off NM NA 14,470,172 15,610 off off NA 8,426,000 134

01/17/07 6.5 6,020 44 8,689 85 off NM NA 14,520,172 15,664 off off NA 8,479,000 136

01/18/07 6.5 6,037 44 8,723 87 off NM NA 14,571,172 15,719 off off NA 8,531,000 133

01/19/07 7.4 6,055 41 8,761 86 NM NM NA 14,627,172 15,779 12.00 3.00 18.0 8,590,000 133

01/20/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/21/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/22/07 22.1 6,111 42 8,871 83 off NM NA 14,793,172 15,958 off off NA 8,764,000 131

01/23/07 6.5 6,127 41 8,904 85 NM NM NA 14,842,172 16,011 13.00 4.00 17.0 8,811,000 121

01/24/07 6.0 6,142 42 8,934 83 NM NM NA 14,887,172 16,060 13.00 3.75 20.0 8,862,000 142

01/25/07 7.4 6,161 43 8,970 81 off NM NA 14,942,172 16,119 off off NA 8,919,000 128

01/26/07 6.9 6,178 41 9,003 80 NM NM NA 14,992,172 16,173 13.25 4.00 21.0 8,972,000 128

01/27/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/28/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/29/07 23.3 6,234 40 9,113 79 off NM NA 15,158,172 16,352 off off NA 9,147,000 125

01/30/07 7.6 6,252 39 9,149 79 off NM NA 15,212,172 16,410 off off NA 9,204,000 125

01/31/07 7.6 6,271 42 9,185 79 NM NM NA 15,261,345 16,463 4.25 3.00 12.0 9,260,000 123

02/01/07 3.0 6,280 50 9,200 83 NM NM NA 15,285,345 16,489 4.50 3.25 13.0 9,283,000 128

02/02/07 9.8 6,307 46 9,255 94 off NM NA 15,367,345 16,578 off off NA 9,368,000 145

02/03/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/04/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/05/07 17.9 6,354 44 9,350 88 off NM NA 15,509,345 16,731 off off NA 9,517,000 139

02/06/07 6.2 6,371 46 9,383 89 NM NM NA 15,559,345 16,785 7.25 3.25 18.0 9,568,000 137

02/07/07 5.9 6,385 40 9,414 88 NM NM NA 15,604,345 16,833 8.00 3.00 18.0 9,618,000 141

02/08/07 5.4 6,400 46 9,443 90 NM NM NA 15,648,345 16,881 8.25 3.60 19.0 9,662,000 136

02/09/07 7.1 6,419 45 9,481 89 off NM NA 15,705,345 16,942 off off NA 9,722,000 141

02/10/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/11/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/12/07 18.8 6,468 43 9,580 88 off NM NA 15,853,345 17,102 off off NA 9,878,000 138

02/13/07 5.7 6,483 44 9,611 91 off NM NA 15,899,345 17,151 off off NA 9,926,000 140

02/14/07 5.6 6,497 42 9,640 86 off NM NA 15,942,345 17,198 off off NA 9,972,000 137

02/15/07 5.4 6,512 46 9,669 90 off NM NA 15,986,345 17,245 off off NA 10,017,000 139

02/16/07 6.1 6,528 44 9,703 93 NM NM NA 16,036,345 17,299 7.00 3.00 17.0 10,066,000 134

02/17/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/18/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/19/07 17.9 6,575 44 9,797 88 NM NM NA 16,177,345 17,451 8.50 3.00 18.0 10,217,000 141

02/20/07 5.0 6,588 43 9,823 87 NM NM NA 16,216,345 17,493 9.00 3.00 18.0 10,258,000 137

02/21/07 4.6 6,599 40 9,842 69 NM NM NA 16,246,345 17,526 9.25 3.50 19.0 10,295,000 134

02/22/07 7.5 6,619 44 9,872 67 NM NM NA 16,296,345 17,580 9.75 3.25 20.0 10,358,000 140

02/23/07 3.7 6,629 45 9,891 86 NM NM NA 16,325,345 17,611 10.00 3.25 20.0 10,388,000 135

02/24/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/25/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/26/07 20.4 6,681 42 9,997 87 off NM NA 16,483,345 17,781 off off NA 10,554,000 136

02/27/07 6.0 6,697 44 10,028 86 off NM NA 16,530,345 17,832 off off NA 10,602,000 133

02/28/07 6.1 6,713 44 10,060 87 off NM NA 16,578,345 17,884 off off NA 10,652,000 137

03/01/07 5.3 6,726 41 10,087 85 NM NM NA 16,618,345 17,927 11.25 3.00 22.0 10,697,000 142

03/02/07 9.0 6,749 43 10,132 83 NM NM NA 16,686,345 18,000 11.30 3.00 21.0 10,767,000 130

03/03/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/04/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

43

44

45

39

40

41

42

37

38

Week Date
Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)

A-6

Op 

Time

Well 1 

Totalizer

Well 1 

Average 

Flow

Well 2 

Totalizer 

Well 2 

Average 

Flow 

Vessel A 

Instant 

Flowrate

Vessel A 

Totalizer

Vessel A 

Calculated 

Flowrate

Cum total 

Throughput

Cum total 

Bed Volume

Vessel A 

ΔP

Vessel B 

ΔP

System 

ΔP

Effluent 

Totalizer

Effluent 

Calculated 

Flowrate

hr kgal gpm kgal gpm gpm gal gpm gal BV psi psi psig gal gpm

03/05/07 24.3 6,811 43 10,255 84 NM NM NA 16,871,345 18,200 12.25 3.00 23.0 10,960,000 132

03/06/07 8.7 6,832 40 10,297 80 NM NM NA 16,934,345 18,268 12.50 3.00 23.0 11,028,000 130

03/07/07 6.2 6,855 62 10,319 59 NM NM NA 16,979,345 18,316 13.00 3.00 22.0 11,077,000 132

03/08/07 6.5 6,864 23 10,361 108 off NM NA 17,030,345 18,371 off off NA 11,128,000 131

03/09/07 5.1 6,878 46 10,387 85 NM NM NA 17,070,345 18,415 14.50 3.00 24.0 11,168,000 131

03/10/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/11/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/12/07 23.2 6,939 44 10,500 81 NM NM NA 17,244,345 18,602 off off NA 11,347,000 129

03/13/07 6.3 6,954 40 10,531 82 off NM NA 17,290,345 18,652 off off NA 11,395,000 127

03/14/07 5.0 6,964 33 10,559 93 NM NM NA 17,322,545 18,687 4.00 3.25 14.0 11,432,000 123

03/15/07 6.2 6,980 43 10,593 91 NM NM NA 17,372,545 18,741 5.00 3.25 14.0 11,479,000 126

03/16/07 5.3 6,994 44 10,622 91 NM NM NA 17,415,545 18,787 5.50 3.25 14.0 11,523,000 138

03/17/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/18/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/19/07 20.6 7,049 44 10,731 88 off NM NA 17,579,545 18,964 off off NA 11,690,000 135

03/20/07 6.3 7,070 56 10,765 90 off NM NA 17,634,545 19,023 off off NA 11,742,000 138

03/21/07 6.0 7,081 31 10,796 86 NM NM NA 17,676,545 19,069 6.75 3.25 16.0 11,790,000 133

03/22/07 6.0 7,096 42 10,829 92 151 12,208,714 NA 17,724,545 19,120 7.00 3.00 17.0 11,839,000 136

03/23/07 6.5 7,114 46 10,864 90 133 12,261,234 135 17,777,065 19,177 6.50 3.00 18.0 11,894,000 141

03/24/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/25/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/26/07 21.0 7,169 44 10,976 89 136 12,431,523 135 17,947,354 19,361 8.00 3.00 17.0 12,067,000 137

03/27/07 6.4 7,186 44 11,010 89 off 12,482,936 134 17,998,767 19,416 off off NA 12,119,000 135

03/28/07 6.6 7,202 40 11,044 86 off 12,535,977 134 18,051,808 19,473 off off NA 12,172,000 134

03/29/07 6.2 7,219 46 11,077 89 off 12,573,640 101 18,089,471 19,514 off off NA 12,222,000 134

03/30/07 5.5 7,233 42 11,108 94 147 12,607,263 102 18,123,094 19,550 9.25 3.25 19.0 12,266,000 133

03/31/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

04/01/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

04/02/07(b) 20.1 7,285 43 11,213 87 off NM NA 18,280,094 19,720 off off NA 12,427,000 133

04/03/07 6.0 7,301 44 11,244 86 off 12,607,264 NA 18,327,094 19,770 off off NA 12,473,000 128

04/04/07 7.1 7,318 40 11,281 87 127 12,665,447 137 18,385,277 19,833 10.00 3.25 19.0 12,530,000 134

04/05/07 6.4 7,336 47 11,315 89 off 12,717,676 136 18,437,506 19,889 off off NA 12,580,000 130

04/06/07 6.1 7,351 41 11,346 85 133 12,766,714 134 18,486,544 19,942 10.50 3.25 20.0 12,627,000 128

04/07/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

04/08/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

04/09/07 22.3 7,409 43 11,463 87 off 12,945,850 134 18,665,680 20,136 off off NA 12,797,000 127

04/10/07 6.4 7,425 42 11,494 81 138 12,995,265 129 18,715,095 20,189 11.00 3.25 21.0 12,844,000 122

04/11/07 8.1 7,446 43 11,539 93 136 13,057,666 117 18,771,996 20,250 3.75 3.00 14.0 12,903,000 121

04/12/07 7.2 7,465 44 11,578 90 133 13,115,840 135 18,830,170 20,313 4.75 3.00 16.0 12,957,000 125

04/13/07 6.5 7,482 44 11,612 87 off 13,167,287 132 18,881,617 20,369 off off NA 13,008,000 131

04/14/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

04/15/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

04/16/07 18.6 7,530 43 11,711 89 off 13,316,668 134 19,030,998 20,530 off off NA 13,153,000 130

04/17/07 5.7 7,545 44 11,741 88 NM 13,363,396 137 19,077,726 20,580 8.50 3.50 18.0 13,197,000 129

04/18/07 6.1 7,561 44 11,774 90 off 13,412,627 135 19,126,957 20,633 off off NA 13,245,000 131

04/19/07 5.5 7,576 45 11,804 91 off 13,457,323 135 19,171,653 20,681 off off NA 13,288,000 130

04/20/07 6.1 7,592 44 11,836 87 off 13,507,175 136 19,221,505 20,735 off off NA 13,336,000 131

04/21/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

04/22/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

04/23/07 18.7 7,640 43 11,935 88 off 13,659,664 136 19,373,994 20,900 off off NA 13,480,000 128

04/24/07 5.5 7,654 42 11,965 91 141 13,705,116 138 19,419,446 20,949 8.00 3.00 21.0 13,523,000 130

04/25/07 6.2 7,670 43 11,997 86 141 13,756,759 139 19,471,089 21,004 8.00 4.00 23.0 13,571,000 129

04/26/07 5.2 7,685 48 12,025 90 142 13,799,149 136 19,513,479 21,050 8.00 4.00 22.0 13,611,000 128

04/27/07 6.9 7,702 41 12,062 89 off 13,854,073 133 19,568,403 21,109 off off NA 13,662,000 123

04/28/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

04/29/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

04/30/07 18.5 7,749 42 12,159 87 off 13,997,104 129 19,711,434 21,264 off off NA 13,804,000 128

05/01/07 5.9 7,765 45 12,191 90 off 14,045,011 135 19,759,341 21,315 off off NA 13,851,000 133

05/02/07 6.1 7,780 41 12,222 85 134 14,093,324 132 19,807,654 21,367 8.50 3.25 22.0 13,897,000 126

05/03/07 6.6 7,799 48 12,257 88 127 14,146,364 134 19,860,694 21,425 9.00 3.25 22.0 13,949,000 131

05/04/07 5.7 7,813 41 12,288 91 off 14,189,364 126 19,903,694 21,471 off off NA 13,993,000 129

05/05/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/06/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

51

52

53

54

47

48

49

50

46

Week Date
Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)

A-7

Op 

Time

Well 1 

Totalizer

Well 1 

Average 

Flow

Well 2 

Totalizer 

Well 2 

Average 

Flow 

Vessel A 

Instant 

Flowrate

Vessel A 

Totalizer

Vessel A 

Calculated 

Flowrate

Cum total 

Throughput

Cum total 

Bed Volume

Vessel A 

ΔP

Vessel B 

ΔP

System 

ΔP

Effluent 

Totalizer

Effluent 

Calculated 

Flowrate

hr kgal gpm kgal gpm gpm gal gpm gal BV psi psi psig gal gpm

05/07/07 19.2 7,862 43 12,370 71 off 14,340,963 132 20,055,293 21,635 off off NA 14,140,000 128

05/08/07 6.7 7,879 42 12,405 87 139 14,393,684 131 20,108,014 21,691 10.00 3.25 21.0 14,191,000 127

05/09/07 4.2 7,889 40 12,426 83 off 14,427,039 132 20,141,369 21,727 off off NA 14,222,000 123

05/10/07 9.6 7,916 47 12,480 94 off 14,502,307 142 20,223,435 21,816 off off NA 14,293,000 123

05/11/07 6.1 7,932 44 12,513 90 off 14,551,446 134 20,272,574 21,869 off off NA 14,341,000 131

05/12/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/13/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/14/07 21.0 7,987 44 12,626 90 off 14,720,824 134 20,441,952 22,052 off off NA 14,504,000 129

05/15/07 6.1 8,003 44 12,658 87 133 14,770,196 135 20,491,324 22,105 6.75 3.25 18.5 14,550,000 126

05/16/07 7.3 8,023 46 12,697 89 off 14,828,617 133 20,549,745 22,168 off off NA 14,606,000 128

05/17/07 9.1 8,046 42 12,745 88 off 14,900,999 133 20,622,127 22,246 off off NA 14,675,000 126

05/18/07 7.0 8,065 45 12,782 88 137 14,956,630 132 20,677,758 22,306 8.25 3.25 18.0 14,727,000 124

05/19/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/20/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/21/07 29.3 8,140 43 12,917 77 off 15,185,220 130 20,906,348 22,553 off off NA 14,943,000 123

05/22/07 9.8 8,165 43 12,967 85 off 15,262,796 132 20,983,924 22,636 off off NA 15,015,000 122

05/23/07 6.6 8,182 43 13,001 86 off 15,314,845 131 21,035,973 22,693 off off NA 15,064,000 124

05/24/07 6.5 8,198 41 13,034 85 137 15,366,779 133 21,087,907 22,749 5.00 3.50 20.0 15,112,000 123

05/25/07 6.6 8,215 43 13,069 88 129 15,419,480 133 21,140,608 22,805 4.75 3.00 20.0 15,162,000 126

05/26/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/27/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/28/07 19.9 8,265 NA 13,172 86 off 15,574,914 130 21,296,042 22,973 off off NA 15,310,000 124

05/29/07(e) 11.1 NM NA 13,231 89 off 15,634,344 89 21,355,472 23,037 off off NA 15,369,000 NA

05/30/07 7.7 NM NA 13,271 87 97 15,675,075 88 21,396,203 23,081 5.50 1.25 16.0 15,410,000 NA

05/31/07 11.1 NM NA 13,330 89 89 15,735,097 90 21,456,225 23,146 4.75 1.00 17.0 15,469,000 NA

06/01/07 4.7 8,265 NA 13,355 89 94 15,760,259 89 21,481,387 23,173 4.75 1.50 17.0 15,494,000 NA

06/02/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/03/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/04/07 23.0 8,315 36 13,472 85 138 15,916,287 113 21,637,415 23,341 9.00 3.25 20.0 15,655,000 117

06/05/07 7.4 8,334 43 13,510 86 off 15,966,792 114 21,687,920 23,396 off off NA 15,711,000 126

06/06/07 17.4 8,376 40 13,587 74 133 16,071,075 100 21,792,203 23,508 4.00 2.50 21.0 15,827,000 111

06/07/07 8.5 8,400 47 13,636 96 NM 16,133,400 122 21,854,528 23,576 4.00 2.00 13.0 15,884,000 112

06/08/07 8.9 8,418 34 13,689 99 off 16,203,380 131 21,924,508 23,651 off off NA 15,951,000 125

06/09/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/10/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/11/07 21.8 8,482 49 13,818 99 off 16,384,253 138 22,105,381 23,846 off off NA 16,114,000 125

06/12/07 10.1 8,512 50 13,876 96 136 16,476,644 152 22,197,772 23,946 5.00 2.75 22.0 16,200,000 142

06/13/07 5.8 8,528 46 13,909 95 134 16,525,897 142 22,247,025 23,999 4.75 2.75 23.0 16,248,000 138

06/14/07 9.7 8,553 43 13,948 67 127 16,599,937 127 22,321,065 24,079 9.00 3.00 23.0 16,321,000 125

06/15/07 11.9 8,582 41 14,003 77 off 16,688,715 124 22,409,843 24,175 off off NA 16,408,000 122

06/16/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/17/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/18/07(f) 18.1 8,628 42 14,095 85 127 16,807,883 110 22,529,011 24,303 3.00 2.75 31.0 16,545,000 126

06/19/07 4.0 8,637 38 14,113 75 off 16,835,554 115 22,556,682 24,333 off off NA 16,573,000 117

06/20/07 9.3 8,660 41 14,159 82 123 16,906,650 127 22,627,778 24,410 7.00 2.75 32.0 16,646,000 130

06/21/07 8.6 8,682 43 14,202 83 off 16,972,763 128 22,693,891 24,481 off off NA 16,715,000 134

06/22/07 6.5 8,700 46 14,234 82 off 17,023,646 130 22,744,774 24,536 off off NA 16,767,000 133

06/23/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/24/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/25/07 21.3 8,758 45 14,315 64 109 17,153,970 102 22,875,098 24,676 2.00 2.00 37.0 16,939,000 135

06/26/07(g) 4.6 8,769 40 14,336 77 117 17,189,009 128 22,910,137 24,714 NM 2.75 37.0 16,976,000 135

06/27/07 6.3 8,784 39 14,369 87 126 17,193,979 NA 22,958,137 24,766 NM 3.75 17.0 17,017,000 108

06/28/07 8.8 8,806 42 14,413 83 off 17,195,169 NA 23,024,137 24,837 NM off NA 17,084,000 127

06/29/07 6.5 8,822 41 14,447 87 off 17,245,048 128 23,074,016 24,891 NM off NA 17,140,000 144

06/30/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/01/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/02/07 21.0 8,874 41 14,553 84 off 17,397,355 121 23,226,323 25,055 NM off NA 17,295,000 123

07/03/07 7.0 8,890 38 14,586 79 off 17,446,997 118 23,275,965 25,109 NM off NA 17,357,000 148

07/04/07 3.5 8,900 48 14,607 101 150 17,479,613 158 23,308,581 25,144 NM 3.00 23.0 17,378,000 101

07/05/07 7.9 8,920 42 14,648 86 off 17,540,551 129 23,369,519 25,210 NM off NA 17,441,000 133

07/06/07 4.0 8,930 42 14,670 92 134 17,572,300 133 23,401,268 25,244 NM 3.00 20.0 17,474,000 138

07/07/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/08/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

63

59

60

61

62

55

56

57

58

Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet

Week Date
Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)

A-8

Op 

Time

Well 1 

Totalizer

Well 1 

Average 

Flow

Well 2 

Totalizer 

Well 2 

Average 

Flow 

Vessel A 

Instant 

Flowrate

Vessel A 

Totalizer

Vessel A 

Calculated 

Flowrate

Cum total 

Throughput

Cum total 

Bed Volume

Vessel A 

ΔP

Vessel B 

ΔP

System 

ΔP

Effluent 

Totalizer

Effluent 

Calculated 

Flowrate

hr kgal gpm kgal gpm gpm gal gpm gal BV psi psi psig gal gpm

05/07/07 19.2 7,862 43 12,370 71 off 14,340,963 132 20,055,293 21,635 off off NA 14,140,000 128

05/08/07 6.7 7,879 42 12,405 87 139 14,393,684 131 20,108,014 21,691 10.00 3.25 21.0 14,191,000 127

05/09/07 4.2 7,889 40 12,426 83 off 14,427,039 132 20,141,369 21,727 off off NA 14,222,000 123

05/10/07 9.6 7,916 47 12,480 94 off 14,502,307 142 20,223,435 21,816 off off NA 14,293,000 123

05/11/07 6.1 7,932 44 12,513 90 off 14,551,446 134 20,272,574 21,869 off off NA 14,341,000 131

05/12/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/13/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/14/07 21.0 7,987 44 12,626 90 off 14,720,824 134 20,441,952 22,052 off off NA 14,504,000 129

05/15/07 6.1 8,003 44 12,658 87 133 14,770,196 135 20,491,324 22,105 6.75 3.25 18.5 14,550,000 126

05/16/07 7.3 8,023 46 12,697 89 off 14,828,617 133 20,549,745 22,168 off off NA 14,606,000 128

05/17/07 9.1 8,046 42 12,745 88 off 14,900,999 133 20,622,127 22,246 off off NA 14,675,000 126

05/18/07 7.0 8,065 45 12,782 88 137 14,956,630 132 20,677,758 22,306 8.25 3.25 18.0 14,727,000 124

05/19/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/20/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/21/07 29.3 8,140 43 12,917 77 off 15,185,220 130 20,906,348 22,553 off off NA 14,943,000 123

05/22/07 9.8 8,165 43 12,967 85 off 15,262,796 132 20,983,924 22,636 off off NA 15,015,000 122

05/23/07 6.6 8,182 43 13,001 86 off 15,314,845 131 21,035,973 22,693 off off NA 15,064,000 124

05/24/07 6.5 8,198 41 13,034 85 137 15,366,779 133 21,087,907 22,749 5.00 3.50 20.0 15,112,000 123

05/25/07 6.6 8,215 43 13,069 88 129 15,419,480 133 21,140,608 22,805 4.75 3.00 20.0 15,162,000 126

05/26/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/27/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

05/28/07 19.9 8,265 NA 13,172 86 off 15,574,914 130 21,296,042 22,973 off off NA 15,310,000 124

05/29/07(e) 11.1 NM NA 13,231 89 off 15,634,344 89 21,355,472 23,037 off off NA 15,369,000 NA

05/30/07 7.7 NM NA 13,271 87 97 15,675,075 88 21,396,203 23,081 5.50 1.25 16.0 15,410,000 NA

05/31/07 11.1 NM NA 13,330 89 89 15,735,097 90 21,456,225 23,146 4.75 1.00 17.0 15,469,000 NA

06/01/07 4.7 8,265 NA 13,355 89 94 15,760,259 89 21,481,387 23,173 4.75 1.50 17.0 15,494,000 NA

06/02/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/03/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/04/07 23.0 8,315 36 13,472 85 138 15,916,287 113 21,637,415 23,341 9.00 3.25 20.0 15,655,000 117

06/05/07 7.4 8,334 43 13,510 86 off 15,966,792 114 21,687,920 23,396 off off NA 15,711,000 126

06/06/07 17.4 8,376 40 13,587 74 133 16,071,075 100 21,792,203 23,508 4.00 2.50 21.0 15,827,000 111

06/07/07 8.5 8,400 47 13,636 96 NM 16,133,400 122 21,854,528 23,576 4.00 2.00 13.0 15,884,000 112

06/08/07 8.9 8,418 34 13,689 99 off 16,203,380 131 21,924,508 23,651 off off NA 15,951,000 125

06/09/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/10/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/11/07 21.8 8,482 49 13,818 99 off 16,384,253 138 22,105,381 23,846 off off NA 16,114,000 125

06/12/07 10.1 8,512 50 13,876 96 136 16,476,644 152 22,197,772 23,946 5.00 2.75 22.0 16,200,000 142

06/13/07 5.8 8,528 46 13,909 95 134 16,525,897 142 22,247,025 23,999 4.75 2.75 23.0 16,248,000 138

06/14/07 9.7 8,553 43 13,948 67 127 16,599,937 127 22,321,065 24,079 9.00 3.00 23.0 16,321,000 125

06/15/07 11.9 8,582 41 14,003 77 off 16,688,715 124 22,409,843 24,175 off off NA 16,408,000 122

06/16/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/17/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/18/07(f) 18.1 8,628 42 14,095 85 127 16,807,883 110 22,529,011 24,303 3.00 2.75 31.0 16,545,000 126

06/19/07 4.0 8,637 38 14,113 75 off 16,835,554 115 22,556,682 24,333 off off NA 16,573,000 117

06/20/07 9.3 8,660 41 14,159 82 123 16,906,650 127 22,627,778 24,410 7.00 2.75 32.0 16,646,000 130

06/21/07 8.6 8,682 43 14,202 83 off 16,972,763 128 22,693,891 24,481 off off NA 16,715,000 134

06/22/07 6.5 8,700 46 14,234 82 off 17,023,646 130 22,744,774 24,536 off off NA 16,767,000 133

06/23/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/24/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

06/25/07 21.3 8,758 45 14,315 64 109 17,153,970 102 22,875,098 24,676 2.00 2.00 37.0 16,939,000 135

06/26/07(g) 4.6 8,769 40 14,336 77 117 17,189,009 128 22,910,137 24,714 NM 2.75 37.0 16,976,000 135

06/27/07 6.3 8,784 39 14,369 87 126 17,193,979 NA 22,958,137 24,766 NM 3.75 17.0 17,017,000 108

06/28/07 8.8 8,806 42 14,413 83 off 17,195,169 NA 23,024,137 24,837 NM off NA 17,084,000 127

06/29/07 6.5 8,822 41 14,447 87 off 17,245,048 128 23,074,016 24,891 NM off NA 17,140,000 144

06/30/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/01/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/02/07 21.0 8,874 41 14,553 84 off 17,397,355 121 23,226,323 25,055 NM off NA 17,295,000 123

07/03/07 7.0 8,890 38 14,586 79 off 17,446,997 118 23,275,965 25,109 NM off NA 17,357,000 148

07/04/07 3.5 8,900 48 14,607 101 150 17,479,613 158 23,308,581 25,144 NM 3.00 23.0 17,378,000 101

07/05/07 7.9 8,920 42 14,648 86 off 17,540,551 129 23,369,519 25,210 NM off NA 17,441,000 133

07/06/07 4.0 8,930 42 14,670 92 134 17,572,300 133 23,401,268 25,244 NM 3.00 20.0 17,474,000 138

07/07/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/08/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

63

59

60

61

62

55

56

57

58

Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet

Week Date
Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)

A-9

Op 

Time

Well 1 

Totalizer

Well 1 

Average 

Flow

Well 2 

Totalizer 

Well 2 

Average 

Flow 

Vessel A 

Instant 

Flowrate

Vessel A 

Totalizer

Vessel A 

Calculated 

Flowrate

Cum total 

Throughput

Cum total 

Bed Volume

Vessel A 

ΔP

Vessel B 

ΔP

System 

ΔP

Effluent 

Totalizer

Effluent 

Calculated 

Flowrate

hr kgal gpm kgal gpm gpm gal gpm gal BV psi psi psig gal gpm

07/09/07 16.5 8,984 54 14,746 77 131 17,712,225 141 23,541,193 25,395 NM 3.25 20.0 17,639,000 166

07/10/07 3.4 8,996 59 14,754 39 off 17,746,641 169 23,575,609 25,432 NM off NA 17,674,000 172

07/11/07 6.2 9,013 46 14,784 81 127 17,792,127 123 23,621,095 25,481 NM 3.25 22.0 17,728,000 146

07/12/07 3.6 9,025 56 14,799 69 off 17,814,176 102 23,643,144 25,505 NM off NA 17,763,000 162

07/13/07 8.8 9,047 42 14,844 85 off 17,868,274 102 23,697,242 25,563 NM off NA 17,832,000 131

07/14/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/15/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/16/07 20.6 9,096 40 14,944 81 121 17,988,299 97 23,817,267 25,693 NM 3.00 28.0 17,981,000 121

07/17/07 6.0 9,110 39 14,973 80 119 18,030,076 NA 23,859,044 25,738 NM 3.00 27.0 18,025,000 122

07/18/07 5.8 9,125 43 15,002 83 126 18,071,817 119 23,900,785 25,783 NM 3.00 28.0 18,068,000 123

07/19/07 8.0 9,145 42 15,041 81 off 18,105,859 71 23,934,827 25,820 NM off NA 18,128,000 125

07/20/07 7.0 9,161 38 15,073 76 off 18,151,511 109 23,980,479 25,869 NM off NA 18,177,000 117

07/21/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/22/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/23/07 21.3 9,209 38 15,169 75 off 18,288,678 107 24,117,646 26,017 NM off NA 18,323,000 114

07/24/07 6.2 9,220 30 15,200 83 off 18,333,928 122 24,162,896 26,066 NM off NA 18,371,000 129

07/25/07 6.8 9,240 49 15,230 73 122 18,378,456 109 24,207,424 26,114 NM 2.75 NA 18,417,000 112

07/26/07 4.4 9,251 42 15,253 87 129 18,408,857 115 24,237,825 26,147 NM 2.75 NA 18,451,000 129

07/27/07 5.6 9,264 39 15,280 80 119 18,446,970 113 24,275,938 26,188 NM 2.75 NA 18,492,000 122

07/28/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/29/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

07/30/07 26.3 9,320 36 15,388 68 104 18,552,090 67 24,381,058 26,301 NM 2.00 43.0 18,656,000 104

07/31/07 5.2 9,331 35 15,407 61 96 18,581,014 93 24,409,982 26,332 NM 2.00 48.0 18,688,000 102

08/01/07 8.0 9,351 42 15,449 87 129 18,638,733 120 24,467,701 26,394 NM 3.25 16.0 18,746,000 121

08/02/07 9.4 9,372 37 15,490 73 off 18,695,213 100 24,524,181 26,455 NM off NA 18,807,000 108

08/03/07 7.2 9,387 35 15,522 74 off 18,739,904 103 24,568,872 26,504 NM off NA 18,854,000 109

08/04/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

08/05/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

08/06/07 26.3 9,440 34 15,629 68 off 18,889,796 95 24,718,764 26,665 NM off NA 19,013,000 101

08/07/07 NA 9,453 42 15,656 87 128 18,928,797 125 24,757,765 26,707 NM 3.50 22.0 19,054,000 NA

08/08/07 10.8 9,480 42 15,711 85 off 19,009,365 124 24,838,333 26,794 NM off NA 19,136,000 127

08/09/07 9.4 9,505 44 15,760 87 off 19,077,285 120 24,906,253 26,868 NM off NA 19,209,000 129

08/10/07 7.2 9,523 42 15,796 83 NM 19,130,022 122 24,958,990 26,924 NM 3.50 22.0 19,263,000 125

08/11/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

08/12/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

08/13/07 25.7 9,587 42 15,866 45 117 19,315,766 120 25,144,734 27,125 NM 3.00 27.0 19,456,000 125

08/14/07 9.1 9,610 42 15,880 26 off 19,378,550 115 25,207,518 27,193 NM off NA 19,523,000 123

08/15/07 11.2 9,638 42 15,935 82 114 19,458,124 118 25,287,092 27,278 NM off NA 19,608,000 126

08/16/07 7.6 9,653 33 15,973 83 off 19,507,750 109 25,336,718 27,332 NM off NA 19,661,000 116

08/17/07(e) 8.0 NM NA 16,014 85 89 19,547,970 84 25,376,938 27,375 NM 1.00 18.5 19,704,000 NA

08/18/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

08/19/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

08/20/07 40.9 9,653 NA 16,212 81 84 19,742,141 79 25,571,109 27,585 NM 1.00 22.0 19,911,000 NA

08/21/07 10.3 9,675 36 16,259 76 off 19,806,769 105 25,635,737 27,655 NM off NA 19,980,000 112

08/22/07 8.1 9,695 41 16,299 82 off 19,863,941 118 25,692,909 27,716 NM off NA 20,041,000 126

08/23/07 7.1 9,713 42 16,333 80 off 19,892,841 68 25,721,809 27,747 NM off NA 20,094,000 124

08/24/07 6.9 9,730 41 16,369 87 130 19,941,561 118 25,770,529 27,800 12.00 3.25 24.0 20,146,000 126

08/25/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

08/26/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

08/27/07 22.9 9,798 49 16,488 87 119 20,099,035 115 25,928,003 27,970 12.00 3.00 24.0 20,310,000 119

08/28/07 7.0 9,807 21 16,525 88 124 20,147,646 116 25,976,614 28,022 11.50 2.75 22.0 20,363,000 126

08/29/07 5.7 9,821 41 16,554 85 119 20,187,584 117 26,016,552 28,065 1.25 3.25 23.0 20,404,000 120

08/30/07 6.0 9,838 47 16,587 92 128 20,228,747 114 26,057,715 28,110 4.75 3.00 15.0 20,444,000 111

08/31/07 7.4 9,858 45 16,628 92 off 20,282,897 122 26,111,865 28,168 off off NA 20,503,000 133

09/01/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/02/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/03/07 19.0 9,909 45 16,735 94 125 20,405,246 107 26,234,214 28,300 4.00 3.00 17.0 20,647,000 126

09/04/07 5.9 9,926 48 16,768 93 off 20,447,587 120 26,276,555 28,346 off off NA 20,692,000 127

09/05/07 5.6 9,941 45 16,799 92 off 20,488,515 122 26,317,483 28,390 off off NA 20,735,000 128

09/06/07 5.5 9,956 45 16,830 94 off 20,529,216 123 26,358,184 28,434 off off NA 20,779,000 133

09/07/07 5.6 9,971 45 16,862 95 off 20,571,012 124 26,399,980 28,479 off off NA 20,827,000 143

09/08/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/09/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

71

72

67

68

69

70

64

65

66

Week Date
Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)

A-10

Op 

Time

Well 1 

Totalizer

Well 1 

Average 

Flow

Well 2 

Totalizer 

Well 2 

Average 

Flow 

Vessel A 

Instant 

Flowrate

Vessel A 

Totalizer

Vessel A 

Calculated 

Flowrate

Cum total 

Throughput

Cum total 

Bed Volume

Vessel A 

ΔP

Vessel B 

ΔP

System 

ΔP

Effluent 

Totalizer

Effluent 

Calculated 

Flowrate

hr kgal gpm kgal gpm gpm gal gpm gal BV psi psi psig gal gpm

09/10/07 20.1 10,025 45 16,974 93 133 20,718,270 122 26,547,238 28,638 5.00 3.50 15.0 20,979,000 126

09/11/07 6.6 10,043 45 17,011 93 off 20,766,487 122 26,595,455 28,690 off off NA 21,030,000 129

09/12/07 5.8 10,058 43 17,044 95 129 20,809,124 123 26,638,092 28,736 4.75 3.00 14.0 21,075,000 129

09/13/07 6.4 10,076 47 17,079 91 off 20,857,474 126 26,686,442 28,788 off off NA 21,127,000 135

09/14/07 5.7 10,076 NA 17,112 96 off 20,907,902 147 26,736,870 28,842 off off NA 21,160,000 NA

09/15/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/16/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/17/07 22.7 10,124 35 17,233 89 off 21,046,413 102 26,875,381 28,992 off off NA 21,329,000 124

09/18/07 6.0 10,139 42 17,265 89 135 21,090,970 124 26,919,938 29,040 12.00 3.50 25.0 21,374,000 125

09/19/07 4.1 10,150 45 17,286 85 134 21,120,539 120 26,949,507 29,072 13.00 3.25 25.0 21,406,000 130

09/20/07(b) 8.3 10,170 40 17,328 84 off NM NA 27,011,507 29,139 off off NA 21,468,000 124

09/21/07 7.1 10,187 40 17,361 77 129 21,137,614 NA 27,061,507 29,193 15.00 2.75 32.0 21,518,000 117

09/22/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/23/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/24/07 27.7 10,255 41 17,494 80 124 21,329,721 116 27,253,614 29,400 15.00 3.00 25.0 21,712,000 117

09/25/07 5.5 10,269 42 17,521 82 127 21,369,613 121 27,293,506 29,443 15.00 3.00 27.0 21,752,000 121

09/26/07 4.0 10,280 46 17,541 83 off 21,398,946 122 27,322,839 29,474 off off NA 21,787,000 146

09/27/07 8.4 10,300 40 17,555 28 off 21,460,204 122 27,384,097 29,541 off off NA 21,843,000 111

09/28/07 4.7 10,312 43 17,578 82 122 21,496,344 128 27,420,237 29,580 15.00 3.00 26.0 21,878,000 124

09/29/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

09/30/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/01/07 19.0 10,359 41 17,673 83 off 21,627,930 115 27,551,823 29,721 off off NA 22,017,000 122

10/02/07 8.6 10,380 41 17,715 81 off 21,677,835 97 27,601,728 29,775 off off NA 22,079,000 120

10/03/07 4.3 10,391 43 17,738 89 137 21,712,004 132 27,635,897 29,812 10.00 3.50 21.0 22,110,000 120

10/04/07 7.7 10,411 43 17,778 87 off 21,770,053 126 27,693,946 29,875 off off NA 22,168,000 126

10/05/07 6.0 10,426 42 17,810 89 130 21,816,109 128 27,740,002 29,924 12.50 3.00 23.0 22,214,000 128

10/06/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/07/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/08/07 20.2 10,477 42 17,912 84 133 21,967,949 125 27,891,842 30,088 15.00 3.00 27.0 22,365,000 125

10/09/07 5.7 10,490 38 17,937 73 131 22,007,388 115 27,931,281 30,131 15.00 3.00 28.0 22,405,000 117

10/10/07 4.8 10,503 45 17,965 97 135 22,046,595 136 27,970,488 30,173 15.00 3.00 27.0 22,443,000 132

10/11/07 6.0 10,518 42 17,995 83 129 22,090,796 123 28,014,689 30,221 15.00 3.00 29.0 22,486,000 119

10/12/07 8.8 10,540 42 18,038 81 133 22,159,015 129 28,082,908 30,294 7.50 3.50 19.0 22,550,000 121

10/13/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/14/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/15/07 20.6 10,592 42 18,142 84 off 22,313,599 125 28,237,492 30,461 off off NA 22,702,000 123

10/16/07 5.7 10,605 38 18,171 85 126 22,355,656 123 28,279,549 30,507 15.00 3.00 31.0 22,742,000 117

10/17/07 7.1 10,626 49 18,205 80 off 22,407,506 122 28,331,399 30,562 off off NA 22,793,000 120

10/18/07 5.8 10,636 29 18,235 86 off 22,451,268 126 28,375,161 30,610 off off NA 22,835,000 121

10/19/07 6.3 10,653 45 18,266 82 129 22,497,196 122 28,421,089 30,659 15.00 3.25 30.0 22,882,000 124

10/20/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/21/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/22/07 19.5 10,698 38 18,361 81 off 22,619,311 104 28,543,204 30,791 off off NA 23,023,000 121

10/23/07 9.0 10,715 31 18,404 80 off 22,677,133 107 28,601,026 30,853 off off NA 23,079,000 104

10/24/07 3.9 10,723 34 18,422 77 97 22,697,575 87 28,621,468 30,875 14.50 1.75 25.0 23,105,000 NA

10/25/07(e) 5.5 10,726 9 18,460 115 off 22,738,447 124 28,662,340 30,919 off off NA 23,146,000 124

10/26/07 10.5 10,726 NA 18,505 71 94 22,783,100 71 28,706,993 30,968 14.00 1.75 20.0 23,191,000 NA

10/27/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/28/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

10/29/07 25.8 10,777 33 18,624 77 off 22,950,872 108 28,874,765 31,149 off off NA 23,360,000 109

10/30/07 5.0 10,789 40 18,647 77 128 22,985,353 115 28,909,246 31,186 15.00 2.75 35.0 23,395,000 117

10/31/07(b) 9.1 10,809 37 18,687 73 off NM NA 28,969,246 31,251 off off NA 23,460,000 119

11/01/07 4.5 10,819 37 18,708 78 124 NM NA 29,000,246 31,284 15.00 2.50 36.0 23,493,000 122

11/02/07 6.2 10,833 38 18,735 73 123 NM NA 29,041,246 31,328 15.00 2.75 37.0 23,537,000 118

11/03/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/04/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/05/07 27.0 10,896 39 18,850 71 off NM NA 29,219,246 31,520 off off NA 23,722,000 114

11/06/07(h) 7.2 10,910 32 NM NA 115 NM NA 29,267,246 31,572 15.00 2.75 36.0 23,770,000 111

11/07/07 5.5 10,922 36 NM NA 109 NM NA 29,305,246 31,613 15.00 2.75 35.0 23,808,000 115

11/08/07 5.3 10,933 35 NM NA off NM NA 29,342,246 31,653 off off NA 23,845,000 116

11/09/07 7.4 10,949 36 NM NA 107 NM NA 29,394,246 31,709 15.00 2.00 39.0 23,897,000 117

11/10/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/11/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

79

80

81

75

76

77

78

73

74

Week Date
Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)

A-11

Op 

Time

Well 1 

Totalizer

Well 1 

Average 

Flow

Well 2 

Totalizer 

Well 2 

Average 

Flow 

Vessel A 

Instant 

Flowrate

Vessel A 

Totalizer

Vessel A 

Calculated 

Flowrate

Cum total 

Throughput

Cum total 

Bed Volume

Vessel A 

ΔP

Vessel B 

ΔP

System 

ΔP

Effluent 

Totalizer

Effluent 

Calculated 

Flowrate

hr kgal gpm kgal gpm gpm gal gpm gal BV psi psi psig gal gpm

11/12/07 22.1 11,009 45 NM NA off NM NA 29,574,246 31,903 off off NA 24,077,000 136

11/13/07 8.6 11,031 43 NM NA 119 NM NA 29,647,246 31,982 9.00 4.00 21.0 24,150,000 141

11/14/07 5.5 11,046 45 NM NA off NM NA 29,695,246 32,034 off off NA 24,198,000 145

11/15/07 5.8 11,061 43 NM NA off NM NA 29,744,246 32,087 off off NA 24,247,000 141

11/16/07 6.5 11,076 38 NM NA 121 NM NA 29,814,246 32,162 10.00 3.25 25.0 24,302,000 141

11/17/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/18/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/19/07 18.5 11,123 42 19,183 NA off NM NA 29,967,246 32,327 off off NA 24,455,000 138

11/20/07 5.8 11,138 43 19,214 89 off NM NA 30,013,246 32,377 off off NA 24,503,000 138

11/21/07 3.9 11,148 43 19,234 85 off NM NA 30,043,246 32,409 off off NA 24,535,000 137

11/22/07 10.0 11,172 40 19,283 82 off NM NA 30,116,246 32,488 off off NA 24,613,000 130

11/23/07 6.7 11,188 40 19,316 82 off NM NA 30,165,246 32,541 off off NA 24,665,000 129

11/24/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/25/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

11/26/07 18.8 11,232 39 19,407 81 NM NM NA 30,300,246 32,686 10.00 3.00 33.0 24,808,000 127

11/27/07 8.2 11,252 41 19,447 81 129 NM NA 30,360,246 32,751 10.00 3.25 31.0 24,872,000 130

11/28/07 6.4 11,267 39 19,477 78 off NM NA 30,405,246 32,800 off off NA 24,920,000 125

11/29/07 5.0 11,279 40 19,503 87 off NM NA 30,443,246 32,841 off off NA 24,960,000 133

11/30/07

12/01/07

12/02/07

12/03/07

12/04/07

12/05/07

12/06/07

12/07/07

12/08/07

12/09/07

12/10/07

12/11/07

12/12/07

12/13/07

12/14/07

12/15/07

12/16/07

12/17/07 0.0 11,558 35 20,065 70 off NM NA 30,443,246 32,841 off off NA 25,065,000 NA

12/18/07 4.4 11,568 38 20,089 91 off NM NA 30,477,246 32,877 off off NA 25,065,000 NA

12/19/07 9.9 11,591 39 20,130 69 off NM NA 30,541,246 32,946 off off NA 25,136,000 120

12/20/07 7.1 11,607 38 20,161 73 off NM NA 30,588,246 32,997 off off NA 25,186,000 117

12/21/07 5.6 11,617 30 20,182 63 103 NM NA 30,619,246 33,030 2.00 2.00 41.0 25,224,000 113

12/22/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/23/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/24/07 18.1 11,661 41 20,271 82 119 NM NA 30,752,246 33,174 9.50 3.00 32.0 25,346,000 112

12/25/07 10.4 11,680 30 20,321 80 off NM NA 30,821,246 33,248 off off NA 25,419,000 117

12/26/07 4.4 11,696 61 20,343 83 122 NM NA 30,859,246 33,289 9.00 3.00 31.0 25,449,000 114

12/27/07 6.6 11,712 40 20,375 81 118 NM NA 30,907,246 33,341 9.50 2.75 33.0 25,493,000 111

12/28/07 4.7 11,726 50 20,402 96 off NM NA 30,948,246 33,385 off off NA 25,530,000 131

12/29/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/30/07 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

12/31/07 21.8 11,771 34 20,490 67 118 NM NA 31,081,246 33,529 14.00 2.50 54.0 25,663,000 102

01/01/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/02/08 15.9 11,809 40 20,568 82 off NM NA 31,197,246 33,654 off off NA 25,781,000 124

01/03/08 5.7 11,823 41 20,596 82 off NM NA 31,239,246 33,699 off off NA 25,822,000 120

01/04/08 7.5 11,834 24 20,626 67 116 NM NA 31,280,246 33,744 7.50 2.00 55.0 25,868,000 102

01/05/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/06/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/07/08 27.3 11,892 35 20,719 57 115 NM NA 31,431,246 33,906 5.00 2.00 53.0 26,015,000 NA

01/08/08 7.6 11,907 33 20,750 68 111 NM NA 31,477,246 33,956 5.25 2.00 51.0 26,057,000 NA

01/09/08 6.8 11,922 37 20,777 66 off NM NA 31,519,246 34,001 off off NA 26,096,000 NA

01/10/08 7.6 11,937 33 20,810 72 113 NM NA 31,567,246 34,053 4.75 2.00 47.0 26,141,000 NA

01/11/08 6.7 11,953 40 20,839 72 109 NM NA 31,612,246 34,102 4.00 2.00 43.0 26,182,000 102

01/12/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/13/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

87

88

89

90

83

84

85

86

82

System out of service and being bypassed because storage tank is being maintained

Week Date
Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)

A-12

Op 

Time

Well 1 

Totalizer

Well 1 

Average 

Flow

Well 2 

Totalizer 

Well 2 

Average 

Flow 

Vessel A 

Instant 

Flowrate

Vessel A 

Totalizer

Vessel A 

Calculated 

Flowrate

Cum total 

Throughput

Cum total 

Bed Volume

Vessel A 

ΔP

Vessel B 

ΔP

System 

ΔP

Effluent 

Totalizer

Effluent 

Calculated 

Flowrate

hr kgal gpm kgal gpm gpm gal gpm gal BV psi psi psig gal gpm

01/14/08 21.5 12,001 37 20,932 72 109 NM NA 31,753,246 34,254 4.00 2.50 41.0 26,310,000 NA

01/15/08 6.2 12,015 38 20,960 75 off NM NA 31,795,246 34,299 off off NA 26,349,000 105

01/16/08 6.4 12,030 39 20,988 73 off NM NA 31,838,246 34,345 off off NA 26,389,000 104

01/17/08 6.4 12,042 31 21,018 78 off NM NA 31,880,246 34,391 off off NA 26,432,000 112

01/18/08 8.9 12,063 39 21,053 66 NM NM NA 31,936,246 34,451 2.50 2.00 44.0 26,468,000 NA

01/19/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/20/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/21/08 17.0 12,109 45 21,152 97 off NM NA 32,081,246 34,608 off off NA 26,563,000 NA

01/22/08 3.4 12,118 44 21,173 103 137 NM NA 32,111,246 34,640 NM NM 17.0 26,588,000 123

01/23/08 6.6 12,136 45 21,211 96 off NM NA 32,167,246 34,700 off off NA 26,636,000 121

01/24/08 2.6 12,143 45 21,226 96 134 NM NA 32,189,246 34,724 NM 3.75 17.0 26,656,000 128

01/25/08 5.0 12,158 50 21,256 100 135 NM NA 32,234,246 34,773 NM 4.00 17.0 26,691,000 117

01/26/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/27/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

01/28/08 16.5 12,203 45 21,355 100 144 NM NA 32,378,246 34,928 6.00 4.00 16.0 26,808,000 118

01/29/08 5.4 12,215 37 21,382 83 off NM NA 32,417,246 34,970 off off NA 26,848,000 123

01/30/08 2.4 12,222 49 21,397 104 off NM NA 32,439,246 34,994 off off NA 26,864,000 111

01/31/08 6.2 12,234 32 21,433 97 138 NM NA 32,487,246 35,046 9.00 3.50 18.0 26,915,000 137

02/01/08 5.7 12,254 58 21,464 91 off NM NA 32,538,246 35,101 off off NA 26,945,000 NA

02/02/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/03/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/04/08 16.6 12,297 43 21,555 91 off NM NA 32,672,246 35,245 off off NA 27,074,000 130

02/05/08 5.0 12,309 40 21,582 90 130 NM NA 32,711,246 35,287 15.00 3.50 27.0 27,117,000 143

02/06/08 5.4 12,321 37 21,609 83 132 NM NA 32,750,246 35,329 15.00 3.50 30.0 27,153,000 111

02/07/08 3.9 12,332 47 21,629 85 128 NM NA 32,781,246 35,363 15.00 3.50 32.0 27,158,000 NA

02/08/08 7.1 12,346 33 21,665 85 136 NM NA 32,831,246 35,417 7.00 3.75 22.0 27,184,000 NA

02/09/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/10/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/11/08 18.5 12,398 47 21,767 92 off NM NA 32,985,246 35,583 off off NA 27,226,000 NA

02/12/08 5.3 12,411 41 21,795 88 134 NM NA 33,026,246 35,627 12.50 3.50 26.0 27,259,000 104

02/13/08 8.3 12,432 42 21,838 86 off NM NA 33,090,246 35,696 off off NA 27,287,000 NA

02/14/08 5.7 12,446 41 21,866 82 119 NM NA 33,132,246 35,741 15.00 3.00 35.0 27,320,000 NA

02/15/08 5.3 12,460 44 21,897 97 142 NM NA 33,177,246 35,790 6.00 3.50 16.0 27,340,000 NA

02/16/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/17/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/18/08 16.6 12,504 44 21,990 93 off NM NA 33,314,246 35,938 off off NA 27,412,000 NA

02/19/08(c) 5.7 12,519 44 22,021 91 off NM NA 33,360,246 35,987 off off NA NM NA

02/20/08 5.3 12,532 41 22,049 88 140 NM NA 33,401,246 36,032 10.50 4.00 26.0 NM NA

02/21/08 5.6 12,547 45 22,079 89 off NM NA 33,446,246 36,080 off off NA NM NA

02/22/08 5.3 12,560 41 22,107 88 off NM NA 33,487,246 36,124 off off NA NM NA

02/23/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/24/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

02/25/08 19.5 12,610 43 22,211 89 129 NM NA 33,641,246 36,290 11.00 3.00 24.0 NM NA

02/26/08 6.4 12,627 44 22,240 76 off NM NA 33,687,246 36,340 off off NA NM NA

02/27/08 3.3 12,636 45 22,265 126 144 NM NA 33,721,246 36,377 11.75 3.75 24.0 NM NA

02/28/08 21.4 12,696 47 22,391 98 127 NM NA 33,907,246 36,577 7.50 2.50 18.0 NM NA

02/29/08 10.4 12,726 48 22,440 79 131 NM NA 33,986,246 36,663 11.50 3.50 23.0 NM NA

03/01/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/02/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/03/08

03/04/08

03/05/08

03/06/08

03/07/08

03/08/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/09/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/10/08 0.0 12,881 46 22,757 94 off NM NA 33,986,246 36,663 off off NA 535,000

03/11/08 3.1 12,889 43 22,776 102 148 NM NA 34,013,246 36,692 9.00 3.75 22.0 565,000 161

03/12/08 4.6 12,902 47 22,789 47 off NM NA 34,039,246 36,720 off off NA 604,000 141

03/13/08 6.9 12,920 43 22,829 97 off NM NA 34,097,246 36,782 off off NA 665,000 147

03/14/08 4.9 12,933 44 22,856 92 139 NM NA 34,137,246 36,826 10.00 3.50 20.0 708,000 146

03/15/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/16/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

99

System was shutdown week of 03/03/08 due to valve issues

95

96

97

98

91

92

93

94

Week Date
Table A-1. EPA Arsenic Demonstration Project at Alvin, TX - Daily System Operation Log Sheet (Continued)

A-13

Op 

Time

Well 1 

Totalizer

Well 1 

Average 

Flow

Well 2 

Totalizer 

Well 2 

Average 

Flow 

Vessel A 

Instant 

Flowrate

Vessel A 

Totalizer

Vessel A 

Calculated 

Flowrate

Cum total 

Throughput

Cum total 

Bed Volume

Vessel A 

ΔP

Vessel B 

ΔP

System 

ΔP

Effluent 

Totalizer

Effluent 

Calculated 

Flowrate

hr kgal gpm kgal gpm gpm gal gpm gal BV psi psi psig gal gpm

03/17/08 14.9 12,976 48 22,938 92 141 NM NA 34,262,246 36,960 12.50 3.50 25.0 835,000 142

03/18/08 5.4 12,986 31 22,967 90 off NM NA 34,301,246 37,002 off off NA 879,000 136

03/19/08 6.9 13,004 43 23,005 92 139 NM NA 34,357,246 37,063 13.75 3.00 26.0 937,000 140

03/20/08 5.8 13,018 40 23,036 89 NM NM NA 34,402,246 37,111 15.00 3.50 27.0 985,000 138

03/21/08 3.7 13,018 0 23,056 90 off NM NA 34,422,246 37,133 off off NA 1,015,000 135

03/22/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/23/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/24/08 20.9 13,083 52 23,173 93 off NM NA 34,604,246 37,329 off off NA 1,192,000 141

03/25/08 5.0 13,096 43 23,201 93 143 NM NA 34,645,246 37,374 11.00 3.00 22.0 1,235,000 143

03/26/08 5.6 13,111 45 23,232 92 142 NM NA 34,691,246 37,423 11.00 3.00 22.0 1,283,000 143

03/27/08 7.0 13,129 43 23,269 88 off NM NA 34,746,246 37,482 off off NA 1,341,000 138

03/28/08 3.2 13,137 42 23,287 94 145 NM NA 34,772,246 37,511 12.00 3.00 21.0 1,368,000 141

03/29/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/30/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

03/31/08 20.9 13,191 43 23,399 89 off NM NA 34,938,246 37,690 off off NA 1,542,000 139

04/01/08 5.8 13,209 52 23,430 89 off NM NA 34,987,246 37,742 off off NA 1,590,000 138

04/02/08 5.7 13,220 32 23,460 88 139 NM NA 35,028,246 37,787 15.00 3.75 25.0 1,638,000 140

04/03/08 6.4 13,236 42 23,494 89 off NM NA 35,078,246 37,841 off off NA 1,690,000 135

04/04/08 6.4 13,252 42 23,527 86 off NM NA 35,127,246 37,893 off off NA 1,739,000 128

04/05/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

04/06/08 NA NM NA NM NA NM NM NA NA NA NM NM NA NM NA

04/07/08 21.1 13,308 44 23,646 94 140 NM NA 35,302,246 38,082 10.50 3.50 22.0 1,920,000 143

04/08/08 7.0 13,326 43 23,684 90 off NM NA 35,358,246 38,143 off off NA 1,979,000 140 103

100

101

102

Week Date

(a) Well 2 totalizer broken from 04/25/06 to 05/21/06. Throughput and BV estimated based on average flowrate of 125 gpm and respective operating time.

(b) Vessel A flowmeter and totalizer broken from 04/26/06 to 05/26/06, on 06/06/06, from 09/06/06 to 10/03/06, from 01/15/07 to 03/21/07,on 04/02/07, on 

09/20/07, and from 10/31/07 to 04/08/08. Throughput and BV estimated based on Wells 1 and 2 totalizers.

(c) Totalizer on treated water line broken from 04/25/06 to 07/10/06, from 08/21/06 to 09/17/06, and from 02/19/08 to 03/07/08. 

(d) No operational data taken from 06/12/06 to 06/19/06, from 09/04/06 to 09/05/06, and from 12/18/06 to 12/22/06.

(e) Well 1 totalizer broken from 05/29/07 to 05/31/07, on 08/17/07, and from 10/25/07 to 10/26/07.

(f) Hour meter broken from 06/18/07 to 08/06/07; operational hours estimated by dividing total volume from Wells 1 and 2 by flowrate readings from Vessel A 

flowmeter/totalizer. 

(g) Tank A pressure readings questionable from 06/26/07 to 08/23/07.

(h) Well 2 totalizer broken from 04/25/06 to 05/21/06. Throughput and BV estimated based on readings of effluent totalizer.

NA = not available. 

NM = not measured. 

off = well pumps not running when operator was onsite taking operational data. 
APPENDIX B

ANALYTICAL DATA
B-1 B-1 

Table B-1. Analytical Results from Long-Term Sampling, Alvin, TX

Parameter Unit

Bed Volume 10^3 - - - - - - - -

361 366 370 370 347 372 363 355 355 347 351 355 346 342 367 363

- - - - - - - - - - - - - - - -

Ammonia (as N) mg/L - - - - - - - - - - - - - - - -

Fluoride mg/L 1.2 1.4 1.3 1.3 - - - - 1.3 1.3 1.3 1.4 - - - -

Sulfate mg/L 1 2 2 2 - - - - 2 2 1 2 - - - -

Nitrate (as N) mg/L <0.05 <0.05 <0.05 <0.05 - - - - <0.05 <0.05 <0.05 <0.05 - - - -

48.5 42.6 <10 <10 48.2 46.0 10.0 <10 34.4 34.3 46.6 48.0 51.5 43.4 18.9 <10

- - - - - - - - - - - - - - - -

15.2 15.7 15.4 15.3 17.0 14.8 16.4 12.6 15.6 16.6 16.0 16.1 15.4 16.2 16.4 16.5

- - - - - - - - - - - - - - - -

0.6 0.3 0.5 0.4 0.3 0.4 0.2 0.2 0.8 0.3 0.2 0.2 0.3 0.5 1.2 0.5

- - - - - - - - - - - - - - - -

pH S.U. 7.9 7.6 7.7 7.6 7.9 7.7 8.0 7.9 8.0 7.5 7.7 7.8 7.8 7.3 7.7 7.6

Temperature °C 27.7 28.1 28.3 27.9 32.8 33.8 32.1 30.7 25.0 25.0 25.0 25.0 27.6 27.2 27.0 27.2

DO mg/L 3.0 1.9 2.8 2.0 2.8 1.8 3.5 2.8 1.5 1.7 1.7 1.2 1.6 1.2 4.2 3.5

ORP mV 217 605 619 628 254 548 292 464 321 407 360 377 365 556 510 397

Free Chlorine mg/L <0.02 1.8 1.5 1.5 - 0.3 0.5 0.2 - 0.7 0.8 0.9 - 0.5 0.1 0.4

Total Chlorine mg/L <0.1 1.8 1.5 1.6 - 0.3 0.7 0.5 - 0.7 0.8 1.0 - 0.6 0.2 0.5

Total Hardness (as CaCO3) mg/L 44.9 44.4 43.8 44.1 - - - - 31.0 30.0 28.4 25.9 - - - -

Ca Hardness (as CaCO3) mg/L 32.7 32.2 32.0 32.3 - - - - 18.8 18.0 17.0 15.7 - - - -

Mg Hardness (as CaCO3) mg/L 12.3 12.2 11.8 11.8 - - - - 12.3 12.0 11.3 10.2 - - - -

30.2 32.1 0.2 <0.1 34.6 34.0 2.4 0.8 34.7 38.1 29.6 27.7 47.9 26.9 3.8 0.6

- - - - - - - - - - - - - - - -

As (soluble) μg/L 27.4 26.2 <0.1 <0.1 - - - - 32.6 30.5 28.5 29.7 - - - -

As (particulate) μg/L 2.9 5.9 <0.1 <0.1 - - - - 2.1 7.6 1.1 <0.1 - - - -

As (III) μg/L 21.9 <0.1 <0.1 <0.1 - - - - 29.5 0.5 26.2 0.6 - - - -

As (V) μg/L 5.5 26.1 <0.1 <0.1 - - - - 3.1 30.0 2.3 29.1 - - - -

72 34 <25 <25 66 42 <25 <25 60 <25 46 <25 87 69 <25 <25

- - - - - - - - - - - - - - - -

Fe (soluble) μg/L 43 <25 <25 <25 - - - - <25 <25 <25 <25 - - - -

61.3 57.1 2.5 0.3 59.2 53.8 1.3 0.4 52.3 45.8 50.9 44.8 56.1 45.4 2.9 0.9

- - - - - - - - - - - - - - - -

Mn (soluble) μg/L 61.0 14.5 1.2 <0.1 - - - - 51.8 1.4 51.3 1.9 - - - -

(a) Due to lack of combined IN sample tap, IN sample taken at Cl2 injection point after Cl2 injection turned off and thus no residual Cl2 detected.

(b) Due to incorrect location of TA sample tap, effluent TA and TB samples taken from tank's 1-inch drain line.

(c) TA and TB sample taps relocated on 05/17/06

(d) IN sample tap relocated on 05/24/06. 

Alkalinity (as CaCO3) mg/L

Silica (as SiO2) mg/L

Fe (total) μg/L

Mn (total) μg/L

As (total) μg/L

Turbidity NTU

06/06/06(b)

IN AC TA TB

05/23/06(c, d)

IN AC TA TB

05/09/06(a, b)

IN AC TA TB

04/25/06(a, b)

TA

Sampling Date

Sampling Location IN AC TB

1.3 2.2 3.4 4.4

Total P (as P) μg/L
Table B-1. Analytical Results from Long-Term Sampling, Alvin, TX (Continued)

B-2

Parameter Unit

Bed Volume 10^3 - - - - - - - -

338 359 371 359 339 352 352 356 340 353 349 353 344 349 357 362

- - - - - - - - - - - - 341 350 354 350

Ammonia (as N) mg/L - - - - - - - - - - - - - - - -

Fluoride mg/L 1.2 1.2 1.3 1.4 - - - - 1.4 1.4 1.7 1.9 - - - -

Sulfate mg/L <1 2 2 1 - - - - <1 1 1 1 - - - -

Nitrate (as N) mg/L <0.05 <0.05 <0.05 <0.05 - - - - <0.05 <0.05 <0.05 <0.05 - - - -

44.5 45.9 13.6 <10 37.8 40.2 12.4 <10 25.2 20.4 <10 <10 35.5 28.9 <10 <10

- - - - - - - - - - - - 31.9 33.0 <10 <10

14.4 14.8 15.3 15.2 15.4 16.3 16.0 15.8 15.1 15.2 15.8 15.6 15.5 16.4 17.0 16.5

- - - - - - - - - - - - 15.9 16.3 16.1 16.8

0.6 0.6 0.5 0.5 0.5 0.5 0.2 0.1 0.1 0.5 0.2 0.1 0.2 0.3 0.3 0.2

- - - - - - - - - - - - 0.2 0.3 0.2 0.2

pH S.U. 7.6 7.6 7.7 7.8 7.5 7.4 7.8 7.7 7.6 7.6 7.9 7.7 7.8 7.6 7.9 7.8

Temperature °C 25.8 25.6 24.6 24.5 24.5 24.5 24.3 24.4 24.7 23.9 23.4 23.8 26.0 24.7 25.1 24.8

DO mg/L 2.1 2.0 3.9 3.2 1.8 1.7 3.3 3.1 1.7 2.3 4.9 4.0 1.4 1.7 3.7 2.9

ORP mV 302 622 568 477 430 667 461 621 437 459 596 631 345 655 644 652

Free Chlorine mg/L - 3.0 1.1 1.1 - 3.2 1.8 1.8 - 1.9 1.5 1.8 - 2.3 1.4 0.9

Total Chlorine mg/L - 2.9 1.3 1.2 - 2.5 1.7 1.7 - 2.2 1.6 1.9 - 2.4 1.4 1.0

Total Hardness (as CaCO3) mg/L 42.5 45.9 44.1 44.5 - - - - 31.1 32.0 31.5 32.7 - - - -

Ca Hardness (as CaCO3) mg/L 28.7 30.8 29.6 29.9 - - - - 19.1 19.3 19.0 19.8 - - - -

Mg Hardness (as CaCO3) mg/L 13.8 15.1 14.5 14.6 - - - - 12.1 12.7 12.5 13.0 - - - -

48.1 32.4 4.8 0.4 44.4 30.5 6.2 0.7 46.3 27.6 6.1 0.8 50.4 34.9 8.3 1.0

- - - - - - - - - - - - 52.5 33.6 7.9 1.1

As (soluble) μg/L 44.2 27.3 4.6 0.4 - - - - 40.7 24.3 6.1 0.7 - - - -

As (particulate) μg/L 4.0 5.0 0.2 <0.1 - - - - 5.5 3.4 <0.1 0.1 - - - -

As (III) μg/L 43.9 0.5 0.4 0.4 - - - - 26.5 1.0 0.6 0.6 - - - -

As (V) μg/L 0.2 26.9 4.2 <0.1 - - - - 14.2 23.3 5.5 0.1 - - - -

66 44 <25 <25 86 95 <25 <25 100 60 <25 <25 40 <25 <25 <25

- - - - - - - - - - - - 40 <25 <25 <25

Fe (soluble) μg/L <25 <25 <25 <25 - - - - <25 <25 <25 <25 - - - -

53.6 50.4 2.0 0.4 52.7 53.5 4.0 0.7 50.0 46.0 2.0 0.5 56.2 50.9 2.5 0.3

- - - - - - - - - - - - 53.5 53.2 1.7 0.2

Mn (soluble) μg/L 52.2 1.1 0.9 0.4 - - - - 49.5 <0.1 0.3 0.1 - - - -

(a) TA and TB taken at each vessel's 1-inch drain line. 

(b) Additional samples for TA and TB taken at sample taps located at panel. 

Alkalinity (as CaCO3) mg/L

Silica (as SiO2) mg/L

6.4

Fe (total) μg/L

Mn (total) μg/L

As (total) μg/L

Turbidity NTU

Sampling Date

Sampling Location TA TB

5.6

TA TB

06/21/06(a, b)

IN AC

7/5/2006

IN AC TA TB

7.3

08/01/06(k)

IN AC TA TB

8.0

7/19/2006

IN AC

Total P (as P) μg/L
Table B-1. Analytical Results from Long-Term Sampling, Alvin, TX (Continued)

B-3

Parameter Unit

Bed Volume 10^3 - - - - - - - -

318 343 331 331 696(d) 384 381 366 352 362 362 362 354 382 388 382

- - - - - - - - - - - - - - - -

Ammonia (as N) mg/L - - - - - - - - - - - - - - - -

Fluoride mg/L 1.4 1.4 1.5 1.4 - - - - 1.4 1.4 1.4 1.4 - - - -

Sulfate mg/L <1 1 2 1 - - - - <1 2 2 2 - - - -

Nitrate (as N) mg/L <0.05 <0.05 <0.05 0.2 - - - - <0.05 <0.05 <0.05 <0.05 - - - -

36.2 39.2 15.9 <10 50.2 53.9 33.0 <10 38.7 42.8 24.6 <10 86.7 95.0 76.3 58.7

- - - - - - - - - - - - - - - -

15.4 15.7 15.6 16.0 14.7 15.2 15.6 15.2 15.3 15.3 15.7 15.8 14.8 15.7 16.1 15.5

- - - - - - - - - - - - - - - -

0.2 0.3 0.2 0.1 0.2 0.3 0.1 0.3 0.2 0.3 0.1 0.2 0.3 0.2 0.2 0.1

- - - - - - - - - - - - - - - -

pH S.U. 7.8 7.6 7.6 7.7 7.6 7.5 7.6 7.7 7.7 7.5 7.6 7.6 7.7 7.5 7.6 7.7

Temperature °C 24.3 23.9 24.1 24.1 25.6 25.2 25.0 24.8 23.4 23.1 23.1 23.1 22.8 22.3 22.1 21.7

DO mg/L 1.2 1.5 1.8 1.5 1.4 1.7 2.2 2.9 1.5 2.0 1.7 1.5 NA NA NA NA

ORP mV 369 655 651 668 423 660 655 655 303 655 639 646 390 660 659 658

Free Chlorine mg/L - 2.5 1.8 1.8 - 2.2 1.7 1.5 - 2.6 1.7 1.6 - 2.9 1.7 1.2

Total Chlorine mg/L - 2.6 1.9 2.0 - 2.1 1.5 1.6 - 2.9 1.7 1.8 - 3.1 2.0 1.4

Total Hardness (as CaCO3) mg/L 37.4 42.5 40.5 42.9 - - - - 37.8 40.7 41.2 41.5 - - - -

Ca Hardness (as CaCO3) mg/L 25.1 29.0 27.8 29.4 - - - - 25.2 26.9 27.2 27.4 - - - -

Mg Hardness (as CaCO3) mg/L 12.3 13.5 12.7 13.5 - - - - 12.7 13.7 14.0 14.1 - - - -

51.0 35.9 8.8 1.1 40.1 23.5 7.6 0.6 49.8 34.9 10.0 0.8 39.8 26.7 10.9 4.3

- - - - - - - - - - - - - - - -

As (soluble) μg/L 45.1 30.5 8.6 0.9 - - - - 44.7 28.6 9.1 0.8 - - - -

As (particulate) μg/L 5.9 5.4 0.1 0.2 - - - - 5.1 6.3 0.9 <0.1 - - - -

As (III) μg/L 44.1 0.7 0.7 0.6 - - - - 39.4 0.4 0.4 0.4 - - - -

As (V) μg/L 1.0 29.8 8.0 0.2 - - - - 5.3 28.1 8.7 0.3 - - - -

52 37 <25 <25 34 42 <25 <25 45 <25 <25 <25 58 43 <25 <25

- - - - - - - - - - - - - - - -

Fe (soluble) μg/L 38 <25 <25 <25 - - - - <25 <25 <25 <25 - - - -

52.3 52.7 1.5 0.4 52.0 50.5 1.2 0.1 53.2 50.0 1.3 <0.1 56.6 54.2 2.0 0.6

- - - - - - - - - - - - - - - -

Mn (soluble) μg/L 54.9 0.8 0.2 0.1 - - - - 52.8 0.7 <0.1 <0.1 - - - -

(a) TA and TB sample taps relocated on 08/09/06. Samples no longer taken after each tank's 1-in drainline. 

(b) DO readings not taken due to error messages from field meter. 

Alkalinity (as CaCO3) mg/L

Silica (as SiO2) mg/L

8.8 9.4 10.3 11.0

09/12/06

IN AC TA TB

08/29/06

IN AC TA TB

08/16/06(a)

IN AC TA TB

Fe (total) μg/L

Mn (total) μg/L

As (total) μg/L

Turbidity NTU

Sampling Date

Sampling Location

09/27/06(b)

IN AC TA TB

Total P (as P) μg/L
Table B-1. Analytical Results from Long-Term Sampling, Alvin, TX (Continued)

B-4

Parameter Unit

Bed Volume 10^3 - - - - - - - -

371 390 399 392 368 381 404 398 350 360 372 364 382 380 384 392

- - - - - - - - - - - - - - - -

Ammonia (as N) mg/L - - - - - - - - - - - - - - - -

Fluoride mg/L 1.3 1.4 1.4 1.5 1.5 1.6 1.6 1.5(c) - - - - 1.5 1.6 1.6 1.5

Sulfate mg/L <1 2 2 2 1 2 2 2 - - - - <1 2 1 1

Nitrate (as N) mg/L <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 - - - - <0.05 <0.05 <0.05 <0.05

28.1 39.3 19.9 <10 28.0 32.7 18.2 <10 26.9 34.8 31.3 <10 43.6 42.5 27.7 <10

- - - - - - - - - - - - - - - -

15.9 16.0 15.3 16.5 15.9 15.7 15.8 15.1 14.7 15.2 15.3 15.4 15.5 15.5 15.7 15.7

- - - - - - - - - - - - - - - -

0.8(h) 0.8(h) 0.4 0.4 0.3 0.4 0.3 0.2 0.4 0.6 0.8(d) 0.8(d) 0.6 0.9 0.6 0.3

- - - - - - - - - - - - - - - -

pH S.U. 7.7 7.5 7.6 7.6 7.7 7.5 7.5 7.6 7.4 7.4 7.5 7.6 7.8 7.6 7.6 7.6

Temperature °C 23.1 22.8 22.8 22.5 21.9 22.0 22.4 22.4 22.3 22.6 22.5 22.2 21.7 21.7 22.0 22.2

DO mg/L NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA

ORP mV 317 675 665 672 448 641 628 643 189 189 190 190 339 679 684 642

Free Chlorine mg/L - 3.3 1.8 1.7 - 2.0 1.1 1.4 - 2.8 1.6 1.6 - 3.2 2.8 2.7

Total Chlorine mg/L - 3.1 1.9 2.0 - 2.2 1.1 1.5 - 3.2 1.7 1.8 - 3.3 2.9 2.8

Total Hardness (as CaCO3) mg/L 39.6 45.6 45.4 46.6 35.8 39.9 39.8 40.3 - - - - 39.6 41.7 40.2 42.6

Ca Hardness (as CaCO3) mg/L 26.3 30.0 29.8 30.4 25.4 28.1 28.1 28.2 - - - - 26.4 27.3 26.1 27.9

Mg Hardness (as CaCO3) mg/L 13.4 15.6 15.6 16.2 10.4 11.9 11.7 12.1 - - - - 13.2 14.4 14.1 14.6

44.0 30.2 10.2 1.4 37.0 22.5 9.9 2.0 46.7 33.1 14.8 2.1 41.3 30.7 14.1 1.5

- - - - - - - - - - - - - - - -

As (soluble) μg/L 44.7 26.6 9.8 1.5 34.7 19.6 9.3 1.7 - - - - 40.9 28.0 12.9 1.6

As (particulate) μg/L <0.1 3.5 0.4 <0.1 2.3 3.0 0.5 0.3 - - - - 0.4 2.7 1.2 <0.1

As (III) μg/L 40.7 0.9 1.1 0.8 27.3 1.3 1.6 1.8 - - - - 27.6 1.2 0.9 0.7

As (V) μg/L 4.1 25.7 8.7 0.8 7.4 18.2 7.7 <0.1 - - - - 13.2 26.8 12.1 0.9

39 <25 <25 <25(b) 56 34 <25 <25 36 <25 <25 <25 133 95 <25 <25

- - - - - - - - - - - - - - - -

Fe (soluble) μg/L <25 <25 <25 <25 33 <25 <25 <25 - - - - 44 <25 <25 <25

52.9 52.6 1.0 0.5 55.8 53.9 1.4 0.2 50.4 50.1 1.7 0.4 48.9 46.2 5.7 0.2

- - - - - - - - - - - - - - - -

Mn (soluble) μg/L 55.6 0.9 0.2 0.2 54.4 1.4 0.6 0.1 - - - - 48.9 1.7 0.2 0.5

(a) Sampling reduced to bimonthly. 

(b) Reanalyzed by the laboratory, orgininally 63.5 μg/L. 

(c) Reanalyzed by laboratory out of hold time, originally 2.6 mg/L. 

(d) Elevated levels remained the same after it was checked by the laboratory. 

13.0

Alkalinity (as CaCO3) mg/L

Silica (as SiO2) mg/L

Fe (total) μg/L

Mn (total) μg/L

As (total) μg/L

Turbidity NTU

Sampling Date

Sampling Location

11.7

10/11/06(a)

IN AC TA TB

11/15/06 12/13/06 01/10/07

IN AC TA TB IN AC TA

14.2

TB IN AC TA TB

15.3

Total P (as P) μg/L
Table B-1. Analytical Results from Long-Term Sampling, Alvin, TX (Continued)

B-5

Parameter Unit

Bed Volume 10^3 - - - - - - - -

372 383 374 383 366 383 378 371 364 364 364 359 389 

[378] 388 381 374

- - - - - - - - 371 354 366 366 - - - -

Ammonia (as N) mg/L - - - - - - - - - - - - - - - -

Fluoride mg/L - - - - 1.5 1.5 1.5 1.5 - - - - 1.1 

[1.2] 1.5 1.6 1.4

Sulfate mg/L - - - - 1 2 2 2 - - - - 2 

[1] 3 2 1

Nitrate (as N) mg/L - - - - <0.05 <0.05 <0.05 <0.05 - - - - <0.05 

[<0.05] <0.05 <0.05 <0.05

36.5 43.2 33.3 <10 40.6 44.8 33.2 <10 43.7 41.1 40.5 16.6 34.6 

[43.5] 44.3 34.5 14.9

- - - - - - - - 41.6 39.5 39.9 16.6 - - - -

15.0 15.9 15.3 15.5 14.7 15.6 15.9 15.2 15.3 14.9 15.2 15.3 15.5 

[16.5] 16.7 16.9 16.4

- - - - - - - - 15.5 15.4 15.2 15.2 - - - -

0.8 0.6 0.4 0.6 0.8 1.1 1.3 0.7 0.4 0.3 0.7 0.4 1.2 

[0.9] 0.7 0.9 0.6

- - - - - - - - 0.5 0.3 0.4 0.1 - - - -

pH S.U. 8.0 7.7 7.7 7.7 7.8 7.5 7.7 7.6 NA NA NA NA NA NA NA NA

Temperature °C 21.5 21.4 21.3 21.1 25.2 25.8 25.5 23.7 NA NA NA NA NA NA NA NA

DO mg/L 2.4 2.0 3.2 2.7 1.7 1.7 2.6 3.3 1.3 1.7 1.6 1.5 1.7 1.6 2.9 2.7

ORP mV 328 655 673 675 210 681 670 679 254 687 670 674 251 673 637 663

Free Chlorine mg/L - 2.1 1.6 1.5 - 2.9 1.2 1.3 - 2.7 1.2 1.2 - 1.6 0.8 1.0

Total Chlorine mg/L - 2.2 1.7 1.6 - 3.0 1.3 1.5 - 2.7 1.3 1.3 - 1.6 0.9 1.1

Total Hardness (as CaCO3) mg/L - - - - 45.3 50.3 48.7 47.7 - - - - 43.2 

[44.4] 48.0 40.9 44.0

Ca Hardness (as CaCO3) mg/L - - - - 33.0 35.3 34.2 33.4 - - - - 31.1 

[30.9] 32.8 28.2 30.7

Mg Hardness (as CaCO3) mg/L - - - - 12.3 15.0 14.6 14.4 - - - - 12.1 

[13.5] 15.2 12.7 13.3

48.4 28.4 16.9 2.0 44.8 30.2 14.8 2.4 39.0 36.1 20.1 4.4 38.6 

[36.9] 25.5 15.1 2.9

- - - - - - - - 39.4 35.6 19.9 4.4 - - - -

As (soluble) μg/L - - - - 39.2 21.9 13.3 2.3 - - - - 34.0

[30.5] 21.3 15.4 2.7

As (particulate) μg/L - - - - 5.6 8.2 1.5 <0.1 - - - - 4.6

[6.4] 4.3 <0.1 0.2

As (III) μg/L - - - - 17.7(a) 1.0 1.1 1.1 - - - - 30.5

[24.1] 0.4 0.5 0.4

As (V) μg/L - - - - 21.5(a) 20.9 12.2 1.2 - - - - 3.5

[6.4] 20.8 15.0 2.3

80 36 <25 <25 41 27 <25 <25 <25 <25 <25 <25 48

[197] 37 <25 <25

- - - - - - - - <25 <25 <25 <25 - - - -

Fe (soluble) μg/L - - - - <25 <25 <25 <25 - - - - 25.3

[<25] <25 <25 <25

47.3 49.1 1.4 0.2 52.2 50.5 7.6 <0.1 50.0 43.5 0.5 <0.1 55.9

[58.1] 52.7 2.3 <0.1

- - - - - - - - 49.9 43.7 0.4 <0.1 - - - -

Mn (soluble) μg/L - - - - 50.9 1.3 <0.1 <0.1 - - - - 49.3

[55.6] 0.7 <0.1 <0.1

(a) Samples were rerun but showed similar results. 

(b) Starting 04/04/07, IN sample taken at original chlorine injection point further downstream of the Well 1 and 2 blending point. 

(c) Samples taken at orginal sample point on 05/09/07. [Sample taken at relocated sample tap on 05/02/07]. 

TA TB

16.8 18.3 19.8 21.4

Alkalinity (as CaCO3) mg/L

Silica (as SiO2) mg/L

Fe (total) μg/L

Mn (total) μg/L

As (total) μg/L

Turbidity NTU

Sampling Date

Sampling Location

02/06/07

IN AC TA TB

03/07/07

IN AC TA TB

Total P (as P) μg/L

05/02/07(c)

IN AC TA TB

04/04/07(b)

IN AC
Table B-1. Analytical Results from Long-Term Sampling, Alvin, TX (Continued)

B-6

Parameter Unit

Bed Volume 10^3 - - - - - - - -

387 363 366 356 377 370 377 365 - - - - - - - -

- - - - - - - - - - - - - - - -

Ammonia (as N) mg/L - - - - - - - - - - - - - - - -

Fluoride mg/L - - - - 1.5 1.7 1.6 1.6 - - - - - - - -

Sulfate mg/L - - - - 2 2 2 2 - - - - - - - -

Nitrate (as N) mg/L - - - - <0.05 <0.05 <0.05 <0.05 - - - - - - - -

36.5 35.1 37.6 26.2 37.3 35.6 27.0 17.6 41.9 38.1 36.8 25.9 41.7 45.6 42.1 32.6

- - - - - - - - - - - - - - - -

16.8 16.2 15.9 16.1 16.1 15.9 16.1 15.7 - - - - - - - -

- - - - - - - - - - - - - - - -

0.8 1.0 0.7 0.6 0.5 0.3 0.4 0.3 - - - - - - - -

- - - - - - - - - - - - - - - -

pH S.U. NA NA NA NA 8.1 7.9 7.9 7.9 NA NA NA NA 8.1 7.8 7.9 7.9

Temperature °C NA NA NA NA 22.7 22.7 22.9 23.0 NA NA NA NA 25.4 25.3 25.2 25.1

DO mg/L NA NA NA NA NA NA NA NA NA NA NA NA 2.2 1.7 3.0 2.0

ORP mV NA NA NA NA 265 546 531 567 NA NA NA NA 239 538 549 367

Free Chlorine mg/L - NA NA NA - 1.4 0.7 0.9 - NA NA NA - 2.2 0.8 0.6

Total Chlorine mg/L - NA NA NA - 1.6 0.8 1.0 - NA NA NA - 2.2 0.8 0.6

Total Hardness (as CaCO3) mg/L - - - - 45.8 47.1 44.6 44.7 - - - - - - - -

Ca Hardness (as CaCO3) mg/L - - - - 31.3 32.8 31.1 31.0 - - - - - - - -

Mg Hardness (as CaCO3) mg/L - - - - 14.5 14.3 13.6 13.7 - - - - - - - -

36.5 34.2 19.8 4.8 29.8 26.6 19.0 4.2 32.1 36.6 22.6 6.0 41.4 40.2 26.0 7.9

- - - - - - - - - - - - - - - -

As (soluble) μg/L - - - - 25.3 22.2 16.5 3.6 - - - - 34.4 28.6 22.1 7.3

As (particulate) μg/L - - - - 4.5 4.4 2.5 0.6 - - - - 6.9 11.6 3.9 0.6

As (III) μg/L - - - - 24.6 <0.1 <0.1 <0.1 - - - - 31.0 0.8 0.8 0.7

As (V) μg/L - - - - 0.7 22.1 16.4 3.5 - - - - 3.4 27.8 21.3 6.7

27 <25 <25 <25 37 30 <25 <25 26 52 <25 <25 117 88 <25 <25

- - - - - - - - - - - - - - - -

Fe (soluble) μg/L - - - - <25 <25 <25 <25 - - - - <25 <25 <25 <25

60.6 52.0 0.8 <0.1 57.2 53.0 2.1 0.3 53.3 42.6 3.1 0.1 55.9 49.1 2.2 <0.1

- - - - - - - - - - - - - - - -

Mn (soluble) μg/L - - - - 60.0 1.9 0.2 0.1 - - - - 56.9 0.4 <0.1 0.6

(a) Starting July 2007, analytes reduced to As, Fe, Mn, and P. Speciation samples are conducted every other month. 

24.8

06/27/07

IN AC TA TB

23.9

Alkalinity (as CaCO3) mg/L

Silica (as SiO2) mg/L

Fe (total) μg/L

Mn (total) μg/L

As (total) μg/L

Turbidity NTU

Sampling Date

Sampling Location

Total P (as P) μg/L

06/12/07

IN AC TA TB

07/25/07(a)

IN AC TA TB

08/22/07

IN AC TA TB

26.1 27.7
Table B-1. Analytical Results from Long-Term Sampling, Alvin, TX (Continued)

B-7

Parameter Unit

Bed Volume 10^3 - - - - - - - -

- - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - -

Ammonia (as N) mg/L 0.2 0.2 - - 0.2 <0.05 <0.05 <0.05 0.2 <0.05 <0.05 <0.05 0.2 0.1 <0.05 <0.05

Fluoride mg/L - - - - - - - - - - - - - - - -

Sulfate mg/L - - - - - - - - - - - - - - - -

Nitrate (as N) mg/L - - - - - - - - - - - - - - - -

46.5 47.3 52.9 52.6 30.5 32.5 32.6 29.7 44.9 47.3 44.8 43.4 42.5 50.5 43.9 38.4

- - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - -

pH S.U. 8.0 7.9 7.9 7.9 8.0 7.7 7.7 7.7 NA NA NA NA NA NA NA NA

Temperature °C 23.9 23.8 23.8 23.7 22.1 22.1 22.4 22.3 NA NA NA NA NA NA NA NA

DO mg/L 2.5 1.2 1.3 1.4 2.7 1.6 2.7 3.1 NA NA NA NA NA NA NA NA

ORP mV 394 272 265 257 245 652 641 656 NA NA NA NA NA NA NA NA

Free Chlorine mg/L - NA NA NA - 2.2 1.2 1.4 - NA NA NA - NA NA NA

Total Chlorine mg/L - NA NA NA - 2.2 1.3 1.3 - NA NA NA - NA NA NA

Total Hardness (as CaCO3) mg/L - - - - - - - - - - - - - - - -

Ca Hardness (as CaCO3) mg/L - - - - - - - - - - - - - - - -

Mg Hardness (as CaCO3) mg/L - - - - - - - - - - - - - - - -

40.9 40.7 27.7 10.4 31.6 31.2 24.9 8.1 44.1 41.2 28.5 10.6 35.6 24.1 21.3 8.5

- - - - - - - - - - - - - - - -

As (soluble) μg/L - - - - 26.9 24.6 20.1 10.8 - - - - - - - -

As (particulate) μg/L - - - - 4.7 6.5 4.8 <0.1 - - - - - - - -

As (III) μg/L - - - - 24.7 0.4 0.4 0.5 - - - - - - - -

As (V) μg/L - - - - 2.2 24.3 19.8 10.3 - - - - - - - -

32 <25 <25 <25 31 <25 <25 <25 137 169 <25 <25 145 47 <25 <25

- - - - - - - - - - - - - - - -

Fe (soluble) μg/L - - - - <25 <25 <25 <25 - - - - - - - -

57.8 53.3 0.2 <0.1 60.7 52.6 <0.1 <0.1 61.0 55.0 9.6 <0.1 53.5 48.5 2.9 0.3

- - - - - - - - - - - - - - - -

Mn (soluble) μg/L - - - - 63.4 <0.1 <0.1 <0.1 - - - - - - - -

(a) One time sampling event for ammonia at IN and AC. 

(b) Chlorine addition was switched to post-chlorination (instead of pre-chlorination) two weeks prior, by mistake. 

(c) Starting Nov 2007, sampling frequency increased to biweekly due to lag vessel total As > 10 ug/L in Sept. Analytes are total As, Fe, Mn, total P, and NH3. 

Alkalinity (as CaCO3) mg/L

Silica (as SiO2) mg/L

Fe (total) μg/L

Mn (total) μg/L

As (total) μg/L

Turbidity NTU

Sampling Date

Sampling Location

Total P (as P) μg/L

TB

28.7 29.8

09/12/07(a, b)

IN AC

10/03/07

TA IN AC TA TB IN AC TA TB

31.6

11/27/07

IN AC TA TB

32.8

11/06/07(c)
Table B-1. Analytical Results from Long-Term Sampling, Alvin, TX (Continued)

B-8

Parameter Unit

Bed Volume 10^3 - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - -

Ammonia (as N) mg/L 0.2 <0.05 <0.05 <0.05 0.2 0.1 0.1 0.1 0.1 

0.1

<0.05 

0.1

<0.05 

<0.05

<0.05 

<0.05 0.1 <0.05 <0.05 <0.05 0.1 <0.05 <0.05 <0.05

Fluoride mg/L - - - - - - - - - - - - - - - - - - - -

Sulfate mg/L - - - - - - - - - - - - - - - - - - - -

Nitrate (as N) mg/L - - - - - - - - - - - - - - - - - - - -

40.0 39.6 36.1 39.1 48.9 51.8 43.9 48.8 - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - -

pH S.U. NA NA NA NA 8.0 7.8 7.9 7.9 NA NA NA NA 8.0 7.8 7.8 7.8 7.9 7.7 7.7 7.7

Temperature °C NA NA NA NA 23.8 23.8 23.6 27.6 NA NA NA NA 21.5 21.4 21.4 21.3 25.0 25.0 25.0 25.0

DO mg/L NA NA NA NA 2.5 2.4 2.5 2.2 2.9 2.9 4.1 4.3 2.7 2.2 2.8 2.0 2.8 2.0 2.2 1.9

ORP mV NA NA NA NA 416 642 483 454 366 593 605 603 395 657 660 653 414 660 708 687

Free Chlorine mg/L - NA NA NA - 2.2 0.7 0.4 - 0.8 0.7 0.8 - 1.5 1.0 0.9 - 1.9 3.2 2.5

Total Chlorine mg/L - NA NA NA - 2.3 0.7 0.4 - 1.0 0.7 0.8 - 1.6 1.2 1.1 - 1.9 3.4 2.6

Total Hardness (as CaCO3) mg/L - - - - - - - - - - - - - - - - - - - -

Ca Hardness (as CaCO3) mg/L - - - - - - - - - - - - - - - - - - - -

Mg Hardness (as CaCO3) mg/L - - - - - - - - - - - - - - - - - - - -

34.4 32.2 22.3 9.2 31.6 27.6 16.7 7.3 27.5 31.1 26.6 10.4 31.3 30.5 23.5 10.2 33.6 28.0 23.2 10.5

- - - - - - - - 27.5 31.4 25.8 10.4 - - - - - - - -

As (soluble) μg/L - - - - - - - - - - - - - - - - - - - -

As (particulate) μg/L - - - - - - - - - - - - - - - - - - - -

As (III) μg/L - - - - - - - - - - - - - - - - - - - -

As (V) μg/L - - - - - - - - - - - - - - - - - - - -

42 32 <25 <25 66 67 29 31 121 91 <25 <25 46 34 <25 <25 93 48 <25 <25

- - - - - - - - 86 51 <25 <25 - - - - - - - -

Fe (soluble) μg/L - - - - - - - - - - - - - - - - - - - -

62.0 50.3 2.0 0.3 50.4 44.0 0.7 0.2 66.6 54.6 1.2 0.6 57.8 50.7 1.1 <0.1 56.7 53.8 1.5 <0.1

- - - - - - - - 64.9 55.4 1.1 0.6 - - - - - - - -

Mn (soluble) μg/L - - - - - - - - - - - - - - - - - - - -

35.0

01/29/08

IN AC TA TB

33.7

01/02/08

IN AC TA TB

Alkalinity (as CaCO3) mg/L

Silica (as SiO2) mg/L

Fe (total) μg/L

Mn (total) μg/L

As (total) μg/L

Turbidity NTU

Sampling Date

Sampling Location

Total P (as P) μg/L

TA TB

36.8

03/25/08

IN AC TA TB

37.4

03/13/08

IN AC

38.1

04/08/08

IN AC TA TB