EPA/600/R-11/026 

March 2011 

Arsenic and Antimony Removal from Drinking Water by 

Point-of-Entry Reverse Osmosis Coupled with Dual Plumbing Distribution

U.S. EPA Demonstration Project at

Carmel Elementary School in Carmel, ME

Final Performance Evaluation Report

by

Lili Wang‡ 

Gary M. Lewis§ 

Abraham S.C. Chen‡ 

§

Battelle, Columbus, OH 43201-2693 

‡

ALSA Tech, LLC, Columbus, OH 43219-0693 

Contract No. EP-C-05-057

Task Order No. 0019 

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 0019 of Contract EP-C-05-057 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 groundwater; prevention and control of indoor air pollution; and restoration of 

ecosystems. NRMRL collaborates with both public and private sector partners to foster technologies that 

reduce the cost of compliance and to anticipate emerging problems. NRMRL’s research provides 

solutions to 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 for and the results obtained from the arsenic and antimony 

removal treatment technology demonstration project at the Carmel Elementary School (CES) in Carmel, 

ME. An innovative approach of employing point-of-entry (POE) reverse osmosis (RO) coupled with dual 

plumbing was demonstrated at CES as a low cost alternative to achieve compliance with arsenic and 

antimony maximum contaminant levels (MCLs) compared with conventional RO treatment. The 

objectives of the project were to evaluate the performance of the RO/dual plumbing system in meeting 

the new arsenic MCL of 10 μg/L and the antimony MCL of 6 μg/L, the reliability of the treatment 

system, the required system operation and maintenance (O&M) and operator skill levels, and the capital 

and O&M cost of the technology. Additionally, the project characterized the water quality of the 

distribution system and process residuals produced by the RO system. 

The original treatment system selected for demonstration at CES was a Watts Premier 9,600-gal/day 

(gpd) RO treatment system, which would require a significant building modification/expansion to house 

the new system and construction of a larger septic/leach field to receive residual water from the RO 

system. To reduce the financial burden on the school, a joint decision was made by United States 

Environmental Protection Agency (EPA), Maine Drinking Water Program (MDWP), CES, and Battelle to 

use a smaller RO system coupled with a dual plumbing distribution system so that only a portion of raw 

water would be treated and consumed as potable water while the untreated water was available for nonpotable use. The only modification required was re-plumbing of the existing distribution system to 

convert it into a duplex system with separate potable and non-potable lines. The potable line supplied 

RO-treated water to the kitchen sinks and dishwasher (both cold and hot water), water fountains in school 

buildings, and cold water facets in restrooms. Based on a water demand study conducted upon 

completing the plumbing modification, it was determined that the potable water demand could be met by 

a Crane Environmental EPRO-1,200 treatment system. A similar but smaller unit, EPRO-600 system, 

had been used by EPA/Battelle for a pilot study conducted at CES in 2006 and was effective at removing 

arsenic and antimony to levels well below their respective MCLs. 

The Crane Environmental EPRO-1,200 RO treatment system consisted of an RO unit, a calcite filter for 

pH adjustment, two 300-gal atmospheric storage tanks, a re-pressurization system, and a post-chlorination 

system. Major components of the RO unit included a 5-μm sediment filter, a 1⁄2-horsepower (hp) booster 

pump, and two 2.5-in × 40-in thin-film composite RO membrane modules. The RO permeate water 

passed through the calcite filter to raise its pH level to near neutral, then was stored in two 300-gal 

atmospheric storage tanks. The water from the storage tank was re-pressurized by a 1-hp booster pump 

before entering the potable distribution line. 

Operation of the EPRO-1,200 RO treatment system began on February 4, 2009, but logging of 

operational data did not begin until April 16, 2009. The types of data collected included system 

operation, water quality (both across the treatment train and in the distribution system), process residuals, 

and capital and O&M cost. Through the performance evaluation study period from April 16 through 

December 15, 2009, the system operated for approximately 1,474 hr, processing approximately 180,700 

gal of water. With an average recovery rate of 40%, the system generated 71,100 gal of permeate and 

109,600 gal of reject water. Daily system run times averaged 11.7 hr/day when the school was in session 

and 1.9 hr/day when the school was out of session.

Arsenic concentrations in source water ranged from 13.6 to 22.6 μg/L and averaged 18.2 μg/L. Soluble 

As(V) was the predominating species, with concentrations ranging from 14.3 to 18.7 μg/L and averaging 

16.7 μg/L. Antimony concentration in source water ranged from 8.6 to 13.2 μg/L and averaged 

10.8 μg/L, with the majority present in the soluble form. Total arsenic concentrations in permeate water 
v

averaged 0.1 μg/L. Total antimony concentrations in permeate water were below the MDL of 0.1 μg/L. 

Based on the average arsenic and antimony concentrations in raw and permeate water, the RO system had 

achieved 99% removal efficiency for both analytes. The RO system had achieved an average of 97% 

rejection for total dissolved solids (TDS), slightly below the specified 98% rejection.

pH values measured in source water averaged 7.9 and decreased to an average of 6.9 after the RO unit. 

Alkalinity concentrations were reduced from an average of 206 mg/L (as CaCO3) in source water to an 

average of 5.6 mg/L (as CaCO3) in permeate water, causing the decrease in pH. After pH adjustment via 

the calcite filter, pH values and alkalinity concentrations were raised, on average, to 7.4 and 16.6 mg/L 

(as CaCO3), respectively.

The RO process concentrated the contaminants into the reject water, which was discharged to the existing 

septic system. During the performance evaluation study, approximately 109,570 gal of reject water was 

generated. The reject water contained, on average, 31.9 μg/L of arsenic, 17.7 μg/L of antimony, 410 

mg/L of TDS, 340 mg/L (as CaCO3) of alkalinity, 352 mg/L (as CaCO3) of total hardness, 18.1 mg/L of 

silica (as SiO2), and 17.9 mg/L of sulfate. Mass balance calculations showed that the RO process 

(permeate and reject water) had recovered 107% of arsenic and 100% of antimony from raw water. 

Distribution system “first draw” samples were collected from a cold water tap in the kitchen on a monthly

basis to determine if the RO treatment had any impacts on the distribution water quality. pH values of the 

distribution “first draw” samples ranged from 6.8 to 9.2, and averaged 8.4. Alkalinity concentrations 

ranged from 10.1 to 58.3 mg/L, and averaged 24.6 mg/L. Arsenic and antimony concentrations in the 

distribution “first draw” samples were both in the sub-parts per billion (ppb) levels (except for one time at 

2.7 μg/L of arsenic), similar to those in the treatment effluent. Lead and copper concentrations were well 

below the respective action levels. Therefore, the RO treatment system did not have any adverse effects 

on the water quality in the distribution system. 

Operational problems encountered during the demonstration study included a bearing failure on the RO 

motor and pump assembly. The problem was corrected promptly by the vendor and has not re-occurred. 

The replacement parts were covered under warranty; however, the cost to diagnose the problem and 

install the replacement parts was not.

The capital investment for the system was $20,452, including $8,600 for the dual plumbing and $11,942 

for the EPRO-1,200 RO system. With the system’s rated capacity of 1,200 gpd, the normalized capital 

cost was $17.12 per gpd of design capacity. 

The O&M cost included the cost incurred by system repairs, electricity consumption, and labor to operate 

the system. The cost to diagnose and install a faulty RO motor and pump assembly was $321. Annual 

electricity consumption was estimated to be 5,078 kWh and cost $376. Routine labor activities consumed 

10 min per day, which translated into $666/yr. The total annual O&M cost was estimated to be $1,404, or 

$12.89/1,000 gal of permeate water produced.
vi

CONTENTS

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

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

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

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

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

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

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

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

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

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

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

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

2.0 SUMMARY AND CONCLUSIONS .................................................................................................... 6

3.0 MATERIALS AND METHODS ........................................................................................................... 7

3.1 General Project Approach ............................................................................................................. 7

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

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

3.3.2 Treatment Plant Water ........................................................................................................ 9

3.3.3 Residual Wastewater ......................................................................................................... 10

3.3.4 Distribution System Water ................................................................................................ 10

3.4 Sampling Logistics ...................................................................................................................... 10

3.4.1 Preparation of Arsenic Speciation Kits ............................................................................. 10

3.4.2 Preparation of Sampling Coolers ...................................................................................... 10

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

3.5 Analytical Procedures ................................................................................................................. 11

4.0 RESULTS AND DISCUSSION .......................................................................................................... 12

4.1 Facility Description and Pre-existing Treatment System Infrastructure ..................................... 12

4.1 Facility Description and Pre-existing Treatment System Infrastructure ..................................... 13

4.1.1 Source Water Quality ........................................................................................................ 14

4.1.2 Distribution System .......................................................................................................... 15

4.2 Treatment Process Description ................................................................................................... 15

4.2.1 Dual Plumbing .................................................................................................................. 15

4.2.2 Treatment Technology Description and System Design ................................................... 16

4.3 System Installation ...................................................................................................................... 24

4.3.1 Permitting.......................................................................................................................... 24

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

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

4.4.1 Operational Parameters ..................................................................................................... 25

4.4.2 Residual Management ....................................................................................................... 26

4.4.3 System/Operation Reliability and Simplicity ................................................................... 28

4.5 System Performance ................................................................................................................... 29

4.5.1 Treatment Plant Sampling................................................................................................. 29

4.5.2 Residual Water Sampling ................................................................................................. 37

4.5.3 Distribution System Water Sampling ............................................................................... 38

4.6 System Cost ................................................................................................................................ 39
vii

4.6.1 Capital Cost....................................................................................................................... 39

4.6.2 Operation and Maintenance Cost ...................................................................................... 40

5.0 REFERENCES .................................................................................................................................... 42

APPENDICES

APPENDIX A: OPERATIONAL DATA

APPENDIX B: ANALYTICAL DATA

FIGURES

Figure 4-1. Pre-existing Facility ............................................................................................................. 12

Figure 4-2. RO Pilot System and Components ....................................................................................... 13

Figure 4-3. Installation of Dual Plumbing System Using PEX Piping ................................................... 16

Figure 4-4. Water Demand Monitoring at CES ...................................................................................... 17

Figure 4-5. Schematic of RO Treatment System .................................................................................... 19

Figure 4-6. Process Flow Diagram and Sampling Locations for Carmel, ME Site ................................ 20

Figure 4-7. Sediment Filter ..................................................................................................................... 21

Figure 4-8. EPRO-1,200 RO Unit........................................................................................................... 21

Figure 4-9. Schematic of RO Membrane Module .................................................................................. 22

Figure 4-10. Calcite Filter ......................................................................................................................... 22

Figure 4-11. Atmospheric Storage Tank (top left), Re-Pressurization Pump (middle), and 

Pressure Tank and Retention Tanks (top right) .................................................................... 23

Figure 4-12. Chlorine Addition System at CES ........................................................................................ 23

Figure 4-13. Percent Recovery Calculations ............................................................................................ 27

Figure 4-14. Flowrate Readings of RO Permeate and Reject Water ........................................................ 27

Figure 4-15. Concentrations of Various Arsenic Species at IN, RO, and AP Sampling Locations.......... 33

Figure 4-16. Total Arsenic Concentrations at IN, RO, AP, and RW Sampling Locations ....................... 34

Figure 4-17. Total Antimony Concentrations at IN, RO, AP, and RW Sampling Locations ................... 34

Figure 4-18. TDS Concentrations at IN, RO, AP, and RW Sampling Locations ..................................... 35

Figure 4-19. pH Levels at IN, RO, AP, and RW Sampling Locations ..................................................... 35

Figure 4-20. Alkalinity Concentrations at IN, RO, AP, and RW Sampling Locations ............................ 36

Figure 4-21. Total Hardness Concentrations at IN, RO, AP, and RW Sampling Locations .................... 36

Figure 4-22. Silica Concentration at IN, RO, AP, and RW Sampling Locations ..................................... 37
viii

TABLES

Table 1-1. Summary of Rounds 1, 2, and 2a Arsenic Removal Demonstration Locations, 

Technologies, and Source Water Quality ............................................................................... 3

Table 1-2. Number of Demonstration Sites for Each Type of Arsenic Removal Technology ................ 5

Table 3-1. Predemonstration Study Activities and Completion Dates .................................................... 7

Table 3-2. Evaluation Objectives and Supporting Data Collection Activities ........................................ 8

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

Table 4-1. Source Water Quality at Carmel, ME .................................................................................. 14

Table 4-2. Design Specifications of EPRO-1,200 RO System .............................................................. 18

Table 4-3. MDWP Punch-List Items and Corrective Actions ............................................................... 24

Table 4-4. Battelle’s Punch-List Items and Corrective Actions ............................................................ 25

Table 4-5. Summary of EPRO-1,200 System Operation ....................................................................... 26

Table 4-6. Summary of Arsenic, Antimony, Iron, and Manganese Analytical Results ........................ 30

Table 4-7. Summary of Other Water Quality Parameter Results .......................................................... 31

Table 4-8. Mass Balance Calculations .................................................................................................. 38

Table 4-9. Distribution System Sampling Results ................................................................................. 38

Table 4-10. Capital Investment Cost for CES at Carmel, ME ................................................................. 39

Table 4-11. Operation and Maintenance Cost for EPRO-1200 RO Unit Treatment System .................. 40
ix

ABBREVIATIONS AND ACRONYMS

AAL American Analytical Laboratories

Al aluminum 

AM adsorptive media 

AQWS Advanced Quality Water Solutions 

As arsenic

ATS Aquatic Treatment Systems

Ca calcium

CES Carmel Elementary School 

Cl chloride

C/F coagulation/filtration 

CRF capital recovery factor

Cu copper 

DO dissolved oxygen 

EPA U.S. Environmental Protection Agency 

Fe iron 

gpd gallons per day

gpm gallons per minute 

HDPE high-density polyethylene 

HIX hybrid ion exchanger 

Hp horsepower 

ICP-MS inductively coupled plasma-mass spectrometry

ID identification

IR iron removal

IX ion exchange 

LCR Lead and Copper Rule 

 

MCL maximum contaminant level

MDL method detection limit

MDWP Maine Drinking Water Program

MEI Magnesium Elektron, Inc.

Mg magnesium 

Mn manganese

mV millivolts

Na sodium 

NA not analyzed

NaOCl sodium hypochlorite 

NRMRL National Risk Management Research Laboratory
x

ABBREVIATIONS AND ACRONYMS (Continued)

NS not sampled 

NSF NSF International 

NTNCWS non-transient, non-community water system

NTU nephelometric turbidity unit 

O&M operation and maintenance 

OIT Oregon Institute of Technology 

ORD Office of Research and Development

ORP oxidation-reduction potential 

Pb lead

PEX cross-linked polyethylene 

P&ID piping and instrumentation diagram 

PO4 orthophosphate 

POE point-of-entry 

POU point-of-use 

Ppb parts per billion

psi pounds per square inch 

QAPP Quality Assurance Project Plan

QA/QC quality assurance/quality control 

RFP Request for Proposal 

RO reverse osmosis

RPD relative percent difference

RW reject water

Sb antimony 

SDWA Safe Drinking Water Act

SiO2 silica

SO42- sulfate

STS Severn Trent Services

TDS total dissolved solids

TFC thin-film composite

VOC volatile organic compound

VSWS very small water system
xi

ACKNOWLEDGMENTS

The authors wish to extend their sincere appreciation to Carmel Elementary School in Carmel, ME for 

monitoring operation of the arsenic removal system and collecting samples from the treatment and 

distribution systems throughout the performance evaluation study. The authors also appreciate the 

technical support provided by Jennifer Grant and Greg DuMonthier of the Maine Drinking Water 

Program and Cindy Klevens of the New Hampshire Department of Environmental Services. 
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). In order to clarify the implementation of the original rule, EPA revised the rule text on March 25, 

2003, to express the MCL as 0.010 mg/L (10 μg/L) (EPA, 2003). The final rule required all community 

and non-transient, non-community water systems to comply with the new standard by January 23, 2006. 

In October 2001, EPA announced an initiative for additional research and development of cost-effective 

technologies to help small community water systems (<10,000 customers) meet the new arsenic standard, 

and to provide technical assistance to operators of small systems to reduce compliance costs. As part of 

this Arsenic Rule Implementation Research Program, EPA’s Office of Research and Development (ORD) 

proposed a project to conduct a series of full-scale, on-site demonstrations of arsenic removal 

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

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

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

water systems. In June 2002, EPA selected 17 out of 115 sites to host the demonstration studies. 

In September 2002, EPA solicited proposals from engineering firms and vendors for cost-effective arsenic 

removal treatment technologies for the 17 host sites. EPA received 70 technical proposals for the 17 host 

sites, with each site receiving from one to six proposals. In April 2003, an independent technical panel 

reviewed the proposals and provided its recommendations to EPA on the technologies that it determined 

were acceptable for the demonstration at each site. Because of funding limitations and other technical 

reasons, only 12 of the 17 sites were selected for the 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. In September 2003, EPA again solicited proposals from engineering firms and vendors for arsenic 

removal technologies. EPA received 148 technical proposals for the 32 host sites, with each site 

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

review the proposals and provide recommendations to EPA with the number of proposals per site ranging 

from none (for two sites) to a maximum of four. The final selection of the treatment technology at the 

sites that received at least one proposal was made, again, through a joint effort by EPA, the state 

regulators, and the host site. Since then, four sites have withdrawn from the demonstration program, 

reducing the number of sites to 28. 

With additional funding from Congress, EPA selected 10 more sites for demonstration under Round 2a. 

Somewhat different from the Round 1 and Round 2 selection process, Battelle, under EPA’s guidance, 

issued a Request for Proposal (RFP) on February 14, 2007, to solicit technology proposals from vendors 

and engineering firms. Upon closing of the RFP on April 13, 2007, Battelle received from 14 vendors a 

total of 44 proposals, which were subsequently reviewed by a three-expert technical review panel 

convened at EPA on May 2 and 3, 2007. Copies of the proposals and recommendations of the review 
2

panel were later provided to and discussed with representatives of the 10 host sites and state regulators in 

a technology selection meeting held at each host site during April through August 2007. The final 

selections of the treatment technology were made, again, through a joint effort by EPA, the respective 

state regulators, and the host sites. 

As one of the 10 Round 2a host sites, the water system at Carmel Elementary School (CES) in Carmel, 

Maine had elevated arsenic and antimony (Sb) in its water supply. The original technology selected was a 

9,600-gal/day (gpd) point-of-entry (POE) reverse osmosis (RO) system designed to treat the entire water 

supply at the school. This would require expansion of the treatment building and installation of a 

septic/leach field for discharge of RO reject water. To reduce the treatment cost, a smaller RO system 

was used to treat only potable water, which was then distributed via a separate distribution system for 

potable purposes. The system evaluated was a 1,200-gpd EPRO-1200 RO System supplied by Crane 

Environmental. 

As of February 2011, 49 of the 50 systems were operational and performance evaluations of all 49 

systems were completed. 

1.2 Treatment Technologies for Arsenic Removal

Technologies selected for Rounds 1, 2, and 2a demonstration included adsorptive media (AM), iron 

removal (IR), coagulation/filtration (C/F), ion exchange (IX), RO, point-of-use (POU) RO, and 

system/process modification. Table 1-1 summarizes the locations, technologies, vendors, system 

flowrates, and key source water quality parameters (including As, iron [Fe], and pH). Table 1-2 presents 

the number of sites for each type of technology. AM technology was demonstrated at 30 sites, including 

four with IR pretreatment. IR technology was demonstrated at 12 sites, including four with supplemental 

iron addition. C/F, IX, and RO technologies were demonstrated at three, two, and one sites, respectively. 

The Sunset Ranch Development site that demonstrated POU RO technology had nine under-the-sink RO 

units. The Oregon Institute of Technology (OIT) site classified under AM had three AM systems and 

eight POU AM units. The Lidgerwood site encompassed only system/process modifications. An 

overview of the technology selection and system design for the 12 Round 1 demonstration sites and the 

associated capital costs is provided in two EPA reports (Wang et al., 2004; Chen et al., 2004), which are 

posted on the EPA Web site at http://www.epa.gov/ORD/NRMRL/arsenic/resource.htm. 

1.3 Project Objectives

The objective of the arsenic demonstration program was to conduct full-scale performance evaluations of 

treatment technologies for arsenic removal from drinking water supplies. The specific objectives were 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 Crane Environmental EPRO-1,200 RO system at CES in 

Carmel, ME, from April 16 through December 15, 2009. The types of data collected included system 

operation, water quality (both across the treatment train and in the distribution system), residuals, and 

capital and O&M cost. 
3

Table 1-1. Summary of Rounds 1, 2, and 2a Arsenic Removal Demonstration 

Locations, Technologies, and Source Water Quality

Demonstration

Location Site Name Technology (Media) Vendor

Design

Flowrate

(gpm)

Source Water Quality

As

(μg/L)

Fe

(μg/L)

pH

(S.U.)

Northeast/Ohio

Carmel, ME Carmel Elementary School RO Norlen’s Water 1,200 gpd 21 <25 7.9

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

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

Woodstock, CT Woodstock Middle School AM (Adsorbsia) Siemens 17 21 <25 7.7

Pomfret, CT Seely-Brown Village AM (ArsenXnp) SolmeteX 15 25 <25 7.3

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(d) 7.3

Conneaut Lake, PA Conneaut Lake Park IR (Greensand Plus) with ID AdEdge 250 28(a) 157(d) 8.0

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

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

Great Lakes/Interior Plains

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

Pentwater, MI Village of Pentwater IR (Macrolite) with ID Kinetico 400 13(a) 466(d) 6.9

Sandusky, MI City of Sandusky IR (Aeralater) Siemens 340(e) 16(a) 1,387(d) 6.9

Delavan, WI Vintage on the Ponds IR (Macrolite) Kinetico 40 20(a) 1,499(d) 7.5

Goshen, IN Clinton Christian School IR & AM (E33) AdEdge 25 29(a) 810(d) 7.4

Fountain City, IN Northeastern Elementary School IR (G2) US Water 60 27(a) 1,547(d) 7.5

Waynesville, IL Village of Waynesville IR (Greensand Plus) Peerless 96 32(a) 2,543(d) 7.1

Geneseo Hills, IL Geneseo Hills Subdivision AM (E33) AdEdge 200 25(a) 248(d) 7.4

Greenville, WI Town of Greenville IR (Macrolite) Kinetico 375 17(a) 7,827(d) 7.3

Climax, MN City of Climax IR (Macrolite) with ID Kinetico 140 39(a) 546(d) 7.4

Sabin, MN City of Sabin IR (Macrolite) Kinetico 250 34(a) 1,470(d) 7.3

Sauk Centre, MN Big Sauk Lake Mobile Home Park IR (Macrolite) Kinetico 20 25(a) 3,078(d) 7.1

Stewart, MN City of Stewart IR &AM (E33) AdEdge 250 42(a) 1,344(d) 7.7

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

Lead, SD Terry Trojan Water District AM (ArsenXnp) SolmeteX 75 24 <25 7.3

Midwest/Southwest

Willard, UT Hot Springs Mobile Home Park IR & AM (Adsorbsia) Filter Tech 30 15.4(a) 332(d) 7.5

Arnaudville, LA United Water Systems IR (Macrolite) Kinetico 770(e) 35(a) 2,068(d) 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
Table 1-1. Summary of Rounds 1, 2, and 2a Arsenic Removal Demonstration 

Locations, Technologies, and Source Water Quality (Continued)

4

Demonstration

Location Site Name Technology (Media) Vendor

Design

Flowrate

(gpm)

Source Water Quality

As

(μg/L)

Fe

(μg/L)

pH

(S.U.)

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

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(d) 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) 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; C/F = coagulation/filtration; HIX = hybrid ion exchanger; IR = iron removal; IR with ID = iron removal with iron addition; 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) Withdrew from program in 2007. Selected originally to replace Village of Lyman, NE site, which withdrew from program in June 2006.

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

(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 

Table 1-2. Number of Demonstration Sites for Each Type of Arsenic 

Removal Technology 

Type of Technologies

Number 

of Sites

Adsorptive Media(a) 26

Adsorptive Media with Iron Removal Pretreatment 4

Iron Removal (Oxidation/Filtration) 8

Iron Removal with Supplemental Iron Addition 4

Coagulation/Filtration 3

Ion Exchange 2

Reverse Osmosis 1

Point-of-Use Reverse Osmosis(b) 1

System/Process Modifications 1

(a) OIT site at Klamath Falls, OR had three AM systems and 

eight POU AM units.

(b) Including nine under-the-sink RO units.
6 

2.0 SUMMARY AND CONCLUSIONS

Based on the information collected during the 10-month system operation, the following conclusions were 

made relating to the overall objectives of the treatment technology demonstration study. 

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

• The dual plumbing system with a smaller 1,200-gpd RO unit was found to be more cost effective 

than the originally proposed 9,600-gpd RO unit treating the entire water supply. The major cost 

saving was from the reduced quantity of reject water that could be discharged to the existing 

septic system.

• The POE RO system was effective in removing arsenic from source water, reducing its 

concentrations (total) from 18.2 to 0.1 μg/L (on average) in permeate water. 

• The POE RO system was effective in removing antimony from source water, reducing its 

concentrations from 10.8 to <0.1 μg/L in permeate water. 

• The POE RO system also was effective in removing total dissolved solids (TDS), manganese, 

and silica, achieving 97%, 95%, and 96% removal, respectively, for these analytes. pH values 

were initially reduced to 6.9 (on average) due to reduction in alkalinity by RO, but was increased 

to 7.4 (on average) after pH adjustment. 

Process residuals produced by the technology: 

• The only process residual produced by the RO system was reject water. The amount produced 

was high, accounting for 60% of feed water. The reject water was discharged to the existing 

septic system at the school. 

• The reject water contained, on average, 31.9 μg/L of arsenic, 17.7 μg/L of antimony, and 410 

mg/L of TDS. The pH of the reject water was 8.0 (on average). 

Required system O&M and operator skill levels:

• Under normal operating conditions, the skills required to operate the EPRO-1,200 RO system 

were minimal. The daily demand on the operator was typically 10 min to visually inspect the 

system and record operational parameters. 

Capital and O&M cost of the technology:

• Total capital cost was $20,542, including $8,600 for dual plumbing and $11,942 for the EPRO1,200 RO system. 

• The annual O&M cost was $1,404, or $12.89/1,000 gal of permeate water treated. 
7 

3.0 MATERIALS AND METHODS

3.1 General Project Approach

Following the predemonstration activities summarized in Table 3-1, the performance evaluation study of the 

EPRO-1,200 RO unit began on April 16, 2009, and ended on December 15, 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 and antimony to below their

respective MCLs of 10 and 6 μg/L through the collection of water samples across the treatment train, as 

described in the Study Plan (Battelle, 2009). The reliability of the system was evaluated by tracking the 

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. The 

vendor (Norlen’s Water Treatment Service [Norlen’s Water]) was contracted by Battelle for system 

installation and assisted in tracking system operation. 

Table 3-1. Predemonstration Study Activities and Completion Dates

Activity Date

Introductory Meeting Held July 24, 2007

Project Planning Meeting Held September 17, 2008

Request for Quotation Issued to Vendor October 10, 2008

Vendor Quotation Received by Battelle November 4, 2008

Purchase Order Completed and Signed December 11, 2008

Permit Issued by MDWP December 19, 2008

Installation of Dual Plumbing System Begun July 1, 2008

Installation of Dual Plumbing System Completed October 1, 2008

RO Equipment Arrived January 5, 2009

System Installation and Shakedown Completed February 4, 2009

Performance Evaluation Begun April 16, 2009

Final Study Plan Issued April 23, 2009

MDWP = Maine Drinking Water Program

The O&M and operator skill requirements were evaluated based on a combination of quantitative data and 

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

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

and general knowledge needed for relevant chemical processes and related health and safety practices. The 

staffing requirements for the system operation were recorded on an Operator Labor Hour Log Sheet. 

The cost of the system was evaluated based on the capital cost per gal/min (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, 

electrical usage, and labor. 

3.2 System O&M and Cost Data Collection

The plant operator performed daily, biweekly, and monthly system O&M and data collection according to 

instructions provided by the vendor and Battelle. On a regular basis, the plant operator recorded system 

operational data such as pressure, flowrate, totalizer, and hour meter readings on a System Operation Log 
8 

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

Evaluation 

Objectives

Data Collection

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

–Ability to consistently meet 6 μg/L of antimony MCL in treated water

Reliability –Unscheduled system downtime

–Frequency and extent of repairs including a description of problems 

encountered, materials and supplies needed, and associated labor and cost 

incurred

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

Cost Effectiveness –Capital cost for equipment, engineering, and installation

–O&M cost for chemical usage, electricity consumption, and labor

Sheet and conducted visual inspections to ensure normal system operations. If any problems occurred, 

the plant operator contacted the Battelle Study Lead and/or Norlen’s Water for troubleshooting. The plant 

operator recorded all relevant information, including the problems encountered, course of actions taken, 

materials and supplies used, and associated cost and labor incurred on the Repair and Maintenance Log 

Sheet. On a monthly basis, Norlen’s Water measured temperature, pH, dissolved oxygen (DO), 

oxidation-reduction potential (ORP), and chlorine residuals and recorded the data on an Onsite Water 

Quality Parameters Log Sheet. 

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

system installation. The O&M cost consisted of the cost for electricity consumption and labor. Labor for 

various activities, such as the routine system O&M, troubleshooting and repairs, and demonstrationrelated work, were tracked using an Operator Labor Hour Log Sheet. The routine system O&M included 

activities such as completing field logs, performing system inspections, and others as recommended by 

the vendor. The labor for demonstration-related work, including activities such as performing field 

measurements, collecting and shipping samples, and communicating with the Battelle Study Lead and the 

vendor, was recorded, but not used for cost analysis. 

3.3 Sample Collection Procedures and Schedules

To evaluate system performance, samples were collected from the wellheads, across the treatment plant, 

and from the distribution system. Table 3-3 presents the sampling schedules and analytes measured 

during each sampling event. Specific sampling requirements for analytical methods, sample volumes, 

containers, preservation, and holding times are presented in Table 4-1 of the EPA-endorsed Quality 

Assurance Project Plan (QAPP) (Battelle, 2007). The procedure for arsenic speciation is described in 

Appendix A of the QAPP. 

3.3.1 Source Water. Source water characterization was peformed by Battelle before and during an 

EPA pilot study in 2005 and 2006 under a separate EAP task order. Source water samples were collected
9 

Table 3-3. Sampling Schedule and Analytes

Sample 

Type

Sample 

Locations(a)

No. of 

Samples

Planned 

Frequency Analytes

Actual 

Sampling Date

Treatment 

Plant Water

(Speciation

Sampling)

IN, RO, and 

AP

3 First week 

of each 

four-week 

cycle

Onsite: pH, temperature, 

DO, and/or ORP 

Offsite: As(III), As(V),

As (total and soluble),

Fe (total and soluble),

Mn (total and soluble),

Sb (total and soluble),

Ca, Mg, NO3, SO4, 

SiO2, P, TDS, turbidity, 

and alkalinity

04/30/09, 05/27/09, 

06/30/09, 07/29/09, 

09/02/09, 09/28/09, 

10/28/09, 12/03/09

Treatment 

Plant Water

(Regular 

Sampling)

Second, 

third, and 

fourth 

week of 

each fourweek cycle

Onsite: pH, temperature,

DO, and/or ORP 

Offsite: As (total), 

Fe (total), Mn (total), 

Sb (total), Ca, Mg, SiO2, 

TDS, turbidity, and 

alkalinity

04/16/09, 05/12/09, 

05/20/09, 06/04/09, 

06/17/09, 09/08/09, 

09/14/09, 09/30/09, 

10/07/09, 10/20/09, 

10/27/09, 11/17/09, 

12/15/09

Residual 

Wastewater

RW 1 Weekly(b) Onsite: pH

Offsite: As (total), 

Fe (total), Mn (total), 

Sb (total), Ca, Mg, NO3, 

SO4, SiO2, P, TDS, 

turbidity, and alkalinity

05/27/09, 06/17/09, 

06/30/09, 07/29/09, 

09/02/09, 09/08/09, 

09/14/09, 09/28/09, 

09/30/09, 10/07/09, 

10/20/09, 10/27/09, 

10/28/09, 11/17/09, 

12/03/09, 12/15/09

Distribution 

System 

Water

Tap in 

school 

(DS1) 

1 Monthly Onsite: free and total Cl2

Offsite: As (total), 

Fe (total), Mn (total), 

Sb (total), Cu (total), 

Pb (total), pH, and 

alkalinity

05/20/09, 06/17/09, 

07/09/09, 08/27/09, 

09/08/09, 09/29/09, 

10/27/09, 11/19/09

(a) Abbreviations in parenthesis corresponding to sample locations shown in Figure 4-6, i.e., IN = 

blended source water; RO = RO permeate; AP = after pH adjustment; RW = reject water; DS1 = 

distribution system. 

(b) Actual sampling spanned from 1 day to 3 weeks. 

DO = dissolved oxygen; ORP = oxidation-reduction potential; TDS = total dissolved solids

from Wells No. 1 and No. 2 on September 13, 2005, during the initial site visit prior to the pilot study. 

More complete source water characterization was conducted on the blended water from both wells during 

the pilot study from March 7 through July 11, 2006. These samples were filtered for soluble arsenic and 

antimony and then speciated for As(III) and As(V) using a field arsenic specitation kit (see Section 3.4.1). 

Results of these source water sampling events are discussed in Section 4.1. 

3.3.2 Treatment Plant Water. Battelle Study Plan (2009) called for weekly sampling of 

treatment plant water samples for onsite and offsite analyses. For the first week of each four-week cycle, 

samples were taken (1) after water from Wells No. 1 and No. 2 had blended (IN), (2) at the RO permeate 

port (RO), and (3) after pH adjustment (AP), speciated onsite, and analyzed for the analytes listed in 
10 

Table 3-3 under “Treatment Plant Water (Speciation Sampling).” For the second, third, and fourth weeks 

of each four-week cycle, samples were collected at the same three locations and analyzed for the analytes 

listed in Table 3-3 under “Treatment Plant Water (Regular Sampling).” During the performance 

evaluation study, actual sampling frequencies spanned from one day to three weeks, with speciation 

samples taken approximately once a month on eight sampling occasions and regular samples taken once 

every one to four weeks on 13 sampling occasions. During the summer break from June 13 through 

August 25, only three sets of samples were taken, including one on June 17 for regular sampling and two 

on June 30 and July 29 for speciation sampling. 

3.3.3 Residual Wastewater. The Battelle Study Plan (2009) called for weekly sampling of reject 

water (RW) from a sampling tap on the RW discharge line leading to the septic system. Actual sampling 

frequencies spanned from 1 days to three weeks. For each sampling event, an unfiltered sample from the 

reject water discharge line was collected in an unpreserved 1-gal wide-mouth high-density polyethylene 

(HDPE) bottle and a 60-mL filtered sample (using 0.45-μm filters) was collected into a 125-mL HDPE 

bottle preserved with nitric acid. Analytes for the reject water samples are listed in Table 3-3. 

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

monthly to determine the impact of the RO system on the water chemistry in the distribution system, 

specifically, the pH, arsenic, antimony, lead, and copper levels. 

The plant operator collected the samples following an instruction sheet developed in accordance with the 

Lead and Copper Monitoring and Reporting Guidance for Public Water Systems (EPA, 2002). The date 

and time of last water usage before sampling and of actual sample collection were recorded for 

calculation of sample stagnation time. All samples were collected from a cold-water faucet that had not 

been used for at least 6 hr to ensure that stagnant water was sampled. 

 

3.4 Sampling Logistics

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

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

al., 1998). Resin columns were prepared in batches at Battelle laboratories in accordance with the 

procedures detailed in Appendix A of the EPA-endorsed QAPP (Battelle, 2007). 

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

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

bottles were new and contained appropriate preservatives. Each sample bottle was affixed with a preprinted, color-coded label consisting of 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 a specific water facility, sampling date, a two-letter code for a specific 

sampling location, and a one-letter code designating the arsenic speciation bottle (if necessary). The 

sampling locations at the treatment plant were color-coded for easy identification. The labeled bottles for 

each sampling location were placed in separate zip-lock bags and packed in the cooler. 

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

instructions, chain-of-custody forms, prepaid/addressed FedEx air bills, and bubble wrap, were included. 

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

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

week’s sampling event. 
11 

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 verified that all samples indicated on the chain-of-custody forms were included and intact. 

Sample IDs were checked against the chain-of-custody forms, and the samples were logged into the 

laboratory sample receipt log. Discrepancies noted by the sample custodian were addressed with the plant 

operator by the Battelle Study Lead. 

Samples for metals analyses were stored at Battelle’s inductively coupled plasma-mass spectrometry 

(ICP-MS) laboratory. Samples for other water analyses were packed in separate coolers and picked up by 

couriers from American Analytical Laboratories (AAL) in Columbus, OH, which was contracted by 

Battelle for this demonstration study. The chain-of-custody forms remained with the samples from the 

time of preparation through analysis and final disposition. All samples were archived by the appropriate 

laboratories for the respective duration of the required hold time and disposed of properly thereafter. 

3.5 Analytical Procedures

The analytical procedures described in detail in Section 4.0 of the EPA-endorsed QAPP (Battelle, 2007)

were followed by Battelle’s ICP-MS laboratory and AAL. 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 vendor using a VWR 

Symphony SP90M5 Handheld Multimeter, which was calibrated for pH and DO prior to use following 

the procedures provided in the user’s manual. The ORP probe also was checked for accuracy by 

measuring the ORP of a standard solution and comparing it to the expected value. The vendor collected a 

water sample in a clean, plastic beaker and placed the Symphony SP90M5 probe in the beaker until a 

stable value was obtained. The vendor also performed free and total chlorine measurements using Hach 

chlorine test kits following the user’s manual. 
12 

4.0 RESULTS AND DISCUSSION

4.1 Facility Description and Pre-existing Treatment System Infrastructure

CES is located on 50 Plymouth Road in Carmel, Maine. Serving approximately 200 students and faculty 

members, the facility is a non-transient, non-community water system (NTNCWS) supplied by two wells, 

i.e., Wells No. 1 and No. 2, with a combined capacity of 30 gpm. The average daily demand was 1,700 to 

1,800 gal during the school year. The pre-existing system consisted of a 576-gal storage tank, a chlorine 

addition system, and three contact/retention tanks configured in parallel (Figure 4-1). About 0.3 mg/L (as 

Cl2) of free chlorine residual was maintained in treated water for disinfection purposes.

Figure 4-1. Pre-existing Facility 

(Clockwise from Top: School Building, Storage Tank, Contact Tanks, and Chlorination System) 

Under a separate EPA task order, Battelle conducted a four-month pilot study on a 600-gpd, skidmounted RO system from March 2 through July 11, 2006. The pilot system was supplied by Crane 

Environmental and installed by Norlen’s Water. The pilot system received a split flow at 2 gpm from the 

wells with the balance (i.e., 28 gpm) continued to supply the school’s water demand. Major components 

of the pilot system included a 5-μm sediment pre-filter, a 1⁄2-horsepower (hp) positive displacement rotary 

vane booster pump, and a single 2.5-in × 40-in thin-film composite RO membrane (Figure 4-2). During 

the pilot study, the RO system operated for a total of 740 hr, processing approximately 76,500 gal of 

water. The system produced 16,300 gal of permeate, corresponding to a recovery rate of 21%. Both 

permeate and reject water were discharged to the septic system. 
13 

Figure 4-2. RO Pilot System and Components

Results of the pilot study were summarized in a letter report dated December 29, 2006. Key conclusions 

are highlighted below: 

• The RO system was effective in removing arsenic and antimony to levels well below their 

respective MCLs.

• A considerable amount of residual wastewater was produced (i.e., 79% of the influent flow) 

by the single-stage RO membrane element. A multiple-stage RO system can achieve a higher 

recovery rate.

• Blending the RO permeate with raw water can help neutralize permeate, reduce the volume of 

reject water, and lower the overall treatment cost. 

1) IN sample tap

2) TDS monitor 

3) Sediment filter

4) Pressure gauges

5) Booster pump 

6) RO membrane

7) Flow meters

8) Totalizer 

9) Timer

10) RO drain line

11) RW drain line

3

2

5

6

7

9

8

4

1

10

11
14 

4.1.1 Source Water Quality. Analytical results from the source water sampling events in 2005 

and 2006 are presented in Table 4-1 and discussed as follows. 

Table 4-1. Source Water Quality at Carmel, ME 

Parameter Unit Battelle Source Water Data

Date 09/13/05(a) 03/07/06(b)

03/21/06–

07/11/06(c)

Well No. 1 No. 2 No. 1 & 2 No. 1 & 2

Alkalinity (as CaCO3) mg/L NA NA 216 202–225

Chloride mg/L NA NA 24 NA

Fluoride mg/L NA NA <0.1 NA

Sulfate mg/L NA NA 11.2 NA

Silica (as SiO2) mg/L NA NA 9.6 NA

TDS mg/L NA NA 246 240–264

pH S.U. 7.9 7.7 7.9 7.5–7.8

Temperature °C NA NA NA 11.0–14.1

Total Hardness (as CaCO3) mg/L NA NA 226 184–247

Ca Hardness (as CaCO3) mg/L NA NA 107 91.2–127

Mg Hardness (as CaCO3) mg/L NA NA 119 88.3–128

Al (total) μg/L NA NA <10 NA

As (total) μg/L 21.2 28.2 21.1 19.7–29.8

As (soluble) μg/L 21.5 28.0 20.3 19.1–29.8

As (particulate) μg/L <0.1 0.2 0.8 <0.1–0.8

As (III) μg/L 0.7 0.7 0.5 0.3–0.7

As (V) μg/L 20.9 27.3 19.8 6.2–29.1

Fe (total) μg/L <25 <25 <25 <25

Fe (soluble) μg/L <25 <25 <25 NA

Mn (total) μg/L 1.7 1.6 2.0 2.1

Mn (soluble) μg/L 1.6 1.6 1.9 NA

Sb (total) μg/L 13.6 14.1 12.6 9.7–12.1

Sb (soluble) μg/L NA NA 12.4 10.1–12.5

V (total) μg/L NA NA 0.5 NA

V (soluble) μg/L NA NA 0.6 NA

Na (total) mg/L NA NA 25.0 NA

(a) Samples collected during initial site visit

(b) Samples collected during startup of pilot system.

(c) Samples collected during pilot study

NA = data not available

Arsenic. Based on the September 13, 2005 sampling data, Well No. 1 water contained a slightly lower 

arsenic concentration than Well No. 2 (i.e., 21.2 vs 28.2 μg/L). These concentrations were well within 

the range of 19.7 to 29.8 μg/L measured in blended source water during the four-month pilot study. Most 

arsenic was present as soluble As(V) with only 0.3 to 0.7 μg/L present as As(III). Therefore, oxidation of 

the water prior to the RO treatment was not required.

Antimony. Water from Wells No. 1 and No. 2 contained similar levels of antimony at 13.6 and 14.1 

μg/L, respectively, based on the September 13, 2005 data. Total antimony concentrations measured in the 

blended source water during the pilot study ranged from 9.7 to 12.6 μg/L. Most antimony was present in 

the soluble form with concentrations ranging from 10.1 to 12.5 μg/L.
15 

Other Water Quality Parameters. TDS concentrations in combined source water ranged from 240 to 

264 mg/L, which were composed primarily of calcium (36 to 51 mg/L), magnesium (35 to 51 mg/L), 

sodium (25.0 mg/L), sulfate (11.2 mg/L), silica (9.6 mg/L), and chloride (24 mg/L). Hardness 

concentrations ranged from 184 to 247 mg/L (as CaCO3); alkalinity from 202 to 225 mg/L (as CaCO3); 

pH values ranged from 7.5 to 7.9. 

4.1.2 Distribution System. Based on the information provided by the school, the distribution 

system material was comprised of a combination of galvanized and copper piping. In preparation for the 

installation of the 1,200-gpd RO unit, the distribution system was modified to be a duplex system in July 

2008, for both potable and non-potable water distribution. Installation of the duplex distribution system is 

further discussed in Section 4.2.1. 

One location inside the school building was selected for monthly distribution system water sampling to 

evaluate the effect of the RO treatment system on the distribution system water quality. 

4.2 Treatment Process Description

4.2.1 Dual Plumbing. The original treatment technology selected for CES was a Watts Premier 

9,600-gpd RO system proposed by Advanced Quality Water Solutions (AQWS) in 2007. The system 

consisted of two Goulds V260 HydroPro diaphragm tanks, a water softener, an RO unit, a 3,000-gal 

atmospheric storage tank, a 30-gpm booster pump, and two acid neutralizers. During an onsite 

introductory meeting attended by EPA, Battelle, MDWP, AQWS, and an engineering firm representing 

CES on July 24, 2007, two main issues were identified: (1) the existing building would need to be 

modified/expanded to house the new 9,600-gpd RO system and (2) a new septic/leach field would need to 

be built to handle residual wastewater produced by the RO system. Based on a rough estimate, the cost 

for constructing a new septic/leach field alone would range from $30,000 to $35,000. CES expressed 

concerns over its ability to cover the cost of these two new requirements. 

To reduce the financial burden on CES, a dual plumbing approach was discussed and later adopted by the 

project team. This approach involved installing a parallel plumbing system dedicated to the potable water 

distribution only and had been successfully employed at schools and small businesses in the State of New 

Hampshire. Because most water consumed at CES was for non-potable use (i.e., lavatory), only a portion 

of raw water would need to be treated for potable use (i.e., kitchen sinks, water fountains, etc.). 

Therefore, a smaller RO system with a separate distribution system was used to meet the potable water 

demand, thus reducing the capital and O&M cost. 

In July 2008, Battelle contracted Patriot Plumbing in Etna, ME to perform the plumbing work necessary 

to convert the existing distribution system into a duplex system. Cross-linked polyethylene (PEX) piping 

with 0.5 and 0.75-in nominal sizes was installed from the boiler room, where the RO system was to be 

housed, to the existing cold water line supplying water fountains and bathroom, break-room, kitchen, and 

locker-room sinks. The PEX piping was installed at hallway ceilings and extended to locations near the 

fixtures receiving potable water. The pre-existing piping at the ceiling feeding these fixtures was capped 

off and the PEX piping was connected to the piping going to the fixtures. The PEX piping is NSF 

International (NSF) 61 certified for use in drinking water systems. Figure 4-3 presents photos of the 

installation of the dual plumbing system using the PEX piping. A water meter was installed on the 

portable line to monitor the water demand. An existing water meter was used to monitor the raw water 

demand (potable and non-potable).

During a project planning meeting attended by EPA, Battelle, MDWP, and CES on September 17, 2008, 

the size of the RO system was discussed. The school expressed a desire that the hot water line supplying 

the kitchen sinks and dishwashers be treated because the hot water might be used for food preparation. 
16 

Figure 4-3. Installation of Dual Plumbing System Using PEX Piping 

(from left to right: prior to Installation, through Ceilings, and to a Hot Water Tank) 

As such, two options were discussed as either refurbishing the old EPRO-600 RO pilot system capable of 

producing 600 gpd or purchasing a new EPRO-1,200 RO system capable of producing 1,200 gpd. A final 

decision was made based on the potable water demand (both hot and cold water) and a cost comparison of 

these two options. 

In October 2008, Patriot Plumbing was contracted again to modify the plumbing to provide RO-treated 

water to a newly installed 62-gal hot water tank supplying the kitchen sinks and dishwashers. PEX piping 

was installed to supply RO-treated water to the hot water tank located in the boiler room and from the hot 

water tank to the kitchen sinks and dishwashers (Figure 4-3). Another water meter was installed on the 

hot water tank feed line to monitor the hot water demand. The existing boiler continued to be fed with 

non-RO water to supply hot water to the rest of the building, i.e., hot water taps in the bathrooms and the 

shower rooms in the gym. 

Water demands were monitored from August 29, 2008, through January 16, 2009, and are shown in 

Figure 4-4. Daily total water demands ranged from 403 to 3,613 gpd and averaged 1,588 gpd, including 

16 to 147 gpd (41 gpd [on average]) of cold potable water and 125 to 401 gpd (223 gpd [on average]) of 

hot potable water. Thus, total daily potable water demands requiring the RO treatment ranged from 143 

to 456 gpd and averaged 257 gpd. This average daily potable water demand accounted for 16% of the 

total daily water demand.

In November 2008, quotations were received from Norlen’s Water for the cost to refurbish the existing 

600-gpd RO system used for the pilot study and the cost to purchase and install a new 1,200-gpd RO 

system. Upon review of the quotations and further discussion with EPA, the EPRO-1,200 RO treatment 

system was selected because: (1) the difference in cost to refurbish the 600-gpd system or to purchase the 

new 1,200-gpd system was rather insignificant, and (2) the larger system could better meet CES’ peak 

demand during lunch time. 

4.2.2 Treatment Technology Description and System Design. The RO system used thin-film 

composite (TFC) RO membranes to remove dissolved solids from source water. Source water was

delivered under pressure to the membranes with dissolved solids removed through RO and permeate 

passed through the membranes. The dissolved solids rejected by the membranes were concentrated into 

the residual wastewater stream and discharged to the existing septic system. 
17 

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

Water Demand (gal)

Date

Potable-Cold Water Demand Potable-Hot Water Demand Total Water Demand

Average = 41 gal

Flow totalizer on potable hot 

water line installed on October 

1, 2008. Average = 223 gal

Average = 1,588 gal

Figure 4-4. Water Demand Monitoring at CES 

The Crane Environmental EPRO-1,200 RO treatment process consisted of an RO unit, a pH adjustment 

unit, two 300-gal atmospheric storage tanks, re-pressurization system, and post-chlorination system. 

Table 4-2 summarizes key system design parameters of the treatment system. Figure 4-5 presents a 

schematic of the treatment system. Figure 4-6 shows a process flowchart, along with the sampling/

analysis schedule for the treatment system. The key process components of the treatment system are 

discussed as follows:

• Intake – Source water was pumped from Wells No. 1 and No. 2 and stored in the pre-existing 

576-gal storage tank. Upon exiting the storage tank, source water was split into potable and 

non-potable water lines. The non-potable water line led water through a retention tank to the 

school non-potable distribution system. The potable water line fed water to the RO system. 

A pre-existing flow meter and a pressure gauge monitored the volume and flowrate of intake 

water and the inlet pressure to the treatment system. A sample tap located at the RO intake 

line was used for the collection of source water samples for water quality analysis. 

• Sediment Filter – Prior to entering the RO unit, source water flowed through a 5-μm, 2.75-in 

× 10-in sediment filter (Figure 4-7) to remove any particulates that could potentially foul the 

RO membranes. The manufacturer recommended that the sediment filter be changed on a 

monthly basis or when the differential pressure became greater than 10% between the 

pressure reading before and after the sediment filter. 

• RO System – Major components of the skid-mounted RO system included a 1⁄2-hp positive 

displacement, a rotary vane booster pump, a TDS monitor, and two 2.5-in × 40-in TFC RO 

membrane modules (Figure 4-8). Figure 4-9 presents a schematic of an RO membrane 

module. The RO system was rated for 1,200 gpd of permeate production with a 40% 

recovery (or 2.5:1, that is, for every 2.5 gal of feed water, 1 gal of permeate water and
18 

Table 4-2. Design Specifications of EPRO-1,200 RO System 

Parameter Value

System Components

No. of Pre-filters 1

Pre-filter Size (μm) 5

No. of RO Membrane Elements 2

RO Membrane Construction Thin film composite

Size of Membrane Elements 2.5-in D × 40-in H

Inlet Water Quality Requirements

Max. Operating Pressure (psi) 300

Max. Operating Temperature (oF) 113

pH Range (S.U.) 2–11

Max. Free Chlorine (mg/L [as Cl2]) <0.1

Max. Turbidity (NTU) 1

Max. Silica (mg/L) <1

Max. Iron (mg/L) <0.01

Max. (mg/L) <1,000

Operating Specifications

Feed Flow (gpd) 3,000

Daily Permeate Production (gpd) 1,200

Recovery (%) 40

Min. Rejection (%) 98

1.5 gal of reject water will be produced). The reject water was discharged into the existing 

septic system. Both permeate and reject water lines were equipped with flow meters and 

totalizers, pressure gauges, and sample taps for monitoring purposes. 

• pH Adjustment – After passing through the RO unit, permeate water flowed through a 10-in 

× 44-in neutralization tank containing 1.25 ft3 of calcite (Figure 4-10). Based on results of 

the pilot study, alkalinity concentrations were reduced from 211 mg/L (as CaCO3) in raw

water to 3 mg/L (as CaCO3) in permeate water while pH values were reduced from 7.7 to 5.7, 

on average. Therefore, it was necessary to raise the pH of the permeate water prior to 

distribution. The calcite filter intended to re-mineralize the permeate water and raise its pH 

to a near neutral level prior to entering the two 300-gal atmospheric storage tanks. 

• Storage Tank and Re-pressurization System – After passing through the calcite filter, 

permeate water was stored in two 300-gal atmospheric storage tanks equipped with float 

switches that controlled the RO unit on/off based on tank levels. A re-pressurization system 

consisted of a Goulds Model J10S 1-hp re-pressurization pump and a 40-gal non-corrosive 

fiberglass pressure tank to supply water to the distribution system at a rate of 16 gpm and an 

average pressure of 38 psi. Figure 4-11 presents photographs of an atmospheric storage tank 

and re-pressurization system.

• Chlorination – The existing chlorination system was relocated to after the re-pressurization 

system to chlorinate the RO permeate. The chlorine injection system consisted of a 37-gal 

solution storage tank, a Chem-Tech Series 100 chemical feed pump rated at 30 gpd, and two 

existing contact/retention tanks (Figure 4-12). The chemical feed pump was tied into the repressurization pump to chlorinate the water as water was pumped to the distribution system. 

The contact/retention tanks were used to allow mixing of the chlorine solution with permeate 

water. The target chlorine residual was 0.6 mg/L.
19

Figure 4-5. Schematic of RO Treatment System
20

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

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

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

Mn (total and soluble), Sb (total and soluble),

Ca, Mg, NO3, SO4, SiO2, P (total),

TDS, turbidity, and alkalinity

INFLUENT

(WELL #1)

Monthly

Carmel, ME

EPRO-1200

Reverse Osmosis System

Design Flow: 1,200 gpd

Footnote

(a) On-site analyses

REVERSE OSMOSIS

SYSTEM

POTABLE

WATER

SEDIMENT FILTER

INFLUENT

(WELL #2)

SEPTIC

SYSTEM

CALCITE FILTER

RO

ATMOSPHERIC

STORAGE TANKS

AP

REPRESSURIZATION 

PUMP

PRESSURE TANK

RETENTION

TANK 1

RETENTION

TANK 2

NaOCl

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

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

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

Mn (total and soluble),

Sb (total and soluble),

Ca, Mg, NO3, SO4, SiO2, P (total),

TDS, turbidity, and alkalinity

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

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

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

Mn (total and soluble),

Sb (total and soluble),

Ca, Mg, NO3, SO4, SiO2, P (total),

TDS, turbidity, and alkalinity

As (total), Fe (total),

Mn (total ), Sb (total ),

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

TDS, turbidity, and alkalinity

NON-POTABLE 

WATER

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

Sb (total), Ca, Mg, SiO2,

TDS, turbidity, and alkalinity

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

Sb (total), Ca, Mg, SiO2,

TDS, turbidity, and alkalinity

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

Sb (total), Ca, Mg, SiO2,

TDS, turbidity, and alkalinity

Weekly

576-GAL

STORAGE TANK

IN

RETENTION TANK

RW

As (total), Fe (total),

Mn (total ), Sb (total ),

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

TDS, turbidity, and alkalinity

FT-4

FT-3

FT-2

FT-1

Backwash Flow

LEGEND

Influent

After RO Unit

Residual Wastewater

NaOCl

INFLUENT

Chlorine Disinfection

Unit Process

Process Flow

RO

Water Sampling Locations

IN

AP

RW

After pH Adjustment

Non-Potable Water

RO Permeate Water

RO Concentrate Water

Flow Totalizers

RO Permeate Water Consumption

FT-1

FT-2

FT-3

FT-4

Figure 4-6. Process Flow Diagram and Sampling Locations for Carmel, ME Site
21

Figure 4-7. Sediment Filter

2 2

1

3

5 4

1) Pressure gauges

2) RO membrane

3) Flow meters

4) Totalizer

5) TDS monitor

Figure 4-8. EPRO-1,200 RO Unit
22

Figure 4-9. Schematic of RO Membrane Module 

Figure 4-10. Calcite Filter 
23

Figure 4-11. Atmospheric Storage Tank (top left), Re-Pressurization Pump 

(bottom), and Pressure Tank and Retention Tanks (top right)

Figure 4-12. Chlorine Addition System at CES
24

4.3 System Installation 

Norlen’s Water was contracted by Battelle to install the RO system at CES. The installation and 

shakedown of the system was completed on February 4, 2009. This section briefly summarizes the 

system installation activities, including permitting, system offloading, installation, shakedown, and 

startup.

4.3.1 Permitting. A treatment system approval package, which included a schematic of the 

proposed system, was submitted to MDWP by Norlen’s Water on December 15, 2008. MDWP did not 

have any review comments and issued approval on December 19, 2008. 

4.3.2 Installation, Shakedown, and Startup. System components were delivered to Norlen’s 

Water’s office during the week of December 22, 2008, and arrived at CES on January 5, 2009. The 

system was installed during the weeks of January 5, 12, and 19, 2009, with installation completed on 

January 26, 2009. Installation activities included offloading, placing, and connecting the EPRO-1,200 

RO unit and re-pressurization system, connecting the system at the tie-in points, completing electrical 

wiring, and relocating the chlorination system to post-treatment. System shakedown was completed on 

February 4, 2009. 

On February 27, 2009, two members from MDWP were onsite to inspect the system and noted several 

punch-list items that needed to be addressed prior to final approval. Table 4-3 summarizes the punch-list 

items and corrective actions taken. MDWP also collected water samples from the distribution system for 

arsenic and antimony analysis. Analytical results indicated that arsenic and antimony concentrations were 

below 0.5 μg/L. Based on these results, MDWP officially lifted off the “DO NOT DRINK ORDER”

previously imposed on CES. 

Table 4-3. MDWP Punch-List Items and Corrective Actions

Date Issues/Problems Indentified Corrective Action Taken

Date(s) of 

Corrective 

Action

Work 

Performed 

by

02/27/09 Valves on RO unit not labeled 

with appropriate positions

Labeled all valves with their 

appropriate positions

04/15/09 Norlen’s 

Water

02/27/09 Difficult to distinguish 

between potable and nonpotable water lines in boiler 

room

Labeled all water lines as either 

potable or non-potable

04/15/09 Norlen’s

Water 

02/27/09 Lines leading to floor drain 

not raised

Raised lines leading to floor 

drain

04/15/09 Norlen’s

Water

02/27/09 Level III operator required to 

operate the system

Hired Norlen’s Water as

school’s contract operator

03/01/10 CES

On April 30, 2009, two Battelle staff members visited CES. While onsite, they inspected the treatment 

system, trained the CES personnel on collection of operational data and water samples, and discussed 

how the remainder of the project would be conducted. Battelle requested the installation of an hour meter 

and a pump discharge pressure gauge on the RO system to help track system operation. Also, they noted 

that the RO system could not keep up with the school’s peak water demand. Upon discussion with EPA 

and Norlen’s Water, it was decided that a second 300-gal atmospheric storage tank would be necessary to 

ensure water supply during peak hours. Table 4-4 summarizes the punch-list items and corrective actions 

taken. 
25

Table 4-4. Battelle’s Punch-List Items and Corrective Actions

Date

Issues/Problems 

Indentified Corrective Action Taken

Date(s) of 

Corrective 

Action

Work 

Performed 

by

04/30/09 System operational hours 

not tracked

Installed an hour meter 

installed on RO unit to track 

operational hours

06/29/09 Norlen’s 

Water

04/30/09 No pump discharge 

pressure gauge on the 

system

Installed a pump discharge 

pressure gauge to help track 

system operation

05/19/09 Norlen’s 

Water

04/30/09 System couldn’t meet 

demand during peak hours

Installed a second 300-gal 

atmospheric storage tank to 

ensure an adequate supply of 

treated water during peak hours

05/05/09 Norlen’s 

Water

4.4 System Operation

4.4.1 Operational Parameters. The operational parameters for the 10-month demonstration study 

were tabulated and are attached as Appendix A. Table 4-5 summarizes key operational parameters. The 

system began operation on February 4, 2009, but logging of operational data did not begin until April 16, 

2009, when a technician from Norlen’s Water travelled to CES to provide training to its personnel on data 

recording. Because an hour meter was not installed until June 29, 2009, recording of hour meter readings 

did not begin until July 7, 2009. From July 7, 2009, through the end of the performance evaluation study 

on December 15, 2009, the system operated for 953.7 hr. Daily system run time averaged 11.7 hr/day 

when the school was in session (from August 25 through December 15, 2009, for a total of 76 days 

excluding weekends) and 1.9 hr/day when the school was out of session (from July 7 through August 24, 

2009, for a total of 35 days excluding weekends). Based on these average run time values, the system 

was assumed to have operated for 519.9 hr from April 16 through July 7, 2009 (including 491.4 hr from 

April 16 through June 12, 2009, when the school was in session and for 28.5 hr from June 15 through July 

2, 2009, when the school was out of session). Therefore, the total system operating time was estimated to 

be 1473.6 hr starting from April 16, 2009, 2,011.8 hr starting from February 4, 2009, or 2,269.2 hr for the 

year of 2009. 

During the 1,473.6 hr of operation from April 16 through December 15, 2009, the RO system treated 

approximately 180,700 gal of water, generating 71,100 gal of permeate and 109,600 gal of reject water. 

Recovery, specified at 40% by the manufacturer, ranged from 33 to 45% and averaged 40% based on 

incremental totalizer readings. The recovery of the RO system was calculated using Equation 1 below 

and presented in Appendix A. Figure 4-13 plots the daily recovery rates during the study period.

Recovery (%) = 100 × VP/(Vp + Vr) (1) 

where 

 VP = Volume of permeate (gal)

 Vr = Volume of reject water (gal)

The potable water demand averaged 562 gpd when the school was in session and 91 gpd when the school 

was out of session. The in-session demand was more than twice the amount recorded during August 28, 

2008 and January 16, 2009, prior to system installation. The non-potable water demand averaged 

924 gpd when the school was in session and 118 gpd when the school was out of session. The in-session 
26

Table 4-5. Summary of EPRO-1,200 System Operation 

Operational Parameter Value/Condition

Duration 04/16/09(a)–12/15/09 

Average Daily Run Time (hr/day) 11.7 (when school was in session)

1.9 (when school was out of session)

Total Operating Time (hr) 1,473.6

Number of Days System in Operation (day) 168

Volume of Permeate (gal) 71,111(b)

Volume of Reject Water (gal) 109,567(c)

Volume of Feed Water to System (gal) 180,678(d)

Average (Range) Recovery (%) 40 (33–45)

(e)

Average (Range) Permeate Water Flowrate (gpm) 0.8 (0.8–1.4)

Average (Range) Reject Water Flowrate (gpm) 1.2 (1.2–1.3)

Average (Range) Inlet Water Pressure (psi) 37 (30–42)

Average (Range) Feed Water Pressure (psi) 37 (28–40)

Average (Range) of Δp Across Sediment Filter (psi) 0.3 (0–6)

Average (Range) Permeate Discharge Pressure (psi) 145 (120–185)

Average (Range) Reject Water Discharge Pressure (psi) 141(110–175)

Average (Range) Re-Pressurization System Pressure (psi) 38 (30–45)

(a) System placed into service on 02/04/09, but logging of operational data did not begin until

04/16/09.

(b) Permeate volume from 04/27/09 through end of study read from permeate totalizer; permeate 

volume from 04/16/09 through 04/24/09 estimated based on 0.8-gpm flowrate and 11.7-

hr/day daily run time for 7 days.

(c) Reject water volume from 04/27/09 through end of study read from reject water totalizer; 

reject water volume from 04/16/09 through 04/24/09 estimated based 1.2-gpm flowrate and 

11.7-hr/day daily run time for 7 days.

(d) Sum of permeate volume and reject water volume.

(e) Calculated by dividing incremental volume of permeate by incremental volume of feed water 

to system. 

average total daily demand (including potable and on-potable demand) was 1,486 gal, which is very close 

to the 1,588 gpd value measured prior to system installation. 

Flowrate, pressure, and TDS also were monitored. As shown in Table 4-5 and Figure 4-14, flowrate 

readings of permeate and reject water stayed consistently at 0.8 and 1.2 gpm, respectively. Both inlet and 

feed water pressure averaged 37 psi with pressure loss across the sediment filter ranging from 0 to 6 psi 

and averaging 0.3 psi. Permeate and reject water discharge pressures were similar, averaging 145 and 

141 psi, respectively. The re-pressurization system pressure ranged from 30 to 45 psi and averaged 38 

psi. All system pressures were within the specified ranges. The permeate TDS monitor showed zero 

readings most of the time except for five times when the reading was 2 mg/L. In contrast, laboratory TDS 

results of the permeate ranged from <2.0 to 34.0 mg/L and averaged 8.6 mg/L. Because the onsite TDS 

monitor was a low-end meter, it was used as a “quick check” of the system performance in the field.

4.4.2 Residual Management. Residuals generated from the RO system operation included RO 

reject water, which was discharged to the existing septic system. 
27

0

5

10

15

20

25

30

35

40

45

50

Recovery (%)

Date

100*Vp/(Vp + Vr)

Recovery (%) = 100*Vp/(Vp + Vr)

where Vp = Volume of permeate (gal)

Vr = Volume of residual wastewater (gal)

Figure 4-13. Percent Recovery Calculations

0

1

2

Flowrate (gpm)

Date

Permeate 

Reject Water

Figure 4-14. Flowrate Readings of RO Permeate and Reject Water
28

4.4.3 System/Operation Reliability and Simplicity. The main operational issue with the EPRO1,200 RO unit was a RO pump and motor that needed to be replaced. When a CES personnel noticed that 

the system was louder than normal, Norlen’s Water visited the site on October 19, 2009, to diagnose the 

problem. After inspections, it was determined that bearings on the RO motor were failing and should be 

replaced along with the RO pump. On October 29, 2009, Norlen’s Water installed a new RO motor and 

pump. 

The system O&M and operator skill requirements are discussed below in relation to pre- and posttreatment requirements, levels of system automation, operator skill requirements, preventative 

maintenance activities, and frequency of chemical/media handling and inventory requirements. 

Pre- and Post-Treatment Requirements. Pre-treatment requirements for the EPRO-1,200 RO unit 

included a 5-μm sediment filter to remove any particulates that could potentially foul the RO membrane. 

Post-treatment requirements included a calcite filter to raise the pH of permeate from an average of 6.9 

after the RO unit to an average of 7.4. Although not a post-treatment requirement, the existing 

chlorination system was placed after the RO unit to provide chlorine residuals in the distribution system. 

System Automation. All major functions of the EPRO-1,200 RO unit were automated and would require 

only minimal operator oversight and intervention if all functions were operating as intended. The 

operator controlled the system operation manually. Once the permeate water in the two atmospheric 

storage tanks reached a pre-set level, a float switch was triggered, and the RO unit shut off. The chemical 

feed pump was tied into the re-pressurization pump to chlorinate the water as water was pumped to the 

distribution system. 

Operator Skill Requirements. Under normal operating conditions, the skills required to operate the 

EPRO-1,200 RO unit were minimal. The operator was typically onsite five times per week and spent 

approximately 10 min each day performing visual inspections and recording system operating parameters 

on the daily log sheets. Normal operation of the system did not require additional skills beyond those 

necessary to operate the existing water supply equipment. 

The level of operator certification is determined by the type and class of public drinking water systems. 

MDWP’s drinking water rules require all community and non-transient, non-community public drinking 

water and distribution systems to be classified based on potential health risks. Classifications range from 

“very small water system (VSWS)” (lowest) to “Class IV” (highest) for treatment systems and from 

“VSWS” to “Class IV” for distribution systems, depending on such factors as the system’s complexity, 

size, and source water. CES is classified as a “VSWS” distribution system and, therefore, a plant operator 

with a “VSWS” certificate was required by the MDWP. To fulfill the plant operator requirements, CES 

hired Nolen’s Water to be their contract operator since they have the appropriate credentials and are 

familiar with the system.

 

Preventive Maintenance Activities. The only regularly scheduled maintenance activities required for 

system operations were (1) replacing the sediment filter on a monthly basis or when the differential 

pressure was greater than 10% and (2) replenishing calcite in the calcite filter as it became depleted. 

Replacement of the sediment filter and calcite replenishment was not required during this performance 

evaluation study.

Chemical/Media Handling and Inventory Requirements. NaOCl solution was used for chlorination. 

The 35-gal chlorine tank was filled with a diluted NaOCl solution using a 3:1 water to 12.5% NaOCl (as 

Cl2) ratio. 
29

4.5 System Performance

The performance of the Crane Environmental EPRO -1,200 RO system was evaluated based on analyses 

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

4.5.1 Treatment Plant Sampling. A total of four locations were sampled from the treatment 

system, including IN, RO, AP, and RW. Water samples were collected on 22 occasions, including one 

duplicate sample, with field speciation performed during eight occasions at IN, RO, and AP. Beginning 

May 27, 2009, sampling was conducted at the RW sample tap so there were only 16 sampling events for 

RW.

Table 4-6 summarizes the analytical results of arsenic, antimony, iron, and manganese measured at the 

four sampling locations across the treatment train. Table 4-7 summarizes the results of other water 

quality parameters. Appendix B contains a complete set of analytical results for the demonstration study. 

The results of the analysis of the water samples collected throughout the treatment system are discussed 

below. 

Arsenic. The key parameters for evaluating the effectiveness of the RO treatment system were the 

arsenic and antimony concentrations in treated water. 

Figure 4-15 contains four bar charts showing concentrations of arsenic species, including particulate 

arsenic, As(III), and As(V) at the IN, RO, and AP locations for each of the eight speciation events. Total 

arsenic concentrations in source water ranged from 13.6 to 22.6 μg/L and averaged 18.2 μg/L (Table 4-6). 

Of the soluble fraction, As(V) was the predominating species, with concentrations ranging from 14.3 to 

18.7 μg/L and averaging 16.7 μg/L. Particulate arsenic concentrations were low, with all concentrations 

below the MDL of 0.1 μg/L except for one outlier. Only a trace amount of As(III) existed, ranging from 

<0.1 to 0.5 μg/L and averaging 0.2 μg/L. The concentrations of source water arsenic species measured 

during the performance evaluation study were consistent with those measured on September 13, 2005, 

and during the pilot study from March 7, 2006 to July 11, 2006 (Table 4-1). 

Total arsenic concentrations measured at IN, RO, AP, and RW are plotted on Figures 4-16. The 

concentrations in the permeate ranged from <0.1 to 0.3 μg/L, averaging 0.1 μg/L. Based on the average 

concentration in source water, the RO unit achieved 99% of arsenic removal. After pH adjustment by the 

calcite filter, total arsenic concentration remained unchanged, as expected. Total arsenic concentration in 

reject water averaged 31.9 μg/L, which was 1.75 times the average raw water concentration, as a result of 

the RO membrane separation. 

Antimony. Total antimony concentrations measured at IN, RO, AP, and RW are plotted on Figures 4-17. 

The concentrations in source water ranged from 8.6 to 13.2 μg/L and averaged 10.8 μg/L with the 

majority present in the soluble form. During the performance evaluation, antimony was consistently 

removed by the RO unit to below the MDL of 0.1 μg/L, achieving a 99% removal rate. As expected,

antimony concentrations after pH adjustment did not change. Total antimony concentration in reject 

water averaged 17.7 μg/L, which was 1.64 times the average raw water concentration, as a result of the 

RO membrane separation. 

Iron and Manganese. Total iron concentrations in source water were all below the MDL of 25 μg/L. 

Total manganese concentrations in source water ranged from 0.5 to 6.3 μg/L and averaged 2.2 μg/L with 

the majority present in the soluble form at an average concentration of 1.3 μg/L. Total manganese 

concentrations after the RO unit were less than the MDL of 0.1 μg/L for all samples, except for three 

measurements at 0.11, 0.25, and 0.28 μg/L. As expected, manganese concentrations after pH adjustment 

remained the same. 
30

Table 4-6. Summary of Arsenic, Antimony, Iron, and Manganese Analytical Results

Parameter

Sampling 

Location Unit

Sample 

Count

Concentration Standard 

Minimum Maximum Average Deviation

As (total)

IN μg/L 22 13.6 22.6 18.2 2.2

RO μg/L 22 <0.1 0.3 0.1 0.1

AP μg/L 21(a) <0.1 0.2 0.1 0.0

RW μg/L 17 23.6 38.1 31.9 4.1

As (soluble)

IN μg/L 8 14.4 19.0 16.9 1.7

RO μg/L 8 <0.1 0.3 0.1 0.1

AP μg/L 7 <0.1 <0.1 <0.1 -

As 

(particulate)

IN μg/L 7(b) <0.1 <0.1 <0.1 -

RO μg/L 8 <0.1 <0.1 <0.1 -

AP μg/L 7 <0.1 <.01 <0.1 -

As (III)

IN μg/L 8 <0.1 0.5 0.2 0.2

RO μg/L 8 <0.1 0.1 0.1 0.0

AP μg/L 7 <0.1 <0.1 <0.1 -

As (V)

IN μg/L 8 14.3 18.7 16.7 1.6

RO μg/L 8 <0.1 0.1 0.1 0.0

AP μg/L 7 <0.1 0.1 0.1 0.0

Sb (total)

IN μg/L 22 8.6 13.2 10.8 1.1

RO μg/L 22 <0.1 <0.1 <0.1 -

AP μg/L 20(c) <0.1 <0.1 <0.1 -

RW μg/L 17 14.5 22.0 17.7 -

Sb (soluble)

IN μg/L 7 9.7 13.3 10.9 1.5

RO μg/L 7 <0.1 <0.1 <0.1 -

AP μg/L 7 <0.1 <0.1 <0.1 -

Fe (total)

IN μg/L 20(d) <25 <25 <25 -

RO μg/L 21 <25 <25 <25 -

AP μg/L 21 <25 <25 <25 -

RW μg/L 17 <25 <25 <25 -

Fe (soluble)

IN μg/L 8 <25 <25 <25 -

RO μg/L 7(e) <25 <25 <25 -

AP μg/L 7 <25 <25 <25 -

Mn (total)

IN μg/L 22 0.5 6.3 2.2 1.3

RO μg/L 22 <0.1 0.3 <0.1 -

AP μg/L 21 <0.1 1.2 0.4 0.3

RW μg/L 16(f) 1.0 3.1 2.0 0.8

Mn (soluble)

IN μg/L 7 <0.1 2.4 1.3 1.0

RO μg/L 7(g) <0.1 <0.1 <0.1 -

AP μg/L 7 <0.1 0.5 0.2 0.2

(a) One outlier (i.e., 10.0 μg/L on 09/14/09) omitted.

(b) One outlier (i.e., 1.2 μg/L on 07/29/09) omitted.

(c) One outlier (i.e., 7.6 μg/L on 09/14/09) omitted.

(d) Two outliers (i.e., 231 μg/L on 06/30/09 and 34.4 μg/L on 10/07/09) omitted.

(e) One outlier (i.e., 74 μg/L on 06/30/09) omitted.

(f) One outlier (i.e., <0.1 on 06/30/09) omitted.

(g) One outlier (i.e., 1.7 μg/L on 06/30/09) omitted.

One-half of detection limit used for non-detect samples for calculations.
31 

Table 4-7. Summary of Other Water Quality Parameter Results

Parameter

Sampling 

Location Unit

Sample 

Count

Concentration Standard 

Minimum Maximum Average Deviation

Alkalinity

(as CaCO3) 

IN mg/L 22 186 220 206 10.1

RO mg/L 22 1.6 20.7 5.6 5.3

AP mg/L 20(a) 2.3 25.9 16.6 5.3

RW mg/L 17 308 375 340 16.0

Sulfate

IN mg/L 8 6.09 11.9 9.8 1.9

RO mg/L 8 <0.1 0.2 <0.1 -

AP mg/L 7 <0.1 0.1 <0.1 -

RW mg/L 7 16.3 19.0 17.9 1.0

Nitrate

(as N)

IN mg/L 8 0.1 0.3 0.2 0.1

RO mg/L 8 <0.05 0.1 <0.05 -

AP mg/L 7 <0.05 0.1 <0.05 -

RW mg/L 7 0.1 0.5 0.2 0.1

Silica

(as SiO2) 

IN mg/L 22 10.0 12.9 11.2 0.6

RO mg/L 22 0.3 1.0 0.5 0.2

AP mg/L 21 0.3 0.9 0.5 0.2

RW mg/L 17 16.6 19.8 18.1 0.8

Phosphorous

(as P)

IN μg/L 8 <10.0 <10.0 <10.0 -

RO μg/L 8 <10.0 12.5 <10.0 -

AP μg/L 7 <10.0 <10.0 <10.0 -

RW μg/L 7 <10.0 <10.0 <10.0 -

Turbidity

IN NTU 22 0.2 10.0 2.3 2.4

RO NTU 22 0.1 2.7 1.0 0.7

AP NTU 21 <0.1 9.4 1.2 2.0

RW NTU 17 0.2 3.7 1.2 1.0

TDS

IN mg/L 22 216 286 255 18.3

RO mg/L 22 <2.0 34.0 8.6 7.8

AP mg/L 21 <2.0 52.0 19.3 13.3

RW mg/L 17 354 468 410 31.7

pH

IN S.U. 16 7.8 8.0 7.9 0.1

RO S.U. 16 6.5 7.2 6.9 0.2

AP S.U. 16 6.8 8.9 7.4 0.6

RW S.U. 16 7.9 8.0 8.0 0.0

Temperature

IN °C 7 12.6 25.3 21.6 4.5

RO °C 7 14.0 25.3 21.8 4.0

AP °C 6 14.3 25.5 21.8 4.3

DO

IN mg/L 7 3.6 5.2 4.3 0.6

RO mg/L 7 1.0 4.4 3.1 1.2

AP mg/L 6 1.4 4.6 3.1 1.2

ORP

IN mV 7 310 445 351 43.7

RO mV 7 324 457 373 42.8

AP mV 6 323 457 364 48.3

Total 

Hardness

(as CaCO3) 

IN mg/L 22 183 275 217 23.6

RO mg/L 22 0.6 2.0 1.2 0.5

AP mg/L 20(b) 8.8 30.1 18.3 5.9

RW mg/L 17 300 496 352 43.6

Ca Hardness

(as CaCO3) 

IN mg/L 21 70 150 107 18.1

RO mg/L 21 <0.25 1.4 0.5 0.3

AP mg/L 20 7.9 64.6 19.3 5.6

RW mg/L 17 113 271 172 34.3
Table 4-7. Summary of Other Water Quality Parameter Results (Continued)

32

Parameter

Sampling 

Location Unit

Sample 

Count

Concentration Standard 

Minimum Maximum Average Deviation

Mg 

Hardness

(as CaCO3) 

IN mg/L 21 84.8 128 110 10.2

RO mg/L 21 0.3 1.0 1.0 0.7

AP mg/L 20(c) 0.7 2.6 1.3 0.5

RW mg/L 17 144 225 180 17.8

(a) One outlier (i.e., 341 mg/L on 09/30/09) omitted.

(b) One outlier (i.e., 136 mg/L on 09/14/09) omitted.

(c) One outlier (i.e., 71.3 mg/L on 09/14/09) omitted.

 One-half of detection limit used for non-detect samples for calculations.

TDS. Salt rejection is an important parameter for a RO system. The manufacturer specified a minimum 

rejection rate to be 98% (Table 4-2), which was calculated according to Equation 2: 

 Rejection (%) = 100 * (TDSIN – TDSRO)/TDSIN (2) 

where 

TDSIN = TDS in raw water (mg/L) 

 TDSRO = TDS in permeate (mg/L) 

TDS concentrations ranged from 216 to 286 mg/L and averaged 255 mg/L in raw water, and ranged from 

<2 to 34 mg/L and averaged 8.6 mg/L in the RO permeate. The rejection rates varied from 88 to 99.6% 

and averaged 96.7%. Therefore, the RO system did not consistently achieve the minimal rejection rate of 

98% as specified. TDS concentrations increased slightly after pH adjustment to an average concentration 

of 19.3 mg/L as expected. Figure 4-18 presents TDS concentrations and rejection rates measured during 

the performance evaluation study.

pH and Alkalinity. Source water pH values measured at the IN location ranged from 7.8 to 8.0 and 

averaged 7.9. pH values of the RO permeate water ranged from 6.5 to 7.2 and averaged 6.9. The 

observed pH drop was caused by the reduction in total alkalinity. The RO unit reduced alkalinity values 

from an average of 206 mg/L (as CaCO3) in source water to an average of 5.6 mg/L (as CaCO3) in RO 

permeate, a 97% reduction on average. After pH adjustment, pH values increased to levels ranging from 

6.8 to 8.9 and averaging 7.4. The rise in pH was attributed to an increase in alkalinity, which averaged 

16.6 mg/L (as CaCO3). pH levels and alkalinity concentrations measured during the performance 

evaluation study are presented in Figures 4-19 and 4-20, respectively. 

Other Water Quality Parameters. Total hardness in source water ranged from 183 to 275 mg/L (as 

CaCO3) and averaged 217 mg/L (as CaCO3) consisting of approximately 49% calcium hardness and 51% 

magnesium hardness. The total hardness was initially reduced to an average concentration of 1.2 mg/L 

(as CaCO3) in the RO permeate water. However, as expected, total hardness concentrations were elevated 

after the calcite filter to an average of 18.3 mg/L (as CaCO3). Figure 4-21 presents total hardness 

concentrations measured during the performance evaluation study. Silica concentrations in source water 

ranged from 10.0 to 12.9 mg/L (as SiO2) and averaged 11.2 mg/L (as SiO2), which was above the vendorsuggested maximum value of 10 mg/L in the feed water to the RO unit. Silica concentrations in RO 

permeate water ranged from 0.3 to 1.0 mg/L (as SiO2) and averaged 0.5 mg/L (as SiO2), indicating 

effective removal by the RO unit. Figure 4-22 presents silica concentrations measured during the 

performance evaluation study. Sulfate and nitrate (as N) concentrations were low in source water, i.e., an 

average of 9.8 and 0.2 mg/L, respectively, and were completely removed to below their respective MDLs 

of 1.0 and 0.05 mg/L. 
33 

0

2

4

6

8

10

12

14

16

18

20

04/30/09 05/27/09 06/30/09 07/29/09 09/02/09 09/28/09 10/29/09 12/03/09

As Concentration (ug/L)

Date

Arsenic Speciation at Wellhead (IN)

As (V) As (III) As (particulate)

0

2

4

6

8

10

12

14

04/30/09 05/27/09 06/30/09 07/29/09 09/02/09 09/28/09 10/29/09 12/03/09

As Concentration (ug/L)

Date

Arsenic Speciation after Reverse Osmosis (RO)

As (V) As (III) As (particulate)

10 μg/L MCL

0

2

4

6

8

10

12

14

04/30/09 06/30/09 07/29/09 09/02/09 09/28/09 10/29/09 12/03/09

As Concentration (ug/L)

Date

Arsenic Speciation after pH Adjustment (AP)

As (V) As (III) As (particulate)

10 μg/L MCL

Figure 4-15. Concentrations of Various Arsenic Species at IN, RO, and AP Sampling Locations 
34 

0

5

10

15

20

25

30

35

40

45

As Concentration (ug/L)

Date

At Wellhead (IN) After Reverse Osmosis (RO) After pH Adustment (AP) Residual Wastewater (RW)

10 μg/L MCL

Figure 4-16. Total Arsenic Concentrations at IN, RO, AP, and RW Sampling Locations 

0

5

10

15

20

25

Sb Concentration (ug/L)

Date

At Wellhead (IN) After Reverse Osmosis (RO) After pH Adjustment (AP) Residual Wastewater (RW)

6 μg/L MCL

Figure 4-17. Total Antimony Concentrations at IN, RO, AP, and RW Sampling Locations 
35 

50%

55%

60%

65%

70%

75%

80%

85%

90%

95%

100%

0

100

200

300

400

500

600

700

800

Rejection (%)

TDS Concentration (mg/L)

Date

At Wellhead (IN) After Reverse Osmosis (RO) After pH Adjustment (AP) Residual Wastewater Rejection (%)

Figure 4-18. TDS Concentrations at IN, RO, AP, and RW Sampling Locations 

6

7

8

9

pH Level (S.U.)

Date

At Wellhead (IN) After Reverse Osmosis (RO) After pH Adjustment (AP) Residual Wastewater

Figure 4-19. pH Levels at IN, RO, AP, and RW Sampling Locations 
36 

0

50

100

150

200

250

300

350

400

Alkalinity Concentration (mg/L)

Date

At Wellhead (IN) After Reverse Osmosis (RO) After pH Adjustment (AP) Residual Wastewater (RW)

Figure 4-20. Alkalinity Concentrations at IN, RO, AP, and RW Sampling Locations 

0

100

200

300

400

500

600

Total Hardness Concentration (mg/L)

Date

At Wellhead (IN) After Reverse Osmosis (RO) After pH Adjustment (AP) Residual Wastewater (RW)

Figure 4-21. Total Hardness Concentrations at IN, RO, AP, and RW Sampling Locations 
37 

0

5

10

15

20

25

SiO2 Concentration (mg/L)

Date

At Wellhead (IN) After Reverse Osmosis (RO) After pH Adjustment (AP) Residual Wastewater (RW)

Figure 4-22. Silica Concentration at IN, RO, AP, and RW Sampling Locations 

4.5.2 Residual Water Sampling. RW samples were collected from the reject water discharge line 

beginning May 27, 2009, for a total of 16 sampling events. The analytical results from the residual 

sampling are summarized in Tables 4-6 and 4-7 and presented in Figures 4-16 through 4-22. As 

expected, residual water contained higher concentrations of arsenic, antimony, TDS, alkalinity, total 

hardness, silica (as SiO2), and sulfate at 31.9 μg/L, 17.7 μg/L, 410 mg/L, 340 mg/L, 352 mg/L, 18.1 

mg/L, and 17.9 mg/L, respectively, on average. Manganese and nitrate concentrations were similar to 

source water concentrations averaging 2.0 μg/L and 0.2 mg/L (as N), respectively. 

Calculations of mass balance for total arsenic and antimony were performed using the average 

concentrations at IN, RO, and RW and the volume of each stream according to Equation 3 as follows: 

CfVf = CpVp + CrVr (3) 

where 

 Cf = feed water total arsenic or antimony concentration

 Vf = volume of feed water 

 Cp = permeate water total arsenic or antimony concentration

 Vp = volume of permeate water

 Cr = reject water total arsenic or antimony concentration

 Vr = volume of reject water.

Results of the mass balance calculations are presented in Table 4-8. During the performance evaluation, 

mass balance data in terms of the mass recovered in the permeate and reject water against the mass in 

feed water were 107% and 100% for total arsenic and antimony, respectively. 
38 

Table 4-8. Mass Balance Calculations

Analyte

Feed Permeate Reject

CpVp + CrVr CfVf

Mass 

Cf Vf Cp Vp Cr Vr Balance

μg/L gal μg/L gal μg/L gal mg mg %

Arsenic 18.2 177,390(a) 0.1 69,780 31.9 107,610 13,019 12,220 107

Antimony 10.8 177,390(a) 0.05(b) 69,780 17.7 107,610 7,222 7,251 100

(a) Calculated based on permeate and residual wastewater production.

(b) All antimony concentrations were below MDL of 0.1 μg/L. Thus, one-half the detection limit was used for 

calculation.

4.5.3 Distribution System Water Sampling. Following the startup of the RO treatment system, 

distribution system “first draw” samples were collected from a cold water tap in the kitchen on a monthly 

basis from May through November 2009. Table 4-9 presents results of the distribution sampling. 

Table 4-9. Distribution System Sampling Results

No. of 

Sampling 

Events

Location DS1

Kitchen Sink

Sample Type LCR

Flushed/1st Draw 1st Draw

Sampling Date

Stagnation Time pHAlkalinityAsFeMnPbCuSb

No. Date hrs S.U. mg/L μg/L μg/L μg/L μg/L μg/L μg/L

1 05/20/09 12.0 6.8 10.1 0.2 <25 0.1 1.0 211 0.1

2 06/17/09 14.0 8.9 22.1 0.3 <25 0.2 0.8 163 0.1

3 07/09/09 NA 7.0 13.9 0.2 <25 0.6 1.4 117 0.4

4 08/27/09 15.0 8.5 58.3 0.5 48.6 0.3 1.2 135 0.3

5 09/08/09 12.0 8.9 22.9 <0.1 <25 <0.1 0.7 147 0.2

6 09/29/09 13.0 9.2 24.7 0.2 <25 1.5 1.9 190 0.1

7 10/27/09 13.5 9.1 19.1 <0.1 <25 0.4 0.5 144 0.1

8 11/19/09 12.0 9.2 25.4 2.7 166 0.3 <0.1 57.6 <0.1

Average 13.1 8.4 24.6 0.5 36 0.4 1.0 146 0.2

NA = not available

Alkalinity concentrations in the distribution “first draw” samples ranged from 10.1 to 58.3 mg/L, and 

averaged 24.6 mg/L, which was slighly higher than the average concentration in the pH-adjusted water 

(i.e., 16.6 mg/L). The slightly higher alkalinity concentration may have partially contributed to the 

elevated pH level in the distribution system which ranged from 6.8 to 9.2, and averaged 8.4, in 

comparison with that of the pH-adjusted water (i.e., ranging from 6.8 to 8.9 and averaging 7.4). Since the 

distribution sample pH was measured in an off-site laboratory, whereas the treatment sample pH was 

measured on site, it is possible that the pH measurement might have also contributed to the one pH unit 

difference (pH 7.4 vs. 8.4) between the distribution water and the pH-adjusted water. 
39 

Arsenic and antimony concentrations in the distribution “first draw” samples were similar to those in the 

system effluent. They were both in the sub-parts per billion (ppb) levels (except for one time at 2.7 μg/L

of arsenic). 

Lead concentrations in the distribution system ranged from <0.01 to 1.9 μg/L and averaged 1.0 μg/L. All 

of the lead values were, therefore, below the action level of 15 μg/L. Copper concentrations ranged 

between 57.6 to 211 μg/L and averaged 146 μg/L, with no samples exceeding the 1,300 μg/L action level. 

Therefore, the RO treatment system did not have any adverse effects on the water quality in the 

distribution system during the performance evaluation study. 

4.6 System Cost

The cost of the treatment system was evaluated based on the capital cost per gpm (or gpd) of the design 

capacity and the O&M cost per 1,000 gal of water treated. This required tracking of the capital cost for 

the equipment, site engineering, and installation and the O&M cost for chemical supply, electricity

consumption, and labor. 

4.6.1 Capital Cost. The total capital investment for the dual plumbing and EPRO-1,200 RO unit 

was $20,542 (Table 4-10). The dual plumbing installation cost was $8,600 (or 42% of the total capital 

investment), which included $2,650 for the plumbing materials and $5,950 for the labor to convert the 

existing plumbing into a duplex distribution system. The cost of the EPRO-1,200 RO treatment system 

was $11,942, including $8,471 for equipment and parts, $300 for shipping, and $3,171 for installation. 

Table 4-10. Capital Investment Cost for CES at Carmel, ME

Description Quantity Cost

% of Capital 

Investment 

Cost

Dual Plumbing

PEX Piping and Materials 1 $2,650 –

Vendor Labor 1 $5,950 –

Subtotal – $8,600 42%

EPRO-1,200 RO System

Crane Environmental EPRO-1,200 RO Unit

Calcite Filter (1.25 ft3), two 300-gal 

Atmospheric Storage Tanks w/Float Controls

1 $6,227 – 

230 V Solution Feed Pump 1 $429 –

Re-pressurization System 1 $946 –

Flow Totalizer 1 $149 –

Pump Discharge Pressure Gauge 1 $80 –

Process Valves and Piping 1 $640 –

Shipping 1 $300 –

Vendor Labor – $3,171 –

Subtotal – $11,942 58%

Total Capital Investment – $20,542 100%

The capital cost of $20,542 was normalized to the system’s rated capacity of 1,200 gpd of permeate, 

which results in $17.12/gpd of design capacity. The capital cost also was converted to an annualized cost 

of $1,939/yr using a capital recovery factor (CRF) of 0.09439 based on a 7% interest rate and a 20-year 

return period. Assuming that the system operated 365 days annually at the design capacity of 1,200 gpd, 
40 

the system would produce 438,000 gal of permeate water. The unit capital cost would be $4.43/1,000 gal. 

During the 10-month demonstration study, the system produced 96,576 gal of permeate. The annual 

production was estimated to be 108,912 gal (see Table 4-11); at this reduced rate of production, the unit 

capital cost was increased to $17.80/1,000 gal of water treated. 

4.6.2 Operation and Maintenance Cost. The O&M cost included the cost incurred by system 

repairs, electricity, and labor, as summarized in Table 4-11. As described in Section 4.4.3, the main 

operational issue that occurred during the study period was replacement of a RO pump and motor 

assembly in November 2009. The equipment was covered under the manufacturer’s warranty, but the 

cost of labor to install the replacement parts was not covered by the warranty. The cost of labor to install 

the replacement parts was $321, which included $96 for diagnostics, $160 for labor, and $65 for shipping. 

This cost was normalized to the volume of permeate water produced between February 4 and December 

15, 2009 during the demonstration study. Therefore, the cost per 1,000 gal of permeate water was 

$3.32/1,000 gal. 

The school did not have a separate electrical meter for the EPRO-1,200 RO system. Based on the total 

operational hours and the rated horsepower of the RO pump and the re-pressurization pump, the annual 

electricity consumption was estimated to be 5,078 kWh. Applying a local electricity rate of 0.074/kWh, 

the annual electrical cost associated with the system operation was estimated to be $376, or $3.45/1,000 

gal of permeate water. 

Table 4-11. Operation and Maintenance Cost for EPRO-1200 RO Unit 

Treatment System

Cost Category Value Assumptions

Permeate Water Volume (gal) 96,576 February 4 through December 15, 2009 (2,012 

hr of operation, 0.8 gpm)

Annual Permeate Production 

(gal/yr)

108,912 January 1 through December 31, 2009

(assuming 2,269 hr of operation, 0.8 gpm)

RO Pump and Motor Assembly Replacement

Diagnostics $96 –

Labor $160 –

Shipping $65 –

Subtotal $321 –

Cost ($/1,000 gal) $3.32 Permeate produced = 96,576 gal 

Electricity

Annual Electricity 

Consumption (kWh/yr)

5,078

1, 1⁄2-hp RO pump, 1 1-hp re-pressurization 

pump, 50% efficiency, 2,269 hr of annual 

operation

Annual Electricity Cost 

(kWh/yr) $376

$0.074/kWh

Electricity Cost ($/1,000 gal) $3.45 Annual production of 108,912 gal

Labor

Average Weekly Labor (hr) 0.8 10 min/day, 5 days a week

Annual Labor (hr/yr) 41.6 52 weeks a year

Annual Labor Cost ($/yr) $666 Labor rate = $16/hr

Labor Cost ($/1,000 gal) $6.12 Annual production of 108,912 gal

Total O&M Cost/1,000 gal $12.89 Total O&M cost = $3.32+$3.45 + $6.12
41 

Under normal operating conditions, routine labor activities to operate and maintain the system consumed 

10 min per day, or 50 min per week. With a labor rate of $16/hr, the estimated annual labor cost was 

$666, or $6.12/1,000 gal of permeate water produced. 

In summary, the total O&M cost was estimated to be $12.89/1,000 gal of permeate water produced based 

on the cost data collected during the performance evaluation study. 
42

5.0 REFERENCES

Battelle. 2007. Quality Assurance Project Plan for Evaluation of Arsenic Removal Technology (QAPP 

ID 355-Q-6-0). Prepared under Contract No.EP-C-05-057. Task Order No. 0019, for U.S. 

Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati, 

OH.

Battelle. 2009. System Performance Evaluation Study Plan: U.S. EPA Demonstration of Arsenic 

Removal Technology Round 2a at Carmel Elementary School in Carmel, Maine. Prepared under 

Contract No. EP-C-05-057, Task Order No. 0019, for U.S. Environmental Protection Agency, 

National Risk Management Research Laboratory, Cincinnati, OH. 

Chen, A.S.C., L. Wang, J.L. Oxenham, and W.E. Condit. 2004. Capital Costs of Arsenic Removal 

Technologies: U.S. EPA Arsenic Removal Technology Demonstration Program Round 1. 

EPA/600/R-04/201. U.S. Environmental Protection Agency, National Risk Management 

Research Laboratory, Cincinnati, OH. 

Edwards, M., S. Patel, L. McNeill, H. Chen, M. Frey, A.D. Eaton, R.C. Antweiler, and H.E. Taylor. 1998. 

“Considerations in As Analysis and Speciation.” JAWWA, 90(3): 103-113. 

EPA. 2001. National Primary Drinking Water Regulations: Arsenic and Clarifications to Compliance 

and New Source Contaminants Monitoring. Federal Register, 40 CFR Parts 9, 141, and 142. 

EPA. 2002. Lead and Copper Monitoring and Reporting Guidance for Public Water Systems. 

EPA/816/R-02/009. U.S. Environmental Protection Agency, Office of Water, Washington, D.C. 

EPA. 2003. Minor Clarification of the National Primary Drinking Water Regulation for Arsenic. 

Federal Register, 40 CFR Part 141. 

Wang, L., W.E. Condit, and A.S.C. Chen. 2004. Technology Selection and System Design: U.S. EPA 

Arsenic Removal Technology Demonstration Program Round 1. EPA/600/R-05/001. U.S. 

Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati, 

OH. 
APPENDIX A

OPERATIONAL DATA
A-1

Table A-1. EPA Arsenic Demonstration Project at Carmel Elementary School at Carmel, ME -- Daily System Operation Log Sheet

Wk Date Time

NonPotable 

Water Pre-Filter RO Unit

Re-pressurization 

System

FT-1

Inlet 

Pressure

Feed 

Pressure

Hour 

Meter

Concentrate Permeate 

Pressure Flowrate FT-2 Flowrate FT-3 Recovery Pressure FT-4

Pump 

Discharge 

Pressure

gal psig psig hrs psig gpm gal gpm gal psi % psig gal

1 04/16/09 11:30 NA 32 30 NA 160 1.3 NA 1.2 NA NA NA 32 212,725

04/17/09 9:40 NA 32 30 NA NA 1.3 NA 1.4 NA NA NA 32 212,890

2 

04/21/09 8:30 NA 32 32 NA 160 1.3 181,840 1.3 NA NA NA 45 212,940

04/22/09 8:30 NA 32 32 NA 160 1.2 181,890 0.8 NA NA NA 45 212,990

04/23/09 8:00 NA 32 32 NA 160 1.3 181,920 0.8 NA NA NA 40 213,030

04/24/09 8:00 NA 32 32 NA 150 1.2 NA 0.8 NA NA NA 32 NA

3 

04/27/09 8:00 NA 35 32 NA 140 1.2 182,420 0.8 400 NA 44 35 213,160

04/28/09 8:00 NA 32 32 NA 140 1.2 183,310 0.8 940 NA 38 30 213,670

04/29/09 8:00 2,957,300 35 32 NA 145 1.2 184,250 0.8 1,490 NA 37 45 214,210

04/30/09 8:00 2,958,500 40 38 NA 145 1.2 185,240 0.8 2,170 NA 41 40 214,790

05/01/09 8:00 2,959,700 34 34 NA 140 1.2 186,250 0.8 2,670 NA 33 35 215,340

4 

05/04/09 8:00 2,960,800 34 34 NA 140 1.2 187,250 0.8 3,260 NA 37 35 215,900

05/05/09(a) 8:00 2,962,000 40 40 NA 140 1.2 188,220 0.8 3,840 NA 37 40 216,470

05/06/09 8:00 2,963,100 35 35 NA 140 1.2 189,580 0.8 4,640 NA 37 35 217,000

05/07/09 8:00 2,964,100 35 35 NA 140 1.2 190,710 0.8 5,310 NA 37 40 217,630

5 

05/11/09 8:00 2,966,500 40 38 NA 140 1.2 192,990 0.8 6,680 NA 38 45 218,820

05/12/09 8:00 2,967,600 40 35 NA 140 1.2 193,860 0.8 7,210 NA 38 40 219,330

05/13/09 8:00 2,968,500 40 40 NA 140 1.2 194,890 0.8 7,820 NA 37 35 219,910

05/14/09 8:00 2,969,900 40 40 NA 140 1.2 196,000 0.8 8,530 NA 39 35 220,620

05/15/09 8:00 2,970,900 35 35 NA 140 1.2 196,960 0.8 9,070 NA 36 45 221,120

6 

05/18/09 8:00 2,972,100 35 35 NA 140 1.2 198,470 0.8 10,000 NA 38 35 221,940

05/19/09(b) 8:00 2,973,000 35 35 NA 140 1.2 199,450 0.8 10,600 135 38 40 222,490

05/20/09 8:00 2,974,100 35 35 NA 140 1.2 200,390 0.8 11,170 135 38 45 223,040

05/21/09 8:00 2,975,100 35 35 NA 140 1.2 201,610 0.8 11,910 135 38 40 223,660

05/22/09 8:00 2,976,200 42 36 NA 140 1.2 202,590 0.8 12,510 135 38 44 224,240

7 

05/26/09 8:00 2,977,200 35 35 NA 140 1.2 203,450 0.8 13,040 140 38 40 224,700

05/27/09 8:00 2,978,200 35 35 NA 140 1.2 204,630 0.8 13,770 140 38 40 225,380

05/28/09 8:00 2,979,300 30 30 NA 140 1.2 205,740 0.8 14,440 148 38 45 226,000

05/29/09 8:00 2,980,800 35 35 NA 140 1.2 206,770 0.8 15,070 140 38 40 226,620

8 

06/01/09 8:00 2,982,200 35 35 NA 140 1.2 207,740 0.8 15,670 145 38 40 227,140

06/02/09 8:00 2,983,300 35 35 NA 140 1.2 208,680 0.8 16,250 145 38 40 227,700

06/03/09 8:00 2,984,700 40 40 NA 140 1.2 209,860 0.8 16,980 145 38 40 228,380
Table A-1. EPA Arsenic Demonstration Project at Carmel Elementary School at Carmel, ME -- Daily System Operation 

Log Sheet (Continued)

A-2

Wk Date Time

NonPotable 

Water Pre-Filter RO Unit

Re-pressurization 

System

FT-1

Inlet 

Pressure

Feed 

Pressure

Hour 

Meter

Concentrate Permeate 

Pressure Flowrate FT-2 Flowrate FT-3 Recovery Pressure FT-4

Pump 

Discharge 

Pressure

gal psig psig hrs psig gpm gal gpm gal psi % psig gal

06/04/09 8:00 2,985,700 40 40 NA 140 1.2 210,660 0.8 17,480 145 38 40 228,888

06/05/09 8:00 2,986,900 35 35 NA 140 1.2 212,050 0.8 18,340 145 38 40 229,750

9 

06/08/09 8:00 2,988,000 35 35 NA 140 1.2 212,940 0.8 18,920 140 39 40 230,290

06/09/09 8:00 2,989,100 35 35 NA 140 1.2 214,000 0.8 19,570 140 38 35 230,900

06/10/09 8:00 2,990,200 40 40 NA 140 1.2 214,980 0.8 20,180 140 38 40 231,490

06/11/09 8:00 2,991,500 35 35 NA 140 1.2 215,960 0.8 20,800 140 39 35 232,070

06/12/09 8:00 2,992,600 35 35 NA 140 1.2 217,010 0.8 21,470 140 39 35 232,700

10

06/15/09 8:30 2,993,700 40 40 NA 140 1.2 217,890 0.8 22,030 140 39 45 233,250

06/16/09 8:30 2,994,700 35 35 NA 140 1.2 218,700 0.8 22,590 140 41 35 233,780

06/17/09 8:30 2,995,200 40 40 NA 140 1.2 219,130 0.8 22,830 140 36 45 233,940

06/18/09 8:30 2,995,200 40 40 NA 140 1.2 219,260 0.8 22,910 140 38 40 233,960

06/19/09 8:30 2,995,300 40 40 NA 140 1.2 219,390 0.8 23,010 140 43 40 233,980

11

06/22/09 8:00 2,995,400 40 40 NA 135 1.2 219,570 0.8 23,130 140 40 35 234,000

06/23/09 8:00 2,995,500 40 40 NA 140 1.2 219,900 0.8 23,350 140 40 35 234,060

06/24/09 8:00 2,995,500 35 35 NA 140 1.2 219,990 0.8 23,410 140 40 35 234,090

06/25/09 8:00 2,995,600 40 40 NA 140 1.2 220,160 0.8 23,600 140 NA 40 234,130

12

06/29/09 8:30 2,995,600 40 40 NA 140 1.2 220,420 0.8 23,760 140 38 40 234,160

06/30/09 8:30 2,995,700 35 35 NA 140 1.2 220,810 0.8 23,990 140 37 40 234,370

07/01/09 8:30 2,995,900 35 35 NA 140 1.2 220,970 0.8 24,090 140 38 40 234,460

07/02/09 8:30 2,996,100 40 40 NA 140 1.2 221,190 0.8 24,240 140 41 40 234,550

13

07/07/09 8:30 2,996,400 35 35 36.3 140 1.2 221,680 0.8 24,590 140 42 40 234,640

07/08/09 8:30 2,996,600 35 35 38.1 140 1.2 221,800 0.8 24,670 140 40 40 234,730

07/09/09 8:30 2,996,700 35 35 41.5 140 1.2 222,010 0.8 24,810 140 40 40 234,790

14

07/13/09 8:30 2,996,800 35 35 42.3 140 1.2 222,090 0.8 24,860 140 38 35 234,850

07/14/09 8:30 2,996,900 35 35 44.1 135 1.2 222,210 0.8 24,960 140 45 35 234,930 

07/15/09 8:30 2,997,100 35 35 47.6 135 1.2 222,390 0.8 25,090 140 42 35 235,010

07/16/09 8:30 2,997,300 35 35 48.8 135 1.2 222,470 0.8 25,140 140 38 35 235,090

15

07/20/09 7:00 2,997,300 38 37 50.7 115 1.2 222,580 0.8 25,220 120 42 40 235,150

07/21/09 6:50 2,997,400 30 28 52.1 110 1.2 222,670 0.8 25,280 125 40 34 235,200

07/22/09 7:20 2,997,500 37 36 53.9 120 1.2 222,780 0.8 25,370 120 45 33 235,260

07/23/09 7:15 2,997,600 30 28 56.8 115 1.2 222,960 0.8 25,490 120 40 37 235,360

16

07/27/09 8:00 2,997,700 38 38 60.7 130 1.2 223,200 0.8 25,670 140 43 35 235,490

07/28/09 8:00 2,997,800 35 35 63.7 135 1.2 223,380 0.8 25,800 140 42 35 235,580

07/29/09 8:00 2,997,900 40 40 65 115 1.2 223,460 0.8 25,860 130 43 42 235,630
Table A-1. EPA Arsenic Demonstration Project at Carmel Elementary School at Carmel, ME -- Daily System Operation 

Log Sheet (Continued)

A-3

Wk Date Time

NonPotable 

Water Pre-Filter RO Unit

Re-pressurization 

System

FT-1

Inlet 

Pressure

Feed 

Pressure

Hour 

Meter

Concentrate Permeate 

Pressure Flowrate FT-2 Flowrate FT-3 Recovery Pressure FT-4

Pump 

Discharge 

Pressure

gal psig psig hrs psig gpm gal gpm gal psi % psig gal

07/30/09 8:00 2,998,100 40 40 69.4 135 1.2 223,780 0.8 26,070 140 40 40 235,740

17

08/03/09 8:30 2,998,200 40 40 72.5 140 1.2 223,940 0.8 26,190 140 43 35 235,840

08/04/09 8:30 2,998,300 35 35 74.4 135 1.2 224,030 0.8 26,260 135 44 35 235,910

08/05/09 8:30 2,998,400 35 35 76.2 135 1.2 224,160 0.8 26,340 135 38 35 235,960

08/06/09 8:30 2,998,500 35 35 77.5 130 1.2 224,250 0.8 26,400 135 40 35 236,030

18

08/10/09 8:30 2,998,600 40 40 81.5 135 1.2 224,490 0.8 26,580 140 43 35 236,180

08/11/09 8:30 2,998,700 40 40 84.0 135 1.2 224,630 0.8 26,680 140 42 35 236,280

08/12/09 8:30 2,998,800 40 40 86.3 135 1.2 224,780 0.8 26,790 140 42 35 236,360

08/13/09 8:30 2,998,800 40 40 86.3 135 1.2 224,780 0.8 26,790 135 NA 35 236,370

19

08/17/09 8:30 2,998,900 40 40 88.8 135 1.2 224,920 0.8 26,900 140 44 35 236,430

08/18/09 8:30 2,999,000 40 38 89.3 135 1.2 224,960 0.8 26,930 140 43 35 236,490

08/19/09 8:30 2,999,400 40 40 93.8 135 1.2 225,230 0.8 27,120 140 41 35 236,680

08/20/09 8:30 2,999,600 40 40 96.5 135 1.2 225,390 0.8 27,230 140 41 35 236,800

20

08/24/09 8:30 2,999,700 40 40 101.7 135 1.2 225,700 0.8 27,460 140 43 35 236,970

08/25/09 8:30 2,999,800 40 40 110.4 135 1.2 226,230 0.8 27,830 140 41 35 237,300

08/26/09 8:30 2,999,900 40 40 111.4 135 1.2 226,590 0.8 28,090 140 42 35 237,560

08/27/09 8:30 3,000,100 40 40 112.4 135 1.2 227,100 0.8 28,430 140 40 35 237,920

21

09/01/09 8:00 3,000,700 35 35 130.6 130 1.2 227,460 0.8 28,700 140 43 35 238,260

09/02/09 8:00 3,001,800 35 35 144.9 130 1.2 228,360 0.8 29,300 140 40 40 238,840

09/03/09 8:00 3,002,700 35 35 156.0 130 1.2 229,060 0.8 29,760 140 40 40 239,260

09/04/09 8:00 3,003,600 35 35 179.0 135 1.2 229,820 0.8 30,260 140 40 40 239,780

22

09/08/09 8:00 3,004,500 35 35 190.9 135 1.2 231,250 0.8 31,240 140 41 40 240,690

09/09/09 8:00 3,005,300 40 40 212.6 135 1.2 232,610 0.8 32,160 140 40 40 241,580

09/10/09 8:00 3,006,400 35 35 220.5 135 1.2 233,490 0.8 32,740 140 40 40 242,190

09/11/09 8:00 3,007,400 35 35 240.0 135 1.2 234,340 0.8 33,310 140 40 40 242,760

23

09/14/09 8:00 3,008,400 35 35 254.6 130 1.2 235,270 0.8 33,930 140 40 35 243,260

09/15/09 8:00 3,009,300 40 40 268.9 130 1.2 236,170 0.8 34,530 140 40 35 243,850

09/16/09 8:00 3,010,300 40 40 286.3 130 1.2 237,270 0.8 35,260 140 40 40 244,580

09/17/09 8:00 3,011,300 35 35 297.4 130 1.2 237,980 0.8 35,760 140 41 40 245,030

09/18/09 8:00 3,012,300 35 35 310.0 130 1.2 238,790 0.8 36,280 140 39 40 245,540

24

09/21/09 8:30 3,013,200 35 35 325.0 140 1.2 239,770 0.8 36,910 140 39 35 246,210

09/22/09 8:30 3,014,100 40 40 341.1 140 1.2 240,750 0.8 37,560 140 40 35 246,840

09/23/09 8:30 3,015,100 40 40 354.1 135 1.2 241,580 0.8 38,110 140 40 35 247,370

09/24/09 8:30 3,015,800 40 40 363.7 135 1.2 242,190 0.8 38,510 140 40 35 247,770
Table A-1. EPA Arsenic Demonstration Project at Carmel Elementary School at Carmel, ME -- Daily System Operation 

Log Sheet (Continued)

A-4

Wk Date Time

NonPotable 

Water Pre-Filter RO Unit

Re-pressurization 

System

FT-1

Inlet 

Pressure

Feed 

Pressure

Hour 

Meter

Concentrate Permeate 

Pressure Flowrate FT-2 Flowrate FT-3 Recovery Pressure FT-4

Pump 

Discharge 

Pressure

gal psig psig hrs psig gpm gal gpm gal psi % psig gal

09/25/09 8:30 3,016,711 40 40 379.1 135 1.2 243,210 0.8 39,190 140 40 40 248,440

25

09/28/09 8:30 3,017,600 40 40 392.0 130 1.2 243,980 0.8 39,710 140 40 40 248,930

09/29/09 8:30 3,018,600 35 35 404.8 130 1.2 244,790 0.8 40,250 140 40 40 249,470

09/30/09 8:30 3,019,500 35 35 423.3 130 1.2 245,960 0.8 41,010 140 39 40 250,210

10/01/09 8:30 3,020,400 40 40 434.4 130 1.2 246,670 0.8 41,500 140 41 40 250,710

10/02/09 8:30 3,021,300 40 40 445.9 130 1.2 247,400 0.8 41,980 140 40 40 251,180

26

10/06/09 8:00 3,023,200 40 40 474.0 130 1.2 249,170 0.8 43,170 140 40 40 252,320

10/07/09 8:00 3,024,200 35 35 489.1 130 1.2 250,170 0.8 43,830 140 40 35 252,990

10/08/09 8:00 3,025,200 35 35 505.8 130 1.2 251,190 0.8 44,510 140 40 35 253,640

10/09/09 8:00 3,025,900 35 35 515.2 130 1.2 251,780 0.8 44,900 140 40 40 254,040

27

10/13/09 8:00 3,026,000 35 35 525.3 140 1.2 252,390 0.8 45,340 140 42 40 254,260

10/14/09 8:00 3,026,900 35 35 540.0 140 1.2 253,330 0.8 45,960 140 40 40 254,880

10/15/09 8:00 3,027,700 35 35 554.6 140 1.2 254,260 0.8 46,560 140 39 40 255,440

28 10/19/09 8:00 3,029,800 35 35 580.9 140 1.2 255,940 0.8 47,670 140 40 35 256,510

10/20/09 8:00 3,030,700 35 35 592.5 140 1.2 256,690 0.8 48,170 140 40 35 256,980

29

10/26/09 8:30 3,034,600 35 35 640.3 140 1.2 259,850 0.8 50,270 140 40 40 259,020

10/27/09 8:30 3,035,500 35 35 653.5 140 1.2 260,730 0.8 50,850 140 40 40 259,580

10/28/09 8:30 3,036,400 35 35 667.5 140 1.2 261,660 0.8 51,460 140 40 35 260,160

10/29/09 8:30 3,037,400 35 35 680.0 140 1.2 262,490 0.8 52,010 140 40 40 260,720

10/30/09 8:30 3,038,300 35 35 690.2 140 1.2 263,230 0.8 52,520 140 41 35 261,190

30

11/02/09 8:30 3,039,300 35 32 699.9 170 1.2 263,930 0.8 53,000 180 41 32 261,670

11/03/09 8:00 3,040,100 40 36 709.6 170 1.2 264,650 0.8 53,480 180 40 35 262,140

11/04/09 8:15 3,041,100 30 30 723.2 170 1.2 265,670 0.8 54,150 180 40 45 262,800

11/05/09 8:00 3,042,100 40 40 731.7 175 1.2 266,300 0.8 54,580 185 41 32 263,230

11/06/09 8:00 3,043,200 34 32 743.6 175 1.2 267,180 0.8 55,160 185 40 45 263,750

31

11/09/09 8:00 3,043,600 40 40 744.6 175 1.2 267,480 0.8 55,320 180 35 45 263,900

11/10/09 8:00 3,044,100 40 40 755.9 175 1.2 268,100 0.8 55,780 180 43 45 264,320

11/12/09 8:30 3,045,100 38 36 767.4 175 1.2 268,960 0.8 56,350 180 40 40 264,880

32

11/16/09 8:00 3,047,100 40 40 789.8 155 1.2 270,630 0.8 57,450 160 40 40 265,900

11/17/09 8:00 3,048,100 35 35 800.6 155 1.2 271,430 0.8 57,980 170 40 35 266,420

11/18/09 8:00 3,049,200 35 35 812.1 160 1.2 272,280 0.8 58,530 170 39 35 266,950

11/19/09 8:00 3,050,100 35 35 825.1 155 1.2 273,250 0.8 59,160 165 39 40 267,560

11/20/09 8:00 3,051,100 40 40 834.1 155 1.2 273,970 0.8 59,620 160 39 35 268,030

33 11/23/09 8:00 3,054,000 40 40 876.6 160 1.2 277,090 0.8 61,640 165 39 40 269,850
Table A-1. EPA Arsenic Demonstration Project at Carmel Elementary School at Carmel, ME -- Daily System Operation 

Log Sheet (Continued)

A-5

Wk Date Time

NonPotable 

Water Pre-Filter RO Unit

Re-pressurization 

System

FT-1

Inlet 

Pressure

Feed 

Pressure

Hour 

Meter

Concentrate Permeate 

Pressure Flowrate FT-2 Flowrate FT-3 Recovery Pressure FT-4

Pump 

Discharge 

Pressure

gal psig psig hrs psig gpm gal gpm gal psi % psig gal

11/24/09 8:00 3,054,800 40 40 886.3 160 1.2 277,810 0.8 62,100 165 39 40 270,310

11/25/09 8:00 3,055,900 40 40 897.6 160 1.2 278,650 0.8 62,640 165 39 40 270,810

11/26/09 8:00 3,056,900 40 40 908.1 160 1.2 279,430 0.8 63,140 165 39 40 271,280

11/27/09 8:00 3,057,800 40 40 918.3 160 1.2 280,190 0.8 63,640 165 40 35 271,780

35

12/07/09 8:00 3,058,900 40 40 931.4 155 1.2 281,170 0.8 64,290 165 40 40 272,320

12/08/09 8:00 3,059,800 40 40 943.6 150 1.2 282,070 0.8 64,890 155 40 35 272,900

12/10/09 8:00 3,061,000 40 40 958.3 155 1.2 283,160 0.8 65,620 155 40 40 273,590

12/11/09 8:00 3,061,900 40 40 969.2 155 1.2 283,970 0.8 66,160 155 40 35 274,120

36

12/14/09 8:00 3,063,100 40 40 979.3 150 1.2 284,720 0.8 66,650 165 40 40 274,580

12/15/09 8:00 3,064,000 40 40 990.0 150 1.2 285,510 0.8 67,180 150 40 40 275,100

(a) Norlen's Water installed second 300-gal atmospheric storage tank.

(b) Norlen's Water installed pump discharge pressure gauge.

NA = not available
APPENDIX B 

ANALYTICAL DATA
B-1

Table B-1. Analytical Results from Long-Term Sampling at Carmel, ME

Sampling Date 04/16/09 04/30/09 05/12/09 05/20/09 05/27/09

Sampling Location

Parameter Unit IN RO AP IN RO AP IN RO AP IN RO AP IN RO AP RW

Alkalinity (as CaCO3) mg/

L 

198 2.3 20.7 209 1.6 15.4 217 2.5 19.9 220 2.7 16.4 215 2.4 NA(a) 337

- - - - - - - - - - - - - - - - 

Sulfate mg/

L - - - 11.9 <0.1 <0.1 - - - - - - 6.1 <0.1 NA(a) 17.7

Nitrate (as N) mg/

L - - - 0.1 <0.05 <0.05 - - - - - - 0.2 <0.05 NA(a) 0.2

Total P (as P) μg/L - - - <10 <10 <10 - - - - - - <10 <10 NA(a) <10

Silica (as SiO2) mg/

L 

11.8 0.4 0.3 12.9 0.6 0.3 11.5 0.5 0.4 11.7 0.5 0.4 11.0 0.3 NA(a) 17.5

- - - - - - - - - - - - - - - -

Turbidity NTU 0.8 0.9 9.4 2.9 1.2 1.6 2.2 0.9 1.6 2.5 1.1 0.7 10.0 2.7 NA(a) 0.7

- - - - - - - - - - - - - - - - 

TDS mg/

L 

270 2.0 35.0 286 8.0 52.0 268 4.0 16.0 276 16.0 26.0 258 8.0 NA(a) 416

- - - - - - - - - - - - - - - - 

pH S.U. NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA - 

NA NA NA 8.2 6.9 7.7 NA NA NA NA NA NA NA NA NA - 

Temperature °C NA NA NA 12.6 14.0 14.3 NA NA NA NA NA NA NA NA NA - 

DO mg/

L NA NA NA 5.2 1.0 1.4 NA NA NA NA NA NA NA NA NA - 

ORP mV NA NA NA 445 457 457 NA NA NA NA NA NA NA NA NA - 

Total Hardness (as CaCO3) mg/

L 

218 0.6 15.0 231 0.9 25.5 203 1.1 22.0 218 0.9 18.8 275 0.7 NA(a) 359

- - - - - - - - - - - - - - - - 

Ca Hardness (as CaCO3) mg/

L 

112 0.3 14.3 110 0.4 24.2 94.2 0.4 20.1 111 <0.25 17.2 150 0.4 NA(a) 197

- - - - - - - - - - - - - - - - 

Mg Hardness (as CaCO3) mg/

L 

106 0.3 0.7 121 0.6 1.4 109 0.7 1.9 107 0.6 1.5 125 0.3 NA(a) 162

- - - - - - - - - - - - - - - -

As (total) μg/L 20.0 <0.1 <0.1 17.7 <0.1 <0.1 18.3 <0.1 <0.1 20.6 <0.1 <0.1 15.7 0.1 NA(a) 31.8

- - - - - - - - - - - - - - - - 

As (soluble) μg/L - - - 18.0 <0.1 <0.1 - - - - - - 15.8 0.2 NA(a) - 

As (particulate) μg/L - - - <0.1 <0.1 <0.1 - - - - - - <0.1 <0.1 NA(a) - 

As (III) μg/L - - - 0.2 <0.1 <0.1 - - - - - - 0.5 0.1 NA(a) - 

As (V) μg/L - - - 17.8 <0.1 <0.1 - - - - - - 15.4 0.1 NA(a) - 

Fe (total) μg/L <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 NA(a) <25

- - - - - - - - - - - - - - - - 

Fe (soluble) μg/L - - - <25 <25 <25 - - - - - - <25 <25 NA(a) - 

Mn (total) μg/L 4.7 <0.1 1.0 2.1 <0.1 1.2 2.3 <0.1 0.7 2.8 <0.1 0.3 2.7 <0.1 NA(a) 3.0

- - - - - - - - - - - - - - - - 

Mn (soluble) μg/L - - - 2.2 <0.1 0.1 - - - - - - 2.2 <0.1 NA(a) - 

Sb (total) μg/L 12.1 <0.1 <0.1 10.4 <0.1 <0.1 10.6 <0.1 <0.1 11.0 <0.1 <0.1 10.2 <0.1 NA(a) 16.9

- - - - - - - - - - - - - - - - 

Sb (soluble) μg/L - - - 10.5 <0.1 <0.1 - - - - - - 10.1 <0.1 NA(a) - 

(a) Data from AP water samples were discarded due to collection of samples from wrong sampling tap.

NA = not available
Table B-1. Analytical Results from Long-Term Sampling at Carmel, ME (Continued)

B-2

Sampling Date 06/04/09 06/17/09 06/30/09 07/29/09 09/02/09

Sampling Location

Parameter Unit IN RO AP IN RO AP RW IN RO AP RW IN RO AP RW IN RO AP RW

Alkalinity (as CaCO3) mg/

L 

210 4.2 13.7 214 2.9 15.4 349 195 2.9 20.6 327 186 3.2 16.6 308 203 2.3 14.7 325

- - - - - - - - - - - - - - - - - - - 

Sulfate mg/

L - - - - - - - 9.4 <0.1 <0.1 16.3 8.3 <0.1 <0.1 19.0 11.1 <0.1 <0.1 19.0

Nitrate (as N) mg/

L - - - - - - - 0.2 <0.05 <0.05 0.3 0.3 0.1 0.1 0.5 0.1 <0.05 <0.05 0.1

Total P (as P) μg/L - - - - - - - <10 <10 <10 <10 <10 12.5 <10 <10 <10 <10 <10 <10

Silica (as SiO2) mg/

L 11.5 0.4 0.5 11.6 0.5 0.7 18.5 10.3 0.6 0.5 16.6 10.6 0.5 0.7 17.0 10.9 0.4 0.4 17.

6

- - - - - - - - - - - - - - - - - - - 

Turbidity NTU 0.9 0.5 0.3 2.0 2.0 0.4 1.1 1.0 0.5 0.5 0.4 3.3 1.0 0.6 0.8 1.8 2.4 1.8 2.6

- - - - - - - - - - - - - - - - - - - 

TDS mg/

L 

262 10.0 12.0 258 <2 4.0 412 220 <2 8.0 354 216 6.0 16.0 362 254 14.0 22.0 406

- - - - - - - - - - - - - - - - - - - 

pH S.U. 7.3 6.7 NA 7.9 6.7 7.0 7.9 7.8 7.2 7.6 8.0 7.8 7.1 7.5 7.9 7.9 6.5 7.1 7.9

NA NA NA - - - - 6.8 6.5 7.4 - 7.3 6.6 7.1 - 7.3 6.5 7.6 - 

Temperature °C 22.5 22.3 NA NA NA NA - 25.0 25.0 25.0 - 25.3 25.3 25.5 - 25.0 25.0 25.0 - 

DO mg/

L 4.7 4.3 NA NA NA NA - 3.9 2.2 2.9 - 3.5 2.9 2.8 - 4.3 3.9 3.6 - 

ORP mV 327 352 NA NA NA NA - 350 365 363 - 340 346 340 - 336 377 378 - 

Total Hardness (as CaCO3) mg/

L 

208 1.7 19.2 215 1.8 30.1 348 199 1.2 16.2 346 218 1.3 10.7 333 190 0.6 9.1 312

- - - - - - - - - - - - - - - - - - - 

Ca Hardness (as CaCO3) mg/

L 

107 0.9 17.5 111 0.8 27.5 176 114 0.7 15.2 201 94.9 0.6 9.5 145 88.7 0.2 8.4 139

- - - - - - - - - - - - - - - - - - - 

Mg Hardness (as CaCO3) mg/

L 

100 0.8 1.7 104 1.0 2.6 172 84.8 0.5 1.1 144 123 0.6 1.2 188 102 0.4 0.7 172

- - - - - - - - - - - - - - - - - - - 

As (total) μg/L 18.7 0.1 <0.1 21.0 0.1 <0.1 38.1 13.6 <0.1 <0.1 23.6 16.4 <0.1 <0.1 30.4 15.1 <0.1 <0.1 26.

7

- - - - - - - - - - - - - - - - - - - 

As (soluble) μg/L - - - - - - - 14.4 <0.1 <0.1 - 15.2 <0.1 <0.1 - 16.7 <0.1 <0.1 - 

As (particulate) μg/L - - - - - - - <0.1 <0.1 <0.1 - 1.2 <0.1 <0.1 - <0.1 <0.1 <0.1 - 

As (III) μg/L - - - - - - - <0.1 <0.1 <0.1 - <0.1 <0.1 <0.1 - <0.1 <0.1 <0.1 - 

As (V) μg/L - - - - - - - 14.3 <0.1 <0.1 - 15.1 <0.1 <0.1 - 16.6 <0.1 <0.1 - 

Fe (total) μg/L <25 <25 <25 <25 <25 <25 <25 231(a

) <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25

- - - - - - - - - - - - - - - - - - - 

Fe (soluble) μg/L - - - - - - - <25 74.0(b) <25 - <25 <25 <25 - - - - - 

Mn (total) μg/L 1.9 <0.1 0.2 1.9 <0.1 0.1 1.1 6.3 <0.1 <0.1 <0.

1 1.0 <0.1 <0.1 1.7 1.1 <0.1 <0.1 1.1

- - - - - - - - - - - - - - - - - - - 

Mn (soluble) μg/L - - - - - <0.1 1.7(a) <0.1 - 0.6 <0.1 0.1 - - - - - 

Sb (total) μg/L 11.8 <0.1 <0.1 11.1 <0.1 <0.1 17.9 10.0 <0.1 <0.1 17.7 13.2 <0.1 <0.1 20.6 13.1 <0.1 <0.1 22.

0

- - - - - - - - - - - - - - - - - - - 

Sb (soluble) μg/L - - - - - - - 10.4 <0.1 <0.1 - 12.9 <0.1 <0.1 - 13.3 <0.1 <0.1 - 

(a) Outlier.

NA = not available
Table B-1. Analytical Results from Long-Term Sampling at Carmel, ME (Continued)

B-3

Sampling Date 09/08/09 09/14/09 09/28/09 09/30/09 10/07/09

Sampling Location

Parameter Unit IN RO AP RW IN RO AP RW IN RO AP RW IN RO AP RW IN RO AP RW

Alkalinity (as CaCO3) mg/L 206 4.0 13.0 349 193 5.6 25.9 343 210 9.5 11.3 344 200 2.7 341(a) 337 204 5.4 24.4 336

- - - - - - - - - - - - 201 1.8 11.8 328 - - - - 

Sulfate mg/L - - - - - - - - 9.8 <0.1 <0.1 18.0 - - - - - - - - 

Nitrate (as N) mg/L - - - - - - - - 0.2 <0.05 <0.05 0.1 - - - - - - - - 

Total P (as P) μg/L - - - - - - - - <10 <10 <10 <10 - - - - - - - - 

Silica (as SiO2) mg/L 11.3 0.8 0.7 18.8 11.2 1.0 0.9 18.0 11.1 0.5 0.5 18.2 11.0 0.4 0.4 18.2 10.6 0.4 0.4 16.9

- - - - - - - - - - - - 11.0 0.4 0.4 17.9 - - - - 

Turbidity NTU 1.6 1.6 0.6 0.9 1.2 0.9 0.6 0.2 0.3 0.1 <0.1 0.2 0.2 0.3 0.2 0.6 1.8 0.7 0.9 1.8

- - - - - - - - - - - - 0.4 0.1 0.1 0.5 - - - - 

TDS mg/L 254 16.0 12.0 414 250 <2 16.0 408 226 <2 <2 354 272 18.0 20.0 460 258 8.0 26.0 418

- - - - - - - - - - - - 258 10.0 20.0 436 - - - - 

pH S.U. 7.9 6.6 7.4 7.9 8.0 7.2 8.9 8.0 7.8 7.1 6.8 7.9 7.9 7.1 7.1 7.5 7.9 6.6 8.9 8.0

 - - - - - - - - - - - - 7.9 6.8 7.1 8.0 - - - - 

Temperature °C NA NA NA - NA NA NA - NA NA NA - NA NA NA - NA NA NA - 

DO mg/L NA NA NA - NA NA NA - NA NA NA - NA NA NA - NA NA NA - 

ORP mV NA NA NA - NA NA NA - NA NA NA - NA NA NA - NA NA NA - 

Total Hardness (as CaCO3) mg/L 196 1.2 11.8 326 196 1.2 136(a) 327 208 0.9 8.8 336 211 0.8 12.3 350 232 0.8 20.5 357

- - - - - - - - - - - - 220 0.8 15.8 348 - - - - 

Ca Hardness (as CaCO3) mg/L 89.0 0.5 10.1 146 88.5 0.5 64.6(a) 148 105 <0.25 7.9 168 103 <0.25 11.4 169 112 0.2 19.2 172

- - - - - - - - - - - - 106 <0.25 14.8 169 - - - - 

Mg Hardness (as CaCO3) mg/L 107 0.7 1.7 180 107 0.7 71.3(a) 179 103 0.7 0.9 167 108 0.6 0.8 181 119 0.6 1.3 185

- - - - - - - - - - - - 114 0.6 0.9 178 - - - - 

As (total) μg/L 15.7 <0.1 <0.1 27.7 16.4 <0.1 10.0(a) 31.6 18.0 0.1 <0.1 30.9 20.1 0.2 0.1 36.5 22.6 <0.1 <0.1 37.4

- - - - - - - - - - - - 20.4 0.3 0.2 35.9 - - - - 

As (soluble) μg/L - - - - - - - - 18.4 0.3 0.2 - - - - - - - - - 

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

As (III) μg/L - - - - - - - - 0.4 0.1 <0.1 - - - - - - - - - 

As (V) μg/L - - - - - - - - 18.1 0.1 0.1 - - - - - - - - - 

Fe (total) μg/L <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 34 <25 <25 <25

- - - - - - - - - - - - <25 <25 <25 <25 - - - - 

Fe (soluble) μg/L - - - - - - - - <25 <25 <25 - - - - - - - - - 

Mn (total) μg/L 0.5 <0.1 <0.1 1.0 0.5 <0.1 0.5 1.1 1.1 <0.1 0.1 1.7 1.6 <0.1 0.2 2.3 3.7 <0.1 0.4 2.1

- - - - - - - - - - - - 1.7 <0.1 0.3 2.3 - - - - 

Mn (soluble) μg/L - - - - - - - - 0.7 <0.1 <0.1 - - - - - - - - - 

Sb (total) μg/L 12.0 <0.1 <0.1 20.4 11.6 <0.1 7.6(a) 19.8 9.8 <0.1 <0.1 16.3 10.4 <0.1 <0.1 17.2 10.2 <0.1 <0.1 16.6

- - - - - - - - - - - - 10.5 <0.1 <0.1 17.1 - - - - 

Sb (soluble) μg/L - - - - - - - - 9.7 <0.1 <0.1 - - - - - - - - - 

(a) Outliers
Table B-1. Analytical Results from Long-Term Sampling at Carmel, ME (Continued)

B-4

Sampling Date 10/20/09 10/27/09 10/28/09 11/17/09 12/03/09

Sampling Location

Parameter Unit IN RO AP RW IN RO AP RW IN RO AP RW IN RO AP RW IN RO AP RW

Alkalinity (as CaCO3) mg/L 207 3.0 21.3 375 194 4.9 16.6 348 195 5.7 13.4 321 220 19.3 22.7 347 220 12.2 18.9 347

- - - - - - - - - - - - - - - - - - - - 

Sulfate mg/L - - - - - - - - 10.6 0.2 0.1 18.2 - - - - 11.0 <0.1 <0.1 17.3

Nitrate (as N) mg/L - - - - - - - - 0.1 <0.05 <0.05 0.2 - - - - 0.1 <0.05 <0.05 0.2

Total P (as P) μg/L - - - - - - - - <10 <10 <10 <10 - - - - <10 <10 <10 <10

Silica (as SiO2) mg/L 10.0 0.4 0.4 18.1 10.8 0.4 0.4 18.2 10.8 0.4 0.5 18.1 11.3 0.4 0.3 18.5 11.7 0.3 0.3 19.0

- - - - - - - - - - - - - - - - - - - - 

Turbidity NTU 8.3 2.2 3.4 3.7 1.0 0.7 0.3 0.8 3.8 1.2 0.5 3.0 0.9 0.4 0.8 1.2 1.5 1.0 0.9 1.8

- - - - - - - - - - - - - - - - - - - - 

TDS mg/L 246 8.0 20.0 468 242 <2 <2 402 242 4.0 12.0 410 256 10.0 12.0 414 284 34.0 48.0 436

- - - - - - - - - - - - - - - - - - - - 

pH S.U. 7.9 7.2 7.5 8.0 8.0 6.9 7.7 8.0 7.9 7.1 6.9 8.0 7.9 6.8 7.3 8.0 7.9 6.8 7.2 8.0

 - - - - - - - - 7.4 6.7 7.5 - - - - - 7.6 6.6 8.3 - 

Temperature °C NA NA NA - NA NA NA - 20.4 20.5 20.5 - - - - - 20.7 20.7 20.7 - 

DO mg/L NA NA NA - NA NA NA - 4.3 4.4 4.6 - - - - - 3.9 2.9 2.3 - 

ORP mV NA NA NA - NA NA NA - 310 324 323 - - - - - 349 389 366 - 

Total Hardness (as CaCO3) mg/L 216 1.1 25.9 380 249 1.8 20.7 393 273 1.9 22.3 496 183 1.9 16.5 300 212 2.0 23.8 350

- - - - - - - - - - - - - - - - - - - - 

Ca Hardness (as CaCO3) mg/L 102 0.3 24.1 179 125 1.0 19.3 198 144 0.9 21.0 271 70 0.8 15.3 113 108 1.4 22.8 176

- - - - - - - - - - - - - - - - - - - - 

Mg Hardness (as CaCO3) mg/L 114 0.8 1.8 202 124 0.9 1.3 196 128 1.0 1.3 225 113 1.0 1.2 187 104 0.7 1.0 174

- - - - - - - - - - - - - - - - - - - - 

As (total) μg/L 18.9 <0.1 <0.1 37.3 18.6 <0.1 <0.1 32.0 17.7 <0.1 <0.1 29.7 19.3 0.3 0.1 32.3 18.6 <0.1 <0.1 30.7

- - - - - - - - - - - - - - - - - - - - 

As (soluble) μg/L - - - - - - - - 17.9 <0.1 <0.1 - - - - - 19.0 <0.1 <0.1 - 

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

As (III) μg/L - - - - - - - - <0.1 <0.1 <0.1 - - - - - 0.3 <0.1 <0.1 - 

As (V) μg/L - - - - - - - - 17.8 <0.1 <0.1 - - - - - 18.7 <0.1 <0.1 - 

Fe (total) μg/L <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25

- - - - - - - - - - - - - - - - - - - - 

Fe (soluble) μg/L - - - - - - - - <25 <25 <25 - - - - - <25 <25 <25 - 

Mn (total) μg/L 1.8 0.1 0.3 3.0 2.2 0.3 0.5 2.8 2.5 0.3 0.4 3.0 1.8 <0.1 <0.1 2.3 2.4 <0.1 0.5 3.1

- - - - - - - - - - - - - - - - - - - - 

Mn (soluble) μg/L - - - - - - - - 2.4 <0.1 0.5 - - - - - 2.2 <0.1 0.5 - 

Sb (total) μg/L 10.2 <0.1 <0.1 18.1 9.8 <0.1 <0.1 16.2 10.5 <0.1 <0.1 16.8 10.3 <0.1 <0.1 16.8 8.6 <0.1 <0.1 14.5

- - - - - - - - - - - - - - - - - - - - 

Sb (soluble) μg/L - - - - - - - - 10.5 <0.1 <0.1 - - - - - 9.7 <0.1 <0.1 - 

(a) Outliers

NA = not available
Table B-1. Analytical Results from Long-Term Sampling at Carmel, ME (Continued)

B-5

Sampling Date 12/15/09

Sampling Location

Parameter Unit IN RO AP RW

Alkalinity (as CaCO3) mg/L 218 4.6 18.6 364

- - - - 

Sulfate mg/L - - - - 

Nitrate (as N) mg/L - - - - 

Total P (as P) μg/L - - - - 

Silica (as SiO2) mg/L 11.6 0.4 0.3 19.8

- - - - 

Turbidity NTU 2.0 0.6 0.5 0.9

- - - - 

TDS mg/L 254 8.0 26.0 402

- - - - 

pH S.U. 8.0 6.7 7.2 8.0

- - - - 

Temperature °C - - - - 

DO mg/L - - - - 

ORP mV - - - - 

Total Hardness (as CaCO3) mg/L 202 1.1 21.5 324

- - - - 

Ca Hardness (as CaCO3) mg/L 101 0.4 20.2 161

- - - - 

Mg Hardness (as CaCO3) mg/L 101 0.7 1.4 163

- - - - 

As (total) μg/L 17.7 <0.1 <0.1 29.3

- - - - 

As (soluble) μg/L - - - - 

As (particulate) μg/L - - - - 

As (III) μg/L - - - - 

As (V) μg/L - - - - 

Fe (total) μg/L <25 <25 <25 <25

- - - - 

Fe (soluble) μg/L - - - - 

Mn (total) μg/L 1.8 <0.1 1.2 0.5

- - - - 

Mn (soluble) μg/L - - - - 

Sb (total) μg/L 9.5 <0.1 <0.1 15.9

- - - - 

Sb (soluble) μg/L - - - -