September 2001
NSF 01/24/EPADW395
Environmental Technology
Verification Report
Physical Removal of Giardia- and
Cryptosporidium-Sized Particles in
Drinking Water
Lapoint Industries
Aqua-Rite Potable Water Filtration
System
Prepared by
®
NSF International
Under a Cooperative Agreement with
&ERA U.S. Environmental Protection Agency
eiVetVeiV
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THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM
&EPA
I'KUliK VM ^
ETV
U.S. Emironmental Protection Agency NSF International
ETV Joint Verification Statement
TECHNOLOGY TYPE:
BAG FILTRAION USED IN DRINKING WATER
TREATMENT SYSTEMS
APPLICATION:
REMOVAL OF GIARDIA- AND CRYPTOSPORIDIUM-SIZED
PARTICLES IN DRINKING WATER
TECHNOLOGY NAME:
AQUA-RITE POTABLE WATER FILTRATION SYSTEM
COMPANY:
LAPOINT INDUSTRIES
ADDRESS:
48 COMMERCIAL STREET
PHONE: (207) 777-3100
LEWISTON, ME 04240
FAX: (207) 777-3177
WEB SITE:
www.lapointindustries.com
EMAIL:
dmosley@lapointindustries.com
The U.S. Environmental Protection Agency (EPA) has created the Environmental Technology
Verification (ETV) Program to facilitate the deployment of innovative or improved environmental
technologies through performance verification and dissemination of information. The goal of the ETV
program is to further environmental protection by substantially accelerating the acceptance and use of
improved and more cost-effective technologies. ETV seeks to achieve this goal by providing high
quality, peer reviewed data on technology performance to those involved in the design, distribution,
permitting, purchase, and use of environmental technologies.
ETV works in partnership with recognized standards and testing organizations; stakeholders groups which
consist of buyers, vendor organizations, and permitters; and with the full participation of individual
technology developers. The program evaluates the performance of innovative technologies by developing
test plans that are responsive to the needs of stakeholders, conducting field or laboratory tests (as
appropriate), collecting and analyzing data, and preparing peer reviewed reports. All evaluations are
conducted in accordance with rigorous quality assurance protocols to ensure that data of known and
adequate quality are generated and that the results are defensible.
NSF International (NSF) in cooperation with the EPA operates the Drinking Water Treatment Systems
(DWTS) Pilot, one of 12 technology areas under ETV. The DWTS Pilot recently evaluated the
performance of a bag filtration system used in package drinking water treatment system applications. This
verification statement provides a summary of the test results for the Lapoint Industries Aqua-Rite Potable
Water Filtration System. Gannett Fleming, an NSF-qualified field testing organization (FTO), performed
the verification testing.
01/24/EPADW395 The accompanying notice is an integral part of this verification statement. September 2001
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ABSTRACT
Verification testing of the Lapoint Industries Aqua-Rite Potable Water Filtration System was conducted
from April of 2000 to January of 2001. The treatment system consisted of a prefilter and a bag filter
connected in series. The treatment system underwent microsphere removal challenge testing at 0%
headloss of the bag filter, at 50% headloss of the bag filter and at greater than 90% headloss of the bag
filter. The microsphere challenges utilized microspheres of 3.7|_im and 6,0|_im size, which were selected
due to their similarity in size to Cryptosporidium oocysts and Giardia cysts, respectively. The treatment
system demonstrated a 3.2 logio removal of the 3.7 |_im microspheres and a 3.5 logio removal of the 6,0|_im
microspheres during the 0% headloss challenge. The system demonstrated 1.9 log10 removal of the
3.7|_im microspheres and a 2.4 log10 removal of the 6,0|_im microspheres during the 50% headloss
challenge. The system demonstrated 2.2 logio removal of the 3.7|_im microspheres and a 2.6 logio removal
of the 6,0|_im microspheres during the greater 90% headloss challenge. Source water characteristics were:
turbidity average 0.75 Nephlometric Turbidity Units (NTU), pH 7.1, and temperature 12.1°C. During the
verification test, the system was operated at a flow rate of 20.69 gallon per minute (gpm). Each bag filter
was operated to the 25 pounds per square inch (psi) of headloss and filtered on average 92,900 gallons. At
approximately 20 gpm, each filter bag was in service for an average of 98 hours before changeout was
required. Filter changeout was done manually and took approximately five minutes to complete. A total
of eight bag filters and three prefilters were used during the testing.
TECHNOLOGY DESCRIPTION
Bag filtration is generally used for the removal of particulate material from ground water or high quality
surface waters with turbidity less than or equal to 1 NTU that do not contain fine colloidal clays or algae.
The Aqua-rite Potable Water Filtration System consisted of a prefilter mounted in a pressure vessel and a
bag filter mounted in a pressure vessel A bag filter is defined as a non-rigid, disposable, fabric filter in
which flow generally is from the inside of bag to the outside. The filter bags are contained within pressure
vessels designed to facilitate rapid change of the filter bags when the filtration capacity has been used up.
The Aqua-Rite Potable Water Filtration System does not employ any chemical coagulation. The
pretreatment employed consists of prefiltration. The manufacturer reports that the pore sizes in the filter
bags designed for protozoa removal are generally small enough to remove protozoan cysts and oocysts
but large enough that bacteria, viruses and fine colloidal clays would pass through.
The treatment system required a pressurized stream of feed water. Water passes first through the prefilter,
which removes larger particulate material. This serves to exclude the larger debris from the feed water,
which would tend to clog the finer pored bag filter and cause premature clogging of the bag. After
prefiltration, the water passes through the bag filter itself where the finer particulate is removed.
VERIFICATION TESTING DESCRIPTION
Test Site
The verification testing site was Burnside Borough's water system chlorination station located in the
Borough of Burnside, Clearfield County, Pennsylvania. The chlorination building is located on Cemetery
Road approximately 1 'A mile west of U.S. Route 219. The Aqua-Rite Filtration System was installed in
the basement of the Burnside Borough's chlorination building.
The source water for he verification testing was from the water system's 208,000 gallon in-ground
covered reservoir located approximately 100 feet in elevation and about one-half mile away from the
chlorination building, which housed the treatment unit. The reservoir is primarily supplied by a natural
spring identified as Spring No. 1 via gravity feed. Spring No. 2, a secondary supply that must be pumped
up to the reservoir, was used on 208 days in 1999. A third spring, Chura Spring, flows into Spring No. 2.
01/24/EPADW395 The accompanying notice is an integral part of this verification statement. September 2001
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There is a well that supplements the production of the springs at the reservoir site. It is used only on an as
needed basis when the production from the springs is inadequate to meet system demand.
Methods and Procedures
All field analyses (i.e. pH, turbidity and temperature) were conducted daily using portable field
equipment according to Standard Methods for the Examination of Water and Waste Water, 18th Ed.,
(APHA, et. al., 1992). Likewise, Standard Methods, 19th Ed., (APHA, 1995) were used for analyses
conducted by CWM laboratory. These analyses included total alkalinity, total hardness, iron, manganese,
total organic carbon (TOC), algae (number and species), and total coliform, Total alkalinity, total
hardness, total coliform and TOC analyses were conducted monthly. Iron and manganese analyses were
conducted twice during the verification testing. Algae analyses were conducted weekly.
Microsphere removal challenge testing was performed using fluorescent microspheres of 3.7|_im and
6,0|_im size. These sizes were selected due to their similarity in size to Cryptosporidium oocysts and
Giardia cysts respectively. There were four separate challenges conducted. The first challenge was
conducted at 0% of the terminal headloss of the bag filter the second and third challenges were done at
approximately 50% of the terminal headloss of the bag filter, and the last challenge was conducted at
greater than 90% of the terminal headloss of the bag filter. The seeding, sampling, and analyses were
conducted using methods as outlined in the Protocol for Equipment Verification Testing for the Physical
Removal of Microbiological and Particulate Contaminants (EPA/NSF, 1999). The microspheres were
added to 500 ml of deionized water to which 0.01% of Tween 20 had been added. This suspension was
constantly mixed and added as a slug dose to the treatment system using diaphragm pumps. The pumps
were operated at about 250 ml per minute and were capable of overcoming the pressure in the feed water
line of the pilot unit. Samples of the filtrate were collected into five gallon containers at a flow rate 10%
of the system flow. A total of 20 gallons was collected and shipped to the laboratory for analysis. In
addition, aliquots of the stock suspension and the feed water were collected and analyzed to calculate
concentrations of the microspheres in the feed water. The two 50% headloss challenges included a stop
and start of the treatment system to simulate conditions likely to occur during normal operation of the
system.
VERIFICATION OF PERFORMANCE
System Operation
The treatment system was capable of normal operations without manual intervention. All operational
data, flows, pressures, turbidity and particle counts were recorded on data logging software that was not
provided as part of the treatment system. Manual intervention was required only to change out the spent
prefilters and bag filters. Daily site visits were conducted to record the operational data, make
adjustments as necessary to maintain the desired flow, and to conduct the required daily onsite testing and
sample collection.
The average feed water flow rate during the ETV study was 20.69 gallon per minute (gpm) and ranged
from 22.04 gpm to 18.12 gpm. The average bag filter effluent flow rate was 20.01 gpm and ranged from
21.19 gpm to 17.45 gpm. The difference between the feed water flow and the bag filter effluent flow was
due to samples being drawn off for the online analytical equipment. The flow rate was recorded twice per
day.
Headloss through the system was calculated from inlet and outlet pressure readings taken from the
prefilter and bag filter. According to the manufacturer, maximum headloss permissible for the prefilter
and the bag filter was 25 psi for each unit. Changeout of the prefilter and bag filter was conducted
according to these criteria. On average, the bag filter produced 92,900 gallons of effluent for every bag
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filter used. The maximum amount of effluent produced with one bag filter was 237,600 gallons; the
minimum effluent produced was 26,700 gallons. The reason for the differences in effluent production per
bag filter is unknown but most likely relates to feed water quality. The average run time per bag filter was
98 hours. The maximum run time for a bag filter was 164 hours; the minimum run time was 24 hours. A
total of eight bag filters were used during the testing. A total of three prefilters were used during the
testing.
Water Quality Results
The initial evaluation of the treatment system involved a verification of consistent performance of bag
filters from the same and from different production lots. This evaluation consisted of quantifying the rate
of headloss development, turbidity and particle removal for bags from the same and different lots.
Analysis of the collected data indicated that there was not a significant difference in bag filter
performance for bag filters from the same and different lots.
The average effluent turbidities as measured by the online turbidimeters during the 10 day variability
testing of filters from the same lot were 0.35, 0.30, and 0.30 NTU in housings #1, #2, and #3,
respectively. The average effluent cumulative particle counts (>2 |_im) during the 10 day variability testing
of filters from the same lot were 15.09, 15.99, and 18.21 total counts per ml in housings #1, #2, and #3,
respectively.
The average effluent turbidities as measured by the online turbidimeters during the 10 day variability
testing of filters from three different lots were 0.85, 0.70, and 0.70 NTU in housings #1, #2, and #3,
respectively. The average effluent cumulative particle counts (>2 |_im) during the 10 day variability
testing of filters from three different lots were 25.16, 25.62, and 31.39 total counts per ml in housings #1,
#2, and #3, respectively.
The treatment system underwent microsphere challenge testing four times during the verification testing.
During the 0% bag filter headloss microsphere challenge testing the system demonstrated a 3.2 log10
removal of the 3.7 |_im microspheres and a 3.5 log10 removal of the 6,0|_im microspheres. During the first
50% bag filter headloss microsphere challenge testing the system demonstrated a 1.9 logio removal of the
3.7 |_im microspheres and a 2.5 logio removal of the 6,0|_im microspheres. During the second 50% bag
filter headloss microsphere challenge testing the system demonstrated a 1.9 logio removal of the 3.7 |_im
microspheres and a 2.4 logio removal of the 6,0|_im microspheres. During the 90% bag filter headloss
microsphere challenge testing the system demonstrated a 2.2 logio removal of the 3.7 |_im microspheres
and a 2.6 logio removal of the 6,0|_im microspheres.
During the verification testing the Aqua-Rite Potable Water Filtration System samples of the feed water
and bag filter effluent were tested for total alkalinity, total hardness, total coliform, iron, manganese, total
organic carbon (TOC), and algae concentrations. No significant reductions were seen in total alkalinity,
total hardness, iron, manganese or TOC. This was not unexpected since these constituents tend to be
present in water in a soluble state and would not be removed by the straining process used by the bag
filter. No reduction was seen in the presence of total coliform in the feed and filtered water. Although
coliform bacteria are by their nature not soluble in water the small size of the organism would render it
capable of passing through the bag filter unimpeded. Algae concentrations were reduced through the
treatment system although given the low levels of algae in the feed water the difference between the feed
water and bag filter effluent concentrations was not statistically significant.
The average turbidity concentration in the feed water was 0.75 NTU and 0.15 NTU in the bag filter
effluent. Particle counts were reduced from an average of 451.017 total counts/ml (2-200|_im) in the feed
water to an average 21.518 total counts/ml (2-200 |_im) in the bag filter effluent.
01/24/EPADW395 The accompanying notice is an integral part of this verification statement. September 2001
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Temperature of the feed water during the verification testing was quite stable. The average temperature
of the feed water was 12.2°C, and ranged from 11.0°C to 13.5°C.
The following table presents the results of the water quality testing of the feed water and filtered water
samples collected during the verification testing:
Feed Water Quality / Filtered Water Quality
Lapoint Industries Aqua-Rite Potable Water Filtration System
Total
Total
Total
Iron
Manganese
Benchtop
Particle
Alkalinity Hardness
Coliforms
TOC
Algae
Turbidity
Counts
(mg/1)
(mg/1)
(cfu/100 ml)
(mg/1)
(mg/1)
(mg/1)
(cells/ml)
(NTU)
(particles/ml)
Average1
71/66
79/72
POS/POS
<0.05/<0.05
0.028/ 0.029
<2.0/<2.0
1/<1
0.80/0.15
451/21.2
Minimum1
N/A
N/A
N/A
<0.05/<0.05
0.021/0.022
N/A
<1/<1
0.50/0.05
123/0.450
Maximum1
N/A
N/A
N/A
<0.05/<0.05
0.035/0.035
N/A
1/<1
1.2/0.50
1305/499
Std. Dev.1
N/A
N/A
N/A
N/A
N/A
N/A
1/NA*
0.20/0.10
—
95%
N/A
N/A
N/A
N/A
N/A
N/A
(
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Availability of Supporting Documents
Copies of the ETV Protocol for Equipment Verification Testing for Physical removal of
Microbiological and Particulate Contaminants dated May 14, 1999, the Verification
Statement, and the Verification Report (NSF Report #01/24/EPADW395) are available
from the following sources:
(NOTE: Appendices are not included in the Verification Report. Appendices are
available from NSF upon request.)
1. Drinking Water Systems ETV Pilot Manager (order hard copy)
NSF International
P.O. Box 130140
Ann Arbor, Michigan 48113-0140
2. NSF web site: http://www.nsf.org/etv (electronic copy)
3. EPA web site: http://www.epa.gov/etv (electronic copy)
01/24/EPADW395 The accompanying notice is an integral part of this verification statement. September 2001
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September 2001
Environmental Technology Verification Report
Physical Removal of Giardia- and Cryptosporidium-sized
Particles in Drinking Water
Lapoint Industries
Aqua-Rite Potable Water Filtration System
Used in Drinking Water Treatment
Prepared for:
NSF International
Ann Arbor, Michigan 48105
Prepared by:
Gannett Fleming
Harrisburg, PA 17106
Under a cooperative agreement with the U.S. Environmental Protection Agency
Jeffrey Q. Adams, Project Officer
National Risk Management Research Laboratory
Cincinnati, Ohio 45268
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Notice
The U.S. Environmental Protection Agency (EPA) through its Office of Research and
Development has financially supported and collaborated with NSF International (NSF) under
Cooperative Agreement No. CR 824815. This verification effort was supported by Drinking
Water Treatment Systems Pilot operating under the Environmental Technology Verification
(ETV) Program. This document has been peer reviewed and reviewed by NSF and EPA and
recommended for public release.
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Foreword
The following is the final report on an Environmental Technology Verification (ETV) test
performed for the NSF International (NSF) and the United States Environmental Protection
Agency (EPA) by Gannett Fleming, Inc., in cooperation with Lapoint Industries. The test was
conducted between April 2000 and January 2001 in Burnside Borough Pennsylvania at the water
system's chlorination station.
Throughout its history, the EPA has evaluated the effectiveness of innovative technologies to
protect human health and the environment. A new EPA program, the Environmental
Technology Verification Program (ETV) has been instituted to verify the performance of
innovative technical solutions to environmental pollution or human health threats. ETV was
created to substantially accelerate the entrance of new environmental technologies into the
domestic and international marketplace. Verifiable, high quality data on the performance of
new technologies is made available to regulators, developers, consulting engineers, and those in
the public health and environmental protection industries. This encourages more rapid
availability of approaches to better protect the environment.
The EPA has partnered with NSF, an independent, not-for-profit testing and certification
organization dedicated to public health, safety and protection of the environment, to verify
performance of small package drinking water systems that serve small communities under the
ETV Drinking Water Treatment Systems (DWTS) Pilot. A goal of verification testing is to
enhance and facilitate the acceptance of small package drinking water treatment equipment by
state drinking water regulatory officials and consulting engineers while reducing the need for
testing of equipment at each location where the equipment's use is contemplated. NSF will meet
this goal by working with manufacturers and NSF-qualified Field Testing Organizations (FTO)
to conduct verification testing under the approved protocols.
The ETV DWTS is being conducted by NSF with participation of manufacturers, under the
sponsorship of the EPA Office of Research and Development, National Risk Management
Research Laboratory, Water Supply and Water Resources Division, Cincinnati, Ohio. It is
important to note that verification of the equipment does not mean that the equipment is
"certified" by NSF or "accepted" by EPA. Rather, it recognizes that the performance of the
equipment has been determined and verified by these organizations for those conditions tested by
the FTO.
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Table of Contents
Section Page
Verification Statement VS-i
Title Page
Notice
Foreword
Contents .
Abbreviations and Acronyms
Acknowledgements
Chapter 1 Introduction
1.1 ETV Purpose and Program Operation
1.2 Testing Participants and Responsibilities
1.2.1 NSF International
1.2.2 Gannett Fleming, Inc
1.2.3 Manufacturer
1.2.4 Host
1.2.5 Analytical Laboratory
1.2.6 U.S. Environmental Protection Agency
1.3 Verification Testing Site
1.3.1 Source Water
1.3.2 Treatment System Effluent Discharge
Chapter 2 Equipment Description and Operating Processes
2.1 Equipment Description
2.1.1 Data Plate
2.2 Operating Process
2.2.1 Feed Water
2.2.2 Prefiltration
2.2.3 Filtration
2.3 Operator Requirements 1
2.4 Safety 1
2.5 Equipment Limitations 1
2.6 Waste Production 1
Chapter 3 Methods and Procedures
3.1 Experimental Design
3.1.1 Objectives
3.1.1.1 Evaluation of Equipment Capabilities
3.1.1.2 Evaluation of Equipment Performance Relative to Water Quality
Regulations
3.1.1.3 Evaluation of Operational Requirements
3.1.1.4 Evaluation of Maintenance Requirements
3.1.2 Equipment Characteristics
3.1.2.1 Qualitative Factors
3.1.2.2 Quantitative Factors
3.2 Verification Testing Schedule
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Table of Contents
Section Page
3.3 Verification Task Procedures 14
3.3.1 Task A: Characterization of Feed Water 14
3.3.1.1 Work Plan 15
3.3.1.2 Evaluation Criteria 15
3.3.2 Task B: Initial Test Runs 15
3.3.2.1 Work Plan 16
3.3.2.2 Bag Filter Effluent Turbidity 17
3.3.2.3 Bag Filter Effluent Particle Levels 17
3.3.2.4 Pressure Differential 17
3.3.2.5 Flow Rate 17
3.3.2.6 Analytical Schedule 17
3.3.2.7 Evaluation Criteria 17
3.3.3 Task 1: Verification Testing Runs 18
3.3.3.1 Evaluation Criteria 18
3.3.4 Task 2: Test Runs for Feed Water and Finished Water Quality 18
3.3.4.1 Evaluation Criteria 19
3.3.5 Task 3: Documentation of Operating Conditions and Treatment Equipment
Performance 20
3.3.5.1 Evaluation Criteria 21
3.3.6 Task 4: Microbial Contaminant Removal 21
3.3.6.1 Seeding Technique 22
3.3.6.2 Electronic Particle Counting 22
3.3.6.3 Microspheres 22
3.3.6.4 Analytical Schedule 23
3.3.6.5 Evaluation Criteria 23
3.3.7 Task 5: Data Management 24
3.3.7.1 Log Books 24
3.3.7.2 Photographs 25
3.3.7.3 Chain of Custody 25
3.3.7.4 Online Measurements 25
3.3.7.5 Data Management Spreadsheets 25
3.3.7.6 Statistical Analysis 26
3.4 Field Operations Procedures 26
3.4.1 Equipment Operations 26
3.4.1.1 Operations Manual 27
3.4.1.2 Analytical Equipment 27
3.5 QA/QC Procedures 27
3.5.1 Daily QA/QC Verification Procedures 27
3.5.1.1 Online Turbidimeter Flow Rate 27
3.5.1.2 Online Particle Counter Flow Rate 28
3.5.1.3 Online Turbidimeter Readout 28
3.5.2 Bi-weekly QA/QC Verification Procedures 28
3.5.2.1 Online Flow Meter Clean Out 28
3.5.2.2 Online Flow Meter Flow Verification 28
3.5.3 Procedures for QA/QC Verifications -Start of Each Testing Period 28
3.5.3.1 Online Turbidimeter 29
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Table of Contents
Section Page
3.5.3.2 Pressure Gauges 29
3.5.3.3 Tubing 29
3.5.3.4 Online Particle Counters 29
3.5.4 On-Site Analytical Methods 29
3.5.4.1 pH 29
3.5.4.2 Temperature 30
3.5.4.3 Turbidity Analysis 30
3.5.5 Chemical and Biological Samples Shipped Off-Site for Analyses 30
3.5.5.1 Total Organic Carbon 30
3.5.5.2 Microbial Parameters: Total Coliform and Algae 31
3.5.5.3 Inorganic Parameters 31
3.5.5.4 Microspheres 31
Chapter 4 Results and Discussions 33
4.1 Introduction 33
4.2 Equipment Characteristics Results 33
4.2.1 Qualitative Factors 33
4.2.1.1 Susceptibility to Changes in Environmental Conditions 33
4.2.1.2 Operational Reliability 34
4.2.1.3 Equipment Safety 34
4.2.1.4 O&M Manual 34
4.2.2 Quantitative Factors 34
4.2.2.1 Power Supply Requirements 34
4.2.2.2 Consumable Requirements 35
4.2.2.3 Waste Disposal 35
4.2.2.4 Length of Operating Cycle 35
4.2.2.5 Estimated Labor Hours for O&M 35
4.3 Characterization of Feed Water 35
4.4 Initial Operations Period Results 36
4.4.1 Flow 37
4.4.2 Pressure Differential 37
4.4.3 Turbidity 37
4.4.4 Particle Counts 38
4.5 Verification Testing Results and Discussion 39
4.5.1 Task 1: Verification Testing Runs 39
4.5.2 Task 2: Test Runs for Feed Water and Finished Water Quality 40
4.5.2.1 Water Quality Analytical Results - Laboratory Analytes 40
4.5.2.2 Discussion of Results 41
4.5.2.3 Water Quality Analytical Results - On-Site Analytes 42
4.5.2.4 Discussion of Results 50
4.5.3 Task 3: Documentation of Operating Conditions and Treatment Equipment
Performance 50
4.5.3.1 Flow Rate 50
4.5.3.2 Head Loss 51
4.5.4 Microbial Contaminant Removal 53
4.5.4.1 Feed Water Testing Results 53
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Table of Contents
Section Page
4.5.4.2 Bag Filter Effluent Testing Results 55
4.5.4.3 Logio Removal 58
4.5.4.4 Discussion of Results 59
4.6 QA/QC Results 59
4.6.1 Daily QA/QC Results 59
4.6.2 Bi-weekly QA/QC Verification Results 60
4.6.3 Results of QA/QC Verifications at the Start of Each Testing Period 60
4.6.4 On-Site Analytical QA/QC 62
4.6.5 Analytical Laboratory QA/QC 63
Chapter 5 References 64
Tables Page
Table 1-1 Lapoint Industries Aqua Rite Potable Water Filtration System Feed Water Quality -
Laboratory Analytes 6
Table 1-2 Lapoint Industries Aqua Rite Potable Water Filtration System Feed Water Quality -
On Site Analytes 7
Table 3-1 Analytical Data Collection Schedule 19
Table 3-2 Operational Data Collection Schedule 20
Table 3-3 Analytical Methodology 32
Table 4-1 Historical Water Quality Results - Spring No. 1 36
Table 4-2 Historical Water Quality Results - Spring No. 2 36
Table 4-3 Historical Water Quality Results - Chura Spring 36
Table 4-4 Online Turbidimeter Effluent Turbidity Results from Bag Filter Variability Tests -
Same Lot 38
Table 4-5 Online Turbidimeter Effluent Turbidity Results from Bag Filter Variability Tests -
Different Lots 38
Table 4-6 Effluent Cumulative Particle Count Results from Bag Filter Variability Tests -
Same Lot 39
Table 4-7 Effluent Cumulative Particle Count Results from Bag Filter Variability Tests -
Different Lots 39
Table 4-8 Feed Water Testing Results - Laboratory Analytes 40
Table 4-9 Prefilter Effluent Testing Results - Laboratory Analytes 41
Table 4-10 Bag Filter Effluent Testing Results - Laboratory Analytes 41
Table 4-11 Turbidity Analyses Results and Removals - Bench Top Turbidimeter 42
Table 4-12 Turbidity Analyses Results and Removal - Four Hour Online Turbidimeter
Results 42
Table 4-13 Feed Water Particle Counts (particles/ml) 44
Table 4-14 Prefilter Effluent Particle Counts (particles/ml) 44
Table 4-15 Bag Filter Effluent Particle Counts (particles/ml) 44
Table 4-16 Daily Average Cumulative Particle Counts - Feed and Bag Filter Effluent, Logio
Particle Removal 45
Table 4-17 Feed Water Quality - On-Site Analytes 49
Table 4-18 Filtration Runs 52
Table 4-19 Microsphere Challenge Events 53
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Table of Contents
Tables Page
Table 4-20 3.7|im and 6.0 |im Spheres Stock Suspension Concentration (counts per ml of
system flow) 54
Table 4-21 Feed Water Particle Counts with Stock Suspension Addition (particles per ml) -
10/25/2000 55
Table 4-22 Feed Water Particle Counts with Stock Suspension Addition (particles per ml) -
1/22/2001 55
Table 4-23 Feed Water Particle Counts with Stock Suspension Addition (particles per ml) -
1/24/2001 55
Table 4-24 Bag Filter Effluent Particle Counts During Challenge Sample Collection (counts per
ml) - 10/25/2000 (50% Headloss Challenge) 57
Table 4-25 Bag Filter Effluent Particle Counts During Challenge Sample Collection (counts per
ml) - 1/22/2001(50% Headloss Challenge) 57
Table 4-26 Bag Filter Effluent Particle Counts During Challenge Sample Collection (counts per
ml) - 1/24/2001 (90% Headloss Challenge) 57
Table 4-27 3.7 |im and 6.0 |im Spheres Effluent Concentration During Challenge (per ml of
system flow) 58
Table 4-28 3.7 |im and 6.0 |im Spheres Feed and Effluent Logio Concentrations and Removal
During Challenge (per ml of system flow) 58
Figures
Figure 2-1 Flow Schematic 9
Figure 4-1 Four-Hour Online Turbidity 43
Figure 4-2 Four-Hour Feed Water Particle Counts 46
Figure 4-3 Four-Hour Prefilter Effluent Particle Counts 47
Figure 4-4 Four-Hour Bag Filter Effluent Particle Counts 48
Figure 4-5 Daily Average Logio Cumulative Particle Removal Graph 49
Figure 4-6 Daily Feed Water and Bag Filter Effluent Flow 51
Figure 4-7 Headloss of Bag Filter System 52
Photographs
Photograph 1-1 Burnside Borough Reservoir 5
Photograph 2-1 Treatment System as Installed at Burnside Borough (including pressure
vessels, pressure gauges and particle counters 10
Appendices
A. Historical Feed Water Quality Data
B. Data Spreadsheets
C. Field Log Book
D. Laboratory Chain of Custody Forms
E. Manufacturer's Operation and Maintenance Manual
F. CWM Laboratory QA/QC Plan
G. Analytical Laboratory Bench Data Sheets
H. Particle Counter Information
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Abbreviations and Acronyms
CaC03
Calcium Carbonate
cfu
colony forming unit
°C
degrees Celsius
DWTS
Drinking Water Treatment System
EPA
U.S. Environmental Protection Agency
ESWTR
Enhanced Surface Water Treatment Rule
ETV
Environmental Technology Verification
°F
degrees Fahrenheit
FOD
Field Operations Document
FTO
Field Testing Organization
gpm
gallon per minute
GUDI
Ground water under the influence of surface water
mg/L
milligram per liter
N/A
Not Applicable
NIST
National Institute of Standards and Technology
NSF
NSF International (formerly known as National Sanitation Foundation)
NTU
Nephlometric Turbidity Units
O&M
Operations and Maintenance
PADEP
Pennsylvania Department of Environmental Protection
psi
pounds per square inch
QA/QC
Quality Assurance/Quality Control
SDWA
Safe Drinking Water Act
SWTR
Surface Water Treatment Rule
TOC
Total Organic Carbon
TSS
Total Suspended Solids
IX
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ACKNOWLEDGMENTS
The Field Testing Organization, Gannett Fleming, Inc., was responsible for all elements in the
testing sequence, including collection of samples, calibration and verification of instruments,
data collection and analysis, data management, data interpretation and the preparation of this
report.
Gannett Fleming, Inc.
P.O. Box 67100, Harrisburg, PA 17106-7100
Contact Person: Mr. Gene Koontz, Project Administrator
The laboratory selected for analytical work of this study exclusive of the microsphere analyses
was:
CWM Laboratories
220 S. Jefferson St., Kittaning, PA 16201
Contact: David Kohl, Laboratory Manager
The laboratory selected for the microsphere enumeration was:
Clancy Environmental Consultants
P.O. Box 314, St. Albans, VT 05478
Contact: Tom Hargy
The Manufacturer of the Equipment was:
Lapoint Industries
48 Commercial Street, Lewiston, ME 04240
Contact: Dan Mosley, Sales Manager
Gannett Fleming wishes to thank NSF International, especially Bruce Bartley, Project Manager,
Carol Becker and Kristie Wilhelm, Environmental Engineers, for providing guidance and
program management.
The Burnside Borough staff including Mr. Richard Hoover, Borough Council President, Mr.
John Ciphert, and Mr. Ron Wolf provided invaluable analytical and operational assistance.
Mr. Dan Mosley, Senior Sales Engineer, Lapoint Industries, was the primary contact for
manufacturer and provided the treatment system and technical and product assistance as
necessary.
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Chapter 1
Introduction
1.1 ETV Purpose and Program Operation
The U.S. Environmental Protection Agency (EPA) has created the Environmental Technology
Verification (ETV) Program to facilitate the deployment of innovative or improved
environmental technologies through performance verification and dissemination of information.
The goal of the ETV program is to further environmental protection by substantially accelerating
the acceptance and use of improved and more cost-effective technologies. ETV seeks to achieve
this goal by providing high quality, peer reviewed data on technology performance to those
involved in the design, distribution, permitting, purchase, and use of environmental technologies.
ETV works in partnership with recognized standards and testing organizations; stakeholders
groups which consist of buyers, vendor organizations, and permitters; and with the full
participation of individual technology developers. The program evaluates the performance of
innovative technologies by developing test plans that are responsive to the needs of stakeholders,
conducting field or laboratory tests (as appropriate), collecting and analyzing data, and preparing
peer reviewed reports. All evaluations are conducted in accordance with rigorous quality
assurance protocols to ensure that data of known and adequate quality are generated and that the
results are defensible.
NSF International (NSF) in cooperation with the EPA operates the Drinking Water Treatment
Systems (DWTS) Pilot, one of 12 technology areas under ETV. The DWTS Pilot evaluated the
performance the Lapoint Industries Aqua-Rite Potable Water Filtration System used in package
drinking water treatment system applications. The system employs a non-rigid, disposable, fabric
bag filter in which flow is from the inside of the bag to the outside.
The Aqua-Rite Potable Water Filtration System equipment capabilities and equipment
performance relative to water quality regulations were evaluated. The equipment's ability to
remove Giardia- sized particles and Cryptosporidium- sized particles was tested. Fluorescent
microspheres in the Giardia and Cryptosporidium size range were utilized to demonstrate
removal capability. This document provides the verification test results for the Aqua-Rite
Potable Filtration System.
1.2 Testing Participants and Responsibilities
The ETV testing of the Aqua-Rite Potable Water Filtration System was a cooperative effort
between the following participants:
NSF International
Gannett Fleming, Inc.
Lapoint Industries
Burnside Borough
U.S. Environmental Protection Agency
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The following is a brief description of each ETV participant and their roles and responsibilities.
1.2.1 NSF International
NSF is a not-for-profit standards and certification organization dedicated to public health safety
and the protection of the environment. Founded in 1946 and located in Ann Arbor, Michigan,
NSF has been instrumental in the development of consensus standards for the protection of
public health and the environment. NSF also provides testing and certification services to ensure
that products bearing the NSF Name, Logo and/or Mark meet those standards. The EPA
partnered with the NSF to verify the performance of drinking water treatment systems through
the EPA's ETV Program.
NSF provided technical oversight of the verification testing. An audit of the field analytical and
data gathering and recording procedures was conducted by NSF. NSF also provided review of
the Field Operations Document (FOD) to assure its conformance with the pertinent ETV generic
protocol and test plan. NSF also conducted a review of this report and coordinated the EPA and
technical reviews of this report.
Contact Information:
NSF International
789 N. Dixboro Rd., Ann Arbor, MI 48105
Phone: 734-769-8010
Fax: 734-769-0109
Contact: Bruce Bartley, ETV Pilot Manager
Email: bartley@nsf.org
1.2.2 Gannett Fleming, Inc.
Gannett Fleming, Inc., a consulting engineering firm, conducted the verification testing of the
Aqua-Rite Potable Water Filtration System. Gannett Fleming is a NSF-qualified Field Testing
Organization (FTO) for the ETV DWTS Pilot.
The FTO was responsible for conducting the verification testing. The FTO provided all needed
logistical support, established a communications network, and scheduled and coordinated
activities of all participants. The FTO was responsible for ensuring that the testing location and
feed water conditions were such that the verification testing could meet its stated objectives. The
FTO prepared the FOD, oversaw the testing, managed, evaluated, interpreted and reported on the
data generated by the testing, as well as evaluated and reported on the performance of the
technology.
The FTO with assistance from Burnside Borough conducted the onsite analyses and data
recording during the testing. Oversight of the daily tests was provided by the FTO's Project
Manager.
Contact Information:
Gannett Fleming, Inc.
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P.O. Box 67100, Harrisburg, PA 17106-7100
Phone: 717-763-7211
Fax: 717-763-1808
Contact: Gene Koontz, Project Director
Email: gkoontz@gfnet.com
1.2.3 Manufacturer
The treatment system is manufactured by Lapoint Industries, a manufacturer of bag and cartridge
filtration systems for municipal and industrial water users. Lapoint Industries is based in
Lewiston, Maine.
The manufacturer was responsible for supplying a field-ready bag filtration system including
filter housing, prefilters, bag filters, instrumentation and controls and O&M manual, for
verification testing. The manufacturer was also responsible for providing logistical and technical
support as needed as well as providing technical assistance to the FTO during operation and
monitoring of the equipment undergoing field verification testing.
Contact Information:
Lapoint Industries
48 Commercial Street, Lewiston, ME 04240
Phone: (207) 777-3100
Fax: (207) 777-3177
Contact: Dan Mosley, Sales Manager
Email: dmosley@lapointindustries.com
1.2.4 Host
The verification testing was hosted by the Borough of Burnside. The borough is located in
Clearfield County Pennsylvania. The water system serves a population of approximately 325
from its 208,000 gallon in-ground covered reservoir. Burnside Borough was interested in
examining the use of bag filtration to treat water which had been stored in its covered reservoir.
The reservoir is supplied by natural spring water.
Contact Information:
Burnside Borough
P. O. Box 31, Burnside, PA 15721
Phone: (814) 845-2376
Fax: (814) 845-7360
Contact: Rick Hoover, Borough President
Email: BLH@Never-ENUFF.net
1.2.5 A nalytical Laboratory
CWM Laboratories provided analytical services for alkalinity, hardness, total organic carbon
(TOC), iron, manganese, and algae (number and species). CWM Laboratories is certified by the
3
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Pennsylvania Department of Environmental Protection (PADEP) for analysis of Microbiological
Contaminants. CWM Laboratories utilized a sub contract lab, Analytical Laboratory Services of
Middletown, Pennsylvania, for the inorganic analyses. The algae analyses were conducted under
contract with CWM by Environmental Associates of Olean, NY.
Contact Information:
CWM Laboratories
220 S. Jefferson St., Kittaning, PA 16201
Phone: (724) 543-3011
Fax: (724) 543-6768
Contact: David Kohl, Laboratory Manager
Email: cwmlab@alltel.net
The microsphere enumeration analyses were conducted by:
Clancy Environmental Consultants
P.O. Box 314
St. Albans, VT 05478
Phone: (802) 527-2460
Fax: (802) 524-3909
Contact: Tom Hargy
Email: thargy@together.net
1.2.6 U.S. Environmental Protection Agency
The EPA through its Office of Research and Development has financially supported and
collaborated with NSF under Cooperative Agreement No. CR 824815. This verification effort
was supported by the Drinking Water Treatment Systems Pilot operating under the ETV
Program. This document has been peer reviewed and reviewed by NSF and EPA and
recommended for public release.
1.3 Verification Testing Site
The verification testing site was Burnside Borough's water system chlorination station located in
the Borough of Burnside, Clearfield County, Pennsylvania. The chlorination building is located
on Cemetery Road approximately 1 Vi mile west of U.S. Route 219. The Aqua-Rite Filtration
System was located in the basement of the Burnside Borough's chlorination building.
1.3.1 Source Water
The source water for the verification testing was from the water system's 208,000 gallon in-
ground covered reservoir located approximately 100 feet in elevation and about one-half mile
away from the chlorination building which housed the treatment unit. The covered reservoir is
shown in Photograph 1-1. The reservoir is primarily supplied by a natural spring identified as
Spring No. 1 via gravity feed. Spring No. 2, a secondary supply which must be pumped up to
4
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the reservoir, was used on 208 days in 1999. A third spring, Chura Spring, flows into Spring No.
2. There is a well that supplements the production of the springs at the reservoir site. It is used
only on an as needed basis when the production from the springs is inadequate to meet system
demand.
Photograph 1-1. Burnside Borough Reservoir
Reservoir Spring No. 1 is located at 40°48'25" latitude and 78°48'23" longitude, and produces a
discharge of 5 to 10 gpm. This spring originates from an unnamed local perched aquifer near the
top of the Glenshaw Formation of the Comemaugh Group. This formation is a variable sequence
of sedimentary rock types, mainly silt and clay shales. Thin bedded sandstones are also found
within limestone and calcareous claystones. Red beds from several feet to over 20 feet are
commonly found. The groundwater systems are usually perched aquifers above the relatively
impermeable red beds and claystone.
The watershed area surrounding Spring No. 1 is mainly wooded with rolling terrain. The soil
group is the Rayne-Gilpin with 15-25% slopes, and on the edge of the Wharton Silt Loam, 3% to
8% slopes. Spring No. 1 is protected from surface runoff by its concrete springbox and a
diversion ditch.
Spring No. 2 is located at 40°48'25" latitude and 78°48'22" longitude and produces a discharge of
3 to 7 gpm. This spring originates from an unnamed local perched aquifer near the middle of the
Glenshaw Formation of the Conemaugh Group. This formation is a variable sequence of
sedimentary rock types, mainly silt and clay shales. Thin bedded sandstones are found along
with thin limestones and calcareous claystones. Red beds from several feet to over 20 feet are
common. Spring No. 2 is primarily used from May to December.
5
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The watershed area for Spring No. 2 is the same as Spring No. 1 except Spring No .2 is located
on the bottom of the slope, approximately 55 feet below Spring No. 1.
Chura Spring is located at 40°41'28" latitude and 78°48'24" longitude and produces a discharge
of 2 to 3 gpm. Chura Spring is primarily used from May to December. The geological and
watershed data are the same as Spring No. 1.
The Reservoir Well is located at 40°48'28" latitude and 78°48'22" longitude and produces a
discharge of 2 to 3 gpm. The static water level depth is 60.78' with casing and grout to 58'.
The covered reservoir and associated springs and well sources of supply are considered high
quality supplies. Limited historical records indicate that normal turbidity levels are less than 1.0
NTU from Spring No. 1 and Chura Spring. Normal turbidity from Spring No. 2 is between 1.0
NTU and 2.0 NTU. Water quality data for each spring is presented in Appendix A. There are no
historical water quality records available for the reservoir well; this supply is treated with a
sequestering agent, indicating the presence of iron and/or manganese.
The PADEP has classified these springs and the reservoir as groundwater under the direct
influence of surface water (GUDI); Burnside Borough is under a consent decree to provide
filtration for these supplies. As such, the source water was considered adequate to verify the
manufacturer's treatment claims.
During the verification testing, the feed water turbidity ranged from 0.50 to 1.2 NTU with an
average of 0.75 NTU. pH was an average of 7.1. A single sample was collected for total
alkalinity and was 71 mg/1 as CaCC>3. Hardness as CaCC>3 was 79 mg/1 as measured in a single
sample. Total organic carbon (TOC) was less than 2.0 mg/1 based on the results of a single
sample. The feed water was coliform bacteria positive. The feed water cumulative particle
counts averaged 451 counts/ml. Temperature averaged 12.2°C. The alga levels during the
verification testing averaged 1 cell/ml. Tables 1-1 and 1-2 present the feed water quality data.
Table 1-1. Lapoint Industries Aqua-Rite Potable Water Filtration System Feed Water Quality- Laboratory
Analytes
Total Total Hardness Total TOC Algae Iron Manganese
Alkalinity Coliforms
Date (mg/1) (mg/1) (Neg.,Pos.) (mg/1) (cells/ml) (mg/1) (mg/1)
10/9/00
71
79
Pos.
<2.0
1
<0.05
0.021
10/19/00
—
-
-
—
1
<0.05
0.035
10/25/00
-
-
-
-
<1
-
-
11/9/00
—
-
-
—
<1
—
—
Average
71
79
Pos.
<2.0
1
<0.05
0.028
Minimum
N/A
N/A
N/A
N/A
<1
<0.05
0.021
Maximum
N/A
N/A
N/A
N/A
1
<0.05
0.035
Std. Dev.
N/A
N/A
N/A
N/A
1
N/A
N/A
95% Confid Int.
N/A
N/A
N/A
N/A
(0,1)
N/A
N/A
N/A = Not applicable because the sample size (n) was 1 or 2.
Pos. = Positive result from a presence / absence test.
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Table 1-2. Lapoint Industries Aqua-Rite Potable Water Filtration System Feed Water Quality - On-Site
Analytes
Total Particle Counts Benchtop Turbidity pH
(counts/ml) (NTU)
Average
451.017
0.75
7.08
Minimum
122.825
0.50
6.85
Maximum
1304.900
1.2
7.35
Std. Dev.
N/A
0.20
0.16
95% Confid Int.
N/A
(0.70, 0.80)
(7.02,7.13)
Number of Samples
183
36
35
N/A = Not applicable. Statistical measurements on cumulative data do not generate meaningful data.
1.3.2 Treatment System Effluent Discharge
The effluent of the system was discharged from the chlorination building to an existing swale.
The PADEP issued a temporary permit for the discharge.
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Chapter 2
Equipment Description and Operating Processes
2.1 Equipment Description
The equipment tested in this ETV program was Lapoint Industries Aqua-Rite Potable Water
Filtration System The system is a compact, package filtration system consisting of a prefilter
and a bag filter. The prefilter was a Valu-Life (column) Bag Filter designated as AP1P2S8T.
The filtration bag used in the system was the HPM-97 CC 2SS. The prefilter and bag filter were
housed in stainless steel pressure vessels. The filters are supported inside the vessels by a
stainless steel wire mesh basket. The filter housings are designed with a recessed basket and a
volume displacer permanently welded to the top cover. A double O-ring seals the vessel cover to
the housing to eliminate any potential bypass. The filter housings had a volume of 1.35 ft3.
The manufacturer reports that the prefilter, the Valu-Life (8 Column) Bag, has greater effective
filtration surface than a standard single layer filter bag. The nominal pore size of the prefilter is
less than 5.0 |im. The greater surface area and increased depth this filter provides both longer
life and higher efficiency.
The filtration bag incorporates a unique graduated layering of media design. The inner layer
consists of a built-in prefilter and progresses to tighter outer layers. Particles are systematically
removed as water travels through the multiple layers, with each individual layer removing a
particular-size range of particles. The graduated layering of media aids in the prevention of
premature blinding, reducing frequency of filter changeout. Due to this unique layering system
there is a wide range of pore sizes in the bag filter itself. The nominal pore size of the "loosest"
layers of the bag filter is less than or equal 1.0 |im with additional layers ranging down to 0.5 |im
or less.
2.1.1 Data Plate
The data plate affixed to the treatment system contains the following information.
a. Equipment name: Aqua-Rite Potable Water Filtration System
b. Filter Model #: HPM-97 CC 2SS
c. Filter Housing Model #: AQ-2-2BSH
d. Prefilter: Valu-Life (column) Bag Filter SP1P2S8T
e. Prefilter Housing Model #: CQX1 -180 - 2- B2NSB
f Electrical requirements: None
g. Serial number: None
h. Warning and caution statements: None
i. Capacity or output rate: 20 - 25 gpm
2.2 Operating Process
2.2.1 Feed Water
The feed water is delivered via gravity into the filtration system.
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2.2.2 Prefiltration
A disposable bag prefilter, Valu-Life (column) Bag Filter, removes large particles prior to the
feed flow entering the final bag filter. The prefilter protects the final filter from the large debris
and extends the life of the final filter. The feed water enters into the inside of the bag and is
filtered as it passes through to the exterior of the bag. The pressure drop across the prefilter is
monitored on a daily basis and it is replaced when the pressure differential reaches 25 psi.
Replacement of the prefilter is accomplished by removing the spent prefilter and discarding it
and replacing it with a new prefilter. The prefilter can not be cleaned and reused. The life of
prefilter is dictated by the raw water quality.
2.2.3 Filtration
The bag filter, the HPM-97 CC 2SS, receives the prefiltered water. The water enters the inside of
the bag, passes through the multiple layers of the filter and exits through the outside of the filter.
The pressure drop across the bag filter is monitored on a daily basis and it is replaced when the
pressure differential reaches 25 psi. Replacement of the filter is accomplished by removing the
spent filter and discarding it and replacing it with a new filter. The filter can not be cleaned and
reused. The life of filter is dictated by the raw water quality and the effectiveness of the prefilter.
Figure 2-1 presents a schematic of the system.
Aqua-Rite Potable Water
Filtration System
1
Prefilter
Bag Filter
Filtrate to Drain
Figure 2-1. Flow Schematic
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Photograph 2-1. Treatment System as Installed at Burnside Borough (including pressure vessels, pressure
gauges and particle counters)
10
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2.3 Operator Requirements
There are minimal operator requirements for tie Aqua-Rite Potable Water Filtration System.
The two primary requirements are monitoring the differential pressures across the prefilter and
bag filter, and the replacing the prefilter and bag filter when terminal loss of head occurs. The
manufacturer reports the equipment itself has no operational licensing requirements.
2.4 Safety
The primary safety concern is excessive pressure build-up in the prefilter and bag filter housings
which could damage the equipment and possibly harm the operator. Lapoint Industries
recommends the installation of a pressure relief valve to prevent over pressurization of the filter
housings. Burnside Borough's chlorine station is fed via gravity flow from the raw water
reservoir. As such, the pressure at the chlorine station can vary only slightly and averages 60 psi.
Accordingly, over pressurization of the filter vessels can not occur.
2.5 Equipment Limitations
Pressure differential should not be allowed to exceed 25 psi in the filter bags. The pressure
vessels themselves are rated for 150 psi continuous service.
2.6 Waste Production
Residue that is removed from the feed water stream is retained within the filter material. When
prefiltered and filter bags become blinded, the filter bags and residue are disposed; they are not
reused.
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Chapter 3
Methods and Procedures
3.1 Experimental Design
The experimental design of this verification study was developed to provide accurate information
regarding the performance of the treatment system. The impact of field operations as they relate
to data validity was minimized, as much as possible, through the use of standard sampling and
analytical methodology. Due to the unpredictability of environmental conditions and mechanical
equipment performance, this document should not be viewed in the same light as scientific
research conducted in a controlled laboratory setting.
Bag filtration is generally used for the removal of particulate material from ground water or high
quality surface waters with turbidity less than or equal to 1 NTU that do not contain fine
colloidal clays or algae. The test site for this verification was a public water supply utilizing
spring water under the influence of surface water. The manufacturer stated that their treatment
system, for this feed water, would not utilize chemical or mechanical pretreatment. One goal of
the testing was to demonstrate whether this technology is suitable for the filtration of this type of
source.
3.1.1 Objectives
The verification testing was undertaken to evaluate the performance of the Aqua-Rite Potable
Water Filtration System equipment. The equipment capabilities and equipment performance
were evaluated to assess the removal capabilities of particles in the size range of Giardia and
Cryptosporidium. Also evaluated were the operational requirements and maintenance
requirements of the system. The details of each of these evaluations are discussed below.
3.1.1.1 Evaluation of Equipment Capabilities
The Aqua-Rite Potable Water Filtration System equipment was tested to demonstrate its ability
to remove particles in the size range of Giardia cysts and Cryptosporidium oocysts. Fluorescent
microspheres were utilized to demonstrate acceptable removal capability.
3.1.1.2 Evaluation of Equipment Performance Relative to Water Quality Regulations
Drinking water regulations require, for filtration plants treating surface water and employing
conventional treatment, a minimum of 3 logio removal/inactivation of Giardia cysts from feed to
finished waters and that finished water turbidity at no time exceeds 5 NTU and that at least 95%
of the daily finished water turbidity samples be less than 0.5 NTU (EPA, Surface Water
Treatment Rule [SWTR], 1989). Recently promulgated rules have modified the SWTR to
include a lower turbidity standard, less than 0.3 NTU in 95% of the daily finished water turbidity
samples, and a requirement to provide a 2 logio removal of Cryptosporidium oocysts (EPA,
Enhanced Surface Water Treatment Rule [ESWTR], 1999). Both of these rules grant the "log
removal credit" if the treatment facility achieves the required turbidity levels.
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The treatment system's ability to achieve required finished water turbidity levels was evaluated
by examining the results of filter effluent turbidity measurements. Log removals for Giardia
sized particles and Cryptosporidium sized particles were quantified using microsphere removal
challenge testing although there is currently no provision for this type of testing in the
regulations.
3.1.1.3 Evaluation of Operational Requirements
An overall evaluation of the operational requirements for the treatment system was undertaken as
part of the verification. This evaluation was qualitative in nature. Tasks performed during daily
operations and during bag changeout were used to develop a subjective judgment of the
operational requirements of the system.
3.1.1.4 Evaluation of Maintenance Requirements
An attempt was made to evaluate the maintenance requirements of the treatment system during
the testing. Due to the short duration of the testing there was no significant maintenance
required. Suggested maintenance activities and experience with common pieces of equipment
(valves etc.) were used to evaluate the maintenance requirements of the treatment system.
3.1.2 Equipment Characteristics
The qualitative, quantitative and cost factors of the tested equipment were identified, in so far as
possible, during the verification testing. The relatively short duration of the testing cycle creates
difficulty in reliably identifying some of the qualitative, quantitative and cost factors.
3.1.2.1 Qualitative Factors
The equipment was operated in such a way as to maintain its operating parameters within
Lapoint Industries' recommendations. The nature and frequency of the changes (i.e. flow
adjustment, prefilter and filter bag replacement, etc.) required to maintain the operating
conditions were used in the qualitative evaluation of the equipment. Frequent and significant
changes/adjustments would indicate relatively lower reliability and higher susceptibility to
environmental conditions, and also the degree of operator experience that would be required.
The effect of operator experience on the bag filtration test results was evaluated. Any difficulties
that the operator experienced in changing the filter bags as well as any instances of a mis-
installation of a bag were used to aid in the evaluation of the effect of operator experience on the
use of this system.
3.1.2.2 Quantitative Factors
The following cost factors were quantified by various means in this test:
$Frequency of bag filter replacement (pre and final)
$Length of operating cycle (number of hours of operation and gallons of water produced)
$Estimated labor hours for operation and maintenance
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$Impact of on/off operation on water quality
These quantitative fictors were used as an initial benchmark to assess equipment performance
and develop operation and maintenance costs factors.
3.2 Verification Testing Schedule
Verification testing activities included equipment setup, initial operations (which included filter
variability testing), verification operations, sampling and analysis. Initial operations were
conducted to be sure the equipment was functioning as intended, and was appropriate for the
quality of the supply. The test schedule was developed to encompass all of these activities.
There were two initial operations periods each 10 days in length during which bag filter
variability within production lots and between production lots was evaluated. These periods
were followed by a 30 day verification testing period.
The first initial operations period began on April 20, 2000. The second initial operations period
commenced May 20, 2000. The verification testing commenced October 9, 2000 and ended
January 26, 2001.
3.3 Verification Task Procedures
The procedures for each task of the verification testing were developed in accordance with the
requirements in the EPA/NSF ETV Protocol (EPA/NSF 1999). The Verification Tasks were as
follows:
¦ Task A: Characterization of Feed Water
¦ Task B: Initial Operations
¦ Task 1: Verification Testing Runs and Routine Equipment Operation
¦ Task 2: Test Runs for Feed Water and Finished Water Quality
¦ Task 3: Documentation of Operating Conditions and Treatment Equipment Performance
¦ Task 4: Microbial Contaminant Removal
¦ Task 5: Data Management
¦ Task 6: QA/QC
Detailed descriptions of each task are provided in the following sections.
3.3.1 Task A: Characterization of Feed Water
This goal of this task was to determine if the chemical, biological, and physical characteristics of
the feed water were appropriate for the bag filtration equipment to be tested. Bag filters have
limited capability to remove fine colloidal clays that cause turbidity in many surface waters and
because feed waters having high concentrations of particulate matter such as algae, particles
consisting of plant material, or sediment can rapidly clog bag filters, necessitating their
replacement.
If the source water used as feed water for the testing program has an excessive amount of the fine
turbidity-causing particles, the bag filtration or cartridge filtration equipment may not be able to
attain sufficient turbidity removal to meet the requirements of the SWTR. Because bag filters do
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not remove viruses, the entire burden of virus control falls on the disinfection process when these
filters are used for water treatment. Excessive turbidity in filtered water could present problems
in attaining effective disinfection and would be a likely cause for rejection of bag filters by
drinking water regulators.
If the source water used as feed water consistently has a very low turbidity and very low
concentration of algae and other particulate matter, drinking water regulators may be reluctant to
approve bag filters for applications in which the source water turbidity or particulate matter
concentration is higher (Alaska Department of Environmental Conservation, 1994). The feed
water quality chosen for Verification Testing can influence both performance of the filtration
equipment and the potential for acceptance of testing results by state regulatory agencies.
For these reasons the characterization of the feed water was an important task in the verification
testing.
The objective of this task was to obtain data from one or more years for the chemical, biological,
and physical characterization of the feed water that will be entering the treatment system. Factors
of particular interest include conditions that affect bag filter cycle lengths, such as turbidity in
runoff events following heavy rainfall or snowmelt, or algae blooms.
3.3.1.1 Work Plan
This task was accomplished by compiling data obtained from the host utility. The host utility had
limited feed water quality information but did have some historical water quality data for
turbidity, pH, temperature, Total and Fecal Coliform, and conductivity. This information is
presented in Appendix A.
A brief description of the watershed that provides the feed water was developed, to aid in
interpretation of feed water characterization. The watershed description included a statement of
the approximate size of the watershed, a description of the topography (i.e. flat, gently rolling,
hilly, mountainous) and a description of the kinds of human activities that take place (i.e. mining,
manufacturing, cities or towns, farming) or animal activities with special attention to potential
sources of pollution that might influence feed water quality. The nature of the water source was
also included.
3.3.1.2 Evaluation Criteria
Feed water quality was evaluated in the context of the treatment system's performance
capabilities and the Surface Water Treatment Rule. The feed water was examined to determine
if it provided a sufficient challenge the capabilities of the equipment but was not be beyond the
range of water quality suitable for treatment by the equipment in question.
3.3.2 Task B: Initial Test Runs
Initial operations allowed the equipment manufacturer to refine the unit's operating procedures
and to make operational adjustments as needed to successfully treat the source water.
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Information gathered during system start up and optimization would have been used to refine the
Field Operations Document (FOD), if necessary. No adjustment to the FOD was necessary as a
result of the initial operations. The initial operations periods were used to evaluate the variability
of the filter bags.
One objective of the initial test runs was to determine whether any pretreatment of the feed water
was required prior to introduction to the system. Bag filtration may not be suitable for some feed
waters. These feed waters may require some type of pretreatment prior to introduction to the bag
filtration system. An evaluation of the historical feed water quality data may indicate the need for
some type of pretreatment. Initial test runs may be necessary to demonstrate the suitability of the
bag filtration system for the particular feed water. Treatment requirements may be different for
feed waters from different test sites or for the feed water from the same site at different times of
testing.
Another objective of the initial test runs was to determine the operating characteristics of the
treatment system. Testing also was used to demonstrate the level of filtered water turbidity that
the equipment can produce at the test site.
The first initial operations period examined the variability of three bags from the same lot and
the second initial operations period examined the variability of three bags from different lots.
The unit was on site and operating in April of 2000.
3.3.2.1 Work Plan
Initial tests were conducted using the filtration equipment that would be used for Verification
Testing. During exploratory tests, filters were operated until sufficient data were collected to
facilitate making reliable projections on the total volume of water that could be filtered through a
filter bag before it clogs and must be replaced.
Initial test runs were also conducted to assess filter variability. Simultaneous testing of three
filters from the same lot and receiving feed water from a single source was carried out for 10
days. Then the filter bags were changed out and replaced with one bag from the first lot tested
and with two other bags from two different lots. Following the change of the bags, another 10
days of simultaneous testing was done with treatment of feed water from a single source. All
filters were operated at the same rate of flow except for reductions in flow caused by head loss.
During the 10 day filter variability testing periods, each filter was operated for 23 hours and
stopped for 1 hour during each of the 10 days of operation.
The testing for water quality focused on turbidity and particle counting only, with no
microbiological sampling done for detection of differences between bags, to obtain data using a
sensitive monitoring technique, but at the same time minimizing the monitoring costs. Three
particle counters were used to obtain continuous readings from each of the tested filters.
Likewise, three on line turbidimeters were used to obtain readings form each of the three tested
filters. Appropriate statistical analyses were carried out to assess the differences in performance
among three bags of the same lot and among three bags from three different lots. Other data
collected included rate of flow and head loss.
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3.3.2.2 Bag Filter Effluent Turbidity
As previously discussed the major focus of the initial operations periods was to test the
variability of the filter bags. One method to quantify this variability was to measure the turbidity
in the effluent from each filter bag assembly. This was accomplished by using three Hach
1720D turbidimeters one connected to each bag filter effluent being tested. The collected data
was statistically analyzed to determine if there was variability in the bag filters.
3.3.2.3 Bag Filter Effluent Particulate Levels
Bag variability was also quantified by examining the level of particulate material in the effluent
from each bag filter assembly. The particle counting was done utilizing three Met One PCX
particle counters.
3.3.2.4 Pressure Differential
Another important measure of filter bag variability was the pressure differential developed by
each of the filter bags being tested. The pressure differential was calculated by subtracting the
pressure of the water at the bag filter effluent from the pressure of the water at the bag filter inlet.
The pressure differentials of each of the bag filter assemblies were compared to determine if
there was a significant variation between filter bags.
3.3.2.5 Flow Rate
The flow rate was measured only on the inlet and outlet of the treatment array. While this
information was not useful in determining filter bag variability it was useful in assuring that the
treatment unit was being operated in a consistent manner.
3.3.2.6 Analytical Schedule
Because these runs were being conducted to define operating conditions for Verification Testing,
a strictly defined schedule for sampling and analysis did not need to be followed.
3.3.2.7 Evaluation Criteria
The Manufacturer and FTO evaluated the data produced during the initial test runs to determine
if the water treatment equipment performed so as to meet or exceed expectations with regard to
water quality.
After the variability testing of multiple bags or cartridges had been completed, the FTO used the
turbidity data and the particle count data collected during the variability testing to calculate 95%
confidence intervals as described in "Protocol for Equipment Verification Testing for Physical
Removal of Microbiological and Particulate Contaminants" (NSF 1999).
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3.3.3 Task 1: Verification Testing Runs
The objective of this task was to operate the treatment for period at least 30 days and to evaluate
equipment performance under a range of circumstances including installation of new bags and
attainment of terminal head loss. The water treatment equipment was operated for verification
testing purposes, with the approach to treatment based on the results of the initial operations
testing.
During the testing period, Tasks 1 through 6 were conducted simultaneously.
During verification testing, water treatment equipment was operated for 37 days. The treatment
equipment was operated from start-up until terminal head loss was attained. During this period of
time, the filtration equipment was operated for 23 hours and turned off for one hour each day.
The one-hour shutdown was done to simulate the on-off operating mode that may be encountered
in many small systems. The 23 hours of operation provided the opportunity for the FTO to log
the maximum number of hours of equipment operation available each day, this helped to
minimize the total number of days of operation needed to attain terminal head loss. When
terminal head loss was attained, the clogged bag was removed and replaced with a new one, and
operation resumed. The duration of each filter run from initial start to terminal head loss and the
volume of water produced by the bag was recorded in the operational results.
3.3.3.1 Evaluation Criteria
The goal of this task was to operate the equipment, including time for changing prefilters and
bag filters and other necessary operating activities, during verification testing. Data is provided
to substantiate the operation for 37 days.
3.3.4 Task 2: Test Runs for Feed Water and Finished Water Quality
The water quality parameters selected for testing included all those necessary to permit
documentation of the treatment systems performance capabilities. The performance of the
prefilter with respect to water quality was also documented. Without such documentation the
range of water quality for which the treatment system may be accepted could be considerably
more restricted.
Table 3-1 lists the daily, weekly, and monthly water quality samples that were collected. The
results of the daily on-site analyses were recorded in the operations log book. The weekly and
monthly laboratory analyses were recorded in laboratory log books and reported to the FTO on
separate laboratory report sheets. The data spreadsheets are attached to this report as Appendix
B.
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Table 3-1. Analjtical Data Collection Schedule
Parameter
Frequency
Feed
Prefilter Effluent
Bag Filter Effluent
Onsite Analytes
Temperature
Daily
1
0
0
pH
Daily
1
0
0
Turbidity
Daily
Continuous
Continuous
Continuous
Particle Counts
Daily
Continuous
Continuous
Continuous
Laboratory Analytes
Total Alkalinity
Once/month
1
0
1
Total Hardness
Once/month
1
0
1
Total Coliforms
Once/month
1
0
1
TOC
Once/month
1
0
1
Iron
Twice/month
1
1
1
Manganese
Twice/month
1
1
1
Algae
Weekly
1
1
1
The manufacturer was responsible for establishing the filtration equipment operating parameters,
on the basis of the initial test runs. The treatment system was operated as described in Section
3.3, Schedule. When terminal head loss was reached, the filter bag was replaced, and filtration
operations was resumed and continued until the end of the test period.
The water quality parameters listed in Table 3-1 under the heading On Site Analytes were
measured by the FTO. Analysis of the remaining water quality parameters was performed by a
state-certified analytical laboratory. The methods used for measurement of water quality
parameters in the field are described in the QA/QC section below and in Table 3-3. Where
appropriate, the Standard Methods reference numbers for water quality parameters are provided
for both the field and laboratory analytical procedures.
Water quality samples that were shipped to the state-certified analytical laboratory for analysis
were collected in appropriate containers (containing preservatives as applicable) prepared by the
laboratory. These samples were preserved, stored, shipped and analyzed in accordance with
appropriate procedures and holding times, as specified by the analytical laboratory.
Turbidity of the feed and filtered water was measured and recorded using a continuous, flow-
through turbidimeter. On a daily basis, a bench model turbidimeter was used to check the
continuous turbidimeter readings.
The water quality parameters were selected to provide State drinking water regulatory agencies
with background data on the quality of the feed water being treated and data on the quality of the
filtered water. The parameters were selected to enhance the acceptability of the verification
testing data to a wide range of drinking water regulatory agencies.
3.3.4.1 Evaluation Criteria
Evaluation of water quality in this task was related to determining whether the treatment system
was capable of meeting the requirements of the Surface Water Treatment Rule.
¦ Turbidity removal equals or exceeds requirements of Surface Water Treatment Rule
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¦ Water quality and removal goals specified by the Manufacturer
¦ Water quality improvement attained by prefiltration
The regulations proposed in the Enhanced Surface Water Treatment Rule (ESWTR) also
provided guidance for the treatment goals established in the Manufacturer's statement of
performance capabilities and was considered in the evaluation criteria.
3.3.5 Task 3: Documentation of Operating Conditions and Treatment Equipment
Performance
The objective of this task was to accurately and fully document the operating conditions that
applied during treatment, and the performance of the equipment. This task was intended to
develop data that described the operation of the equipment and develop data to create cost
estimates for operation of the equipment.
During each day of verification testing, operating conditions were documented. This included
descriptions of treatment processes used and their operating conditions. In addition, the
performance of the water treatment equipment was documented, including rate of filter head loss
gain, water pressure at the inlet and outlet of the pre and bag filter pressure vessels, length of
filter run and terminal head loss.
The operational parameters and frequency of readings are listed in Table 3-2 below.
Table 3-2. Operational Data Collection Schedule
Parameter Frequency
Raw Flow
2/day
Filtrate flow
2/day
Prefilter inlet pressure
2/day
Prefilter outlet pressure
2/day
Bag filter inlet pressure
2/day
Bag filter outlet pressure
2/day
A complete description of each process was developed. Provided data on the filter included:
¦ flow capacity
¦ nominal pore rating of filter bag and the method used to determine this pore rating
¦ number of filter bags housed within the pressure vessel
¦ maximum operating pressure of filter vessel
¦ volume of filter vessel
¦ a complete description of the pre-filtration equipment
In addition, system reliability features including redundancy of components were observed.
Spatial requirements for the equipment (footprint) were obtained. The above requirements were
met by information provided by the manufacturer.
During each day of verification testing, treatment equipment operating parameters for treatment
system were monitored and recorded on a routine basis. This included rate of flow, filtration rate,
pressure at filter vessel inlet and outlet, and maximum head loss. Performance was evaluated to
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develop data on the number of gallons of water that was treated by each bag and on energy
needed for operation of the process train being tested.
A daily log was kept in which events in the watershed are noted if they influenced source water
quality. This included such things as major storm systems, rainfall, snowmelt, temperature, cloud
cover, and upstream construction activities that disturbed soil.
The performance of the prefiltration equipment was documented in the same manner as the bag
filtration portion of the treatment system.
3.3.5.1 Evaluation Criteria
The data developed from this task was analyzed to determine the treatment system's
performance capabilities. The quantity of water that was produced and met quality criteria for
acceptance was an important factor in this evaluation.
3.3.6 Task 4: Microbiological Contaminant Removal
Removal of microbiological contaminants is a primary purpose of filtration of surface waters.
Consequently, the treatment system's microbial removal effectiveness was evaluated in this task.
Assessment of treatment efficacy was made on the basis of removal of polymeric microspheres.
The bag filtration process removes particles from water by physically straining out the particles
and trapping them in the bag filter. Because particle removal is accomplished primarily by
straining out particles from water on the basis of the sizes of the particles and of the pores in the
filter, the applicability of surrogate particles depends on their size, shape and pliability, rather
than on their biological nature. Thus appropriately sized microspheres could be suitable
surrogates for protozoan cysts and oocysts.
Cysts and oocysts are biological particles without hard shells or skeletons, so they are capable of
deforming slightly and squeezing through pores that might seem to be small enough to prevent
their passage. In addition, the pore sizes for filter bags are not absolute, and these filters have
some pores that are larger and some that are smaller than the nominal size. Therefore they do not
provide an absolute cutoff for particles at or slightly larger than their nominal size. For these
reasons, microspheres used in challenge tests were slightly smaller than the smallest size for the
protozoan organism for which the microspheres were a surrogate.
Removal of turbidity by bag filtration is not synonymous with removal of protozoan organisms
because turbidity-causing particles can be much smaller than protozoa. This results in bag filters
being able to remove protozoan-sized particles while passing particles in the size range of
bacteria, or the micron-sized and sub-micron-sized particles that cause turbidity. Therefore
turbidity removal is not a surrogate for protozoan removal in bag filtration.
Use of electronic particle counting to assess protozoan removal is appropriate only for feed
waters containing large numbers of particles in the size range of Cryptosporidium. For
Cryptosporidium oocyst removal, assessment of particle removal in the size range of 3 to 5 |im is
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appropriate. For a general evaluation of particle removal capabilities, total particles in the 2 to 15
|im range were also be counted. Sufficient concentrations of appropriately sized particles were
not present in the feed water so the use of electronic particle counting was not capable of
demonstrating adequately high log removals.
The objective of this task was to evaluate removal of particles and microbiological contaminants
during verification testing by measuring removal of polystyrene fluorescent microspheres seeded
into the feed water. Task 4 consisted of particle counting and tests involving seeded microspheres.
3.3.6.1 Seeding Technique
During seeding tests, the concentrated suspension of microspheres was gently stirred to maintain
the particles in suspension. The concentrated microspheres were suspended in a solution of
distilled water with 0.01% Tween 20. Before each run with seeded microspheres, the holding
vessel was washed with hot water and laboratory glassware detergent and thoroughly rinsed with
tap water. Microspheres were added to the feed water using variable speed chemical feed
pumps. Mixing of seeded particles into the feed water was done with an in-line mixer that
attains a head loss of about 0.3 to 0.5 feet of water during operation.
3.3.6.2 Electronic Particle Counting
Particle counts in feed water just before entry into the treatment system were measured to
determine the concentration of particles before filtration, and particle counts in the filtered water
were measured. For assessing Cryptosporidium oocyst removal, particles in the size range of 3 to
5 |im were counted. For assessing Giardia cyst removal, particles in the size range of 5 to 15 |im
were counted. Since appropriately sized particles were not present in sufficient densities
(concentrations) in the feed water to permit calculation of log removals consistent with the
SWTR and ESWTR requirements, particle counting for log removal was done during
microsphere challenge events. For a general evaluation of particle removal capabilities, total
particles in the size range of 2 to 15 |im were counted.
3.3.6.3 Microspheres
Evaluation of microsphere removal was conducted by determining the number of microspheres
added to the feed water in a slug dose and then measuring the total number of microspheres
detected in the filtered water. Microspheres used as surrogates for Cryptosporidium oocysts were
3.69 |im (+/- 0.05 |im) in diameter. Microspheres used as surrogates for Giardia cysts were 5.68
|im (+/- 0.433 |im) in diameter. Both Cryptosporidium oocysts sized microspheres and Giardia
cysts sized microspheres were used during the challenge tests in order to develop log removals
for each organism.
The number of microspheres used were sufficient to permit calculation of log removals that
exceed the removal capability as set forth in the SWTR and ESWTR requirements. Recovery of
microspheres in filtered water provided data for use in calculating definite removal percentages.
Fluorescent microspheres and an optical microscope equipped with ultraviolet illumination were
used for the enumeration.
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A slug dose of the microspheres of a concentration of approximately 3.6* 108 for the 3.69 |im and
2 i*io8 for the 5.68 |im microspheres were added instantaneously to the feed water influent. An
aliquot of the stock feed suspension was collected for analysis to calculate the concentration of
the stock feed suspension. Additionally, samples of the feed water after the addition of the
microspheres were collected to calculate the concentration of microspheres added to the
treatment system. A sample of the feed water was collected prior to the introduction of the
microspheres to check for the presence of interfering fluorescent particles in the feed water. Ten
percent of the filtrate flow was collected in a side stream sample. The side stream was run at two
gallons per minute until 20 gallons has been collected. The resulting 20 gallons of filtrate was
shipped on ice overnight to the analytical laboratory for analysis using EPA Method 1622.
Concentration of the microspheres in the collected water samples was done based on methods
described in EPA Method 1622 using the approved disk track side etch membrane filter. Elution
of the microspheres from the membrane was done using the method published in the original
EPA draft of Method 1622. The enumeration of the microspheres was done using the method
used by Abbaszadegan et al. (1997) as referenced in the ETV Test Plan Protocol. (EPA/NSF
ETV Protocol - NSF Equipment Verification Testing Plan Bag Filters and Cartridge Filters for
the Removal of Microbiological and Particulate Contaminants, May, 1999).
3.3.6.4 Analytical Schedule
Feed and filtered water analysis was done using flow-through particle counters equipped with
recording capability so data can be collected on a 24-hour-per-day basis during verification
testing.
Microspheres were seeded for evaluating the performance of a continuously running filter three
times during a run: at the start-up of the equipment after a new filter bag has been installed, near
the middle of the run when headloss has approached one half of the recommended terminal
headloss, and near the end of the run after headloss has exceeded 90 percent of recommended
terminal headloss. In addition, after the seeding challenge and sampling event in the middle of
the run had been completed, the filter flow was stopped and preparations were made for another
round of sampling. The treatment system was restarted and sampling was done again to evaluate
the effect of stopping and starting a filter that has removed a very large number of microspheres.
Microsphere samples were analyzed by Clancy Environmental Consultants.
3.3.6.5 Evaluation Criteria
Performance of the Treatment System was evaluated in the context of the SWTR and ESWTR
turbidity requirements and Giardia and Cryptosporidium removal goals. Turbidity results were
analyzed to determine the percentage of turbidity data in the range of 0.50 NTU or lower, the
percentage between 0.51 NTU and 1.0 NTU, the percentage between 1.0 and 5 NTU, and the
percentage that exceed 5 NTU. The time intervals used for determining filtered water turbidity
values were the same for all data analyzed, and because continuous turbidimeters were used to
collect turbidity data, the intervals were every 15 minutes. In addition, the highest filtered water
turbidity observed each day was tabulated.
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Electronic particle count data were evaluated by calculating the change in total particle counts
from feed water to filtered water, expressing the change as log reduction. Because of possible
complications in conducting electronic particle counts on feed water, four hour time intervals
were used for analysis of particle counting data for log reduction of particles. Total particle
counts from the feed and finished water were selected from the ten minute "continuous"
readings. These four hour readings were used to calculate a four hour log removal of total
particle counts. The four hour readings are presented in a table and graphically and the log
reductions are presented graphically.
Data on the density (concentration) of microspheres in feed water and filtered water were
analyzed to determine the median log removal and 95th percentile log removal during the
verification testing period. This analysis was done separately for each filter operating condition:
at start-up with a new bag filter, midway through a run (with the previously discussed stop and
restart of the filter system), and after 85 to 95 percent of terminal headloss has been attained.
3.3.7 Task 5: Data Management
Documentation of study events was facilitated through the use of logbooks, photographs, data
sheets and chain of custody forms. Data handling is a critical component of any equipment
evaluation or testing. Care in handling data assures that the results are accurate and verifiable.
Accurate sample analysis is meaningless without verifying that the numbers are being entered
into spreadsheets and reports accurately and that the results are statistically valid.
The data management system used in the verification testing program involved the use of
computer spreadsheet software and manual recording methods for recording operational
parameters for the membrane filtration equipment on a daily basis. Weekly and monthly water
quality testing data were submitted to the FTO by CWM Laboratory representatives, verified,
and entered into computer spreadsheets.
There were two primary objectives of the data handling portion of the study. One objective was
to establish a viable structure for the recording and transmission of field testing data such that the
FTO provides sufficient and reliable operational data for the NSF for verification purposes. A
second objective was to develop a statistical analysis of the data, as described in the "EPA/NSF
ETV Protocol for Equipment Verification Testing for Physical Removal of Microbiological and
Particulate Contaminants" (EPA/NSF 1999).
The data handling procedures were used for all aspects of the verification test. Procedures
existed for the use of the log books used for recording the operational data, the documentation of
photographs taken during the study, the use of chains of custody forms, the gathering of inline
measurements, entry of data into the customized spreadsheets, and the methods for performing
statistical analyses.
3.3.7.1 Log Books
Field testing operators recorded data and calculations by hand in the field logbook. The field
logbook provided carbon copies of each page. The original logbook was stored on-site; the
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carbon copy sheets were collected by the FTO at least once per week. This protocol not only
eased referencing the original data, but also offered protection of the original record of results.
Pilot operating logs include a description of the bag filtration equipment (description of test runs,
names of visitors, description of any problems or issues, etc); such descriptions were provided in
addition to experimental calculations and other items.
Field log books were bound with numbered pages and labeled with project name. The log book
is attached to this report as Appendix C. Log books were used to record equipment operating
data. Each line of the page was dated and initialed by the individual responsible for the entries.
Errors had one line drawn through them and the line was initialed and dated. Although the FTO
attempted to initial and date each page and individual line entries review of the log book at the
conclusion of testing indicated that in a few instances the entries had not been initialed. Field
testing operators recorded data and calculations by hand in laboratory notebooks. Daily
measurements were recorded on specially prepared data log sheets. The laboratory notebook
was photocopied weekly. The original notebooks were stored on-site; the photocopied sheets
were stored at the office of the FTO. This procedure eased referencing the original data and
offered protection of the original record of results. Treatment unit operating logs included a
description of the treatment equipment (description of test runs, names of visitors, description of
any problems or issues, etc); such descriptions were provided in addition to experimental
calculations and other items.
3.3.7.2 Photographs
Photographs were logged in the field log book. These entries include time, date, direction,
subject of photo and the identity of the photographer.
3.3.7.3 Chain of Custody
Samples which were collected by the FTO and hand delivered to the laboratory were logged into
the laboratory's sample record upon arrival at the laboratory. Submitted samples were collected
and hand delivered to the laboratory accompanied by chain of custody forms. The chain of
custody forms are included in Appendix D.
3.3.7.4 Online Measurements
Data from the computers recording the online measurements were copied to disk at least on a
weekly basis. This information was stored on site and at the FTO's office.
3.3.7.5 Data Management Spreadsheets
The database for the project was set up in the form of custom-designed spreadsheets. The
spreadsheets were capable of storing and manipulating each monitored water quality and
operational parameter from each task, each sampling location, and each sampling time. All data
from the field logbook were entered into the appropriate spreadsheet. Data entry was conducted
off-site by the designated FTO representatives. All recorded calculations were checked at this
time. Following data entry, the spreadsheet was printed out and the print-out was checked
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against the handwritten data sheet. Any corrections were noted on the hard-copies and corrected
on the screen, and then a corrected version of the spreadsheet was printed out. Each step of the
verification process was initialed by the FTO representative performing the entry or verification
step.
Each experiment (e.g. each filtration test run) was assigned a run number which was then tied to
the data from that experiment through each step of data entry and analysis. As samples were
collected and sent to the analytical laboratory, the data were tracked by use of the same system of
run numbers. Data from the outside laboratory were received and reviewed by the FTO. These
data were entered into the data spreadsheets, corrected, and verified in the same manner as the
field data.
3.3.7.6 Statistical Analysis
Water quality data developed from grab samples collected during filter runs, the operational data
recorded in the logbook, and the online data were analyzed for statistical uncertainty. The FTO
calculated the average, minimum, maximum, standard deviation, and the 95% confidence
intervals. The statistics developed are helpful in demonstrating the degree of reliability with
which water treatment equipment can attain quality goals. The FTO calculated a 95%
confidence interval for selected parameters. These calculations were carried out on data from
inline monitors and for grab samples of algae, pH, and temperature. The equation used is:
95% confidence interval = X ± tn_j 0 975 (s l4n\
where: X is the sample mean;
S is the sample standard deviation;
n is the number of independent measurements included in the data set; and
t is the Student's t distribution value with n-1 degrees of freedom.
Results of these calculations are expressed as the sample mean +/- the statistical variation.
3.4 Field Operations Procedures
In order to assure data validity NSF Verification Testing Plan procedures were followed. This
ensured the accurate documentation of both water quality and equipment performance. Strict
adherence to these procedures resulted in verifiable performance of equipment.
3.4.1 Equipment Operations
The operating procedures for the Aqua-Rite Potable Water Filtration System are described in the
Operations Manual (Appendix E) (Lapoint 2001). Analytical procedures are described in CWM
Laboratory's Quality Assurance Plan (Appendix F) (CWM 2000).
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3.4.1.1 Operations Manual
The Operations Manual for the treatment system was not available during the testing but is
attached to this report as Appendix E. An evaluation of the O&M manual was conducted to
evaluate the instructions and procedures for their applicability.
3.4.1.2 Analytical Equipment
The following analytical equipment was used during the verification testing:
¦ A Fisher Accumet Model AP61 portable pH meter was used for pH analyses.
¦ A Hach 21 OOP portable turbidimeter was used for turbidity analyses.
¦ An Ertco 1003-FC NIST traceable thermometer was used for temperature analyses. The
thermometer had a range -1 to 51°C with scale divisions of 0.1°C.
¦ Hach 1720D turbidimeters were used for feed, prefilter effluent, and bag filter effluent
turbidity.
¦ Met One PCX particle counters were used for feed, prefilter effluent, and bag filter effluent
particle analysis.
3.5 QA/QC Procedures
Quality assurance and quality control of the operation of the bag filtration equipment and the
measured water quality parameters was maintained during the Verification Testing Program.
The objective of this task was to maintain strict QA/QC methods and procedures during the
equipment verification testing. Maintenance of strict QA/QC procedures is important, in that if a
question arises when analyzing or interpreting data collected for a given experiment, it will be
possible to verify exact conditions at the time of testing.
Equipment flow rates and associated signals were verified and verification recorded on a routine
basis. A routine daily walk-through during testing was established to verify that each piece of
equipment or instrumentation was operating properly. In-line monitoring equipment such as
flow meters, etc. were checked to verify that the readout matches with the actual measurement
(i.e. flow rate) and that the signal being recorded is correct. The items listed are in addition to
any specified checks outlined in the analytical methods.
3.5.1 Daily QA/QC Verification Procedures
Daily QA/QC procedures were performed on the online turbidimeter and online particle counter
flow rates and online turbidimeter readout.
3.5.1.1 Online Turbidimeter Flow Rate
The online turbidimeter flow rate was verified volumetrically over a specific time. Effluent from
the unit was collected into a graduated cylinder while being timed. Acceptable flow rates, as
specified by the manufacturer, ranged from 250 ml/minute to 750 ml/minute. The target flow
rate was 500 ml/minute. Adjustments to the flow rate were made by adjusting the valve
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controlling flow to the unit. Fine adjustments to the flow rate were difficult to make. If
adjustments to the flow rate were made they were noted in the field logbook by including the
flow rate prior to adjustment in parentheses next to the description of what adjustment was made.
3.5.1.2 Online Particle Counter Flow Rate
The flow rates for the feed water and filtrate online particle counters were verified volumetrically
over a specific time. Effluent from the units was collected into a graduated cylinder while being
timed. Acceptable flow rates, as specified by the manufacturer, ranged from 90 ml/minute to
110 ml/minute. The target flow rate was 100 ml/minute. Care was taken to maintain the flow
rate between 95 ml/minute and 105 ml/minute. Changes to the flow rate were made by adjusting
the level of the discharge from the overflow weir. If adjustments to the flow rate were made they
were noted in the field logbook by including the flow rate prior to adjustment in parentheses next
to the description of what adjustment was made.
3.51.3 Online Turbidimeter Readout
Online turbidimeter readings were checked against a properly calibrated bench model. Samples
of the feed prefilter effluent, and filtrate were collected and analyzed on a calibrated bench
turbidimeter. The readout of the bench model and the online turbidimeters were recorded. Exact
agreement between the two turbidimeters is not likely due to the differences in the analytical
techniques of the two instruments.
3.5.2 Bi-weekly QA/QC Verification Procedures
Bi-weekly QA/QC procedures were performed on the online flow meter. Meter was checked to
determine if cleaning was necessary and verification of flow was performed.
3.5.2.1 Online Flow Meter Clean Out
Examination of the online flow meters indicated that clean out was not required during the
verification testing. This was due to the short duration of the study and the high quality of the
feed water.
3.5.2.2 Online Flow Meter Flow Verification
Verification of the readout of the feed, and filtrate flow meters was conducted bi-weekly during
the testing period. This was done by taking the instantaneous reading from the meter and
comparing it to a volume collected over the time period.
3.5.3 Procedures for QA/QC Verifications at the Start of Each Testing Period
Verifications of the online turbidimeter, pressure gauges, tubing, and particle counters were
conducted. These verification procedures follow.
28
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3.5.3.1 Online Turbidimeter
The online turbidimeter reservoir was cleaned by removing the plug from the bottom of the unit
and allowing the body to drain. The body of the unit was then flushed with water. The unit was
recalibrated following manufacturer's recommendations.
3.5.3.2 Pressure Gauges
Pressure gauge readings were verified through the use of a dead weight test meter. Procedures
for the use of the meter were included with the meter. Generally, the procedure consisted of
placing the gauge on the meter adding weight to the meter and comparing the reading obtained to
the known amount of weight.
3.5.3.3 Tubing
The tubing and connections associated with the treatment system were inspected to verify that
they were clean and did not have any holes in them. Also, the tubing was inspected for
brittleness or any condition which could cause a failure
3.5.3.4 Online Particle Counters
Calibration of the particle counter is generally performed by the instrument manufacturer. The
calibration data were provided by the instrument manufacturer for entry into the software
calibration program. Once the calibration data were entered it was verified using calibrated
mono-sized polymer microspheres. Microspheres of 5|im, 10|im and 15|im were used for
particle size verification. The following procedure was used for instrument calibration
verification:
¦ Analyze the particle concentration in the dilution water;
¦ Add an aliquot of the microsphere solution to the dilution water to obtain a final
particle concentration of 2,000 particles per ml;
¦ Analyze a suspension of each particle size separately to determine that the peak
particle concentration coincides with the diameter of particles added to the dilution
water;
¦ Prepare a cocktail containing all three microsphere solutions to obtain a final particle
concentration of approximately 2,000 particles per ml of each particle size; and
¦ Analyze this cocktail to determine that the particle counter output contains peaks for
all the particle sizes.
3.5.4 On-Site A nalytical Methods
Procedures for daily calibration, duplicate analysis, and performance evaluation for pH,
temperature, and residual chlorine are discussed in the following sections.
3.5.4.1 pH
Analysis for pH was performed according to Standard Methods 4500-H . A two-point
calibration of the pH meter was performed each day the instrument was in use. Certified pH
29
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buffers in the expected range were used. After the calibration, a third buffer was used to check
linearity. The values of the two buffers used for calibration, the efficiency of the probe
(calculated from the values of the two buffers), and the value of the third buffer used as a check
were recorded in the logbook.
pH measurements do not lend themselves to "blank" analyses. Duplicates were run once a week.
Performance evaluation samples were analyzed during the testing period. Results of the
duplicates and performance evaluation were recorded.
3.5.4.2 Temperature
Readings for temperature were conducted in accordance with Standard Methods 2550. Raw
water temperatures were obtained once per day by submerging the thermometer in the feed water
reservoir. A National Institute of Standards and Technology (NIST) certified thermometer
having a range of - 1°C to +51°C, subdivided in 0.1°C increments was used for all temperature
readings.
Temperature measurements do not lend themselves to "blank" analyses. Duplicates were run on
every sample. The temperature of the feed water was not recorded until two like readings were
obtained, indicating that the thermometer had stabilized. Two equivalent readings were
considered to be duplicate analyses.
3.5.4.3 Turbidity Analysis
Turbidity analyses were performed according to Standard Methods 2130. The bench-top
turbidimeter was calibrated at the beginning of verification test and on a weekly basis using
primary turbidity standards according to manufacturer's recommendations. Primary turbidity
standards of 0.1, 0.5 and 5.0 NTU were checked after calibration to verify instrument
performance. Deviation of more than 10 % of the true value of the primary standards indicated
that recalibration or corrective action should be undertaken on the turbidimeter. Secondary
standards were used on a daily basis to verify calibration.
3.5.5 Chemical and Biological Samples Shipped Off-Site for Analyses
CWM Laboratory conducted the analysis of chemical and biological parameters. CWM's QA
Plan outlines sample collection and preservation methods (CWM 2000) (Appendix F). Sample
collection was done by representatives of the FTO.
3.5.5.1 Total Organic Carbon
Sample(s) for analysis of TOC were collected in glass bottles supplied by the CWM laboratory
and held at approximately 4°C during delivery to the analytical laboratory. These samples were
preserved, held, and delivered in accordance with Standard Method 5010B. Storage time before
analysis was minimized, according to Standard Methods. Specific QA/QC procedures are
detailed in CWM's QA Plan included as Appendix F.
30
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3.5.5.2 Microbial Parameters: Total Coliform and Algae
Total coliform samples were collected in bottles supplied by CWM Laboratories and held at
approximately 4°C during delivery to the analytical laboratory. Total coliforms were analyzed
using procedures presented in CWM's QA Plan. These procedures are based on Standard
Methods 9222B. Samples were processed for analysis by CWM Laboratory within the time
specified for the relevant analytical method. The laboratory kept the samples at approximately
4°C until initiation of analysis. Specific QA/QC procedures are detailed in CWM's QA Plan
included as Appendix F.
Algae samples were analyzed according to Standard Method 10200 F. The samples were
preserved with Lugol's solution after collection, stored and shipped in a cooler at a temperature
of approximately 4°C, and held at that temperature range until counted. Specific QA/QC
procedures are detailed in CWM's QAPlan included as Appendix F.
3.5.5.3 Inorganic Parameters
Inorganic chemical samples, including alkalinity, hardness, iron, and manganese, were collected,
preserved and held in accordance with Standard Methods 301 OB, paying particular attention to
the sources of contamination as outlined in Standard Method 3010C. The samples were
refrigerated at approximately 4°C immediately upon collection, shipped in a cooler, and
maintained at a temperature of approximately 4°C. The laboratory kept the samples at
approximately 4°C until initiation of analysis. Specific QA/QC procedures are detailed in
CWM's QAPlan included as Appendix F.
Total alkalinity analyses were conducted according to Standard Methods 2320 B. Total
Hardness analyses were conducted according to Standard Methods 2340 C. Iron and manganese
analyses were conducted according to Standard Methods 3113 B.
3.5.5.4 Microspheres
Filtrate samples for microsphere analysis were shipped overnight in a cooler and maintained at a
temperature of approximately 2 to 8°C during shipment and in the analytical laboratory, until
they were analyzed.
Recovery of microspheres from suspensions held in glassware was evaluated by preparing a
suspension of microspheres in which the number of microspheres used to make the suspension is
estimated, based on either the weight of dry microspheres or the volume of microspheres in
liquid suspension as provided by the supplier. After the suspension was prepared and mixed
until it was homogeneous, five aliquots were taken and counted in the hemocytometer. After the
microsphere density (concentration) had been calculated, aliquots of the suspension were diluted
and filtered through polycarbonate membrane filters having 1 //m pore size. The elution and
concentration steps described in Task 4 of the NSF Equipment Verification Testing Plan Bag and
Cartridge Filters were followed, and the microspheres were counted in a hemocytometer. This
was done five times, so that statistics could be developed on the recovery of microspheres in the
sampling procedure.
31
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As a check on possible interference from fluorescing organisms in the feed water during three of
the four verification testing runs in which fluorescent microspheres were used, a sample of feed
water with no seeded microspheres was filtered through a polycarbonate membrane, and the
particulate matter on the membrane was concentrated using the procedures for microsphere
analysis, and the concentrate was examined in a hemocytometer by microscope, with UV
illumination. If no objects of the size and shape of the microspheres are seen to fluoresce,
displaying the same color as the microspheres, then fluorescent objects of the proper color seen
in samples with seeded microspheres can be considered to be microspheres.
Microspheres may adhere to surfaces of tanks, vessels, and glassware. All glassware, holding
tanks, and membrane filter manifolds were cleaned between seeding events or sampling events.
Analytical methodology is presented in Table 3-3.
Table 3-3. Analytical Methodology
Parameter
F acility
Standard Methods Number or Other Method Reference
Temperature
On-Site
2550 B
PH
On-Site
4500-H*
Total Alkalinity
Lab
2320 B
Total Hardness
Lab
2340 C
Total Organic Carbon
Lab
5310 C
Turbidity
On-Site
2130 B
Particle Counts (electronic)
On-Site
Manufacturer
Iron
Lab
3113 B
Manganese
Lab
3113 B
Algae, number and species
Lab
10200F
Total Coliform
Lab
9222 B
Microsphere Counts
Lab
Abbaszadegan et al. (1997)
32
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Chapter 4
Results and Discussions
4.1 Introduction
The verification testing for the Aqua-Rite Potable Water Filtration System occurred in the
Borough of Burnside located in Clearfield County, Pennsylvania. The variability testing portion
of the initial operations period occurred during two ten day periods. The first 10 day testing
period began on April 20, 2000; the second 10 day test period began on May 20, 2000. The
verification testing commenced October 9, 2000 and concluded its 30-day period on November
12, 2000. Microbial contaminant removal testing was conducted on October 9 and 25, 2000 and
January 22 and 24, 2001.
This section of the verification report presents the results of the testing and offers a discussion of
the results. Results and discussions of the following are included: equipment characterization
results, characterization of feed water, initial operations, verification testing runs and routine
equipment operation, documentation of operating conditions and treatment equipment
performance, microbiological contaminant removal, feed and finished water quality, and QA/QC
4.2 Equipment Characteristics Results
The qualitative, quantitative and cost factors of the tested equipment were identified during
verification testing, in so far as possible. The results of these three factors are limited due to the
relatively short duration of the testing cycle.
4.2.1 Qualitative Factors
Qualitative factors that were examined during the verification testing were the susceptibility of
the equipment to changes in environmental conditions, operational reliability, and equipment
safety. Also an evaluation of the manufacturer's O&M manual was conducted.
4.2.1.1 Susceptibility to Changes in Environmental Conditions
Changes in environmental conditions that cause degradation in feed water quality can have an
impact on the treatment system. The short duration of the testing cycle minimized the
opportunity for significant changes in environmental conditions. The filtered water quality did
degrade during the second 10 days of initial testing. This was apparent due to the fact that the
filtered water turbidity did not increase during the second 10 days of testing as it had during the
first 10 days of testing. This was most likely caused by a change in the feed water quality. Since
the initial testing focused primarily on testing the variability of the filter bags themselves there
was no feed water quality testing conducted and the cause for the degradation of the filtered
water quality is unknown.
33
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4.2.1.2 Operational Reliability
The treatment system consisted of a prefilter housing, a prefilter, a bag filter housing, and a bag
filter. The system as provided was only capable of manual operation. The only process
adjustment required was to adjust the inlet flow valve as the flow rate decreased due to increased
head loss through the filters. The system required daily checks for flow rate head loss and feed
and bag filter effluent turbidity.
4.2.1.3 Equipment Safety
Evaluation of equipment safety was conducted as part of the verification testing. Evaluation of
the safety of the treatment system was done by examination of the components of the system and
identification of hazards associated with these components. A judgment as to the safety of the
treatment system was made from these evaluations.
The only safety hazards associated with the treatment system are due to the presence of
pressurized filter vessels. The water pressure inside the treatment system was relatively low and
did not represent an unusual safety risk. Procedures for depressurization of the filter vessel are
detailed in the O&M manual (Lapoint 2000) which is presented in Appendix E.
No injuries or accidents occurred during the testing.
4.2.1.4 O&M Manual
The manufacturer supplied O&M manual was rather brief and discussed safety issues as they
relate to pressure relief from the vessels and the filter changeout procedures. The manual was
adequate although no trouble shooting procedures were provided to aid the operator in
identifying possible causes rapid headloss increases, high filtrate turbidity, or other water quality
or operational difficulties. Procedures to identify a mis-installation of the bag filter were not
included.
4.2.2 Quantitative Factors
Quantitative factors that were examined during verification testing were power supply
requirements, consumable requirements, waste disposal technique, and length of operating cycle.
Cost factors for the above items are discussed where applicable. It is important to note that the
figures discussed here are for the Lapoint Aqua-Rite Potable Filtration System operated at an
average flow rate of 20.68 gpm and treating the feed water at the test site. Costs will vary if the
system is operated at different sites and different flow rates.
4.2.2.1 Power Supply Requirements
The treatment system itself had no electrical requirements.
34
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4.2.2.2 Consumable Requirements
The only consumables required for operation are the prefilters and bag filters. The prefilter was
changed two times during the testing; although this was not required given the operational
performance of the prefilters. Change out of the bag filters due to high headloss was required
seven times during the 37 days of testing. A total of eight bag filters and three prefilters were
used during testing. The average amount of water filtered during a filtration cycle was 92,900
gallons. This equates to approximately one bag per 100,000 gallons of filtered water.
4.2.2.3 Waste Disposal
The only waste generated by the treatment system was the spent prefilters and bag filters. These
can be disposed of in a sanitary landfill and would not contain hazardous materials assuming the
feed water is free of hazardous particulates.
4.2.2.4 Length of Operating Cycle
The operating cycle of the treatment system during the verification testing averaged 92,900
gallons per bag filter. The average filter run lasted 98 hours. The length of the cycle will vary
depending on feed water quality.
4.2.2.5 Estimated Labor Hours for O&M
The only repetitive O&M task required for the treatment system is the change out of the prefilter
and bag filters. These tasks are relatively simple and can be accomplished in approximately 5
minutes per bag change. The operator should inspect the condition of the pressure vessel, the
mesh basket that holds the filter, and the basket and cover gaskets during change out.
4.3 Characterization of Feed Water
The source water for the verification testing was from the water system's 208,000 gallon in-
ground covered reservoir located approximately 100 feet in elevation and about one-half mile
away from the chlorine building which housed the treatment unit. The reservoir is primarily
supplied by Spring No. 1 via gravity feed. Spring No. 2, a secondary supply which must be
pumped up to the reservoir, was used on 208 days in 1999. A third spring, Chura Spring, flows
into Spring No. 2.
The covered reservoir and associated springs and well source are considered high quality
supplies. Limited historical of the spring and well water quality exists. The data was developed
during testing to determine if the Borough's sources were ground water under the influence of
surface water (GUDI). Testing was conducted between October 1995 and Jknuary of 1996.
Records indicate that normal turbidity levels are less than 1.0 NTU from Spring No. 1 and Chura
Spring. Normal turbidity from Spring No. 2 is between 1.0 NTU and 2.0 NTU. Fecal and total
coliform bacteria were detected in all of the spring supplies with the total coliform counts being
greater than 500 colonies per 100 ml of water in all three springs. Water from Spring No. 1
contained 0.8 CFU/100 ml of fecal coliform and 726 CFU/100 ml of total coliform on average.
35
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The average fecal coliform density in Spring No. 2 was 0.4 CFU/100 ml; the average total
coliform density was 507 CFU/100 ml. Water from Chura Spring contained 0.4 CFU/100 ml of
fecal coliform and 624 CFU/100 ml of total coliform on average. The pH of all three springs
averaged 7. The conductivity of the water from Spring No. 1 averaged 82.9 umhos. The
conductivity of the water from Spring No. 2 averaged 112.6 umhos. The conductivity of the
water from Chura Spring averaged 74.0 umhos. Temperature of the water in Spring No. 1 and
Spring No. 2 averaged 52°F. The temperature of the water from Chura Spring averaged 55.8°F.
Historical water quality data for each spring is presented in Appendix A. There are no historical
water quality records available for the reservoir well; this supply is treated with a sequestering
agent, indicating the presence of iron and/or manganese.
Table 4-1. Historical Water Quality Results - Spring No. 1
Parameter
Turbidity
PH
Total Coliforms
Fecal Coliforms
Temperature
Conductivity
Date
NTU
CFU/100 ml
CFU/100 ml
°F
(cells/ml)
Number of Samples
30
30
5
5
30
30
Average
0.85
7
726
0.8
52
82.9
Minimum
0.6
7
166
0
52
66.8
Maximum
1.2
7
1484
4
52
113.7
Table 4-2. Historical Water Quality Results - Spring No. 2
Parameter
Turbidity
PH
Total Coliforms
Fecal Coliforms
Temperature
Conductivity
Date
NTU
CFU/100 ml
CFU/100 ml
°F
(cells/ml)
Number of Samples
30
30
5
5
30
30
Average
1.8
7
506.8
0.4
52
112.6
Minimum
1.1
7
87
0
52
72.8
Maximum
3.1
7
1100
2
52
147
Table 4-3. Historical Water Quality Results - Chura Spring
Parameter
Turbidity
PH
Total Coliforms
Fecal Coliforms
Temperature
Conductivity
Date
NTU
CFU/100 ml
CFU/100 ml
°F
(cells/ml)
Number of Samples
30
30
5
5
30
30
Average
0.80
7
624
0.4
55.8
74.0
Minimum
0.35
7
77
0
52
54.4
Maximum
2
7
1529
2
56
103.3
The PADEP has classified these springs and the reservoir as a GUDI; Burnside Borough is
therefore under a consent decree to provide filtration for these supplies. As such, the source
water should be adequate to verify the manufacturer's treatment claims. The determination was
made the feed water was suitable for use in the verification testing program.
4.4 Initial Operations Period Results
The initial test runs were used to determine the operating characteristics of the treatment system.
Also, initial test runs were conducted to facilitate simultaneous testing of multiple bags to
document any performance variability between bags within one production lot and between bags
of different manufacturing lots. The first initial operations period lasted 10 days and examined
36
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variability among bags from the same production lot (Lot # 22435). The second period lasted 10
days and examined variability among bags from different production lots (Lot #22853 and
22854). Another objective of the initial operations was to determine whether any pretreatment of
the feed water is required prior to introduction to the system. Bag filtration may not be suitable
for some feed waters. These feed waters may require some type of pretreatment prior to
introduction to the bag filtration system.
The performance of the filters was evaluated by examining the flow through the system, the
differential pressure, the turbidity, and particle counts from each bag filter.
4.4.1 Flow
The flow rate of the treatment system ranged from 15.2 to 17.4 gpm during the first 10 days of
testing. The average flow rate was 16.7 gpm. During the second 10 days of initial testing the
flow rate to the system averaged 17.3 gpm and ranged from 16.6 to 18.3 gpm.
4.4.2 Pressure Differential
The pressure drop across the filter in housing #1 was 0.5 psi after the first 10 days of testing.
The pressure gauges monitoring the inlet and outlet pressures in housing #2 actually showed a
slight increase in the pressure through the filter. The pressure increased a total of 0.6 psi after
the first 10 days of testing. This was undoubtedly caused by slight differences in the
performance of the pressure gauges themselves at the very low levels of pressure differential
exhibited. The pressure change across the filter in housing #3 likewise increased by 0.4 psi.
There was not a significant difference in the pressure differential exhibited by the three tested
filters during the first 10 days of testing.
The pressure drop across the filter in housing #1 was 0.9 psi during the second 10 days of testing.
The filter in housing #2 again showed a slight increase of 0.2 psi during the second ten days of
testing. The pressure drop across the filter in housing #3 was 0.3 psi during the second 10 days
of testing. There was not a significant difference in the pressure differential exhibited by the
three tested filters during the second 10 days of testing.
4.4.3 Turbidity
The average effluent turbidity as measured by the online turbidimeter produced by the filter in
housing #1 during the first 10 days (testing variability of filters from the same lot) of testing was
0.35 NTU. The average effluent turbidity as measured by the online turbidimeter produced by
the filter in housing #2 during the first 10 days of testing was 0.30 NTU. The average effluent
turbidity as measured by the online turbidimeter produced by the filter in housing #3 during the
first 10 days of testing was 0.30 NTU.
The average effluent turbidity as measured by the online turbidimeter produced by the filter in
housing #1 during the second 10 days of testing (testing variability of filters from the three
different lot) was 0.85 NTU. The average effluent turbidity as measured by the online
turbidimeter produced by the filter in housing #2 during the second 10 days of testing was 0.70
37
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NTU. The average effluent turbidity as measured by the online turbidimeter produced by the
filter in housing #3 during the second 10 days of testing was 0.70 NTU.
Table 4-4. Online Turbidimeter Effluent Turbidity Results from Bag Filter Variability Tests - Same Lot
Housing #1
Housing #2
Housing #3
NTU
NTU
NTU
Number of Samples
11
11
11
Average
0.35
0.30
0.30
Minimum
0.20
0.20
0.15
Maximum
0.75
0.70
0.65
Std. Deviation
0.15
0.15
0.15
95% Confidence Interval
(0.25, 0.45)
(0.20, 0.40)
(0.20, 0.40)
Table 4-5. Online Turbidimeter Effluent Turbidity Results from Bag Filter Variability Tests - Different Lots
Housing #1
Housing #2
Housing #3
NTU
NTU
NTU
Number of Samples
10
10
10
Average
0.85
0.70
0.70
Minimum
0.55
0.55
0.55
Maximum
1.7
0.95
0.90
Std. Deviation
0.30
0.15
0.10
95% Confidence Interval
(0.65, 1.0)
(0.65, 0.80)
(0.65, 0.75)
Analysis of this data indicates that there is not a significant difference in the turbidity produced
by bag filters from the same or different production lots.
There was some concern given the high levels of turbidity passing through all of the bag filter
canisters during the second 10 days of initial testing. All three filter effluent turbidities averaged
greater than the current requirements of the SWTR and ESWTR (EPA 1989, 1999). It is most
likely that this change in performance was caused by a change in feed water quality. Since the
function of the initial operations task was to test variability in the filter bags themselves there is
no data on the feed water turbidity or particle counts for the initial operations period. Therefore
the supposition that a change in feed water quality caused the change in bag filter effluent quality
is not verifiable. Due to this substandard turbidity removal performance Lapoint Industries
agreed to provide a final cartridge filter for use during times that the bag filter effluent turbidity
was in excess of 0.5 NTU. Use of the cartridge filter was for turbidity removal was not required
during the 37 days of verification testing.
4.4.4 Particle Counts
The average effluent cumulative particle counts (>2 |im) produced by the filter in housing #1
during the first 10 days (testing variability of filters from the same lot) of testing was 15.09 total
counts per ml. The average effluent cumulative particle counts (>2 |im) produced by the filter in
housing #2 during the first 10 days of testing was 15.99 total counts per ml. The average effluent
cumulative particle counts (>2 |im) produced by the filter in housing #3 during the first 10 days
of testing was 18.21 total counts per ml.
38
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The average effluent cumulative particle counts (>2 |im) produced by the filter in housing #1
during the second 10 days of testing (testing variability of filters from the three different lot) was
25.16 total counts per ml. The average effluent cumulative particle counts (>2 |im) produced by
the filter in housing #2 during the second 10 days of testing was 25.62 total counts per ml. The
average effluent cumulative particle counts (>2 |im) produced by the filter in housing #3 during
the second 10 days of testing was 31.39 total counts per ml.
Table 4-6. Effluent Cumulative Particle Count Results from Bag Filter Variability Tests - Same Lot
Housing #1 Housing #2 Housing #3
Total Counts / ml Total Counts / ml Total Counts / ml
Number of Samples
11
11
11
Average
15.09
15.99
18.21
Minimum
6.63
8.17
10.24
Maximum
28.84
34.45
43.96
Std. Deviation
8.39
8.41
9.48
95% Confidence Interval
(10.13, 20.05)
(11.02, 20.96)
(12.61, 23.81)
Table 4-7. Effluent Cumulative Particle Count Results from Bag Filter Variability Tests - Different Lots
Housing #1 Housing #2 Housing #3
Total Counts / ml Total Counts / ml Total Counts / ml
Number of Samples
10
10
10
Average
25.16
25.62
31.39
Minimum
14.04
10.50
13.17
Maximum
38.96
49.34
54.29
Std. Deviation
8.40
11.38
15.66
95% Confidence Interval
(20.19, 30.12)
(18.90, 32.35)
(22.13, 40.65)
Analysis of this data hdicates that there was not a significant difference in the cumulative
particle counts produced by bag filters from the same or different production lots.
4.5 Verification Testing Results and Discussion
The results and discussions of verification testing runs and routine equipment operation, test runs
for feed water and finished water quality, documentation of operating conditions and treatment
equipment performance, and microbiological contaminant removal tasks of the verification
testing are presented below.
4.5.1 Task 1: Verification Testing Runs
The verification testing runs in this task consisted of continued evaluation of the treatment
system, using the operational parameters defined in the initial test runs.
Verification testing commenced on October 9, 2000 and concluded its normal testing on
November 12, 2000. One verification testing period, lasting 35 days, was used to evaluate the
performance of a treatment system. Additional testing was conducted during the month of
January 2001 to accommodate additional microsphere challenge testing. During the 35 day
period of time, the filtration equipment was operated for 23 hours and turned off for one hour
each day. The one-hour shutdown was done to simulate the on-off operating mode that may be
39
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encountered in many small systems. The 23 hours of operation provided the opportunity for the
FTO to log the maximum number of hours of equipment operation available each day. When
terminal head loss was attained, the clogged bag was removed and replaced with a new one, and
operation resumed. The duration of each filter run from initial start to terminal head loss and the
volume of water produced by the bag was recorded in the operational results. The bag filter was
changed seven times during the 37 days of operation. The prefilter was changed twice during the
testing. Specific operating parameters such as the duration of each filter run, number of gallons
of water produced during each filter run, rate of pressure loss through the filter during each filter
run were recorded during the testing. The results of these readings are presented in Section
4.4.3.
4.5.2 Task 2: Test Runs for Feed Water and Finished Water Quality
The objective of this task was to quantify parameters of interest in the feed and finished water
quality during the verification testing. Testing was conducted of feed water, prefilter effluent,
and bag filter effluent during the verification testing according to the schedule presented in Table
3-2.
4.5.2.1 Water Quality Analytical Results - Laboratory Analytes
Analyses for total alkalinity, total hardness, total coliforms, iron, manganese, total organic
carbon, and algae were conducted by a contract laboratory.
Table 4-8 presents the results of testing conducted by the contract laboratory on the feed water
for total alkalinity, total hardness, total coliforms, iron, manganese, total organic carbon, and
algae.
Table 4-8. Feed Water Testing Results - Laboratory Analytes
Parameter
Total Alkalinity Total Hardness Total Coliforms
Date (mg/1) (mg/1) (Neg.,Pos.)
TOC
(mg/1)
Algae
(cells/ml)
Iron
(mg/1)
Manganese
(mg/1)
10/9/00
71
79
Pos.
<2.0
1
<0.05
0.021
10/19/00
—
—
—
-
1
<0.05
0.035
10/25/00
—
—
—
-
<1
-
—
11/9/00
-
-
-
-
<1
-
-
Average
71
79
Pos.
<2.0
1
<0.05
0.028
Minimum
N/A
N/A
N/A
N/A
<1
<0.05
0.021
Maximum
N/A
N/A
N/A
N/A
1
<0.05
0.035
Std. Dev.
N/A
N/A
N/A
N/A
1
N/A
N/A
95% Confid Int.
N/A
N/A
N/A
N/A
(0,1)
N/A
N/A
N/A = Not applicable because the sample size (n) was 1 or 2.
Pos. = Positive result from a presence / absence test.
Table 4-9 presents the results of testing conducted by the contract laboratory on the prefilter
effluent for iron, manganese, and algae.
40
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Table 4-9. Prefilter Effluent Testing Results- Laboratory Analytes
Parameter
Iron Manganese Algae
(mg/1) (mg/1) (cells/ml)
10/9/00
<0.05
0.021
<1
10/19/00
<0.05
0.035
<1
10/25/00
-
-
<1
11/9/00
-
-
<1
Average
<0.05
0.028
<1
Minimum
<0.05
0.021
<1
Maximum
<0.05
0.035
<1
Std. Deviation
N/A1
N/A1
0
95% Confidence Interval
N/A1
N/A1
N/A
N/A= Not Applicable because standard deviation = 0.
N/A1= Not applicable because the sample size (n) was 2.
Table 4-10 presents the results of testing conducted by the contract laboratory
on the bag filter
effluent water for total alkalinity, total hardness, total coliforms,
iron, manganese, total
organic
carbon, and algae.
Table 4-10. Bag Filter Effluent Testing Results- Laboratory Analytes
Parameter
Total Alkalinity
Total Hardness
Iron
Manganese
Total Coliforms
TOC
Algae
(mg/1)
(mg/1)
(mg/1)
(mg/1)
(cfu/100 ml)
(mg/1)
(cells/ml)
10/9/00 66
72
<0.05
0.022
Pos.
<2.0
<1
10/19/00
-
<0.05
0.035
-
-
<1
10/25/00
-
-
-
-
-
<1
11/9/00
-
-
-
-
-
<1
Average 66
72
<0.05
0.029
Pos.
<2.0
<1
Minimum N/A
N/A
<0.05
0.022
N/A
N/A
<1
Maximum N/A
N/A
<0.05
0.035
N/A
N/A
<1
Std. Deviation N/A
N/A
N/A1
N/A1
N/A
N/A
0
95% Confid Int. N/A
N/A
N/A1
N/A1
N/A
N/A
N/A1
N/A = Not applicable because the sample size (n) was 1 or 2.
N/A1= Not Applicable because standard deviation = 0.
Pos. = Positive result from a presence / absence test.
4.5.2.2 Discussion of Results
The treatment system had little or no effect on the total alkalinity, and total hardness for the
conditions tested. This was not unexpected since these parameters are not present in the water as
solid constituents and are not amenable to reduction by physical straining.
Likewise there was no reduction in the manganese concentrations in the bag filter effluent. This
would seem to indicate that these constituents are present in the water in a dissolved state and
therefore not removable by physical straining.
The results indicate that the algal concentration of the bag filter effluent was less than the feed
water concentration in two of the four samples tested. In the other two samples no algae were
detected in the feed water so removal could not be demonstrated. The reader is cautioned that
41
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due to the very low concentration of algae in the feed water, one cell in two of four samples, the
treatment unit's ability to consistently remove algae from feed water is unproven.
Total coliform bacteria were observed in both the feed and finished water. One sample of the
feed and one sample of the bag filter effluent were examined for the presence of total coliform.
Each produced a positive result. This may indicate that the treatment unit is not capable of
removing total coliform bacteria. This would tend to indicate that the individual bacteria are
small enough to pass through the bag filter.
No iron or total organic carbon was detected in the feed water so removal of those constituents
could not be demonstrated.
4.5.2.3 Water Quality Analytical Results - On Site Analytes
The onsite analyses conducted during the verification testing were turbidity, particle counts, pH,
and temperature.
Results of testing for turbidity in the feed and finished water were examined to verify the stated
turbidity treatment ability. Table 4-11 presents the results of turbidity readings from the feed,
prefilter effluent, and bag filter effluent and the amount removed from feed to bag filter effluent.
Table 4-11. Turbidity Analyses Results and Removal- Bench Top Turbidimeter
Sample
Feed
Prefilter Effluent
Bag Filter Effluent
Parameter
Turbidity
Turbidity
Turbidity
Amount Removed
(NTU)
(NTU)
(NTU)
(NTU)
Number of Samples
36
36
36
Average
0.75
0.45
0.15
0.60
Minimum
0.50
0.25
0.05
0.25
Maximum
1.2
0.90
0.50
0.90
Standard Deviation
0.20
0.15
0.10
0.15
95% Confidence Interval
(0.70, 0.80)
(0.40, 0.50)
(0.15, 0.20)
(0.55, 0.65)
Turbidity of the feed, prefilter effluent, and bag filter effluent were also measured on a
continuous basis using online turbidimeters. That data was used to create four hour turbidity
measurements for the feed, prefilter effluent, and bag filter effluent. Table 4-12 presents the
average, minimum, maximum, standard deviation and confidence interval for these four hour
readings.
Table 4-12. Turbidity Analyses Results and Removal- Four Hour Online Turbidimeter Results
Sample Feed Prefilter Effluent Bag Filter Effluent
Parameter Turbidity Turbidity Turbidity
(NTU) (NTU) (NTU)
Number of Samples
159
163
180
Average
0.65
0.40
0.10
Minimum
0.30
0.20
<0.05
Maximum
1.2
0.90
0.50
Standard Deviation
0.15
0.15
0.10
95% Confidence Int.
(0.65, 0.70)
(0.40, 0.45)
(0.10, 0.10)
42
-------
Figure 4-1 shows the results of the four-hour feed water, prefilter effluent, and bag filter effluent
turbidity readings. Due to problems associated with the data logging equipment the feed water
turbidity readings from run time 688 hour to 768 hour and the prefilter effluent turbidity readings
from run time 636 hour to 700 hour were lost and are not available.
Figure 4-1. Four-Hour Online Turbidity
The bag filter effluent online turbidimeter readings averaged 0.10 NTU; the benchtop
turbidimeter readings averaged 0.15 NTU. While this may initially appear to be a significant
difference, it is most likely due to the low level of turbidity in the bag filter effluent and the
differences in methodology of the two pieces of analytical equipment. The discrepancy between
these two results can be explained by differences in the analytical techniques between the online
and benchtop turbidimeter and the low level of turbidity in the bag filter effluent. The benchtop
turbidimeter uses a glass cuvette to hold the sample; this cuvette can present some optical
difficulties for the benchtop turbidimeter. The inline turbidimeter has no cuvette to present a
possible interference with the optics of the instrument. The low level of turbidity in the bag filter
effluent also can create analytical difficulties, particularly for the benchtop.
Particle count testing was conducted on the feed, prefilter effluent, and bag filter effluent during
the verification testing. Particle count readings were taken on a continuous basis and recorded
every 10 minutes. Average particle count calculations were calculated from these readings. The
feed water cumulative counts (>2 |im) averaged 451.017 particles per ml. The prefilter effluent
cumulative counts (>2 |im) averaged 220.518 particles per ml. The finished water cumulative
counts (>2 |im) averaged 21 counts per ml. The average logio removal for the cumulative counts
43
-------
was 1.76. The low particle counts for each size range in the bag filter effluent indicated good
system performance throughout the testing period. The treatment system seems to be an
effective removal mechanism for particle removal.
Average feed water particle counts are presented in Table 4-13. Table 4-14 presents the average
prefilter effluent particle counts. The bag filter effluent average particle counts are presented in
Table 4-15. A complete data table is presented in Appendix B. Figures 4-2, 4-3, and 4-4 depict
results of four hour particle counts for feed water, prefilter effluent, and bag filter effluent
respectively. Figure 4-5 graphically depicts daily logio removals for cumulative particle counts.
Table 4-13. Feed Water Particle Counts (particles/ml)
Size
2-3 (im
3-5(im
5-7(im
7-10nm
10-15(im
>15(im
Cumulative
Number of Samples
183
183
183
183
183
183
183
Average
253.803
171.704
14.929
7.865
1.452
1.265
451.017
Minimum
36.875
39.350
3.600
1.050
0.075
0.000
122.825
Maximum
656.125
528.225
78.375
97.500
73.150
60.725
1304.900
Standard Deviation
111.973
82.392
12.383
9.520
5.679
6.126
N/A
95% Confidence
(237.445,
(159.667,
(13.120,
(6.474,
(0.622,
(0.370,
N/A
Interval
270.160)
183.740)
16.738)
9.256)
2.282)
2.160)
N/A = Not applicable. Statistical measurements on cumulative data do not generate meaningful data.
Table 4-14. Prefilter Effluent Particle Counts (particles/ml)
Size
2-3 urn
3-5 urn
5-7 urn
7-10nm
10-15|im
>15|im
Cumulative
Number of Samples
146
146
146
146
146
146
146
Average
126.548
80.662
6.131
3.461
1.082
2.634
220.518
Minimum
8.275
3.925
0.475
0.225
0.050
0.000
13.325
Maximum
455.025
444.175
74.175
68.850
38.150
174.000
1114.950
Standard Deviation
81.165
62.324
8.873
7.573
4.108
15.503
N/A
95% Confidence
(113.382,
(70.553,
(4.692,
(2.233,
(0.416,
(0.119,
N/A
Interval
139.713)
90.771)
7.570)
4.690)
1.748)
5.149)
N/A = Not Applicable. Statistical measurements on cumulative data do not generate meaningful data.
Table 4-15. Bag Filter Effluent Particle Counts (particles/ml)
2-3 (im
3-5(im
Size
5-7 (im
7-10nm
10-15nm
>15(im
Cumulative
Number of Samples
185
185
185
185
185
185
185
Average
11.794
5.512
0.564
0.317
0.108
2.945
21.240
Minimum
0.200
0.250
0.000
0.000
0.000
0.000
0.450
Maximum
307.800
76.675
10.700
9.700
4.675
155.300
499.250
Standard Deviation
37.164
11.348
1.239
0.940
0.454
16.796
N/A
95% Confidence
(6.439,
(3.877,
(0.385,
(0.181,
(0.043,
(0.525,
N/A
Interval
17.149)
7.148)
0.742)
0.452)
0.174)
5.365)
N/A = Not Applicable. Statistical measurements on cumulative data do not generate meaningful data.
44
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Table 4-16. Daily Average Cumulative Particle Counts - Feed and Bag Filter Effluent, Logio Particle
Removal
Date
Feed
Filtrate
Logio Removal
(particles/ml)
(particles/ml)
(particles/ml)
10/11/00
222.20
4.66
1.68
10/12/00
270.11
7.60
1.55
10/13/00
598.86
29.24
1.31
10/14/00
1178.04
57.24
1.31
10/15/00
680.23
297.51
0.36
10/16/00
258.89
285.80
-0.04
10/17/00
628.77
27.93
1.35
10/18/00
649.33
8.26
1.90
10/19/00
649.42
6.90
1.97
10/20/00
523.68
8.54
1.79
10/21/00
467.72
9.45
1.69
10/22/00
409.91
4.88
1.92
10/23/00
352.26
3.09
2.06
10/24/00
311.68
2.27
2.14
10/25/00
392.56
3.81
2.01
10/26/00
262.27
1.61
2.21
10/27/00
258.56
1.20
2.33
10/28/00
301.95
1.24
2.39
10/29/00
369.61
2.11
2.24
10/30/00
360.57
3.09
2.07
10/31/00
371.30
3.29
2.05
11/01/00
366.78
2.89
2.10
11/02/00
350.86
3.57
1.99
11/03/00
335.01
3.77
1.95
11/04/00
364.49
4.43
1.92
11/05/00
395.58
5.39
1.87
11/06/00
383.79
6.35
1.78
11/07/00
364.09
7.47
1.69
11/08/00
401.27
21.59
1.27
11/09/00
443.94
6.34
1.85
11/10/00
426.12
6.01
1.85
11/11/00
476.54
7.88
1.78
11/12/00
458.49
6.88
1.82
45
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Feed Water Particle Counts vs. Time
700
600
500
o 400
300
200
100
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750
Run Time (Hours)
Figure 4-2. Four Hour Feed Water Particle Counts
46
-------
Prefilter Effluent Particle Counts vs. Time
450
400
350
0 100 200 300 400 500 600
Run Time (Hours)
Figure 4-3. Four Hour Prefilter Effluent Particle Counts
47
-------
Bag Filter Effluent Particle Counts vs. Time
120
100
0 50 1 00 1 50 200 250 300 350 400 450 500 550 600 650 700 750
Run Time (Hours)
Figure 4-4. Four Hour Bag Filter Effluent Particle Counts
48
-------
Daily Average LogioCumulative Particle Removal vs. Date
z.o
2.0 "
>
0
E
0)
EC
rl 15 "
o>
0
-I
O
>
ra
3
E
~
O 1.0"
CD
o>
IB
Nci>
T?°°
/ / / / / / 4? / ^ / J / / ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ./
Date
Figure 4-5. Daily Average Log10 Cumulative Particle Removal Graph
Temperature of the feed water was fairly stable during the thirty day testing from a high of
13.5°C to a low of 11.0°C. The average temperature was 12.2°C.
The pH of the feed water averaged 7.08. The pH ranged from a high of 7.35 to a low of 6.85
during the verification testing.
Table 4-17. Feed Water Quality -
On-Site Analytes
Temperature
°C
PH
Number of Samples
35
35
Average
12.2
7.08
Minimum
11.0
6.85
Maximum
13.5
7.35
Std. Deviation
0.6
0.16
95% Confidence Interval
(12.0, 12.4)
(7.02,7.13)
49
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4.5.2.4 Discussion of Results
The results of the testing indicated that the system was capable of treating the feed water and
producing a turbidity of less than 0.3 NTU on average during the 37 days of verification testing.
The turbidity standards as presented in the ESWTR are that the filter effluent turbidity must be
less than or equal to 0.3 NTU in at least 95 percent of the measurements taken each month. (EPA
1999). As noted, the bag filter effluent turbidity measurements during one of the 10-day initial
operations periods and six measurements during the verification test were in excess of 0.3 NTU.
The use of a post cartridge filter may be required at some times of the year in order to comply
with regulatory requirements for filtered water turbidity for the feed water tested.
The low particle counts for each size range in the bag filter effluent indicated good system
performance throughout the testing period. The treatment system seems to be an effective
removal mechanism for particle removal.
4.5.3 Task 3: Documentation of Operating Conditions and Treatment Equipment
Performance
The performance of the water treatment equipment was documented by recording daily the
parameters of flow and pressure at the inlet and outlet of the prefilter and bag filter. These
readings were used to calculate rate of filter head loss gain, length of filter run (to terminal
headloss), and total water produced during each filter run. The daily readings for these
parameters are presented in Appendix B. In addition, daily observations of meteorological
conditions that may have impacted the feed water quality were recorded. Summaries of the data
are tabulated below. Graphs depicting rate of headloss gain and flow rate are presented below.
4.5.3.1 Flow Rate
The average feed water flow rate during the verification testing was 20.69 gpm. During the
verification testing the maximum feed water flow rate was 22.04 gpm; the minimum was 18.12
gpm. The average bag filter effluent flow rate during the verification testing was 20.01 gpm.
During the verification testing the maximum feed water flow rate was 21.19 gpm; the minimum
was 17.45 gpm. The difference between the feed water flow and the bag filter effluent flow was
due to samples being drawn off for the online analytical equipment.
Figure 4-6 presents a graph of the feed water flow and bag filter effluent flow readings taken
during the verification testing.
50
-------
Flow Rate Vs. Time
Run Time (Hours)
Figure 4-6. Daily Feed Water and Bag Filter Effluent Flow
4.5.3.2 Head Loss
The maximum terminal headloss of the bag filter system as reported by the manufacturer is 25
psi. The bag filter was replaced according to this criteria during the verification testing. A total
of seven bag filter changes were required during the verification testing. The prefilter was
changed out twice during the testing but the pressure differential did not dictate that the change
be made. The average life of the bag filter was 98 hours. The minimum life was 24 hours and
the maximum life was 164 hours. The average amount of water produced during each bag filter
run was 92,900 gallons. The minimum amount of water produced during a bag filter run was
26,700 gallons. The maximum amount of water produced during a bag filter run was 237,600
gallons. The large difference between the minimum and maximum amounts of filtered water
produced is presumably due to differences in the feed water quality during the two filter runs.
However, examination of feed water particle count and turbidity data does not reveal significant
differences in the feed water between the two filter runs. The reason for the difference in
performance during the minimum and maximum production run is unknown.
51
-------
By comparing the headloss obtained during each run to the amount of water produced during the
runs, it is possible to calculate an average minimum and maximum amount of water produced
per psi of headloss. The average amount of water produced to psi headloss is 3,760 gallons. The
minimum amount of water produced per psi of headloss is 1,030 gallons.
Table 4-18 presents data on the number of filter runs, the length of the runs, the amount of water
produced during each run, and the headloss at the end of each run.
Table 4-18. Filtration Runs
Run Number
Length of Run
Amount of filtrate
Headloss
(Hours)
(Gallons)
(psi)
1
164
237,600
23.0
2
24
26,700
26.0
3
95
82,300
27.0
4
95
80,700
27.0
5
103
83,900
26.0
6
112
109,300
28.0
7
106
68,500
26.0
8
85
53,800
22.0
Figure 4-7 depicts the headloss development profile generated during the verification testing.
Figure 4-7. Headloss of Bag Filter System
52
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4.5.4 Task 4: Microbiological Contaminant Removal
The purpose of this task was to demonstrate the treatment unit's ability to remove Giardia and
Cryptosporidium sized particles. Challenges were conducted at the start of a filter run, when the
bag filter had reached 50% of its terminal headloss, and when the bag filter had reached greater
than 90% of its terminal headloss. Two of the 50% headloss challenges were conducted due to
less than expected results obtained during the first 50% headloss challenge. The microsphere
removal challenges took place on October 9 and 25, 2000 and January 22 and 24, 2001. During
the challenge of 10/9/00 the system operated at a flow rate of 20.52 gpm. During the challenge
of 10/25/00 the system operated at a flow rate 21.19 gpm. During the challenge of 1/22/01 the
system operated at 23.00 gpm. The flow rate for the final challenge was 25.20 gpm.
Table 4-19. Microsphere Challenge Events
Challenge Filter Run
Date
Flow Rate
0% Terminal Headloss
#1
10/9/00
20.52
50% Terminal Headloss
#4
10/25/00
21.19
50% Terminal Headloss
Additional Run
1/22/01
23.00
90% Terminal Headloss
Additional Run
1/24/01
25.20
4.5.4.1 Feed Water Testing Results
During the 0% headloss challenge testing the feed water had a pH of 6.85, a benchtop turbidity
reading of 0.55 NTU, and a temperature of 13.5°C. During the 50% headloss challenge testing of
October 25 the feed water had a pH of 7.25, a benchtop turbidity reading of 0.65 NTU, and a
temperature of 13.0°C. During the 50% headloss challenge testing of January 22 the feed water
had a pH of 7.55, a benchtop turbidity reading of 0.35 NTU, and a temperature of 4.8°C. During
the 90%) headloss challenge testing of January 24 the feed water had a pH of 7.00, a turbidity of
0.35 NTU, and a temperature of 4.8°C. The online feed water turbidity readings taken during
the addition of the microspheres to the feed water indicate that the feed water turbidity did not
change during the microsphere addition. No online turbidity readings are available for the
October 9 challenge due to the loss of the online data caused by a computer malfunction.
Based on the results of the analysis of the stock suspension the suspension contained 7,000 of the
3.7|im spheres per ml of system flow and 700 of the 6.0|im spheres per ml of system flow during
the 0% headloss challenge of October 9. No feed water samples, before or during the dosing
procedure, were collected. Due to problems with the particle counting software the feed water
particle counts for this challenge were lost.
The analysis of the stock suspension that was used for the 50% headloss October 25 challenge
indicated that the concentration of the 3.7|im spheres was 2,300 spheres per ml of system flow
and the concentration of the 6.0|im spheres was 340 spheres per ml of system flow. The slug
dosing procedure was used to add the stock suspension to the treatment system. This created a
difficulty in collecting a representative feed water sample after the addition of the microspheres.
The collection was conducted during the two minutes that the stock suspension was being added
to the treatment system. Because of the use of the slug dosing procedure and the questionable
nature of the results of the analysis of the feed water sample the log removal calculations are
based on the stock suspension concentration. Analysis of a sample of the feed water collected
53
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prior to the addition of the microspheres indicated that there were no interfering fluorescing
compounds in the feed water. Results of the analyses of the stock suspensions and feed water
samples are attached in Appendix B. It was believed that due to the high levels of particles
which would be in the feed water and the short duration of the slug dosing of the microspheres
that the feed particle counter would be saturated and not generate reliable feed water particle
count results. For that reason a sample of the feed water was collected, diluted by a factor of 50
and fed through the particle counter for enumeration. Based on the diluted sample results the
feed water 2-7 |im particle counts averaged 99,662.25 counts per ml.
The third challenge test, at 50% headloss, was conducted on January 22. Analysis of the stock
suspension revealed that 2,000 of the 3.7|im spheres per ml of system flow were added to the
feed water. Six hundred and ninety of the 6.0|im spheres per ml of system flow were added to
the feed water. As previously mentioned the use of the slug dose technique rendered the data
generated by the analysis of the feed water sample after the addition of the spheres questionable.
The final challenge test, at 90% headloss, was conducted on January 24. Analysis of the stock
suspension indicated that 4,400 of the 3.7|im spheres and 1,000 of the 6.0|im spheres per ml of
system flow were added to the feed water. A sample of the feed water collected before the
addition of the spheres indicated that there was a fluorescing compound present in the feed
water. Investigation indicated that it was a 3.7|im sphere which most likely was a remnant of a
previous challenge. The concentration was 0.012 sphere per ml of system flow which was an
insignificant amount compared to the feed water concentration after the addition of the
microspheres. No other fluorescing compounds were detected. The use of the slug dose
technique rendered the feed water concentration results questionable.
The results of the analyses of the stock suspension are listed in Table 4-20. Bench data sheets
and report from the laboratory are enclosed in Appendix G. Particle count results of the
enumeration of the diluted feed water to which the stock suspension had been added are
presented in Tables 4-21, 4-22, and 4-23.
Table 4-20. 3.7jim and 6.0 jim Spheres Stock Suspension Concentration (counts per ml of system flow)
Date (Challenge
10/9/00
10/25/00
1/22/01
1/24/01
Description)
(0% Headloss)
(50% Headloss)
(50% Headloss)
(90% Headloss)
Replicate
3.7(im
6.0 (jm
3.7(im
6.0 (jm
3.7(im
6.0 (im
3.7(im
6.0 (jm
spheres
spheres
spheres
spheres
spheres
spheres
spheres
spheres
1
6400
660
2200
360
1800
670
5100
1200
2
6900
680
1900
340
1900
690
2500
950
3
7800
760
2700
330
2200
700
5600
950
Average
7,000
700
2,300
340
2000
690
4,400
1,000
Standard
710
53
400
15
210
15
1,700
140
Deviation
95% Confidence
(6,200,
(640, 760)
(1,800,
(330, 360)
(1,700,
(670, 700)
(2,500,
(840,
Interval
7,800)
2,700)
2,200)
6,300)
1,200)
54
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Table 4-21. Feed Water Particle Counts with Stock Suspension Addition (concentration per ml of system flow) -
10/25/2000 (50% Headloss Challenge)
Size
2-3|im 3-5(im 5-7(im 7-10(im 10-15(im >15(im Cumulative
Number of
5
5
5
5
5
5
5
Samples
Average
3,202.08
4,147.78
1,362.47
680.34
317.22
137.10
9,847.01
Minimum
2,677.00
3,456.25
1,192.75
552.50
254.35
110.65
8,244.65
Maximum
3,937.90
5,057.75
1,627.60
821.25
368.75
172.00
11,946.50
StdDev
545.74
666.20
179.51
112.87
55.289
26.145
N/A
95% Confid
(2,723.73,
(3,563.84,
(1,205.13,
(581.41,
(268.76,
(114.18,
N/A
Interval
3,680.43)
4,731.72)
1,519.81)
779.27)
365.68)
160.02)
N/A = Not Applicable. Statistical measurements on cumulative data do not generate meaningful data.
Table 4-22. Feed Water Particle Counts with Stock Suspension Addition (concentration per ml of system flow) -
1/22/2001 (50% Headloss Challenge)
Size
2-3 |im 3-5|im 5-7|im 7-10|im 10-15|im >15|im Cumulative
Number of
5
5
5
5
5
5
5
Samples
Average
3,758.15
4,875.13
1,328.46
1,522.34
859.47
357.02
12,701.05
Minimum
3,619.95
4,712.88
1,285.00
1,484.63
787.20
277.75
12,315.25
Maximum
4,020.33
5,167.70
1,388.00
1,584.25
928.63
432.43
13,168.25
StdDev
161.986
181.842
43.2528
39.9989
51.257
59.870
N/A
95% Confid
(3,616.16,
(4,715.74,
(1,290.54,
(1,487.28,
(814.54,
(304.54,
N/A
Interval
3,900.13)
5,034.51)
1,366.37)
1,557.40)
904.40)
409.49)
N/A = Not Applicable. Statistical measurements on cumulative data do not generate meaningful data.
Table 4-23. Feed Water Particle Counts with Stock Suspension Addition (concentration per ml of system flow) - 1/24/2001
(90% Headloss Challenge)
Size
2-3(im 3-5(im 5-7(im 7-10(im 10-15(im >15(im Cumulative
Number of
5
5
5
5
5
5
5
Samples
Average
982.85
1,234.78
283.78
269.52
155.01
87.93
3,013.86
Minimum
648.38
878.43
199.63
201.80
116.18
61.58
2,106.00
Maximum
1,799.58
2,048.75
417.08
359.88
224.83
148.75
4,862.33
StdDev
481.915
490.954
94.5496
78.5755
44.208
34.659
N/A
95% Confid
(560.44,
(804.45,
(200.91,
(200.65,
(116.26,
(57.55, 118.31)
N/A
Interval
1,405.25)
1,665.11)
366.65)
338.39)
193.76)
N/A = Not Applicable. Statistical measurements on cumulative data do not generate meaningful data.
4.5.4.2 Bag Filter Effluent Testing Results
The bag filter effluent was collected and analyzed for the presence of the 3.7|im and the 6.0|im
microspheres. Analyses were also conducted for bag filtrate turbidity and particle counts during
the challenge events. The bag filter effluent turbidity as measured by the online turbidimeter
during the 0% headloss challenge is unavailable due to a computer malfunction. The bag filter
effluent turbidity as measured by the online turbidimeter during the first 50% headloss challenge
averaged 0.05 NTU. The average online bag filter effluent turbidimeter reading for the day was
0.05 NTU. The bag filter effluent turbidity as measured by the online turbidimeter during the
second 50% headloss challenge averaged 0.05 NTU. The average online bag filter effluent
turbidimeter reading for the day was 0.05 NTU. The bag filter effluent turbidity as measured by
the online turbidimeter during the 90% headloss challenge averaged 0.05 NTU. The average
55
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online bag filter effluent turbidimeter reading for the day was 0.05 NTU. There was not a
significant difference in the average turbidity of the bag filter effluent produced during the
challenges compared to the average bag filter effluent turbidity produced during the entire day
the challenges were conducted.
The bag filter effluent particle counts were recorded during the challenges of October 25,
January 22 and January 24. The results of these analyses are presented in Tables 4-24, 4-25, and
4-26.
Samples of the bag filter effluent collected during the challenges were analyzed for the presence
and concentration of the 3.7|im spheres and the 6.0|im spheres. The results of the analysis of
the bag filter effluent from the 0% headloss challenge indicated that the effluent contained 4.2 of
the 3.7|im spheres and 0.30 of the 6.0|im spheres per ml of system flow. Table 4-27 presents the
results of these analyses.
The analysis of the bag filter effluent sample from the first 50% headloss challenge indicated that
the effluent contained 25 of the 3.7|im spheres and 1.3 of the 6.0|im spheres per ml of system
flow. As prescribed by the Protocol, a second set of bag filter effluent samples were collected
after flow to the treatment system was stopped and then restarted. The results of the analysis of
the second sample indicated that the effluent contained 4.9 of the 3.7|im spheres and 0.17 of the
6.0(am spheres per ml of system flow. By combining the results of the analyses of the two sets of
samples analyzed an overall concentration of 30 of the 3.7(am spheres and 1.4 of the 6.0|im
spheres per ml of system flow was obtained. Table 4-27 presents the results of these analyses.
Table 4-24 presents the results of bag filter effluent particle counts that were taken during the
challenge.
The analysis of the bag filter effluent sample from the second 50% headloss challenge indicated
that the effluent contained 22 of the 3.7(am spheres and 2.2 of the 6.0|im spheres per ml of
system flow. Since this challenge was conducted as a repeat of the 50% headloss challenge the
system flow was stopped and restarted and a second set of bag filter effluent samples were
collected. The results of the analysis of the second sample indicated that the effluent contained
1.0 of the 3.7|im spheres and 0.074 of the 6.0|im spheres per ml of system flow. By combining
the results of the analyses of the two sets of samples analyzed an overall concentration of 23 of
the 3.7|im spheres and 2.3 of the 6.0|im spheres per ml of system flow was obtained. Table 4-27
presents the results of these analyses. Table 4-25 presents the results of bag filter effluent
particle counts that were taken during the challenge.
The 90% headloss challenge was conducted on January 24. The analysis of the bag filter effluent
sample from that challenge indicated that the effluent contained 38 of the 3.7(am spheres and 3.2
of the 6.0|im spheres per ml of system flow. The results of these analyses are presented in Table
4-27. Table 4-26 presents the results of bag filter effluent particle counts that were taken during
the challenge.
56
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Table 4-24. Bag Filter Effluent Particle Counts During Challenge Sample Collection (counts per ml) -
10/25/2000 (50% Headloss Challenge)
Size
Time
2-3|im
3-5(im
5-7(im
7-10(im
10-15(im
>15(im
Cumulative
10:23
1.900
0.950
0.075
0.075
0.025
0.100
3.125
10:33
82.950
136.800
10.000
0.225
0.000
0.000
229.975
10:43
1.050
0.950
0.025
0.025
0.000
0.025
2.075
11:17
2.100
0.975
0.125
0.000
0.000
0.000
3.200
Table 4-25. Bag Filter Effluent Particle Counts During Challenge Sample Collection (counts per ml) -
1/22/2001 (50% Headloss Challenge)
Size
Time
2-3 (im
3-5(im
5-7(im
7-10(im
10-15(im
>15(im
Cumulative
11
03
1.400
1.225
0.500
0.250
0.000
0.125
3.500
11
05
4.575
3.575
0.425
0.575
0.475
1.375
11.000
11
07
5.625
3.175
0.400
0.750
0.950
14.325
25.225
11
09
2.725
1.375
0.425
0.350
0.000
0.200
5.075
11
11
1.825
1.575
0.350
0.350
0.000
0.125
4.225
11
13
16.700
10.600
1.275
1.425
1.700
15.225
46.925
11
15
19.500
22.625
2.775
1.675
1.450
16.525
64.550
11
17
88.650
157.525
15.950
1.750
2.150
17.650
283.675
11
19
81.375
140.900
15.125
2.175
2.075
21.700
263.350
11
21
29.200
40.725
4.525
1.600
2.000
22.000
100.050
11
23
10.850
9.525
1.525
1.125
1.900
21.800
46.725
11
25
8.375
7.225
1.125
0.700
1.875
22.475
41.775
11
27
7.175
3.900
0.825
0.700
0.275
4.950
17.825
11
29
0.000
0.000
0.000
0.000
0.000
0.000
0.000
11
31
0.125
0.000
0.075
0.000
0.000
0.075
0.275
11
49
21.950
44.275
22.675
13.200
3.075
3.800
108.975
11
51
7.875
8.900
2.075
0.900
0.250
0.625
20.625
11
53
5.075
6.100
1.150
0.475
0.075
0.850
13.725
11
55
3.475
3.275
0.700
0.250
0.025
0.975
8.700
11
57
2.225
2.275
0.300
0.225
0.000
0.200
5.225
11
59
2.725
2.175
0.350
0.225
0.100
1.050
6.625
Table 4-26. Bag Filter Effluent Particle Counts During Challenge Sample Collection (counts per ml) -
1/24/2001 (90% Headloss Challenge)
Size
Time 2-3um 3-5um 5-7um 7-10um 10-15um >15um Cumulative
10:08
2.025
1.350
0.375
0.050
0.050
0.200
4.050
10:18
1.575
1.275
0.225
0.025
0.025
0.150
3.275
10:28
5.500
8.100
1.225
0.325
0.025
0.650
15.825
10:38
1.825
1.550
0.400
0.100
0.000
0.100
3.975
10:46
1.850
1.350
0.150
0.125
0.000
0.200
3.675
10:48
1.400
1.850
0.350
0.175
0.000
0.050
3.825
57
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Table 4-27. 3.7jim and 6.0 jim Spheres Effluent Concentration During Challenge (per ml of system flow)
Date (Challenge
10/9/00 (0% Headloss)
10/25/00 (50%
1/22/01 (50%
1/24/01 (90%
Description)
Headloss)
Headloss)
Headloss)
Replicate
3.7(im
6.0 (jm
3.7(im
6.0 (jm
3.7(im
6.0 (im
3.7(im
6.0 (im
spheres
spheres
spheres
spheres
spheres
spheres
spheres
spheres
1
4.7
0.39
31
1.5
21
2.0
32
2.7
2
5.4
0.45
32
1.5
26
2.6
41
4.0
3
2.6
0.070
28
1.3
22
2.2
42
2.9
Average
4.2
0.30
30
1.5
23
2.2
38
3.2
Std. Dev.
1.5
0.20
2.1
0.12
2.5
0.30
5.5
0.70
95% Confid Int.
(2.6, 5.9)
(0.072, 0.53)
(28, 32)
(1.3, 1.6)
(20, 26)
(1.9,2.6)
(32, 45)
(2.4, 4.0)
4.5.4.3 Logio Removal
The logio removal of 3.7|im spheres and of the 6.0|im spheres was calculated from the stock
suspension concentration and the effluent concentration. This was done due to the previously
discussed difficulties in obtaining an accurate feed water concentration while using the slug
dosing technique. The logio removal was calculated by converting the concentration of the
3.7|im spheres and of the 6.0|im spheres in the stock suspension and the bag effluent to their
logio equivalent and subtracting the logio of the bag filter effluent concentration from the logio of
the stock feed suspension concentration. The resulting difference was the logio removal of the
treatment system for the 3.7|im spheres and of the 6.0|im spheres.
Using this method, the logio removal for the 3.7|im and the 6.0|im spheres during the initial
challenge on a new filter bag was 3.2 and 3.5 respectively. The logio removal for the 3.7|im
spheres during the 50% headloss challenge was 1.9. The logio removal for the 6.0|im spheres
during this challenge, which was conducted on October 25, was 2.4. Due to the change in the
logio removal performance the manufacturer requested that the 50% headloss challenge be
repeated. This was done on January 22. The logio removal for the 3.7|im spheres during this
challenge was again 1.9. The logio removal for the 6.0|im spheres during this challenge was 2.5.
The logio removal for the 3.7|im spheres during the 90% headloss challenge was 2.0. The logio
removal for the 6.0|im spheres during this challenge, which was conducted on January 24, was
2.5. A summary of these results is presented in Table 4-28.
Table 4-28. 3.7fim and 6.0 jim Spheres Feed and Effluent Login Concentrations and Removal During
Challenge (per ml of system flow)
Date
10/9/00
10/25/00
1/22/01
1/24/01
(0% Headloss)
(50% Headloss)
(50% Headloss)
(90% Headloss)
3.7(im
6.0 (jm
3.7(im
6.0 (jm
3.7(im
6.0 (im
3.7(im
6.0 (jm
spheres
spheres
spheres
spheres
spheres
spheres
spheres
spheres
Logio Feed
3.8
2.8
3.4
2.5
3.3
2.8
3.6
3.0
Concentration
Logio Bag Filter
0.6
-0.5
1.5
0.2
1.4
0.3
1.6
0.5
Effluent
Concentration
Logio Removal
3.2
3.4
1.9
2.4
1.9
2.5
2.0
2.5
58
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4.5.4.4 Discussion of Results
The 3.7|im spheres were used as surrogates for Cryptosporidium oocysts. The ESWTR requires
an overall minimum 2 logo removal of Cryptosporidium oocysts (EPA, 1999). During the four
challenges the minimum removal of the 3.7|im spheres was 1.9 logio. The 6.0|im spheres were
used as surrogates for Giardia cysts. The SWTR requires an overall minimum 3 logio
removal/inactivation of Giardia cysts (EPA, 1989). According to the Pennsylvania DEP's Public
Water Supply Manual the design of filtration processes must ensure a minimum 99% (or 2 logio)
removal of Giardia cysts (PADEP, 1997). During the four challenges the minimum removal of
the 6.0|im spheres was 2.4 logio.
The logio removal was less during the higher pressure differential challenges. This decline in the
removal efficiency may be due to the increase in the pressure differential.
4.6 QA/QC Results
The daily, bi-weekly, initial, and the analytical laboratory QA/QC verification results are
presented below.
4.6.1 Daily QA/QC Results
Daily readings for the inline turbidimeter flow rate and readout and online particle counter flow
rate QA/QC results were taken and recorded.
The online feed water turbidimeter flow rate averaged 531 ml/minute. The flow rate was verified
volumetrically using a graduated cylinder and stop watch. The maximum rate measured, during
the testing was 700 ml/minute; the minimum was 300 ml/minute. The acceptable range of flows
as specified by the manufacturer is 250 ml/minute to 750 ml/minute. The target flow rate for the
turbidimeter was 500 ml/minute. Flow rates within +/- 40% of the target were considered
acceptable. The flow rate required adjustment on two of the 37 days of testing.
The online prefilter effluent turbidimeter flow rate averaged 526 ml/minute. To determine the
flow rate of the online prefilter turbidimeter, the flow was measured using a graduated cylinder
and stop watch. The maximum rate measured during the testing was 680 ml/minute; the
minimum was 420 ml/minute. The acceptable range of flows as specified by the manufacturer is
250 ml/minute to 750 ml/minute. The target flow rate for the turbidimeter was 500 ml/minute.
Flow rates within +/- 40% of the target were considered acceptable. The flow rate did not
require adjustment during the 37 days of testing.
The online bag filter effluent turbidimeter flow rate averaged 570 ml/minute. To determine the
flow rate of the online prefilter turbidimeter, the flow was measured using a graduated cylinder
and stop watch. The maximum rate measured during the testing was 750 ml/minute; the
minimum was 450 ml/minute. The acceptable range of flows as specified by the manufacturer is
250 ml/minute to 750 ml/minute. The target flow rate for the turbidimeter was 500 ml/minute.
Flow rates within +/- 40% of the target were considered acceptable. The flow rate required
adjustment once during the 37 days of testing.
59
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The feed water particle counter flow rate averaged 97 ml/minute. To determine the flow rate of
the inline filtrate turbidimeter, the flow was measured using a graduated cylinder and stop watch.
The maximum flow rate measured was 108 ml/minute; the minimum was 92 ml/minute. The
target flow rate specified by the manufacturer is 100 ml/minute. Efforts were made to keep the
flow rate between 95 ml/minute to 105 ml/minute or within 5% of the target flow rate.
Adjustments to the flow rate were not required during the verification study.
The prefilter effluent particle counter flow rate averaged 98 ml/minute. To determine the flow
rate of the inline filtrate turbidimeter, the flow was measured using a graduated cylinder and stop
watch. The maximum flow rate measured was 108 ml/minute; the minimum was 91 ml/minute.
The target flow rate specified by the manufacturer is 100 ml/minute Efforts were made to keep
the flow rate between 95 ml/minute to 105 ml/minute or within 5% of the target flow rate.
Adjustments to the flow rate were not required during the verification study.
The finished water particle counter flow rate averaged 97 ml/minute. The flow rate was verified
using a graduated cylinder and stop watch. The maximum flow rate measured was 105
ml/minute; the minimum was 90 ml/minute. The target flow rate specified by the manufacturer
is 100 ml/minute. Efforts were made to keep the flow rate between 95 ml/minute to 105
ml/minute or within 5% of the target flow rate. Adjustments to the flow rate were not required
during the verification study.
4.6.2 Bi-weekly QA/QC Verification Results
Every two weeks checks were made on the feed and effluent flow meters; the meters were
cleaned out if necessary and the flow readouts were verified. Clean out of the meters was not
necessary due to the high quality of the feed and finished water. The flow meter readout was
compared to the results obtained from the actual amount measured using a graduated cylinder
and stopwatch. The acceptable range of accuracy for the feed and finished meters was +/- 10%
of the target flow. The feed water meter readout averaged 2.3% higher than actual according to
the results obtained during the flow verification. None of the readings obtained during the four
flow meter verifications was greater than +/- 10% of the target flow. The effluent meter readout
averaged 1.7% higher than actual according to the results obtained during the flow verification.
None of the readings obtained during the four flow meter verifications was greater than +/- 10%
of the target flow.
4.6.3 Results of QA/QC Verifications at the Start of Each Testing Period
At the start of the testing period the online turbidimeter was cleaned out and recalibrated, the
pressure gauges/transmitters readouts were verified, the tubing was inspected, and the online
particle counter calibration was checked.
The online turbidimeter reservoir was drained and cleaned and the unit was recalibrated
according to manufacturer's recommendations. No corrective action was required as a result of
these activities.
60
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The inlet and outlet pressure gauges on each of the filter housings were checked prior to the start
of testing. Dead weights of 0, 5,15, 25, 35, 45, 55, 65, 75, and 85 pounds were used on the inlet
and outlet of housing #3. The inlet water pressure gauge averaged 3.0 psi higher than actual. The
outlet pressure gauge read, on average, 3.0 psi higher than actual. Dead weights of 0, 10, 20, 30,
40, 50, 60, 70, and 80 pounds were used on the inlet and outlet of housings #1, #2, and the
prefilter housing. The inlet pressure gauge on housing #2 agreed with the dead weights used at
all the weights tested. The outlet to housing #2 agreed, on average with the dead weights used.
The zero reading on the housing #2 outlet pressure gauge read 2.0 psi and the 30 pound dead
weight produced a reading of 30.5 psi. All the other readings agreed with the dead weights.
The inlet pressure gauge on housing #1 (which was the housing used to house the bag filter
during the 30 day test) read on averaged about 2.0 psi higher than the dead weights. The effluent
pressure gauge of housing #1 read 0.5 psi higher than the dead weight at 60, 70, and 80 psi. The
readings obtained from the prefilter housing inlet pressure gauge equaled the dead weight values
except for the 10 pound weight which produced a reading of 11.0 psi. The prefilter housing
outlet pressure gauge equaled the dead weight values except for the 10 pound weight which
produced a reading of 11.0 psi and the 60, 70, and 80 pound dead weights which produced
readings 1.0 psi less than actual on the gauge. A complete table listing the results of the
calibration is presented in Appendix B.
The tubing used on the treatment system was inspected for cracks and flaws which could have
caused unexpected failure prior to the initiation of testing. The tubing was in good condition and
replacement was not necessary. It was noted during the NSF field audit that some of the waste
tubing from the turbidimeters had become discolored. The tubing was replaced.
The calibration of the online particle counters was checked twice during the study. The first
check was done prior to the start of the initial operations period. The second calibration check
was conducted prior to the start of the 30 day test. This second check was done due to the long
delay between the completion of the initial testing and the start of the 30 day test as well as the
fact that the particle counters were sent back for repair prior to the start of the 30 day test.
Calibration was carried out by preparing a cocktail of microspheres to create an initial
concentration of 2,000 particles/ml for each of the 5 |im, 10 |im, and 15 |im sized particles.
During the first calibration the particle counter designated as "C" (which became the feed water
particle counter during the 30 day test) showed an average response for the 5 |im size of 1841.86
counts/ml; the 10 |im size showed an average response of 1873.28 counts/ ml; the 15 |im size
showed an average response of 1899.16 counts/ ml. This corresponds to a difference of 8.59%,
6.76%, and 5.31% respectively in particle counts.
The first calibration of the particle counter designated "B" (which became the prefilter effluent
during the 30 day test) showed an average response for the 5 |im size of 1820.06 counts/ml; the
10 |im size showed an average response of 1956.85 counts/ ml; the 15 |im size showed an
average response of 1886.82 counts/ ml. This corresponds to a difference of 9.89%, 2.21%, and
6.00% respectively in particle counts.
61
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The results of the first calibration of the particle counter designated "A" (which became the bag
filter effluent particle counter during the 30 day test) showed an average response for the 5 |im
size of 1859.77 counts/ml; the 10 |im size showed an average response of 1777.64 counts/ ml;
the 15 |im size showed an average response of 1751.21 counts/ ml. This corresponds to a
difference of 7.54%, 12.51%, and 14.21% respectively in particle counts. The 10 |im and 15 |im
results were outside of the generally recognized range of +/- 10 %. As previously mentioned the
particle counters were sent back for recalibration prior to the start of the 30 day test.
The results of the second calibration of the feed water particle counter showed an average
response for the 5 |im size of 1844.80 counts/ml; the 10 |im size showed an average response of
1803.58 counts/ ml; the 15 |im size showed an average response of 1898.59 counts/ ml. This
corresponds to a difference of 8.41%, 10.89%, and 5.34%, respectively, in particle counts.
Although the 10 |im size results were slightly in excess of 10% the decision was made to
commence the testing rather than returning the unit for service.
The results of the second calibration of the prefilter effluent particle counter showed an average
response for the 5 |im size of 1905.54 counts/ml; the 10 |im size showed an average response of
1875.74 counts/ ml; the 15 |im size showed an average response of 1821.65 counts/ ml. This
corresponds to a difference of 4.96%, 6.62%, and 9.19% respectively in particle counts.
The second calibration of the bag filter effluent particle counter showed an average response for
the 5 |im size of 1882.24 counts/ml; the 10 |im size showed an average response of 1884.37
counts/ ml; the 15 |im size showed an average response of 1833.68 counts/ ml. This corresponds
to a difference of 6.26%, 8.84%, and 9.01% respectively in particle counts.
The particle counters used during the testing were Met-One PCX models. The units had
capabilities of measuring particles as small as 2 |im and a coincidence error of less than 10 %.
Particle counter model, serial number, calibration certificate, and calculation of coincidence error
are included in Appendix H.
4.6.4 On-Site Analytical QA/QC
Samples for pH, turbidity, and temperature were examined onsite.
The results of the pH analyses were evaluated for accuracy and precision. Accuracy was
determined by analyzing a known sample and comparing the result to the true value of the
sample. The average accuracy of the pH analyses was 101.2%. The minimum accuracy of the
pH analyses was 100%; the maximum accuracy was 104%. Precision of the pH analyses was
determined by calculating the relative percent deviation of the duplicate analyses. The average
relative percent deviation of the pH analyses was 0.45%. The minimum relative percent
deviation of the pH analyses was 0%; the maximum was 1.61%.
The results of the turbidity analyses were evaluated for accuracy and precision. Accuracy of the
benchtop turbidimeter was determined by analyzing a known sample and comparing the result to
the true value of the sample. The average accuracy of the turbidity at the 0.1 NTU level was
99%. The average accuracy of the turbidity at the 0.5 NTU level was 102%. The average
62
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accuracy of the turbidity at the 5.0 NTU level was 104%. Precision of the turbidity analyses was
determined by comparing the results obtained from the online analyzers to the results obtained
using the benchtop turbidimeter and calculating the relative percent deviation of the analyses.
The average relative percent deviation for the feed water turbidity analyses was 4.0%. The
average relative percent deviation for the prefilter effluent turbidity analyses was 4.9%. The
average relative percent deviation for the bag filter effluent turbidity analyses was 16.0%. The
discrepancy between these two results can be explained by differences in the analytical
techniques between the online and benchtop turbidimeter and the low level of turbidity in the bag
filter effluent. The benchtop turbidimeter uses a glass cuvette to hold the sample; this cuvette
can present some optical difficulties for the benchtop turbidimeter. The online turbidimeter has
no cuvette to present a possible interference with the optics of the instrument. The low level of
turbidity in the bag filter effluent also can create analytical difficulties, particularly for the
benchtop.
The thermometer used for temperature analyses was a NIST traceable thermometer. The
analytical procedure for temperature was to allow the thermometer to sit in a stream of running
feed water until two equivalent readings were obtained. Therefore, the temperature results
recorded were the result and the duplicate analysis. For this reason the relative percent deviation
would always equal zero and the results are not tabulated.
4.6.5 Analytical Laboratory QA/QC
Analyses conducted on feed and finished water are listed in Table 3-1. QA/QC procedures are
based on Standard Methods, 19th Ed., (APHA, 1995).
Calibration results of the analytical instrumentation used to conduct the analyses listed in Table
3-1 on finished water is recorded and kept on file at the contract laboratory.
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Chapter 5
References
The following references were used in the preparation of this report:
American Public Health Association, American Water Works Association, Water Environment
Federation. Standard Methods for the Examination of Water and Wastewater, APHA.
AWWA, WEF, 19th Ed., 1995.
Lapoint Industries. Operations & Maintenance Manual for Aqua-Rite Potable Water Filtration
System, May 2001.
CWM Laboratories. Laboratory Quality Manual, Non Published, June 10, 2000.
U.S. EPA Enhanced Surface Water Treatment Rule (ESWTR) - 40 CFR Parts 9, 141 and 142,
EPA, February 16, 1999.
U.S. EPA Surface Water Treatment Rule (SWTR) - 54 FR 27486 June 29, 1989, EPA1989b.
U.S. EPA/NSF International. ETV Protocol - Protocol for Equipment Verification Testing for
Physical Removal of Microbiological and Particulate Contaminants. May 1999.
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