DECISION MEMO

DECISION MEMO
Blue Ridge Fault Trench
January 2011
USDA Forest Service, Mt. Hood National Forest
Hood River Ranger District
Hood River County, Oregon
The crest of the Cascade Range of Oregon has been built by the continuing eruptions of hundreds
of volcanoes ranging in age from a few million years old to just a few hundred years old. Most of
the eruptions have occurred at small cinder cones and produce lava flows that cover a few
hundred acres to a few square miles. A few larger volcanoes including Mount Hood, the Three
Sisters, and Mount McLoughlin, alternate between lava flows and explosive eruptions of ash,
pumice, and broken lava.
Purpose and Need for Action
The Oregon Department of Geology and Mineral Industries (DOGAMI) has been working on a
research project to conduct LIDAR surveys of active High Cascade Volcanoes, including Mount
Hood. The LIDAR surveys revealed previously undiscovered fault scarps on the mountain.
LIDAR (Light Detection and Ranging) is an optical remote sensing technology that measures
properties of scattered light to find range and/or other information of a distant target. A scarp is
defined as steep slope resulting from the movement of rock strata down the dip of a normal fault.
A fault-line scarp is coincident with a fault, yet not actually formed by faulting, but through
erosion of weaker rocks which have been brought alongside stronger ones through movements
along a fault. Faults can reveal information on past volcanic sequence of the mountain and can
be a useful tool in the prediction of future volcanic events.
The newly discovered fault scarps require field verification. This verification process consists of
trench excavation perpendicular to the fault line. The trenches can reveal clues about landform
processes specific to that location, including the recovery of organic material that may be
suitable for carbon dating. In May 2010, DOGAMI submitted a proposal to the Forest Service to
conduct this field verfication on National Forest System lands in order to study a fault scarp on
Blue Ridge on the Hood River Ranger District. The overall purpose of this project is to conduct
field verification on the fault scarp in order to learn more on the geologic history of Mount Hood.
The underlying need for action is for DOGAMI to build a trench to collect data on the scarp. The
trenches will provide full access to the fault to allow data to be collected. The data will help
discover the history of volcanic activity on Mount Hood and contribute to the overall geologic
knowledge of the mountain.
Proposed Action
The site is several hundred feet below the ridge crest of Blue Ridge. The proposed project is
located on the Hood River Ranger District of the Mt. Hood National Forest in T1S, R9E, NW ¼
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of SE ¼ of Section 18, Willamette Meridian. The site is upslope from Forest Service Road 1640.
See Figure 1 – Overview Map of Trench Sites.
The trench(s) will be on a gentle slope (about 20 percent), inside an old plantation, and about
1200 feet from the nearest creek (Marco Creek). The picture below is the project site (Figure 2).
A short (about 300 feet) temporary access road will be needed to get equipment into the site. The
intent will be to complete all the needed data collection using one trench; however, a second
trench will be considered if the first trench proves too difficult to excavate. Both trenches are
shown on Figures 3 and 4.
Figure 2: Picture of Trench Site
DOGAMI will excavate a backhoe trench approximately 100-feet long, by three to four feet
wide, by ten to fifteen feet deep. When the trench is excavated, the top soil and vegetation will
be separated in order to be used when restoring the site. The trench will be open for
approximately two to three weeks while the data on the fault scarp is collected. Following the
completion of the data collection, DOGAMI will have the trench backfilled, re-graded and
replanted (if needed). While the trench is open, a spoil pile will be located near the trench.
The project will be completed in the Spring 2011 with the goal of completing all restoration
work by the beginning of fire season 2011 (approximately July). During project implementation,
the researchers will set up a temporary camp for the staff working in the trench to avoid the long
drive to the site. The temporary camp will include the necessary bathroom facilities.
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Figure 1: Overview Map of Trench Sites
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Figure 3: Map of Trench Site A
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Figure 4: Map of Trench Site B
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Project Design Features/Mitigation Measures
The National Environmental Policy Act defines “mitigation” as avoiding, minimizing, rectifying,
reducing, eliminating or compensating project impacts presented in the proposed action. These
project design features are used to minimize the environmental impacts of the proposed actions.
The following are a required component of the proposed action to address resource management
concerns and to guide the removal of trees for restoration projects.
Standard contract provisions that require washing equipment before entering the Mt.
Hood National Forest will be included in the contract(s).
Avoid parking machinery, equipment, and vehicles in areas that are infested with
knapweed. Workers should check under vehicle and equipment before leaving the area;
remove any knapweed plants or plant parts that may become lodged in the carriages.
Workers should also check clothing and tools for knapweed seeds. If knapweed plants or
seeds are found during inspections they should be incinerated at an approved location.
Disturbed areas should be mulched immediately following refilling and shaping the
trenched zone.
Disturbed areas should be seeded with locally available native seed (consult a Forest
Service botanist) immediately after project completion or as recommended by the Forest
Service soils scientist. Mulch should be certified weed-free. Consult Forest Service
botanist or soils scientist for an approved erosion control seed mix and sources of
certified weed-free straw.
If groundwater is encountered in the excavation and needs to be pumped out, DOGAMI
will need to ensure that no sediment leaves the site. Since the site is greater than an acre,
they will have to secure an National Pollutant Discharge Elimination System (NPDES)
permit if there is a chance that there will be runoff from the site.
In the event of a run-off generating storm, erosion control such as straw bales or silt fence
should be applied down slope of the spoils pile to minimize erosion of material off-site.
Scoping and Pubic Involvement
The Forest Service conducted public scoping to identify any concerns with the proposed
activities. The Blue Ridge Fault Trench project was published on the Mt. Hood National Forest
website in October 2010 and included in the quarterly SOPA (Schedule of Proposed Actions)
report. No comments were received during this effort. If DOGAMI requests additional research
sites based on the LIDAR surveys, additional public involvement would be completed as part of
the site-specific NEPA process.
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Decision
I have decided to implement this project as proposed. It is my decision to implement the
excavation of the trench at Blue Ridge fault scarp. The project excavates a trench in order to
conduct research on the fault scarp and learn more on the geologic history of Mount Hood. The
research will help discover the history of earthquake activity on Mount Hood and contribute to
the overall geologic knowledge of the mountain.
Reasons for Categorical Exclusion
I find the proposed action for Blue Ridge Fault Trench can be categorically excluded from
documentation in an Environmental Assessment or Environmental Impact State because the
action fits into Category 31.2-3 [36 CFR 220.6(e)(3)], described in Forest Service Handbook
1909.15-2007-1, April 17, 2009. This category states: “Approval, modification, or continuation
of minor special uses of NFS lands that require less than five contiguous acres of land.”
I find the proposed action can be categorically excluded because there are no extraordinary
circumstances identified by the interdisciplinary team of resource specialists that analyzed this
proposal. Resource conditions that were considered in determining whether extraordinary
circumstance related to the proposed action warrant further analysis and documentation are listed
below (A-F). As stated in Section 30.3 of the handbook, “the mere presence of one or more of
these resource conditions does not preclude use of a categorical exclusion. It is the degree of the
potential effect of a proposed action on these resource conditions that determines whether
extraordinary circumstances exist” (FSH 1909.15).
A. Federally listed threatened or endangered species or designated critical habitat, species
proposed for Federal listing or proposed critical habitat, or Forest Service sensitive
species. The Endangered Species Act requires that federal activities do not jeopardize the
continued existence of any species federally listed or proposed as threatened or endangered,
or result in adverse modification to such species designated critical habitat. Biological
Evaluations were prepared for sensitive, threatened or endangered wildlife, fish and botanical
species. These are available in the project record, located at the Hood River Ranger District
in Parkdale, Oregon.
The project is not located in a riparian reserve and would not impact any existing streams,
springs, seeps, or wetlands. As a result, the proposed Blue Ridge Fault Trench Project will
have no effect to Regional Forester's Special Status Aquatic Species Listed as Threatened,
including lower Columbia River steelhead trout, lower Columbia River Chinook salmon,
lower Columbia River coho salmon, or Columbia River bull trout. There will be no adverse
impacts to Chinook or coho salmon Essential Fish Habitat. The project will have no impact
on Regional Forester's Special Status Aquatic Species Listed as Sensitive, including interior
redband trout, Columbia duskysnail, barren juga, purple-lipped juga, basalt juga, or Scott's
aptanian caddisfly.
The following wildlife species are found in the project area: mule deer, elk, and migratory
birds. These species are Forest Management Indicator species. This project would remove
some trees from the area, but due to the small size of the trees, they would not be expected to
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provide nesting habitat for migratory bird species and therefore, there is no impact to these
species. Mule deer and elk would possibly use the project area in the summer months, but
plantations in this area are abundant and these species can easily move from one area to
another with minimal disturbance, therefore there would be no impact to these species. Since
these are the only species present in the project area, there is no impact to Region 6 Sensitive
Species and there is no effect to federally listed species.
No listed botanical species were not present in the project area and there are no known sites
in the area; therefore, the proposed project would have no impact on R6 Sensitive Plants or
rare and uncommon botanical species. Consultation is not required for wildlife, fish or
botanical species.
B. Floodplains, wetlands, or municipal watersheds. The proposed project will not impair
floodplain function as no work is proposed with an active floodplain. There are no municipal
watersheds or wetlands in the action area. Impacts to the aquatic resources are included in the
hydrology specialist report and fisheries biological evaluation, located in the project record.
C. Congressionally designated areas, such as wilderness, wilderness study areas, or
national recreation areas. The project is not located in congressionally designated areas.
D. Inventoried roadless areas. The project is not located in inventoried roadless areas.
E. Research natural areas. The project is not located in research natural areas.
F. American Indians and Alaska Native religious or cultural sites / Archaeological sites, or
historic properties or areas. A complete heritage resource inventory survey was performed
for the proposed projects. The heritage resource survey followed protocol established in the
2004 Programmatic Memorandum of Agreement between the Region 6 USDA Forest
Service, the Oregon State Historic Preservation Office, and the Advisory Council on Historic
Preservation. No new heritage resources were discovered or revealed as a result of the survey
for this project. The survey was conducted in a manner deemed adequate to discover historic
properties.
Findings Required by Other Laws
National Forest Management Act: The interdisciplinary team reviewed the applicable
Standards and Guidelines of this proposal. The analysis demonstrated that this decision is
consistent the Mt. Hood Land and Resource Management Plan (Forest Plan), as amended, as
required by the National Forest Management Act.
Northwest Forest Plan: I have determined that the Proposed Action is consistent with the
Standards and Guidelines for the Northwest Forest Plan (NWFP) Record of Decision (USDA
and USDI, 1994), including the subsequent decisions regarding the Aquatic Conservation
Strategy and Survey and Manage.
Aquatic Conservation Strategy: I find that this project is consistent with the Aquatic
Conservation Strategy (ACS) objectives. The ACS analysis is contained in the Fisheries
Biological Evaluation and Hydrology reports, located in the project record. The project is located
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outside riparian reserves and will be completed during the dry season. In the event of a run-off
generating storm, the project design features would protect the aquatic resources.
Survey and Manage: No habitat for aquatic or wildlife rare and uncommon species was present,
so surveys were not required. Surveys for botanical species were conducted according to the
protocols in the 2001 Survey and Manage Record of Decision. As such, this project is consistent
with the Record of Decision and Standards and Guidelines for Amendments to the Survey and
Manage, Protection Buffer, and other Mitigation Measures Standards and Guidelines (USDA and
USDI, 2001).
Clean Water Act and State Water Quality Laws: The Hydrology Specialist Report has
determined that this project complies with the Clean Water Act and state water quality laws,
which will protect beneficial uses. With project design criteria and Best Management Practices,
water quality will be maintained through implementation of this proposed action.
Invasive Plants: By considering the prevention of invasive plant introduction, establishment and
spread of invasive plants, the planning process is consistent with the Pacific Northwest Invasive
Plant Program Preventing and Managing Invasive Plants Record of Decision issued in 2005 and
the Site-Specific Invasive Plant Treatments for Mt. Hood National Forest and Columbia River
Gorge National Scenic Area in Oregon, including Forest Plan Amendment #16 Record of
Decision issued in 2008. A noxious weed risk assessment was prepared for this project.
Other Laws or Requirements: Finding associated with the Endangered Species Act,
Magnuson-Stevens Fishery Conservation and Management Act and National Historic
Preservation Act are discussed under the Reasons for Categorical Exclusion section of this
document. The proposed action is consistent with all other Federal, State, or local laws or
requirements for the protection of the environment and cultural resources.
Implementation
Implementation of this decision may occur immediately. While this decision is not subject to
appeal pursuant to Forest Service regulations at 36 CFR 215.8(a)(4), I encourage you to discuss
this project with me if you have any concerns about implementation.
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Contact Person
Detailed records of this environmental analysis are available for public review at the Hood River
Ranger District. For further information about this decision or the Forest Service appeal process,
please contact Jennie O’Connor Card at the Hood River Ranger Station, 6780 Highway 35
Parkdale, Oregon 97041; Phone: 541-352-1255; Fax: 541-352-7365; or Email:
jennieoconnorcard@fs.fed.us.
SIGNATURE OF DECIDING OFFICER
/s/ Daina L. Bambe January 6, 2011
Daina L. Bambe Date
District Ranger, Hood River Ranger District
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The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, gender, religion,
age, disability, political beliefs, sexual orientation, or marital or family status. (Not all
prohibited bases apply to all programs.) Persons with disabilities who require
alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write USDA, Director, Office of Civil
Rights, Room 326-W, Whitten Building, 14th and Independence Avenue, SW,
Washington, DC 20250-9410 or call (202) 720-5964 (voice and TDD). USDA is an
equal opportunity provider and employer.
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