**Biological Evaluation**

**Marathon Petroleum Company LLC**

**Detroit Heavy Oil Upgrade Project**

Pursuant to Section 7 of the Endangered Species Act (ESA), (87 Stat.
884, as amended; 16 U.S. C. 1531 et seq.), the U.S. Environmental
Protection Agency has reviewed the biological information and analysis
related to a Prevention of Significant Deterioration permit for the
Marathon Petroleum Company LLC (Marathon) Detroit, Michigan, refinery to
determine what impact there may be to any threatened or endangered
species in the area around the facility. EPA has followed the informal
consultation process as specified in the "Endangered Species
Consultation Handbook, procedures for conducting consultation and
conference activities under Section 7 of the Endangered Species Act,
(March 1998 final)," by the U.S. Fish and Wildlife Service and National
Marine Fisheries Service. EPA prepared this biological assessment
following the guidance provided in the ESA consultation handbook, as
well as the recommended content suggested in the ESA regulations found
in 50 CFR Part 402.12(f). As part of developing the biological
evaluation, Cambridge Environmental Inc. prepared the document,
"Ecological Screening Evaluation for the Proposed Detroit Heavy Oil
Upgrade Project," dated November 2, 2007, which discusses the results of
project modeling. (Attachment 1)

**Project Description**

Marathon intends to install new process units and support equipment to
allow the processing of a new source of crude oil and to expand the
nominal capacity of the Detroit Refinery from 100,000 barrels of crude
oil per day to 115,000 barrels of crude oil per day. Planned
modifications include the installation of a new delayed coker and coker
gas plant, hydrogen plant, sulfur recovery unit, and distillate
hydrotreater unit. Modifications to existing equipment will also be
necessary to accommodate the increased refinery capacity. Criteria
pollutant emission increases expected from these projects are as
follows:

  ----------------------------------- -----------------------------------
  Filterable Particulate Matter (PM)  35.35 tons per year

  Particulate Matter less than 10     54.02 tons per year
  microns in aerodynamic diameter     
  (PM10)                              

  Nitrogen Oxides (NOx)               113 tons per year

  Sulfur Dioxide (SO~2~)              204 tons per year

  Carbon Monoxide (CO)                185 tons per year

  Volatile Organic Compounds (VOC)    6 tons per year
  ----------------------------------- -----------------------------------

The project will also result in increases in some Hazardous Air
Pollutant (HAP) emissions. Table 2 "Projected Ambient Air Impacts,"
included in the Cambridge Environmental report provides a list of the
HAPs associated with this project and the expected increases in each HAP
resulting from the project.

**Action Area**

The action area for this project was considered to be the area within a
15 km radius of the refinery. The area surrounding the refinery is
predominantly medium to high intensity developed land. The Detroit River
is to the east, and the River Rouge is to the north of the facility. A
map showing land cover data is included as Attachment 2.

**List of Species**

There are three threatened or endangered species potentially occurring
in Wayne County, Michigan.

1\. Indiana Bat (*Myotis sodalist*): The Indiana bat hibernates in caves
and mines, and forage in small stream corridors with well developed
riparian woods and upland forests.

2\. Eastern Prairie Fringed Orchid (*Platanthera leucophaea*): Occur in
mesic to wet prairies and meadows.

> 3\. Northern riffleshell (*Dysnomia torulosa rangiana*): Occur in
> large streams and small rivers in firm sand of riffle.

**Summary of Analysis**

Cambridge Environmental performed air deposition modeling using AERMOD.
Soil concentrations of most chemicals of potential concern (COPC) were
estimated with a simple mixing model recommend in Chapter 3 of EPA's
draft "Screening Level Ecological Risk Assessment Protocol for Hazardous
Waste Combustion Facilities," which assumes pollutants deposit from the
atmosphere over a period of one hundred years of facility operation and
remain within a shallow layer of soil near the surface. Surface water
impacts were calculated assuming all stack emissions are mixed within
the Detroit River, a known habitat for the Northern riffleshell.
Sediment impacts were calculated assuming all stack emissions become
mixed with suspended sediment in the Detroit River, then deposit to form
bed sediment.

**ESA Effects Analysis**

[Criteria Pollutants]{.underline}

VOC: The project will result in an increase in VOC emissions of 6 tons/
year. At the current time, EPA is unaware of any reliable means to
assess ozone changes through \"point source\" modeling. Although point
source screening models have been developed, they have not been
consistently applied with success for source changes of this small
magnitude. Such screening models were developed for much larger VOC and
NOx sources and/or emissions changes. Urban scale photochemical ozone
models, such as the Urban Airshed Model, could be employed to assess the
ambient impact of emission increases as well as emission decreases
resulting from the implementation of emissions control programs. Past
experience, however, with such models indicates that a VOC change of 6
tons/year would not produce a predicted change in ozone concentrations.
The Urban Airshed Model, for example, has been shown to be relatively
insensitive to changes in VOC emissions. Past modeling results
considering VOC emissions changes on the order of hundreds to several
thousand tons per year of VOC in major urban areas have shown only
modest decreases in predicted peak ozone concentrations. Therefore, it
is concluded that such models would likely show a zero ozone change for
a VOC increase of 6 tons/year. Stated another way, based on the best
available tools and information that exist today, one would not expect
any measurable change in ambient ozone concentrations due to the
project's projected worst case VOC emissions increase of 6 tons/year.
Based on this information, EPA concludes the project will have no
measurable effect, if not no effect, on the endangered species with
respect to ozone. At a minimum, the project is not likely to adversely
effect the endangered species as no measurable change in ozone will
result from the project.

PM/PM10: The project will result in an increase in PM10 emissions of
54.02 tons/year. PM10 emissions are estimated to be about 71% of the PM
emissions resulting from the project. The portion of PM/PM10 emissions
of concern for the potentially affected species would be the HAP
component.

SO~2~: The projected increase in SO~2~ emissions from the proposed
project is 204 tons/year. The project increase will not cause an
exceedence of the primary or secondary National Ambient Air Quality
Standards (NAAQS). While EPA did not specifically consider any of the
listed species in potentially affected by this project when establishing
the NAAQS, the secondary standards were developed considering effects on
vegetation. EPA is not aware of data that suggests the NAAQS would not
be protective of the species potentially present within the action area.

CO: The anticipated increase in CO emissions from this project is 185
tons/year. The project increase will not cause an exceedence of the
NAAQS for CO. While EPA did not specifically consider the species
potentially affected by this project in the development of the NAAQS,
EPA is not aware of data that would suggest that the NAAQS would not be
protective of these species.

NOx: NOx emissions are primarily a concern for the eastern prairie
fringed orchid. Nitrogen deposition can adversely affect plant species
such as the eastern prairie fringed orchid by providing nutrients to
competing plant species that do not similarly thrive in nitrogen-poor
soils. The project is estimated to result in an 113 tons/year increase
in NOx emissions. The project will also result in increased emissions of
ammonia. Cambridge Environmental did not model nitrogen deposition
resulting from the project. Ambient increases in ammonia were modeled
using AERMOD. The highest annual-average concentration predicted at a
location that could potentially be suitable habitat for the eastern
prairie fringed orchid was 0.0094 μg/m^3^. The existing background
concentration of ammonia is 1.8 μg/m^3^. Based on this information, the
project would result in about a 0.5% increase in ambient concentrations
of ammonia. With respect to NOx emissions, the project also includes the
permanent shut down and removal of equipment that will result in
decrease of NOx of 205 tons/year. It is likely that nitrogen deposition
in the area will decrease as a result of this project. Based on this
information, EPA has concluded that the project is not likely to
adversely impact a species with respect to these pollutants.

[Hazardous Air Pollutants]{.underline}

Attachment 3 provides tables showing the worst case modeled impacts for
soil, surface water and sediment, background concentrations, and
benchmarks for the HAP emissions associated with this project. Limited
data is available for existing background concentrations of HAPs in
surface water, and no data was available for background concentrations
in sediment. The project impacts on sediment are very conservative, as
the evaluation assumes that all emissions from the stack will mix with
the sediment. Even so, the projected impacts are considerably lower than
the benchmarks. Most are less than 3% of the benchmark for sediment.
With respect to COPCs for which surface water data was not available,
project contributions are less than 1% of the benchmark.

Benchmarks for soil were taken from either EPA's Ecological Soil
Screening Levels (<http://www.epa.gov/ecotox/ecossl/>) or EPA, Region 5,
RCRA Ecological Screening Levels
(<http://www/e%5Ba.gov/RCRIS-Region-5/ca/ESL.pdf>) whenever possible.
For soil, neither EPA sources had a screening level for molybdenum, and
the lowest value found in the Risk Assessment Information System
(<http://rais.ornl.gov/index.shtml>) was used as a benchmark. For
sediment, no benchmark could be located for barium, cadmium, hexavalent
chromium, molybdenum, selenium, or vanadium. For surface water, EPA
sources did not provide screening levels for hexavalent chromium,
manganese, molybdenum, ammonia, chrysene, benzo(k)fluoranthene,
1,3-butadiene, acetaldehyde, butane, formaldehyde, hexane, or propylene.
The benchmarks selected for propylene and chrysene are the lowest values
for surface water found in the Risk Assessment Information System. The
benchmarks for hexavalent chromium, manganese, ammonia, acetaldehyde,
formaldehyde, and hexane were taken from the Michigan Department of
Environmental Quality (MDEQ) Rule 57 Water Quality Values. No benchmark
could be located for benzo(k)fluoranthene, 1,3-butadiene, or pentane.
The MDEQ value for ammonia is below the range for criteria continuous
concentration for freshwater mussels provided as interim guidance by
Augspurger, Keller, Black, Cope and Dwyer (2003).

Based on the available information, the HAPs of greatest concern are
cadmium, nickel and zinc with respect to soil impacts, and mercury with
respect to water impacts.

Cadmium: The background levels of cadmium in soil exceed the benchmark.
The project contribution on 5.48 x 10^-3^ mg/kg is about 0.50% of
background and 1.5% of the benchmark. The project impacts are
insignificant in comparison to existing background. It would not likely
be possible to measure or detect any negative response to an endangered
species in response to the project contribution.

Mercury: The background levels of mercury in surface water exceed the
benchmark. The project contribution on 1.95 x 10^-5^ μg/l is about 0.30%
of background and 1.5% of the benchmark. The project impacts are
insignificant in comparison to existing background. It would not likely
be possible to measure or detect any negative response to an endangered
species in response to the project contribution with respect to surface
water. Background levels of mercury in sediment are not available. The
project contribution to sediment of 2.02 x 10^-3^ mg/kg is about 0.26%
of the benchmark. It would not likely be possible to measure or detect
any negative response to an endangered species in response to the
project contribution with respect to sediment.

Nickel: The background levels of nickel in soil exceed the benchmark.
The project contribution on 1.05 x 10^-2^ mg/kg is about 0.07% of
background and 0.08% of the benchmark. The project impacts are
insignificant in comparison to existing background. It would not likely
be possible to measure or detect any negative response to an endangered
species in response to the project contribution.

Zinc: The background levels of zinc in soil exceed the benchmark. The
project contribution on 1.45 x 10^-1^ mg/kg is about 0.12% of background
and 0.18% of the benchmark. The project impacts are insignificant in
comparison to existing background. It would not likely be possible to
measure or detect any negative response to an endangered species in
response to the project contribution.

**ESA Determination**

After reviewing the analysis provided by Cambridge Environmental, the
pollutants with the greatest potential for adverse impact would include
NOx, cadmium, mercury, nickel and zinc. However, due to the conservative
assumptions made and the small contribution of these contaminants in
comparison to existing background conditions or benchmarks, EPA has
concluded that it would not likely be possible to measure or detect an
adverse response as a result of the proposed project.

Considering this analysis in its entirety, EPA concludes that the
proposed construction and operation of this facility may affect, but is
not likely to adversely affect, any of the threatened and endangered
species.

References Cited

Augspurger, T., A.E. Keller, M.C. Black, W.G. Cope and F.J. Dwyer, 2003.
Water Quality Guidance for Protection of Freshwater Mussels (Unionidae)
From Ammonia Exposure. Environmental Toxicology and Chemistry
22(12):2569-2575.