EPA/600/R-05/079
September 2005
Arsenic Removal from Drinking Water by Adsorptive Media
USEPA Demonstration Project at Desert Sands MDWCA, NM
Six-Month Evaluation Report
Chris T. Coonfare
Abraham S.C. Chen
Lili Wang
Julia M. Valigore
Battelle
Columbus, OH 43201-2693
Contract No. 68-C-00-185
Task Order No. 0019
for
Thomas J. Sorg
Task Order Manager
Water Supply and Water Resources Division
National Risk Management Research Laboratory
Cincinnati, OH 45268
National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
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DISCLAIMER
The work reported in this document is funded by the United States Environmental Protection Agency
(EPA) under Task Order 0019 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 first six months
of the arsenic removal treatment technology demonstration project at the Desert Sands Mutual Domestic
Water Consumers Association (MDWCA) facility in Anthony, NM. The objectives of the project are to
evaluate the effectiveness of Severn Trent Services (STS) Arsenic Package Unit-300 (APU-300)
SORB 33™ media in removing arsenic to meet the new arsenic maximum contaminant level (MCL) of 10
Hg/L, the reliability of the treatment system, the simplicity of required system operation and maintenance
(O&M) and operator's skills, and the cost-effectiveness of the technology. The project is also
characterizing water in the distribution system and process residuals produced by the treatment system.
The STS treatment system became operational on January 16, 2004. The types of data collected include
system operation, water quality (both across the treatment train and in the distribution system), process
residuals, and capital and O&M costs. After treating approximately 14,647,000 gallons, or 12,200 bed
volumes, of water, which was approximately 9% of the vendor estimated working capacity for the
adsorptive media, total arsenic concentrations were reduced from 20.7-30.1 |o,g/L in raw water to 2.8 |o,g/L
in the treated water. As(III) was the predominating species in raw water, averaging 21.1 |o,g/L.
Prechlorination was effective in oxidizing As(III) to As(V), as evident by the low As(III) concentrations
(i.e., 0.5 to 1.1 ng/L) in water sampled immediately after prechlorination. Total and free chlorine
residuals measured before and after the adsorption vessels were nearly identical at 0.3-0.5 mg/L (as C12)
and 0.4-0.6 mg/L (as C12), respectively, indicating little or no chlorine consumption by the SORB 33™
media. Concentrations of iron, manganese, silica, orthophosphate, and other ions in raw water were not
high enough to impact arsenic removal by the media.
Comparison of the distribution system sampling results before and after the operation of the STS system
showed a decrease in arsenic concentration (from 22.4-28.2 |o,g/L to 1.8-10.4 |og/L) at all three sampling
locations. However, the concentrations measured after system operation were higher than those in the
plant effluent. This likely was due to the blending with untreated water produced by a separate well in the
distribution system. Neither lead nor copper concentrations at the sample sites appeared to have been
affected by the operation of the system.
Two sets of backwash water samples were collected during the first six months of system operation.
Dissolved arsenic concentrations in the backwash water ranged from 3.5-12.1 |o,g/L, which were
significantly lower than those measured in raw water, indicating removal of arsenic by the media during
backwash. Dissolved iron and manganese concentrations in backwash water correlated more closely with
the influent concentrations.
The capital investment cost of $153,000 includes $112,000 for equipment, $23,000 for site engineering,
and $18,000 for installation. Using the system's rated capacity of 320 gpm, the capital cost was $476 per
gallon of design capacity and the equipment-only cost was $350 per gallon of design capacity. These
calculations do not include the cost of a building addition to house the treatment system.
O&M costs for the STS system included only incremental costs associated with the APU-300 system,
such as media replacement and disposal, chemical supply, electricity, and labor. Because the incremental
costs for chemical supply and electricity were negligible, only media replacement and disposal and O&M
labor would impact the O&M costs. O&M costs for media replacement were estimated based upon media
replacement cost and projected breakthrough and will be determined once the actual throughput and cost
at the time of the media replacement become available.
IV
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The STS system experienced excessive flow restriction, imbalanced flow, and/or elevated pressure
differential across the adsorption vessels and the entire system during the first four months of system
operation. After extensive on-site and off-site investigations and hydraulic testing, the system was
retrofitted in May 2004 and, thus, able to operate according to the original design specifications
thereafter. After the retrofit, the only O&M issue encountered was the temporary failure of the digital
flow meters on the vessels on two separate occasions for one to two days at a time.
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CONTENTS
FOREWORD iii
ABSTRACT iv
FIGURES vii
TABLES vii
ABBREVIATIONS AND ACRONYMS ix
ACKNOWLEDGMENTS xi
1.0 INTRODUCTION 1
1.1 Background 1
1.2 Treatment Technologies for Arsenic Removal 1
1.3 Project Objectives 2
2.0 CONCLUSIONS 3
3.0 MATERIALS AND METHODS 4
3.1 General Project Approach 4
3.2 System O&M and Cost Data Collection 5
3.3 Sample Collection Procedures and Schedules 6
3.3.1 Source Water Sample Collection 6
3.3.2 Treatment Plant Water Sample Collection 6
3.3.3 Backwash Water Sample Collection 6
3.3.4 Backwash Solid Sample Collection 6
3.3.5 Distribution System Water Sample Collection 6
3.4 Sampling Logistics 8
3.4.1 Preparation of Arsenic Speciation Kits 8
3.4.2 Preparation of Sampling Coolers 8
3.4.3 Sample Shipping and Handling 9
3.5 Analytical Procedures 9
4.0 RESULTS AND DISCUSSION 10
4.1 Facility Description 10
4.1.1 Existing System 10
4.1.2 Source Water Quality 10
4.1.3 Distribution System 14
4.2 Treatment Process Description 15
4.3 System Installation 15
4.3.1 Permitting 15
4.3.2 Building Construction 18
4.3.3 Installation, Shakedown, and Startup 19
4.4 System Operation 19
4.4.1 Operational Parameters 19
4.4.2 System Retrofit 21
4.4.3 Backwash 25
4.4.4 Residual Management 25
4.4.5 System Operation Reliability and Simplicity 25
4.5 System Performance 27
4.5.1 Treatment Plant Sampling 27
4.5.2 Backwash Water Sampling 34
4.5.3 Distribution System Water Sampling 34
VI
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4.6 System Costs 36
4.6.1 Capital Costs 38
4.6.2 Operation and Maintenance Costs 39
5.0 REFERENCES 41
APPENDIX A: OPERATIONAL DATA
APPENDIX B: ANALYTICAL RESULTS
FIGURES
Figure 4-1. Map of the Desert Sands MDWCA Service Area 11
Figure 4-2. Well No. 3 (Left) and In-Line Sand Separator (Center) Adjacent to the Pump
House (Right) at the Desert Sands MDWCA Site 12
Figure 4-3. Piping Inside the Pump House at the Desert Sands MDWCA Site 12
Figure 4-4. Process Flow Diagram and Sampling Locations 17
Figure 4-5. Photograph of APU-300 System at the Desert Sands MDWCA Site 18
Figure 4-6. Pump House (on the right) and System Enclosure 19
Figure 4-7. Vessels A and B Flowrates Before and After System Retrofitting 21
Figure 4-8. Pressure Losses (Ap) across Each Vessel and the System over Time 22
Figure 4-9. Schematic Diagram of STS APU-300 System as Installed at Desert Sands
MDWCA in December 2003 24
Figure 4-10. Schematic Diagram of STS APU-300 System after System Retrofitting in
May 2004 26
Figure 4-11. Concentration of Arsenic Species in the Influent, After Prechlorination, and in the
Combined System Effluent 32
Figure 4-12. Total Arsenic Breakthrough Curve 33
Figure 4-13. Total Manganese Concentrations over Time 33
Figure 4-14. Concentrations of Manganese Species 35
Figure 4-15. Media Replacement and O&M Cost for the Desert Sands MDWCA APU-300
System 39
TABLES
Table 1-1. Summary of Arsenic Removal Demonstration Technologies and Source Water
Quality Parameters 2
Table 3-1. Pre-Demonstration Study Activities and Completion Dates 4
Table 3-2. Evaluation Objectives and Supporting Data Collection Activities 5
Table 3-3. Sample Collection Schedule and Analyses 7
Table 4-1. Desert Sands MDWCA Well No. 3 Water Quality Data 13
Table 4-2. Desert Sands MDWCA Distribution System Water Quality Data 14
Table 4-3. Physical and Chemical Properties of SORB 33™ Media 16
Table 4-4. Design Features for the APU-300 System 16
Table 4-5. Summary of APU-300 System Operation 20
Table 4-6. Results of Hydraulic Testing of STS APU-300 Systems 23
Table 4-7. Summary of Arsenic, Iron, and Manganese Analytical Results 28
Table 4-8. Summary of Water Quality Parameter Measurements 29
Table 4-9. Backwash Water Sampling Results 36
vn
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Table 4-10. Distribution System Sampling Results 37
Table 4-11. Capital Investment for the APU-3 00 System at the Desert Sands MDWCA Site 38
Table 4-12. O&M Costs for the APU-300 System at the Desert Sands MDWCA Site 40
Vlll
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ABBREVIATIONS AND ACRONYMS
Ap differential pressure
AA activated alumina
AAL American Analytical Laboratories
Al aluminum
AM adsorptive media
APU arsenic package unit
As arsenic
bgs below ground surface
BV bed volume(s)
c/f coagulation/filtration
Ca calcium
C12 chlorine
CRF capital recovery factor
Cu copper
DO dissolved oxygen
EBCT empty bed contact time
EPA U.S. Environmental Protection Agency
F fluoride
Fe iron
FRP fiberglass reinforced plastic
GFH granular ferric hydroxide
GFO granular ferric oxide
gpd gallons per day
gpm gallons per minute
HOPE high-density polyethylene
ICP-MS inductively coupled plasma-mass spectrometry
ID identification
IX ion exchange
LCR (EPA) Lead and Copper Rule
MCL maximum contaminant level
MDL method detection limit
MDWCA Mutual Domestic Water Consumers Association
Mg magnesium
mg/L milligrams per liter
Hg/L micrograms per liter
Mn manganese
Mo molybdenum
mV millivolts
IX
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N/A not applicable
Na sodium
NA not available
NaOCl sodium hypochlorite
NMED New Mexico Environmental Department
NTU nephlemetric turbidity unit
O&M operation and maintenance
ORD Office of Research and Development
ORP oxidation-reduction potential
Pb lead
psi pounds per square inch
PO4 orthophosphate
PVC polyvinyl chloride
QA quality assurance
QA/QC quality assurance/quality control
QAPP Quality Assurance Project Plan
RPD relative percent difference
Sb antimony
SDWA Safe Drinking Water Act
SiO2 silica
SO4 sulfate
SOC synthetic organic compound
STMGID South Truckee Meadows General Improvement District
STS Severn Trent Services
TBD to be determined
TCLP Toxicity Characteristic Leaching Procedure
TDS total dissolved solids
TOC total organic carbon
TSS total suspended solids
V vanadium
VOC volatile organic compound
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ACKNOWLEDGMENTS
The authors wish to extend their sincere appreciation to the staff of the Desert Sands Mutual Domestic
Water Consumers Association in Anthony, New Mexico. The Desert Sands staff monitored the treatment
system daily, and collected samples from the treatment system and distribution system on a regular
schedule throughout this reporting period. This performance evaluation would not have been possible
without their efforts.
XI
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1.0 INTRODUCTION
1.1 Background
The Safe Drinking Water Act (SOWA) mandates that U.S. Environmental Protection Agency (EPA)
identify and regulate drinking water contaminants that may have adverse human health effects and that
are known or anticipated to occur in public water supply systems. In 1975 under the SDWA, EPA
established an maximum contaminant level (MCL) for arsenic at 0.05 mg/L. Amended in 1996, the
SDWA required that EPA develop an arsenic research strategy and publish a proposal to revise the
arsenic MCL by January 2000. On January 18, 2001, EPA finalized the arsenic MCL at 0.01 mg/L (EPA,
2001). In order to clarify the implementation of the original rule, EPA revised the rule text on March 25,
2003 to express the MCL as 0.010 mg/L (10 (ig/L) (EPA, 2003). The final rule requires all community
and non-transient, non-community water systems to comply with the new standard by January 23, 2006.
In October 2001, EPA announced an initiative for additional research and development of cost-effective
technologies to help small community water systems (<10,000 customers) meet the new arsenic standard,
and to provide technical assistance to operators of small systems in order to reduce compliance costs. As
part of this Arsenic Rule Implementation Research Program, EPA's Office of Research and Development
(ORD) proposed a project to conduct a series of full-scale, on-site demonstrations of arsenic removal
technologies, process modifications, and engineering approaches applicable to small systems. Shortly
thereafter, an announcement was published in the Federal Register requesting water utilities interested in
participating in the first round of this EPA-sponsored demonstration program to provide information on
their water systems. In June 2002, EPA selected 17 sites from a list of 115 sites to be the host sites for the
demonstration studies. The Desert Sands Mutual Domestic Water Consumers Association (MDWCA)
water system in Anthony, NM was selected as one of the 17 Round 1 host sites for the demonstration
program.
In September 2002, EPA solicited proposals from engineering firms and vendors for cost-effective arsenic
removal treatment technologies for the 17 host sites. EPA received 70 technical proposals for the 17 host
sites, with each site receiving from one to six proposals. In April 2003, an independent technical review
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. Severn Trent Services,
(STS) using the Bayoxide E33 media developed by Bayer AG, was selected for the Desert Sands
MDWCA facility. STS has given the E33 media the designation "SORB 33™."
1.2 Treatment Technologies for Arsenic Removal
The technologies selected for the 12 Round 1 EPA arsenic removal demonstration host sites include nine
adsorptive media systems, one anion exchange system, one coagulation/filtration system, and one process
modification with iron addition. Table 1-1 summarizes the locations, technologies, vendors, and key
source water quality parameters (including arsenic, iron, and pH) of the 12 demonstration sites. The
technology selection and system design for the 12 demonstration sites have been reported in an EPA
report (Wang et al., 2004) posted on an EPA web site (http://www.eap.gov/ORD/NRMRL/arsenic/
resource.htm).
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Table 1-1. Summary of Arsenic Removal Demonstration Technologies and Source
Water Quality Parameters
Demonstration Site
Bow, NH
Rollinsford, NH
Queen Anne's County, MD
Brown City, MI
Climax, MN
Lidgerwood, ND
Desert Sands MDWCA, NM
Nambe Pueblo, NM
Rimrock, AZ
Valley Vista, AZ
Fruitland, ID
STMGID, NV
Technology
(Media)
AM (G2)
AM (E33)
AM (E33)
AM (E33)
C/F
SM
AM (E33)
AM (E33)
AM (E33)
AM (AAFS50)
IX
AM (GFH)
Vendor
ADI
AdEdge
STS
STS
Kinetico
Kinetico
STS
AdEdge
AdEdge
Kinetico
Kinetico
USFilter
Design
Flowrate
(gpm)
70(a)
100
300
640
140
250
320
145
90(a)
37
250
350
Source Water Quality
As
(Hg/L)
39
36(b)
19(b)
14(b)
39(b)
146(b)
23(b)
33
50
41
44
39
Fe
(HS/L)
<25
46
270(c)
127(o)
546(c)
l,325(c)
39
<25
170
<25
<25
<25
pH
7.7
8.2
7.3
7.3
7.4
7.2
7.7
8.5
7.2
7.8
7.4
7.4
AM = adsorptive media process; C/F = coagulation/filtration process; IX = ion exchange process;
SM = system modification;
STMGID = South Truckee Meadows General Improvement District.
(a) Due to system reconfiguration from parallel to series operation, the design flowrate is reduced by 50%.
(b) Arsenic exists mostly as As(III).
(c) Iron exists mostly as soluble Fe(II).
1.3
Project Objectives
The objective of the Round 1 arsenic demonstration program is to conduct 12 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 simplicity of required system operation and maintenance (O&M)
and operator's skill levels.
• Determine the cost-effectiveness of the technologies.
• Characterize process residuals produced by the technologies.
This report summarizes the results gathered during the first six months of the STS system operation from
January 16 through July 16, 2004. The types of data collected include system operational data, water
quality data (both across the treatment train and in the distribution system), residuals characterization
data, and capital and preliminary O&M cost data.
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2.0 CONCLUSIONS
The STS APU-300 system became operational on January 16, 2004. After treating approximately
14,647,000 gallons, or 12,200 bed volumes (BV), of water, which was approximately 9% of the vendor
estimated working capacity for SORB 33™, the media reduced total arsenic concentrations from 20.7-30.1
|o,g/L in raw water to 2.8 |o,g/L in the treated water. As(III) was the predominating species in raw water,
and was effectively oxidized to As(V) with sodium hypochlorite before entering the adsorption vessels.
Little or no chlorine was consumed by the SORB 33™ media. Concentrations of iron, manganese, silica,
orthophosphate, and other ions in raw water were not high enough to cause adverse effects on arsenic
removal.
Arsenic concentrations in the distribution system were reduced from the pre-demonstration levels of 22.4-
28.2 |o,g/L to 1.8-10.4 |o,g/L after the sytem became operational. However, the reduced concentrations
were still higher than those in the plant effluent, probably due to the blending of the treated water with
untreated water produced by a separate well in the distribution system. Neither lead nor copper
concentrations appear to have been affected by operation of the system.
Dissolved arsenic concentrations in the backwash water ranged from 3.5-12.1 |o,g/L, which were
significantly lower than those measured in raw water, indicating removal of arsenic by the media during
backwash. Dissolved iron and manganese concentrations correlated more closely with the influent
concentrations.
The capital investment costs for equipment, site engineering, and installation were $153,000. Using the
system's rated capacity of 320 gpm, the capital cost was $476 per gallon of design capacity and the
equipment-only cost was $350 per gallon of design capacity. These calculations do not include the cost
of a building addition to house the treatment system.
O&M costs included only incremental costs, such as media replacement and disposal, chemical supply,
electricity, and labor. Because the incremental costs for chemical supply and electricity were negligible,
only media replacement and disposal and O&M labor would impact the O&M costs. O&M costs for
media replacement will be determined once the actual throughput and cost data at the time of the media
replacement become available.
The APU-300 system has experienced excessive flow restriction, imbalanced flow, and elevated pressure
differential across the adsorption vessels and entire system since the inception of the study in January
2004. After a series of on-site and off-site investigations and hydraulic testing, the system was retrofitted
in May 2004. Since then, the system has been operated as originally specified by the vendor.
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3.0 MATERIALS AND METHODS
3.1
General Project Approach
Following the pre-demonstration activities summarized in Table 3-1, the performance evaluation study of
the STS treatment system began on January 16, 2004. Table 3-2 summarizes the types of data collected
and/or considered as part of the technology evaluation process. The overall performance of the system
was determined based on its ability to consistently remove arsenic to the target MCL of 10 |o,g/L; this was
monitored through the collection of weekly and monthly water samples across the treatment train. The
reliability of the system was evaluated by tracking the unscheduled system downtime and frequency and
extent of repair and replacement. The unscheduled downtime and repair information were recorded by
the plant operator on a Repair and Maintenance Log Sheet.
Simplicity of the system operation and the level of operator skill required were evaluated based on a
combination of quantitative data and qualitative considerations, including any pre-treatment and/or post-
treatment requirements, level of system automation, operator skill requirements, task analysis of the
preventive maintenance activities, frequency of chemical and/or media handling and inventory
requirements, and general knowledge needed for safety requirements and chemical processes. The
staffing requirements on the system operation were recorded on a Field Log Sheet.
The cost-effectiveness of the system is evaluated based on the cost per 1,000 gallons ($/l,000 gallons) of
water treated. This requires the tracking of capital costs such as equipment, engineering, and installation
costs, as well as O&M costs for media replacement and disposal, chemical supply, electrical power use,
and labor hours. The capital costs have been reported in an EPA report (Chen et al., 2004) posted on an
EPA web site (http://www.epa.gov/ORD/NRMRL/arsenic/resource.htm). Data on O&M costs were
limited to chemicals, electricity, and labor hours because media replacement did not take place during the
six months of operation.
Table 3-1. Pre-Demonstration Study Activities and Completion Dates
Activity
Introductory Meeting
Request for Quotation Issued to Vendor
Vendor Quotation Submitted to Battelle
Purchase Order Completed and Signed
Letter Report Issued
Concrete Pad Poured
Engineering Package Submitted to NMED
APU-300 Unit Shipped by STS
Draft Study Plan Issued
APU-300 Unit Delivered to Desert Sands MDWCA
System Installation Completed
Permit Issued by NMED
Building Construction Begun
System Shakedown Completed
Performance Evaluation Begun
Final Study Plan Issued
Building Construction Completed
Date
August 20, 2003
August 26, 2003
September 17, 2003
October 3, 2003
October 16, 2003
October 30, 2003
November 18, 2003
November 18, 2003
November 26, 2003
December 1, 2003
December 11,2003
December 22, 2003
December 23, 2003
January 15, 2004
January 16, 2004
January 19, 2004
January 23, 2004
NMED = New Mexico Environmental Department.
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Table 3-2. Evaluation Objectives and Supporting Data Collection Activities
Evaluation Objectives
Performance
Reliability
Simplicity of Operation and
Operator Skill
Cost-Effectiveness
Residual Management
Data Collection
-Ability to consistently meet 10 jag/L of arsenic in effluent
-Unscheduled downtime for system
-Frequency and extent of repairs to include labor hours, problem description,
description of materials, and cost of materials
-Pre- and post-treatment requirements
-Level of system automation for data collection and system operation
-Staffing requirements including number of operators and labor hours
-Task analysis of preventative maintenance to include labor hours per month and
number and complexity of tasks
-Chemical handling and inventory requirements
-General knowledge needed of safety requirements and chemical processes
-Capital costs including equipment, engineering, and installation
-O&M costs including chemical and/or media usage, electricity, and labor
-Quantity of the residuals generated by the process
-Characteristics of the aqueous and solid residuals
The quantity of aqueous and solid residuals generated was estimated by tracking the amount of backwash
water produced during each backwash cycle and the need to replace the media upon arsenic breakthrough.
Backwash water was sampled and analyzed for chemical characteristics.
3.2
System O&M and Cost Data Collection
The plant operator performed daily, weekly, and monthly system O&M and data collection following the
instructions provided by STS and Battelle. On a daily basis, the plant operator recorded system
operational data, such as pressure, flowrate, totalizer, and hour meter readings on a Battelle-provided
Daily Field Log Sheet; checked the sodium hypochlorite drum level; and conducted visual inspections to
ensure normal system operations. In the event of problems, the plant operator would contact the Battelle
Study Lead, who then would determine if STS should be contacted for troubleshooting. The plant
operator recorded all relevant information on the Repair and Maintenance Log Sheet. Weekly or bi-
weekly, the plant operator measured water quality parameters, including temperature, pH, dissolved
oxygen (DO)/oxidation-reduction potential (ORP), and residual chlorine, and recorded the data on a
Weekly Water Quality Parameters Log Sheet. Monthly, the plant operator inspected the system control
panel to ensure that moisture had not penetrated into the panel (STS, 2004). A monthly backwash of the
media was originally recommended by STS; however, since it had been retrofitted in May 2004, the
system was backwashed automatically when triggered by an increase in differential pressure across each
adsorption vessel.
Capital costs for the STS system consisted of costs for equipment, site engineering, and system
installation. The O&M costs consisted primarily of costs for the media replacement and spent media
disposal, chemical and electricity consumption, and labor. The sodium hypochlorite and electricity
consumption was tracked using the Daily Field Log Sheet. Labor hours for various activities, such as the
routine system O&M, system troubleshooting and repair, and demonstration-related work, were tracked
using an Operator Labor Hour Record. The routine O&M included activities such as filling field logs,
replenishing the sodium hypochlorite solution, ordering inventories, performing system inspection, and
others as recommended by STS. The demonstration-related work included activities such as performing
field measurements, collecting and shipping samples, and communicating with the Battelle Study Lead.
The demonstration-related activities were recorded but not used for the cost analysis.
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3.3 Sample Collection Procedures and Schedules
To evaluate the performance of the system, samples were collected from the source, treatment plant,
distribution system, and adsorptive vessel backwash. Table 3-3 provides the sampling schedules and
analytes measured during each sampling event. Specific sampling requirements for analytical methods,
sample volumes, containers, preservation, and holding times are presented in Table 4-1 of the EPA-
endorsed Quality Assurance Project Plan (QAPP) (Battelle, 2003).
3.3.1 Source Water Sample Collection. During the initial visit to the site, Battelle collected one
set of source water samples for detailed water quality analyses. The source water also was speciated for
particulate and soluble As, iron (Fe), manganese (Mn), aluminum (Al), and As(III) and As(V). The
sample tap was flushed for several minutes before sampling; special care was taken to avoid agitation,
which might cause unwanted oxidation. Arsenic speciation kits and containers for water quality samples
were prepared as described in Section 3.4. Additionally, Battelle arranged for the plant operator to collect
one set of source water samples for sulfide analysis.
3.3.2 Treatment Plant Water Sample Collection. During the system performance evaluation
study, water samples were collected across the treatment train by the plant operator. After receiving
training, the plant operator also performed on-site arsenic speciation once every four weeks. For the first
three months of the demonstration, samples were collected weekly, on a four-week cycle. For the first
week of each four-week cycle, treatment plant samples were collected at three locations (i.e. the wellhead
[IN], after chlorination but before splitting to the two vessels [AC], and from the combined effluent of the
two vessels [TT] (as designated in Table 3-3) and analyzed for the analytes listed under the monthly
treatment plant analyte list (see Table 3-3). For the second, third, and fourth week, treatment plant
samples were collected at four locations (i.e. IN, AC, after the first vessel [TA], and after the second
vessel [TB]) and analyzed for the analytes listed under the weekly treatment plant analyte list. Since
April 14, 2004, the sampling frequency was reduced from weekly to biweekly due to the low water
demand and the resulting low volume throughput to the system. Under this revised schedule, the
"monthly" speciation and sampling remained unchanged; however, the "weekly" sampling at IN, AC,
TA, and TB was reduced from three weeks of each four-week cycle to one week.
3.3.3 Backwash Water Sample Collection. Two backwash water samples were collected on
May 23 and July 13, 2004 from the sample taps located at the backwash water effluent line from each
vessel. Unfiltered samples were measured on site for pH using a field pH meter and a one-gallon sample
was sent to American Analytical Laboratories (AAL) for total dissolved solids (TDS) and turbidity
measurements. Filtered samples using 0.45-(im filters were sent to Battelle's inductively coupled plasma-
mass spectrometry (ICP-MS) laboratory for soluble As, Fe, and Mn analyses. Arsenic speciation was not
performed for the backwash water samples.
3.3.4 Backwash Solid Sample Collection. Backwash solid samples were not collected in the
initial six months of this demonstration. Two to three solid/sludge samples will be collected from the
overflow discharge pond at the site. A dipper (EPA III-l) or a scoop (EPA II-3) will be used for solid
sample collection. The solid/sludge samples will be collected in glass jars and submitted to TCCI
Laboratories for Toxicity Characteristic Leaching Procedure (TCLP) tests.
3.3.5 Distribution System Water Sample Collection. Samples were collected from the
distribution system to determine what impact the addition of the arsenic treatment system would have on
the water chemistry in the distribution system, and specifically on the lead and copper level. In December
2003, prior to the startup of the treatment system, three baseline distribution system sampling events were
conducted at three locations per sampling event within the distribution system. Following the installation
-------
Table 3-3. Sample Collection Schedule and Analyses
Sample
Type
Source
Water
Treatment
Plant Water
(three of
every four
weeks)
Treatment
Plant Water
(once every
four weeks)
Distribution
Water
Backwash
Water
Residual
Sludge
Sample Locations'3'
Wellhead (IN)
Wellhead (IN), after
chlorination (AC) ,
after first vessel
(TA), and after
second vessel (TB)
Wellhead (IN), after
chlorination (AC),
and combined
effluent (TT)
One home (an LCR
sampling site) and
two sample taps
within the area
served by Well No.
3, according to
MDWCA models
Sample ports on
backwash discharge
line from each
vessel
Overflow
discharge pond
No. of
Samples
1
4
o
J
3
2
2-3
Frequency
Once
during the
initial site
visit
Weekly (b)
Monthly
Monthly
Monthly(c)
TBD
Analytes
As(total), paniculate and
soluble As, As(III), As(V),
Fe (total and soluble), Mn
(total and soluble), Al (total
and soluble), Na, Ca, Mg,
V, Mo, Sb, Cl, SO4, sulfide,
F, SiO2, PO4, TOC, and
alkalinity.
On-site: pH, temperature,
DO/ORP, C12 (free and
total) (except at wellhead).
Off-site: As (total), Fe
(total), Mn (total), SiO2,
PO4, turbidity, and
alkalinity.
On-site: pH, temperature,
DO/ORP, and C12 (free and
total) (except at wellhead).
Off-site: As(total),
paniculate and soluble As,
As(III), As(V), Fe (total
and soluble), Mn (total and
soluble), sulfide, SiO2, PO4,
turbidity, alkalinity, SO4, F,
NO3, Ca, and Mg.
As, pH, alkalinity, Cu, Pb,
Fe, and Mn.
TDS, turbidity, pH, As
(soluble), Fe (soluble), and
Mn (soluble)
TCLP Metals
Date(s) Samples
Collected
08/20/03
01/28/04,02/04/04,
02/11/04,02/25/04,
03/03/04, 03/10/04,
03/24/04,03/31/04,
04/07/04, 04/30/04,
05/26/04, 06/23/04,
07/07/04
01/23/04, 02/18/04,
03/17/04, 04/14/04,
05/12/04, 06/09/04
Baseline
sampling(d):
12/08/03, 12/11/03,
12/30/03
Monthly sampling:
02/11/04,03/10/04,
04/07/04, 05/12/04,
06/23/04
05/23/04
07/13/04
TBD
(a) The abbreviation in each parenthesis corresponds to the sample location in Figure 4-4.
(b) Reduced to once per every four-week cycle after April 14, 2004.
(c) Though scheduled for monthly sampling, the frequency has been reduced to quarterly.
(d) Three baseline sampling events were performed before the system became operational.
TBD = to be determined.
-------
of the arsenic adsorption system, distribution system sampling continued on a monthly basis at the same
three locations.
Baseline and monthly distribution system samples were collected by the plant operator. Samples were
collected at one home, which were included in the current Desert Sands MDWCA Lead and Copper Rule
(LCR) sampling schedule (the home of the operator), as well as two non-LCR sampling taps, with all
three locations served by the water produced from Well No. 3, as indicated by the Desert Sands MDWCA
distribution system model. Analytes for the baseline samples coincided with the monthly distribution
system water samples as described in Table 3-3. Arsenic speciation was not performed for the
distribution water samples. The samples collected at the LCR location were taken following an
instruction sheet developed according to the Lead and Copper Rule Reporting Guidance for Public Water
Systems (EPA, 2002). Sampling at the two non-LCR locations was performed with the first sample taken
at the first draw and the second sample after flushing the sample tap for several minutes. The first draw
sample was collected from a cold-water faucet that had not been used for at least six hours to ensure that
stagnant water was sampled. The sampler recorded the date and time of last water use before sampling
and the date and time of sample collection for calculation of the stagnation time.
3.4 Sampling Logistics
All sampling logistics including arsenic speciation kits preparation, sample cooler preparation, and
sample shipping and handling are discussed as follows:
3.4.1 Preparation of Arsenic Speciation Kits. The arsenic field speciation method used an anion
exchange resin column to separate the soluble arsenic species, As(V) and As(III) (Edwards et al., 1998).
Arsenic speciation kits were prepared in batches at Battelle laboratories according to the procedures
detailed in Appendix A of the EPA-endorsed QAPP (Battelle, 2003).
3.4.2 Preparation of Sampling Coolers. All sample bottles were new and contained appropriate
preservatives. Each sample bottle was taped with a pre-printed, colored-coded, and water proof label.
The sample label consisted of sample identification (ID), date and time of sample collection, sampler
initials, location, sent to, analysis required, and preservative. The sample ID consisted of a two-letter
code for a specific water facility, the sampling date, a two-letter code for a specific sampling location, and
a one-letter code for the specific analysis to be performed. The sampling locations were color-coded for
easy identification. For example, red, orange, yellow, and green were used to designate sampling
locations for IN, TA, TB, and TT, respectively. Pre-labeled bottles were placed in one of the plastic bags
(each corresponding to a specific sampling location) in a sample cooler. When arsenic speciation samples
were to be collected, an appropriate number of arsenic speciation kits also were included in the cooler.
When appropriate, the sample cooler was packed with bottles for the three distribution system sampling
locations and/or the two backwash sampling locations (one for each vessel). For the distribution system
sampling, each set of bottles consisted of one 1-L high-density polyethylene (HOPE) wide-mouth bottle
with no preservative for pH and alkalinity analyses, and one 250-mL plastic bottle for metals analysis
(As, Fe, Mn, Pb, and Cu), which was preserved with nitric acid upon receipt at the laboratory. For the
backwash sampling, each set of bottles consisted of one 1-gal wide-mouth HOPE jar with no preservative
used for analysis of pH, TDS, and turbidity, and one 125-mL HOPE bottle preserved with 0.625 mL of
40% ultrapure nitric acid, which was to be filled with 60 mL of a filtered sample for analysis of soluble
As, Fe, and Mn.
In addition, a packet containing all sampling and shipping-related supplies, such as latex gloves, sampling
instructions, chain-of-custody forms, prepaid Federal Express air bills, ice packs, and bubble wrap, also
was placed in the cooler. Except for the operator's signature, the chain-of-custody forms and prepaid
-------
Federal Express air bills had already been completed with the required information. The sample coolers
were shipped via Federal Express to the facility approximately one week prior to the scheduled sampling
date.
3.4.3 Sample Shipping and Handling. After sample collection, samples for off-site analyses were
packed carefully in the original coolers with wet ice and shipped to Battelle. Upon receipt, sample
custodians verified that all samples indicated on the chain-of-custody forms were included and intact.
Sample label identifications were checked against the chain-of-custody forms and the samples were
logged into the laboratory sample receipt log. Discrepancs, if noted, were addressed by the field sample
custodian, and the Battelle Study Lead was notified.
Samples for water quality analyses by Battelle's subcontract laboratories were packed in coolers at
Battelle and picked up by a courier from either AAL (Columbus, OH) or TCCI Laboratories (New
Lexington, OH). The samples for arsenic speciation analyses were stored at Battelle's ICP-MS
Laboratory. The chain-of-custody forms remained with the samples from the time of preparation through
analysis and final disposition. All samples were archived by the appropriate laboratories for the
respective duration of the required hold time, and disposed of properly thereafter.
3.5 Analytical Procedures
The analytical procedures are described in detail in Section 4.0 of the EPA-endorsed QAPP (Battelle,
2003). Field measurements of pH, temperature, and DO/ORP were conducted by the plant operator using
a WTW Multi 340i handheld meter, which was calibrated prior to use following the procedures provided
in the user's manual. The plant operator collected a water sample in a 400-mL, plastic beaker and placed
the Multi 340i probe in the beaker until a stable measured value was reached. The plant operator also
performed free and total chlorine measurements using Hach chlorine test kits.
Laboratory quality assurance/quality control (QA/QC) of all methods followed the guidelines provided in
the QAPP (Battelle, 2003). Data quality in terms of precision, accuracy, method detection limit (MDL), and
completeness met the criteria established in the QAPP, i.e., relative percent difference (RPD) of 20%,
percent recovery of 80-120%, and completeness of 80%. The quality assurance (QA) data associated with
each analyte will be presented and evaluated in a QA/QC Summary Report to be prepared under separate
cover and to be shared with the other 11 demonstration sites included in the Round 1 arsenic study.
-------
4.0 RESULTS AND DISCUSSION
4.1 Facility Description
Desert Sands MDWCA has been in operation as a non-profit association under the Sanitary Projects Act
since December 1978. The governing board consists of five members, and the staff members consist of
an office manager (Secretary of the Association), a full-time operator, a part-time customer service clerk,
and a part-time contracted operator intern. Desert Sands MDWCA serves its customers through an
existing supply, storage, and distribution network that covers an area of approximately four square miles
of unincorporated area in Southern Dona Ana County. The water treatment facility is located
approximately 2 miles north of Anthony, NM and serves an area generally situated between Interstate 10
on the east, NM 478 on the west, O'Hara Road on the south, and Ernesto Road on the north.
According to the 40 Year Water Plan (Desert Sands MDWCA, 2002a) prepared for the water utility,
Desert Sands MDWCA currently serves 1,886 community members. It is projected that population in the
Desert Sands MDWCA service area will increase by approximately 5,600 over a 40-year planning period,
assuming a median growth rate of 3.5%. The water production and use have fluctuated over the past
several years with the peak production occurring in 1998 at 63.5 million gallons. In 2002, total water
production and use were approximately 56.1 and 51.4 million gallons, respectively. Water loss
percentages ranged from 6.3 to 14.1% during 1998 through 2002, with the lowest and highest loss
occurring in 2002 and 1998, respectively.
4.1.1 Existing System. The existing system consists of two production wells (Wells No. 2 and 3)
with a combined capacity of 420 gpm, one 99,000-gallon and one 240,000-gallon storage tank, and
approximately 30 miles of distribution piping. Figure 4-1 presents a map of the Desert Sands MDWCA
delivery service area.
Prior to the installation of the STS arsenic removal system, the treatment plant consisted of Well No. 3
(located about 20 ft from the pump house), a pump house, and a drainage pond. Well No. 3 is screened
from 690 to 740 ft below ground surface (bgs) with the static groundwater table is at 45 ±1 ft bgs. The
well water was filtered through an in-line sand separator (shown along with Well No. 3 on Figure 4-2)
and then fed into the pump house (see piping in the pump house on Figure 4-3). A pressure of 75 pounds
per square inch (psi) was maintained through the system. The maximum daily production was
approximately 259,000 gallons per day (gpd) and the average daily production was 158,000 gpd.
Before entering the distribution system, 0.4 to 0.5 mg/L of sodium hypochlorite (NaOCl) was added to
the water using a peristaltic pump for a target chlorine residual level of 0.3 mg/L (as C12). The two
storage tanks are filled with excess water from the distribution system.
4.1.2 Source Water Quality. Source water samples were collected from Well No. 3 on August
20, 2003 and subsequently analyzed for the analytes shown in Table 3-3. The results of the source water
analyses, along with those provided by the facility to EPA for the demonstration site selection and those
independently collected and analyzed by EPA, are presented in Table 4-1.
10
-------
»
I
^^§^agl*»^g
DESERT SANDS MUTUAL DOMESTIC
WATER CONSUMERS ASSOCIATION
DONA ANA COUNTY, NEW MEXICO
n f'/
V *l
STOIUGF
IANK.S
1 • 245,000 sal.
1- 99,000 gal.
""«.„, •' ' , / / %
""?/ " > ' ; -
PROJECT COST ESTIMATES
" PHASB 1 COST KSTIMATT-s"
_ luUJUUlUI JUJIUiUlt. lll»j"il_LJJMItUll.,. 'II^_J.J^7,, ,,..,7ITm -U. "jTuu
X
««
S-i
iig^^
aSr^BKS
Figure 4-1. Map of the Desert Sands MDWCA Service Area
-------
Figure 4-2. Well No. 3 (Left) and In-Line Sand Separator (Center) Adjacent
to the Pump House (Right) at the Desert Sands MDWCA Site
Figure 4-3. Piping Inside the Pump House at the Desert Sands MDWCA Site
12
-------
Table 4-1. Desert Sands MDWCA Well No. 3 Water Quality Data
Parameter
Units
Sample Date
pH
Total Alkalinity
Hardness
Chloride
Fluoride
Sulfide
Sulfate
Silica
Orthophosphate
TOC
As(total)
As (total soluble)
As (paniculate)
As(III)
As(V)
Total Fe
Soluble Fe
Total Al
Soluble Al
Total Mn
Soluble Mn
Total V
Soluble V
Total Mo
Soluble Mo
Total Sb
Soluble Sb
Total Na
Total Ca
Total Mg
—
mg/L (as CaCO3)
mg/L (as CaCO3)
mg/L
mg/L
mg/L
mg/L
mg/L (as SiO2)
mg/L
mg/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
W?/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
Mfi/L
mg/L
mg/L
mg/L
Utility
Data
NA
7.6
240
152
253
NA
NA
158
NA
O.065
NA
22.0
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
266
43.0
11.0
EPA
Data
09/24/02
NA
185
NA
161
0.5
NA
180
34.6
0.1
NA
17.0
NA
NS
NA
NA
73.0
NA
<25
NA
8.9
NA
NA
NA
NA
NA
<25
NA
225
26.3
3.4
Battelle
Data
08/20/03
7.7
188
84.0
180
1.0
O.05
190
35.1
<0.10
1.6
22.7
22.3
0.4
21.6
0.7
38.9
<30
27.2
<10
10.0
9.0
0.5
0.5
11.6
11.9
<0.1
0.1
189
27.2
3.9
NA = not available.
Total arsenic concentrations in raw water ranged from 17.0 to 22.7 |o,g/L. Based on the August 20, 2003
sampling results, arsenic existed primarily as As(III) (i.e., 96.9% at 21.6 (ig/L), with a small amount also
present as As(V) (i.e., 0.7 |o,g/L ) and particulate As (i.e., 0.4 ng/L). Because As(V) adsorbs better with
the SORB 33™ media, it was desirable to oxidize As(III) to As(V) before adsorption.
Raw water pH values ranged from 7.6 to 7.7, which was within the STS-recommended range. Therefore,
pH adjustment was not recommended.
The concentrations of iron (38.9 to 73.0 (ig/L) and other ions in the raw water were sufficiently low that
pretreatment prior to the adsorption process was not required. The concentrations of Orthophosphate and
13
-------
silica also were sufficiently low (i.e., <0.1 mg/L and <35.1 mg/L, respectively) and, therefore, were not
expected to affect the As adsorption on the SORB 33™ media.
Although sulfide odor has been observed by the operator and by sampling personnel, sulfide was not
detected at a detection limit of 0.05 mg/L. Additional samples were collected monthly during the
demonstration study and analyzed for sulfide using a detection limit of 0.005 mg/L. The results are
discussed in Section 4.5.1.
4.1.3 Distribution System. The Desert Sands MDWCA distribution system consists of a looped
distribution line supplied by Wells No. 2 and No. 3. After chlorination, water from the two wells is
pumped into the distribution system at two different locations, separated by approximately 2 miles. When
the water production from the two wells exceeds the consumer demand, the excess flows under pressure
into the two storage tanks (i.e., Tank No. 2 at 75 ft tall by 15 ft in diameter, and Tank No. 3 at 86 ft tall by
22 ft in diameter), that are connected to the distribution system by 6- and 10-inch-diameter polyvinyl
chloride (PVC) pipe, respectively. The distribution system is constructed of PVC pipe, measuring
approximately 30 miles in total length and varying from 2 to 10 inches in diameter. The well pumps are
activated by level sensors in the storage tanks, which signal the pumps to turn on and off when the tank
level reaches a pre-set low and high level, respectively.
Water from Wells No. 2 and No. 3 blends within the distribution system and the storage tanks. Desert
Sands MDWCA has completed a modeling effort to examine the portions of the system served by the
individual wells. The results of this modeling study were used to select distribution system sampling
locations from areas that appear to be served by Well No. 3.
Desert Sands MDWCA samples water periodically from the distribution system for several analytes: once
a month for bacteria; once every three years for inorganics (such as heavy metals, cyanide, and F),
volatile organic compounds (VOCs), and synthetic organic compounds (SOCs); and once every four years
for radionuclides. Under the LCR, samples have been collected from customer taps at 20 locations every
three years, with samples most recently collected in 2000. The monitoring results for 2002 (except for the
LCR results that were reported in 2000) are summarized in Table 4-2.
Table 4-2. Desert Sands MDWCA Distribution System Water Quality Data(:
Parameter
Arsenic (total)
Barium
Cadmium
Chromium
Copper03'
Nickel
Lead(b)
Selenium
Thallium
Units
tig/L
Hg/L
tig/L
tig/L
Hg/L
tig/L
HB/L
HB/L
W?/L
Detected Level (range)
19 (10.4 to 19.3)
52 (34.1 to 55.2)
0.2 (0 to 0.2)
6 (3.3 to 5.5)
93 (2.8 to 103.5)
1 (0.54 to 1.2)
6 (0 to 6.9)
2 (1.1 to 1.6)
0.12(0 to 0.12)
(a) Desert Sands MDWCA's Consumer Confidence Report (2002b) also includes
results for the contaminants that are monitored every three years for inorganics,
VOCs, and SOCs, or four years for radionuclides.
(b) Lead and copper data reported based on the result of 20 samples collected on
August 29, 2000.
14
-------
4.2 Treatment Process Description
The STS APU is designed for arsenic removal for small systems with flowrates greater than 100 gpm. It
uses Bayoxide® E33 (branded as SORB 33™ by STS), an iron-based adsorptive media developed by
Bayer AG, for the removal of arsenic from drinking water supplies. Table 4-3 presents physical and
chemical properties of the media. Unlike some other iron-based media, the SORB 33™ media is
delivered in a dry crystalline form and has NSF 61 approval for use in drinking water.
The STS APU system is a fixed-bed down-flow adsorption system using SORB 33™ granular ferric
oxide (GFO) media for the adsorption of dissolved arsenic. When the media reaches its capacity, the
spent media is removed and disposed of after being subjected to the EPA TCLP test.
STS provided an APU-300 system for the Desert Sands MDWCA site. The APU-300 system consists of
two pressure vessels operating in parallel. The design features of the APU-300 system are summarized in
Table 4-4, and a flow diagram along with the sampling/analysis schedule are presented in Figure 4-4.
Four key process components are discussed as follows:
• Intake and In-Line Sand Separation. Raw water supplied from Well No. 3 passes
through the in-line sand separator before it is chlorinated and fed into the APU-300
system.
• Prechlorination. The previously existing chlorination system, i.e., sodium hypochlorite
(NaOCl) fed with a metering pump, is used for prechlorination to oxidize As(III) and
hydrogen sulfide.
• Adsorption. The APU-300 system consists of two 63-inch-diameter, 86-inch-tall vessels
configured in parallel, each containing 80 ft3 of SORB 33™ media supported by a gravel
underbed. The tanks are fiberglass reinforced plastic (FRP) construction, rated for 75 psi
working pressure, skid mounted, and piped to a valve rack mounted on a polyurethane
coated, welded frame. Empty bed contact time (EBCT) for the system is 3.7 minutes in
each vessel. Hydraulic loading to each vessel based on a design flowrate of 320 gpm is
approximately 7.3 gpm/ft2. Figure 4-5 shows the APU-300 system before the building
enclosure was completed around it.
• Backwash. STS recommends that the SORB 33™ media be backwashed approximately
once per month to loosen up the media bed. Automatic backwash may be initiated either
by timer or by differential pressure in the vessels. Controllers for the backwash system
include actuated valves for the adsorption, backwash and forward flush (fast rinse)
cycles, timers, and pressure sensors. The backwash water is directly discharged into a
drainage pond adjacent to the treatment facility.
4.3 System Installation
The installation of the STS APU-300 system at the site was completed in December 2003, with
shakedown and startup activities continuing into January 2004. The system installation and building
construction activities were carried out by the plant operator as a subcontractor to STS.
4.3.1 Permitting. Engineering plans for the system permit application were prepared by Bohannon
Huston, an STS subcontractor located in Las Cruces, NM. The plans included diagrams and
specifications of the APU-300 system, as well as drawings detailing the connections of the new unit to the
15
-------
Table 4-3. Physical and Chemical Properties of SORB 331M Media
Physical Properties
Parameter
Matrix
Physical form
Color
Bulk density (g/cm3)
Bulk density (lb/ft3)
BET surface area (m2/g)
Attrition (%)
Moisture content (%)
Particle size distribution
Crystal size (A)
Crystal phase
Values
Iron oxide composite
Dry granular media
Amber
0.45
28.1
142
0.3
<15% by weight
10 x 35 mesh
70
a -FeOOH
Ch emical An afysis
Constituents
FeOOH
CaO
SiO2
MgO
Na2O
SO3
A12O3
MnO
TiO2
P205
Cl
Weight %
90.1
0.27
0.06
1.00
0.12
0.13
0.05
0.23
0.11
0.02
0.01
Source: STS.
Table 4-4. Design Features for the APU-300 System
Parameter
Number of adsorbers
Configuration
Vessel size (inches)
Type of media
Quantity of media (ftVvessel)
Pretreatment
Backwash hydraulic loading (gpm/ft2)
Backwash frequency (per month)
Backwash duration (min/vessel)
Peak flow rate (gal/min)
EBCT (min)
Average use rate (gal/day)
Estimated working capacity (BV)
Est. gallons to breakthrough (gal)
Estimated media life (months)
Value
2
Parallel
63x86
Bayoxide E33
80
NaOCl
5-6
1
20-25
320
3.7
345,600
132,000
158,400,000
15
Remarks
—
—
—
—
Media loss has been observed
Prechlorination
9-1 1 gpm/ft2 recommended and used
by STS on site
Or based on a set pressure differential
—
—
Based on the peak flow of 320 gpm
Based on 18 hours of daily operation
at 320 gpm
Bed volumes to 10 ug/L As
breakthrough
1 BV= 1,200 gal (both vessels)
Based on 18 hours of daily operation
(i.e., 75% utilization) at 320 gpm
16
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INFLUENT
(WELL #3)
Monthly
pH®, temperature®, DO/ORP®, sulfide,
alkalinity, turbidity, SiO2, F, NO3, SO4, PO4, ^
As speciation, Fe (total and soluble),
Mn (total and soluble), Ca, Mg
pH®, temperature®, DO/ORP®, sulfide,
C12 (free and total)®,
alkalinity, turbidity, SiO2, F, NO3, SO4, PO4,
As speciation, Fe (total and soluble),
Mn (total and soluble), Ca, Mg
IN-LINE SAND
SEPARATION
Desert Sands MDWCA
Anthony, NM
SORB-33™ Technology
Design Flow: 320 gpm
DA: NaOCl
pH, IDS,
turbidity,
As (soluble),
Fe (soluble),
Mn (soluble)
Weekly
pH®, temperature®, DO/ORP®,
"sulfide, alkalinity, turbidity,
SiO2, PO4, As, Fe, Mn
pH®, temperature®, DO/ORP®,
^sulfide, C12 (free and total)®,
"alkalinity, turbidity, SiO2, PO4,
As, Fe, Mn
pH®, temperature®, DO/ORP®,
^sulfide, C12 (free and total)®,
"alkalinity, turbidity, SiO2, PO4,
As, Fe, Mn
pH®, temperature®, DO/ORP®, sulfide,
C12 (free and total)®,
alkalinity, turbidity, SiO2, F, NO3, SO4, PO4,-
As speciation, Fe (total and soluble),
Mn (total and soluble), Ca, Mg
i
r
DISTRIBUTION
SYSTEM
Footnote
(a) On-site analyses
c
0
8
U
"
5
LEGEND
©Influent
^.^
( AC J After Chlonnation
e Vessel A Effluent
Vessel B Effluent
f TT J Total Combined Effluent
( BWj Backwash Sampling Location
f SS J Sludge Sampling Location
INFLUENT Unit Process
DA: NaOCl Chlorination
^ -P. -p.
Figure 4-4. Process Flow Diagram and Sampling Locations
17
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Figure 4-5. Photograph of APU-300 System at the Desert Sands MDWCA Site
existing facility. After incorporating comments from Desert Sands MDWCA and Battelle, the plans were
submitted by Desert Sands MDWCA to the NMED Drinking Water Bureau for review and approval on
November 18, 2003. The NMED issued a letter of approval on December 22, 2003, requiring that Desert
Sands MDWCA flush and disinfect the system and associated plumbing, and retain negative results from
bacteriological sampling prior to sending treated water to the distribution system.
4.3.2 Building Construction. Desert Sands MDWCA constructed an addition to its existing pump
house at Well No. 3 to house the APU-300 system. The structure measures 15 ft by 15.5 ft at the base
(232.5 ft2) with a total height of 12 ft, and consists of a concrete floor, a steel frame, insulated steel
sidings and roofing, and a walk-through door. The structure is just large enough to house the APU-300
system and the inlet and outlet plumbing. A photograph of the new structure, adjacent to the existing
block pump house, is shown in Figure 4-6.
The building construction began on October 30, 2003, as the concrete pad was poured. After the APU-
300 system had been placed on the pad, the work on frame and roof began on December 23, 2003 and
was completed on January 5, 2004. Installation of the siding and insulation was completed by January
23,2004.
18
-------
Figure 4-6. Pump House (on the right) and System Enclosure
4.3.3 Installation, Shakedown, and Startup. The APU-300 system was delivered to the site on
December 1, 2003. The plant operator, subcontracted to STS, performed the off-loading and installation
of the system, including connections to the existing entry and distribution piping. The system installation
and media loading were completed and the system shakedown and startup commenced on December 11,
2003.
During system shakedown and startup, it was noticed that the system could produce no more than 40 gpm
of flow in either the service or backwash mode, and that under-sized orifice plates had caused the
unwanted flow restriction. The opening of the orifice plates had to be enlarged in an STS shop and
repeatedly tested on-site from 0.5 to 1.5 inch (by January 8, 2004) and then to 1.875 inch (by January 15,
2004) in order to achieve the 150-gpm/vessel target flowrate in the service mode and 160 gpm/vessel in
the backwash mode. Moreover, while operating at 320 gpm, the system experienced a pressure loss of 18
psi across the system, which was significantly higher than the STS specified value of <8 psi. The
pressure loss across the adsorption vessels and the associated valve controllers also was elevated,
exceeding the maximum valued of the differential pressure gauge readouts (i.e., 15 psi). Because of this
elevated pressure loss (which was higher than the would-be set point of about 15 psi for triggering the
automatic backwash), the pressure-actuated automatic backwash feature at the control panel had to be
disabled to avoid the system operating in an constant backwash mode.
Under the conditions described above, the performance evaluation study officially began on January 16,
2004. Battelle provided operator training on data and sample collection and collected the first set of
samples from the APU-300 system.
4.4
System Operation
4.4.1 Operational Parameters. The operational parameters of the system are tabulated and
attached as Appendix A. Key parameters are summarized in Table 4-5. From January 16 through July
16, 2004, the APU-300 system operated for approximately 909 hours based on the well pump hour meter
readings collected daily at the well head. The operational time represented a utilization rate of
approximately 21%, or 5 hours/day, over the 26-week period. The low utilization rate experienced at
19
-------
Table 4-5. Summary of APU-300 System Operation
Duration
Operating Time (hr)
Average Daily
Operating Time (hr)(a)
Throughput (kgal)
Average Flowrate (gpm)
Range of Flowrate
Readings (gpm)
Average EBCT (min)(b)
Range of EBCTs (min)(b)
Pressure Loss (psi)
Time between Two
Backwash Events (hr)
Before System Retrofitting
01/16/04 - 05/16/04 (Week 1 - Week 17)
493
4.0 for January; 4.2 for February;
4.5 for March; 3.5 for April; 5.9 for May
Vessel A
3,442
116
110-150
5.2
5.4-1.0
>20
22-63 (33)
Vessel B
4,433
150
140-180
4.0
4.3-3.3
>20
22-63 (33)
Total
7,875
266
250-330
N/A
N/A
~30(c)
N/A
After System Retrofitting
05/24/04 - 07/16/04 (Week 19 - Week 26)
416
5.9 for May; 7.8 for June;
8.3 for July
Vessel A
3,284
132
135-150
4.5
4.4-4.0
2.75-10.0
48-119(79)
Vessel B
3,488
140
140-180
4.3
4.3-3.3
2.5-10.0
48-119(79)
Total
6,772
271
175-330
N/A
N/A
6-12(c)
N/A
(a) Overall average daily operating time was 5 hours/day.
(b) Calculated based on 80 ft3 of media per vessel. The underbedding in each vessel was 14 ft3 and the free
board in Vessels A and B was 16.5 and 16.3 inches, respectively, as measured after the system retrofit.
(c) Pressure loss across the entire system.
N/A = not applicable.
Well No. 3 was due primarily to a relatively low consumer demand and the concurrent use of Well No. 2
to supply water to the distribution system. The average daily operating time for Well No. 3 increased
steadily (except for April) from 4.0 hours in January to 8.3 hours in July, as it would be expected to have
more water demand in the summer than in the winter.
The total system throughput during this 26-week period was approximately 14,055,000 gallons, according
to the flow totalizer located in the pump house. Based on the flow totalizers installed on the adsorption
vessels, however, the combined system throughput totaled 14,647,000 gallons, including 6,726,000 and
7,921,000 gallons through Vessels A and B, respectively. The unbalanced flow observed between the
two vessels occurred mainly before Week 18, when the system was shut down for repair and retrofitting
(see Section 4.4.2). For example, the cumulative throughputs for Vessels A and B were 3,442,000 and
4,433,000 gallons, respectively, from Weeks 1 through 17, but were 3,284,000 and 3,488,000 gallons,
respectively, from Weeks 19 through 26. The increased throughput after system retrofitting was due
mainly to the increased system operating time, as the system flowrate remained relatively constant
throughout the six-month duration (i.e., at 266 and 271 gpm before and after retrofitting, respectively,
which were 83.1 and 84.7% of the peak flowrate [see Table 4-5]). Before retrofitting, however, Vessel B
received preferential flow at 150 gpm (vs. 116 gpm through Vessel A). The problems associated with the
imbalanced flow were resolved with system retrofitting. Figure 4-7 presents the flowrates through
Vessels A and B both before and after retrofitting.
Because of the imbalanced flow problem, the EBCT varied significantly from 3.3 to 5.4 min between the
two adsorption vessels before system retrofitting. After retrofitting, EBCT varied in a much tighter range
from 3.3 to 4.4 min and averaged 4.3 min for Vessel A and 4.5 min for Vessel B. (Note that EBCT was
calculated based on instant flowmeter readings and that averaged EBCT was calculated based on total
throughput and operating hours).
20
-------
Other problems encountered during the first four months of the system operation related to pressure losses
across both the adsorption vessels and the entire system. As observed during the system shakedown and
startup, the differential pressure (Ap) across each vessel consistently exceeded the upper range of the
factory-installed gauges (i.e., 15 psi) and that of the replacement gauges (i.e., 20 psi) (see Figure 4-8).
The Ap across the entire system based on the difference between the pressure readings at the system inlet
and outlet typically increased from the low- to mid-20s to more than 30 psi between two consecutive
backwash events. After system retrofitting, the Ap across each vessel and the entire system was restored
to as low as 2.5 and 6 psi, respectively, immediately after backwash. Similar to the imbalanced flow
problems, the problems associated with the pressure losses appeared to have been resolved with system
retrofitting.
As part of the effort to reduce Ap, more frequent backwash was performed during the first four months of
system operation. For example, the time elapsed between two consecutive backwash events increased
significantly from 22-63 hours before retrofitting to 48-119 hours after retrofitting. Note that, before
retrofitting, the backwash was initiated manually (see Section 4.4.3); after retrofitting, the backwash was
set at 10 psi Ap across each vessel.
E 100-
50-
..System was turned off for
/ repairs from 5/17/04-5/23/04
J
1/20/04 2/9/04
4/9/04 4/29/04
Date
Figure 4-7. Vessels A and B Flowrates Before and After System Retrofitting
4.4.2 System Retrofit. Difficulties encountered during the first two months of system operation
(including an incident that occurred on February 3, 2004 when the flow through Vessel A dropped to 40
gpm with a system inlet pressure reaching 100 psi) prompted STS to perform a series of systematic
hydraulic testing at STS' Torrance, CA shop and at the Round 1 study site in Brown City, MI, where two
similar APU-300 systems installed also had experienced problems related to flow restriction, imbalanced
flow, and elevated pressure losses. Before reaching the decision to perform the hydraulic testing, STS
initially suggested that the problems encountered might have been caused by damaged media (media
crushed by zero to 300 gpm flow swings after flow restrictors had been temporarily removed from the
system to troubleshoot the flow restriction problem during the initial startup), insufficient backwash
21
-------
flowrates (due to the presence of restrictor plates in the valve controllers), and clogged top distributors
and/or bottom laterals. As part of its investigative work, STS performed a more aggressive backwash and
collected media samples for a sieve analysis on February 19 and 26, 2004, and, on March 8, 2004,
installed a 3-inch-diameter bypass line around the valve controller on each vessel with the intent to
decrease the pressure loss and increase backwash flowrate. These efforts, however, did not to help
resolve the problems, and the results of the particle size distribution analysis did not appear to support the
speculation regarding the media damage. These results led STS to focus its investigative work on the
system plumbing design and construction thereafter.
Vessels A and B had maximum
gauge readings of 15 psi
Gauge was replaced 03/15/04 and
has a maximum reading of 20 psi
1/19/04 2/8/04
2/28/04 3/19/04 4/8/04 4/28/04 5/18/04 6/7/04 6/27/04 7/17/04
Date
Figure 4-8. Pressure Losses (Ap) across Each Vessel and the System over Time
Systematic hydraulic testing on the two APU-300 systems installed at Brown City, MI, was conducted on
March 19, 2004 with no media loaded in the vessels. While operating the system at 103 to 115 gpm (vs. a
design flowrate of 160 gpm/vessel), a pressure loss of 7 to 8 psi was observed across each empty vessel,
and 24 to 26 psi across the entire system. These results suggested that the system plumbing most likely
was the source of the high pressure losses, and that the media mostly likely was not responsible for the
difficulties encountered at the Desert Sands MDWCA site. Replacement of the restrictive orifices from
1.25 to 1.875 inch (as was used for the Desert Sands MDWCA system) did not solve the elevated
pressure loss problems. Additional hydraulic testing was conducted at Brown City, MI and STS'
Torrance, CA facility in mid-April 2004. Table 4-6 summarizes the hydraulic test results collected at
Brown City, MI, Torrance, CA, and Anthony, NM.
Pressure profile data were collected across major components of the system at Brown City, MI and a
similar APU-300 system at STS' Torrance, CA facility. As listed in Table 4-6 and shown in Figure 4-9,
the major system components across each treatment train included a piping inlet, an automatic variable
diaphragm valve (to control flow), a strainer, a programmable Fleck valve controller (to control flow from
a service to backwash mode), an FRP vessel with top diffuser and bottom laterals, a restrictive orifice, and
an outlet. Pressure gauges were across the treatment train so that a complete pressure profile might be
established.
22
-------
Table 4-6. Results of Hydraulic Testing of STS APU-300 Systems
Site
Date
Vessel
Flowrate
(gpm)
Pressure (psi)
PI
P2
P3
P4
P5
P6
AP (psi)
Vessel00
System
System Components
Variable
Diaphragm Valve
Valve Controller
Strainer
Vessel
Top Diffuser
sS
'"8
S
Underbedding
Bottom Laterals
Restrictive Orifice
Before System Retrofitting
Desert Sands
MDWCA, NM
Brown City, MI
Torrance, CA
02/10/04
03/19/04
04/06/04
04/08/04
04/14/04
A
B
A (unit 1)
B (unit 1)
A (unit 2)
B (unit 2)
A
B
A
B
A
120
180
115
113
105
113
160
160
150
150
158
84
84
82
82
84
84
80
80
44
44
64
71
71
43
64
61
34
54
33
53
58
58
30
50
54
54
58
58
58
58
58
58
30
>15
>15
7
8
8
8
13
13
13
13
14
30
30
24
24
26
26
22
22
14
14
NA
•/
^
^
^
^
^
^
^
^
^
^
•/
^
^
^
^
^
^
^
^
^
^
•/
^
^
^
^
^
•/
^
^
•/
^
^
^
^
^
^
^
^
^
^
•/
•/
•/
•/
•/
•/
•/
•/
•/
•/
•/
•/
•/
•/
•/
•/
•/
•/
•/
•/
After System Retrofitting
Torrance, CA
Brown City, MI
Desert Sands
MDWCA, NM
04/20/04
04/29/04
05/24/04
A
B
A
B
A
B
A
B
165
165
170
155
190
190
140
135
23
52
34
34
62
62
66
66
22
51
33
34
19
50
30
33
19
50
30
30
58
58
60
60
3
1
3
1
0
0
3
3
4
2
4
4
4
4
6
6
^
^
^
^
•/
•/
•/
•/
•/
•/
•/
•/
•/
•/
•/
•/
to
OJ
PI = at system inlet.
P2 = after variable diaphragm valve and before entering strainer, valve controller, and vessel.
P3 = at top of vessel.
P4 = at bottom of vessel.
P5 = after vessel and valve controller and before entering restrictive orifice (if present).
P6 = at system outlet.
AP across vessel (including valve controller) = P2 - P5.
AP across vessel = P3 - P4 (after retrofitting).
AP across system (treatment train) = PI - P6.
(a) Including valve controller before system retrofitting.
-------
Note that Ap across the vessel as measured at Desert Sands MDWCA included the pressure loss across
the strainer, valve controller, and vessel, which was equipped with a top diffuser and bottom laterals and
loaded with 14 ft3 of underbedding and 80 ft3 of media.
Figure 4-9. Schematic Diagram of STS APU-300 System as Installed at
Desert Sands MDWCA in December 2003
The results of the Brown City testing on April 6, 2004 showed that, after removing the restrictive orifice,
strainer, and top diffuser, pressure losses were observed across the variable diaphragm valve (from 80 to
71 psi) and valve controller and bottom laterals (from 61 to 58 psi). These results were consistent with
those observed during the April 8, 2004 testing at Torrance, CA, except for the 1-psi loss (from 44 to 43
psi) across the variable diaphragm valve. It was not clear what had caused the 11 psi loss across the
variable diaphragm valve at Brown City; one possible explanation was that the valve was partially
throttled during the testing. The pressure loss across the valve controller, strainer, top diffuser, and
bottom laterals at Torrance, CA was 13 psi (from 43 to 30 psi), identical to that found at Brown City, MI.
Furthermore, the pressure loss across top diffuser and bottom laterals was 1 psi (from 34 to 33 psi),
indicating little or no loss across these system components.
The test results at Brown City, MI and Torrance, CA were further confirmed during a separate test in
Torrance, CA on April 14, 2004, which showed no loss across the variable diaphragm valve, 1 psi loss
(from 54 to 53 psi) across top diffuser and bottom lateral, 13 psi loss (from 64 to 50 psi and less 1 psi
across the top diffuser and bottom laterals) across the valve controller, and possibly 20 psi across the
restrictive orifice (see the 20 psi increase at the inlet after restrictive orifice was restored to the system in
Table 4-6). It was therefore evident that the main sources of the pressure loss came from the valve
controller and restrictive orifice.
24
-------
Upon completion of the hydraulic testing, STS recommended four options to address the problems at
Desert Sands MDWCA (and Brown City):
1. Replace the submersible pump by the host site,
2. Install a booster pump,
3. Run the existing submersible pump for longer periods each day, or
4. Retrofit the STS system.
After reviewing the merits of each option, STS decided to retrofit the STS systems at both the Desert
Sands MDWCA, NM and Brown City, MI sites. The changes included replacement of the 3-inch-
diameter pipe with 4-inch-diameterpipe; removal of the diaphragm valves, restrictive orifices, and valve
controllers; and installation of a nested system of fully-ported actuated butterfly valves and a new control
panel. A schematic diagram of the new system design is presented in Figure 4-10.
The test results collected at Torrance, CA, Brown City, MI, and Desert Sands MDWCA, NM after the
system retrofit are presented in Table 4-6. With the Torrance, CA and Brown City, MI systems operating
at 155 to 190 gpm without media or underbedding loaded in the vessels, the pressure losses across the
vessel (along with bottom laterals) and the system were 0-3 and 2-4 psi, respectively. The system was
returned to service on May 24, 2004 with the modified pipe design, a new upper distributor, and new
control panel in place. STS measured the freeboard as the new upper distributors were being installed,
observing between 16.25 and 16.5 inches of freeboard in each vessel. Startup testing of the retrofitted
unit showed a pressure loss across the media-filled vessels of 3 psi, and a total pressure loss across the
system of 6 psi.
4.4.3 Backwash. STS recommended the SORB 33™ media be backwashed manually or
automatically approximately once per month to loosen up the media bed. Automatic backwash could be
initiated either by timer or by differential pressure in the vessels. The system was backwashed 15 times
during the first 17 weeks of operation leading up to the mid-May retrofit. The backwash was performed
automatically five times from May 24 through the end of the first six months of system operation. Before
retrofitting, the time elapsed between two backwash events ranged from 22 to 63 hours, averaging 33
hours. The interval between backwash events was much longer after retrofitting, ranging from 48 to 119
hours of operating time, with an average of 79 hours.
The backwash was performed at approximately 200 gpm, or 9 gpm/ft2, as set by STS on May 24 using the
manual valve on the backwash discharge line. Each backwash event lasted for 20 minutes, followed by a
four-minute rinse, producing approximately 4,800 gallons of water per vessel during each backwash
event. Due to the cycles of consumer demand, automated backwash events typically occurred overnight,
when the operator was not present. The vessels will be backwashed manually for selected events during
the remaining six months of the demonstration to facilitate backwash water sampling and improved
observation of the backwash events.
4.4.4 Residual Management. Residuals produced by the operation of the APU-300 system
include spent media and backwash water. The media was not exhausted during the first six months of
system operation; therefore, the only residual produced was backwash wastewater. Above ground piping
for backwash water from both vessels is combined before extending outside the building below the base
of the wall. Backwash water flows from the pipe into the pond, where it either evaporates or infiltrates.
Any particulates carried in the backwash water remain in the pond.
4.4.5 System Operation Reliability and Simplicity. The overall system reliability and simplicity
was examined both before and after retrofitting of the system in May 2004. Aside from the excessive
pressure losses and imbalance flow prior to the system retrofit, the only other O&M issue encountered
25
-------
Figure 4-10. Schematic Diagram of STS APU-300 System after System Retrofitting in May 2004
was the temporary failure of the digital flow meters on the vessels on two separate occasions for one to
two days at a time.
Unscheduled downtime during the first six months of system operation was caused by the need to address
elevated pressure losses and imbalanced flows, as discussed above. The system was shut down on
February 19 for a system inspection, February 26 for media sampling, March 8 for the installation of a
bypass line around the valve controller, and May 16 through 24 for system retrofitting. Neither scheduled
nor unscheduled downtime has been required since the completion of the system retrofit.
The simplicity of system operation and operator skill requirements are discussed according pre- and post
treatment requirements, levels of system automation, operator skill requirements, preventative
maintenance activities, and frequency of chemical/media handling and inventory requirements.
Pre- and Post-Treatment Requirements. Pre-treatment at the site consisted of the injection of sodium
hypochlorite upstream of the system for oxidation of sulfide and As(III) to As(V). The prechlorination
system was already in place to provide chlorine residuals in water before entering the distribution system.
Vigilant oversight of the prechlorination system was necessary to ensure that the residual chlorine levels
were maintained properly. Post-treatment was not required at this site.
System Automation. The backwash cycle was controlled automatically, triggered by the differential
pressure across each vessel. Since the retrofit, the system was backwashed automatically on five
26
-------
occasions, with the interval between backwash events reaching approximately 14 days and the amount of
water treated reaching approximately 2,000,000 gallons.
Although backwash of the vessels was triggered automatically, on some occasions only one vessel
reached the trigger level. In this situation, the one vessel that was backwashed subsequently was able to
receive water at a higher flowrate, producing an imbalanced flow. When this occurred, the operator
initiated a manual backwash on the second vessel, returning the system to a balanced flow. All other
functions of the APU-300 system were automated.
Operator Skill Requirements. Under normal operating conditions, the skill requirements to operate the
APU-300 system were minimal. The daily demand on the operator was 15 minutes to allow the operator
to visually inspect the system and record the operating parameters on the log sheets. The operation of the
system did not appear to require additional skills beyond those necessary to operate the existing
production equipment. Based on the size of the population served and the treatment technology, the State
of New Mexico requires Level 2 Certification for system operation.
Preventative Maintenance Activities. Preventative maintenance tasks recommended by STS included
monthly inspection of the control panel, quarterly checking and calibration of the flow meters, biannual
inspection of the actuator housings, fuses, relays, and pressure gauges, and annual inspection of the
butterfly valves. STS recommended checking the actuators at each backwash event to ensure that the
valves were opening and closing in the proper sequence. Further, inspection of the adsorber laterals and
replacement of the underbedding gravel was recommended to be performed concurrent with the media
replacement. During this reporting period, the operator inspected the valves and wiring monthly, which
consumed approximately 15 minutes/month. The operator also compared the flow meter and totalizer
data from the STS system to his existing meters on a consistent basis, which did not require any
appreciable time expenditure.
Chemical/Media Handling and Inventory Requirements. Chemical use was not required beyond the
prechlorination system already in place. At the current water production rate, Desert Sands MDWCA
orders one 53-gallon drum of sodium hypochlorite per month. The plant operator switched the metering
pump inlet tube from the empty drum to the new drum when necessary.
4.5 System Performance
The system performance was evaluated based on analyses of water samples collected from the treatment
plant, backwash lines, and distribution system.
4.5.1 Treatment Plant Sampling. Water samples were collected at five locations through the
treatment train: the inlet (IN), after prechlorination (AC), at the effluent of Vessels A and B (TA and TB,
respectively), and at the combined effluent (TT). Field-speciated samples at IN, AC, and TT were
collected once every four weeks throughout this reporting period. Table 4-7 summarizes the arsenic, iron,
and manganese analytical results. Table 4-8 summarizes the results of other water quality parameters.
Appendix B contains a complete set of analytical results through the first six months of system operation.
The results of the water samples collected throughout the treatment plant are discussed below.
Arsenic. The key parameter for evaluating the effectiveness of the APU-300 system was the
concentration of arsenic in the treated water. The treatment plant water was sampled on 19 occasions
during the first six months of system operation, with field speciation performed on seven of the 19
occasions. Samples were collected at the IN and AC sample ports at each of the 19 sampling events. TA
and TB were sampled 12 times, and TT was sampled seven times.
27
-------
Table 4-7. Summary of Arsenic, Iron, and Manganese Analytical Results
Parameter
As (total)
As(total
soluble)
As
(paniculate)
As(III)
As(V)
Total Fe
Dissolved
Fe
Total Mn
Dissolved
Mn
Samp
ling
Locat
ion
IN
AC
TA
TB
TT
IN
AC
TT
IN
AC
TT
IN
AC
TT
IN
AC
TT
IN
AC
TA
TB
TT
IN
AC
TT
IN
AC
TA
TB
TT
IN
AC
TT
Units
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
^g/L
Number of
Samples
20
20
13
13
7
7
7
7
7
7
7
7
6
7
7
6
7
20
20
13
13
7
7
7
7
20
20
13
13
7
7
7
7
Minimum
Concentration
20.7
21.2
1.4
1.4
0.9
21.9
20.3
0.8
0.1
0.2
0.1
17.6
0.5
0.3
0.5
19.4
0.3
<25
<25
<25
<25
<25
<25
<25
<25
7.0
7.1
<0.1
0.1
<0.1
7.1
5.3
<0.1
Maximum
Concentration
30.1
30.1
2.4
2.8
3.0
24.8
24.7
2.8
4.7
5.1
0.2
22.8
1.1
1.8
5.6
23.6
1.6
106
112
46
41
<25
43
<25
<25
11.0
10.3
0.5
0.5
0.8
10.5
9.2
0.50
Average
Concentration
25.3
25.6
1.9
1.9
1.8
23.1
22.8
1.7
2.7
3.2
0.2
21.1
0.9
1.0
1.9
21.8
0.8
49
43
18
16
<25
17
<25
<25
9.0
8.6
0.2
0.2
0.3
8.6
6.6
0.2
Standard
Deviation
2.7
2.7
0.3
0.4
0.8
1.0
1.4
0.7
1.5
2.0
0.1
1.7
0.2
0.5
1.8
1.4
0.5
25
26
12
10
0.0
11.5
0.0
0.0
0.9
0.9
0.1
0.1
0.3
1.1
1.5
0.2
One-half of the detection limit was used for nondetect samples for calculations.
Duplicate samples were included in the calculations.
28
-------
Table 4-8. Summary of Water Quality Parameter Measurements
Parameter
Alkalinity
Fluoride
Sulfate
Orthophosphate
(as PO4)
Silica
Sulfide
Nitrate (as N)
Turbidity
pH
Temperature
Dissolved
Oxygen
Sampling
Location
IN
AC
TA
TB
TT
IN
AC
TT
IN
AC
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
IN
AC
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TA
TB
TT
IN
AC
TA
Units
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
HB/L
mg/L
mg/L
mg/L
NTU
NTU
NTU
NTU
NTU
s.u.
s.u.
s.u.
s.u.
s.u.
°c
°c
°c
°c
°c
mg/L
mg/L
mg/L
Number
of
Samples
20
20
13
13
7
7
7
7
7
7
7
19
19
12
12
7
20
20
13
13
7
12
7
7
7
19
19
12
12
7
18
18
10
10
7
18
18
10
10
7
18
18
10
Minimum
Concentration
164
170
169
169
173
0.5
0.5
0.5
170
170
180
0.10
0.10
0.10
O.10
0.10
36.4
36.4
35.3
36.3
37.2
<5.0
O.05
O.05
0.05
0.2
0.1
0.1
0.1
0.1
7.6
7.7
7.7
7.7
7.6
28.4
28.8
28.9
29.0
29.5
1.0
1.1
1.1
Maximum
Concentration
226
197
199
194
189
0.7
0.7
0.7
190
190
190
0.20
0.18
0.10
O.10
0.15
41.8
41.7
39.9
40.0
38.6
5.7
0.1
0.1
0.1
3.5
1.5
0.7
0.8
0.7
8.1
8.0
8.0
7.9
8.0
31.6
31.5
31.2
31.1
31.6
1.9
2.0
2.0
Average
Concentration
187
183
184
182
182
0.6
0.6
0.6
184
181
184
0.06
0.06
0.10
O.10
0.06
38.3
38.2
37.7
38.0
37.8
3.2
0.04
0.04
0.04
1.0
0.5
0.3
0.3
0.3
7.9
7.9
7.9
7.8
7.8
30.2
30.3
30.3
30.3
30.5
1.3
1.4
1.4
Standard
Deviation
13
8
8
7
6
0.1
0.1
0.1
8
9
5
0.03
0.03
0.00
0.00
0.04
1.3
1.3
1.3
1.1
0.5
1.3
0.03
0.03
0.03
1.0
0.4
0.2
0.2
0.2
0.1
0.1
0.1
0.1
0.1
0.8
0.8
0.8
0.7
0.8
0.3
0.3
0.3
29
-------
Table 4-8. Summary of Water Quality Parameter Measurements (Continued)
Parameter
Dissolved
Oxygen (Cont.)
ORP
Free C12
Total C12
Total Hardness
(as CaCO3)
Sampling
Location
TB
TT
IN
AC
TA
TB
TT
AC
TA
TB
TT
AC
TA
TB
TT
IN
AC
TT
Units
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
Number
of
Samples
10
7
7
7
3
o
3
4
15
9
8
7
13
7
6
6
7
7
7
Minimum
Concentration
1.1
1.3
42
486
503
510
495
0.3
0.3
0.3
0.3
0.4
0.5
0.5
0.5
78.4
79.2
74.5
Maximum
Concentration
1.9
2.3
81
550
531
528
561
0.5
0.5
0.5
0.5
0.6
0.6
0.6
0.6
101.1
111.1
110.1
Average
Concentration
1.4
1.5
57
518
518
521
525
0.4
0.4
0.4
0.4
0.5
0.5
0.5
0.5
86.5
88.0
86.8
Standard
Deviation
0.3
0.4
13
26
14
10
31
0.1
0.1
0.1
0.1
0.1
0.1
0.0
0.0
7.8
10.9
11.3
One-half of the detection limit was used for nondetect samples for calculations.
Duplicate samples are included the calculations.
Figure 4-11 contains three bar charts showing the concentrations of total As, particulate As, As(III), and
As(V) at the IN, AC, and TT locations for each sampling event. Total arsenic concentrations in raw water
ranged from 20.7 to 30.1 |o,g/L and averaged 25.3 |o,g/L (Table 4-7). As(III) was the predominating
species, ranging from 17.7to22.8 |o,g/L and averaging 21.1 |o,g/L. Only trace amounts of particulate As
and As(V) existed, with concentrations averaged 2.7 and 1.9 |o,g/L, respectively. The arsenic
concentrations measured during this six-month period were consistent with those in the raw water sample
collected on August 20, 2003 (Table 4-1).
The prechlorination step oxidized As(III) to As(V) and provided required chlorine residuals to the
distribution system. Samples collected downstream of the chlorine addition point (AC) had average
As(III) and As(V) concentrations of 0.9 and 21.8 |o,g/L, respectively. As (III) concentrations after
prechlorination remained consistently low (ranging from 0.5 to 1.1 ng/L), indicating complete oxidation.
Analytical results for As(III) and As(V) were not available for the June 9, 2004 sample, so the data from
that date showed only the soluble and particulate concentrations (Figure 4-11).
Free and total chlorine was monitored at the AC, TA, TB, and TT sampling locations to ensure that the
target chlorine residual level was properly maintained. Typically, free chlorine was measured at 0.3 to
0.5 mg/L at the AC location, with total chlorine levels ranging from 0.4 to 0.6 mg/L (Table 4-7). The
residual chlorine measured at the TA, TB, and TT locations was nearly identical to that measured at the
AC location, indicating little or no chlorine consumption through the SORB 33™ vessels.
Total As concentrations in the combined effluent (TT) ranged from 0.9 to 3.0 |o,g/L and averaged 1.8 |o,g/L
(Table 4-7). The average particulate As, As(III), and As(V) concentrations in the combined effluent were
0.2, 1.0, and 0.8 |o,g/L, respectively. The average As(III) concentration of 1.0 |o,g/L at the TT location
30
-------
indicated that little or no As(III) removal by the SORB 33™ media (Figure 4-11). The total As and
As(V) concentrations in the treated water increased slightly during the two most recent sampling events,
after remaining at or below 1.6 |o,g/L for the first five sampling events. The total As concentrations at the
TT location will be monitored throughout the next reporting period to determine if the recent increase was
the beginning of a trend or simply a temporary spike. By the end of the first six months of system
operation, the APU-300 system treated approximately 14,647,000 gallons of water, equivalent to 12,206
bed volumes during this reporting period, approximately 9% of the STS estimated working capacity for
this media (132,000 bed volumes), as shown in Table 4-4.
The results of the total arsenic analyses at each sampling location throughout the first six months of
system operation are plotted against the bed volumes of treated water in Figure 4-12. The plots clearly
demonstrated the similarity in total arsenic concentrations at the IN and AC ports, and significant
decreases in concentrations at the outlet of each vessel (TA and TB) and the combined outlet (TT). The
plot also showed that the samples at the effluent of each vessel were very similar, even though the
imbalanced flow problems had caused some variation in EBCT before system retrofitting. The difference
in the TA and TB plots could be explained by the imbalanced flow and the difference in the number of
bed volumes treated by each vessel. Thus far, the STS APU-300 has removed arsenic from the influent
water to levels well below the 10 |o,g/L MCL.
Iron. Total iron concentrations varied from <25 to 112 |o,g/L (Table 4-7) with nearly all of the
concentrations at the TA, TB, and TT locations being <25 |o,g/L. Dissolved iron concentrations were <25
|o,g/L for all samples with the exception of the IN sample on July 7, 2004 at 43 |o,g/L. These data indicate
that the majority of the total iron entering the system was in particulate form, and that the iron particles
were captured by the media beds.
Manganese. The treatment plant water samples were analyzed for total Mn for all sampling events, but
also for soluble Mn during speciation week sampling. The total Mn concentrations at the various
sampling locations are plotted overtime in Figure 4-13. The total and soluble Mn concentrations are
shown in Figure 4-14. Influent total Mn levels ranged from 7.0 to 11.0 |o,g/L (Table 4-7), with the
majority being soluble Mn(II). After prechlorination, about 27% (in average) of the Mn(II) was oxidized
to form particulate Mn and the rest remained in the soluble form, indicating incomplete oxidation of
Mn(II). This was consistent with previous findings that free chlorine was relatively ineffective to oxidize
Mn(II) unless the solution pH value was above 8.0 to 8.5 (Knocke et al., 1987 and 1990). However, total
Mn concentrations at the TA, TB, and TT locations were reduced to <0.1 to 0.8 |og/L, indicating removal
of Mn by the SORB 33™ media. Knocke et al. (1990) reported that the presence office chlorine in the
filter promoted Mn(II) removal on MnOx-coated media; and that in the absence of free chlorine, Mn(II)
removal was by adsorption only. Unlike the MnOx-coated media, SORB 33™ media could not remove
Mn(II) via adsorption in the absence of free chlorine, based on the data collected from the Rollinsford
demonstration site. Therefore, Mn(II) was likely removed via an oxidation/filtration mechanism on the
SORB 33™ media surface where free chlorine existed.
Other Water Quality Parameters. In addition to arsenic analyses, other water quality parameters were
analyzed to provide insight into the chemical processes occurring within the treatment system. The
results of the water quality parameters are included in Appendix B, and are summarized in Table 4-8.
31
-------
Arsenic Species at the Inlet (IN)
30
25
I
I 2°
1
c 15
10
•
n
-
— i
DAs (participate)
• As(V)
D As (III)
3/17/2004 4/14/2004 5/12/2004
Date
i 15-
Arsenic Species After Prechlorination (AC)
1/23/2004 2/18/2004 3/17/2004
4/14/2004 5/12/2004
Date
Arsenic Species After Tanks Combined (TT)
6^/2004 7/7/2004
i 15
n , FL
1/23/2004 2/18/2004 3/17/2004
4/14/2004 5/12/2004
Date
6/9/2004 7/7/2004
DAs (particulate)
• As(V)
DAs(lll)
DAs (particulate)
• As (V)
DAs (III)
Figure 4-11. Concentration of Arsenic Species in the Influent,
After Prechlorination, and in the Combined System Effluent
32
-------
35
30 -
25 -
' 20 -
15 -
10 -
5 -
4 6
Bed Volumes of Water Treated (*103)
10
12
Figure 4-12. Total Arsenic Breakthrough Curve
10-
i
o
o
2-
1/16/04 2/5/04 2/25/04 3/16/04 4/5/04 4/25/04 5/15/04 6/4/04 6/24/04 7/14/04
Date
Figure 4-13. Total Manganese Concentrations over Time
33
-------
On-site measurements of pH remained consistent at all sampling locations, ranging from 7.8 to 8.1.
Sulfate concentrations ranged from 170 to 190 mg/L, and remained constant throughout the treatment
train. Alkalinity results ranged from 164 to 199 mg/L, measured as CaCO3. The results indicated that the
alkalinity was not affected by the prechlorination or the media. Historically, sulfide odor in the raw water
had been detected by the system operator. Samples for sulfide were collected at the IN sampling location
on six occasions. Sulfide was detected in two samples, at 5.2 |o,g/L on March 3, 2004 and 5.7 |o,g/L on
March 31, 2004. All other sulfide samples were below the detection limit of 5 |o,g/L. The treatment plant
samples were analyzed for hardness only during speciation weeks. The total hardness results ranged from
74.5 to 90.1 mg/L as CaCO3. The samples had predominantly calcium hardness (approximately 75-80%).
Hardness was not affected by either the prechlorination or the media.
Fluoride results ranged from 0.5 to 0.7 mg/L. Fluoride concentrations, measured only during speciation
weeks, were not affected by the treatment unit. Orthophosphate was below the detection limit of 0.10
mg/L at all sampling points in every sampling event, with the exception of the first event on January 23,
2004, when the Orthophosphate results were 0.2 mg/L at each sampling point. The silica (as SiO2)
concentration ranged from 36.0 to 41.8 mg/L, and was not removed by the treatment media.
Sodium hypochlorite was added upstream of the treatment system. In addition to the original purpose of
disinfecting water, chlorine also oxidized As(III) to As(V) to increase the arsenic removal capacity of the
media. Free and total chlorine measurements were performed and recorded at each sampling event along
with the pH, DO, ORP, and temperature readings. Free and total chlorine was monitored at the AC, TA,
TB, and TT sampling locations. Free chlorine typically was measured at 0.3 to 0.5 mg/L at the AC
location with total chlorine levels ranging from 0.4 to 0.6 mg/L. The total chlorine remained about 0.1
mg/L higher than the free chlorine. The residual chlorine measured at the TA, TB, and TT locations was
nearly identical to that measured at the AC port indicating little or no loss of chlorine through the APU-
300.
DO levels ranged from 1.0 to 2.3 mg/L with most measurements being less than 1.6 mg/L. The DO levels
were not affected by the prechlorination or the media. ORP readings were collected using a dedicated
ORP probe since April 14, 2004. In the seven subsequent events, the ORP readings at the IN location
varied from 42 to 81 mV, indicating an reducing environment. After prechlorination, the ORP readings at
the AC, TA, TB, and TT locations increased significantly, ranging from 486 to 561 mV.
4.5.2 Backwash Water Sampling. Backwash water was sampled on May 23 and July 13, 2004.
Samples were collected from the sample ports located in the backwash effluent discharge lines from each
vessel. Unfiltered samples were analyzed for pH, turbidity, and TDS/TSS. Filtered samples (using 0.45-
|om disc filters) were analyzed for soluble As, Fe, and Mn. Turbidity and soluble Fe and Mn results from
the May 23, 2004 sample were significantly higher than the concentrations in raw water measured during
the study. This was caused by a sampling error with unfiltered water being inadvertently added to the
sample bottles. Soluble Fe and Mn concentrations measured in the July 13, 2004 sample correlated more
closely with the influent concentrations for these parameters. Soluble As concentrations in the backwash
water ranged from 3.5 to 12.1 |o,g/L and were significantly lower than those measured in raw water,
indicating that arsenic was removed as it passed through the media during backwash. The analytical
results from the two backwash water sampling events are summarized in Table 4-9.
4.5.3 Distribution System Water Sampling. Distribution system samples were collected to
investigate if the water treated by the arsenic removal system would impact the lead and copper level and
water chemistry in the distribution system. Prior to the installation and operation of the system, baseline
distribution water samples were collected on December 8, 11, and 30, 2003. Following the installation of
the system, distribution water sampling continued on a monthly basis at the same three locations, with
34
-------
Inlet (IN)
1 6
1
n
1/23/2004 2/18/2004 3/17/2004 4/14/2004 5/12/2004 6/9/2004 7/7/2004
After Pre-Chlorination (AC)
R
1/23/2004 2/18/2004 3/17/2004 4/14/2004 5/12/2004 6/9/2004 7/7/2004
After Tanks Combined (TT)
1 6
i
1/23/2004 2/18/2004 3/17/2004
4/14/2004
Date
5/12/2004 6/9/2004 7/7/2004
Figure 4-14. Concentrations of Manganese Species
35
-------
Table 4-9. Backwash Water Sampling Results
Units
5/23/2004(a)
7/13/2004
Vessel A
pH
-
7.45
7.88
Turbidity
NTU
180
220
TDS
mg/L
203
766
Soluble
As00
Hg/L
3.5
12.1
Soluble
Fe(b)
Hg/L
825
69.8
Soluble
Mn(b)
Hg/L
89.0
7.6
Vessel B
pH
-
7.9
7.88
Turbidity
NTU
99
160
TDS
mg/L
202
756
Soluble
Asw
Hg/L
5.6
9.6
Soluble
Fe(b)
Hg/L
2,166
83
Soluble
Mn(b)
Hg/L
131.0
8.21
(a) Samples were mistakenly analyzed for TSS rather than TDS.
(b) Filtered (0.45 |am) samples.
samples collected on February 11, March 10, April 7, May 12, and June 23, 2004. The samples were
analyzed for pH, alkalinity, arsenic, iron, manganese, lead, and copper.
Samples at the DS1 location were collected according to the procedures in the LCR (first draw samples).
Both first draw and flushed samples were collected at the DS2 and DS3 non-LCR locations. The main
difference observed from the baseline samples to the present was a decrease in the arsenic concentrations
at each of the sampling locations. Arsenic concentrations in the baseline samples ranged from 22.4 to
28.2 ng/L, whereas the concentrations measured since the treatment system was started ranged from 1.8
to 10.4 |og/L. The arsenic concentrations measured during system operation were lower than the baseline
values, but higher than the system effluent results. This was due probably to the blending of water
produced by Well No. 3 in the distribution system with untreated water from Well No. 2. A sample
collected from Well No. 2 on June 2, 2004 exhibited a 14.9 |o,g/L concentration of total arsenic.
Measured pH values ranged from 7.5 to 8.0, with one outlier of 7.1 at DS1 during the first baseline
sampling event. Alkalinity levels ranged from 168 to 265 mg/L as CaCO3. Iron concentrations in the
first draw samples ranged from <25 to 931 |o,g/L, with the majority of the samples <25 |o,g/L. Iron
concentrations in the flushed samples from DS1 and DS2 ranged from <25 to 55 |o,g/L. In general, the
iron concentrations in the distribution system samples decreased since the system began operating. The
concentrations of manganese in the distribution system samples ranged from <0.1 to 94.1 |o,g/L, but the
only results greater than 7.7 |o,g/L were first draw samples at DS2. Manganese levels appear slighly lower
since the system began to operate.
Lead levels ranged from 0.2 to 71.7 |og/L, with 7 of the 34 samples exceeding the action level of 15 |o,g/L.
Five of the action level exceedances for lead were from first draw samples at DS2, with the remaining
two exceedances in first draw samples from DS3. Copper concentrations ranged from 1.6 to 393 |o,g/L,
with no samples exceeding the 1,300 |o,g/L action level. Neither lead nor copper concentrations in the
distribution system appeared to have been affected by the operation of the arsenic treatment unit. The
results of the distribution system sampling are summarized in Table 4-10.
4.6
System Costs
The cost-effectiveness of the system is evaluated based on the dollar cost per 1,000 gallons of water
treated. This includes the tracking of capital costs such as equipment, engineering, and installation costs
and O&M costs such as media replacement and disposal, chemical supply, electrical power use, and
labor.
36
-------
Table 4-10. Distribution System Sampling Results
No. of
Sampling
Events
BL1
BL2
BL3
1
2
3
4
5
Address
Sample Type
Flushed/lst Draw
Sampling Date*
12/8/2003
12/11/2003
12/30/2003
2/11/2004
3/10/2004
4/7/2004
5/12/2004
6/23/2004
DS1
12 Warthen
LCR
1st Draw
Stagnation
Time (hrs)
8
8.5
7.7
8.5
7.8
8.5
8.1
8.1
I
O.
7.1
7.8
7.7
7.6
7.8
7.7
7.8
8.0
ft-
c
'~m
.^
<
200
178
197
207
230.0
249
223
183
M
<
23.3
26.0
22.4
10.4
8.1
9.3
9.5
1.8
S.
48
40
<25
49
<25
<25
<25
<25
c
5.0
4.0
2.0
1.9
1.9
3.5
1.7
1.0
£
0.9
0.6
1.1
0.4
0.7
0.2
1.7
2.0
O
9.1
7.1
17.0
NA
12.5
7.5
156
33.7
DS2
Crossroads
Non-Residence
1st Draw
i
O.
7.7
7.8
NS
7.8
7.8
7.8
7.8
7.9
..&
c
is
££
187
196
NS
182
235.0
257
237
195
M
<
26.3
28.2
NS
7.4
8.8
10.2
7.2
3.1
£
37
931
NS
783
97.7
27
<25
<25
c
6.4
94.1
NS
34.1
10.8
23.8
1.8
1.4
£
22.5
16.8
NS
60.2
71.7
15.9
1.7
6.0
O
99.5
206
NS
393
159
105
15.5
84.7
Flushed
i
O.
NS
NS
7.8
7.8
7.8
7.8
7.8
7.9
..&
c
is
££
NS
NS
201
186
230.0
265
241
195
M
<
NS
NS
23.4
2.5
8.3
9.5
7.6
4.3
£
NS
NS
<25
55
<25
<25
<25
<25
c
NS
NS
2.3
0.6
2.7
1.3
2.2
1.2
£
NS
NS
1.2
2.9
1.5
0.8
2.3
9.3
O
NS
NS
8.6
25.7
9.3
6.6
11.4
1.6
DS3
Guillermo
Non-residence
1st Draw
i
O.
7.8
7.9
NS
7.7
7.9
8.0
7.8
8.0
..&
c
is
££
181
200
NS
198
197.0
168
229
195
M
<
26.3
23.7
NS
5.3
2.4
2.8
5.1
2.5
£
74
40
NS
47
22.5
<25
<25
<25
c
7.5
7.7
NS
1.7
5.6
4.1
1.9
0.6
£
8.2
1.0
NS
8.7
41.3
3.3
3.4
22.9
O
33.6
10.1
NS
30.0
315
42.5
19.6
121
Flushed
i
O.
NS
NS
7.8
7.7
8.0
7.9
7.8
7.9
..&
c
is
££
NS
NS
207
215
185.0
180
233
175
M
<
NS
NS
23.6
6.7
1.8
2.5
5.6
4.5
£
NS
NS
<25
48
<25
<25
<25
<25
c
NS
NS
2.1
2.3
0.1
0.1
1.0
1.2
£
NS
NS
1.1
1.0
6.2
0.9
2.1
3.8
O
NS
NS
9.1
17.0
14.5
10.8
11.0
19.2
: System operation started on January 16, 2004.
The unit for analytical parameters is |ig/L, except for pH (no unit) and alkalinity (mg/L as CaCO3).
Lead action level =15 |ig/L; copper action level =1.3 mg/L.
NS = not sampled; NA = not available; BL = baseline sampling.
-------
4.6.1 Capital Costs. The capital investment costs for equipment, site engineering, and installation
were $153,000 (see Table 4-11). The equipment costs were $112,000 (or 73% of the total capital
investment), which included $72,200 for the APU-300 skid-mounted unit, $24,000 for the SORB 33™
media (i.e., $150/ft3 or $5.34/lb to fill two vessels), and vendor's labor and travel for the system
shakedown and startup.
Table 4-11. Capital Investment for the APU-300 System at the Desert Sands MDWCA Site
Description
Quantity
Cost
% of Capital
Investment Cost
Equipment Costs
APU-300 Skid-Mounted System
SORB 33™ Media
Miscellaneous Equipment and Materials
Vendor Labor
Vendor Travel
Equipment Total
1 unit
160 ft3
-
-
-
-
$72,200
$24,000
$2,500
$9,500
$3,800
$112,000
-
-
-
-
-
73%
Engineering Costs
Subcontractor
Vendor Labor
Engineering Total
—
—
—
$16,300
$6,700
$23,000
—
—
15%
Installation Cost
Subcontractor
Vendor Labor
Vendor Travel
Installation Total
Total Capital Investment
—
—
—
—
-
$9,000
$5,600
$3,400
$18,000
$153,000
—
—
—
12%
100%
The engineering costs included the costs for the preparation of the system layout and footprint, design of
the piping connections up to the distribution tie-in points, design of the electrical connections, and
assembling and submission of the engineering plans for the permit application (Section 4.3.1). The
engineering costs were $23,000, which was 15% of the total capital investment.
The installation costs included the costs for the equipment and labor to unload and install the APU-300
system, perform the piping tie-ins and electrical work, and load and backwash the media (Section 4.3.3).
The installation was performed by STS and the Desert Sands MDWCA plant operator subcontracted to
STS. A variety of elevated pressure and flow restriction issues caused the actual system startup date to be
delayed, eventually prompting STS to redesign the system's piping, valving, and instruments and
controls. The costs for the system retrofitting were not included in this cost analysis. The installation
costs were $18,000, or 12% of the total capital investment.
Desert Sands MDWCA constructed an addition to its existing pump house at Well No. 3 to house the
APU-300 system (Section 4.3.2). The structure was built by the Desert Sands MDWCA plant operator
with the exception of the electrical tie-in. The total cost for the building was $3,700, with $2,700 for
materials and $1,000 for labor. Approximately 80 hours of labor were required to complete the
construction effort.
The total capital cost of $153,000 and equipment cost of $112,000 were converted to a unit cost of
$0.06/1,000 gallon and $0.04/1,000 gallon, respectively, using a capital recovery factor (CRF) of 0.06722
38
-------
based on a 3% interest rate and a 20-year return period (Chen et al., 2004). These calculations assumed
that the system operated 24 hours a day, 7 days a week at the system design flowrate of 320 gpm. The
system operated only 4 to 8.3 hours a day (see Table 4-5), producing 14,647,000 gallons of water during
the 6-month period, so the total unit cost and equipment-only unit cost were increased to $0.35/1,000
gallon and $0.26/1,000 gallon, respectively, at this reduced rate of usage. Using the system's rated
capacity of 320 gpm, the capital cost was $476 per gallon of design capacity and equipment-only cost was
$350 per gallon of design capacity. These calculations did not include the building construction cost.
4.6.2 Operation and Maintenance Costs. O&M costs for the Desert Sands MDWCA system
includes only incremental costs associated with the APU-300 system, such as media replacement and
disposal, chemical supply, electricity, and labor. These costs are summarized in Table 4-12. Because
media replacement and disposal did not take place during the first six-months of operation, its cost per
1,000 gallons of water treated was calculated based upon a projected breakthrough and an estimated
media changeout cost (i.e., $26,800 to change out both vessels) (Figure 4-15). This media changeout
cost included costs for media, freight, labor, travel expenses, and media profiling and disposal fee. At the
vendor-estimated media capacity of 132,000 BV (Table 4-4), the media replacement cost is projected to
be $0.17/1,000 gallons (Figure 4-15). This cost, however, will be determined once the actual
breakthrough occurs and the cost of media replacement becomes available.
re
ra
o
o
o
» O&M cost
Media replacement cost
20
30
40 50 60 70 80 90 100 110 120
Media Working Capacity, Bed Volumes (xlOOO)
130 140
150
Figure 4-15. Media Replacement and O&M Cost for the Desert Sands MDWCA APU-300 System
39
-------
Table 4-12. O&M Costs for the APU-300 System at the Desert Sands MDWCA Site
Cost Category
Volume processed (kgal)
Value
14,647
Assumptions
Through July 16, 2004
Media Replacement and Disposal
Media cost ($/ft3)
Total media volume (ft3)
Media replacement cost ($)
Labor cost ($)
Media disposal fee ($)
Subtotal
Media replacement and disposal cost
($71,000 gal)
$150
160
$24,000
$2,120
$680
$26,800
See Figure 4-15
Vendor quote
Both vessels
Vendor quote
Vendor quote
Vendor quote
Vendor quote
Based upon media run length at 10-|ag/L
arsenic breakthrough
Chemical Usage
Chemical cost ($)
$0.000
No additional chemicals required.
Electricity
Electric utility charge ($/kWh)
Usage (kWh)
Total electricity cost ($)
Electricity cost ($71,000 gal)
$0.14
108
$15.12
$0.001
Rate provided by DSMDWCA
All prior to retrofit on May 16, 2004
-
$0.01/1,000 gal prior to retrofit
Labor
Average weekly labor (hrs)
Labor cost ($71,000 gal)
Total O&M cost ($71,000 gal)
1.75
$0.053
See Figure 4-15
15 minutes/day
Labor rate = $17/hr
Based upon media run length at 10-|j,g/L
arsenic breakthrough
The only chemical cost was the use sodium hypochlorite for prechlorination, which was in place prior to
the installation of the APU-300 system for the purpose of providing chlorine residual prior to distribution.
The APU-300 system did not change the use rate of the sodium hypochlorite solution. Therefore, the
chemical cost was negligible.
Electrical power consumption also was negligible, particularly since the system retrofit in May 2004.
After retrofitting, the electric meter stopped registering power consumption. The operator assumed that
the meter was faulty, and replaced it with a new and factory-tested meter, which also did not register any
power consumption. The APU-300 system did not consume enough electricity to register on the meter.
The routine, non-demonstration related labor activities consume only 15 minutes per day, as noted in
Section 4.4.5. Therefore, the labor cost is $0.053/1,000 gallons of water treated.
40
-------
5.0 REFERENCES
Battelle. 2003. Revised Quality Assurance Project Plan for Evaluation of Arsenic Removal Technology.
Prepared under Contract No. 68-C-00-185, Task Order No. 0019, for U.S. EPA NRMRL.
November 17.
Battelle. 2004. Final System Performance Evaluation Study Plan: U.S. EPA Demonstration of Arsenic
Removal Technology at Desert Sands MDWCA in Anthony, New Mexico. Prepared under
Contract No. 68-C-00-185, Task Order No. 0019 for U.S. EPA NRMRL. January 19.
Chen, A.S.C., L. Wang, J. Oxenham, and W. 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. EPA NRMRL, Cincinnati, OH.
Desert Sands MDWCA. 2002a. 40 Year Water Plan 2003-2004. July 18.
Desert Sands MDWCA. 2002b. Consumer Confidence Report for 2002.
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 (March): 103-113.
Knocke, W.R., et al. 1987. "Using Alternative Oxidants to Remove Dissolved Manganese from Waters
Laden with Organics." J. AWWA (March), 79:3:75.
Knocke, W.R., et al. 1990. Alternative Oxidants for the Remove of Soluble Iron and Manganese. Final
report prepared for the AWWA Research Foundation, AWWARF, Denver, Colorado (March).
Severn Trent Services. 2004. Operation and Maintenance Manual, Model APU-300, Desert Sands
MDWCA (Anthony), NM. June 30.
U.S. Environmental Protection Agency. 2003. Minor Clarification of the National Primary Drinking
Water Regulation for Arsenic. Federal Register, 40 CFR Part 141. March 25.
U.S. Environmental Protection Agency. 2002. Lead and Copper Monitoring and Reporting Guidance
for Public Water Systems. Prepared by EPA's Office of Water. EPA/816/R-02/009. February.
U.S. Environmental Protection Agency. 2001. National Primary Drinking Water Regulations: Arsenic
and Clarifications to Compliance and New Source Contaminants Monitoring. Fed. Register.,
66:14:6975. January 22.
Wang, L., W. Condit, and A. Chen. 2004. Technology Selection and System Design: U.S. EPA Arsenic
Removal Technology Demonstration Program Round 1. EPA/600/R-05/001. U.S. EPA
NRMRL, Cincinnati, OH.
41
-------
APPENDIX A
OPERATIONAL DATA
-------
EPA Arsenic Demonstration Project at Desert Sands MDWCA, NM - Daily System Operation Log Sheet
Week
No.
1
2
3
4
5
6
7
8
Date
01/23/04
01/24/04
01/25/04
01/26/04
01/27/04
01/28/04
01/29/04
01/30/04
01/31/04
02/01/04
02/02/04
02/03/04
02/04/04
02/05/04
02/09/04
02/10/04
02/11/04
02/12/04
02/13/04
02/16/04
02/17/04
02/18/04
02/19/04
02/20/04
02/23/04
02/24/04
02/25/04
02/26/04
02/27/04
02/28/04
02/29/04
03/01/04
03/02/04
03/03/04
03/04/04
03/05/04
03/06/04
03/07/04
03/08/04
03/09/04
03/10/04
03/11/04
03/12/04
03/13/04
03/14/04
Pump House
Pump
Hour
Meter
hr
15128.0
15132.9
15141.0
15146.0
15148.0
15153.0
15157.0
15161.0
15164.0
15168.0
15172.0
15177.6
15178.9
15186.9
15198.4
15198.8
15204.5
15209.2
15214.1
15228.2
15233.4
15238.4
15245.9
15251.4
15262.8
15267.1
15271.4
15275.3
15278.2
15282.2
15286.4
15290.5
15295.1
15299.1
15303.7
15310.6
15315.6
15321.5
15323.2
15326.0
15331.0
15336.8
15340.1
15343.5
15349.7
Opt
Hours
hr
0.0
4.9
8.1
5.0
2.0
5.0
4.0
4.0
3.0
4.0
4.0
5.6
1.3
8.0
11.5
0.4
5.7
4.7
4.9
14.1
5.2
5.0
7.5
5.5
11.4
4.3
4.3
3.9
2.9
4.0
4.2
4.1
4.6
4.0
4.6
6.9
5.0
5.9
1.7
2.8
5.0
5.8
3.3
3.4
6.2
Master Flow
Meter
Kgal
234,081
234,153
234,282
234,359
234,403
234,476
234,540
234,597
234,658
234,713
234,771
234,845
234,866
234,989
235,167
235,174
235,225
235,333
235,408
235,623
235,701
235,777
235,891
235,976
236,151
236,216
236,282
236,342
236,387
236,448
236,51 1
236,575
236,644
236,715
236,775
236,801
236,876
236,966
236,994
237,035
237,112
237,201
237,253
237,305
237,377
Avg
Flowrate
gpm
NA
245
265
257
367
243
267
238
339
227
244
221
264
256
258
292
150
382
256
254
250
253
253
258
256
252
256
256
259
254
250
260
250
296
217
63
250
254
275
244
257
256
263
255
194
APU
Electric
Meter
KWH
14
15
16
17
18
19
NR
33
34
35
35
38
40
NR
44
44
45
46
47
48
49
50
51
51
53
54
55
55
56
56
57
57
58
58
59
60
60
61
61
61
62
62
63
63
64
Instrument Panel
Flow Totalizer 1
gpm
150
off
off
off
off
150
off
off
off
off
off
off
120
off
off
120
120
120
off
off
off
120
off
off
off
off
120
off
off
off
off
off
off
120
off
off
120
120
120
off
110
off
off
off
off
Kgal
221
266
335
375
399
438
471
501
538
568
584
600
615
620
753
756
799
830
863
956
990
1,025
1,074
1,112
1,192
1,221
1,250
1,279
1,298
1,327
1,356
1,384
1,415
1,446
1,475
1,480
1,521
1,563
1,563
1,594
1,631
1,671
1,694
1,717
1,749
Cum. Bed
Volume
Totalizer 1
#of BV
75
190
257
297
362
417
467
528
578
605
632
657
665
887
892
963
1015
1070
1225
1282
1340
1422
1485
1618
1667
1715
1763
1795
1843
1892
1938
1990
2042
2090
2098
2167
2237
2237
2288
2350
2417
2455
2493
2547
Flow Totalizer 2
gpm
150
off
off
off
off
150
off
off
off
off
off
off
180
off
off
180
180
180
off
off
off
180
off
off
off
off
180
off
off
off
off
off
off
170
off
off
170
175
170
off
150
off
off
off
off
Kgal
216
259
327
367
391
428
461
491
526
558
603
663
681
757
868
872
926
969
1,015
1,111
1,158
1,207
1,277
1,328
1,436
1,476
1,516
1,555
1,582
1,623
1,660
1,698
1,740
1,782
1,820
1,836
1,883
1,936
1,936
1,977
2,022
2,083
2,105
2,137
2,180
Cum. Bed
Volume
Totalizer 2
#of BV
72
185
252
292
353
408
458
517
570
645
745
775
902
1087
1093
1183
1255
1332
1492
1570
1652
1768
1853
2033
2100
2167
2232
2277
2345
2407
2470
2540
2610
2673
2700
2778
2867
2867
2935
3010
3112
3148
3202
3273
Head Loss (psi)
Tank A
>15
off
off
off
off
>15
off
off
off
off
off
off
24
off
off
>15
>15
>15
off
off
off
>15
off
off
off
off
>15
off
off
off
off
off
off
>15
off
off
>15
>15
>15
off
>15
off
off
off
off
TankB
>15
off
off
off
off
>15
off
off
off
off
off
off
24
off
off
>15
>15
>15
off
off
off
>15
off
off
off
off
>15
off
off
off
off
off
off
>15
off
off
>15
>15
>15
off
>15
off
off
off
off
Pressure (psig)
Influent
76
52
56
58
54
78
54
60
60
60
55
60
80
52
NR
84
84
86
56
54
50
82
54
50
50
50
82
52
50
50
50
50
52
82
54
59
82
84
82
off
80
off
off
off
off
Effluent
56
52
56
58
54
60
54
60
60
60
55
60
56
52
NR
54
56
56
56
54
50
56
54
50
50
50
56
52
50
50
50
50
52
58
54
54
60
60
56
off
56
off
off
off
off
AP
psig
20
NA
NA
NA
NA
18
NA
NA
NA
NA
NA
NA
24
NA
NA
30
28
30
NA
NA
NA
26
NA
NA
NA
NA
26
NA
NA
NA
NA
NA
NA
24
NA
NA
22
24
26
NA
24
NA
NA
NA
NA
System
Back-
washed
Yes/No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
-------
EPA Arsenic Demonstration Project at Desert Sands MDWCA, NM - Daily System Operation Log Sheet (Continued)
Week
No.
9
10
11
12
13
14
15
Date
03/15/04
03/16/04
03/17/04
03/18/04
03/19/04
03/20/04
03/21/04
03/22/04
03/23/04
03/24/04
03/25/04
03/26/04
03/27/04
03/28/04
03/29/04
03/30/04
03/31/04
04/01/04
04/02/04
04/03/04
04/04/04
04/05/04
04/06/04
04/07/04
04/08/04
04/09/04
04/10/04
04/11/04
04/12/04
04/13/04
04/14/04
04/15/04
04/16/04
04/17/04
04/18/04
04/19/04
04/20/04
04/21/04
04/22/04
04/23/04
04/24/04
04/25/04
04/26/04
04/27/04
04/28/04
04/29/04
04/30/04
05/01/04
05/02/04
Pump House
Pump
Hour
Meter
hr
15352.7
15360.3
15367.2
15369.1
15377.5
15379.7
15383.0
15386.2
15390.2
15395.3
15401.1
15405.4
15409.0
15412.5
15416.8
15420.3
15424.6
15429.4
15432.3
15435.3
NR
15441.6
15444.5
15446.5
15450.4
15453.2
15456.7
15459.6
15462.8
15465.7
15468.9
15473.2
15476.6
15480.6
15484.0
15488.0
15491.6
15495.7
15498.6
15501.9
15505.7
15510.1
15513.9
15517.9
15521.9
15525.0
15528.8
15534.2
15539.3
Opt
Hours
hr
3.0
7.6
6.9
1.9
8.4
2.2
3.3
3.2
4.0
5.1
5.8
4.3
3.6
3.5
4.3
3.5
4.3
4.8
2.9
3.0
NA
6.3
2.9
2.0
3.9
2.8
3.5
2.9
3.2
2.9
3.2
4.3
3.4
4.0
3.4
4.0
3.6
4.1
2.9
3.3
3.8
4.4
3.8
4.0
4.0
3.1
3.8
5.4
5.1
Master Flow
Meter
Kgal
237,455
237,564
237,671
237,698
237,799
237,864
237,924
237,963
238,025
238,103
238,199
238,258
238,315
238,369
238,434
238,494
238,554
238,628
238,674
238,719
238,772
238,816
238,868
238,893
238,952
238,995
239,049
239,093
239,135
239,188
239,235
239,301
239,353
239,413
239,465
239,525
239,580
239,634
239,687
239,737
239,795
239,860
239,919
239,980
240,023
240,101
240,147
240,230
240,291
Avg
Flowrate
gpm
433
239
258
237
200
492
303
203
258
255
276
229
264
257
252
286
233
257
264
250
NA
116
299
208
252
256
257
253
219
305
245
256
255
250
255
250
255
220
305
253
254
246
259
254
179
419
202
256
199
APU
Electric
Meter
KWH
65
65
66
67
67
68
70
70
71
71
72
72
73
74
75
75
76
76
77
78
79
80
81
81
82
83
83
84
84
85
85
86
87
87
88
89
90
91
91
92
92
93
94
94
95
96
97
98
98
Instrument Panel
Flow Totalizer 1
gpm
110
off
110
115
off
115
off
115
off
115
off
off
off
off
off
off
off
off
off
off
off
off
off
110
off
off
off
off
120
120
110
110
110
110
110
110
110
110
110
110
110
110
110
off
off
off
120
110
110
Kgal
1,784
1,839
1,889
1,902
1,949
1,979
2,003
2,025
2,053
2,088
2,138
2,166
2,192
2,217
2,246
2,273
2,301
2,341
2,363
2,384
2,408
2,428
2,449
2,464
2,497
2,517
2,542
2,562
2,582
2,606
2,627
2,664
2,688
2,715
2,739
2,767
2,791
2,816
2,846
2,870
2,896
2,926
2,953
2,955
2,955
2,955
2,983
3,022
3,030
Cum. Bed
Volume
Totalizer 1
#of BV
2605
2697
2780
2802
2880
2930
2970
3007
3053
3112
3195
3242
3285
3327
3375
3420
3467
3533
3570
3605
3645
3678
3713
3738
3793
3827
3868
3902
3935
3975
4010
4072
4112
4157
4197
4243
4283
4325
4375
4415
4458
4508
4553
4557
4557
4557
4603
4668
4682
Flow Totalizer 2
gpm
140
off
140
155
off
160
off
160
off
155
off
off
off
off
off
off
off
off
off
off
off
off
off
150
off
off
off
off
140
140
140
140
140
140
140
140
140
140
140
140
140
140
140
140
140
140
140
140
140
Kgal
2,227
2,299
2,360
2,377
2,434
2,472
2,502
2,531
2,567
2,613
2,676
2,710
2,743
2,775
2,813
2,848
2,884
2,934
2,960
2,987
3,018
3,043
3,071
3,090
3,130
3,155
3,186
3,212
3,237
3,268
3,296
3,341
3,372
3,407
3,438
3,473
3,505
3,537
3,575
3,604
3,638
3,676
3,711
3,746
3,779
3,817
3,850
3,895
3,953
Cum. Bed
Volume
Totalizer 2
#of BV
3352
3472
3573
3602
3697
3760
3810
3858
3918
3995
4100
4157
4212
4265
4328
4387
4447
4530
4573
4618
4670
4712
4758
4790
4857
4898
4950
4993
5035
5087
5133
5208
5260
5318
5370
5428
5482
5535
5598
5647
5703
5767
5825
5883
5938
6002
6057
6132
6228
Head Loss (psi)
Tank A
>20
off
>20
>20
off
>20
off
>20
off
>20
off
off
off
off
off
off
off
off
off
off
off
off
off
>20
off
off
off
off
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
TankB
>20
off
>20
>20
off
>20
off
>20
off
>20
off
off
off
off
off
off
off
off
off
off
off
off
off
>20
off
off
off
off
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
Pressure (psig)
Influent
80
off
82
off
off
84
54
84
off
84
off
off
off
off
NR
NR
NR
NR
NR
NR
NR
NR
NR
60
NR
NR
NR
NR
82
82
84
84
82
84
84
84
84
82
82
80
80
80
82
82
82
82
82
82
82
Effluent
60
off
60
off
off
62
off
62
off
off
off
off
off
off
60
60
58
60
58
58
60
60
60
82
62
58
60
60
60
60
60
60
60
60
60
60
60
58
60
60
60
60
60
60
60
60
60
60
60
AP
psig
20
NA
22
NA
NA
22
NA
22
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
22
NA
NA
NA
NA
22
22
24
24
22
24
24
24
24
24
22
20
20
20
22
22
22
22
22
22
22
System
Back-
washed
Yes/No
Yes
Yes
Yes
Yes
Yes
Yes
>
-------
EPA Arsenic Demonstration Project at Desert Sands MDWCA, NM - Daily System Operation Log Sheet (Continued)
Week
No.
16
17
Date
05/03/04
05/04/04
05/05/04
05/06/04
05/07/04
05/08/04
05/09/04
05/10/04
05/11/04
05/12/04
05/13/04
05/14/04
05/15/04
05/16/04
Pump House
Pump
Hour
Meter
hr
15542.1
15546.0
15550.5
15557.1
15562.8
15569.0
15575.0
15580.7
15588.2
15592.2
15599.1
15602.4
15608.1
15621.0
Opt
Hours
hr
2.8
3.9
4.5
6.6
5.7
6.2
6.0
5.7
7.5
4.0
6.9
3.3
5.7
12.9
Master Flow
Meter
Kgal
240,360
240,400
240,478
240,577
240,664
240,759
240,849
240,936
241,034
241,110
241,215
241,266
241,353
241,554
Avg
Flowrate
gpm
411
171
289
250
254
255
250
254
218
317
254
258
254
260
APU
Electric
Meter
KWH
99
100
101
101
102
102
103
103
104
105
106
106
107
108
Instrument Panel
Flow Totalizer 1
gpm
110
110
110
110
110
110
110
110
110
110
110
110
110
110
Kgal
3,077
3,104
3,136
3,188
3,229
3,274
3,315
3,356
3,402
3,436
3,493
3,517
3,557
3,663
Cum. Bed
Volume
Totalizer 1
#of BV
4760
4805
4858
4945
5013
5088
5157
5225
5302
5358
5453
5493
5560
5737
Flow Totalizer 2
gpm
140
140
140
140
140
140
140
150
150
140
145
140
140
140
Kgal
3,968
4,002
4,042
4,107
4,157
4,210
4,262
4,312
4,368
4,412
4,478
4,507
4,557
4,649
Cum. Bed
Volume
Totalizer 2
#of BV
6253
6310
6377
6485
6568
6657
6743
6827
6920
6993
7103
7152
7235
7388
Head Loss (psi)
Tank A
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
TankB
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
>20
Pressure (psig)
Influent
82
82
80
80
82
80
80
82
80
80
80
80
80
80
Effluent
60
60
60
60
60
60
60
60
58
60
60
60
60
60
AP
psig
22
22
20
20
22
20
20
22
22
20
20
20
20
20
System
Back-
washed
Yes/No
Yes
>
System was turned off for repairing
19
20
21
22
05/24/04
05/25/04
05/26/04
05/27/04
05/28/04
05/29/04
05/30/04
05/31/04
06/01/04
06/02/04
06/03/04
06/04/04
06/05/04
06/06/04
06/07/04
06/08/04
06/09/04
06/10/04
06/11/04
06/12/04
06/13/04
06/14/04
06/15/04
06/16/04
06/1 7/04
06/18/04
06/19/04
06/20/04
15625.6
15632.6
15638.8
15644.6
15648.4
15657.3
15663.7
15670.2
15679.0
15686.8
15693.7
15699.0
15705.8
15712.2
15721.4
15728.1
15738.5
15747.7
15752.1
15761.6
15767.7
15778.0
15787.2
15794.7
15804.4
15812.5
15821.4
15827.4
4.6
7.0
6.2
5.8
3.8
8.9
6.4
6.5
8.8
7.8
6.9
5.3
6.8
6.4
9.2
6.7
10.4
9.2
4.4
9.5
6.1
10.3
9.2
7.5
9.7
8.1
8.9
6.0
241,646
241,746
241,846
241,940
242,002
242,146
242,248
242,353
242,498
242,617
242,725
242,810
242,917
243,018
243,164
243,270
243,432
243,576
243,645
243,795
243,891
244,054
244,203
244,321
244,477
244,606
244,747
244,843
333
238
269
270
272
270
266
269
275
254
261
267
262
263
264
264
260
261
261
263
262
264
270
262
268
265
264
267
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
140
145
145
off
off
145
140
135
135
140
off
off
135
140
off
135
140
135
135
off
off
off
150
off
135
off
off
off
3,663
3,705
3,759
3,809
3,842
3,919
3,972
4,029
4,104
4,166
4,223
4,266
4,321
4,373
4,446
4,499
4,580
4,652
4,680
4,761
4,808
4,837
4,910
4,972
5,055
5,123
5,198
5,248
5737
5807
5897
5980
6035
6163
6252
6347
6472
6575
6670
6742
6833
6920
7042
7130
7265
7385
7432
7567
7645
7693
7815
7918
8057
8170
8295
8378
135
140
145
off
off
145
140
135
135
135
off
off
140
145
off
140
145
140
130
off
off
off
150
off
135
off
off
off
4,649
4,752
4,779
4,820
4,852
4,929
4,983
5,040
5,116
5,179
5,231
5,283
5,341
5,396
5,476
5,534
5,621
5,700
5,739
5,821
5,872
5,970
6,054
6,116
6,197
6,263
6,337
6,387
7388
7560
7605
7673
7727
7855
7945
8040
8167
8272
8358
8445
8542
8633
8767
8863
9008
9140
9205
9342
9427
9590
9730
9833
9968
10078
10202
10285
3
3
3
off
off
3
3
3
3
3
off
off
4
3
off
3
5
5
6
off
off
off
3
off
4
off
off
off
3
3
3
off
off
3
3
3
3
3
off
off
4
3
off
3
5
6
8
off
off
off
3
off
4
off
off
off
66
68
64
52
52
56
62
66
68
60
off
off
60
56
off
56
62
67
64
off
off
off
66
off
70
off
off
off
60
62
58
52
52
50
56
60
62
54
52
50
52
50
58
50
52
56
58
52
58
58
60
62
62
58
60
52
6
6
6
NA
NA
6
6
6
6
6
NA
NA
8
6
NA
6
10
11
6
NA
NA
NA
6
NA
8
NA
NA
NA
Yes
Yes
Yes
-------
EPA Arsenic Demonstration Project at Desert Sands MDWCA, NM - Daily System Operation Log Sheet (Continued)
Week
No.
23
24
25
26
Date
06/21/04
06/22/04
06/23/04
06/24/04
06/25/04
06/26/04
06/27/04
06/28/04
06/29/04
06/30/04
07/01/04
07/02/04
07/03/04
07/04/04
07/05/04
07/06/04
07/07/04
07/08/04
07/09/04
07/10/04
07/11/04
07/12/04
07/13/04
07/14/04
07/15/04
07/16/04
Pump House
Pump
Hour
Meter
hr
15842.4
15851.5
15857.0
15866.8
15872.6
15879.0
15885.0
15891.4
15898.7
15904.2
15911.0
15916.9
15927.1
15932.4
15940.7
15949.8
15955.9
15969.3
15977.3
15987.2
15995.2
16003.5
16008.2
16021.6
16029.9
16036.9
Opt
Hours
hr
15.0
9.1
5.5
9.8
5.8
6.4
6.0
6.4
7.3
5.5
6.8
5.9
10.2
5.3
8.3
9.1
6.1
13.4
8.0
9.9
8.0
8.3
4.7
13.4
8.3
7.0
Master Flow
Meter
Kgal
245,019
245,164
245,251
245,407
245,509
245,602
245,706
245,794
245,91 1
245,999
246,109
246,205
246,368
246,455
246,588
246,735
246,832
247,046
247,175
247,333
247,468
247,597
247,672
247,886
248,022
248,136
Avg
Flowrate
gpm
196
266
264
265
293
242
289
229
267
267
270
271
266
274
267
269
265
266
269
266
281
259
266
266
273
271
APU
Electric
Meter
KWH
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
112
102
0
0
0
down
down
down
down
down
Instrument Panel
Flow Totalizer 1
gpm
140
off
150
off
off
140
off
130
off
125
145
145
off
off
135
off
140
off
off
off
135
135
off
off
off
140
Kgal
5,349
5,415
5,461
5,542
5,589
5,643
5,697
5,742
5,803
5,849
5,907
5,958
6,045
6,090
6,158
6,227
6,277
6,384
6,453
6,535
6,603
6,667
6,703
6,815
6,886
6,947
Cum. Bed
Volume
Totalizer 1
#of BV
8547
8657
8733
8868
8947
9037
9127
9202
9303
9380
9477
9562
9707
9782
9895
10010
10093
10272
10387
10523
10637
10743
10803
10990
11108
11210
Flow Totalizer 2
gpm
145
off
150
off
off
135
off
130
off
125
145
145
off
off
140
off
145
off
off
off
140
135
off
off
off
135
Kgal
6,479
6,555
6,600
6,683
6,732
6,786
6,841
6,887
6,948
6,994
7,051
7,101
7,189
7,230
7,301
7,385
7,437
7,554
7,621
7,705
7,777
7,848
7,891
8,006
8,076
8,137
Cum. Bed
Volume
Totalizer 2
#of BV
10438
10565
10640
10778
10860
10950
11042
11118
11220
11297
11392
11475
11622
11690
11808
11948
12035
12230
12342
12482
12602
12720
12792
12983
13100
13202
Head Loss (psi)
Tank A
3
off
3
off
off
6
off
8
off
10
3
3
off
off
4
off
4
off
off
off
6
3
off
off
off
3
TankB
3
off
3
off
off
6
off
8
off
10
3
3
off
off
3
off
3
off
off
off
6
3
off
off
off
3
Pressure (psig)
Influent
60
off
58
off
off
72
off
76
off
80
62
58
off
off
62
off
63
off
off
off
68
62
off
off
off
62
Effluent
56
off
52
58
60
60
58
60
62
60
56
52
60
58
56
52
54
58
60
62
56
56
54
56
56
56
AP
psig
4
NA
6
NA
NA
12
NA
16
NA
20
6
6
NA
NA
6
NA
9
NA
NA
NA
12
6
NA
NA
NA
6
System
Back-
washed
Yes/No
Yes
Yes
>
Note: 4/27/04 - 4/29/04 Unit A Flow meter quit working and worked again on 4/29/04
Green highlight indicates a calculated value
NR = No reading; NA = Not available
-------
APPENDIX B
ANALYTICAL DATA
-------
Analytical Results from Long-Term Sampling, Desert Sands MDWCA
Sampling Date
Sampling Location
Parameter Unit
Alkalinity
Fluoride
Sulfate
orthophosphate
Silica (as SiO2)
Sulfide
N03-(N)
Turbidity
PH
Temperature
DO
ORP
Free Chlorine
Total Hardness
Ca Hardness
Mg Hardness
As (total)
As (total soluble)
As (particulate)
As (III)
As(V)
Total Fe
Dissolved Fe
Total Mn
Dissolved Mn
mg/L(a)
mg/L
mg/L
mg/L
mg/L
jjg/L
mg/L
NTU
-
°C
mg/L
mV
mg/L
mg/L«
mg/L(a)
mg/L«
jjg/L
jjg/L
jjg/L
jjg/L
re/L
jjg/L
jjg/L
jjg/L
jjg/L
1/23/04°°
IN
173
0.5
180
0.2
41.8
<5
<0.05
3.5
7.8
28.7
1.0
NA
NA
81.1
65.5
15.6
26.1
23.2
2.9
17.6
5.6
45
<25
9.1
9.4
AC
173
0.5
170
0.2
41.7
NA
<0.05
1.2
7.9
29.4
1.4
NA
0.5
80.7
67.5
13.2
26.7
23.0
3.7
1.1
21.9
43
<25
8.4
8.1
TT
173
0.5
180
0.2
37.2
NA
<0.05
0.1
7.9
29.7
2.3
NA
0.3
81.5
67.6
13.9
1.5
1.2
0.2
0.9
0.3
<25
<25
0.2
0.1
1/28/04
IN
173
<0.10
40.5
0.2
8.1
28.4
1.9
NA
NA
26.0
73
10.1
AC
173
<0.10
40.8
0.2
8.0
28.8
2.0
NA
0.3
25.9
70
10.3
TA
169
<0.10
38.5
0.1
8.0
28.9
•=-5
2.0
NA
0.3
1.9
<25
0.3
TB
169
<0.10
39.2
<0.1
7.9
29.0
1.9
NA
0.3
1.5
<25
0.1
2/4/04
IN
180
<0.10
36.4
0.5
8.1
30.2
1.1
NA
NA
26.2
106
9.4
AC
176
<0.10
37.3
NA
0.8
8.0
29.5
1.8
NA
NA
27.0
112
9.5
TA
180
<0.10
35.3
NA
0.2
7.9
29.9
1.5
NA
0.4
2.0
45
0.1
TB
178
<0.10
36.4
NA
0.2
7.9
29.8
1.5
NA
0.4
1.7
35
0.1
2/11/04
IN
186
<0.10
36.6
0.4
7.9
29.9
1.0
NA
NA
25.3
98
9.6
AC
190
<0.10
37.4
0.5
7.9
30.0
1.6
NA
NA
27.5
97
9.0
TA
186
<0.10
36.2
0.2
7.9
30.2
1.5
NA
NA
2.0
46
0.1
TB
182
<0.10
37.0
0.2
7.9
29.9
1.4
NA
NA
2.0
42
0.2
(a) Measured as CaCO3.
(b) Water quality parameters sampled on January 27, 2004.
IN = inlet; AC = after prechlorination; TA = after tank A; TB = after tank B; TT = after tanks combined.
NA = not analyzed.
-------
Analytical Results from Long Term Sampling, Desert Sands MDWCA
Sampling Date
Sampling Location
Parameter Unit
Alkalinity
Fluoride
Sulfate
orthophosphate
Silica
Sulfide
NO3-(N)
Turbidity
PH
Temperature
DO
ORP
Free Chlorine
Total Chlorine
Total Hardness
Ca Hardness
Mg Hardness
As (total)
As (total soluble)
As (particulate)
As (III)
As(V)
Total Fe
Dissolved Fe
Total Mn
Dissolved Mn
mg/L(a)
mg/L
mg/L
mg/L
mg/L
re/L
mg/L
NTU
-
°C
mg/L
mV
mg/L
mg/L
mg/L(a)
mg/L(a)
mg/L(a)
jjg/L
jjg/L
jjg/L
jjg/L
re/L
re/L
re/L
re/L
re/L
2/18/04
IN
193
0.6
190
<0.10
38.4
<0.08
2.4
7.8
29.8
1.2
NA
NA
NA
89.4
71.9
17.5
28.6
23.9
4.7
22.8
1.1
55
<25
9.9
9.0
AC
191
0.6
190
<0.10
39.0
<0.08
0.2
7.9
30.1
1.3
NA
0.4
0.5
87.4
70.7
16.7
28.7
23.6
5.1
1.1
22.6
36
<25
9.4
6.0
TT
189
0.6
190
<0.10
38.2
<0.08
0.7
7.9
30.2
1.4
NA
0.4
0.5
89.2
71.1
18.1
1.5
1.4
0.1
1.1
0.3
<25
<25
0.3
0.1
2/25/04
IN
185
<0.10
39.3
0.3
7.9
29.7
1.2
NA
NA
NA
27.6
35
9.7
AC
185
<0.10
38.9
0.3
7.9
28.9
1.2
NA
0.4
0.5
27.9
31
9.5
TA
185
<0.10
39.0
0.1
7.9
29.0
5.2
1.1
NA
0.4
0.5
1.7
<25
0.1
TB
185
<0.10
38.5
0.1
7.9
29.4
1.6
NA
0.4
0.5
1.5
<25
0.1
3/3/04
IN
177
<0.10
37.9
0.3
7.9
29.9
1.3
NA
NA
NA
29.8
39
9.5
AC
179
<0.10
37.3
NA
0.1
7.9
29.7
1.3
NA
NA
NA
28.6
30
9.1
TA
179
<0.10
37.9
NA
0.2
NA
NA
NA
NA
NA
NA
1.8
<25
0.1
TB
181
<0.10
38.3
NA
<0.1
NA
NA
NA
NA
NA
NA
1.7
<25
0.1
3/10/04
IN
181
<0.10
36.4
0.4
8.0
30.4
1.3
NA
NA
NA
23.0
53
8.3
AC
189
<0.10
36.4
0.3
7.9
30.8
1.2
NA
0.4
0.5
23.2
47
8.2
TA
185
<0.10
36.0
0.2
7.8
30.6
1.2
NA
0.4
0.5
1.4
<25
0.2
TB
181
<0.10
36.3
0.2
7.8
30.6
1.2
NA
0.4
0.5
1.4
<25
0.3
(a) Measured as CaCO3.
IN = inlet; AC = after chlorination; TA = after tank A; TB = after the tank B; TT = after tanks combined.
-------
Analytical Results from Long Term Sampling, Desert Sands MDWCA
Sampling Date
Sampling Location
Parameter Unit
Alkalinity
Fluoride
Sulfate
orthophosphate
Silica
Sulfide
NO3-(N)
Turbidity
PH
Temperature
DO
ORP
Free Chlorine
Total Chlorine
Total Hardness
Ca Hardness
Mg Hardness
As (total)
As (total soluble)
As (particulate)
As (III)
As(V)
Total Fe
Dissolved Fe
Total Mn
Dissolved Mn
mg/L(a)
mg/L
mg/L
mg/L
mg/L
re/L
mg/L
NTU
-
°C
mg/L
mV
mg/L
mg/L
mg/Lw
mg/L(a)
mg/L(a)
jjg/L
jjg/L
jjg/L
jjg/L
re/L
re/L
re/L
re/L
re/L
3/17/04
IN
182
0.5
190
<0.10
38.7
<0.05
0.5
7.9
30.4
1.3
NA
NA
NA
78.4
63.9
14.5
22.6
22.4
0.2
20.7
1.7
49
<25
8.5
7.5
AC
182
0.5
180
<0.10
38.4
<0.05
0.2
7.9
30.4
1.2
NA
0.4
0.5
82.1
67.4
14.7
22.3
22.1
0.2
0.5
21.6
32
<25
7.6
5.3
TT
178
0.5
190
<0.10
38.6
<0.05
0.2
7.9
30.6
1.3
NA
0.4
0.5
81.9
66.6
15.3
0.9
0.8
0.1
0.3
0.5
<25
<25
<0.1
<0.1
3/24/04
IN
189
<0.10
38.5
0.4
7.9
30.4
1.5
NA
NA
NA
25.9
33
8.4
AC
189
<0.10
38.3
0.3
7.9
31.0
1.2
NA
0.4
0.5
25.9
30
7.9
TA
185
<0.10
38.0
0.1
7.9
30.9
5.7
1.1
NA
0.5
0.5
2.4
<25
0.1
TB
193
<0.10
38.4
0.1
7.8
31.1
1.1
NA
0.4
0.5
2.5
<25
0.1
3/31/04
IN
183
<0.10
37.9
1.0
7.8
30.2
1.2
NA
NA
NA
20.7
71
9.0
AC
181
<0.10
37.2
NA
1.5
7.9
30.6
1.2
NA
0.5
0.6
21.2
69
9.4
TA
185
<0.10
37.6
NA
0.5
7.9
31.0
1.3
NA
0.5
0.6
1.8
<25
<0.1
TB
181
<0.10
37.8
NA
0.2
7.9
31.0
1.1
NA
NA
NA
1.9
<25
0.1
4/7/04
IN
180
<0.10
39.4
0.9
NA
NA
NA
NA
NA
NA
30.1
<25
7.5
AC
180
<0.10
40.2
1.0
NA
NA
NA
NA
NA
NA
30.1
<25
7.3
TA
184
<0.10
39.9
0.2
NA
NA
NA
NA
NA
NA
1.9
<25
0.1
TB
180
<0.10
40.0
0.4
NA
NA
NA
NA
NA
NA
1.8
<25
0.1
(a) Measured as CaCO3.
IN = inlet; AC = after chlorination; TA = after tank A; TB = after the tank B; TT = after tanks combined.
-------
Analytical Results from Long Term Sampling, Desert Sands MDWCA
Sampling Date
Sampling Location
Parameter Unit
Alkalinity
Fluoride
Sulfate
orthophosphate
Silica
Sulfide
N03-(N)
Turbidity
PH
Temperature
DO
ORP
Free Chlorine
Total Chlorine
Total Hardness
Ca Hardness
Mg Hardness
As (total)
As (total soluble)
As (particulate)
As (III)
As(V)
Total Fe
Dissolved Fe
Total Mn
Dissolved Mn
mg/Lw
mg/L
mg/L
mg/L
mg/L
|xg/L
mg/L
NTU
-
°C
mg/L
mV
mg/L
mg/L
mg/L(a)
mg/Lw
mg/L(a)
re/L
|xg/L
Hg/L
|xg/L
|xg/L
re/L
Hg/L
re/L
Hg/L
4/14/04
IN
164
0.7
190
<0.10
38.2
0.05
0.6
7.9
29.6
1.3
42
NA
NA
85.7
71.1
14.6
28.5
24.8
3.7
22.0
2.8
<25
<25
8.3
8.0
AC
170
0.7
190
<0.10
38.1
0.05
0.3
7.9
29.5
1.3
550
0.4
0.5
85.3
70.9
14.4
29.6
24.7
4.9
1.1
23.6
<25
<25
8.1
6.2
TT
178
0.7
180
<0.10
37.6
0.05
0.3
8.0
29.5
1.3
561
0.5
0.6
84.0
69.4
14.6
1.5
1.6
<0.1
0.9
0.7
<25
<25
0.2
0.1
4/30/04
IN
199
38.1
7.9
30.3
1.2
48
NA
NA
24.2
32
9.1
AC
175
38.0
7.9
30.6
1.2
542
0.4
0.5
23.6
27
7.9
TA
199
38.0
180
7.9
30.1
1.1
521
0.4
0.5
1.7
<25
0.5
TB
179
37.9
7.8
30.5
1.2
525
0.4
0.5
1.6
<25
0.5
5/12/04
IN
194
0.6
<0.10
37.4
<5
<0.05
0.7
7.8
30.7
1.2
52
NA
NA
101.1
83.7
17.4
25.8
22.0
3.8
21.2
0.8
<25
7.0
7.1
AC
194
0.6
180
<0.10
37.5
NA
<0.05
0.6
7.8
30.9
1.1
537
0.4
0.5
111.1
91.9
19.2
25.4
20.3
5.1
0.9
19.4
<25
<25
7.1
5.9
TT
188
0.6
180
<0.10
37.7
NA
<0.05
0.5
7.8
31.2
1.3
541
0.4
0.5
110.1
86.6
23.5
1.6
1.4
0.2
0.8
0.6
<25
<25
<0.1
<0.1
5/26/04
IN
226
194
<0.10
<0.10
38.3
38.1
2.8
1.5
7.9
31.0
1.2
62
NA
NA
21.4
21.2
64
51
9.9
9.1
AC
190
186
<0.10
<0.10
37.3
37.1
0.8
0.5
7.8
31.3
1.1
525
0.5
0.6
21.7
21.7
40
38
8.6
8.4
TA
194
190
<0.10
<0.10
37.9
37.1
0.4
0.7
7.8
31.2
1.6
503
0.5
0.6
1.7
2.0
<25
<25
0.3
0.3
TB
194
194
<0.10
<0.10
37.6
37.2
0.5
0.8
7.7
31.1
1.5
510
0.5
0.6
2.1
2.4
<25
<25
0.3
0.3
CO
(a) Measured as CaCO3.
IN = inlet; AC = after chlorination;
TA = after tank A; TB = after the tank B; TT = after tanks combined.
<25
-------
Analytical Results from Long Term Sampling, Desert Sands MDWCA
Sampling Date
Sampling Location
Parameter Unit
Alkalinity
Fluoride
Sulfate
orthophosphate
Silica
Sulfide
NO3-(N)
Turbidity
PH
Temperature
DO
ORP
Free Chlorine
Total Chlorine
Total Hardness
Ca Hardness
Mg Hardness
As (total)
As (total soluble)
As (particulate)
As (III)
As(V)
Total Fe
Dissolved Fe
Total Mn
Dissolved Mn
mg/Lw
mg/L
mg/L
mg/L
mg/L
Hg/L
mg/L
NTU
-
°C
mg/L
mV
mg/L
mg/L
mg/Lw
mg/L(!l)
mg/Lw
Mg/L
Mg/L
Hg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
06/09/04
IN
187
0.6
170
<0.10
37.8
<0.04
2.7
7.8
31.6
1.8
55
NA
NA
89.8
72.5
17.3
25.1
23.1
2.0
22.6
0.5
50
<25
11.0
10.5
AC
187
0.6
170
<0.10
37.8
<0.04
0.6
7.8
31.5
1.4
488
0.4
0.5
90.1
73.0
17.1
25.4
23.5
1.9
NA
NA
28
<25
8.8
9.2
TT
182
0.6
180
<0.10
37.2
<0.04
0.3
7.7
31.6
1.7
495
0.5
0.5
86.6
70.1
16.5
3.0
2.8
0.2
1.8
1.0
<25
<25
0.8
0.5
06/23/04
IN
195
<0.10
38.7
<5
0.8
7.7
31.1
1.7
$§0
NA
NA
<0.2
25.0
36
7.9
AC
179
<0.10
38.3
NA
0.7
7.7
31.3
1.5
501
0.5
0.5
25.6
34
7.7
TA
171
<0.10
38.1
NA
0.4
7.7
30.9
1.5
631
0.5
0.5
2.4
<25
<0.1
TB
175
<0.10
38.9
NA
0.5
7.7
30.8
1.4
528
0.4
0.5
2.8
<25
<0.1
07/07/04
IN
197
0.6
<0.10
38.0
0.2
7.6
30.6
1.3
81
NA
NA
80.2
64.1
16.1
23.7
21.9
1.8
21.0
0.9
58
8.9
8.6
AC
197
0.6
190
<0.10
37.9
<0.2
0.2
7.7
31.2
1.2
486
0.4
0.4
79.2
63.1
16.1
23.9
22.5
1.4
1.1
21.4
50
<25
9.4
5.7
TT
189
0.6
190
<0.10
38.2
<0.2
0.1
7.6
31.0
1.5
502
0.4
0.5
74.5
60.6
13.9
2.8
2.6
0.2
1.2
1.4
<25
<25
0.5
0.3
(a) Measured as CaCO3.
IN = inlet; AC = after chlorination; TA = after tank A; TB = after the tank B; TT = after tanks combined.
NA = not available.
------- |