EPA/600/R-09/113
October 2009
Arsenic Removal from Drinking Water by Coagulation/Filtration
U.S. EP A Demonstration Project at City of Three Forks, MT
Final Performance Evaluation Report
by
Abraham S.C. Chen
Brian J. Yates
Wendy E. Condit
Lili Wang
Battelle
Columbus, OH 43201-2693
Contract No. 68-C-00-185
Task Order No. 0029
for
Thomas J. Sorg
Task Order Manager
Water Supply and Water Resources Division
National Risk Management Research Laboratory
Cincinnati, Ohio 45268
National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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DISCLAIMER
The work reported in this document was funded by the United States Environmental Protection Agency
(EPA) under Task Order 0029 of Contract 68-C-00-185 to Battelle. It has been subjected to the Agency's
peer and administrative reviews and has been approved for publication as an EPA document. Any
opinions expressed in this paper are those of the author(s) and do not, necessarily, reflect the official
positions and policies of the EPA. Any mention of products or trade names does not constitute
recommendation for use by the EPA.
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FOREWORD
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the Nation's
land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to
formulate and implement actions leading to a compatible balance between human activities and the ability
of natural systems to support and nurture life. To meet this mandate, EPA's research program is
providing data and technical support for solving environmental problems today and building a science
knowledge base necessary to manage our ecological resources wisely, understand how pollutants affect
our health, and prevent or reduce environmental risks in the future.
The National Risk Management Research Laboratory (NRMRL) is the Agency's center for investigation
of technological and management approaches for preventing and reducing risks from pollution that
threaten human health and the environment. The focus of the Laboratory's research program is on
methods and their cost-effectiveness for prevention and control of pollution to air, land, water, and
subsurface resources; protection of water quality in public water systems; remediation of contaminated
sites, sediments and ground water; prevention and control of indoor air pollution; and restoration of
ecosystems. NRMRL collaborates with both public and private sector partners to foster technologies that
reduce the cost of compliance and to anticipate emerging problems. NRMRL's research provides
solutions to environmental problems by: developing and promoting technologies that protect and improve
the environment; advancing scientific and engineering information to support regulatory and policy
decisions; and providing the technical support and information transfer to ensure implementation of
environmental regulations and strategies at the national, state, and community levels.
This publication has been produced as part of the Laboratory's strategic long-term research plan. It is
published and made available by EPA's Office of Research and Development to assist the user
community and to link researchers with their clients.
Sally Gutierrez, Director
National Risk Management Research Laboratory
in
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ABSTRACT
This report documents the activities performed during and the results obtained from the arsenic removal
treatment technology demonstration project at the City of Three Forks, MT facility. The objectives of the
project were to evaluate: 1) the effectiveness of Kinetico's FM-248-AS Arsenic Removal System using
Macrolite® media in removing arsenic to meet the maximum contaminant level (MCL) of 10 |og/L, 2) the
reliability of the treatment system for use at small water facilities, 3) the required system operation and
maintenance (O&M) and operator skill levels, and 4) the capital and O&M cost of the technology. The
project also characterized water in the distribution system and residuals generated by the treatment
process. The types of data collected included system operation, water quality, process residuals, and
capital and O&M cost.
After review and approval of the engineering plan by the State, the FM-248-AS treatment system was
installed and became operational on October 30, 2006. The system consisted of two 63-in x 86-in fiber
reinforced plastic (FRP) contact tanks and two 48-in x 72-in FRP pressure filtration vessels, both
configured in parallel. Each pressure filtration vessel was loaded with 25 ft3 of Macrolite® media to
which filtration rates up to 10.0 gpm/ft2 was applied. During the performance evaluation study from
November 27, 2006, and February 8, 2008, the system operated at an average flowrate of 206 gal/min
(gpm) for 8.9 hr/day, producing 30,499,000 gal of water. This average flowrate corresponded to an
average contact time of 6.2 min and an average filtration rate of 8.0 gpm/ft2.
Problems encountered during the performance evaluation study included programmable logic controller
(PLC) settings, arsenic and iron particulate breakthrough, and increased differential pressure across the
media beds, which led to shorter useful run lengths and more frequent backwashing. The actions taken to
address these problems are detailed in this report.
Source water from Well 2 had an average pH value of 7.5 and contained 59.8 (ig/L to 96.7 |o,g/L of total
arsenic, 46.8 to 50.8 mg/L of silica (as SiO2), and 17.1 to 53.7 |o,g/L of phosphorus (as P). The
predominant soluble arsenic species was As(V) with an average concentration of 74.5 |o,g/L. Total iron
concentrations were below the method reporting limit, therefore, in order to make the planned
coagulation/filtration process work, an iron addition system was installed to provide iron for soluble
As(V) removal. The amounts of iron added ranged from 1.1 to 2.5 mg/L (as Fe), compared to the target
dosage of 2.0 mg/L (as Fe).
After the contact tanks, most soluble As(V) was converted to particulate arsenic, presumably via
adsorption and coprecipitation. As much as 10.6 (ig/L of soluble As(V), however, remained in the
contact tank effluent. Higher iron dosages appear to have very little effect on additional soluble As(V)
removal. Silica and phosphorus in the raw water might have competed with arsenic for available
adsorptive sites, thus rendering the coagulation process less effective. The use of higher iron dosages also
increased solid loading to the pressure filters, causing premature breakthrough of arsenic-laden particles
within 2 to 4 hr of filter runs.
Filter effluent samples taken during the first three weeks of system operation contained 17.3 to 30.6 (ig/L
of total arsenic and 236 to 936 (ig/L of total iron. Of the total amount of total arsenic measured, 23.5
(ig/L, on average, existed as particulate arsenic. All iron existed in the particulate form. These results
suggest that arsenic-laden particles broke through the pressure filters during the filter runs. To examine
breakthrough characteristics and methods to improve the filter performance, several special studies,
including some jar tests, were conducted, which included the use of a higher iron dose, implementation of
a finer Macrolite® media size fraction, and addition of a polymer/coagulant aid. However, only a
IV
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blending scheme using water from Wells 5, 6, 8, and 9 was successful in reducing arsenic concentrations
to below the MCL.
In general, filter backwash was triggered manually three times a week (i.e., Monday, Wednesday, and
Friday) for the first five months and then automatically 5 times a week by the 8 hr run time setpoint.
Approximately 1,173,000 gal of wastewater, or 3.8% of the amount of water treated, was generated
during the study. However, because the useful filter run length (i.e., the maximum filter run length that
consistently yielded <10 ug/L total arsenic and <300 ug/L total iron in the effluent) was much shorter
than the actual filter run lengths observed during the study, the percentage of processed water used for
backwashing would have been much higher than 3.8% had the useful filter run length been implemented
throughout the study. The backwash wastewater contained between 310 mg/L and 388 mg/L of total
dissolved solids (TDS) and between 130 mg/L and 328 mg/L of total suspended solids (TSS). On
average, approximately 0.06 Ib of arsenic, 1.6 Ib of iron, and 0.006 Ib of manganese were discharged
during each backwash event.
The capital investment for the treatment system was $305,447, consisting of $168,142 for equipment,
$53,435 for site engineering, and $83,870 for installation, shakedown, and startup. Using the system's
rated capacity of 250 gpm (or 360,000 gal/day [gpd]), the capital cost was $l,222/gpm (or $0.85/gpd).
This calculation does not include the cost of the building to house the treatment system. O&M cost,
estimated at $0.18/1,000 gal, included only the incremental cost for chemicals, electricity, and labor.
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CONTENTS
DISCLAIMER ii
FOREWORD iii
ABSTRACT iv
APPENDICES vii
FIGURES vii
TABLES viii
ABBREVIATIONS AND ACRONYMS ix
ACKNOWLEDGMENTS xii
1.0: INTRODUCTION 1
1.1 Background 1
1.2 Treatment Technologies for Arsenic Removal 2
1.3 Project Objectives 2
2.0: SUMMARY AND CONCLUSIONS 5
3.0: MATERIALS AND METHODS 7
3.1 General Project Approach 7
3.2 System O&M and Cost Data Collection 8
3.3 Sample Collection Procedures and Schedules 8
3.3.1 Source Water 11
3.3.2 Treatment Plant Water 11
3.3.3 Backwash Wastewater 11
3.3.4 Distribution System Water 11
3.3.5 Residual Solids 11
3.4 Special Studies 12
3.5 Sampling Logistics 13
3.5.1 Preparation of Arsenic Speciation Kits 13
3.5.2 Preparation of Sampling Coolers 13
3.5.3 Sample Shipping and Handling 14
3.6 Analytical Procedures 14
4.0: RESULTS AND DISCUSSION 15
4.1 Site Description 15
4.1.1 Pre-existing Facility 15
4.1.2 Source Water Quality 16
4.1.3 Distribution System 18
4.2 Treatment Process Description 19
4.3 Treatment System Installation 25
4.3.1 System Permitting 25
4.3.2 Building Construction 26
4.3.3 System Installation, Startup, and Shakedown 26
4.4 System Operation 27
4.4.1 Service Operation 27
4.4.2 Chlorine and Iron Additions 32
4.4.3 Backwash Operation 33
4.4.3.1 PLC Settings 35
4.4.3.2 Backwash Flowrates 35
4.4.4 Residual Management 35
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4.4.5 Reliability and Simplicity of Operation 36
4.4.5.1 Pre- and Post-Treatment Requirements 36
4.4.5.2 System Automation 36
4.4.5.3 Operator Skill Requirements 36
4.4.5.4 Preventative Maintenance Activities 36
4.4.5.5 Chemical Handling and Inventory Requirements 36
4.5 System Performance 37
4.5.1 Treatment Plant Sampling 37
4.5.1.1 Arsenic and Iron 37
4.5.1.2 Manganese 43
4.5.1.3 Chlorine Residual 43
4.5.1.4 Other Water Quality Parameters 43
4.5.2 Special Studies 43
4.5.2.1 Effect of Ap and Filter Run Time 43
4.5.2.2 Effect of Higher Iron Dosage 44
4.5.2.3 Effect of Media Size Fraction 45
4.5.2.4 Effect of Polymers/Coagulants Aids 46
4.5.3 Backwash Wastewater Sampling 49
4.5.4 Distribution System Water Sampling 51
4.6 System Cost 51
4.6.1 Capital Cost 53
4.6.2 O&MCost 54
Section 5.0: REFERENCES 55
APPENDICES
Appendix A: OPERATIONAL DATA
Appendix B: ANALYTICAL DATA TABLES
FIGURES
Figure 3-1. Process Flow Diagram and Sampling Schedule and Locations 10
Figure 4-1. Pre-existing Well 2 Pump House 15
Figure 4-2. Interior Piping of Well 2 Pump House 16
Figure 4-3. One-million Gallon Water Tank by Treatment Building 19
Figure 4-4. Schematic of Kinetico's Macrolite® Arsenic Removal System 20
Figure 4-5. Chemical Feed Systems 22
Figure 4-6. Contact Tanks with Inlet and Exit Piping 23
Figure 4-7. Filtration Vessels and Valve Rack 23
Figure 4-8. Hach™ Turbidimeter for Control of Backwash Duration 24
Figure 4-9. Backwash Recycle System 25
Figure 4-10. Treatment System Building 26
Figure 4-11. Treatment System Delivery at Three Forks, MT Site 27
Figure 4-12. Relocation of IN Sampling Location and Chemical Inject Points 29
Figure 4-13. Differential Pressure vs. Filter Run Time 31
Figure 4-14. Vessels A and B Service Time between Backwash Cycles 32
Figure 4-15. Chlorine and Ferric Chloride Dosages Over Time 33
Figure 4-16. Backwash Frequency Histogram 34
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Figure 4-17. Arsenic Speciation Results 41
Figure 4-18. Total Arsenic Concentrations across Treatment Train 42
Figure 4-19. Total Iron Concentrations across Treatment Train 42
Figure 4-20. Total Arsenic and Iron Levels with Use of a Higher Iron Dosage 44
Figure 4-21. Total Arsenic Breakthrough from Filters with 40/60 Mesh Media Only and 40/60
and 70/80 Mesh Amendment 46
Figure 4-22. Total Arsenic and Iron Levels with Use of C-05 Blend 47
Figure 4-23. Ap vs. Run Time with Use of C-05 Blend 48
TABLES
Table 1-1. Summary of Arsenic Removal Demonstration Sites 3
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 Analyses 9
Table 3-4. Coagulant Aids Jar-Tested by Hawkins 13
Table 4-1. Three Forks, MT Well 2 Source Water Data 17
Table 4-2. Three Forks, MT Historic Water Quality Data 18
Table 4-3. Properties of 40/60 Mesh Macrolite® Media 20
Table 4-4. Design Specifications of Macrolite® System 21
Table 4-5. System Inspection Punch-List Items 28
Table 4-6. Treatment System Operational Parameters 30
Table 4-7. Unscheduled System Downtime 30
Table 4-8. Summary of PLC Settings for Backwash Operations 34
Table 4-9. Summary of Arsenic, Iron, and Manganese Analytical Results 38
Table 4-10. Summary of Other Water Quality Parameter Results 39
Table 4-11. C-05 FeCl3/Polymer Blend Jar Test Results 47
Table 4-12. Jar Test Results with Alum and Various Polymers 49
Table 4-13. Backwash Wastewater Sampling Test Results 50
Table 4-14. Comparison of Soluble Arsenic and Iron Concentrations in Backwash Wastewater 51
Table 4-15. Distribution System Sampling Results 52
Table 4-16. Capital Investment for FM-248-AS Treatment System 53
Table 4-17. O&M Cost for FM-248-AS Treatment System 54
Vlll
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ABBREVIATIONS AND ACRONYMS
Ap differential pressure
(ig/L micrograms per liter
(im micrometers
AAL American Analytical Laboratories
AL polyaluminum hydroxychloride
AM adsorptive media
Al Aluminum
As arsenic
ATS Aquatic Treatment Systems
bgs below ground surface
C/F coagulation/filtration
Ca calcium
CaCO3 calcium carbonate
Cd cadmium
Cl chlorine
Cu copper
DO dissolved oxygen
EPA U.S. Environmental Protection Agency
F fluoride
Fe iron
FeCl3 ferric chloride
FRP fiberglass reinforced plastic
FTW filter-to-waste
gpd gallons per day
gph gallons per hour
gpm gallons per minute
HOPE high-density polyethylene
HIX hybrid ion exchanger
hp horsepower
ICP-MS inductively coupled plasma-mass spectrometry
ID identification
IN wellhead sampling location
IX ion exchange
LCR (EPA) Lead and Copper Rule
MCL maximum contaminant level
MDL method detection limit
MEI Magnesium Elektron, Inc.
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Mg magnesium
Mn manganese
MT DEQ Montana Department of Environmental Quality
mV millivolts
Na sodium
NA not analyzed
NaOCl sodium hypochlorite
ND not detected
Ni nickel
NTU nephelometric turbidity units
O&M operation and maintenance
OIP operator interface panel
OIT Oregon Institute of Technology
ORD Office of Research and Development
ORP oxidation-reduction potential
P phosphorus
P&ID piping and instrumentation diagram
Pb lead
PD polydiallyldimethylammonium chloride
psi pounds per square inch
psig pounds per square inch gauge
PLC programmable logic controller
PO4 phosphate
POU point-of-use
PVC polyvinyl chloride
PY polyquaternary amine
QA/QC quality assurance/quality control
QAPP Quality Assurance Project Plan
RPD relative percent difference
rpm rotations per minute
RO reverse osmosis
SCADA system control and data acquisition
SDWA Safe Drinking Water Act
SiO2 silica
SMCL secondary maximum contaminant level
SO4 sulfate
SOC synthetic organic compounds
STS Severn Trent Services
TA
TB
TCLP
TDH
TDS
Vessel A sampling location
Vessel B sampling location
toxicity characteristics leaching procedure
total dynamic head
total dissolved solids
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TOC total organic carbon
TSS total suspended solids
TT combined Vessel A and Vessel B sampling location
U uranium
UPS uninterruptible power supply
V vanadium
VOC volatile organic compounds
Zn zinc
XI
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ACKNOWLEDGMENTS
The authors wish to extend their sincere appreciation to Mr. Randy Johnson of the City of Three Forks,
MT. Mr. Johnson monitored the treatment system and collected samples from the treatment and
distribution systems on a regular schedule throughout the study. This performance evaluation would not
have been possible without his support and dedication.
Ms. Julia Valigore was the Battelle Study Lead from the inception of this demonstration project through
July 2007. She is currently pursuing a doctoral degree at the University of Canterbury in New Zealand.
xn
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1.0 INTRODUCTION
1.1 Background
The Safe Drinking Water Act (SDWA) mandates that the U.S. Environmental Protection Agency (EPA)
identify and regulate drinking water contaminants that may have adverse human health effects and that
are known or anticipated to occur in public water supply systems. In 1975 under the SDWA, EPA
established a maximum contaminant level (MCL) for arsenic (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 (ig/L) (EPA, 2003). The final rule required all community
and non-transient, non-community water systems to comply with the new standard by January 23, 2006.
In October 2001, EPA announced an initiative for additional research and development of cost-effective
technologies to help small community water systems (< 10,000 customers) meet the new arsenic standard
and to provide technical assistance to operators of small systems in order to reduce compliance costs. As
part of this Arsenic Rule Implementation Research Program, EPA's Office of Research and Development
(ORD) proposed a project to conduct a series of full-scale, onsite demonstrations of arsenic removal
technologies, process modifications, and engineering approaches applicable to small systems. Shortly
thereafter, an announcement was published in the Federal Register requesting water utilities interested in
participating in Round 1 of this EPA-sponsored demonstration program to provide information on their
water systems. In June 2002, EPA selected 17 out of 115 sites to host the demonstration studies.
In September 2002, EPA solicited proposals from engineering firms and vendors for cost-effective arsenic
removal treatment technologies for the 17 host sites. EPA received 70 technical proposals for the 17 host
sites, with each site receiving one to six proposals. In April 2003, an independent technical panel
reviewed the proposals and provided its recommendations to EPA on the technologies that it determined
were acceptable for the demonstration at each site. Because of funding limitations and other technical
reasons, only 12 of the 17 sites were selected for the demonstration project. Using the information
provided by the review panel, EPA, in cooperation with the host sites and the drinking water programs of
the respective states, selected one technical proposal for each site.
In 2003, EPA initiated Round 2 arsenic technology demonstration projects that were partially funded with
Congressional add-on funding to the EPA budget. In June 2003, EPA selected 32 potential demonstration
sites, and the community water system in the City of Three Forks, MT was one of those selected.
In September 2003, EPA again solicited proposals from engineering firms and vendors for arsenic
removal technologies. EPA received 148 technical proposals for the 32 host sites, with each site
receiving from two to eight proposals. In April 2004, another technical panel was convened by EPA to
review the proposals and provide recommendations to EPA with the number of proposals per site ranging
from none (for two sites) to a maximum of four. The final selection of the treatment technology at the
sites that received at least one proposal was made, again, through a joint effort by EPA, the state
regulators, and the host site. Since then, four sites have withdrawn from the demonstration program,
reducing the number of sites to 28. Kinetico's Macrolite® Arsenic Removal Technology was selected for
demonstration at the Three Forks facility.
As of September 2009, 39 of the 40 systems were operational, and the performance evaluation of 33
systems was completed.
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1.2 Treatment Technologies for Arsenic Removal
The technologies selected for the Round 1 and Round 2 demonstration host sites include 25 adsorptive
media (AM) systems (the Oregon Institute of Technology [OIT] site has three AM systems), 13
coagulation/filtration (C/F) systems, two ion exchange (IX) systems, and 17 point-of-use (POU) units
(including nine under-the-sink reverse osmosis [RO] units at the Sunset Ranch Development site and
eight AM units at the OIT site), and one system modification. Table 1-1 summarizes the locations,
technologies, vendors, system flowrates, and key source water quality parameters (including As, iron
[Fe], and pH) at the 40 demonstration sites. An overview of the technology selection and system design
for the 12 Round 1 demonstration sites and the associated capital cost is provided in two EPA reports
(Wang et al., 2004; Chen et al., 2004), which are posted on the EPA Web site at
http://www.epa.gov/ORD/NRMRL/wswrd/dw/arsenic/index.html.
1.3 Project Objectives
The objective of the arsenic demonstration program is to conduct full-scale arsenic treatment technology
demonstration studies on the removal of arsenic from drinking water supplies. The specific objectives are
to:
• Evaluate the performance of the arsenic removal technologies for use on small
systems.
• Determine the required system operation and maintenance (O&M) and operator skill
levels.
• Characterize process residuals produced by the technologies.
• Determine the capital and O&M cost of the technologies.
This report summarizes the performance of the Kinetico system at the City of Three Forks in Montana
from November 27, 2006, to February 8, 2008. The types of data collected include system operation,
water quality (both across the treatment train and in the distribution system), residuals, and capital and
preliminary O&M cost.
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Table 1-1. Summary of Arsenic Removal Demonstration Sites
Demonstration
Location
Site Name
Technology (Media)
Vendor
Design
Flowrate
(gpm)
Source Water Quality
As
(HS/L)
Fe
(MS/L)
PH
(S.U.)
Northeast/Ohio
Wales, ME
Bow,NH
Goffstown, NH
Rollinsford, NH
Dummerston, VT
Felton, DE
Stevensville, MD
Houghton, NY(d)
Newark, OH
Springfield, OH
Springbrook Mobile Home Park
White Rock Water Company
Orchard Highlands Subdivision
Rollinsford Water and Sewer District
Charette Mobile Home Park
Town of Felton
Queen Anne's County
Town of Caneadea
Buckeye Lake Head Start Building
Chateau Estates Mobile Home Park
AM (A/I Complex)
AM (G2)
AM (E33)
AM (E33)
AM (A/I Complex)
C/F (Macrolite)
AM (E33)
C/F (Macrolite)
AM (ARM 200)
AM (E33)
ATS
ADI
AdEdge
AdEdge
ATS
Kinetico
STS
Kinetico
Kinetico
AdEdge
14
70W
10
100
22
375
300
550
10
250W
38W
39
33
36W
30
30W
19W
27W
15W
25W
<25
<25
<25
46
<25
48
270(c)
l,806(c)
1,312W
1,615W
8.6
7.7
6.9
8.2
7.9
8.2
7.3
7.6
7.6
7.3
Great Lakes/Interior Plains
Brown City, MI
Pentwater, MI
Sandusky, MI
Delavan, WI
Greenville, WI
Climax, MN
Sabin, MN
Sauk Centre, MN
Stewart, MN
Lidgerwood, ND
City of Brown City
Village of Pentwater
City of Sandusky
Vintage on the Ponds
Town of Greenville
City of Climax
City of Sabin
Big Sauk Lake Mobile Home Park
City of Stewart
City of Lidgerwood
AM (E33)
C/F (Macrolite)
C/F (Aeralater)
C/F (Macrolite)
C/F (Macrolite)
C/F (Macrolite)
C/F (Macrolite)
C/F (Macrolite)
C/F&AM (E33)
Process Modification
STS
Kinetico
Siemens
Kinetico
Kinetico
Kinetico
Kinetico
Kinetico
AdEdge
Kinetico
640
400
340(e)
40
375
140
250
20
250
250
14W
13w
16W
20W
17
39W
34
25W
42W
146W
127W
466W
1,387W
l,499(c)
7827(c)
546W
l,470(c)
3,078W
l,344(c)
1,325W
7.3
6.9
6.9
7.5
7.3
7.4
7.3
7.1
7.7
7.2
Midwest/Southwest
Amaudville, LA
Alvin, TX
Bruni, TX
Wellman, TX
Anthony, NM
Nambe Pueblo, NM
Taos, NM
Rimrock, AZ
Tohono O'odham
Nation, AZ
Valley Vista, AZ
United Water Systems
Oak Manor Municipal Utility District
Webb Consolidated Independent School
District
City of Wellman
Desert Sands Mutual Domestic Water
Consumers Association
Nambe Pueblo Tribe
Town of Taos
Arizona Water Company
Tohono O'odham Utility Authority
Arizona Water Company
C/F (Macrolite)
AM (E33)
AM (E33)
AM (E33)
AM (E33)
AM (E33)
AM (E33)
AM (E33)
AM (E33)
AM (AAFS50/ARM 200)
Kinetico
STS
AdEdge
AdEdge
STS
AdEdge
STS
AdEdge
AdEdge
Kinetico
770W
150
40
100
320
145
450
90(b)
50
37
35W
19W
56(a)
45
23(a)
33
14
50
32
41
2,068(c)
95
<25
<25
39
<25
59
170
<25
<25
7.0
7.8
8.0
7.7
7.7
8.5
9.5
7.2
8.2
7.8
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Table 1-1. Summary of Arsenic Removal Demonstration Sites (Continued)
Demonstration
Location
Site Name
Technology (Media)
Vendor
Design
Flow rate
fepm)
Source Water Quality
As
Oig/L)
Fe
(MS/L)
PH
(S.U.)
Far West
Three Forks, MT
Fruitland, ID
Homedale, ID
Okanogan, WA
Klamath Falls, OR
Vale, OR
Reno, NV
Susanville, CA
Lake Isabella, CA
Tehachapi, CA
City of Three Forks
City of Fruitland
Sunset Ranch Development
City of Okanogan
Oregon Institute of Technology
City of Vale
South Truckee Meadows General
Improvement District
Richmond School District
Upper Bodfish Well Cffi-A
Golden Hills Community Service
District
C/F (Macrolite)
IX (A300E)
POU RO(1)
C/F (Electromedia-I)
POE AM (Adsorbsia/ARM 200/ArsenXnp)
and POU AM (ARM 200)®
IX (Arsenex II)
AM (GFH/Kemiron)
AM (A/I Complex)
AM(HIX)
AM (Isolux)
Kinetico
Kinetico
Kinetico
Filtronics
Kinetico
Kinetico
Siemens
ATS
VEETech
MEI
250
250
75gpd
750
60/60/30
525
350
12
50
150
64
44
52
18
33
17
39
37W
35
15
<25
<25
134
69w
<25
<25
<25
125
125
<25
7.5
7.4
7.5
8.0
7.9
7.5
7.4
7.5
7.5
6.9
AM = adsorptive media process; C/F = coagulation/filtration; EHX = hybrid ion exchanger; IX = ion exchange process; RO = reverse osmosis
ATS = Aquatic Treatment Systems; MEI = Magnesium Elektron, Inc.; STS = Severn Trent Services
(a) Arsenic existing mostly as As(III).
(b) Design flowrate reduced by 50% due to system reconfiguration from parallel to series operation.
(c) Iron existing mostly as Fe(II).
(d) Withdrew from program in 2007. Selected originally to replace Village of Lyman, NE site, which withdrew from program in June 2006.
(e) Facilities upgraded systems in Springfield, OH from 150 to 250 gpm, Sandusky, MI from 210 to 340 gpm, and Amaudville, LA from 385 to 770 gpm.
(f) Including nine residential units.
(g) Including eight under-the-sink units.
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2.0 SUMMARY AND CONCLUSIONS
Based on the information collected from November 27, 2006, to February 8, 2008, the following
summary and conclusions are provided relating to the overall objectives of the treatment technology
demonstration study.
Performance of the arsenic removal technology for use on small systems:
• Operating at 8 gpm/ft2, Kinetico's FM-248-AS Arsenic Removal System with Macrolite®
media can remove arsenic to below its MCL of 10 (ig/L. However, above MCL levels of
arsenic, present in both soluble and particulate forms, can break through the filters within 2 hr
of service time, rendering the filtration process ineffective.
• The use of ferric chloride (FeCl3) coagulant can reduce levels of soluble arsenic, present
predominantly as As(V), after the contact tanks. However, close to or above MCL levels of
soluble arsenic remain untreated in the contact tank effluent. Increasing the iron dosage to as
much as 2.5 mg/L (at 31:1 Fe: As ratio) does not appear to be effective in improving the
treatment results. The poor treatment results might have been caused by the presence of
silica (at 48.5 mg/L [as SiO2]) and phosphorus, which competed with As(V) for available
adsorptive sites on iron solids.
• Increasing iron dosage also increases solids loading to the pressure filters, causing premature
breakthrough of arsenic-laden iron solids from the pressure filters. The use of an organic
polymer, C-05 FeCl3/polymer blend, does not appear to be effective in improving the filter
performance. The use of C-05 caused clogging to the filters, as evidenced by an increase in
differential pressure (Ap) buildup rate (i.e., 1.4 to 1.6 psi/hr versus 1.0 psi/hr with the use of
FeCl3 alone) and several backwash alarms (resulting from the inability to achieve a preset
turbidity threshold within the maximum backwash time).
• The use of a smaller media size fraction (70/80 mesh vs. 40/60 mesh) does not appear to be
effective in improving the filter's ability to remove arsenic-laden iron particles.
• Blending with water from other available wells is capable of reducing arsenic concentrations
to below MCL levels.
Required system O&Mand operator skill levels:
• The daily demand on the operator was short, averaging 30 min for routine O&M.
• A significant amount of time and effort was required to adjust and monitor the chemical feed
system for coagulation/filtration.
Characteristics of residuals produced by the technology:
• Approximately 3,700 gal of wastewater were produced during each backwash event for both
vessels. The wastewater contained 0.06 Ib of arsenic, 1.6 Ib of iron, and 0.006 Ib of
manganese, most of which existed in the particulate form as part of the 4.6 Ib of solids
discharged to the sewer.
• Soluble arsenic and iron concentrations in the backwash wastewater were high (i.e., 10.5 to
50.4 (ig/L for arsenic and 120 to 846 (ig/L for iron) when compared with those measured at
the rest of the arsenic demonstration sites. The soluble metals measured may include
dispersed colloidal particles due to the presence of elevated silica in water.
-------
Capital and O&M cost of the technology:
• The capital investment for the system was $305,447, consisting of $168,142 for equipment,
$53,435 for site engineering, and $83,870 for installation, shakedown, and startup.
• The unit capital cost was $l,222/gpm (or $0.85/gpd) based on a 250-gpm design capacity.
This calculation does not reflect the building cost as it was funded by the City.
• The O&M cost was $0.18/1,000 gal including incremental cost for chemicals, electricity, and
labor.
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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 Kinetico treatment system began on November 27, 2006, and operational data collection ended on
February 8, 2008. Table 3-2 summarizes the types of data collected and considered as part of the
technology evaluation process. The overall system performance was based on its ability to consistently
remove arsenic to below the target MCL of 10 |o,g/L through the collection of water samples across the
treatment train, as described in the Study Plan (Battelle, 2006). The reliability of the system was
evaluated by tracking the unscheduled system downtime and frequency and extent of repair and
replacement. The unscheduled downtime and repair information were recorded by the plant operator on a
Repair and Maintenance Log Sheet.
The O&M and operator skill requirements were assessed through quantitative data analysis and
qualitative observational considerations, including the need for pre- and/or post-treatment, level of system
automation, extent of preventative maintenance activities, frequency of chemical handling and inventory,
and general knowledge needed for relevant chemical processes and related health and safety practices.
The staffing requirements for the system operation were recorded on an Operator Labor Hour Log Sheet.
The quantity of aqueous and solid residuals generated was estimated by tracking the volume of backwash
water produced during each backwash cycle. Backwash wastewater was sampled and analyzed for
chemical characteristics.
The cost of the system was evaluated based on the capital cost per gal/min (gpm) (or gal/day [gpd]) of
design capacity and the O&M cost per 1,000 gal of water treated. This task required tracking the capital
cost for equipment, engineering, and installation, as well as the O&M cost for media replacement and
disposal, chemical supply, electricity usage, and labor.
Table 3-1. Predemonstration Study Activities and Completion Dates
Activity
Introductory Meeting Held
Project Planning Meeting Held
Draft Letter of Understanding Issued
Final Letter of Understanding Issued
Request for Quotation Issued to Vendor
Vendor Quotation Received
Purchase Order Established
Letter Report Issued
Engineering Package Submitted to MT DEQ
Study Plan Issued
System Permit Granted by MT DEQ
Building Construction Permit Granted by MT DEQ
Building Construction Began
FM-248-AS System Shipped/Delivered
System Installation Completed
Building Completed
System Shakedown Completed
Performance Evaluation Began
Date
November 30, 2004
April 5, 2005
April 12, 2005
April 22, 2005
April 22, 2005
May 19, 2005
June 8, 2005
June 15, 2005
November 2, 2005
September 14, 2005
January 26, 2006
April 7, 2006
April 13, 2006
May 24/30, 2006
June 5, 2006
July 3 1,2006
October 30, 2006
November 27, 2006
MT DEQ = Montana Department of Environmental Quality
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Table 3-2. Evaluation Objectives and Supporting Data Collection Activities
Evaluation Objective
Performance
Reliability
System O&M and Operator
Skill Requirements
Residual Management
System Cost
Data Collection
-Ability to consistently meet 10 ug/L of arsenic in treated water
-Unscheduled system downtime
-Frequency and extent of repairs including a description of problems, materials
and supplies needed, and associated labor and cost
-Pre- and post-treatment requirements
-Level of automation for system operation and data collection
-Staffing requirements including number of operators and laborers
-Task analysis of preventative maintenance including number, frequency, and
complexity of tasks
-Chemical handling and inventory requirements
-General knowledge needed for relevant chemical processes and health and
safety practices
-Quantity and characteristics of aqueous and solid residuals generated by
system operation
-Capital cost for equipment, engineering, and installation
-O&M cost for chemical usage, electricity consumption, and labor
3.2
System O&M and Cost Data Collection
The plant operator performed daily, weekly, and monthly system O&M and data collection according to
instructions provided by the vendor and Battelle. As long as possible, the plant operator recorded daily
system operational data, such as pressure, flowrate, totalizer, and hour meter readings on a Daily System
Operation Log Sheet, checked the sodium hypochlorite (NaOCl) and FeCl3 levels, and conducted visual
inspections to ensure normal system operations. If any problem occurred, the plant operator contacted the
Battelle Study Lead, who determined if the vendor should be contacted for troubleshooting. The plant
operator recorded all relevant information, including the problem encountered, course of actions taken,
materials and supplies used, and associated cost and labor incurred, on the Repair and Maintenance Log
Sheet. On a weekly basis, the plant operator measured several water quality parameters onsite, including
temperature, pH, dissolved oxygen (DO), oxidation-reduction potential (ORP), and residual chlorine, and
recorded them on a Weekly Onsite Water Quality Parameters Log Sheet. Monthly backwash data also
were recorded on a Backwash Log Sheet.
The capital cost for the arsenic removal system consisted of the cost for equipment, site engineering, and
system installation. The O&M cost consisted of the cost for chemical usage, electricity consumption, and
labor. Consumption of NaOCl and FeCl3 was tracked on the Daily System Operation Log Sheet.
Electricity consumption was determined from utility bills. Labor for various activities, such as routine
system O&M, troubleshooting and repairs, and demonstration-related work, was tracked using an
Operator Labor Hour Log Sheet. The routine system O&M included activities such as completing field
logs, replenishing chemical solutions, ordering supplies, performing system inspections, and others as
recommended by the vendor. Labor hours 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, were recorded, but not used for the cost analysis.
3.3
Sample Collection Procedures and Schedules
To evaluate system performance, samples were collected at the wellhead, across the treatment plant,
during Macrolite® filter backwash, and from the distribution system. Table 3-3 provides the sampling
schedule and analytes measured during each sampling event. Figure 3-1 presents a flow diagram of the
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Table 3-3. Sampling Schedule and Analyses
Sample
Type
Source
Water
Treatment
Plant Water
Backwash
Wastewater
Residual
Sludge
Distribution
Water
Sample
Locations(a)
IN
IN, AC,
TA, and TB
IN, AC, and
TT
Discharge
Line
Discharge
Area
One
Residence
and Two
Non-
Residences
No. of
Samples
1
4
3
2
2-3
3
Frequency
Once
Weekly
(non-
speciation
sampling)
Monthly
(speciation
sampling)
Monthly
Once
Monthly
Analytes
Onsite: pH,
temperature, DO, and
ORP
Offsite: As(III), As(V),
As (total and soluble),
Fe (total and soluble),
Mn (total and soluble),
U (total and soluble),
V (total and soluble),
Na, Ca, Mg, Cl, F, NO2,
NO3, NH3, SO4, SiO2,
PO4, alkalinity,
turbidity, TDS, and
TOC
Onsite: pH,
temperature, DO, ORP,
and C12 (total and free)
Offsite: As (total),
Fe (total), Mn (total),
SiO2, P (total),
alkalinity, and turbidity
Onsite: pH,
temperature, DO, ORP,
and C12 (total and free)
Offsite: As(III), As(V),
As (total and soluble),
Fe (total and soluble),
Mn (total and soluble),
Ca, Mg, F, NO3, SO4,
SiO2, P (total),
alkalinity, and turbidity
As (total and soluble),
Fe (total and soluble),
Mn (total and soluble),
TDS, TSS, andpH
TCLP metals and
total Al, As, Ca, Cd,
Cu, Fe, Mg, Mn, Ni, P,
Pb, Si, and Zn
As (total), Fe (total),
Mn (total), Cu, Pb, pH,
and alkalinity
Collection
Date(s) and
Results
Table 4-1
Appendix B
Appendix B
Table 4-13
Not
Sampled
Table 4-15
(a) IN = at wellhead; AC = after contact tanks; TA = after Vessel A; TB = after Vessel B;
TT = after filter effluent combined
TCLP = toxicity characteristics leaching procedure; TDS = total dissolved solids; TOC =
total organic carbon; TSS = total suspended solids
-------
Monthly (speciation sampling)
pHW, temperature^, DOW, ORPW,
As speciation, Fe (total and soluble), Mn (total
and soluble), Ca, Mg, F, NO3, SO4, SiO2,
P (total), alkalinity, and turbidity
pHW, temperature^, DOW, ORPW,
C12 (total and free), As speciation, Fe
(total and soluble), Mn (total and
soluble), Ca, Mg, F, NO3, SO4, SiO2,
P (total), alkalinity, and turbidity
SANITARY SEWER
TO LAGOON
TCLP metals, Al
_ (total), As, Ca, Cd,
' Cu, Fe, Mg, Mn, Ni,
P, Pb, Si and Zn
Three Forks, MT
Macrolite® Arsenic Removal System
Design Flow: 250 gpm
- Weekly (non-speciation sampling)
pHW, temperature^, DOW, ORPW,
As (total), Fe (total), Mn (total), SiO2,
P (Total), alkalinity and turbidity
90%
BACKWASH
RECYCLE TANK
pH, TDS, turbidity,
As (total, soluble),
Fe (total, soluble),
Mn (total, soluble)
pHW, temperatureW, DOW, ORPW,
^C12 (total and free)W, As (total), Fe
"(total), Mn (total), SiO2, P (total),
alkalinity and turbidity
pHW, temperatureW, DOW, ORPW,
C12 (total and free)W, As (total), Fe
(total), Mn (total), SiO2, P (total),
alkalinity and turbidity
pHW, temperatureW, DOW, ORPW,
C12 (total and free), As speciation, Fe
(total and soluble), Mn (total and
soluble), Ca, Mg, F, NO3, SO4, SiO2,
P (total), alkalinity, and turbidity
Footnote
(a) On-site analyses
1
T)
r
DISTRIBUTION
SYSTEM
Water Sampling Locations
LEGEND
(IN) At Well Head
f AC J After Contact Tanks
(TA) After Tank A
(TB) After Tank B
(TT) After Filter Effluent Combined
fBWj Backwash Sampling Location
( SS J Sludge Sampling Location
INFLUENT Unit Process
DA: C12 Chlorine Disinfection
^ .
Figure 3-1. Process Flow Diagram and Sampling Schedule and Locations
10
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treatment system along with the analytes and schedule for each sampling location. Specific sampling
requirements for analytical methods, sample volumes, containers, preservation, and holding times are
presented in Table 4-1 of the EPA-endorsed Quality Assurance Project Plan (QAPP) (Battelle, 2004).
The procedure for arsenic speciation is described in Appendix A of the QAPP.
3.3.1 Source Water. During the initial site visit, one set of source water samples was collected
and speciated using an arsenic speciation kit (Section 3.5.1). The sample tap was flushed for several
minutes before sampling; special care was taken to avoid agitation, which might cause unwanted
oxidation. Analytes for the source water samples are listed in Table 3-3.
3.3.2 Treatment Plant Water. The initial plan was for the plant operator to collect treatment
plant water samples weekly, on a four-week cycle, for on- and offsite analyses. For the first week of each
four-week cycle, samples were collected at the wellhead (IN), after the contact tanks (AC), and after the
effluent from the two filtration vessels combined (TT), and speciated onsite and analyzed for the analytes
listed under speciation sampling in Table 3-3. On the second, third, and fourth weeks of the four-week
cycle, samples were collected at IN, AC, after Vessel A (TA), and after Vessel B (TB) and analyzed for
the analytes listed under non-speciation sampling in Table 3-3. Sampling following this schedule was
only conducted in November to December 2006, and March to April 2007. Due to earlier-than-expected
particulate iron and arsenic breakthrough in the filter effluent, this sampling schedule was discontinued
and a series of special studies under varying process conditions was conducted as described in
Section 3.4.
3.3.3 Backwash Wastewater. Five sets of backwash water samples were collected by the plant
operator from December 2006 to April 2007. Tubing, connected to the tap on the discharge line of each
vessel, directed a portion of backwash wastewater at about 1 gpm into a clean, 32-gal container over the
entire backwash duration from each vessel. After the content in the container was thoroughly mixed,
composite samples were collected and/or filtered onsite with 0.45-(im disc filters. Analytes for the
backwash samples are listed in Table 3-3.
3.3.4 Distribution System Water. Prior to system startup from June to September 2005, four
monthly baseline distribution water samples were collected from two non-residences and one residence
that had been included in the City's Lead and Copper Rule (LCR) sampling. Among others, the samples
were analyzed for arsenic, lead, and copper. Following system startup, distribution system water
sampling continued on a monthly basis at the same three locations from December 2006 to January 2008.
Homeowners collected samples following an instruction sheet developed according to the Lead and
Copper Monitoring and Reporting Guidance for Public Water Systems (EPA, 2002). The dates and times
of last water usage before sampling and of actual sample collection were recorded for calculation of the
stagnation time. All samples were collected from a cold-water faucet that had not been used for at least 6
hr to ensure that stagnant water was sampled.
The distribution system water sampling might not achieve the intended results because the Well 2 treated
water had been blended with source water from Wells 5, 6, 8, and 9, which contained little or no arsenic.
Nonetheless, the sampling proceeded as planned.
3.3.5 Residual Solids. Residual solids produced by the treatment process consisted of only
backwash wastewater solids. Residual solids were not sampled due to the request of the operator to end
the study after February 8, 2008 prior to sample collection.
11
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3.4 Special Studies
A series of special studies was conducted to improve the performance of the pressure filters for iron and
arsenic removal. The studies were necessary because the analytical results from the first three weeks of
treatment plant sampling (i.e., from November 29 through December 12, 2006) indicated significantly
elevated arsenic and iron concentrations in the filter effluent. The studies performed involved:
• Filter run-length with the use of higher iron doses. A filter run length study was
conducted on December 20, 2006, and then on January 10, 2007. The December 20
study involved collecting treatment plant water samples from all four sampling
locations at 1 and 4 hr of service time and analyzing the samples for total arsenic,
iron, and manganese. The January 10 study encompassed the collection of similar
water samples at approximately 1.0, 2.0, and 4.0 hr and the analysis of the samples
for all five onsite analytes (Table 3-3) and total and/or soluble arsenic, iron, and
manganese. The iron dosages applied during the two studies were 1.8 and 2.2 mg/L
(as Fe), respectively. Regular sampling as outlined in Table 3-3 was temporarily
suspended from December 12, 2006, to March 21, 2007.
• Use of a finer filter media size fraction. Because a significant amount of arsenic-
laden iron particles continued to prematurely break through the pressure filters, the
top 6-in of the filter media at 40/60 mesh was replaced with a 6-in layer of finer
media at 70/80 mesh. Upon completion of the media replacement on March 13,
2007, regular sampling as outlined in Table 3-3 resumed on March 21, 2007, and
lasted until April 25, 2007.
• Use of an iron/organic polymer blend. Analytical results collected between March 21 and
April 25, 2007, revealed that the media bed modification failed to produce the anticipated
result and that a significant amount of particulate iron and arsenic continued to penetrate
through the pressure filters. Efforts were then made to determine if the use of a coagulant aid
might help form more filterable floes, thereby improving the filter performance. An iron/
polymer mixture (C-05, a blend of 38% FeCl3 with an organic polymer; the amount and type
of the polymer were unknown) was recommended by Kinetico to replace the FeCl3, so that no
additional feed equipment would be needed for separate polymer addition.
To evaluate iron and polymer dosages, 12 jar tests were performed by Kinetico on June 4,
2007. Source water collected from the IN location was dosed with three free chlorine
dosages, i.e., 0.5, 1.0, and 1.5 mg/L (as C12), and four C-05 dosages, i.e., 1.0, 1.5,2.0, and 2.5
mg/L (as Fe). After mixing for 8 min, supernatant in each jar was filtered with 0.45-(im disc
filters before being analyzed for arsenic and iron.
The use of C-05 in the full-scale system was started on July 6, 2007 with the chlorine and C-
05 blend dosages set at 1.5 mg/L (as C12) and 2.5 mg/L (as Fe), respectively. (The C-05
blend was delivered to the injection point by ramping up the feed pump stroke length by
about 10% to account for the polymer content in the blend.) A run-length study was carried
out on July 17, 2007, with filter effluent samples collected at approximately 3, 6, and 10 hr
and analyzed for arsenic and iron. Because of lack of improvement to the filter effluent, the
use of C-05 blend was discontinued in August 2007.
While awaiting the implementation of C-05 iron/polymer blend, regular sampling as outlined
in Table 3-3 was suspended again from April 25, 2007 to July 17, 2007. Afterwards, regular
sampling was suspended indefinitely.
12
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• Use of other coagulant aids. On October 30, 2007, eight jar tests were conducted onsite by a
chemical supplier, Hawkins, to further investigate the use of coagulant aids, including alum
and seven polymer blends, on coagulation of arsenic and iron particulates. The jar tests were
performed because the use of the C-05 blend resulted in minimal, if any, improvement to the
filter effluent. Water, collected from the AC location containing 2.2 mg/L of iron (as Fe),
was dosed with a varying amount of the coagulant aids listed in Table 3-4. After mixing for
20 min, supernatant from each jar was filtered with 0.45-(im disc filters before being
analyzed for arsenic and iron. The use of these coagulant aids was never implemented at the
site because of concerns over media fouling by the facility operator.
For each run length study, rise of Ap across the pressure filters was carefully monitored, along with
particulate iron and arsenic concentrations, against incremental filter run times. These studies allowed for
the evaluation of filter performance between consecutive backwash events. The results of the run length
studies and associated jar tests are discussed in Section 4.5.2.
During the special study period, the City began to increase the blending ratio between treated water from
Well 2 and raw water from other wells to meet the 10-(ig/L arsenic MCL within the distribution system.
Table 3-4. Coagulant Aids Jar-Tested by Hawkins
Polymer
Aqua Hawk 427
Aqua Hawk 6527
Aqua Hawk 6547
Alum
Aqua Hawk 9827
Aqua Hawk 9827
Aqua Hawk 9847
Aqua Hawk 9847
Description
Polymer blend (AL/PD/PY)
PD
PD
NA
Long chain polymer
Long chain polymer
Long chain polymer
Long chain polymer
Unit Cost
($/sal)
$10.61
$11.33
$16.04
NA
NA
NA
NA
NA
Dosage
(mg/L)
1
1
1
10
0.2
0.5
0.2
0.5
3.5
AL = Polyaluminum hydroxychloride
PD = Polydiallyldimethylammonium chloride
PY = Polyquaternary amine
Sampling Logistics
3.5.1 Preparation of Arsenic Speciation Kits. The arsenic field speciation method uses an anion
exchange resin column to separate the soluble arsenic species, As(V) and As(III) (Edwards et al., 1998).
Resin columns were prepared in batches at Battelle laboratories according to the procedures detailed in
Appendix A of the QAPP (Battelle, 2004).
3.5.2 Preparation of Sample Coolers. For each sampling event, a sample cooler was prepared
with the appropriate number and type of sample bottles, disc filters, and/or speciation kits. All sample
bottles were new and contained appropriate preservatives. Each sample bottle was affixed with a pre-
printed, colored-coded label consisting of the sample identification (ID), date and time of sample
collection, collector's name, site location, sample destination, analysis required, and preservative. The
sample ID consisted of a two-letter code for the demonstration site, the sampling date, a two-letter code
for a specific sampling location, and a one-letter code designating the arsenic speciation bottle (if
13
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necessary). The sampling locations at the treatment plant were color-coded for easy identification. The
labeled bottles were separated by sampling location, placed in Zip-lock® bags, and packed into 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 airbills were complete except for the operator's signature and the sample dates and
times. After preparation, the sample cooler was sent to the site via FedEx for the following week's
sampling event.
3.5.3 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 metal analyses were stored at Battelle's inductively coupled plasma-mass spectrometry (ICP-
MS) laboratory. Samples for other water quality analyses were packed in separate coolers and picked up
by couriers from American Analytical Laboratories (AAL) in Columbus, OH; TCCI Laboratories in New
Lexington, OH; and/or Belmont Labs in Englewood, OH, all of which were under contract with Battelle
for this demonstration study. The chain-of-custody forms remained with the samples from the time of
preparation through analysis and final disposition. All samples were archived by the appropriate
laboratories for the respective duration of the required hold time and disposed of properly thereafter.
3.6 Analytical Procedures
The analytical procedures described in Section 4.0 of the QAPP (Battelle, 2004) were followed by
Battelle ICP-MS, AAL, TCCI Laboratories, and Belmont Labs. Laboratory quality assurance/quality
control (QA/QC) of all methods followed the prescribed guidelines. Data quality in terms of precision,
accuracy, method detection limits (MDLs), and completeness met the criteria established in the QAPP (i.e.,
relative percent difference [RPD] of 20%, percent recovery of 80% to 120%, and completeness of 80%).
The quality assurance data associated with each analyte will be presented and evaluated in a QA/QC
Summary Report to be prepared under separate cover upon completion of the Arsenic Demonstration
Project.
Field measurements of pH, temperature, DO, and ORP were conducted by the plant operator using a
WTW Multi 340i handheld field meter, which was calibrated for pH and DO prior to use following the
procedures provided in the user's manual. The ORP probe also was checked for accuracy by measuring
the ORP of a standard solution and comparing it to the expected value. The plant operator collected a
water sample in a clean, plastic beaker and placed the probe in the beaker until a stable value was
obtained. The plant operator also performed free and total chlorine measurements using Hach chlorine
test kits following the user's manual.
14
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4.0 RESULTS AND DISCUSSION
4.1
Site Description
4.1.1 Pre-existing Facility. The City of Three Forks had a population of approximately 2,000
residents. The water system was supplied by five wells (Wells 2, 5, 6, 8, and 9), which had a maximum
combined capacity of 1,200,000 gpd. Located near the Jefferson River, Wells 5, 6, 8, and 9 did not
contain elevated levels of arsenic and were used by the City to meet the daily water demand of
approximately 120,000 gpd. Well 2, located adjacent to an active pasture at Connor's Ranch, drew water
from the Madison River, which was rich in arsenic from the upflow of geothermal water at Yellowstone
National Park. Therefore, Well 2 was designated for this demonstration study. Prior to startup of the
arsenic treatment system, Well 2 had been used only in the summer for cemetery irrigation for 5 to 8
hr/day and 3 day/week. After startup, the treated water from Well 2 also was used to supply water to the
distribution system.
Well 2 was 12.5-in in diameter and 150 ft deep with a screened interval extending from 75.5 to 150 ft
below ground surface (bgs). The static water table was at 18 ft bgs. Well 2 was equipped with a 30-
horsepower (hp) submersible pump rated for 250 gpm at 85 psi of total dynamic head (TDH). Figure 4-1
shows the pre-existing Well 2 pump house, which housed the wellhead piping, a pressure gauge, and a
sample tap (Figure 4-2). Raw water from Well 2 was not treated prior to the demonstration study.
An onsite sewer system discharged wastewater into a lagoon and then the Madison River during the
summer months. Designed to serve a population of 2,200 people, the lagoon was composed of two 7-acre
cells with depths ranging from 3.5 to 5 ft.
Figure 4-1. Pre-existing Well 2 Pump House
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Figure 4-2. Interior Piping of Well 2 Pump House
4.1.2 Source Water Quality. Samples of Well 2 water were collected by Battelle on November
30, 2004, during the introductory meeting for this demonstration project. The source water was filtered
for soluble arsenic, iron, manganese, uranium, and vanadium, and then speciated for As(III) and As(V)
using the field speciation method modified from Edwards (1998) by Battelle (Wang et al, 2000). In
addition, pH, temperature, DO, and ORP were measured onsite using a WTW Multi 340i field meter.
Table 4-1 summarizes the analytical results of the Well 2 source water sampling and those provided by
the facility for the demonstration site selection and by the selected technology vendor (Kinetico).
Historical data collected by MT DEQ from July 1993 through July 1998 also are included in the table.
Overall, Battelle's data are comparable to those provided by other parties with the exception of a few
parameters provided by the facility. Well 2 had not been sampled by MT DEQ since 1998 as it was not
used as a drinking water well nor connected to the City' distribution system.
The treatment system for the Three Forks site included iron addition, adsorption/coprecipitation, and
Macrolite® pressure filtration. Several factors, such as arsenic speciation, iron concentration, pH,
16
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Table 4-1. Three Forks, MT Well 2 Source Water Data
Parameter
Unit
Date
pH
Temperature
DO
ORP
Total Alkalinity (as CaCO3)
Hardness (as CaCO3)
Turbidity
TDS
TOC
Nitrate (as N)
Nitrite (as N)
Ammonia (as N)
Chloride
Fluoride
Sulfate
Silica (as SiO2)
Orthophosphate (as P)
As (total)
As (total soluble)
As (paniculate)
As(III)
As(V)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
U (total)
U (soluble)
V (total)
V (soluble)
Na (total)
Ca (total)
Mg (total)
S.U.
°c
mg/L
mV
mg/L
mg/L
NTU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Hg/L
ug/L
Hg/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
mg/L
mg/L
mg/L
Facility
Data
NA
7.4
NA
NA
NA
NA
246
NA
692
65(b)
11.5
NA
NA
19.0
NA
NA
49.0
0.86
72.0
NA
NA
NA
NA
<30
NA
NA
NA
NA
NA
NA
NA
NA
NA
13.1
Kinetico
Data
10/22/03
7.4
NA
NA
NA
236
185
NA
NA
NA
<1.0
NA
NA
19.7
2.2
18
49.2
<0.5
85.0
NA
NA
NA
NA
<30
NA
<10
NA
NA
NA
NA
NA
47.0
52.0
13.5
Battelle
Data
11/30/04
7.5
11.3
5.2
62
260
205
0.2
292
0.8
0.4
<0.01
0.05
17.0
2.2
18
48.7
O.06
64.3
63.7
0.6
1.3
62.4
<25
<25
<0.1
0.1
3.6
3.8
8.0
8.4
43.9
59.3
13.7
MTDEQ
Data(a)
07/07/93-07/21/98
NA
NA
NA
NA
NA
NA
NA
NA
NA
0.42
O.005
NA
NA
0.2-2.4
23
NA
NA
60-78
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
(a) MT DEQ historical data collected from 1993 through 1998 tabulated in Table 4-2.
(b) Data questionable.
NA = not analyzed
turbidity, total organic carbon (TOC), and competitive anions, may affect the system performance. The
results of the source water assessment and implications for water treatment are discussed below.
Arsenic. Total arsenic concentrations ranged from 60 to 85 |o,g/L. Based on the November 30, 2004,
speciation results, arsenic existed almost entirely in the soluble form. Of the soluble fraction, 1.3 |o,g/L
existed as As(III) and 62.4 |o,g/L as As(V). Therefore, As(V) was the predominant species and
prechlorination for the oxidation of As(III) to As(V) was not required for treatment. Prechlorination was
used for disinfection purposes through the treatment system and to maintain chlorine residuals in the
distribution system.
17
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The presence of As(V) as the predominant species is consistent with the relatively high DO level of 5.2
mg/L measured for the same sample. The ORP reading was 62 mV, somewhat lower than what would be
expected for an oxidizing water. ORP readings were carefully monitored during the performance
evaluation study.
Iron and Manganese. The source water did not contain detectable levels of iron or manganese.
Therefore, adsorptive media would be ideal candidates for this source water. However, because of
concerns over the O&M cost, the City decided to choose coagulation/filtration using FeCl3 rather than
adsorptive media. For effective arsenic removal via the coagulation/filtration process, the iron
concentration should be 20 times the arsenic concentration (Sorg, 2002). The treatment process relied
upon adsorption and coprecipitation of As(V) onto/with iron solids.
Other Water Quality Parameters. The pH range of 7.4 to 7.5 was within the target range of 5.5 to 8.5
for arsenic removal via adsorption/coprecipitation onto/with iron solids. Results of other water quality
parameters shown in Table 4-1 are comparable with exception to the results provided by the facility for
nitrate (i.e., 11.5 mg/L), orthophosphate (i.e., 0.86 mg/L), total dissolved solids (TDS) (i.e., 692 mg/L),
and TOC (i.e., 65 mg/L). These values are all significantly higher than those provided by other parties.
The extremely high TOC was believed to be an error.
The raw water also was sampled by MT DEQ for heavy metals, such as antimony, barium, beryllium,
cadmium, chromium, mercury, nickel, selenium, and thallium (see Table 4-2). These metals were not
detected except for antimony (i.e., 0.003 mg/L) and barium (i.e., 0.02 mg/L) on one occasion.
Table 4-2. Three Forks, MT Historic Water Quality Data
Parameter
Unit
Date
Nitrate (as N)
Nitrite (as N)
Nitrate + Nitrite (as N)
Fluoride
Sulfate
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Mercury
Nickel
Selenium
Thallium
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Well 2 Raw Water Data
07/07/93
NA
NA
0.52
2.4
23
0.003
0.06
0.02
ND
ND
ND
ND
ND
ND
ND
07/05/94
NA
NA
ND
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
09/20/94
NA
NA
0.13
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
09/11/95
NA
NA
0.19
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
06/19/96
0.42
ND
0.42
0.2
23
ND
0.078
ND
ND
ND
ND
ND
ND
ND
ND
07/21/98
NA
NA
0.44
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Source: MT DEQ.
NA = not analyzed; ND = not detected
4.1.3 Distribution System. The distribution system for the City of Three Forks consisted of an 8-
mile closed distribution line supplied by Wells 5, 6, 8, and 9 prior to the demonstration study. The
distribution system was extended to include Well 2 after startup of the arsenic treatment system.
According to the utility operator, the distribution system piping was a combination of 6-, 8-, 10-, and 12-
in ductile iron, polyvinyl chloride (PVC), and asbestos cement. The service lines were galvanized,
18
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copper, and polyethylene piping. Well water was pumped into a 1,000,000-gal water tank (Figure 4-3)
immediately adjacent to the treatment building for storage and distribution. The three locations that were
selected for monthly baseline and distribution system water sampling were impacted by all five wells.
The City of Three Forks sampled water from the distribution system for several parameters: monthly at
two residences for bacterial analysis; once every three years at 10 residences for LCR analysis; and once
every nine years for asbestos analysis. Wells 5, 6, 8, and 9 also were sampled yearly for nitrate and
nitrite; once every three years for arsenic, volatile organic compounds (VOCs), synthetic organic
compounds (SOCs), inorganics, and periodically for radionuclides.
4.2
Figure 4-3. One-million Gallon Water Tank by Treatment Building
Treatment Process Description
The arsenic treatment system installed was a Kinetico coagulation/filtration system that included
Macrolite® pressure filtration. Macrolite® is a ceramic media manufactured by Kinetico approved for use
in drinking water applications under NSF International (NSF) Standard 61. As claimed by the vendor, the
spherical, low density and chemically inert media is designed to allow for filtration rates up to 10 gpm/ft2.
The physical properties of this media are summarized in Table 4-3.
Figure 4-4 is a schematic of the Macrolite® FM-248-AS arsenic removal system. The treatment system
was composed of two chemical feed systems for chlorine and FeCl3, two contact tanks (arranged in
parallel), two pressure filtration vessels (arranged in parallel), and associated instrumentation to monitor
inlet and outlet pressure, system flowrate, backwash flowrate, and backwash wastewater turbidity. The
system also was equipped with a central control panel that housed a touch screen operator
19
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Table 4-3. Properties of 40/60 Mesh Macrolite® Media
Property
Color
Thermal Stability (°F)
Uniformity Coefficient
Sphere Size Range (in)
Bulk Density (g/cm3 or lb/ft3)
Specific Gravity
Value
Taupe, Brown, Grey
2000
1.1
0.014-0.009
0.86 or 54
2.05
interface panel (OIP), a programmable logic controller (PLC), a modem, and an uninterruptible power
supply (UPS). The Allen Bradley PLC automatically controlled the system by actuating PVC pneumatic
valves using a 7.5-hp compressor depending on various inputs and outputs of the system and
corresponding PLC setpoints. The system featured schedule 80 PVC solvent bonded plumbing and all
necessary isolation and check valves and sampling ports. The system's design specifications are
summarized in Table 4-4.
Kinetico® FM-248-AS Arsenic Removal System
Feed Water
at 50-100 psi..
NaOCI
I
I
I
FeCls
63" x 86"
63" x 86"
I
| Existing or |
I Supplied by,
' Three Forks'
Contact
Vessels
Backwash Waste
to Existing Lagoon
or Backwash
Recycle System
Filtered Water
to Storage/Distribution
by Others
Figure 4-4. Schematic of Kinetico's Macrolite® Arsenic Removal System
The treatment technology includes the following major process steps and system components:
• Intake. Raw water was pumped from Well 2, which was equipped with a 30-hp submersible
pump rated for 250 gpm at 85 psi TDH to the distribution system. The well pump was
controlled by a pair of high/low level sensors in the 1,000,000-gal water storage tank.
• Chlorination. The prechlorination system was used for disinfection purposes through the
treatment system and to maintain a total chlorine residual level of approximately 0.9 mg/L (as
C12) in the distribution system. MT DEQ requires that a minimum of 0.2 to 0.5 mg/L (as C12)
20
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Table 4-4. Design Specifications of Macrolite® System
Parameter
Value
Remarks
Influent Specifications
Peak Flowrate (gpm)
Arsenic Concentration (|J.g/L)
Iron Concentration (M-g/L)
250
<90
<25
—
-
-
Pretreatment
Chlorine Residual (mg/L [as C12])
Iron Addition (mg/L)
0.9
2.0
From 12.5% NaOCl stock
From 35% FeCl3 stock (diluted 1 :4)
Contact
Number of Tanks
Configuration
Tank Size (in)
Contact time (min)
2
Parallel
63 D x 86 H
5
-
-
-
—
Filtration
Number of Vessels
Configuration
Vessel Size (in)
Media Volume (ft3/vessel)
Media Bed Depth (in)
Peak Filtration Rate (gpm/ft2)
2
Parallel
48 D x 72 H
25
24
10
—
—
-
-
-
-
Backwash
Pressure Drop (psi)
Initiating Pressure (psi)
Initiating Standby Time (hr)
Initiating Service Time (hr)
Hydraulic Loading Rate (gpm/ft2)
Duration (min/vessel)
Turbidity Setpoint (NTU)
Wastewater Production (gal/event)
10-12
20
48
24
8-10
10-15
10
2,000-3,750
Across a clean bed
Across bed at end of filter run
-
-
100 to 125 gpm
-
To terminate backwash
From backwashing both vessels
Effluent Specifications
Peak Flowrate (gpm)
Maximum Daily Production (gpd)
Hydraulic Utilization (%)
Arsenic Concentration (|J.g/L)
Iron Concentration (|J.g/L)
250
360,000
6-21
<10
<25
Typically expected
Based on peak flowrate, 24 hr/day
Estimate based on expected demand(a)
-
-
(a) Operation of approximately 10 hr/week during winter and 35 hr/week during summer.
of free chlorine residuals be maintained at distant points of a distribution system. The
chlorine feed system (Figure 4-5) consisted of a 55-gal high-density polyethylene (HDPE)
day tank containing a 12.5% NaOCl solution, a 0.04-hp chemical feed pump (LMI B711-
490HI model) with a maximum flowrate of 1.6 gal/hr (gph), a maximum pressure of 150 psi,
and a 66-gal polyethylene spill containment pallet (U.S. Plastic model 2316). The feed pump
was energized only when the well pump was on.
• Iron Addition. FeCl3 was added at a target dosage of approximately 2.0 mg/L (as Fe) to
remove soluble As(V). The FeCl3 feed system consisted of a 55-gal HDPE day tank
containing a solution mixed from a 35% FeCl3 stock, a 1/20-hp, 1,550 rotations per minute
(rpm) overhead mixer (Pulsafeeder model J40456-F-M-TE-Fi/WRD/Vinyl), and a chemical
feed pump (Pulsation LPH5MA-VTC3-XXX) rated at 3.15 gph nominal flowrate and 150 psi
maximum pressure.
21
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Figure 4-5. Chemical Feed Systems
The iron and chlorine addition systems shared the same spill containment pallet as shown in
Figure 4-5. The chemical feed pump was energized only when the Well 2 pump was on.
Adsorption/Coprecipitation. Two 63-in x 86-in FRP tanks arranged in parallel provided 5
min of contact time to enhance the formation of arsenic-laden iron solids prior to pressure
filtration. Each 1,160-gal tank had a 6-in top and a 6-in bottom flange connecting to the exit
and inlet piping, respectively, for an upflow configuration. Figure 4-6 shows the two contact
tanks along with the inlet and exit piping.
Pressure Filtration. Removal of arsenic-laden iron particles from the contact tank effluent
was achieved via downflow filtration through two 48-in x 72-in FRP pressure filtration
vessels configured in parallel. The vessels were floor mounted and piped to a valve rack
mounted on a welded, stainless steel frame (Figure 4-7). Each filtration vessel was filled with
approximately 24 in (or 25 ft3) of 40/60 mesh Macrolite® media supported by fine garnet
underbedding filled to 1 in above a stainless steel wedge-wire underdrain with 0.006-in slots.
The flow through each vessel was regulated to 125 gpm with a flow-limiting device. The
normal system operation with both vessels online provided a total system flowrate of 250
gpm.
22
-------
Figure 4-6. Contact Tanks with Inlet and Exit Piping
Figure 4-7. Filtration Vessels and Valve Rack
23
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Filter Backwash. At a 10-gpm/ft2 loading rate and a 24-in bed depth, the anticipated
pressure drop across a clean Macrolite® filter bed was 10 to 12 psi. The filters were
automatically backwashed in succession in an upflow mode based on a service time, a
standby time, or a Ap setpoint. Initial design specified that during each backwash cycle,
water was drained from the first filtration vessel, which was then sparged with air at 150 psi
for 2 min using a Speedaire Model 1WD61 air compressor. After a 25-min settling period,
the filtration vessel was backwashed with treated water from the distribution system until the
backwash wastewater reached a desired turbidity threshold setpoint (e.g., 20 nephelometric
turbidity units [NTU]) as measured by an inline Hach™ turbidimeter (Figure 4-8). These
design values were altered throughout the course of the demonstration study as discussed in
Section 4.4.3.1. The filtration vessel then underwent a filter-to-waste rinse before returning
to service, and the second filtration vessel was backwashed thereafter. Shortly after system
startup, it was determined that a booster pump needed to be installed to achieve the required
backwash pressure from the treated water line due to the treatment system being constructed
at the same elevation as the 1,000,000-gallon storage tank. To remedy this, a 7.5-hp booster
pump (Blador 11SH model) was installed.
ss
Figure 4-8. Hach™ Turbidimeter for Control of Backwash Duration
As originally designed, the backwash wastewater was discharged to a recycling tank. The
backwash recycle system (Figure 4-9) consisted of a 92-in diameter, 3,000 gal cone-shaped-
bottom holding tank and a 5-hp Blador G&L pump (Model SSV). Upon completion of a
backwash, wastewater in the backwash wastewater tank was allowed to settle for a period of
time (Section 4.4.3.1) before the supernatant was pumped at 100 to 120 gpm through a 20-in,
5-(im bag filter back to the head of the treatment train. Two weeks after commencement of
24
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the performance evaluation study, the City installed piping and a manual diverter valve to
drain the recycle tank supernatant directly to the sewer. This was done to help
isolate/identify factors that adversely affected the treatment results (i.e., apparent
breakthrough of soluble As[V] and arsenic-laden iron particles from the filters) observed
during the first two weeks of system operations. Wastewater recycling was never put back
into service throughout the remainder of the evaluation study. Had recycling been
implemented as designed, the sludge that settled and accumulated in the recycle tank would
be removed periodically from the bottom of the tank through a sludge removal port.
€'
4.3
Figure 4-9. Backwash Recycle System
Water Storage and Distribution. After leaving the treatment train, the treated water was
transferred into the 1,000,000-gal storage tank located next to the treatment building. The
stored effluent was allowed to flow to the distribution system based on demand.
Treatment System Installation
4.3.1 System Permitting. The system engineering package, prepared by Kinetico and its
subcontractor, Morrison Maierle, Inc., included a system design report, a general arrangement and piping
and instrumentation diagram (P&ID), electrical and mechanical drawings and component specifications,
25
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and building construction drawings detailing connections from the system to the inlet piping and the
City's water and sanitary sewer systems. The engineering package was certified by a Professional
Engineer registered in the State of Montana and submitted to MT DEQ for review and approval on
November 2, 2005. A water supply construction permit was issued by MT DEQ on January 26, 2006.
The permit approval letter required that a complete set of record drawings be signed, stamped, certified
(that the system was constructed in accordance with approved plans and specifications), and submitted to
MT DEQ within 90 days following completion of the construction.
4.3.2 Building Construction. A permit for building construction was approved by MT DEQ on
April 7, 2006. Construction began on April 13, 2006 and was completed on July 31, 2006. The building
was 15 ft x 29 ft with sidewall and roof peak heights of 17 and 22 ft, respectively. The foundation had a
102-in-depth overlain with a 6-in concrete slab. Wastewater discharge was facilitated with a 1,500-gal
underground sump that emptied by gravity into the sanitary sewer. In addition to electrical and plumbing
connections, a phone line also was installed to enable the equipment vendor to dial into the modem in the
control panel for any troubleshooting. Figure 4-10 shows photographs of the constructed building.
Figure 4-10. Treatment System Building
4.3.3 System Installation, Startup, and Shakedown. The treatment system was delivered to the
site on May 30, 2006 (see Figure 4-11). The vendor, through its subcontractor, performed the off-loading
and installation of the system, including connections to the entry and distribution piping and electrical
interlocking. System installation, hydraulic testing, and media loading were completed on June 5, 2006,
but system startup and shakedown were delayed due to the absence of power to the building; power
connection was completed on June 26, 2006. Startup/shakedown activities began on July 11, 2006, but
ended prematurely due to insufficient pressure in the treated waterline for backwash (Section 4.2). A 20-
26
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hp Goulds 11SH model booster pump was then procured and installed by the City under Kinetico's
guidance and became operational on October 25, 2006. Kinetico technicians remained onsite to perform
system startup and shakedown, which lasted until October 30, 2006. The shakedown and startup
activities included PLC testing, instrument calibration, prolonged backwashing to remove Macrolite®
media fines, chlorine disinfection and residual testing, and operator training on system O&M.
Two Battelle staff members traveled to the site to perform system inspections and operator training on
sample and data collection on November 28 and 29, 2006. As a result of the system inspections, several
punch-list items were identified and are summarized in Table 4-5.
4.4
Figure 4-11. Treatment System Delivery at Three Forks, MT Site
System Operation
4.4.1 Service Operation. System operational parameters are tabulated and attached as Appendix
A with key parameters summarized in Table 4-6. The performance evaluation study began on November
27, 2006, and ended on February 8, 2008, with the treatment plant treating approximately 30,499,000 gal
of water. The amount of water treated was based on readings from a flow meter/totalizer installed at the
effluent side of the pressure filters.
Through the study period, the system operated for a total of 2,543 hr, based on well pump hour meter
readings from November 27, 2006, to February 16, 2007, and filter run time from February 16, 2007, to
February 8, 2008. The system operated for 2 to 7 days per week for a total of 284 days, excluding some
weekends and weekdays when the system was not operating (see Appendix A) and some weekdays when
27
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Table 4-5. System Inspection Punch-List Items
Item
No.
1
2
3
4
5
6
7
8
9
Punch-List Item Description
Check programming to determine
cause for Vessel A's returning to
service only after reaching 45 min
delay time following backwashing
Check/revise maximum backwash
time programming
Adjust recycle flowrate and low
backwash flowrate setpoint to meet
State requirements and provide
effective backwashing
Adjust delay time for backwash
wastewater recycling
Repipe influent piping (Figure 4-
12), which was not installed per
Drawing 2-1251-01
Reset differential pressure setpoint
to 25 psi
Adjust/improve backwash water
recycling programming
Repair air relief valves, which
leaked water constantly
Repair leaky recycle piping
Corrective Action(s) Taken
• Programming checked; Vessel A returned to
service upon completion of backwashing
• Programming checked, no further action required
• Recycle flowrate reduced from 44 to 20 gpm
• Low backwash flowrate setpoint increased from
20 to 100 gpm
• Increased delay time from 45 to 240 min to allow
for settling of backwash solids
• Raw water sample tap relocated to >10 ft from
chemical addition points; Chlorine and ferric
chloride injection points relocated further
downstream (Figure 4-12)
• A differential pressure trigger lockout added to
allow for increased differential pressure during
backwash
• Further explanation given on PLC/alarm interface
• Total maximum backwash time reduced to 20 min
• Gaskets of air relief valves replaced
• Piping repaired by City
Resolution
Date
12/01/06
12/01/06
12/01/06
12/08/06
12/11/06
12/11/06
12/15/06
12/15/06
12/15/06
the system or Well 2 was taken offline for repair and/or maintenance (see Table 4-7). To curb the
elevated arsenic concentrations in the pressure filter effluent, the City implemented an increased blending
scenario by reducing the operating schedule for Well 2 from 5-7 day/week to only 3 day/week on
Mondays, Wednesdays, and Fridays. The average daily operating time was 8.9 hr/day, representing a
daily use rate of 37%. With 30,499,000 gal of water treated, the average daily demand was 107,400 gpd,
compared to 120,000 gpd reported by the facility prior to this demonstration study.
System flowrates were tracked by both instantaneous readings of the flow meter/totalizer installed at the
effluent side of the pressure filters and calculated values based on readings of the flow totalizer and well
hour meter or filter run time. As shown in Table 4-6, instantaneous flowrate readings ranged from 140 to
216 gpm and averaged 202 gpm, which is comparable to the calculated value of 206 gpm, but 19.2%
lower than the design value of 250 gpm. As a result, the average contact time in the two contact tanks
increased from the design value of 5 to 6.2 min and the average filtration rate through each pressure filter
decreased from the design value to 10.0 to 8.0 gpm/ft2.
Contact time was initially recommended by the vendor for 5 min, which was determined to be sufficient
to contact arsenic with precipitating iron particles and allow iron floes to form. However, competition
from silicates for available adsorptive sites as well as interaction of Fe(III) with silicates that cause the
formation of soluble polymers and highly dispersed colloids (Her, 1979; Robinson, et al., 1992) might
have led to greater contact time needs than provided by the treatment system design. In addition, despite
lower than the designed hydraulic loading at 8.0 gpm/ft2 (compared to the design value of 10 gpm/ft2),
breakthrough of both iron and arsenic particulates was experienced (see Section 4.5.2).
28
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Former IN
Sample Location
Former FeCK
Injection Location
Former NaOCI
Injection Location
Modified
Sample Location
Modified FeCI?
Injection Location
Modified NaOCI
Injection Location
Figure 4-12. Relocation of IN Sampling Location and Chemical Inject Points
-------
Table 4-6. Treatment System Operational Parameters
Parameter
11/27/06-02/08/08
Average [Range]
Pretreatment
NaOCl Dosage (mg/L [as C12])
FeCl3 Dosage (mg/L [as Fe])
2.4 [0.3-7.1]
2.1 [0.2-6.1]
Coagulation/Filtration
Total Operating Time (hr)
Total Operating Days (day)
Average Daily Operating Time (hr)
Throughput (gal)
Average Daily Demand (gal)
Instantaneous Flowrate (gpm)
Calculated Flowrate (gpm)
Contact Time (min)
Filtration Rate (gpm/ft2)
Ap across Each Filtration Vessel (psi)
Ap across System (psi)
Filter Run Time between Backwash Cycles (hr)
Throughput between Backwash Cycles (gal/event)
2,543
284
8.9
30,499,000
107,400
202 [140-216]
206 [77-261]
6.2 [5.8-8.9]
8.0 [5.6-8.6]
12 [5.0-31]
25 [19-44]
8.3 [0.1-21.1]
101,325 [1,128-580,376]
Backwash
Frequency (occurrence/vessel/day)
Number of Cycles (Vessel A/Vessel B)
Flowrate (gpm)(a'b)
Hydraulic Loading Rate (gpm/ft2)
Duration (mm/vessel)
Backwash Volume (gal/vessel/cycle)
Filter to Waste Volume (gal/vessel/cycle)
Wastewater Produced (gal/vessel/cycle)
1 [0-5]
301/303
114 [85-133]
9.1 [6.7-10.6]
10 [9-13]
1,167 [1,100-1,300]
700
1,867 [1,800-2,000]
(a) Average of both vessels' calculated backwash flowrate. Outlier of 44 gpm
on 12/11/06 removed from calculations.
(b) Outlier of 44 gpm backwash lasting for 27 and 25 min for Vessels A and B,
respectively, removed from average calculation.
Table 4-7. Unscheduled System Downtime
Date
12/13/06
02/14/07
02/15/07
05/22-23/07
05/28-29/07
07/08-09/07
08/25-27/07
01/14-21/08
Total
Number of Days
with System
off/down
1
1
0
2
2
2
3
7
18
Cause(s) of System
off/down
Influent piping modifications and recycling
tank piped to sewer
Communication between plant and well down
Coaxial cable replacement and hand switches
added to well (system remained online)
Well 2 offline for repairs
Well 2 offline for repairs
A 480 V, 65 amp breaker at Well 2 broken due
to storm
Plant and Well 2 shut down due to low
backwash flow alarm
Well 2 offline for repairs
-------
Ap readings ranged from 5 to 31 psi across each filter and from 19 to 44 psi across the system. As
expected, Ap readings increased with increasing duration of the filter runs (Figure 4-13), presumably
caused by the buildup of arsenic-laden iron solids within the filter media. Figure 4-13 also presents data
for the Ap behavior with the filter runs using polymer amended systems (Section 4.5.2). It does not
appear from these data that polymer addition significantly altered the trend of pressure drop with filter run
time during the filter service cycles. Data in Figure 4-13 also indicate that backwash was effective in
restoring the filters, as evidenced by the relatively low differential pressure readings, i.e., 5 to 8 psi,
immediately after backwashing. Backwash will be further discussed in Section 4.4.3.
Filter run times between backwash cycles ranged from 0.1 to 21.1 hr and averaged 8.3 hr (Figure 4-14).
The corresponding throughputs ranged from 1,128 to 580,376 gal/event and averaged 101,325 gal/event.
Each backwash cycle consumed an average of 3,734 gal of treated water, which represents 3.8% of the
average throughput between backwash cycles. These numbers are based on the time in service between
backwash cycles and the average daily flowrate (taken from the totalizer) from that day.
*TAwithFeCI3
TB with FeCIS
*TAwith FeCIS/Polymer Blend
n TB with FeCIS/Polymer Blend
6 8 10 12 14
Run Time Since Last Backwash (hr)
16
18
20
Figure 4-13. Differential Pressure vs. Filter Run Time
31
-------
-------
V
g
v
o
FeCIS (mg/L as Fe)
NaCIO (mg/L as CI2)
/
Date
Figure 4-15. Chlorine and Ferric Chloride Dosages Over Time
4.4.3 Backwash Operation. As noted in Section 4.2, backwash could be initiated by a service run
time, a standby time, or a Ap setpoint. The vendor recommended in the original design documentation
that backwash be initiated: (1) when Ap across a single filter had reached 20 psi, (2) after the system had
achieved 24 hr of service time, or (3) after the system had sat idle for 48 hr, whichever occurred first.
Since system startup, these and several other settings had been adjusted a number of times based on
system performance and filter effluent water quality data. Further, backwash cycles were manually
initiated during the first five months of system operation and manual backwash was discontinued on April
16, 2007. Table 4-8 summarizes adjustments to PLC settings throughout the study period.
Since system startup, Vessels A and B were backwashed 301 and 303 times, respectively. Among the
284 days when the system was operational, Vessels A and B were backwashed once a day for 207 and
202 days, respectively. There were days when the vessels were either not backwashed (31 and 34 days,
respectively), or backwashed two times a day (43 and 44 days, respectively) or even three times a day
(three days each). On February 5, 2007 when the operator tried to initiate backwash from offsite, Vessel
B was backwashed consecutively for five times due to unknown control issues with the City's system
control and data acquisition (SCADA) system. The system had to be restarted to resume normal
operations. Figure 4-16 shows a backwash frequency histogram.
The backwash duration for each filter was affected by the minimum and maximum backwash time
settings and the ability of backwash wastewater to meet the turbidity threshold setting as measured by the
in-line Hach™ turbidimeter. If backwash wastewater failed to meet the set threshold value prior to
reaching the maximum backwash time, the backwash failure alarm had to be acknowledged and a
successful backwash cycle completed before the vessel could return to the service mode. Each backwash
was followed by a 3-min filter-to-waste (FTW) step to rinse off any left-over particles from the filter.
33
-------
Table 4-8. Summary of PLC Settings for Backwash Operations
Parameter (for Each Vessel)
Drain Time (min)
Service Time Trigger (hr)
Standby Time Trigger (hr)
Ap Trigger (psi)
Minimum Backwash Time (min)
Maximum Backwash Time (min)
Turbidity Threshold (MTU)
Low Flowrate Threshold (gpm)
Filter-to -Waste Time (min)
Recycle Pump Run Time Delay (min)
Recycle Pump Flowrate (gpm)
Date of Adjustments
*«*
\0
o
f>
0
^H
5
24
48
40
15
45
12
20
3
25
44
-------
wastewater produced was 1,867 gal/vessel or 3,734 gal for both vessels. One backwash occurred on
February 11, 2007 and lasted for 27 and 25 min for Vessels A and B, respectively and, therefore, was not
included in the average calculation for the wastewater produced. The total amount of wastewater
produced was equivalent to 3.8% of the amount of water treated. However, as discussed in Section 4.5.2,
because the useful filter run length (i.e., the maximum filter run length which consistently yielded <10
ug/L total arsenic and <300 ug/L total iron in the effluent) was much shorter than the actual filter run
lengths observed during the study, the percentage of processed water used for backwashing would have
been much higher than 3.8% had the useful filter run length been implemented throughout the study.
4.4.3.1 PLCSettings. As shown in Table 4-8, the initial backwash PLC settings set by vendor
technicians on November 3, 2006 during system shakedown and startup were quite different from those in
the original design documentation and those for several similar Macrolite® pressure filtration systems
already operational at other arsenic demonstration sites (Condit and Chen, 2006; Condit and Chen, 2008;
Valigore et al., 2008a). Six subsequent modifications were made on November 14, 22, and 29, 2006, as
well as December 1, 7, and 8, 2006, by the facility operator and the vendor based on Battelle's punch-list
items summarized during the November 28 and 29, 2006, trip to the facility. The modifications made
included:
• Decreasing the setpoint for the Ap trigger to 25 psi to more closely match the original design
value.
• Decreasing the setpoint for the service time trigger to 20 hr to reduce particulate
breakthrough from the filters.
• Increasing the setpoint for the standby time trigger to 96 hr to reduce the number of backwash
cycles triggered based on standby time.
• Decreasing the maximum backwash time to 20 min and increasing the turbidity threshold to
20 NTU to reduce wastewater production.
• Increasing the low flowrate threshold to 100 gpm to more closely match the intended
backwash flowrate of 100 to 125 gpm.
The facility operator decided to manually initiate backwash on a daily basis during the first five months of
system operation; automatic backwash triggers were utilized only after April 16, 2007. On November 29,
2006, it was noticed that Vessel A after a backwash cycle would not return to service until it had reached
the 45-min recycle pump delay time. This programming problem was resolved by the vendor through
dialing to the PLC.
Since April 16, 2007, other changes to the PLC were made, including 1) temporarily increasing the
setpoint for the service time trigger to 24 hr to accommodate a special study on the use of the C-05
iron/organic polymer blend, and then decreasing the setpoint to 5 to 6 hr to continue to address issues
with particulate breakthrough, and 2) increasing the turbidity threshold from 20 to 30 NTU due to filter
clogging caused by C-05 dosing.
4.4.3.2 Backwash Flowrates. Backwash flowrates ranged from 85 to 133 gpm and averaged 114
gpm, which was within the range of the design values of 100 to 125 gpm. There were only two backwash
instances where the backwash times were over 13 min and thus, the backwash flowrates were considered
sufficient for the backwash operation.
4.4.4 Residual Management. Residuals produced by the Macrolite® Arsenic Removal System
included backwash wastewater and FTW rinse water, which contained arsenic-laden solids. Backwash
35
-------
wastewater was analyzed for metals. As originally designed, 10% of the wastewater would be discharged
via the sewer to a lagoon used for irrigation and the other 90% of the wastewater would be reclaimed after
being passed through a bag filter. In June 2006, Battelle considered installing an additional totalizer after
a three-way valve on the backwash recycle line in order to quantify the amounts of recycled water.
Because the City decided to discharge the backwash wastewater directly to the lagoon via the sewer, the
totalizer was not installed.
4.4.5 Reliability and Simplicity of Operation. Inability to achieve acceptable arsenic removal
due to inefficient coagulation/filtration of arsenic-laden particles, and backwash-related issues including
PLC settings were the primary sources of concern during the study. The filter performance issues were
not successfully resolved and the treatment system was not able to achieve the 10-|o,g/L arsenic MCL
within reasonable service run lengths. Therefore, the City relied primarily on a blending scheme to meet
the 10-|o,g/L MCL prior to entering the distribution system.
4.4.5.1 Pre- and Post-Treatment Requirements. Pretreatment consisted of the addition of chlorine
and ferric chloride. Although unnecessary due to the oxidizing nature of source water, prechlorination
was used for disinfection and maintaining a total chlorine residual in the distribution system. Iron
addition, using a 35% FeCl3 stock (diluted 1:4) solution, was required to remove arsenic. Iron was added
upstream of the contact tank within the treatment plant where solution levels were tracked daily.
4.4.5.2 System Automation. The treatment system was automatically controlled by the PLC in the
central control panel. The control panel contained a modem and a touch screen OIP that facilitated
monitoring of system parameters, changing of system setpoints, and checking the alarm status. Service
time, standby time, and Ap settings (Table 4-8) automatically determined when the filters were
backwashed. The touch screen OIP also enabled the operator to manually initiate the backwash sequence.
4.4.5.3 Operator Skill Requirements. Under normal operating conditions, the daily demand on the
operator was about 30 min for visual inspection of the system and recording of operational parameters,
such as pressure, volume, flowrate, and chemical usage on field log sheets. After receiving proper
training during the system startup, the operator understood the PLC, knew how to use the touch screen
OIP, and was able to work with the vendor to troubleshoot problems and perform minor onsite repairs.
MT DEQ has five certification classes for water system operators (first to fifth class). First class covers
all operators in operation of a system treating surface water using chemical coagulation, filtration and
disinfection serving more than 20,000 people. Fifth class covers operators in operation of a system
treating well water serving fewer than 100 people, with or without disinfection. The Three Forks operator
possesses the third class certification, which covers operation of a system treating well water serving
greater than 2,500 people with or without disinfection.
4.4.5.4 Preventative Maintenance Activities. The vendor recommended several routine maintenance
activities to prolong the integrity of the treatment system (Kinetico, 2006). Daily preventative
maintenance tasks included recording pressures, flowrates, chemical drum levels, and visually checking
for leaks, overheating components, proper manual valve positioning and pumps lubricant levels, and any
unusual conditions. The vendor recommended weekly checking for trends in the recorded data that might
indicate a decline in system performance, and semi-annually servicing and inspecting ancillary equipment
and replacing worn components. Cleaning and replacement of sensors and replacement of o-ring seals
and gaskets of valves were performed as needed.
4.4.5.5 Chemical Handling and Inventory Requirements. Chlorine and iron addition were required
for disinfection and effective arsenic removal, respectively. The operator tracked the use of the chemical
solutions daily (by volume), coordinated the supplies, and refilled the day tanks as needed. A 15%
36
-------
NaOCl solution, supplied in 55-gal drums by Hawkins, was transferred to the day tank and injected
without dilution. A 35% FeCl3 stock solution, supplied in 350 Ib drums by Hawkins, was diluted 1:4 in
the 55-gal day tank prior to injection into raw water. The speed and stroke settings of the chemical pumps
were adjusted, as needed, to acquire the target chlorine residuals (as measured regularly with a Hach
pocket colorimeter) and iron concentrations after the contact tanks.
4.5 System Performance
The performance of the Macrolite® FM-248-AS Arsenic Removal System was evaluated based on
analyses of water samples collected from the treatment plant, backwash line, and distribution system.
4.5.1 Treatment Plant Sampling. The treatment plant water was sampled on 11 occasions,
including one duplicate and three speciation sampling events, during the study. A complete set of the
analytical results is tabulated and included in Appendix B. Table 4-9 summarizes the results for arsenic,
iron, and manganese. Table 4-10 summarizes the results for other water quality parameters. The results
of the water samples collected across the treatment plant are discussed below.
4.5.1.1 Arsenic andiron. Figure 4-17 presents the results of three speciation events taken across the
treatment train (at IN, AC, and TT locations). Figure 4-18 shows total arsenic concentrations measured
across the treatment train. Total arsenic concentrations in raw water ranged from 59.8 to 96.7 |o,g/L and
averaged 84.0 |o,g/L. Of the soluble fraction, As(V) was the predominant species averaging 74.5 |o,g/L
with low levels of As(III) also present at 0.7 |o,g/L (on average). Comparatively low levels of particulate
arsenic were present, averaging 4.2 |og/L.
Similar to the observation made during the initial site visit on November 30, 2004, source water from
Well 2 was rather oxidizing, with DO concentrations ranging from 2.1 to 3.3 mg/L and averaging 2.6
mg/L and ORP readings ranging from 239 to 334 mV and averaging 272 mV. These DO and ORP data
support the speciation results, which indicate the presence of primarily soluble As(V). DO levels
remained relatively constant throughout the treatment plant at 2.2 to 2.4 mg/L (on average). ORP
readings increased significantly to 342 mV (on average) after chlorination and remained relatively
constant thereafter at 330 to 400 mV.
Soluble As(V) and As(III) after the contact tanks averaged 8.7 |o,g/L and 0.8 |og/L, respectively. Following
iron addition (Figure 4-19) and contact tanks, the majority of arsenic was present, as expected, in the
particulate form at 71.3 |o,g/L as a result of adsorption and/or coprecipitation of As(V) with iron solids.
The close-to-10 |o,g/L soluble As(V) concentrations measured after the contact tanks suggest the need for
more iron, which, presumably, would produce more iron solids and shorten already short filter run times,
as discussed in Section 4.5.2.
The results of the first three weeks of treatment plant sampling indicated that total arsenic concentrations
were only reduced to the range of 17.3 to 30.6 (ig/L, significantly higher than the 10 (ig/L MCL. Based
on the November 29, 2006 speciation results, of the 28.3 (ig/L total arsenic, 23.5 (ig/L existed as
particulate arsenic and 4.8 as soluble arsenic. This, together with the 936 (ig/L particulate iron measured
in the same sample, suggests breakthrough of arsenic-laden iron particles from the pressure filters. In
light of the unsatisfactory treatment results, the regular sampling schedule was temporarily suspended and
a series of special studies was carried out to determine the needs for process modifications to improve the
filter performance. The results of the special studies are described in Section 4.5.2, including filter media
run length, use of a higher iron dosage, use of a finer filter media size fraction, use of a C-05 iron/polymer
blend, and use of other coagulant aids.
37
-------
Table 4-9. Summary of Arsenic, Iron, and Manganese Analytical Results
Parameter
As (total)
As (soluble)
As (paniculate)
As (III)
As(V)
Fe (total)
Fe (soluble)
Mn (total)
Mn (soluble)
Sample
Location
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TT
IN
AC
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TT
Unit
HB/L
HB/L
W?/L
HB/L
HB/L
W?/L
HB/L
HB/L
HB/L
W?/L
HB/L
HB/L
W?/L
HB/L
HB/L
HB/L
W?/L
HB/L
HB/L
^g/L
HB/L
HB/L
HB/L
HB/L
HB/L
HB/L
HB/L
HB/L
HB/L
HB/L
W?/L
HB/L
HB/L
HB/L
W?/L
HB/L
^g/L
^g/L
Hg/L
Sample
Count
11
11
8
8
3
4
4
1
1
3
4
4
1
1
3
3
3
3
3
3
3
11
11
8
8
3
4
4
1
1
3
10
10
7
7
3
3
3
3
Concentration
Minimum
59.8
61.2
8.4
8.2
16.8
59.7
5.9
4.4
3.8
4.8
0.1
55.4
4.0
4.5
9.6
0.1
0.1
0.1
59.0
5.0
3.2
<25
1,153
111
96.1
225
<25
<25
<25
<25
<25
<0.1
8
0.5
0.6
3.2
<0.1
3.1
2.6
Maximum
96.7
95.0
22.4
30.6
28.3
85.5
11.7
4.4
3.8
7.2
10.3
79.8
4.0
4.5
23.5
1.4
1.3
1.6
85.4
10.6
6.0
<25
2,502
323
561
936
<25
41.5
<25
<25
<25
0.1
15
6
7
9
0.4
6
5
Average
84.0
(a)
.(a)
.(a)
.(a)
76.8
.(a)
.(a)
(a)
.(a)
4.2
.(a)
.(a)
.(a)
.(a)
0.7
.(a)
.(a)
74.5
.(a)
.(a)
<25
(a)
.(a)
.(a)
.(a)
<25
.(a)
(a)
_(a)
_(a)
<0.1
10
3
3
5
0.2
4
3
Standard
Deviation
12.4
.(a)
.(a)
.(a)
.(a)
11.6
.(a)
.(a)
.(a)
.(a)
5.0
.(a)
.(a)
.(a)
.(a)
0.7
.(a)
.(a)
13.7
.(a)
.(a)
0
.(a)
.(a)
.(a)
.(a)
0
.(a)
.(a)
.(a)
.(a)
0.0
2.2
1.5
2.1
o
J
0.2
1.8
1
(a) Statistics not meaningful for data obtained under three separate sets of process conditions.
38
-------
Table 4-10. Summary of Other Water Quality Parameter Results
Parameter
Alkalinity
(as CaCO3)
Fluoride
Sulfate
Nitrate
(asN)
Total P
(asP)
Silica
(as SiO2)
Turbidity
Total
Organic
Carbon
pH
Temperature
Sample
Location
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
Unit
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
^g/L
mg/L
mg/L
mg/L
mg/L
mg/L
NTU
NTU
NTU
NTU
NTU
mg/L
mg/L
mg/L
mg/L
mg/L
S.U.
S.U.
S.U.
S.U.
S.U.
°C
°c
°c
°c
Sample
Count
10
10
7
7
o
J
o
J
o
J
0
0
o
J
o
J
o
J
0
0
o
J
o
J
o
J
0
0
o
6
9
10
7
7
3
10
10
7
7
3
9
10
7
7
3
1
1
0
0
1
10
10
7
7
3
10
10
7
7
Concentration
Minimum
266.0
267.0
265.0
267.0
262.0
2.1
2.1
NS
NS
2.2
20.0
20.0
NS
NS
20.0
0.3
0.3
NS
NS
0.3
17.1
5.0
5.0
5.0
11.0
46.8
46.4
45.6
45.6
47.8
0.1
0.6
0.3
0.3
0.4
1.7
0.5
NS
NS
0.5
7.3
7.1
7.1
7.1
7.2
10.7
10.5
10.3
10.4
Maximum
297.0
302.0
295.0
291.0
288.0
3.0
3.1
NS
NS
3.0
22.0
22.0
NS
NS
22.0
0.4
0.4
NS
NS
0.3
53.7
53.5
15.6
14.8
18.6
50.8
51.0
49.2
49.1
50.3
1.1
3.3
1.5
0.9
0.9
1.7
0.5
NS
NS
0.5
7.8
7.9
7.9
8.0
7.9
15.7
15.7
13.4
13.3
Average
284.5
280.8
281.0
279.9
278.0
2.4
2.5
NS
NS
2.5
21.0
20.7
NS
NS
21.0
0.3
0.4
NS
NS
0.3
32.8
29.9
.(a)
>)
>)
48.5
48.7
47.4
47.1
49.2
0.5
>)
>)
>)
0.7
NA
NA
NS
NS
0.5
7.5
7.5
7.5
7.5
7.6
12.6
12.3
11.8
11.8
Standard
Deviation
10.4
11.1
9.6
10.1
14.0
0.5
0.6
NS
NS
0.5
1.0
1.2
NS
NS
1.0
0.0
0.1
NS
NS
0.0
12.3
14.2
_(a)
(a)
.(a)
1.3
1.4
1.4
1.3
1.3
0.3
(a)
.(a)
(a)
0.3
NA
NA
NS
NS
-
0.2
0.3
0.3
0.4
0.4
1.4
1.6
1.1
1.1
-------
Table 4-10. Summary of Other Water Quality Parameter Results (Continued)
Parameter
Temperature
(Cont)
Dissolved
Oxygen
ORP
Free
Chlorine
(as C12)
Total
Chlorine
(as C12)
Total
Hardness (as
CaCO3)
Ca Hardness
(as CaCO3)
Mg
Hardness
(as CaCO3)
Sample
Location
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
AC
TA
TB
TT
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
Unit
°C
mg/L
mg/L
mg/L
mg/L
mg/L
mV
mV
mV
mV
mV
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Sample
Count
o
J
9
9
6
6
o
J
10
10
7
7
o
J
10
7
7
o
J
10
7
7
o
J
o
J
o
J
0
0
o
J
o
J
o
J
0
0
o
J
o
J
3
0
0
3
Concentration
Minimum
11.1
2.1
1.7
1.6
1.5
2.0
239.1
280.7
313.6
312.7
307.6
0.4
0.4
0.5
0.6
0.4
0.4
0.5
0.6
180.7
183.7
NS
NS
177.8
128.4
131.6
NS
NS
128.5
50.6
51.0
NS
NS
49.3
Maximum
15.8
3.3
3.9
2.9
2.8
3.1
334.6
506.9
523.1
548.1
362.6
3.2
3.1
2.7
0.8
3.2
2.8
3.1
1.0
222.2
247.6
NS
NS
255.7
167.4
195.9
NS
NS
204.1
54.8
52.1
NS
NS
55.1
Average
13.2
2.6
2.4
2.4
2.2
2.4
272.3
341.9
389.3
400.1
330.4
0.9
1.0
1.0
0.7
0.9
0.9
1.0
0.8
199.4
211.2
NS
NS
215.4
146.8
159.7
NS
NS
163.4
52.6
51.6
NS
NS
52.0
Standard
Deviation
2.4
0.4
0.7
0.4
0.6
0.6
36.7
80.1
87.6
96.3
28.7
0.8
1.0
0.8
0.1
0.8
0.9
1.0
0.2
21.1
32.9
NS
NS
39.0
19.6
32.9
NS
NS
38.1
2.1
0.6
NS
NS
2.9
NA = not available; NS = not sampled
Figure 4-19 presents total iron concentrations measured across the treatment train. Iron was required
because the facility decided to use the coagulation/filtration process rather than adsorptive media to
remove arsenic. The addition of FeCl3 before the contact tanks resulted in total iron concentrations
ranging from 1,153 (ig/L to 2,502 (ig/L and averaging 1,834 (ig/L. Of the total iron, more than 98% was
in the insoluble form based on the use of 0.45 (im disc filters during speciation sampling. Care must be
taken in evaluating these data, however, since the presence of silica can cause the formation of dispersed
colloidal material, which may penetrate through the 0.45 (im disc filters and be considered as particulates
(Meng et al., 2000). Silica was present in the Three Forks source water at, on average, 48.5 mg/L (as
SiO2).
40
-------
Arsenic Speciation at the Wellhead (IN)
I As (participate)
lAs (III)
DAs(V)
3/21/2007
Date
Arsenic Speciation after Chlorination (AC)
90
80
70
60
50
40
30
20
10
0
DAs (particulate)
• As (III)
DAs(V)
1 1 /29/06 03/21/07 04/1 8/07
Date
Arsenic Speciation after Total Combined Effluent (TT)
80-
70-
60-
50-
40-
30-
20-
10-
03/21/07
Date
Figure 4-17. Arsenic Speciation Results
41
-------
100
90
80
IT 70
3
c 60
O
+J
| 50
V
o
g 40
O
£ 30
20
10
0
-IN
-AC
TA
AsMCL = 10
Date
Figure 4-18. Total Arsenic Concentrations across Treatment Train
3000
2500 -
200° '
.o
2 1500
'c
a)
o
c
o
^ 1000 -
500 -
-IN
-AC
TA
-TB
-TT
Fe SMCL = 300 |ig/L
/L A
v
Date
Figure 4-19. Total Iron Concentrations across Treatment Train
42
-------
The removal of soluble arsenic onto iron solids also can be impacted by elevated pH and the presence of
competing anions such as silica and phosphorus. pH values across the treatment train remained relatively
constant at 7.5 (on average) (Table 4-10) and thus, should not have any major impact on arsenic removal.
Silica begins to inhibit arsenic removal by ferric hydroxide at concentrations above 1 mg/L (Meng et al.,
2000). At 48.5 mg/L, silica might have caused lower than expected soluble arsenic removal in the contact
tanks. Phosphorus at 32.8 (ig/L (as P) also might compete with As(V) for available adsorption sites on
iron solids.
4.5.1.2 Manganese. Manganese concentrations in raw water were <0.1 ng/L during all sampling
events. Both total and soluble manganese (Mn) concentrations increased after the contact tanks,
averaging 10 and 4 (ig/L, respectively. This is thought to be due to impurities in the chemicals used.
Because the pressure filters removed only particulates, manganese levels after the pressure filters were
lower on average at 5.0 (ig/L. Studies have found that incomplete oxidation of Mn(II) occurs using free
chlorine at pH values less than 8.5 (Knocke et al., 1987 and 1990; Condit and Chen, 2006; McCall et al.,
2007).
4.5.1.3 Chlorine Residual. Total chlorine residuals remained relatively constant at 0.8 to 1.0 mg/L
(as C12) (on average) throughout the treatment train. Of these total chlorine levels, almost all existed as
free chlorine, indicating the absence of ammonia in source water.
4.5.1.4 Other Water Quality Parameters. Alkalinity, fluoride, sulfate, nitrate, temperature, and
hardness levels remained relatively constant across the treatment train and were not affected by the
treatment process (Table 4-10). TOC, however, was removed with 1.7 mg/L in raw water, but only 0.5
mg/L after the contact tanks and pressure filters. It is known that TOC can be removed via coagulation/
filtration with iron solids.
4.5.2 Special Studies. Several special studies were carried out in an attempt to improve the
performance of the pressure filters. Key parameters investigated included buildup of Ap across the filters
over run time as well as arsenic and iron concentrations in the filter effluent. The studies included the use
of a higher iron dosage, a finer filter media size fraction, and various coagulant aids/polymers. For the
duration of the special study period, in order to achieve the 10-(ig/L MCL, the City implemented a
blending scenario with other wells to reduce the effect of high arsenic concentrations from Well 2. This
involved reducing the operating schedule for Well 2 to three days per week (i.e., Monday, Wednesday
and Friday). The blending resulted in arsenic concentrations between 4.4 and 8.6 (ig/L prior to entering
the distribution system.
4.5.2.1 Effect of Ap and Filter Run Time. A special study was carried out on December 20, 2006 to
evaluate buildup of Ap across the filters over run time. With the addition of 1.8 mg/L of iron, Ap values
across the pressure filters were 6 to 8 psi at 1 hr and 9 to 11 psi at 4 hr. This corresponds to a buildup rate
of 1 psi/hr. Total arsenic concentrations in the filter effluent ranged from 8.1 to 8.3 (ig/L at 1 hr and from
12.3 to 15.5 (ig/L at 4 hr. Coinciding with the increase in total arsenic concentration was an increase in
total iron concentration (i.e., from <25 (ig/L at 1 hr to as high as 176 (ig/L at 4 hr). These results indicate
that the pressure filters can produce treatment effluent that meet the 10-(ig/L MCL, but that their useful
run lengths can be very short, i.e., <4 hr. Because speciation was not performed during the study, it was
not clear if the arsenic that broke through the filters was present in the soluble or particulate form. If a
significant amount of arsenic indeed was present in the soluble form (like what was observed during the
first three months of regular sampling [Section 4.5.1.1]), there would be value to add more iron to achieve
better soluble As(V) removal prior to pressure filtration. Conversely, the use of a higher iron dosage
would inevitably produce more iron solids, which could further shorten useful run lengths, thus rendering
the pressure filtration process virtually infeasible.
43
-------
4.5.2.2 Effect of Higher Iron Dosage. For this special study (conducted on January 10, 2007) the
FeCl3 dosage was increased from 1.8 to 2.2 mg/L (as Fe). The objective was to determine the effect of a
higher iron dosage on total and soluble arsenic removal as well as particulate iron breakthrough. The
increase in iron dosage appears to have very little impact on the Ap buildup rate (data not shown), with a
Ap buildup rate of 1 psi/hr observed for both filters. For Vessel A, arsenic levels increased from 7.6 and
6.8 ug/L (at 1.4 hr) to 8.8 and 6.0 ug/L (at 2.4 hr) and to 11.9 and 6.4 ug/L (at 4.4 hr) for total and soluble
arsenic, respectively. For Vessel B, arsenic levels increased from 10.8 and 6.2 ug/L (at 1.0 hr)to 11.8
and 6.2 ug/L (at 2.0 hr) and to 17.5 and 6.2 ug/L (at 4.0 hr) for total and soluble arsenic, respectively.
The data illustrate that even at a higher iron dose, a significant amount of the total arsenic in the treated
water was in the soluble form. As discussed in Section 4.5.1.1, silica and, to a lesser extent, phosphorus,
might compete with arsenic for available adsorptive sites on iron solids, making removal of soluble
arsenic less effective. Silica is also known to form complexes with arsenic in the colloidal size range,
which is small enough to pass through 0.45 um filters and thus increase the apparent soluble arsenic
concentration. As the filter run continued, particulate arsenic began to break through the filters, with
concentrations increasing from 0.8 and 4.6 ug/L (at 1.4 hr) to 2.8 and 5.6 ug/L (at 2.4 hr) and to 5.5 and
11.3 ug/L (at 4.4 hr) for Vessels A and B, respectively. The entirety of the iron breakthrough was in the
particulate form, illustrating breakthrough of arsenic-laden iron solids.
20 !
18
16
Tank A (Total As)
-Tank B (Total As)
Tank A (Total Fe)
-Tank B (Total Fe)
-- 350
-- 300
-- 250
-if
,„-""**
400
200
c
o
§
c
o
O
0)
-- 150
-- 100
-- 50
0 0.5 1 1.5
2 2.5 3 3.5 4 4.5 5
Elapsed Time (hr)
Figure 4-20. Total Arsenic and Iron Levels with Use of a Higher Iron Dosage
While increasing the iron dosage from 1.8 to 2.2 mg/L (as Fe) (or increasing the Fe:As ratio from 22:1 to
27:1) was not particularly effective in completely removing soluble arsenic from the contact tank and
pressure filter effluent, it resulted in increased solids loading and increased particulate breakthrough from
the pressure filters. A significant amount of particulate iron broke through the filters even within 1 hr of
44
-------
filter run time and greater than 10 (ig/L of arsenic breakthrough occurred within 2 hr of filter run time,
thus reducing the useful filter runtime under these operational conditions. As such, it was evident that
increasing the iron dosage most likely would not produce better treatment results and that other treatment
strategies needed to be developed to improve filter performance.
4.5.2.3 Effect of Media Size Fraction. After consulting with the vendor, a decision was made to
modify the filter beds by replacing a 6-in layer of the 40/60 mesh Macrolite® media with an equivalent
amount of finer media, i.e., 70/80 mesh, in an attempt to achieve better particulate removal by the filters.
After the media replacement on March 13, 2007, both vessels were backwashed to <5 NTU. After this,
regular sampling as outlined in Table 3-3 resumed, with the treatment plant water samples collected in
seven occasions (including one duplicate and two speciation sampling events) during March 21 and April
25, 2007. Regular sampling was suspended again on April 25, 2007 due to poor filter performance.
Analytical results as presented in Figures 4-17 through 4-20 and Appendix B indicated the following:
• With the addition of 1.8 mg/L of iron (as Fe) (on average), soluble arsenic concentrations
were reduced from 80.4-85.5 at the influent sample tap to 10.7-11.7 (ig/L after the contact
tanks and to 5.8-7.2 (ig/L after the pressure filters, with the soluble arsenic existing primarily
as As[V] based on the March 21 and April 18, 2007, speciation sampling results. The
speciation results also showed that particulate arsenic concentrations increased significantly
to 78.7-79.8 (ig/L after the contact tanks. These results were consistent with those obtained
during the first three weeks of regular sampling (Section 4.5.1.1) and the above-mentioned
special studies (Sections 4.5.2.1 and 4.5.2.2).
• After pressure filtration, total arsenic concentrations were reduced to 12.3-22.8 (ig/L (or 16.1
(ig/L on average) (Appendix B), which were somewhat lower than those observed during the
first three weeks of regular sampling, but very close to those collected at approximately 4 hr
during the above-mentioned special studies. Of the 16.9-(ig/L (on average) total arsenic
measured during the two speciation sampling events, 6.5 (ig/L existed as soluble arsenic and
10.4 (ig/L as particulate arsenic. These results again were similar to those collected during
the above-mentioned special studies. Figure 4-21 displays the total arsenic breakthrough
based on the filter run length for regular sampling events before (vessels with only 40/60
mesh) and after (vessels with 40/60 mesh and 70/80 mesh) media replacement. There
appears to be no benefit in total arsenic reduction resulting from the media replacement.
• Even after media replacement, >10-ug/L arsenic breakthrough was observed even less than 2
hr. This is similar to what was found during the previous special study. Thus, the useful
filter run length was not affected by the media replacement.
• 134 to 338 (ig/L of total ion was measured in the filter effluent, with almost all existing in the
particulate form. These results also were similar to those collected during the above-
mentioned special studies.
The results obtained during this study period clearly suggest that the media bed modification failed to
effectively remove arsenic-laden particles to below the MCL levels, which, in conjunction with the
soluble arsenic, pushed the arsenic concentrations in the filter effluent well beyond the MCL level.
45
-------
35
30 --
25
-^—TAwith only 40/60 mesh
•••—TA with 40/60 and 70/80 mesh
-^TB with only 40/60 mesh
•»-TB with 40/60 and 70/80 mesh
6 8
Filter Run Length (hr)
10
12
14
Figure 4-21. Total Arsenic Breakthrough from Filters with 40/60 Mesh Media
Only and 40/60 and 70/80 Mesh Amendment
4.5.2.4 Effect of Polymers/Coagulant Aids. The use of polymers/coagulant aids was then tested to
determine their effects on particulate removal. A series of jar test was carried out by the vendor on June
4, 2007 to determine the optimum chlorine and iron/polymer dose when applying an iron/organic polymer
mixture named C-05. The results of the jar tests are presented in Table 4-11. As shown in the table,
arsenic removal to below 10 ug/L might be achieved only with the use of 2.5 mg/L (as Fe) of the C-05
blend. (Note that the impact of chlorine dosage on the treatment results appears to be minimal). At this
dosage, the Fe:As ratio was 31:1, which is higher than the 22:1 and 27:1 ratios used for the above-
mentioned special studies. Not including the particulate arsenic that might break through the filters, the
use of the C-05 blend would produce a filter effluent containing 9 ug/L of arsenic, at best.
Nonetheless, the use of the C-05 blend was implemented at the site on July 6, 2007 with a special run
length study carried out on July 17, 2007. Figures 4-22 and 4-23 compare the results of this special study
with those of an above-mentioned special study discussed in Section 4.5.2.2. By injecting 1.5 mg/L (as
C12) of chlorine and 2.5 mg/L (as Fe) of C-05, total arsenic levels increased from 8.2-8.4 ug/L (at 2.7 hr)
to 14.9-15.4 ug/L (at 5.3-5.7 hr) and to 22.9-24.3 ug/L (at 9.4-9.6 hr). Total iron concentrations
increased from 96.1-111 ug/L (at 2.7 hr) to 332-358 ug/L (at 5.3-5.7 hr) to 547-614 ug/L (at 9.4-9.6 hr).
The results collected at 2.7 and 5.3-5.7 hr were close to those of the previous special study collected at
2.0-2.4 and 4.0-4.4 hr, respectively, indicating little or no improvement in filter performance with the use
of the C-05 blend. Throughout the special study, soluble arsenic concentrations in the filter effluent were
relatively constant at 3.8-4.5 ug/L and the total iron was in particulate form. These results further support
the observation that minimum improvement, if any, was achieved with the use of the C-05 blend,
although this special study does show somewhat increased soluble arsenic removal over the previous
special study for iron addition.
46
-------
Table 4-11. C-05 FeCl3/Polymer Blend Jar Test Results
Sample
No.
0
1
2
3
4
5
6
7
8
9
10
11
12
Chlorine
Dosage
(mg/L
as [C12])
0
0.5
0.5
0.5
0.5
1.0
1.0
1.0
1.0
1.5
1.5
1.5
1.5
C-05
Blend
Dosage
(mg/L
[as Fe])
0
1.0
1.5
2.0
2.5
1.0
1.5
2.0
2.5
1.0
1.5
2.0
2.5
Filtered
Concentration
Iron
(HS/L)
O.03
O.03
O.03
O.03
O.03
O.03
O.03
O.03
O.03
O.03
<0.03
O.03
<0.03
Arsenic
(HS/L)
81
34
24
14
10
35
21
18
10
33
24
13
9
25
-TAAsw/FeCI3
-TBAsw/FeCI3
TA Fe w/ FeCI3
-TBFew/FeCI3
20
-TA As w/ FeCI3/Polymer
-TB As w/ FeCI3/Polymer
TA Fe w/ FeCI3/Polymer
TB Fe w/ FeCI3/Polymer
1000
800
Figure 4-22. Total Arsenic and Iron Levels with Use of C-05 Blend
47
-------
Figure 4-23 shows the effect of the C-05 blend on Ap buildup over filter run time. For Vessel A, Ap
levels increased from 13 to 23 psi after 6.9 hr. For Vessel B, Ap levels increased from 11 to 22 psi after
6.7 hr. This corresponds to a Ap buildup rate of 1.4 to 1.6 psi/hr, which is higher than the 1.0 psi/hr
buildup rate with the use of FeCl3 alone. The initial Ap levels after 2.7 hr of operation at 11 to 13 psi also
were relatively elevated. It was noticed that the use of C-05 not only failed to produce lower levels of
arsenic and iron in the filter effluent, but also promoted clogging of the filters. This was evidenced by
several backwash alarms resulting from the inability to achieve the 20 NTU turbidity threshold within the
maximum backwash time of 20 min. This resulted in a progressive increase in the turbidity threshold
setting in the PLC from 20 to 25 and to 30 NTU in late July 2007 (Table 4-8). One disadvantage noted
was that the coupled iron and polymer dosing with one chemical feed apparatus provided less flexibility
in optimizing the polymer dose to avoid overdosing and clogging of the filters.
On August 1, 2007, FeCl3 addition was resumed pending investigation into other coagulation approaches.
-A-TAw/FeCI3
-B-TBw/FeCI3
-±-TA w/ FeCI3/Polymer
-D-TB w/ FeCI3/Polymer
Run Time (hr)
Figure 4-23. Ap vs. Run Time with Use of C-05 Blend
A chemical supplier, Hawkins, was contacted and agreed to perform a series of jar tests to evaluate the
effects of alum and several organic polymers on the filter performance. The results summarized in Table
4-12 indicate that the use of alum or organic polymer(s) can achieve below the arsenic MCL-level of
treatment results (i.e., 6.2 to 7.3), although any particulate breakthrough can easily push the effluent
levels over the MCL. AquaHawk 427 at a 1 mg/L dosage was recommended by Hawkins based upon its
lower cost and the lowest soluble arsenic concentration in the jar test supernatant. The polyacrylamide
polymers were not considered due to the need for a special make-up system and vendor's concerns over
the compatibility of the polymers with Macrolite® media. Alum was eliminated from further consideration
due to the high dosage at 10 mg/L. In November 2007, the operator elected not to install a separate
chemical feed system for polymer dosing and the alternate AquaHawk 427 polymer was not further tested
in the treatment plant.
48
-------
Table 4-12. Jar Test Results with Alum and Various Polymers
Polymer
AquaHawk 427
AquaHawk 6527
AquaHawk 6547
Alum
Aqua Hawk 9827
Aqua Hawk 9827
Aqua Hawk 9847
Aqua Hawk 9847
Ingredient (s)
Polymer Blend [AL/PD/PY]
PD
PD
NA
Long Chain Polymer
Long Chain Polymer
Long Chain Polymer
Long Chain Polymer
Unit Cost
($/gal)
$10.69
$11.33
$16.04
NA
NA
NA
NA
NA
Polymer
Dosage
(mg/L)
1.0
1.0
1.0
10
0.2
0.5
0.2
0.5
Filtered
Concentration
Iron
(HS/L)
<25
<25
<25
<25
<25
<25
<25
<25
Arsenic
(Hg/L)
6.2
6.7
6.7
6.6
6.8
7.3
7.3
7.3
AL = Polyaluminum hydroxychloride
PD = Polydiallyldimethylammonium chloride
PY = Polyquaternary amine
4.5.3 Backwash Wastewater Sampling. Table 4-13 presents the analytical results from five
monthly backwash wastewater sampling events. The backwash wastewater quality was similar for both
vessels, indicating that the two vessels performed relatively consistently. For all events, the backwash
wastewater had a pH of 7.2 to 7.5, with the majority of metals existing in the particulate form. The
backwash wastewater samples collected from Events 1 to 4 were characteristic of normal operating
conditions with iron addition. TDS ranged from 310 to 388 mg/L and averaged 350 mg/L; TSS ranged
from 130 to 328 mg/L and averaged 235 mg/L. Concentrations of total arsenic, iron, and manganese
ranged from 2,162 to 3,672 (ig/L, 62,299 to 107,914 (ig/L, and 202 to 411 (ig/L, respectively. Assuming
that these average results existed during the production of 1,167 gal/vessel of backwash wastewater,
approximately 0.06 Ib of arsenic, 1.6 Ib of iron, and 0.006 Ib of manganese were discharged from both
filtration vessels during each backwash event. Of the amount discharged, some arsenic, iron, and
manganese existed in the soluble form, including 10.5 to 50.4 (ig/L of arsenic, 120 to 846 (ig/L of iron,
and 2.3 to 6.2 ug/L of manganese. The soluble arsenic and iron concentrations in the backwash
wastewater were high when compared with those measured at most of the arsenic demonstration sites
(Table 4-14). Because the presence of elevated silica (at 48.5 mg/L [as SiO2] on average in Well 2 water)
could cause the formation of dispersed colloidal material, which might penetrate through the 0.45 um disc
filters and be considered as particulate (Meng et al, 2000), some of the "soluble" arsenic and iron might,
in fact, exist as colloidal particles.
49
-------
Table 4-13. Backwash Wastewater Sampling Test Results
Sampling Event
No.
1
2
3
4
5
Date
12/11/06
01/17/07
-------
Table 4-14. Comparison of Soluble Arsenic and Iron Concentrations in Backwash Wastewater
Demonstration
Location
Reno, NV
(Gumming et al., 2009)
Three Forks, MT
Bruni, TX
(Williams et al., 2007)
Arnaudville, LA
Lidgerwood, ND
(Condit et al., 2006)
Sabin, MN
(Condit et al., 2008)
Climax, MN
(Condit et al., 2006)
Sandusky, MI
(Valigore et al., 2008b)
Pentwater, MI
(Valigore et al., 2008a)
Arsenic Removal Technology
GFH adsorptive media
Coagulation/Macrolite® filtration with
chlorine and iron addition
AD-33 adsorptive media
Iron removal/Macrolite® filtration with
chlorine (or KMnO4) and iron addition
Coagulation/sand filtration with
iron/KMnO4/polymer addition
Iron removal/Macrolite® filtration with
chlorine addition
Coagulation/Macrolite® filtration with
chlorine and iron addition
Iron removal/AERAL ATER® Type II
sand filtration with chlorine addition
Coagulation/Macrolite® filtration with
chlorine and iron addition
Si02
Concentration
in Raw Water(a)
(mg/L)
72.6(51.5-95.1)
48.5 (46.8-50.8)
41.9 (40.6^3.9)
41.0 (38.4^3.5)
31.2(29.0-34.2)
30.3 (28.5-32.5)
28.7 (16.8-39.2)
12.0(11.2-13.5)
11.2(10.1-13.2)
Soluble Concentration in
Backwash Wastewater(a)
As
(HS/L)
15.7(15.4-15.9)
20.3 (10.5-50.4)
NA
18.0 (13.0-28.3)
9.8(7.5-11.9)
15.5(6.1-27.6)
12.4 (6.4-25.6)
3.2 (0.7-7.0)
8.8(6.5-11.4)
Fe
(HS/L)
29.7 (<25-34.0)
296 (120-846)
NA
44.2 (<25-81.2)
<25
405 (67.3-827)
119(<25-771)
86.1 (<25-196)
157 (48.5-263)
(a) Data presented including average and range (in parentheses).
4.5.4 Distribution System Water Sampling. Table 4-15 summarizes the results of the
distribution system sampling events. Before system startup, total arsenic concentrations in the baseline
samples ranged from 4.0 to 11.6 (ig/L and averaged 6.1 ug/L. Because Well 2 was used only for
cemetery irrigation, the baseline sampling results reflect mainly the quality of Wells 5, 6, 8, and 9 water,
which, as discussed in Section 4.1.1, did not contain elevated levels of arsenic. After system startup, total
arsenic concentrations across the three distribution system sampling locations ranged from 0.9 to 14.9
(ig/L and averaged 6.8 (ig/L, which is much lower than the 17.7 (ig/L (on average) of the treated water
samples collected during November 29, 2006, and July 17, 2007. This is due to the blending of the
treated Well No. 2 water with source water from Wells No. 5, 6, 8, and 9 with low levels of arsenic.
After the treatment system began operation, arsenic concentrations decreased at DS3 from an average
baseline value of 5.3 to 4.2 (ig/L. In contrast, arsenic concentrations increased slightly at both DS1 (from
an average baseline value of 6.3 to 8.3 (ig/L) and DS2 (from an average baseline value of 6.8 to 8.2
(ig/L). Samples at the DS3 location exhibited lower arsenic concentrations (about half of the average
readings at DS1 and DS3), while exhibiting higher iron and manganese levels.
Alkalinity, pH, and lead concentrations remained fairly consistent before and after system startup.
Copper concentrations increased significantly from 45.6 to 176 (ig/L (on average) at DS1 and from 44.2
to 205 (on average) at DS3. At DS2, its concentrations decreased slightly from 153 to 142 (ig/L. All
concentrations were lower than the action level of 1.3 mg/L for copper.
4.6
System Cost
The system cost was evaluated based on the capital cost per gpm (or gpd) of design capacity and the
O&M cost per 1,000 gal of water treated. Capital cost of the treatment system included cost for
equipment, site engineering, and system installation, shakedown, and startup. O&M cost included cost
51
-------
Table 4-15. Distribution System Sampling Results
Sampling
Event
No.
BL1
BL2
BL3
BL4
1
2
3
4
5
6
7
8
9
10
11
12
13
Date
06/20/05*°
07/19/05
08/16/05
09/20/05
-------
for chemicals, electricity, and labor. Cost associated with the building including the sump, sanitary sewer
connections, and water system telemetry was not included in the capital cost because it was not included
in the scope of this demonstration project and was funded separately by the City.
4.6.1 Capital Cost. The capital investment for the FM-248-AS system was $305,447 (Table 4-16).
The equipment cost was $168,142 (or 55% of the total capital investment), which included cost for a
chlorine and an iron addition system, two contact tanks, two pressure vessels each loaded with 25 ft3 of
Macrolite® media, instrumentation and controls, miscellaneous materials and supplies, labor, and system
warranty. The system warranty cost covered the cost for repair and replacement of defective system
components and installation workmanship for 12 months after system startup.
Table 4-16. Capital Investment for FM-248-AS Treatment System
Description
Cost
% of Capital
Investment Cost
Equipment
Tanks, Valves, and Piping
Macrolite® Media (50 ft3)
Instrumentation and Controls
Air Scour System
Iron Addition System
Additional Sample Taps and Totalizers/Meters
Labor
Freight
Equipment Total
$79,349
$10,939
$21,970
$5,373
$6,454
$1,717
$35,311
$7,029
$168,142
-
-
-
-
-
-
-
-
55%
Engineering
Labor
Subcontractor
Engineering Total
$40,810
$12,625
$53,435
-
-
18%
Installation, Shakedown, and Startup
Labor
Subcontractor
Travel
Installation, Shakedown, and Startup
Total Capital Investment
$14,000
$66,000
$3,870
$83,870
$305,447
-
-
-
27%
100%
The site engineering cost covered the cost for preparing the required permit application submittal,
including a process design report, a general arrangement drawing, P&IDs, electrical diagrams,
interconnecting piping layouts, tank fill details, and a schematic of the PLC panel, and obtaining the
required permit approval from MT DEQ. The engineering cost of $53,435 was 18% of the total capital
investment.
The installation, shakedown, and startup cost covered the labor and materials required to unload, install,
and test the system for proper operation. All installation activities were performed by the vendor's
subcontractor, and startup and shakedown activities were performed by the vendor with the operator's
assistance. The installation, startup, and shakedown cost of $83,870 was 27% of the total capital
investment.
53
-------
The total capital cost of $305,447 was normalized to $l,222/gpm ($0.85/gpd) of design capacity using the
system's rated capacity of 250 gpm (or 360,000 gpd). The total capital cost also was converted to an
annualized cost of $28,831/yr using a capital recovery factor of 0.09439 based on a 7% interest rate and a
20-yr return period. Assuming that the system operated 24 hr/day, 7 day/week at the design flowrate of
250 gpm to produce 131,400,000 gal/yr, the unit capital cost would be $0.22/1,000 gal. During the first
year, the system produced approximately 27,234,000 gal of water, so the unit capital cost increased to
$1.06/1,000 gal.
A 37'/3 ft x 33 !/3 ft building with a side wall height of 16 ft was constructed by the City to house the
treatment system (Section 4.4.2). Not included in the capital cost, the total cost of the building and
supporting utilities, which were sized for two treatment systems, was approximately $120,000.
4.6.2 O&M Cost. O&M cost included chemical usage, electricity consumption, and labor for a
combined unit cost of $0.18/1,000 gal (Table 4-17). No cost was incurred for repairs because the system
was under warranty. Since chlorination was used only for disinfection purposes, the O&M cost only
includes the incremental chemical cost for iron addition at $0.016/1,000 gal. Electrical power
consumption was calculated based on the difference between the average monthly cost from electric bills
before and after building construction and system startup. The difference in cost was approximately
$209.50/month or $0.006/1,000 gal of water treated. Based on this time commitment and a labor rate of
$19.63/hr, the labor cost was $0.16/1,000 gal of water treated.
Table 4-17. O&M Cost for FM-248-AS Treatment System
Category
Volume Processed (1,000 gal)
Value
31,147
Remarks
From 1 1/27/06 through 2/08/08
Chemical Usage
31-42% FeCl3 Unit Cost ($/lb)
FeCl3 Consumption (lb/1,000 gal)
Chemical Cost ($/l,000 gal)
$0.34
0.048
$0.016
Supplied in 600 Ib drums including tax,
surcharges, and drum deposit
Electricity Consumption
Electricity Cost ($/month)
Electricity Cost ($/l,000 gal)
$209.50
$0.006
Average incremental consumption after
system startup; including building
heating and lighting
Labor
Labor (hr/week)
Labor Cost ($/l,000 gal)
Total O&M Cost ($/l,000 gal)
4.7
$0.16
$0.18
30 mm/day, 5 day/week
Labor rate = $19.63/hr
Including FeCl3 usage
54
-------
5.0. REFERENCES
Battelle. 2004. Quality Assurance Project Plan for Evaluation of Arsenic Removal Technology.
Prepared under Contract No. 68-C-00-185, Task Order No. 0029, for U.S. Environmental
Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH.
Battelle. 2006. System Performance Evaluation Study Plan: U.S. EPA Arsenic Removal Technology
Demonstration at City of Three Forks, MT. Prepared under Contract No. 68-C-00-185, Task
Order No. 0029, for U.S. Environmental Protection Agency, National Risk Management
Research Laboratory, Cincinnati, OH.
Chen, A.S.C., L. Wang, J.L. Oxenham, and W.E. Condit. 2004. Capital Costs of Arsenic Removal
Technologies: U.S. EPA Arsenic Removal Technology Demonstration Program Round 1.
EPA/600/R-04/201. U.S. Environmental Protection Agency, National Risk Management
Research Laboratory, Cincinnati, OH.
Condit, W.E. and A.S.C. Chen. 2006. Arsenic Removal from Drinking Water by Iron Removal, U.S. EPA
Demonstration Project at Climax, MN, Final Performance Evaluation Report. EPA/600/R-
06/152. U.S. Environmental Protection Agency, National Risk Management Research
Laboratory, Cincinnati, OH.
Condit, W.E., A.S.C. Chen, and L. Wang. 2006. Arsenic Removal from Drinking Water by Process
Modifications to Coagulation/Filtration, U.S. EPA Demonstration Project at Lidgerwood, ND,
Final Evaluation Report. EPA/600/R-06/159. U.S. Environmental Protection Agency, National
Risk Management Research Laboratory, Cincinnati, OH.
Condit, W.E. and A.S.C. Chen. 2008. Arsenic Removal from Drinking Water by Iron Removal, U.S. EPA
Demonstration Project at Sabin, MN, Six-Month Evaluation Report. EPA/600/R-08/005. U.S.
Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati,
OH.
Cumming, L.J., A.S.C. Chen, and L. Wang. 2009. Arsenic and Antimony Removal from Drinking Water
by Adsorptive Media, U.S. EPA Demonstration Project at South Truckee Meadows General
Improvement District (STMGID), NV, Final Performance Evaluation Report. EPA/600/R-09/016.
U.S. Environmental Protection Agency, National Risk Management Research Laboratory,
Cincinnati, OH.
Edwards, M., S. Patel, L. McNeill, H. Chen, M. Frey, A.D. Eaton, R.C. Antweiler, and H.E. Taylor.
1998. "Considerations in As Analysis and Speciation." J. AWWA, 90(3): 103-113.
EPA. 2003. Minor Clarification of the National Primary Drinking Water Regulation for Arsenic.
Federal Register, 40 CFRPart 141.
EPA. 2002. Lead and Copper Monitoring and Reporting Guidance for Public Water Systems.
EPA/816/R-02/009. U.S. Environmental Protection Agency, Office of Water, Washington, D.C.
EPA. 2001. National Primary Drinking Water Regulations: Arsenic and Clarifications to Compliance
and New Source Contaminants Monitoring. Federal Register, 40 CFR Parts 9, 141, and 142.
Her, R.K. 1979. The Chemistry of Silica. Wiley-Interscience, New York.
55
-------
Kinetico. 2006. The City of Three Forks, MT: Installation Manual; Suppliers Literature; and Operation
and Maintenance Manual, Macrolite FM-248-AS Arsenic Removal System. Newbury, OH.
Knocke, W.R., R.C. Hoehn, and R.L. Sinsabaugh. 1987. "Using Alternative Oxidants to Remove
Dissolved Manganese From Waters Laden With Organics." J. AWWA, 79(3): 75-79.
Knocke, W.R., J.E. Van Benschoten, M. Kearney, A. Soborski, and D.A. Reckhow. 1990. "Alternative
Oxidants for the Removal of Soluble Iron and Mn." AWWA Research Foundation, Denver, CO.
Meng, X., S. Bang, and G.P. Korfiatis. 2000. "Effects of Silicate, Sulfate and Carbonate on Arsenic
Removal by Ferric Chloride." Water Research, 34(4): 1255-1261
McCall S.E., A.S.C. Chen, and L. Wang. 2007. Arsenic Removal from Drinking Water by Adsorptive
Media, U.S. EPA Demonstration Project at Chateau Estates Mobile Home Park in Springfield,
OH, Final Performance Evaluation Report. EPA/600/R-07/072. U.S. Environmental Protection
Agency, National Risk Management Research Laboratory, Cincinnati, OH.
Robinson, R.B., Reed, G.D. and Frazier, B. 1992. "Iron and Manganese Sequestration Facilities Using
Sodium Silicate" J. AWWA, 84(2): 77-82
Sorg, T.J. 2002. "Iron Treatment for Arsenic Removal Neglected." Opflow, 28(11): 15.
Valigore, J.M., A.S.C. Chen, W.E. Condit, and L. Wang. 2008a. Arsenic Removal from Drinking Water
by Coagulation/Filtration, U.S. EPA Demonstration Project at Village ofPentwater, MI, Final
Performance Evaluation Report. EPA/600/R-08/011. U.S. Environmental Protection Agency,
National Risk Management Research Laboratory, Cincinnati, OH.
Valigore, J.M., A.S.C. Chen, W.E. Condit, and L. Wang. 2008b. Arsenic Removal from Drinking Water
by Iron Removal, U.S. EPA Demonstration Project at City ofSandusky, MI, Final Performance
Evaluation Report. EPA/600/R-08/007. U.S. Environmental Protection Agency, National Risk
Management Research Laboratory, Cincinnati, OH.
Wang, L., A.S.C. Chen, and K.A. Fields. 2000. Arsenic Removal from Drinking Water by Ion Exchange
and Activated Alumina Plants. EPA/600/R-00/088. U.S. Environmental Protection Agency,
National Risk Management Research Laboratory, Cincinnati, OH.
Wang, L., W.E. Condit, and A.S.C. Chen. 2004. Technology Selection and System Design: U.S. EPA
Arsenic Removal Technology Demonstration Program Round 1. EPA/600/R-05/001. U.S.
Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati,
OH.
Williams, S., A.S.C. Chen, and L. Wang. 2007. Arsenic Removal from Drinking Water by Adsorptive
Media, U.S. EPA Demonstration Project at Webb Consolidated Independent School District in
Bruni, TX, Six-Month Evaluation Report. EPA/600/R-07/049. U.S. Environmental Protection
Agency, National Risk Management Research Laboratory, Cincinnati, OH.
56
-------
APPENDIX A
OPERATIONAL DATA
-------
US EPA Arsenic Demonstration Project at Three Forks, MT - Daily System Operation
Week
No.
1
2
3
4
5
6
7
8
9
10
Day
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Tue
Wed
Thu
Fri
Mon
Wed
Fri
Mon
Wed
Fri
Mon
Wed
Fri
Mon
Wed
Fri
Mon
Wed
Fri
Date
11/27/06
11/28/06
11/29/06
11/30/06
12/01/06
12/04/06
12/05/06
12/06/06
12/07/06
12/08/06
12/11/06
12/12/06
12/14/06
12/15/06
12/18/06
12/19/06
12/20/06
12/21/06
12/22/06
12/26/06
12/27/06
12/28/06
12/29/06
01/01/07
01/03/07
01/05/07
01/08/07
01/10/07
01/12/07
01/15/07
01/17/07
01/19/07
01/22/07
01/24/07
01/26/07
01/29/07
01/31/07
02/02/07
Time
5:50
7:30
7:30
6:30
7:00
5:00
4:30
6:00
5:30
4:00
5:30
7:30
6:00
6:00
5:00
6:00
6:00
6:00
6:30
5:00
6:00
6:00
7:30
6:00
7:00
7:00
7:00
6:00
6:00
5:00
7:00
7:00
4:30
7:30
6:30
5:15
7:15
7:00
Run Time
Totalizer
Vessel
A
hr
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Vessel
B
hr
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Daily
Vessel
A
hr
9.3
12.3
10.8
10.7
11.3
10.3
13.0
13.3
11.7
12.2
13.9
12.5
8.7
11.8
11.6
12.5
11.4
11.6
12.0
11.9
12.9
11.8
11.8
10.3
8.9
8.3
9.9
8.2
8.7
9.2
9.2
10.0
8.6
9.1
9.2
9.4
10.2
9.9
Vessel
B
hr
9.3
12.3
10.8
10.7
11.3
10.3
13.0
13.3
11.7
12.2
13.9
12.5
8.7
11.8
11.6
12.5
11.4
11.6
12.0
11.9
12.9
11.8
11.8
10.3
8.9
8.3
9.9
8.2
8.7
9.2
9.2
10.0
8.6
9.1
9.2
9.4
10.2
9.9
12.5%
C12
Tank
Level
in
26.0
31.0
30.0
28.5
27.5
26.3
25.0
23.3
22.0
20.5
19.0
17.3
26.5
25.3
24.0
22.5
21.3
19.8
18.5
17.0
15.5
14.0
12.5
36.5
35.3
34.8
33.8
32.8
32.0
31.0
30.0
29.0
28.0
27.0
25.8
24.8
23.5
22.3
35%
FeCl3
Tank
Level
in
14.0
33.0
29.0
24.3
19.0
14.3
31.0
25.3
19.8
14.0
32.0
27.3
23.5
19.0
34.0
29.3
25.0
34.0
29.8
25.3
20.3
15.5
10.5
34.0
31.0
27.8
24.3
22.5
16.3
35.0
31.5
27.8
24.3
20.5
17.0
12.5
34.0
30.3
Pressure Filtration
Inlet
psig
44
45
45
43
43
45
39
41
42
42
38
39
40
41
37
40
35
40
35
56
41
36
43
38
37
38
37
38
38
38
37
36
38
38
38
38
37
38
TA
psig
17
26
19
28
21
23
28
21
27
26
25
25
21
24
23
23
25
23
25
25
23
25
22
22
22
22
22
22
22
22
23
22
22
22
22
22
23
23
TB
psig
29
21
29
20
27
21
23
29
22
22
22
25
29
24
24
26
27
26
27
27
25
27
25
24
24
24
24
24
24
24
24
25
24
24
24
24
24
24
Outlet
psig
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
Flow
rate
gpm
188
185
185
188
189
186
200
195
191
192
200
198
195
193
199
196
207
195
205
190
191
204
189
200
200
200
200
196
200
200
200
200
200
198
200
200
200
200
Totalizer to
Distribution
Daily
Flow
kgal
99
141
118
50
125
116
143
174
132
136
159
148
93
135
132
143
124
133
131
136
150
129
133
117
102
98
100
109
98
107
105
114
101
130
105
109
118
115
Cal
Flow
rate
gpm
177
191
182
NA
184
188
183
218
187
186
190
197
178
190
190
191
182
191
181
190
193
183
188
189
191
196
169
222
188
194
190
190
196
239
190
193
192
193
Backwash
Tank
A
No.
14
15
15
16
16
17
18
18
19
20
21
22
22
23
24
25
26
27
28
28
29
30
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
Tank
B
No.
13
13
14
14
15
15
16
17
17
18
19
20
21
21
22
23
24
25
26
26
27
28
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
Daily
Volume
kgal
1.0
1.0
1.0
1.3
1.4
1.0
2.6
1.1
1.3
2.6
3.2
2.3
1.1
0.9
NA
4.9
2.4
2.3
2.3
0.0
2.1
2.3
0.0
2.3
2.3
2.2
NA
2.6
4.2
2.3
2.3
2.2
2.3
2.4
2.3
2.3
2.3
2.3
Run Time Since
Last BW
Vessel
A
hr
17.0
8.2
NA
4.3
15.4
9.9
2.3
15.5
6.9
3.5
5.7
8.1
16.3
10.4
7.5
11.8
2.7
11.1
2.5
14.1
12.7
4.0
15.8
9.4
8.3
7.9
8.1
9.0
7.9
8.7
8.5
7.5
8.1
8.7
8.5
8.8
9.6
9.4
Vessel
B
hr
4.5
11.9
13.5
17.8
8.5
18.9
12.4
5.7
17.3
8.9
11.5
9.2
4.6
16.3
8.0
11.3
2.2
10.5
2.1
14.0
12.3
3.7
15.4
8.9
7.9
7.5
7.7
8.5
7.5
8.3
8.1
6.9
7.8
8.2
8.1
8.4
9.1
8.9
-------
US EPA Arsenic Demonstration Project at Three Forks, MT - Daily System Operation (Continued)
Week
No.
11
12
13
14
15
16
17
18
19
20
21
22
Day
Mon
Wed
Fri
Mon
Fri
Mon
Wed
Fri
Mon
Wed
Fri
Mon
Wed
Fri
Mon
Wed
Fri
Mon
Tue
Wed
Fri
Mon
Wed
Fri
Mon
Wed
Fri
Mon
Wed
Fri
Mon
Wed
Fri
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Date
02/05/07
02/07/07
02/09/07
02/12/07
02/16/07
02/19/07
02/21/07
02/23/07
02/26/07
02/28/07
03/02/07
03/05/07
03/07/07
03/09/07
03/12/07
03/14/07
03/16/07
03/19/07
03/20/07
03/21/07
03/23/07
03/26/07
03/28/07
03/30/07
04/02/07
04/04/07
04/06/07
04/09/07
04/11/07
04/13/07
04/16/07
04/18/07
04/20/07
04/23/07
04/24/07
04/25/07
04/26/07
04/27/07
04/28/07
04/29/07
Time
5:45
7:20
6:15
5:30
6:30
6:15
6:15
6:10
7:15
7:00
6:15
5:00
7:00
7:00
5:30
7:15
7:35
5:30
7:25
4:00
7:00
5:00
5:00
7:00
5:30
6:00
7:30
5:00
4:30
5:30
4:45
5:30
6:00
5:00
7:30
7:30
11:00
11:00
10:00
11:00
Run Time
Totalizer
Vessel
A
hr
NA
NA
NA
NA
NA
8.1
16.5
25.2
33.4
41.7
49.8
58.0
67.4
77.1
87.0
98.4
105.1
115.9
127.3
127.5
142.0
152.0
163.7
175.4
185.7
196.7
207.6
217.9
230.0
241.6
253.7
264.2
277.1
289.2
303.1
307.9
317.6
323.7
329.8
337.1
Vessel
B
hr
NA
NA
NA
NA
NA
8.0
16.5
25.2
33.6
41.8
49.9
58.2
67.6
77.2
87.2
99.6
105.0
115.7
127.5
129.6
142.4
152.4
164.1
175.9
186.1
197.1
208.1
218.5
230.8
242.4
254.4
264.9
277.8
290.5
302.9
305.8
318.6
324.7
330.8
338.1
Daily
Vessel
A
hr
9.9
9.8
9.6
10.3
10.0
8.1
8.4
8.7
8.2
8.3
8.1
8.2
9.4
9.7
9.9
11.4
6.7
10.8
11.4
0.2
14.5
10.0
11.7
11.7
10.3
11.0
10.9
10.3
12.1
11.6
12.1
10.5
12.9
12.1
13.9
4.8
9.7
6.1
6.1
7.3
Vessel
B
hr
9.9
9.8
9.6
10.3
10.0
8.0
8.5
8.7
8.4
8.2
8.1
8.3
9.4
9.6
10.0
12.4
5.4
10.7
11.8
2.1
12.8
10.0
11.7
11.8
10.2
11.0
11.0
10.4
12.3
11.6
12.0
10.5
12.9
12.7
12.4
2.9
12.8
6.1
6.1
7.3
12.5%
C12
Tank
Level
in
21.0
19.8
18.5
17.3
16.0
15.0
13.8
12.5
11.0
21.3
20.0
19.0
18.0
16.8
15.3
13.8
34.8
33.5
32.3
32.0
30.5
29.3
28.0
26.5
25.5
24.0
23.0
21.8
20.3
18.8
17.5
34.0
31.8
30.5
28.8
27.8
26.5
25.8
25.0
23.8
35%
FeCl3
Tank
Level
in
26.3
22.5
18.5
14.0
27.0
23.5
19.8
15.8
12.0
33.5
30.0
26.8
22.5
18.5
14.0
31.8
29.0
24.5
19.5
18.8
34.8
30.8
26.0
20.5
16.5
11.3
35.5
30.3
25.5
20.3
15.0
32.8
27.3
21.8
16.0
12.8
34.0
31.5
28.8
25.8
Pressure Filtration
Inlet
psig
38
37
37
39
39
37
37
36
37
37
37
37
38
38
38
32
37
40
43
33
43
40
41
42
40
40
39
41
41
41
42
33
37
35
33
35
34
42
37
37
TA
psig
22
22
23
21
22
22
22
22
22
23
22
22
22
22
22
25
23
22
23
24
22
21
22
21
23
22
22
21
21
21
22
24
23
23
22
25
27
22
23
22
TB
psig
24
24
24
24
23
24
24
25
24
24
24
24
24
24
24
26
23
22
25
26
22
23
22
23
22
22
24
23
24
23
22
25
23
25
24
26
29
22
23
22
Outlet
psig
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
Flow
rate
gpm
199
200
200
196
197
201
200
202
199
202
199
202
198
200
198
212
201
195
190
210
189
196
190
191
194
194
197
194
191
191
191
209
200
205
205
204
207
196
198
201
Totalizer to
Distribution
Daily
Flow
kgal
116
108
111
121
116
99
104
107
102
101
100
101
115
117
121
138
84
124
141
19
158
120
139
139
123
154
128
124
144
137
144
128
154
154
152
83
107
72
74
87
Cal
Flow
rate
gpm
195
184
192
195
NA
NA
204
205
205
204
206
204
203
201
202
193
231
191
202
281
193
200
198
197
200
234
195
199
197
197
199
203
199
207
192
361
158
196
202
199
Backwash
Tank
A
No.
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
78
79
81
83
84
86
86
87
88
Tank
B
No.
44
49
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
79
80
82
84
85
87
87
88
89
Daily
Volume
kgal
2.3
5.5
2.3
2.3
2.3
2.2
2.2
2.2
2.3
2.3
2.3
2.2
2.1
2.3
2.4
2.2
2.4
2.3
2.3
2.4
2.3
2.3
2.3
2.3
2.2
2.3
2.3
2.4
2.2
2.3
2.4
4.7
2.3
4.8
4.9
2.2
4.8
0.0
2.3
2.4
Run Time Since
Last BW
Vessel
A
hr
9.5
9.0
9.1
9.9
9.5
8.0
8.4
7.0
8.3
8.2
8.0
7.0
9.4
9.6
9.9
11.4
6.7
10.3
11.8
1.2
13.4
10.0
11.7
11.8
10.2
11.0
8.1
10.3
12.1
11.5
12.1
2.3
7.1
3.5
4.2
1.9
0.4
6.5
4.5
3.7
Vessel
B
hr
8.7
7.5
8.6
9.0
8.8
7.6
7.7
6.4
7.5
7.8
7.6
6.6
9.0
9.0
9.4
10.9
6.1
9.8
11.4
0.8
13.0
9.6
10.9
11.4
9.8
10.6
7.7
7.8
11.8
11.2
11.6
1.9
6.7
3.2
3.7
1.6
0.0
6.1
4.1
3.3
-------
US EPA Arsenic Demonstration Project at Three Forks, MT - Daily System Operation (Continued)
Week
No.
23
24
25
26
27
28
29
Day
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Mon
Thu
Sat
Sun
Wed
Thu
Fri
Sat
Sun
Mon
Tue
Sat
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Date
04/30/07
05/01/07
05/02/07
05/03/07
05/04/07
05/05/07
05/06/07
05/07/07
05/08/07
05/09/07
05/10/07
05/11/07
05/12/07
05/13/07
05/14/07
05/15/07
05/16/07
05/17/07
05/18/07
05/19/07
05/20/07
05/21/07
05/24/07
05/26/07
05/27/07
05/30/07
05/31/07
06/01/07
06/02/07
06/03/07
06/04/07
06/05/07
06/09/07
06/10/07
06/11/07
06/12/07
06/13/07
06/14/07
06/15/07
06/16/07
06/17/07
Time
10:30
10:45
11:00
12:00
11:30
12:15
11:25
10:30
6:15
7:30
8:00
8:00
8:20
7:15
7:45
8:00
7:30
8:00
8:00
8:00
8:00
8:00
7:00
5:00
NA
7:00
7:00
7:30
9:00
7:30
5:00
6:00
8:30
8:00
9:00
7:00
7:30
8:00
6:45
8:00
9:00
Run Time
Totalizer
Vessel
A
hr
344.7
352.4
360.5
367.0
374.0
379.5
385.6
395.8
404.9
413.8
424.1
430.3
436.0
445.6
457.1
466.6
472.2
484.5
491.3
501.8
512.7
522.2
531.2
541.3
545.3
554.4
564.4
574.3
579.7
589.4
599.5
610.0
620.9
632.4
640.4
650.1
661.2
672.6
678.8
684.4
696.4
Vessel
B
hr
345.7
353.9
361.8
368.0
375.0
380.5
386.6
396.8
405.9
414.8
425.1
431.4
437.5
446.7
458.2
467.7
473.3
485.6
492.3
502.8
513.7
523.3
532.2
542.4
546.4
555.5
565.6
575.3
580.8
590.5
600.6
611.2
622.0
633.4
641.4
651.1
662.5
673.6
678.8
685.5
697.2
Daily
Vessel
A
hr
7.6
7.7
8.1
6.5
7.0
5.5
6.1
10.2
9.1
8.9
10.3
6.2
5.7
9.6
11.5
9.5
5.6
12.3
6.8
10.5
10.9
9.5
9.0
10.1
4.0
9.1
10.0
9.9
5.4
9.7
10.1
10.5
10.9
11.5
8.0
9.7
11.1
11.4
6.2
5.6
12.0
Vessel
B
hr
7.6
8.2
7.9
6.2
7.0
5.5
6.1
10.2
9.1
8.9
10.3
6.3
6.1
9.2
11.5
9.5
5.6
12.3
6.7
10.5
10.9
9.6
8.9
10.2
4.0
9.1
10.1
9.7
5.5
9.7
10.1
10.6
10.8
11.4
8.0
9.7
11.4
11.1
5.2
6.7
11.7
12.5%
C12
Tank
Level
in
22.5
21.5
20.3
19.3
18.0
17.3
16.5
14.8
33.8
32.8
31.3
30.5
29.5
28.3
26.8
34.5
33.8
32.0
31.0
29.8
28.3
27.5
26.3
24.8
24.3
23.0
21.0
19.8
18.8
17.3
15.8
14.0
35.3
34.0
32.8
31.5
30.0
28.3
27.5
26.5
24.8
35%
FeCl3
Tank
Level
in
22.3
18.8
15.0
36.3
33.5
31.5
29.0
24.5
34.0
30.5
26.0
23.5
34.3
30.5
25.5
32.0
29.8
24.5
21.5
33.0
29.0
32.5
29.0
24.5
22.8
18.5
33.0
29.0
26.5
22.5
33.8
29.3
25.0
20.0
16.3
33.3
28.8
24.0
21.0
32.0
27.8
Pressure Filtration
Inlet
psig
37
36
37
33
34
36
35
37
37
38
33
37
37
37
34
35
33
37
35
36
32
34
35
37
33
35
36
36
35
36
38
33
36
38
36
33
35
39
37
35
38
TA
psig
23
22
23
25
27
24
24
24
25
23
25
24
24
23
25
25
25
24
24
24
25
25
25
24
25
25
25
24
25
24
24
26
25
24
24
26
25
24
25
25
24
TB
psig
24
22
22
26
28
25
26
26
25
25
26
24
26
25
26
26
26
25
26
25
26
26
26
25
26
26
26
25
26
26
25
27
26
26
25
27
26
26
26
27
26
Outlet
psig
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
Flow
rate
gpm
201
203
204
208
209
200
203
201
200
197
208
196
202
198
205
204
209
200
205
198
208
205
204
202
206
208
201
200
206
203
200
209
206
200
206
212
206
200
205
211
204
Totalizer to
Distribution
Daily
Flow
kgal
92
99
95
79
84
61
74
122
110
106
126
73
74
111
139
138
68
147
81
125
124
121
108
121
50
110
122
116
67
117
121
129
130
138
97
120
137
134
78
69
142
Cal
Flow
rate
gpm
201
207
198
208
200
184
203
199
201
198
204
195
208
198
202
241
203
199
201
198
189
211
200
199
207
201
202
197
204
201
199
203
200
200
202
206
204
199
228
186
200
Backwash
Tank
A
No.
89
90
91
92
93
93
94
95
96
97
99
99
100
101
103
104
105
106
107
108
110
111
112
113
114
115
116
117
118
119
120
122
123
124
125
127
128
129
130
131
132
Tank
B
No.
90
91
92
93
94
94
95
96
97
98
100
100
101
102
104
105
106
107
108
109
111
112
113
114
115
116
117
118
119
120
121
123
124
125
126
128
129
130
131
132
133
Daily
Volume
kgal
2.3
2.3
2.4
2.3
2.4
0.0
2.4
1.9
2.9
2.3
4.9
0.0
2.3
2.2
4.6
2.4
2.4
2.4
2.4
2.4
4.7
2.4
2.4
2.4
2.3
2.4
2.4
2.2
2.4
2.3
2.4
4.7
2.4
2.2
2.4
4.2
2.9
2.3
2.3
2.4
2.4
Run Time Since
Last BW
Vessel
A
hr
3.2
3.3
3.1
2.0
1.0
5.6
3.6
5.7
6.7
7.5
1.6
7.8
5.7
6.9
2.2
3.6
1.1
5.3
4.0
6.4
0.5
2.5
3.4
5.4
1.3
2.4
4.4
6.0
3.3
4.9
6.9
1.3
4.0
7.4
7.3
0.8
4.1
7.1
5.2
2.7
6.7
Vessel
B
hr
2.8
2.9
2.7
1.0
0.0
5.2
3.2
5.3
6.3
7.1
1.2
7.5
5.3
6.5
1.8
3.2
0.7
4.9
3.5
5.9
0.1
2.1
2.9
5.0
0.9
2.0
3.9
5.5
2.9
4.5
6.5
0.9
3.6
6.9
6.8
0.3
3.6
6.6
4.8
2.3
5.9
-------
US EPA Arsenic Demonstration Project at Three Forks, MT - Daily System Operation (Continued)
Week
No.
30
31
32
33
34
35
36
Day
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Date
06/18/07
06/19/07
06/20/07
06/21/07
06/22/07
06/23/07
06/24/07
06/25/07
06/26/07
06/27/07
06/28/07
06/29/07
06/30/07
07/01/07
07/02/07
07/03/07
07/04/07
07/05/07
07/06/07
07/07/07
07/08/07
07/10/07
07/11/07
07/12/07
07/13/07
07/16/07
07/17/07
07/18/07
07/19/07
07/20/07
07/23/07
07/24/07
07/25/07
07/26/07
07/27/07
07/30/07
07/31/07
08/01/07
08/02/07
08/03/07
Time
7:00
7:00
5:30
6:45
4:00
4:30
6:00
4:30
4:00
4:00
4:00
4:00
4:00
2:30
2:30
2:30
2:30
2:30
2:30
2:30
4:50
2:30
2:30
2:30
6:00
8:30
4:00
8:30
7:30
6:00
7:30
6:00
7:30
6:30
6:00
9:30
8:00
4:30
9:00
6:00
Run Time
Totalizer
Vessel
A
hr
701.7
711.7
725.4
736.2
747.6
760.3
771.4
784.7
798.1
809.0
821.3
834.4
849.3
863.5
877.8
896.5
913.9
928.7
948.1
971.0
993.3
994.0
1010.4
1027.2
1032.7
1043.6
1053.5
1063.0
1068.8
1074.6
1081.7
1088.2
1098.4
1104.7
1116.5
1122.8
1126.6
1135.6
1137.8
1145.0
Vessel
B
hr
702.8
712.8
724.5
737.3
748.7
761.4
772.5
786.0
799.2
810.0
822.4
835.5
850.1
864.2
878.9
897.7
915.0
929.8
949.2
972.1
994.3
995.0
1011.5
1028.3
1033.8
1044.9
1054.7
1064.1
1069.8
1075.5
1082.6
1089.1
1099.1
1105.4
1116.2
1123.6
1128.5
1136.1
1138.8
1146.0
Daily
Vessel
A
hr
5.3
10.0
13.7
10.8
11.4
12.7
11.1
13.3
13.4
10.9
12.3
13.1
14.9
14.2
14.3
18.7
17.4
14.8
19.4
22.9
22.3
0.7
16.4
16.8
5.5
10.9
9.9
9.5
5.8
5.8
7.1
6.5
10.2
6.3
11.8
6.3
3.8
9.0
2.2
7.2
Vessel
B
hr
5.6
10.0
11.7
12.8
11.4
12.7
11.1
13.5
13.2
10.8
12.4
13.1
14.6
14.1
14.7
18.8
17.3
14.8
19.4
22.9
22.2
0.7
16.5
16.8
5.5
11.1
9.8
9.4
5.7
5.7
7.1
6.5
10.0
6.3
10.8
7.4
4.9
7.6
2.7
7.2
12.5%
C12
Tank
Level
in
24.0
25.8
24.0
22.0
20.3
18.3
37.5
35.8
34.0
32.5
30.8
28.8
26.5
24.5
22.5
19.5
16.8
14.3
33.0
29.8
26.8
26.5
24.0
21.5
20.8
19.0
17.5
16.0
15.3
14.5
13.5
34.8
33.3
32.5
31.3
30.5
29.8
28.8
28.5
27.5
35%
FeCl3
Tank
Level
in
24.8
33.5
27.0
23.5
18.3
12.3
32.8
27.3
21.8
17.0
33.5
28.5
22.0
32.3
26.5
29.8
22.5
16.0
13.3
28.8
19.0
37.3
30.5
23.5
21.0
16.0
33.5
29.8
27.5
24.5
21.5
34.5
30.0
27.3
22.3
19.0
17.3
18.8
17.5
33.5
Pressure Filtration
Inlet
psig
36
37
34
39
34
37
34
37
36
37
35
38
37
36
34
37
37
36
39
41
39
38
39
39
38
39
42
34
42
39
37
35
38
36
39
31
37
37
36
36
TA
psig
26
25
26
24
26
25
26
25
26
25
26
24
25
25
26
26
25
26
25
25
26
25
24
24
26
25
23
28
25
26
26
27
26
28
26
22
25
26
27
25
TB
psig
26
25
27
26
27
27
27
26
27
26
27
26
26
26
27
27
26
26
26
26
27
27
26
26
27
27
26
29
26
27
27
28
27
28
27
23
27
27
27
27
Outlet
psig
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
Flow
rate
gpm
207
205
214
201
215
205
216
205
210
205
212
200
205
207
211
205
206
207
200
198
204
203
203
201
205
199
195
213
195
203
205
212
204
206
203
168.7
205
205
206
203
Totalizer to
Distribution
Daily
Flow
kgal
70
126
138
198
120
154
138
165
163
132
152
159
182
173
173
228
210
180
234
275
268
8
221
201
68
132
116
113
68
70
86
78
127
76
129
89
48
113
27
89
Cal
Flow
rate
gpm
214
211
182
280
175
201
207
205
204
202
206
202
205
203
199
203
202
203
201
200
200
193
224
199
205
200
196
200
197
202
201
199
210
201
190
217
184
227
186
206
Backwash
Tank
A
No.
133
134
136
137
139
140
142
143
145
146
148
149
151
153
155
157
159
161
163
166
169
169
171
173
174
175
176
178
178
179
180
181
183
184
185
186
187
189
190
191
Tank
B
No.
134
135
137
138
140
141
143
144
146
147
149
150
152
154
156
158
160
162
164
167
170
170
172
174
175
176
177
179
179
180
181
182
184
185
186
187
188
190
191
192
Daily
Volume
kgal
2.3
2.3
4.6
2.4
4.7
2.2
4.6
2.4
4.9
2.3
4.7
2.4
4.7
4.6
4.8
4.7
4.5
4.7
4.6
7.1
7.0
0.0
4.7
4.7
2.4
2.2
2.2
4.7
0.0
2.4
2.4
2.2
6.2
2.3
2.3
4.1
2.3
5.3
1.7
2.4
Run Time Since
Last BW
Vessel
A
hr
3.8
5.7
1.2
5.9
1.1
5.7
0.6
6.0
3.0
5.8
2.0
7.0
5.7
3.7
1.8
4.3
5.5
4.1
7.3
5.9
3.9
4.6
4.8
5.4
2.8
5.8
7.5
0.4
6.2
3.9
2.9
1.3
3.8
2.0
4.7
3.9
3.6
2.4
2.0
4.2
Vessel
B
hr
3.4
5.3
0.8
5.5
0.7
5.3
0.2
5.7
2.7
5.4
1.6
6.6
5.3
3.3
1.4
3.9
5.1
3.7
7.0
5.5
3.5
4.1
4.4
5.0
2.4
5.4
7.1
0.0
5.7
3.5
2.5
0.9
3.3
1.5
4.2
3.4
3.2
2.1
1.6
3.8
-------
US EPA Arsenic Demonstration Project at Three Forks, MT - Daily System Operation (Continued)
Week
No.
37
38
39
40
41
42
43
Day
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Tue
Wed
Tue
Wed
Thu
Fri
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Date
08/06/07
08/07/07
08/08/07
08/09/07
08/10/07
08/11/07
08/12/07
08/13/07
08/14/07
08/15/07
08/16/07
08/17/07
08/18/07
08/19/07
08/20/07
08/21/07
08/22/07
08/23/07
08/24/07
08/25/07
08/28/07
08/29/07
09/04/07
09/05/07
09/06/07
09/07/07
09/10/07
09/11/07
09/12/07
09/13/07
09/14/07
09/15/07
09/16/07
09/17/07
09/18/07
09/19/07
09/20/07
09/21/07
09/22/07
09/23/07
Time
7:00
6:00
6:30
6:00
5:30
8:00
6:30
6:00
4:00
6:00
4:30
5:30
7:30
11:30
5:45
6:00
6:00
6:00
7:00
8:00
13:00
6:00
5:30
7:00
6:00
6:00
5:00
7:00
7:00
9:00
6:00
7:30
6:30
6:00
7:00
7:00
6:30
7:00
7:00
12:00
Run Time
Totalizer
Vessel
A
hr
1152.0
1163.3
1176.4
1189.8
1201.7
1213.6
1223.4
1236.3
1247.3
1259.5
1274.3
1285.6
1294.6
1303.2
1306.3
1317.0
1327.6
1339.4
1351.9
1361.7
1369.8
1374.4
1384.8
1393.7
1401.6
1408.0
1414.0
1421.8
1428.0
1434.8
1441.9
1449.2
1458.2
1469.5
1477.4
1485.4
1489.9
1496.1
1501.5
1509.4
Vessel
B
hr
1152.9
1164.3
1177.4
1190.8
1202.7
1214.5
1224.3
1236.2
1248.3
1260.5
1272.3
1284.6
1295.6
1304.4
1307.3
1318.1
1325.7
1340.6
1353.0
1362.1
1370.8
1375.3
1385.7
1394.7
1402.5
1409.0
1415.0
1422.9
1429.1
1435.9
1442.8
1450.2
1459.3
1470.6
1478.5
1480.5
1491.1
1497.2
1502.6
1511.0
Daily
Vessel
A
hr
7.0
11.3
13.1
13.4
11.9
11.9
9.8
12.9
11.0
12.2
14.8
11.3
9.0
8.6
3.1
10.7
10.6
11.8
12.5
9.8
8.1
4.6
10.4
8.9
7.9
6.4
6.0
7.8
6.2
6.8
7.1
7.3
9.0
11.3
7.9
8.0
4.5
6.2
5.4
7.9
Vessel
B
hr
6.9
11.4
13.1
13.4
11.9
11.8
9.8
11.9
12.1
12.2
11.8
12.3
11.0
8.8
2.9
10.8
7.6
14.9
12.4
9.1
8.7
4.5
10.4
9.0
7.8
6.5
6.0
7.9
6.2
6.8
6.9
7.4
9.1
11.3
7.9
2.0
10.6
6.1
5.4
8.4
12.5%
C12
Tank
Level
in
26.8
25.5
23.8
22.0
20.5
18.8
17.5
16.0
14.5
12.5
11.0
9.0
30.0
29.0
28.5
27.3
26.0
24.5
22.8
21.5
20.5
19.8
18.5
17.3
16.3
15.3
14.3
34.8
34.0
33.0
32.3
31.5
30.3
29.0
28.0
27.3
26.5
25.5
25.0
24.0
35%
FeCl3
Tank
Level
in
30.5
26.0
22.5
31.3
26.5
21.5
34.0
29.5
24.5
33.0
28.5
23.5
32.5
29.3
27.8
34.0
30.0
25.0
19.5
15.5
33.5
31.8
27.5
23.8
20.5
17.5
14.5
34.5
31.8
29.0
26.0
22.8
19.0
13.8
35.3
32.8
30.0
27.5
35.5
32.5
Pressure Filtration
Inlet
psig
35
37
35
39
36
39
40
36
40
36
39
36
39
39
35
36
35
34
34
37
35
37
36
35
37
37
38
40
38
37
37
36
37
39
40
38
36
35
39
39
TA
psig
27
26
27
26
27
26
26
26
25
27
25
26
26
25
27
26
26
27
27
26
26
26
26
26
26
26
25
25
26
26
26
26
26
25
25
26
26
27
26
25
TB
psig
28
27
28
26
27
26
26
27
27
27
26
27
27
27
28
27
28
28
28
27
28
26
27
27
26
26
27
27
26
27
27
27
27
27
27
27
28
28
26
27
Outlet
psig
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
Flow
rate
gpm
210
203
212
201
210
204
199
205
199
205
199
205
202
199
210
207
210
210
209
205
205
203
205
205
203
202
202
200
204
205
207
207
207
201
200
204
209
211
202
198
Totalizer to
Distribution
Daily
Flow
kgal
99
126
159
162
147
141
118
146
146
149
165
151
132
107
40
137
131
147
153
118
98
52
129
112
96
79
75
96
77
83
87
91
110
136
99
78
77
75
64
103
Cal
Flow
rate
gpm
237
185
202
202
206
199
201
196
211
203
207
213
221
204
219
213
240
183
205
208
194
192
207
209
204
204
209
203
206
204
208
205
202
200
208
261
171
204
198
210
Backwash
Tank
A
No.
193
194
196
197
199
200
201
203
204
206
207
209
210
211
212
215
217
219
221
222
224
224
226
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
242
243
Tank
B
No.
194
195
197
198
200
201
202
204
205
207
208
210
211
212
213
216
218
220
222
223
225
225
227
229
230
231
232
233
234
236
236
237
238
239
240
241
242
243
243
244
Daily
Volume
kgal
4.7
2.2
4.8
2.3
5.3
2.3
2.4
4.5
2.2
4.6
2.3
4.7
2.3
3.1
4.6
7.2
4.8
4.8
4.7
2.2
4.6
0.0
4.7
4.7
2.4
2.3
2.4
2.4
2.2
2.4
2.3
2.3
2.4
2.3
2.4
2.3
2.3
2.4
0.0
2.3
Run Time Since
Last BW
Vessel
A
hr
1.0
4.1
1.1
6.4
2.2
5.9
7.6
3.3
7.3
3.3
7.0
3.1
6.0
6.5
1.5
2.5
1.0
0.7
0.9
4.6
0.5
5.1
3.3
2.8
4.6
4.9
4.8
7.7
5.8
4.5
3.5
2.7
3.6
6.8
6.6
4.9
3.0
1.0
6.4
6.7
Vessel
B
hr
0.5
3.8
0.7
6.2
1.7
5.4
7.1
2.8
6.9
2.9
6.6
2.7
5.6
6.1
0.9
2.2
0.6
0.3
0.5
4.2
0.0
4.5
2.7
2.4
4.2
4.5
4.5
7.3
5.4
4.1
2.9
2.2
3.2
6.4
6.2
4.4
2.6
0.6
5.9
6.3
-------
US EPA Arsenic Demonstration Project at Three Forks, MT - Daily System Operation (Continued)
Week
No.
44
45
46
47
48
49
50
51
52
Day
Mon
Tue
Wed
Sun
Mon
Tue
Fri
Mon
Tue
Fri
Mon
Tue
Fri
Mon
Tue
Fri
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Mon
Wed
Thu
Fri
Sat
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Date
09/24/07
09/25/07
09/26/07
09/30/07
10/01/07
10/02/07
10/05/07
10/08/07
10/10/07
10/12/07
10/15/07
10/17/07
10/19/07
10/22/07
10/24/07
10/26/07
10/29/07
10/30/07
10/31/07
11/01/07
11/02/07
11/03/07
11/04/07
11/05/07
11/06/07
11/07/07
11/08/07
11/09/07
11/10/07
11/11/07
11/12/07
11/14/07
11/15/07
11/16/07
11/17/07
11/18/07
11/19/07
11/20/07
11/21/07
11/22/07
11/23/07
11/24/07
Time
1:00
6:30
1:30
1:30
2:30
6:00
6:00
7:30
7:00
7:30
5:30
7:00
6:00
4:00
6:00
8:00
6:00
7:30
6:00
6:00
6:00
6:00
6:00
5:30
6:00
6:00
6:00
6:00
6:00
6:00
5:30
6:00
6:00
6:00
5:30
5:30
5:30
6:00
6:00
5:30
6:00
6:30
Run Time
Totalizer
Vessel
A
hr
1515.3
1520.6
1531.2
1534.9
1538.3
1552.3
1558.8
1565.2
1575.1
1586.3
1591.4
1599.9
1609.9
1619.6
1632.1
1639.0
1648.4
1658.7
1661.9
1666.1
1673.0
1678.8
1687.3
1693.1
1698.8
1706.7
1712.4
1716.7
1720.4
1724.1
1728.7
1733.9
1738.7
1744.2
1749.9
1755.2
1760.9
1765.8
1770.0
1773.9
1781.2
1788.1
Vessel
B
hr
1516.4
1521.8
1532.3
1536.0
1539.5
1553.4
1559.5
1566.3
1576.1
1587.3
1592.5
1600.9
1610.9
1620.6
1633.1
1640.0
1649.4
1659.7
1663.0
1667.2
1674.0
1681.0
1688.4
1694.2
1699.9
1707.7
1713.6
1717.7
1721.6
1723.4
1729.9
1735.2
1740.0
1745.4
1751.0
1756.3
1762.2
1767.1
1771.3
1775.2
1782.6
1789.4
Daily
Vessel
A
hr
5.9
5.3
10.6
3.7
3.4
14.0
6.5
6.4
9.9
11.2
5.1
8.5
10.0
9.7
12.5
6.9
9.4
10.3
3.2
4.2
6.9
5.8
8.5
5.8
5.7
7.9
5.7
4.3
3.7
3.7
4.6
5.2
4.8
5.5
5.7
5.3
5.7
4.9
4.2
3.9
7.3
6.9
Vessel
B
hr
5.4
5.4
10.5
3.7
3.5
13.9
6.1
6.8
9.8
11.2
5.2
8.4
10.0
9.7
12.5
6.9
9.4
10.3
3.3
4.2
6.8
7.0
7.4
5.8
5.7
7.8
5.9
4.1
3.9
1.8
6.5
5.3
4.8
5.4
5.6
5.3
5.9
4.9
4.2
3.9
7.4
6.8
12.5%
C12
Tank
Level
in
23.3
22.5
21.8
20.3
19.8
17.5
16.3
15.3
13.5
11.5
10.8
31.5
29.8
28.5
26.8
25.5
24.5
22.5
22.3
21.8
20.5
19.3
18.0
17.0
16.0
14.8
13.8
13.0
12.5
11.8
10.8
32.8
32.0
31.3
30.8
29.8
28.8
28.0
27.5
26.8
25.8
24.8
35%
FeCl3
Tank
Level
in
30.0
27.8
23.5
37.3
35.8
30.3
27.5
25.0
20.5
15.5
13.3
34.3
30.3
26.3
21.0
18.0
13.5
33.5
32.3
30.3
27.5
24.5
21.5
18.8
16.3
29.3
26.8
25.0
23.5
21.8
19.5
35.8
34.0
32.0
29.8
27.5
25.0
23.0
21.0
19.3
16.0
34.8
Pressure Filtration
Inlet
psig
39
35
37
40
35
35
39
37
34
37
34
35
36
36
34
33
35
37
39
35
34
33
33
38
36
35
34
37
34
37
37
39
36
36
38
39
34
34
38
38
37
37
TA
psig
26
27
26
25
26
26
25
24
26
25
26
26
25
24
26
26
26
25
24
25
25
25
26
24
25
25
26
25
26
24
24
24
25
26
24
25
26
24
26
25
25
24
TB
psig
27
28
27
25
27
27
25
26
27
26
27
26
26
26
27
27
27
26
25
25
26
26
27
26
26
26
27
25
27
26
27
26
26
27
25
26
27
26
26
25
26
26
Outlet
psig
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
Flow
rate
gpm
202
210
203
196
207
212
197
202
207
202
208
206
202
200
205
210
205
200
195
204
206
208
208
200
201
202
207
199
207
199
207
196
202
208
196
202
206
197
204
199
198
198
Totalizer to
Distribution
Daily
Flow
kgal
67
67
128
43
67
169
77
79
122
129
68
102
120
116
152
82
115
123
38
53
83
83
90
69
69
95
70
49
47
44
55
62
58
66
67
65
70
57
52
46
88
83
Cal
Flow
rate
gpm
197
207
203
195
323
202
204
199
206
193
220
200
200
199
203
199
204
199
193
211
202
215
189
198
202
201
200
195
207
269
166
197
202
201
198
203
200
195
206
196
200
201
Backwash
Tank
A
No.
244
245
246
246
247
249
249
250
252
253
254
255
256
257
259
260
261
262
262
263
264
265
266
266
267
268
269
269
270
270
271
271
272
273
273
274
275
275
276
276
277
278
Tank
B
No.
245
246
247
247
248
250
250
251
253
254
255
256
257
258
260
261
262
263
263
264
265
266
267
267
268
269
270
270
271
271
272
272
273
274
274
275
276
276
277
277
278
279
Daily
Volume
kgal
2.3
2.5
2.3
0.0
2.4
4.5
0.0
2.4
4.4
2.2
2.3
2.4
2.2
2.3
4.7
2.3
2.3
2.2
0.0
2.4
2.3
2.3
2.4
0.0
2.3
2.3
2.4
0.0
2.3
0.0
2.3
0.0
2.3
2.4
0.0
2.3
2.3
0.0
2.3
0.0
2.4
2.3
Run Time Since
Last BW
Vessel
A
hr
4.0
1.2
3.7
7.4
2.8
0.5
7.0
5.3
1.7
4.8
1.9
2.2
4.1
5.7
2.0
0.8
2.2
4.4
7.6
3.7
2.5
1.3
0.6
6.4
4.0
3.8
1.5
5.7
1.4
5.3
1.5
6.7
3.4
0.8
6.5
3.7
1.4
6.2
2.3
6.2
5.4
4.2
Vessel
B
hr
3.6
0.9
3.3
7.0
2.4
0.1
6.5
4.9
1.3
4.5
1.5
1.8
3.7
5.3
1.7
0.4
1.8
4.0
7.3
3.3
2.1
0.9
0.2
6.0
3.6
3.4
1.1
5.2
1.0
4.8
1.1
6.5
3.0
0.3
5.9
3.2
0.9
5.8
1.9
5.8
5.1
3.8
-------
US EPA Arsenic Demonstration Project at Three Forks, MT - Daily System Operation (Continued)
Week
No.
53
54
55
56
57
58
59
60
61
62
Day
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Mon
Tue
Wed
Fri
Mon
Wed
Fri
Mon
Wed
Fri
Sat
Mon
Wed
Fri
Sat
Mon
Wed
Fri
Sat
Mon
Mon
Wed
Fri
Mon
Wed
Fri
Date
11/25/07
11/26/07
11/27/07
11/28/07
11/29/07
11/30/07
12/01/07
12/02/07
12/03/07
12/04/07
12/05/07
12/06/07
12/07/07
12/08/07
12/09/07
12/10/07
12/11/07
12/12/07
12/14/07
12/17/07
12/19/07
12/21/07
12/24/07
12/26/07
12/28/07
12/29/07
12/31/07
01/02/08
01/04/08
01/05/08
01/07/08
01/09/08
01/11/08
01/12/08
01/14/08
01/21/08
01/23/08
01/25/08
01/28/08
01/30/08
02/01/08
Time
5:00
5:30
8:00
6:00
6:00
6:00
6:00
5:00
5:30
6:00
6:00
6:00
6:00
6:30
6:00
6:00
7:00
6:00
8:30
5:30
7:00
7:00
5:00
8:24
9:00
11:00
9:00
9:00
9:00
14:30
10:00
13:00
10:30
15:00
13:00
9:00
9:30
8:00
8:00
8:00
8:00
Run Time
Totalizer
Vessel
A
hr
1795.7
1802.4
1815.4
1818.8
1825.4
1829.7
1833.7
1837.5
1842.6
1848.5
1855.0
1859.8
1866.0
1872.9
1879.8
1886.1
1892.8
1899.1
1904.5
1909.8
1915.6
1919.6
1924.5
1927.0
1933.3
1939.9
1945.3
1954.9
1964.6
1973.8
1980.9
1991.3
2001.4
2004.5
2016.1
2025.8
2034.4
2042.0
2049.1
2058.5
2067.8
Vessel
B
hr
1797.0
1803.8
1816.7
1821.1
1827.2
1830.9
1834.9
1838.7
1843.9
1849.9
1856.4
1861.1
1867.4
1874.2
1881.1
1889.1
1894.6
1900.4
1905.8
1911.1
1917.0
1921.0
1925.8
1929.0
1934.7
1941.3
1946.8
1956.4
1966.1
1975.3
1982.4
1992.8
2002.9
2011.1
2017.6
2027.2
2030.9
2043.0
2050.6
2060.0
2068.9
Daily
Vessel
A
hr
7.6
6.7
13.0
3.4
6.6
4.3
4.0
3.8
5.1
5.9
6.5
4.8
6.2
6.9
6.9
6.3
6.7
6.3
5.4
5.3
5.8
4.0
4.9
2.5
6.3
6.6
5.4
9.6
9.7
9.2
7.1
10.4
10.1
3.1
11.6
9.7
8.6
7.6
7.1
9.4
9.3
Vessel
B
hr
7.6
6.8
12.9
4.4
6.1
3.7
4.0
3.8
5.2
6.0
6.5
4.7
6.3
6.8
6.9
8.0
5.5
5.8
5.4
5.3
5.9
4.0
4.8
3.2
5.7
6.6
5.5
9.6
9.7
9.2
7.1
10.4
10.1
8.2
6.5
9.6
3.7
12.1
7.6
9.4
8.9
12.5%
C12
Tank
Level
in
23.5
22.5
20.5
19.5
18.8
18.0
17.3
16.8
15.8
14.8
13.8
13.0
11.8
33.3
32.3
31.3
30.3
29.0
28.5
27.5
26.8
26.0
25.3
25.0
24.0
22.8
21.8
20.3
18.8
17.0
15.8
14.0
12.0
10.8
9.5
7.8
29.0
28.0
26.8
25.3
24.0
35%
FeCl3
Tank
Level
in
31.8
29.0
23.8
21.5
35.0
33.5
32.0
30.5
28.3
25.8
23.0
36.8
34.0
31.5
28.5
25.3
23.0
20.0
18.0
34.2
32.0
30.5
28.3
27.3
24.5
21.8
19.3
15.0
33.0
29.5
26.5
32.8
28.8
25.3
22.5
18.3
33.8
30.8
27.8
34.5
31.0
Pressure Filtration
Inlet
psig
36
35
38
35
34
37
34
37
37
39
37
35
34
33
38
36
35
35
34
37
35
38
38
38
35
34
37
32
33
35
33
35
36
36
36
38
36
36
36
36
55
TA
psig
26
25
25
25
26
25
26
25
25
23
24
25
25
23
24
25
25
25
24
24
25
24
25
25
24
25
23
25
24
24
24
24
23
24
23
22
23
23
23
23
3
TB
psig
26
27
25
26
27
26
27
25
27
25
26
26
26
25
25
25
26
26
25
26
26
26
26
25
25
26
24
26
25
26
25
24
24
24
25
24
25
25
25
24
33
Outlet
psig
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
Flow
rate
gpm
202
203
197
204
206
197
208
200
204
194
198
206
208
195
196
200
202
206
196
199
203
197
200
198
201
205
197
209
205
204
205
202
200
197
199
195
198
198
202
198.7
140
Totalizer to
Distribution
Daily
Flow
kgal
91
81
177
54
73
45
48
46
62
70
79
58
76
81
84
76
81
77
64
64
70
47
59
30
76
80
63
118
117
110
86
124
120
98
81
114
105
88
91
113
108
Cal
Flow
rate
gpm
200
199
228
230
193
187
202
200
201
195
203
204
202
196
204
177
220
211
196
203
198
196
202
174
211
202
191
204
200
199
202
199
198
288
149
198
283
149
206
200
197
Backwash
Tank
A
No.
279
280
281
282
283
283
284
284
285
285
286
287
288
288
289
290
291
292
292
293
294
294
295
295
296
297
297
299
300
301
302
303
304
305
306
307
308
309
310
311
312
Tank
B
No.
280
281
282
283
284
284
285
285
286
286
287
288
289
289
290
291
292
293
293
294
295
295
296
296
297
298
298
300
301
302
303
304
305
306
307
308
309
310
311
312
313
Daily
Volume
kgal
2.3
2.4
2.0
2.6
2.3
0.0
2.4
0.0
2.3
0.0
2.3
2.2
2.3
0.0
2.3
2.5
2.2
2.2
0.0
2.3
2.3
0.0
2.3
0.0
2.5
2.3
0.0
4.6
2.4
2.3
2.3
2.3
2.2
2.3
2.3
2.3
2.3
1.9
2.7
2.3
2.3
Run Time Since
Last BW
Vessel
A
hr
3.7
2.4
7.3
3.5
1.6
5.3
1.2
5.0
2.0
7.9
6.4
3.0
1.2
8.0
6.9
5.0
3.6
1.8
7.2
4.4
2.1
6.1
2.9
5.5
3.6
2.1
7.5
0.9
2.5
3.6
2.6
4.9
6.9
6.9
5.4
6.8
7.5
7.0
6.0
7.3
0.0
Vessel
B
hr
3.3
2.0
6.9
3.1
1.1
4.9
0.7
4.5
1.6
7.0
6.0
2.6
0.8
7.6
6.4
4.6
3.2
1.4
6.8
4.1
1.8
5.9
2.4
4.9
3.2
1.8
7.2
0.5
2.1
3.2
2.2
4.5
6.5
6.5
5.8
6.5
7.1
6.0
5.6
6.9
7.7
1 >
-------
US EPA Arsenic Demonstration Project at Three Forks, MT - Daily System Operation (Continued)
Week
No.
63
Day
Mon
Fri
Date
02/04/08
02/08/08
Time
7:30
6:30
Run Time
Totalizer
Vessel
A
hr
2075.9
2084.8
Vessel
B
hr
2077.4
2086.3
Daily
Vessel
A
hr
8.1
8.9
Vessel
B
hr
8.5
8.9
12.5%
C12
Tank
Level
in
22.5
21.0
35%
FeCl3
Tank
Level
in
27.5
23.5
Pressure Filtration
Inlet
psig
32
32
TA
psig
25
24
TB
psig
26
26
Outlet
psig
12
12
Flow
rate
gpm
212
208
Totalizer to
Distribution
Daily
Flow
kgal
104
131
Cal
Flow
rate
gpm
208
245
Backwash
Tank
A
No.
314
315
Tank
B
No.
315
316
Daily
Volume
kgal
4.5
2.3
Run Time Since
Last BW
Vessel
A
hr
0.4
1.2
Vessel
B
hr
0.4
0.8
Highlighted columns indicate calculated values.
Note: Chemical drums are tapered; C12 and FeCl3 levels measured from bottom of drum.
Note: Backwash wastewater supernatant recycled until 12/12/06. Afterwards, wastewater discharged to sewer.
Note: Run time until 02/16/07 estimated by Well No. 2 Hour Meter.
NA = data not available
-------
APPENDIX B
ANALYTICAL DATA TABLES
-------
Analytical Results from Long-Term Sampling at Three Forks, MT
Sampling Date
Sampling Location
Parameter Unit
Alkalinity (as CaCO3)
Fluoride
Sulfate
Nitrate (as N)
Total P (as P)
Silica (asSiO2)
Turbidity
pH
Temperature
DO
ORP
Free Chlorine
Total Chlorine
Total Hardness (as CaCO3)
Ca Hardness (as CaCO3)
Mg Hardness (as CaCO3)
As (total)
As (soluble)
As (particulate)
As (III)
As(V)
re (total)
Fe (soluble)
Mn (total)
Mn (soluble)
mg/L
mg/L
mg/L
mg/L
LJg/L
mg/L
NTU
S.U.
°C
mg/L
mV
mg/L
mg/L
mg/L
mg/L
mg/L
LJg/L
LJg/L
LJg/L
LJg/L
Ljg/L
Ljg/L
ng/L
Ljg/L
ng/L
11/29/06
IN
266
3.0
21
0.4
17.1
48.5
0.4
7.4
13.3
3.3
335
-
-
181
128
52.3
59.8
59.7
0.1
0.6
59.0
<25
<25
<0.1
<0.1
AC
270
3.1
20
0.4
21.3
48.8
1.8
7.7
12.9
2.4
281
0.5
0.4
184
132
52.1
61.2
5.9
55.4
0.9
5.0
2,502
42
15.4
6.3
TT
262
3.0
21
0.3
11.7
47.8
0.9
7.8
12.7
3.1
321
0.8
1.0
178
129
49.3
28.3
4.8
23.5
1.6
3.2
936
<25
8.5
4.9
12/05/06
IN
271
-
-
-
<10
47.0
0.1
7.8
12.7
2.7
312
-
-
-
64.4
-
-
-
-
<25
-
0.1
AC
271
-
-
<10
47.1
1.8
7.3
13.5
3.9
468
0.4
0.5
-
-
-
72.2
-
-
1,153
-
12.3
TA
280
-
<10
45.9
0.8
7.8
12.4
2.7
503
0.4
0.5
-
17.3
-
323
-
5.5
-
TB
111
-
-
-
<10
45.8
0.9
7.6
12.5
2.5
524
0.5
0.5
-
30.6
-
-
-
-
561
-
7.2
12/12/06
-------
Analytical Results from Long-Term Sampling at Three Forks, MT (Continued)
Sampling Date
Sampling Location
Parameter Unit
Alkalinity (as CaCO3)
Fluoride
Sulfate
Nitrate (as N)
Total P (as P)
Silica (as SiO2)
Turbidity
PH
Temperature
DO
ORP
Free Chlorine
Total Chlorine
Total Hardness (as CaCO3)
Ca Hardness (as CaCO3)
Mg Hardness (as CaCO3)
As (total)
As (soluble)
As (particulate)
As (III)
As(V)
-e (total)
Fe (soluble)
Mn (total)
Mn (soluble)
mg/L
mg/L
mg/L
mg/L
ug/L
mg/L
NTU
S.U.
°C
mg/L
mV
mg/L
mg/L
mg/L
mg/L
mg/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
04/04/07
IN
282
-
36.5
46.8
0.3
7.5
11.3
3.1
325
-
-
-
92.8
-
<25
-
<0.1
-
AC
284
-
34.7
46.4
1.6
7.2
10.5
2.7
355
0.5
0.5
-
-
90.5
-
1,650
-
9.2
-
TA
279
-
<10
45.6
0.8
7.2
10.3
2.7
348
0.5
0.4
-
-
22.4
-
309
-
3.0
-
TB
274
-
<10
45.6
0.6
7.1
10.5
2.7
321
0.7
0.5
-
-
22.8
-
338
-
3.1
-
04/11/07
IN
296
-
53.7
47.4
0.9
7.7
11.9
2.2
242
-
-
-
91.1
-
<25
-
<0.1
-
AC
288
-
53.5
47.9
3.3
7.9
11.8
1.7
294
0.7
0.6
-
-
91.9
-
1,373
-
9.9
-
TA
286
-
15.6
47.4
1.5
7.9
11.7
1.6
314
0.6
0.5
-
-
16.6
-
161
-
2.9
-
TB
291
-
14.8
47.0
0.8
7.9
11.7
1.7
353
0.7
0.6
-
-
15.6
-
156
-
2.9
-
04/18/07(a)
IN
288
2.1
22
0.3
42.9
49.7
0.5
7.4
11.6
2.6
239
-
195
145
50.6
91.7
85.5
6.2
0.1
85.4
<25
<25
0.1
0.1
AC
288
2.2
22
0.4
43.5
50.3
1.5
7.8
11.1
2.3
287
0.9
0.9
202
151
51.0
90.4
10.7
79.8
0.1
10.6
2,277
39
10.7
3.1
TT
288
2.2
22
0.3
11.0
49.5
0.4
7.9
11.1
2.0
308
0.8
0.8
213
157
55.1
17.0
5.8
11.2
0.1
5.7
229
<25
3.5
2.6
04/25/07
IN
297
295
-
28.0
25.1
49.1
49.5
0.3
0.4
7.7
10.7
2.1
258
-
-
-
96.7
82.9
-
<25
<25
-
O.1
0.1
-
AC
302
287
-
28.4
25.0
49.3
49.7
1.4
0.6
7.9
10.5
1.9
301
1.0
1.0
-
-
95.0
86.8
-
2,053
1,990
-
10.1
9.6
-
TA
295
287
-
<10
<10
49.2
49.2
0.5
0.3
7.8
10.6
2.5
327
0.9
1.0
-
-
15.5
12.3
-
153
147
-
2.4
2.2
-
TB
290
290
-
<10
<10
49.1
47.9
0.4
0.7
8.0
10.4
1.5
353
1.0
1.0
-
-
14.8
12.5
-
145
155
-
2.4
2.2
-
07/17/07(b)
IN
-
-
7.6
13.7
3.0
251
-
-
-
80.5
81.7
O.1
<25
<25
-
-
AC
-
-
7.7
13.3
2.6
507
3.2
3.2
-
-
79.6
6.3
73.3
2,301
<25
-
-
TA
-
-
7.7
13.4
2.9
523
3.1
2.8
-
-
8.4
4.4
4.0
111
<25
-
-
TB
-
-
7.7
13.3
2.8
548
2.7
3.1
-
-
8.2
3.8
4.5
96
<25
-
-
(a) Stroke of chlorine addition pump increased from 20 to 30 on 04/16/07.
Samples collected 2.7 hr after backwash.
(b) Addition of FeCI3/polymer blend began 07/06/07. Stroke of iron addition pump set at 25.
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