J Protection
Region 5
Eastern District Office
25089 Center Ridge Road
Westlake, Ohio 44145
EPA-905/4-88-003
June 1986
£EPA Michigan Dioxin Studies
Dow Chemical
Wastewater Characterization
Study
Tittabawassee River Sediments
and Native Fish
-------
DOW CHEMICAL WASTEWATER CHARACTERIZATION STUDY
TITTABAWASSEE RIVER SEDIMENTS AND NATIVE FISH
JULY 1986
GARY A. AMENDOLA
DAVID R. BARNA
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION V
ENVIRONMENTAL SERVICES DIVISION
EASTERN DISTRICT OFFICE
WESTLAKE, OHIO
U.S. Environmental Protection Agtflcy
Region 5, Library (PL-12J)
77 West Jackson Boulevard, 12th
Chicago, It 60604-3590
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ACKNOWLEDGMENTS
This report presents results of environmental studies at the Dow Chemical -
Midland Plant and in the Tittabawassee River spanning the period 1978 to 1985.
The combined efforts of many dedicated people from the Michigan Department of
Natural Resources (MDNR), the United States Environmental Protection Agency, and
contract laboratories were required to complete this work.
The 1978 Dow Chemical, river sediment, and activated carbon studies were
planned by Mr. Karl Bremer and Mr. Gary Amendola of Region V in consultation with
Mr. Richard Powers and Mr. Thomas Rohrer of the MDNR Toxic Chemical Evaluation
Section. The field sampling was conducted by Mr. Willie Harris and Mr. Philip
Gehring with members of the Region V Eastern District Office field crew.
Mr. Linn Duling of the MDNR directed the collection of Tittabawassee River fish
in 1978. Environmental samples were processed and analyzed by USEPA's Pesticide
Monitoring Laboratory, Bay St. Louis, Mississippi, under the direction of
Dr. Aubry DuPuy and by Mr. Robert Harless at USEPA's Environmental Monitoring
and Support Laboratory at Research Triangle Park, North Carolina, or, by the
University of Nebraska.
The 1981 Dow Chemical wastewater characterization and bioaccumulation
studies were planned by Mr. Richard Powers and Mr. Linn Duling of the MDNR;
Mr. Jonathan Barney, Mr. Howard Zar of the Region V Water Division; and
Mr. Charles Stiener and Mr. Gary Amendola of the Region V Environmental Services
Division. The wastewater sampling was directed by Mr. Willie Harris and
Mr. Philip Gehring of the Region V Eastern District Office. Mr. Linn Duling,
Mr. Charles Stiener and members of the MDNR Toxic Chemical Evaluation Section
conducted the bioaccumulation study. Analytical work associated with the 1981
studies was coordinated by Mrs. Marcia Kuehl of the Region V Central Regional
Laboratory under direction of Mr. Curtis Ross, laboratory director. Analytical
contractors included GCA Corporation and Battelle Memorial Institute, Columbus,
Ohio. Special note is made of the contribution of Mr. Robert Harless who
conducted supplemental quality assurance analyses of water and fish for PCDDs
and PCDFs and who provided invaluable assistance in evaluating and interpreting
data.
Native fish from the Tittabawassee River were collected in 1983 by the MDNR
Toxic Chemical Evaluation Section under the direction of Mr. Linn Duling. The
fish were analyzed for dioxin by USEPA's Environmental Research Laboratory in
Duluth, Minnesota under the direction of Dr. Douglas Kuehl.
The 1984 Dow Chemical in-plant and effluent and Tittabawassee River studies
were planned by Mr. David Barna and Mr. Gary Amendola of the Region V Eastern
District Office and Mr. Jonathan Barney of the Region V Water Division in
consultation with Mr. Richard Powers, Mr. James Grant, and Mr. Thomas Rohrer of
the MDNR Toxic Chemical Evaluation Section and Region V's Dioxin Task Force
under the direction of Mr. David Stringham. Mr. Philip Gehring directed the
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Eastern District Office field crew and Region V Water Division personnel in the
conduct of the field sampling. Mrs. Marcia Kuehl and Mr. Frank Thomas under
the direction of Mr. Curtis Ross of the Region V Central Regional Laboratory
coordinated the analytical work and provided quality assurance reviews of the
data developed by the following contract laboratories: the Brehm Laboratory
of Wright State University; Midwest Research Institute; Battelle Memorial
Institute; Compuchem; West Coast Technical/IT Corporation; Versar; California
Analytical Labs, Inc.; U.S. Testing Company; Rocky Mountain Analytical; and
Science Applications, Inc. Mr. Brian Buckham of the Eastern District Office
compiled and reduced much of the data presented in this report. The summary of
supplemental studies of the Tittabawassee and Saginaw Rivers and Saginaw Bay
was prepared by Larry Fink of USEPA's Great Lakes National Program Office.
The authors also wish to acknowledge the cooperation of the Dow Chemical
Company for the completion of the 1984 Midland Plant wastewater sampling
program.
This report was typed by Ms. Carol Kopcak and Mrs. Ellen Harrison of the
Eastern District Office. The figures and graphs were prepared by Belinda
Robinson of the Region V Graphic Arts Department.
NOTICE
This document has been reviewed in accordance with U.S. Environmental
Protection Agency policy and approved for publication. Mention of trade names
or commercial products does not constitute endorsement or recommendation for
use.
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TABLE OF CONTENTS
Page
Table of Contents iv
List of Tables vii
List of Figures x
I. INTRODUCTION 1
II. OBJECTIVES 2
III. SCOPE OF WORK 2
IV. MAJOR FINDINGS AND CONCLUSIONS 3
V. DOW CHEMICAL - MIDLAND PLANT 9
VI. FIELD STUDY RESULTS 22
A. Dow Chemical Untreated Wastewaters 22
and In-Plant Sludges
1. Untreated Wastewaters 22
2. In-plant Sludges 28
3. Tertiary Pond Sediments 38
B. Wastewater Effluent Sampling - Outfall 031 ... 44
(1978-1985)
1. Conventional, Nonconventional, and Toxic Pollutants 45
2. PCDDs and PCDFs 48
3. Biomonitoring 61
a. 1981 USEPA Survey 61
b. Dow Chemical NPDES Monitoring 66
C. River Sediment Surveys 67
1. 1978 USEPA Sediment Survey 67
2. 1981 USEPA Sediment Survey 71
3. 1984 USEPA Sediment Survey 71
D. Bioaccumulation Studies 80
1. 1981 USEPA-MDNR Study 80
2. Dow Chemical Biouptake Study - October 1985 96
E. Tittabawassee River Native Fish Collection 1978-1985 98
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TABLE OF CONTENTS (continued)
Page
VII. NPOES PERMIT - BEST AVAILABLE TECHNOLOGY 107
A. Clean Water Act Requirements 107
B. NPDES Permit MI0000868 108
C. Applicable Effluent Limitations Guidelines. ... 108
D. Comparison of Dow Chemical Wastewater 109
Treatment Technologies with EPA Model
Wastewater Treatment Technologies
E. Best Available Technology Considerations .... 113
REFERENCES 115
APPENDICES
A. Dow Chemical Untreated Wastewaters and In-Plant Sludges
A-l Major Process Sewers
A-2 Nonprocess Wastewater Sources
A-3 In-Plant Sludges
A-4 Tertiary Pond Sediments
B. Dow Chemical Wastewater Effluent Sampling
B-l Conventional, Nonconventional, and Toxic Pollutants
1981 USEPA Study
B-2 Conventional, Nonconventional, and Toxic Pollutants
1984 USEPA Study
B-3 Conventional, Nonconventlonal, and Toxic Pollutants
Dow Chemical Data
B-4 PCDDs and PCDFs
1978 USEPA Study
B-5 PCDDs and PCDFs
1981 USEPA Study
8-6 PCDDs and PCDFs
1984 USEPA Study
B-7 PCDDs and PCDF
Dow Chemical Data
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TABLE OF CONTENTS (continued)
APPENDICES (continued)
C. Tittabawassee River Sediments
C-l 1978 USEPA Sediment Survey
C-2 1981 USEPA Sediment Survey
C-3 1984 USEPA Sediment Survey
D. Bioaccumulation Studies
D-l PCDDs and PCDFs
1981 USEPA-MDNR Study
D-2 Other Organic Pollutants
1981 USEPA-MDNR Study
D-3 Dow Chemical Biouptake Study
October 1985
E. Supplemental Environmental Studies
Tittabawassee River
Saginaw River
Saginaw Bay
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LIST OF TABLES
Page
Table 1 A Compilation of the Commercially Significant .... 11.
Chlorophenolic Compounds Manufactured on the
Midland Plant Site of the Dow Chemical Company
Table 2 Dow Chemical, Disposal Well Data 14
Table 3 Volatile Pollutant Summary, Untreated Wastewaters ... 24
Dow Chemical - Midland Plant
August 29, 1984; October 23, 1984
Table 4 Semi-Volatile Pollutant Summary, Untreated Wastewaters. . 26
Dow Chemical - Midland Plant
August 28-29, 1984; October 23, 1984
Table 5 PCDD and PCDF Summary, Untreated Wastewaters 27
Dow Chemical - Midland Plant
August 28-29, 1984; October 23, 1984; December 4, 1984
Table 6 Metal Pollutant Summary, Untreated Wastewaters .... 29
Dow Chemical - Midland Plant
August 28-29, 1984; October 23, 1984
Table 7 Conventional and Nonconventional Pollutant Summary ... 30
Untreated Wastewaters
Dow Chemical - Midland Plant
August 28-29, 1984; October 23, 1984
Table 8 Volatile Organic Pollutant Summary, In-Plant Sludges . . 31
Dow Chemical - Midland Plant
October 1984
Table 9 Acid and Base Neutral Pollutant Summary, In-Plant Sludges 32
Dow Chemical - Midland Plant
October 1984
Table 10 Metal Summary, In-Plant Sludges 33
Dow Chemical - Midland Plant
October 1984
Table 11 PCDDs and PCDFs, In-Plant Sludges 34
Dow Chemical - Midland Plant
October 1984
Table 12 Pollutant Summary, Riverbank Revetment Section #1 Sediment 36
Dow Chemical - Midland Plant
October 1984
Table 13 TCDDs In Dow Chemical - Midland Plant Samples .... 39
October 1978
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LIST OF TABLES (continued)
Page
Table 14 Toxic Organic Pollutant Summary 42
Dow Chemical Treatment Pond Sediments
July 1984
Table 15 PCDD and PCDF Summary 43
Dow Chemical Treatment Pond Sediments
July 1984
Table 16 Conventional and Non-Conventional Pollutants Summary . . 46
Dow Chemical - Midland Plant, Outfall 031
Table 17 Volatile Organic Summary, Dow Chemical - 47
Midland Plant, Outfall 031
Table 18 Acid and Base Neutral Pollutant Summary 49
Dow Chemical - Midland Plant
Outfall 031
Table 19 Herbicides/PCB/Pesticides Summary, Dow Chemical - ... 50
Midland Plant, Outfall 031
Table 20 Metals Summary, Dow Chemical - Midland Plant 51
Outfall 031
Table 21 1978 USEPA Dioxin Study, Tittabawassee River 54
Dow Chemical - Midland Plant
Large Volume Activated Carbon Samples
Table 22 Large Volume Water Sampling for PCDDs and PCDFs .... 56
Dow Chemical - Midland Plant
September 9-10, 1981
Table 23 PCDDs And PCDFs, Water Intakes, Outfall 031 57
Pilot Plant Filter
Dow Chemical - Midland Plant
Table 24 Dow Chemical Effluent Monitoring 59
Tetrachloro Dibenzo-p-Dioxins
Table 25 Pilot Plant Filtration Studies, Dow Chemical - Midland Plant 60
March 1984, PCDDs and 2378-TCDD
Table 26 2378-TCDD Discharge Loadings 62
Outfall 031, Dow Chemical - Midland Plant
Table 27 Dow Chemical - Midland Plant, Static Daphnia Bioassays. . 64
September 15-16, 1981
vn i
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LIST OF TABLES (continued)
Page
Table 28 Dow Chemical - Midland Plant, Static Algal Assay. ... 65
September 15-16, 1981
Table 29 1978 USEPA Sediment Survey, Tittabawassee and 70
Saginaw Rivers, October 1978
Table 30 1981 USEPA Sediment Survey, Tittabawassee River .... 72
March 1981
Table 31 1984 USEPA Sediment Survey, Tittabawassee River .... 74
Sediments and Flood Plain, Toxic Organic Pollutants
July 1984
Table 32 1984 USEPA Sediment Survey, Tittabawassee River .... 76
Sediments and Flood Plain Samples, PCDOs and PCDFs
July 1984
Table 33 Distribution of TCDDs, Dow Chemical Treatment 79
Pond and Wastewaters, Tittabawassee River Sediments
and Flood Plain Samples
Table 34 1981 USEPA-MDNR Bioaccumulation Study 83
Dow Chemical - Midland Plant, Contract Laboratory Results
Battelle Memorial Institute
Table 35 1981 USEPA-MDNR Bioaccumulation Study 86
Dow Chemical - Midland Plant
Between-Lab Comparison for 2378-TCDD
Table 36 1981 USEPA-MDNR Bioaccumulation Study 87
Dow Chemical - Midland Plant, USEPA Split Sample Analyses
Table 37 Dow Chemical Biouptake Study, October 1985 97
Table 38 Tittabawassee River Native Fish Collections, 2378-TCDD . . 99
1978-1985
Table 39 Tittabawassee River Native Fish Collections 102
Trends in 2378-TCDD Concentrations
Table 40 PCDDs and PCDFs, Native Fish Collection 104
Tittabawassee River 1985
Table 41 Toxic Organic Pollutants, Native Fish Collection ... 105
Tittabawassee River 1985
Table 42 National Effluent Limitations Guidelines 110
Model BAT Wastewater Treatment Technologies
Table 43 Dow Chemical Wastewater Flow Summary 112
ix
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LIST OF FIGURES
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Page
Location Map - Tittabawassee River Basin 10
Dow Chemical - Midland Plant
Location Map - Dow Chemical - Midland 13
Plant - Brine System
Location Map - Dow Chemical Riverbank 16
Revetment System
Schematic Diagram - Dow Chemical Wastewater .... 19
Treatment Facilities
Location Map - Dow Chemical Landfills 21
Location Map - USEPA Sampling Locations - .... 23
Dow Chemical Process Sewers, August 1984
Location Map - USEPA Sampling Locations - .... 35
Process Sewer Sludge - October 1984
Location Map - USEPA Sampling Locations - .... 41
Dow Chemical Tertiary Pond Sediments -
July 1984
Location Map - 1978 USEPA Dioxin Study - 53
Tittabawassee River, Dow Chemical -
Midland Plant
Dow Chemical - Midland Plant, 2378-TCDD 63
Discharges - July 1984-March 1986
Location Map - USEPA River Sediment 68
Sampling Surveys 1978-1984
Location Map - USEPA River Sediment 69
Sampling Surveys 1978-1984 (Dow Chemical -
Midland Plant Area)
PCDDs in Tittabawassee River Sediment and 77
Flood Plain Samples - July 1984 USEPA Survey
PCDFs in Tittabawassee River Sediment and 78
Flood Plain Samples - July 1984 USEPA Survey
USEPA-MDNR 1981 Bioaccumulation Study 81
Caged Fish Sites
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LIST OF FIGURES (continued)
Page
Figure 16 USEPA-MDNR 1981 Bioaccumulation Study 89
TCDD Results
Figure 17 USEPA-MDNR 1981 Bioaccumulation Study 90
2378-TCDD Uptake - Outfall 031 Plume
Figure 18 USEPA-MDNR 1981 Bioaccumulation Study 92
Base Neutral Compounds
Figure 19 USEPA-MDNR 1981 Bioaccumulation Study 93
Acid Compounds
Figure 20 USEPA-MDNR 1981 Bioaccumulation Study 94
Pesticides and PCBs
Figure 21 Tittabawassee River Native Fish 101
1983 and 1985 Collections - 2378-TCDD
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I. INTRODUCTION
In June 1978 the Michigan Division of Dow Chemical Company in Midland,
Michigan, (Dow Chemical) informed the Michigan Department of Natural Resources
(MDNR) and the Michigan Department of Public Health (MDPH) that rainbow trout
exposed to a mixture of Dow Chemical's treated effluent prior to discharge from
outfall 031 to the Tittabawassee River at Midland accumulated up to 50 parts
per trillion (ppt) 2,3,7,8-tetrachlorodibenzo-p-dioxin (2378-TCDD) in edible
portions, and up to 70 ppt in whole fish. Supplemental analyses of edible
portions (skin-off filet) of Tittabawassee River native catfish previously
collected in 1976 downstream of Dow Chemical's discharge ranged from 70 to
230 ppt of 2378-TCDD. Fish collected upstream of the Dow Dam did not contain
detectable levels. The company also reported that 2378-TCDD concentrations in
Tittabawassee River native fish collected in 1977 ranged from not detected (ND)
to 240 ppt for various species. Most species tested yielded positive findings
from 20 to 170 ppt.
The results of these and related Dow Chemical studies prompted the MDPH to
issue a fish consumption advisory in June 1978 for any fish collected from the
Tittabawassee River downstream of the Dow Dam. (The advisory remained in
effect until March 1986, when it was modified to include only catfish and
carp.) In September 1978 the United States Environmental Protection Agency
(USEPA) made a preliminary determination that concentrations of 2378-TCDD in
Tittabawassee River fish represented a substantial risk to the public health
pursuant to Section 8(e) of the Toxic Substances Control Act of 1976.
In November 1978 Dow Chemical released a report on "The Trace Chemistries
of Fire ..." which discusses sources of dioxins in the environment. Dow Chemical
concluded that dioxins, including 2378-TCDD, are ubiquitous as a result of a
wide variety of combustion processes, that dioxins detected in Michigan Division
air, dust, soils and wastewater come from power house, rotary kiln and tar
burner combustion, but that Michigan Division chemical manufacturing processes
could not be ruled out as a source of dioxins detected in one sample of
wastewater collected from a Dow Chemical process sewer.
Follow-up studies conducted by USEPA and the U.S. Food and Drug Adminis-
tration (USFDA) in 1979 and 1980 determined that 2378-TCDD persisted at levels
of concern in Tittabawassee River, Saginaw River and Saginaw Bay native fish,
despite closing of Dow Chemical production facilities for manufacture of 2,4,5-
trichlorophenol and the derivative 2,4,5-T herbicide.
Dow Chemical's first wastewater discharge permit under the Clean Water
Act's National Pollutant Discharge Elimination System (NPDES) expired in
September 1979. As part of the development of a second round NPDES permit,
the MDNR and USEPA Region V cooperated in development of a wastewater charac-
terization study for the Dow Chemical - Midland Plant during the spring and
summer of 1981. The MDNR and USEPA-Region V conducted the study because of the
nature of the process operations at Dow Chemical , concern over actual and
-------
potential discharges of toxic substances from the Midland plant, and, at that
time, the unavailability of production process information. Preliminary results
from that study were released in March 1983. _!/ The study results documented
the discharge of 2378-TCDO from Dow Chemical and quantified the release of
other toxic, nonconventional , and conventional pollutants to the Tittabawassee
River. Recommendations for further study of dioxins presented in the 1983
report were subsequently incorporated into USEPA's Dioxin Strategy and National
Oioxin Study. 21
In the summer of 1983, USEPA-Region V initiated a series of comprehensive
studies of dioxins and other toxic pollutants at the Dow Chemical - Midland
Plant and in and around the city of Midland. Those studies were conducted in
response to a request from the Michigan Department of Natural Resources to
follow-up the 1983 report and were consistent in objectives with the then-
evolving USEPA Dioxin Strategy. In 1984, the MDNR issued to Dow Chemical an
interim NPDES permit which includes water quality-based effluent limitations
for several toxic pollutants and an associated administrative order which sets
out interim effluent limitations for the discharge of 2378-TCDD. Also, in
1984, the USEPA and Dow Chemical settled litigation regarding USEPA's access
to in-plant information necessary for the development of Best Available
Technology (BAT) NPOES permit conditions for the Midland plant. _3_/ As a result
of these regulatory actions, wastewater discharge issues at Dow Chemical have
become better defined and substantial progress has been made toward reducing
the discharge of toxic pollutants.
This report presents final results associated with the 1983 report; compares
those results with recent monitoring from Region V's comprehensive studies of
dioxins and other toxic pollutants and recent monitoring by Dow Chemical;
reviews recent data for PCDDs and PCDFs in Tittabawassee River sediments and
fish; compares the wastewater treatment systems installed at the Dow Chemical -
Midland Plant to model wastewater treatment technologies considered by USEPA
during development of national effluent limitations guidelines (Best Available
Technology effluent limitations); and presents a preliminary assessment of
additional wastewater treatment technologies and Best Management Practices that
may be necessary to attain Best Available Technology effluent limitations for
the Midland plant. Also, presented in Appendix E is a summary of supplemental
studies of the Tittabawassee and Saginaw Rivers and Saginaw Bay conducted by
state and federal agencies.
The term "dioxin" is often used to describe 2,3,7,8-tetrachlorodibenzo-p-
dioxin (2378-TCDD). The isomer 2378-TCDD is the most toxic of the dioxin
isomers. In this report, the term "PCDDs" means all polychlorinated dibenzo-p-
dioxin isomers and "PCDFs" means all polychlorinated dibenzofuran isomers.
la
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II. OBJECTIVES
The primary objectives of this work are to quantify the conventional,
nonconventional, toxic organic and toxic inorganic pollutant discharges from the
Dow Chemical - Midland Plant and to assess the need for additional wastewater
treatment and best management practices necessary to achieve Best Available
Treatment Economically Achievable (BAT) as defined by the Clean Water Act.
The information and data contained in this report are being used by the Michigan
Department of Natural Resources and USEPA-Region V to develop a proposed BAT
NPDES permit for Dow Chemical.
Secondary objectives include: (1) characterization of untreated wastewaters
and in-plant sludges and sediments; (2) determination of the types and the
extent of bioaccumulation of pollutants discharged by Dow Chemical in fish;
(3) sub-part per trillion analyses of effluent samples for PCDDs and PCDFs;
and (4) development of information about contamination of native fish and
sediments in the Tittabawassee River.
III. SCOPE OF WORK
Major field surveys were conducted by Region V and MDNR in 1981 and by
Region V in 1984. A multi-phased field program was planned in the spring and
summer of 1981 and executed in late summer and early fall of 1981. Field
programs included the following: (1) a sediment survey of the Tittabawassee
River to determine whether significant toxic pollutant contamination of the
sediments has occurred; (2) four 24-hour composite samples of Dow Chemical
water intakes and effluent discharges to determine pollutant discharges at the
low parts per billion range; (3) one large-volume 24-hour composite sample of
Dow Chemical water intakes, certain effluent discharges, and the receiving
water to determine discharge rates of PCDDs and PCDFs in the sub-part per
trillion range; (4) a static daphnia bioassay and an algal assay to determine
whether or not the Dow Chemical main process wastewater effluent exhibits acute
toxic effects or stimulatory effects on algal growth; (5) an Ames test of the
main process wastewater discharge to determine whether the effluent exhibits
mutagenic properties; (6) a fish bioaccumulation study to determine the level
and rate of bioaccumulation of pollutants discharged by Dow Chemical; and
(7) analyses of native fish from the Grand River for organic compounds.
As part of USEPA's comprehensive study of dioxins and other toxic pollutants,
sampling was conducted in 1984 at the major process wastewater sewers at Dow
Chemical; at other nonprocess wastewaters, including incinerator wastewaters,
ground water collection systems, and landfill dewatering systems; at the treated
discharge to the Tittabawassee River; and for Tittabawassee River sediments.
Data obtained from USEPA's 1981 and 1984 surveys are compared with Dow Chemical
monitoring data and other available data from preliminary dioxin investigations
conducted by Region V in 1978.
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IV. MAJOR FINDINGS AND CONCLUSIONS
A. Dow Chemical - Midland Plant
1. Untreated Wastewaters and Sewer Sludges
Untreated wastewaters from process and nonprocess operations at the Dow
Chemical - Midland Plant contain high levels of numerous chemical compounds.
Raw waste loadings of volatile compounds determined during the 1984 USEPA
survey [carbon tetrachloride (940 Ibs/day); methylene chloride (920 Ibs/day);
styrene (570 Ibs/day); chloromethane (410 Ibs/day); toluene (350 Ibs/day);
benzene (160 Ibs/day); and ethyl benzene (122 Ibs/day)] were greater than raw
waste loadings of semi-volatile compounds [phenol (520 Ibs/day); 2,4-dichloro-
phenol (45 Ibs/day); 1,2-dichlorobenzene (20 Ibs/day); pentachlorophenol (16
Ibs/day); 2,4,6-trichlorophenol (13 Ibs/day); and naphthalene (13 Ibs/day)].
The high levels of volatile compounds are significant from an air pollution
standpoint. Emission of one-sixth of the volatile compounds from the sewerage
and wastewater treatment systems would be sufficient to classify the plant as a
major source of volatile organic carbon (VOC). The findings of chlorinated
benzenes and pentachlorophenol in untreated wastewaters long after termination
of production of these compounds suggests continued leaching of the compounds
from sewer system sludges and plant soils.
Most of the untreated wastewater loading of PCDDs and PCDFs can be attributed
to contributions from various process sewers and the hazardous waste incin-
erator. The raw waste loading of TCDDs was estimated to be about 6.9 x 10"^
Ibs/day (3.1 x 10'4 kg/day) and about 1.3 x 10~2 Ibs/day (6.1 x 10~3 kg/day) for
TCDFs. Although 2378-TCDD was not detected in untreated wastewaters from the
process sewers or the hazardous waste incinerator, other tetra-octa CDDs and
CDFs were found in the 1984 USEPA study.
2. Tertiary Pond Sediments
Sediments from the tertiary pond system were found to be contaminated with
several organic chemicals. Surface sediments from the primary (pentagonal) and
secondary (rectangular) ponds were found to contain larger numbers and higher
levels of pollutants than found in tertiary pond sediments. These data suggest
the pond system has been at least partially effective in removing settleable
pollutants not removed in the biological treatment facility. Chlorinated
benzenes were found at relatively high levels in primary and secondary pond
sediments (13-67 ppm) compared to tertiary pond sediments (ND-1.5 mg/1).
Surface sediments in the ponds were generally found to be more heavily
contaminated than bottom pond sediments.
The gradient of PCDDs and PCDFs across the pond system was substantially
less than for other pollutants. These data suggest that PCDDs and PCDFs entering
the pond system are attached to finer particles that tend to settle over a
wider area than other semi-volatile pollutants which may be associated with
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heavier particles. 2378-TCDD was detected at 1.7 ppb in primary pond surface
sediments, 3.8 ppb in secondary pond surface sediments, and from 0.10 to 0.93
ppb in tertiary pond surface sediments.
B. Dow Chemical - Outfall 031 Discharge
1. Wastewater Characterization
Process changes at the Midland plant and water conservation measures have
resulted in a gradual reduction in the average discharge flow from outfall
031 from over 50 MGD in the mid 1970s to less than 20 MGD today. Recent
monitoring by USEPA and Dow Chemical suggest that discharges of toxic organic
pollutants and certain nonconventional pollutants have been reduced since 1981.
The apparent increase in the discharge of toxic metals is attributed to chromium
discharges which are higher than measured by USEPA in 1981. A summary of
annualized effluent discharge loadings is presented below:
Estimated Annualized Discharge in Tons
Total dissolved solids
Total suspended solids
Total kjeldahl nitrogen
Ammonia-N
Total phosphorus
Toxic organic pollutants
Toxic metal pollutants
1981
USEPA Survey
148,000
680
330
270
46
15.5
5.7
1984
USEPA Survey
150,000
,040 [180]
87
27
14 [5]
1.9
6.9
1984-1985
Dow Chemical Monitoring
1
129,000
420
(net)
(net)
23 (net)
11
4.9
16.7
Note: [ ] Estimated current annual full-scale discharge
loading based upon pilot plant filter data. Effluent
phosphorus data from the full-scale filter system
installed in November 1985 are not available at
this writing.
The estimated annual discharge of phosphorus from outfall 031 is 5 tons/year
based upon limited pilot plant studies, about 90% less than loadings determined
in 1981.
2. PCDDs and PCDFs
Based upon six months of full-scale operation of the effluent filtration
system, Dow Chemical has achieved a 67% reduction in the discharge loading of
2378-TCDD (9.9 x 10~7 kg/day to 3.3 x 10'7 kg/day). The current estimated annual
discharge is 1.20 x 10~4 kg/year. TCDD analyses by Dow Chemical indicate that
2378-TCDD comprises less than 3% of the total TCDDs present. The predominant
TCDD isomers, both before and after pilot filtration, are 1368-TCDD, 1379-TCDD,
and 1237+1238-TCDD. Based upon limited data, the unfiltered outfall 031
discharge appears to contain higher levels of TCDFs than TCDDs and higher
levels of other PCDFs than corresponding PCDDs. Pilot plant filter data suggest
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the full-scale filter may be achieving more than 90% removal of TCDDs, 2378-TCDF,
and HxCDDs, HpCDFs and OCDD. Only data for 2378-TCOD have been reported for
the full-seale filter system at this writing.
3. Biomonitoring
Static bioassays (Daphnia magna) conducted by USEPA in 1981 for the outfall
031 discharge indicated the discharge exhibited no acute toxicity to test
organisms. The discharge exhibited a stimulatory effect on algal growth and
caused no mutagenicity in the Ames test (direct and rat liver enzyme activated
test procedures). The 1981 USEPA studies were completed at a time when the
average effluent discharge was about 34 MGO. Biomonitoring conducted by Dow
Chemical in 1985 as required by NPOES permit MI0000868 yielded the following
results for flow-through studies:
Daphnia Magna Pimephelas Promelas
(fathead minnow)
Acute toxicity
48-Hour LCso 40% effluent No toxicity
Chronic toxicity
MATC (geometric mean) 35.8% effluent 21.7% effluent*
*embryo-l arval test
At the time of the Dow Chemical studies, the discharge flow was about 20
MGD. Dow Chemical attributed acute toxicity to daphnia to the salinity of the
effluent. The mass discharge of salts was about the same as that encountered
during the 1981 USEPA studies. However, the concentration of dissolved solids
was about 40% higher due to the reduction in discharge flow. Dow Chemical also
reports that for the minnow study (embryo-larval test), there were no observed
concentration related effects at hatch and a normal hatch occurred, yet no
organisms survived beyond 13 days. No cause for the chronic toxicity observed
was suggested by Dow Chemical . Test water for the Dow Chemical bioassays
was prefiltered through a 25-micron sock. Since chemical analyses of the
wastewater before and after filtration were not reported, the effects of this
procedure are not known.
4. Bioaccumulation Studies
Final results from the 1981 USEPA-MDNR bioaccumulation study confirmed
preliminary results with respect to the discharge of 2378-TCDD from outfall 031
and the accumulation of 2378-TCDD and other TCDDs in caged catfish exposed to
the plume of outfall 031 in the Tittabawassee River. The preliminary contract
laboratory results for PCDFs could not be confirmed. A unique finding is that
1368-TCDO accumulated in caged fish exposed to the outfall/river water mixture
at higher levels than 2378-TCDD. After 28 days of exposure, 2378-TCDD reached
nearly 40 ppt and 1368-TCDD to about 160 ppt. Penta-CDDs (140 ppt), hexa-CDDs
(43 ppt), and TCDFs (454 ppt) were found in these fish by USEPA analysts. There
was no indication that an equilibrium level of 2378-TCDD had been reached after
-------
28 days of exposure. The fish exposed to the plume of the discharge accumulated
greater numbers and higher levels of other organic chemicals, including poly-
nuclear aromatic compounds, chlorinated phenols, and pesticides, than did fish
exposed at control sites.
A recent biouptake study conducted by Dow Chemical did not demonstrate
significant uptake of 2378-TCDO or 2378-TCDF in catfish exposed for 28 days to
a mixture of 15% effluent and 85% river water. Hexachlorobenzene uptake reached
3.7 ppm (whole fish sample) in the Dow Chemical study. Most other organic
chemicals included in the study protocol did not exhibit significant accumu-
lation over the test period. As with other biomonitoring by Dow Chemical, the
test water was prefiltered using a 25-micron sock prior to exposing the
organisms. The effect of that procedure on the test results is not known.
5. Pollutants of Concern
From a wastewater treatment technology standpoint, the principal toxic
pollutants of concern are listed below. The evaluation of appropriate Best
Available Technology effluent limitations and Best Management Practices programs
will focus primarily on these toxic pollutants.
Volatile Organic Pollutants
Benzene
Carbon tetrachloride
Ethyl benzene
Methylene chloride
Toluene
Styrene
Semi-Volatile Organic Pollutants
2,4-Dichlorophenol
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
Pentachlorophenol
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
1,2,4-Trichlorobenzene
1,2,4,5-Tetrachlorobenzene
Hexachlorobenzene
2,4-D
2,6-D
2,4,5-T
Dinoseb
Bis(chlorobutyl) ether
2,3,7,8-TCDD (PCDDs and PCDFs)
Toxic Metal Pollutants
Antimony
Chromium
Nickel
Zinc
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C. Tittabawassee River
1. River Sediments
Tittabawassee River sediments are composed principally of sand and gravel
with few pockets of distinctly organic material. Low ppm levels of several
pollutants including substituted benzenes and their derivatives were identified
in 1981 by Region V. Relatively few compounds were found in similar samples
obtained in 1984. The 1984 data indicate that pesticide contamination of river
sediments originates upstream from Dow Chemical.
2378-TCOO was not detected at 10 to 30 ppt in Tittabawassee River sediments
or flood plain samples obtained in 1984. Other PCDDs and PCDFs were found in
river sediments. The highest levels were found near Smith's Crossing Road,
located just downstream from Dow Chemical. TCDDs ranged from not detected to
0.15 ppb in sediments obtained near the Dow plant; PeCDDs from not detected to
0.03 ppb; HxCDDs from not detected to 0.11 ppb; HpCDDs from 0.03 to 1.1 ppb;
and OCDD from 0.25 to 6.8 ppb. PCDFs were found at similar levels. 2378-TCDF
was identified in river sediments obtained near Dow Chemical. HpCDDs, OCDD,
HpCOFs, and OCDF were found at concentrations less than 0.5 ppb in sediments
collected upstream and well downstream of Dow Chemical. Other PCDDs and PCDFs
were not detected in these samples. These data indicate the measurable extent
of river sediment contamination by PCDDs and PCDFs attributable to Dow Chemical
operations extends downstream to the Gratiot Road/Center Road reach of the
river (about 17.1 to 19.5 miles). Limited data for flood plain samples collected
within 100 yards of the river indicate these samples are contaminated at higher
levels than nearby river sediments.
The distribution of TCDDs in Dow Chemical tertiary pond sediments, outfall
031 wastewater solids, and Tittabawassee River sediments and flood plain samples
is consistent, establishing another direct linkage between the discharge and
contamination of the river.
2. Native Fish
Bottom feeding fish (carp and catfish) collected downstream of the Dow
Chemical - Midland Plant exhibit 2378-TCDD contamination about an order of
magnitude greater than game fish when edible portions of fish are compared.
Typical levels of 2378-TCDD in skin-off filet samples of catfish are 39 to
75 parts per trillion (ppt). Average levels in skin-off carp filets may range
from 30 to 50 ppt, with maximum values greater than 500 ppt. The variability
of 2378-TCDD in skin-on filet samples of game fish (walleye, smallmouth bass,
white bass, crappie, and northern pike) is more limited with average values by
species in the range of 3 to 10 ppt. Maximum single fish values recorded in
crappie, walleye, and northern pike are 5 ppt, 14 ppt and 15 ppt, respectively.
The level of 2378-TCDF in walleye (skin-on filet) collected downstream of Dow
Chemical is about 12 times greater than the levels of 2378-TCDD. Other TCDDs,
HxCDDs, HpCDDs and OCDD were also found in walleye at levels exceeding those of
2378-TCDD.
-------
While lower levels of 2378-TCDD were detected in catfish collected in 1985
than in those collected in 1978 (limited number of samples analyzed), available
data do not suggest a significant decrease in 2378-TCDD concentrations in carp
from 1978 to 1985, or in walleye or smallmouth bass from 1983 to 1985. Given
the persistence of PCOOs and PCOFs in the environment, the contamination of
Tittabawasee River sediments, the widespread presence of PCDDs and PCDFs in
Midland area soils, and continued low-level releases from the Dow Chemical -
Midland Plant, it is highly probable that native fish in the Tittabawassee
River will remain contaminated with 2378-TCDD and other PCDDs and PCDFs at or
near current levels for several years.
Data available for skin-on filet samples of game fish for other toxic
organic pollutants show that white bass and northern pike contain higher levels
of pollutants than do walleye. Smallmouth bass samples had the lowest lipid
content and the lowest levels of organic contamination.
D. Best Available Technology
1. To a large extent, the wastewater treatment facilities installed by Dow
Chemical at the Midland plant are consistent with model wastewater treatment
systems considered by USEPA during development of national effluent limitations
guidelines. Treatment of volatile toxic organic pollutants is either deficient
or lacking at certain Dow Chemical processes.
2. Most of the process operations at the Midland plant fall within the
following major industrial categories for which EPA has either promulgated or
proposed national effluent limitations guidelines:
Organic Chemicals and Plastics and Synthetic Fibers
Inorganic Chemical s
Pesticides
Pharmaceutical s
Final effluent limitations guidelines have not been promulgated for the Organic
Chemicals and Plastics and Synthetic Fibers Category which accounts for about 70%
of the process operations at the Midland Plant. Wastewaters from categorical
processes account for about one-third of the discharge from outfall 031. The
balance is distributed among noncategorical process wastewaters, nonprocess
wastewaters, storm water, and noncontact cooling water. In the absence of
final effluent limitations guidelines for most of the process and nonprocess
operations, proposed NPDES permit BAT effluent limitations and best management
practices control programs must be developed on a best professional judgment
basis pursuant to Section 402(a)(l) of the Clean Water Act.
3. Proposed BAT effluent limitations for toxic pollutants will likely be
developed at the process level for certain pesticide processes, and on a
plant-wide basis for other process and nonprocess operations. Volatile organic
pollutants may be limited at the process level in certain circumstances.
Effluent limitations for conventional and nonconventional pollutants will
likely be proposed as plant-wide limitations. Best management practices
programs may be proposed for specific pollutants and areas of the plant.
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V. DOW CHEMICAL - MIDLAND PLANT
A. Production Operations
The Dow Chemical Midland plant is a large chemical manufacturing complex
encompassing about 1500 acres along both banks of the Tittabawassee River at
Midland, Michigan (Figure 1). Throughout its history, Dow Chemical has
manufactured over 1000 different inorganic and organic chemicals at Midland
including cyclical intermediates; industrial organic and inorganic chemicals;
plastic materials; synthetic resins; nonvulcanized elastomers; medicinal chemi-
cals; surface active agents; finishing agents; sulfonated oils; insecticides;
herbicides; and formulated pesticides.
The manufacture of chlorinated phenols for use in herbicide, pesticide, and
other products has been a significant operation at the Midland plant. According
to Dow Chemical, commercial production of chlorinated phenols began in the
1930s and continued at substantial levels into the 1970s. _4/ Dow reports that
only two chlorinated phenolic products are currently manufactured:
• 2,4-dichlorophenol
• 2,4-dichlorophenoxyacetic acid (2,4-D).
Production of all other chlorinated phenolic intermediates and products was
terminated in the late 1970s. A complete list of chlorinated phenolic compounds
produced at the Dow site is presented in Table 1.
The Dow Chemical Midland plant falls within Tiers 1, 2, 3, 4, and 6 of the
USEPA Dioxin Strategy 2]: 2,4,5-trichlorophenol (2,4,5-TCP) was produced
(Tier 1); 2,4,5-TCP was used to make pesticide products (Tier 2); and 2,4,5-TCP
and derivatives were formulated into pesticide products (Tier 3). The plant is
a combustion source (Tier 4), and Dow Chemical operates processes for other
organic chemicals or pesticides that are considered to have a low potential for
dioxin formation (Tier 6).
B. Dow Chemical Brine Operations and Chemical Disposal Wells
The Dow Chemical Company was founded in Midland in 1897 as a producer of
brine chemicals. Dow Chemical mined naturally occurring brine from the Sylvania
aquifer, a dense sandstone formation with interbedded limestone about 5000 feet
deep, ranging in thickness from about 200 to about 500 feet. The raw calcium
chloride brine was conveyed through a network of underground piping and ancillary
equipment to the Dow Chemical complex in Midland. After removal of salts and
minerals, the spent brine was sent to Brine Pond #6 on-site for holding prior
to filtration and pressure injection to the same formation through return
wells.
The brine system, as permitted by Michigan DNR, consists of the following:
-------
Figure 1
Location Map
Tittabawassee River Basin
Dow Chemical - Midland Plant
Dow Chemical Co.
10
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Table 1
A Compilation of the Commercially Significant Chiorophenolic
Compounds Manufactured on the Midland Plant Site
of the Dow Chemical Company
Chlorophenols
2-chlorophenol
4-chlorophenol
*2,4-dichlorophenol
2,4,5-trichlorophenol
Sodium 2,4,5-trichlorophenate
Zinc 2,4,5-trichlorophenate
2,4,6-trichlorophenol
Sodium tetrachlorophenate
2,3,4,6-tetrachlorophenol
Pentachlorophenol
Sodium pentachlorophenate
Chlorophenoxy Derivatives*
*2,4-dichlorophenoxyacetic acid (2,4-D)
2-(2,4-dichlorophenoxy) propanoic acid
2-methyl-4-chlorophenoxyacetic acid
2,4,5-trichlorophenoxyacetic acid (2,4,5-T)
2-(2,4,5-trichlorophenoxy) propanoic acid
Other Chlorophenol Derivatives
2-(2,4,5-trichlorophenoxy) ethanol
2-(2,4,5-trichlorophenoxy) ethyl 2,2-dichloropropanoate
0,0-dimethyl-0-(2,3,5-trichlorophenyl) phosphorothioate
2-cyclopentyl-4-chlorophenol
4-t-butyl-2-chlorophenol
4-t-butyl-2-chlorophenyl methyl N-methyl-phosphoramidate
Chlorinated phenyl phenols
Chlorinated diphenyl oxide derivatives
*2,4-dichlorophenol and 2,4-D are the only compounds from this
list that are currently being manufactured on the Midland plant
site.
Ijhese chlorophenoxy acid derivatives have also been converted
into various water soluble salts.
Source: Point Sources and Environmental Levels of 2378-TCDD (2,3,7,8-tetrachlorodi-
benzo-p-dioxin) on the Midland Plant Site of the Dow Chemical Company and in
the City of Midland, Michigan, Dow Chemical Company, Midland, Michigan,
November 1984.
11
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• 70 brine production wells
• 35 brine injection wells
7 solution mining wells
• about 150 miles of pipelines, 25-30 years old.
The brine system occupies portions of three counties:
• Midland County (Midland, Ingersoll, Homer, Lee, Larkin, Greendale,
Porter, and Mt. Haley Townships)
• Bay County (Williams Township)
• Saginaw County (Richland, Freemont, Bryant, Thomas, St. Charles, and
Swan Creek Townships)
The areal extent of the Dow Chemical brine operation is illustrated by
Figure 2.
The physical make-up of the calcium chloride brine mined by Dow is as
follows:
• 70% water
• approximately 20% calcium chloride
• approximately 5% sodium chloride
• approximately 5% other inorganic salts
Brine processing in the Dow Chemical complex removed iodine, bromine, and
calcium. USEPA has previously reported the chemical composition of Dow
Chemical brines and compared the Dow Chemical brines to other Michigan brines
and oil and gas brines from other parts of the country. _5/ In May 1985, Dow
Chemical entered into a consent order with Michigan DNR calling for a phased
shutdown of the Dow brine system. The consent order requires shutdown of the
entire brine system by December 31, 1986. 6/ At this writing, Dow Chemical has
ceased brine mining operations and is in the process of closing the system. 6a/
The Dow Chemical brines are similar in composition to other oil and gas
brines in Michigan and from elsewhere in the United States, including low levels
of benzene, toluene, phenol, and various polynuclear aromatic hydrocarbons.
The Dow Chemical spent brines may also contain trace levels of PCDDs and PCDFs.
Dow Chemical has also operated chemical disposal wells, injecting process
chemical wastes into the Sylvania and Dundee formations. TJ Michigan DNR data
for Dow Chemical underground industrial waste disposal systems have been
reviewed. According to these data, phenolic compounds were reported to have
been injected into the Sylvania formation. Other chemical process wastes,
including copper, butyl alcohol, chlorinated benzene compounds, phenolic com-
pounds, pyridines, and the pesticides 2,4,5-T and tordan were also injected
into the Dundee formation. Table 2 summarizes chemical disposal well location,
receiving formation, interval of receiving aquifer, and injected fluid char-
acteristics obtained from the MDNR data. According to Dow Chemical, use of
chemical disposal wells was discontinued in December 1982. 8/
12
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Figure 2
Location Map
Dow Chemical - Midland Plant
Brine System
Legend
Production Well
Remjection Well
Gratiot County
13
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Chemical
Disposal
Well No.
U.O. #1
W.D. 12
W.D. #3
I4CD
W.D. #S
W.O. *8
W.D. 19
Table 2
Dow Chemical
Disposal Well Data
Location (Midland County)
NE 1/4, NE 1/4. SE 1/4; Sec. 27. T14N; R2E
SE 1/4. SH 1/4. SE 1/4; Sec. 22. T14N; R2E
Interval of
Receiving Receiving
Formation Aquifer
Dundee
Dundee
3606'-3985'
3645'-3984'
SW 1/4. NH 1/4. SW 1/4; Sec. 21. T14N; R2E Dundee 3645'-3900'
SW 1/4. SW 1/4. SW 1/4; Sec. 22, T14N; R2E Sylvanla 4986'-5117'
NW 1/4. NW 1/4. NW 1/4; Sec. 28. T14N; R2E Dundee 3645'-3888'
SE 1/4. SW 1/4, NE 1/4; Sec. 27. T14N; R2E Sylvanla 4925'-5150'
SE 1/4. SE 1/4. NE 1/4; Sec. 26. T14N; R2E Sylvanla 4917'-5182'
Injected Fluid Characteristics
Activated sludge.
Copper, butyl alcohol, chlorinated
benzene compounds, phenolic compounds,
tordan. pyrldenes, 2,4,5-T.
Copper, butyl alcohol, chlorinated
benzene compounds, phenolic compounds,
tordan, pyrldenes, 2,4,5-T.
Phenolic compounds.
Copper, butyl alcohol, chlorinated
benzene compounds, phenolic compounds,
tordan, pyrldenes, 2,4,5-T.
Phenolic compounds.
Phenolic compounds.
Source: Michigan Department of Natural Resources Geological Survey Division
Well and Reservoir Data on Underground Industrial Waste Disposal Systems.
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C. Riverbank Revetment System
Dow Chemical has installed a revetment ground water interception system
(RGIS) for about 11,700 feet along the northeast bank of the Tittabawassee
River at the Midland plant. 4/ The RGIS consists of sheet piling to stabilize
the riverbank and minimize tFe inflow of river water to the collection system;
a trench containing drain tile for collection of ground water; a clay cap; and
a series of sumps for accumulation and removal of ground water. Six sumps on
the northeast bank inside the sheet piling collect ground water from the site
to prevent mixing with river water or ground water beneath the river. At this
writing, Dow Chemical is evaluating the effectiveness of the RGIS pursuant to
RCRA 40 CFR Part 265. Depending upon the results of that evaluation, additional
corrective actions may be required to address ground water contamination at the
site. The company has recently applied for state permits to extend the revetment
system along the riverbanks. The RGIS results in about 1 MGD of discharge to
the Midland plant wastewater treatment system. The locations of the existing
drainage system and sumps are shown in Figure 3.
The company also operates a drain tile collection system along the opposite
bank of the Tittabawassee River at brine pond No. 6 and the tertiary pond to
collect wastewaters leaking from those ponds.
D. Dow Chemical Sewerage and Wastewater Treatment System
Solid and liquid wastes generated at Dow Chemical and wastewaters received
from outside sources are disposed of by one of three methods: (1) concentrated
liquids and burnable solid wastes are incinerated; (2) "biodegradable" dilute
liquids and a substantial volume of cooling water are processed in the wastewater
treatment facilities tributary to outfall 031; and (3) nonburnable solid wastes
are landfilled.
Dow Chemical discharges contact and noncontact cooling waters, storm water
runoff, and treated process and sanitary wastewaters to the Tittabawassee River
through five outfalls. _9/ In addition to the wastewaters generated at the
Midland plant, the company also treats wastewater from other sources. These
include about 1.7 MGD of process wastewaters from the nearby Dow Corning silicone
products facility; about 0.18 MGD of sanitary and laboratory wastewaters from
the Consumers Power Midland Nuclear Plant (when construction was in process);
about 0.02 MGD of truck washing wastewaters from the Chemical Leaman and Coastal
Trucking Line at Midland; about 1 MGD of ground water collected in the revetment
system sumps noted above; about 0.01 MGD of leachate from the Dow Chemical
Salzburg Road landfill; and roughly 0.002 MGD of collected leachate from the
Rockwell landfill. Dow Chemical also collects and treats about 0.05 MGD of
leachate and intercepted ground water from the Poseyville Road landfill to
limit migration of contaminated ground waters away from the site.
According to Dow Chemical's most recent NPDES permit application (1982), the
average daily wastewater flows from these outfalls are as follows:
15
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91
Dow Chemical property line
CD
-*
o-
eo
3J
~
00 o -
CD 3" 3
^ CD 3
las
» .5
Cb
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CD
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en S«
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-------
Outfall 005 - 3.9 MGD
Outfall 012 - 30.0 MGD
Outfall 014 - 0.7 MGD
Outfall 015 - 0.3 MGD
Outfall 031 - 26.5 MGD
Total - 61.4 MGD
The average discharge for outfall 031 on the sampling dates for the 1981
USEPA survey was 35.4 MGD. When the 1984 USEPA surveys were conducted, the
average flow had been reduced to about 20 MGD. Most of the discharge orginates
as Tittabawassee River water diverted at the Dow dam into the plant for process
and cooling purposes. Other intake water sources include the city of Midland
and Lake Huron. Lake Huron water is chlorinated and demineralized prior to use
in various processes. The other intake waters are generally not treated prior
to use.
Descriptions of the sources of effluent discharged through the outfalls
active during the various surveys are presented below:
Outfall 002 - At the time of the 1981 survey, the discharge from outfall
002 was about 5 MGD to the Tittabawassee River via Lingle Drain. The
discharge has since been diverted to the wastewater treatment facilities
tributary to outfall 031. The discharge consisted of untreated noncontact
cooling water from coolers and heat exchangers in the monomer and polymer
plastic production area and various hydrocarbon production processes.
Outfall 005 - The discharge from this outfall is overflow from an ash
pond serving the power house. Cooling water, general use water, and boiler
blowdown are also diverted to the ash pond. The discharge is to the
Tittabawassee River via Ashby Drain.
Outfall 012 - Dow Chemical refers to this outfall as the "H" flume.
Noncontact cooling water from the west power house condensers and excess
river water are discharged directly to the Tittabawassee River.
Outfall 031 - This discharge consists of treated process wastewaters,
cooling water, water softener backwash, cooling tower blowdown, other
noncontact cooling water, incinerator scrubber water, sanitary wastewaters,
surface water runoff, landfill leachate, and ground water collected in the
RGIS. Treatment is provided in an end-of-pipe biological treatment facility
followed by three settling ponds, the largest of which is called the tertiary
pond. The tertiary pond effluent is pumped through mixed-media sand filters
prior to discharge to the Tittabawassee River. Dow Chemical has also
installed numerous in-process product and by-product recovery systems and
pollution control systems. Recent data indicate the flow from outfall 031
has been reduced to less than 20 MGD.
Other active Dow Chemical outfalls not described above include outfalls
001, 014, and 015. Outfall 001 serves as an emergency standby for outfall 031
and would convey wastewater from the biological treatment plant directly to the
17
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river. Outfalls 014 and 015 convey air conditioner cooling water from the
plant administration building directly to the Tittabawassee River. These
outfalls were not sampled during the 1981 or 1984 surveys.
Wastewater Treatment Plant - "Biodegradable" dilute liquids (process and
sanitary wastewaters) are separated into two categories - phenolic wastewaters
and other organic wastewaters. Figure 4 is a schematic diagram of the wastewater
treatment plant. Wastewaters from the phenolic processes are pumped through
enclosed and open conduits to the phenolics pretreatment system, where suspended
solids are removed by primary clarification. The phenolic wastewaters are then
processed in trickling filters and an activated sludge system operated in series.
After final clarification, the phenolic plant effluent is directed to the
larger biological treatment facility for further treatment with all process
wastewaters, nonprocess wastewaters, noncontact cooling waters, landfill lea-
chates, collected ground water, and surface runoff from the site. There are
several sections of the major sewer system where wastewaters are conveyed
through open conduits or ditches as opposed to enclosed conduits.
The wastewaters from the remainder of the plant are collected and directed
to primary settling tanks where suspended solids are removed. Wastewaters high
in BOD and toxic wastewaters can be diverted to a diversion basin during spills
or emergencies and metered into the treatment system at controlled rates. The
overflow from the primary tanks is combined with the effluent from the phenolics
treatment plant prior to entering activated sludge aeration basins for
biological treatment. From the aeration basins, the wastewater is fed to
secondary clarifiers. Settled activated sludge is recycled to the aeration
basins. Effluent from the secondary clarifiers is pumped to the tertiary
ponds, which are about 200 acres in area and have a maximum capacity of about
600 million gallons. The retention time in the ponds provides for temperature
equalization and continued biological action. The effluent from the tertiary
ponds is discharged to the Tittabawassee River through outfall 031 after
filtration through recently installed mixed-media filters.
Primary sludge from the biological treatment facility was pumped to clay-
lined sludge dewatering pits located near the intersection of Saginaw and
Salzburg Roads. Recently, Dow Chemical installed additional mechanical sludge
dewatering equipment at the wastewater treatment facility. The sludge dewater
pits are maintained for emergency use. The dewatered sludge is ultimately
disposed of at Dow Chemical's Salzburg Road landfill. Supernatant from the
sludge dewatering pits was returned to the wastewater treatment plant. Sludge
from the phenolic treatment system is either recycled or processed in the other
biological treatment system. Sludge from the biological treatment system is
thickened, filtered, stored on-site, and landfilled.
E. Dow Chemical Waste Incinerators
The incineration area includes a rotary kiln (refuse burner) and a tar burner
(thermal oxidizer). £/ The tar burner is a standby unit for the rotary kiln.
The tar burner operates at 1000°C in a single combustion chamber with a retention
time of about 2 seconds. Only liquids or gases are incinerated in this unit.
The liquid feed rate is 7.5 gpm. The refuse burner is fed with solid and liquid
18
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Figure 4
Schematic Diagram
Dow Chemical
Wastewater Treatment Facilities
Phenolic
aewers
Strong
Weak Phenc
r
Equliazation
>l
Mixing and
pH Control
fc
"
Genera!
Sewers
^ "~
Lime
pH
Control
*
Diversion
Pond
Incineration
Aeration
Basin
Biological
Treatment
Outfall 031
Tittabawassee River
19
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wastes at rates of approximately 5 to 6 tons per hour, and 2 to 4 tons per
hour, respectively. The rotary kiln, or primary combustion chamber, provides
about 45 minutes of solid waste retention at a design combustion temperature of
650° to 950°C. Exit gases are routed to an afterburner section, in which a
retention time of 1.5 to 1.8 seconds at 1000° to 1100°C is provided.
Solid wastes are fed to the refuse burner in loose form and, in the case of
specialized wastes from process and laboratory areas, in individual containers
weighing a maximum of 200 pounds. The containers are introduced to the rotary
kiln every five to six minutes. Concentrated liquid wastes enter the rotary
kiln through two air-atomized nozzles, along with a third nozzle firing low-BTU
liquid wastes composed of dilute contaminated water from processes or surface
runoff. Another concentrated liquid waste nozzle is located in the afterburner
section; this nozzle is steam-atomized. Combustion may be supplemented with
natural gas at all three nozzles. Incinerator ash is landfilled at the Salzburg
Road landfill. Incinerator stack gases are scrubbed with effluent from the
wastewater treatment system. The scrubber effluent is then returned to the
wastewater treatment system.
Studies by Dow Chemical identified a number of PCDDs and 2378-TCDF in
incinerator stack gases, stack gas particulates, and scrubber waters. 47
Incinerator scrubber waters are quantitatively characterized in Section VII.A.I.
Region V also characterized incinerator emissions, incinerator feeds, ash, and
scrubber waters (report in preparation).
F. Dow Chemical Landfills
Dow Chemical has been operating a landfill located on Salzburg Road since
January 1981. The landfill was approved by MDNR for hazardous waste disposal
on February 10, 1982, and has qualified for interim status under RCRA. As
noted above, incinerator ash, wastewater treatment sludges, contaminated soil,
and demolition material are currently landfilled at this site. Leachate
collected from the landfill is diverted to the wastewater treatment plant.
Dow Chemical used two off-site landfill sites, near Poseyville Road and
Rockwell Drive, which are now closed. Dow activity at these sites includes
leachate collection, site dewatering, and ground water monitoring. At the
Poseyville Road landfill, Dow Chemical also operates ground water intercepting
wells to collect contaminated ground water leaving the site. Figure 5 presents
the location of the off-site landfills. The company also disposed of chemical
manufacturing wastes and other solid waste on the plant site at several
locations.
Several modifications to Dow Chemical's solid waste, wastewater collection,
and wastewater treatment facilities will be completed as Dow Chemical comes
into compliance with the implementing regulations of the Resource Conservation
and Recovery Act (RCRA) and the Hazardous and Solid Waste Amendments of 1984.
It is likely that the open sewers at the plant will be enclosed or replaced and
modifications will be made to the diversion basin and other treatment facilities.
20
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Figure 5
Location Map
Dow Chemical Landfills
21
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VI. FIELD STUDY RESULTS
The results of USEPA field studies conducted from 1978 to 1984 at the Dow
Chemical - Midland plant and in the Tittabawassee River are reported here along
with recent monitoring data obtained by Dow Chemical. The USEPA surveys include
Midland plant untreated wastewater and in-plant sludge sampling (1978, 1984);
treated wastewater effluent sampling (1978, 1981, 1984); treated effluent bio-
monitoring (1981); a bioaccumulation study (1981); and Tittabawassee River
sediment sampling (1978, 1981, 1984). Summaries of the data and major findings
are presented below. The complete field and laboratory data are presented in
the respective appendices noted for each aspect of the studies. Also presented
in the appendices for each study where such analyses were completed are
tentatively identified compounds from broad scan analyses. For the most part
the tentatively identified compounds are not reviewed in this section.
A. Dow Chemical Untreated Wastewaters and In-Pi ant Sludges
1. Untreated Wastewaters (Appendices A-l, A-2)
Figure 6 presents a sewer system schematic diagram for the Midland plant.
Water samples were obtained at or near the confluence of each major sewer
system with the main inteceptor sewers tributary to the wastewater treatment
facilities. Samples of incinerator wastewater streams, landfill leachate
collection systems, and the riverbank revetment system were also obtained. The
sampling locations are designated on Figure 6 for the major process sewers.
The principal purposes of sampling the major process wastewater sewers and
other nonprocess wastewaters were to identify the toxic, conventional, and
nonconventional pollutants present in each major sewer system and to determine
whether these pollutants are effectively treated or removed as the wastewaters
are processed in the wastewater treatment facilities. Also, the data have been
used to target areas of the Midland plant where additional in-process or end-of-
process controls might be necessary to attain BAT.
Table 3 presents a summary of the mass discharges of volatile pollutants
from the major process wastewater sewers and nonprocess sources. These data
represent the conditions present at the time of the sampling event and may or
may not be representative of conditions experienced over the longer term.
Nonetheless, the data present an order of magnitude estimate of the mass
discharge of volatile pollutants to the wastewater treatment system. As shown,
the total discharge on the sampling dates was in excess of 3700 Ibs/day
(1700 kg/day). Carbon tetrachloride, methylene chloride, styrene, chloro-
methane, toluene, benzene, and ethyl benzene were present at levels in excess of
100 Ibs/day (45.4 kg/day). As shown elsewhere, the current mass discharge of
volatile pollutants to the Tittabawassee River from outfall 031 is about
10 Ibs/day (4.5 kg/day).
22
-------
(ND
CO
Figure 6
Location Map
USEPA Sampling Locations
Dow Chemical Process Sewers
August 1984
Legend
Sampling Site
76 Sewer
Sewer #
100
200
300
400 ~^t<)_
500
76
601
610
-------
Table 3
Volatile Pollutant Summary
Untreated Wastewaters
Dow Chemical - Midland Plant
August 29, 1984; October 23, 1984
Mass Discharge
to Wastewater Treatment
Volatile Pollutant
acrylonitrile
benzene
carbon tetrachloride
chlorobenzene
1,2-dichloroethane
1,1,1-trichloroethane
1,1-dichloroethane
chloroform
trans-1,2-dichloroethane
1,2-dichloropropane
ethyl benzene
methylene chloride*
chloromethane
tetrachloroethene
toluene
trichloroethene
acetone*
2-butanone*
styrene
xylenes (total)
bromomethane
bromoform
carbon disulfide
1,1-dichloroethene
vinyl chloride
chloroethane
4-methyl-2-pentanone
Ibs/day
38.7
158.6
942.4
72.1
3.9
58.5
8^3
1.1
0.7
122.1
922
407.6
28.8
347.3
1.4
11.2
4.1
572.1
55.0
0.1
1.1
l.*2
0.9
0.2
0.1
kg/day
17.6
72.1
427.5
32.8
1.8
26.5
3.8
0.5
0.3
55.5
419.1
184.9
13.1
157.9
0.6
5.1
1.9
259.5
25.0
<0.1
0.5
0.5
0.4
<0.1
<0.1
Total 3759.7 Ibs/day
1707.4 kg/day
*0etected in field blank samples.
contamination.
Data corrected for field blank
24
-------
The mass discharge of volatile pollutants in untreated wastewaters at these
levels is significant from an air pollution standpoint. Volatilization in open
sumps, sewers, and tanks and air stripping from biological reactors and other
wastewater treatment plant vessels can be highly efficient. Air stripping
of only 15% of the raw waste loading of volatile pollutants would exceed
the 100 ton/year criterion necessary for qualification as a major air pollu-
tion source of hydrocarbon emissions. 10/ Estimated current annual ized
emissions of volatile pollutants from process sources at the plant are about
3600 tons/year. 10a/
Best Available Technology (BAT) for volatile pollutants is reviewed in
Section VII. The model BAT treatment systems under consideration by USEPA
include in-process steam stripping systems to remove and recover volatile
pollutants. Because of the high raw waste loadings of volatile pollutants,
additional in-process or end-of-process controls for certain Dow Chemical
process areas will be evaluated for BAT,
Table 4 is a similar table for semi-vol atil e pollutants. Semi-vol atil e
pollutants are defined as those determined with EPA Method 625 by GC/MS (gas
chromatography/mass spectrometry) for acid and base/neutral organic fractions.
Phenol accounted for nearly 80% of the 670 Ibs/day (304 kg/day) raw waste
loading of semi-volatile pollutants. Several chlorinated phenols including
2-chlorophenol; 2,4-dichlorophenol ; 2,4,5-trichlorophenol ; 2,4,6-trichl oro-
phenol ; and pentachlorophenol accounted for about 83 Ibs/day (37.6 kg/day), or
about 12% of the raw waste loading. The balance is principally comprised of
lesser amounts of chlorinated benzenes and polynuclear aromatic hydrocarbons.
The changes in chlorinated phenols production in the late 1970s by Dow Chemical
have most likely resulted in substantially lower raw waste discharges of
chlorinated phenols and chlorinated benzenes to the treatment systems. A
substantial portion of the current raw waste loading of these pollutants is
likely due to sludges and sediments deposited in the sewerage system. As shown
later in this report, semi-volatile pollutants are efficiently removed in the
existing end-of-pipe wastewater treatment facilities.
Table 5 presents data for polychl orinated dibenzo-p-dioxins (PCODs) and
polychlorinated dibenzofurans (PCDFs) for the major process sewers, the incin-
erator streams, landfills, and revetment system (RGIS). These data indicate
that the incinerator streams and the process sewers generally account for nearly
all of the PCODs and PCDFs reaching the wastewater treatment facility.
2378-TCDD was identified in one sample of Salzburg Landfill leachate (11 ppq).
The Rockwell Landfill dewatering sample was found to contain 2378-TCDD at a
concentration of 270 ppq (parts per quadrillion). However, the data are suspect.
The laboratory completing the analyses did not meet quality assurance objectives
for other PCDDs and PCDFs. Although 2378-TCDD was not detected in incinerator
wastewaters, data obtained by Dow Chemical indicate that the incinerator streams
are the most significant wastewater source of 2378-TCDD and other PCDDs and
that much of the 2378-TCDD discharged to the Tittabawassee River originates
from the incinerator. _4/ Dow Chemical is currently installing a pretreatment
system for incinerator wastewaters to reduce dioxin discharges to the biological
wastewater treatment plant. Dow Chemical has also isolated three other
wastewater sources of 2378-TCDD -- (1) a dewatering sump in the abandoned
25
-------
Table 4
Semi-Volatile Pollutant Summary
Untreated Wastewaters
Dow Chemical - Midland Plant
August 28-29, 1984; October 23, 1984
Mass Discharge
to Wastewater Treatment
Semi-Volatile Pollutant
2,4,6-trichlorophenol
2-chlorophenol
2,4-dichlorophenol
pentachlorophenol
phenol
benzoic acid
4-methylphenol
2,4,5-trichlorophenol
1,2,4-trichlorobenzene
hexachlorobenzene
bi s(2-chloroethyl)ether
1,2-dichlorobenzene
1,3-dichlorobenzene
1,4-dichlorobenzene
fluoranthene
bi s(2-chloroi sopropyl)ether
naphthalene
phenanthrene
4-ch1oropheny1phenylether
n-nitrosodiphenyl amine
bis(2-ethylhexyl)phthalate
dimethyl phthalate
benzyl alcohol
2,4-dimethyl phenol
2-methylphenol
acenaphthene
di-n-butylphthalate
diethylphthalate
acenaphthalene
anthracene
fluorene
2-methylnaphthalene
Ibs/day
12.8
6.9
44.8
16.4
520.3
5.2
11.9
2.1
1.7
0.8
20.0
0.4
8.1
oil
12.9
oi2
0.4
0.4
1.2
kg/day
5.8
3.1
.3
.4
20.
7,
236.0
2.4
5.4
1.0
0.8
oi4
9.1
.2
3.7
5.9
cO.l
0.1
cO.l
0.2
0.2
0.5
Total 667.9 Ibs/day
303.9 kg/day
26
-------
Table 5
2378-TCOD
Total Tetra CDDs
Total Penta CDDs
Total Hexa CDDs
Total Hepta CDDs
OCDD
2378-TCDF
Total Tetra CDFs
Total Penta CDFs
Total Hexa CDFs
Total Hepta CDFs
OCDF
PCDD and PCDF Summary
Untreated Wastewaters
Dow Chemical - Midland Plant
August 28-29, 1984; October 23, 1984; December 4, 1984
Mass Discharge to Wastewater Treatment Facility
(Ibs/day)
Process
Sewers
Incinerator
Streams
3.9xlO-4
__
l.OxlO-7
1.2x10-4
1.7x10-3
7.8xlO-6
7.6x10-3
6.1x10-5
6.2x10-5
6.6x10-4
1.0x10-2
3.0xlO-4
2.7x10-6
— —
7.3x10-5
4.5x10-4
4.2x10-6
5.8x10-3
3.4x10-5
6.5x10-5
1.4x10-4
1.9x10-4
Landfill(1)
5.0x10-9
Revetment
System
Total
Ibs/day kg/day
1.2x10-6
__
__
5.9x10-7
2.9x10-6
4.6x10-8
8.0x10-8
__
—
—
--
6.9x10-4
2.7x10-6
1.0x10-7
1.9x10-4
2.2x10-3
1.2x10-5
1.34x10-2
9.5x10-5
12.7x10-5
8.0x10-4
1.0x10-2
3.1x10-4
1.2x10-6
4.5x10-8
8.6x10-5
1.0x10-3
5.4x10-6
6.1x10-3
4.31x10-5
5.8x10-5
3.6x10-4
4.5x10-3
Note: (1) Positive findings of 2378-TCDD in the Rockwell Landfill dewatering sample are qualified.
Data for other PCDDs and PCDFs are not valid for this sample.
-------
trichlorophenol production area; (2) a dewatering sump in the abandoned strong
phenolic wastewater treatment facilities; and (3) sludges in a section of the
major sewer system. £/ At this writing, Dow Chemical has ceased pumping the two
dewatering sumps and is studying remedial measures for the sludges, which must
be disposed of in accordance with RCRA and HSWA requirements.
Table 6 presents untreated wastewater loadings of toxic and nonconventional
metal pollutants. Iron and aluminum comprise about 87% of the 3500 Ibs/day
(1600 kg/day) loading with lesser amounts of zinc, copper, manganese, chromium,
lead, nickel, and barium accounting for over 12%. Effluent data for outfall
031 indicate that metal pollutants are effectively treated in the wastewater
treatment facilities.
Raw waste data for conventional and other nonconventional pollutants are
presented in Table 7.
2. In-Plant Sludges (Appendix A-3)
Tables 8, 9, 10, and 11 present the range of concentrations of volatile,
semi-volatile, metal, and PCDO and PCDF compounds found in sludges from major
sewer systems in the Midland plant. Sludge samples were obtained to determine
whether the sludges could be significant wastewater sources of PCDOs and PCDFs
or other toxic pollutants. Figure 7 shows the sample locations. Sampling was
limited to those sites at or near the mouth of each major sewer where represen-
tative samples could be obtained in a reasonable and safe manner. A sediment
sample was also taken from a sump serving a major section of the underground
revetment system (RGIS). Data for the revetment system sump are presented in
Table 12.
The general sewer is an open ditch which conveys wastewaters to the main
wastewater treatment area. Most plant sewers are tributary to the general
sewer with the exception of the strong phenolic wastewaters (50 sewer, 76 sewer)
and half of the incinerator water streams (venturi/demister). Dow Chemical
reports that accumulation of solids in the general sewer requires cleaning about
every two years with the last cleaning occurring in 1984. 4/ Proper removal of
these contaminated solids will be addressed by future in-pTant remedial actions
conducted pursuant to RCRA regulations.
The highest concentrations of organic compounds were found in the incinera-
tor area samples taken from the general sewer. Chlorinated benzene concentra-
tions ranged from 2,200-110,000 ppm for the incinerator area #2 sample. The 50
sewer also exhibited chlorinated benzenes at lesser concentrations (20-1410
ppm). The 50 sewer carried wastewater from chlorophenol manufacturing opera-
tions that are now shut down and from a shallow dewatering sump located in that
area. Relatively lower levels of chlorinated phenols were found in certain
sewers.
A review of the PCDD and PCDF data show that 2378-TCDD was identified
in four of the samples: 300 sewer (0.5 ppb), 500 sewer (0.4 ppb), 50 sewer
(11 ppb), and the general sewer-incinerator area #1 (9.2 ppb). The latter
sample was also characterized by elevated concentrations (14-35,000 ppb) of
28
-------
Table 6
Metal Pollutant Summary
Untreated Wastewaters
Dow Chemical - Midland Plant
August 28-29, 1984; October 23, 1984
Mass Discharge
to Wastewater Treatment
Metal
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Copper
Iron
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Tin
Vanadium
Zinc
Ibs/day
400
4.5
3.3
15.3
/"fl 1
SVj • ±
0.6
58.0
0.8
87.7
2705
24.7
70.9
0.1
17.1
0.2
0.1
f.3
181
kg/day
181.4
2.0
1.5
6.9
0.3
26.3
0.4
39.8
1230
11.2
32.2
<0.1
7.8
0.1
<0.1
<0.1
oie
82.1
Total 3570.9 Ibs/day
1623.1 kg/day
29
-------
Table 7
Conventional and Nonconventional Pollutant Summary
Untreated Wastewaters
Dow Chemical - Midland Plant
August 28-29, 1984; October 23, 1984
Pollutant
Total dissolved solids
Total suspended solids
Biochemical oxygen demand (5-day)
Total kjeldahl nitrogen
Ammonia-nitrogen
Total phosphorus
Phenols (4AAP)
Mass Discharge
to Wastewater Treatment
Ibs/day
678,500
68,800
17,700
1,000
560
1,080
2,420
kg/day
308,400
31,300
8,030
455
253
490
1,100
30
-------
Table 8
Volatile Organic Pollutant Summary
In-Plant Sludges
Dow Chemical - Midland Plant
October 1984
Volatile Compound
Benzene
Carbon tetrachloride
Chlorobenzene
Chloroform
Ethyl benzene
Methylene chloride
Tetrachloroethene
Toluene
Trichloroethene
Acetone
Carbon disulfide
Styrene
Total xylenes
Range of Concentrations (ppm)
0.01-738
ND-520
0.04-24,000
ND-<10
ND-590
ND-440B
0.03-6300
ND-178
ND-26
ND-0.6B
ND-0.03
ND-670
ND-96
8 = Blank contamination.
31
-------
Table 9
Acid and Base Neutral Pollutant Summary
In-Plant Sludges
Dow Chemical - Midland Plant
October 1984
Acid and Base Neutral Compound
2,4,6-trichlorophenol
2-chlorophenol
2,4-dichlorophenol
Pentachlorophenol
Phenol
2,4,5-trichlorophenol
1,2,4-trichl orobenzene
Hexachlorobenzene
1,2-dichl orobenzene
1,3-dichlorobenzene
1,4-di chlorobenzene
4-chlorophenyl phenyl ether
Hexachiorobutadi ene
Naphthalene
Phenanthrene
Range of Concentrations (ppm)
ND-<0.33
ND-<0.33
ND-1.6
ND-1.8
ND-130
ND-<1.6
ND-80,000
ND-2200
ND-110,000
NO-8100
ND-100,000
NO-4 3
ND-<20
NO-9300
ND-<0.33
32
-------
Table 10
Metal Summary
In-Plant Sludges
Dow Chemical - Midland Plant
October 1984
Metal
Alumi num
Antimony
Arsenic
Barium
Beryl lium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Thai li urn
Tin
Vanadium
Zinc
Range of Concentrations (ppm)
771-7220
NO-464
NO-65
13-125
ND-10
ND-4
ND-180,000
43-667
ND-7
21-238
4160-20,100
ND-13
494-87,100
33-561
ND-1.8
13-96
1280-14,600
ND
ND-17
249-1,400
ND
ND-44
6-59
31-556
33
-------
Table 11
PCDDs and PCOFs
In-Plant Sludges
Dow Chemical - Midland Plant
October 1984
(Concentrations in ppb.)
2378-TCDD
Total tetra CDDs
Total penta CDDs
Total hexa CDDs
Total hepta CDOs
OCDD
2378-TCDF
Total tetra CDFs
Total penta CDFs
Total hexa CDFs
Total hepta CDFs
OCDF
50
Sewer
11
21
11
25
14
NO
8.8
11
12
6.2
38
102
100/200
Sewer
NO
ND
0.2
13
34
72
4.6
6.7
8.8
ND
24
12
300
Sewer
0.5
2.6
7.0
43
39,000
ND
1.1
3.9
14
40
29,000
1700
500
Sewer
0.4
0.4
ND
3.3
85
134
0.8
0.8
ND
0.2
68
377
General
Sewer
Incinerator
Area #1
9.2
139
189
870
30,000
ND
14
304
293
988
4300
35,000
General
Sewer
Incinerat
Area #2
ND
0.03
0.07
0.4
1.3
0.7
ND
0.05
0.02
0.1
4.0
5.8
34
-------
en
Figure 7
Location Map
USEPA Sampling Locations
Dow Chemical Process Sewer Sludge
October 1984
Legend
50
Sampling Site
50 Sewer
-------
Table 12
Pol lutant Summary
Riverbank Revetment Section #1 Sediment
Dow Chemical - Midland Plant
October 1984
Pol 1utant Concentration (ppm)
Volatiles
Benzene 24
Chlorobenzene 184
Chloroform 22
Tetrachloroethene 6300
Trichloroethene 38
Acid and Base Neutral
2,4-dichlorophenol 42
Phenol 25
1,2,4-trichlorobenzene 940
Hexachl orobenzene 1730
Hexachloroethane 150
1,2-dichlorobenzene 1180
1,3-dichlorobenzene 250
1,4-dichlorobenzene 960
Fluoranthene <20
Hexachlorobutadiene 5300
Hexachlorocyclopentadiene 5300
Naphthalene <20
Phenanthrene <20
Pyrene <20
Metals
Aluminum 4570
Antimony 50
Arsenic 113
Barium 125
Beryllium NO
Cadmium NO
Chromium 15
Cobalt ND
Copper 114
Iron 120,000
Lead ND
Manganese 253
Nickel 52
Selenium NO
Silver 20
Thallium NO
Ti n ND
Vanadium 48
Zinc 178
36
-------
Table 12 (continued)
Pollutant Concentration (ppb)
PCDDs and PCDFs
2378-TCDO 4
Total tetra CODs 146
Total penta CDOs 111
Total hexa COOs 180
Total hepta CDOs 365
OCOO 916
2378-TCOF 64
Total tetra COFs 249
Total penta COFs 127
Total hexa COFs 109
Total hepta CDFs 853
OCOF 2739
37
-------
other PCDOs and PCDFs. This area is impacted by discharges from the sludge
dewatering building, the incinerator, and contaminated sludges upstream in
the sewer system.
The sludge sample from the revetment system sump contain relatively high ppm
levels of several toxic organic pollutants including tetrachloroethene (6300
ppm); hexachlorobutadiene (5300 ppm); hexachl orocyclopentadiene (5300 ppm);
hexachl obenzene (1730 ppm); and other chlorinated benzenes and phenols at
levels up to about 1000 ppm. 2378-TCDD and 2378-TCDF were found at 4 ppb and
64 ppb, respectively, with levels of other PCODs and PCOFs in the high ppb to
low ppm range. These data suggest ground water at the site is highly contami-
nated at certain locations and that the RGIS has been at least partially
effective in intercepting contaminated ground water.
In 1978, after Dow Chemical notified the Michigan Department of Public Health
that it had found dioxin in native fish from the Tittabawassee River, Region V
conducted wastewater treatment system sludge and river sediment sampling
programs. The in-plant sludges and river sediments were analyzed for total
TCDDs. At that time, USEPA's analytical contractor (University of Nebraska)
could not conduct isomer-specific analyses for 2378-TCDD. The TCDD results for
the wastewater sludges are presented in Table 13. Phenol treatment system
sludges ranged from not quantifiable to 160 ppt (0.16 ppb) in the waste activated
sludge. TCDDs in the general treatment system sludges ranged from 283-5800 ppt
(0.28-5.8 ppb).
The highest concentration (5800 ppt) was found in the waste primary sludge
from the main plant wastewater treatment system, with lesser amounts in other
wastewater treatment system solids. Also, 0.38 ppt (380 ppq) of TCDD was found
in the untreated phenolic wastewater prior to treatment. TCDDs were not detected
at 0.25 ppt (250 ppq) in 2,4-D process waste then being disposed of by deep
well injection. At the time, Dow Chemical was disposing of wastewater treatment
plant sludges by incineration or landfilling.
An experimental wastewater and river water sampling program using activated
carbon to determine whether the wastewater discharge from Dow Chemical was a
dioxin source was also conducted in 1978. The results of that study are reviewed
in Section VI.8.2.
3. Tertiary Pond Sediments (Appendix A-4)
As noted earlier, Dow Chemical discharges the effluent from the biological
treatment facilities to a series of three ponds for additional treatment prior
to discharge to the Tittabawassee River via outfall 031. The flow is routed
first through a relatively small pentagon-shaped pond, then through a narrow
rectangular pond, followed by a large final polishing pond, called the tertiary
pond. The three ponds cover about 220 acres and average about 3-4 feet in
depth, resulting in a volumetric capacity of about 600 million gallons. The
estimated retention time is about 30 days for typical effluent flows in the
range of 20 million gallons per day.
38
-------
Table 13
USEPA-Region V
Sample Number
EA06S18A
EA06S18B
EA06S19
EA06S24
EA06S25
EA06S26
EA06S28
UNL
Number
UN166
UN167
UN168
UN169
UN170
UN171
UN172
TCDDs In Dow Chemical - Midland Plant Samples
October 1978
EA06S29
UN173
Sample Site
Phenol Treatment System - Waste Primary Sludge
Phenol Treatment System - Waste Primary Sludge
Phenol Treatment System - Waste Activated Sludge
General Treatment System - Waste Primary Sludge
General Treatment System - Primary Skimmings
General Treatment System - Waste Activated Sludge
2,4-D Process Waste to Deep Well
Raw Phenol Wastewaters after Equalization
TCDDs
(ppt) DL
NQ
( 8)
NQ
160
5800
470
283
ND
( 8)
(12)
(56)
(10)
(48)
(0.25)
Analyst's Notes
Small positive signals
detected near detection
limit.
Peak observed at M/Z 320
and 322, but isotope
ratio incorrect for
positive identification.
0.38 (0.20)
Note: (1) UNL - University of Nebraska - Analytical Contractor
(2) DL - Analytical detection level
(3) ND - Not detected at stated detection level
(4) NQ - Detected at or near detection level, but not quantified
-------
In July 1984, Region V collected unconsolidated sediment samples at five
locations in the ponds, one each in the primary (pentagonal) and secondary
(rectangular) ponds and three in the larger tertiary pond. Figure 8 presents
the approximate sampling locations. At each site, surface sediments (approxi-
mately 0-3") and bottom pond sediments (bottom 3") were collected and analyzed
for metals, volatile pollutants, and semi-volatile pollutants, including PCBs,
pesticides, and PCDDs and PCDFs. At the time samples were collected, the
unconsolidated sediment layers above the clay layers in the primary and secondary
ponds were found to be about twelve to fifteen inches, while sediments in the
tertiary pond averaged about six inches in thickness. Dow Chemical reports that
sediments have not been dredged from the ponds since they were put into service.
Table 14 presents a summary of the positive findings for volatile and semi-
volatile pollutants. Data for PCDDs and PCDFs are presented in Table 15.
Metals data are presented in Appendix A-4. Because the sediment layer in each
pond was not compacted, the bottom sediment samples may have contained some of
the pond bottom clay layer as opposed to only sediments. The results reviewed
below should be viewed accordingly.
Volatile pollutants, including benzene, chlorobenzene, ethylbenzene,
toluene, acetone, and xylenes were found at the highest levels in the surface
sediments from the primary pond. Concentrations ranged from 310 ppb (xylenes)
to 4000 ppb (chlorobenzene). Lower levels of the same pollutants found in
surface sediments (10 to 190 ppb) were also found in primary pond bottom
sediments. The secondary pond surface sediments were contaminated by the same
pollutants to a lesser extent (<10 to 230 ppb) than the primary pond surface
sediments. In similar fashion, the secondary pond bottom sediments were not as
highly contaminated (<10 to 50 ppb) as the secondary pond surface sediments.
Relatively few volatile pollutants were found in the tertiary pond surface
sediments and virtually none at low ppb levels in the bottom sediments.
On a gross basis, the semi-volatile organic pollutants were distributed in
roughly the same manner as were the volatile pollutants. However, the secondary
pond surface sediments contained relatively high levels of a few pollutants
(4-methyl phenol-17,000 ppb; l,2,4-trichlorobenzene-35,000 ppb; 1,2-dichloro-
benzene-2700 ppb; and heptachlor-12,000 ppb) not found in primary pond surface
sediments. 1,3-Dichlorobenzene and 1,4-dichlorobenzene were found in primary
pond sediments at 13,000 ppb and 67,000 ppb, respectively. The tertiary pond
surface sediments contained pentachlorophenol (3950 ppb) and pyrene (2300 ppb)
which were not found in surface or bottom sediments from the other ponds. The
tertiary pond surface sediments also contained relatively low ppb levels (27 to
61 ppb) of four pesticide products.
Without long-term data on the effluent characteristics from Dow Chemical's
biological treatment facility and some notion of sediment deposition rates, it
is difficult to determine what the significance of these findings might be.
However, pollutants associated with the production of chlorinated phenols,
notably the chlorinated benzenes, appear to be the principal organic pollutants
found in the sediments. Inasmuch as most of the chlorinated phenols production
at the Midland plant was terminated in the late 1970s, the contribution of
these pollutants from process wastewaters in the future should be considerably
less than in the past. The current raw wastewater loadings of chlorinated
40
-------
Figure 8
Location Map
USEPA Sampling Locations
Dow Chemical Tertiary Pond Sediments
July 1984
Legend
Surface and Bottom Sediment
Sampling Site
-------
Table 14
Volatile
Pollutants
Benzene
Chiorobenzene
Ethyl benzene
Methylene chloride
Chloroform
Bromoform
Tetrachloroethane
Toluene
Trichloroethene
Acetone
Styrene
Total xylenes
Toxic Organic Pollutant Summary
Dow Chemical Treatment Pond Sediments
July 1984
ug/kg (parts per billion (ppb))
Primary Pond Secondary Pond Tertiary Pond
Surface Bottom Surface Bottom Surface Bott<
500
4000
2800
1900B
340
1300
310
20
78
190
1100B
9.4
<50
9.7
Acid and Base Neutral Pollutants**
4-nitrophenol
Pentachlorophenol
Phenol
4-methylphenol
1,2,4-trichlorobenzene
Hexachlorobenzene
1,2-dichl orobenzene
1,3-dichlorobenzene 13,000
1,4-dichl orobenzene 67,000
Naphthalene <10
Bis(2-ethylhexyl )phthalate 9500
Di-n-butyl phthalate <10
Di-n-octyl phthalate
Chrysene <10
Pyrene
PCB/Pesticide Pollutants
4,4'-DDT
Endrin
Endrin aldehyde
Heptachlor
2000
10,000
30
160
230
988
16
110
<2.5
<50
<2.5
39
17,000
35,000
2700
<10
8500
2300
480
330
12,000
<2.5
23
25
50 B
<2.5
9.8
12
26
<2.5
15
1700
10.2
6.2
160 B
367
<17 B
<50
3950
<5
1460
<1800
1600
<5
2300
39
61
40
27
Notes: (1) -- = Not detected.
(2) B = Blank contamination.
(3) *Average of three (3) tertiary pond samples.
(4) **Tertiary pond surface based on average of two (2) samples,
42
-------
Table 15
CO
PCDDs and PCDFs
2378-TCDD
Total tetra CDDs
Total penta CDDs
Total hexa CDDs
Total hepta CDDs
OCDD
2378-TCDF
Total tetra CDFs
Total penta CDFs
Total hexa CDFs
Total hepta CDFs
OCDF
Primary Pond
Surface
1.7
18
10
14
125
482
_ _
95
26
20
84
117
Bottom
0.87
10
5.9
17
64
168
0.25
19
6.5
7.0
18
22
PCDD and PCDF Summary
Dow Chemical Treatment Pond Sediments
July 1984
ng/g (parts per billion (ppb))
Secondary Pond
Surface
3.8
26
23
38
840
920
1.8
93
14
16
320
256
Bottom
— —
0.25
--
--
6.0
16
0.10
1.5
--
--
1.3
2.8
Upper
Surface
0.14
1.5
0.81
2.6
17
72
0.09
15
2.5
1.8
4.5
7.3
Teritary Pond
Bottom
0.05
0.41
0.26
0.49
2.0
12
0.04
3.6
0.43
0.29
0.50
0.94
Mid
Surface
0.93
9.2
6.3
26
201
324
0.90
44
3.4
8.0
31
33
Bottom
0.02
0.23
0.08
0.75
6.4
23
0.06
1.5
0.26
0.20
0.80
1.7
Lower
Surface
0.10
2.0
0.67
1.7
11
44
0.15
22
2.0
1.4
5.1
5.6
Bottom
0.03
0.11
--
--
1.0
4.4
0.02
0.49
0.09
0.06
0.20
0.35
Notes: (1) -- = Not detected.
(2) Data reported on wet weight basis with the
exception of tertiary pond-lower-bottom sample.
-------
benzene as depicted in Table 4 is relatively low (about 30 Ibs/day, 13.6 kg/day).
The presence of semi-volatile compounds in pond sediments should not be of
great concern from an effluent discharge standpoint since operation of the
recently installed effluent filter should effectively minimize any slug dis-
charges of pollutants that might have occurred during periods of turbulent
conditions in the ponds. The filter system affords little or no protection for
volatile pollutants that may be released from pond sediments. The distribution
of these pollutants in the three ponds suggest that slug discharges at outfall
031 resulting from disturbing the sediments in the primary or secondary ponds,
are not likely. Continued low-level releases of the compounds over time can be
expected.
PCDOs and PCDFs are more evenly distributed throughout the pond system than
other semi-volatile pollutants (Table 15). This is probably due to the relative
particle size distribution of the suspended solids to which the PCDOs and PCDFs
are attached. Dow Chemical reports that much of the discharge of 2378-TCDO
from outfall 031 can be attributed to wastewaters from the hazardous waste
incinerator. _4/ Fine particulates scrubbed from the exhaust gases are believed
to pass through the biological treatment facility. If this is the case, one
would expect 2378-TCDD, as well as other PCDDs and PCDFs, to be distributed
over the large surface area of the pond system. The data presented in Table 15
support this hypothesis. Note that higher levels of PCDDs and PCDFs were found
in primary and secondary pond sediments than in tertiary pond sediments; also,
the lowest levels of PCDDs and PCDFs were found in tertiary pond surface
sediments closest to the discharge from the pond to outfall 031. Based upon
recent soil study results for the Midland area, Region V has concluded that
atmospheric deposition of 2378-TCDD from Dow Chemical incinerator emissions and
other process and fugitive sources have resulted in widespread low-level
2378-TCDD contamination of city soils. IQb/ If atmospheric deposition was the
primary transport mechanism for PCDDs and PCDFs to pond sediment, one would
expect a fairly uniform distribution across the system. The data presented
here indicate the principal source of PCDDs and PCDFs in pond sediments is the
biological treatment plant effluent as opposed to atmpspheric deposition.
As with the other semi-volatile pollutants, operation of Dow Chemical's effluent
filter should minimize any slug discharges of PCDDs and PCDFs from outfall 031
during turbulent pond conditions. These data suggest the pond system has
provided a measure of effluent reduction benefit not otherwise available until
installation of the final effluent filter system. Tittabawassee River sediments
are compared with treatment pond sediments elsewhere in this report.
B. Wastewater Effluent Sampling - Outfall 031 (1978-1985)
Over the past several years, Dow Chemical has significantly reduced the
wastewater discharge flow to the Tittabawassee River from the Midland plant.
In the early 1970's, wastewater discharge flows in excess of 50 MGD were common.
During the 1981 survey, the average discharge was about 34 MGD, and at the time
of the August 1984 survey, the average discharge was about 20 MGD. At this
writing (February 1986), the discharge from outfall 031 is averaging about
18 MGD. The reduction of flow is largely accounted for by changes in production
operations at the Midland plant and installation of cooling water recycle
systems and other water conservation measures.
44
-------
Trends in the discharge loadings of conventional, nonconventional, and
toxic pollutants from outfall 031 are reviewed below. Data for PCDDs and PCDFs
and available biomonitoring data are reviewed separately. At the time of the
last USEPA sampling program (December 1984), Dow Chemical had not completed
construction of the final effluent mixed-media filtration system for the dis-
charge from outfall 031. Region V initiated a short-term grab sampling program
of a pilot filter system to estimate the likely effects of the full-scale
filter on effluent quality. Tables 16-26 present summaries of the effluent
data from the Region V September 1981 and August 1984 surveys, recent Dow
Chemical monitoring data, and the December 1984 USEPA sampling program for the
filtration pilot plant.
The USEPA effluent data presented in Tables 16-26 are gross discharge
loadings or concentrations as opposed to net loadings or concentrations.
Gross discharge loadings and concentrations are presented because most pollu-
tants were either not detected or not detected at significant levels in the
Tittabawassee River. Also, the retention time of the water in the Midland
plant is so long (up to 30 days) that adjusting effluent concentrations for
intake concentrations for intake and effluent samples collected simultaneously
would not be meaningful. Water intake data are presented in the appendices
with effluent data collected during the same surveys. The Dow Chemical data
for total dissolved solids, total suspended solids, BODs, and ammonia-N are
net discharge loadings reported in accordance with the terms of NPDES permit
MI0000868.
1. Conventional. Non-Conventional, and Toxic Pollutants
(Appendices B-1 (1981 data); B-2 (1984 data); B-3 (Dow Chemical data)
Table 16 presents data for conventional and nonconventional pollutants.
Despite a reduction in flow of more than 40%, the discharge of total dissolved
solids monitored by USEPA has remained within a narrow range of 809,000 to
830,000 Ibs/day. More frequent monitoring by Dow Chemical confirm the magnitude
of the total dissolved solids discharge. About 75% of the total suspended
solids contained in the tertiary pond effluent and more than half of the influent
total phosphorus loading were removed by the pilot filter. Recent NPDES permit
self-monitoring data by Dow Chemical with the full-scale filtration system on
line confirm the expected performance for suspended solids removal. Based upon
the 1981 survey, Region V characterized the discharge for outfall 031 as the
largest point source of phosphorus to the Saginaw Bay drainage basin. The
annual discharge was estimated to be about 40 tons. The August 1984 sampling
data indicate the annual discharge before filtration may have been reduced to
about 16 tons. The pilot plant data indicate the current annual discharge may
be in the range of 5 to 6 tons. Phosphorus data for the full-scale filtration
system are not available at this writing.
Table 17 summarizes volatile pollutant data. The more recent data indicate
that the discharge of volatile pollutants has been significantly reduced from
1981. Fewer compounds were detected by Region V in 1984, and those detected
were generally found at lower levels. The discharge loadings of chloroform,
carbon tetrachloride, and methylene chloride were in the range of 1 to 3 Ibs/day,
with lesser amounts of 1,2-dichloroethane and 1,1,1-trichloroethane. Methylene
chloride, carbon tetrachloride, and chloroform were found at the highest levels
45
-------
Table 16
CTt
Conventional and
Other Pollutants
Total dissolved solids
Chloride
Fluoride
Sulfate
Total suspended solids
Chemical oxygen demand
Total organic carbon
BOD5
Total kjeldahl nitrogen
Ammonia-N
N02 and N03-N
Total phosphorus
Conventional and Non-Conventional Pollutants Summary
Dow Chemical - Midland Plant
Outfall 031
(Gross Discharge Loadings in Ibs/day
except as noted - See Note 1)
USEPA - September 1981
Max.
960,000
428,000
200
87,000
7130
41,300
7880
1500
2070
1750
115
420
Min.
676,000
303,000
160
64,000
1450
29,200
4640
1370
1630
1180
11
130
Avg.
809,000
357,000
190
77,000
3700
35,900
6010
1440
1820
1470
68
254
USEPA -
Aug. 1984
815,000
7485
1338
355
134
90
Dow Chemical -
July 1984-December 1985
Max.
960,000
4778
893
508
140
Min.
454,000
663
18
0
24
Avg.
705,000
2308
423
124
62
USEPA - December 1984
Pilot
Plant
Influent
(031)
830,000
3905
\
602
163
68
Pilot
Plant
Effluent
828,000
976
391
162
30
Notes (1) Dow Chemical phosphorus data are monthly averages based upon average flow and phosphorus data from
monthly operating reports (MORs) submitted to Michigan DNR. Dow Chemical data for total dissolved
solids, total suspended solids, BODs, and ammonia-N are net discharge loadings.
(2) USEPA September 1982 average data are based upon four 24-hour composite samples taken at weekly
invervals.
(3) USEPA August 1984 data are for one 24-hour composite sample.
(4) USEPA December 1984 pilot plant filter data are for one grab sample.
-------
Table 17
Volatile Toxic
Organic Pollutants
Volatile Organic Summary
Dow Chemical - Midland Plant
Outfall 031
(Gross Discharge Loadings in Ibs/day)
USEPA - September 1981
Max.
45.00B
5.25
1.80
9.38B
3.75B
4.13
18.77
1.24B
1.91
1.39
4.88
7.51
1.00
4.50
—
Min.
1.30B
0.70
1.00
2.87B
2.00B
0.92
2.10
* -
0.55
0.35
__
0.80
__
—
—
Avg.
24.14B
2.27
1.37
5.08B
2.72B
2.02
8.22
0.69
1.12
0.78
1.97
3.15
0.33
1.50
—
USEPA -
Aug. 1984
Avg.
1.71B
__
--
3.25
0.98
0.80
2.76
-_
--
--
—
—
--
--
<0.81
Dow Chemical -
July 1984-December 1985
Max.
8.8
--
--
5.5
--
5.2
14.4
--
--
--
__
3.5
--
31.4
5.1
Min.
._
--
--
—
--
--
--
--
—
--
--
--
--
--
Avg.
2.5
__*
__*
2.2
__*
1.2
4.1
__*
--*
*
__*
0.5
0.05
2.9
0.9
Methylene chloride
1,1-di chloroethylene
1,1-dichloroethane
Chloroform
1,2-dichloroethane
1,1,1-trichloroethane
Carbon tetrachloride
Bromodichloromethane
1,2-dichloropropane
Trichloroethylene
Dibromochloromethane
1,1,2,2-tetrachloroethane
Chlorobenzene
Bromoform
Tetrachloroethene
1,2-dibromoethane
1,1,2-trichloroethane
Notes (1) — = Not detected.
(2) B = Blank contamination.
(3) * = One sample only.
(4) Dow Chemical data are monthly averages based on monthly operating reports (MORs) submitted to Michigan DNR for
the period of July 1984-December 1985 unless otherwise noted.
USEPA - December 1984
Pilot
Plant
Influent
(031)
2.93B
—
0.81
Pilot
Plant
Effluent
3.42B
1.79
0.81
-------
in the untreated wastewaters (Table 7). Dow Chemical monitoring data for the
period July 1984 to December 1985 indicate the average discharges of carbon
tetrachloride, methylene chloride, bromoform, and chloroform are in the 2 to
4 Ibs/day range. Other volatile pollutants routinely found in the outfall 031
discharge by Dow Chemical include 1,1,1-trichloroethane, tetrachloroethene, and
1,1,2,2-tetrachloroethane. Limited data for the filtration pilot plant suggest
the full-scale filtration system will have little or no impact on the discharge
of volatile pollutants from the Midland plant. The physical and chemical
properties of the volatile compounds are such that filtration is not an effective
removal mechanism.
Data for semi-volatile compounds are presented in Table 18. During the
1984 USEPA survey, semi-volatile compounds were not detected in the discharge
from outfall 031, while in 1981, several compounds, including chlorinated
phenols and chlorinated benzenes, were discharged in the 0.1 to 2.0 Ibs/day
range. It is likely that some semi-volatile compounds were present in 1984
but not detected. Detection levels at the USEPA contract laboratory were
in the 10 to 100 ppb range. Recent monitoring by Dow Chemical also detected
chlorinated benzenes in the same range as the 1981 data, and bischlorobutyl
ether as high as 10.7 Ibs/day. Other compounds detected by Dow Chemical include
chlorinated benzenes (average discharge in the range of 0.5 Ibs/day); chlorinat-
ed phenols, including 2,4-dichlorophenol; 2,4,6-trichlorophenol and pentachloro-
phenol; and bis (2-ethylhexyl) phthalate. The USEPA pilot plant sampling
suggests that traces of 2,4,6-trichlorophenol and pentachlorophenol may remain
in the discharge after filtration. Table 19 presents data for herbicides,
pesticides, and PCBs. The more recent USEPA and Dow Chemical data suggest no
detectable discharge of pesticides and PCBs, but continued discharge of silvex,
2,4-D, 2,6-D, and Dinoseb. Many semi-volatile organic compounds including
herbicides, pesticides, and PCBs tend to associate with suspended particulates
in aqueous systems. Thus, operation of the full-scale filtration system is
expected to result in lower discharge levels of these pollutants than would
otherwise occur.
Metals data are presented in Table 20. Most toxic metals were found at
relatively low concentrations in both the 1981 and more recent sampling programs
(i.e., less than 50 ppb). Zinc is the only toxic metal detected in the pilot
plant effluent (about 100 ppb); a projected full-scale discharge loading is
about 21 Ibs/day. Dow Chemical reported discharges of chromium and zinc without
the final effluent filter in place of 33 and 50 Ibs/day, respectively. Lower
discharge levels are expected with the full-scale filtration system in place.
2. PCDDs and PCDFs
(Appendix 8-4 (1978 data); B-5 (1981 data); B-6 (1984 data);
B-7 (Dow Chemical data))
As noted earlier, Region V conducted an experimental monitoring study at
the Dow Chemical - Midland Plant during September 1978 to determine if the
presence of dioxin in fish from the Tittabawassee River was attributable to the
discharge from outfall 031. At that time, USEPA did not have the capability to
analyze for 2378-TCDD in water samples at concentrations in the sub-part per
trillion range. In an attempt to concentrate 2378-TCDD that may have been
present, Region V developed a granular activated carbon canister sampling
48
-------
Table 18
Acid and Base
Neutral Pollutants
2-chlorophenol
Phenol
2,4-dichlorophenol
2,4,6-trichlorophenol
Pentachlorophenol
Pyrene
2-chloronaphthalene
1,2-dichlorobenzene
1,3-dichlorobenzene
1,4-dichlorobenzene
1,2,4-trichlorobenzene
Di-n-butyl phthalate
Butyl benzyl phthalate
Bis(2-ethylhexyl) phthalate
Bis(2-chloroethyl) ether
Isophorone
Dioctyl phthalate
Acenaphthene
Bis(2-chloroisopropyl) ether
1,2,3-trichlorobenzene
1,2,4,5-tetrachlorobenzene
Bis(chlorobutyl) ether
Aniline
Naphthalene
Acid and Base Neutral Pollutant Summary
Dow Chemical - Midland Plant
Outfall 031
(Gross Discharge Loadings in Ibs/day)
USEPA - September 1981
Max.
0.28
0.28
0.35
1.25
4.35
0.27
0.26
trace
0.71
0.75
1.39
0.21B
trace
60. 68
1.28
trace
2.05
0.17
__
— _
__
__
_._
Min.
trace
__
__
__
__
__
__
__
0.18
0.19
0.32
—
__
3.42
0.04
— B
_-
_-
__
_ —
_ _
— —
- —
Avg.
0.07
0.07
0.15
0.31
1.46
0.07
0.07
trace
0.42
0.47
0.87
0.05B
trace
23.08B
0.46
trace
0.51
0.04
——
_ _
__
__
__
USEPA -
Aug. 1984
„
--
—
--
—
--
--
—
--
--
—
—
—
--
--
--
—
--
— —
__
—
Dow Chemical -
July 1984-December 1985
Max.
0.2
0.7
0.7
1.0
4.6
--
—
3.7
0.9
1.8
1.9
—
--
--
0.7
—
—
--
_..
0.25
1.59
10.73
0.08
.1
Min.
_ —
—
—
—
—
—
—
—
—
—
—
--
--
—
--
--
--
--
• _
__
0.53
0.37
0.02
—
Avg.
0.01
0.3
0.1
0.1
1.5
__*
__*
0.5
0.2
0.3
0.5
—
__*
0.67*
0.3
__*
*
__*
__**
0.08**
1.00**
4.26**
0.03**
0.04
Notes
(1)
(2)
(3)
(4)
(5)
(6)
B =
* =
** =
< =
USEPA - December 1984
Pilot
Plant
Influent
(031)
—
<0.16B
<0.49
<0.49
Pilot
Plant
Effluent
<0.33
<0.33
<0.33
<0.49
<0.49
Not detected.
Blank contamination.
One sample only.
Average of three samples.
Compound present but at less than stated value
Dow Chemical data are monthly averages based on monthly operating reports (MORs) submitted to Michigan DNR
for the period of July 1984-December 1985 unless otherwise noted.
-------
Table 19
tn
CD
Herbicides/
PCB/Pesticides
Pollutants
Herbicides
Dichloroprop
2.4-D
S i 1 vex
2,4,5-T
2,6-D
Dinoseb
PCB/Pesticides
Aldrin
4,4'-ODD
Endosulfan I
Endrin aldehyde
Heptachlor epoxide
Beta-BHC
Gamma-BHC
PCB-1242
PCB-1254
PC8-1260
Herbicides/PCB/Pesticides Summary
Dow Chemical - Midland Plant
Outfall 031
(Gross Discharge Loadings in Ibs/day)
USEPA - September 1981
Max.
0.22
0.30
2.14
0.40
--
0.21
O.OlBl
0.03
0.021
0.022
0.01
0.01
1.10
0.09
0.20
Min.
.-
—
--
--
"
--
—
__
—
._
--
--
Avg.
0.06
0.08
0.94
0.15
--
"
0.08 B
0.005
0.008
0.011
0.011»2
0.003
0.003
0.28
0.02
0.05
USEPA -
Aug. 1984
—
~
__
__
_ w
__
--
Dow Chemical -
July 1984-December 1985
Max.
0.058
1.44
_ _
0.84
1.95
—
— —
__
_ _
w_
__
—
Min.
0.004
0.45
._
0.44
*~ ~
--
—
— _
_ —
— —
__
--
Avg.
0.015*
1.01**
__ **
0.59**
1.22**
--
__ **
— ^.
— —
— —
. .
--
USEPA - December 1984
Pilot
Plant
Influent
(031)
—
—
— _
— _
— _
— _
-_
Pilot
Plant
Effluent
—
—
•» — .
_ ^
* »
» ^
--.
Notes (1) — = Not detected.
(2) B = Blank contamination.
(3) *Not confirmed on second column GC/ECD.
(4) 2Not confirmed on second column GC/ECO due to interference.
(5) * = Dow Chemical monthly average MOR data.
(6) ** = Average of three samples; other Dow Chemical data - one sample.
-------
Table 20
Metals Summary
Dow Chemical - Midland Plant
Outfall 031
(Discharge Loadings in Ibs/day)
USEPA - September 1981
Metal Pollutants Max.
Al umi num
Antimony
Arsenic 0.87
Barium
Beryl lium
Cadmium
Chromium 3.75
Cobalt
Copper 1.40
Iron
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Thai li urn
Tin
Vanadi urn
Zinc 39.4
Min.
--
--
2.30
--
--
18.0
Avg.
0.22
--
3.21
0.78
--
26.9
USEPA -
Aug. 1984
— B
1.35
—
6.67
--
--
—
—
1.3
5.86
—
31.9
--
4.39
—
—
—
5.21
--
4.07
Dow Chemi cal -
December 1985
Max.
--
—
—
--
—
—
—
--
—
—
—
--
Min.
--
—
--
--
--
—
--
—
--
--
--
--
Avg .
8.34
--
--
--
33.36
—
—
--
--
--
--
50.0
USEPA - December 1984
Pilot
Plant
Inf 1 uent
(031)
21.6
8.95
0.21
6.8
66.7
48.2
2.76
39.2
Pilot
Plant
Effluent
—
9.27
0.39
2.1
3.7
17.4
45.6
2.44
21.2
Notes (1) B = Blank contamination.
(2) -- = Not detected.
(3) Dow Chemical metals data based on one-time sampling event.
-------
system to sample large volumes of water over time. The study design called for
suspending three sampler assemblies in the discharge from outfall 031 (tertiary
pond overflow) and two assemblies at each of the following locations in the
Tittabawassee River: upstream of the Dow Dam; downstream of outfall 031 near
Smith's Crossing Road; and at Freeland Road (Appendix B-4). Figure 9 shows the
approximate sampling locations. The plan was to operate the samplers for up to
one week, until 10,000 liters of water were filtered, or until the filters
became clogged with sediment. The volumetric flow through the filters ranged
from 1100 liters to 5800 liters after several days of operation in the field.
The results are presented in Table 21.
Only filters from Dow Chemical outfall 031 and from the Tittabawassee River
upstream of the Dow Dam were extracted by EPA's Pesticides Monitoring Laboratory
at Bay St. Louis, Mississippi, and analyzed by EPA's Environmental Monitoring
Systems Laboratory at Research Triangle Park, North Carolina. 2378-TCDD was
not detected in the extract from either sample. However, three other TCDD
isomers were detected in the extract from the outfall 031 sample; none were
detected in the Tittabawassee River upstream sample. Because neither the
collection efficiency of the activated carbon sampling systems for 2378-TCDD
and other PCDDs, nor the efficiency of extracting those compounds from the
carbon were known, the results must be characterized as only qualitative.
Nonetheless, the limited results from this study indicated that Dow Chemical
was discharging TCDDs to the Tittabawassee River.
In September 1981, Region V conducted additional dioxin studies at the Dow
Chemical- Midland Plant. I/ As part of that work, an experimental large volume
effluent sampling scheme was developed to allow the detection of 2378-TCDD and
other PCDDs and PCDFs in the sub-part per trillion range. A method validation
pilot study was conducted by the Brehm Laboratory at Wright State University
under contract to Region V. 117 In short, this method consists of obtaining a
large volume water sample; performing an extraction with a suitable solvent for
an extended period; performing solvent exchange and clean up; and, analyses of
the extract for the desired compounds by HRGC-HRMS. After completion of the
pilot study, actual effluent and river samples were obtained at the following
locations:
Dow Chemical - Midland Plant
. Lake Huron Water Intake
. Tittabawassee River Intake
. Outfall 005 (Power House Fly Ash Pond Discharge)
. Outfall 031 (Main Process Wastewater Discharge)
Tittabawassee River
. Outfall 031 Plume
. Smith's Crossing Road
Because of the large volume of sample required for analysis, the 24-hour
composite sample for each site was collected as two separate 12-hour composite
samples in separate containers. The analytical contractor, Battelle Columbus
Laboratories, Columbus, Ohio (formerly Battelle Memorial Institute), was to
52
-------
Figure 9
Location Map
1978 USEPA Dioxin Study
Tittabawassee River
Dow Chemical - Midland Plant
See detail below for additional
sampling locations
River at Smiths Crossing
re
River at Freeland Road
River Upstream
of Oow Oam
Dow The Oow Chemical Company
Oam
Oow Tertiary Pond
Over* low
53
-------
Table 21
en
Sample No.
EA06S01
EA06S02
EA06S03
EA06S04
EA06S05
EA06S06
EA06S07
EA06S08
EA06S09
EA06S10
EA06S11
1978 USEPA Dioxin Study
Tittabawassee River - Dow Chemical - Midland Plant
Large Volume Activated Carbon Samples
Sample Site
Dow Chemical-Outfall 031
Tittabawassee River upstream
of Dow Dam at Dow Bridge
Tittabawassee River near
Smith's Crossing Road
Tittabawassee River at
Freeland Road
Blank Carbon No. 1
Blank Carbon No. 2
Volume of Water
Sampled
3900 liters
3100
4600
5800
3100
1400
1100
5000
4300
Analytical Results
2378-TCDD
NA
ND
ND
NA
NA
NA
NA
NA
NA
Note 1
Note 2
Notes 3 and 4
Note 3
Note 1
Notes: (1) Samples EA06S01 (Dow Chemical-Outfall 031) and EA06S10 (Blank Carbon No. 1) were provided
to Dow Chemical for comparative analyses. Analytical results were not received from Dow
Chemical for these samples.
(2) NA - Not analyzed.
(3) ND - Not detected; detection levels of 35ci_TCDD reported as 2.0 parts per quadrillion
(1015) for sample EA06S03 and 50 parts per quintillion for sample EA06S04. The
detection limits are based upon theoretical 100% collection and extraction efficiency.
(4) Three TCDD isomers were detected in sample EA06S03 (Dow Chemical effluent).
(5) The collection and analytical extraction efficiencies of the carbon filters for 2378-TCDD
had not been determined at the time of the 1978 study.
-------
conduct solvent extraction on the entire volume of sample collected at each
site and perform HRGC/HRMS analyses on each extract. However, Battelle
extracted only one portion of the 24-hour composite sample. After the results
were reported, Region V could not arrange for confirmatory analyses on the same
samples analyzed by Battelle because of insufficient extract volume remaining
from the Battelle analyses. Consequently, Region V made arrangements for
extraction of the remaining sample at USEPA's Pesticide Monitoring Laboratory at
Bay St. Louis, Mississippi, and analyses of the extracts by USEPA's Environmental
Monitoring Systems Laboratoy (EMSL) at Research Triangle Park, North Carolina.
Unfortunately, because Battelle did not extract the entire volume of sample
obtained at each site, subsequent analyses by USEPA-EMSL were not conducted on
the same samples analyzed by Battelle. Thus, the Battelle and USEPA-EMSL data
presented in Table 22 are not fully comparable.
Based upon the quality control work completed for the Battelle analyses,
including the USEPA-EMSL analyses, the data reported at Battelle for PCDDs are
considered tentative. Due to the presence of chlorinated diphenyl ethers, as
determined by USEPA-EMSL in the remaining sample volumes, the Battelle results
for PCDFs are not considered valid and have not been reported in Table 22.
Based upon the quality control work completed for the USEPA-EMSL analyses,
those results for PCDOs are considered valid. EMSL qualified the PCDF data
as tentative without confirmation by a second laboratory. Dow Chemical was
provided split samples for this study along with the extraction and analytical
protocols. Analytical results for the split samples were not received from Dow
Chemical.
Although the data presented in Table 22 have limitations as described above,
they do provide a clear indication that Dow Chemical was discharging PCDDs and
PCDFs to the Tittabawassee River. The Lake Huron and Tittabawassee River water
intakes had no detectable PCDDs or PCDFs, while the discharge from outfall 031
was found to contain 2378-TCDD at 50 ppq (Battalia's analysis), and 1368-TCDD
(144 ppq) and 1379-TCDD (29 ppq) by EMSL. HxCDDs, OCDDs, TCDFs, HpCDFs, and
OCDFs were also found in the discharge by EMSL. The Tittabawasee River
downstream from outfall 031 was also found to be contaminated with PCDDS and
PCDFs. 2378-TCOD was identified at 39 ppq by USEPA, along with higher levels of
higher chlorinated PCDDs and PCDFs than found in outfall 031. OCDD was found
in the discharge from outfall 005 at 228 ppq, most likely the result of ash
handling operations from the powerhouse. The 1981 data reported for outfall
031 from EMSL are consistent with data reported by USEPA for samples obtained in
1984 and subsequent analyses reported by Dow Chemical.
Table 23 presents a summary of data for PCDDs and PCDFs at Dow Chemical
water intakes, outfall 031, and the pilot effluent filter discussed earlier.
These samples were obtained by USEPA during August and December 1984. The
Tittabawassee River intake, located downstream of outfall 005-Powerhouse Ash
Pond, did not contain any 2378-TCDD or 2378-TCDF but was found to contain 43
ppq of other TCDFs and nearly 200 ppq of OCDD. The ash pond discharge is the
suspected source of this contamination, although other upstream sources cannot
be ruled out with these data. Other PCDDs and PCDFs were not found to be present
at stated detection levels. The Lake Huron intake was found to be free of all
PCDDs and PCDFs at stated detection levels except OCDD which was detected at
55
-------
Table 22
Large Volume Water Sampling for PCOOs and PCOFs
Dow Chemical - Midland Plant
September 9-H). 1981
Results in parts per quadrillion (ppq)
Sample Location
Sample Number
Laboratory
PCODs
1368-TCDO
1379-TCOD
2378-TCDD
Total TCOOs
Total PeCODs
Total HxCOUs
Total HpCUOs
OCOO
PCOFs
2378-TCDF
Total TCOFs
Total PeCDFs
Total HxCOFs
Total HpCDFs
OCDF
Lake Huron
Water Intake
H1EH07S26
BM1-C EPA
NA
NA
<10
<10
<20
<40
<80
<100a
NV
NV
NV
NV
NV
NV
NO (8)
NO (8)
NO (8)
NA
ND(18)
NOJ18)
N0(37)
N0(72)
NO (3)
NO (7)
NA
NA
ND(43)
ND{53)
T1 ttabawasse
River Intake
81EH07S13
BM1-C EPA
NA
NA
<10
<10
<20
<40
<80*
<100*
NV
NV
NV
NV
NV
NV
Nl) (7)
NO (7)
NO (7)
NA
ND(32)
N0(32)
N0(60)
NO (60)
NO (8)
NA
NA
NA
N0(54)
NO(S4)
Outfal 1 005
81EII075HH
BMl-C EPA
NA
NA
<120a
2300
<20
<40
<80
<100
NV
NV
NV
NV
NV
NV
Nf) (23)
Nl) (8)
NO (23)
NA
Nl)(108)
Nl)(108)
Nl) (62)
228 (62)
NO (20)
NA
NA
NA
Nl) (55)
NO (53)
Outfall 031
81EH07S39
BMl-C EPA
NA
NA
50
80
<20
<40
<80
<100
NV
NV
NV
NV
NV
NV
144 (8)
29 (8)
NO (8)
NA
NA
143(21)
ND(99)
543(99)
NO(ll)
50 to
2000C
NA
NA
453(55)
254(55)
Outfall 031
Plume Mixing Zone
81EH07S53
BMl-C EPA
NA
NA
45
70
50
<40a
-------
Table 23
PCDDs And PCDFs
Water Intakes, Outfall 031, Pilot Plant Filter
Dow Chemical - Midland Plant
Results in parts per quadrillion (ppq)
Water Intakes
August 28-29, T984
Tittabawassee River Lake Huron
2378-TCDD
Total Tetra CDDS
Total Penta CDDs
Total Hexa CDDs
Total Hepta CDDs
OCDD
2378-TCDF
Total Tetra CDFs
Total Penta CDFs
Total Hexa CDFs
Total Hepta CDFs
OCDF
NO (22)
ND (12)
ND(120)
ND (46)
ND (81)
188
ND (22)
43
ND (51)
ND (36)
ND (54)
ND(175)
ND (45)
ND (15)
ND(150)
ND (57)
ND(158)
305
ND (29)
ND (13)
ND (51)
ND (43)
ND(104)
ND(126)
Outfall 031
August 28-29, 1984 December 4. 1984
ND (50)
ND (35)
ND(126)
ND (82)
ND(191)
ND(333)
ND (56)
3940
ND (46)
ND (79)
ND (84)
ND(209)
ND (9)a
2000
350
180
1400
5400
ND (9)a
12000
1700
1500
7400
6600
Pilot Plant
Effluent
December 4, 1984
ND (8)3
69
ND(17)
180&
790&
ND (7)
1500
ND(33)
ND(15)
86
440b
Notes: (1) Samples obtained on August 28-29, 1984, were 24-hour composite samples.
(2) Samples obtained on December 4, 1984, were grab samples.
(3) a = Data for 2378-TCDD and 2378-TCDF were generated 3/1/85 using a Gometer SP 2330 column.
(4) b = Possible carryover from previous injection of analytical standard.
(5) ( ) = Detection level.
%
Removal
97
100
88
100
100
99
-------
about 300 ppq. This level would not be of concern from a public health stand-
point. OCDD is relatively nontoxic compared to 2378-TCDD and other PCDDs.
The presence of OCDO in this sample may be due to laboratory-induced contamina-
tion since OCOO is particularly difficult to clean from laboratory, apparatus.
2378-TCDD and other PCDOs were not detected in the discharge from outfall 031
during the August sampling study at detection levels ranging from 35 ppq (TCDDs)
to 333 ppq (OCDD). (Dow Chemical measured 2378-TCDD during August 1984 at 3.1
and 3.7 ppq). TCDFs were found at 3900 ppq. 2378-TCDF and other PCDFs were
not detected at detection levels ranging from 46 ppq (PeCDF) to 209 ppq (OCDF).
In December 1984, Region V obtained grab samples at the influent and
effluent of the pilot filter plant operated by Dow Chemical on the discharge
from outfall 031. These samples were obtained to further characterize the
discharge from outfall 031 for PCDDs and PCDFs and to obtain a rough assessment
of the expected performance for the full-scale filter system. The pilot plant
influent sample is listed as the December 4, 1984, outfall 031 effluent sample
in Table 23. 2378-TCDD and 2378-TCDF were not detected in the influent or
effluent samples at detection levels ranging from 7 to 9 ppq. (Dow Chemical
reported the 2378-TCDD concentration in outfall 031 as 5 ppq for a sample
obtained on December 4, 1984). The outfall 031 sample was found to contain
relatively high levels of other PCDDs and PCDFs. Despite some analytical
interferences for the pilot plant effluent sample, these limited data and the
data presented in Table 25 indicate the filter system should remove about 90%
of the PCDDs and PCDFs present in the outfall 031 discharge. The rate of
removal for PeCDOs, TCDFs, PeCDFs, HxCDFs, HpCDFs, and OCDF as determined by
the USEPA monitoring is about the same as that determined from the USEPA and Dow
data for TCDDs. Dow Chemical does not routinely report data for any PeCDDs nor
TCDFs (other than 2378-TCDF) or HxCDFs, HpCDFs, or OCDF. Further characteriza-
tion of the full-scale filter system now in operation should be conducted to
assess the residual loadings of PCDDs and PCDFs to the Tittabawassee River. As
shown below, Dow Chemical has characterized the full-scale filter operation for
2378-TCDD for the brief period of time the filter has been operated.
As part of its point source study of dioxin at the Midland plant _4/, Dow
Chemical conducted several measurements of PCDDs for outfall 031. Table 24
presents isomer-specific analyses of TCDOs for two samples conducted in 1983
and 2378-TCDD data for a third sample collected in early 1984. These samples
were obtained at outfall 031 prior to installation of the full-scale filter
system. Although the concentration of the sum of all TCDDs in each sample
varied (about 600 ppq vs 1600 ppq), the distribution of TCDDs remained about
the same. 1368-TCDD and 1379-TCDD were predominant. This is also true of
other data obtained at outfall 031 by Dow Chemical during pilot filtration
studies in March 1984. These data are presented in Table 25 along with data
for 2378-TCDF and higher chlorinated PCDDs. The 1368-TCDD and 1379-TCDD isomers
were the predominant TCDDs found in all of the effluent samples. These isomers
are often associated with combustion operations and the manufacture of 2,4-D.
127 The sum of the TCDDs in these sample generally exceeds the sum of the
higher chlorinated HxCDDs, HpCDDs, and even OCDD. This is not the case in most
environmental samples where HpCDDs and OCDD are generally found at much higher
levels than TCDDs. The tertiary pond sediments exhibited the latter, more common
environmental pattern.
58
-------
Table 24
Dow Chemical Effluent Monitoring
Tetrachloro Dibenzo-p-Dioxins
Outfall 031
Sample Date:
April 4, 1983
May 13, 1983
Species Monitored
Total ISO-TCDDS
ppq
Concentration
(LQD) Relative
Concentration
ppq (LOD) Relative %
1469. TCDD
1269. TCDD
1267. TCDD
1289. TCDD
1369. TCDD
1247+1248. TCDD
1278. TCDD
1268. TCDD
1237+1238. TCDD
1279. TCDD
1246. TCDD
1478. TCDD
1236. TCDD
1239. TCDD
1249. TCDD
1368. TCDD
1379. TCDD
1378. TCDD
1234. TCDD
N
N
N
N
11.0
67.0
12.0
11.0
360.0
9.0
N
7.0
7.0
N
8.0
750.0
270.0
34.0
5.0
(6.0)
(6.0)
(6.0)
(6.0)
(6.0)
( )
(6.0)
(6.0)
( )
(6.0)
(5.0)
(5.0)
(5.0)
(5.0)
(5.0)
( )
( " )
(5.0)
(5.0)
N
N
N
N
0.7
4.2
0.8
0.7
22.6
0.6
N
0.4
0.4
N
0.5
47.1
17.0
2.1
0.3
N
N
N
N
4.0
22.0
N
3.0
94.0
N
3.0
N
N
N
2.0
345.0
97.0
11.0
N
(3.0)
(3.0)
(3.0)
(3.0)
(2.0)
( )
(370)
(2.0)
( )
(2.0)
(2.0)
(2.0)
(2.0)
(2.0)
(2.0)
( )
( " )
(3.0)
(3.0)
N
N
N
N
0.7
3.7
N
0.5
15.9
N
0.5
N
N
N
0.3
58.3
16.4
1.9
N
1551.0
97.5
581.0
98.1
2378.TCDD 40.0 ( _ )
13C.2378.TCDD Recovery 85%
2.5
11.0
(2.0)
87%
1.9
Notes: (1) N = Not detected at LOD i.e. 2.5 X peak-to-valley noise.
(2) (_) = Signifies response > = 25 X peak-to-valley noise.
(3) 2I78-TCDD was detected at 31 ppq on January 30, 1984.
(4) Analyses completed by Dow Chemical Company.
59
-------
Table 25
Pilot Plant Filtration Studies
Dow Chemical - Midland Plant
March 1984
PCDDs and 2378-TCOFs
Parts per quadrillion (ppq)
Outfall 031
Species Monitored
1469. TCDO
1269. TCDO
1267. TCDD
1289. TCDD
1369. TCDD
1247+1248. TCDD
1278. TCDD
1268. TCDD
1237+1238. TCDD
1279. TCDD
1246. TCOD
1478. TCDD
1236. TCDD
1239. TCDD
1249. TCDD
1368. TCOO
1379. TCDD
1378. TCDD
1234. TCDD
Total ISO-TCDDs
2378. TCDD
2378. TCDF
124679+124689. HCDDS
123468. HCDD
123679+123689. HCDDs
123469. HCDD
123478. HCDD
123678. HCDD
123467+123789. HCDDs
Total HCDDs
1234679. HC7DD
1234678. HC7DD
Total H7CDDS
Discharge
Range
„
ND-3
—
--
6-35
62-750
5-40
6-80
1200-14000
—
ND-8
--
—
ND-21
3-12
2000-30000
1200-18000
78-1000
2-9
4564-63958
13-76
16-120
87-580
52-700
150-1300
—
35-390
--
19-150
343-3120
770-4100
690-4800
1460-8900
Pilot
Filter
Effluent
Average
ND
1
ND
ND
16
337
22
36
6100
ND
3
--
ND
8
6
12000
7267
416
5
26219
35
54
272
307
577
--
172
--
70
1398
1943
2150
4093
Range
„
--
-_
--
--
12-45
ND-4
2-5
200-630
--
ND-1
__
--
--
--
360-1100
220-790
16-46
—
810-2619
2-5
4-8
15-40
8-40
28-75
--
ND-15
__
ND-10
51-180
96-160
83-160
179-320
Average
ND
ND
ND
ND
ND
29
2
4
460
ND
ND
__
ND
ND
ND
853
577
34
ND
1959
3
6
27
23
48
__
9
_-.
6
114
125
118
243
Percent
Removal
__
__
-_
100
91
91
89
92
-_
— _
__
__
100
100
93
92
92
100
93
91
89
90
93
92
__
95
__
91
92
94
95
94
OCDD 7800-60000 25633 690-1300
Note: (1) Analyses completed by Dow Chemical Company.
60
930
96
-------
The above data indicate that the TCDDs, including 2378-TCDD, may be bound
to smaller (and lighter) particles that do not settle out as readily in the
pond system. Of interest is that the relative distribution of the PCDDs in the
filtered and unfiltered samples remains about the same, although the absolute
levels in the filtered samples are generally 90 to 95% less than in the
unfiltered samples. This suggests that the filter system may not preferentially
remove dioxin-containing suspended solids of any given size (or weight) classes.
As noted earlier, Dow Chemical reports that much of the dioxins in the outfall
031 discharge prior to filtration can be attributed to fine particulates from
the hazardous waste incinerator which pass through the wastewater treatment
facilities. 4/ In order to further control the discharge, the company is
installing a clarifier for incinerator wastewaters prior to discharge to the
biological treatment facility.
Under the terms of NPDES permit MI0000868, Dow Chemical is required to
monitor the discharge from outfall 031 for 2378-TCDD twice monthly. 13/ Table 26
presents a summary of Dow Chemical effluent monitoring data for 23~78-TCDD for
the period July 1984 to March 1986. The monthly average discharge loadings to
the Tittabawassee River are displayed in Figure 10 for the period July 1984 to
October 1985, which was prior to installation of the final effluent filter.
The monthly average discharge ranged from 4.1 to 49.2 x 10"7 Ibs/day (1.9 to
22.3 x x 10~7 kg/day) and averaged 21.9 x 10-7 Ibs/day (9.9 x 10~7 kg/day).
There are no apparent seasonal or cyclical trends in the discharge. Limited
data obtained after installation of the filter (November 1985-April 1986)
indicate the long-term average discharge may be on the order of 7.2 x 10~7
Ibs/day (3.3 x 10~7 kg/day), suggesting a 67% reduction in the discharge loading.
The reported 2378-TCDD concentrations for the outfall 031 discharge ranged from
2 to 8 ppq during this period. The final effluent limitation is currently set
at 10 ppq. Longer-term dioxin data, including at least one summer and fall
season, are necessary to fully characterize the performance of the filter
system and a pretreatment system for incinerator wastewaters now being installed
by Dow Chemical .
3. Biomonitoring
a. 1981 USEPA Survey
(1) Static Bioassay
Static bioassays, using Daphnia magna, were completed on samples
obtained on September 15-16, 1981.Samples were obtained from the Dow
Chemical Lake Huron and Tittabawassee River intakes and outfall 031. A
field blank was also prepared. The bioassay was begun on September 22,
1981, and conducted by the Region V Central Regional Laboratory according
to the protocol outlined in "Standard Operating Procedure for Static
Bioassay Screening Test," EPA Region V - Central Regional Laboratory. The
results of the bioassay are presented in Table 27.
The Lake Huron intake sample produced 100% mortality in both aliquots.
The mortalities are due to the presence of chlorine in the sample which was
not removed prior to testing. The Lake Huron water supply is chlorinated
61
-------
Table 26
2378-TCDD Discharge Loadings
Outfall 031
Dow Chemical - Midland Plant
Month
Average Discharge
Flow (MGD)
Average 2378-TCDD
Concentration (ppq)
Prior to filter installation
1984 July
August
September
October
November
December
1985 January
February
March
April
May
June
July
August
September
October
.2
.5
.4
.1
19.
13,
21.8
22.9
17.8
19.
22,
17.9
21.0
24.7
16.7
21.0
16.7
21.1
27.8
20.3
Mean
After filter installation
November
December
1986 January
February
March
April
Mean
2378-TCDD
Discharge Loading
(Ibs/day) (kg/day)
16.8
5.1
6.2
11.8
18.6
20.2
35.0
18.7
49.1
38.1
4.2
28.9
44.6
29.9
8.6
15.1
21.9
2.9
7.7
8.9
12.0
5.7
6.5
7.3
x 10-7
7.6
2.3
2.8
5.4
8.4
9.2
15.9
8.5
22.3
17.3
1.9
13.1
20.2
13.6
3.9
6.8
9.9
1.3
3.5
4.0
5.5
2.6
2.9
3.3
Notes: (1) Average monthly discharge flow based upon daily measurements.
(2) Average 2378-TCDD concentration based upon two measurements per month.
62
-------
C
(0
E
o
Q
0-6
c «
2 £
m "O in
2 qj i_
4) X «
—i 1 r
^fr CN O 00
CN CN CN «-
CO
T
CN
O
00
CO
00
O
-------
Table 27
Dow Chemical - Midland Plant
Static Daphnia Bioassays
September 15-16, 1981
Number of Survivors and Percent Mortality in Duplicate Test Aliquots
Ali quot No. of Survivors Percent Mortality
Time (Hours)
Control
Lake Huron Intake
Outfall 031
Tittabawassee River Intake
Field Blank
a.
b.
a.
b.
a.
b.
a.
b.
a.
b.
0
10
10
10
10
10
10
10
10
10
10
24
9
9
0
0
10
10
9
10
8
7
48
9
9
0
0
10
10
9
10
8
0
0
0
0
0
0
0
0
0
0
0
0
24
10
10
100
100
0
0
10
0
20
30
48
10
10
100
100
0
0
10
0
20
100
64
-------
by Dow Chemical at its lake pumping station. This result would be common
for testing of public water supplies where chlorine was not removed. The
mortalities observed in the other samples, including the blank and controls,
are not considered significant. The discharge from outfall 031 on September
15-16, 1981, did not exhibit acute toxic effects to Daphnia magna.
(2) Algal Assay
A static algal assay was conducted on the same samples collected
for the Daphnia bioassay. The algal assay followed the procedure,
"Standard Operating Procedure for Screening Algal Assay for Determination
of Inhibiting or Stimulating Effects of Effluents," EPA Region V - Central
Regional Laboratory. The results, which are based on a comparison to a
control population, are presented below in Table 28.
Table 28
Dow Chemical - Midland Plant
Static Algal Assay
September 15-16, 1981
Sample Effect
Lake Huron Intake Inhibition 51.3%
Tittabawassee River Intake Stimulation 63.9%
Outfall 031 Stimulation 191.6%
Field Blank Stimulation 102.8%
The Lake Huron sample inhibited algal growth because of the chlorine
present in the sample. The discharge from outfall 031 and the field blank
showed high stimulatory effects on algal growth. The effect produced by
the discharge from outfall 031 is about twice that of the field blank and
three times higher than the Tittabawassee River upstream of outfall 031.
This effect is attributed to the levels of nutrients in the discharge.
The observed stimulatory effect in the field blank is believed to be a
result of low level nutrient concentrations present in the sample, possibly
the result of the bottle preparation or the distilled water used to make
up the blank.
(3) Ames Test
The Ames Test was used for the purpose determining whether the discharge
from outfall 031 exhibits mutagenic properties. This test was conducted on
the samples described above. For each sample, a concentrated sample extract
(lOOx) was used to conduct a direct test and a rat liver enzyme activated
(RLEA) test for five bacteria test strains. No mutagenic activity was found
in either the direct or the RLEA test.
65
-------
b. Dow Chemical NPDES Monitoring
Special Condition 10 of NPOES permit MI0000868 required that Dow
Chemical determine chronic toxicity of the effluent from outfall 031 to
Daphnia magna and rainbow trout or the fathead minnow. 13/ Dow Chemical
conducted acute and chronic flow through studies with Tjaphnia magna and
fathead minnows under a protocol approved by the MDNR as provided for in
NPDES permit MI0000868. The 48-hour acute and 21-day chronic flow-through
Daphnia magna studies and the 96-hour acute and 31-day embryo-larval fathead
minnow tests were conducted in January 1986 using outfall 031 effluent.
The test water was again filtered in the laboratory through a 25 micron
filter prior to contact with the test organising. 14/ Note that as of
January 1986, the full-scale final effluent filtration system was in
operation. Thus, the test water was filtered twice-once in the field and
once in the laboratory. The extent to which the test organisms in either
test were exposed to chemical components typically present in the discharge
is not known. Chemical characterizations of the outfall 031 effluent and
the test waters were not presented with either test report. 15,16/
The results of the acute and chronic toxicity studies, as reported by
Dow Chemical, are presented below:
Daphnia magna
1. Acute toxicity
48-hour LC50 (95% C.I.) 40% (33.3-46.7%) tertiary effluent
2. Chronic toxicity
MATC 24.3%
-------
tration related effects on hatchability of embryos and normal larvae at
hatch were observed. However, survival was reported to drop precipitously
after six days of exposure, with no survival beyond 13 days. The results
are summarized below:
Pimepheleas Promelas
1. Acute toxicity
48-hour LC50 no toxicity
2. Chronic toxicity (embryo-larval test)
MATC 15.9%
-------
Figure 11
Location Map
USEPA River Sediment Sampling Surveys
1978- 1984
Saginaw
Bay
cr>
CO
Legend
• River Sediment Site
A Flood Plain Site
I 1978
II 1981
III 1984
( ) Station
-------
Figure 12
Location Map
USEPA River Sediment Sampling Surveys
1978- 1984
(Dow Chemical - Midland Plant Area)
Legend
% River Sediment Site
A Flood Plain Site
I 1978
II 1981
1111984
( [Station
The Dow X^Chemical Company
Consumers Power
Cooling Pond
IIHFP-2)
69
-------
TABLE 29
1978 USEPA SEDIMENT SURVEY
TITTABAWASSEE AND SAG1NAW RIVERS
OCTOBER 1978
USEPA-Reglon V
Sample Number
EA06S12
EA06SUA
EA06S13B
EA06S14
UNL
Number
UN 159
UN160
UN161
UN162
o
EA06S15
EA06S16
EA06S17
UN163
UN164
UN165
TCOOs
Sample Site (ppt)
Tlttabawassee River - Dow Chemical Bridge Upstream NO
of Dow Dam
Tlttabawassee River - near Smith's Crossing Road NO
Tlttabawassee River - near Smith's Crossing Road ND
Tlttabawassee River - at Freeland Road ND
Tlttabawassee River - at Center Road Upstream from ND
Saglnaw
Saglnaw River - 1-75 at Zllwaukee ND
Saglnaw River - Salzburg Road at Bay City ND
PL Analyst Notes
( 8)
(41)
(12)
(680)
(48)
(10)
Peak observed at M/Z 320 and 322.
but Isotope ratio Incorrect for
positive Identification.
NOTES: (1) Samples were analyzed by Department of Chemistry. University of Nebraska-Lincoln.
(2) Analyses are for total tetrachlorodlbenzo-p-dioxlns.
-------
wastewater treatment system sludges were found to contain TCDOs at concentra-
tions ranging from barely detected at 8 ppt to 5800 ppt (Table 13). One internal
plant untreated wastewater was found to contain TCDDs at 0.38 ppt. While TCODs
were found in untreated wastewaters and treatment plant sludges inside the Dow
Chemical - Midland Plant, TCDOs could not be confirmed in river sediments
downstream from the plant at that time.
2. 1981 USEPA Sediment Survey (Appendix C-2)
The 1981 sediment survey encompassed an area of the Tittabawassee River from
0.5 miles upstream of State Route M-20 downstream to Smith's Crossing Road.
River sediment grab samples were obtained on March 18-19, 1981, for analysis at
eight locations shown on Figures 11 and 12. Each sediment sampling site is
described in Appendix C-l. Because the stream bottom is mostly sand and gravel,
an attempt was made to select sites which appeared to have accumulations of
organic material. For this reason, the samples do not represent average or
typical Tittabawassee River sediment quality. However, the data obtained do
provide an indication of the types of compounds discharged in the area that
accumulate in sediments. The positive findings presented in Table 30 show that
many of the compounds either positively or tentatively identified were
substituted benzenes or their derivatives. Also, more than 90% of the compounds
detected were found in samples obtained at sampling stations which are near or
downstream of Dow Chemical - Midland Plant discharges. Most of the compounds
detected were found at concentrations in the low or sub parts per million range
(mg/kg). Only one compound, di-n-octylphthalate, was identified upstream of
the Dow dam.. Several unidentified compounds were detected in some of the
sediment samples. As noted above, the sediment samples were not analyzed for
PCDDs or PCDFs.
3. 1984 USEPA Sediment Survey (Appendix C-3)
The primary objectives of the 1984 sediment survey were to determine ambient
levels of PCDDs, PCDFs, and other toxic organic pollutants at selected
Tittabawassee River and flood plain sites; to determine the extent of PCDD and
PCDF contamination in Tittabawassee River sediments; and to determine whether
the distribution of PCDDs and PCDFs in river sediments and flood plain samples
matched the distribution in Dow Chemical tertiary pond sediments and wastewater
samples. Nine Tittabawassee River sediment samples and three flood plain
samples were collected on July 25 and 27, 1984. The samples were collected
from about 0.2 miles downstream from the confluence of the Chippewa River with
the Tittabawassee River, to Center Road near the city of Saginaw. Approximate
sampling locations are shown on Figures 11 and 12. Descriptions of the sampling
sites and sampling methods are presented in Appendix C-2 along with the complete
analytical results. Toxic metals data for these samples are also presented in
Appendix C-3. Positive findings are reviewed below.
The data for toxic organic pollutants are summarized in Table 31. The
findings are consistent with data collected in 1981. Relatively few toxic
organic pollutants were found in any of the sediment or flood plain samples
collected. The presence of methylene chloride at low levels in most of the
samples may be attributable to field or laboratory operations. Methylene
71
-------
TABLE 30
1981 USEPA SEDIMENT SURVEY
TITTABAWASSEE KIVER
MARCH 1981
mg/kg (parts per million)
Station:
Location:
Sample Number:
8
Titt. River
Above Dow Dam
EH03S02
<0.2
<0.0
<0.6
<0.5
2.1
Base/Neutral & Acid Pollutants
4-Bromophenylpheny1 ether
Hexachlorobenzene
Pyrene
Di -n-butylphthalate
Di-n-octylphthalate
Volatile Pollutants
Chlorobenzene
Tentatively Identified Pollutants
Hydrocarbons (§)1.0
Sulfur (S8) 1.4
1,7,7-trimethyl-bicyclo
[2.2.1] heptan-2-one
Titt. River
Below H Flume
EH03S03
<3.3
<0.4
<8.9
<7.3
2.0
Titt. River
Near #6 Brine
Pond
EH03S04
<3.6
<0.5
<9.7
6.6
8.4
Titt. River
Below Bullock
Creek
EH03S05
2.4
0.1
<6.5
<5.3
5.3
Titt. River
Below Lingle
Drain
EH03S06
<0.2
<0.1
11.2
<0.5
9.2
1.5
Titt. River
Above Smith's
Crossing
EH03S07
<0.8
23.0
0.0038
0.2
NOTES: (1) < = Not detected at specified detection limit.
-------
TABLE 30 (continued)
mg/kg (parts per million)
Station:
7
8
Location:
Sample Number:
Tentatively Identified Pollutants
Titt. River
Above Dow Dam
EH03S02
Titt. River
Below H Flume
EH03S03
—i
CO
Octanoic acid
Beta-gurjunene
Alpha-fornesene
l-methoxy-4-(phenylethynyl)benzene
Unidentified compounds (Spectrum 340)
compounds
(Spectrum 395)
(Spectrum 406)
(Spectrum 467)
(Spectrum 517)
(Spectrum 520)
(Spectrum 560)
(Spectrum 591)
Unidentified
Unidentified compounds
Unidentified compounds
Unidentified compounds
Unidentified compounds
Unidentified compounds
Unidentified compounds
Hydrocarbons (2)
Sec-butylethylbenzene
3,5-dimethyl-2-cyclohexen-l-one
1,3,5-tris(l-methylethylJbenzene
1,1'-oxybisbenzene
2-phenoxy-l,1'-biphenyl
terphenyl
1,1' :3' ,1-terphenyl
hydrocarbons (11)
sulfur molecule (S8)
1,1'-biphenyl
Unidentified silicon compounds (10)
Hexaethylbenzene
4-phenoxy-l,1'-bi pheny1
Tetraethylbenzene (1 isomer)
1,2,4,5-tetrakis (1-methylethyl)-
benzene
Titt. River
Near #6 Brine
Pond
EH03S04
0.8
0.3
0.3
1.1
0.2
0.4
0.9
1.7
0.9
1.6
0.8
2.8
0.5
Titt. River
Below Bullock
Creek
EH03S05
0.3
0
0
0
0.8
0.1
0.3
2.2
4.0
Titt. River
Below Lingle
Drain
EH03S06
0.5
0.1
0.8
0.1
3.3
Titt. River
Above Smith's
Crossing
EH03S07
3.0
5.3
7.7
4.7
2.3
1.4
0.9
-------
TABLE 31
1984 USEPA SEDIMENT SURVEY
TITTABAWASSEE RIVER SEDIMENTS AND FLOOD PLAIN
TOXIC ORGANIC POLLUTANTS
JULY 1984
ppb (ug/kg)
Station Number: TR-1 TR-2 TR-3
FP-1
TR-4
FP-2
TR-5 TR-6 TR-7 FP-3
TR-8
TR-9
Location:
Benzene
Methylene chloride*
Toluene
Xylenes
Bis(2-ethylhexyl)phthalate*
Di-n-butyl phthalate*
Di-n-octyl phthalate*
Diethyl phthalate*
4,4'-DDT
4,4'-DDE
4,4'-ODD
Above
Ash
Pond
__
2400
5.2
Below
Ash
Pond
_. _
32
__
Above
Lingle
Drain
_ _.
29
_ —
Flood
Plain
G» T.
Pond
— _
85
-.—
Flood
Smith's Plain &
Crossing White &
Bridge Debolt
— » __
17
_ .. . _
Upstream
of
Brown
Mills
- «
46
__
Free-
land
__
16
__
Titta.
Road
__
57
* —
Flood
Plain
-------
chloride is used as a cleaning solvent. The high levels in two samples (2400 ppb
above Dow Chemical ash pond, and 9500 ppb flood plain at Tittabawassee Road)
are much greater than expected from field or laboratory operations. Findings
of methylene chloride at these levels in environmental samples would not be
expected. Three pesticide compounds (4,4'-ODT; 4,4'-DDE; and 4,4'-DDD) were
found in four river sediment samples and each of the three flood plain samples.
The data suggest contributions upstream of the Dow Chemical - Midland Plant as
all three compounds were found in samples collected upstream of outfall 031 as
well as in the downstream sediments.
Table 32 presents PCDD and PCDF data for the sediment and flood plain
samples. The data are graphically displayed in Figures 13 and 14. Sediment
results clearly distinguish the Dow Chemical - Midland Plant as the primary
source of PCDDs and PCDFs to the Tittabawassee River system. Upstream of the
Dow dam only low levels of HpCDDs (0.02-0.11 ppb); OCDD (0.08-0.47 ppb); HpCDFs
(0.01-0.06 ppb); and OCDF (0.02-0.17 ppb) were found. Other PCDDs and PCDFs
were not detected in these samples at detection levels ranging from 0.01 to
0.03 ppb. The highest levels of PCDDs and PCDFs were found in the sediment and
flood plain samples collected near and immediately downstream of the outfall
031 discharge. Concentrations generally decrease with travel downstream.
Concentrations of OCDD at Gratiot and Center Roads are about the same as those
found in sediments immediately upstream of the Midland plant. HpCDDs were not
found in these samples. The levels of HpCDFs and OCDF exhibit the same trend.
However, the concentration of TCDFs in the Gratiot Road sample (1.4 ppb) is
much higher than in most of the upstream samples. Also, the levels of PCDDs
and more notably PCDFs, in the flood plain sample obtained near Tittabawassee
Road suggest either a heavy deposition of PCDDs and PCDFs at that point
from the Dow Chemical discharge or possibly another point source of PCDFs in
that area. Other significant point sources could not be identified in the
vicinity of the sampling station. Examination of the distribution of PCDFs in
Dow Chemical tertiary pond sediments suggest outfall 031 is the source. Based
upon the production history of chlorinated phenols at the Midland plant, it is
likely that past discharges may account for these findings.
The sediment and flood plain data indicate that sediment contamination
extends from Dow Chemical wastewater discharges downstream to the Gratiot Road
to Center Road reach of the river (17.1 to 19.5 miles). Although 2378-TCDD was
not detected in any of the river sediment or flood plain samples, based upon
Dow Chemical discharge data and historical and current findings in native fish,
it is undoubtedly present at levels less than analytical detection levels for
this survey (0.01 to 0.03 ppb or 10 to 30 ppt). The river sediment data are
not sufficient to determine whether there are highly contaminated areas that
may warrant removal.
Table 33 presents a comparison of the distribution of TCDDs in Dow Chemical
treatment pond surface sediments, wastewater discharges, and river and flood
plain sediments. The data plainly demonstrate a clear pattern. The percent
contribution of the 1368- and 1379-TCDD isomers present in treatment pond
sediments is mirrored in river and flood plain sediments for the reach of the
river most heavily impacted by the Dow Chemical discharge.
75
-------
TABLE 32
1984 USEPA SEDIMENT SURVEY
T1TTABAWASSEE RIVER SEDIMENTS AND FLOOD PLAIN SAMPLES
PCDOs and PCDFs
JULY 1984
Concentrations 1n parts per billion (ppb).
Station Number:
TR-1
TR-2
TR-3
TR-4
TR-5
TR-6
TR-7
TR-8
TR-9
FP-1
FP-2
FP-3
Location:
2378-TCDD
Total Tetra CDDs
Total Pent a CDDs
Total Hexa CDOs
Total Hepta CDDs
OCDD
en 2378-TCDF
Total Tetra CDFs
Total Penta COFs
Total Hexa CDFs
Total Hepta CDFs
OCDF
Above
Ash
Pond
NO/0.03
NO/0.01
ND/0.03
NO/0.03
0.11
0.47
ND/0.03
ND/0.03
ND/0.03
ND/0.03
0.06
0.17
NOTES: (1) Sample analyzed by
2) NO -
3) See
4) Data
Not detected
Figures 11 and
Below Above
Ash Llngle
Pond Drain
ND/0.01 NO/0.01
ND/0.01 0.15
ND/0.01 ND/0.01
ND/0.01 0.02
0.02 0.29
0.08 1.6
NO/0.01 0.01
NO/0.01 2.7
NO/0.01 0.02
NO/0.01 0.03
0.01 0.16
0.02 0.30
Brehm Laboratory.
at stated detection
12 for approximate
for TR-4. TR-5, TR-6 reported on
At
Smith's
Crossing
NO/0.01
0.08
0.03
0.11
1.1
6.8
0.10
0.43
0.20
0.37
1.3
3.0
Wright State
level.
Upstream
of Brown
Mill's
Run
ND/0.01
0.01
ND/0.01
ND/0.01
0.03
0.26
0.02
0.19
NO/0.01
NO/0.01
0.04
0.10
University
At
Freeland
Road
NO/0.01
0.02
NO/0.01
0.01
0.05
0.25
0.03
0.20
0.02
0.05
0.07
0.07
At
Tltta.
Road
NO/0.01
0.01
ND/0.01
NO/0.01
0.05
0.46
0.02
0.13
ND/0.01
0.02
0.05
0.12
At
Grattot
Road
ND/0.02
NO/0.02
ND/0.05
NO/0.07
NO/0.04
0.33
0.03
1.4
ND/0.03
ND/0.03
NO/0.04
0.08
At
Center
Road
ND/0.01
NO/0.01
ND/0.03
NO/0.03
ND/0.04
0.30
ND/0.02
0.09
NO/0.03
NO/0.03
0.03
0.10
At Dow
Tertiary
Pond
NO/. 01
0.11
0.09
0.14
2.1
16
0.02
1.0
0.10
0.15
0.65
1.3
At Ha He
& Debolt
Drain
NO/. 01
0.13
ND/.01
HO/. 01
0.53
3.9
0.11
1.5
0.09
0.04
0.65
1.5
At
Tltta.
Road
NO/. 03
0.36
0.12
0.20
1.3
7.8
2.18
7.6
4.1
1.7
1.9
2.3
sample locations.
wet weight
basis.
-------
LL
Concentration (ppb)
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-------
00
Figure 14
PCDFs in Tittabawassee River Sediment
and Flood
July 1984
Plain Samples
USEPA Survey
Legend
(parts per billion - ppb) LH2378TCDF
-------
TABLE 33
DISTRIBUTION OF TCDDs
DOW CHEMICAL TREATMENT POND and WASTEWATERS
TITTABAWASSEE RIVER SEDIMENTS and FLOOD PLAIN SAMPLES
TCDD Isomers (% of Total)
1237
Treatment Pond Surface Sediments 1368 1379 1238 2378 Other
Primary 51 22 10 9 8
Secondary 44 21 10 14 11
Tertiary 54 19 10 9 8
Wastewater Discharges 49 23 22 1 6
River Sediments
Upstream of Dow Dam (TR-1, 2) ND ND ND ND ND
Dow Dam to Smith's Crossing (TR-3, 4) 58 26 12 ND 4
Smith's Crossing - Tittabawassee Road (TR-5,6,7) 59 20 6 ND 15
Gratiot Road - Center Road (TR-8, 9) ND ND ND ND ND
Flood Plain
Dow Tertiary Pond (FP-1) 49 25 20 ND 7
Waite and Debolt Drain (FP-2) 54 27 19 ND ND
Tittabawassee Road (FP-3) 57 23 14 ND 6
NOTES: (1) Tertiary pond data are averages for three samples.
(2) Wastewater discharge data are averages for five
Dow Chemical samples (see Tables 24 and 25).
(3) River sediment data are averages for listed stations.
(4) ND = Not detected.
79
-------
The river sediment data for metals presented in Appendix C-2 do not indicate
any significant contributions from Dow Chemical operations. Generally, there
are no significant differences in concentrations of detected metals between
sediments collected upstream and downstream of the Midland plant. Concen-
trations of several toxic metals (arsenic, beryllium, cadmium, chromium, cobalt,
nickel, and zinc) found in flood plain sediments were generally about twice as
high as levels found in river sediments. This finding is most likely due to
the method and pattern of deposition of these pollutants under high river
stage.
D. Bioaccumulation Studies
1. 1981 USEPA-MDNR Study (Appendix D-l)
Region V and the Michigan Department of Natural Resources conducted a
bioaccumulation study in the Tittabawassee River around the Dow Chemical -
Midland Plant during September 1981. The study was conducted to determine
which toxic organic pollutants discharged by Dow Chemical bioaccumulate in fish
exposed to the effluent. Caged catfish were exposed to the plume of Dow
Chemical's process wastewater effluent (outfall 031) in the Tittabawassee River
for a period of 28 days. Whole fish were analyzed after various periods of
exposure for PCDDs, PCDFs, and other toxic organic compounds. The caged fish
were fed during the experiment to maintain body weight and general health.
All of the fish were acclimated in a laboratory prior to the study. Caged fish
were exposed to the Tittabawassee River both upstream and downstream of Dow
Chemical to establish appropriate controls and reference points. At the request
of the MDNR, caged fish were also placed in the Grand River at Jones Road near
Grand Ledge, Michigan, and analyzed along with native fish from the Grand River.
The cages were suspended in the water column at each site. Thus, the fish were
not exposed to bottom sediments, but were exposed to suspended matter in the
water column.
The original study plan called for exposing the fish directly to Dow
Chemical's process wastewater effluent at the outlet of the tertiary pond just
prior to discharge from outfall 031, and also analyzing native fish from the
tertiary pond. However, Dow Chemical objected, contending that USEPA's legal
authority under Section 308 of the Clean Water Act did not extend to such
activities. Rather than engage in lengthy arguments, and possibly litigation,
over the matter at that time, Region V and MDNR modified the study plan to
place the caged fish in the plume of outfall 031 in the Tittabawassee River
rather than in the outlet of the tertiary pond. Based upon conductivity and
dissolved solids measurements of the discharge from outfall 031 and the plume
conducted during the study, the fish in the plume were exposed to the outfall
discharge diluted at or less than 1:1 by river water. Preliminary results from
the study were reported previously. \J
The locations at which caged fish were exposed are listed below and shown
on Figure 15.
80
-------
Figure 15
USEPA-MDNR
1981 Bioaccumulation Study
Caged Fish Sites
Pine River Confluence
2 3 miles Upstream
Sanford \
Lake \
81
-------
Station
Number Location
Control - Central Regional Laboratory
A Tittabawassee River Upstream of Sanford Dam
1 Tittabawassee River at Poseyville Road
2 Tittabawassee River Downstream of Dow
Dam but Upstream of Outfall 031
3 Tittabawassee River in Outfall 031 Mixing
Zone (plume)
4 Tittabawassee River Outside of the Outfall 031
Mixing Zone (about 1.98 miles downstream
from the Dow Dam)
5 Tittabawassee River (about 2.65 miles
downstream from the Dow Dam)
B Grand River at Jones Road near Grand Ledge,
Michigan
The complete study results are presented in Appendix D. Significant
findings are presented below:
a. PCDOs and PCDFs (Appendix 0-1)
The analytical requirements for the study included isomer specific analyses
for 2378-TCDD, 1368-TCDD, and 2378-TCDF as well as analyses for total penta
through hepta-CDDs and CDFs, OCDD, and OCDF. Unfortunately, not all of the
analytical objectives were achieved by the analytical contractor. Quality
control reviews and reanalyses of sample extracts by USEPA indicate that the
PCDF data produced were not valid due to interferences by hexa through deca
chlorinated diphenyl ethers; quantitation of penta through hepta CDDs is
questionable due to lack of internal standards; and the digestion procedure
used used may have destroyed native OCDD present. 187 Notwithstanding these
problems, the valid data confirmed by EPA duplicate analyses and split sample
analyses by Dow Chemical 197 demonstrate that the outfall 031 discharge contained
2378-TCDD and other TCDDs found in Tittabawassee River native fish. In an
attempt to determine the rate at which PCDDs and PCDFs may accumulate in fish,
specimens were analyzed after 2, 4, 8, 14, 21, and 28 days of exposure to the
outfall 031 plume. Specimens were analyzed after 14 and 28 days of exposure at
other sites. Duplicate (separate) fish samples were obtained at selected sites
after 14 and 28 days of exposure. Split samples (homogenate of whole fish
composite samples) were provided to Dow Chemical for analyses for the fish
food, control fish, Grand River native fish, and caged fish from Stations 2, 3,
4, 5, and B. Table 34 presents the results generated by Region V's analytical
contractor, Battelle Memorial Institute, Columbus, Ohio. Table 35 presents
split sample results from the Region V contractor, Dow Chemical and USEPA-EMSL.
Table 36 presents the complete USEPA analytical results for Day 28 fish at
outfall 031. These analyses were conducted on an extract prepared by the
Region V analytical contractor.
82
-------
Table 34
1981 USEPA-MONR Bioaccumulation Study
Dow Chemical - Midland Plant
Contract Laboratory Results - Battelle Memorial Institute
(analyses in parts per trillion)
Sample
Number: 81LS
2378-TCDD
1368-TCDD
Total TCUD
Penta COD
Hexa COD
Hepta CDD
OCDD
Fish
Food
15S08
<6
<5
<6
<4
<2
<1
<1
Control Fish
Day 0 Day 0
11S01 11D01
<7 <3
<5 <3
7 <3
<4 <4
<1 <7
<3 <1
<6 <4
Station A
Sanford Dam
Day 14 Day 28
15S06 17S06
<4 <3
<4 <5
<2 4
<3 <3
<3 <1
<7 <2
<4 <3
Station 1
Upstream
Poseyville Road
Day 14 Day 28 Day 28
15S01 17S01 17D01
2 8 <13
<3 <5 <13
2 8 <13
<5 <6 <3
<3 <2 <1
<4 <1 <5
<4 <7 <2
Station 2
Upstream of Outfall 031
Day 14 Day 28 Day 28
15S02 17S02 17D02
<3 <3 <3
<3 <3 <3
<3 <3 <3
<6 <2 <3
<4 <3 <2
<4 <2 <2
<3 <3 <3
00
co
Notes: (1) OCDD data for fish are not valid; ethanolic KOH digestion procedure may have destroyed OCDD.
(2) Quantitation of penta-octa CDDs questionable due to lack of 1JCjp-OCDD internal standard.
(3) Tetra-octa CDF data not valid due to interference by hexa-deca chlorinated diphenyl ethers.
-------
Table 34 (continued)
1981 USEPA-MDNR Bioaccumulation Study
Dow Chemical - Midland Plant
Contract Laboratory Results - Battelle Memorial Institute
(analyses in parts per trillion)
Sample
Number: 81LS
2378-TCDD
1368-TCDD
Total TCDD
Penta CDD
Hexa CDD
Hepta CDD
OCDD
Station 3
Day 2
12S01
<4
<4
<4
<5
<3
<2
<4
Day 4
13S01
64
NR
140
<8
<7
<9
<10
Day 8
14S01
7
NR
84
<3
<4
<8
<4
Outfall
Day 14
15S03
12
<3
12
<4
<5
<6
<6
031 Plume
Day 14
15D03
<4
<4
<4
<7
<4
<3
<2
Day 21
16S01
17
NR
50
<7
<4
<3
<3
Day 28
17S03
110
590
820
<6
<6
<4
<5
Day 28
17D03
80
NR
770
510
<1
<1
<1
Station
4
Downstream of Outfall 031
Day 14
15S04
<3
<3
<3
<3
<7
<1
<2
-1.98 mi
Day 28
17S04
2
NR
11
<4
<4
<3
<8
les
Day 28
17D04
<3
NR
110
<4
<7
<4
<3
00
Notes: (1) OCDD data for fish are not valid; ethanolic KOH digestion procedure may have destroyed OCDD.
(2) Quantitation of penta-octa CDDs questionable due to lack of 13Cj<>-OCDD internal standard.
(3) Tetra-octa CDF data not valid due to interference by hexa-deca chlorinated diphenyl ethers.
NR Data not valid; poor recovery of internal standards.
-------
Table 34 (continued)
1981 USEPA-MDNR Bioaccumulation Study
Dow Chemical - Midland Plant
Contract Laboratory Results - Battelle Memorial Institute
(analyses in parts per trillion)
en
Sample
Number: 81LS
2378-TCDD
1368-TCDD
Total TCDD
Penta CDD
Hexa CDD
Hepta CDD
OCDD
Station 5
Downstream of Outfall 031
-2.65 miles
Day 14 Day 28 Day 28
15S05 17S05 17D05
NR 8 <3
NR NR <3
NR 39 <3
NR <2 <4
NR <2 <4
NR 10 <5
NR <1 130
Station B
Grand River
Day 14 Day 28
15S07 17S07
<3 <7
<3 <7
<3 <7
<2 <1
<6 <3
<1 <2
<4 <4
Sample
Number: 82LS
07S01
<3
<3
<3
<3
<4
<4
<3
Grand
07S02
NR
NR
NR
NR
NR
NR
NR
River
07S03
<3
<3
<3
<3
<4
<3
<7
Native
07S04
NR
NR
NR
NR
NR
NR
NR
Fish
07S05
23
<5
20
25
<3
<4
<6
07S06
<5
<11
<11
<3
<1
<5
<3
Notes: (1) OCDD data for fish are not valid; ethanolic
(2) Quantitation of penta-octa
(3) Tetra-octa CDF data not valid due to interference by
NR Data not valid; poor recovery of internal standards.
valid; ethanolic KOH digestion procedure may have de
CDDs questionable due to lack of ^Cjo-OCDD internal
id due to interference by hexa-deca chlorinated diph
destroyed OCDD.
standard.
diphenyl ethers.
-------
Table 35
1981 USEPA-MDNR Bioaccumulation Study
Dow Chemical - Midland Plant
Between-Lab Comparison for 2378-TCDD
(analyses in parts per trillion)
Sample
Number: 81LS
Battelle
Memorial
Institute
Dow Chemical
Fish
Food
15S08
ND (6)
ND (0.3)
Control Fish
Day 0 Day 0
11S01 11D01
ND (7) ND (3)
6.4 7.1
Station 2
Upstream of
Outfall 031
Day 28 Day 28
17S02 17D02
ND (3) ND (3)
6.1 7.1
Station 3
Outfall
Day 4 Day 8 Day 14
13S01 14S01 15S01
64 7 12
11 13 21
031 Plume
Day 14 Day 28(1)
15D03 17S03
ND (4) 110
19 38
Day 28
17D03
80
41
Notes: NA = Not analyzed.
NR = Not reported.
ND = Not detected (detection limit).
(1) = USEPA-EMSL results in triplicate for Station 3 outfall 031 plume,
Day 28 (sample 81LS17S03) are 35, 31, and 46 ppt, respectively.
-------
Table 36
1981 USEPA-MDNR Bioaccumulation Study
Dow Chemical - Midland Plant
USEPA-EMSL Split Sample Analyses
Sample Identification
Field Sample Number:
Laboratory Sample Number:
1368-TCDD
1379-TCDD
2378-TCDD
Penta CDDs
Hexa CDDs
Hepta CDDs
OCDD
Outfall 031 Plume
Station 3 - Day 28
81LS17S03
D-654
160 (34)
ND (34)
35 (34)
ND (78)
628 (78)
D-678-A
158 (12)
ND (12)
31 (12)
46
D-678
—
140 (32)
438 (32)
ND (100)
ND (100)
2378-TCDF
Tetra CDFs
Hepta CDFs
OCDF
ND (6)
454 (6)
Interfences
ND (77)
Notes: (1) Analytical results in parts per trillion (ppt)
(2) Method Efficiency
D-654 ~ 9% Recovery 37C14-TCDD
D-678-A — 102% Recovery 37C14-TCDD
D-678 -- 82% Recovery 37C14-OCDD
(3) Seven TCDF isomers were tentatively
identified in sample D-678-A.
87
-------
Data for 2378-TCDD and total TCDDs for the control fish (Day 0) and Day 14
and Day 28 fish from each caged fish site are graphically displayed in Figure 16.
The fish food, control fish (laboratory) and upstream caged fish and Grand River
caged fish contained little or no TCDDs initially or after 28 days of exposure.
After 28 days fish exposed to the outfall 031 plume accumulated from 80 to
110 ppt of 2378-TCDD (Battelle analyses). Duplicate analyses by EPA and split
sample analyses by Dow Chemical indicate the actual 2378-TCDD levels in Day 28
fish for the outfall 031 plume site may be in the range of 35 to 46 ppt. Caged
fish exposed in the Tittabawassee River at Station 4 and 5 (about 2 and 2.7 miles
downstream from outfall 031, respectively) contained lower ppt levels of (ND-30
ppt) of 2378-TCDD after 28 days of exposure based upon Battelle and Dow Chemical
analyses. The data for total TCDDs exhibit the same trend. The finding of
TCDDs other than 2378-TCDO at levels well in excess of 2378-TCDD is believed to
be unique to this study. Most studies indicate that 2378-TCDD is the only TCDD
encountered in native fish. 207 For this study the data presented in Table 36
indicate that 1368-TCDD accounted for most of the TCDDs found. While unique,
these data are consistent with the wastewater characterizations for outfall 031
(Tables 24 and 25).
Since the caged fish were not exposed to bottom sediments, which may have
contained historical deposits of 2378-TCDD, the study results clearly indicate
the outfall 031 discharge at that time was contributing 2378-TCDD and other
TCDDs to the Tittabawassee River system. It is considered likely that fine
suspended sediments in the discharge containing dioxin were ingested by the
test organisms over the exposure period.
Figure 17 presents a comparison of Battelle and Dow Chemical 2378-TCDD
split sample analyses of caged fish exposed to the outfall 031 plume throughout
the study. USEPA-EMSL duplicate analytical results for the Day 28 fish are also
presented. The high concentration measured by Battelle for Day 4 (64 ppt
2378-TCDD) does not follow the trends established by the remaining Battelle
data or the Dow Chemical data. This value may be the result of analytical
error or possibly a nonhomogenous sample caused by a test organism ingesting an
unusually high level of dioxin from the outfall. Aside from the one anomalous
data point for Day 4, both the Battelle and Dow data exhibit a fairly uniform
increase in concentration through 21 days of exposure, with divergence in the
analyses at Day 28. The duplicate sample results by USEPA-EMSL confirm the Dow
Chemical data and distinguish the Battelle data as not representative.
Discounting the Battelle Day 4 and Day 28 data, the remaining data approximate
a straight line as illustrated in Figure 17 (Y = Ax + b, where A = 1.132, and
b = 0.312; r = 0.908 indicating a reasonably good fit of the data to the straight
line depicted by the coefficients A and b). The results do not indicate a
steady state concentration was achieved after 28 days of exposure.
Based upon Battelle analyses, the Grand River caged fish (Station B) did
not contain 2378-TCDD after 28 days of exposure (detection level of 7 ppt).
However, Dow Chemical's analyses of the duplicate field sample for 28 days of
exposure was 4.4 ppt. Grand River native fish (whole carp) were found to
contain up to 23 ppt of 2378-TCOD. A Tier 3 (Dioxin Strategy) facility located
near the fish collection site is the likely source of the dioxin contamination
in native fish. 21/
88
-------
68
Concentration (ppt)
1 1
1 1
Du
tio
flSH
OOD
CONTRO
FISH
A
SANFO
DAM
OS
R
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TFA
031
AM
LL
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031
PLUM
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5J ~j o
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-------
06
Concentration (ppt)
NJ
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I
o
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00
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b. Base Neutral Compounds (Appendix D-2)
Figure 18 summarizes the results for base neutral compounds. These analyses
and those for other organic compounds reviewed below were completed by GCA
Corporation under contract to Region V. These data show that fish exposed to
outfall 031 readily accumulated several base neutral compounds, principally
chlorinated benzenes (dichloro, trichloro, and hexachloro). Aside from contami-
nation by phthalate compounds and naphthalene and phenanthrene, the control
fish did not contain the same base neutral compounds as found in the fish
exposed to the outfall 031 plume. 1,2,4-Trichlorobenzene was found in fish from
Station 1 upstream of Dow Chemical at a level 15 to 20 times lower than found
in fish exposed to the outfall 031 plume. The downstream Tittabawassee River
fish exhibited lower levels of most of the chlorinated benzene compounds
accumulated in fish exposed to the plume from outfall 031. The Day 28 fish and
duplicate Day 28 fish from the Grand River showed highly variable levels of
naphthalene. Chlorinated benzenes were not found in the Grand River fish.
c. Acid Compounds (Appendix D-2)
The control fish showed no accumulation of acid compounds (Figure 19).
Phenol was detected but not confirmed in fish exposed at Station A - Sanford
Dam and Station 1 - Poseyville Road. 2,4,6-Trichlorophenol and pentachloro-
phenol were found in caged fish exposed at Poseyville Road for 28 days at
levels of 160 and 630 ppb, respectively. These results may be due to the
influence of the Pine River which empties into the Tittabawassee River via the
Chippewa River upstream of Poseyville Road. The Pine River is known to have
contaminated sediments and receives industrial discharges. Pentachlorophenol
was found in fish exposed to the outfall 031 plume at levels up to 1300 ppb.
Phenolic compounds were not found in fish exposed at Stations 4 and 5, downstream
from Dow Chemical.
d. Pesticides, PCBs (Appendix D-2)
The data summarized in Figure 20 illustrate that the greatest number and
highest levels of pesticides were found in the fish exposed to the plume of
outfall 031. The total weight of accumulated pesticides generally increase
with time of exposure. It is important to note that some of the pesticides
were detected but not confirmed on a second GC/ECO column (see Appendix D-2).
While analyses of compounds could not be confirmed due to the complex sample
matrix of the fish exposed to the outfall 031 discharge, the data clearly show
the discharge from the outfall results in bioaccumulation of more compounds at
higher levels than do background river stations. Some of the pesticides were
also detected but not confirmed at the background stations. Confirmation
consists of analyzing the sample on a second instrument column to positively
verify the compound identification. The results presented in Figure 19 should
be viewed accordingly.
The control fish contained aldrin; ODD; DDE; dieldrin; endosulfan I;
endosulfan sulfate; and heptachlor at values ranging from 5 to 34 ppb. ODD,
dieldrin, and endosulfan I values were confirmed. Fish exposed at Station A -
Sanford Dam contained most of the same compounds at similar levels and also
91
-------
Figure 18
USEPA-MDNR
1981 Bioaccumulation Study
Base Neutral Compounds
(5) = No of Compounds
0 Phthalates
Without Phthalates
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92
-------
Figure 19
USEPA-MDNR
1981 Bioaccumulation Study
Acid Compounds
U)
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3
u
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Legend
(2) - No of Compounds
* = Not Confirmed
1600
1400
1200
1OOO
800
60O
400
200
0
K
1 o l°° 1 ['«'
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Sdnlord
Dam
TilUlJawast.ee River
Near Posoyville Rd
Tillabdwassee River
Upsisrediii ul Oulldll 031
Titiabawdsseu River
Oulfdll03l Mixing Zone
STATION DAY
Tiltdbdwassee River
Downstream ol
Oulldll 031 Mining Zone
Tiiiabawassae River
2 65 Miles Downstream
of Oow Dam
ai Jonei Rd
-------
Figure 20
USEPA-MDNR
1981 Bioaccumulation Study
Pesticides and PCBs
1000
900
800
CD
Q.
0-
O
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D
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700
6OO
5OO
400
300
200
100
Legend
(5) - No of Compounds
Note Some Pesticides not Confirmed on
Second Column GC/ECO
Data Presented are for both Confirmed
and Unconfirmed Compounds
1
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(11)
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(4 JB J8U U 11 160 14 It ItO
Conuo No A No 1 No 2 No 3 No 4 No 5 No 8
Sanford Tmabawassee River TiiidbawdSbee River Tittabawassee River Tittabawassee River Tiltabawassee River Grand River
Dam Near Poseyville Rd Upstream ol Outfall 031 Outfall 031 Mixing Zone Downstream of 2 65 Miles Downstream at Jones Rd
Outfall 031 Mixing Zone of Dow Dam
STATION DAY
-------
alpha-BHC at about 6 ppb. Alpha-BHC, ODD, DDE, and dieldrin were confirmed at
this site. Slightly higher levels of most of the same compounds were detected
in fish from Station 1 - Poseyville Road in addition to alpha-BHC (5 to 15
ppb), endosulfan II (21 ppb), and PCB-1248 (46 ppb). Alpha-BHC, ODD, DDE, and
endosulfan I were confirmed at Stations 1 and 2. The influence of the Pine
River may account for the higher levels and additional compounds. The data
obtained at Station 2 (downstream of the Dow Dam but upstream of outfall 031)
show similar levels of most of the same compounds found at Station 1 in addition
to endrin aldehyde and heptachlor.
The fish exposed to the outfall 031 plume contained unconfirmed levels of
aldrin in excess of 200 ppb; alpha-BHC in excess of 200 ppb; beta-BHC in excess
of 20 ppb; gamma-BHC at 16 ppb; endosulfan sulfate in excess of 200 ppb; and
endrin at 63 ppb. Confirmed levels of ODD (as high as 42 ppb); DDE (as high as
65 ppb); DDT (as high as 37 ppb); dieldrin (as high as 12 ppb); endrin aldehyde
(as high as 26 ppb); and heptachlor epoxide (as high as 46 ppb) were also found
in fish exposed to the plume of outfall 031. Data obtained from fish exposed
at Stations 4 and 5 show lower levels of pesticide accumulation than did the
fish exposed in the plume of outfall 031. Aldrin, ODD, dieldrin, and heptachlor
epoxide were confirmed in fish from Station 4, while alpha-BHC, ODD, DDE,
dieldrin, heptachlor epoxide, and heptachlor were confirmed in fish at Station 5.
The caged fish at Station B (Grand River at Jones Road) contained confirmed
levels of alpha-BHC, gamma-BHC, and ODD at less than 20 ppb, and unconfirmed
levels of DDE, endosulfan I, endrin aldehyde, endosulfan sulfate, and endo-
sulfan II, all less than 23 ppb. The Grand River native fish contained much
higher confirmed levels of pesticides than the caged fish from the Tittabawassee
and Grand Rivers, particularly ODD (18-300 ppb); DDE (37-330 ppb); and DDT
(48-230 ppb). The native Grand River fish also contained PCBs at confirmed
levels ranging from 160 to 1020 ppb (PCB-1254) and 160-1360 ppb (PCB-1260).
e. Other Extractable Compounds (Appendix D-2)
The fish samples from the bioaccumulation study were also analyzed for
extractable organic compounds not included in the toxic (priority) pollutant
list. These compounds were determined by the analyst by selecting the best fit
from a computerized library search program to the mass spectra obtained for
each sample. The quantitation of these compounds was not accomplished using
a pure standard of each compound, but was calculated against the response of an
internal standard. Thus, the concentrations presented are considered estimates.
Many of these compound were found at levels significantly higher than those
noted above. The data are also presented in Appendix D-2.
s—\Attempts were also made to develop analytical methods for analyses of
herbicide compounds in fish, but these efforts were abandoned due to the
complexity of the task and resource constraints. Frozen homogenate of the fish
samples from this study have been archived at the USEPA National Water Quality
Laboratory at Duluth, Minnesota.
95
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2. Dow Chemical Biouptake Study - October 1985 (Appendix D-3)
As required by Special Condition 9 of NPDES permit MI0000868, Dow Chemical
conducted a 28-day flow-through biouptake study to simulate the effects of
outfall 031 on Tittabawassee River native fish. Catfish were used as the test
organism. For control purposes unexposed whole and gutted fish and whole and
gutted fish exposed to Tittabawassee River water taken from upstream from
outfall 031 were analyzed. To simulate the dilution of the outfall 031 discharge
by the river, test organisms were exposed to a mixture of 15% outfall 031
discharge and 85% river water. The study was conducted in aquaria. According to
Dow Chemical, both river water and the outfall 031 discharge were filtered
through a 25-micron sock to protect test apparatus flow control valves from
being fouled by particulate matter present in the test waters. 22/ The study
results reported to date by Dow Chemical to the MDNR are presented in Table 37.
The chemical composition of the test water was not reported by Dow Chemical.
In marked contrast to the USEPA-MDNR study results from the 1981 in-situ study
reviewed above, the test organisms in Dow's study did not exhibit measurable
bioaccumulation of 2378-TCDD or most other organic compounds analyzed. The
analytical detection limits reported by Dow Chemical were in the range of 0.6 to
3.6 ppm for heptachlor epoxide; 2,4-dichlorophenol ; aldrin; pentachlorophenol ;
1,2,3-trichlorobenzene; aniline; and alpha-BHC. None of these compounds were
found in control or exposed fish. Detection levels for the other compounds
listed in Table 34 were less than 11 ppb. Because of the relatively high
analytical detection levels reported by Dow Chemical for the above-listed
compounds, the results from this study cannot be compared directly with results
from the 1981 USEPA-MDNR study where analytical methods with low ppb detection
levels were used.
The levels of 2378-TCDD and 2378-TCDF found in fish exposed to the 15/85
mixture of outfall 031 and the Tittabawassee River were about the same as that
found in the control fish and fish exposed to the Tittabawassee River water
taken upstream from outfall 031. Hexachlorobenzene accumulated to 3.7 ppm in
whole fish exposed to the outfall/river mixture vs. no detectable levels and
22 ppb in the unexposed fish and fish exposed to the upstream river water,
respectively. Levels of 1,2,4,5-tetrachlorobenzene were higher in whole fish
exposed to the outfall/river mixture than in fish exposed to the river (4.9 ppm
vs. 1.5 ppm). 1,2,4-Trichlorobenzene and pentachlorobenzene were found in the
0.2 to 0.5 ppm range in fish exposed to the outfall/river mixture. The results
for the chlorinated benzenes are consistent with the findings from the 1981
USEPA-MDNR study.
As part of its point source investigation of 2378-TCDD contamination at the
Midland plant, Dow Chemical conducted particle size analyses of the particulate
matter in the outfall 031 discharge. 4/ These data indicate that the particle
size range for the outfall 031 discharge prior to filtration is about 2 to 100
microns, with over 90% of the particles less than 25 microns in diameter.
A pilot plant filter effluent contained about 90% fewer particles by volume, but
the distribution of the particles present was about the same as that of the
particles in the unfiltered water. These results indicate that the 25-micron
sock used to protect flow control devices during the biouptake study would be
96
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TABLE 37
DOW CHEMICAL BIOUPTAKE STUDY
OCTOBER 1985
Day 0 Fish
Day 28 Fish
100% River Water
Whole Fish
NQ(0.004)
NQ(1.8)
NQ(3.6)
NQJ2.6)
NQ(0.004)
NQ(0.004)
NQ(0.004)
NQ(0.8)
NQ(0.6)
NQ(0.04)
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(O.OH)
NQ(1.9)
NQ(0.007)
NQ(0.006)
0.7 ppt
2.4 ppt
NQ(2.1)
NQ(O.OOOl)
NQ(O.Oll)
NQ(O.Oll)
Gutted Fish
NQ(0.004)
NQ(1.8)
NQ(3.6)
NQ(2.6)
NQ(0.004)
NQ(0.004)
NQ(0.004)
NQ(0.8)
NQ(0.6)
NQJ0.04)
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(O.Oll)
NQ(1.9)
NQ(0.007)
NQ(0.006)
0.7 ppt
2.1 ppt
NQ(2.1)
NQ(O.OOOl)
NQ(O.Oll)
NQ(O.Oll)
Acrylonitrile
Aldrin
alpha-BHC
Aniline
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
2,4-Dichlorophenol
Heptachlor epoxide
Hexachlorobenzene
PCB Isomers
Dichloro-
Trichloro-
Tetrachloro-
Pentachloro-
Hexachloro-
Pentachlorobenzene
Pentachlorophenol
1,2,3,4-Tetrachlorobenzene
1,2,4,5-Tetrachlorobenzene
2,3,7,8-TCDD
2,3,7,8-TCDF*
1,2,3-Trichlorobenzene
1,2,4-Trichlorobenzene
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
Notes: (1) All results in parts per million (ppm), unless otherwise noted.
(2) * Qualified: isomer specificity cannot be proven.
(3) Dow Chemical completed a 28-day fish biouptake study pursuant to
Special Condition #9, NPDES permit MI0000868 using catfish as the
test organisms.
(4) Analyses by Dow Chemical Company.
Whole Fish
NQ(0.004)
NQ(1.8)
NQ(3.6)
NQ(2.6)
NQ(0.004)
NQ(0.004)
NQ(0.004)
NQ(0.8)
NQ(0.6)
0.022
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(O.Oll)
NQ(1.9)
1.1
1.5
0.9 ppt
2.4 ppt
NQ(2.1)
NQ(O.OOOl)
NQ(O.Oll)
NQ(O.Oll)
Gutted Fish
NQ(0.004)
NQ(1.8)
NQ(3.6)
NQ(2.6)
NQ(0.004)
NQ(0.004)
NQ(0.004)
NQJ0.8)
NQ(0.6)
0.017
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(2.3)
0.2
NQ(1.9)
2.3
0.5
0.9 ppt
2.4 ppt
NQ(2.1)
NQ(O.OOOl)
NQ(O.Oll)
NQ(O.Oll)
Day 28 Fish
15% 031 Effluent/85% River Water
Whole Fish
NQ(0.004)
NQ(1.8)
NQ(3.6)
NQ(2.6)
NQ(0.004)
NQ(0.004)
NQ(0.004)
NQ(0.8)
NQ(0.6)
3.7
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(2.3)
0.5
NQ(1.9)
1.0
4.9
1.2 ppt
2.5 ppt
NQ(2.1)
0.29
NQ(O.OH)
NQ(O.Oll)
Gutted Fish
NQ( 0.004)
NQ(1.8)
NQ(3.6)
NQ(2.6)
NQ(0.004)
NQ(0.004)
NQ( 0.004)
NQ(0.8)
NQ(0.6)
0.2
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(2.3)
NQ(O.Oll)
NQ(1.9)
NQ(0.007)
NQ(0.006)
1.2 ppt
2.3 ppt
NQ(2.1)
0.5
NQ(O.Oll)
NQ(O.Oll)
-------
expected to remove a portion of the suspended solids present in the wastewaters.
The amount of suspended solids removed has not been reported but would probably
include particles with diameters less than 25 microns as the filter media
became loaded with larger particles. Thus, the test organisms would not be
exposed to any bioaccumulative pollutants associated with the suspended solids
removed. Without chemical characterization of the filtered water used in this
study and the unfiltered water from the effluent, it is not possible to fully
assess the study results.
The accumulation of hexachlorobenzene and other chlorinated benzenes in
fish after 28 days of exposure is noted. These data and the untreated wastewater
and sewer sludge data presented earlier suggest a residual loading of chlorinated
benzenes in the Midland plant sewerage system despite termination of chlorinated
benzene production in the early 1980s. The results also suggest that the
chlorinated benzenes discharged are either dissolved or attached to fine
particles.
E. Tittabawassee River Native Fish Collections
Table 38 presents a summary of 2378-TCDD analyses of native fish collected
from the Tittabawassee River during the period 1978 to 1985. 23,24,25,26.277
The data are displayed by collection event, species, and type of sample (whole
fish, skin-on filet, or skin-off filet). Because of limited data, it is
difficult to discern statistically significant trends or patterns in the levels
of 2378-TCDD in fish over time. However, it is clear that bottom feeding fish
such as carp and catfish contain consistently higher levels of 2378-TCDD than
other species which may not forage on the stream bottom to the same extent as
carp and catfish. Also, the concentrations found in bottom-feeding fish are
not normally distributed. For the 1978 and 1983 surveys the range of concentra-
tions found was large. The 1983 MDNR-USEPA study included analyses of 25
individual carp filets. Most of the detected concentrations were well below
the mean value of 50 ppt, with a few samples in the 100-200 ppt range and a
maximum of 530 ppt. Concentrations in walleyes are much more uniform. This
may be due to the fact that many walleye are transitory as opposed to carp and
catfish. Figure 21 presents the results of the 1983 and 1985 fish collections.
Comparable data by species, location, and sample type from the different surveys
are reviewed in Table 39.
98
-------
TABLE 38
Study
Tittabawassee River Native Fish Collections
2378-TCDD
1978-1985
(parts per trillion)
Whole Fish Filet - Skin On
Location/Species
No. Range Average
No. Range Average
Filet - Skin Off
No. Range Average
1978 USEPA Dow Dam to
Center Road
Carp
Channel Catfish
Yellow Perch
Dublin Road
Carp
1980 MDNR/ Dow Dam to
USEPA Center Road
Carp
White Sucker
Emerson Park
Carp
1983 MDNR/ Smiths Crossing
USEPA Road
Carp
Catfish
Smallmouth Bass
Walleye
5
3
3
lb
33-142
3-10
7-62
89.6
7.0
40.7
190
lb
5
2.8-5.1
5.1
3.9
6
3
33
1
25
lb
ND-93
42-695
ND-20
12-530
41
337
10
ND
50
75
VO
Notes: (1) a - includes two, 2-fish composites
(2) b - five-fish composite
(3) ND - not detected
(4) The Dublin Road sampling site is located upstream of
the Dow Chemical - Midland Plant.
(5) The Emerson Park sampling site is located upstream of
the Dow Chemical - Midland Plant.
-------
TABLE 38 (continued)
Tittabawassee River Native Fish Collections
2378-TCDD
1978-1985
(parts per trillion)
Study
Location/Species
Whole Fish
No. Range Average
Filet - Skin On
No. Range Average
Filet - Skin Off
No. Range Average
1985 MDNR/
MDPH/FDA/Oow
Chemical
1985 Dow
Chemical
Dow Dam to
Smith's Crossing
Road
Walleye-Spring Run
Wai 1 eye-Summer
Resident
Crappie
Northern Pike
White Bass
Smallmouth Bass
Smith's Crossing
Road
Carp
Catfish
Walleye
Dublin Road
Carp
8
6
3C
3
4d
3
5
2.5- 7.6
2.6-14.0
2.8- 4.5
6.1-15.0
5.7-15.0
2.8- 6.4
ND-3.6
4.4
6.5
3.9
9.5
8.2
5.0
2.3
2
1
3
3.8-54
ND-24
28.9
39
8.6
o
o
Notes: (1) c - three-fish composite for each measurement
(2) d - includes three 3-fish composite and one 4-fish composite
(3) ND - not detected
(4) The Dublin Road sampling site is located upstream of
the Dow Chemical - Midland Plant.
-------
Figure 21
Tittabawassee River Native Fish
1983 and 1985 Collections
2378-TCDD
540 -i
520-
500-
100-
Q.
Q.
g 80H
o
00
n
CM
60-
40-
20-
Lagend
— r- Max
-O-Awe
-J-
Single
measurement
i
Carp
Cdllish Walleye
1983
Smallmouth
Bass
Carp Cattish Walleye Smallmouth
Bass
1985
Species/Year
Crappie
Northern
Pike
White
Bass
-------
TABLE 39
Tittabawassee River Native Fish Collections
Trends in 2378-TCDD Concentrations
2378-TCDD (ppt)
Year
Number
Carp - Whole Fish
1980 5
1983 5 (comp)
Carp - Skin-off Filet
33-142
1978
1983
1985
6
25
2
Catfish - Skin-off Filet
1978
1983
1985
3
(comp)
1
ND-93
12-530
3.8-54
42-695
Walleye - Skin-on Filet
1983-summer 5
1985-spring 8
-summer 6
-fall 5
2.8-5.1
2.5-7.6
2.6-14.0
ND-3.6
Smallmouth Bass - Skin-on Filet
2.8-6.4
1983
1985
5 (comp)
3
Average
89.6
190
41
50
28.9
337
75
39
3.9
4.4
6.5
2.3
5.1
5.0
These data do not suggest any significant changes in the levels of 2378-TCDD
in carp over time. Based upon limited data, it would appear that levels of
2378-TCDD in catfish have decreased from 1978 to 1985. Sufficient data are not
available to make this conclusion with any degree of confidence. There is
virtually no change in average 2378-TCDD levels in walleye or smallmouth bass
from 1983. Typical levels for both species tend to center on about 5.0 ppt.
Because of the distribution of 2378-TCDD in Midland area soils and the
persistence of 2378-TCDD in the environment, bottom feeding fish and other game
fish from the Tittabawassee River may not exhibit significantly lower levels of
2378-TCDD in the near future. Runoff from the city, the wastewater discharge
from Dow Chemical, and atmospheric deposition from Dow Chemical operations will
continue to contribute 2378-TCDD to the river system. Although Dow Chemical
has initiated measures which should reduce the wastewater discharge and
102
-------
atmospheric emissions, continued low-level releases from the Midland plant are
expected over the foreseeable future. Currently, there does not appear to be any
feasible means of controlling contributions from area runoff outside the Dow
plant. A river bottom improvement program without an area-wide runoff control
or soil management program would not yield measureable benefits. Thus, while
the concentrations of 2378-TCDD in Tittabawassee River fish should decrease
slowly over time, residual levels in the low ppt range for walleye, bass, and
other game fish, and somewhat higher levels in carp and catfish can be expected
for at least several years. This discussion is presented to indicate that
measurable progress in reducing dioxin levels in Tittabawassee River fish will
probably occur slowly overtime and not immediately after control measures are
implemented. This is not to suggest that further efforts to improve the
river system not be undertaken or that in-place control measures be abandoned.
Under the terms of a consent order with USEPA, Dow Chemical is required to
monitor native fish in the Tittabawassee River every two years through 1991. _3/
Table 40 presents the 1985 results for 2378-TCDD, 2378-TCDF, and total TCDDs,
HxCDDs, HpCDDs, and OCDD. The 2378-TCDD data are consistent with prior findings
presented in Table 38. The results for walleyes are of interest. 2378-TCDF
concentrations are roughly 12 times higher than 2378-TCDD in skin-on filet
samples. The concentrations of other TCDDs were much more variable in the same
samples. The levels of 2378-TCDD and 2378-TCDF were about 10 times higher in a
walleye viscera composite than in filet samples. The relatively high levels of
2378-TCDF and other PCDDs suggest that the presence of other PCDDs and PCDFs in
addition to 2378-TCDD should be considered when evaluating health risks from
consumption of fish from the Tittabawassee River. 28/ USEPA's evaluation of
the potential health risks associated with consumption of fish taken from the
Tittabawassee River will be presented separately.
Table 41 presents analytical results for a number of toxic organic pollutants
selected by the Michigan Department of Public Health for fish collected as part
of the 1985 cooperative study by MDPH, MDNR, FDA, and Dow Chemical. The fish
were collected in the vicinity of Smith's Crossing Road. Individual fish
skin-on filet samples or composite skin-on filet samples of the following
species were analyzed: crappie, white bass, smallmouth bass, walleye, and
northern pike. As with 2378-TCDD, the limited data do not allow for much
statistical analysis. Nonetheless, species to species comparisons of average
fish flesh concentrations indicate that white bass and northern pike contained
the highest levels of contaminants while smallmouth bass contained the lowest
levels. Highest contaminant levels were generally found in those samples with
higher lipid (% fat) content. The lipid content of the white bass samples
averaged 3.5%, while that of the northern pike samples averaged 1.2%. Although
the average lipid content of the walleye samples was 2.1%, the levels of most
pollutants were below those for northern pike. The lipid content of the
smallmouth bass samples was about 0.1%, the lowest encountered in this study.
The native fish all exhibited substantially lower levels of hexachloro-
benzene (0.008 to 0.038 ppm) than did catfish exposed to a filtered mixture of
15% outfall 031 effluent and 85% Tittabawassee River water from Dow Chemical's
1985 biouptake study (Table 37). Those fish accumulated hexachlorobenzene to
3.7 ppm while control fish exposed to filtered Tittabawassee River water only
contained 0.022 ppm, which is in the range of values found in five species of
native fish.
103
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TABLE 40
PCDDs and PCOFs
NATIVE FISH COLLECTION
TITTABAWASSEE RIVER, 1985
(parts per trillion)
Species
Date
Taken
Walleye 8/22/85
Walleye 8/22/85
Walleye 8/22/85
Walleye 8/22/85
Walleye(a) 8/22/85
Location
Taken
Smith's Crossing
Smith's Crossing
Smith's Crossing
Smith's Crossing
Smith's Crossing
Composite of Walleye Viscera (b)
Carp(c) 8/22/85
Carp 8/22/86
Catfish(d) 8/30/85
Carp
Carp
Carp
10/21/85
10/21/85
10/21/85
Smith's Crossing
Smith's Crossing
Smith's Crossing
Dublin Road
Dublin Road
Dublin Road
2378-TCDD 2378-TCDF
2.5
2.6
3.0
3.6
ND(1.8)
22
3.8
54
39
ND(1.7)
1.9
24
34
24
28
40
11
300
8.7
94
28
ND(4.4)
3.3
83
Total
Tetrachloro
Dioxin Isomers
2.8
1.9
17
ND(1.4)
ND(1.5)
36
7.8
59
92
ND(2.3)
ND(8.8)
ND(1.6)
Total
Hexachloro
Dioxin Isomers
36
19
5.6
ND(2.7)
NDJ2.5)
ND(5.3)
6.8
ND(9.1)
23
ND(2.0)
ND(3.8)
15
Total
Heptachloro
Dioxin Isomers
34
26
6.2
ND(ll)
ND(2.8)
ND(3.9)
9.3
26
27
ND(3.7)
5.1
15
Octachloro
Dioxin
95
55
16
15
6.4
29
15
26
43
3.8
8.5
14
Notes: (1) Walleye - Skin-on filet.
(2) Carp and catfish - skin-off filet.
(3) Total tetrachlorodioxin isomers do not include 2378-TCDD.
(4) Samples collected and analyzed by Dow Chemical Company pursuant to settlement agreement in Civil
Action No. 83-CV7011BC (United States vs The Dow Chemical Company).
(5) The Dublin Road sampling site is located upstream of the Dow Chemical - Midland Plant.
(6) Percent lipid content for selected samples are as follows (average of 10 replicate 2 gm samples)
,4%
,8%
,4%
(a)
(b)
(c)
(d)
Walleye filet
Walleye viscera
Carp filet
Catfish filet
composite -
1.9%
14.6%
3.0%
9.1%
0.
0.
0.
2.7%
-------
TABLE 41
TOXIC ORGANIC POLLUTANTS
NATIVE FISH COLIFCTION
MDPII/MDNR/FDA/DOW CHEMICAL
TITTABAWASSEE RIVER 1985
mg/ky (parts per million)
Grapple
White Bass
O
en
% Fat (hexane extractables)
Terphenyls (5433, 5442)
PCB (1254)
alpha-Chlordane
gamma-Chlordane
Oxychlordane
Cls-nonachlor
Trans-nonachlor
p.p'-DOD
p.p'-DDE
p.p'-DDT
Dleldrln
Hexachlorobenzene
Toxaphene
Octachlorostyrene
Heptachlor epoxlde
No. of
Analyses
3
3
3
3
3
3
3
3
3
3
3
3
3
3
2
1
Range
0.3-0.6
NO-0.050
0.087-0.185
0.003-0.004
0.001-0.002
0.004-0.008
0.002-0.007
0.003-0.003
0.036-0.068
0.027-0.039
0.002-0.003
0.001-0.003
0.008-0.013
0.020-0.025
0.001-0.001
--.
Average
0.5
0.017
0.130
0.004
0.002
0.006
0.004
0.003
0.052
0.033
0.003
0.002
0.010
0.023
o.noi
Nl)
Small Mouth Bass
No. of
Analyses
4
4
4
4
4
4
4
4
4
4
4
4
4
4
3
1
Range
2.3-4.9
0.200-0.330
1.076-1.650
0.012-0.021
0.004-0.006
0.010-0.018
0.006-0.016
0.010-0.024
0.085-0.316
0.099-0.260
0.003-0.020
0.007-0.023
0.014-0.020
0.048-0.137
0.001-0.003
—
Average
3.5
0.232
1.328
0.017
0.005
0.014
0.010
0.018
0.155
0.160
0.009
0.013
0.017
0.089
0.002
0.004
No. of
Analyses
3
3
3
3
3
3
3
3
3
3
3
3
3
3
2
3
Range
0.1-0.15
NO-0.050
0.024-0.085
NO-0.002
NO-0.001
NO-0.002
ND-0.003
ND-0.002
0.010-0.053
0.009-0.033
0.001-0.005
ND-0.001
NO -0.004
NO-0.025
ND-0.001
Average
0.11
0.017
0.045
<0.001
<0.001
<0.001
0.001
<0.001
0.028
0.018
0.002
<0.001
0.002
0.008
NO
<0.001
NOTES: (1) Fish collected from the Tlttabawassee River between the now Dam In Midland and the vicinity
of Smith's Crossing Road.
(2) Crapple analyses conducted on 3-flsh composites; white bass analyses conducted on one 4-flsh
composite and three 3-flsh composites; other analyses conducted on Individual fish.
(3) All samples are skin-on filets.
-------
TABLE 41 (continued)
mg/kg (parts per million)
Walleye
Northern Pike
o
en
% Fat (hexane extractables)
Terphenyls (5432, 5442)
PC8 (1254)
alpha-Chlordane
gamma-Chlordane
Oxychlordane
Cis-nonachlor
Trans-nonachlor
p.p'-OOO
p.p'-DDE
p,p'-l)l)T
Dleldrln
Hexachlorobenzene
Toxaphene
Octachlorostyrene
Heptachlor epoxltle
No. of
Analyses
14
14
14
14
14
14
14
14
14
14
14
14
14
14
10
14
Range
0.70-3.2
ND-O.SOO
0.197-1.658
ND-0.014
NO-0.011
ND-0.012
NO-0.018
NO-0.036
ND-0.098
0.034-0.212
NO-0.026
NO-0.007
0.002-0.038
NO-0.222
NO-0.003
ND-0.005
Average
2.1
0.093
0.5H8
0.010
0.1)04
0.005
0.010
0.015
0.051
0.100
0.012
0.001
0.009
0.097
0.001
0.002
No.
Anal
of
yses
3
3
3
3
3
3
3
3
3
3
3
3
3
3
2
3
Range
1.1-1.3
NO-0.125
0.230-0.685
0.005-0.118
0.002-0.034
0.009-0.018
0.006-0.051
0.006-0.149
0.061-0.606
0.066-0.131
0.009-0.020
ND-0.007
0.006-0.017
0.038-0.107
0.002-0.005
0.001-0.009
Average
1.2
0.042
0.382
0.044
0.014
0.014
0.022
0.057
0.270
0.105
0.013
0.002
0.012
0.068
0.004
0.004
NOTES: (1) F1sh collected from the Tlttahawassee River between the Dow Dam In Midland and the vicinity
of Smith's Crosstny Road.
(2) Grapple analyses conducted on 3-fish composites; white bass analyses conducted on one 4-flsh
composite and three 3-flsh composites; other analyses conducted on Individual fish.
(3) All samples are sk1n-on filets.
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VII. NPDES PERMIT - BEST AVAILABLE TECHNOLOGY
A. Clean Water Act Requirements
Section 402 of the Clean Water Act (CWA) establishes a National Pollutant
Discharge Elimination System (NPDES) permit program. The NPDES program is
designed to limit the discharge of pollutants into navigable waters of the
United States from point sources through a combination of various requirements
including technology-based and water quality-based effluent limitations. The
Act provides that the Administrator of USEPA can delegate the permit program to
state pollution control agencies and that the Administrator or his designee,
must concur with permits issued by delegated state agencies. The NPDES permit
program for Michigan was delegated to the Michigan Department of Natural
Resources by USEPA on October 17, 1973. 29/
Sections 301, 304, 306, and 307 of the Act also provide that USEPA must
promulgate national effluent limitations guidelines and standards of performance
for major industrial categories for three major classes of pollutants: (1) con-
ventional pollutants (total suspended solids, biochemical oxygen demand, oil
and grease, and pH); (2) toxic pollutants (e.g., toxic metal and toxic organic
pollutants); and (3) nonconventional pollutants (e.g., ammonia, fluoride,
phenols (4AAP)). Six types of national effluent limitations guidelines and
standards must be promulgated for each industrial category:
Abbreviation Type of Effluent Limitations Guideline or Standard
BPT Best Practical Control Technology Currently Available
BAT Best Available Technology Economically Achievable
8CT Best Conventional Pollutant Control Technology
NSPS New Source Performance Standards
PSES Pretreatment Standards for Existing Sources
PSNS Pretreatment Standards for New Sources
The pretreatment standards are applicable to industrial facilities with waste-
water discharges to publicly owned treatment works (POTWs) which generally are
municipal wastewater treatment plants. The effluent limitations guidelines
and new source performance standards are applicable to industrial facilities
with direct discharges to navigable waters. Thus, only the first four types of
guidelines are applicable to the Dow Chemical - Midland Plant.
Section 301 of the CWA requires that BPT limitations were to have been
achieved by July 1, 1977; BAT effluent limitations for toxic pollutants by
July 1, 1984; BAT effluent limitations for nonconventional pollutants within
three years from date of promulgation but no later than July 1, 1987. BCT
effluent limitations were to have been achieved by July 1, 1984. Section
402(a)(l) of the Act provides that in the absence of promulgated effluent
limitations guidelines and standards, the Administrator or his designee may
107
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establish limitations for specific dischargers on a case-by-case basis.
USEPA regulations provide that these limits may be established using "best
professional judgment" taking into account proposed effluent limitations
guidelines and standards and other relevant scientific, technical, and economic
information.
B. NPDES Permit MI0000868
As part of the NPDES permit program, the Michigan Water Resources Commission
issued NPDES permit MI0000868 to Dow Chemical on May 17, 1984. In accordance
with EPA's NPDES permit regulations (40 CFR §123.44), Region V commented on and
concurred with issuance of the permit by the state. 30,31/ The permit has a
four-year term and expires on June 30, 1988. An administrative order was
issued by the Water Resources Commission concurrently with the NPDES permit,
ordering Dow Chemical to install an end-of-pipe treatment facility (mixed media
filter) for control of 2378-TCDD and to initiate other dioxin control measures.
The NPDES permit contains water quality-based effluent limitations for several
toxic organic pollutants developed by the Michigan Department of Natural
Resources and effluent limitations for conventional, nonconventional, and other
toxic pollutants. The permit also contains several special conditions that
require Dow Chemical to conduct chemical wastewater characterizations, a fish
biouptake study, acute and chronic bioassays and toxicity studies, and a
phosphorus minimization study. The results of the chemical wastewater charac-
terization and biomonitoring studies were reviewed earlier in this report.
As a condition of its concurrence in the issuance of NPDES permit MI0000868,
USEPA Region V stated that the permit could not be considered to be a BAT permit,
since it did not fully implement the requirements of the Clean Water Act
with respect to BAT. 3_1/ Accordingly, the MDNR and Region V agreed that the
next NPDES permit issued to Dow Chemical would contain appropriate water
quality-based effluent limitations, and technology-based effluent limitations
and control programs to meet the requirements of the Clean Water Act. Region V
has agreed to provide technical assistance to MDNR for developing the proposed
technology-based effluent limitations and control programs.
The remainder of this section presents a brief review of the status of
those effluent limitations guidelines applicable to the Dow Chemical - Midland
Plant; a comparison of wastewater treatment technologies installed by Dow
Chemical with technologies considered by EPA for developing national effluent
limitations guidelines; and a preliminary assessment of the types of treatment
technologies and control programs Region V believes will be necessary for Dow
Chemical to comply with Section 402 of the Clean Water Act. To protect
confidential business information, only general information and data are
presented in this report. A separate document that includes development of
specific BAT effluent limitations will be prepared to support the proposed BAT
NPDES permit for the Midland plant.
C. Applicable Effluent Limitations Guidelines and Standards
Most of the current process operations at the Dow Chemical - Midland Plant
fall within the following industrial categories for which USEPA has either
proposed or promulgated effluent limitations guidelines and standards:
108
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Organic Chemicals 40 CFR Part 414
Inorganic Chemicals 40 CFR Part 415
Plastics and Synthetic Fibers 40 CFR Part 416
Pharmaceuticals 40 CFR Part 439
Pesticides 40 CFR Part 455
In addition, there are numerous nonprocess sources at the Midland plant that
contribute significant volumes of contaminated wastewaters that must be treated.
These sources include hazardous waste incinerator wastewaters, landfill lea-
chates, utilities, tank car washings, the riverbank ground water collection
system, and sanitary wastewaters. Dow Chemical also treats wastewaters from
the nearby Dow Corning silicone chemicals plant. Aside from the Dow Corning
wastewaters, none of the nonprocess wastewaters at the Midland plant are limited
by categorical effluent limitations or standards.
At this writing, USEPA has promulgated final effluent limitations guidelines
and standards for the Inorganic Chemicals, Pesticides, and Pharmaceuticals
Categories _32/ and has proposed effluent limitations guidelines and standards
for the Organic Chemicals, Plastics and Synthetic Fibers Categories, which have
been combined into one category. The Agency's latest proposal of effluent
limitations guidelines and standards for the Organic Chemicals, Plastics and
Synthetic Fibers Category was published on March 21, 1983. 33/ That proposal
included effluent limitations for several volatile and semi-volatile toxic
organic pollutants. About 70% of the operations at the Midland plant fall
within the Organic Chemicals, Plastics and Synthetic Fibers Category. In the
absence of promulgated effluent limitations guidelines and standards for most
of the process operations at the plant, the development of best available
technology and best conventional technology effluent limitations and control
programs must be developed largely on a best professional judgment (BPJ) basis
pursuant to Section 402(a)(l) of the Clean Water Act and 40 CFR §125.3(c)(2).
None of the final or proposed effluent limitations guidelines address 2378-TCDD
or other PCDDs and PCDFs.
The model wastewater treatment technologies considered by USEPA in devel-
oping proposed or final BAT effluent limitations guidelines for the industrial
categories relavent to production operations at Dow Chemical are summarized in
Table 42.
D. Comparison of Dow Chemical Wastewater Treatment Technologies with EPA
Model Wastewater Treatment Technologies
As noted in Section V, the Dow Chemical - Midland Plant is a large chemical
manufacturing complex comprised of numerous separate production facilities
covering about 1500 acres. Chemical manufacturing at the site began prior to
1900. The plant has undergone continual rebuilding over the years as the
product mix was changed in response to market developments. For most of its
recent history, the Midland plant has had a central sewerage and wastewater
treatment system. As shown in Figure 4, the existing wastewater treatment
facilities are comprised of equalization, primary settling, biological treatment
(completely mixed activated sludge and trickling filters), secondary settling,
a three-pond system for additional suspended materials removal, and a final
109
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TABLE 42
National Effluent Limitations Guidelines
Model BAT Wastewater Treatment Technologies
Category
Final ELGs
Inorganic Chemicals
Pesticides
Pharmaceuticals
Summary of Model Treatment
No discharge; return of spent brines
to mined formation
In-process recovery and control;
biological treatment
In-process recovery and control;
biological treatment
Proposed ELGs
Organic Chemicals, Plastics,
and Synthetic Fibers
In-process recovery and control;
biological treatment
Sources: 1.
USEPA Final Development Document for Effluent Limitations
Guidelines and Standards for the Inorganic Point Source
Category, EPA 440/1-82/007, June 1982.
2. USEPA Final Development Document for Effluent Limitations
Guidelines and Standards for the Inorganic Point Source
Category, Phase II, EPA 440/1-84/007, August 1984.
3. USEPA Final Development Document for Effluent Limitations
Guidelines and Standards for the Pesticides Chemicals'
Category, EPA 440/1-85/079, September 1985.
4. USEPA Final Development Document for Effluent Limitations
Guidelines and Standards for the Pharmaceutical Manufacturing
Point Source Category, EPA 440/1-83/084, September 1983.
5. USEPA Proposed Development Document for Effluent Limitations
Guidelines and Standards for the Organic Chemicals and Plastics
and Synthetic Fibers Point Source Category, EPA 440/l-83/009b,
February 1983.
110
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effluent polishing filter. In addition, there are varying levels of pretreat-
ment installed at the production processes. The sewerage system at the Midland
plant is constructed to collect all process wastewaters, nonprocess wastewaters,
noncontact cooling waters, sanitary wastewaters, and surface runoff from the
plant site. Most of the sewer system is enclosed underground piping; however,
there are several sections of open ditches or conduits which are considered by
Region V to be regulated surface impoundments for purposes of RCRA.
Table 43 presents a summary of wastewater flows at the Dow Chemical -
Midland Plant. These data are based upon information developed by Dow Chemical
and supplied to Region V and MDNR in accordance with the terms of a consent
order for Civil Action No. 83-CV7011BC. _3/ Tne data were current as of August
1984. Current year (1986) data will be used to develop proposed BAT effluent
limitations for the next NPDES permit for the Midland plant. These data
indicate that only about one-third of the total discharge from outfall 031 is
process wastewater from production operations potentially regulated by USEPA
categorical effluent limitations guidelines; about one-third of the accounted
for discharge is comprised of noncontact cooling; and the balance is attributed
to noncategorical sources.
The central (main plant) wastewater treatment system installed by Dow
Chemical includes all of the unit operations considered as part of the model
wastewater treatment facilities by USEPA for treatment of wastewaters from
organic chemicals, plastics, and pharmaceutical processes. The pond system and
final effluent polishing filter installed by Dow Chemical are additional
treatment facilities not included in USEPA's model treatment facilities. While
the "end-of-pipe" treatment facilities installed at the Midland plant are
equivalent to or exceed those facilities considered as best available technology
(BAT) by USEPA, data presented in this report suggest that in-process controls
for several organic chemical processes are not equivalent to BAT, even when
considered with superior end-of-pipe treatment. This is particularly true of
certain volatile organic chemical pollutants (see Table 3). Also, data
presented herein indicate the continued presence of residual levels of
toxic semi-volatile organic pollutants (e.g., pentachlorophenol, chlorinated
benzenes), despite termination of both production and substantial usage of these
materials at the Midland plant. These data suggest that scattered or diffuse
sources throughout the plant (sewer sludges, contaminated soils, pond sediments)
may be contributing residual discharge loadings to the outfall.
USEPA promulgated effluent limitations guidelines requiring zero discharge
for many inorganic chemical production processes including some of those at the
Midland plant. The model technology for these processes includes reinjection
of spent brines to underground formations and reuse and recovery of process
materials. According to Dow Chemical records, zero discharge of pollutants had
not been achieved at certain inorganic chemical processes at the Midland plant.
The status of these processes will be reviewed in light of the recent termination
of brine mining operations by Dow Chemical.
Dow Chemical has installed process-specific treatment systems for certain
pesticide processes consistent with those considered by USEPA when developing
the pesticide effluent limitations guidelines. The current NPDES permit
includes process-specific limits for the 2,4-D process. 13/
111
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TABLE 43
Dow Chemical Wastewater Flow Summary
Categorical Processes
Organic Chemicals
Plastics
Inorganic Chemicals
Pesticides
Pharmaceuticals
Dow Corning
Typical Wastewater Flow
Gal/Min MGD m3/Day
SUBTOTAL 2265
1200
Noncategorical Process Wastewaters
Incinerator
Landfill Leachates
Tank Car Washings
River Bank Collection
R & D Services
General Plant Services
Other (including sanitary)
SUBTOTAL
Other Wastewaters
Storm Water
Noncontact Cooling Water
3.25
1.73
12302
6548
1880
43
35
180
350
320
116
2924
674
910
3727
2.71
0.06
0.05
0.26
0.50
0.46
0.17
4.21
0.97
1.31
5.37
10257
227
189
984
1893
1741
643
15934
3671
4958
20325
TOTAL 11700
16.84
63738
Source: Dow Chemical Company, August 24, 1984.
112
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E. Best Available Technology Considerations
As noted above, the wastewater treatment facilities installed by Dow
Chemical are, to a large extent, consistent with process control and wastewater
treatment technologies considered by USEPA during development of final and
proposed national effluent limitations guidelines and standards. However,
several factors preclude a relatively simple application of categorical effluent
limitations and guidelines to develop BAT permit conditions. These include the
size and complexity of the site; the historical development of central sewerage
and wastewater treatment facilities; the volume of wastewater from noncate-
gorical sources; the presence of certain toxic pollutants not regulated by
effluent limitations guidelines (e.g., PCDOs, PCDFs); and, lack of final
effluent limitations guidelines for the organic chemicals and plastics opera-
tions, comprising about 70% of the current chemical production facilities at
the plant. Thus, the proposed BAT permit conditions will be largely based upon
best professional judgment.
Based upon information developed as part of this study, the following
factors will be considered in developing the proposed BAT effluent limitations:
1. Final Effluent Limitations Guidelines for the Pesticide Category
It is likely that process-specific effluent limitations for pesticide
chemicals will be developed for each pesticide operation with a wastewater
discharge. These limitations will be applied at the process discharge prior to
mixing with noncontact cooling waters or wastewaters from other operations.
Effluent limitations for conventional pollutants (total suspended solids, 8005,
pH) will be considered as part of the plant-wide limitations applicable to
outfall 031.
2. Final Effluent Limitations Guidelines for the Inorganic Chemicals Category
Each inorganic chemical process will be evaluated for conformance with
promulgated guidelines. Where appropriate, process specific limitations (no
discharge) will be applied. Inorganic chemical processes not regulated by the
effluent limitations guidelines probably will be controlled by the plant-wide
effluent limitations.
3. Final Effluent Limitations Guidelines for the Pharmaceutical Category
Since the central wastewater treatment system includes treatment operations
beyond those considered in the development of the national effluent limitations
guidelines, the plant-wide limitation for conventional pollutants will be used
to regulate pharmaceutical operations.
4. Proposed Effluent Limitations Guidelines for the Organic Chemicals,
Plastics and Synthetic Fibers Category
The proposed effluent limitations guidelines will be considered for the
organic chemicals and plastics operations. Emphasis is expected to be placed
on controls for volatile pollutants at certain processes. Semi-volatile
113
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pollutants will largely be controlled by plant-wide limitations for specific
toxic organic pollutants and conventional pollutants. If final effluent
limitations guidelines for organic chemicals and plastics operations are
promulgated prior to issuance of the next NPOES permit for the Midland plant,
the final guidelines will be considered in development the final NPDES permit
limits.
5. Nonprocess Wastewaters
Wastewaters from nonprocess operations (contaminated ground water, utili-
ties, landfill leachates, tank car washings, RAD services, sanitary wastewater)
will be controlled by plant-wide limitations and best management practices
programs (see below).
6. Noncontact Cooling Water
In the development of plant-wide BAT effluent limitations, no allowance or
effluent limitations credits will be proposed for noncontact cooling waters
tributary to outfall 031. Noncontact cooling waters generally dilute process
and nonprocess wastewaters.
7. Plant-Wide Effluent Limitations
Proposed BCT effluent limitations for outfall 031 for total suspended solids
will be based upon performance standards for the final effluent filtration
system, taking into account normal process variability. Proposed effluent
limitations for toxic organic pollutants will be developed considering the
proposed effluent limitations guidelines and process and nonprocess wastewater
flow rates from appropriate sources. The current plant-wide effluent limitation
of 10 ppq for 2378-TCDD will be reviewed in the context of BAT.
8. Best Management Practices (BMPs)
The proposed BAT NPDES permit will likely include best management practices
programs developed under Section 304(e) dealing with: (1) specific chemicals
that continue to be found in the effluent despite no production or substantial
usage at the plant; (2) specific chemicals that are of concern from a water
quality or human health standpoint as identified by MDNR; and (3) elimination
of open sewers and possibly cleaning certain sections of sewers to remove
accumulations of toxic chemicals.
Final NPDES permit effluent limitations for conventional, toxic, and
nonconventional pollutants determined to be present at significant levels will
be set either through the technology-based approach described above, or through
an independent assessment of the discharge levels necessary to assure compliance
with state water quality standards. The more stringent effluent limitations
developed from these assessments will be governing.
114
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REFERENCES
1. Dow Chemical - Midland Plant, Wastewater Characterization Study (Prelimi-
nary Summary of Results), U.S.EnvironmentalProtection Agency, Region V,
Environmental Services Division, Eastern District Office, Westlake, Ohio,
March 28, 1983.
2. Dioxin Strategy, Office of Water Regulations and Standards, Office of Solid
Waste .and Emergency Response, Dioxin Strategy Task Force, U.S. Environmental
Protection Agency, Washington, D.C., October 20, 1983.
3. Consent Decree - Civil Action No. 83-CV7011BC (United States of America,
Plantiff, vs. the Dow Chemical Company, d/b/a Dow Chemical, U.S.A., Michigan
Division, Defendant), March 30, 1984.
4. Point Sources and Environmental Levels of 2378-TCDD (2,3,7,8-tetrachlorodi-
"benzo-p- dioxin) on the Midland Plant Site of the Dow Chemical Company and
in the City of Midland, Michigan, Dow ChemicalCompany, Midland, Michigan,
November 5, 1984.
5. Michigan Dioxin Studies, Screening Survey of Surface Water Supplies,
Potable Ground Water, and Dow Chemical Brine Operations, U.S. Environmental
Protection Agency, Region V, Environmental Services Division, Eastern
District Office, Westlake, Ohio, December 1985.
6. State of Michigan, Michigan Department of Natural Resources, Consent Order,
in the matter of the Dow Chemical Company, Midland Brine System, Midland,
Bay, and Saginaw Counties, Michigan, MW01-56-84, May 3, 1985.
6a. Personal communication with J. M. Rio, Manager Environmental Services,
Michigan Division, Dow Chemical Company, Midland, Michigan, May 28, 1986.
7. Michigan Department of Natural Resources file data.
8. Veurink, Gary R., Manager, Environmental Services, Michigan Division, Dow
Chemical USA, Midland, Michigan, to (Gary A. Amendola, U.S. Environmental
Protection Agency, Region V, Eastern District Office, Westlake, Ohio)
July 12, 1985, ALS, 8 pp.
9. Dow Chemical Company - Michigan Division, NPDES permit application,
December 28, 1982.
10. Clean Air Act, 42 USC 7401, et. seq., Section 110.
lOa. Rio, J. M., Manager, Environmental Services, Michigan Division, Dow Chemical
USA, Midland, Michigan, to (Mike Jury, Air Quality Division, Michigan
Department of Natural Resources, Saginaw, Michigan), March 14, 1986, 2 pp.
plus attachments.
115
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REFERENCES (continued)
lOb. Soil Screening Survey at Four Midwestern Sites, U.S. Environmental Pro-
tection Agency, Region V, Environmental Services Division, Eastern District
Office, Westlake, Ohio, EPA 905/4-85-005, June 1985.
11. Wright State University - Large Volume Sampling Report.
12. Personal communication with Robert Harless, U.S. Environmental Protection
Agency, Research Triangle Park, North Carolina, March 11, 1986.
13. Michigan Water Resources Commission National Pollutant Discharge Elimination
System (NPDES) Permit, No. MI0000868, May 14, 1984.
14. Personal communication with J. E. Garvey, Environmental Services, Michigan
Division, Dow Chemical Company, Midland, Michigan, March 11, 1986.
15. The Acute and Chronic Toxicity of the Michigan Division (The Dow Chemical
Company, Midland, Michigan) Tertiary Effluent to Daphnia Magna Straus,
Gersich, F. M., Mayes, M. A., Milazzo, D. P., and Richardson, C. H., The
Dow Chemical Company, Michigan Division, Midland, Michigan, February 14,
1986.
16. The Acute and Chronic Toxicity of the Michigan Division (The Dow Chemical
Company, Midland, Michigan) Tertiary Effluent to the Fathead Minnow,
Pimepales Promelas Rafinesque, Gersich, F. M., Mayes, M. A., Milazzo, D. P.,
and Richardson, C. H., The Dow Chemical Company, Michigan Division, Midland,
Michigan, February 26, 1986.
17. Personal communication with Linn Duling, Michigan Department of Natural
Resources, Lansing, Michigan, February 20, 1986.
18. Memorandum: Analysis of CDDs and CDFs in Extracts of Water and Fish;
Harless, Robert, Advanced Analysis Techniquies Branch, Envi ronmental Moni-
toring Division, Environmental Monitoring and Support Laboratory, U.S.
Environmental Protection Agency, Research Triangle Park, North Carolina to
(Curtis Ross, Director, Central Regional Laboratory, Region V, U.S.
Environmental Protection Agency, Chicago, Illinois) January 17, 1984, ALS,
4 pp. with attachments.
19. 1981 U.S. Environmental Protection Agency-Michigan Department of Natural
Resources Bioaccumulation Study - Dow Chemical split sample results.
20. Personal communication with Douglas W. Kuehl, Environmental Research Labora-
tory, U.S. Environmental Protection Agency, Duluth, Minnesota, April 9,
1986.
21. Final Report, National Dioxin Study, Tier 3 Dioxin Screening, ETM
Enterprises, Inc., Grand Ledge, Michigan, TDD R05-8404-09/MI0330, Sroonian,
S. R., Ecology and Environment, Inc., Chicago, Illinois, July 16, 1984.
116
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REFERENCES (continued)
22. Personal communication with J. E. Garvey, Environmental Services, Michigan
Division, Dow Chemical Company, Midland, Michigan, February, 1986.
23. Oswald, Edward, 0., Chief, Analytical Chemistry Branch, ETD/HERL/EPA to
(Karl E. Bremen, Toxic Substances Coordinator, U.S. Environmental Protection
Agency, Region V, Chicago, Illinois) December 20, 1979, ALS, 8 pp.
24. 2,3,7,8-Tetrachlorodibenzo(p)dioxin Residues in Fish From The Tittabawassee
River and Saginaw Rivers and Sabinaw Bay - 1980.Rohrer,Thomas,K77
Michigan Department of Natural Resources, January 12, 1982.
25. Duling, Linn, Aquatic Biologist, Toxic Chemical Evaluation Section, Surface
Water Quality Division, Michigan Department of Natural Resources, Lansing,
Michigan, to (Gary A. Amendola, U.S. Environmental Protection Agency,
Region V, Eastern District Office, Westlake Ohio) February 6, 1986,
ALS, 1J pp.
26. Rio, J.M., Manager, Environmental Services, Michigan Division, Dow Chemical
USA, Midland, Michigan, to (Gary A. Amendola, U.S. Environmental Protec-
tion Agency, Region V, Eastern District Office, Westlake, Ohio) December 26,
1985, ALS, 3 pp.
27. Rio, J.M., Manager, Environmental Services, Michigan Division, Dow Chemical
USA, Midland, Michigan, to (Gary A. Amendola, U.S. Environmental Protec-
tion Agency, Region V, Eastern District Office, Westlake, Ohio) March 13,
1986, ALS, 2 pp.
28. Risk Assessment Procedures for Mixtures of Chlorinated Dioxins and Dibenzo-
furans (CDDs and CDFs) (Draft), ChlorinatedDioxinsWorkGroupPosition
Paper, U.S.EnvironmentalProtection Agency, Washington, D.C., March 15,
1985.
29. Train, Russell E., Administrator, U.S. Environmental Protection Agency,
Washington, D.C., to (Honorable William G. Milliken, Governor of Michigan,
Lansing, Michigan) October 17, 1973, ALS, 2 pp.
30. Sutfin, Charles H., Director, Water Division, Region V, U.S. Environmental
Protection Agency, Chicago, Illinois, to (Paul Zugger, Chief, Water Quality
Division, Michigan Department of Natural Resources, Lansing, Michigan)
March 29, 1984, ALS, 5 pp. with attachments.
31. Sutfin, Charles H., Director, Water Division, Region V, U.S. Environmental
Protection Agency, Chicago, Illinois, to (Paul Zugger, Chief, Water Quality
Division, Michigan Department of Natural Resources, Lansing, Michigan)
May 14, 1984, ALS, 3 pp.
32. Code of Federal Regulations (July 1985) 40 CFR Parts 415, 439 and 455.
117
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REFERENCES (continued)
33. Federal Register, 48 FR 11828, March 21, 1983.
34. Stringham, David A., Chief, Solid Waste Branch, Waste Management Division,
Region V, U.S. Environmental Protection Agency to (J. M. Rio, Manager
Environmental Services, Michigan Division, Dow Chemical U.S.A., Midland,
Michigan) March 26, 1986, ALS, 3 pp. with attachments.
118
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