903R86010
SUMMARY REPORT
DIOXIN ANALYSIS OF PHILADELPHIA
NORTHWEST INCINERATOR
hWTIC
TD
796
.X54
v. 1
U.S. Environmental Protection Agency, Region III
Philadelphia, Pennsylvania
January, 1986
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<&*"**.
1650 Arch St.
Philadelphia, PA j9103
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SUMMARY REPORT
DIOXIN ANALYSIS OF PHILADELPHIA
NORTHWEST INCINERATOR
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Prepared by:
Israel Z k' Milner
Air Toxics Coordinator
Date
Approved by:
.
Lewis K. Felleisen, Chief
Source Emissions & Evaluation
Section
ssre. Sydno*, Chief
Programs iBranch
Date
Date
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TABLE OF CONTENTS
Section Title Page
I. Introduction 1
II. Conclusions and Recommendations 3
III. Background 4
IV. Summary of Analysis and Results 6
IV, 1. Introduction 6
IV,2. Air Quality Analysis/Risk
Assessment 6
IV,3. Soil Analysis 9
IV,4. Ash Pile Analysis 9
IV,5. Operating Procedures 10
V.
References
12
Appendices
A Volume I, Contractor Technical Report
B Ambient Air Dioxin Concentration Predictions
C Risk Assessment of Dioxin Emissions
D Field Trip Report, Soil Screening for Dioxin
E Ash Pile Evaluation Documents
F Task Force Report on Operating Procedures
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Section I - Introduction
The primary objective of the study conducted by the
Environmental Protection Agency (EPA) is to determine the
dioxin-related impact of the Philadelphia Northwest Incinerator
on public health. More specifically, the study was designed
to determine the effect of formation and emissions of a
family of compounds known as polychlorinated dibenzo-p-dioxins
and polychlorinated dibenzofurans . In this report these
substances are referred to collectively by the commonly
used term "dioxins". This report summarizes the findings
presented in greater detail in other documents and reports
which are referenced herein or included as appendices.
A major portion of EPA's efforts was the quantitative
assessment of risks to public health as a result of emissions
into the ambient air of the aforementioned dioxins (See
Table I, page 8). Also considered in the study was the
potential effect of deposition of dioxins on the soil in
the vicinity of the Northwest Incinerator. In addition,
investigations were conducted to determine whether the
concentration of the dioxin isomer 2,3,7,8 Tetrachlorinated
dibenzo-p-dioxin (TCDD) in the residue ash of the incinerator
posed a potential hazard. Of the many variants of dioxins,
the isomer 2,3,7,8 TCDD is considered to be the most toxic.
Concern has also been expressed regarding the operation
of a sister facility, the East Central Incinerator located
adjacent to the Delaware River, across from Camden, New
Jersey. Therefore the EPA study included effects of
emissions from that facility as well. Additionally, it is
to be noted that the analysis of the residue ash at the
Northwest Incinerator actually included the ash from the
East Central Incinerator. The latter had been transported
to the ash pile at the Northwest Incinerator where it was
combined with the ash of that facility prior to eventual
disposal of all the ash in a permanent landfill.
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The procedures used throughout this entire program to
sample, measure, and assess effects of dioxins are very
complex and represent the most current state-of-the-art
technology. Care has been taken to assure the guality of
the data obtained and upon which the findings are based.
Furthermore, this study has been coordinated with those
parties responsible for ongoing broader dioxin studies
conducted by EPAj this to ensure that implementation of
its activities will have been conducted in a manner con-
sistent with the Agency's national policy.
The following Section II presents the overall con-
clusions and recommendations. Section III provides back-
ground information and discusses the events which led to the
decision to carry out the complex and arduous tasks of
this study. Section IV presents a summary of the analysis
and results obtained. Documents related to this study are
listed in the references of Section V; several of these
which are considered key are included herein as appendices.
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Section TI - Conclusions and Recommendations
To establish the health significance of the dioxin
emissions from the Philadelphia Northwest Incinerator, EPA
has estimated the upper limit of excess lifetime cancer risk
attributable to these emissions. Additionally, the Agency
has estimated the upper limit of excess annual cancer incidence
(i.e., number of added cancer cases per year) in the population
of about five million persons exposed to emissions from that
facility within a radius of 50 kilometers (approximately 30
miles). On the basis of these analyses, EPA believes that
these emissions do not present a significant near-term health
concern to people living in the vicinity of the Philadelphia
Northwest Incinerator. This conclusion also applies to the
East Central Incinerator. However, in view of the estimated
(upper-bound) increased lifetime cancer risk of 5 chances in
100,000 in the area of the Northwest Incinerator, and 2 chances
in 100,000 in the area of the East Central Incinerator, EPA
believes that actions to reduce emissions should be taken as
soon as feasible in order to diminish further the low probability
of increased long-term health concerns. Furthermore, because
the measured emissions of dioxins from the Northwest Incin-
erator were determined to be significantly higher than what
EPA has observed at well designed and properly operated
municipal waste combustors elsewhere, and because it has
been out of compliance with Philadelphia's emission standards
for particulate matter, the Agency believes that these emissions
can be reduced further. EPA believes this can be accomplished
by implementation of the corrective measures referred to in
the following paragraph and detailed in the accompanying
Appendix F.
EPA has also concluded from the non-detection of dioxin
in the soil and from leachate test results that the soil and
water media present no health hazards.
A task group formed to evaluate the operation of the
Philadelphia Northwest Incinerator found that a number of
improper or inadequate procedures and equipment deficiencies
existed at the facility. Specific proposals for remedial
action were also provided. A subsequent review by EPA of
those proposals confirms the expectation that implementing
them, as well as implementing some additional changes, will
improve the performance of the Northwest Incinerator and thus
reduce emissions. Accordingly, it is recommended that all
the reported deficiencies and potential remedies be reviewed
by the Northwest Incinerator Task Force with appropriate
City officials as soon as possible. Those corrective actions
that have not yet been taken, and which are feasible, should
be implemented expeditiously at both the Northwest and East
Central Incinerators.
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Section III - Background
The city-owned Philadelphia Northwest Incinerator has
had a history of non-compliance with local regulations.
Specifically, public concern was brought on by problems
attributable to poor housekeeping, odors, visible emissions,
and other nuisances at this facility which processes
approximately 20% of the City's trash. Because of these
problems, court action against the City of Philadelphia was
initiated by a number of community groups. At approximately
the same time that the litigants had generally agreed to
the terms of a Consent Order designed to rectify conditions
at the facility, increased public awareness of incinerator-
related dioxins raised new concerns. These concerns were
heightened by publicity elsewhere concerning "high" levels
of dioxin associated with improper operation of incinerators,
As a consequence, the EPA was requested to determine
the existence of dioxins at the Northwest Incinerator and
whether they posed a threat to public health. In August,
1984, EPA conducted a screening of the flyash collected by
the facility's electrostatic precipitators. Test results
revealed flyash dioxin levels for one of the two incinerator
units that were approximately ten times higher than had
been previously observed in ash screening tests at another
incinerator. The latter facility had been considered to be
marginally acceptable for individuals exposed via the air
medium.
The above development led to the formation in October
1984 of the Northwest Incinerator Task Force consisting of
officials representing the City of Philadelphia, the
Commonwealth of Pennsylvania, and EPA Region III. The
task force agreed to conduct investigations enumerated as
follows and which are discussed in more detail in Section
IV of this report:
* The formation of dioxins is generally understood to occur
as a result of burning organic material with chlorine-
containing materials, both prevalent in municipal waste.
Further, this situation is aggravated by improper combustion
conditions such as incineration at temperatures too low or
incineration with insufficient residence times of the refuse
in the furnace.
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1) Following shut down and needed repairs of one
of two units which demonstrated higher than expected dioxin
levels in the ash, comprehensive tests of stack emissions and
ash analyses would be conducted at the Northwest Incinerator.
The level of dioxin emissions to the atmosphere would help
determine any threat to public health. It was subsequently
decided to analyze the East Central Incinerator's ash as well;
however, stack testing at that facility would not be performed
in view of the limited resources available.
2) Tests for dioxin content in the soil would be
conducted in the vicinity of the incinerator. Results
would establish possible threats to health through contact
with the soil.
3) Tests would be conducted to determine the
dioxin content in the ash pile which contained co-mingled
incinerator bottom ash and flyash from both the Northwest
and East Central Incinerators. The level of dioxin would
establish any need to require special disposal.
4) An evaluation of the City's incineration
facilities was to be undertaken in order to examine
operating practices related to emissions of air pollutants
including dioxin.
These investigations were implemented during the
succeeding several months culminating in March, 1985 with
the comprehensive tests of both units of the Northwest
Incinerator following refurbishing of the defective unit.
As previously noted, limited tests were also performed at
that time at the East Central Incinerator. A summary
discussion of the analyses performed and the results obtained
is presented in the following Section.
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Section IV - Summary of Analysis and Results
1. Introduction
The following paragraphs provide a brief summary of
each of the analyses conducted to assess the implications
on public health of dioxins that are attributable to the
operation of the Northwest Incinerator as well as to assess
the operation itself. As alluded to previously, a quantitated
assessment of the risks to the public because of emissions
of dioxin into the ambient air was the major part of this
study. Also discussed are those tests to measure dioxin
levels in the soil near the incinerator and in the residual
ash; qualitative judgments concerning effects of those
levels are presented. Each of the succeeding paragraphs
identifies and refers to those documents where the various
aspects of the study are reported in detail.
2. Air Quality Analysis/Risk Assessment
This portion of the study was designed to determine
the maximum lifetime excess risk of developing cancer to
the most exposed individual due to concentration of dioxin
in the ambient air. The analysis also was designed to
determine the upper limit excess annual cancer incidence in
the population exposed to incinerator emissions.
The key documents relating to this effort range from:
(a) the initial contractor work assignment to perform
incinerator field tests to: (b) contractor-reported results
and subsequent air quality and risk analyses performed by
EPA. These appear in the list of references as items 1
through 12. Table I presents a summary of the calculated
results of these analyses which are fully detailed in the
following appendices:
Appendix A - Volume I, Technical Report
(Reference 9)
Appendix B - Ambient air dioxin concentration
predictions (Reference 11)
Appendix C - Risk assessment of dioxin emissions
(Reference 12)
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It is pertinent to point out that while the emphasis
of this entire study has been on the Northwest Incinerator,
interest in possible impacts of the East Central Incinerator
due to its similarity to the Northwest Incinerator suggested
that estimates also be made of its dioxin emissions.
However these are open to question since stack emission
tests for dioxin were performed only on the Northwest
Incinerator units; emissions from the East Central Incinerator
were estimated by scaling them to the Northwest Incinerator
emissions in proportion to their respective refuse charging
rates, as reported by the City of Philadelphia. A summary
of the resulting estimated excess cancer risk and incidence
that relate to the East Central Incinerator is also presented
in Table I. The table lists East Central Incinerator
impacts estimated for its operation alone as well as presenting
the estimated impact due to the combined operation of the
two incinerators inasmuch as their receptor areas overlap.
Obviously such a calculation must be understood not to
include dioxin emissions from any other conceivable sources
of dioxin in the area.
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TABLE I - Excess Cancer Risk/Incidence Attributable
to Air Emissions of Dioxins*
Northwest Incinerator (alone)
Maximum individual
lifetime risk to
develop cancer
5 x 10~5
or
5 chances in
100,000
Upper limit of
annual excess
cancer incidence
.07
or
1 cancer every
14 years
East Central Incinerator (alone)
Combined Operation of
Northwest and East Central
Inc inerators
2 x 10~5
or
2 chances in
100,000
5 x 10~5
or
5 chances in
100,000
.06
or
1 cancer every
17 years
.12
or
1 cancer every
8 years
* See References 11 and 12 for
caveats and assumptions
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3. Soil Analysis
The existence of the dioxin isomer 2,3,7,8 TCDD in the
incinerator flyash, as determined in the screening test of August,
1984 also raised concern about the levels of dioxin that might be
present in the soil in the vicinity of the Northwest Incinerator
site. Therefore, in October 1984, a total number of 38 samples
were collected in accordance with established procedures from
various locations within a 2-kilometer radius of the site. A
field report of this effort, containing area maps and the proced-
ures employed, is included herein as Appendix D (also listed
as Reference 13).
The samples were sent to contract laboratories for analysis.
They reported to EPA that no 2,3,7,8 TCDD was detected in any of
the samples (References 14, 15, and 16). On the basis of those
findings, it was concluded that deposition of dioxins on ground
level surfaces with which persons are likely to come into contact
does not represent any measurable health hazard.
4. Ash Pile Analysis
The bottom ash from the incinerators and the flyash
collected by the electrostatic precipitators is co-mingled
and temporarily stored in a pile on the grounds of the
Northwest Incinerator. (The weight fraction of flyash is
approximately 3.6% as reported by the City of Philadelphia).
The mixing procedure is also followed at the East Central
Incinerator whose ash is trucked to Northwest Incinerator
ash pile. Periodically, the City of Philadelphia has the
stored ash hauled off to a landfill for burial.
When it was determined that the electrostatic precipitator
flyash contained levels of dioxin higher than had been
previously observed in flyash elsewhere, there arose questions
concerning safe disposal of all the ash. Coincident with the
collection of soil samples, representative samples were also
collected from various locations in the ash pile. Again this
effort was in accordance with procedures described in Appendix
D. The samples were sent to EPA laboratories for analysis in
order to determine whether the contents of the pile constituted
a health risk and would reguire special disposal technigues.
As reported in Appendix E (also listed as Reference 17) the
levels of 2,3,7,8 TCDD ranged from 26 to 89 parts per
trillion.
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EPA forwarded these results to the Center for Environmental
Health at the Centers for Disease Control (CDC) for an evaluation
The conclusion reached by CDC was that the measured values
did not constitute a significant public health threat provided
the ash was disposed of in a properly designed and maintained
sanitary landfill. An exchange of correspondence (References
18 and 19) which documents the disposal issue is included in
Appendix E.
There had also been questions raised concerning the
possibility of constituents of the ash pile migrating into
surface water. Based on field investigations, which although
conducted under generally dry weather conditions, it is EPA's
view that migration is not a problem (Reference 20). Further,
as is evidenced by the difficulty of extracting dioxins from
carbonaceous ash as part of the above-mentioned laboratory
analytical procedures, the likelihood of dioxin in the leachate
from the ash pile is extremely small. Tests performed for
the City of Philadelphia to determine EP (Extractable Procedure)
Toxicity in leachate from samples of the ash pile concluded
that the residue is not EP toxic (Reference 21 and Appendix
E). Although these tests did not test for dioxins per se,
the results reinforce EPA's view that the presence of dioxin in
the leachate is remote.
5. Operating Procedures
As stated in Section III of this report, the task force
formed to investigate issues concerning the Northwest Incinerator
agreed to an evaluation of the operating practices at that
facility. The evaluation not only consisted of on-site
observations but also of reviews of city and plant records
and currently available literature on municipal incinerators.
As a result of a number of findings, recommendations to
improve operation at the Northwest Incinerator have been
made. These are included in the November, 1985 Task Force
Report on Operating Procedures (Reference 22) which is
incorporated herein as Appendix F. The task force report
will be the basis for discussion and necessary follow-up
action to correct equipment deficiencies and improve operating
and maintenance practices.
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Since the design of the East Central Incinerator is
similar to the Northwest Incinerator, the task force believed
that its findings and recommendations concerning the latter
facility would, in general, also be applicable to the East
Central Incinerator. As a consequence, there was no special
investigation conducted at that facility. It is therefore
expected that any actions to be implemented by the City of
Philadelphia would be applicable to both the Northwest and
East Central Incinerators.
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Section V - References
1. Work Assignment, EPA Contract 68-02-3891 dated 13 November
1984; Dioxin Analysis of Philadelphia Northwest and East
Central Incinerators.
Attachment A - List of dioxin and furan homologs
Attachment B - Sampling for the Determination of
Chlorinated Organic Compounds in Stack
Emiss ions
Attachment C - Methods Manual, Sampling and Analysis
Procedures for Assessing Organic Emiss-
ions from Stationary Combustion Sources
Exposure Evaluation Division Studies,
EPA-560/5-82-014 , January, 1982
Attachment D - Analytical Procedures to Assay Stack
Effluent Samples and Residual Combustion
Products for Polychlorinated Dibenzo-p-
Dioxins (PCDD) and Polychlorinated Di-
benzofurans (PCDF), Prepared by Group C -
Environmental Standards Workshop, Sponsored
by the American Society of Mechanical
Engineers, U.S. Department of Energy, and
U.S Environmental Protection Agency, dated
September 18, 1984 (draft).
2. Work Assignment, EPA Contract 68-02-3891, Change No. 1,
dated 21 February, 1985; Dioxin Analysis of Philadelphia
Northwest and East Central Incinerators.
3. Work Assignment, EPA Contract 68-02-3891, Change No. 2,
dated 21 August, 1985; Dioxin Re-Analysis of one (1)
Philadelphia Northwest Incinerator-sample and review of
existing chromatograms from previously conducted sampling.
4. Dioxin Analysis of Philadelphia Northwest and East Central
Incinerators, Work Plan, EPA Contract 68-02-3891, Midwest
(MRI) Project No. 8281-L(1), December 7,
5 .
Research
1984.
Ins titute
Dioxin Analysis of Philadelphia Northwest and East Central
Incinerators: Ouality Assurance Program Plan (QAPP), EPA
Contract No. 68-02-3891, MRI Project No. 8281-L(1), February
8, 1985.
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Dioxin Analysis of Philadelphia Northwest and East Central
Incinerators: Field Data, EPA Contract No. 68-02-3891, MRI
Project No. 8281-L(1), July 8, 1985.
Dioxin Analysis of Philadelphia Northwest and East Central
Incinerators: Laboratory Results for Particulate and
Chlorides, EPA Contract NO. 68-02-3891, MRI Project No.
8281-L(1), July 8, 1985.
Dioxin Analysis of Philadelphia Northwest and East Central
Incinerators: GC/MS Raw Data, EPA Contract No. 68-02-3891,
MRI Project No. 8281-L(1), July 8, 1985.
Part 1 - Analytical Standards
Part 2 - MM5 Samples
Part 3 - Flyash Samples
Part 4 - Bottom Ash Samples
Emissions Test Report: City of Philadelphia Northwest and
East Central Municipal Incinerators, EPA Contract No. 68-02-
3891, MRI Project No. 8281-L(1), October 31, 1985
Volume 1 - Technical Report
Volume II - Appendices A - D, Particulate Calculations,
Particulate and Chlorides
Laboratory Report -
PCDDs/PCDFs, and Quality
Assurance Unit Report
Volume III - Appendices E - F, Field Data and Modified
Method 5 Calibration
Data
Continuous Emission
Monitoring Data
Chromatograms for
Modified Method 5 Samples
Chromatograms for ESD
Flyash Samples
Chromatograms for Bottom
Ash Samples
Chromatograms for Sample
Reanalys is
Second Laboratory Report
(Triangle Laboratories,
Inc . )
Chromatograms for Analytical
Volume IV
Volume V
Volume VI
Volume VII -
Volume VIII-
Volume IX -
Appendix G,
Appendix H,
Appendix I,
Appendix J,
Appendix K,
Appendix L,
Volume X - Appendix M,
Standards
10. Sample Analysis: City of Philadelphia Northwest and East
Central Municipal Incinerators, Appendix 1 - Chromatograms
EPA Contract No. 68-02-3891, MRI Project No. 8481-L(1),
December 6 , 1985.
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11. Memorandum from Alan J. Cimorelli to W. Ray Cunningham dated
January 10, 1986, Ambient Air Dioxin Concentration
Predictions for the Philadelphia Northwest Incinerator.
12. Memorandum from David H. Cleverly to Donald Barnes,
Chairperson, Chlorinated Dioxin Work Group and W. Ray
Cunningham, Director, Air Management Division, Region III,
dated January 10, 1986, Risk Assessment of Emissions
of CDD's/CDF's from the Philadelphia Northwest Municipal
Inc inerator.
13. Report R-585-11-4-11, A Field Trip Report for Northwest
Incinerator Dioxin Screening, prepared under EPA Contract
No. 68-01-6699 dated February 11, 1985.
14. Memorandum from John Austin to Walter Lee dated November 9,
1984 documenting soil sampling results by California
Analytical Laboratories.
15. Memorandum from Central Regional Laboratory staff dated
November 29, 1984 documenting soil sampling results
by ETC Corporation.
16. Memorandum from Diana J. Pickens to Walter Lee dated
February 12, 1985 documenting soil sampling results by ETC
Corporation.
17. Memorandum from Robert Kramer to Bruce Smith and Ray
Cunningham dated December 27, 1984; EPA Laboratory Analysis
Dioxin Concentration - Ash Storage Philadelphia NW Incinerator,
18. Letter from Stanley L. Laskowski (Region III) to Georgi
Jones (CDC) dated December 17, 1984 requesting health
assessment of ash samples.
19. Memorandum from Vernon D. Houk, MD (Centers for Disease
Control) to Charles J. Walters (EPA Region III) dated
December 26, 1984; Review of Northwest Incinerator Dioxin
Screening Results of Ash Pile Philadelphia, Pennsylvania.
20. Memorandum from Leo J. Clark to Harry Harbold dated
September 17, 1984; Trip Report, Northwest Incinerator.
21. Lancaster Laboratories Analysis Report to the City of
Philadelphia dated December 14, 1984.
22. Northwest Incinerator Operating Procedures, Task Force
Report dated November, 1985.
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