EPA/600/R-10/166

December 2010

Arsenic Removal from Drinking Water by Coagulation/Filtration

U.S. EPA Demonstration Project at the City of Okanogan, WA

Final Performance Evaluation Report

by

Abraham S.C. Chen* 

Anbo Wang**

Lili Wang* 

**Battelle, Columbus, OH 43201-2693 *

ALSA Tech, LLC, Columbus, OH 43201-0693

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 during and the results obtained from the arsenic removal 

treatment technology demonstration project at the City of Okanogan, WA facility. The objectives of the 

project were to evaluate: (1) the effectiveness of Filtronics’ FH-13 Electromedia®I Arsenic Removal 

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

of the treatment system for use at small water facilities, (3) the required system operation and 

maintenance (O&M) and operator skill levels, and (4) the capital and O&M cost of the technology. The 

project also characterized water in the distribution system and residuals generated by the treatment 

process. The types of data collected included system operation, water quality, process residuals, and 

capital and O&M cost.

After review and approval of the engineering plan by the State of Washington, the FH-13 Electromedia®I 

treatment system was installed and became operational on August 14, 2008. The system consisted of two 

4-ft × 8-ft carbon steel contact tanks, and one 7-ft × 91

/3-ft horizontal carbon steel filter tank loaded with 

174 ft3 of Electromedia®Ifilter media, 33 ft3 of support media, and 43 ft3 of concrete. The filter tank was 

fitted with semi-elliptical ends and upper and lower manifold assemblies, providing a filtration area of 75 

ft2

. At a design flowrate of 750 gal/min (gpm), the hydraulic loading rate to the filter was 10 gpm/ft2. 

The system used two chemical addition assemblies, one each for prechlorination and supplemental iron 

addition. The chlorine addition system was installed to oxidize As(III) and Fe(II) and form As(V)-laden 

iron solids prior to the filtration tank. The iron addition system was installed to increase the removal of 

soluble As(V) through adsorption and/or coprecipitation with iron solids. The target chlorine and iron 

dosages were 0.7 mg/L (as Cl2) and 0.9 mg/L (as Fe), respectively. 

A wastewater recycle system was incorporated into the treatment system to reclaim backwash wastewater 

and eliminate the need to discharge wastewater into the sanitary sewer. The recycle system consisted of a 

reclaim pump and a 22,500-gal concrete reclaim tank equipped with high/low float switches. 

From August 14, 2008, through August 14, 2009, the treatment system operated for an average of 13.6

hr/day, producing 139,435,000 gal of water. This production rate corresponded to an average flowrate of 

527 gpm, comparable to the 550-gpm extraction rate allowed for Well No. 4 by water rights. At 527 

gpm, it yielded a contact time of 2.8 min in the two contact tanks and a filtration rate of 7.0 gpm/ft2

. 

Source water from Well No. 4 had an average pH value of 7.6 and contained 14.7 to 22.7 μg/L of total 

arsenic. The predominant arsenic species was As(III) with an average concentration of 13.4 μg/L. Total 

iron concentrations ranged from <25 to 230 μg/L and averaged 78 μg/L, existing mostly in the soluble 

form (averaged at 49 μg/L). This amount of soluble iron corresponded to a soluble iron to soluble arsenic 

ratio of 2.7:1, indicating insufficient iron for arsenic removal. Ferric chloride was added to chlorinated 

water to achieve a target iron concentration of 0.9 mg/L (50 times the soluble arsenic concentration in 

source water) for more effective arsenic removal, presumably through adsorption and/or coprecipitation 

with iron solids.

Total arsenic concentrations after the pressure filter ranged from 2.9 to 14.9 μg/L and averaged 6.2 μg/L. 

Filter performance was maintained with backwash, which was triggered either by a preset run time of 8 hr 

or when the water level in the storage reservoir reached the “Stop” setpoint. Backwashing every 8 hr 

appeared to be adequate to maintain proper filter performance for arsenic and iron removal. The filter 

tank was backwashed 2.3 times/day, producing approximately 6,150 gal of wastewater/time. A total of 

4,667,850 gal of wastewater was produced during the study, equivalent to 3.3% of the total amount of 

water treated. On average, the backwash wastewater contained 108 mg/L of total suspended solids (TSS), 

462 μg/L of arsenic, 38.1 mg/L of iron, and 1,157 μg/L of manganese, with the majority existing as 
v

particulate. During each backwash, 2.5 kg of solids was produced, which included 10.6 g of arsenic, 882

g of iron, and 26.3 g of manganese.

Arsenic levels in distribution system water as sampled at DS3, a non-Lead and Copper Rule (LCR) 

sampling location, were very close to those in treatment system effluent (i.e., 6.8 versus 6.2 μg/L, on 

average). Because the other two sampling locations (DS1 and DS2) selected for distribution water 

sampling were impacted by all four wells supplying Okanogan’s distribution system, the effect of the 

treatment system on the distribution water quality could not be evaluated directly. The average lead 

concentration within the distribution system was 1.5 μg/L with no samples exceeding the action level of 

15 μg/L. The average copper concentration was 61.6 μg/L with no samples exceeding the 1,300 μg/L 

action level.

The capital investment for the system was $424,817, including $296,430 for equipment, $48,332 for site 

engineering, and $80,055 for installation, shakedown, and startup. Using the system’s rated capacity of 

550 gpm (or 792,000 gal/day [gpd]), the capital cost was $772/gpm (or $0.54/gpd). This unit cost does 

not include the cost of the building to house the treatment system and recycle system utilized to reclaim 

the backwash water. O&M cost, estimated at $0.18/1,000 gal, included cost for chemicals usage, 

electricity consumption, and labor.
vi

CONTENTS 

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

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

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

APPENDICES ............................................................................................................................................vii

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

TABLES ....................................................................................................................................................viii

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

ACKNOWLEDGMENTS ..........................................................................................................................xii

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

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

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

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

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

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

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

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

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

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

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

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

3.3.4 Distribution System Water........................................................................................ 8

3.3.5 Residual Solids........................................................................................................ 11

3.4 Sampling Logistics............................................................................................................... 11

3.4.1 Preparation of Arsenic Speciation Kits................................................................... 11

3.4.2 Preparation of Sample Coolers................................................................................ 11

3.4.3 Sample Shipping and Handling............................................................................... 11

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

4.0 RESULTS AND DISCUSSION .......................................................................................................... 13

4.1 Site Description.................................................................................................................... 13

4.1.1 Pre-existing Facility. ............................................................................................... 13

4.1.2 Distribution System................................................................................................. 14

4.1.3 Source Water Quality.............................................................................................. 14

4.2 Treatment Process Description ............................................................................................ 16

4.3 Treatment System Installation.............................................................................................. 22

4.3.1 System Permitting................................................................................................... 22

4.3.2 Building Construction............................................................................................. 22

4.3.3 System Installation, Startup, and Shakedown ......................................................... 24

4.4 System Operation................................................................................................................. 25

4.4.1 Service Operation.................................................................................................... 25

4.4.2 Chlorine and Iron Additions.................................................................................... 28

4.4.3 Backwash Operation ............................................................................................... 32

4.4.3.1 Other Problems Related to Backwash System........................................ 33

4.4.4 Residual Management............................................................................................. 33

4.4.5 System/Operation Reliability and Simplicity.......................................................... 34

4.4.5.1 Pre- and Post-Treatment Requirements.................................................. 34
vii

4.4.5.2 System Automation ................................................................................ 34

4.4.5.3 Operator Skill Requirements .................................................................. 34

4.4.5.4 Preventative Maintenance Activities...................................................... 34

4.4.5.5 Chemical Handling and Inventory Requirements................................... 35

4.5 System Performance............................................................................................................. 35

4.5.1 Treatment Plant Sampling....................................................................................... 35

4.5.1.1 Arsenic.................................................................................................... 35

4.5.1.2 Iron .......................................................................................................... 40

4.5.1.3 Manganese .............................................................................................. 41

4.5.1.4 pH, DO, and ORP ................................................................................... 42

4.5.1.5 Chlorine .................................................................................................. 42

4.5.1.6 Other Water Quality Parameters............................................................. 43

4.5.2 Backwash Water and Solids Sampling ................................................................... 44

4.5.3 Distribution System Water Sampling...................................................................... 45

4.6 System Cost.......................................................................................................................... 48

4.6.1 Capital Cost............................................................................................................. 48

4.6.2 O&M Cost............................................................................................................... 49

5.0 REFERENCES .................................................................................................................................... 51

APPENDICES

APPENDIX A: OPERATIONAL DATA

APPENDIX B: ANALYTICAL DATA TABLE

APPENDIX C: SUMMARY OF RESPONSIBILITIES ARSENIC DEMONSTRATION PROJECT AT 

OKANOGAN, WA

APPENDIX D: BACKWASH LOG SHEETS EPA ARSENIC DEMONSTRATION PROJECT AT 

OKANOGAN, WA

FIGURES

Figure 3-1. Process Flow Diagram and Sampling Schedules and Locations.......................................... 10

Figure 4-1. Well No. 4 in a Fenced Area................................................................................................ 13

Figure 4-2. Manhole for Well No. 4 ....................................................................................................... 14

Figure 4-3. Plan View of Filtronics’ FH-13 Treatment System ............................................................. 17

Figure 4-4. Treatment System Components ........................................................................................... 19

Figure 4-5. Chlorine and Iron Addition Systems.................................................................................... 20

Figure 4-6. Reclaim System Components .............................................................................................. 21

Figure 4-7. New Building and Reclaim Tank Under Construction ........................................................ 23

Figure 4-8. New Building and Reclaim Tank......................................................................................... 23

Figure 4-9. Equipment Delivery and Unloading..................................................................................... 24

Figure 4-10. Schematic Illustration of Filtration and Supporting Media Layers in Filtration Tank......... 25

Figure 4-11. Treatment System Normalized Daily Operating Times....................................................... 27

Figure 4-12. Treatment System Flowrates................................................................................................ 28

Figure 4-13. Differential Pressure Across Pressure Filter ........................................................................ 29

Figure 4-14. Differential Pressure Across Pressure Filter Before and After Backwash........................... 29

Figure 4-15. Chlorine Dosage Test Results.............................................................................................. 31

Figure 4-16. Chlorine Doses over Demonstration Study Period .............................................................. 32

Figure 4-17. Calculated Iron Doses vs. Measured Iron Concentrations................................................... 33
viii

Figure 4-18. Total Arsenic Concentrations Across Treatment Train........................................................ 38

Figure 4-19. Arsenic Speciation Results................................................................................................... 39

Figure 4-20. Total Iron Concentrations Across Treatment Train ............................................................. 40

Figure 4-21. Total Manganese Concentrations across Treatment Train................................................... 41

Figure 4-22. Chlorine Residuals Measured Throughout Treatment Train................................................ 42

Figure 4-23. Arsenic and Iron Concentrations Measured During Filter Run Length Study..................... 43

Figure 4-24. Effect of Treatment System on Arsenic, Iron, and Manganese in Distribution 

System.................................................................................................................................. 47

TABLES 

Table 1-1. Summary of the Arsenic Removal Demonstration Sites........................................................ 3

Table 3-1. Pre-Demonstration and Demonstration Study Activities and Completion Dates .................. 6

Table 3-2. Evaluation Objectives and Supporting Data Collection Activities........................................ 7

Table 3-3. Sampling Locations, Schedules, and Analyses...................................................................... 9

Table 4-1. Well No. 4 Water Quality Data............................................................................................ 15

Table 4-2. Well No. 4 Historic Water Quality Data.............................................................................. 16

Table 4-3. Design Specifications of FH-13 Treatment System............................................................. 18

Table 4-4. Filter Break-in Schedule ...................................................................................................... 25

Table 4-5. Treatment System Operational Parameters.......................................................................... 26

Table 4-6. Issues/Problems Encountered Related to Chlorine Addition System .................................. 30

Table 4-7. Summary of Arsenic, Iron, and Manganese Analytical Results........................................... 36

Table 4-8. Summary of Other Water Quality Parameters Results......................................................... 37

Table 4-9. Arsenic Speciation vs. DO and ORP.................................................................................... 40

Table 4-10. Backwash Wastewater Sampling Results ............................................................................ 44

Table 4-11. Backwash Solids Sampling Test Results ............................................................................. 45

Table 4-12. Distribution System Sampling Results................................................................................. 46

Table 4-13. Capital Investment for Filtronics’ FH-13 Electromedia®I System....................................... 49

Table 4-14. O&M Costs for Filtronics’ FH-13 Electromedia®I System ................................................. 50
ix

ABBREVIATIONS AND ACRONYMS

∆p differential pressure

AAL American Analytical Laboratories

AM adsorptive media

As arsenic

ATS Aquatic Treatment Systems

bgs below ground surface

C/F coagulation/filtration

Ca calcium

CDB community development block

Cl chlorine

CRF capital recovery factor

Cu copper

D diameter

DBPR Disinfection Byproducts Rule

DO dissolved oxygen

EPA U.S. Environmental Protection Agency

F fluoride

Fe iron 

FeCl3 ferric chloride

G&O Gray and Osborne

gpd gallons per day

gph gallons per hour

gpm gallons per minute

H height

HAAs heloacetic acids

HIX hybrid ion exchanger

hp horsepower

ICP-MS inductively coupled plasma-mass spectrometry

ID identification

IX ion exchange

L length

LCR (EPA) Lead and Copper Rule

MCL maximum contaminant level 

MDL method detection limit

MEI Magnesium Elektron, Inc.

Mg magnesium
x

ABBREVIATIONS AND ACRONYMS (Continued)

μm micrometer

Mn manganese

mV millivolts

Na sodium

NA not analyzed/not available

NaOCl sodium hypochlorite

ND not detected

NSF NSF International

NTU nephelometric turbidity units

O&M operation and maintenance

OIP operator interface panel

OIT Oregon Institute of Technology

ORD Office of Research and Development

ORP oxidation-reduction potential

P phosphorus

P&ID piping and instrumentation diagram

Pb lead

pCi/L picocuries per liter

PLC programmable logic controller

PO4 phosphate

POU point-of-use

psi pounds per square inch

psig pounds per square inch gauge

PVC polyvinyl chloride

QA/QC quality assurance/quality control

QAPP Quality Assurance Project Plan

RFQ request for quotation

RPD relative percent difference

RO reverse osmosis

SDWA Safe Drinking Water Act

SiO2 silica

SMCL secondary maximum contaminant level

SO4 sulfate

SOCs synthetic organic compounds

STS Severn Trent Services

TDH total dynamic head 

TDS total dissolved solids

THMs trihalomethanes

TOC total organic carbon

TSS total suspended solids
xi

ABBREVIATIONS AND ACRONYMS (Continued)

V vanadium

VOCs volatile organic compounds

WA DOH Washington Department of Health

WQE Water Quality Engineering 
xii

ACKNOWLEDGMENTS

The authors wish to extend their sincere appreciation to Mr. Ray Doll and Mr. Loren Howell of the City 

of Okanogan in Washington. Mr. Doll and Mr. Howell monitored the treatment system and collected 

samples from the treatment and distribution systems on a regular schedule throughout the study. This 

performance evaluation would not have been possible without their support and dedication.

Ms. Julia Valigore, who is currently pursuing a doctoral degree at the University of Canterbury in New 

Zealand, served as the Battelle Study Lead during the planning stage of this demonstration project.
1

1.0 INTRODUCTION

1.1 Background

The Safe Drinking Water Act (SDWA) mandates that the U.S. Environmental Protection Agency (EPA) 

identify and regulate drinking-water contaminants that may have adverse human health effects and that 

are known or anticipated to occur in public water supply systems. In 1975 under the SDWA, EPA 

established a maximum contaminant level (MCL) for arsenic (As) at 0.05 mg/L. Amended in 1996, the 

SDWA required that EPA develop an arsenic research strategy and publish a proposal to revise the 

arsenic MCL by January 2000. On January 18, 2001, EPA finalized the arsenic MCL at 0.01 mg/L (EPA, 

2001). To clarify the implementation of the original rule, EPA revised the rule text on March 25, 2003, to 

express the MCL as 0.010 mg/L (10 μg/L) (EPA, 2003). The final rule required all community and nontransient, 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 for reducing 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, onsite demonstrations of arsenic removal 

technologies, process modifications, and engineering approaches applicable to small systems. Shortly 

thereafter, an announcement published in the Federal Register requested water utilities interested in 

participating in Round 1 of this EPA-sponsored demonstration program to provide information on their 

water systems. In June 2002, EPA selected 17 of the 115 candidate 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 recommendations to EPA on the technologies it determined 

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 community water system in the City of Okanogan, WA was one of those selected. 

In September 2003, EPA again solicited proposals from engineering firms and vendors for arsenicremoval technologies. EPA received 148 technical proposals for the 32 host sites, with each site 

receiving from two to eight proposals. In April 2004, EPA convened another technical panel to review 

the proposals and provide recommendations to EPA; the number of proposals per site ranged from none 

(for two sites) to a maximum of four. Final selection of the treatment technology at sites receiving 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. 

Filtronics’ FH-13 system using Electromedia®I was selected for demonstration at the Okanogan facility. 

As of December 2010, 39 of the 40 systems were operational and the performance evaluation of all 39 

systems was completed.
2

1.2 Treatment Technologies for Arsenic Removal

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

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

coagulation/filtration (C/F) systems, two ion exchange (IX) systems, 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, iron 

[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 cost is provided in two EPA reports 

(Wang et al., 2004; Chen et al., 2004), which are posted on the EPA Web site at 

http://www.epa.gov/ORD/NRMRL/wswrd/dw/arsenic/index.html. 

1.3 Project Objectives

The objective of the 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 Filtronics system at the City of Okanogan in Washington

from August 14, 2008 through August 14, 2009. The types of data collected include 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 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

Buckeye Lake, 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 from operation of Filtronics’ FH-13 treatment system with 

Electromedia®I media at the City of Okanogan, WA from August 14, 2008 to August 14, 2009, the 

following summary and conclusions are provided relating to the overall objectives of the treatment 

technology demonstration study. 

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

• With proper pre-chlorination and supplemental iron addition, Filtronics’ FH-13 

Electromedia®I system was able to remove arsenic to <10 μg/L. 

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

from 13.4 μg/L (on average) in source water to 2.2 μg/L (on average) after the contact tanks.

• At an average filtration rate of 7.0 gpm/ft2 and filter run time of 8 hr, no particulate arsenic 

leakage was observed. 

• Backwashing at a rate of 17.9 gal/min (gpm)/ft2 was effective at restoring the pressure filter 

for subsequent service runs.

Required system O&M and operator skill levels:

• Minimal time was required to operate and maintain the system. The daily demand on the 

operator to perform routine O&M was 45 min.

• The treatment system was reliable and easy to operate.

Characteristics of residuals produced by the technology:

• Backwash solids were the only residual produced by the treatment system. Approximately 

2.5 kg of backwash solids was generated during each backwash event, including 0.4% by 

weight of arsenic, 35.3% by weight of iron, and 1.1% by weight of manganese.

Capital and O&M cost of the technology:

• The capital investment for the system was $424,817, consisting of $296,430 for equipment, 

$48,332 for site engineering, and $80,055 for installation, shakedown, and startup.

• The unit capital cost was $772/gpm (or $0.54 gal/day [gpd]) based on a flowrate of 550 gpm. 

This calculation does not reflect the cost for the building and recycle system, which were

funded by the City of Okanogan.

• The O&M cost was 0.18/1,000 gal including incremental cost for chemicals, electricity, and 

labor.
6 

3.0 MATERIALS AND METHODS 

3.1 General Project Approach

Table 3-1 summarizes the pre-demonstration and demonstration activities and completion dates. 

Following the pre-demonstration activities, the performance evaluation study of the Filtronics treatment 

system began on August 14, 2008, and ended on August 14, 2009. 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. The reliability of the system 

was evaluated by tracking unscheduled system downtime and frequency and extent of repair and 

replacement. The plant operator recorded unscheduled downtime and repair information on a Repair and 

Maintenance Log Sheet. 

Table 3-1. Pre-Demonstration and Demonstration Study Activities and Completion Dates 

Activity Date

Introductory meeting held October 28, 2004

Project planning meeting held May 13, 2005

Draft letter of understanding issued May 23, 2005

Final letter of understanding issued August 5, 2005

Request for quotation issued to(a):

• Equipment vendor (Filtronics)

• System installer (including site engineering) 

– City of Okanogan/Gray and Osborne 

(G&O) 

• System installer (including site engineering) 

– Triad Mechanical/Water Quality 

Engineering (WQE)

July 5, 2005

August 5, 2005

April 12, 2006

Letter report issued September 30, 2005

Quotation received from:

• Filtronics

• City/G&O

• Triad Mechanical/WQE

October 7, 2005

January 18, 2006

May 24, 2006

Purchase order established:

• Filtronics

• Triad Mechanical/WQE

October 17, 2005

December 11, 2006

Engineering package submitted to WA DOH May 10, 2007

System permit granted by WA DOH June 5, 2007

Study plan issued June 22, 2007

Building construction began March 3, 2008

Building construction completed July 11, 2008

FH-13 Electromedia®I system delivered July 14, 2008

System installation completed July 24, 2008

System shakedown completed August 14, 2008

Performance evaluation began August 14, 2008

Performance evaluation completed August 14, 2009

(a) Parties performing system installation and site engineering were 

sought after equipment vendor had declined to include site 

engineering and system installation in its quote. 

WA DOH = Washington Department of Health
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 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, engineering, and installation

O&M cost for chemical use, electricity consumption, and labor

O&M and operator skill requirements were assessed through a combination of quantitative data and 

qualitative considerations, including needs for pre- and/or post-treatment, level of system automation, 

extent of preventative maintenance activities, frequency of chemical and/or media handling and 

inventory, and general knowledge needed for relevant chemical processes and related health and safety 

practices. Staffing requirements for the system operation were recorded on an Operator Labor Hour Log 

Sheet. 

The quantity of aqueous and solid residuals generated was estimated by tracking the volume of backwash 

wastewater produced during each backwash cycle. Backwash wastewater was sampled and analyzed for 

chemical characteristics. 

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 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, weekly, and monthly system O&M and data collection following the

instructions provided by the vendor and Battelle. On a daily basis, the plant operators recorded system 

operational data such as pressure, flowrate, totalizer, and hour meter readings (see Appendix A) on a 

Daily System Operation Log Sheet; checked sodium hypochlorite (NaOCl) and ferric chloride (FeCl3) 

levels; and conducted visual inspections to ensure normal system operations. If any problem occurred, 

the plant operators contacted the Battelle Study Lead, who determined if the vendor should be contacted 

for troubleshooting. The plant operators recorded all relevant information, including the problems 

encountered, course of action taken, materials and supplies used, and associated cost and labor incurred, 

on a Repair and Maintenance Log Sheet. On a weekly basis, the plant operators measured several water 

quality parameters onsite, including temperature, pH, dissolved oxygen (DO), oxidation-reduction 

potential (ORP), and residual chlorine, and recorded the data on a Weekly Onsite Water Quality 

Parameters Log Sheet. Backwash data also were recorded on a Backwash Log Sheet.
8 

The capital cost for the arsenic removal system consisted of the expenditure for equipment, site 

engineering, and system installation. The O&M cost consisted of the expenditure for chemical use, 

electricity consumption, and labor. Consumption of NaOCl and FeCl3 was tracked on the Daily System 

Operation Log Sheet. Electricity consumption was determined from utility bills. Labor for various 

activities such as routine system O&M, troubleshooting and repairs, and demonstration-related work, was 

tracked using an Operator Labor Hour Log Sheet. Routine system O&M included activities such as 

completing field logs, replenishing chemical solutions, ordering supplies, performing system inspections, 

and others as recommended by the vendor. The 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 and system installer, was recorded, but not used for the cost analysis.

3.3 Sample Collection Procedures and Schedules 

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

during filter backwash, and from the distribution system. Table 3-3 shows 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 for each sampling location. 

Specific sampling requirements for analytical methods, sample volumes, containers, preservation, and 

holding times are presented in Table 4-1 of the EPA-endorsed Quality Assurance Project Plan (QAPP) 

(Battelle, 2004). The procedure for arsenic speciation is described in Appendix A of the QAPP.

3.3.1 Source Water. During the initial site visit on October 28, 2004, one set of source water 

samples was collected and speciated using an arsenic speciation kit (Section 3.4.1). The sample tap was 

flushed for several minutes before sampling; special care was taken to avoid agitation, which might cause 

unwanted oxidation. Table 3-3 lists analytes for the source water samples.

3.3.2 Treatment Plant Water. During system inspections and operator training on August 14, 

2008, a Battelle staff member and the operators took the first set of treatment plant water samples at the 

wellhead (IN), after the contact tanks (AC), and after filter tank (TT). The samples were speciated onsite 

and analyzed for the analytes listed in Table 3-3 under “monthly” treatment plant water (or speciation 

sampling). Under Battelle’s direction, the operators took the second set of samples from the same 

locations for the analytes listed in Table 3-3 under “weekly” treatment plant water (or regular sampling). 

Beginning on October 7, 2008, the plant operators used the protocols established to collect treatment plant 

water samples weekly, on a four-week cycle, for onsite and offsite analyses. For the first week of each 

four-week cycle, speciation sampling was performed. For the next three weeks, regular sampling was 

performed. Sampling was skipped during the 2008 Thanksgiving and Christmas holidays and during the 

week of February 9, 2009. 

3.3.3 Backwash Wastewater. The operators collected monthly backwash wastewater samples 

from October 2008 through July 2009. Backwash wastewater sampling was performed by directing a 

portion of backwash wastewater at approximately 1 gpm via a plastic tubing connected to the tap on the

backwash wastewater discharge line into a clean, 32-gal container over the duration of filter backwash. 

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 wastewater samples are listed in Table 3-3. 

3.3.4 Distribution System Water. Water samples were collected from the distribution system to 

determine the impact of the arsenic treatment system on its water chemistry, specifically, the arsenic, 

lead, and copper levels. Prior to system startup, four monthly baseline distribution water samples were 

collected from three locations within the distribution system from September 2005 to January 2006. 
9 

Table 3-3. Sampling Locations, Schedules, and Analyses

Sample 

Type

Sample 

Locations(a)

No. of 

Samples Frequency Analytes Collection Date(s)

Source 

Water

IN 1 Once

(during 

initial site 

visit)

Onsite: pH, temperature, 

DO, and ORP

Offsite: 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, NH3, 

NO2, NO3, SO4, SiO2, PO4, 

TOC, TDS, turbidity, and 

alkalinity

10/28/04

Treatment 

Plant Water 

IN, AC, TT 3 Weekly

(Regular 

Sampling)

Onsite(b): pH, temperature, 

DO, ORP, and Cl2 (free 

and total)

Offsite: As (total), 

Fe (total), Mn (total), 

SiO2, P (total), turbidity, 

and alkalinity

See Appendix B

IN, AC, TT 3 Monthly

(Speciation 

Sampling)

Same as weekly analytes 

shown above plus 

following: 

Offsite: As (soluble), 

As(III), As(V), 

Fe (soluble), Mn (soluble),

Ca, Mg, F, NO3, and SO4

See Appendix B

Backwash 

Wastewater

BW 1 Monthly As (total and soluble), 

Fe (total and soluble), 

Mn (total and soluble), 

pH, TDS, and TSS

See Table 4-10

Distribution 

System 

Water

Two LCR 

and one nonLCR 

residences 

3 Monthly Total As, Fe, Mn, Cu, and 

Pb, pH, and alkalinity

See Table 4-12

Backwash 

Solids

BW 1 Once Total As, Ba, Ca, Fe, Mg, 

Mn, P, and Si 

04/14/09

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

contact tanks; TT = after filter tank; and BW = at backwash discharge line.

(b) Onsite chlorine measurements not performed at IN.

DO = dissolved oxygen; LCR = Lead and Copper Rule; ORP = oxidation-reduction potential; TDS = total 

dissolved solids; TOC = total organic carbon. 

Following system startup, distribution system water sampling continued on a monthly basis at the same

locations. The three locations selected for distribution water sampling included two Lead and Copper

Rule (LCR) locations (i.e., 150 Hennepin Street and 650 4th Avenue South) impacted by all wells in the 

distribution system, and one residence (i.e., 341 River Avenue) impacted predominantly by Well No. 4. 

Water from Well No. 4 was treated to remove arsenic under this demonstration project (Section 4.1.1).

Homeowners collected samples following an instruction sheet developed by Battelle in accordance with 
10

CONTACT TANK

DISTRIBUTION

SYSTEM

INFLUENT

(WELL NO. 4) FH-13 System

Average Flow: 550 gpm

Okanogan, WA

Footnotes

(a) On-site analyses

IN

AC

BW

pH, TDS, TSS,

As (total and soluble),

Fe (total and soluble),

Mn (total and soluble)

Weekly

Monthly

NaOCl

ELECTROMEDIA® I

PRESSURE 

FILTRATION

SANITARY 

SEWER

TT

TCLP,

metals

FeCl Iron Addition 3

NaOCl Chlorine Addition

LEGEND

CONTACT

TANK Unit Process

IN At Inlet

BW Backwash Sampling Location

SS Sludge Sampling Location

Process Flow

Backwash Flow

AC After Contact Tanks

TT After Filter Tank

Water Sampling Locations

pH(a), temperature(a), DO(a), ORP(a),

As (total and soluble), As (III),

As (V), Fe (total and soluble),

Mn (total and soluble),

Ca, Mg, F, NO3, SO4, SiO2, P,

turbidity, alkalinity

pH(a), temperature(a), DO(a), ORP(a),

As (total), Fe (total), Mn (total),

SiO2, P (total), turbidity, alkalinity

pH(a), temperature(a), DO(a), ORP(a),

Cl2 (free and total),

As (total and soluble), As (III),

As (V), Fe (total and soluble),

Mn (total and soluble),

Ca, Mg, F, NO3, SO4, SiO2, P, 

turbidity, alkalinity

pH(a), temperature(a), DO(a), ORP(a),

Cl2 (free and total), As (total),

Fe (total), Mn (total), SiO2,

P (total), turbidity, alkalinity

FeCl3

pH(a), temperature(a), DO(a), ORP(a),

Cl2 (free and total), As (total),

Fe (total), Mn (total), SiO2,

P (total), turbidity, alkalinity

pH(a), temperature(a), DO(a), ORP(a),

Cl2 (free and total),

As (total and soluble), As (III),

As (V), Fe (total and soluble),

Mn (total and soluble),

Ca, Mg, F, NO3, SO4, SiO2, P, 

turbidity, alkalinity

CONTACT TANK

RECYCLE PUMP

RECLAIM

TANK

(22,500 gal)

SS

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

the Lead and Copper Monitoring and Reporting Guidance for Public Water Systems (EPA, 2002). Firstdraw samples were collected from cold-water faucets that had not been used for at least 6 hours to ensure

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

sampling, as well as 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 on the 

distribution water samples.

3.3.5 Residual Solids. Residual solids produced by the treatment process consisted of only

backwash wastewater solids. After solids in the backwash wastewater containers (Section 3.3.3) had 

settled and supernatant carefully decanted, residual solids samples were collected on one occasion. The 

solids/water mixture was air-dried for metals analyses.

3.4 Sampling Logistics

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

sampling shipping and handling, are discussed below.

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

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

Resin columns were prepared in batches at Battelle laboratories in accordance with the procedures 

detailed in Appendix A of the QAPP (Battelle, 2004). 

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

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

bottles were new and contained appropriate preservatives. Each sample bottle was affixed with a preprinted, color-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 demonstration site, the 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 separated in a zip-lock bag (each corresponding to 

a specific sample location), and packed in the cooler. When needed, the sample cooler also included 

bottles for the distribution system sampling. 

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

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

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

sample dates and times. After preparation, the sample cooler was sent to the site via FedEx for the 

following week’s sampling event. 

3.4.3 Sample Shipping and Handling. After sample collection, samples for offsite 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. The Battelle Study Lead addressed discrepancies noted by the 

sample custodian with the plant operator. The shipment and receipt of all coolers by Battelle were 

recorded on a cooler tracking log. 

Samples for metal analyses were stored and analyzed at Battelle’s Inductively Coupled Plasma-Mass 

Spectrometry (ICP-MS) Laboratory. Samples for other water quality analyses were packed in separate 

coolers and picked up by couriers from American Analytical Laboratories (AAL) in Columbus, OH; 

TCCI Laboratories in New Lexington, OH; and/or Belmont Labs in Englewood, OH, all of which were 
12

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 QAPP (Battelle, 2004) were followed by 

Battelle ICP-MS, AAL, TCCI Laboratories, and Belmont Labs. Laboratory quality assurance/quality 

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

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

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

QA data associated with each analyte will be presented and evaluated in a QA/QC Summary Report to be 

prepared under separate cover upon completion of the Arsenic Demonstration Project.

Field measurements of pH, temperature, DO, and ORP were conducted by the plant operators using a 

handheld field 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 operators collected a water sample in a clean, 

plastic beaker and placed the probe in the beaker until a stable value was obtained. The plant operators 

also performed free and total chlorine measurements using Hach chlorine test kits following the user’s 

manual.
13

4.0 RESULTS AND DISCUSSION

4.1 Site Description 

4.1.1 Pre-existing Facility. Serving a population of 2,500 people, the water system at the City of 

Okanogan is supplied by four wells, i.e., Wells No. 2, 3, 4, and 5, each having a capacity of 205, 650, 

650, and 550 gpm, respectively. These wells help meet the city’s daily demand of approximately 

1,000,000 gal during the summer and 450,000 gal during the winter. Well No. 4 was designated for this

demonstration study. 

Well No. 4 has a 12-in-diameter, 283-ft casing. A 75-horsepower (hp), 6-in submersible pump is set at 

215 ft below ground surface (bgs) and can yield 650 gpm of water at 390 ft of total dynamic head (TDH). 

However, water rights limit the extraction rate to 550 gpm. The well has one 10-in diameter, 60-slot 

screen and one 10-in diameter, 30-slot screen, extending from 248 to 268 ft bgs and from 268 to 278 ft 

bgs, respectively. The depth of the static water level is at 19 ft bgs. Figure 4-1 shows Well No. 4

wellhead located in a fenced area. A manhole located outside of the fenced area (Figure 4-2) provides 

access to an underground vault where a sample tap, a water meter, and a clay valve are located. The clay 

valve was inoperable, but a gate valve was used to restrict the flow to the 550-gpm extraction limit. The 

well pressure increases from 115 to 160 lb/in2

 (psi) as the well flowrate decreases from 650 to 550 gpm. 

Approximately 120 psi is required for distribution. 

Figure 4-1. Well No. 4 in a Fenced Area
14

Figure 4-2. Manhole for Well No. 4

Prior to installation of the arsenic removal system, well water without chlorination was pumped directly 

into the distribution system and stored in three aboveground reservoirs (East [550,000 gal], North 

[550,000 gal], and Highland [200,000 gal]) and two underground reservoirs (New West [200,000 gal] and 

Existing West [200,000 gal]) with a combined capacity of 1,700,000 gal. 

4.1.2 Distribution System. The distribution system consists of a 17-mile, mostly looped 

distribution line supplied by Wells No. 2, 3, 4, and 5. The distribution system material is a combination 

of 4- to 18-in cast iron (40%), asbestos concrete (35%), polyvinyl chloride (PVC) (15%), and ductile iron 

(10%). Service lines to individual homes are galvanized steel (75%), copper (25%), and polyethylene 

(<1%) piping. 

The City of Okanogan samples water periodically from the distribution system for a number of 

parameters, including monthly at two residences for bacterial analysis and once every three years at 10 

residences for lead and copper under EPA’s LCR. Well No. 1 also is sampled quarterly for arsenic; 

yearly for partial chemistry and volatile organic compounds (VOCs); once every three years for synthetic 

organic compounds (SOCs); and once every nine years for metals and radionuclides.

After the arsenic removal system began operation, the City sampled once at three residences for 

trihalomethanes (THMs) and haloacetic acids (HAAs) under EPA’s Disinfection Byproducts Rule 

(DBPR), as requested by WA DOH. Because of low THM and HAA results, the City was not required to 

sample THMs and HAAs again.

4.1.3 Source Water Quality. Battelle collected source water samples from Well No. 4 on October 

28, 2004 during the initial site visit. Table 4-1 presents the Battelle results and those provided by the 
15

facility to EPA for site selection and by the selected technology vendor (Filtronics). Historic raw water 

data from Well No. 4, obtained from the facility, also are summarized in Table 4-1 and tabulated in 

Table 4-2. In general, Battelle’s data were comparable to those provided by other parties with exception 

to three outliers found in the historic raw water data provided by the facility (Table 4-2). 

Table 4-1. Well No. 4 Water Quality Data

Parameter Unit

Facility

Data

Battelle 

Data

Filtronics

Data

Historical 

Facility 

Data

Sampling Date

Not 

Specified 10/28/04

07/12/05–

07/15/05 1985–2004

pH S.U. 7.6 8.0 8.0–8.1 NA

Temperature °C NA 16.0 15.0 NA

DO mg/L NA 1.8 NA NA

ORP mV NA -47 NA NA

Alkalinity (as CaCO3) mg/L NA 185 176 NA

Hardness (as CaCO3) mg/L NA 286 NA 179–243

Turbidity NTU NA 0.2 NA 0.1–0.5(a)

TDS mg/L NA 346 421 NA

TOC mg/L NA <0.7 NA NA

Nitrate (as N) mg/L NA <0.04 NA ND–0.15

Nitrite (as N) mg/L NA <0.01 NA NA

Ammonia (as N) mg/L NA 0.05 NA NA

Chloride mg/L ND 2.0 NA NA

Fluoride mg/L NA 0.4 NA 0.5–0.7

Sulfate mg/L 111 110 NA 108–116

Silica (as SiO2) mg/L NA 24.1 NA NA

Orthophosphate (as PO4) mg/L NA <0.06 NA NA

As (total) μg/L 17 18.4 18–19 17–20(b)

As (soluble) μg/L NA 18.6 NA NA

As (particulate) μg/L NA <0.1 NA NA

As(III) μg/L NA 3.0 NA NA

As(V) μg/L NA 15.6 NA NA

Fe (total) μg/L 70 69 55–78 50–151(c)

Fe (soluble) μg/L NA 45 NA NA

Mn (total) μg/L 60 70.2 NA 49–92

Mn (soluble) μg/L NA 70.3 NA NA

U (total) μg/L NA 0.4 NA NA

U (soluble) μg/L NA 0.5 NA NA

V (total) μg/L NA 0.3 NA NA

V (soluble) μg/L NA 0.3 NA NA

Na (total) mg/L 21 30.1 NA 19–25

Ca (total) mg/L NA 54.7 NA NA

Mg (total) mg/L NA 36.3 NA NA

(a) One outlier of 2.7 NTU not included in this range.

(b) One outlier of <10 μg/L not included in this range

(c) One outlier of 1,140 μg/L not included in this range.

DO = dissolved oxygen; NA = not available; NTU = nephelometric turbidity unit; ORP = oxidation-reduction 

potential; TDS = total dissolved solids; TOC = total organic carbon
16

Table 4-2. Well No. 4 Historic Water Quality Data

Parameter Unit Historical Facility Data

Year 1985 1988 1992 1994 1995 1997 1998 1999 2001 2002 2003 2004

Conductivity μS/cm 530 530 530 - - 533 - - 539 - - 685

Hardness mg/L 240 240 222 - 223 179 - - 218 - - 243

Turbidity NTU 0.1 0.4 2.7(a) - - 0.2 - - 0.5 - - 0.1

Nitrate mg/L ND ND ND ND ND ND ND ND ND ND 0.15 ND

Fluoride mg/L 0.5 0.6 0.6 - 0.7 0.6 - - 0.7 - - 0.6

Sulfate mg/L - - - - 113 111 - - 108 - - 116

As (total) μg/L <10(a) 18 17 - 20 20 - - 18 20 - 20

Fe (total) μg/L 100 100 1,140(a) - 50 70 - - 151 - - ND

Mn (total) μg/L 80 88 92 - 60 60 - - 49 - - 64

Na (total) mg/L 19 21 23 - 22 21 - - 22 - - 25

(a) Results not consistent with other data.

ND = not detected.

Arsenic. Historically, total arsenic concentrations ranged from 17 to 20 μg/L, with one exception 

(<10 μg/L) occurring in 1985 (Table 4-2). Out of 18.4 μg/L of total arsenic measured by Battelle on 

October 28, 2004, 3.0 μg/L existed as soluble As(III) and 15.6 μg/L as soluble As(V). As such, soluble 

As(V) was the predominant species. (Note that soluble As[III] became the predominant species during 

the 1-year performance evaluation study [Section 4.5.1.1]). Chlorine provides near-complete oxidation of 

As(III) to As(V), typically in less than 30 seconds (Ghuyre and Clifford, 2001). Because NaOCl was 

added to raw water and more than 2 min of contact time was provided prior to filtration, all As(III) should 

be oxidized prior to filtration where it was removed along with iron solids formed. 

Iron. Source water had low levels of iron (50 to 151 μg/L) with one exception (1,140 μg/L) occurring in 

1992 (Table 4-2). Typically, soluble iron concentrations should be at least 20 times soluble arsenic 

concentrations for effective arsenic removal via coagulation using iron salt as a coagulant. Therefore, 

ferric iron had to be added to raw water to remove arsenic. Based on the arsenic and native iron data

obtained by Battelle, at least 0.3 mg/L of iron would need to be added to raw water to reach the generally 

recommended ratio of 20:1 between soluble iron and soluble arsenic concentrations for satisfactory 

arsenic removal. 

Manganese. Manganese concentrations ranged from 49 to 92 μg/L, existing almost entirely in a soluble 

form, based on the speciation result obtained by Battelle on October 28, 2004. Manganese concentrations 

were over manganese’s secondary maximum contaminant level (SMCL) of 0.050 mg/L. Removal of 

manganese might be achieved via chlorination (to form manganese dioxide solids) and filtration, 

depending on oxidation kinetics. 

Other Water Quality Parameters. pH values of raw water ranged from 7.6 to 8.1, which were within 

the commonly agreed range of 5.5 to 8.5 for iron coagulation. Therefore, no provisions were made for pH 

adjustment. Concentrations of all other analytes appear to be low enough not to adversely affect arsenic 

removal with iron solids and the subsequent pressure filtration process. 

4.2 Treatment Process Description

The treatment process involved chlorination, iron addition, adsorption/coprecipitation, and 

Electromedia®I pressure filtration. The filter media is processed from naturally occurring minerals. The 

filter media and support gravels are approved for use in drinking water applications under NSF
17

International (NSF) Standard 61. Information related to the physical properties of the media and support 

gravels is considered proprietary and is not attainable from the vendor. 

Figure 4-3 presents a plan view of the FH-13 treatment system, which consisted of two chemical addition 

systems (for NaOCl and FeCl3), two contact tanks (arranged in series), one horizontal filter tank, 

backwash wastewater reclaim equipment, sample taps, and associated instrumentation for pressure and 

flow monitoring. Fully automated, the system featured a graphic display operator interface panel (OIP), a 

programmable logic controller (PLC), and a US Robotics 56K external modem that allowed for remote 

programming changes and troubleshooting. A 2-hp compressor was used to actuate pneumatic solenoid 

valves, enabling backwash or service mode. The system was skid-mounted with schedule 40 steel piping, 

150 lb forged steel flanges, and 125 lb cast iron flange fittings. Table 4-3 specifies key design parameters 

of the treatment system. Figure 4-4 presents photographs of several system components.

Contact Tanks

Filter Tank

Source: Filtronics, 2006.

Figure 4-3. Plan View of Filtronics’ FH-13 Treatment System

Major process components are discussed as follows:

• Intake. Source water was pumped from Well No. 4 at approximately 550 gpm via 10-in 

schedule 40 steel pipe into the treatment system. The amount of water pumped was tracked 

with a totalizer installed at the wellhead. The well pump was activated and deactivated based 

on level sensors in the City’s water reservoirs. The well pump was shut down when the 

water level in the reservoirs reached the “Stop” set level and was turned on when the water 

level was reduced to the “Start” set level. Figure 4-4 includes a photo of the well pump 

control box with an hour meter for tracking the system operation hours. 

• Chlorination. NaOCl at 12.5% was added to raw water to oxidize As(III) to As(V) and 

Fe(II) to Fe(III). The chlorine addition system consisted of a 1.3-gal/hr (gph) IWAKI 

WalChem (Model EWC 15 F1-DC) metering pump, a calibration column, a chemical supply 

manifold, and three 53-gal chemical drums (Figure 4-5). The metering pump was energized 

only when the well pump was on. To achieve the target chlorine dosage of 0.7 mg/L (as Cl2), 

the operator adjusted the speed and stroke length settings of the pump. The NaOCl

consumption was tracked by measuring solution levels in the drums using a yardstick. The 

measurements would be accurate only for the straight-wall portion of the drums. 

• Iron Addition. A 42% FeCl3 solution was injected to raw water to enhance arsenic removal. 

Similar to the chlorine addition system, the iron addition system consisted of a 1.3-gph

IWAKI WalChem metering pump, a calibration column, a chemical supply manifold, and 
18

Table 4-3. Design Specifications of FH-13 Treatment System

Parameter Value Remarks

Pretreatment

Chlorine Addition (mg/L) 0.7 Field determined

Iron Addition (mg/L) 0.9 Field determined

Contact

No. of Tanks 2 Arranged in series

Tank Size (ft) 4 D × 8 H Fitted with semi-elliptical heads

Tank Volume (ft3/vessel) 100 –

Contact Time (min) 2 Based on design flowrate of 750 

gpm and both tanks combined 

Filtration

No. of Tank 1 –

Tank Size (ft) 7 D × 91

/3 L(a) Fitted with semi-elliptical ends

Electromedia-I

® (ft3

) 174 25- to 27-in depth

Support Media and Concrete (ft3) 76 25-in depth

Available Surface Area (ft2) 75 –

Design Flowrate (gpm) 750 Design capacity

Well Flowrate (gpm) 550 Based on allowed extraction rate

Hydraulic Loading Rate (gpm/ft2) 10 Based on design flowrate

Backwash

Backwash Flowrate (gpm) 1,500 Water at 20 oC

Hydraulic Loading Rate (gpm/ft2) 20 Water at 20 oC

Backwash Duration (min) 4 –

Design Filter-to-Waste Flowrate (gpm) 750 Well flowrate 550 gpm 

Filter-to-Waste Duration (min) 1 –

Wastewater Production (gal/cycle) 6,750 –

Frequency (hr/backwash) 8 –

(a) 91/3 ft is straight length, which does not include inner height of semi-elliptical heads. 

D = diameter; L = length; H = height

two 55-gal chemical drums (Figure 4-5). The target iron dosage was 0.9 mg/L (as Fe). The 

chemical dosage was controlled by the speed and stroke length settings of the pump. The 

FeCl3 solution consumption was measured based on solution levels using a yardstick. The 

measurements would be accurate only for the straight-wall portion of the drums.

• Adsorption/Coprecipitation. Two 4-ft-diameter × 8-ft-high carbon steel contact tanks fitted 

with semi-elliptical heads were used to enhance formation of iron flocs prior to pressure 

filtration. Arranged in series, the skid-mounted tanks provided a total of 2 min of contact 

time at the design flowrate of 750 gpm. Each tank had two 10-in connections, one 4-in drain, 

and one 12-in ×16-in access handhole (Figure 4-4). 

• Pressure Filtration. Removal of arsenic-laden flocs was achieved via downflow filtration of 

the effluent from the contact tanks. The horizontal filter tank was 7-ft in diameter and 9.3-ft 

long, fitted with semi-elliptical ends and upper and lower manifold assemblies. The filter 

tank also had two 10-in connections, one 4-in drain, one 12-in ×16-in access handhole, and 

one 20-in access manway (Figure 4-4). Constructed of carbon steel, the floor-mounted tank 

was rated for a working pressure of 150 psi. 

In the filter tank, 25 to 27 in (or 174 ft3

) of Electromedia®I media was loaded on top of three 

layers of support gravels (i.e., T208, S202, and S200), each having a different nominal
19

Figure 4-4. Treatment System Components

(from left to right and top to bottom: Contact Tanks; Filtration Vessel; Sample Tap; 

Backwash and Effluent Flowmeters; PLC Control Panel; 

Filtration Media; Well Pump Controller and Hour Meter) 
20

Figure 4-5. Chlorine and Iron Addition Systems

 (Clockwise from top left: NaOCl Addition System; Iron Addition System;

NaOCl and Iron Injection Points)

particle size. The support gravels (33 ft3 total) were placed, in turn, on top of a concrete

layer, which was poured at the bottom of the filter tank with its top surface laid just below the 

bottom laterals. The total depth of the concrete and support gravel layers was approximately 

25 in. Additional layers of light purple gravel and anthracite were then placed on top of 

Electromedia®I media, leaving approximately 16 to 20 in of freeboard for filter backwashing. 

Installation of the multiple filtration and support layers allowed a filtration surface area of 

approximately 75 ft2

, which would yield a hydraulic loading rate of 10 gpm/ft2 at the design 

flowrate of 750 gpm. Actual flowrates and throughput values through the filter tank were 

monitored using a propeller flow meter/totalizer, as shown in Figure 4-4.

• Backwash. Backwashing removes particulates accumulating in the filter bed, thereby 

reducing pressure buildup. The filter was automatically backwashed by one of two triggers: 

(1) shutdown of the treatment system when water level in the City’s reservoirs reached the 

“Stop” set level, and (2) preset run time, typically 8 hr (with a 10-psi differential pressure 

override). There was a time delay before the system went into a backwash cycle. This was 

incorporated to allow for the flow to stop from the well pump before closing filtered water 
21

outlet valves. The chemical feed systems were automatically shut down during backwash. 

Each backwash cycle involved backwashing the filter at 1,500 gpm (or 20 gpm/ft2

) for 4 min 

using treated water from the distribution system and rinsing the filter at 550 gpm for 1 min

using the effluent from the contact tanks. Backwash flowrate was monitored using a 

propeller flow meter/totalizer (Filtronics 10-in tube meter), as shown in Figure 4-4.

• Backwash Reclaim System. Backwash wastewater was stored in a 22,500-gal reclaim tank 

provided by the facility (Figure 4-6). The reclaim tank was equipped with high/low float 

switches interlocked with the PLC, a floating suction strainer (to prevent uptake of solids), a 

10-hp reclaim pump, and 2-in recycle loop piping. The lower float switch was for stopping 

the reclaim pump. Whenever the filter was in the filtration mode and the water level in the 

reclaim tank was over that of the lower float, the reclaim pump would be activated until the 

water level hit the lower float. The upper float switch was for the reclaim high level alarm. 

When the water level was above that of this switch during filtration, the reclaim level light 

would flash. If the water level in the reclaim tank was above the alarm level when the filter 

was calling for backwash, the drain valve under the reclaim tank would open until the level in 

the reclaim tank dropped below the alarm level. The filter would then begin backwash.

The reclaim pump recycled supernatant from the reclaim tank through the recycle loop piping 

to the head of the treatment train (downstream of chemical addition points), where the

supernatant was blended with raw water at a rate of approximately 7 gpm controlled by a

fixed rate orifice flow control valve. For every four backwashes, solids accumulating at the

bottom of the reclaim tank were disposed of from the 5% sloped-bottom reclaim tank through

a drain to a sewer (Figure 4-6). 

Figure 4-6. Reclaim System Components

(From left to right and top to bottom: Reclaim Tank; Reclaim pump; 

Float Switches in Reclaim Tank; Floating Suction Strainer; Reclaim Tank Drainage) 
22

4.3 Treatment System Installation

At most arsenic removal technology demonstration sites, equipment vendors served as sole subcontractors 

to Battelle to provide treatment systems and associated engineering and installation services. This 

turnkey approach was adopted by Battelle to expedite the procurement process and minimize potential 

disputes among multiple contractors working on the same projects. Filtronics, however, did not provide 

such services for its treatment system. Gray and Osborne (G&O), the engineering firm responsible for the 

building design and construction for the City, was initially interested in taking on such responsibilities. 

However, due to unfamiliarity with Filtronics’ system and difficulties of separating the scope of work 

between the City and Battelle, G&O produced a cost estimate far exceeding the budget. Filtronics was 

contacted for a list of installers that were familiar with its systems; Triad Mechanical (Triad) was one of 

the firms identified and contacted. Triad, teaming with Water Quality Engineering (WQE), submitted a 

cost proposal for engineering and installation services, which was accepted by Battelle. The process of 

identifying a firm capable of providing engineering and installation services spanned from May 13, 2005, 

when the initial project planning meeting was held (see Table 3-1) to April 12, 2006, when a request for 

quotation (RFQ) was issued to Triad, causing repeated delays to the demonstration study. 

Upon issuance of a purchase order, Triad/WQE worked with Battelle, Filtronics, and the City/G&O for 

system permitting, installation, startup, and shakedown. Significant efforts were made by Battelle to 

coordinate work among all parties involved. To ensure that all project scopes were covered and all 

project activities were completed in a timely manner, a responsibility matrix was developed by Battelle 

and is presented in Appendix C. 

4.3.1 System Permitting. The system engineering package was prepared by Triad and WQE with 

input from G&O, and included the following documents and drawings: 

 

• A system design report 

• A general arrangement and piping and instrumentation diagram (P&ID) 

• Electrical and mechanical drawings and component specifications 

• Building construction drawings detailing connections from the system to the inlet piping and 

the City’s water and sanitary sewer systems. 

The engineering package was submitted to WA DOH for review and approval on May 10, 2007. After 

WA DOH’s review comments were addressed, the package was resubmitted, along with a permit 

application, on May 23, 2007. A water supply construction permit was issued by WA DOH on June 5, 

2007, and fabrication of the system began thereafter. 

4.3.2 Building Construction. A permit for building construction was issued by the City of 

Okanogan in August 2007. The City opened bids for building construction in August 2007. Due to lack 

of responses from qualified contractors and due to high bid prices (at least twice the amount of the 

community development block [CDB] grant the City received) from the two initial bidders, the City 

rejected the initial bids and reopened the bids in October 2007. Two bids were received, with the lowest 

bid still $180K higher than the CDB grant. Upon receipt of additional CDB funds, the City applied for 

and obtained, the City awarded the contract to the lowest bidder, Rains Contracting, Inc. on December 4, 

2007. The building construction began on March 3, 2008, and was completed on July 11, 2008. Figure 

4-7 shows photographs of the treatment building and reclaim tank under construction. Figure 4-8 

presents a photograph of the treatment system building and reclaim tank.

 
23

Figure 4-7. New Building and Reclaim Tank Under Construction

Figure 4-8. New Building and Reclaim Tank
24

4.3.3 System Installation, Startup, and Shakedown. The FH-13 Electromedia®I treatment 

system was delivered to the site on July 14, 2008. Triad performed offloading (Figure 4-9) and began 

installation of the system, including connections to the entry and distribution piping and electrical 

interlocking. System installation and hydraulic testing were completed on July 24, 2008. 

Figure 4-9. Equipment Delivery and Unloading

Filtration and support media were loaded into the filter tank following Filtronics’ instructions. A layer of 

concrete was poured at the bottom of the filter tank with its top surface laid 2-in below bottom laterals. 

On top of the concrete layer were three layers of support gravels (6, 3, 12 in of S200, S202, and T208, 

respectively), each having a different nominal particle size. The concrete and support layers had a total 

depth of approximately 25 in. The Electromedia®I media was loaded on top of the support gravels with a 

depth of 25 to 27 in. A layer of light purple gravel plus a layer of carbon anthracite covered the top of the 

filtration media bed to prevent media loss during backwash. Figure 4-10 shows the cross section of the

horizontal filter tank with layers of filtration and support media in the tank.
25

25"

7"

25"

84"

2"

ELECTROMEDIA® I

SUPPORTING

MEDIA

CONCRETE

T 208

S 202

CARBON ANTHRACITE

LIGHT PURPLE GRAVELS

LATERAL

S 200

25"

7"

25"

84"

2"

ELECTROMEDIA® I

SUPPORTING

MEDIA

CONCRETE

T 208

S 202

CARBON ANTHRACITE

LIGHT PURPLE GRAVELS

LATERAL

S 200

Figure 4-10. Schematic Illustration of Filtration and Supporting Media 

Layers in Filtration Tank

A water sample was collected and passed bacteriological tests and startup and shakedown activities were 

completed on August 14, 2008. Startup and shakedown activities included PLC testing, instrument 

calibration, chlorine disinfection and residual testing, and operator training on system O&M. Startup

activities included steps to “break in” the filter according to the schedule shown in Table 4-4. Battelle 

performed system inspections and operator training on sample and data collection on August 14, 2008. 

The 1-year demonstration study started on August 14, 2008.

Table 4-4. Filter Break-in Schedule

Day

Maximum 

Filter Run 

Time 

(hr)

Minimum 

Number 

of 

Backwashes

Total 

Minimum 

Filter Run 

Time 

(hr)

1 2 4 8

2 2 4 8

3 3 3 9

4 4 2 8

5 5 2 10

6 6 2 12

7 7 2 14

8 8 1 8

4.4 System Operation

4.4.1 Service Operation. Operational parameters of the treatment system are tabulated and 

attached as Appendix A with key parameters summarized in Table 4-5. The performance evaluation 

study began on August 14, 2008, and ended on August 14, 2009. The treatment system operated for a 

total of 4,358 hr based on the hour meter of the well pump. Because the operation data log was not filled 
26

out during weekends and because the daily log was not necessarily recorded at the same time each day 

during weekdays, recorded incremental operating times were normalized to obtain daily operating times 

(by dividing the incremental hours by the number of days since last recording times). As shown in

Table 4-5. Treatment System Operational Parameters 

 Note: Data presented included average and [range].

(a) Based on dosage data collected after November 20, 2008, when proper 

chlorine dosage was established. 

(b) Data before October 2, 2008, when system was not operating constantly 

(Section 4.4.2), were not included in calculation.

(c) Based on totalizer readings at system outlet.

(d) Based on flow meter readings at system outlet.

(e) Calculated flowrates based on incremental throughput and incremental

operating time. 

(f) Based on instantaneous flowrate readings.

(g) Two outliers (i.e., 10 and 13 psi on 12/24/08 and 12/29/08, respectively) 

omitted.

(h) Estimated based on backwash totalizer and averaged volume of wastewater 

generated per backwash. 

(i) Based on monthly data recorded on the Backwash Log Sheets.

Figure 4-11, normalized daily operating times fluctuated significantly from 2.5 to 23.8 hr and averaged 

13.6 hr (not including two outliers on August 15 and 18, 2008). Seasonal variations were observed with

relatively longer operating times during summer months (averaged 17.3 hr from May through August) 

and relatively shorter operating times during winter months (averaged 10.2 hr from December through 

March).

Parameter Value

Operating Period 08/14/08–08/14/09

Pretreatment Operation

NaOCl Dosage (mg/L [as Cl2])(a) 0.7 [0.2–1.5]

FeCl3 Dosage (mg/L [as Fe]) 0.9 [0.2–4.4]

Service Operation

Total Operating Time (hr) 4,358

Average Daily Operating Time(b) (hr) 13.6

Throughput(c) (gal) 139,435,000

Average Daily Demand(b,c) (gal) 414,000

Instantaneous Flowrate(d) (gpm) 527 [460–590]

Calculated Flowrate(e) (gpm) 538 [351–738]

Contact Time in Contact Tanks(f) (min) 2.8 [2.5–3.3]

Hydraulic Loading over Pressure Filter(f) (gpm/ft2) 7.0 [6.1–7.9]

∆p Across filter tank(g) (psi) 0.8[0–4]

Backwash Operation

Average Frequency(h) (backwash/day) 2.3

Number of Backwash Cycles(h) 759

Flowrate(i) (gpm) 1,344 [1,000–1,750]

Hydraulic Loading Rate (gpm/ft2) 17.9 [13.3–23.3]

Duration (min) 4 [4–5]

Backwash Volume (gal/cycle) 5,400 [4,000–7,000]

Filter-to-Waste Volume (gal/cycle) 750

Wastewater Produced (gal/cycle) 6,150 [4,750–7,750]
27

0

5

10

15

20

25

30

Daily Operating Time (hrs)

Figure 4-11. Treatment System Normalized Daily Operating Times 

Total system throughput was approximately 138,151,000 gal based on flow totalizer readings at the 

wellhead and was 139,435,000 gal based on flow totalizer readings measured at the system outlet. The 

throughput values as measured by propeller flow meter/totalizer at the system outlet matched closely with 

those by electromagnetic flow meter/totalizer (Siemens, SITRANS M MAGFLO MAG 5000) at the 

wellhead, with only 0.9% difference observed through the 1-year study period. Average daily demand of 

414,000 gpd was calculated by dividing the total throughput from October 2, 2008, through August 14, 

2009, by the number of operating days during the period. The calculation did not include the data 

collected before October 2, 2008, because the treatment system did not operate constantly due to 

shakedown and chlorine dosage tests (Section 4.4.2). The average daily demand increased to 520,000 

gpd during summer months (from May through August) and decreased to 332,000 gpd during winter 

months (from December to March).

System flowrates were tracked by two flow meters/totalizers located at the wellhead and system outlet. 

Flowrates also were calculated based on readings of the two flow meters/totalizers located at the wellhead 

and system outlet and corresponding hour meter readings. As shown in Figure 4-12, instantaneous

flowrate readings and calculated flowrate values matched closely at both the wellhead and system outlet, 

with relative error within 2% on average. Instantaneous flowrate readings at the system outlet ranged

from 460 to 590 gpm and averaged 527 gpm, compared to the average value of 550 gpm expected at the 

site (see Table 4-3). The 527 gpm flowrate corresponded to a contact time of 2.8 min in the two contact 

tanks (compared to the design value of 2.0 min) and a filtration rate of 7.0 gpm/ft2 over the pressure filter 

(compare to the design value of 10 gpm/ft2

) (Table 4-3). 
28

0

100

200

300

400

500

600

700

Flowrate (gpm)

Instantaneous Flowrate at Wellhead Averaged Flowrate at Wellhead

Instantaneous Flowrate at System Effluent Averaged Flowrate at System Effluent

Figure 4-12. Treatment System Flowrates

Differential pressure (Δp) readings across the pressure filter typically ranged from 0 to 4 psi and averaged 

0.8 psi (Figure 4-13). As shown in the figure, a few spikes were measured during December 17, 2008, 

through January 6, 2009, due to malfunctioning of a 10-in control valve on the backwash line (Section 

4.4.3.1). These spikes were excluded from Δp calculations in Table 4-5. Figure 4-14 compared Δp 

readings before and after backwash as recorded on the Backwash Log Sheet (Appendix D). Δp across the 

filter was typically 1 to 2 psi right before a backwash and was reduced to 0 psi right after a backwash 

except for a few occasions. This indicates that backwashing was generally effective under the conditions 

specified in Table 4-5.

4.4.2 Chlorine and Iron Additions. Chemical pretreatments include chlorine and iron additions. 

During the first three months of system operation, several operational issues/problems related to the 

chlorine addition system arose and are summarized in Table 4-6. 

At the beginning of the performance evaluation study, the chlorine addition system operated at a Battelle 

recommended residual level of 0.5 mg/L (as Cl2) in system effluent. On September 8, 2008, Filtronics 

asked the operator to shut down the treatment plant, claiming that the Electromedia®I might be damaged 

due to the low chlorine residual (0.5 mg/L [as Cl2]). Filtronics stated that the free chlorine residual level

following the filter tank must be 10% above chlorine breakpoint or 0.5 mg/L, whichever was greater. 

Filtronics suggested a set of chlorine dosage tests to determine the optimal dosage. 
29

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

∆P (psi)

Backwash was not conducted automatically, due to 

the malfuntion of the 10" control valve on the 

backwash line.

Figure 4-13. Differential Pressure Across Pressure Filter

0

1

2

3

4

5

6

7

8

Differential Pressure Across Filtration Tank (psi)

Pressure Drop before Backwash Pressure Drop after Backwash

Backwash was not conducted automatically, due to 

the malfuntion of the 10" control valve on the 

backwash line.

Figure 4-14. Differential Pressure Across Pressure Filter Before and After Backwash
30

Table 4-6. Issues/Problems Encountered Related to Chlorine Addition System

Date Issue/Problem Encountered Corrective Action

09/08/08 to 

10/02/08

Filtronics asked to shut down treatment system

on 09/08/08, because it believed that the target 

chlorine residual level of 0.5 mg/L (as Cl2) in

system effluent was lower than what would be 

required by the system.

Under instructions of Filtronics, a 

series of chlorine dosage tests were 

conducted by operator to determine 

“optimal chlorine dosage.” Based 

on test results, a target chlorine feed

rate of 0.7 gph was recommended by 

Filtronics. Treatment system was 

put back to service with this feed 

rate on 10/02/08 

08/14/08 to 

10/23/08

Airlock observed in chlorine feed line, causing

unstable and fluctuating chlorine feed rates

On 10/23/08, leaks in chlorine feed 

system’s manifold identified and 

repaired 

Late 

October to 

11/20/08 

City received complaints about red water and 

chlorine odor in water 

A conference call was held on 

11/20/08 with city, G&O, EPA, and 

Battelle; consensus was reached to

restore target chlorine residual level

to 0.5 mg/L (as Cl2) in system 

effluent

With the assistance of the plant operator, a Filtronics technician was onsite to perform the chlorine dosage 

tests in September 2008. During the tests, the NaOCl feed rate was gradually increased from 0.1 to 0.9 

gph at a 0.1 gph increment, and total and free chlorine residuals in system effluent were measured. 

Actual feed rates during each test also were measured both at the beginning and end of the test. The 

average chlorine dose added to the influent water at each feed rate was calculated based on the actual 

system flowrate and average of actual feed rates and plotted in Figure 4-15. These calculations assumed a 

constant stock chlorine concentration of 12.5% (as Cl2). 

Comparison between calculated chlorine doses at AC and total and chlorine residuals in system effluent 

during each test indicated some chlorine demand across the pressure filter. For example, 0.53 mg/L of 

chlorine (as Cl2) was consumed at a 0.2-gph feed rate (or ~1.0 mg/L [as Cl2]), leaving 0.47 mg/L (as Cl2) 

of total chlorine in system effluent. At 0.7 gph (or ~2.7 mg/L [as Cl2]), 1.2 mg/L (as Cl2) was consumed 

and 1.5 mg/L (as Cl2) was measured in system effluent. The chlorine demand across the pressure filter 

continued to increase to 2.0 mg/L (as Cl2) at a 0.9-gph feed rate (or ~4.5 mg/L [as Cl2]), leaving 2.5 mg/L 

(as Cl2) of total chlorine in system effluent. 

Based on the dosage tests, Filtronics determined the chlorine feed rate to be 0.7 gph (or ~2.7 mg/L [as 

Cl2]). The treatment system was put back in operation on October 2, 2008. As shown in Figure 4-16, at 

the target feed rate of 0.7gph, the total chlorine residual measured in system effluent was 1.53 mg/L (as 

Cl2). Since system re-startup on October 2 through the end of October, total chlorine residuals measured

in the plant effluent ranged from 1.2 to 2.0 mg/L (as Cl2) (see discussion in Section 4.5.1.5). These high 

chlorine residuals led to a number of consumer complaints, as discussed below.

Since system startup on August 14 through October 23, 2008, airlocks observed in the chlorine feed 

system caused unstable and fluctuating chlorine feed rates. The airlock problem was resolved on October 

23, 2008, when leaks in the feed system manifold were identified and repaired. A stable chlorine feed 

rate was established since repair of the leak. 
31

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Chlorine Concentration (mg/L as Cl2)

NaOCl Target Feed Rate (gph)

Free Cl2 (09/17/08) Free Cl2 (09/19/08) Free Cl2 (09/23/08) Free Cl2 (09/25/09)

Free Cl2 (09/26/08) Total Cl2 (09/17/08) Total Cl2 (09/19/08) Total Cl2 (09/23/08)

Total Cl2 (09/25/08) Total Cl2 (09/26/08)

Residual Chlorine in System Effluent

Calculated chlorine dose based on actual feed rate

Figure 4-15. Chlorine Dosage Test Results

In late October, the city received complaints about red water and chlorine smell in consumers’ tap water. 

A local newspaper reported the incident on October 29, 2008. Total chlorine residuals measured in plant 

effluent ranged from 1.2 to 2.7 mg/L (as Cl2) during the period between October 23 (after the airlock 

problem was resolved) to November 20, 2008. In response, a teleconference was held on November 20, 

2008, with the city, G&O, EPA, and Battelle to discuss the issue. A consensus was reached to reduce the 

chlorine feed rate so that residual levels in plant effluent could be maintained at approximately 0.5 mg/L 

(as Cl2). Upon implementation of this decision, customer complaints discontinued and total chlorine 

residual levels measured throughout the rest of the study period were from 0.3 to 0.6 mg/L (as Cl2) and 

averaged 0.5 mg/L (as Cl2). With these residual levels, arsenic concentrations in system effluent were 

maintained at levels below 10 μg/L (except for one occasion on December 3, 2008, when the chlorine 

pump was not functioning properly as discussed in Section 4.5.1.1).

Figure 4-16 presents chlorine doses, as calculated based on incremental NaOCl consumption (as 

measured by changes in solution level in the chemical barrel) and corresponding incremental throughput 

(according to the system effluent totalizer). Between October 2, 2008 (when the system was put back in 

service with an intended feed rate of 0.7 gph), and October 23, 2008, measured chlorine doses fluctuated 

significantly due to leaks in the chlorine system’s manifold as discussed above. After the manifold was 

repaired on October 23, 2008, the chlorine feed rate was restored presumably to the target level of 0.7 

gph. Total chlorine residuals measured during October 23, 2008, through November 20, 2008 (when the 

feed rate was reduced to allow for a target total chlorine residual of 0.5 mg/L [as Cl2] in plant effluent) 

ranged from 1.2 to 2.7 mg/L (as Cl2) and averaged 2.1 mg/L (as Cl2). After November 20, 2008, 

measured chlorine doses were reduced significantly to levels ranging from 0.2 to 1.5 mg/L (as Cl2) and 

averaging 0.7 mg/L, which was very close to the target level of 0.5 mg/L (as Cl2).
32

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

2.2

2.4

2.6

2.8

3

NaOCl Dosage (mg/L as Cl2)

Fluctuating 

residual 

levels due 

to leaks in 

feed 

system's 

manifold

High chlorine 

residual levels 

measured during 

period with 

customer's 

complaints about 

red water and 

chlorine odor 

Figure 4-16. Chlorine Doses over Demonstration Study Period

With the amounts of reducing species (such as As[III], Fe[II], and Mn[II]) and ammonia in raw water (see 

Section 4.5.1), 0.12 mg/L of chlorine (as Cl2) would be needed to oxidize As(III), Fe(II), and Mn(II) to 

form As(V), Fe(III), and Mn(IV), and 0.57 mg/L of chlorine (as Cl2) needed to react with 0.075 mg/L of 

ammonia (as N) to reach breakpoint chlorination. Therefore, with 0.7 mg/L of chlorine added, 0.01 mg/L 

(as Cl2) of free chlorine would be produced in system effluent (Section 4.5.1.5).

Iron was added to source water as a coagulant to remove soluble arsenic through adsorption and/or 

coprecipitation with iron solids. Figure 4-17 presents calculated FeCl3 doses (mg/L [as Fe]) and iron 

concentrations (mg/L [as Fe]) measured after the contact tanks (at AC) over the entire study period. 

Similar to chlorine doses, iron doses were calculated based on incremental FeCl3 consumption (by 

changes in solution level in the chemical barrel) and the corresponding throughput (according to the 

system effluent totalizer). Note that Figure 4-17 does not include an outlier of 7.2 mg/L of total iron

measured at AC on November 4, 2008, when backwash solids appeared to have been reintroduced from 

the reclaim tank (Section 4.5.1). 

During the entire study period, calculated iron doses ranged from 0.21 to 4.4 mg/L (as Fe) and averaged 

0.9 mg/L (as Fe), which was consistent with the iron concentrations in samples taken following the 

contact tanks (i.e. ranged from 0.16 to 1.3 mg/L [as Fe] and averaged at 0.9 mg/L [as Fe]).

4.4.3 Backwash Operation. The system PLC was set to initiate a backwash based on one of two 

potential triggers: (1) preset filter run time of 8 hr and (2) automatic shutdown of the treatment system 

when water level in the city’s reservoirs reached the “Stop” set level. Each backwash lasted for 4 min at

an average flowrate of 1,344 gpm (Table 4-5 and Appendix D). The filter then underwent a 1-min filter- 
33

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

Fe Dosage (mg/L as Fe)

Measured After Contact Tanks (AC) Injected Dosage 

Figure 4-17. Calculated Iron Doses vs. Measured Iron Concentrations

to-waste rinse at up to 550 gpm before returning to filtration service. Estimated based on readings of the 

backwash wastewater totalizer and average backwash wastewater production, the filter was backwashed 

759 times during the performance evaluation study from August 14, 2008, through August 14, 2009. The 

average backwash frequency was 2.3 times per day. Considering the average daily operation time of 13.6 

hr and the preset filter run time of 8 hr, backwash was triggered at least once a day by the preset filter run 

time. The backwash frequency was higher during the summer (i.e., 3.1 times per day from May to 

August) and lower during the winter (i.e., 1.5 times per day from December to March), which was 

consistent with the longer daily operation times in the summer and shorter operation time in the winter. 

Filter run times between backwash events were either 8 hr, or any time between 0 to 8 hr depending on 

the trigger of a backwash. 

4.4.3.1 Other Problems Related to Backwash System. Two backwash related problems were 

encountered during the 1-year demonstration study. Starting on December 17, 2008, Δp across the filter 

surged several times from the typical range of 0 to 2 psi to as high as 13 psi. It was found that backwash 

was not conducted automatically due to malfunctioning of a 10-in control valve on the backwash line. 

Differential pressure readings across the filter went back to the normal range after the control valve was 

taken offline and cleaned on January 14, 2009. On February 6, 2009, the automatic drain valve of the 

reclaim tank was not functioning automatically. The drain valve was repaired on February 20, 2009.

4.4.4 Residual Management. Residuals produced by the operation of the treatment system 

consisted of only backwash solids, which accumulated at the bottom of the reclaim tank. The reclaim 

tank drain valve was set to open every four backwashes to discharge approximately 12 in of sludge to the 
34

sewer (Figure 4-7). Approximately 1,670 kg of backwash solids was produced during the performance 

evaluation study based on 759 backwash events (Table 4-5) and 2.5 kg of backwash solids produced per 

backwash event (Section 4.5.2).

4.4.5 System/Operation Reliability and Simplicity. The system experienced a number of 

downtimes during the initial 7-week of system operation (for chlorine dosage tests as discussed in Section 

4.4.2) and a 7-day downtime in February 2009 (for operators to attend a training class). Since then, there 

was no additional downtime. No major operational problems were encountered during the 1-year 

demonstration study, except for a few minor issues such as leaks in the chlorine feed system manifold

(Section 4.4.2), malfunctioning of a 10-in backwash control valve (Section 4.4.3.1), and malfunctioning 

of a reclaim tank drain valve (Section 4.4.3.1). The simplicity of system operation and operator skill 

requirements are discussed according to pre- and post-treatment requirements, levels of system 

automation, operator skill requirements, preventative maintenance activities, and frequency of 

chemical/media handling and inventory requirements. 

4.4.5.1 Pre- and Post-Treatment Requirements. Pre-treatment consisted of chemical additions to 

improve arsenic removal. A 12.5% NaOCl solution was added upstream of the contact tanks to oxidize 

As(III) and Fe(II), and provide chlorine residuals to the distribution system. In addition to measuring 

solution levels in the NaOCl drums, the operator monitored chlorine concentrations to ensure that 

residuals existed throughout the treatment train. A 42% FeCl3 solution was added downstream of the 

chlorine addition point, but upstream of the contact tanks. Solution levels in the FeCl3 drums were 

tracked daily. No post-treatment was required.

4.4.5.2 System Automation. The treatment system was automatically controlled by the PLC in the 

central control panel. The control panel also contained a modem and a touch screen OIP to facilitate 

setting and monitoring of system parameters, such as filter run time, filter backwash time, filter rinse 

time, backwash wastewater reclaim time, etc. All major functions of the treatment system were 

automated and required only minimal operator oversight and intervention if all functions were operating 

as intended. Automated processes included system startup and shutdown, filter backwash and rinse, and 

chemical addition system on/off. The touch screen OIP also enabled the operator to manually initiate a 

backwash sequence. 

4.4.5.3 Operator Skill Requirements. Under normal operating conditions, the daily demand on the 

operator was about 45 min for visual inspection of the system and recording of operational parameters 

such as pressure, volume, flowrate, and chemical usage on field log sheets. After receiving proper 

training during system startup, the operators understood the PLC, knew how to use the touch screen OIP, 

and were able to work with the equipment vendor to troubleshoot problems and perform minor onsite 

repairs.

Based on population served and the treatment technology, the State of Washington required Basic 

Treatment Operator certification for operating the Filtronics treatment system at the City of Okanogan 

facility. The State of Washington has five levels of certification for operation of water treatment systems 

based on population served by the plant, water supply source, and complication of the treatment system

(including chemical treatment/addition process, coagulation process, filtration process, 

clarification/sedimentation process, and residuals disposal, etc.). The certification levels range from

Basic Treatment Operator (BTO) for small and simple treatment systems to Water Treatment Plant 

Operator Levels 1 to 4 for larger and more complicate treatment systems. 

4.4.5.4 Preventative Maintenance Activities. Daily preventative maintenance activities included 

recording pressure and flowrate readings and chemical drum levels and visually checking for leaks, 

overheating components, and any unusual conditions. To maintain the integrity of the treatment system, 
35

the vendor recommended several routine maintenance activities, including checking the oil level in the 

valve oiler on the filter control panel weekly, checking the temperature of backwash water monthly, and 

adjusting monthly backwash flowrate according to the “Backwash Rate Versus Temperature Chart”. The 

vendor also recommended checking the filter differential pressure weekly right after a backwash to ensure 

that the Δp was the same as that recorded at system startup. 

4.4.5.5 Chemical Handling and Inventory Requirements. Chlorine and iron additions were 

required for effective arsenic removal. The operators tracked usage of the chemical solutions daily (by 

solution levels), coordinated supplies, and started a new chemical drum as needed. A 12.5% NaOCl 

solution supplied in 53-gal drums and a 42% FeCl3 solution supplied in 55-gal drums by Oxarc, Inc. were 

injected without dilution. Speed and stroke length settings of the chemical feed pumps were adjusted, as 

needed, to acquire the target chlorine residuals as measured regularly with a Hach pocket colorimeter and 

iron concentrations after the contact tanks.

4.5 System Performance

The performance of the Filtronics FH-13 Electromedia®I arsenic removal system was evaluated based on 

analyses of water samples collected from the treatment plant and distribution system.

4.5.1 Treatment Plant Sampling. The treatment plant water was sampled on 47 occasions (including 

four duplicate events) during the 1-year performance evaluation period. Field speciation also was 

performed for 12 of the 47 occasions. Table 4-7 summarizes the analytical results for arsenic, iron, and 

manganese. Table 4-8 summarizes the results of the other water quality parameters. One outlier with 

uncharacteristically high arsenic, iron, manganese, and phosphorus concentrations at the AC sampling 

location on November 4, 2008, was not included in statistical calculations shown in Tables 4-7 and 4-8. 

These elevated concentrations probably were caused by reintroduction of backwash solids from the 

reclaim tank. Appendix B contains a complete set of analytical results. The results of the water samples 

collected across the treatment train are discussed below.

4.5.1.1 Arsenic. Figure 4-18 shows total arsenic concentrations measured across the treatment train 

and Figure 4-19 presents the results of the 12 speciation events. Total arsenic concentrations in source 

water ranged from 14.7 to 22.7μg/L and averaged 17.9 μg/L with soluble As(III) existing as the 

predominant species at 13.4 μg/L (on average). Low concentrations of particulate arsenic and soluble 

As(V) also were present in source water, with concentrations averaging 0.8 and 4.7 μg/L, respectively. 

As shown in Figure 4-19, soluble As(III) was the predominant species in source water during all but two

speciation events on November 4, 2008, and February 3, 2009. These results were in contrary to that 

obtained during the initial site visit on October 28, 2004, when As(V) was predominant (Table 4-1). The 

reason for the difference observed is unclear. As shown in Table 4-9, for the three sampling events with 

higher soluble As(V) concentrations, only the sampling event on February 3, 2009, had a higher-thanaverage DO level that might contribute to the high As(V) concentration measured. ORP values for the 

three events were either similar to or significantly lower than the average ORP level, which could not

contribute to high soluble As(V) concentration. Except for As(III), As(V), and ORP, all other water 

quality data measured during the 1-year performance evaluation study were consistent with those 

collected on October 28, 2004.

Following prechlorination and the contact tanks, total arsenic concentrations remained essentially 

unchanged at 17.8 μg/L (on average). However, arsenic existed primarily as particulate arsenic (8.7 μg/L 

[on average]) and soluble As(V) (8.1 μg/L [on average]). Note that the average total and particulate 

arsenic concentrations at the AC location do not include one outlier on November 4, 2008, when the 

concentrations spiked to over 100 μg/L for total arsenic and 91.5 μg/L for particulate arsenic. Particulate 
36

Table 4-7. Summary of Arsenic, Iron, and Manganese Analytical Results

Parameter

Sampling 

Location Unit

Number 

of 

Samples

Concentration

Standard 

Minimum Maximum Average Deviation

As (total) IN μg/L 47 14.7 22.7 17.9 1.6

AC μg/L 46(a) 14.5 23 17.8 1.7

TT μg/L 45(b) 2.9 14.9 6.2 1.7

As (soluble) IN μg/L 12 14.9 21.2 18.0 2.0

AC μg/L 12 6.4 17.1 10.2 3.7

TT μg/L 12 5.0 14.6 6.9 2.6

As 

(particulate)

IN μg/L 12 <0.1 2.9 0.8 0.9

AC μg/L 11(a) 2.7 12.0 8.7 3.2

TT μg/L 12 <0.1 1.1 0.3 0.3

As (III) IN μg/L 12 3.7 19.8 13.4 4.5

AC μg/L 12 0.2 13.9 2.2 4.2

TT μg/L 12 0.3 8.9 1.2 2.5

As (V) IN μg/L 12 <0.1 14.7 4.7 4.1

AC μg/L 12 1.6 16.7 8.1 3.4

TT μg/L 12 4.6 8.2 5.7 1.0

Fe (total) IN μg/L 47 <25 230 78 31.4

AC μg/L 46(a) 163 1,345 902 188

TT μg/L 45(b) <25 107 20.5 19.9

Fe (soluble) IN μg/L 12 <25 89 49 26.6

AC μg/L 12 <25 37 <25 9.4

TT μg/L 12 <25 26 14 4.0

Mn (total) IN μg/L 47 44.1 77.0 62.5 5.6

AC μg/L 46(a) 46.4 76 63.9 5.8

TT μg/L 45(b) 0.4 51.9 21.0 11.5

Mn (soluble) IN μg/L 12 43.4 74.1 61.4 9.4

AC μg/L 12 18.3 77.0 43.2 16.8

TT μg/L 12 0.2 43.3 16.3 12.5

(a) One outlier on November 4, 2008 (i.e., 100, 91.5, 7247, and 369 μg/L of total As, particulate As, 

total Fe, and total Mn; respectively) omitted.

(b) Two outliers on November 13, 2008 (duplicate samples) omitted.

iron and particulate manganese concentrations also spiked to 7,213 and 347 μg/L, suggesting 

reintroduction of backwash solids from the reclaim tank. 

Of the soluble fraction at the AC location, As(III) was less than 0.9 μg/L (except for one data point at 7.2 

μg/L on August 14, 2008, and one data point at 13.9 μg/L on December 3, 2008 ), indicating effective 

oxidation of As(III) by chlorine. The reason for the high As(III) concentrations on August 14 and

December 3, 2008, was insufficient chlorine addition. Total chlorine concentration measured at AC on 

August 14, 2008 (the system startup day) was 0 mg/L, indicating that the chlorine addition system was 

not operating properly. On December 3, 2008, the suction tube valve of the chlorine pump was not 

functioning correctly, causing low total and free chlorine concentrations (0.3 and 0.02 mg/L [as Cl2], 

respectively) measured in the system effluent. As much as 8.1 μg/L of As(V) was measured following 

the contact tanks, suggesting the need for further increasing iron dose rates.
37

Table 4-8. Summary of Other Water Quality Parameter Results

Parameter

Sampling 

Location Unit

Number 

of 

Samples

Concentration

Standard 

Minimum Maximum Average Deviation

Alkalinity 

(as CaCO3) 

IN mg/L 47 175 196 183 5.4

AC mg/L 47 171 196 181 5.2

TT mg/L 47 171 192 181 5.3

Ammonia

(as N)

IN mg/L 1 0.1 0.1 0.1 -

AC mg/L 1 0.1 0.1 0.1 -

TT mg/L 1 0.1 0.1 0.1 -

Fluoride

IN mg/L 12 0.6 1.0 0.7 0.1

AC mg/L 12 0.6 0.9 0.7 0.1

TT mg/L 12 0.6 0.8 0.7 0.1

Sulfate

IN mg/L 12 119 131 125 3.6

AC mg/L 12 119 130 123 3.0

TT mg/L 12 119 130 124 3.4

Nitrate 

(as N)

IN mg/L 12 <0.05 <0.05 <0.05 -

AC mg/L 12 <0.05 0.3 0.05 0.1

TT mg/L 12 <0.05 <0.05 <0.05 -

Phosphorus 

(as P)

IN μg/L 46 31.3 94.8 50.8 9.7

AC μg/L 45(a) 33.9 104 49.5 10.3

TT μg/L 46 <10 72.0 15.0 13.6

Silica 

(as SiO2) 

IN mg/L 47 23.1 29.4 25.9 1.3

AC mg/L 47 23.0 32.2 26.0 1.7

TT mg/L 47 22.5 28.7 25.6 1.3

Turbidity

IN NTU 47 0.13 1.8 0.5 0.4

AC NTU 47 0.14 16.0 1.4 2.3

TT NTU 47 <0.1 2.6 0.6 0.7

pH

IN S.U. 41 7.4 7.8 7.6 0.1

AC S.U. 41 7.5 7.9 7.7 0.1

TT S.U. 41 7.6 9.5 7.8 0.3

DO

IN mg/L 35 1.0 4.2 2.7 0.9

AC mg/L 36 1.3 5.6 3.3 0.9

TT mg/L 36 1.0 6.1 2.7 1.0

ORP

IN mV 42 361 486 458 23.3

AC mV 42 371 650 512 57.9

TT mV 42 358 666 521 61.3

Free Chlorine 

(as Cl2) 

AC mg/L 38 0.18 1.8 0.4 0.4

TT mg/L 37 0.14 1.8 0.3 0.4

Total Chlorine 

(as Cl2) 

AC mg/L 39 0.0 2.0 0.7 0.4

TT mg/L 37 0.3 2.0 0.6 0.3

Total Hardness 

(as CaCO3) 

IN mg/L 12 227 356 269 37.0

AC mg/L 12 227 358 272 38.2

TT mg/L 12 223 345 271 36.0

Ca Hardness 

(as CaCO3) 

IN mg/L 12 110 185 137 20.1

AC mg/L 12 116 196 141 20.9

TT mg/L 12 56.9 201 134 32.8

Mg Hardness 

(as CaCO3) 

IN mg/L 12 113 241 133 34.8

AC mg/L 12 104 240 131 35.6

TT mg/L 12 101 234 137 41.0

(a) One outlier (i.e., 362 μg/L on 11/04/08) omitted.
38

0

10

20

30

40

50

60

70

80

90

100

110

Total As Concentration (μg/L)

At Inlet (IN) After Contact Tanks (AC) After Filter Tank (TT)

10μg/L MCL

Figure 4-18. Total Arsenic Concentrations Across Treatment Train

Total arsenic concentrations after the pressure filter ranged from 2.9 to 14.9 μg/L and averaged 6.2 μg/L. 

Based on the speciation results, arsenic in system effluent existed primarily as As(V) with concentrations 

ranging from 4.6 to 8.2 μg/L and averaging 5.7 μg/L. Some soluble As(III) (1.2 μg/L [on average]) and 

particulate arsenic (0.3 μg/L [on average]) also were present in system effluent. As shown in Figure 4-18, 

total arsenic concentrations in system effluent exceeded the arsenic MCL on two occasions on November 

13 and December 3, 2008. As discussed above, the December 3, 2008, sampling event resulted in a high 

As(III) concentration at the AC location due to insufficient chlorine addition, which led to high total 

arsenic and As(III) concentrations in system effluent. As(III) cannot be effectively removed via the C/F 

process.

The elevated arsenic concentrations in system effluent on November 13, 2008 appeared to have been 

caused by a sampling error. Total arsenic, iron, and manganese concentrations measured after the contact 

tanks on this day were 20.0, 886, and 62.7 μg/L, respectively, which were comparable to the average 

values measured during the 1-year performance evaluation study, implying that the high concentrations in 

system effluent were due neither to insufficient iron addition nor to reintroduction of backwash solids. In

addition, as shown in Figures 4-18, 4-20, 4-21, concentrations at TT were higher than those at AC for all 

three metals (As, Fe, and Mn) during the sampling event, suggesting that the high concentrations 

measured in system effluent were not due to breakthrough of particulate metals. The filter run time 

during which the sampling event took place was approximately 4 hr, which was only half of the filter run 

time designed for the filtration system. This also supported the speculation that the high arsenic, iron, and 

manganese concentrations measured were not caused by particulate metals breakthrough.
39

0

5

10

15

20

25

30

As Concentration (μg/L)

Arsenic Species at Wellhead (IN)

As (Particulate)

As (V)

As (III)

0

5

10

15

20

25

30

As Concentration (μg/L)

Arsenic Species after Contact Tanks (AC)

As (Particulate)

As (V)

As (III) Particulate As = 91.5 μg/L

0

5

10

15

20

25

30

As Concentration (μg/L)

Arsenic Species after Filter Tank (TT)

As (Particulate)

As (V)

As (III)

10 μg MCL

Figure 4-19. Arsenic Speciation Results
40

Table 4-9. Arsenic Speciation vs. DO and ORP

Date

As(III)

(μg/L)

As(V)

(μg/L)

DO

(mg/L)

ORP

(mV)

Average value during 1-year study 13.4 4.7 2.7 458

10/28/04 (initial site visit) 3.0 15.6 1.8 -47

11/04/08 6.0 11.1 2.5 465

02/03/09 3.7 14.7 4.2 460

The particulate arsenic, iron, and manganese concentration spikes observed at AC on November 4, 2008, 

presumably were caused by the reintroduction of backwash solids but did not cause arsenic breakthrough 

from the pressure filter.

4.5.1.2 Iron. Figure 4-20 presents total iron concentration measured across the treatment train. 

Total iron concentrations in source water ranged from <25 to 230 μg/L and averaged 78 μg/L, 63% of 

which existed in the soluble form. 

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

5,000

5,500

6,000

6,500

7,000

7,500

Total Fe Concentration (μg/L)

At Inlet (IN) After Contact Tanks (AC) After Filter Tank (TT)

11/04/08

11/13/08

Figure 4-20. Total Iron Concentrations Across Treatment Train

As shown in Figure 4-20, total iron concentration spiked on November 4, 2008, probably due to 

reintroduction of backwash solids from the reclaim tank (Section 4.5.1.1). Total iron concentrations after 

the contact tanks varied significantly, ranging from 163 to 1,345 μg/L and averaging 902 μg/L (not 

including the outlier on November 4, 2008). Total iron concentrations in system effluent ranged from 

<25 to 107 μg/L, and averaged 20.5 μg/L (not including the outlier on November 13, 2008, caused by a 
41

sampling error [Section 4.5.1.1]). Approximately 80% of the samples collected at the system outlet had 

total iron concentrations below the method reporting limit of 25 μg/L. 

4.5.1.3 Manganese. Figure 4-21 presents total manganese concentrations measured during the 

demonstration study. Manganese concentrations in source water ranged from 44.1 to 77.0 μg/L and 

averaged 62.5 μg/L, existing almost entirely in the soluble form. After chlorination, iron addition, and the 

contact tanks, average total manganese concentration remained at a similar level (63.9 μg/L, not including 

the outlier on November 4, 2008), but average soluble manganese concentrations decreased from 61.4 to 

43.2 μg/L. About 30% of the soluble manganese was oxidized and precipitated to become particulate 

manganese. This rather incomplete Mn(II) oxidation was the result of slow reaction kinetics with 

chlorine, as reported by Knocke et al. (1987 and 1990). After the pressure filter, 77% of particulate 

manganese and 62% of soluble manganese were removed, leaving an average of 21.0 and 16.3 μg/L of 

total and soluble manganese, respectively, in filter effluent. Removal of soluble manganese by filtration 

media in the presence of free chlorine was observed previously by Knocke et al. (1990) and Cumming et 

al. (2009) at another arsenic removal demonstration site at Rollinsford in New Hampshire. Knocke et al. 

reported that the presence of free chlorine promotes Mn(II) removal on MnOx-coated media. At 

Rollinsford, in the absence of free chlorine, AD33 adsorption media had a limited adsorptive capacity for 

Mn(II). With the presence of 0.1 to 0.2 mg/L (as Cl2) of free chlorine, total manganese concentrations in 

system effluent were reduced from an average of 100 μg/L (with 77% in the soluble form) to <10 μg/L. 

At Okanogan, the presence of 0.4 mg/L (as Cl2) of free chlorine at AC (Table 4-8) might have promoted 

removal of 62% of soluble manganese through precipitation of Mn(II) on the Electromedia®I filtration 

media.

0

50

100

150

200

250

300

350

400

Total Mn Concentration (μg/L)

At Inlet (IN) After Contact Tanks (AC) After Filter Tank (TT)

11/04/08

Figure 4-21. Total Manganese Concentrations across Treatment Train
42

4.5.1.4 pH, DO, and ORP. pH values in source water ranged from 7.4 to 7.8 and averaged 7.6. This 

average value was slightly lower than the pH measurement taken by Battelle during the source water 

sampling on October 28, 2004 (i.e., 8.0 in Table 4-1). DO levels of source water ranged from 1.0 to 4.2 

mg/L and averaged 2.7 mg/L. DO levels at AC and TT remained rather unchanged at 3.3 and 2.7 mg/L, 

respectively. ORP readings of source water were uncharacteristically high, ranging from 361 to 486 mV 

and averaging 458 mV. These high values most likely were caused by the handheld meter, which tends to 

drift during measurements. After prechlorination, average ORP readings increased significantly to 512 

mV after the contact tanks and to 521 mV after the pressure filter.

4.5.1.5 Chlorine. Figure 4-22 presents total and free chlorine residuals measured throughout the 

treatment train. As shown in the figure, before November 20, 2008, total and free chlorine residuals were 

high, due to the high chlorine dosage requested by the equipment vendor (Section 4.4.2) Average total 

and free chlorine residuals during this period were 1.4 and 1.3 mg/L (as Cl2), respectively. After the 

chlorine dosage was reduced to an average of 0.7 mg/L (as Cl2), average total and free chlorine residuals

were reduced to 0.5 mg/L (as Cl2) and 0.2 mg/L (as Cl2), respectively. 

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

Chlorine Residual (mg/L as Cl2)

Total at AC

Total at TT

Free at AC

Free at TT

Unstable Cl2

dosage due to 

the leak in 

feeding system 

manifold

High Cl2 dosage 

initially instructed by 

the vendor, customers

complained chlorine in 

water

Figure 4-22. Chlorine Residuals Measured Throughout Treatment Train

Assuming that an average of 0.7 mg/L of NaOCl (as Cl2) had been applied to source water

(Section 4.4.2), 0.12 mg/L (as Cl2) would have reacted with As(III), Fe(II), and Mn(II) based on the 

respective average concentrations of 13.4, 49.0, and 61.4 μg/L in source water (Table 4-7). The ammonia 

level in source water was measured twice, once before system startup on October 28, 2004 at 0.05 mg/L 

(as N) and once after system startup on December 3, 2008 at 0.1 mg/L (as N). Assuming an average 
43

ammonia level of 0.075 mg/L (as N) in source water, 0.57 mg/L (as Cl2) would have reacted with 

ammonia to reach breakpoint chlorination. As such, 0.01 mg/L (as Cl2) would have been present as free 

chlorine in treated water. This theoretical amount appears to fall below the measured levels for total and 

free residuals as shown in Figure 4-22. 

4.5.1.6 Other Water Quality Parameters. Alkalinity, ammonia, fluoride, sulfate, nitrate, silica, 

hardness and turbidity remained relatively constant across the treatment train and were not affected by the 

treatment process (Table 4-8). Phosphorus levels after the contact tanks were the same as those in source

water (i.e., 49.5 at AC vs. 50.8 μg/L at IN [on average]). Phosphorus levels decreased 70% (to 15 μg/L 

[on average]) after the pressure filter, indicating removal via C/F. 

4.5.2 Filter Run Length Study. A filter run length study was conducted to delineate arsenic and 

iron breakthrough during the 8-hr preset filter run time on December 2, 2008, after a proper chlorine 

dosage had been established (Section 4.4.2). Hourly water samples were collected at AC and TT and a 

portion of the samples was filtered with 0.45 μm disc filters during the 8-hour time period. Iron 

concentrations at the TT location also were measured onsite. Figure 4-23 presents the study results. 

0

5

10

15

20

25

0 1 2 3 4 5 6 7 8 9

As Concentration (μg/L)

Filter Run Time after Last Backwash (hr)

Total As at AC

Total As at TT

Souble As at TT

0

200

400

600

800

1000

1200

0 1 2 3 4 5 6 7 8 9

Fe Concentration (μg/L)

Filter Run Time after Last Backwash (hr)

Total Fe at AC

Total Fe at TT

Souble Fe at TT

Total Fe measured on-site

Figure 4-23. Arsenic and Iron Concentrations Measured During Filter Run Length Study
44

As shown in the figure, total arsenic concentrations measured at TT during the 8-hr filter run ranged from 

6.3 to 6.9 μg/L and averaged 6.5 μg/L, existing primarily as soluble arsenic (i.e. over 96%). Total iron 

was removed to below the MDL of 25 μg/L at TT from the beginning of the filter run to 5.5 hr into the 

run. Total iron concentrations at TT then began to increase (to 72 μg/L at the end of the 8 hr-run) with 

soluble iron concentrations remaining at <25 μg/L, indicating particulate iron breakthrough. The results 

of the run length study suggested that conducting backwash every 8 hr was sufficient to maintain effective

filter performance for arsenic and iron removal. 

4.5.3 Backwash Water and Solids Sampling. Treated water was used for backwash. Table 4-10

presents analytical results from 11 backwash wastewater sampling events during the 1-year performance 

evaluation study. Most of the sampling events took place after a filter run time of 8 hr. Events 3 through 

6 had shorter filter run times, ranging from 1.5 to 7 hr. The filter run time for Event 1 on October 21, 

2008, was not recorded. The results from Events 1 and 6 were excluded from average and range 

calculations as described below. Excluding the two unrepresentative sampling events, the average filter 

run time was 7.4 hr.

Table 4-10. Backwash Wastewater Sampling Results

Sampling

Event

Filter Run TimepHTDSTSSAs (total)As (soluble)As (particulate)Fe (total)Fe (soluble)Mn (total)Mn (soluble)

No. Date hr S.U. mg/L mg/L μg/L μg/L μg/L μg/L μg/L μg/L μg/L

1 10/21/08 - 8.0 340 54 204 7.3 197 16,691 150 537 8.9

2 11/18/08 8.0 7.9 330 195 898 8.0 890 76,519 41 3,170 4.9

3 12/16/08 7.0 7.9 360 114 489 8.9 480 51,395 267 1,236 28.4

4 01/20/09 5.6 7.9 362 100 394 7.0 387 27,028 118 884 26.9

5 02/18/09 5.9 7.8 298 78 259 5.4 253 22,858 59 410 27.0

6 03/17/09 1.5 7.9 348 10 98 5.8 93 5,677 56 204 29.3

7 04/14/09 8.0 7.9 346 94 383 6.6 376 32,486 274 562 24.5

8 05/12/09 8.0 7.9 370 90 420 10.5 409 36,169 563 1,054 42.5

9 06/09/09 8.0 7.8 376 114 450 6.8 444 31,687 122 1,148 34.6

10 07/09/09 8.0 7.8 350 80 389 6.8 382 26,581 131 960 34.3

11 07/29/09 8.0 7.8 400 105 476 3.5 472 38,060 122 992 42.1

TDS = total dissolved solids; TSS = total suspended solids

pH, TDS, and total suspended solids (TSS) values ranged from 7.8 to 7.9 (averaged 7.9), from 298 to 400 

mg/L (averaged 355 mg/L), and from 78 to 195 mg/L (averaged 108 mg/L), respectively. The average 

pH value of backwash wastewater (7.9) was slightly higher than those across the treatment train (i.e., 7.6 

at IN, 7.7 at AC, and 7.8 at TT). Concentrations of total arsenic, iron, and manganese ranged from 259 to 

898 μg/L (averaged 462 μg/L), from 22.9 to 76.5 mg/L (averaged 38.1 mg/L), and 410 to 3,170 μg/L

(averaged 1,157 μg/L), respectively. Over 97.5% of these metals were present in the partculate form. 

Assuming that 6,150 gal (Table 4-5) of backwash wastewater would be generated from each backwash 

event and that 108 mg/L of TSS would be produced, approximately 2.5 kg of solids was generated and 

discharged into the reclaim tank during each backwash event. Based on the average particulate metal data 

in Table 4-9, approximately 10.6 g of arsenic (i.e., 0.4% by weight), 882 g of iron (i.e., 35.3 % by 
45

weight), and 26.3 g of manganese (i.e., 1.1 % by weight) were generated from each vessel during each 

backwash event. 

Solids loadings to the reclaim tank also were monitored through collection of backwash solids (Section 

3.3.5). Table 4-11 presents analytical results of the solid samples collected on April 14, 2009. Arsenic, 

iron, and manganese levels in solids averaged 3.9 mg/g (or 0.4% by weight), 381 mg/g (or 38.1% by 

weight), and 1.1 mg/g (or 1% by weight), respectively. These amounts matched very closely with those 

derived from the backwash wastewater metal analysis (i.e. 0.4%, 35.3%, and 1.1%, respectively). 

Table 4-11. Backwash Solids Sampling Results 

Sample ID

Mg Si P Ca Fe Mn As Ba

μg/g μg/g μg/g μg/g μg/g μg/g μg/g μg/g

04-14-09 Sample A 10,262 5,759 12,853 57,890 389,821 10,705 4,031 1,086

04-14-09 Sample B 10,084 5,682 12,496 56,078 372,911 10,308 3,835 1,060

Average 10,173 5,720 12,675 56,984 381,366 10,507 3,933 1,073

4.5.4 Distribution System Water Sampling. Prior to system startup, four monthly baseline 

distribution water samples were collected from September 2005 to January 2006 at three locations within 

the distribution system. The three locations selected for distribution system water sampling included two 

LCR residences and one non-LCR residence. Following system startup, distribution system water 

sampling continued on a monthly basis at the same locations. The two LCR locations (DS1 and DS2) 

were impacted by water from all four wells in the distribution system. The non-LCR location (DS3) was

impacted by water from all wells before system startup, but was impacted predominantly by water from 

the treatment plant after system startup. Table 4-12 summarizes results of the distribution system water 

sampling. All stagnation times for the sampling met the 6-hr minimum stagnation time requirement, 

except for three occasions on October 7, 2008, at DS1 (5.8 hr), November 13, 2008, at DS2 (1.0 hr), and 

December 16, 2008, at DS2 (5.5 hr).

There was no change in pH before and after system startup. pH values before startup ranged from 7.6 to 

8.4 and averaged 7.9; pH values after system startup ranged from 7.4 to 8.4 and averaged 7.9. Alkalinity 

levels remained essentially unchanged, with concentrations ranging from 185 to 308 mg/L (as CaCO3) 

before startup and from 157 to 354 mg/L (as CaCO3) after startup.

Arsenic concentrations during the four baseline sampling events varied significantly, ranging from 3.4 to 

15.9 μg/L and averaging 10.3 μg/L, with comparable concentrations among the three sampling locations. 

The baseline arsenic concentrations observed were significantly lower than those in source water (14.7 to 

22.7 μg/L and averaged 17.9 μg/L), as shown in Table 4-7. These results were expected, because before 

system startup, water at DS1, DS2, and DS3 were from all four wells (Wells 2, 3, 4, and 5) in the 

distribution system. 

After system startup, arsenic concentrations at DS3 (with water supplied by the treatment plant alone) 

decreased to an average of 6.8 μg/L, which was very close to that in system effluent (6.2 μg/L in Table 4-

7). Figure 4-24 illustrates the effects of the treatment system on arsenic, iron, and manganese 

concentrations in the distribution system.
46

Table 4-12. Distribution System Sampling Results

Stagnation TimepHAlkalinityAsFe

MnPbCuStagnation TimepHAlkalinityAsFeMnPbCuStagnation TimepHAlkalinityAsFeMnPbCu

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 09/27/05(b) 9.5 7.8 194 13.9 <25 25.6 1.2 67.9 7.8 7.9 185 13.8 <25 28.3 0.3 11.2 8.6 7.9 194 12.0 55 36.2 9.8 4.8

BL2 10/25/05 7.1 7.8 198 9.0 <25 10.3 1.3 147 7.8 7.6 290 4.4 <25 2.0 1.6 238 12.5 7.6 308 3.4 <25 0.3 1.1 66.6

BL3 11/22/05 8.8 7.7 255 7.1 <25 1.6 0.7 246 8.3 7.8 290 5.0 <25 0.8 0.3 160 15.5 7.8 194 10.7 <25 <0.1 0.2 4.4

BL4 01/04/06 10.0 8.0 185 14.4 <25 17.1 1.2 77.9 7.5 8.2 194 14.5 <25 18.3 0.7 48.2 13.0 8.4 189 15.9 <25 <0.1 0.3 5.5

1 09/02/08 7.0 8.0 184 11.1 <25 9.6 1.2 57.8 7.0 8.1 184 8.8 <25 17.4 0.8 30.4 8.3 8.4 186 11.2 43 <0.1 0.8 9.7

2 10/07/08 5.8 7.7 184 7.1 <25 7.4 2.2 117 6.3 7.9 180 6.7 <25 4.0 1.4 58.5 12.0 7.7 175 6.6 <25 0.7 0.7 28.3

3 11/13/08 8.0 7.8 178 8.9 <25 2.0 0.9 63.6 1.0 8.1 178 8.4 <25 1.8 0.1 13.3 NA 8.0 187 7.5 <25 1.7 0.4 5.8

4 12/16/08 7.8 7.9 172 8.2 84 8.7 9.9 87.5 5.5 8.0 176 6.9 <25 7.1 1.1 30.2 NA 8.0 178 7.2 85 9.6 2.6 7.9

5 01/21/09 6.9 7.9 169 6.8 <25 7.3 1.4 77.7 6.0 8.0 174 6.9 <25 9.1 0.5 17.2 11.1 8.2 176 6.4 <25 1.9 0.3 5.0

6 02/18/09 8.5 7.4 221 4.1 <25 11.2 1.4 151 6.8 7.4 347 3.4 <25 3.1 1.8 109 11.0 7.5 354 3.3 <25 0.1 0.4 17.9

7 03/18/09 6.0 7.8 174 6.7 <25 8.8 1.6 86 7.3 8.1 178 6.6 <25 6.3 2.2 123 10.5 8.2 180 7.6 <25 0.7 0.2 5.0

8 04/15/09 9.3 7.6 157 4.5 <25 19.2 0.5 89 6.0 8.0 180 6.1 <25 7.1 0.4 37 10.0 8.2 175 6.8 77 1.3 2.3 18.4

9 05/13/09 6.5 8.0 178 6.1 <25 8.4 2.5 78 6.0 8.1 188 6.6 <25 7.7 2.4 102 9.0 8.2 181 5.6 <25 2.2 1.5 21.7

10 06/04/09 6.3 7.6 198 5.0 <25 5.9 1.9 119 6.0 7.7 190 6.4 <25 9.0 1.7 104 16.0 7.8 200 6.5 <25 0.5 0.2 10.8

11 07/01/09 7.5 7.6 196 5.8 <25 8.1 1.7 130 6.5 7.7 212 4.9 <25 8.0 0.6 69 10.0 8.0 236 6.4 <25 0.9 0.7 18.5

12 08/12/09 NA(c) NA(c) NA(c) NA(c) NA(c) NA(c) NA(c) NA(c) 6.0 7.8 190 7.3 <25 7.5 2.2 184 12.0 7.8 183 6.8 <25 5.4 0.5 35.9

(a) Water softener present at this location. 

(b) Sample DS3 collected on 09/26/05.

(c) Homeowner was not available during sampling

BL = baseline sampling; NA = data not available.

Lead action level = 15 μg/L; copper action level = 1,300 μg/L.

Alkalinity measured in mg/L as CaCO3.

Sampling

Event

150 Hennepin St 650 4th Ave South 341 River Ave

LCR

 1st draw

LCR

 1st draw

Residence

1st Draw

DS1 DS2 DS3(a)

 
47

0

5

10

15

20

25

30

35

Total As Concentration (μg/L)

10μg/L MCL

11/13/08

12/03/08

0

200

400

600

800

1000

1200

1400

1600

Total Fe Concentration (μg/L)

11/13/08

0

20

40

60

80

100

Total Mn Concentration (μg/L)

After Filter Tank (TT) DS1 DS2 DS3

Figure 4-24. Effect of Treatment System on Arsenic, Iron, and Manganese in Distribution System

Iron concentrations in the baseline samples were low, ranging from <25 to 55.5 μg/L and averaging 16.1 

μg/L. Similar to arsenic, iron concentrations were lower than those in source water (ranging from <25 to 

230 μg/L and averaging 78 μg/L in Table 4-7). After system startup, the average iron concentration at 

DS3 increased to 26.5 μg/L, which was slightly higher than the average iron concentration of 20.5 μg/L in 

system effluent (Table 4-7). As shown in Figure 4-24, for the most part, iron concentrations at DS3 were 

<25 μg/L, which was similar to those in treatment system effluent.
48

Total manganese concentrations in the distribution system averaged 11.7 μg/L before system startup and 

decreased to 6.1 μg/L (on average) after system startup. Total manganese concentrations at DS3 averaged 

2.1 μg/L, which was lower than those measured in system effluent (i.e. 21 μg/L [on average] at TT 

location, Table 4-7). The reduction in total manganese concentration might be due to continuing 

oxidation and precipitation of soluble manganese in the distribution system. 

Lead concentrations within the distribution system remained unchanged from the baseline levels; copper 

concentrations decreased slightly. Baseline lead concentrations ranged from 0.2 to 9.8 μg/L and averaged 

1.6 μg/L. After system startup, lead levels remained at 1.5 μg/L (on average) with no samples exceeding 

the action level of 15 μg/L. Baseline copper concentrations ranged from 4.4 to 246 μg/L and averaged 

89.8 μg/L. After system startup, copper concentrations decreased to an average of 61.6 μg/L with no 

samples exceeding the 1,300 μg/L action level.

4.6 System Cost

The system cost 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. Capital cost of the treatment system included the expenditure

for equipment, site engineering, and system installation, shakedown, and startup. O&M cost included the 

expenditure for chemicals, electricity, and labor. Cost associated with the building, including the reclaim 

system was not included in the capital cost because it was not included in the scope of this demonstration 

project and was funded separately by the City of Okanogan. 

4.6.1 Capital Cost. The capital investment for the Filtronics FH-13 Electromedia®I arsenic removal 

system was $424,817 (Table 4-13). The equipment cost was $296,430 (or 70% of the total capital 

investment), which included cost for chemicals addition systems, two contact tanks, one filtration vessel, 

174 ft3

 of Electromedia®I, 76 ft3 of supporting media and concrete, instrumentation and controls, 

miscellaneous materials and supplies, and labor. 

The site engineering cost covered the expenditure for preparing the required permit application submittal, 

including a process design report, a general arrangement drawing, P&IDs, electrical diagrams, 

interconnecting piping layouts, and obtaining the required permit approval from WA DOH. The 

engineering cost of $48,332 was 11% of the total capital investment.

The installation, shakedown, and startup cost covered the labor and materials required to unload, install, 

and test the system for proper operation. The installation activities were performed by Triad Mechanical 

and the vendor, and startup and shakedown activities were performed by the vendor with the operator’s 

assistance. The installation, startup, and shakedown cost of $80,055 was 19% of the total capital 

investment.

The total capital cost of $424,817 was normalized to $772/gpm ($0.54/gpd) of design capacity using the 

system’s rated capacity of 550 gpm (or 792,000 gpd). The total capital cost also was converted to an 

annualized cost of $40,098 gal/yr using a capital recovery factor (CRF) of 0.09439 based on a 7% interest 

rate and a 20-yr return period. Assuming that the system operated 24 hr/day, 7 day/week at the design 

flowrate of 550 gpm to produce 289,080,000 gal/yr, the unit capital cost would be $0.14/1,000 gal. 

During the 1-year demonstration study, the system produced 139,435,000 gal of water (Table 4-5); 

therefore, the unit capital cost increased to $0.29/1,000 gal. These calculations did not include the 

building construction cost.
49

Table 4-13. Capital Investment for Filtronics’ FH-13 Electromedia®I System

Description Quantity Cost

% of Capital 

Investment 

Cost

Equipment

Filter Vessel 1 $51,540 –

Reaction Vessels Assembly of Two Tanks 1 $32,730 –

Chemical Feed Systems 1 $4,700 –

Pipes, Valves, Fittings, & Skid Mounting 1 $49,970 –

Electromedia and Support Layers 1 $25,500 –

Instrumentation and Controls 1 $57,700 –

Sample Taps and Totalizer/Meters 6 $2,430 –

Reclaim Equipment 1 $15,100 –

Shipping – $47,560 –

Labor – $9,200 –

Equipment Total – $296,430 70%

Engineering

Contractor 1 $48,332 –

Engineering Total – $48,332 11%

Installation, Shakedown, and Startup 

Vendor 1 $7,000 –

Contractor 1 $73,055 –

Installation, Shakedown, and Startup – $80,055 19%

Total Capital Investment – $424,817 100%

A building was constructed by the City of Okanogan to house the treatment system (Section 4.3.2). In

addition to the building, a 22,500-gal concrete backwash/reclaim tank was installed (Section 4.2). The 

total cost of the building, recycle system, and supporting utilities was approximately $530,000, which was 

not included in the capital cost. 

4.6.2 O&M Cost. The O&M cost included expenditure for chemicals use, electricity consumption, 

and labor for a combined unit cost of $0.18/1,000 gal (Table 4-14). No cost was incurred for repairs 

because the system was under warranty. Incremental chemical cost for iron addition was $0.03/1,000 gal 

and for NaOCl was $0.01/1,000 gal. Electrical power consumption was calculated based on the 

difference between the average monthly cost from electric bills before and after building construction and 

system startup. The difference in cost was approximately $910/month or $0.08/1,000 gal of water treated. 

The routine, non-demonstration related labor activities consumed approximately 45 min/day (Section 

4.4.5.3). Based on this time commitment and a labor rate of $30/hr, the labor cost was $0.06/1,000 gal of 

water treated.
50

Table 4-14. O&M Costs for Filtronics’ FH-13 Electromedia®I System

Category Value Remarks

Volume Processed (1,000 gal) 139,435 From 08/14/08 through 08/14/09

Chemical Usage

42% FeCl3 Unit Cost ($/lb) $0.50 Supplied in 12 55-gal drums (665 lb) 

including freight

FeCl3 Consumption (1b/1,000 gal) 0.057 –

FeCl3 Cost ($/1,000 gal) $0.03 –

12.5% NaOCl Unit Cost ($/lb) $0.23 Supplied in 16 53-gal drums (530 lb) 

including freight

NaOCl Consumption (1b/1,000 gal) 0.061 –

NaOCl Cost ($/1,000 gal) $0.01 –

Total Chemicals Cost ($/1,000 gal) $0.04 –

Electricity Consumption

Electricity Cost ($/month) $910.00 Average incremental consumption after 

system startup; including building 

heating and lighting

Electricity Cost ($/1,000 gal) $0.08 –

Labor

Labor (hr/week) 5.25 45 min/day, 7 day/week

Labor Cost ($/1,000 gal) $0.06 Labor rate = $30/hr

Total O&M Cost ($/1,000 gal) $0.18 –
51

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.

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. 

Cumming ,L.J., A.S.C. Chen, and L. Wang 2009. Final Performance Evaluation Report: Arsenic 

Removal from Drinking Water by Adsorptive Media EPA Demonstration Project at Rollinsford, 

NH. Prepared under Contract No. 68-C-00-185, Task Order No. 0037 for Environmental 

Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH.

Edwards, M., S. Patel, L. McNeill, H. Chen, M. Frey, A.D. Eaton, R.C. Antweiler, and H.E. Taylor. 

1998. “Considerations in As Analysis and Speciation.” J. AWWA, 90(3): 103-113.

EPA. 2003. Minor Clarification of the National Primary Drinking Water Regulation for Arsenic. 

Federal Register, 40 CFR Part 141.

EPA. 2002. Lead and Copper Monitoring and Reporting Guidance for Public Water Systems. 

EPA/816/R-02/009. U.S. Environmental Protection Agency, Office of Water, Washington, D.C. 

EPA. 2001. National Primary Drinking Water Regulations: Arsenic and Clarifications to Compliance 

and New Source Contaminants Monitoring. Federal Register, 40 CFR Parts 9, 141, and 142. 

Ghuyre, G. and D.A. Clifford. 2001. Laboratory Study on the Oxidation of Arsenic III to Arsenic V. 

EPA/600/R-01/021. U.S. Environmental Protection Agency, National Risk Management 

Research Laboratory, Cincinnati, OH.

Knocke, W.R., R.C. Hoehn, and R.L. Sinsabaugh. 1987. “Using Alternative Oxidants to Remove 

Dissolved Manganese from Waters Laden With Organics.” J. AWWA, 79(3): 75.

Knocke, W.R., J.E. Van Benschoten, M. Kearney, A. Soborski, and D.A. Reckhow. 1990. “Alternative 

Oxidants for the Removal of Soluble Iron and Mn.” AWWA Research Foundation, Denver, CO.

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 Demonstration Project At Okanogan, WA – Daily Operational Log Sheet

hr hr gpm kgal gpm gpm kgal gpm psi psi psig hr hr # # Kgal gal/hr gal/hr

08/14/08 27,848.9 NA 543 129 NA 540 144 NA 100 100 0 - - - - 84 - -

08/15/08 27,850.1 1.2 542 167 528 543 180 500 100 100 0 - - - - 89 - -

08/16/08 - - - - - - - - - - - - - - - - - -

08/17/08 - - - - - - - - - - - - - - - - - -

08/18/08 27,854.8 4.7 316 528 550 329 528 100 100 0 - - - - 117 - -

08/19/08

08/26/08

08/27/08 27,883.1 28.3 - 1,232 539 540 1,223 527 102 100 2 - - - - 164 - -

08/28/08 27,914.7 31.6 - 2,255 540 534 2,227 530 102 100 2 - - - - 184 - -

08/29/08 27,932.4 17.7 - 2,819 531 532 2,787 527 102 100 2 - - - - 194 - 0.09

08/30/08 27,955.4 23.0 - 3,568 543 533 3,539 545 104 100 4 - - - - 209 - -

08/31/08 - - - - - - - - - - - - - - - - -

09/01/08 28,003.0 47.6 - - NA 530 5,081 540 102 100 2 - - - - 240 - -

09/02/08 28,027.0 24.0 - 5,869 536 530 5,857 539 102 100 2 - - - - 255 0.09 0.07

09/03/08 28,047.8 20.8 - 6,538 536 535 6,530 539 100 100 0 - - - - 270 0.09 0.10

09/04/08 28,011.4 NA - 7,291 NA 535 7,298 NA 102 100 2 - - - - 285 - -

09/05/08

10/01/08

10/02/08 28,223.0 - - 12,140 - 534 12,143 - 101 100 1 - - - - 403 - -

10/03/08 28,246.0 23.0 - 12,870 529 525 12,879 533 102 101 1 - - - - 413 0.08 0.23

10/04/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) - - - - NM(a) - -

10/05/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) - - - - NM(a) - -

10/06/08 28,253.7 7.7 - 13,102 502 535 13,106 491 102 100 2 - - - - 424 0.29 0.53

10/07/08 28,275.9 22.2 - 13,806 529 533 13,801 522 102 100 2 - - - - 439 0.04 0.28

10/08/08 28,291.8 15.9 - 14,313 531 527 14,301 524 102 101 1 - - - - 449 0.11 0.09

10/09/08 28,305.4 13.6 - 14,744 528 530 14,723 517 102 100 2 - - - - 460 0.08 0.33

10/10/08 28,315.2 9.8 - 15,056 531 530 15,049 554 102 100 2 - - - - 481 0.08 0.21

10/11/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) - - - - NM(a) - -

10/12/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) - - - - NM(a) - -

10/13/08 28,355.6 40.4 - 16,335 528 530 16,353 538 102 101 1 - - - - 517 0.17 0.02

10/14/08 28,368.4 12.8 - 16,741 529 528 16,773 547 101 100 2 - - - - 532 0.15 0.22

10/15/08 28,380.5 12.1 - 17,124 528 570 17,155 526 102 100 2 - - - - 542 0.19 0.34

10/16/08 28,393.2 12.7 - 17,527 529 534 17,565 538 102 101 1 - - - - 557 0.06 0.28

10/17/08 28,410.4 17.2 - 18,074 530 520 18,128 546 102 101 1 - - - - 573 0.10 0.31

10/18/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) - - - - NM(a) - -

10/19/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) - - - - NM(a) - -

10/20/08 28,442.6 32.2 527 NM(b) - 580 19,161 535 102 100 2 - - - - 608 0.17 0.06

10/21/08 28,450.5 7.9 540 NM(b) - 530 19,418 542 100 100 0 - - - - 618 0.66 0.60

10/22/08 28,457.0 6.5 531 NM(b) - 590 19,632 549 101 100 1 - - - - 628 0.46 0.13

10/23/08 28,469.2 12.2 537 NM(b) - 590 20,037 553 100 100 0 - - - - 666 0.25 0.64

10/24/08 28,481.6 12.4 552 NM(b) - 550 20,441 543 100 100 0 - - - - 677 0.18 0.55

10/25/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) - - - - NM(a) - -

10/26/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) - - - - NM(a) - -

10/27/08 28,517.3 35.7 538 21,465 - 540 21,612 547 101 100 1 8 - 10 7 715 0.25 0.14

10/28/08 28,528.1 10.8 531 21,811 534 557 21,956 531 102 100 2 8 6:25 10 5 726 0.52 0.11

10/29/08 28,542.7 14.6 530 22,276 531 535 22,434 546 101 100 1 8 4:27 10 3 736 0.49 0.11

10/30/08 28,549.3 6.6 533 22,485 528 557 22,640 520 101 100 1 8 6:45 10 1 747 0.37 0.25

10/31/08 28,560.6 11.3 540 22,847 534 535 23,013 550 101 99 2 8 7:51 10 9 757 0.53 0.11

11/01/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

11/02/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

11/03/08 28,591.4 30.8 529 23,829 531 590 24,010 540 102 100 2 8 5:25 10 4 784 0.10 0.53

11/04/08 28,602.7 11.3 NM(a) 24,185 525 NM(a) 24,372 534 NM(a) NM(a) NM(a) N 8:00 10 2 794 0.13 0.33

11/05/08 28,613.4 10.7 527 24,515 514 520 24,709 525 102 100 2 8 4:39 10 1 800 0.19 0.54

11/06/08 28,625.1 11.7 532 24,890 534 580 25,087 538 101 100 1 8 6:56 - - 810 0.06 0.49

11/07/08 28,630.0 4.9 534 25,051 548 533 25,255 571 101 100 1 8 7:37 10 7 820 0.15 0.34

11/08/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

11/09/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

11/10/08 28,642.6 12.6 NM(a) 25,442 517 NM(a) 25,664 541 NM(a) NM(a) NM(a) NM(a) 0:00 10 2 845 0.12 0.07

11/11/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

11/12/08 28,658.0 15.4 534 25,943 542 530 26,180 558 101 99 2 8 5:30 10 9 861 0.11 0.51

11/13/08 28,674.1 16.1 529 26,450 525 570 26,692 530 102 101 1 8 6:10 10 6 877 0.14 0.28

11/14/08 28,680.5 6.4 537 26,653 529 575 26,897 534 100 99 1 8 7:18 10 5 882 0.18 0.32

11/15/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

11/16/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

11/17/08 28,717.9 37.4 537 27,840 529 535 28,101 537 102 100 2 8 7:47 10 9 914 0.15 0.40

11/18/08 28,726.1 8.2 539 28,098 524 535 28,362 530 101 100 1 8 7:37 10 8 919 0.18 0.40

11/19/08 28,742.5 16.4 540 28,617 527 540 28,885 532 100 99 1 8 7:49 10 5 935 0.18 0.43

11/20/08 28,756.3 13.8 527 29,059 534 560 29,339 548 103 101 2 8 5:41 10 3 946 0.16 0.42

11/21/08 28,763.8 7.5 539 29,296 527 535 29,577 529 100 99 1 8 7:29 10 1 957 0.25 0.11

11/22/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

11/23/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

11/24/08 28,795.5 31.7 520 30,299 527 520 30,602 539 103 100 3 8 8:00 10 7 977 0.17 0.16

11/25/08 28,801.9 6.4 538 30,503 531 530 30,809 539 100 100 0 8 7:37 10 5 988 0.82 0.19

11/26/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

11/27/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

11/28/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

11/29/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

11/30/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

actual

BW Counter

Preset actual

Filter Run time

Preset

-

-

-

8

Totalizer Totalizer

dP 

across 

Filter

Inst. 

Avg Flow Flow

Treatment System Shakedown

BW 

totalizer

Avg 

Flow 

1

42% 

FeCl3 

Usage

Hour 

Meter

Well #4 

Incre. Run 

Time Inlet Outlet 

2

3

9

-

Inst. 

Flow

Date

Week 

No.

Treatment System Taken Offline for Chlorine Dosage Tests

12.5% 

NaOCl 

Usage

Filter

4

5

6

7
A-2 

Table A-1. US EPA Demonstration Project At Okanogan, WA – Daily Operational Log Sheet (Continued)

hr hr gpm kgal gpm gpm kgal gpm psi psi psig hr hr # # Kgal gal/hr gal/hr

12/01/08 28,876.1 74.2 533 32,853 528 530 33,195 536 101 100 1 8 6:55 10 3 1049 0.08 0.16

12/02/08 28,885.2 9.1 535 33,142 529 530 33,579 703 101 100 1 8 6:40 10 1 1059 0.16 0.18

12/03/08 28,894.5 9.3 534 33,437 529 530 33,775 351 101 100 1 8 6:40 10 9 1070 0.02 0.02

12/04/08 28,906.8 12.3 536 33,830 533 530 34,161 523 101 100 1 8 7:12 10 6 1083 0.15 0.13

12/05/08 28,919.6 12.8 534 34,240 534 530 34,565 526 101 100 1 8 6:18 10 4 1093 0.12 0.16

12/06/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/07/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/08/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/09/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/10/08 28,976.7 57.1 537 36,059 531 525 36,391 533 101 100 1 8 7:34 4 2 1138 0.13 0.16

12/11/08 28,980.0 3.3 539 36,190 662 525 36,525 677 100 100 0 8 7:45 4 1 1142 2.27 2.49

12/12/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/13/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/14/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/15/08 29,027.3 47.3 532 37,673 523 530 38,037 533 101 100 1 8 4:25 4 2 1177 0.13 0.14

12/16/08 29,030.2 2.9 537 37,770 557 530 38,127 517 100 99 1 8 6:29 4 3 1183 0.13 0.07

12/17/08 29,044.3 14.1 531 38,223 535 525 38,585 541 101 99 2 8 5:40 4 1 1188 0.12 0.12

12/18/08 29,058.5 14.2 530 38,585 425 525 38,944 421 102 99 3 8 7:18 4 3 1189 0.16 0.13

12/19/08 29,067.8 9.3 526 38,958 668 520 39,314 663 103 99 4 8 6:42 4 1 1189 0.10 0.22

12/20/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/21/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/22/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/23/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/24/08 NM(a) - 500 40,490 - 495 40,831 - 109 99 10 8 5:00 4 1 1190 - -

12/25/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/26/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/27/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/28/08 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

12/29/08 29,179.2 111.4 481 42,276 267 460 42,599 265 113 100 13 8 9:36 4 3 1191 0.07 0.08

12/30/08 29,186.6 7.4 534 42,502 509 530 42,821 500 100 99 1 8 2:52 4 3 1204 0.15 0.17

12/31/08 29,198.6 12.0 536 42,881 526 525 43,208 538 100 99 1 8 5:45 4 1 1212 0.12 0.14

01/01/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

01/02/09 29,219.0 20.4 534 43,533 533 525 43,869 540 100 99 1 8 13:40 4 1 1235 0.13 0.14

01/03/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

01/04/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

01/05/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

01/06/09 29,264.2 45.2 513 44,946 521 500 45,278 520 105 100 5 8 7:10 4 1 1239 0.14 0.15

01/07/09 29,275.9 11.7 534 45,315 526 525 45,654 536 101 100 1 8 5:10 4 1 1267 0.13 0.14

01/08/09 29,287.9 12.0 532 45,700 535 525 46,033 526 100 100 0 8 6:47 4 3 1279 0.11 0.14

01/09/09 29,296.0 8.1 530 45,955 525 525 46,297 543 101 100 1 8 3:50 4 2 1285 0.12 0.18

01/10/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

01/11/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

01/12/09 29,324.6 28.6 536 46,871 682 520 47,219 691 100 99 1 8 6:17 4 1 1311 0.12 0.12

01/13/09 29,335.4 10.8 535 47,217 534 525 47,571 543 100 99 1 8 6:26 4 3 1322 0.17 0.13

01/14/09 29,343.5 8.1 536 47,475 531 525 47,830 533 100 99 1 8 6:06 4 2 1333 0.19 0.20

01/15/09 29,353.3 9.8 537 47,787 531 525 48,153 549 100 99 1 8 6:38 4 4 1344 0.15 0.21

01/16/09 29,364.5 11.2 536 48,145 533 525 48,516 540 100 99 1 8 6:15 4 2 1354 0.13 0.15

01/17/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

01/18/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

01/19/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

01/20/09 29,403.1 38.6 534 49,380 533 525 49,768 541 100 100 0 8 6:38 4 3 1380 0.14 0.12

01/21/09 29,411.0 7.9 535 49,634 536 525 50,027 546 100 100 0 8 6:10 4 1 1380 0.14 0.31

01/22/09 29,418.7 7.7 535 49,881 535 525 50,283 554 100 100 0 8 5:46 4 3 1389 0.15 0.16

01/23/09 29,427.4 8.7 533 50,158 531 520 50,560 531 100 99 1 8 6:16 4 1 1395 0.13 0.14

01/24/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

01/25/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

01/26/09 29,464.7 37.3 534 51,347 655 525 51,749 655 100 100 0 8 6:50 4 2 1424 0.12 0.15

01/27/09 29,473.2 8.5 533 51,619 533 520 52,023 537 100 100 0 8 4:46 4 4 1434 0.18 0.15

01/28/09 29,485.8 12.6 534 52,020 530 525 52,432 541 100 100 0 8 7:00 4 2 1448 0.15 0.15

01/29/09 29,494.9 9.1 534 52,309 529 520 52,720 527 100 100 0 8 6:12 4 4 1459 0.12 0.09

01/30/09 29,507.4 12.5 531 52,709 533 520 53,131 548 100 100 0 8 3:37 4 2 1469 0.15 0.16

01/31/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

02/01/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

02/02/09 29,540.3 32.9 539 53,756 733 525 54,176 738 100 100 0 8 7:53 4 4 1492 0.19 0.24

02/03/09 29,551.0 10.7 537 54,096 530 525 54,514 526 100 100 0 8 7:21 4 4 1513 0.16 0.13

02/04/09 29,563.7 12.7 532 54,519 555 520 54,943 563 100 100 0 8 5:34 1 1 1522 0.12 0.10

02/05/09 29,577.2 13.5 527 54,934 512 520 55,366 522 101 100 1 8 1:45 2 1 1533 0.11 0.12

02/06/09 29,583.7 6.5 535 55,139 526 525 55,573 531 100 100 0 8 6:53 2 1 1544 0.17 0.13

02/07/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

02/08/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

02/09/09 29,617.3 33.6 534 56,210 633 525 56,656 640 101 100 1 8 6:39 4 1 1577 0.14 -

02/10/09

02/11/09

02/12/09

02/13/09

02/14/09

02/15/09

02/16/09

02/17/09 29,625.5 8.2 524 56,474 537 520 56,915 526 102 100 2 8 0:29 4 3 1589 0.05 0.65

02/18/09 29,632.7 7.2 532 56,702 528 520 57,234 738 101 100 1 8 6:01 4 1 1601 0.16 0.17

02/19/09 29,640.7 8.0 536 56,959 535 525 57,419 385 100 100 0 8 6:40 4 3 1612 0.09 0.05

02/20/09 29,652.4 11.7 535 57,331 530 525 57,784 520 100 100 0 8 6:16 4 4 1624 0.10 0.18

02/21/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

02/22/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

Date

Hour 

Meter

Treatment System Shut Down for Operators to Attend Training Class

Incre. Run 

Time

Well #4 

Inst. 

Week Flow Totalizer Avg Flow

No.

Filter Filter Run time BW Counter

Inst. 

Flow Totalizer

Avg 

Flow Inlet

BW 

totalizer

42% 

FeCl3 

Usage

12.5% 

NaOCl 

Outlet Usage

dP 

across 

Filter Preset actual Preset actual

10

11

14

12

13

15

16

18

20

21

17

19
A-3 

Table A-1. US EPA Demonstration Project At Okanogan, WA – Daily Operational Log Sheet (Continued)

hr hr gpm kgal gpm gpm kgal gpm psi psi psig hr hr # # Kgal gal/hr gal/hr

02/23/09 29,681.5 29.1 529 58,258 744 520 58,727 749 101 100 1 8 3:23 4 4 1648 0.14 0.11

02/24/09 29,686.6 5.1 540 58,421 533 530 58,886 520 100 100 0 8 7:52 4 2 1656 0.18 0.32

02/25/09 29,696.4 9.8 536 58,734 532 520 59,202 537 100 100 0 8 6:40 4 1 1663 0.11 0.13

02/26/09 29,708.3 11.9 535 59,116 535 525 59,588 541 100 100 0 8 6:06 4 3 1673 0.09 0.14

02/27/09 29,715.3 7.0 538 59,340 533 525 59,815 540 100 100 0 8 6:35 4 2 1679 0.16 0.21

02/28/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

03/01/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

03/02/09 29,752.2 36.9 529 60,519 634 520 61,014 644 101 100 1 8 1:23 4 4 1714 0.13 0.14

03/03/09 29,763.8 11.6 527 60,888 530 520 61,387 536 101 100 1 8 0:35 4 2 1725 0.13 0.14

03/04/09 29,772.2 8.4 534 61,155 530 525 61,656 534 100 100 0 8 7:07 4 4 1737 0.16 0.12

03/05/09 29,779.0 6.8 536 61,372 532 525 61,875 537 100 100 0 8 6:42 4 2 1749 0.14 0.18

03/06/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

03/07/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

03/08/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

03/09/09 29,818.7 39.7 534 62,646 535 525 63,179 547 100 100 0 8 4:40 4 3 1790 0.13 0.15

03/10/09 29,830.5 11.8 529 63,025 535 525 63,563 542 101 100 1 8 1:06 4 1 1801 0.03 0.17

03/11/09 29,843.7 13.2 534 63,414 491 525 63,956 496 100 100 0 8 6:18 4 2 1819 0.20 0.19

03/12/09 29,853.7 10.0 533 63,763 582 525 64,310 590 102 100 2 8 6:49 4 4 1829 0.07 0.16

03/13/09 29,865.2 11.5 531 64,134 538 520 64,690 551 100 100 0 8 6:40 4 1 1847 0.16 0.14

03/14/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

03/15/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

03/16/09 29,899.4 34.2 531 65,221 530 520 65,802 542 101 100 1 8 1:50 4 3 1883 0.09 0.17

03/17/09 29,906.4 7.0 536 65,445 533 525 66,025 531 100 100 0 8 7:16 4 1 1895 0.32 0.12

03/18/09 29,916.7 10.3 536 65,775 534 525 66,364 549 100 100 0 8 7:13 4 2 1912 0.05 0.14

03/19/09 29,927.8 11.1 537 66,130 533 525 66,729 548 100 100 0 8 7:20 4 4 1924 0.07 0.19

03/20/09 29,940.5 12.7 528 66,534 530 520 67,144 545 101 100 1 8 2:46 4 4 1935 0.15 0.16

03/21/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

03/22/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

03/23/09 29,961.1 20.6 550 67,193 533 525 67,815 543 100 100 0 8 8:00 4 1 1965 0.16 0.22

03/24/09 29,973.5 12.4 538 67,593 538 525 68,221 546 100 100 0 8 7:26 4 3 1977 0.18 0.23

03/25/09 29,984.2 10.7 541 67,933 530 520 68,569 542 100 100 0 8 7:50 4 4 1994 0.05 0.08

03/26/09 29,991.0 6.8 539 68,152 537 525 68,792 547 100 100 0 8 7:37 4 2 2006 0.11 0.09

03/27/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

03/28/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

03/29/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

03/30/09 30,028.0 37.0 537 69,344 537 525 69,998 543 99 99 0 8 6:20 4 3 2048 0.12 0.16

03/31/09 30,038.0 10.0 530 69,671 545 520 70,332 557 100 100 0 8 1:52 4 2 2054 0.15 0.19

04/01/09 30,046.0 8.0 539 69,931 542 525 70,593 544 99 99 0 8 7:23 4 3 2071 0.09 0.21

04/02/09 30,064.0 18.0 523 70,510 536 520 71,184 547 101 100 1 8 0:08 4 1 2083 0.15 0.14

04/03/09 30,076.0 12.0 529 70,884 519 520 71,557 518 100 100 0 8 6:31 4 1 2108 0.12 0.14

04/04/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

04/05/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

04/06/09 30,106.3 30.3 533 71,837 524 520 72,529 535 100 100 0 8 7:35 4 3 2144 0.17 0.15

04/07/09 30,117.0 10.7 532 72,200 565 520 72,897 573 100 100 0 8 6:09 4 3 2162 0.11 0.17

04/08/09 30,133.0 16.0 534 72,700 521 525 73,412 536 100 100 0 8 6:08 4 1 2174 0.12 0.15

04/09/09 30,151.0 18.0 530 73,272 530 520 73,989 534 100 100 0 8 2:51 4 2 2192 0.10 0.11

04/10/09 30,163.0 12.0 532 73,645 518 520 74,360 515 100 100 0 8 6:37 4 3 2209 0.16 0.17

04/11/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

04/12/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

04/13/09 30,200.4 37.4 537 74,828 527 525 75,558 534 100 100 0 8 7:41 4 1 2242 0.15 0.15

04/14/09 30,215.0 14.6 534 75,309 549 520 76,044 555 100 100 0 8 6:14 4 2 2258 0.10 0.11

04/15/09 30,228.0 13.0 532 75,709 513 560 76,449 519 100 100 0 8 5:47 4 4 2269 0.14 0.13

04/16/09 30,247.0 19.0 529 76,341 554 520 77,075 549 100 100 0 8 4:16 4 1 2286 0.14 0.13

04/17/09 30,261.0 14.0 525 76,784 527 520 77,538 551 101 100 1 8 0:20 4 3 2298 0.13 0.18

04/18/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

04/19/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

04/20/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

04/21/09 30,320.0 59.0 531 78,663 531 520 79,427 534 100 100 0 8 6:17 4 1 2353 0.13 0.17

04/22/09 30,334.0 14.0 536 79,108 530 525 79,876 535 100 100 0 8 6:17 4 3 2363 0.13 0.15

04/23/09 30,353.0 19.0 530 79,691 511 520 80,465 517 100 100 0 8 6:11 4 3 2385 0.12 0.13

04/24/09 30,371.0 18.0 531 80,257 524 520 81,038 531 100 100 0 8 6:00 4 4 2400 0.12 0.16

04/25/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

04/26/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

04/27/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

04/28/09 30,440.0 69.0 526 82,458 532 520 83,258 536 101 100 1 8 1:20 4 2 2458 0.13 0.14

04/29/09 30,455.0 15.0 530 82,935 530 525 83,737 532 101 100 1 8 7:13 4 3 2475 0.12 0.16

04/30/09 30,471.0 16.0 531 83,439 525 525 84,249 533 100 100 0 8 2:58 4 1 2485 0.14 0.15

05/01/09 30,494.0 23.0 526 84,193 546 520 85,005 548 101 100 1 8 2:51 4 2 2503 0.13 0.14

05/02/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

05/03/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

05/04/09 30,539.7 45.7 532 85,606 515 520 86,436 522 100 100 0 8 6:13 4 1 2554 0.23 0.16

05/05/09 30,561.0 21.3 526 86,290 535 520 87,125 539 101 100 1 8 2:42 4 1 2572 0.12 0.08

05/06/09 30,568.0 7.0 528 86,525 560 520 87,362 564 100 100 0 8 6:06 4 4 2583 0.16 0.18

05/07/09 30,579.0 11.0 528 86,877 533 520 87,715 535 100 100 0 8 7:20 4 2 2594 0.14 0.00

05/08/09 30,591.0 12.0 531 87,250 518 520 88,092 524 100 100 0 8 7:25 4 4 2605 0.16 0.17

05/09/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

05/10/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

05/11/09 30,645.0 54.0 526 88,952 525 515 89,810 530 101 100 1 8 3:50 4 4 2650 0.12 0.18

05/12/09 30,670.0 25.0 524 89,757 537 520 90,620 540 101 100 1 8 0:21 4 1 2667 0.12 0.10

05/13/09 30,685.0 15.0 533 90,245 542 520 91,101 534 100 100 0 8 6:41 4 2 2683 0.15 0.19

05/14/09 30,702.0 17.0 532 90,783 527 520 91,640 528 100 100 0 8 7:50 4 3 2699 0.13 0.15

05/15/09 30,716.0 14.0 530 91,218 518 520 92,086 531 101 100 1 8 6:56 4 1 2710 0.13 0.18

05/16/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

05/17/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

Totalizer

Avg 

Flow Inlet

BW 

totalizer

42% 

FeCl3 

Usage

12.5% 

NaOCl 

Usage

Inst. 

Flow

33

28

26

27

24

Week 

No. Date

Hour 

Meter

Well #4 Filter

Outlet 

dP 

across 

Filter

Incre. Run 

Time Totalizer Avg Flow actual

Filter Run time BW Counter

Preset actual

Inst. 

Flow

23

25

30

Preset

22

29

32

31
A-4 

Table A-1. US EPA Demonstration Project At Okanogan, WA – Daily Operational Log Sheet (Continued)

hr hr gpm kgal gpm gpm kgal gpm psi psi psig hr hr # # Kgal gal/hr gal/hr

05/18/09 30,777.9 61.9 524 93,160 523 560 94,034 525 103 101 2 8 5:38 4 4 2758 0.13 0.16

05/19/09 30,798.0 20.1 522 93,801 532 520 94,677 533 101 100 1 8 0:35 4 2 2768 0.07 0.08

05/20/09 30,821.0 23.0 526 94,536 533 555 95,416 536 101 100 1 8 3:51 4 2 2788 0.16 0.14

05/21/09 30,832.0 11.0 530 94,902 555 520 95,787 562 102 100 2 8 1:10 4 4 2799 0.14 0.15

05/22/09 30,858.0 26.0 532 95,726 528 520 96,608 526 100 100 0 8 7:07 4 4 2819 0.12 0.14

05/23/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

05/24/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

05/25/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

05/26/09 30,902.6 44.6 524 97,122 522 520 98,012 525 101 100 1 8 2:48 4 2 2851 0.15 0.17

05/27/09 30,922.0 19.4 530 97,748 538 520 98,641 540 100 100 0 8 1:50 4 3 2867 0.00 0.08

05/28/09 30,937.0 15.0 534 98,249 557 515 99,143 558 101 100 1 8 6:28 4 4 2883 0.12 0.16

05/29/09 30,953.0 16.0 533 98,731 528 515 99,622 531 100 100 0 8 6:09 4 1 2899 0.12 0.13

05/30/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

05/31/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

06/01/09 31,005.1 52.1 538 100,331 512 520 101,247 520 100 100 0 8 7:52 4 3 2953 0.15 0.17

06/02/09 31,021.0 15.9 537 100,921 618 525 101,842 624 100 100 0 8 7:27 4 3 2973 0.05 0.10

06/03/09 31,036.0 15.0 535 101,383 513 520 102,306 516 100 100 0 8 6:27 4 1 2983 0.10 0.11

06/04/09 31,056.0 20.0 528 102,016 528 520 102,946 533 102 100 2 8 2:37 4 2 2998 0.11 0.14

06/05/09 31,077.0 21.0 527 102,683 529 515 103,615 531 102 100 2 8 2:40 4 3 3012 0.14 0.16

06/06/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

06/07/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

06/08/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

06/09/09 31,133.0 56.0 533 104,475 533 520 105,445 545 100 100 0 8 6:40 4 3 3097 0.12 0.15

06/10/09 31,152.0 19.0 532 105,078 529 520 106,064 543 100 100 0 8 7:28 4 2 3124 0.10 0.11

06/11/09 31,164.0 12.0 530 105,481 560 520 106,473 568 100 100 0 8 6:10 4 4 3135 0.19 0.21

06/12/09 31,180.0 28.0 529 105,979 536 515 106,983 547 100 100 0 8 3:20 4 1 3151 0.09 0.10

06/13/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

06/14/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

06/15/09 31,229.9 49.9 527 107,545 523 510 108,562 527 101 100 1 8 4:12 4 4 3197 0.12 0.13

06/16/09 31,240.0 10.1 527 107,883 558 510 108,908 571 101 100 1 8 3:08 4 1 3213 0.07 0.16

06/17/09 31,260.0 20.0 536 108,529 538 525 109,555 539 100 100 0 8 4:06 4 1 3233 0.09 0.06

06/18/09 31,272.0 12.0 531 108,909 528 520 109,938 532 100 100 0 8 6:16 4 2 3249 0.16 0.17

06/19/09 31,291.0 19.0 525 109,513 530 520 110,555 541 101 100 1 8 2:40 4 3 3264 0.16 0.17

06/20/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

06/21/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

06/22/09 31,330.6 39.6 531 110,745 519 510 111,797 523 102 101 1 8 7:42 4 2 3315 0.18 0.20

06/23/09 31,341.4 10.8 528 111,090 532 515 112,148 542 100 100 0 8 6:43 4 3 3332 0.03 0.00

06/24/09 31,359.1 17.7 525 111,650 527 560 112,716 535 101 100 1 8 5:40 4 1 3343 0.13 0.14

06/25/09 31,376.3 17.2 531 112,196 529 515 113,263 530 100 100 0 8 6:30 4 1 3364 0.09 0.19

06/26/09 31,399.0 22.7 525 112,915 528 510 113,994 537 102 100 2 8 1:54 4 2 3379 0.15 0.14

06/27/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

06/28/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

06/29/09 31,461.7 62.7 529 114,896 527 515 115,959 522 101 100 1 8 7:33 4 4 3431 0.13 0.16

06/30/09 31,481.0 19.3 529 115,507 528 510 116,566 524 100 100 0 8 7:19 4 1 3447 0.17 0.21

07/01/09 31,499.2 18.2 528 116,080 525 510 117,146 531 100 100 0 8 6:26 4 1 3469 0.12 0.13

07/02/09 31,517.7 18.5 528 116,667 529 510 117,746 541 100 100 0 8 6:31 4 1 3490 0.12 0.14

07/03/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

07/04/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

07/05/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

07/06/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

07/07/09 31,566.0 48.3 522 118,205 531 510 119,309 539 101 100 1 8 1:36 4 3 3543 0.11 0.14

07/08/09 31,583.6 17.6 519 118,730 497 510 119,839 502 102 100 2 8 0:35 4 4 3560 0.11 0.14

07/09/09 31,599.0 15.4 520 119,234 545 565 120,347 550 102 100 2 8 3:49 4 4 3580 0.15 0.21

07/10/09 31,619.0 20.0 522 119,864 525 565 120,986 533 102 100 2 8 5:07 4 4 3602 0.11 0.16

07/11/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

07/12/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

07/13/09 31,663.2 44.2 522 121,237 518 520 122,373 523 101 100 1 8 4:44 4 3 3649 0.15 0.16

07/14/09 31,676.0 12.8 523 121,640 525 510 122,780 530 101 100 1 8 4:00 4 1 3660 0.06 0.13

07/15/09 31,695.0 19.0 520 122,250 535 515 123,386 532 101 100 1 8 5:10 4 2 3676 0.20 0.17

07/16/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

07/17/09 31,732.0 37.0 519 123,403 519 510 124,560 529 102 100 2 8 4:48 4 3 3713 0.10 0.16

07/18/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

07/19/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

07/20/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

07/21/09 31,809.0 77.0 515 125,837 527 510 127,011 531 102 100 2 8 0:55 4 2 3782 0.13 0.16

07/22/09 31,825.0 16.0 520 126,326 509 560 127,508 518 101 100 1 8 4:38 4 2 3804 0.14 0.21

07/23/09 31,843.0 18.0 518 126,889 521 510 128,081 531 102 100 2 8 2:40 4 2 3825 0.12 0.14

07/24/09 31,861.0 18.0 522 127,448 518 510 128,641 519 101 100 1 8 6:14 4 3 3841 0.12 0.14

07/25/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

07/26/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

07/27/09 31,910.8 49.8 521 129,025 528 510 130,231 532 102 100 2 8 5:19 4 3 3882 0.14 0.03

07/28/09 31,929.0 18.2 523 129,589 516 510 130,795 516 100 100 0 8 6:20 4 4 3897 0.08 0.00

07/29/09 31,947.0 18.0 521 130,165 533 510 131,379 541 102 100 2 8 2:28 4 1 3913 0.08 0.18

07/30/09 31,969.0 22.0 523 130,832 505 510 132,046 505 100 100 0 8 6:52 4 1 3933 0.17 0.19

07/31/09 31,990.0 21.0 516 131,507 536 510 132,729 542 102 100 2 8 3:08 4 2 3947 0.11 0.20

08/01/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

08/02/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

Inlet Outlet actual

dP 

across 

Filter Preset actual Preset

Filter Run time BW Counter

BW 

totalizer

42% 

FeCl3 

Usage

12.5% 

NaOCl 

Usage

Inst. 

Flow Totalizer Avg Flow

Inst. 

Week Flow Totalizer

No. Date

Hour 

Meter

Incre. Run 

Time

Well #4 Filter

Avg 

Flow 

43

40

41

42

34

39

38

37

35

36

44
A-5 

Table A-1. US EPA Demonstration Project At Okanogan, WA – Daily Operational Log Sheet (Continued)

hr hr gpm kgal gpm gpm kgal gpm psi psi psig hr hr # # Kgal gal/hr gal/hr

08/03/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

08/04/09 32,053.0 63.0 521 133,454 515 510 134,690 519 100 100 0 8 7:43 4 1 4014 0.11 0.16

08/05/09 32,074.0 21.0 520 134,122 530 510 135,360 532 100 100 0 8 7:30 4 2 4030 0.14 0.16

08/06/09 32,090.0 16.0 514 134,623 522 505 135,869 530 102 100 2 8 2:39 4 4 4040 0.14 0.15

08/07/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

08/08/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

08/09/09 NM(a) - NM(a) NM(a) - NM(a) NM(a) - NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) NM(a) - -

08/10/09 32,150.4 60.4 514 136,474 511 555 137,750 519 102 100 2 8 3:50 4 2 4114 0.09 0.14

08/11/09 32,167.0 16.6 519 136,997 525 505 138,281 533 100 100 0 8 7:20 4 2 4137 0.09 0.15

08/12/09 32,182.0 15.0 512 137,461 516 555 138,757 529 102 100 2 8 3:44 4 3 4154 0.10 0.00

08/13/09 32,194.0 12.0 550 137,867 564 545 139,165 567 100 100 0 8 7:30 4 4 4170 0.12 0.07

08/14/09 32,207.0 13.0 529 138,280 529 510 139,579 531 100 100 0 8 7:10 4 2 4180 0.12 0.22

Highlighted columns indicate calculated values.

(a) Operational data not recorded during weekends and holidays.

Inlet Outlet 

dP 

across 

Filter Preset actual

BW 

totalizer

42% 

FeCl3 

Usage

12.5% 

NaOCl 

Usage

Inst. 

Flow Totalizer Avg Flow

Inst. 

Week Flow Totalizer Preset actual

No. Date

Hour 

Meter

Incre. Run 

Time

Well #4 Filter Filter Run time BW Counter

Avg 

Flow 

46

45
APPENDIX B

ANALYTICAL DATA TABLE
B-1

Table B-1. Analytical Results from Long Term Sampling at Okanogan, WA 

Sampling Date 08/14/08 09/02/08 10/07/08 10/14/08 10/21/08

Sampling Location IN AC TT IN AC TT IN AC TT IN AC TT IN AC TT Parameter Unit

Alkalinity (as CaCO3) mg/L 183 181 188 182 180 184 177 184 177 175 177 175 183 181 183

- - - - - - - - - - - - - - -

Ammonia (as N) mg/L - - - - - - - - - - - - - - -

Fluoride mg/L 0.7 0.7 0.8 - - - 0.6 0.6 0.6 - - - - - -

Sulfate mg/L 126 123 122 - - - 123 125 125 - - - - - -

Nitrate (as N) mg/L <0.05 <0.05 <0.05 - - - <0.05 <0.05 <0.05 - - - - - -

Total P (as P) μg/L 50.1 47.1 <10 NA NA NA 60.0 54.0 16.4 43.2 41.1 <10 44.0 47.6 12.2

- - - - - - - - - - - - - - -

Silica (as SiO2) mg/L 26.9 27.1 25.8 27.0 26.8 26.7 26.8 26.8 27.1 24.1 23.4 23.7 23.3 23.0 22.5

- - - - - - - - - - - - - - -

Turbidity NTU 0.3 1.3 0.2 0.2 0.4 <0.1 0.1 0.1 1.4 0.2 0.6 0.1 0.3 1.7 0.1

- - - - - - - - - - - - - - -

pH S.U. 7.7 7.8 9.5(a) NA(b) NA(b) NA(b) 7.5 7.8 7.8 7.7 7.8 7.9 7.8 7.8 7.9

Temperature °C 21.7 21.5 20.5 NA(b) NA(b) NA(b) 16.4 16.4 16.4 16.4 16.3 16.4 16.7 16.5 16.5

DO mg/L 2.0 2.0 1.0 NA(b) NA(b) NA(b) 3.6 4.2 4.0 NA(c) NA(c) NA(c) NA(c) NA(c) NA(c)

ORP mV 361 374 358 NA(b) NA(b) NA(b) 381 615 628 428 424 416 460 440 512

Free Chlorine (as Cl2) mg/L - NA NA - NA(b) NA(b) - NA NA - 1.3 NA - 1.3 NA

Total Chlorine (as Cl2) mg/L - 0.0 NA - NA(b) NA(b) - NA NA - 1.4 NA - 1.6 NA

Total Hardness (as CaCO3) mg/L 272 261 267 - - - 274 277 273 - - - - - -

Ca Hardness (as CaCO3) mg/L 142 138 56.9 - - - 145 149 146 - - - - - -

Mg Hardness (as CaCO3) mg/L 130 123 210 - - - 129 128 127 - - - - - -

As (total) μg/L 22.7 22.5 6.8 18.6 19.3 9.2 19.9 19.8 8.9 18.1 16.1 4.3 18.1 18.8 6.4

- - - - - - - - - - - - - - -

As (soluble) μg/L 21.2 15.6 6.5 - - - 18.3 17.1 8.6 - - - - - -

As (particulate) μg/L 1.5 6.9 0.3 - - - 1.6 2.7 0.3 - - - - - -

As(III) μg/L 19.8 7.2 0.4 - - - 14.4 0.4 0.4 - - - - - -

As(V) μg/L 1.4 8.4 6.1 - - - 3.9 16.7 8.2 - - - - - -

Fe (total) μg/L 104 1,036 <25 78 526 <25 84 163 41 73 717 <25 73 972 <25

- - - - - - - - - - - - - - -

Fe (soluble) μg/L 89 <25 <25 - - - <25 <25 <25 - - - - - -

Mn (total) μg/L 77.0 76.2 0.6 59.3 60.5 51.9 60.5 61.0 5.7 71.1 63.9 31.8 68.4 70.5 18.9

- - - - - - - - - - - - - - -

Mn (soluble) μg/L 74.1 77.0 0.3 - - - 62.5 18.3 0.9 - - - - - -

(a) The high pH value measured caused by media manufacturing process.

(b) Water quality data not measured on 09/02/08.

(c) DO probe not functional, waiting for Battelle to send a new probe.

 
 

B-2

Table B-1. Analytical Results from Long Term Sampling at Okanogan, WA (Continued)

Sampling Date 10/28/08 11/04/08 11/13/08 11/18/08 12/03/08 12/10/08

Sampling Location IN AC TT IN AC TT IN AC TT IN AC TT IN AC TT IN AC TT Parameter Unit

Alkalinity (as CaCO3) mg/L 179 175 175 182 184 179 180 180 178 179 179 176 182 186 182 182 178 176

- - - - - - 178 178 185 - - - - - - - - -

Ammonia (as N) mg/L - - - - - - - - - - - - 0.1 0.1 0.1 - - -

Fluoride mg/L - - - 0.6 0.8 0.6 - - - - - - 0.6 0.6 0.6 - - -

Sulfate mg/L - - - 119 119 120 - - - - - - 127 124 120 - - -

Nitrate (as N) mg/L - - - <0.05 0.3 <0.05 - - - - - - <0.05 <0.05 <0.05 - - -

Total P (as P) μg/L 52.0 54.5 13.4 57.3 362 19.3 67.9 47.6 70.7 47.5 45.7 15.5 56.4 58.3 17.8 58.5 54.2 17.1

- - - - - - 49.7 50.1 72.0 - - - - - - - - -

Silica (as SiO2) mg/L 26.8 26.7 26.1 24.9 32.2 24.2 26.6 26.5 26.9 26.0 26.1 26.3 25.4 26.1 25.3 25.2 25.5 25.3

- - - - - - 26.3 26.3 26.1 - - - - - - - - -

Turbidity NTU 0.1 0.6 <0.1 0.5 16.0 0.2 0.6 1.7 2.3 0.1 0.7 0.2 0.9 1.6 0.3 0.4 0.7 0.1

- - - - - - 1.2 2.5 2.1 - - - - - - - - -

pH S.U. 7.7 7.8 7.8 7.5 7.6 7.7 7.6 7.7 7.8 7.4 7.6 7.7 7.6 7.7 7.8 7.6 7.7 7.7

Temperature °C 16.2 16.0 16.0 16.1 16.1 16.2 15.7 15.6 15.6 16.9 16.9 16.9 15.8 15.7 15.6 15.3 15.4 15.4

DO mg/L 4.1 4.3 4.0 2.5 2.5 2.5 3.6 3.7 3.5 2.6 3.0 3.3 NA NA NA 3.0 2.5 2.2

ORP mV 467 635 648 465 650 666 461 638 636 456 641 650 455 371 365 470 530 532

Free Chlorine (as Cl2) mg/L - 1.1 1.1 - 1.8 1.8 - NA 1.1 - 1.3 1.4 - 0.04 0.02 - 0.2 0.2

Total Chlorine (as Cl2) mg/L - 1.3 1.2 - 2.0 2.0 - NA 1.3 - 1.6 1.2 - 0.4 0.3 - 0.6 0.5

Total Hardness (as CaCO3) mg/L - - - 232 230 248 - - - - - - 269 270 273 - - -

Ca Hardness (as CaCO3) mg/L - - - 115 116 128 - - - - - - 145 144 145 - - -

Mg Hardness (as CaCO3) mg/L - - - 117 114 120 - - - - - - 124 126 128 - - -

As (total) μg/L 18.1 18.8 5.8 18.2 100.1(d) 7.0 20.5 20.0 29.1 19.6 18.8 8.1 18.2 19.2 14.9(e) 18.5 18.4 6.9

- - - - - - 20.6 20.1 29.4 - - - - - - - - -

As (soluble) μg/L - - - 17.1 8.6 6.6 - - - - - - 15.3 15.5 14.6(e) - - -

As (particulate) μg/L - - - 1.2 91.5(d) 0.4 - - - - - - 2.9 3.7 0.2 - - -

As(III) μg/L - - - 6.0 0.3 0.3 - - - - - - 15.3 13.9(e) 8.9(e) - - -

As(V) μg/L - - - 11.1 8.3 6.3 - - - - - - <0.1 1.6 5.7 - - -

Fe (total) μg/L 75 1,052 <25 61 7247(d) <25 67 886 1,383 58 815 107 <25 920 <25 109 1,041 29

- - - - - - 67 867 1,338 - - - - - - - - -

Fe (soluble) μg/L - - - 52 34 <25 - - - - - - <25 <25 <25 - - -

Mn (total) μg/L 70.8 75.5 3.8 69.5 369 0.4 61.8 62.7 66.5 58.1 58.2 5.4 63.5 64.8 42.8 56.6 58.9 10.5

- - - - - - 60.8 63.1 66.0 - - - - - - - - -

Mn (soluble) μg/L - - - 67.8 21.9 0.2 - - - - - - 43.4 65.9 43.3 - - -

(d) Unusually high As and Fe concentrations confirmed by sample reanalysis and might be due to sampling error.

(e) High As(III), indicating insufficient chlorination, which might cause high total As concentration at TT.
 

B-3

Table B-1. Analytical Results from Long Term Sampling at Okanogan, WA (Continued)

Sampling Date 12/16/08 01/08/09 01/13/09 01/20/09 01/27/09

Sampling Location IN AC TT IN AC TT IN AC TT IN AC TT IN AC TT Parameter Unit

Alkalinity (as CaCO3) mg/L 178 178 178 178 178 175 176 174 174 180 176 178 175 171 175

- - - - - - - - - - - - 178 173 175

Ammonia (as N) mg/L - - - - - - - - - - - - - - -

Fluoride mg/L - - - 0.6 0.6 0.6 - - - - - - - - -

Sulfate mg/L - - - 122 120 122 - - - - - - - - -

Nitrate (as N) mg/L - - - <0.05 <0.05 <0.05 - - - - - - - - -

Total P (as P) μg/L 51.8 52.0 15.5 94.8 104 37.2 53.9 55.5 16.2 58.6 56.6 16.7 52.0 53.3 14.7

- - - - - - - - - - - - 54.7 53.7 14.8

Silica (as SiO2) mg/L 23.6 23.3 23.5 24.4 24.4 23.8 25.2 25.0 25.3 24.6 24.5 24.2 26.0 26.1 25.4

- - - - - - - - - - - - 26.6 25.6 25.4

Turbidity NTU 0.2 0.6 0.1 0.1 0.7 0.1 0.2 0.6 0.1 0.4 0.8 0.2 0.2 0.6 0.1

- - - - - - - - - - - - 0.2 0.6 0.1

pH S.U. 7.8 7.9 7.9 7.7 7.8 7.8 7.5 7.7 7.8 7.4 7.6 7.7 7.5 7.7 7.8

Temperature °C 10.9 11.1 11.3 12.9 12.8 12.8 14.3 14.5 14.5 13.1 13.3 13.4 16.5 16.5 16.5

DO mg/L 3.5 3.9 3.2 3.8 4.6 3.9 5.2 5.6 4.4 NA 3.5 3.8 3.3 4.3 2.5

ORP mV 477 505 502 483 500 513 449 503 503 467 501 517 461 481 519

Free Chlorine (as Cl2) mg/L - 0.3 0.2 - 0.3 0.2 - 0.3 0.2 - 0.3 0.2 - 0.4 0.2

Total Chlorine (as Cl2) mg/L - 0.6 0.6 - 0.6 0.6 - 0.6 0.5 - 0.6 0.5 - 0.6 0.5

Total Hardness (as CaCO3) mg/L - - - 356 358 345 - - - - - - - - -

Ca Hardness (as CaCO3) mg/L - - - 116 118 111 - - - - - - - - -

Mg Hardness (as CaCO3) mg/L - - - 241 240 234 - - - - - - - - -

As (total) μg/L 18.9 18.4 6.1 19.5 21.3 6.9 16.4 16.6 5.7 17.1 16.6 5.7 17.3 17.4 5.7

- - - - - - - - - - - - 17.3 17.4 5.6

As (soluble) μg/L - - - 19.7 9.3 6.9 - - - - - - - - -

As (particulate) μg/L - - - <0.1 12.0 <0.1 - - - - - - - - -

As(III) μg/L - - - 16.5 0.9 0.9 - - - - - - - - -

As(V) μg/L - - - 3.2 8.3 6.0 - - - - - - - - -

Fe (total) μg/L 84 993 <25 53 777 <25 66 803 <25 67 779 <25 66 847 <25

- - - - - - - - - - - - 69 846 <25

Fe (soluble) μg/L - - - <25 <25 <25 - - - - - - - - -

Mn (total) μg/L 58.3 60.2 22.7 44.1 46.4 12.2 59.8 60.0 18.3 59.1 58.5 17.8 59.2 60.9 20.3

- - - - - - - - - - - - 59.5 61.3 20.5

Mn (soluble) μg/L - - - 43.6 29.5 8.9 - - - - - - - - -
 

B-4

Table B-1. Analytical Results from Long Term Sampling at Okanogan, WA (Continued)

Sampling Date 02/03/09 02/18/09 02/24/09 03/03/09 03/10/09

Sampling Location IN AC TT IN AC TT IN AC TT IN AC TT IN AC TT Parameter Unit

Alkalinity (as CaCO3) mg/L 178 175 173 188 186 183 177 175 177 184 179 181 181 179 179

- - - - - - 175 173 173 - - - - - -

Ammonia (as N) mg/L - - - - - - - - - - - - - - -

Fluoride mg/L 0.6 0.6 0.7 - - - - - - 1.0 0.9 0.7 - - -

Sulfate mg/L 125 125 126 - - - - - - 128 123 127 - - -

Nitrate (as N) mg/L <0.05 <0.05 <0.05 - - - - - - <0.05 <0.05 <0.05 - - -

Total P (as P) μg/L 47.1 42.5 <10 43.7 42.1 12.3 53.0 51.6 17.8 53.6 53.4 19.6 58.4 55.7 16.4

- - - - - - 53.4 53.3 18.4 - - - - - -

Silica (as SiO2) mg/L 26.3 27.2 25.9 24.6 24.2 23.9 25.8 25.8 25.3 26.4 26.4 26 25.6 25.7 25.6

- - - - - - 26.0 25.7 25.7 - - - - - -

Turbidity NTU 0.2 0.7 0.1 0.2 0.7 0.2 0.2 0.6 0.1 0.2 0.6 <0.1 0.1 0.6 0.1

- - - - - - 0.2 0.6 <0.1 - - - - - -

pH S.U. 7.6 7.7 7.7 7.6 7.7 7.8 7.5 7.6 7.6 7.6 7.7 7.7 7.6 7.6 7.6

Temperature °C 17.5 17.4 17.5 17.1 17.0 17.0 16.5 16.3 16.1 16.2 16.1 16.1 15.9 15.8 15.8

DO mg/L 4.2 4.1 2.3 3.8 3.8 6.1 2.9 1.8 1.5 1.2 2.8 1.4 1.8 2.3 1.5

ORP mV 460 512 516 473 532 507 486 516 506 455 500 493 466 507 518

Free Chlorine (as Cl2) mg/L - 0.2 0.2 - 0.2 0.2 - 0.2 0.2 - 0.2 0.2 - 0.3 0.2

Total Chlorine (as Cl2) mg/L - 0.5 0.5 - 0.6 0.5 - 0.5 0.5 - 0.6 0.5 - 0.6 0.4

Total Hardness (as CaCO3) mg/L 259 257 254 - - - - - - 237 227 223 - - -

Ca Hardness (as CaCO3) mg/L 136 138 137 - - - - - - 124 123 121 - - -

Mg Hardness (as CaCO3) mg/L 123 119 117 - - - - - - 113 104 101 - - -

As (total) μg/L 19.6 19.7 6.6 16.2 15.9 4.2 17.7 17.8 6.1 17.5 18.1 6.3 19.5 18.8 6.4

- - - - - - 17.6 17.7 6.0 - - - - - -

As (soluble) μg/L 18.3 7.7 6.2 - - - - - - 17.3 6.4 5.2 - - -

As (particulate) μg/L 1.2 12.0 0.4 - - - - - - 0.3 11.6 1.1 - - -

As(III) μg/L 3.7 0.2 0.3 - - - - - - 14.4 0.6 0.6 - - -

As(V) μg/L 14.7 7.5 6.0 - - - - - - 2.9 5.8 4.6 - - -

Fe (total) μg/L 69 964 <25 63 810 <25 71 790 <25 67.5 762 78.5 72.3 939 27.6

- - - - - - 68 782 <25 - - - - - -

Fe (soluble) μg/L 67 <25 <25 - - - - - - 40.8 <25 <25 - - -

Mn (total) μg/L 61.4 64.2 21.5 53.7 55.5 36.0 63.6 64.5 24.6 65.2 65.9 28.1 60.7 62.1 19.6

- - - - - - 63.4 63.9 25.4 - - - - - -

Mn (soluble) μg/L 63.6 46.3 21.7 - - - - - - 62.0 35.7 22.2 - - -
 

B-5

Table B-1. Analytical Results from Long Term Sampling at Okanogan, WA (Continued)

Sampling Date 03/17/09 03/24/09 03/31/09 04/07/09 04/15/09

Sampling Location IN AC TT IN AC TT IN AC TT IN AC TT IN AC TT Parameter Unit

Alkalinity (as CaCO3) mg/L 180 178 176 180 176 182 190 182 177 193 186 186 178 178 171

- - - - - - - - - - - - - - -

Ammonia (as N) mg/L - - - - - - - - - - - - - - -

Fluoride mg/L - - - - - - 0.7 0.6 0.6 - - - - - -

Sulfate mg/L - - - - - - 124 121 125 - - - - - -

Nitrate (as N) mg/L - - - - - - <0.05 <0.05 <0.05 - - - - - -

Total P (as P) μg/L 49.1 45.3 12.6 49.9 49.3 14.4 31.3 33.9 <10 54.4 52.3 <10 56.4 54.1 12.3

- - - - - - - - - - - - - - -

Silica (as SiO2) mg/L 24.9 25.3 25.1 24.5 24.3 24.4 23.3 23.8 23.7 23.1 23.1 22.7 28.4 27.6 26.6

- - - - - - - - - - - - - - -

Turbidity NTU 0.2 0.6 0.1 0.5 0.6 <0.1 1.2 1.6 0.9 0.6 0.8 0.3 0.5 1.1 0.7

- - - - - - - - - - - - - - -

pH S.U. 7.6 7.7 7.8 7.8 7.7 7.9 7.7 7.7 7.7 NA NA NA 7.6 7.6 7.7

Temperature °C 16.4 16.3 16.3 16.0 16.3 15.9 16.3 16.3 16.3 16.6 16.5 16.5 16.1 16.1 16.0

DO mg/L 1.6 3.1 2.2 NA NA NA NA NA NA NA NA NA 1.0 1.8 1.2

ORP mV 458 491 524 456 515 516 460 514 516 446 519 543 457 524 527

Free Chlorine (as Cl2) mg/L - 0.4 0.2 - 0.3 0.2 - 0.3 0.3 - 0.6 0.3 - 0.3 0.2

Total Chlorine (as Cl2) mg/L - 0.6 0.5 - 0.6 0.5 - 0.7 0.3 - 0.7 0.6 - 0.6 0.6

Total Hardness (as CaCO3) mg/L - - - - - - 261 263 258 - - - - - -

Ca Hardness (as CaCO3) mg/L - - - - - - 134 135 132 - - - - - -

Mg Hardness (as CaCO3) mg/L - - - - - - 127 128 126 - - - - - -

As (total) μg/L 17.2 17.0 5.7 17.6 18.1 6.3 18.1 18.6 6.2 17.1 16.5 5.8 16.0 15.7 5.4

- - - - - - - - - - - - - - -

As (soluble) μg/L - - - - - - 18.8 9.2 6.0 - - - - - -

As (particulate) μg/L - - - - - - <0.1 9.4 0.2 - - - - - -

As(III) μg/L - - - - - - 15.9 0.6 0.6 - - - - - -

As(V) μg/L - - - - - - 2.9 8.6 5.4 - - - - - -

Fe (total) μg/L 78.8 867 <25 84.3 910 <25 230 1,186 26 109 1,251 <25 116 1,299 <25

- - - - - - - - - - - - - - -

Fe (soluble) μg/L - - - - - - 45 37 <25 - - - - - -

Mn (total) μg/L 65.2 63.8 17.5 66.6 67.6 8.5 59.6 61.3 13.7 58.1 57.9 13.8 50.0 50.2 12.7

- - - - - - - - - - - - - - -

Mn (soluble) μg/L - - - - - - 58.6 40.3 12.1 - - - - - -
 

B-6

Table B-1. Analytical Results from Long Term Sampling at Okanogan, WA (Continued)

Sampling Date 04/21/09 04/28/09 05/07/09 05/13/09 05/21/09

Sampling Location IN AC TT IN AC TT IN AC TT IN AC TT IN AC TT Parameter Unit

Alkalinity (as CaCO3) mg/L 182 182 182 188 178 180 187 184 184 186 181 181 183 183 183

- - - - - - - - - - - - - - -

Ammonia (as N) mg/L - - - - - - - - - - - - - - -

Fluoride mg/L - - - 0.6 0.7 0.6 - - - - - - - - -

Sulfate mg/L - - - 122 121 119 - - - - - - - - -

Nitrate (as N) mg/L - - - <0.05 <0.05 <0.05 - - - - - - - - -

Total P (as P) μg/L 56.8 57.7 <10 61.5 54.2 19.4 49.2 50.4 11.1 49.6 48.5 12.0 45.6 44.5 11.4

- - - - - - - - - - - - - - -

Silica (as SiO2) mg/L 26.8 26.2 24.9 29.4 29.8 28.7 27.7 27.7 27.6 27.7 28.3 28.3 27.5 27.2 26.9

- - - - - - - - - - - - - - -

Turbidity NTU 0.5 1.0 0.4 0.6 1.4 0.3 1.0 3.4 1.6 0.2 2.0 2.4 1.0 2.4 2.6

- - - - - - - - - - - - - - -

pH S.U. 7.4 7.5 7.6 7.5 7.7 7.7 7.4 7.5 7.6 7.7 7.8 7.8 7.6 7.7 7.7

Temperature °C 16.0 16.0 16.0 16.2 16.1 16.1 15.6 15.7 15.6 15.9 15.8 15.9 16.5 16.4 16.5

DO mg/L 1.1 1.3 1.1 2.9 3.1 3.2 2.6 2.7 3.2 2.9 4.7 2.3 1.9 2.4 1.9

ORP mV 457 525 550 482 481 532 459 515 513 471 508 525 444 504 515

Free Chlorine (as Cl2) mg/L - 0.3 0.3 - 0.3 0.2 - 0.3 0.2 - 0.3 0.2 - 0.3 0.2

Total Chlorine (as Cl2) mg/L - 0.6 0.6 - 0.6 0.6 - 0.6 0.5 - 0.6 0.6 - 0.6 0.5

Total Hardness (as CaCO3) mg/L - - - 227 258 270 - - - - - - - - -

Ca Hardness (as CaCO3) mg/L - - - 110 143 155 - - - - - - - - -

Mg Hardness (as CaCO3) mg/L - - - 117 115 116 - - - - - - - - -

As (total) μg/L 19.9 19.8 6.2 21.3 19.7 6.5 16.5 16.2 4.7 16.4 16.6 5.8 18.4 17.4 6.1

- - - - - - - - - - - - - - -

As (soluble) μg/L - - - 21.1 10.5 6.6 - - - - - - - - -

As (particulate) μg/L - - - 0.2 9.2 <0.1 - - - - - - - - -

As(III) μg/L - - - 15.4 0.7 0.6 - - - - - - - - -

As(V) μg/L - - - 5.7 9.9 6.0 - - - - - - - - -

Fe (total) μg/L 96 1,345 <25 85 1,011 63 83 1,102 <25 82 1,022 <25 62 851 61

- - - - - - - - - - - - - - -

Fe (soluble) μg/L - - - 84 27 26 - - - - - - - - -

Mn (total) μg/L 64.8 67.0 12.1 72.7 74.8 21.1 67.4 70.2 49.0 67.0 69.2 12.5 60.6 63.8 20.3

- - - - - - - - - - - - - - -

Mn (soluble) μg/L - - - 70.6 52.5 20.4 - - - - - - - - -

 
 

B-7

Table B-1. Analytical Results from Long Term Sampling at Okanogan, WA (Continued)

Sampling Date 05/28/09 06/03/09 06/09/09 06/16/09 06/24/09

Sampling Location IN AC TT IN AC TT IN AC TT IN AC TT IN AC TT Parameter Unit

Alkalinity (as CaCO3) mg/L 187 185 185 192 190 192 186 184 186 190 190 188 191 187 189

- - - - - - 190 186 186 - - - - - -

Ammonia (as N) mg/L - - - - - - - - - - - - - - -

Fluoride mg/L 0.6 0.8 0.8 - - - - - - - - - 0.6 0.6 0.6

Sulfate mg/L 131 130 130 - - - - - - - - - 124 123 127

Nitrate (as N) mg/L <0.05 <0.05 <0.05 - - - - - - - - - <0.05 <0.05 <0.05

Total P (as P) μg/L 45.8 45.7 13.9 38.9 40.1 <10 38.0 39.0 <10 43.3 42.4 <10 45.2 44.7 <10

- - - - - - 41.6 41.2 <10 - - - - - -

Silica (as SiO2) mg/L 26.5 25.9 25.9 27.2 27.0 27.1 26.2 26.4 26.3 26.5 26.4 26.2 25.9 26.0 25.6

- - - - - - 26.5 26.7 26 - - - - - -

Turbidity NTU 0.4 0.8 0.3 0.6 1.2 0.3 1.4 1.6 1.6 0.9 1.7 0.7 0.5 1.2 0.5

- - - - - - 1.8 1.0 0.9 - - - - - -

pH S.U. 7.8 7.8 7.9 7.6 7.6 7.7 7.6 7.6 7.7 7.6 7.7 7.8 7.6 7.7 7.7

Temperature °C 16.8 16.7 16.9 16.6 16.6 16.7 16.9 16.9 16.8 16.9 17.0 17.1 16.4 16.4 16.5

DO mg/L 2.5 4.2 2.9 2.0 3.3 2.8 2.6 3.5 2.7 3.8 3.9 2.8 3.5 4.0 2.7

ORP mV 477 487 500 470 517 523 446 475 517 459 485 521 459 510 521

Free Chlorine (as Cl2) mg/L - 0.3 0.2 - 0.3 0.2 - 0.4 0.2 - 0.3 0.2 - 0.3 0.2

Total Chlorine (as Cl2) mg/L - 0.6 0.5 - 0.6 0.5 - 0.6 0.5 - 0.5 0.5 - 0.6 0.5

Total Hardness (as CaCO3) mg/L 323 334 340 - - - - - - - - - 268 273 255

Ca Hardness (as CaCO3) mg/L 185 196 201 - - - - - - - - - 149 152 141

Mg Hardness (as CaCO3) mg/L 138 138 140 - - - - - - - - - 119 121 114

As (total) μg/L 14.7 14.5 5.0 17.6 18.3 6.6 17.4 18.0 6.3 17.1 17.1 6.0 17.9 18.1 5.6

- - - - - - 17.5 17.7 6.2 - - - - - -

As (soluble) μg/L 14.9 6.6 5.0 - - - - - - - - - 17.8 8.2 5.6

As (particulate) μg/L <0.1 7.9 <0.1 - - - - - - - - - 0.1 9.9 <0.1

As(III) μg/L 12.1 0.2 0.3 - - - - - - - - - 13.7 0.3 0.3

As(V) μg/L 2.8 6.4 4.7 - - - - - - - - - 4.1 7.9 5.3

Fe (total) μg/L 78 970 <25 60 908 <25 72 904 <25 61 874 <25 76 999 <25

- - - - - - 64 916 <25 - - - - - -

Fe (soluble) μg/L 55 <25 <25 - - - - - - - - - 71.2 <25 <25

Mn (total) μg/L 61.6 64.5 22.8 65.5 72.0 23.1 66.2 71.0 21.6 66.1 67.7 25.8 64.2 68.7 20.4

- - - - - - 66.6 70.0 21.9 - - - - - -

Mn (soluble) μg/L 63.1 42.8 22.2 - - - - - - - - - 65.6 44.9 20.5

 

 
 

B-8

Table B-1. Analytical Results from Long Term Sampling at Okanogan, WA (Continued)

Sampling Date 06/30/09 07/09/09 07/15/09 07/22/09 07/29/09

Sampling Location IN AC TT IN AC TT IN AC TT IN AC TT IN AC TT Parameter Unit

Alkalinity (as CaCO3) mg/L 189 185 189 196 196 191 189 187 189 177 179 184 181 174 177

- - - - - - - - - - - - - - -

Ammonia (as N) mg/L - - - - - - - - - - - - - - -

Fluoride mg/L - - - - - - - - - 0.7 0.6 0.6 - - -

Sulfate mg/L - - - - - - - - - 131 126 124 - - -

Nitrate (as N) mg/L - - - - - - - - - <0.05 <0.05 <0.05 - - -

Total P (as P) μg/L 47.6 45.9 11.9 37.0 35.9 <10 39.9 35.4 <10 48.4 48.2 12.3 50.3 51.1 15.6

- - - - - - - - - - - - - - -

Silica (as SiO2) mg/L 25.6 25.8 25.7 26.3 26.1 25.6 26.5 26.6 25.6 27.7 27.2 27.2 26.0 25.9 25.9

- - - - - - - - - - - - - - -

Turbidity NTU 0.3 0.8 0.3 0.6 1.0 0.7 0.4 0.8 0.5 1.5 2.0 1.8 0.3 0.7 0.7

- - - - - - - - - - - - - - -

pH S.U. 7.6 7.8 7.8 7.6 7.7 7.7 7.5 7.6 7.7 7.5 7.6 7.7 7.7 7.7 7.8

Temperature °C 16.7 16.6 16.6 16.9 16.9 16.9 16.8 16.8 16.8 17.3 17.2 17.2 18.8 18.7 18.7

DO mg/L 1.5 3.2 1.7 2.3 4.2 3.2 3.1 2.4 2.9 2.7 3.6 2.5 2.5 3.8 3.3

ORP mV 471 511 523 444 505 534 482 524 521 451 490 511 453 517 443

Free Chlorine (as Cl2) mg/L - 0.3 0.2 - 0.3 0.2 - 0.3 0.2 - 0.2 0.1 - 0.2 0.2

Total Chlorine (as Cl2) mg/L - 0.6 0.5 - 0.6 0.5 - 0.6 0.5 - 0.5 0.5 - 0.5 0.5

Total Hardness (as CaCO3) mg/L - - - - - - - - - 253 253 251 - - -

Ca Hardness (as CaCO3) mg/L - - - - - - - - - 139 140 139 - - -

Mg Hardness (as CaCO3) mg/L - - - - - - - - - 114 113 112 - - -

As (total) μg/L 18.6 18.1 6.3 16.6 16.3 5.7 17.2 15.7 5.9 16.8 17.7 5.1 14.8 14.6 2.9

- - - - - - - - - - - - - - -

As (soluble) μg/L - - - - - - - - - 16.4 7.9 5.2 - - -

As (particulate) μg/L - - - - - - - - - 0.4 9.8 <0.1 - - -

As(III) μg/L - - - - - - - - - 13.1 0.6 0.5 - - -

As(V) μg/L - - - - - - - - - 3.3 7.3 4.7 - - -

Fe (total) μg/L 78 952 <25 57 832 <25 60 818 <25 169 871 <25 70 829 39

- - - - - - - - - - - - - - -

Fe (soluble) μg/L - - - - - - - - - 46 <25 <25 - - -

Mn (total) μg/L 64.0 64.2 19.3 61.6 62.6 21.5 63.5 61.6 21.5 63.3 64.4 23.5 61.1 63.7 37.6

- - - - - - - - - - - - - - -

Mn (soluble) μg/L - - - - - - - - - 61.9 43.3 23.0 - - -

 
 

B-9

Table B-1. Analytical Results from Long Term Sampling at Okanogan, WA (Continued)

Sampling Date 08/05/09 08/12/09

Sampling Location IN AC TT IN AC TT

Parameter Unit

Alkalinity (as CaCO3) mg/L 178 178 178 183 183 178

- - - - - -

Ammonia (as N) mg/L - - - - - -

Fluoride mg/L - - - - - -

Sulfate mg/L - - - - - -

Nitrate (as N) mg/L - - - - - -

Total P (as P) μg/L 47.2 48.2 12.8 48.4 46.2 11.7

- - - - - -

Silica (as SiO2) mg/L 24.8 23.2 26.0 25.1 25.4 25.1

- - - - - -

Turbidity NTU 0.4 1.0 0.3 0.7 1.5 0.5

- - - - - -

pH S.U. 7.6 7.7 7.8 7.6 7.7 7.7

Temperature °C 17.7 17.5 17.6 16.9 16.8 16.9

DO mg/L 2.1 3.0 2.5 3.7 3.2 2.4

ORP mV 466 531 521 450 490 468

Free Chlorine (as Cl2) mg/L - 0.3 0.2 - 0.2 0.2

Total Chlorine (as Cl2) mg/L - 0.6 0.5 - 0.5 0.5

Total Hardness (as CaCO3) mg/L - - - - - -

Ca Hardness (as CaCO3) mg/L - - - - - -

Mg Hardness (as CaCO3) mg/L - - - - - -

As (total) μg/L 16.0 15.2 4.4 15.8 15.2 4.0

- - - - - - 

As (soluble) μg/L - - - - - -

As (particulate) μg/L - - - - - -

As(III) μg/L - - - - - -

As(V) μg/L - - - - - -

Fe (total) μg/L 68 868 <25 61 810 <25

- - - - - -

Fe (soluble) μg/L - - - - - -

Mn (total) μg/L 60.2 63.6 23.8 58.5 59.4 43.1

- - - - - -

Mn (soluble) μg/L - - - - - -

 
APPENDIX C

SUMMARY OF RESPONSIBILITIES 

ARSENIC DEMONSTRATION PROJECT AT OKANOGAN, WA
C-1 

Table C-1. Summary of Responsibilities

Task Subtask

Responsible Party

Filtronics Triad/WQE

City of 

Okanogan/

G&O Battelle

Engineering System drawings (P&IDs, tank arrangement, and control 

panel assembly drawings)

√

System technical specifications and electrical/conduit 

requirements

√

Site engineering drawings required for electrical and 

mechanical tie-ins

√

Package including engineering drawings and report 

stamped by WA PE and submitted to WA DOH

√

As-built engineering drawings and other post-construction 

documentation

√

Building engineering and permitting including all nonFiltronics supplied equipment and residuals handling√

Equipment 

Supply

Electromedia®-I, FH-13 System for 750 gpm and other 

equipment per Quotation No. 050802-1.A

√

Shop testing of PLC input/output to reduce on-site needs √

Spare parts for installation/startup √

3 copies including: O&M instructions, as-built drawings, 

and manufacturers' bulletins

√

Shipment to the Okanogan, WA site √

Receive and inspect shipment for damage/missing parts √

Staging area/storage at site prior to installation/startup √

Reclaim tank √

Installation Photographs of equipment arrival, unloading, placement, 

media loading, etc. √ √

Periodic installation inspection and supervision as needed √

Equipment unloading and placement including provision of 

crane/fork lift, jacking pads, etc. √ 

Equipment leveling, alignment, grouting, and anchoring √

Reclaim tank anchoring √

FH-13 and Proposed Equipment Installation √

Filter vessel and internals (1) √

Reaction vessels (2) √

Concrete, sealant, and filter media loading √

Floating strainer and suction hose for reclaim tank √

Recycle pump installation, alignment, and lubrication √

Chemical feed equipment and manifold assemblies 

installation (2) √

Air compressor and starter installation √

Finish paint on installed equipment and piping as required √

Instrumentation and Controls Installation √

Allen Bradley SLC 5/05 programmable controller including 

field interconnection wiring √ 
 

C-2 

Table C-1. Summary of Responsibilities (Continued)

Task Subtask

Responsible Party

Filtronics Triad/WQE

City of 

Okanogan/

G&O Battelle

Installation

(Continued)

Panelview operator interface panel √

Solenoid valves and field interconnection wiring to PLC √

Flow control valve, butterfly valves, and check valve √

Reclaim tank float switches and wiring to PLC √

Pressure gauges installation for filter headloss 

measurements √

Pressure switch for low air pressure √

Tube meter for backwash and treated water including 

wiring to PLC √ 

Backwash flow control valve √

Piping and Other Mechanical Connections √

All equipment lubrication √

All pipes and fittings, supports/hangers, and valves for 

filtering, draining, and backwashing per drawings √

Face piping and valve assembly √

Installation of sample tap assemblies (to be provided by 

Filtronics) √ 

Installation of air vent valve (to be provided by Filtronics) √

Air tubing for pneumatic butterfly valve actuators √

Electrical and Control Wiring Connections √

Equipment grounding (vessels, pumps, compressor, etc.) √

Interlock the system operation with the well pump and 

reservoir √

All conduits and electrical wiring from process equipment 

to power distribution panel/MCC √ 

All conduits, electrical wiring, and signal wiring to/from 

instrumentation to PLC √

Circuit breaker panel √

Recycle pump and starter wiring √

Shakedown, 

Startup, 

Inspection

System startup/shakedown** √ √ √

Mechanical, electrical, and instrumentation inspection √

PLC input/output testing and instrumentation 

calibration/adjustment √

Electrical continuity testing and motor rotation checks √

Cleaning, flushing, and draining of all tanks and piping 

prior to startup to remove debris √

Fill tanks and piping with clean water for leak/pressure 

testing (hydrostatic test) √ √

Fill tanks and piping with clean water for hydraulic 

shakedown/leak testing √ √
 

C-3 

Table C-1. Summary of Responsibilities (Continued)

Task Subtask

Responsible Party

Filtronics Triad/WQE

City of 

Okanogan/

G&O Battelle

Shakedown, 

Startup, 

Inspection

(Continued)

Operator training on system O&M √

Disinfection and bacteriological testing prior to startup to 

distribution √

Chemical 

Supply

Ferric chloride √

Sodium hypochlorite √

Secondary containment of chemicals √

Safety equipment/signs for chemical use/storage √

Well Pumps Motor starter for well pump √

Communication point in building for control interface with 

well pumps and reservoirs through SCADA √ 

Hour meter/totalizer on well pump √

Building Building infrastructure √

Watermains from building to distribution system √

Floor drains √

Wastewater drain lines to sanitary sewer √

Backwash/residuals handling and backwash storage tank √

Utilities (heat, light, electricity, potable water, etc.) √

Grounding location √

Phone line for troubleshooting via modem √

Power distribution panel for all equipment and 3/4" 

conduit to within 10 ft of skid √

Site sign identifying Okanogan as participant in EPA's 

program √

Drinking fountains, if desired √

Emergency shower, if desired √

Restroom, if desired √

Demo Study One-year of technical assistance for troubleshooting √

Repair or replace faulty Filtronics-supplied parts or 

equipment through warranty period √

Repair or replace faulty installation work through warranty 

period √ 

Treatment system O&M √

Prepare Study Plan describing protocol for collecting data 

during the demonstration √

Monitor treatment system and provide data to EPA, City, 

Filtronics, and WA DOH quarterly √

Note: For system shakedown and startup, Triad provided mechanical/electrical labor for assistance during shakedown 

activities; the City provided operator. 
APPENDIX D

BACKWASH LOG SHEETS

EPA ARSENIC DEMONSTRATION PROJECT AT OKANOGAN, WA
D-1 

Table D-1. Backwash Log Sheets 

Date 

Δp Before 

Backwash

Δp After 

Backwash

Backwash 

Start

Backwash 

End

Backwash 

Flowrate 

Backwash 

Duration

Wastewater 

Generated

Average 

Flowrate

psig psig Time kgal Time kgal gpm min Kgal gpm

08/14/08 2 0 - 78 - 84 1250 4 5.9 1475

08/15/08 0 0 10:47 90 - 95 1200 4 5.0 1250 

08/18/08 1 0 11:55 112 11:59 117 1250 4 5.0 1250

08/27/08 2 0 11:57 164 12:01 169 1100 4 5.0 1250

08/28/08 2 0 16:21 185 16:25 189 1400 4 4.0 1000

08/29/08 2 0 8:33 194 8:38 199 1320 5 5.0 1000

08/30/08 2 0 8:54 209 - 214 1190 4 5.0 1250

09/01/08 2 1 9:34 240 9:38 245 1250 4 5.0 1250

09/02/08 2 1 9:55 245 9:59 250 1200 4 5.0 1250

09/03/08 2 0 10:19 270 10:23 275 1100 4 5.0 1250

09/04/08 2 0 10:30 285 10:34 290 1200 4 5.0 1250

10/02/08 2 2 15:52 403 15:56 408 1250 4 5.0 1250

10/03/08 2 2 8:06 413 8:10 419 1250 4 6.0 1500

10/07/08 2 0(a) 12:35 439 12:39 445 1250 4 6.0 1500

10/09/08 1 0(a) 11:50 460 11:54 465 1200 4 5.0 1250 

10/13/08 1 2 11:43 517 11:47 522 1200 4 5.0 1250

10/16/08 2 1 15:29 557 15:33 562 1250 4 5.0 1250

10/20/08 2 2 13:44 608 13:48 613 1300 4 5.0 1250

10/21/08 0 0 10:05 618 10:09 624 1200 4 6.0 1500

10/28/08 1 0(a) 15:24 726 15:28 731 1150 4 5.0 1250

11/13/08 2 0(a) 14:36 877 14:40 882 1200 4 5.0 1250

11/18/08 2 0(a) 15:12 919 15:16 924 1200 4 5.0 1250 

12/16/08 2 1 13:26 1183 13:30 1188 1500 4 5.0 1250

12/30/08 3 1 14:53 1204 14:55 1206 720 2 2 1000

12/31/08 2 0 14:56 1212 15:00 1218 1500 4 6.0 1500

01/02/09 1 0 14:57 1235 15:01 1239 1000 4 4.0 1000

01/09/09 2 0 11:14 1285 11:18 1290 1250 4 5.0 1250

01/12/09 2 0 14:47 1311 14:51 1316 1250 4 5.0 1250

01/13/09 2 0 14:08 1322 14:12 1327 1250 4 5.0 1250

01/14/09 2 0 14:01 1333 14:05 1338 1250 4 5.0 1250

01/15/09 2 0 14:05 1344 14:09 1349 1250 4 5.0 1250

01/16/09 1 0 13:27 1354 13:31 1359 1250 4 5.0 1250

01/21/09 0 0 15:42 1380 15:46 1385 1250 4 5.0 1250

01/22/09 1 0 13:07 1389 13:11 1393 1000 4 4.0 1000

01/23/09 0 14:56 1396 15:00 1400 1000 4 4.0 1000 

01/26/09 1 0 15:10 1424 15:14 1429 1250 4 5.0 1250

01/27/09 1 0 13:30 1434 13:38 1443 1100 8 9 1125

01/28/09 1 0 14:03 1448 14:07 1453 1250 4 5.0 1250

01/29/09 1 0 13:30 1459 13:34 1464 1250 4 5.0 1250

01/30/09 0 0 11:15 1469 11:19 1473 1000 4 4.0 1000

02/02/09 0 0 10:06 1492 10:10 1497 1200 4 5.0 1250

02/03/09 0 0 10:40 1513 10:44 1519 1250 4 6.0 1500
 

D-2 

Table D-1. Backwash Log Sheets (Continued)

Date 

Δp Before 

Backwash

Δp After 

Backwash

Backwash 

Start

Backwash 

End

Backwash 

Flowrate 

Backwash 

Duration

Wastewater 

Generated

Average 

Flowrate

psig psig Time kgal Time kgal gpm min kgal gpm

02/04/09 2 0 13:19 1522 13:23 1528 1500 4 6.0 1500

02/05/09 2 0 12:20 1533 12:24 1538 1250 4 5.0 1250 

02/06/09 1 0 13:22 1544 13:26 1550 1500 4 6.0 1500

02/09/09 1 0(a) 8:36 1577 8:40 1583 1250 4 6.0 1500

02/17/09 2 0 15:43 1589 15:47 1595 1500 4 6.0 1500

02/18/09 1 0 12:40 1601 12:44 1607 1500 4 6.0 1500

02/19/09 2 0 14:45 1612 14:49 1618 1500 4 6.0 1500

02/20/09 1 0 11:29 1624 11:33 1629 1250 4 5.0 1250

02/23/09 1 0 13:10 1648 13:14 1653 1250 4 5.0 1250

02/24/09 0 0 15:00 1656 15:04 1662 1300 4 6.0 1500

02/25/09 1 0 14:02 1662 14:06 1668 1300 4 6.0 1500

02/27/09 0 0 14:45 1679 14:49 1685 1500 4 6.0 1500

03/02/09 1 0 9:15 1714 9:19 1719 1300 4 5.0 1250

03/03/09 1 0 8:21 1725 8:25 1731 1400 4 6.0 1500

03/04/09 0 0 15:00 1737 15:04 1743 1400 4 6.0 1500 

03/05/09 0 0 14:36 1749 14:40 1755 1375 4 6.0 1500

03/09/09 0 0 12:21 1790 12:25 1796 1400 4 6.0 1500

03/10/09 1 0 11:55 1801 11:59 1807 1400 4 6.0 1500

03/12/09 0 0 9:29 1829 9:33 1835 1400 4 6.0 1500

03/13/09 0 0 11:55 1847 11:59 1853 1400 4 6.0 1500

03/16/09 1 0(a) 12:38 1883 12:42 1889 1400 4 6.0 1500

03/17/09 0 0 9:15 1895 9:19 1901 1400 4 6.0 1500 

03/18/09 0 0(a) 13:03 1912 13:07 1918 1400 4 6.0 1500

03/19/09 0 0 14:37 1924 14:41 1930 1400 4 6.0 1500

03/20/09 1 0 12:12 1935 12:16 1941 1400 4 6.0 1500

03/24/09 0 0 9:50 1977 9:54 1983 1400 4 6.0 1500

03/25/09 0 0 15:07 1994 15:11 2000 1350 4 6.0 1500

03/26/09 0 0 13:58 2006 14:02 2012 1400 4 6.0 1500

03/31/09 0 0 12:45 2054 12:49 2060 1400 4 6.0 1500

04/02/09 0 0 7:44 2083 7:48 2090 1450 4 7.0 1750

04/06/09 0 0 7:11 2144 7:15 2150 1450 4 6.0 1500

04/07/09 0 0 13:38 2162 13:42 2168 1420 4 6.0 1500

04/08/09 0 0 13:09 2174 13:13 2180 1450 4 6.0 1500

04/09/09 0 0 13:59 2192 14:03 2198 1400 4 6.0 1500

04/10/09 0 0 15:10 2209 15:14 2215 1350 4 6.0 1500 

04/13/09 0 0 6:57 2242 7:01 2247 1300 4 5.0 1250

04/14/09 1 0 14:45 2258 14:49 2264 1300 4 6.0 1500

04/15/09 1 0 14:50 2269 14:54 2275 1350 4 6.0 1500

04/16/09 1 0 15:08 2286 15:12 2292 1400 4 6.0 1500

04/17/09 1 0 8:55 2298 8:59 2303 1400 4 5.0 1250

04/21/09 0 0 15:04 2353 15:08 2358 1400 4 5.0 1250

04/23/09 1 0 14:27 2385 14:31 2390 1400 4 5.0 1250

04/24/09 0 0 13:30 2400 13:34 2406 1400 4 6.0 1500
 

D-3 

Table D-1. Backwash Log Sheets (Continued)

Date 

Δp Before 

Backwash

Δp After 

Backwash

Backwash 

Start

Backwash 

End

Backwash 

Flowrate 

Backwash 

Duration

Wastewater 

Generated

Average 

Flowrate

psig psig Time kgal Time kgal gpm min kgal gpm

04/28/09 1 0 13:06 2458 13:10 2464 1400 4 6.0 1500

04/29/09 1 0 16:02 2475 16:06 2481 1400 4 6.0 1500 

04/30/09 1 0 13:32 2487 13:36 2492 1400 4 5.0 1250

05/01/09 1 0 13:29 2503 13:33 2509 1400 4 6.0 1500

05/04/09 1 0 15:24 2554 15:29 2560 1350 5 6.0 1200

05/05/09 1 0(a) 13:39 2572 13:43 2577 1400 4 5.0 1250

05/08/09 1 0 12:10 2605 12:14 2611 1350 4 6.0 1500

05/12/09 1 0 14:12 2667 14:16 2672 1350 4 5.0 1250

05/15/09 1 0(a) 9:25 2710 9:29 2716 1350 4 6.0 1500

05/19/09 1 0 9:25 2768 9:29 2773 1350 4 5.0 1250

05/20/09 1 0 15:04 2788 15:08 2794 1350 4 6.0 1500

05/21/09 2 0 8:41 2799 8:45 2805 1350 4 6.0 1500

05/22/09 1 0 14:48 2819 14:52 2824 1300 4 5.0 1250

05/27/09 0 0 8:50 2867 8:54 2872 1300 4 5.0 1250

05/29/09 1 0 13:14 2899 13:18 2904 1300 4 5.0 1250 

06/01/09 0 0 11:48 2953 11:52 2958 1300 4 5.0 1250

06/03/09 2 0 13:42 2983 13:46 2988 1350 4 5.0 1250

06/04/09 2 0 9:56 2998 10:00 3002 1150 4 4.0 1000

06/05/09 2 0 8:24 3012 8:28 3017 1350 4 5.0 1250

06/09/09 2 0 15:20 3097 15:24 3103 1350 4 6.0 1500

06/12/09 1 0 7:59 3151 8:03 3156 1325 4 5.0 1250

06/15/09 1 0 15:16 3197 15:20 3202 1325 4 5.0 1250 

06/16/09 1 0 16:54 3218 16:58 3223 1300 4 5.0 1250

06/18/09 1 0(a) 11:20 3249 11:24 3254 1300 4 5.0 1250

06/19/09 1 0 9:25 3264 9:29 3269 1300 4 5.0 1250

06/24/09 1 0 9:20 3343 9:24 3348 1300 4 5.0 1250

06/25/09 2 0 13:00 3364 13:04 3369 1350 4 5.0 1250

06/26/09 2 0 9:52 3379 9:56 3385 1350 4 6.0 1500

06/30/09 1 0 10:25 3447 10:29 3453 1300 4 6.0 1500

07/02/09 0 0 10:00 3490 10:04 3495 1300 4 5.0 1250

07/07/09 2 0 10:52 3543 10:56 3549 1350 4 6.0 1500

07/09/09 2 0 9:00 3581 9:04 3586 1350 4 5.0 1250

07/10/09 2 0 13:16 3602 13:20 3607 1325 4 5.0 1250

07/14/09 2 0 12:22 3660 12:26 3665 1300 4 5.0 1250

07/17/09 2 0 8:37 3713 9:01 3718 1350 4 5.0 1250 

07/21/09 2 0 8:49 3782 8:53 3788 1400 4 6.0 1500

07/22/09 2 0 9:11 3804 9:15 3809 1350 4 5.0 1250

07/23/09 2 0 8:46 3825 8:50 3830 1400 4 5.0 1250

07/24/09 3 0 14:19 3841 14:23 3846 1300 4 5.0 1250

07/28/09 2 0 15:23 3897 15:27 3902 1350 4 5.0 1250

07/29/09 2 0 9:03 3913 9:07 3918 1350 4 5.0 1250

07/31/09 2 0 9:53 3947 9:57 3952 1300 4 5.0 1250

08/04/09 1 0 14:22 4014 14:26 4020 1400 4 6.0 1500
 

D-4 

Table D-1. Backwash Log Sheets (Continued)

Date 

Δp Before 

Backwash

Δp After 

Backwash

Backwash 

Start

Backwash 

End

Backwash 

Flowrate 

Backwash 

Duration

Wastewater 

Generated

Average 

Flowrate

psig psig Time kgal Time kgal gpm min kgal Gpm

08/06/09 2 0 14:32 4044 14:56 4049 1400 4 5.0 1250

08/07/09 1 0 16:22 4065 16:26 4071 1400 4 6.0 1500 

08/11/09 2 0 13:29 4137 13:33 4143 1400 4 6.0 1500

08/12/09 2 0(a) 10:41 4154 10:45 4159 1350 4 5.0 1250

(a) Pressure drop across the filter is zero because reservoirs full and system shutdown.