NC0000272_Meeting Notes_20000525

PIGEON RIVER JOINT WATERSHED ADVISORY COMMITTEE MEETING
THURSDAY, MAY 25, 2000
REGISTRATION
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PIGEON RIVER JOINT WATERSHED ADVISORY COMMITTEE MEETING
INTERCHANGE BUILDING, 59 WOODFIN PLACE, ASHEVILLE, NC 28801
THURSDAY, MAY 25, 2000, 1:00 PM
AGENDA
I. Introduction of Committee Members, EPA Representatives, Tennessee and North
Carolina Staff Members, Blue Ridge Paper Representatives and Other Visitors -
(1:00 - 1:10)
II. Review of Agenda and the Materials Previously Provided to Committee Members
-- Paul Davis and Forrest Westall - (1:10 - 1:25)
A. Agenda Review
B. Brief Review of the Items Provided
C. Questions/Changes From the Committee
III. Charge to the Committee -- Mike McGhee, EPA - (1:25 - 1:55)
A. Review of the Permit Agreement Condition that Created this Committee
(Section IV, Paragraph 32)
B. Comments on Blue Ridge Paper's NPDES Permit Renewal
C. Review of Other Pigeon River Watershed Issues
IV. Mill Status: -- Bob Williams, Blue Ridge Paper Products - (1:55 - 2:15)
A. Mill Ownership Issues
B. Color Effluent Discharge Levels/Removal Performance
C. Future Improvements
V. Break - (2:15 - 2:30)
VI. Mill Related Water Quality Issues -- Paul Davis, Mike McGhee and Forrest Westall
- (2:30 - 3:00)
A. Permit Agreement, NPDES and Variance Compliance
B. Dioxin Data and Trends
C. Ecological Data (Fisheries and Aquatic Insect Information)

VII. General Pigeon River Water Quality Issues/Concerns - (3:00 - 3:30)
A. Status of Permit Agreement Ecological Assessment Provision (Section V,
Paragraph 33) -- Mike McGhee
B. Tennessee and NC Watershed Planning Initiatives -- Paul Davis and
Forrest Westall
C. Recreation/Rafting Use of the Pigeon -- Paul Davis and Forrest Westall
D. Waterville Lake/CP&L Issues -- Paul Davis and Forrest Westall
Vill. Committee Discussion, Identification of Other Issues and Committee Business -
(3:30 - 4:00)
A. Reaction of Committee's Charge
B. Otherlssues
C. Establishing Committee Responsibilities -- Electing Co-Chairs
D. Setting Next Meeting Date and Location in Tennessee
IX. Adjournment - (4:00)
-2-

PIGEON RIVER JOINT WATERSHED ADVISORY COMMITTEE MEETING
INTERCHANGE BUILDING, 59 WOODFIN PLACE, ASHEVILLE, NC 28801
THURSDAY, MAY 25, 2000, 1:00 PM
AGENDA
I. Introduction of Committee Members, EPA Representatives, Tennessee and North
Carolina Staff Members, Blue Ridge Paper Representatives and Other Visitors -
(1:00 - 1:10)
II. Review of Agenda and the Materials Previously Provided to Committee Members
-- Paul Davis and Forrest Westall - (1:10 - 1:25)
A. Agenda Review
B. Brief Review of the Items Provided
C. Questions/Changes From the Committee
III. Charge to the Committee -- Mike McGhee, EPA - (1:25 - 1:55)
A. Review of the Permit-Agreement Condition that Created this Committee
(Section IV, Paragraph 32)
B. Comments on Blue Ridge Paper's NPDES Permit Renewal
C. Review of Other Pigeon River Watershed Issues
IV. Mill Status: -- Bob Williams, Blue Ridge Paper Products - (1:55 - 2:15)
A. Mill Ownership Issues
B. Color Effluent Discharge Levels/Removal Performance
C. Future Improvements
V. Break - (2:15 - 2:30)
VI. Mill Related Water Quality Issues -- Paul Davis, Mike McGhee and Forrest Westall
- (2:30 - 3:00)
A. Permit Agreement, NPDES and Variance Compliance
B. Dioxin Data and Trends
C. Ecological Data (Fisheries and Aquatic Insect Information)

VII. General Pigeon River Water Quality Issues/Concerns - (3:00 - 3:30)
A. Status of Permit Agreement Ecological Assessment Provision (Section V,
Paragraph 33) -- Mike McGhee
B. Tennessee and NC Watershed Planning Initiatives -- Paul Davis and
Forrest Westall
C. Recreation/Rafting Use of the Pigeon -- Paul Davis and Forrest Westall
D. Waterville Lake/CP&L Issues -- Paul Davis and Forrest Westall
Vill. Committee Discussion, Identification of Other Issues and Committee Business -
(3:30 - 4:00) ,
A. Reaction of Committee's Charge
B. Other Issues
C. Establishing Committee Responsibilities -- Electing Co-Chairs
D. Setting Next Meeting Date and Location in Tennessee
IX. Adjournment - (4:00)
-2-

PIGEON FIVER JOINT WATERSHED ADVISORY COMMITTEE MEETING
INTERCHANGE BUILDING, 59 WOODFIN PLACE, ASHEVILLE, NC 28801
THURSDAY, MAY 25, 2000, 1:00 PM
AGENDA
I. Introduction of Committee Members, EPA Representatives, Tennessee and North
Carolina Staff Members, Blue Ridge Paper Representatives and Other Visitors -
(1:00 - 1:10)
II. Review of Agenda and the Materials Previously Provided to Committee Members
-- Paul Davis and Forrest Westall - (1:10 : 1:25)
A. Agenda Review
B. Brief Review of the Items Provided
C. Questions/Changes From the Committee
III. Charge to the Committee -- Mike McGhee, EPA - (1:25 - 1:55)
A. Review of the Permit Agreement Condition that Created this Committee
(Section IV, Paragraph 32)
B. Comments on Blue Ridge Paper's NPDES Permit Renewal
C. Review of Other Pigeon River Watershed Issues
IV. Mill Status: -- Bob Williams, Blue Ridge Paper Products - (1:55 - 2:15)
A. Mill Ownership Issues
B. Color Effluent Discharge Levels/Removal Performance
C. Future Improvements
V. Break - (2:15 - 2:30)
VI. Mill Related Water Quality Issues -- Paul Davis, Mike McGhee and Forrest Westall
- (2:30 - 3:00)
A. Permit Agreement, NPDES and Variance Compliance
B. Dioxin Data and Trends
C. Ecological Data (Fisheries and Aquatic Insect Information)

VII. General Pigeon River Water Quality Issues/Concerns - (3:00 - 3:30)
A. Status of Permit,Agreement Ecological Assessment Provision (Section V,
Paragraph 33) -- Mike McGhee
B. Tennessee and NC Watershed Planning Initiatives -- Paul Davis and
Forrest Westall
C. Recreation/Rafting Use of the Pigeon -- Paul Davis and Forrest Westall
D. Waterville Lake/CP&L Issues -- Paul Davis and Forrest Westall
Vill. Committee Discussion, Identification of Other Issues and Committee Business -
(3:30 - 4:00)
A. Reaction of Committee's Charge
B. Other Issues
C. Establishing Committee Responsibilities -- Electing Co-Chairs
D. Setting Next Meeting Date and Location in Tennessee
IX. Adjournment - (4:00)
-2-

Status of Champion, Canton, NC
1997 Settlement Agreement
The following is a status of the elements contained in Champion at Canton,NC 1997 Settlement
Agreement in Paragraphs 32 and 33.Paragraph 32 focused on"Assistance to downstream communities and
community input," while Paragraph 33 focused on,"Ecological assessment of the Pigeon River system and the
Waterville Reservoir." All of the other commitments in the agreement were included in the permit and variance
issued by NC and are reported on by them.Champion sold the Canton mill to Blue Ridge Paper Products(BRPP)
in 1999.BRPP assumed responsibility for the Settlement Agreement as a result of that sale.
- EPA will identify available programs, initiatives,and technical resources within the agency which
may support and further such(recreation,tourism,and other economic opportunities)development
opportunities in Cocke County.
Status; EPA did provide information on the above matters to the County and
followed up with communications on those matters.EPA continues to
provide the County with advice and consultation on a variety of matters.
- EPA will also work closely with TVA on its Quality Communities Initiative,the goal of which is to
develop a long-term economic development strategy for Cocke County and surrounding areas.
Status; This program was initiated in 1997.EPA has both discussed the program
and offered our assistance to the members,but has not been called upon
for specific inputs.We understand that the program is not meeting frequently
at this time.
- N.C. and TN will foster joint planning and public input by establishing a joint Watershed Advisory
Committee.
Status; First committee meeting held on May 25,2000.
- Champion will establish a facility Community Advisory Committee.
Status; A committee was established by BRPP.The first meeting was held on
February 2,2000,and the second meeting was held on March 27,2000.
EPA Region 4
May 25, 2000

EPA will lead, in cooperation with NC and TN,an independent
evaluation of current information on the Pigeon River.Evaluation will
include convening a group of scientists to evaluate existing data, identify
additional data needed,and if necessary,to conduct an ecological
assessment.Also,determine whether any significant ecological or
health risks exist.If so,what if any,steps could be taken to address
those risks.
Status; EPA has contracted with TVA to compile all existing
data into a useable database(this is the first step in
this task).A draft report is expected in May 2000. EPA
will convene a group of scientists to evaluate the data,
when the report is finalized.
EPA Region 4
May 25, 2000

PIGEON RIVER JOINT WATERSHED ADVISORY COMMITTEE MEETING
INTERCHANGE BUILDING, 59 WOODFIN PLACE, ASHEVILLE, NC 28801
THURSDAY, MAY 25, 2000, 1:00 PM
AGENDA
I. Introduction of Committee Members, EPA Representatives, Tennessee and North
Carolina Staff Members, Blue Ridge Paper Representatives and Other Visitors -
(1:00 - 1:10)
11. Review of Agenda and the Materials Previously Provided to Committee Members
-- Paul Davis and Forrest Westall - (1:10 - 1:25)
A. Agenda Review
B. Brief Review of the Items Provided
C. Questions/Changes From the Committee
III. Charge to the Committee -- Mike McGhee, EPA - (1:25 - 1:55)
A. Review of the Permit Agreement Condition that Created this Committee
(Section IV, Paragraph 32)
B. Comments on Blue Ridge Paper's NPDES Permit Renewal
C. Review of Other Pigeon River Watershed Issues
IV. Mill Status: -- Bob Williams, Blue Ridge Paper Products - (1:55 - 2:15)
A. Mill Ownership Issues
B. Color Effluent Discharge Levels/Removal Performance
C. Future Improvements
V. Break - (2:15 - 2:30)
VI. Mill Related Water Quality Issues -- Paul Davis, Mike McGhee and Forrest Westall
- (2:30 - 3:00)
A. Permit Agreement, NPDES and Variance Compliance
B. Dioxin Data and Trends
C. Ecological Data (Fisheries and Aquatic Insect Information)

VII. General Pigeon River Water Quality Issues/Concerns - (3:00 - 3:30)
A. Status of Permit Agreement Ecological Assessment Provision (Section V,
Paragraph 33) -- Mike McGhee
B. Tennessee and NC Watershed Planning Initiatives -- Paul.Davis and
Forrest Westall
C. Recreation/Rafting Use of the Pigeon -- Paul Davis and Forrest Westall
D. Waterville Lake/CP&L Issues -- Paul Davis and Forrest Westall
Vill. Committee Discussion, Identification of Other Issues and Committee Business -
(3:30 - 4:00)
A. Reaction of Committee's Charge
B. Otherlssues
C. Establishing Committee Responsibilities -- Electing Co-Chairs
D. Setting Next Meeting Date and Location in Tennessee
IX. Adjournment - (4:00)
-2-

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12/1/97
CHRONOLOGY OF CHAMPION PERMIT/VARIANCE
COLOR REQUIREMENTS
December 1997
-Settlement agreement signed to resolve challenges to the December 1996 NC
permit/variance
- The Technology Review Workgroup (chaired by EPA), consisting of 3 EPA
representatives, 2 TN environmental agency representatives, and 2 NC environmental
agency representatives, shall make itself available to consult with and provide
information to community representatives at appropriate times.
-Champion or any successor-in-interest to Champion's ownership/operation of the mill:
1) will use best efforts in good faith to continue to fully operate BFR on the pine line on
a continuing basis subject to the Agreement's terms; and 2) will not increase the mill's
current pulp production capacity.
-NPDES Permit and Variance modified to reflect settlement agreement
- Champion will meet all dioxin and other requirements (including monitoring) of the
Cluster Rule based on the timeframes established by the Rule.
January 1, 1998
- Champion continues to meet 50 true color units at the TN state line.
- Monthly average effluent color loading limit of 95,000#/day applies.
-Champion will continue to monitor color at 8 instream stations, including 3 in NC.
June 1, 1998
-Champion to implement 4 specific BMPs with high potential for color
reduction/implementability.
- Champion to submit a report(including strategy/timelines)to the Technology Review
Workgroup and NPDES Committee on: 1) identification of potential opportunities for
preventing/controlling black liquor spills/leaks; 2) improving the existing BMP
program; and 3)modification of process operations/controls to remove/reduce sewer
generated color.
October 1, 1998
-The Technology Review Workgroup recommends to the NPDES Committee alternate
interim limits and an alternate effective date if they have determined by this date that
the December 1, 1998 limits cannot be met due to overwhelming technical, economic,
or operational barriers.
December 1, 1998
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-Annual average color limit of 60,000#/day/monthly average limit of 69,000 #/day (or
NPDES Committee-approved alternate interim limits) become effective.
-Instream color @ Hepco gage shall be no more than 50 true color units whenever
monthly average flows are greater than 330 efs and in 91% of the applicable time
(monthly average flow and percentage will change if NPDES Committee-approved
alternate interim limits become effective).
-Champion to submit a contingency plan to the Technology Review Workgroup for
review for mitigating the occurrence and degree of potential exceedances when color @
Hepco gage might exceed 50 true color units.
January 1, 1999
-Champion begins implementing BFR on recycling the Eo stage of the hardwood line.
February 1, 1999
- The Technology Review Workgroup recommends approval of, or modifications to,
the 12/1/98 Champion contingency plan to the NPDES Committee.
March 1, 1999
-NPDES Committe-approved contingency plan becomes effective for mitigating
occurrence and degree of potential exceedances when color @ Hepco gage might
exceed 50 true color units.
December 1, 1999
-Champion provides an evaluation to the Technology Review Workgroup and the
NPDES Committee of partial BFR implementation on the hardwood line and assesses
the potential for full implementation of BFR on the hardwood line.
June 1,2000
- Full implementation of the Near-Term Package (consisting of 4 specific BMPs, full
BFR on the pine line, partial BFR on the hardwood line, and additional BMPs and
sewer generated color reduction measures) is anticipated, resulting in a target annual
average color effluent limit range of 48,000-52,000 #/day.
January 1,2001
-Champion submits report to the Technology Review Workgroup on whether the target
annual average color limit range of 48,000-52,000 #/day is feasible, based on full
implementation of the Near-Tenn Package.
March 1,2001
- Champion to submit report to the Technology Review Workgroup and the NPDES
Committee that assesses incremental color removal technologies on a
continuous/intermittent basis and at river lowflows, as well as providing the results of
all ongoing and any additional planned color reduction activities. The Workgroup will
evaluate the combined report and make recommendations to the Committee for further
color reduction targets for inclusion in the next NPDES permit.
April 1,2001
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-The Technology Review Workgroup recommends the lowest annual and monthly
average limits which are achievable, based on the 111/01 feasibility report and the
demonstrated performance of the mill.
May 1,2001
-Annual average limit within target range of 48,000-52,000#/day and corresponding
monthly limit become effective (or the permit is modified to reflect alternate interim
limits, if not within the target range).
-Instream color @ Hepco gage shall be no more than 50 true color units 96% of the
applicable time. (percentage will change if NPDES Committee-approved alternate
interim limits become effective).
December 2001
-NPDES permit expires. Instream montoring data collected during 1997 Permit term
will be evaluated to determine whether the Permit limits attained color levels as
expressed in the Variance. If not,new requirements will be developed for the next
permit to further reduce color in the river.
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12/1/97
CHRONOLOGY OF CHAMPION PERMIT/VARIANCE
COLOR REQUIREMENTS
December 1997
-Settlement agreement signed to resolve challenges to the December 1996 NC
permit/variance
-The Technology Review Workgroup (chaired by EPA), consisting of 3 EPA
representatives, 2 TN environmental agency representatives, and 2 NC environmental
agency representatives, shall make itself available to consult with and provide
information to community representatives at appropriate times.
-Champion or any successor-in-interest to Champion's ownership/operation of the mill:
1)will use best efforts in good faith to continue to fully operate BFR on the pine line on
a continuing basis subject to the Agreement's terms; and 2) will not increase the mill's
current pulp production capacity.
-NPDES Permit and Variance modified to reflect settlement agreement
- Champion will meet all dioxin and other requirements (including monitoring) of the
Cluster Rule based on the timeframes established by the Rule.
January 1, 1998
- Champion continues to meet 50 true color units at the TN state line.
-Monthly average effluent color loading limit of 95,000#/day applies.
-Champion will continue to monitor color at 8 instream stations, including 3 in NC.
June 1, 1998
-Champion to implement 4 specific BMPs with high potential for color
reduction/implementability.
- Champion to submit a report(including strategy/timelines) to the Technology Review
Workgroup and NPDES Committee on: 1) identification of potential opportunities for
preventing/controlling black liquor spills/leaks; 2) improving the existing BMP
program; and 3) modification of process operations/controls to remove/reduce sewer
generated color.
October 1, 1998
-The Technology Review Workgroup recommends to the NPDES Committee alternate
interim limits and an alternate effective date if they have determined by this date that
the December 1, 1998 limits cannot be met due to overwhelming technical, economic,
or operational barriers.
December 1, 1998
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-Annual average color limit of 60,000#/day/monthly average limit of 69,000#/day (or
NPDES Committee-approved alternate interim limits) become effective.
-Instream color @ Hepco gage shall be no more than 50 true color units whenever
monthly average flows are greater than 330 cfs and in 9 1% of the applicable time
(monthly average flow and percentage will change if NPDES Committee-approved
alternate interim limits become effective).
-Champion to submit a contingency plan to the Technology Review Workgroup for
review for mitigating the occurrence and degree of potential exceedances when color @
Hepco gage might exceed 50 true color units.
January 1, 1999
-Champion begins implementing BFR on recycling the Eo stage of the hardwood line.
February 1, 1999
-The Technology Review Workgroup recommends approval of, or modifications to,
the 12/1/98 Champion contingency plan to the NPDES Committee.
March 1, 1999
-NPDES Committe-approved contingency plan becomes effective for mitigating
occurrence and degree of potential exceedances when color @ Hepco gage might
exceed 50 true color units.
December 1, 1999
-Champion provides an evaluation to the Technology Review Workgroup and the
NPDES Committee of partial BFR implementation on the hardwood line and assesses
the potential for full implementation of BFR on the hardwood line.
June 1, 2000
-Full implementation of the Near-Term Package (consisting of 4 specific BMPs, full
BFR on the pine line, partial BFR on the hardwood line, and additional BMPs and
sewer generated color reduction measures) is anticipated,resulting in a target annual
average color effluent limit range of 48,000-52,000 #/day.
January 1,2001
-Champion submits report to the Technology Review Workgroup on whether the target
annual average color limit range of 48,000-52,000#/day is feasible, based on full
implementation of the Near-Term Package.
March 1,2001
- Champion to submit report to the Technology Review Workgroup and the NPDES
Committee that assesses incremental color removal technologies on a
continuous/intermittent basis and at river lowflows, as well as providing the results of
all ongoing and any additional planned color reduction activities. The Workgroup will
evaluate the combined report and make recommendations to the Committee for further
color reduction targets for inclusion in the next NPDES permit.
April 1,2001
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-The Technology Review Workgroup recommends the lowest annual and monthly
average limits which are achievable, based on the 1/l/01 feasibility report and the
demonstrated performance of the mill.
May 1, 2001
-Annual average limit within target range of 48,000-52,000 #/day and corresponding
monthly limit become effective (or the pein it is modified to reflect alternate interim
limits, if not within the target range).
-Instream color @ Hepco gage shall be no more than 50 true color units 96% of the
applicable time. (percentage will change if NPDES Committee-approved alternate
interim limits become effective).
December 2001
-NPDES permit expires. Instream montoring data collected during 1997 Permit term
will be evaluated to determine whether the Permit limits attained color levels as
expressed in the Variance. If not, new requirements will be developed for the next
permit to further reduce color in the river.
http://www.epa.gov/region4/my_4tual/Champeh2.htm 1/14/98

FRENCH BROAD RIVER
BASINWIDE WATER QUALITY PLAN
(Includes the French Broad, Pigeon
and Nolichucky River Watersheds)
DRAFT Executive Summary
for
Environmental Management Commission Review
May 2000
NCDENR
Division of Water Quality /Planning
1617 Mail Service Center
Raleigh, NC 27699-1617
DarleneXuckennu,ncmail.net
[phone] ext. 354

Executive Summary
North Carolina's Basinwide Approach to Water Quality Management
Basinwide water quality planning is a nonregulatory watershed-based approach to restoring and
protecting the quality of North Carolina's surface waters. Basinwide water quality plans are
prepared by the NC Division of Water Quality for each of the seventeen major river basins in the
state. Each basinwide plan is revised at five-year intervals. While these plans are.prepared by
the Division of Water Quality, their implementation and the protection of water quality entails
the coordinated efforts of many agencies, local governments and stakeholders in the state. The
first basinwide plan for the French Broad River basin was completed in 1995.
Goals of the Basinwide Approach
The primary goals of DWQ's basinwide program are to:
identify water quality problems and restore full use to impaired waters;
identify and protect high value resource waters;
protect unimpaired waters while allowing for reasonable economic growth;
develop appropriate management strategies to protect and restore water quality;
• assure equitable distribution of waste assimilative capacity for dischargers; and
improve public awareness and involvement in the management of the state's surface waters.
French Broad River Basin Overview
The French Broad River basin drains to the Gulf of Mexico via the Tennessee, Ohio and
Mississippi Rivers. The boundaries of the French Broad River basin within NC contain portions
or all of Transylvania, Buncombe, Henderson,Madison, Haywood, Yancey, Mitchell and Avery
counties.
The basin is composed of three major drainages: French Broad River, Pigeon River and
Nolichucky River. These rivers individually flow northwest into Tennessee. There are seven
man-made lakes in the basin monitored by DWQ: Lake Julian, Burnett Reservoir, Beetree
Reservoir, Busbee Reservoir, Lake Junaluska, Allen Creek Reservoir and Walters (Waterville)
Lake. I
-
About one-half of the land in the basin is forested, with much of the basin within Pisgah National
Forest or Pisgah Game Lands. The northwest comer of Haywood County is in the Great Smoky
Mountains National Park. Steep slopes limit the land area suitable for development and crop
production. Therefore, most agricultural and developed lands are concentrated within the river
valleys. Between 1982 and 1992, cultivated and uncultivated croplands decreased by about 67
percent, while urban and developed lands increased by about 42 percent.
Executive Summary i

The population of the basin,based on 1990 census data,was estimated at 357,932. The overall
population density of the basin of 128 persons per square mile is comparable to the statewide
average of 123 persons per square mile. The percent population growth over the past ten years
(1980 to 1990)was 8.5 % versus a statewide increase of 12.7%. Population density is greatest in
and around the cities of Asheville and Hendersonville.
Water quality is generally good throughout the basin, although there are several areas of concern.
Trout waters are abundant and many waters are classified as High Quality or Outstanding
Resource Waters.
Assessment of Water Quality in the French Broad River Basin
Waters are classified according to their best intended uses. Determining how well a waterbody
supports its designated uses is an important method of interpreting water quality data and
assessing water quality. This determination results in a use support rating. The use support
ratings refer to whether the classified uses of the water(such as water supply, aquatic life
protection and swimming) are fully supported,partially supported or not supported. For
instance, waters classified for fishing and water contact recreation(Class C) are rated as fully
supporting if data used to determine use support (such as chemical/physical data collected at
ambient sites or benthic macroinvertebrate bioclassifications) did not exceed specific criteria.
However, if these criteria were exceeded,then the waters are rated as partially supporting or not
supporting, depending on the degree of exceedence. Streams rated as either partially supporting
or not supporting are considered impaired.
A summary of current use support ratings for the French Broad River basin is presented in Table
1. For further information and definition of monitored and evaluated streams, refer to Appendix
A-III.
Table 1 Use Support Summary Information for All Monitored and Evaluated Streams in
the French Broad River Basin (1999)
Monitored and Monitored
Evaluated Streams* Streams Only**
Miles % Miles %
Fully Supporting 3190.9 77 812.2 90
Impaired 88.5 2-
Partially Supporting 50.6 1 50.1 6
Not Supporting 37.9 1 37.9 4
Not Rated 856.5 21
Total 4135.9 900.2
* = Percent based on total of all named and classified streams,both monitored and evaluated.
**= Percent based on total of all monitored streams.
Recommended Management Strategies for Restoring Impaired Waters
Executive Summary ii

The long-range mission of basinwide management is to provide a means of addressing the
complex problem of planning for increased development and economic growth while protecting
and/or restoring the quality and intended uses of the French Broad River basin's surface waters.
In striving towards its mission, DWQ's highest priority near-term goals are to:
➢ identify and restore impaired waters in the basin;
➢ identify and protect high value resource waters and biological communities.of special
importance; and
➢ protect unimpaired waters while allowing for reasonable economic growth.
Within this basinwide plan, DWQ presents management strategies for those waters considered to
be impaired. Table 2 presents impaired waters in the French Broad River basin, the sources of
impairment, summaries of the recommended management strategies, and location of further
information in the basinwide plan.
These waters are impaired, at least in part, due to nonpoint sources (NPS) of pollution. The tasks
of identifying nonpoint sources of pollution and developing management strategies for these
impaired waters is very resource intensive. Accomplishing these tasks is overwhelming, given
the current limited resources of DWQ, other agencies (e.g.,Division of Land Resources,
Division of Soil and Water Conservation, Cooperative Extension Service, etc.) and local
governments. Therefore, only limited progress towards restoring NPS impaired waters can be
expected during this five-year cycle unless substantial resources are put toward solving NPS
problems.
DWQ plans to further evaluate the impaired waters in the French Broad River basin in
conjunction with other NPS agencies and develop management strategies for a portion of these
impaired waters for the next French Broad River Basinwide Water Quality Plan.
Addressing Waters on the State's 303(d) List
For the next several years, addressing water quality impairment in waters that are on the state's
303(d) list will be a DWQ priority. The waters in the French Broad River basin that are on this
list are presented in the individual subbasin descriptions in Section B.
Section 303(d) of the federal Clean Water Act-requires states to develop a 303(d) list of waters
not meeting water quality standards or which have impaired uses. States are also required to
develop Total Maximum Daily Loads (TMDLs) or management strategies for 303(d) listed
waters to address impairment. EPA issued guidance in August 1997 that called for states to
develop schedules for developing TMDLs for all waters on the 303(d) list within 8-13 years.
There are approximately 470 stream segments on the 303(d) list in NC. The rigorous and
demanding task of developing TMDLs for each of these waters during an 8 to 13-year time
frame will require the focus of much of the water quality program's resources. Therefore, it will
be a priority for North Carolina's water quality programs over the next several years to develop
TMDLs for 303(d) listed waters. This task will be accomplished through the basinwide planning
process and schedule.
Executive Summary iii

Table 2 Impaired Waters within the French Broad River Basin (as of 1999)
Subbasin Chapter in Listed Use Support Potential Recommended Management Strategy
Section B Water Rating Sources
04-03-01 1 Peter Weaver PS P DWQ will resample this creek to obtain information
Creek for a management strategy. Holders of individual
NPDES permits will be required to conduct
upstream/downstream sampling during summer
months.
04-03-01 1 Morgan Mill PS P DWQ will resample this creek to obtain information
Creek for a management strategy. Holders of individual
NPDES permits will be required to conduct
upstream/downstream sampling during summer
months.
04-03-02 2 Gash Creek NS NP Local actions are needed on NPS inventory.
04-03-02 2 Mill Pond PS NP DWQ will continue to monitor to better identify
Creek problem parameters.
04-03-02 2 Mud Creek NS NP Local restoration initiatives are underway,and DWQ
P will continue to monitor results.
04-03-02 2 Bat Fork Creek PS NP DWQ will continue to monitor the creek and increase
coordination with other agencies to address the
various pollution sources.
04-03-02 2 Clear Creek PS NP Local actions are needed to expand buffer and BMP
implementation.
04-03-02 2 Hominy Creek PS NP There is a need to increase the funding and
implementation of chemical handling facilities.
04-03-02 2 South Hominy 'NS NP There is a need to increase the funding and
Creek implementation of chemical handling facilities.
04-03-02 2 Ross Creek NS NP Local initiatives are underway,and DWQ will
continue to monitor results.
04-03-03 3 Mills River NS NP Local initiatives are underway,and DWQ will
continue to monitor results.
04-03-03 3 Brandy Branch PS NP Local projects aimed at identifying sources of
pollution and necessary actions would be very useful
to DWQ and various funding agencies. DWQ will
continue to monitor Brandy Branch to better identify
problem parameters.
04-03-04 4 Little Ivy Creek PS NP Local restoration initiatives are underway,and DWQ
will continue to monitor results.
04-03-05 5 Pigeon River PS ' NP DWQ will continue to monitor process improvements
P made at BRPP and work with the Joint Watershed
Advisory Group. Local nonpoint source initiatives are
needed.
04-03-05 5 Richland Creek PS NP Local restoration initiatives are underway,and DWQ
will continue to monitor results.
Key: NS=Not Supporting PS=Partially Supporting NP=Nonpoint sources P=Point Sources
'= Only limited progress towards developing and implementing NPS strategies for these impaired waters can be expected
without additional resources.
•= These waters are also on the 303(d)list,and a TMDL and/or management strategy will be developed to remove the water
from the list.
Executive Summary iv

EXECUTIVE SUMMARY
Sportfish and bottom feeding species were collected in 1999 from six locations in the Pigeon
River and analyzed for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 2,3,7,8-
tetrachlorodibenzofuran (TCDF) and other CDD and CDF isomers. TCDD and TCDF
residues were not detected in any of the 10 sportfish fillet composites collected downstream of
the Blue Ridge Paper Canton mill. Sportfish used were redbreast sunfish, rock bass, black
I crappie, largemouth bass, and smallmouth bass. TCDD and TCDF concentrations in fillet
composites from bottom feeders were very low (range=non-detected to 1.1 ppt) at the three
riverine locations downstream of the mill. Bottom feeders used at these locations were
I common carp and smallmouth buffalo. TCDD concentrations in bottom feeder fillet
composites at the two Waterville Lake locations were 0.58 ppt and 4.7 ppt (Stations 4A and
4B, respectively) for carp, and 0.83 for channel catfish at Station 4A and non-detect for
flathead catfish at Station 4B. Since 1990, TCDD concentrations in common carp fillets have
declined dramatically (86-99 percent) at all downstream stations (Figure-ES-1).
vii

FIGURE ES-1 . TCDD CONCENTRATIONS IN CARP FILLETS COLLECTED FROM
25 THE PIGEON RIVER, 1990-1999 (Stations 2 and 3).
20 ----- -------------------------------------------------------------------------------------------------------------------------
e
0
•E 1s -------------- --------------------------------------------------
-----------------------------------------------------------------------------------------------
N. o.
r � .
r•
a
v
op1p ______________________
5 -------------
------------------------------------------------------
---- ---•---
9 . —I
logo 1991 1992 1993 1994 1995 1999 1997 1998 logo
YEAR
—!— Station 2 - } -- Station 3

FIGURE ES-1 (Cont.). TCDD CONCENTRATIONS IN CARP FILLETS COLLECTED FROM
70
THE PIGEON RIVER, 1990-1999 (Stations 4A and 413).
50 ------------------
`-------------------;--------------------------------
------------------------------
L40 -----------_----------- _________.____;________.
-------------------------------------------------------------------------------
kCL
C
30 --------- -----------
0
FV-
70 — — -------�---------
--------------------
1990 1991 1992 1993 1994 1995 1996 1997 1998 logo
YEAR
E— Station 4a i Station 4b

5
1:
r
- ncasi
NATIONAL COUNCIL FOR AIR AND STREAM IMPROVEMENT
AN UPDATE OF PROCEDURES
FOR THE MEASUREMENT OF
COLOR IN PULP MILL
WASTEWATERS
TECHNICAL BULLETIN NO. 803
MAY 2000
by
Diana Cook
National Council for Air and Stream Improvement, Inc.
West Coast Regional Center, Corvallis, OR
Nikki Frum
National Council for Air and Stream Improvement, Inc.
West Coast Regional Center, Corvallis, OR

J
J .
Acknowledgments
This report was prepared by Diana Cook,Senior Research Scientist,and Nikki From,Research Associate,a[the
NCASI West Coast Regional Center.
For more information about this research,contact:
Diana Cook Reid Miner
Senior Research Scientist Vice President,Water&Pollution Prevention Programs
NCASI West Coast Regional Center NCASI
P.O.Box 458 P.O.Box 13318
Corvallis,OR 97339 Research Triangle Park,NC 27709-3318
[phone] [phone]
[e-mail] [e-mail]
For information about NCASI publications,contact:
NCASI
P.O.Box 13318
Research Triangle Park,NC 27709-3318
[phone]
[e-mail]
National Council for Air and Stream Improvement,Inc.(NCASI). 2000. An update of procedures for the
measurement of color in pulp mill wastewaters. Technical Bulletin No.803. Research Triangle Park,NC:
National Council for Air and Stream Improvement,Inc.
©2000 by the National Council for Air and Stream Improvement,Inc.

■
ncasi
serving the environmental research needs of the forest products industry since 1943
PRESIDENT'S NOTE
One of NCASI's roles in support of the pulp and paper industry's environmental programs is the
evaluation and development of analytical methods useful in characterizing the constituents and
properties of process effluents and wastewaters. In 1971,NCASI developed and published a method
for the measurement of color in effluents from pulping operations and their receiving waters. Since
then,the NCASI color method has been widely used in mill effluent monitoring and compliance
assessment programs;it has also been used to evaluate receiving water properties. But in the nearly
three decades since the color method was published, a number of innovations have occurred in pulp
and papermaking techniques. The impact of these innovations on effluent quality has been significant
enough to suggest that the NCASI color procedure be re-evaluated using modem pulping effluents.
This bulletin describes a recent evaluation of the method and provides an updated procedure for color
measurement. The procedural updates were designed to enhance the repeatability and reproducibility
of the method while maintaining the existing fundamental basis of historical pulp mill effluent color
measurement.
Aspects of the color measurement procedure that were evaluated included wavelength for lower color
effluents, turbidity removal,pH during and following filtration, and sample cell path length. The
updated procedure was subjected to single-and multi-laboratory evaluations, and the results were
used to determine quality assurance and quality control criteria for assessing method performance.
The updated method was also compared to the 1971 version and found to yield similar values in most
cases. The complete, updated method,NCASI Method Color 71.01, is included as an appendix to
this report. The results of this investigation will be useful to mills that measure color in process
effluents,treated final effluents,and receiving waters.
y'lY�
Ronald A. Yeske
May 2000
National Council for Air and Stream Improvement

AN UPDATE OF PROCEDURES FOR THE MEASUREMENT OF
COLOR IN PULP MILL WASTEWATERS
TECHNICAL BULLETIN NO. 803
MAY 2000
ABSTRACT
NCASI Method 253 was originally developed in 1971 to provide a technique for color measurement
in pulping wastewaters and their receiving waters. Because the processes of pulp and paper
production have changed considerably since that time, a study was undertaken with the objective of
updating the method. The color of pulp mill effluents is highly pH-dependent, and the pH adjustment
procedure included in Method 253 sometimes resulted in less than optimum stability of pH during the
analytical procedure. The use of a buffer to stabilize pH and reduce the erroneous increase in
absorbance was investigated and successfully implemented. Experiments were conducted to
investigate approaches for removing turbidity from pulp mill wastewater samples, since turbidity can
interfere with the assessment of color by scattering light and introducing a high bias. Centrifugation
was investigated as an alternative to filtration for the removal of turbidity. The percent decrease in
turbidity was consistently higher for aliquots treated using filtration vs. centrifugation. In addition,
the resultant color values were consistently higher for samples that were centrifuged. The current
technique, use of a 0.8 µm membrane filter,proved to be an effective method of turbidity removal in
pulp mill wastewaters. Pre-filtration of the samples using a 1 µm glass fiber filter was confirmed as
an acceptable method for reducing filter plugging of the 0.8 µm membrane filters. Comparisons of
three different types of membrane filters demonstrated that similar results could be obtained with any
of the three filter types. The selection of a wavelength of 465 Tim was confirmed to be valid in low
color effluents for the spectrophotometric measurement of absorbance. Finally, the method was
assessed at both the single-and the inter-laboratory level for ruggedness, precision,and accuracy.
The average relative standard deviations for the single laboratory precision were 2.8%in biologically
treated effluents and 7.1%in treatment plant influents. The average relative standard deviations for
the inter-laboratory precision were 15%in biologically treated effluents and 24.1%in treatment plant
influents. A well-defined and documented method for the measurement of color was developed;
including quality control and quality assurance criteria. The updated method is included in this report
as Appendix B.
KEYWORDS
color units,true color, turbidity,filtration,pH stability, spectrophotometer,platinum cobalt
RELATED NCASI PUBLICATIONS
Technical Bulletin No.253 (December 1971). An investigation of improved procedures far
measurement of mill effluent and receiving water color.
National Council for Air and Stream Improvement

CONTENTS
1.0 INTRODUCTION........................................................................................................................I
2.0 BACKGROUND..........................................................................................................................1
3.0 RESEARCH OBJECTIVES.........................................................................................................2
4.0 EXPERIMENTS AND RESULTS...............................................................................................2
4.1 Sampling Site Selection and Sample Collection.................................................................2
4.2 Analytical Methods and Instrumentation............................................................................3
4.3 Wavelength Selection Verification.....................................................................................3
4.4 pH Adjustment Validation Experiments.............................................................................4
4.5 Turbidity Removal Experiments.........................................................................................7
4.6 Sample Volume Selection.................................................................................................13
4.7 Effects of Various Light Path Lengths on Resultant Color Values...................................13
5.0 UPDATED METHOD COLOR 71.01 VALIDATION AND QAIQC.......................................15
5.1 Brief Description of NCASI Method Color 71.01: The Updated Color Method.............15
5.2 Preparation of the Calibration Curve ................................................................................15
5.3 Daily Calibration Verification...........................................................................................15
5.4 Single Laboratory Precision..............................................................................................16
5.5 Comparison of Updated NCASI Method Color 71.01 to NCASI Method 253.................17
5.6 Inter-laboratory Investigation of NCASI Method Color 71.01.........................................18
6.0 SUMMARY AND CONCLUSIONS .........................................................................................21
REFERENCES .....................................................................................................................................22
APPENDICES
AStatistical Data.................................................................................................................Al
BNCASI Method Color 71.01 ............................................................................................B 1
C Inter-laboratory Study Plan,Procedure, and Data Sheet..................................................Cl
D Youden Pair Statistical Analysis Plots.............................................................................DI
National Council for Air and Stream Improvement

TABLES
Table4.1 Description of Mills............................................................................................................3
Table 4.2 Effects of Pre-filtration vs.No Pre-filtration on True Color...............................................8
Table 4.3 Comparison of Various Membrane Filters........................................................................11
Table 4.4 Effects of Sample Volume on the True Color Value Determined ....................................13
Table 4.5 Calibration Curves for Various Light Path Length Cells..................................................14
Table 4.6 Summary of Light Path Length Experiments....................................................................14
Table 5.1 Summary of Daily Instrument Calibration Checks...........................................................16
Table 5.2 Summary of the Statistics Comparing NCASI Methods 253 and Color 71.01
inDifferent Matrices.........................................................................................................18
Table 5.3 Summary of the True Color Results and Percent Recoveries for the
QA/QC 125 PCU Standard...............................................................................................19
Table 5.4 Inter-laboratory Study: Summary of Results ....................................................................20
Table 5.5 Results of the Inter-laboratory Study Youden Pair Analyses............................................21
FIGURES
Figure 4.1 Absorption Curve Overlap..................................................................................................4
Figure 4.2 Effects of Sample pH on True Color Value Determined....................................................5
Figure 4.3 pH Stabilization Using Various Buffers in an Effluent Sample with a
Color Value of Approximately 100 PCU............................................................................6
Figure 4.4 pH Stabilization Using Various Buffers in an Effluent Sample with a
Color Value of Approximately 360 PCU............................................................................7
Figure 4.5 Effects on Sample Turbidity and Color:Filtration vs. Centrifugation................................8
Figure 4.6 Filter Porosity Effects on Mill B Effluent Turbidity and Color..........................................9
Figure 4.7 Filter Porosity Effects on Mill C Influent Turbidity and Color........................................10
Figure 4.8 Turbidity Agent Removal Results: Effluent Sample.........................................................12
Figure 4.9 Turbidity Agent Removal Results: Lignin Solution Sample.............................................12
Figure 4.10 Color Units of Five Effluent Samples Using Various Light Path Length Cells................14
Figure 5.1 Comparison of Resultant Color Values in Different Sample Matrices Using
NCASI Methods 253 and Color 71.01..............................................................................17
Figure 5.2 Comparison of Post-filtration pH in Different Sample Matrices Using
NCASI Methods 253 and Color 71.01..............................................................................18
National Council for Air and Stream Improvement

1
AN UPDATE OF PROCEDURES FOR THE MEASUREMENT OF COLOR IN
PULP MILL WASTEWATERS
1.0 INTRODUCTION
Many mills routinely monitor color as a tool in assessing wasteload for Best Management Practices
(BMP), to assist in evaluating process changes, as a requirement of a facility's National Pollution
Discharge Elimination System(NPDES)permit, and to monitor effluent and receiving water quality.
In 1971, in an effort to standardize the measurement of color in pulp mill wastewaters,NCASI
published Technical Bulletin No.253,An investigation of improved procedures for measurement of
mill effluent and receiving watercolor(NCASI 1971). Since then, the nature of pulp mill wastewater
samples has changed due to the application of process technologies such as oxygen delignification
and chlorine dioxide substitution, as well as improvements in spent liquor management.
Subsequently, the matrices currently being assessed differ from the matrices initially used to develop
the NCASI method. In some instances, problems have been encountered with pH stability and
turbidity interfering with the accurate assessment of true color, using Method 253. In addition, an
effort was made to make the method more consistent with current NCASI method protocols and to
define quality assurance and quality control (QA/QC) parameters. In response to these issues,
NCASI initiated a task to optimize the NCASI color method for application to pulp mill wastewaters.
2.0 BACKGROUND
Color in pulp mill effluents may result from the presence of several substances in the wastewater that
contribute different chromophoric characteristics to the matrix. The largest portion of this
chromophoric component is thought to be the high molecular mass materials that result from
degradation of lignin during pulping and bleaching processes. This high molecular mass material
(molecular weights greater than1000)carries several chromophoric structures that impart light-
absorbing qualities to the resulting effluents (Kringstad and Lindstrom 1984). The measurement of
color in industrial wastewater samples is typically limited to true color, which is the color of samples
from which turbidity has been removed. The measurement of color present in pulp mill wastewaters
can be determined using several different methods,including the visual comparison method,
spectrophotometric method,colorimetric method,and tristimulus filter method (Standard Methods
1998;USEPA 1971, 1978). Within the pulp and paper industry, the spectrophotometric methods,
which include NCASI Method 253, are frequently used to assess true color in wastewaters. NCASI
Method 253 measures the absorbance of a pulping mill wastewater or receiving water sample at a
wavelength of 465 rlm, once the sample has been adjusted to pH 7.6 and filtered through a 0.8 µm
membrane filter to remove turbidity.
The determination of a true color value is extremely pH dependent, with the color value increasing as
the pH of the sample increases. Therefore, controlling the pH of the sample during filtration and
measurement of absorbance is of great importance.
The turbidity of the sample can also influence the color value determined. Turbidity is an expression
of optical properties that cause light to be scattered or absorbed rather than transmitted in a straight
line through the sample. Suspended materials such as clay, fiber, titanium dioxide, precipitated
calcium carbonate, humic materials, and lignin may cause turbidity in pulp mill wastewaters.
Because much of the color in effluent samples is due to high molecular mass (HMM) materials which
are byproducts of the degradation of lignin, it is difficult to devise an optimal method for removing
turbidity without removing some of the true color. The true color in a sample,when determined using
a spectrophotometric method,is the dissolved color which absorbs light as it is transmitted through
the sample. It is desirable to remove the greatest amount of turbidity from the samples while limiting
National Council for Air and Stream Improvement

2 Technical Bulletin No. 803
the amount of true color removed. This optimum may vary from sample to sample, depending on the
particles contributing to the overall turbidity and true color, and the ease with which they are
removed. The majority of color measurement methods, including NCASI Method 253, use filtration
or centrifugation for the removal of turbidity from a sample. The filtration technique can produce
results that are consistent from day to day in the same lab and among different labs, but may also
remove some of the true color. Centrifugation avoids the interaction of color with the filtering
material,but it can be difficult to obtain consistent results due to variations in the nature of the
sample,the size and speed of the centrifuge in use, and reintrainment of turbidity during sample
transfer.
When a spectrophotometer is utilized for the determination of color, several instrumental parameters
can also influence the overall results. These parameters include the wavelength selected for
measurement of absorbance, differences in light path lengths, the condition of the cell, the presence of
stray radiation,reflection losses, scattering losses,photocell fatigue, source fluctuations, and loss of
wavelength calibration (Ingle and Crouch 1988). It is also critical that the cells used to measure
absorbance are clean,free of scratches, and reproducibly placed in the spectrophotometer. For these
reasons, use of properly calibrated equipment in good working order is important.
3.0 RESEARCH OBJECTIVES
The four primary objectives of this research project were to:
1. evaluate the performance of NCASI Method 253 for the measurement of color when used on
influent and effluent samples from present-day pulp mills exhibiting low effluent color;
2. develop and evaluate various approaches to improve the color measurement procedure for the
assessment of true color in influent and effluent samples from present-day pulp mills exhibiting
low effluent color. This objective involves the development of techniques to stabilize sample pH
during filtration and absorbance(color)measurement, and the investigation of potential
interference in the color method(including different sources of turbidity);
3. provide a well-defined and documented method for the measurement of color that incorporates
quality assurance and quality control (QA/QC) criteria and is consistent with EPA's method
development guidelines, NCASI method protocols, and current NPDES requirements for the
industry; and
4. assess precision and accuracy by conducting infra-and inter-laboratory investigations using the
updated procedure.
4.0 EXPERIMENTS AND RESULTS
4.1 Sampling Site Selection and Sample Collection
Table 4.1 provides summary descriptions of the mills that provided samples for this research.
Information in the table shows wood type, bleaching sequence, average daily production, average
daily water usage, and wastewater treatment plant (WTP)type. Grab and composite samples were
collected from six bleached kraft mills that utilize oxygen delignification and/or high chlorine dioxide
substitution. During the course of this research, additional samples from a thermomechanical pulping
mill and an unbleached kraft mill were also tested. Samples of biologically treated effluent, influent
to the treatment system,primary effluent(effluent from primary treatment before secondary
treatment), and receiving water were analyzed. The unpreserved samples were collected by mill
personnel and shipped overnight on ice to the NCASI West Coast Regional Center(WCRC). The
samples were stored at 4°C until analyzed. Prior to manipulations,the samples were removed from
National Council for Air and Stream Improvement

Technical Bulletin No. 803 3
the refrigerator and allowed to warm to room temperature. Settled solids were re-suspended by
vigorously shaking the sample bottles prior to use.
Table 4.1. Description of Mills
Mill Wood Bleaching Average Daily Average Daily WTP
Code Type Sequence Production Water Usage` Typef
A SW D(EO)WDED 950 16 ASB
B SW/HW (CD)EHD 1450 44 AS
C SW/HW O(CD)ED 1850 28 ASB
D SW/HW (CD70)(EP)D 680 13.5 AS
E SW/HW CEDD 1700 32 AS
F SW unbleached 1090 24 ASB
G SW sodium hydrosulphite 750 5 ASB
H SW OM(EOP)MP 500 11 ASB
° The mills sampled in this study used the kraft process(with the exception of Mill G, which is a TMP mill).
b SW= softwood; HW=hardwood.
` D=chlorine dioxide;E=alkaline extraction;C=chlorine;H=hypochlorite;0=oxygen;
M=chlorine monoxide;P=hydrogen peroxide;W=washing stage.
a Average daily production in air dried tons/day.
` Average daily water usage in million gallons/day.
f ASB=aeration stabilization basin;AS=activated sludge.
4.2 Analytical Methods and Instrumentation
4.2.1 Brief Description of NCASI Method 253
NCASI Method 253 (NCASI 1971) involves selecting a 200 mL sample of wastewater or water and
adjusting the pH to 7.6 with hydrochloric acid (HC]) or sodium hydroxide(NaOH), while assuring
less than a I% change in the sample volume. A 50 mL aliquot of this pH-adjusted sample is filtered
through a 0.8 µm porosity membrane filter pre-rinsed with distilled water. A portion of the filtered
sample is transferred to an absorption cell, and the sample's absorbance is measured at 465 t)m using
a spectrophotometer. The color is determined by spectrophotometric comparison of the sample with
known concentrations of platinum cobalt solutions.
4.2.2 Instrumentation
Measurements were conducted at the NCASI WCRC using a Spectronic 21D spectrophotometer
equipped with a digital readout. This spectrophotometer utilizes a tungsten light source and has a
wavelength range of 340 to 1000 t)m, with a spectral slit width of 10 Bm. The color units for a
sample are determined by comparing the absorbance reading with a standard curve prepared using
solutions of platinum cobalt. Turbidity measurements were done on a Hach Model 18900 Ratio
Turbidimeter with ranges of 1 to 2, 1 to 20, and 1 to 200 nephelometric turbidity units(mu). The unit
is equipped with a tungsten lamp,and was operated using the procedure in the instrument manual
(Hach 1991).
4.3 Wavelength Selection Verification
Selection of the wavelength used to measure the absorbance of the samples influences the accuracy
and precision of color measurements. Ideally, the absorbance observed for samples of similar color
values should overlap the absorption of the standard selected to assess the color value(Ingle and
Crouch 1988). NCASI conducted experiments during the development of Method 253 to determine
National Council for Air and Stream Improvement

4 Technical Bulletin No. 803
the wavelength at which the platinum cobalt standard overlapped the absorption curve of pulp mill
wastewater samples. The experiments involved plotting the absorption curves for bleached kraft mill
effluent samples in each of 18 sets of data from a survey representing 18 different instruments. The
results of the experiments indicated that the areas of the visible spectrum yielding an exact match of
sample with the platinum cobalt color standard occurred in the range of 450 to 480 Tlm(NCASI
1971). The results also indicated that accuracy and precision could be achieved by measuring the
absorbance at a wavelength of 465 T)m.
To verify this wavelength selection in current sample matrices, an experiment was performed which
involved measuring the absorption curve for a 200 platinum cobalt unit(PCU) standard, a
biologically treated effluent(Mill A), and a treatment system influent(Mill B). The absorption
curves were prepared within a wavelength range of 400 to 700 rlm in intervals of 10 rlm using
samples with color values of approximately 200 PCUs. The absorption curves for this experiment are
plotted in Figure 4.1. Ideally,the plots for the absorbance vs. wavelength for the samples tested
should show lines overlapping the platinum cobalt standard curve at the wavelength used for
measuring sample absorbance in the method. The mill wastewater samples tested did not show
distinct peaks, indicating that a mixture of chromophores are responsible for the resulting color
observed. As wavelength increased,the absorbance of light gradually decreased. Optimum overlap
occurred in the range of 460 to 470 ilm. The selection of a wavelength of 465 rlm for the
measurement of effluent and influent color was valid.
0.20
-Color Standard !
0.15
�-Effluent
0 0.10 Influent
a 0.05
0.00
400 410 420 430 440 450 460 470 480 490 500 510 520 530 540 550
Wavelength (nm)
Figure 4.1. Absorption Curve Overlap.
4.4 pH Adjustment Validation Experiments
4.4.1 The Effects of pH on Color Determinations
In NCASI Method 253, the pH of the sample is to be adjusted to 7.6 using a solution of NaOH or
HCI. As previously noted, users of this method sometimes find the pH difficult to stabilize. In most
cases, the pH of the sample increases following filtration through a 0.8 µm membrane filter and over
time. Comparative work conducted as part of an inter-laboratory evaluation of the updated NCASI
Method Color 71.01 confirmed these observations (Section 5.5,Figure 5.1).
To examine the effects of pH on the color value determined for a biologically treated pulp mill
effluent sample, the absorbance of a sample at various pH values was measured. A 200 mL aliquot of
sample(Mill A)was adjusted to pH 7.6 and filtered through a 0.8 µm membrane filter. A 25 mL
aliquot was taken from the filtrate and transferred to a beaker. The initial pH and absorbance were
National Council for Air and Stream Improvement

Technical Bulletin No. 803 5
measured. The sample pH was then adjusted from 7.0 to 8.4 in increments of 0.2. Absorbance was
measured at each pH level and color values were calculated based on these measurements. This
experiment was repeated with a biologically treated effluent from Mill C. The results of the
experiments are illustrated in Figure 4.2. The color values for Mill A showed a consistent increase
across the range of pH values tested. The color values for Mill C appeared to be somewhat stable
between pH 7.6 and 8.0. Color values measured at pH 8.2 and 8.4 indicate a sharp increase,then
decrease,which could not be effectively explained. The percent increases in the color values
determined from pH 7.6 to 8.4 were 7.2%and 2.7%for Mill A and Mill C,respectively, while the
percent decreases in the color values determined from pH 7.6 to 7.0 were 6.5010 and 4.0% for Mill A
and Mill C,respectively.
This experiment demonstrates the importance of stabilizing the pH of pulp mill effluent samples at a
given value and recording the value at which color assessments are determined.
Mill A Effluent Mill C Effluent
460 260
440 j
430 } 255
Va 420 T a 250
410 T
> 400 1 245 I
390 ° 240
o
U 380 U
370 t 235
360 230
O N V: t0 m O N
n n r n r m ci m n n r r� 6 ai m
pH pH
Figure 4.2. Effects of Sample pH on True Color Value Determined.
4.4.2 pH Stabilization Experiments
Given the importance of pH stabilization,NCASI investigated different buffering systems in an effort
to stabilize the pH of samples, and thereby reduce errors in color measurement associated with
fluctuations in pH. Several buffering systems were examined,including a phosphate buffer solution
(dibasic sodium phosphate and monobasic sodium phosphate,pH 7.6) which was found to stabilize
the pH of pulp mill effluents during research conducted by NCASI in 1981 (NCASI 1981).
Additional buffers investigated include a dry phosphate buffer in the form of a capsulated powder
(dibasic sodium phosphate and monobasic potassium phosphate,pH 7.0), and a biological buffer
solution of beta,beta-dihydroxy-1,4-piperazinebis (propanesulfonic acid) dihydrate (POPSO,
pH 7.2 to 8.5) (Ferguson et al. 1980) prepared at a concentration of 3 g/L in organic free reagent
grade deionized water(Barnstead'M water).
Each buffer was studied for its effectiveness in stabilizing the pH of the samples during the filtration
process and over time. Four 50 mL aliquots of an effluent sample from Mill H with a color value in
the range of 99 to 176 PCU were prepared for use in this experiment. The first aliquot was not treated
with a buffer, the second was treated with 1 mL of the pH 7.6 phosphate buffer solution,the third was
treated with 0.60 grams of the pH 7 phosphate buffer capsule, and the fourth was treated with 1 mL of
the POPSO buffer solution. Each sample was then adjusted to pH 7.6±0.05 using a 20% sodium
hydroxide solution or 10%hydrochloric acid solution, and filtered through a 0.8 µm membrane filter.
National Council for Air and Stream Improvement

6 Technical Bulletin No. 803
To determine the stability of sample pH,the pH was recorded initially, during adjustment, after
filtration, at 15-minute intervals for one hour, and then hourly for three hours. After filtration the
absorbance of each aliquot was measured using a spectrophotometer set at a wavelength of 46571m.
The color value was determined from the measured absorbance and the equation derived from the
calibration curve.
As indicated in Figure 4.3,the pH of the sample containing no buffer and the sample containing the
POPSO buffer increased following filtration and continued to gradually increase over the three-hour
period. In comparison, the pH of the samples buffered with phosphate remained relatively constant.
The fluctuation in pH observed between the buffered and non-buffered solutions represents a 77%
increase in the color values determined immediately following filtration of the sample.
tNo Buffer tPhosphate Buffer Solution —A. Phosphate Buffer Capsule POPSO
8.3
8.2
8.1
8 176 PCU
Y _
y 7.9
° 78
7.7
7.6
7.5
99 PCU
7.4
S C h O pl O Cl!Cl! 0 `
G fV O:
O C
FO
71me (hours)
Figure 4.3. pH Stabilization Using Various Buffers in an Effluent Sample
with a Color Value of Approximately 100 PCU.
This experiment was repeated using a biologically treated effluent from Mill A with a color value in
the range of 362 to 420 PCU. The experiment followed the procedure outlined above, with two
exceptions. The pH was measured every hour for four hours, then once again after a period of
24 hours. The results of this experiment are presented in Figure 4.4, and follow the same general
trends in this effluent using the various buffers. The fluctuation in pH between the phosphate
buffered and non-buffered samples represents a 16%increase in the color values determined
immediately following filtration.
Based on the results of these experiments, the color procedure was modified to include the addition of
a phosphate buffer prior to filtration. The phosphate buffer capsule proved to be a convenient and
effective method for stabilizing the pH of effluent and influent samples. Additional experiments were
conducted to determine if pH 7 or pH 8 phosphate buffer capsules stabilized the sample pH more
effectively. The use of pH 7 or pH 8 buffer capsules followed by fine adjustment of the final pH to
7.6±0.05 with NaOH or HCl resulted in the stabilization of the sample pH at 7.6±0.05 following
filtration. It was observed that the pH 7 buffer capsule dissolved more readily into the effluent
samples;therefore it was utilized throughout the remainder of this study.
National Council for Air and Stream Improvement

Technical Bulletin No. 803 7
-�No Buffer —F Phosphate Buffer Solution Phosphate Buffer Capsule -X POPSO
8:3
8.2
8.1
8 419 PCU E�
7.9
x
° 78
7.7
7.6
A
7.5
362 PCU
7.4
p O
O `
Time (hours)
6
Figure 4.4. pH Stabilization Using Various Buffers in an Effluent Sample
with a Color Value of Approximately 360 PCU.
4.5 Turbidity Removal Experiments
The presence of turbidity in a sample can cause light scattering and/or increase the absorption,
thereby increasing the resultant color value. True color is the color due to dissolved substances that
absorb light. The objective in this research was to determine a reliable method for removing a
majority of sample turbidity with the smallest corresponding change in the true color value. Due to
the nature of the multi-component matrix and the different methods used for assessing true color and
turbidity,this can be a very difficult task.Several techniques for the removal of turbidity were
investigated as part of this work. Experiments were conducted to examine the effects of a pre-
filtration step, centrifugation vs. filtration, and filter porosity on the true color value of pulp mill
wastewater samples.
4.5.1 Pre-filtration Experiments
Clogging of filters has been observed during filtration of pulp mill wastewater samples using the
recommended 0.8 µm membrane filters (NCASI 1971). This can result in artificially low color
values because clogging effectively reduces the pore size of the filter,resulting in the removal of true
color bodies from the sample. Slow sample filtration can also increase the time required to process
samples, and require the use of multiple 0.8 pm membrane filters. It is sometimes useful to remove
large particulate matter by pre-filtering the sample through a 1.0 µm glass fiber filter. This allows the
sample to pass more readily through the smaller porosity membrane filters, and reduces the likelihood
that the filter will plug and remove true color along with turbidity.
An experiment to investigate pre-filtration was simultaneously conducted with the buffer comparison
experiment. Samples were treated with the buffers as described in Section 4.4.2,but one set of
samples was filtered with a 1.0 µm glass fiber filter before treatment, and one set of samples was not
pre-filtered before treatment with the various buffers. As indicated in Table 4.2,less than 4.6%
variation was observed in all cases between the results with and without pre-filtration with a 1.0 µm
glass fiber filter.
National Council for Air and Stream Improvement

8 Technical Bulletin No. 803
The color values were slightly higher in the samples that were pre-filtered,indicating that the pre-
filtration of samples may have decreased clogging of the 0.8 µm membrane filters, resulting in less
true color removal.
Table 4.2. Effects of Pre-filtration vs.No Pre-filtration on True Color
Phosphate Phosphate
No Buffer Buffer POPSO
Buffer Solution Capsule Buffer
Filtration Technique Added Added Added Added
Pre-filtered 1.0 µm GFF then 0.8 µm MF 419 396 362 396
0.8 µm W 402 379 346 396
Relative percent difference (RPD) 4.0% 4.4% 4.6% 0%
a GFF is a glass fiber filter.
s MF is a membrane filter.
4.5.2 Centrifugation Experiments
Centrifugation was also investigated as an alternative to filtration for the removal of turbidity from
pulp mill wastewater samples. Samples of biologically treated effluent from Mills A, F, G, and H
were utilized to determine the effectiveness of centrifugation vs. filtration through a 0.8 µm
membrane filter for the removal of sample turbidity. Color values were also determined. The initial
turbidities of the effluent samples were determined by measuring duplicate samples and calculating
the average turbidity of the two samples. Then,200 mL aliquots were buffered (pH 7 phosphate
buffer capsule) and the pH was adjusted to 7.6±0.05 using a 10% sodium hydroxide solution. The
aliquots were split into four aliquots of 50 mL each. Two aliquots were filtered using a 0.8 µm
membrane filter, and the absorbances were measured at 465 Bm. The true color values were
determined for the samples using the absorbance measurements. The turbidity of each aliquot was
also measured. The remaining two aliquots were centrifuged for 30 minutes at 2100 revolutions per
minute(rpm), and the absorbances and turbidities of the supernatant layer were measured. The
results are presented in Figure 4.5, which shows the average color value determined for the duplicate
samples from each mill on the Y axis. The color values are represented by bars, and the percent
decreases in sample turbidity after each treatment are represented by lines, with corresponding values
on the right axis.
OFiltered =Centrifuged +Filtered —o—Centrifuged
800 100 y
700 '°
80 Z
600 r N
500 s 60
400 X1
L 300PO
`n _ 40 d
c 200 20
00
0 0
Mill A Mill F Mill G Mill H
Mill Code
Figure 4.5. Effects on Sample Turbidity and Color: Filtration vs. Centrifugation.
National Council for Air and Stream Improvement

Technical Bulletin No. 803 9
The percent decrease in turbidity was consistently higher for aliquots treated using filtration through a
0.8 µm membrane filter than for samples treated using centrifugation for 30 minutes at 2,100 rpm.
The resultant color values were consistently higher for the samples that were centrifuged to remove
turbidity. The average increase in the color values determined for the centrifuged samples relative to
the filtered samples was 21%,with a range of 2 to 32%.
4.5.3 Filter Porosity Verification Experiments
NCASI Method 253 recommends the use of a 0.8 µm membrane filter for removal of turbidity. To
verify that this filter porosity is still appropriate for low color effluents, an experiment was conducted
to evaluate the amount of color and turbidity being removed using filters of various porosities. This
involved filtering the same 50 mL aliquot of sample through successively smaller filters to observe
the change in color and turbidity determined with each filtration. The filtration series included 2.7,
1.5, and 1.0 µm glass fiber filters, followed by 0.8, 0.65,0.45, and 0.22 µm membrane filters.
Absorbance and turbidity were measured after each filtration. The macromolecules that constitute the
true color in a pulp mill wastewater sample are in the range of 0.1 to 0.7 microns (NCASI 1971),
therefore the color observed above I µm was assumed to represent color due to suspended and
dissolved components (apparent color) as well as true color(dissolved components only). Figures 4.6
(effluent, Mill B) and 4.7 (influent,Mill C) illustrate the changes in sample color and turbidity
following filtration through the I to 0.22 µm membrane filters (x-axis);the values for the 2.7 and
1.5 µm glass fiber filters are excluded. The graph on the left illustrates the changes in color observed
following each filtration, while the graph on the right shows the effects on sample turbidity. The
percentage of the initial turbidity removed following each filtration is indicated above the bars of the
graph on the right. In all cases, as the filter porosity decreased, the resulting color value decreased.
Due to the interactive nature of light scattering(due to turbidity) and absorbance (due to true color),
this would be the anticipated trend.
88%
150 149 1.4 1
1.2 I
ZD 145 142 a 1 1
CIO ]4
140 139 136 p $ 94%
94.5%
135 132 a 0.6 1 95%
c130 F 0.4 97%
U 125 0.2
120 0
1 0.8 0.65 0.45 0.22 1 0.8 0.65 0.45 0.22
Filter Porosity (µm) Filter Porosity (µm)
Figure 4.6. Filter Porosity Effects on Mill B Effluent Turbidity and Color.
It is difficult to determine whether the continual decrease in the color values was due to an increase in
the turbidity removed or to the removal of color bodies from the samples by the filters. For the
Mill B effluent sample, filtration below 0.8 pm resulted in a difference of 7% in the resultant color
value,down to a filter porosity of 0.22 pm. Between the 1 µm and 0.8 pm filtrations, 95% of the
color remained while 50%of the remaining turbidity was removed; and between the 0.8 pm and
0.65 pm filtrations,97%of the color remained while 14% of the remaining turbidity was removed.
Following filtration through the 0.8 µm filter, 94% of the initial turbidity was removed, as indicated
by the numbers above the bars. The initial measurement of turbidity was 4.1 ntu.
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10 Technical Bulletin No. 803
Successive filtration continued to remove portions of the turbidity,but in smaller increments. This
may be due to the removal of color bodies by the smaller porosity filters. A regression analysis of the
change in turbidity vs. color did not show a significant relationship between the two (Appendix A,
Section A2). In other words, an incremental change in turbidity did not correlate to an incremental
change in color. Therefore, it is more likely that the changes noted in the color values were related to
the removal of color bodies from the samples than to the removal of additional turbidity.
250 221 198 6 198.5%
U 200 188 181 175 5 I
a v41
ti 150 j
e=a 3 -100 99.4%
`o 2 99.6%
U 50 F" 1 99.8% 99.9%
p 0
1 0.8 0.65 0.45 0.22 1 0.8 0.65 0.45 0.22
Filter Porosity (pm) Filter Porosity (pm)
Figure 4.7. Filter Porosity Effects on Mill C Influent Turbidity and Color.
For the Mill C influent sample, filtration below 0.8 µm resulted in a difference of 12% in the resultant
color value,down to a filter porosity of 0.22 µm. Between the 1 pm and 0.8 µm filtrations, 90%of
the color remained while 60%of the remaining turbidity was removed; and between the 0.8 µm and
0.6 pm filtrations, 95% of the color remained while 43%of the remaining turbidity was removed.
The overall decrease in the color value determined between the 0.8 µm and 0.22 µm filtrations was
13%, but the majority of the turbidity in the initial sample (99.4%) was removed following filtration
through the 0.8 µm membrane filter. A regression analysis of the change in turbidity vs. color for the
Mill C influent did not show a significant relationship between these two variables (Appendix A,
Section A2). These results indicate that the 0.8 µm membrane filter removed the bulk of sample
turbidity while having a minimal effect on the dissolved color bodies within the sample.
4.5.4 Comparison of Filter Types
There are several brands and types of membrane filters on the market,therefore this work included an
evaluation of various types of filters. Comparative experiments were conducted using three brands of
filters: Gelman MetricelTM, Gelman Supor 800TM, and Nucleopore Membra-Fi1TM filters. Both
Gelman Metricel and Nucleopore Membra-Fil filters are made of mixed cellulose esters. The Gelman
Supor 800 filter is a hydrophilic polysulfone membrane filter.
A 400 rrL aliquot of a biologically treated effluent sample from Mill D was adjusted to pH 7.6,then
50 mL portions were filtered through each membrane filter. Experiments involved three replicates
using Supor filters and three replicates using Metricel filters. The samples were not buffered prior to
pH adjustment.
The Nucleopore Membra-Fil was utilized because of the wide range of porosities commercially
available for this filter type. An experiment was conducted to compare the Nucleopore Membra-Fil
filter to the Gelman Metricel filter. A 400 mL aliquot of a biologically treated effluent sample from
Mill F was adjusted to pH 7.6,then 50 mL portions of this sample were filtered through each
membrane filter. Experiments involved three replicates using Nucleopore Membra-Fil filters and
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Technical Bulletin No. 803 11
three replicates using Metricel filters. The absorbances were measured and statistically compared for
differences.
The results for these two filter comparison experiments were evaluated using analysis of variance
(alpha=0.05) to determine if filter type affected color value. The results, shown in Table 4.3, do not
reveal a statistically significant impact of filter type on measured color.
Table 4.3. Comparison of Various Membrane Filters
Comparison p-value
Metricel and Supor 0.13
Metricel and Nucleopore Membra-Fil 0.42
The Metricel filters were used in the majority of the color experiments. The Nucleopore Membra-Fil
filters were used during the successive filtration experiments because they were available in a wider
range of porosities.
4.5.5 Investigations of Possible Turbidity Agents
NCASI examined several different turbidity agents potentially present in pulp mill wastewaters which
may interfere with the determination of true color. The purpose of these experiments was to
determine if a 0.8 µm membrane filter was effective in removing the turbidity agent while having a
minimal effect on true color, and to determine how different turbidity agents might interfere with the
determination of true color in biologically treated effluents. The turbidity agents explored included
precipitated calcium carbonate, titanium dioxide,lime mud, fiber, and green liquor dregs.
Each of these agents was added to separate aliquots of water in an amount adequate to achieve
approximately 25 to 50 ntu of turbidity when 500 µL of the solution was spiked into a 50 mL volume.
These spiking stocks were spiked into 50 mL of deionized water, which was then buffered, pH
adjusted to 7.6±0.05, and filtered through a 0.8 µm membrane filter(Sample A). The same spike
amount of the turbidity agent solution was then added to 50 mL of an effluent sample(Mill A),
buffered,pH adjusted, and filtered(Sample B). Finally, 50 mL of an effluent sample without the
added turbidity agent was buffered,pH adjusted, and'filtered (Sample Q. The absorbance and
turbidity values were measured and recorded for each sample (A,B,and C) initially, after the addition
of buffer and pH adjustment, and after filtration. The experiment was conducted with three replicates
of each sample type(A,B, and Q.
The average turbidity of each set of three replicates was calculated. The average value calculated for
Sample C (no turbidity added) and Sample A (turbidity spike in water) were added together. This
value was then compared to the turbidity value of Sample B, the turbidity-spiked effluent. This
comparison was conducted to determine if the turbidity value was affected by the sample matrix. The
turbidity values determined for Sample C plus Sample A were equivalent to the turbidity values
measured for Sample B,indicating that the turbidity agent spike was not affected by the sample
matrix.
An additional component of this experiment was to determine whether some turbidity agents are more
readily removed by filtration than others. The presence of turbidity in the samples following filtration
can cause erroneously high color values due to light scattering. Figure 4.8 illustrates the average true
color value determined for the three replicates of each sample type following filtration through the
0.8 µm membrane filter. The color values are indicated on the y-axis,while the x-axis lists the
turbidity agent used. The black bars represent the average true color value determined for Sample C
(effluent only) and the white bars represent the average color value determined for Sample B (effluent
National Council for Air and Stream Improvement

12 Technical Bulletin No. 803
plus turbidity agent). The percentage of the turbidity removed by filtration is indicated above each
set.
25% 97%a 92% 98%n 96%
Lon) 600 r I
a 550
d
—'� 500 T
c 450
U 400 L
Titanium Fiber Dregs Lime Mud Calcium
Dioxide Carbonate
(PCC)
Figure 4.8. Turbidity Agent Removal Results: Effluent Sample.
The results indicate that the 0.8 µm membrane filter effectively removes the turbidity introduced by
the indicated agents, with the exception of titanium dioxide. The results also indicate that the true
color values determined for the samples with and without added turbidity varied by less than 3%
following filtration through a 0.8 µm membrane filter.
The experiment was repeated using a solution of lignin which served as a surrogate for pulp mill
wastewater true color to examine the trends in a solution that contained no other source of turbidity
except the spiked turbidity agent. As indicated in Figure 4.9, turbidity was effectively removed for all
of the agents tested except the titanium dioxide. In addition, the true color values determined for the
lignin sample with and without added turbidity from fiber, dregs, lime mud, and precipitated calcium
carbonate varied by less than 7%, although in general the color values determined in the turbidity
agent spiked lignin samples resulted in slightly increased color values. The true color values
determined for the lignin sample with and without added titanium dioxide varied by 25%.
350 T
300 L 23% 97% 93% 95% 95%
250
200 L
150 1
c 100 T
U 50
0
Titanium Fiber Dregs Lime Mud Calcium
Dioxide Carbonate
(PCC)
Figure 4.9. Turbidity Agent Removal Experiments: Lignin Solution Sample.
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Technical Bulletin No. 803 13
4.6 Sample Volume Selection
It was previously observed that the volume chosen for filtration by each analyst can significantly alter
the final color reported for the sample and may account for increased variability in observed results
(NCASI 1971). This occurrence is usually related to filter plugging that can occur when filtering a
larger sample volume. The filter plugging reduces the effective filter pore size, which can remove
some of the components contributing to the true color of a sample. To investigate this observation,
duplicates of four aliquots of sample with volumes of 25, 50, 100,and 200 mL were treated
identically (i.e., buffered,pH adjusted, and filtered through 0.8 µm membrane filter). This
experiment was repeated using biologically treated effluents from Mill A and Mill B and an influent
to the treatment system from Mill B. If the filtering rate slowed or foaming was observed,the
filtration was stopped and another filter was used to complete the filtration of the total aliquot of
sample. The results of this experiment are shown in Table 4.4. The percent relative standard
deviation of the color values determined using the 25,50, 100, and 200 mL volumes ranged from 0.7
to 5.6%,indicating that when using this technique,sample volume did not effect the overall color
value determined. Therefore, a 50 mL sample volume was chosen for ease in manipulation and
filtering, and the appropriate filtration technique is specified in the updated method (Appendix B).
The 50 mL sample volume was selected over a 25 mL sample to allow for easier pH adjustment of the
initial sample without changing the sample volume by more than I%.
Table 4.4. Effects of Sample Volume on the True Color Value Determined
25 mL 50 nil 100 mL 200 mL Average RSDa
Sample (PCU) (PCU) (PCU) (PCU) (PCU) M
Mill A Effluent 617 580 597 583
603 603 580 b 595 2.2
Mill B Effluent 173 176 176 176
176 173 176 176 175 0.7
Mill B Influent 189 186 186 206
193 176 203 209 194 5.6
Relative standard deviation expressed as a percent.
b This determination was not available due to a limited sample availability.
4.7 Effects of Various Light Path Lengths on Resultant Color Values
An experiment was conducted to investigate the effect of light path length on the determined color
value. Samples from five different mills(Mills A,E,F, G, and H) were measured to determine the
color value of each matrix using a 10,20,25, 50, and 100 min light path length cell. The samples
were analyzed in replicates of three, and the color values were calculated using the equations in
Table 4.5 for each specific light path length cell. These calibration curve equations were obtained by
analyzing a calibration curve ranging from 10 to 500 PCU using a curvette with the light path length
indicated in Table 4.5.
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14 Technical Bulletin No. 803
Table 4.5. Calibration Curves for Various Light Path Length Cells
Linear Equation y = mx +b R-squared Light Path Length (mm)
y =0.0003x—0.0003 1.000 10
y=0.0005x+0.0028 0.9988 20
y= 0.0006x—0.0004 0.9999 25
y = 0.0014x—0.0003 1.000 50
y =0.0027x+0.0018 1.000 100.
The average color values determined for the various samples, the range of color values reported, and
the relative standard deviations of these averages expressed as a percent are presented in Table 4.6.
Table 4.6. Summary of Light Path Length Experiments
Average Color Value Range of Color Values Relative Standard Deviation
Mill Code (PCU) (PCU) (%a)
A 514 486-547 5
E 184 178 - 190 3
F 78 75 -81 3
G 274 265 -288 4
H 1186 1112- 1271 6
Figure 4.10 illustrates the results of this experiment. The color values of the samples used in this
experiment ranged from 75 to 1,271 PCU. The values plotted in Figure 4.10 are the average PCUs
determined for the three replicates using the indicated light path length cells. Due to limited sample
volumes,Mill H was not measured in the 100 mm light path length cell.
e Mill A ■Mill E ♦Mill F e Mill G aC Mill H
1400
1200
1000
a.
800
0 600
400
e e e e
200 • • • •
■ ■ ■ ■
0 .
0 10 20 30 40 50 60 70 80 90 100
Light Path Length (nun)
Figure 4.10. Color Units (PCU) of Five Effluent Samples Using Various Light Path Length Cells.
The relative standard deviations (RSD),expressed as percents, are similar to the infra-and inter-
laboratory relative standard deviations determined for replicate analyses (Section 5.6). The RSDs are
also below EPA's color method precision criteria of 10%listed in the Federal Register(Federal
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Technical Bulletin No. 803 15
Register 1997), indicating that for color value determinations of samples within the range of 70 to
1,300 PCU,cell light path length is not likely to be important.
5.0 UPDATED METHOD COLOR 71.01 VALIDATION AND QA/QC
The previous sections of this bulletin presented the results of experiments conducted to optimize the
NCASI color measurement method in pulp mill wastewaters./This section presents information
relating to the validation of the updated method (NCASI Method Color 71.01)and development of
quality control and quality assurance criteria.
5.1 Brief Description of NCASI Method Color 71.01: The Updated Color Method
The updated procedure involves adding half of a pH 7 buffer capsule to a 50 mL sample of
wastewater or water to stabilize the pH, adjusting the pH to 7.6±0.05 with HCl or NaOH (such that
the volume change of the sample is less than I%), and filtering the aliquot through a 0.8 µm porosity
membrane filter pre-rinsed with distilled water. A portion of the filtered sample is then transferred to
an absorption cell and the absorbance is measured at 465 r1m using a spectrophotometer with a
tungsten lamp source and 10'gm spectral slit width. The spectrophotometer capabilities should
include an operating range of 400 to 700 T)m and an ability to emit light at a selectable wavelength of
465 111m. The color units for the sample are determined by comparing the absorbance reading with a
standard curve prepared using dilutions of a platinum cobalt stock solution. A full description of the
updated method can be found in Appendix B.
5.2 Preparation of the Calibration Curve
The linearity of the spectrophotometer used for this work was assessed by analyzing a five-point
calibration curve that ranged in concentration from 25 to 500 PCU. The calibration curve was
prepared using a stock platinum cobalt solution with an initial color value of 500 in volumes of 2.5,
10, 20, and 25 mL. These volumes were diluted with BamsteadT"r deionized water to 50 ml,in a
volumetric flask. The corresponding color unit values of these solutions were 25, 100,200,and
250 PCU. In addition, an aliquot of the undiluted stock platinum cobalt solution with a color value of
500 PCU was measured and included in the curve. The absorbances of these solutions were measured
at a wavelength of 465 r1m on a Spectronic 21D spectrophotometer with a tungsten lamp light source.
The various curves analyzed in this research utilized cuvettes with 10, 20, 25,50, or 100 min light
paths. Calibration curves were prepared using the results of these measurements by plotting the
absorbance values against the color units of each of the standards measured. A linear regression
equation was generated for each curve and used to calculate the color units of the samples from their
measured absorbances. Calibration criteria(Appendix B, Sections 10 and 17) were determined by
measuring several curves and developing acceptable criteria based on the coefficient of determination
(r-squared) from the linear equations generated for each curve. Throughout the course of this study, a
total of thirteen calibration curves were generated, with the results displayed in Appendix B,Table 6.
All of the curves analyzed had an r-squared value greater than0.9968.
5.3 Daily Calibration Verification
Virtually all instrumental analysis methods require that some type of calibration verification be
conducted at the beginning of each day or prior to analysis of samples. One objective of this project
was to bolster the QA/QC requirements of the color method (NCASI 1971). Therefore, a mechanism
for accomplishing daily calibration checks was employed during this investigation. The results from
these experiments form the basis for daily calibration criteria incorporated in the updated color
method (Appendix B, Section 9.2).
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16 Technical Bulletin No. 803
For all of the color analyses conducted as part of this project,the validity of the instrument calibration
curve was verified prior to sample preparation. Different calibration points were selected on each day
in order to verify the calibration over the full range of the curve. The results of the calibration
verification were calculated by dividing the measured concentration by the known concentration of
the standard and were reported as percent recovery.
During the course of this work, calibration verifications were completed on 47 occasions using
various light path length cells and color ranges from 25 to 500 PCU. The results of these calibration
verifications yielded an average percent recovery of 95%, a range of 88 to 118%, and a standard
deviation of 6.7. The distribution of percent recovery results can be used to suggest limits around
which the analyst should consider further evaluation of instrument performance or re-calibration of
the instrument. For this method, warning and action limits were calculated as the mean plus and
minus two standard deviations and three standard deviations,respectively. These limits are shown in
Table 5.1. When warning limits are exceeded,the analyst should investigate possible instrument
problems,perform a calibration verification of the instrument as recommended by the instrument
manual, check for contamination and evaporation of standard solutions, examine glassware for
scratches,re-zero the spectrophotometer, and reanalyze the standard. When the action limits are
exceeded, the analyst should likewise investigate potential problems,prepare a new calibration curve,
and reanalyze the curve as recommended in Section 5.2.
Table 5.1. Summary of Daily Instrument Calibration Checks
Average Warning Action Minimum Maximum Color Unit
Recovery' Standard Limits` Limitsd Recovery Recovery Range
M Deviationb M M M M (PCU)
94.9 6.7 81 - 108 75 - 115 88 118 25 -500
' Average recovery for 47 daily calibration checks.
b Standard deviation of the recoveries for 47 daily calibration checks.
` Average recovery plus and minus two times the standard deviation.
d Average recovery plus and minus three times the standard deviation.
5.4 Single Laboratory Precision
5.4.1 Instrument Precision
The instrument precision of the Spectror&21D, which was utilized throughout the single laboratory
validation of the updated method at NCASI's West Coast Regional Center, was verified by the
analysis of the midpoint of the calibration curve a total of seven times over an eight-hour period. The
results of the instrument precision experiment yielded a relative standard deviation of 1.4% for the
seven replicates of the 100 PCU standard.
5.4.2 Method Precision
The precision of the method was characterized and continuously monitored using duplicate analyses.
Throughout the single laboratory assessment of precision, a total of twelve different duplicate sample
pairs of both biologically treated effluent and treatment system influent from the mills listed in
Table 4.1, were analyzed. The relative percent differences for the duplicates ranged from 0.4 to
14.1% for the biologically treated effluents, with an average relative percent difference of 2.8%. The
color values of the samples utilized in this assessment ranged from 81 to 1,112 PCU,indicating that
the precision of the method is consistent over a wide range of color values. The relative percent
differences observed for the treatment system influent duplicate pairs ranged from 0.1 to 13.2%, with
an average relative percent difference of 7.1%. The average relative percent differences for the
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• Technical Bulletin No. 803 17
effluent and influent sample duplicates were below EPA's standardized quality assurance and quality
control acceptance criteria of 10% for precision in color methods listed in the Federal Register
(Federal Register 1997).
5.5 Comparison of Updated NCASI Method Color 71.01 to NCASI Method 253
A comparison of the updated method and NCASI Method 253 was made using data from two
different NCASI laboratories. This comparison was done using biologically treated effluents from
Mills A and B,influents to the treatment system from Mills A and B, a prepared lignin solution,and a
receiving water sample collected below the discharge of Mill D. Trends that suggest there may be
some method differences were observed. The color values determined in five of the six matrices
tested were lower using the updated procedure(Figure 5.1). This lower color value often
corresponded to an observed difference in the post-filtration pH between the two methods
(Figure 5.2). In the matrices tested, a pH of 7.6±0.05 was achieved using the updated method,but
NCASI Method 253 samples were not buffered, and the post-filtration pH increased. The influent
sample from Mill A was an exception to this trend. This sample yielded a higher color value using
Color 71.01, although the pH of the sample remained at 7.6±0.05 using this method.
■Color-71.01 ❑Method 253
830
s 730
a 630
d 530
430
` 330
c 230
OF I
U 130
30 ,
c ¢ d Ca CID
a
Sample Matrix
Figure 5.1. Comparison of Resultant Color Values in Different Sample Matrices
Using NCASI Methods 253 and Color 71.01.
The statistical difference between the two methods was evaluated through the use of F-tests and p-
values. The statistical calculations used for this evaluation utilized a one-tailed F test to determine if
the updated Method Color 71.01 was more precise than Method 253. The F-test considers the ratio of
the squares of the two sample standard deviations such that calculated F is always greater than one. If
the F-ratio is less than the critical value of F,the variances are assumed to be equal (precision of the
two methods is similar). The p-values were utilized to determine if the two methods generated
comparable color values. The F-ratios,p-values (a=0.05), and critical values for F are presented in
Table 5.2. The p-values were calculated assuming equal variances as justified by the F-test results. If
the calculated p-values are less than the selected alpha of 0.05 for a 95% confidence level,the mean
color values are not considered to be significantly different. A full report of the statistical analysis
can be found in Appendix A, Section A3, along with definitions of the statistical terms.
National Council for Air and Stream Improvement

18 Technical Bulletin No. 803
■Color-71.01 ❑Method 253
8.10
x 8•00
7.90
7.80
7.70
w 7.60
n 7s0
0
0. 7.40
7.30
Iignin MillA MillB MMA MillB MillD
Effluent Effluent Influent Influent Receiving
Water
Sample Matrix
Figure 5.2. Comparison of Post-Filtration pH in Different Sample Matrices
Using NCASI Methods 253 and Color 71.01.
As the results indicate, a significant difference in the resultant color determinations was observed for
the influent from Mill B and the receiving water from Mill D, with higher color values reported when
using Method 253.
Table 5.2. Summary of the Statistics Comparing NCASI Methods 253
and Color 71.01 in Different Matrices
Sample Matrix F-Ratio Critical Value of F p-Value
Lignin Solution 0.098 9.27 0.572
Effluent Mill A 0.229 9.27 0.961
Effluent Mill B 0.304 9.27 0.655
Influent Mill A 0.159 9.27 0.053
Influent Mill B 1.52 9.27 0.009
Receiving Water Mill D 1.46 9.27 0.019
5.6 Inter-Laboratory Investigation of NCASI Method Color 71.01
In an effort to assess the ruggedness and precision of the updated method, an inter-laboratory study
was conducted which included industry and NCASI laboratories. A total of eight laboratories
participated in a study to determine the intra-and inter-laboratory precision of the updated color
procedure using several matrices. The samples included biologically treated effluents from Mills A
and B, influents to the treatment system from Mills A and B,portions of a prepared lignin solution, a
receiving water sample collected from the discharge stream of Mill D,and a platinum cobalt color
standard. Mill personnel collected the influent(24-hour composites),effluent, and receiving water
(grab) samples into one-gallon amber glass bottles with TefloiJm-lined screw caps. NCASI received
the iced samples from the mills via overnight delivery.
To minimize the potential for bias,the samples were thoroughly mixed and split into separate 100 mL
portions. This step ensured that any differences in study results could be attributed to analytical
method variables and not to sampling or compositing procedures. The samples were then shipped on
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Technical Bulletin No. 803 19
ice via overnight carrier to the eight participating laboratories along with a study plan, analytical
procedures, and a data sheet(Appendix Q. The participating labs received the samples blind, along
with a calibration check standard prepared at a color value of 125 PCU. The check standard was
prepared by diluting a 500 PCU color standard using Barnstead""deionized water. The color units
and percent recoveries of the QA/QC check standard analyses are presented in Table 5.3. Each
laboratory also received replicates of the various matrix types so that the intra-laboratory precision
could be assessed. The laboratories were asked to analyze the samples on the date of receipt
according to the procedure and study plan presented in Appendix-C, and report the data on the data
sheet also included in the appendix.
The inter-laboratory data were evaluated statistically using Youden matched pairs of similar matrices
(Youden and Steiner 1975). The sample results are summarized in Table 5.4. The codes Ll through
L8 identify the participating laboratories,and each matrix type is designated by a letter code. The
table also includes information on the light path length of the cells used at each laboratory, although
the use of a specific light path length was not part of the study plan.
Table 5.3. Summary of the True Color Values and Percent Recoveries
for the QA/QC 125 PCU Standard
Laboratory Code Color Units (PCU) Recovery (%)
Ll 106 85
L2 145° 116
L3 106 85
L4 113 90
L5 129 103
L6 123 98
L7 118 94
L8 103b 82
Average 118 94
Standard Deviation 13.2 10.6
Relative Standard Deviation(%) 11.2 11.3
° Although this value is high in relationship to the other laboratory results,it was not an outlier based on
Grubb or Dixon tests.
b Although this value is low in relationship to the other laboratory results,it was not an outlier based on Grubb
or Dixon tests.
The Youden matched pair analyses were initiated by preparing an xy plot of the data points for each
sample type using one pair of data for the x-axis and one pair of data for the y-axis. Appendix D,
Figures DI through D6, present the sample plots for each matrix. This analysis is conducted in order
to assess bias in the data and identify outlying data points. The average value obtained for the y-axis
data is represented by the horizontal line and the average of the data plotted on the x-axis is represent
by the vertical line. Random variability is demonstrated if the data are evenly distributed within the
four quadrants around the intersection of the x and y averages. The closer the data points are to the
intersection, the better the analytical precision. High and low laboratory bias is demonstrated when
the sample results from a given laboratory are at an extreme along the 45-degree line of the graph.
Points distant from the 45-degree line indicate a lack of agreement between results from the same
laboratory. Careful review of these plots indicate that although the majority of data points lie near
the intersection of the average values, some laboratory bias exists. Examination of the plots indicate
that Labs 2 and 3 were biased high, while Lab 4 was biased low. Cochran's, Grubb's, and Dixon's
outlier tests were utilized to determined the significance of these laboratory biases (AOAC 1989).
National Council for Air and Stream Improvement

20 Technical Bulletin No. 803
Table 5.4. Inter-laboratory Study: Summary of Results (Color Values Reported in PCU)
Laboratory Code: Ll L2 L3 1-4 L5 L6 L7 L8
Light Path 10 mm 10 mm 10 mm 10 mm 28 mm 100 mm 16 mm 10 mm
Length°: (sq.)
Sample Type
Lignin 1 49 90 140 46 59 57 75 43
Lignin 2 49 70 105 51 54 58 68 43
Effluent Mill A-1 509 695 745 454 646 605 515 509
Effluent Mill A-2 516 745 830 440 621 607 515 496
Effluent Mill B-1 162 290 305 147 199 194 195 153
Effluent Mill B-2 159 295 260 141 196 173 168 143
Influent Mill A-1 712 1040 970 556 811 746 640 623
Influent Mill A-2 686 990 1000 533 771 678 638 589
Influent Mill B-1 89 205 210 83 154 141 110 96
Influent Mill B-2 89 205 300 87 132 144 168 89
RW"Mill D-I 136 220 180 112 169 149 180 116
RWs Mill D-2 132 215 240 113 167 165 140 116
All cells utilized in this study were cylindrical unless otherwise noted.
s RW is receiving water.
Dixon's test evaluates the occasional aberrant average value. Cochran's test is applied to test for the
removal of laboratories showing significantly greater intra-laboratory variability than the other
laboratories in the study for a given matrix type. Grubb's test is applied to assess whether a
laboratory has an extreme average value. If no outliers are determined using a single Grubb's test,
which is a determination of a single laboratory with high or low bias, then a double Grubb's test is
performed to determine if the outliers are masked by the presence of both high and low extremes. Of
the five pairs of data plotted,Lab 3 consistently fell outside the range of averages using the Dixon's
test. These results may be due to the lack of experience of the analyst performing the measurements
at this laboratory, since it was the analyst's first experience conducting measurements of color in pulp
mill matrices. In addition,Lab 2 data fell outside the range of averages using the Dixon's tests for the
Mill B effluent,Mill A influent, and Mill B receiving water samples.
Once the outliers were removed, statistical calculations were performed to assess the intra-laboratory
(repeatability, r) and inter-laboratory (reproducibility,R)precision of the method. The intra-
laboratory repeatability is a measure of the closeness of agreement between successive results
obtained with the same method on identical matrices under the same conditions and is calculated
based on the sum of squares of the laboratory ranges between the two duplicate samples (refer to
Appendix A for definitions). The inter-laboratory reproducibility is the variation arising from
different operators in different laboratories using different apparatus and is composed of the total
within-sample variation. It is calculated by combining the between-laboratory variation, the
laboratory-sample interaction, and the between-replicate variance(refer to Appendix A for
definitions). Table 5.5 lists the results for the Youden pair analyses, which includes the mean of the
laboratory averages, the repeatability and reproducibility standard deviations, and the repeatability
and reproducibility relative standard deviations. The results indicated that the infra-laboratory
precision (agreement of replicate values within a particular laboratory) of the method ranged from 2.3
to 13.8%. The inter-laboratory precision (agreement in values among laboratories) of the method
ranged from 13.1 to 35%. The influent Mill B samples (35%) and the lignin stock solutions (24%)
resulted in the largest variations.
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Technical Bulletin'No. 803 21
Table 5.5. Results of the Inter-laboratory Study Youden Pair Analyses
Receiving
Lignin Effluent Effluent Influent Influent Water
Parameter Solution Mill A Mill B Mill A Mill B Mill D
Number of labs 7a 7a 6 b6 b7a 6
Mean of lab averages 58.0 562 169 665 128 141
s (r)repeatability standard 5.8 17.2 7.1 15.4 17.6 13.2
deviation
s (R) reproducibility standard 13.9 95.2 22.1 87.7 44.8 25.6
deviation
RSD (r)repeatability relative 10.0 3.1 4.2 2.3 13.8 9.3
standard deviation
RSD ( R) reproducibility 24.0 16.9 13.1 13.2 35.0 18.1
relative standard deviation
° Lab 3 was an outlier and was removed prior to completing the calculations in this table.
b Labs 2 and 3 were outliers and were removed prior to completing the calculations in this table.
6.0 SUMMARY AND CONCLUSIONS
The purpose of this study was to evaluate and optimize NCASI Method 253 when used on
biologically treated effluents and treatment plant influents from low color pulp mill effluents. This
work has resulted in a well-defined and documented method for the measurement of true color which
includes quality control and quality assurance criteria. Appendix B contains the updated color
method,NCASI Method Color 71.01,that was prepared as a result of this work.
The selection of a wavelength to measure sample absorbance influences the accuracy and precision of
color measurements; therefore,the wavelength of 465 Bm used in NCASI Method 253 was verified in
current sample matrices. Optimum overlap of absorbance curves for a 200 platinum cobalt standard,
wastewater treatment system influent, and biologically treated effluent occurred in the range of 460 to
470 Bm,indicating that the use of a wavelength of 465 rlm was valid in modem mill effluents.
The color of pulp mill effluents is highly pH dependent, and the pH adjustment procedure included in
Method 253 sometimes resulted in less than optimum stability of pH during the analytical procedure.
As sample pH increases, the measured absorbance value increases, resulting in higher color values.
One objective of updating Method 253 was to examine techniques to stabilize sample pH. Several
buffering systems were examined,including a phosphate buffer solution, a dry phosphate buffer
capsule, and a biological buffer solution. The buffer capsule(dibasic sodium phosphate and
monobasic potassium phosphate,pH 7.0) stabilized the sample pH most effectively. The buffer
capsule stabilized the sample pH at 7.6±0.05 for the duration of a 24-hour experiment. In addition,it
is a convenient technique for pH stabilization that does not contribute to sample dilution.
Experiments to investigate methods for the removal of sample turbidity while minimizing effects on
true color were also conducted. Pre-filtration of samples with a 1 µm glass fiber filter was
determined to help reduce problems associated with clogging of the 0.8 µm membrane filter.
Experiments to assess turbidity removal using centrifugation vs.filtration indicate that filtration using
a 0.8 µm membrane filter removed a larger percentage of the turbidity in wastewater samples. These
experiments also indicate that higher color values were determined in centrifuged samples.
Successive filtration experiments using a range of filter porosities between 1.0 and 0.22 µm indicate
that the majority of sample turbidity,94 to 99.4%, was removed using the 0.8 µm membrane filter. In
addition,experiments to investigate the removal of turbidity agents including precipitated calcium
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22 Technical Bulletin No. 803
carbonate, titanium dioxide,lime mud, fiber, and green liquor dregs indicate that 92 to 98% of the
turbidity was removed using the 0.8 pm membrane filter for each agent except titanium dioxide (23 to
25%removal). Therefore,the 0.8 pm membrane filter was verified as an effective method for the
removal of turbidity in modern pulp mill wastewater samples. Several types of 0.8 Nm membrane
filters are available commercially. A comparison of color values determined using three different
types of 0.8 pm membrane filters did not reveal a statistically significant impact of filter type on
measured color value.
The volume of sample selected for filtration was investigated. It was determined that when using the
techniques recommended in the updated method, sample volume did not effect the overall color value
determined. Therefore, a 50 mL sample volume was chosen for ease of manipulation and filtering.
Samples from five different mills were used to investigate the effect of the light path length on the
resultant color value. It was demonstrated that color values varied by a relative standard deviation of
less than 6% when measured using light path lengths of 10, 20, 25, 50, and 100 mm.
Method ruggedness, precision, and accuracy of the updated method (Color 71.01) were determined at
the single laboratory level. Instrument precision, expressed as the percent relative standard deviation
of seven replicates of a 100 PCU color standard, was determined to be 1.4%. Precision was
calculated in both biologically treated effluents and treatment plant influents. At the single laboratory
level, the average relative percent difference in duplicate analyses for biologically treated effluents
was 2.8% (n= 12 duplicate/sample sets), and for treatment plant influents it was 7.1% (n = 12
duplicate/sample sets). Calibration curves prepared using light path lengths of 10 to 100 mm yielded
r-squared values of greater than 0.9968 for twelve different calibration curves. The average recovery
for 43 daily calibration checks was 94.9%, with a standard deviation of 6.7.
Eight laboratories participated in a multi-laboratory study to assess the ruggedness, accuracy and
precision of the updated color measurement procedure. The samples included biologically treated
effluents from Mills A and B,influents to the treatment systems from Mills A and B,portions of a
prepared lignin solution, a receiving water sample collected from the discharge stream of Mill D, and
a platinum cobalt color standard. The platinum cobalt color standard data were utilized to assess
method accuracy, and yielded an average recovery of 94% and a relative standard deviation of 11.3%.
The precision for the inter-laboratory assessment resulted in a relative standard deviation of 15% for
biologically treated effluents, 24.1% for treatment plant influents, and 18.1% for the receiving water
sample. The intra-laboratory precision(agreement of replicate values within a particular laboratory)
was also assessed during this multi-laboratory study and resulted in a relative standard deviation of
3.6% for biologically treated effluents, 8.1% for treatment plant influents, and 9.3%for the receiving
water sample.
The precision and accuracy of NCASI Method 253 was determined to be similar for effluents from
Mills A and B, a lignin solution, an influent from Mill A, and a receiving water from Mill D when
compared to the NCASI Method Color 71.01 during studies conducted at two different laboratories.
The only exception was found in an influent sample from Mill B which gave higher color values
when NCASI Method 253 was utilized.
REFERENCES
Association of Official Analytical Chemists (AOAC). 1989. Guidelines for Collaborative Study
Procedures. Journal of the Association of Official Analytical Chemists 72(4):701-4.
Ferguson, W. J., K. I. Braunschweiger,W. R. Braunschweiger,J. R. Smith, J.J. McCormick, C. C.
Wasmann,N.P. Jarvis,D. H. Bell, and N. E. Good. 1980. Hydrogen ion buffers for biological
research. Analytical Biochemistry 104:300-10.
National Council for Air and Stream Improvement

Technical Bulletin No. 803 23
Federal Register. 1997. Volume 62,No. 123. 40 CFR Parts 126 and 141. Guidelines Establishing
Test Procedures for the Analysis of Pollutants and National Primary Drinking Water Regulations;
Flexibility in Existing Test Procedures and Streamlined Proposal of New Test Procedures;
Correction,Announcement of Meetings and Extension of Comment Period. June 26.
Hach Company. 1991. Hach Ratio Turbidimeter Model 18900-00 Manual. Loveland,CO: Hach
Company.
Ingle, J. D., and S. R. Crouch. 1988. Spectrochemical analysis.Englewood Cliffs,NJ: Prentice Hall.
Kringstad, K., and K.Lindstrom. 1984. Spent liquors from pulp bleaching. Environmental Science
and Technology 18(8):236A-48A.
National Council for Air and Stream Improvement,Inc. (NCASI). 1971. An investigation of
improved procedures for measurement of mill effluent and receiving watercolor. Technical
Bulletin No. 253. Research Triangle Park,NC: National Council for Air and Stream
Improvement, Inc.
. 1981. Further investigations of the color measurement procedure to improve its utility.
NCASI Report. Research Triangle Park,NC: National Council for Air and Stream
Improvement,Inc.
Standard Methods for the Examination of Water and Wastewater. 20`h Edition. 1998. Washington,
DC: American Public Health Association. 2-1 to 2-8.
United States Environmental Protection Agency (USEPA). 1971. Color Method 110.2
(Colorimetric-Platinum Cobalt). 110.2-1 to 110.2-3.
. 1978. Color Method 110.1 (Colorimetric,ADMI). 110.1-I to 110.1-3.
Youden,W.J. and E. H. Steiner. 1975. Statistical Manual of the Association of Official Analytical
Chemists. Benjamin Franklin Station,Washington,DC: Association of Official Analytical
Chemists.
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Technical Bulletin No. 803 Al
APPENDIX A
STATISTICAL DATA
Al. DEFINITIONS AND DESCRIPTIONS OF STATISTICAL TERMS
The statistical procedures and tests utilized throughout this technical bulletin are defined as follows.
Relative Standard Deviation (RSD). A measure of the spread or dispersion of data expressed as a
percentage.
Relative Percent Difference (RPD). A measure of the spread or dispersion of a sample and
duplicate pair expressed as a percentage.
F-ratio. A ratio of the two sample set variances(i.e.,the ratios of the squares of the standard
deviations).
p-value.The probability that the difference in means is due to random variability of samples pulled
from a normal distribution.
t-test. A test that determines whether two means from two independent,normally distributed samples
differ.
Cochran's test. A statistical test for homogeneity of variance. The hypothesis is that the variances
across different levels are equal;if the significance levels are greater than 0.05,do not reject the
hypothesis that the variances are not different.
Grubb's test. A test that is applied to assess whether a laboratory has an extreme average value.
Dixon's test. A statistical test for assessing suspect measurements. Examines the ratio of the suspect
value minus the value nearest it and the difference between the highest and lowest measurements.
Repeatability variance(s(r)^2). Sum of the squares of the laboratory ranges divided by two times
the number of participating laboratories minus one.
Reproducibility variance (s(R)^2). The true variance between replicate determinations (60 z)plus
the true variance between laboratories ((YC).
6 Z. Sum of squares of individual replicates minus one divided by the number of replicates times the
sum of the squares of the replicate totals, all divided by the number of participating laboratories times
the number of replicates minus one.
6L2. Determined by finding the mean square of the between-laboratory variance which is
MSL=r6Lz+ooz and using the result from above(602),rearranging the equation and solving for
GLz.
MSL. One divided by the number of replicates times the sum of the squares of the replicate totals
minus one divided by the number of participating laboratories times the number of matrices times the
number of replicates all times the square of the grand total of the results for all replicates divided by
the number of participating laboratories minus one.
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A2 Technical Bulletin No. 803
A2. REGRESSION ANALYSIS OF THE CHANGE IN TURBIDITY VS. COLOR VALUE
Effluent Mill B
Dependent variable -Color value (PCU)
Independent variable- Change in turbidity
Parameter Estimate Standard Error t-statistic p-value
Intercept 136.2 5.8 23.7 0.0018
Slope 0.03 0.17 0.20 0.8599
Analysis of Variance
Source Sum of squares Df Mean square F-ratio p-value
Model 1.08 1 1.08 0.04 0.8599
Residual 53.7 2 26.8
Total (corr.) 54.75 3
Influent Mill C
Dependent variable-Color value(PCU)
Independent variable-Change in turbidity
Parameter Estimate Standard Error t-statistic p-value
Intercept 164.4 30.6 5.4 0.0329
Slope 0.44 0.62 0.69 0.5566
Analysis of Variance
Source Sum of squares Df Mean square F-ratio p-value
Model 57.6 1 57.6 0.49 0.5566
Residual 235.4 2 117.7
Total (corr.) 293.0 3
National Council for Air and Stream Improvement

Technical Bulletin No. 803 A3
A3. SUMMARY OF F-TEST AND T-TEST STATISTICS
Method 253 Compared to Method Color 71.01
Lignin Solution Method 253 Color 71.01
Mean 51.3 52.7
Variance 2.3 22.9
Standard Deviation 1.5 4.8
Observations 4 4
df 3 3
F 0.098
p-value of F 0.883
t -0.598
p-value oft 0.571
Effluent Mill A Method 253 Color 71.01
Mean 575 573
Variance 1144 4992
Standard Deviation 33.8 70.6
Observations 4 4
df 3 3
F 0.229
p-value of F 0.257
t 0.051
p-value oft 0.961
Effluent Mill B Method 253 Color 71.01
Mean 185 179
Variance 139 459
Standard Deviation 11.8 21.4
Observations 4 4
df 3 3
F 0.304
p-value of F 0.354
t 0.469
p-value oft 0.655
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A4 Technical Bulletin No. 803
Influent Mill A Method 253 Color 71.01
Mean 672 745
Variance 509 3201
Standard Deviation 22.6 56.6
Observations 4 4
df 3 3
F 0.159
p-value of F 0.165
t 2.40
p-value oft 0.052
Influent Mill B Method 253 Color 71.01
Mean 213 116
Variance 1601 1053
Standard Deviation 40.0 32.4
Observations 4 4
df 3 3
F 1.52
p-value of F 0.738
t 3.77
p-value of t 0.009
Receiving Water Mill Method 253 Color 71.01
D
Mean 151 125
Variance 162 111
Standard Deviation 12.7 10.5
Observations 4 4
df 3 3
F 1.46
p-value of F 0.761
t 3.15
p-value of t 0.019
National Council for Air and Stream Improvement

Technical Bulletin No. 803 B1
APPENDIX B
NCASI METHOD COLOR 71.01
COLOR MEASUREMENT IN PULP MILL WASTEWATERS
BY SPECTROPHOTOMETRY
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B2 Technical Bulletin No. 803
Acknowledgments
This method was prepared by Diana Cook,Senior Research Chemist,and Nikki From,Research Associate,
at the NCASI West Coast Regional Center.
For more information about this method,contact:
Diana Cook Reid Miner
NCASI West Coast Regional Center NCASI
P.O.BOX 458 P.O.BOX 13318
Corvallis,OR 97339 Research Triangle Park,NC 27709-3318
[phone] [phone]
[e-mail] [e-mail]
For information about NCASI publications,contact:
NCASI
P.O.Box 13318
Research Triangle Park,NC 27709-3318
[phone]
[e-mail]
National Council for Air and Stream Improvement,Inc. (NCASI). 1999. Methods Manual. NCASI
Method Color 71.01: color measurement in pulp mill wastewaters by spectrophotometry. Research
Triangle Park,NC: National Council for Air and Stream Improvement,Inc.
© 1999 by the National Council for Air and Stream Improvement,Inc.
NCASI's Mission
To serve the forest products industry as a center of excellence for providing technical information and
scientific research needed to achieve the industry's environmental goals.
Disclaimer
The mention of trade names or commercial products does not constitute endorsement or recommendation
for use.
This method is included in the NCASI Methods Manual as an update to NCASI Method 253. The purpose
of including this updated method in the NCASI Methods Manual is to make it known that a method
revision is under development and to solicit comments regarding the technical merit and applicability of the
revised method. Those electing to apply the method are strongly encouraged to conduct rigorous QA/QC
or validation so that the quality of the data generated can be evaluated.
National Council for Air and Stream Improvement

Technical Bulletin No. 803 B3
NCASI METHOD COLOR 71.01
COLOR MEASUREMENT IN PULP MILL WASTEWATERS
BY SPECTROPHOTOMETRY
1.0 Scope and Application
1.1 This procedure utilizes a spectrophotometer to measure the absorbance of light as
it passes through a sample. The color is determined by comparison of the
absorbance of the sample to the absorbance of colored solutions of known
concentrations. The colored solutions used in this procedure are platinum cobalt
stocks. The unit of color is the color produced by 1 mg platinumiliter in the form
of the chloroplatinate ion, or PCU.
The term "color"represents the true color of an aqueous sample from which
turbidity has been removed (1). Turbidity can cause the color value determined
for a sample to be elevated due to an increase in light scattering. In this
procedure, filtration is used to remove turbidity from the sample. The optimal
method for removing turbidity without affecting the color value determined has
not been found, but filtration using a 0.8-micron (µm) membrane filter has been
demonstrated to be effective for most pulp mill effluent samples.
The color value determined for a specific sample is pH dependent and increases
as the pH of an aqueous sample increases. Therefore, a buffer is used to stabilize
pH during the filtration and measurement process.
1.2 This method has been validated at the single and inter-laboratory level in
wastewater treatment plant influents, biologically treated effluents from kraft pulp
and paper mills, and receiving waters. Demonstration of method performance for
specific matrix types is recommended.
1.3 The estimated method detection limit (MDL) achievable is instrument and light
path length dependent and was found to be 4 PCU for a river water sample using a
10-mm light path length (2). The MDL determined in a kraft mill treated effluent
was found to be 7 PCU using a 10-mm light path length. These values are
provided as guidance. Due to improvements in instrumentation and changes in
matrix effects, each laboratory should establish its own MDL. The lower
instrument calibration limit (LCL) for this method is approximately 10 PCU.
Lower calibration levels can be obtained by using an increased light path length.
The concentration range used during the single and inter-laboratory method
validation was from 10 to 500 PCU. Sample values above 500 PCU may be
determined by quantitative dilution.
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B4 Technical Bulletin No. 803
2.0 Summary of Method
2.1 Biologically treated effluents and wastewater influents
Place a 50-mL aliquot of unpreserved influent (effluent) into a 100-mL beaker.
Measure the initial pH of the sample and add approximately one-half of the solid
from a pH 7 buffer capsule. Dissolve the buffer capsule completely using a
mechanical stir plate and stir bar. Add an appropriate amount of sodium
hydroxide solution (NaOH) or hydrochloric acid (HCl) to adjust the pH to 7.6
±0.05. Filter the sample through a 0.8-µm membrane filter. If the analyst cannot
filter the sample through the membrane because of significant clogging, a pre-
filtration step may be added prior to pH measurement and adjustment. To verify
pH stability, periodically measure the post-filtration pH.
2.2 Quantitative analysis
Assess the color load by measuring the absorbance of the solution in a
spectrophotometer set at a wavelength of 465 nanometers (rlm). Calculate the
color units using the linear regression equation developed in Section 12.L
2.3 Quality assurance
Quality is assured through reproducible calibration and testing of the sample
preparation and spectrophotometer system. A method blank is analyzed with each
sample set (samples started through the process on a given day, to a maximum of
20, along with sample duplicates to ensure quality data). A complete description
of quality control procedures, calculations, and method performance criteria are
listed in Sections 9.0 and 10.
3.0 Definitions
3.1 These definitions are specific to this method, but conform to common usage as
much as possible.
3.1.1 PCU—platinum cobalt color unit
3.1.2 May—this action, activity, or procedural step is neither required nor
prohibited
3.1.3 May not—this action, activity,or procedural step is prohibited
3.1.4 Must—this action, activity, or procedural step is required
3.1.5 Should—this action, activity, or procedural step is suggested, but not
required
4.0 Interferences
4.1 Reagents, glassware, and other sample processing hardware may contribute
analytical interferences resulting in inaccurate absorbance readings. Run method
blanks initially and with each subsequent sample set to demonstrate that the
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Technical Bulletin No. 803 B5
reagents, glassware, and other sample processing hardware are free from
interferences under the conditions of the method.
4.2 Turbidity causes the measured color value to be greater than the true color value.
Therefore, it is necessary to remove turbidity in the sample prior to measuring the
sample's absorbance in a spectrophotometer. Interferences will vary considerably
from source to source, depending on the diversity of the site being sampled. This
procedure recommends the use of a 0.8-µm membrane filter to remove turbidity
prior to measuring the absorbance in the spectrophotometer. As needed, the
analyst can pre-filter the sample with a 1.0 µm glass fiber filter or use more than
one 0.8-µm membrane filter if clogging prevents the sample from readily passing
through the membrane filter.
4.3 The color value determined for a given sample is highly pH dependent. As pH
increases the color value determined for the sample also increases. Therefore,
stabilization of the pH at a given value for all measurements is required. This
procedure is conducted with the sample at a pH of 7.6±0.05 to maintain
consistency with standard methods currently in use.
4.4 All glassware must be clean and free of scratches. In addition, the cells used for
spectrophotometric measurement of the samples must be free of all oil or residue
that may cause interference in the absorbance measurement. It is recommended
that the same cell be utilized for the measurement of the calibration curve, daily
calibration checks,blanks, and samples.
5.0 Safety
5.1 Each chemical compound should be treated as a potential health hazard.
Exposure to these compounds should be reduced to a level protective of human
health. This method does not address all safety issues associated with its use.
The laboratory is responsible for maintaining a current awareness file of OSHA
regulations regarding the safe handling of the chemicals specified in this method.
A reference file of data handling sheets should also be made available to all
personnel involved in these analyses.
5.2 The platinum cobalt solution is corrosive and a suspected carcinogen.
Hydrochloric acid (HCI) and sodium hydroxide (NaOH) are also corrosive and
should be handled with caution. Take appropriate measures to avoid contact with
the chemicals by wearing chemical-resistant gloves, eye protection, and other
protective clothing.
5.3 As with all samples, precautions should be taken to avoid exposure to potentially
toxic, caustic, or nuisance odor compounds. Samples should be handled with
gloves and opened in a fume hood.
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B6 Technical Bulletin No. 803
6.0 Equipment and Supplies
Note: Brand names, suppliers, and part numbers are cited for illustrative
purposes only. No endorsement is implied. Equivalent performance may be
achieved using equipment and materials other than those specified here, but
demonstration of equivalent performance that meets the requirements of this
method is the responsibility of the laboratory.
6.1 A spectrophotometer with-ftungsten lamp source and a 10-rlm spectral slit width
is required. The instrument must be capable of emitting light at a selectable
wavelength of 465 rlm with an operating range of 400 to 700 rlm. Verify that the
spectrophotometer is calibrated correctly by following the directions from the
manufacturer for your specific instrument.
6.2 Do not use glassware with any star fractures, cracks, or severe scratches. All
glassware should be washed with detergent, rinsed with tap water, then rinsed
with reagent grade water prior to use.
6.3 Equipment for sample preparation
6.3.1 Filtration apparatus consisting of a flask, a vacuum source, and a filtration
holder that will accommodate a 47-mm filter
6.3.2 Pasteur pipettes
6.3.3 50-mL graduated cylinder
6.3.4 Teflorflm-coated stir bar
6.3.5 100-mL beaker
6.3.6 47-min, 1.0-µm glass fiber filters for pre-filtration
6.3.7 47-mm, 0.8-µm membrane filters
6.4 Other apparatus
6.4.1 pH meter calibrated using a two-point calibration procedure at pH 7 and
pH 8 using the appropriate buffer solutions
6.4.2 Magnetic stirrer
6.4.3 Sample cuvettes (absorption cell) for the measurement of absorbance, cell
path length is determined by the required MDL, refer to Table 1 for the
path length specific MDLs (3)
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Technical Bulletin No. 803 B7
7.0 Reagents and Standards
7.1 Reagents
7.1.1 Metrepak pHydrion buffer capsules, or an equivalent supplier(dibasic
sodium phosphate and monobasic potassium phosphate,pH 7.0), to
stabilize sample pH
7.1.2 Organic-free reagent water in which color is not detected by this method
7.2 Standards
7.2.1 Fisher or an equivalent supplier, platinum cobalt color standard, 500 PCU
stock
7.2.2 If a reliable source of platinum cobalt color standard is not available,
prepare a solution of potassium chloroplatinate. Dissolve 1.246 g of
potassium hexachloroplatinate, K2PtC16 (Aldrich or an equivalent
supplier), and 1.00 g of crystallized cobalt (II) chloride hexahydrate,
COC12.6 H2O (Aldrich or an equivalent supplier), in a portion of organic
free reagent water containing 100 mL of concentrated HCI. Dilute this
solution with distilled water to the desired color value. For example,
dilution to 1000 mL will provide a standard with a color value of
500 PCU. Dilution to 500 mL will provide a standard with a color value
of 1000 PCU.
7.2.3 Prepare a five-point calibration curve encompassing the sample
concentration range. Prepare a calibration curve by diluting 5, 10, 20, and
50 mL of 500 color unit stock solution of platinum cobalt in 100 mL of
deionized water. Include the absorbance measurement of the 500 color
unit stock solution of platinum cobalt in the curve. The prepared
calibration standards will have color units of 25, 50, 100, 250, and 500. It
is necessary to prepare a calibration curve that brackets the expected
values of color in the samples.
7.2.4 Stock solutions of the color standards do not need to be refrigerated, but
care should be taken to protect the standards from evaporation, light, and
contamination when not in use. Remember that the color standard
solutions have pHs less than 2.0 and should be handled with care. Stock
solutions of all standards should be checked for signs of concentration or
formation of precipitates prior to the preparation of calibration or
performance test standards. Replace the stock solutions if a change in
concentration is indicated by the inability to meet the criteria specified in
Sections 9.2 and 10.3.
7.3 Reagents for sample preservation and pH adjustment
7.3.1 Sodium hydroxide, ACS reagent grade, is used to adjust sample pH during
processing. Prepare a 20% solution by adding 20 grams of sodium
hydroxide pellets very slowly to 100 mL of reagent grade water using a
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B8 Technical Bulletin No. 803
stir bar and stir plate. Because this reaction is exothermic, take care that
the heat generated by the addition of the NaOH to the water does not break
the glassware.
7.3.2 Hydrochloric Acid, ACS reagent grade, is used to adjust sample pH during
processing. Prepare a 10% solution by adding 10 mL of concentrated HCl
to approximately 85 mL of reagent grade water using a stir bar and stir
plate. Bring the volume to 100 mL once the heat has dissipated.
8.0 Sample Collection, Preservation, and Storage
8.1 Sample collection
Collect grab or composite samples using clean sampling containers that are free
from contaminants which may interfere with the analyses. Composite samples
should be refrigerated during the sampling period. The color determination
should be made as soon as possible following sample collection. An assessment
of sample stability should be done on a matrix specific basis since biological
changes which can occur during storage may affect the color and alter the pH of
the sample.
8.2 Sample preservation
Samples are not preserved prior to analysis, as a change in pH can greatly affect
the resulting color determination. Samples should be refrigerated prior to
analyses (4°C). Sample refrigeration should occur as soon as possible after
sample collection.
9.0 Quality Control
9.1 Each laboratory that uses this method should operate a formal Quality Assurance
Program. The minimum requirements of this program consist of an initial
demonstration of laboratory capability, and ongoing analyses of standards and
blanks as a test of continued performance. Laboratory performance is compared
to established performance criteria to determine if the results of analyses meet the
performance characteristics of the method.
9.2 Spectrophotometer performance and calibration verification
9.2.1 Fill the sample cuvette with reagent grade water and place it in the
spectrophotometer. Adjust the absorbance reading to zero. Verify zero
after every four to six samples using the same process.
9.2.2 Determine that the spectrophotometer system is operating within
acceptable parameters by conducting a calibration check before each set of
analyses (samples started through the measurement process on a given
day). The calibration check involves reanalyzing one of the standard
calibration solutions used to prepare the calibration curve (Sections 7.2.3
and 10.3). The percent recovery determined for the calibration check
should be within the calculated warning limits (Section 17, Table 2). The
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• Technical Bulletin No. 803 B9
color determination may be sensitive to spectrophotometer and cell
conditions such as dirty glassware. If the calibration check fails to meet
the acceptance criterion, locate a new sample cuvette or perform
appropriate maintenance and reanalyze the calibration check sample. If
this fails to correct the calibration verification difficulties, the calibration
curve should be re-prepared and analyzed.
9.2.3 Verify that the spectrophotometer is calibrated properly by periodically
measuring an independent color standard check sample. If all calibration
checks and adjustments fail to correct the problem, calibrate the
instrument electronically. Electronically calibrate the instrument by first
selecting the transmittance option and setting the wavelength to 45011m.
With the 100% T/Zero control, set the display to read 100.0, insert an
occluder in the sample well, and close the cover. Adjust the %T
adjustment knob to read exactly 0.0 and remove the occluder.
9.3 Frequency
One sample per analytical batch of no more than twenty samples of similar matrix
type should be allocated for quality control (i.e., duplicate analyses). A
representative sample from each new or untested source or sample matrix should
be treated as a quality control sample.
9.4 Blanks
9.4.1 Demonstrate that the analytical system is free of color by preparing and
analyzing a blank with each sample set (20 samples or less). Prepare a
method blank using the same procedure outlined in Section 11.0 utilizing
reagent grade water for the sample.
9.4.2 If color is found in the blank at a value greater than 10% of the method
detection limit or the lowest calibration limit, analysis of samples is halted
until the source of contamination is eliminated and a blank shows no
evidence of contamination at this level.
9.5 Sample and duplicate precision
Analyze a sample and duplicate for each matrix type with each set of samples to
assess the precision of the analyses. Calculate the relative percent difference
(RPD) in color for each sample and duplicate pair using Equation 1. The
calculated RPD should be less than 14%.
Equation 1
Relative Percent Difference=(Highest Color Value —Lowest Color Value) x100
Average Color Value of the sample and duplicate
A summary of the precision determined in the single laboratory validation is
provided in Section 17,Table 3 for treatment system influent and biologically
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B10 Technical Bulletin No. 803
treated effluent samples. The average relative standard deviation for the single
laboratory precision was 2.8% in biologically treated effluents and 7.1% in
treatment plant influents. A summary of the accuracy and precision determined
during an inter-laboratory validation is provided in Section 17, Tables 4 and 5 for
treatment system influent, biologically treated effluent, and a receiving water
sample.
9.6 Field replicates and field spikes
Depending on specific program requirements, field replicates may be required to
assess the precision and accuracy of the sampling and sample transporting
techniques.
10.0 Calibration and Standardization
10.1 Zero the spectrophotometer (Section 9.2.1) and establish the operating conditions
outlined below. Use the same operating conditions to analyze all samples, blanks,
calibration curves, and calibration verification samples.
10.2 Quantitation
10.2.1 Analyze the calibration standards (Section 7.2.3) at a wavelength of
465 flm using the procedure described in Section 11.2.3. Construct a
calibration curve by plotting the absorbances and the color units of the
calibration curve points. An example of a calibration curve plot is located
in Section 17, Figure 1.
10.2.2 If the r-squared value determined for the curve is 0.991 or greater, the
calibration curve is assumed to be linear and acceptable. The linear
equation determined from the curve can then be used to calculate sample
color(Section 12.1). If the curve is not linear, evaluate the problem,
undertake the appropriate remedial action, and reanalyze the calibration
curve solutions. If remedial actions and reanalysis fail to produce an r-
squared value of at least 0.991, prepare new calibration curve solutions
and analyze them. The statistics for calibration curve linearity determined
during a single laboratory validation of this method are included in
Section 17, Table 6.
10.3 Verify calibration prior to the analysis of each set of samples (Sections 9.2).
Analyze one of the calibration standards (Section 7.2.3) prior to the analysis of
each set of samples. It is recommended that the selected calibration standard vary
over time in order to verify the calibration of the instrument over the full
calibration range of the method. Recalibrate if the percent recovery for the color
standard of the analyzed calibration solution is outside of the warning criteria
(Table 2).
10.4 Process a blank with the curve to confirm that the glassware, sample cuvette,
reagents, and other components are free from contamination. Prepare the blank
with deionized water using the procedure for the preparation of the samples
(Section 11).
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i
Technical Bulletin No. 803 B11
10.5 Demonstrate that color is detectable at the minimum level using the lowest level
calibration curve solution and the same path length of the sample cuvette that will
be used to analyze all curve points, calibration verifications, and samples.
11.0 Procedure
This section includes the procedures used to adjust pH, and filter the treatment plant
influent and biologically treated effluent samples. The pH adjustment and filtering
procedures are used for all types of samples and method blanks.
11.1 pH adjustment of the sample
11.1.1 Remove the sample from the refrigerator and allow the sample to come to
room temperature. Calibrate the pH meter using a two-point calibration
with pH 7 and pH 8 buffer solutions. Shake the sample to ensure
homogeneity and immediately measure 50 mL of the sample using a 50-
mL graduated cylinder. For method blanks, measure 50 mL of reagent
grade water.
11.1.2 Measure and record the sample pH (initial pH). Gently open a pH 7
Metripak pHydrion (or equivalent) buffer capsule and add approximately
one-half of the contents (powder only) to the sample. Stir until all of the
buffer has dissolved. Reserve the remaining half of the buffer for the next
sample. Adjust the sample pH to 7.6±0.05 by adding a small volume of
sodium hydroxide solution (preferably 20%) dropwise. If the pH is
adjusted slightly too high, hydrochloric acid (preferably 10%) may be
added dropwise to readjust the sample pH. The sample aliquot must be
discarded and re-prepared if the sample volume changes by more than 1%
before the pH is within the desired range. Differing strength acid and/or
base solutions may be used to meet this criteria. Record the adjusted pH.
11.1.3 Assemble an aspiration-type filtering apparatus and pre-wet a 0.8-µm
membrane filter with approximately 1 mL of deionized and/or distilled
water on each side of the membrane. Gently shake off the excess water,
place the filter onto the filter support, secure the filter holder/funnel in
place, turn the aspirator on, and slowly add the sample. A rapid decline in
the rate of flow through the membrane or foam coming off the membrane
filter, can indicate filter plugging. If the filter plugs, immediately replace
the filter with a new filter pre-wet with deionized and/or distilled water,
and continue filtering the remaining sample.
11.1.4 If filtration through the 0.8-µm membrane filter is excessively difficult,
the 50 mL of sample can be pre-filtered through a 1.0-µm glass fiber filter
prior to sample manipulation. Transfer the sample filtrate to a 100-mL
beaker equipped with a Teflon stir bar. Place the beaker on a mechanical
stir plate and gently stir the sample. Buffer, adjust pH, and filter through a
0.8-µm membrane filter as described in Sections 11.1.2 and 11.1.3.
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B12 Technical Bulletin No. 803
11.2 Spectrophotometer analysis
11.2.1 The spectrophotometer conditions should be set according to the criteria
described in Section 9.2.3.
11.2.2 Perform the calibration verification as outlined in Section 9.2.2.
11.2.3 Verify that the spectrophotometer is zeroed (Section 9.2.1). Rinse the cell
with a small amount of the filtered sample. Discard the rinse. Transfer
enough of the filtered samples to the sample cuvette, filling to the
reference line. Measure and record the absorbance at 46511m and discard
the sample. Rinse the cell thoroughly with deionized and/or distilled
water. Periodically verify that the spectrophotometer is zeroed.
12.0 Data Analysis and Calculations
12.1 Quantitation
12.1.1 The linear regression equation from the calibration curve (Section 10.2) is
used to calculate the corresponding color value of the samples. Calculate
the color value in the sample using Equation 2.
Equation 2
y=mx+b
where:
y is the absorbance
m is the slope
b is the y-intercept
x is the calculated color value
Calculate the color units for each sample by utilizing the measured
absorbance value and the linear equation derived from the calibration
curve (Section 10.2).
12.1.2 The calibration curve slope and y-intercept will vary depending on the
light path length of the sample cuvette used in each different
spectrophotometer. Therefore it is important to use the same light path
length for all measurements. The following is an example calculation
from a calibration curve prepared in one laboratory.
Example Calculation:
Absorbance measured for the sample(y) 0.039
Equation y = 0.0003x + 0.0016
x = v- 0.0016
0.0003
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Technical Bulletin No. 803 B13
• Substitution x = 0.039 - 0.0016
0.0003
Calculated Color Units (x) x = 125 PCU
12.2 Data review requirements
12.2.1 Review the data to assess the accuracy and precision of the determined
color value, spectrophotometer problems, interferences, and bias using the
guidance provided in Section 9.0 and 10.0. Correct any problems prior to
reporting the analytical results.
12.2.2 Assess the need for sample dilutions. The procedure for conducting
sample dilutions and reanalysis is described in Section 12.3.
12.2.3 Resolve inconsistencies between duplicates as necessary.
12.2.4 If review of the data shows any problems which could affect subsequent
analyses, discontinue the analyses until the problems are resolved.
12.3 Results outside the calibration range
If the calculated color value exceeds the highest color calibration point, dilute an
aliquot of the sample with reagent grade water prior to sample processing to bring
the concentration within the calibration range of the method and continue the
sample preparation process from Section 11.
13.0 Method Performance
Single laboratory performance for this method is detailed in Section 17,Tables 2,
3, and 6. Acceptance criteria were established from an inter-laboratory study
using the draft method. The data from this study are given in Tables 4 and 5.
14.0 Pollution Prevention
Pollution prevention approaches have not been evaluated for this method.
15.0 Waste Management
15.1 It is the laboratory's responsibility to comply with all federal, state, and local
regulations governing waste management, particularly the hazardous waste
identification rules and land disposal restrictions, and to protect the air, water, and
land by minimizing and controlling releases from fume hoods and bench
operations. Compliance with all sewage discharge permits and regulations is also
required.
15.2 Instructions for sample and waste handling and disposal
15.2.1 Dispose of all samples as required by federal, state and local regulations.
15.2.2 Neutralize the sodium hydroxide solution and pour it down the drain with
copious amounts of water.
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B14 Technical Bulletin No. 803
15.2.3 Neutralize the calibration standard solutions to pH 7 and pour the aqueous
portion of the extracted sample aliquot down the drain with copious
amounts of water.
15.3 For further information on waste management, the Environmental Protection
Agency suggests you consult The Waste Management Manual for Laboratory
Personnel, and Less is Better: Laboratory Chemical Management for Waste
Reduction. Both are available from the American Chemical Society's Department
of Government Relations and Science Policy, 1155 16a' Street NW,Washington,
DC, 20036.
16.0 References
1. Standard Methods for the Examination of Water and Wastewater, 20th Edition,
American Public Health Association,Washington, DC, 1998, 2-1 to 2-8.
2. Federal Register, "Appendix B to Part 136-Definition and procedure for the
determination of the method detection limit-revision 1.11." Vol. 49, No. 209.
October 26, 1984.
3. National Council for Air and Stream Improvement, Inc. (NCASI). 1971. An
investigation of improved procedures for measurement of mill effluent and
receiving water color. Technical Bulletin No. 253. Research Triangle Park, NC:
National Council for Air and Stream Improvement, Inc.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
Table 1. Minimum Detectable Color for Various Light Path Length Sample Cuvettes
Sample Cuvette Light Path Length Minimum Detectable Color Units
30 1
20 5
10 7a
5 10
1 25
a Determined using a treated effluent from a haft mill.
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Technical Bulletin No. 803 B15
• Table 2. Daily Calibration Verification Criteria
Average Standard Warning Action Limits Color Unit Range
Recoverya(%) Deviation Limits`(%) M (PCU)
94.9 6.7 81 - 108 75 - 115 10 - 500
a Average recovery for 47 daily calibration checks.
b Standard deviation of the recoveries for 47 daily calibration checks.
e Average recovery plus or minus two times the standard deviation.
d Average recovery plus or minus three times the standard deviation.
Table 3. Single Laboratory Precision: NCASI Color-71.01
Sample Type' Range RPDb Average RPDe
Effluent 0.4 - 14.1% 2.8%
Influente 0.1 - 13.2% 7.1%
a Precision of the target analytes native to treatment system influents and
biologically treated effluents.
b Range of relative percent differences observed between a sample and a duplicate.
e Pooled average relative percent difference for all sample and duplicate pairs
analyzed.
d Range and average RDP for 12 duplicate pairs.
e Range and average RDP for 12 duplicate pairs.
Table 4. Inter-Laboratory Accuracya
Average Percent Standard Relative Standard
Recovery Deviation Deviation (%)
94 10.6 11.3
a Summary of the percent recoveries for a 125 PCU color standard analyzed by eight
different laboratories using eight different spectrophotometers.
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B16 Technical Bulletin No. 803
Table 5. Results of an Inter-Laboratory Study Youden Pair Analyses
to Assess Intea- and Inter-Laboratory Precision
Receiving
Lignin Effluent Effluent Influent Influent Water
Parameter Solution Mill A Mill B Mill A Mill B Mill D
Number of Labs 7 7 6 6 7 6
Mean of Lab Averages 58.0 562 169 665 128 141
s( r) repeatability 5.8 17.2 7.1 15.4 17.6 13.2
standard deviation
s( R)reproducibility 13.9 95.2 22.1 87.7 44.8 25.6
standard deviation
RSD (r) repeatability 10.0 3.1 4.2 2.3 13.8 9.3
relative standard
deviation '
RSD (R ) reproducibility 24.0 16.9 13.1 13.2 35.0 18.1
relative standard
deviation
a Intra-laboratory(repeatability)precision of the method.
b Inter-laboratory(reproducibility)precision of the method.
Table 6. Calibration Curve Linearity
Linear Equation y=mx +b R-squared Light Path Length (mm)
y = 0.0153x-0.0108 0.9981 10
y =0.0003x + 0.0052 0.9968 10
y= 0.0003x + 0.0016 0.9999 10
y= 0.0003x +0.0010 0.9997 10
y = 0.0005x + 0.0014 0.9999 20
y =0.0003x + 0.0004 1.0000 10
y =0.0005x+ 0.0004 0.9999 20
y =0.0003x + 0.0003 0.9999 10
y=0.0003x-0.0030 1.0000 10
y= 0.0005x + 0.0028 0.9988 20
y= 0.0006x-0.0004 0.9999 25
y = 0.0014x-0.0003 1.0000 50
y =0.0027x + 0.0018 1.0000 100
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Technical Bulletin No. 803 B17
0.16
0.14
0.12
$ 0.1
c
m
0.08
0
N
a
0.06
0.04
0.02 y=0.0003x+0.0016
If=0.9999
0
0 100 200 300 400 500 600
Color Units
Figure 1. Typical Calibration Curve.
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0
y Technical Bulletin No. 803 Ct
APPENDIX C
INTER-LABORATORY STUDY PLAN, PROCEDURE, AND DATA SHEET
1.0 SCOPE
This study is intended to evaluate the precision and accuracy of an updated color method when
applied to pulp mill effluents. The following sections describe the sample collection, analysis
requirements, and data reporting requirements for the study.
2.0 SAMPLE COLLECTION,STORAGE,AND SHIPMENT
Grab samples of pulp mill treatment system influents and Final effluents will be collected from two
kraft mills equipped with secondary biological treatment. Sample matrices will represent mills
pulping hardwood and softwood, utilizing oxygen delignification and high chlorine dioxide
substitution. In addition to the above samples, a receiving water sample will also be assessed. The
samples will be collected and shipped via overnight FedEx on ice to the NCASI West Coast Regional
Center where they will be homogenized and split into sample containers for shipment to the
participating laboratories. In addition to the effluent and influent samples,a color reference material
solution and platinum cobalt standard solution (color standard solution) will also be included in the
shipment. All samples will be unpreserved and should be stored at 4°C until analyzed. Sampling will
be scheduled to ensure sample shipment to each of the participating labs on the same day(Target
Date:February 17). Upon receipt,the laboratory must maintain the samples at 0 to 4°C and analyze
for color within 24 hours using the NCASI Updated Color Measurement Procedure(see attached).
A total of twelve samples and one color solution check standard will be sent to each laboratory. For
those laboratories that do not routinely measure color,a set of calibration curve solutions will also be
included in order for the lab to measure a standard curve prior to sample analyses.
3.0 SAMPLE ANALYSIS REQUIREMENTS
Each sample matrix will be analyzed for color using the attached NCASI Updated Color
Measurement Procedure. Since the objective of this study is to compare the results obtained using the
procedure, it is important that the laboratory strictly adhere to the method requirements. These
requirements are clearly defined in the attached procedure.
3.1 Method Requirements
All instruments should be zeroed using reagent grade water prior to standard and sample readings.
The calibration check standard(Bottle 1) should be read prior to the samples. Each sample should be
measured using the attached procedure. Please provide the information specified on the attached data
sheet for each sample measured.
3.2 Data Deliverables
Complete the attached NCASI Color Measurement Study Data Sheet with the information requested
and return it to our laboratory in the enclosed envelope. We realize that some laboratories utilize
spectrophotometers with software programs that do not provide the option of viewing the calibration
curve equation. If possible, we request that you provide NCASI with the absorbance readings for the
calibration points measured. If this is not an option, leave this portion of the sheet blank. We also
recognize that you may only be able to provide color units for samples A through J,but request that
you also include the measured absorbance when possible. It would be helpful to include any
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C2 Technical Bulletin No. 803
observations that you feel may have had an effect on your results (condition of cells,instrument
function, clogging of filters, etc.) in the comment section.
3.3 Data Evaluation
The data will be evaluated for the following information:
• Completeness of the data sheet, including all data deliverables requested
Correct reporting units and significant figures
• Results for the calibration check standard
Results for the average concentration, standard deviation, and relative standard deviation
for each sample matrix analyzed by the procedure
• Inter- and intra-laboratory precision using Youden pair analyses
• Method precision using ANOVA statistics
3.4 Report of Findings
The analytical results and statistical evaluation will be summarized in a report. Codes will be used to
identify results associated with each lab. The names of the participating labs will not be identified.
This study is not intended to endorse or verify a laboratory, but rather to evaluate the inter-and intra-
laboratory precision using the updated color procedure. Participating laboratories will be provided
with a final copy of the report when it is completed.
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Technical Bulletin No. 803 C3
NCASI UPDATED COLOR MEASUREMENT PROCEDURE
1.0 GENERAL DISCUSSION
This procedure utilizes a spectrophotometer to measure the absorbance of light as it passes through a
sample. The color is determined by comparison of the sample to colored solutions of known
concentrations. The color solutions used in this procedure are platinum cobalt stocks. The unit of
color is the color produced by I mg platinum/liter in the form of the chloroplatinate ion, PCU.
The term"color"represents the true color of an aqueous sample from which turbidity has been
removed. Turbidity can cause the color value determined for a sample to be elevated due to an
increase in light scattering. In this procedure, filtration is used to remove the turbidity in the sample
which may interfere with the determination of color. The optimal method for removing turbidity
without affecting the color value determined has not been found,but filtration using a 0.8 µm
membrane filter has been demonstrated to be effective for most pulp mill effluent samples.
The color value determined for a specific sample is pH dependent and increases as the pH of the
aqueous sample increases. Therefore,a buffer is used to stabilize the pH during the measurement
process.
2.0 EQUIPMENT AND SUPPLIES
2.1 Equipment
• Spectrophotometer with a tungsten lamp source and 10 T)m spectral slit width;the operating
range should include 400 to 700 Tim and the instrument should be capable of emitting light
at a selectable wavelength of 465'gm
• pH meter
• Mechanical stir plate
• TeflonTl stir bar
• Filtration system that will accommodate a 47 mm filter
• Pasteur pipettes
• 50-mL graduated cylinder
• 100-mL beaker
2.2 Supplies provided by NCASI in the sample kit
• 47 mm, 1.0 µm glass fiber filters from Gelman for prefiltration
a 47 nun,0.8 µm membrane filters from Nucleopore,Membra-Fil
• pH 7 buffer capsules to stabilize sample pH
• Color standard calibration check solution
• Set of calibration standard stock solutions (if your lab requested them)
2.3 Reagents laboratories will need to supply
• Sodium hydroxide solution (preferably 20%,but 10% may be sufficient)
• Hydrochloric acid(preferably 4%, but a more dilute solution may be sufficient)
3.0 CALIBRATION STANDARDS
The calibration curve standards were prepared by making dilutions of a 500 color unit stock solution
of platinum cobalt. The prepared calibration standards have color units of 10,25, 50, 100, 250, and
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C4 Technical Bulletin No. 803
500 PCU. Refrigeration of the calibration standard solutions is not necessary, but care should be
taken to protect the standards from evaporation and contamination when not in use.
4.0 CALIBRATION CURVE
4.1 All calibration standard and sample measurements must be conducted with the
spectrophotometer set at a wavelength of 465 tlm.
4.2 Make sure that the cell to be used is clean and free of scratches, oils, and/or dirt. It is
recommended that the cell be placed in the spectrophotometer in the same position for each
reading. This can be accomplished by orienting a mark on the tube in the same position for
each reading. Allow the spectrophotometer to warm up as recommended in the instrument
manual. Zero the spectrophotometer using deionized and/or distilled water.
4.3 Rinse the cell with a small amount of the color calibration standard to be measured. Discard
this rinse and transfer a portion of the color calibration standard to the cell. Measure the
absorbance of the sample in the spectrophotometer and record the reading. Repeat this
process for each of the six calibration standards.
4.4 Plot the absorbance vs. the color value of the six calibration standards and fit the curve using
a linear regression model. Record the R-squared value(correlation coefficient) and the
equation on the data sheet. The curve is considered linear if the correlation coefficient is
greater than or equal to 0.991. If the curve does not meet this criteria, the procedure should
be repeated until this criteria is met.
4.5 The pH of the calibration stock solutions is below 2;therefore these solutions should be
neutralized prior to disposal.
5.0 MEASUREMENT OF COLOR STANDARD CALIBRATION CHECK
5.1 Make sure that the cell to be used is clean and free of scratches, oils, and/or dirt. Allow the
spectrophotometer to warm up as recommended in the instrument manual. Zero the
spectrophotometer using deionized and/or distilled water.
5.2 Rinse the cell with a small amount of the color standard calibration check(Bottle#1)to be
measured. Discard this rinse and transfer a portion of the color standard calibration check to
the cell. Measure the absorbance of the sample in the spectrophotometer and record the
reading. Calculate the color value of the color standard calibration check using the process
described in Section 7.0. Record the value on the data sheet.
6.0 MEASUREMENT OF SAMPLES
6.1 Remove the sample bottles (Samples A through J) from the refrigerator and allow the
samples to come to room temperature. Calibrate the pH meter using a two-point calibration
with pH 7 and pH 8 buffer solutions.
6.2 Invert the sample bottle several times to re-suspend the solids that may have settled during
storage. Measure 50 mL of the sample using a 50-mL graduated cylinder.
6.3 Pre-filter the 50 mL of sample through a 1.0-pin glass fiber filter prior to sample
manipulation. Transfer the sample filtrate to a 100-mL beaker equipped with a Teflon stir
bar. Place the beaker on a mechanical stir plate and gently stir the sample.
6.4 Measure and record the sample pH (initial pH). Gently open a buffer capsule and add
approximately one-half of a pH 7 Metripak, pHydrion buffer capsule(powder only); stir until
National Council for Air and Stream Improvement

Technical Bulletin No. 803 C5
all of the buffer has dissolved. Reserve the remaining half of the buffer for the next sample.
Adjust the sample pH to 7.6±0.05 by adding a small volume of sodium hydroxide solution
(preferably 20%) dropwise or hydrochloric acid (preferably 4%), depending on the initial pH
of the sample. The sample aliquot must be discarded and re-prepared if the sample volume
changes by more than 2% before the pH is within the desired range. Differing strength acid
and/or base solutions may be used to meet this criteria. Record this adjusted pH on the data
sheet.
6.5 Assemble an aspiration-type filtering apparatus and pre-wet a 0.8 µm membrane filter with
approximately 1 mL of deionized and/or distilled water on each side of the membrane.
Gently shake off the excess water, place the filter onto the filter support, secure the filter
holder/funnel in place, turn the aspirator on, and slowly add the sample. Watch for a rapid
decline in the rate of flow through the membrane or foam coming off the membrane filter,
which can indicate filter plugging. If the filter plugs,immediately replace the filter with a
new filter pre-wet with deionized and/or distilled water and continue filtering the remaining
sample. Record the number of filters used to prepare each of the samples on the data sheet.
6.6 Verify that the spectrophotometer is still zeroed. Rinse the cell with a small amount of the
filtered sample. Discard the rinse. Transfer a portion of the filtered sample to the cell and
measure the absorbance at 465 ilm. Transfer all of the filtered sample back into the original
beaker. Measure and record the sample's pH and record this value on the data sheet as the
post-filtration pH. Rinse the cell thoroughly with deionized and/or distilled water. Verify
once again that the spectrophotometer is zeroed.
7.0 CALCULATIONS AND REPORTING
7.1 Calculate the color units for each sample by utilizing the measured absorbance value and the
linear equation derived from the calibration curve(Section 4.0) in your lab. The following is
an example calculation from a calibration curve prepared in our laboratory.
7.2 The calibration curve slope and y-intercept will vary depending on the light path length of the
cell used in each different spectrophotometer. Therefore it is important to use the same cell
for all measurements.
Example Calculation:
Absorbance 0.039
Equation y=0.0003x+0.0016
x=y-0.0016
0.0003
Substitution x=0.039 -0.0016
0.0003
National Council for Air and Stream Improvement

1
C6 Technical Bulletin No. 803
NCASI COLOR MEASUREMENT STUDY DATA SHEET
Participating Company
Address
Phone Number Contact Person
Apparatus:
Instrument Manufacturer Model
Wavelength Used Cell Path Length
Calibration Curve:
Standard Level (CU) Absorbance
10
25
50
100
250
500
**If your lab uses a spectrophotometer that stores calibration curve data, please record the
stored absorbances or color units if possible.
Calibration Curve Equation R Value
Calibration Check:
Absorbance and/or color units of color standard calibration check
Date Analyzed
Samples:
Sampl Initial Adjuste Post- Number of Absorbanc Color Date
e Code pH d pH Filtration membranes a Units Analyze
PH used (PCU) d
A
B
C
D
E
F
G
H
I
J
K
L
Comments:
National Council for Air and Stream Improvement

Technical Bulletin No. 803 Di
APPENDIX D
YOUDEN PAIR STATISTICAL ANALYSIS PLOTS
Figure D 1 illustrates the raw data received for the two lignin samples analyzed as part of the inter-
laboratory study. The plots are made by using the results for one sample as abscissa, and the results
of the other sample as ordinate. The average of all the data points for Lignin 1 and Lignin 2 are
represented by the vertical and horizontal lines in the middle of the graph. The ideal situation would
result in data points found along the 45-degree line of the graph with the data clustered near the
intersection of the two average lines. The closeness of the individual points to the 45-degree line
reflects the within-laboratory precision, and the overall spread in either the abscissa or ordinate
direction reflects the overall precision or reproducibility. The data from laboratory L3 is biased high,
as indicated by its location removed from the other laboratory results to the high extreme on the x and
y axes. Dixon's test for outliers indicated that the results from L3 could be removed from the data
set.
140
120
U 100
L3
v � j
�
8t] L7 • L2
bA 60
40 * Lg/ ..
20
40 60 80 100 120 140
Lignin 2(PCU)
Figure D1. Youden Pair Plot for Lignin 1 and Lignin 2.
National Council for Air and Stream Improvement

D2 Technical Bulletin No. 603
Figure D2 illustrates the raw data received for the two effluent samples (Mill A) analyzed as part of
the inter-laboratory study. The data from laboratory L3 is biased high, as indicated by its location
removed from the other laboratory results to the high extreme on the x and y axes. Dixon's test for
outliers indicated that the results from L3 could be removed from the data set.
800
U 750 s L2 • L3
0 700 I /-
Q 650
600 -L6 L7
550
IIl�ii i
a 500 L87
W450 L4
♦
400
400 500 600 700 800 900
Effluent Mill A-2 (PCU)
Figure D2. Youden Pair Plot for Effluent Mill A-1 and Effluent Mill A-2.
Figure D3 illustrates the raw data received for the two influent samples (Mill A) analyzed as part of
the inter-laboratory study. The data from laboratories L3 and L2 are biased high, as indicated by their
locations removed from the other laboratory results to the high extreme on the x and y axes. Dixon's
test for outliers indicated that the results from L3 and L2 could be removed from the data set.
1100
w 1000
T • L3 • L2
i
/
9w800 T L5
c 700 1 L6
�$7�
600 I �
1 ♦ L4
500
500 600 700 800 900 1000 1100
Influent Mill A-2 (PCU)
Figure D3. Youden Pair Plot for Influent Mill A-1 and Influent NMI A-2.
National Council for Air and Stream Improvement

Technical Bulletin No. 803 D3
Figure D4 illustrates the raw data received for the two effluent samples (Mill B) analyzed as part of
the inter-laboratory study. The data points plotted from laboratory L3 and L2 are biased high,as
indicated by their locations removed from the other laboratory results to the high extreme on the
x and y axes. Dixon's test for outliers indicated that this bias was significant and these laboratories
were removed from the data set.
300
pU w L3
250
W i
200 • T
r
L1 i
150 L4,8 '
W
100
140 160 180 200 220 240 260 280 300 320
Effluent Mill B-2 (PCU)
Figure D4. Youden Pair Plot for Effluent Mill B-1 and Effluent Mill B-2.
Figure D5 illustrates the raw data received for the two influent samples (Mill B) analyzed as part of
the inter-laboratory study. The data from laboratory L3 is biased high, as indicated by its location
removed from the other laboratory results to the high extreme on the x and y axes. Dixon's test for
outliers indicated that this bias was significant and this laboratory was removed from the data set.
300
!
pUv., 250
CG 200 • L2
i
150 L6 LS
� i I
100 i� L*tL+ L8
C
50
80 100 120 140 160 180 200 220
Influent Mill B-2 (PCU)
Figure D5. Youden Pair Plot for Influent Mill B-1 and Influent Mill B-2.
National Council for Air and Stream Improvement

D4 Technical Bulletin No. 803
Figure D6 illustrates the raw data received for the two receiving water samples (Mill D) analyzed as
Part of the inter-laboratory study. The data points plotted from laboratory L3 and L2 are biased high,
as indicated by their location removed from the other laboratory results to the high extreme on the
x and y axes. Dixon's test for outliers indicated that this bias was significant and these laboratories
were removed from the data set.
240
220
pU., 200 L2
180
L1 -
I I
140
3 .�i' • L7
x 120 . L►4U
100
100 120 140 160 180 200 220
RW Mill D-2 (PCU)
Figure D6. Youden Pair Plot for Receiving Water Mill D-1 and Receiving Water Mill D-2.
1
National Council for Air and Stream Improvement

Chartetts'. biect.
Fund Select
Presentation to:
Pigeon River Fund
September, 2001
James E. Holmes, III Director
200 W. Second Street, Suite 500
Deutsche Banc Alex. Brown
Winston-Salem, NC 27101
Deutsche Bank [phone]

Pigeon River Fund
Fund Select "at a glance"
Fund Select is a mutual fund managed account program that provides clients
with access to a large number of the leading mutual funds in the industry and
allows clients to build a diversified portfolio that meets their goals and
objectives.
Fund Select Features:
• $100,000 minimum investment
• More than 120 mutual funds from traditional load and no load fund families.
• Access to 14 model portfolios that range from 100% equity to various
weightings of equity and fixed income (taxable and tax-exempt) funds.
• Tactical asset allocation that "tweaks" the allocations among equity funds, bond
funds, and cash based on the valuations in the financial markets.
• Ongoing screening of more than 10,000 stock and bond funds. The screening
criteria includes:
• consistency of performance over various time periods;
• superior risk-adjusted returns with minimal volatility; and
• acceptable tenure of management.
• Annual portfolio rebalancing.
Deutsche Banc Alex. Brown
Deutsche Bank u �.
-2- ChartertSelec#

--- -- - - ---
Pigeon River Fund
The Fund Select Investment Process
Identify Objectives
Inventory/1� nd Evaluate
'• Assets
L—+Monitor
Performance
Allocation Plan
Rebalance
/-!
Implement the Plzw
Deutsche Banc Alex.Brown ,
Deutsche Bank ❑ a-
Charte4blect.

Pigeon River Fund ,
Identify Goals and objectives through
Client Profile
The client profile helps to determine the asset allocation recommendation
which is consistent with your goals and objectives:
Acceptable
Appropriate
Desired return Other
Driun by yowr narestrent obelc#i,111'+es
Deutsche Banc Alex. Brown
Deutsche Bank 0 Charterer elect.
-a-

Pigeon River Fund
Understanding Your Needs
Asset allocation begins with the Deutsche Banc Alex. Brown Private Client Profile.
• Facilitates interactive discussions to assess
your complete financial situation.
Deutsche Banc Alex.Brown
Private Client Profile • Asks specific questions about your financial
goals (i.e. retirement, education expenses)
and current portfolio holdings.
• Recommends a portfolio based on your
answers.
• Helps develop a personal investment strategy
tailored to fit your particular financial goals,
risk tolerance and investment time horizon.
Invea�t Repec-a�—.
F IePa
Deutsche Banc Alex. Brown
Deutsche Bank �
-5- ChartetObtect

Pigeon River Fund
Make Strategic Asset Allocation `
Recommendation
• After evaluating your client profile, a model or custom portfolio
is recommended, which is consistent with your goals and objectives.
• For example, assume you are seeking more capital appreciation
than your existing portfolio is designed to generate:
Cash
Stocks Cash
Overweight-stocks,
NI
Underweight cash
Bonds
Stocks
Bonds
Deutsche Banc Alex.Brown
Deutsche Bank ��1.
_s_ Chartereci:

Pigeon River Fund
Asset allocation and portfolio structuring
The goal of asset allocation is to find the portfolio that best meets the
client's goals and objectives.
Aggressive
Moderate
Conservative
E
or
o:
e
0
Risk(Standard Deviation)
Deutsche Banc Alex. Brown
Deutsche Bank �.
_,_ Charte�Seleci:

Pigeon River Fund ��
Asset allocation and portfolio structuring
1st level diversification — the big 5
Bonds
Cash
Large Cap
Small
r International
Equity
This chart represents the 5 key components used to construct a well diversified portfolio. Weighting of each component will very according to client risk profile.
Deutsche Banc Alex.Brown
Deutsche Bank 0 �.
-a- Charter6select.

Pigeon River Fund ,-
Asset allocation and portfolio structuring - -
2nd level diversification
7Bonds
Cash
arge Cap
Growth vs. Value
Long-term Bonds vs.
Intermediate-term
layBonds
Taxable vs Tax- Mid Cap
Exempt Bonds
Emerging Markets
Hi-Yield Bonds
Deutsche Banc Alex.Brown
Deutsche Bank 0 Chart& blest.
-s-

Pigeon River Fund
Risk/reward profile for various mixes of
stocks and bonds
Standard & Poor's 50015 Year Treasury Notes Total Return
Annual observations from 1926 through 1998
12%
80%S&P500
11 °/ r 0%T-Notes 100%S&P500
D ort�e
j 10% 50%S&P500/ ��1C`ert�t
0 9°/O
CO
50%T-Notes
a�
Ca8%
80%T-Notes
m 7% 20%S&P500
0
m
6%
5%
100%T-Note
4%
4% 8% 12% 16% 20% 24%
Standard deviation (risk)
Past performance is not indicative of future results. Source:Ibbotson Associates
Deutsche Banc Alex. Brown
Deutsche Bank 0 -10-
ChartO'Q561ect

Pigeon River Fund
Growth Versus Value
S&P Growth vs. S&P Value
(Total rehirn above or below the S&P 500 Stock Index)
15%
10%
5%
S&P 500 p '
Index 0 /o 1 oil
-5%
-10%
-15%
-20%
1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 19941995 1996 1997 1998
■ S&P Growth ■ S&P Value
Source:Ibbotson Associates
Deutsche Banc Alex. Brown
Deutsche Bank 0 �T�
_„_ Charter�S�lect

- -
Pigeon River Fund
Fund Select Investment Style Weightings ,
(Base Allocation With Taxable Bonds)
100%
90%
80%
70%
60%
60%
40%
30%
20%
10%
0% Modell Modell Model Model Modal5
■Cash 2.0% 2.0% 2.0% 2.0% 2.0%
0 High Yld Taxable 5.0% 5.0% 5.0% 10.0%
e Long Term Taxable 5.0% 10.0% 15.0%
la kit temTexable 10.0% 15.0% 25.0% 30.0%
■ShttennTexable 10.0°% 15.0% 20.0%
O Emerging Intl 3.0%
0 Established kill 10.0°A 10.0% 7.0% 5.0%
■Large Cap Growth 25.0°% 21.5% 18.0% 14.0% 11.5%
O Large Cap Value 25.0% 21.5% 18.0% 14.0% 11.5%
O Mid Cap Growth 10.0% 7.5% 5.0% 5.0%
m Mid Cap VeNe 10.0% 7.5°% 5.0% 5.0%
O SmaO Cap Grow th 7.5% 7.5% 5.0%
a SmaO Cap V 8Ne 7.5°A 7.5% 5.0°%
Higher Return Lower Return
Higher Volatility Less Volatility
Deutsche Banc Alex.Brown
Deutsche Bank IZI _12_ Charter select

Pigeon River Fund
Fund Select Investment Style Weightings
(Base Allocation With Tax-Exempt Bonds)
100%
90%
80%
70%
50%
50%
40%
30%
20% 1
10%
mi
0% Model Model Model Models
■Cash 2.0% 2.0% 2.0% 2.0°%
o High Yld Tax Free 5:0°% 5.00A 5.0% 10.0%
B Long Term Tex Free 5.0% 10.0% 15.0% 20.0%
O ht term Tax Free 5.0°% 10.0% 20.0°% 25.0%
*Sht Tam Tex Free 10.0% 15.0% 20.0%
06rergng Intl
■Established Intl 10.0% 7.0% 5.0%
■Large Cap Growth 21.5% 18.0% 14.0% 11.5%
O Large Cap VBWe 21.5% 18.0% 14.0% 11.5%
O Mid Cep Grow th 7.5°% 5.0% 5.0%
O Mid Cep Vahle 7.5% 5.0% 5.0%
o Smw Cap Growth 7.5% 5.0%
*Sm it Cap Value 7.5% 5.0%
Higher Return Lower Return
Higher Volatility P, Less Volatility
Deutsche Banc Alex.Brown
Deutsche Bank 0 -13-
Chartei'&&Iect.

Pigeon River Fund
Fund Select Investment Style Weightings
(Base Allocation With No International Equity)
100.0%
90.0%
solo%
70.0%
60.0%
50.0%
40.0%
30.0%
20.0%
10.0%
0.0% ModeI1D Wde12 MNbdel3D Model4D Model5D
■CASH 2.0% 2.0% 2.0% 2.0% 2.0%
■KGh Vld Taxable 5.0% 5.0% 5.0% 10.0%
■Long Tenn Taxable 5.0% 10.0% 15.0%
®let term Taxable 10.0% 15.0% 25.0% 30.0%
■Sht term Taxable 10.0% 15.0% 20.0%
Cl Emerging Intl
■Established Iml
■Large Cap Grow th 31.5% 26.5% 21.5% 16.5% 11.5%
D Large Cap Value 31.5% 26.5% 21.5% 15.5% 11.5%
D NGd Cap Grmvth 10.0% 7.5% 5.0°% 5.0%
■NGd Cap Vahe 10.0% 7.5% 5.0% 5.0%
O Small Cep Growth 7.5% 7.5% 5.0%
E Small Cap Value 7.5% 7.5% 5.0%
Higher Return Lower Return
Higher Volatility Less Volatility
Deutsche Banc Alex. Brown
Deutsche Bank �
44_ ChutCY0610CL

I
Pigeon River Fund
Fund Select Tactical Asset Allocation Ranges
(Tactical Asset Allocation Generated by Econometric Model)
Model 1, 1D Model 2, 2D, & 6 Model 3, 3D, & 7 Model 4, 413, & 8 Model 5, 5D, & 9
Cash 17% 32% 32% 32% 32%
Bearish Negative Bonds 0% 0% 20% 40% 45%
Equities 83% 68% 48% 28% 23%
sa�.4
Cash 2% 2% 2% 2% 2%
LZ
ZY_ Y
J;c
Neutral Bonds 0% 15% 35% 55% 75%
- Equities 98% 83% 63% 43% 23%
Cash 2% 2% 2% 2% 2%
Bullish Bonds 0% 0% 20% 40% 60%
Equities 98% 98% 78% 58% 38%
The same tactical allocations apply for the portfolios with tax-exempt bonds and portfolios without international equity.
Deutsche Banc Alex. Brown
Deutsche Bank IZI �.
As- Charterlecd:

Pigeon River Fund
Recommended Mutual Fund Performance - �'
Tot Ret Tot Ret %Rank Tot Ret %Rank Tot Ret %Rank
(Returns Through 07131101) Morningstar Tot Ret Annlzd Annlzd Cat Annlzd Cat Atmlzd Cat
Category YTD 12 Mo 3 Yr 3 Yr 5 Yr 5 Yr 10 Yr 10 Yr
Large Growth
American Funds Growth Fund A Large Growth -8.46 -14.54 17.94 1 23.05 2 17.15 5
Cat:Large Growth Large Growth -18.79 -30.83 2.88 - 12.53 - I Z29 -
Large Value
American Funds Wash Mutual A Large Value 4.34 18.1 7.49 26 16.39 17 15.25 15
Cat:Large Value Large Value -1.41 6.9 5.17 - 12.9 13.11
Mid-Cap Growth
MFS Mid-Cap Growth Mid-Cap Growth -13.29 -18.87 22.73 4 20.88 8 - -
Cat.Mid-Cap Growth Mid-Cap Growth -17.53 -26.07 9.17 - 12 - 12.48 -
Mid-Cap Value
PIMCO Renaissance A Mid-Cap Value 7.46 37.87 17.95 12 23.98 3 18.97 4
Cat:Mid-Cap Value Mid-Cap Value 4.75 18.42 9.96 - 14.03 - 14.01 -
Small Growth
Touchstone Emerging Growth A Small Growth 0.06 4.95 23.95 11 22.96 5 - -
Cat:Small Growth Small Growth -8.27 -15.32 11.28 - 11.31 - 12.92 -
Intermediate-term Bond
PIMCO Total Return A Intermediate-term Bond 5.85 12.74 7.06 7 - - - -
Cat:Interm-Term Bond Intermediate-tern:Bond 5.68 11.58 5.71 - 6.9 - 7.56 -
Short-term Bond
PIMCO Low Duration A Short-term Bond 5.92 9.73 6.33 37 - - - -
Cat:Short-Term Bond Short-tern:Bond 5.41 10.06 6.13 - 6.28 - 6.51 -
Deutsche Banc Alex. Brown
Deutsche Bank �.
-16- Chartertse/ec#.

Pigeon River Fund
Recommended Mutual Fund Performance
Annual Annual Annual Annual Annual Annual Annual Annual Annual Annual
(Returns Through07131101) Morningstar Return Return Return Return Return Return Return Return Return Return
Category 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991
Large Growth
American Funds Growth Fund A Large Growth 7.49 45.7 31.78 26.86 14.94 29.75 0.02 14.54 7.35 35.85
Cat:Large Growth Large Growth -14.54 41.01 33.29 25.13 19.11 32.39 -2.23 10.8 6.24 43.54
Large Value
American Funds Wash Mound A Large Value 9.06 1.16 19.37 33.29 20.18 41.22 0.49 13.05 9.1 23.5
Cal:Large Value Large Value 6.46 6.7 12.88 26.98 20.62 32.56 -0.55 13.75 9.94 28.22
Mid-Cap Growth
MFS Mid-Cap Growth A Mid-Cap Growth 7.76 78.61 20.28 11.67 19.44 22.25 4.39 - - -
Cat:Mid-Cap Growth Mid-Cap Growth -5.73 63.4 15.33 16.97 17.54 34.98 -0.94 15.17 8.75 52.49
Mid-Cap Value
PIMCO Renaissance A Mid-Cap Value 37.73 9.83 11.51 35.92 25.34 28.59 -4.35 22.1 8.78 -
Cat:Mid-Cap Value Mid-Cap Value 17.78 8.87 3.66 26.85 20.26 29.7 -1.96 18.19 IS.S 31.72
Small Growth
Touchstone Emerging Growth A Small Growth 25.92 45.85 2.65 32.2 10.56 22.53 - - - -
Cat:Small Growth Small Growth -4.28 58.28 3.64 18.97 19.35 33.56 -0.21 16.18 11.47 54.45
Intermediate-term Bond
PIMCO Total Return A Intermediatc-term Bond 11.56 -0.82 9.25 - - - - - - -
Cat:Interm-Term Bond Intermediate-term Bond 9.52 -1.33 7.48 8.87 3.3 17.56 -3.82 10.53 7.35 16.91
Short-term Bond
PIMCO Low Duration A Short-term Bond 7.2 2.48 6.66 - - - - - - -
Cat:Short-Term Bond Short-term Bond 7.98 2.15 6.2 6.57 4.38 11.37 -0.78 6.99 6.33 13.92
Deutsche Banc Alex. Brown
Deutsche Bank 0 ��1
-17- Chutertseleci:

Pigeon River Fund
Recommended Mutual Fund Statistics - ti %"
Std Std Std
(Returns Through07131101) Morningstar Sharpe R2 Beta Alpha Dev Dev Dev
Category Ratio 3 Yr 3 Yr 3 Yr 3 Yr 5 Yr 10 Yr
Large Growth
American Funds Growth Fund A Large Growth 0.52 74 1.06 14.53 27.79 24.36 18.9
Car.Large Growth Large Growth -0.11 72 1.2 1.16 29.3 27.24 21.16
Large Value
American Funds Wash Mutual A Large Value 0.15 51 0.61 3.13 17.31 16.98 14.01
Cat:Large Value Large Value -0.02 67 0.75 1.08 18.35 17.57 14.36
Mid-Cap Growth
MFS Mid-Cap Growth A Mid-Cap Growth 0.42 68 1.58 23.44 47.1 38.3 -
Cat:Mid-Cap Growth Mid-Cap Growth 0.1 49 1.27 10.09 41.21 34.78 27
Mid-Cap Value
PIMCO Renaissance A Mid-Cap Value 0.63 50 0.73 13.86 23.03 21 15.97
Cat:Mid-Cap Value Mid-Cap Value 0.25 53 0.73 6.06 21.11 19.66 16.01
Small Growth
Touchstone Emerging Growth A Small Growth 0.63 41 0.9 21.4 33.79 28.13 -
Cat:Small Growth Small Growth 0.14 41 1.18 12.19 42.04 35.19 27.44
Intermediate-term Bond
PIMCO Total Return A Intermediate-term Bond 0.53 95 1.16 -0.15 4.05 - -
Cat:Interm-Term Bond Intermediate-term Bond 0.16 84 1 -1.15 3.75 3.74 4.34
Short-term Bond
PIMCO Low Duration A Short-term Bond 0.63 75 0.52 0.18 2.02 -
Cat:Short-Term Bond Short-term Bond 0.53 73 0.52 0 2.1 1.92 Z56
Deutsche Banc Alex. Brown
Deutsche Bank 0 �-Tb.
-18- Charter�Selec#

Pigeon River Fund
Tactical Asset Allocation/ y
Monitor Performance
Tactical Asset Allocation
• Driven by an Econometric Model that evaluates market
quarterly to determine whether stocks are over-priced,
under-priced, or fairly-priced.
• Model incorporates the past 5 years of price/earnings (P/E) and
Price/Book (P/B) ratios of the S&P 400, and the past 5 years of long-term
corporate bond yields
• Account reviewed quarterly to determine if adjustments are necessary to
asset class weighting
• Portfolio rebalanced annually
Deutsche Banc Alex.Brown
Deutsche Bank [?] Charterer ei@c>f
-19-

Pigeon River Fund
Tactical Asset Allocation/
Monitor Performance
Monitor Performance through Quarterly Reporting
Quarterly Reports Include:
• Time-Weighted Rates of Return
• Performance Comparisons to the Appropriate Indices
• General Market Commentary
• Portfolio Holdings
• Transaction Summary
• Cost Basis Information for Each Mutual Fund
Deutsche Banc Alex.Brown
Deutsche Bank IZI �.
-20- Charterect.