4.1-1 4.1 – Geological Resources

4.1 GEOLOGICAL RESOURCES 

The following section describes geological resources and potential impacts related to the various 

aspects of the proposed Project, including the waterway for LNG marine traffic, the Jordan Cove 

LNG terminal, and the Pacific Connector pipeline and associated facilities. 

4.1.1 Waterway for LNG Marine Traffic 

The waterway for LNG marine traffic would extend west from the coast of Oregon and up the 

Coos Bay navigation channel to the proposed terminal. Structurally, this area is within the 

Cascadia Subduction Zone (CSZ), the active convergent plate boundary between the subducting 

Explorer, Juan de Fuca, and Gorda Plates and the overriding North America Plate. The 

waterway for LNG marine traffic is located in a seismic region of historically (over the past 170 

years) moderate activity within the CSZ (Wong 2005). Geological evidence suggests that large 

megathrust earthquakes have also occurred along the CSZ during the Holocene epoch, prior to 

the written historical record. The seismic hazards of the region are discussed below under 

section 4.1.2. The results of the required Probabilistic Seismic Hazard Analysis (PSHA) and 

geotechnical investigations of the terminal site are summarized in Section 4.1.2.6. 

As described in sections 4.2.1 and 4.5.2.1, vessels in Coos Bay would contribute little to 

shoreline erosion. The effects in Coos Bay would be small because waves from LNG traffic 

would be infrequent and the magnitude of those waves would fall within the range of waves that 

occur naturally in the bay. Near the docking location, the channel substrate would be disturbed 

over the narrow width of the propeller wash, causing some sediment movement during vessel 

arrivals and departures. Because the LNG carriers would be restricted to the navigation channel, 

where any mineral resource development is already precluded, the LNG marine traffic associated 

with the Project would not have an impact on future development of mineral resources. 

The west coast of the United States has historically been subject to inundation from tsunamis 

generated by distant earthquakes in South America, Alaska, and Japan. Kelsey et al. (2005), note 

that tsunamis generated from these distant subduction zone earthquakes have minor inundation 

effects because of the long diagonal approach of tsunami waves to the west coast from these 

sources. Based on this explanation and observations made around the Indian Ocean following 

the 2004 megathrust Sumatran earthquake, a tsunami generated by a megathrust earthquake on 

the CSZ would likely present the greatest tsunami inundation risk at the site. 

The tsunami analysis in our draft EIS relied upon data from DOGAMI that pre-dated the 2004 

Sumatra event (Priest et al. 2002, Priest 1995a and 1995b), and predicted a maximum tsunami 

runup height in Coos Bay of about 13.5 feet. Because of uncertainties associated with the 

DOGAMI tsunami impact predictions, the draft EIS recommended that prior to construction 

Jordan Cove perform a site-specific tsunami hazard analysis to develop appropriate wave height, 

wave run-up, and velocity values for use during final design of the facility. This analysis was 

filed by Jordan Cove with the FERC on December 1, 2008 (see section 4.1.2.4). 

Jordan Cove’s site-specific model for predicting the force of a tsunami at the Jordan Cove LNG 

terminal was produced by the Center for Coastal Margin Observations and Predictions of the 

Oregon Health and Science University (OHSU). It was assumed that a seismic event from a 

Southern Cascadia source would cause a series of tsunami waves. In the worst case scenario, 

predicted to occur once every 450 years, the first wave to hit the ocean side of the North Spit 
4.1-2 4.1 – Geological Resources 

would be about 10 m high, and the Coos Bay wave would be about 6 m high (21 feet above 

MSL) at the LNG terminal slip. The maximum velocity of the tsunami waves in the worst case 

scenario would be up to 5 meters per second (m/s) (Zhang 2008). A tsunami wave making 

contact with the size of LNG carrier being considered for the JCE & PCGP Project would not 

likely cause any damage to the vessel. Such a wave could, however, cause the vessel to roll or 

pitch (depending on the direction in relation to the heading of the vessel). There would be little 

affect of such a wave on an LNG carrier while in the open ocean between the outer limit of the 

EEZ and the outer limit of the waterway way 12 miles from the entrance to the Coos Bay 

navigation channel. Only ships at or near the channel entrance during the events would 

experience the full force of tsunami waves. As with other matters relating solely to LNG carrier 

operations, any measures or protocols deemed necessary for LNG carrier response to tsunamis 

would be imposed by the Coast Guard at the appropriate time. Jordan Cove would have to 

comply with all requirements set forth by the Coast Guard. 

4.1.2 LNG Terminal 

4.1.2.1 Geologic Setting 

The LNG terminal facilities and slip would be located at the western edge of the coastal 

headlands of the central Coast Range, on the North Spit of Coos Bay, which marks the southern 

edge of the Coos Dune Sheet. The proposed site is at the eastern edge of the CSZ, the active 

convergent plate boundary between the subducting Explorer, Juan de Fuca, and Gorda Plates and 

the overriding North America Plate. 

The proposed site is mantled by thick (over 100 feet) late-Holocene and late-Pleistocene dune 

sheets. Recent dating of dune sand in the Florence and Coos dune sheets indicates the dunes 

near the proposed site were deposited during the late Holocene epoch (Peterson et al. 2005). The 

sands are relatively clean and fine grained. Weathered sandstone is generally encountered 

beneath the dune sands to a depth of about 125 feet. The weathered sandstone is a very dense, 

weakly cemented sand and has a silt content varying between a trace of silt to silty (GRI 2007a). 

Jordan Cove completed 11 deep borings at the location of the proposed tanks. These subsurface 

explorations identified sand extending to depths of 124 to 133 feet. Organic debris, shell 

fragments, and scattered wood were encountered at some of the borings at various depths within 

the sand. A 4-foot thick layer of wood debris interpreted as a buried log was encountered at 35.5 

feet in one of the borings. When encountered, the sandstone extended to maximum depths 

explored (ranging from 146.5 to 200.3 feet). Scattered wood debris was encountered at a depth 

of 129 feet in one boring. Scattered low-grade coal was encountered below a depth of 155 feet 

in one boring (GRI 2007a). 

Jordan Cove conducted an overwater geophysical seismic reflection survey between the 

proposed LNG terminal site and the Southern Oregon Regional Airport located on the east side 

of Coos Bay navigation channel. The subsurface profile is shallow bedrock, which becomes 

progressively deeper toward Pony Slough (southeast of the airport), to a depth of approximately 

150 feet below the bay floor (GRI 2007a). 

Impacts to surface geology would be limited primarily to the construction phase of the LNG 

terminal, when the topographic features at specific locations on the site would be altered. 

Construction site preparation would require clearing and grading of the site to an approximate 
4.1-3 4.1 – Geological Resources

elevation of +20 feet for the LNG storage tank area and +55 feet for the process areas and 

tsunami barrier. Individual excavations would be made for equipment foundations. Following 

completion of foundations, the site would be filled, compacted, and brought up to final grade. 

Final grading and landscape would consist of gravel surfaced areas, asphalt surfaced areas, 

concrete paved surfaces, and grass areas. 

The LNG storage tank and process areas would entail approximately 1.2 mcy of cut and fill. The 

planned site work would not require any disposal of material off the LNG terminal site. No 

blasting would be required during any phase of construction of the LNG terminal because the 

entire site consists of unconsolidated material. Any shoreline areas disturbed by the Project 

would be armored to protect against erosion or shifting beyond the Project design limits. 

The Port’s construction of the slip and access channel would require the excavation of 2.3 mcy 

of material, and dredging of 3.3 mcy of material, for a total of approximately 5.6 mcy. See 

sections 2.1.4 and 2.4.1 of this EIS for additional discussion of dredging and dredged material 

disposal. The LNG terminal would involve changes to the surface geology of the site, 

potentially including impacts to fluvial bedforms and migrating knickpoints related to changes in 

hydrology. 

4.1.2.2 Mineral Resources 

In 2005, the principal mineral production of Oregon (in order of value) was construction sand 

and gravel, crushed stone, Portland cement, diatomite, and perlite. The value of production was 

$398 million (National Mining Association 2006). 

Mineral resources available in Coos County, Oregon include chromium, gold, clay, manganese, 

sand and gravel, silica, stone, and titanium. There are 11 producing mines within 5 miles of the 

proposed LNG terminal. The closest mines are 1.3 miles to the southeast (a sand and gravel pit 

at the airport), and 1.5 miles to the northeast (Coos-Sand Corp.; silica, sand and gravel) (U.S. 

Geological Survey [USGS] 2004a,b). 

Based on studies of coal and natural gas resources in the Coos Bay area completed in the 1970s 

and 1980s (Newton 1980; Mason and Hughes 1975), coal may occur at depths within or below 

sandstone at the site. Natural gas may also occur at depth within the underlying sandstone. 

Initial exploratory tests (Sproule Associates, Inc. 2004, 2005, 2006) indicate a promising but 

unproven coal gas resource in the Coaledo coals of the basin. This prospect carries risk 

commensurate with an exploration play and could require several years to reach commerciality. 

Gas in place in Coos Bay is estimated to be 1,166 Bscf. The majority of the gas (93 percent) is 

held in the Lower Coaledo coals. 

The dredged material would be temporarily stockpiled at the Port site. Following the 

recommendation of the BLM, Jordan Cove conducted a marketing survey and found one 

potential market for the sand, a bulk market in the San Francisco Bay area for fine aggregate. 

Preliminary analysis of the sand indicates that the run-of-production sand has a size distribution 

that is suitable for use as fine aggregate in the production of Portland cement. Further analysis 

indicates that as-produced the sand contains a small amount of heavier minerals that may make it 

unsuitable for glass manufacture. However, there are standard processing techniques that can be 

used to treat the sand to meet float glass standards. Additional characterization testing is 

currently being undertaken to determine whether the high-value application in glass manufacture 
4.1-4 4.1 – Geological Resources 

is a viable market. Both markets would be served by barge. However, the approximate 3.3 mcy 

to be dredged would exceed the immediate market requirements and would require stockpiling in 

order to meet the supply and demand of the long term market requirements. Jordan Cove has 

assumed that sand would be sold at a rate of approximately 500,000 cy per year requiring 

approximately 7 years to market the entire stockpile. 

Construction and operation of the LNG terminal facilities and slip and access channel would not 

affect any known mineral resources or the recovery of any mineral resources. Development of 

the site would not preclude future utilization of potential leasable resources in deeper, underlying 

geologic formations. It should be noted that while the Port would be purchasing the surface 

rights from Weyerhaeuser, Weyerhaeuser would retain the mineral rights. Any leases for these 

minerals would have to be obtained from Weyerhaeuser. 

4.1.2.3 Seismic-Related Hazards 

The results of the geotechnical investigation (GRI 2007a) indicate that subsurface conditions at 

the proposed Jordan Cove terminal are generally suitable for LNG facilities, provided that 

adequate site preparation and foundation design and construction methods are implemented. The 

LNG terminal facilities would be designed to account for these conditions. No faults are 

reported at the site, and the Coos Bay area is located in a region with historically (over the past 

170 years) moderate to low seismic activity within the active CSZ (Wong 2005). Numerous 

earthquakes of magnitude 4.0 or greater on the Richter scale have been recorded in or near 

western Oregon in the historical record of the Pacific Northwest. Geological evidence suggests 

that large megathrust earthquakes have also occurred along the CSZ during the Holocene epoch, 

prior to the written historical record. There is no historical record of earthquakes of magnitudes 

greater than 3.0 within a 50-kilometer (km) or 31-mile radius of the site. An earthquake off the 

coast of Crescent City, California (275 km or 170 miles away), and one off the coast of Newport, 

Oregon (105 km or 65 miles away), were felt near the site (GRI 2007b). 

The Blanco Transform Fault Zone, an ocean transform fault related to the movement of tectonic 

plates, begins about 100 miles off of Cape Blanco, which is approximately 25 miles south of 

Coos Bay, and extends in a northwest direction to about 300 miles off of Newport, Oregon. 

During the past 40 years, approximately 1,500 earthquakes of magnitude 4.0 or greater and many 

thousands of smaller earthquakes have occurred along this fault zone. Only the largest of these 

earthquakes are detectable by land-based seismographs along the Oregon coast. The risk of a 

major tsunami from an earthquake in this transform fault is low because the tectonic plates slip 

laterally with little vertical displacement of the ocean floor (Oregon State University 2008). 

Through consultation with DOGAMI, eleven faults located within 150 km (93 miles) of the 

proposed LNG terminal were treated as individual seismic sources in the seismic hazard model 

in the Site-Specific Seismic Hazard Study (GRI 2007a). The three closest faults are the CSZ (13 

km or 8 miles), the South Slough (16 km or 10 miles), and the Coquille Anticline (30 km or 18.6 

miles). There are three faults within 67 km (41.6 miles) of the site, and five within 133 km (82.6 

miles) of the site. The CSZ, a megathrust fault, has the greatest potential maximum moment 

magnitude (Mw) of 8.3 to 9.0. The estimated maximum potential Mw of the other faults range 

from 6.3 to 7.7 (GRI 2007b). 

Briggs (1994) indicated the possibility of a Holocene-active fault located in Pony Slough, 

immediately southeast of the LNG terminal site; however, the seismic reflection profile obtained 
4.1-5 4.1 – Geological Resources

specifically for this proposed Project did not indicate the presence of a fault either at Pony 

Slough or across the bay from the Jordan Cove terminal (GRI and Ian Madin, chief scientist at 

the DOGAMI). This analysis is available in Site-Specific Seismic Hazard Study, Proposed 

Jordan Cove LNG Facility filed as Appendix B.6 of the environmental Resource Report 6 of 

Jordan Cove’s application (GRI 2007b, revised August 24, 2007). 

Soil Liquefaction 

Loose to medium dense sands and some softer, low-plasticity, fine-grained soils (such as sandy 

silts) can experience increased pore water pressure if saturated and subject to cyclic shear 

stresses of a sufficient magnitude and duration. Under certain conditions, the material would 

lose most of its shear strength and deform as a viscous fluid (complete liquefaction) (GRI 

2007a). 

The majority of the soils at the proposed LNG terminal are dense enough to resist liquefaction 

during design-level earthquakes. Analyses indicate the potential for liquefaction in a relatively 

consistent zone below the water table in the upper 15 feet of the soil profile corresponding to 

historical fill. Liquefaction is also predicted at depths ranging from 25 to 45 feet in zones that do 

not appear to be continuous across the proposed site. Of the liquefiable zones, the majority of 

the predicted liquefaction would occur at depths of 30 to 40 feet (GRI 2007a). The detailed 

analysis of liquefaction potential is available in Geotechnical Investigation, Proposed Jordan 

Cove LNG Facility filed as Appendix B.6 of the environmental Resource Report 6 of Jordan 

Cove’s application (GRI 2007a, revised August 24, 2007). 

Lateral spreading involves horizontal displacement of soil at the surface as a result of 

liquefaction of a saturated surface or near-surface layer. Based on the distance of the proposed 

LNG storage tanks to the edge of the flat slopes, and the limited extent of liquefiable soils, the 

risk of lateral spreading at the proposed LNG storage tank site is low (GRI 2007a). 

Jordan Cove would densify the upper 15 feet of the fill material to mitigate the risk of strength 

loss at shallow depths beneath the tanks (GRI 2007a). Review of estimated liquefaction-induced 

settlement from the deeper isolated layers between 25 and 45 feet suggests that the settlements 

associated with the design earthquakes would be within allowable ranges. The deepest 

liquefiable layer was identified west of the western limits of the proposed slip. Depending on the 

extent of this deep liquefiable layer, lateral spreading could occur toward the proposed slip. 

Further analysis of that potential would be obtained prior to final design and mitigated as 

appropriate. 

Subsidence 

Modeling of megathrust earthquake ruptures on the CSZ indicates sequences of interseismic 

uplift and coseismic coastal subsidence. The predictions for coastal subsidence are supported by 

events associated with the A.D. 1700 CSZ earthquake, including submerged trees and buried 

intertidal marshes (see section 4.1.2.4 below). This repeated coastal subsidence pattern has been 

documented along the length of the CSZ (Atwater et al. 1995). Leonard et al. (2004) estimate 

the coseismic subsidence in the Coos Bay area could range from 0.0 to about 1.5 m (5.0 feet) as a 

result of a future Mw 8 to Mw 9 megathrust earthquake. Because of the significant potential for 

coseismic subsidence and other seismic hazards associated with the site, we recommend that all 

required civil and structural design measures be assessed by a qualified independent Board of 
4.1-6 4.1 – Geological Resources 

Consultants prior to receiving authorization from the Director of OEP to proceed with 

construction. 

4.1.2.4 Tsunami Hazards 

In its Safety Advisory Report dated October 4, 2007, the ODE stated that “[t]he Department is 

particularly concerned about the potential for tsunami. Recent statements by DOGAMI 

following the 2005 (sic) tsunami in Sumatra indicate that maximum tsunami height could be up 

to 20 feet higher than previously thought. DOGAMI staff stationed at Newport, Oregon have 

indicated that deepening the channel would tend to increase maximum tsunami height, and 

therefore, FERC should require that the design basis tsunami takes into account the height 

increase caused by dredging the channel.” 

Jordan Cove’s geotechnical consultants, GRI Geotechnical & Environmental Consultants (GRI) 

of Beaverton, Oregon and Moffat & Nichol International (Moffat & Nichol) reviewed the 

DOGAMI tsunami maps and local site conditions relating to the proposed LNG terminal location 

(GRI 2007a, see footnote in section 4.1.2.1). Based on review and observations and lessons 

learned from the 2004 Indian Ocean tsunami, GRI and Moffat & Nichol identified possible risk 

associated with a tsunami-induced breach of the North Spit at the existing industrial waste pond 

west of the site. In this scenario, an initial wave could potentially breach the narrow berms that 

separate the existing pond from the ocean and bay, allowing subsequent waves to enter the bay 

immediately southwest of the site. These waves could cause higher runups in the upper bay and 

have a more direct impact on the cities of North Bend and Coos Bay. 

In the draft EIS, we requested that Jordan Cove conduct further site-specific analysis of potential 

tsunami effects and factor the proposed dredging and other site improvements into the analysis. 

Jordan Cove has coordinated with Dr. Daniel Cox (Director of the O.H. Hinsdale Wave Research 

Laboratory at Oregon State University), Dr. George Priest (Geologist at DOGAMI) and other 

representatives from OHSU and DOGAMI to provide updated estimates of tsunami runup at the 

North Spit. Jordan Cove filed the study, entitled Final Report, Site-Specific Tsunami Modeling 

at the Jordan Cove LNG Facility, Coos County Oregon, with the Secretary on December 1, 2008 

(Zhang 2008). Jordan Cove collected high-resolution Light Detection and Ranging (LiDAR) 

topographical data for the North Spit, as required by the model. Using this accurate topographic 

information allowed realistic simulation of the hydrodynamic forces that would impact the Coos 

Bay region. The study used the SELFE hydrodynamic computer simulation model, a state-ofthe-art model and the best tool currently available. Researchers throughout the Pacific 

Northwest, including the Center for Coastal Margin Observation and Prediction at OHSU in 

Portland, use this model. The potential tsunami hazard near the proposed LNG terminal was 

studied using three earthquake scenarios for this region. Maximum tsunami wave inundations 

and velocities around the Project site were calculated. 

Using the current suite of earthquake scenarios, the maximum calculated tsunami inundation at 

the site is about 21 feet above MSL. Velocities of at least 2 to 5 m/s are modeled in the shipping 

channel. Fastest flow (greater than 10 m/s) is predicted over the sand dunes in the worst-case 

scenarios, and the maximum flow (approximately 15 m/s) is predicted west and southwest of the 

slip. The model predicts that flow would slow to approximately 2 m/s upon reaching the slip. 

To mitigate for potential tsunami hazards at the proposed LNG terminal site, the LNG storage 

tanks would be located within an area enclosed by a barrier with a peak crest elevation of +55 
4.1-7 4.1 – Geological Resources

feet. Foundations for all critical process equipment and structures located within the barrier 

would be installed at an elevation of +20 feet and all others at a nominal grade of +55 feet. This 

elevation is higher than the tsunami runups directly on the coastline predicted by DOGAMI 

(Priest 1995a; Priest et al. 2002) and Jordan Cove’s tsunami study (Zhang 2008). There are no 

obvious mechanisms whereby failure of the North Spit at the industrial wastewater ponds would 

amplify the runup at the coastline. The Jordan Cove modeling study confirms that a barrier with 

a crest at +55 feet elevation would provide sufficient protection from a tsunami. The proposed 

berm remains above the maximum inundation line in all modeled scenarios. Similar to most of 

the rest of the site, the proposed barriers are underlain by very dense sand that is generally too 

dense to liquefy. The barrier is proposed to be constructed of compacted, dense sand that would 

be armored to reduce the risk of tsunami scour. In the event that it is determined from the initial 

design analysis, through consultation with DOGAMI, that a more robust interior barrier core is 

required, cement treated sands would be considered for barrier construction. 

For the barrier slopes, including slope areas above elevation +25 feet, alternative erosion control 

measures and wave run up protection would be used. Slopes would be protected against tsunami 

runup using either concrete cellular mattresses (CCMs), grout-injected geotextile fabric 

mattresses (fabriform), or other suitable means as determined during detailed design. The design 

of the slope protection against tsunami wave run up would be developed through consultation 

with DOGAMI. The erosion control measures would be designed in accordance with the Oregon 

Department of Transportation (ODOT) Erosion Control Manual. 

Jordan Cove’s tsunami model assumes that structures (e.g., jetties, barriers, dunes) would remain 

immobile throughout the tsunami event. Design of the barrier wall considers the effects of 

tsunami waves, including scour and deposition in the path of the scenario tsunamis, flow 

velocities, any highly probable impact loads from potential floating objects including adrift 

vessels and barges, breaking waves, prolonged inundation, and the effects of tectonic subsidence 

(prolonged changes in tidal elevation inherent in the earthquake source scenarios used for 

tsunami generation). 

Under the largest earthquake scenario modeled in the Jordan Cove tsunami study, the first 

tsunami wave would arrive at the beach approximately 20 minutes after an earthquake. It would 

reach the Jordan Cove LNG terminal location about 5 minutes later. Maximum inundation near 

the site would occur about 40 minutes after the earthquake, and the second tsunami wave would 

arrive about 55 minutes after the earthquake, and would compound on the retreating water from 

the first wave in some places. The third wave would arrive about 72 minutes after the 

earthquake, but would be substantially smaller than the first two. The model predicts that 

modifying the landscape for the proposed LNG terminal would result in slightly smaller waves 

and less water spilling into the Henderson Marsh. Construction of the slip would result in some 

localized wave patterns. According to geologists researching tsunami hazards in southern 

Oregon (including Dr. George Priest), the most critical work to ensure public safety related to 

tsunamis is to provide accurate maps of the tsunami danger zone and educate the public on what 

to do when they feel a big earthquake (The Oregonian 2008). The earthquake would be the 

clearest warning that a tsunami were approaching. 

The Jordan Cove tsunami study provides predictions for wave size and timing to allow for 

prompt warnings and evacuation of areas susceptible to inundation after a large earthquake. 

According to NOAA (2006), warnings are issued within 10 minutes after earthquake occurrence. 

Tsunami warnings include estimated wave arrival times for key coastal locations in the warned 
4.1-8 4.1 – Geological Resources 

area. Mariners in deep water (600 feet or greater) are advised to stay at sea. Those in shallow 

water or harbors are advised to move to deep water if time and weather conditions allow. 

Warnings are broadcast through standard National Weather Service (NWS) dissemination 

methods such as the NOAA Weather Radio-All Hazards, the Emergency Alert System, and the 

Emergency Managers Weather Information Network. The Oregon Emergency Management 

Department (OEMD) would receive the message through the Federal Emergency Management 

Agency’s (FEMA's) National Warning System and the NOAA Weather Wire. The OEMD 

would immediately pass warnings to local jurisdictions. The Coast Guard would relay the 

message via radio. The warnings would be posted on the West Coast and Alaska Tsunami 

Warning Center and NWS Web sites and be issued through a public e-mail list server. Many 

Oregon coastal communities supplement the basic notification systems with sirens, automatic 

phone messaging systems, and other alerts (NOAA 2006). 

We believe that the site-specific tsunami study, coupled with the Jordan Cove’s proposed 

mitigation measures indicate that the site is not unsuitable due to tsunami hazards. 

In a filing with the FERC on February 20, 2009, Jordan Cove addressed potential impacts on an 

LNG carrier at the terminal berth from a tsunami. Assuming that the early warning systems 

discussed above are in place and working, there should be advance notice that a tsunami wave 

could reach the LNG terminal slip about 25 minutes after an earthquake. During that period, 

Jordan Cove would ensure that all LNG and BOG interconnections between the terminal and an 

LNG carrier at berth were disconnected. Provided that directions would be given by the Coast 

Guard, the LNG carrier could either exit the terminal and proceed to the open ocean before the 

tsunami hits Coos Bay, or it could remain at the berth and ride out the wave. The predictive 

models run in 2008 by OHSU show either a relatively weak tsunami wave moving into the slip 

from the west, or a slightly stronger wave coming in from the south; but in no scenario did the 

two waves converge simultaneously at this location. Also, for all the models the rate of change 

of velocity for a tsunami at the terminal would be low, in the range of 0.03 m/s2. Jordan Cove 

estimated the velocity of a typical flood tide in lower Coos Bay at about 1 m/s. It therefore 

estimated that the impact of a tsunami would be roughly equivalent to the forces exerted by a 

flood tide. Given the relatively low velocity of a tsunami wave at the slip, Jordan Cove believes 

that the lines attaching the LNG carrier to the berth would probably hold fast, and could be 

supplemented by the tug boats restraining the LNG carrier at the berth or within the slip. 

4.1.2.5 Summary of Geologic Features/Hazards and Seismic Design Requirements 

• The primary geologic hazard for the LNG terminal is the CSZ, which can generate strong 

horizontal and vertical ground motions and tsunami waves. The seismic source for the 

CSZ is located 13 km (8.0 miles) below the site. 

• Two potential zones have been identified where liquefaction may occur at the site. These 

are: 1) saturated sand between the depths of 10 and 15 feet corresponding to historical fill 

and 2) discontinuous sand lenses between depths of 25 feet and 45 feet. Maximum 

liquefaction settlements were estimated to be 4.2 inches. Jordan Cove has proposed that 

the upper liquefaction zone would be mitigated by dynamic compaction and/or roller recompaction while the lower zone would be mitigated by compaction grouting. 

• Lateral spreading also poses a potential problem for the site, especially at the shoreline. A 

further series of geotechnical studies would be performed during detailed design, and 

ground improvement would be utilized to mitigate the hazard. 
4.1-9 4.1 – Geological Resources

• There is an absence of mapped faults near the site; therefore, the risk of fault offset 

rupture at the site is considered low. 

• The potential for coseismic subsidence of the site is significant associated with a 

megathrust earthquake on the CSZ. It is estimated that the coseismic subsidence at the 

site would range between 0 and 1.5 meters (5.0 feet) during a future megathrust 

earthquake located along the portion of the CSZ nearest the site. 

• A tsunami generated by a megathrust earthquake on the CSZ would present the greatest 

inundation risk at the site. 

DOT Seismic Design Requirements (NFPA 59A-2001) 

The seismic design requirements for LNG facilities are contained in the DOT regulations at 49 

CFR Part 193, which adopts the seismic design provisions of the NFPA 59-A (2001). NFPA 

59A (2001) defines two levels of earthquake motions, the Operating Basis Earthquake (OBE) 

and the Safe Shutdown Earthquake (SSE). The OBE and SSE ground motions must be 

determined by site-specific evaluations and are defined in terms of 5 percent damped response 

spectra with the following probability levels: 

The OBE ground motions at the site are defined as the lesser of: 

1. ground motion with a 10 percent probability of exceedance within a 50-year period (475 

year return period); or 

2. two-thirds (2/3) of the Maximum Considered Earthquake (MCE) ground motion. 

In NFPA 59A (2001), the MCE is defined as future potential ground motion with a 2 percent 

probability of exceedance within a 50-year period (2,475-year return period) with deterministic 

limits. 

The SSE ground motions at the site are defined as the lesser of: 

1. 1 percent probability of exceedance within a 50-year period (4,975-year return period); or 

2. two times the OBE. 

These motions would be used as the basis for the earthquake-resistant design of the LNG facility, 

applied to the following limited specific list of critical safety-related structures, systems and 

components per NFPA 59-A (2001) 4.1.3: 

1. LNG storage containers and their impounding systems; 

2. system components required to isolate the LNG container and maintain it in a safe 

shutdown condition; 

3. structures and systems, including fire protection systems, the failure of which could affect 

the integrity of (1) or (2) above. 

NFPA 59-A (2001) specifies that the above-referenced structures, systems and components must 

be designed to remain operable during and after an OBE, and must provide for no loss of 

containment capability of the primary container during and after an SSE. The facility design 

must also provide for the ability to isolate and maintain the LNG container during and after an 

SSE. After an SSE event, the container must be emptied and inspected prior to resumption of 

container filling operations. As a minimum, the impounding system must be designed to 
4.1-10 4.1 – Geological Resources 

withstand an SSE, while empty and an OBE while holding the maximum operating volume of 

the LNG container. Seismic recording instrumentation is also required. 

FERC Seismic Design Guidelines for LNG Facilities 

There are areas where NFPA 59A (2001) does not provide specific seismic design requirements 

to enable a comprehensive philosophical approach to the overall seismic safety of an LNG 

facility. Consequently there can be a wide range of opinions by technical experts on how various 

requirements are to be applied. In its Draft Seismic Design Guidelines and Data Submittal 

Requirements for LNG Facilities (FERC Seismic Guidelines, released January 2007), FERC staff 

gives specific guidance to applicants on its interpretation of the requirements of NFPA 59A 

(2001), providing consistent design specifications throughout the nation, and a basis for uniform 

reviews of various LNG terminal sites, structures, components and systems under FERC 

jurisdiction. 

In general, the FERC Seismic Guidelines are based on existing rules and procedures found in 

ASCE 7-05, ASCE 4-98, API 650 Appendix E, and other current standards documents applicable 

to LNG facilities. The guidelines also rely on the National Seismic Hazard Maps and the 2006 

International Building Code (IBC 2006) MCE Ground Motion Maps, which were developed 

specifically for use in the design of buildings and other structures in the United States by the 

USGS. 

The FERC Seismic Guidelines classifies the structures, components, and systems identified in 

NFPA 59A (2001) 4.1.3.3 (i.e., items 1, 2, and 3 listed above), as Seismic Category I. The 

remaining structures, systems and components are classified as either Seismic Category II or III. 

Seismic Category II and III structures, systems and components are to be designed in accordance 

with the seismic design requirements of ASCE 7-05 (i.e., IBC 2006). Category II structures, 

systems and components must meet the seismic performance goals for “essential” facilities. 

Category II facilities are expected to survive the Design Earthquake ([DE], which is 2/3 the 

MCE) with potential structural damage that would not be so severe as to preclude continued 

occupancy and function of the facility. An Importance Factor (I or Ip) of 1.5 is specified for 

design of Category II facilities. 

Category III facilities are considered non-essential. Normal, non-essential facilities would be 

designed for the DE in accordance with ASCE 7-05, and are expected to sustain repairable 

damage when subjected to DE ground motions, although it may not be economical to do so. An 

Importance Factor of 1.0 is specified for design of Category III facilities. 

The FERC Seismic Guidelines also provide guidance in determining the appropriate Site Class 

spectral amplification values and long-period spectra displacement cutoff transition period per 

ASCE 7-05, inelastic reduction factors for the SSE, minimum safety factors for tank foundation 

loading and settlement, minimum freeboard requirements for LNG sloshing heights, and 

selection and location of seismic recording devices. 

4.1.2.6 Site-Specific Geotechnical Investigation and Seismic Hazard Analysis 

Geotechnical Site Characterization 

The proposed LNG terminal site is relatively flat and ranges in elevation from 20 feet to 50 feet. 

Groundwater levels range between 9 and 13 feet below the ground surface. Based on subsurface 
4.1-11 4.1 – Geological Resources

investigations performed by GRI, the subsurface of the proposed Jordan Cove LNG terminal site 

is typically mantled with relatively clean, fine-grained very dense sand that is underlain by 

weathered sandstone. Historical records indicate that the upper 10 to 15 feet of the sand deposit 

is likely fill; however, the transition to the underlying dune sand was indiscernible based on 

visual observation. The sand typically contains a trace of silt and is brown near the ground 

surface and transitions to gray below depths of 27 to 50 feet. Weathered sandstone occurs at a 

depth of about 125 feet. 

Liquefaction analyses performed by GRI have identified two potential zones where limited 

liquefaction may occur at the site: 1) saturated sand between the depths of 10 and 15 feet below 

ground surface (bgs) corresponding to historical fill and 2) discontinuous sand lenses between 

depths of 25 feet and 45 feet. Maximum liquefaction settlements were estimated to be 4.2 inches. 

The measured shear velocity (Vs), in feet per second (fps), of the soil profile was a follows: 

• 0 to 35 bgs Vs = 650 fps 

• 35 to 75 bgs Vs = 750 fps 

• 75 to 115 bgs Vs = 1050 fps 

• greater than 180 bgs Vs = 2100 fps 

The average shear wave velocity in the upper 100 feet of the soil profile is about 750 fps. This 

shear wave velocity along with the observation that the soil profile is very dense sand 

characterizes the area as Site Classification D in accordance with the provisions of the 2006 IBC 

(2007 Oregon State Structural Specialty Code) and ASCE 7-05. 

Controlling Seismic Events 

Based on deaggregation of seismic sources from the GRI Probabilistic Seismic Hazard Analysis 

(PSHA), the controlling seismic source is a megathrust earthquake occurring on the CSZ. The 

proposed Jordan Cove LNG terminal is located 13 km (8.0 miles) from the CSZ. In its PSHA, 

GRI has considered two different scenario events for the CSZ megathrust earthquake. These are 

a megathrust earthquake with a moment magnitude of 8.3 and a megathrust earthquake with a 

moment magnitude of 9.0. Both scenario events are given an equal weighting in the PSHA. The 

CSZ also is the controlling seismic source for tsunamis, which is a significant hazard for the site. 

Input Ground Motions 

Input ground motions for the terminal site (also called Design Ground Motions) were determined 

based on site-specific seismic hazard analysis prepared for the LNG terminal by GRI. The input 

ground motions were developed in accordance with recommendations of the FERC Seismic 

Guidelines. These design ground motions also satisfy the requirements for ground motion 

determination of the 2007 Oregon Structural Safety Specialty Code (2006 IBC). The input 

ground motions for the LNG terminal recommended by GRI are as follows: 

• The site-specific MCE ground motion parameters based on site response analysis are SMS

= 1.20g and SM1 = 1.08g. The site-specific MCE peak horizontal ground acceleration 

based on site response analysis is 0.48g. 
4.1-12 4.1 – Geological Resources 

• The site-specific DE ground motion parameters adjusted for site effects (which are twothirds of the MCE value adjusted for site effects) are SDS = 0.80g and SD1 = 0.72g. The 

site-specific DE peak horizontal ground acceleration is 0.32g. 

• The OBE was taken as the earthquake ground motion having a probability of exceedance 

of 10 percent in 50 years (Return Period = 475 years). The GRI-recommended sitespecific OBE design ground motion response spectra at the ground’s surface has a peak 

horizontal ground acceleration (i.e., zero period acceleration) based on site response 

analysis of 0.27g. The peak site specific vertical OBE design surface acceleration is 

0.24g. 

• The SSE was taken by GRI as equal to the lesser of an earthquake motion that has a 

probability of exceedance of 1 percent in 50 years (Return Period = 4,975 years) or twice 

the OBE, in accordance with NFPA-59A-2001 but not less than the site specific MCE as 

recommended in the FERC Seismic Guidelines. The GRI-recommended site-specific 

SSE design ground motion response spectra has a SSE peak horizontal ground 

acceleration at the ground surface of 0.48g. The vertical SSE design ground motion has a 

peak vertical ground surface acceleration of 0.43g. 

Proposed/Necessary Site Improvements 

The LNG storage tanks would be supported on mat foundations. Buildings, process equipment, 

and pipe rack foundations would be supported with drilled pier foundations, spread footings, or 

mats. GRI has recommended that the shallow upper zone be improved where mat foundations 

are used to mitigate the potential for seismic soil liquefaction. Where necessary, Jordan Cove is 

currently proposing to utilize dynamic compaction and/or roller recompaction to improve the 

shallow zones and compaction grouting for the deeper zones. Final design decisions for 

foundation improvements would be done during detailed engineering. 

The LNG terminal site would undergo extensive earthwork. A slip area and the access channel 

in the bay would generate 5.6 mcy of excavated and dredged materials. The portion of a dune on 

the east of the site adjacent to the proposed LNG storage tank locations would be graded to 

approximately elevation +20 feet. Some of this sand would be used to generally raise the site 

outside the tank area. The remainder would be used to create a multi-purpose containment storm 

surge barrier that surrounds the tanks with a crest elevation currently proposed at 55 feet. FERC 

staff recommendations are provided and included as part of this EIS that assure that final site 

improvement designs would satisfy both the FERC Seismic Guidelines and the 2007 Oregon 

Structural Safety Specialty Code. 

Proposed Foundation Design 

The LNG tank structures would be base isolated with a friction pendulum bearing system. The 

base isolators would be located between concrete slabs with a thickness of about 2.6 feet each. 

The top of the lower concrete slab would be founded at about elevation +20 feet, near existing 

site grade. Buildings, process equipment, and pipe rack foundations would be supported with 

drilled pier foundations, spread footings or mats founded on improved subgrade. Conditions are 

provided and included as part of this EIS that assure that final foundation designs would satisfy 

both the FERC Seismic Guidelines and the 2007 Oregon Structural Safety Specialty Code. 
4.1-13 4.1 – Geological Resources

Board of Consultants 

Given the high seismic risk associated with proximity of the proposed Jordan Cove LNG 

terminal to the CSZ, the high seismic loads and performance criteria that the facility must 

accommodate in the event of an SSE, the special design measures associated with the proposed 

seismic base-isolation system for the LNG storage tanks, and the need to ensure that all the 

critical safety-related structures, systems, and components of the facility are properly designed, 

seismically qualified, and implemented as anticipated, we believe it is essential that all of the 

required civil and structural design measures be assessed by a qualified independent entity. 

Therefore, we recommend that: 

• Prior to construction of the LNG terminal and pipeline, Jordan Cove and Pacific 

Connector should retain a “Board of Consultants” (Board) composed of three or 

more qualified independent engineering consultants experienced in the critical 

disciplines of geotechnical, civil, structural, and mechanical engineering, to review 

the final design and to perform construction quality inspections of the civil and 

structural aspects of the Project in accordance with the specifications contained in 

the FERC’s Draft Seismic Design Guidelines and Data Submittal Requirements for 

LNG Facilities (FERC Seismic Guidelines) and other measures agreed to by Jordan 

Cove and Pacific Connector. 

• Jordan Cove and Pacific Connector should file with the Secretary the names and 

qualifications of the Board members for approval by the Director of OEP. 

• The Board should certify that all civil and structural detailed design calculations, 

analyses, and construction documents are in compliance with all applicable codes 

and standards, Project-specific civil, structural, and mechanical design criteria, and 

other engineering requirements of the Order, including the FERC Seismic 

Guidelines. The Board should further certify, based on construction inspections by 

the Board that all civil and structural construction of the terminal facilities is in 

conformance with the Project construction documents. The Board should also 

certify that all procured equipment has been properly seismic qualified in 

conformance with the Project-specific seismic qualification requirements, and the 

FERC Seismic Guidelines, that seismic detailing of structures has been properly 

implemented, and the pipeline has been designed to minimize the hazard of rupture 

due to ground instability. 

• Among other things, the Board should assess the adequacy of the following: 

a. final geotechnical investigations necessary to support all final foundation designs 

in satisfying the FERC Seismic Guidelines, and final pipeline routing/mitigation 

measures through geologically hazardous areas; 

b. field tests and associated results used to verify ground improvement, pile 

driving, and all civil and structural construction; 

c. selection and implementation of the final seismic design categorization of all 

structures, systems, and components of the LNG terminal in satisfying the 

FERC Seismic Design Guidelines; 
4.1-14 4.1 – Geological Resources 

d. proposed seismic recording instrumentation and shutdown alarms in satisfying 

the FERC Seismic Design Guidelines; 

e. construction procedures and progress; and 

f. continuous and/or periodic inspections made by the Board to ensure that the 

construction quality of all Seismic Category I, II, and III structures, systems, 

and components is acceptable. 

• The Board should meet as necessary to allow the timely progress of the final design 

approvals and construction of the Project in accordance with Jordan Cove and 

Pacific Connector's production of acceptable interim and final design data. 

• Before each meeting, Jordan Cove and Pacific Connector should file the following 

material with the Commission and furnish copies to members of the Board, and 

other appropriate federal and/or state agencies at the request of the Director of 

OEP: 

a. a statement of the specific level of review the Board is expected to provide; 

b. an agenda for the meeting; 

c. a list of the items to be discussed; 

d. a discussion of significant events in the design and construction that have 

occurred since the previous Board meeting; 

e. drawings of the design and construction features; and 

f. documentation of the details, calculations, and analyses of the design and 

construction features to be discussed. 

• Jordan Cove and Pacific Connector should ensure that the Commission and the 

Board has sufficient time to review all pertinent materials before each meeting. 

• Within 30 days of each Board meeting, Jordan Cove and Pacific Connector should 

file with the Commission copies of the Board's report and a statement of intent to 

comply with the Board's recommendations or a statement of a plan to resolve the 

issue(s). Jordan Cove and Pacific Connector must provide detailed reasons for any 

recommendation of the Board not implemented. 

• The Board's review comments should be submitted prior to or simultaneously with 

Jordan Cove and Pacific Connector’s request(s) for approval to proceed with any 

specific construction-related activities that may be required by the Order. The 

Director of OEP must approve in writing all requests to proceed with construction. 

• Prior to commissioning of the LNG terminal or commencing service through the 

pipeline, Jordan Cove and Pacific Connector should file the Board’s final report, 

which should contain a statement indicating the Board’s opinion with respect to the 

construction, safety, and adequacy of the LNG terminal structures and mitigation 

measure employed along the pipeline route in areas subject to ground instability. 

Additional Recommendations 

The design of the facility is currently at the FEED level of completion. A feasible design has 

been proposed but a significant amount of detailed design work still remains to be completed 
4.1-15 4.1 – Geological Resources

before Jordan Cove would be authorized to proceed with any construction activities, if the 

Commission approves the Project. The final engineering design for the LNG terminal would 

incorporate detailed seismic specifications and other measures to mitigate the impacts of seismic 

hazards. Information pertaining to the following specific recommendations would be filed with 

the Secretary for review and approval by the Director of OEP prior to commencing final design, 

prior to construction, or prior to commissioning as indicated by each specific recommendation. 

All detailed design documents (drawings, calculations, specifications, etc.) and design submittals 

should satisfy the requirements of Section 4, Part II of the FERC Seismic Guidelines. In addition 

to the above-mentioned, we recommend the following: 

• In consideration that the LNG terminal design is currently at the FEED stage, 

Jordan Cove should implement the following prior to construction: 

a. Final seismic specifications to be used in conjunction with the procuring 

Category I, II, and III equipment as described in section 3.10 of Part II of the 

Commission’s Draft Seismic Design Guidelines and Data Submittal 

Requirements for LNG Facilities (FERC Seismic Guidelines) should be 

submitted for review prior to commencing final design. The final seismic 

specifications should satisfy Part I of the FERC Seismic Guidelines. 

b. Final Quality Control and Assurance procedures as described in section 3.11 of 

Part II of the FERC Seismic Guidelines that would be used for design and 

construction should be submitted for review prior to commencing final design of 

the LNG terminal. The Final Quality Control and Assurance procedures should 

satisfy Part I of the FERC Seismic Guidelines. 

c. A final list of Seismic Category assignments for all structures, systems and 

components should be submitted for review prior to commencing final design as 

described in section 3.6 of Part II of the FERC Seismic Guidelines. The final 

classification definitions and assignments should satisfy Part I of the FERC 

Seismic Guidelines. 

d. Final Seismic Design Criteria should be provided for all Seismic Design 

Category I, II, and III structures, systems, and components as described in 

section 3.7 of Part II of the FERC Seismic Guidelines prior to commencing final 

design. The Final Seismic Design Criteria should satisfy Part I of the FERC 

Seismic Guidelines. 

e. LNG Tank and Foundation Design should comply with Part I of the FERC 

Seismic Guidelines. Submittals that demonstrate compliance should be provided 

prior to commencing final design. 

f. The Seismic Isolation system for the LNG tanks shall comply with the design, 

analysis and testing requirements of Chapter 17 of ASCE 7-05 and the 

additional requirements below. Peer Review of the design shall be performed as 

required by Chapter 17. Submittals that demonstrate compliance shall be 

provided prior to commencing final design. 

i. Non-linear response history analysis shall be performed of the LNG tank and 

isolation system. The analysis shall simultaneously include all three 

components of ground motion. The response spectra of the time history 
4.1-16 4.1 – Geological Resources 

vertical component of motion shall envelope the site specific vertical design 

response spectra developed for the project. 

ii. The non-linear analyses will be performed for both maximum and minimum 

design liquid levels of the LNG tanks. 

iii. Separate non-linear analysis will be performed to account for variations of 

design stiffness, minimum values of friction and other properties as required 

by Sections 17.5 and 17.2.4.1 of ASCE 7-05. 

iv. The Lateral Displacement Capacity of the Seismic Isolation Bearings shall 

not be taken as less than 24 inches. 

g. Potential zones of liquefaction at the terminal site should be mitigated. Details of 

the liquefaction mitigation method(s), procedures, plan extent, and verification 

methods proposed to verify mitigation of liquefaction potential should be 

provided prior to commencing final design. 

h. Where necessary, detailed calculations of seismic slope stability and lateral 

movements anticipated after the liquefaction mitigation is implemented should 

be provided prior to commencing final design to verify the stability of critical 

structures for the LNG terminal design earthquake motions. 

i. Final foundation design recommendations including foundation design and/or 

liquefaction mitigation measures for all other structures should be submitted for 

review and approval prior to construction. Final foundation design 

recommendations should satisfy Part I of the FERC Seismic Guidelines. 

j. The results of the hydrostatic load tests on the LNG storage tanks, including 

settlement data as described in section 7.4.1 should be provided prior to 

commissioning. 

4.1.3 Pacific Connector Pipeline 

A wide variety of terrain and geological conditions exists along the proposed Pacific Connector 

pipeline alignment. During route planning and siting, Pacific Connector identified and attempted 

to avoid geological resource areas and hazards. The pipeline would be constructed by 

conventional trench excavation and pipe burial methods along most of its length. The depth of 

soil cover above the pipeline would be a minimum of 2 feet in consolidated rock and generally 3 

to 5 feet in all other locations. The typical pipeline trench construction depth would range from 

6 to 10 feet. At this depth of excavation, a wide variety of soil and rock materials would be 

encountered in the pipeline trench excavation. Hard rock would be expected to be encountered 

in some areas; ripping, hammering, or blasting could be expected in some of the hard rock areas 

(see section 2.4.2.2 of this EIS). 

The proposed pipeline route was evaluated with respect to seismic, landslide, erosion and scour, 

mine, and volcanic hazards that may potentially occur across or near the alignment and that 

could adversely affect the pipeline. In addition, an evaluation was made of the potential impact 

that pipeline construction and operation could have on the natural geological environment and 

geological processes in the proposed pipeline vicinity. 

Pacific Connector selected the proposed pipeline route through an iterative process to avoid areas 

with high risk of geological hazards. The initial pipeline route was changed in numerous 

locations to avoid high hazard areas as more detailed data were collected. Responding to staff 
4.1-17 4.1 – Geological Resources

recommendations in the draft EIS, in a December 4, 2008 filing Pacific Connector adopted some 

additional changes into its proposed route. The new segments of the proposed route are 

identified and discussed in the Alternatives section (3.4) of this final EIS. During construction, 

Pacific Connector would implement site-specific construction techniques and BMPs to mitigate 

local geological hazards that could not be completely avoided. The following sections discuss 

these hazards and how they would be mitigated. 

4.1.3.1 Surface and Bedrock Geology 

The proposed pipeline route crosses four main physiographic provinces: the Coast Range, 

Klamath Mountains, Cascade Range, and Basin and Range. The pipeline route begins on the 

North Spit of Coos Bay and proceeds eastward over the Coast Range physiographic province, an 

area underlain by estuarine and alluvial deposits in lowland areas and sedimentary rocks in the 

uplands. The proposed route then passes through the Klamath Mountains physiographic 

province, which consists of several complex geological terranes composed of metamorphosed 

and fractured volcanic and marine sedimentary rocks. East of the Klamath Mountains province, 

the proposed pipeline enters the Western Cascades sub-province, an ancestral range of deeply 

eroded (extinct) volcanoes, and then continues through the High Cascades sub-province, a chain 

of geologically active volcanoes with high andesitic peaks. The easternmost section of the 

proposed route is within the Basin and Range physiographic province within the Klamath Basin, 

an area characterized by ridges and valleys that are separated by faulting (Burns 1998). Between 

the mountain ranges are several valleys, predominantly filled with recent alluvial materials. 

Some of the major river valleys and their tributaries crossed by the pipeline route include the 

Coquille River Valley, Umpqua River Valley, Rogue River Valley, and Klamath River Valley 

(see section 4.3 of this EIS for more information about waterbodies). 

The pipeline would pass through varying soil and lithologic units ranging from soft sediments to 

hard granite. Unconsolidated silt, sand, and cobbles occur locally in streambeds, alluvial fans, 

and valley floodplains in all four physiographic provinces. Detailed descriptions of geology 

along the pipeline route as proposed in September 2007 are included in table B-1 in Appendix B 

of the Geologic Hazards and Mineral Resources Report filed as environmental Resource Report 

6 of Pacific Connector’s application (GeoEngineers 2007b) 26. GeoEngineers (2009) revised the 

geology descriptions (in table B-1 Revised) based on updates to the proposed pipeline route. The 

following paragraphs provide a more detailed description of each of the physiographic provinces 

from west to east. 

Coast Range 

The proposed pipeline route passes through the southernmost part of the Coast Range province 

for approximately 71 miles. The Coast Range is 30 to 60 miles wide and averages 1,500 feet in 

elevation, although the highest point (Mary’s Peak) reaches an altitude of 4,097 feet (Orr and Orr 

2000). 

The Coast Range is composed of relatively soft marine sedimentary rock units that overlie basalt 

at depth. The wet conditions of the western slopes of the Coast Range, along with steep terrain 

composed of relatively weak rock, contribute to an active erosional environment with frequent 

landslides. 

 

26 Pacific Connector updated its Geologic Hazard Evaluation with an addendum report filed January 21, 2009 covering the route 

changes filed December 4, 2008 (GeoEngineers 2009). 
4.1-18 4.1 – Geological Resources 

Uplift of the Coast Range deposits has deformed the bedrock units with folds and faults. Coastal 

uplift of the present Coast Range over the past 10 to 15 million years has been simultaneous with 

stream incision and coastal erosion and depositional processes. Ocean-cut terraces exist near the 

shoreline, some of which have been elevated to altitudes of up to 1,600 feet (Orr and Orr 2000). 

Low-lying areas near the coast are underlain by modern beach deposits, sand dunes, estuarine 

mud and alluvial sediments. 

Klamath Mountains 

The proposed pipeline route passes through the northeast corner of the Klamath Mountain 

physiographic province for approximately 49 miles. The province has a rugged landscape of 

high peaks and deep canyons, with a total local relief of 2,000 to 5,000 feet (Baldwin 1964). The 

highest peak of the Klamath Mountains is Mt. Ashland, at 7,530 feet (Burns 1998). Most of the 

Klamath Mountain physiographic province is composed of highly deformed volcanic and marine 

sedimentary rocks, as well as metamorphic terranes. The physiographic province also contains 

deformed pieces of the oceanic crust and granitic intrusive bodies (Walker and MacLeod 1991). 

Bedrock is often intensely metamorphosed and fractured. 

The proposed pipeline route passes through three exotic geological terranes in the Klamath 

Mountain segment of the alignment. West to east and youngest to oldest, these terranes are: 1) 

the Franciscan and Dothan belt; 2) the Western Jurassic terrane; and 3) the Western Paleozoic 

and Triassic terrane. The alignment crosses through the northernmost part of the Franciscan and 

Dothan belt, an area composed of turbidite sandstone, mudstone, and chert formed on the 

continental slope and subsequently scraped off the ocean floor during accretion. East of the 

Franciscan and Dothan belt, the alignment passes through the northern section of the Western 

Jurassic terrane, an area composed of volcanic flows and ash altered to greenstone, ophiolite, and 

metamorphosed ocean sediments, including conglomerate, siltstone, and sandstone. Between the 

Western Jurassic terrane and the Western Paleozoic and Triassic terrane, the alignment crosses 

the White Rock pluton (a large body of intrusive igneous rock that solidified within the crust). 

The Western Paleozoic and Triassic terrane is composed of metamorphosed pieces of ocean crust 

(ophiolites) and metamorphosed ocean-island basalt (Orr and Orr 2000). 

Cascade Range 

Approximately 60 miles of the proposed route crosses Oregon’s southern Cascade Range. The 

Cascades consist of two north-south trending mountain chains: (1) the older, more weathered 

Western Cascades; and (2) the younger, higher-elevation High Cascades. The Western Cascades 

drain westward and reach altitudes of 5,800 feet. The southern High Cascades drain toward the 

east and the west and reach altitudes of up to 9,493 feet at the summit of Mt. McLoughlin (USGS 

2006a). 

Precipitation of 60 to 100 inches annually on the western side of the Cascades results in extreme 

weathering of bedrock and soil deposits and larger rivers (Orr and Orr 2000). Both the Western 

Cascades and the High Cascades consist primarily of volcanoes formed as a result of the 

subduction of the Juan de Fuca oceanic plate beneath the North American continental plate. The 

Western Cascades terrane consists of deeply dissected volcanoes that formed between about 42 

and 8 to 10 million years ago (USGS 2006a). The volcanoes of the High Cascades began 

erupting about 5 million years ago. As the High Cascades volcanoes erupted, their magma 

chambers emptied and collapsed, creating calderas (large craters). Crater Lake, north of the 
4.1-19 4.1 – Geological Resources

pipeline alignment in Klamath County, is one of these calderas. During the Quaternary, 

andesitic cones formed the range’s notable high peaks. 

After the formation of the high-altitude andesitic peaks, volcanic activity in the High Cascades 

has continued intermittently to the present. Minor volcanic vents manifest near the proposed 

pipeline alignment. These include Brown Mountain, which is a Quaternary-aged volcano 

situated about 3 miles north of the pipeline route near MP 167. 

Repeated glaciation of the High Cascades during the Pleistocene Epoch produced glacial Ushaped valleys, cirques, and jagged mountain ridges. No active glaciers exist along or near the 

pipeline alignment. 

Basin and Range 

Approximately 45 miles of the easternmost portion of the proposed route passes through the 

southwestern corner of the Basin and Range province in Oregon, an area named the Klamath 

Basin. The Klamath Basin contains the Upper Klamath Lake and Lower Klamath Lake National 

Wildlife Refuge, which, unlike the rest of the province, drain to the Pacific Ocean via the 

Klamath River. 

The Basin and Range is a complex series of alternating uplifted mountain blocks (horsts) and 

down-dropped basins (grabens). These mountain ranges and valleys are separated by generally 

north-south trending normal (extensional) faults. The altitude of the Basin and Range province 

is generally over 4,000 feet, and the summit of Steens Mountain in southeast Oregon reaches 

9,670 feet. 

Crustal extension is responsible for development of the Basin and Range physiographic 

province. The extension occurred in two phases, the first of which happened between 20 and 10 

million years ago and produced widespread volcanic activity resulting in thousands of feet of 

basaltic flows and tuffs. The second phase of extension occurred in the last 10 million years and 

produced the distinct horst and graben topography. 

The low precipitation and runoff rates east of the Cascades restrict the amount of erosional debris 

that can be transported from watersheds. As a result, sediment has accumulated in the basins, in 

thicknesses greater than 1,000 feet in some places. Eroded material is deposited in alluvial fans 

and channels around the margins of the basins and as marsh and lake deposits in the lower 

elevations. During the wetter and cooler periods of the ice ages, the basins were occupied by 

much larger lakes; at maximum extent, Pluvial Lake Modoc extended over the pipeline 

alignment from Klamath Marsh, north of Upper Klamath Lake, to the Tule Lake basin in 

northern California (Orr and Orr 2000). 

4.1.3.2 Seismic Setting 

The proposed pipeline route crosses a complex geological area that has developed through 

extensive crustal deformation and volcanic activity. However, most of the pipeline construction 

area has experienced very few earthquakes during the period of historical record. Two primary 

mechanisms for generating earthquakes of design significance exist along the pipeline alignment: 

1) a major, regional earthquake associated with the CSZ; and 2) local earthquakes associated 

with a seismic hot spot near Klamath Falls. 
4.1-20 4.1 – Geological Resources 

Geological maps of the pipeline area show many faults that cross the pipeline alignment or are 

located near the proposed pipeline corridor (Walker and MacLeod 1991). With the exception of 

the Klamath Falls area, these mapped surface faults are not considered active and are not 

believed to be capable of renewed movement or earthquake generation (USGS 2002). 

Infrequent, but potentially large, earthquakes occur when the offshore boundary between the 

Juan de Fuca and North American plates ruptures suddenly. Researchers believe that the last 

major earthquake occurred on January 26, 1700 and produced a tsunami that was recorded in 

Japan (Clague et al. 2000; Satake et al. 1996). This offshore earthquake is estimated to have 

been a magnitude 9.0 event. In addition to intense, long-duration ground shaking, these 

earthquakes resulted in up to about 3 feet of vertical ground subsidence locally along Oregon 

coastal areas near the offshore fault rupture zone (Peterson et al. 1997; Leonard et al. 2004). 

They can also result in coastal subsidence and tsunamis that can impact low-lying coastal areas. 

Geological studies indicate that megathrust earthquakes have occurred numerous times in prehistory (Nelson et al. 2006). The recurrence interval between megathrust events has been 

irregular and ranges from about 100 to 1,000 years (Atwater and Hemphill-Haley 1997). Typical 

recurrence intervals are thought to be on the order of 400 to 600 years (Clague et al. 2000). 

Recent work by Goldfinger and others (2008) suggests that while the average recurrence interval 

for full-margin Cascadia events is 520 years, the southern Cascadia margin has a repeat time of 

220 years. 

Deep earthquakes can also potentially occur beneath the continent within the subducting Juan de 

Fuca Plate. These earthquakes may result in ground shaking at the surface, but there is no risk of 

fault offsets at the ground surface associated with these deep earthquakes. 

The subducting plate eventually descends to a sufficient depth and reaches a sufficient 

temperature that it partially melts. The magma generated by this process rises to the surface and 

forms the chain of volcanoes in the Cascade Range. Earthquakes are often associated with 

volcanic activity, such as the many hundreds of earthquakes that occurred before and after the 

eruption of Mt. St. Helens in Washington State. 

Relatively shallow earthquakes also occur in the North American Plate in response to crustal 

stresses induced by plate movements. Most of these earthquakes are not associated with faults 

that extend to the ground surface. However, some of the earthquake activity in the vicinity of the 

Klamath Falls seismic area may be tied to Quaternary faults with surface expressions (USGS 

2006b). 

With the exception of the Klamath Falls area, historical earthquake activity has been generally 

quiet in the areas crossed by the proposed pipeline. A total of 336 earthquakes have been 

recorded within 100 miles of the proposed pipeline route (Pacific Northwest Seismograph 

Network 2006; Johnson et al. 1994). The majority of these were low magnitude; specifically, 52 

percent were less than magnitude 4.0 and 94 percent were less than magnitude 5.0 (table 

4.1.3.2-1). 
4.1-21 4.1 – Geological Resources

TABLE 4.1.3.2-1. 

Historical Earthquakes within 100 Miles of the Proposed Pacific Connector Pipeline a/ 

Magnitude Range b/ Number of Earthquakes Epicenter Distance From Alignment (miles) 

3.0 to 3.99 174 5 to 100 

4.0 to 4.99 143 3 to 99 

5.0 to 5.99 15 8 to 100 

6.0 to 6.99 3 9 to 74 

7.0 to 7.99 1 82 

a/ Earthquake catalog data from the Pacific Northwest Seismograph Network (2006) and the Earthquake Database for Oregon, 

1833 to 1993 (Johnson et al. 1994). 

b/ Earthquakes with less than M3.0 are termed micro-earthquakes and are not usually felt (Reiter 1990). Earthquakes of M5.0 

and greater are generally considered to have engineering significance. 

Major historical earthquakes near the proposed pipeline route include two events in 1873: 1) an 

estimated magnitude 7.0 earthquake at the southwestern tip of Oregon; and 2) a magnitude 6.3 

earthquake near Coos Bay. In addition, a magnitude 6.0 event occurred in 1938 approximately 

75 miles south of Coos Bay. On September 21, 1993, two earthquakes occurred within about 2 

hours with epicenters located about 15 miles northwest of Klamath Falls: a magnitude 5.9 event 

followed by a magnitude 6.0 earthquake (Yelin et al. 1994). 

Many earthquakes of magnitude 2.0 and larger have occurred during historical times in the 

Klamath Falls area. Most earthquake epicenters are clustered northwest of Klamath Falls, near 

the southwest shoreline of Upper Klamath Lake. Epicenters of these earthquakes are typically at 

depths of 5 to 8 km. These events seem to be associated geographically with the boundary 

between the Basin and Range province and the Cascade Range province. The earthquake 

clusters also may be associated with volcanic activity (Cole and Bugni 1993). 

The primary seismic hazards to pipelines include potential strong ground shaking, surface fault 

rupture, soil liquefaction (and related lateral spreading), earthquake-induced landslides, and 

regional ground subsidence. The degree of risk from these hazards varies and depends on 

several factors, including the magnitude (or size) of the earthquake, the distance of the 

earthquake origin from the pipeline facilities (lateral and vertical), soil/rock conditions, and slope 

angle of the ground. 

Empirical reviews of historical earthquakes demonstrate that welded steel pipelines are not prone 

to failure due to earthquakes. A 1996 study of earthquake performance data for steel 

transmission lines and distribution supply lines operated by SoCal Gas over a 61-year period 

found that post-1945 arc-welded transmission pipelines in good repair have never experienced a 

break or leak during a southern California earthquake and are the most resistant type of piping, 

vulnerable only to very large and abrupt ground displacement (e.g., severe landslides), and are 

generally highly resistant to traveling ground wave effects and moderate amounts of permanent 

deformation (O’Rourke and Palmer 1994). 

In addition to ground shaking, subsidence and ground rupture from seismic activity, tsunamis 

can be generated by strong ground motions associated with offshore earthquakes or submarine 

landslides. Coastal areas of Oregon, including Coos Bay, could experience the effects of 

tsunamis. The portion of the proposed pipeline near the proposed LNG terminal occurs in the 

relatively sheltered areas of Coos Bay, where the effects of a tsunami on the pipeline would be 

expected to be relatively minor. 
4.1-22 4.1 – Geological Resources 

Seismic hazards for the proposed pipeline were evaluated by reviewing available historical data, 

by researching geological evidence of prehistoric earthquakes for the Pacific Northwest, and by 

qualitatively evaluating the potential risk to the pipeline along the overland sections of the 

alignment. Quantitative evaluation of the potential for liquefaction, lateral spreading, and 

tsunami inundation was accomplished for the Coos Bay crossing, where liquefaction and lateral 

spreading hazard were identified during the initial assessment. 

Regional Seismicity 

If a major earthquake occurred during the operating life of the pipeline, the ground shaking and 

possible ground subsidence would be strongest in the Coast Range province and in low-lying 

areas near Coos Bay. Although ground shaking would likely be felt throughout the length of the 

pipeline from such an event, hazards would diminish in the eastward direction, with increasing 

distance from the offshore epicenter. Regional ground subsidence would not necessarily pose a 

risk to the pipeline. Documented subsidence zones associated with the 1960 subduction zone 

earthquake in Chile (Plafker and Savage 1970) indicate subsidence on the order of 3 to 6 feet 

vertically distributed over a wide trough of approximately 60 miles. If a similar event were to 

occur in the pipeline area, the resultant strain on the proposed pipeline distributed over that 

length of pipe is not considered significant. Additional background information on regional 

seismic hazards is presented above in section 4.1.2. 

Ground Shaking and Peak Horizontal Ground Acceleration 

The ASCE Technical Council on Lifeline Earthquake Engineering defines the 10 percent 

probability of exceedance in 50 years (475-year return period) as the contingency design 

earthquake for pipeline design. The International Building Code (IBC 2003) has adopted the 2 

percent probability of exceedance in 50 years (2,475-year return period) for design of buildings. 

Using the historical seismicity record and the available data on Quaternary faults in the United 

States, the USGS (2002) produced probabilistic seismic hazard mapping for the entire U.S. This 

mapping was used to address two risk levels: 10 percent probability of exceedance in 50 years 

(475-year return period), and 2 percent probability of exceedance in 50 years (2,475-year return 

period). The output from the seismic hazard mapping includes estimates of the peak horizontal 

ground acceleration (PGA) and spectral accelerations (Sa) for 0.2 and 1.0 second structural 

periods. Based on USGS (2002), the 475-year return period PGAs in the vicinity of the proposed 

pipeline are in the range of about 10 to 30 percent g (0.10 to 0.30 g). Ground accelerations of 10 

to 18 percent g typically generate strong ground shaking and relate to expected “light” potential 

damage, while ground accelerations of 18 to 30 percent g typically generate very strong ground 

shaking and relate to expected “moderate” potential damage (University of Washington 2001). 

The highest potential PGA along the proposed pipeline alignment is in the Coos Bay area. This 

reflects the potential for a future Cascadia megathrust event during the design life of the pipeline. 

Surface Rupture Potential from Faulting 

Differential, or shear, movements of fault surfaces can be entirely subsurface, or they can extend 

to the ground surface as surface fault rupture. The nature of the shear movements at the surface 

depend on the character of fault movement. In general, surface fault rupture across a pipeline 

alignment can result in rapid differential ground displacements across the pipe, with 

displacement magnitudes ranging from a few inches to several feet. 
4.1-23 4.1 – Geological Resources

Regional Quaternary and Holocene age fault zones include the following north-northwest 

trending fault complexes (USGS 2006b): 

• The South Slough Thrust and Reverse faults, extending parallel to the Isthmus Slough, 

south of Coos Bay near MPs 8 to 14; 

• The Sky Lakes fault zone, east of Klamath Falls near MPs 174 and 178; 

• The South Klamath Lake section of the Klamath Graben fault system near MP 213; and 

• The Saddle Blanket fault zone, southeast of Klamath Falls and south of the southeast end 

of the Pacific Connector alignment near MP 230. 

The draft EIS reported that the nearest mapped Holocene-age fault (active within the last 15,000 

years) that crosses the proposed pipeline route occurs within the South Klamath Lake section of 

the Klamath Graben fault system, near Klamath Falls (MP 213). LiDAR imagery and color 

stereo aerial photographs do not show features indicative of recent fault movements at the 

ground surface, however, a subsurface investigation to determine recency of movement had not 

yet been done when the draft EIS was released. Older Quaternary-age faults (younger than 1.6 

million years, but older than 15,000 years) mapped across the proposed pipeline include traces of 

the Sky Lakes fault zone located at approximately MP 174 and MP 178. In a supplemental 

analysis requested by the FERC staff, Pacific Connector analyzed the previously mapped fault 

crossing locations at MP 174, MP 178, and MP 213 to determine whether there was evidence of 

Holocene displacement. This analysis, prepared by GeoEngineers (2008), was filed with the 

Commission on December 4, 2008 as part of Pacific Connector’s comments on the draft EIS. 

Only the fault location at MP 213 was determined to be of Holocene age. The other faults were 

determined to be older Quaternary faults. 

As mitigation for the pipeline crossings of these areas, Pacific Connector proposed to have the 

pipeline trenches near MP 174, MP 178, and MP 213, carefully examined during construction by 

a qualified professional (following State of Oregon license standards for Professional Geologists 

and/or Professional Engineers) for evidence of stratigraphic offsets potentially related to ground 

rupture. If such features were observed, Pacific Connector would implement additional 

mitigation measures at these locations. Specific unique designs for fault mitigation would be 

developed at that time, however the intent would be to follow published guidance to estimate the 

potential amount and direction of fault offsets as well as the magnitude of strain accumulation at 

the pipe crossing location (Takada et al. 2001; Honegger and Nyman 2004). Such measures 

could include burying the pipe in a wide trench that was backfilled with loose gravel or sand, 

which would allow for relatively unrestrained movement of the buried pipe within the zone of 

fault movement. 

We agreed with Pacific Connector’s general approach to addressing the potential hazards of 

active fault crossings, but requested that the detailed investigations and mitigating design 

measures be completed and reviewed prior to any pipeline construction in the area. Based on the 

subsequent study, Pacific Connector proposes to analyze the fault crossing at MP 213 prior to 

construction by calculating the fault displacement and resulting induced stresses on the pipeline. 

The appropriate mitigation measures for a fault rupture and resulting pipeline stresses would be 

selected based on the results of the field investigation and engineering analysis. The final design 

analysis and proposed mitigation measures would be reviewed by OEP staff and the Board of 

Consultants to ensure that the design and mitigation measures minimize the likelihood of a 

pipeline rupture in the event of a displacement across the fault. 
4.1-24 4.1 – Geological Resources 

Liquefaction Potential 

The potential for soil liquefaction from an earthquake is a function of the intensity or strength of 

the earthquake shaking (high PGA), the duration of strong earthquake shaking, the nature of the 

soil (it must generally be loose to medium dense and granular such as silt or sand), and 

groundwater conditions (the soil must be saturated with a shallow groundwater table). In 

general, liquefaction that results in permanent ground deformation or buoyant displacement of 

buried pipelines has the potential to result in pipeline damage (O’Rourke and Liu 1999). The 

evaluation of liquefaction potential is complex and depends on numerous site parameters, 

including soil grain size, soil density, age of soil deposit, depth and gradient of water table, site 

geometry, static stresses, and design accelerations. 

Pipeline damage associated with liquefaction typically occurs where a sharp transition exists 

between liquefiable and non-liquefiable materials. Shear or bending movements at such sharp 

transitions can damage pipelines. In addition, liquefaction can change the buoyancy forces such 

that the pipeline may float if not mitigated during design. Mitigation for these conditions can 

include avoidance by routing around or under the potentially liquefiable materials, by reinforcing 

the pipe with thicker walls, and/or by weighting the pipe with a concrete coating. 

The potential for liquefaction along the proposed pipeline was evaluated based on topography 

and soil conditions obtained from geological maps, NRCS soil surveys and, at some sites, limited 

geotechnical boring data. Liquefaction potential was identified for portions of the proposed 

route that would be expected to encounter loose to medium dense sandy soils (generally 

occurring in alluvial valleys or near rivers, streams, sloughs, lakes or other waterbodies). These 

areas are listed in table 4.1.3.2-2 as having potential for liquefaction and/or lateral spreading. In 

the December 1, 2008 report, GeoEngineers further investigated six features originally 

characterized as unknown. In the March 30, 2009 report, GeoEngineers investigated features 

along the proposed pipeline reroute alignment. Pacific Connector filed the Revised Geotechnical 

Engineering Services Report (GeoEngineers 2009) with the FERC on April 8, 2009. The 

potential for liquefaction and lateral spreading along the proposed route is characterized as low 

to high, unknown, or mitigated. Those listed as low potential include sites with subsurface 

conditions of fine-grained soils that are not susceptible to liquefaction or soils that are not 

expected to be saturated. Those listed as high potential include sites that are underlain by 

potentially saturated loose to medium dense granular soils. The unknown potential site is an area 

of private property where no site-specific subsurface information is available due to lack of 

access. Sites identified as mitigated include areas where the pipeline would be buried below the 

liquefiable materials (for protection from scour), or where the pipeline would be installed by 

HDD and would be beneath the anticipated zone of potential liquefaction or lateral spreading. 

TABLE 4.1.3.2-2. 

Summary of Potential Liquefaction and Lateral Spreading Hazards 

From 

MP To MP Feature 

Liquefaction Potential/ Lateral 

Spreading Potential Ownership 

0.00R 2.20R Haynes Inlet High/High Private, State 

2.20R 4.20R Haynes Inlet High/Low Private, State 

6.20R 6.40R Kentuck Inlet High/High Private, State 

8.30R 8.50R Willanch Slough High/High Private, State 

10.5R 11.4R Cooston Channel High/High Private, State 

7.7 8.8 Coos River High a/ Private, State 

10.10 10.40 Stock Slough Low/Low Private 
4.1-25 4.1 – Geological Resources

TABLE 4.1.3.2-2. 

Summary of Potential Liquefaction and Lateral Spreading Hazards 

From 

MP To MP Feature 

Liquefaction Potential/ Lateral 

Spreading Potential Ownership 

10.80 11.40 Catching Slough Low/Low Private, State 

15.72 15.77 Boone Creek Low/Low Private 

22.60 23.10 North Fork Coquille River Low/Low Private 

27.00 27.15 Park Creek (aka Middle Creek) Low/Low BLM, Private 

29.40 30.20 East Fork Coquille River Low/Low Private 

48.00 48.40 Deep Creek Low/Low County, Private, BLM 

49.70 50.45 Middle Fork Coquille River Low/Low Private 

55.80 56.60 Alluvial Valley Low/Low Private 

56.90 59.00 Olalla Creek Low/Low Private 

66.85 67.05 Willis Creek High/High Private 

68.95 69.80 South Umpqua River #1 High a/ ODOT 

88.20 88.65 Days Creek Low/Low Private 

94.55 94.80 South Umpqua River #2 High a/ Private 

122.55 122.75 Rogue River High a/ Private, State 

128.50 128.70 Indian Creek Unknown b/ Private 

131.80 132.00 Neil Creek Low/Low Private 

191.50 199.00 Klamath Valley High/Low Private 

199.00 201.00 Klamath River High a/ Private, State, BOR 

201.00 214.00 Lost River Valley Low/Low Private, State, BOR 

217.10 218.30 Alluvial valley Low/Low Private 

221.80 224.40 Alluvial valley Moderate/Low Private 

229.00 230.90 Alluvial valley High/Low Private 

a/ A potential for occurrence may exist, but hazard would be mitigated. 

b/ Landowner permission to evaluate site was not granted. 

Three river crossings are planned using HDD technology to minimize the environmental impacts 

of construction and to install the pipeline below zones of potentially liquefiable soil. In areas of 

conventional open-cut construction across rivers that are subject to scour and migration (South 

Umpqua River), the pipeline would be buried below soil that may be subject to liquefaction and 

lateral spreading. Moderate to high liquefaction and/or lateral spreading potential was identified 

at eight other sites (Haynes Inlet, Kentuck Slough, Willanch Slough, Cooston Channel, Willis 

Creek, Klamath Valley, and the alluvial valleys between MPs 221.80 and 224.40 and between 

MPs 229.00 and 230.90). GeoEngineers recommended that numerical modeling be completed 

for those sites to estimate the magnitude of liquefaction-induced settlement and lateral spreading 

that would be expected during the design earthquake event. If the numerical modeling indicated 

that liquefaction settlement and/or lateral spreading would result in excessive pipe stress 

conditions, GeoEngineers recommended further mitigation, such as deeper pipeline burial below 

the liquefiable soils, thicker pipe, and/or concrete coating. 

To ensure that appropriate mitigation measures are implemented, we recommend that:

• Prior to pipeline construction, Pacific Connector should file with the Secretary for 

the review and approval of the Director of OEP, results of numerical modeling for 

Haynes Inlet, Kentuck Slough, Willanch Slough, Cooston Channel, Willis Creek, 

Indian Creek, Klamath Valley, and the alluvial valleys between MPs 221.8 and 

224.4 and between MPs 229.0 and 230.9, as well as measures that would be 
4.1-26 4.1 – Geological Resources 

implementedany site-specific measures that would be implemented to mitigate 

impacts associated with liquefaction or lateral spreading at these pipeline crossings. 

Because the crossing of Coos Bay would have the greatest potential along the proposed pipeline 

route for liquefaction and lateral spreading in the event of an earthquake, Pacific Connector had a 

geotechnical consultant perform a site-specific analysis (GeoEngineers 2007a). Pacific 

Connector changed its route, in a filing on December 4, 2008, to limit the length of the pipeline 

crossing in Coos Bay to 2.4 miles between about MPs 1.7 and 4.1. 

Pacific Connector also identified other measures that would reduce potential impacts on its 

pipeline in Coos Bay from liquefaction and lateral spreading. The proposed route within the 

estuary would keep the pipeline away from the navigation channel slope. In addition, Pacific 

Connector would construct the pipeline within Coos Bay with thicker wall pipe and concrete 

coating. 

Even with these measures, it is not possible to completely mitigate the risk of pipeline damage in 

Coos Bay resulting from lateral spreading during a megathrust seismic event. If such an event 

should occur and cause a pipeline failure in Coos Bay, the MLVs that would be installed on 

either side of the bay crossing (MP 0.0 and MP 7.7) would need to be shut to stop delivery of gas 

to the pipeline and isolate the damaged section. The pipeline would be inspected and repairs 

made to damaged sections of the pipeline as appropriate before the line would be placed back in 

service. 

In some sites, sufficient subsurface data were unavailable to characterize the risk of occurrence 

for the draft EIS. Pacific Connector conducted additional subsurface exploration at all but one 

site where access was not allowed and filed those data on December 4, 2008 (GeoEngineers 

2008). Hazard ratings have been updated in table 4.1.3.2-2. 

Lateral Spreading Potential 

In addition to settlement or pipeline buoyancy, the possibility exists that liquefaction could result 

in lateral spreading. Lateral spreading involves lateral displacement of surficial blocks of nonliquefied soil as the underlying soil layer liquefies. Lateral spreading generally develops in areas 

where sloping ground is present or near a free face, such as along the banks of rivers, sloughs, 

canals, or lakes. If liquefaction were to occur within loose to medium dense saturated sand 

deposits, there would be a high potential for lateral spreading to occur along slopes or near a free 

face. 

Because lateral spreading is associated with liquefaction of soils, the potential for lateral 

spreading along the proposed pipeline alignment was evaluated based on the same criteria as 

liquefaction potential. If an area is characterized as having a high liquefaction potential and the 

topography is sloping or adjacent to a free face, then the potential for lateral spreading to occur 

as well is high. Lateral spreading can occur on very gentle slopes; therefore, all areas with 

liquefaction potential also are considered to have potential for lateral spreading. The potential 

for lateral spreading is particularly acute in the immediate vicinity of the crest of the open-cut 

navigation channel in Coos Bay. However, Pacific Connector’s newly proposed route keeps the 

pipeline some distance away from the navigation channel (no closer than 2,500 feet). 

Two models were used to predict the lateral extent of ground movements associated with lateral 

spreading. The output indicate that a large earthquake (greater than magnitude 6.0) could trigger 
4.1-27 4.1 – Geological Resources

lateral spreading up to 10 feet near the crest of the dredged channel slope, decreasing to less than 

1 foot at a distance of about 300 to 400 feet from the slope crest (GeoEngineers 2007a). 

As described above under Liquefaction Potential, we have recommended that Pacific Connector 

quantify the magnitude of liquefaction and lateral spreading in those locations classified as 

having a high or unknown hazard in table 4.1.3.2-2. If the analysis indicated that the pipeline 

would be subject to stresses beyond code limitations during a seismic event, appropriate 

mitigation measures would be developed and implemented to prevent damage and protect the 

pipeline during a seismic event. 

Seismically Induced Landslides and Rockfalls 

Strong ground shaking associated with an earthquake may induce landslide failures at great 

distances from the earthquake source (Keefer 1984). The potential exists, at least locally along 

portions of the proposed pipeline route, for ground shaking to induce rockfalls, landslides, or soil 

slumps (USGS 2006b, 2002). Potential areas of seismically induced landslides include the 

mapped existing landslides summarized in Table B-2 (Attachment EIR RR6-1) from Pacific 

Connector’s Response to June 2, 2008 Data Request. This table was revised based on changes to 

the proposed pipeline route in Pacific Connector’s January 21, 2009 filing of GeoEngineers’ 

Addendum to Geologic Hazards Evaluation (2009). 

Areas of potential ground shaking of sufficient intensity to initiate landslides or rockfalls include 

the areas of greatest seismic activity: the Klamath Falls region (with relatively recent events of 

magnitudes 5.9 and 6.0) and the Coos Bay region (with the potential for very large, long 

recurrence interval, megathrust events). The proposed pipeline route has been selected to avoid 

areas with a high potential for landslide and rockfall hazards to the extent practicable. 

Landslide Hazards 

Pacific Connector conducted an initial landslide hazards evaluation in three phases: initial office 

review, aerial reconnaissance, and surface reconnaissance. The initial office review identified 

existing landslides as well as areas susceptible to landsliding within 0.25 mile of the proposed 

pipeline route by reviewing published maps (e.g., Hofmeister et al. 2002) and aerial photographs. 

GIS modeling, calibration with limited field evaluations, and comparisons with historical 

landslide inventories were also used in this initial phase. Aerial and surface reconnaissance was 

then used to further evaluate those hazard sites that represented potentially moderate or high risk 

to the pipeline. 

Pacific Connector made numerous pipeline route adjustments to avoid identified hazards as a 

result of the first three phases of landslide evaluation. At about the same time, Pacific Connector 

obtained LiDAR digital elevation data for the initial pipeline route, and identified numerous new 

potential landslide features from interpretation of the LiDAR data. This then led to stereoscopic 

evaluation of new aerial photography, additional field reconnaissance, and further pipeline route 

modifications. 

Some of the pipeline route adjustments intended to avoid identified hazards, as well as land 

acquisition issues, resulted in route alignments that extended outside the area of LiDAR 

coverage. Supplemental LiDAR and aerial photograph data were acquired for many of these 

localized reroute areas. Nevertheless, some of Pacific Connector’s later reroute alignments are 
4.1-28 4.1 – Geological Resources 

outside the area of LiDAR and aerial photograph coverage obtained by Pacific Connector. 

Therefore, we recommend that: 

• Pacific Connector should characterize potential landslide hazards through other 

means in areas where LiDAR and aerial photograph coverage are not available. 

This information should be filed with the Secretary prior to pipeline construction. 

Landslide Hazard Types and Their Effects on Pipelines

Many types of landslides occur that can affect property and public safety. However, most 

landslides can be placed in two general categories: 1) shallow-rapid landslides (debris 

slides/flows) and 2) deep-seated landslides. Shallow-rapid, or rapidly moving, landslides 

generally originate on very steep slopes, often where no prior indications of movement are 

present. In the Coast Range, especially in the Tyee formation, recurring debris flows produce 

debris chutes. These are evident by narrow concave gullies containing activity indicators such as 

bare rock, soil generation, and vegetation stratification. Fans and coalescing fans (from multiple 

chute discharges) form plains. Deep-seated landslide movement can occur where no previous 

movement is evident, but commonly occurs where topographic and vegetative indications of past 

or chronic slope movements are present. 

Rapid-shallow landslides, inclusive of debris slides/avalanches and channelized debris flows 

typically originate on very steep and strongly convergent hill slopes variously termed colluvial 

swales, hollows, or headwalls. Mass-movement of rapid-shallow landslides is typically triggered 

by large, infrequent storm events. Channel gradient and junction angle strongly influence the 

effect of the debris flow on the stream channel: scour, transport, or deposition. Deep-seated 

landslides range in depth from tens to hundreds of feet and can occur anywhere on a hill slope. 

The larger deep-seated landslide complexes may occupy several square miles of terrain. These 

features can usually be identified on topographic maps or aerial photos based on distinctive 

contour or vegetative patterns. Slope movement can vary from rapid to nearly imperceptible, 

and may entail small to large displacements. The greatest risk of deep-seated landslide 

movement arises from existing (dormant) features that can reactivate in response to land 

management practices, seismic activity, stream erosion and/or prolonged periods of precipitation. 

Risk is greatest where the direction of slide movement is across (perpendicular to) the proposed 

pipeline alignment. This typically occurs where the pipeline crosses a slope instead of 

descending straight down the fall line. Although the greatest risk is where a pipeline crosses a 

landslide, headward (upslope) expansion of the slide could eventually involve a pipeline located 

upslope of an active landslide. 

Significant strain can develop within a pipeline from slope movements. Strain can develop 

slowly from a deep-seated landslide as a result of long-term slow movement, or it can develop 

quickly as a result of a single movement event. Shallow-rapid landslides are unlikely to induce 

long-term strain to a pipeline, but rather more likely to expose the pipe and result in a loss of 

support where it crosses a debris slide source area. Once mobilized into a debris flow, shallowrapid landslides often have tremendous erosional potential. Debris flows that originate upslope 

of the pipeline also have the potential to scour, expose, and damage the pipeline by debris 

impact. 
4.1-29 4.1 – Geological Resources

Rapidly Moving Landslide Risk Assessment 

The portion of the proposed pipeline alignment that crosses the Coast Range physiographic 

province has the greatest risk of being affected by rapidly moving landslides because of rugged 

terrain composed of relatively weak sedimentary bedrock and relatively high precipitation rates. 

In particular, studies indicate that the Tyee Core Area within this province has a higher 

susceptibility to rapidly moving landslides than other areas of the proposed pipeline (Robinson et 

al. 1999). 

The potential for rapidly moving landslides to occur east of MP 166 (east of the Cascade Range) 

generally is considered to be relatively low based on geological conditions, relatively little 

rainfall, and statistically fewer past historical rapidly moving landslide occurrences (Hofmeister 

et al. 2002). Climate change models predict a drier climate east of the Cascade Range, including 

less snowpack (and snowmelt), more rain instead of snow in low elevation basins, lower summer 

and early fall streamflows, and decreased soil moisture (University of Oregon 2008). These 

conditions are not likely to increase the potential for rapidly moving landslides in this region. 

Slopes east of MP 166 were reviewed to identify high-risk sites based on general guidelines of 

the Oregon Department of Forestry (ODF 2000). Based on available topographic mapping, no 

slopes along the pipeline alignment east of MP 166 exceed 65 percent or appear to be at high risk 

of rapidly moving landslide occurrence. 

Pacific Connector conducted an initial risk assessment to evaluate the potential risk where the 

proposed pipeline alignment crosses the mapped hazard areas using some of the input parameters 

used for the DOGAMI model (Hofmeister et al. 2002). Depositional, transport, and source zones 

were primarily distinguished with a simplified approach based on slope/channel gradient without 

consideration of other factors such as stream junction angles. 

The initial relative risk to the proposed pipeline posed by the source, transport, and depositional 

zones are considered to be high, moderate, and low, respectively. If a pipeline was located 

within a rapidly moving landslide source area, the pipeline could lose support as a result of 

displacement of the slide mass, and could be subject to excessive strain depending on the 

orientation of the pipeline and the distance over which support was lost. Once mobilized into the 

“transport” zone, a rapidly moving landslide has the potential to erode and scour the slope and 

could potentially expose a buried pipe, at which time debris could impact and damage the 

pipeline. Based on research and empirical data, the scour potential is greater where rapidly 

moving landslides are confined within stream channels. This risk is discussed further in later 

sections. 

Other factors that influence the potential risk from rapidly moving landslides include the slope 

form (geometry) and the orientation of the pipeline to the slope. For instance, convergent 

(concave) slopes are generally less stable and have a higher potential for landslide occurrence 

than planar or divergent slopes. In general, the risk of landslide occurrence and mobilization 

increases with slope gradient and with the degree of convergence (concavity). 

Using LiDAR where available, 10-meter digital elevation model (DEM) and aerial photography, 

Pacific Connector identified moderate and high risk rapidly moving landslide sites along the 

proposed pipeline route. Pacific Connector then conducted a surface reconnaissance of these 

sites to further evaluate potential risk. 
4.1-30 4.1 – Geological Resources 

A total of 304 pipeline segments were initially identified within rapidly moving landslide hazard 

areas. Based on the risk assessment, approximately 128 of these sites were considered to be a 

potentially moderate or high risk and were selected for further study. Site-specific 

reconnaissance was conducted in certain areas with the potential for shallow-rapid landslide 

hazards, as documented on tables B-3a and B-3b of Appendix B in GeoEngineers’ (2007) 

Geologic Hazards and Mineral Resources Report filed in place of Resource Report 6 of Pacific 

Connector’s September 2007 application with the FERC. 

Pacific Connector provided an Addendum to Geologic Hazards Evaluation (GeoEngineers 2009) 

in a January 21, 2009 filing. Their geotechnical consultant examined the Statewide Landslide 

Information Database of Oregon (SLIDO) prepared by DOGAMI in 2008. Twelve previously 

unknown landside areas within 0.25 mile of the pipeline route were identified from the 2008 

SLIDO. However, based on a desk-top review of the newly identified areas using stereo aerial 

photography and LiDAR DEM, either these landslides are not apparent or do not appear to pose 

a risk to the proposed pipeline. 

Deep-seated Landslide Risk Assessment 

Deep-seated landslides can range in thickness from tens to hundreds of feet and can occur 

anywhere on a slope. Larger landslides can usually be identified from topographic maps 

(including LiDAR) and aerial photographs. Movement can be complex, ranging from slow to 

rapid, and may include small to large slope displacements. 

The greatest risk of deep-seated landslide movement is from existing (dormant) deep-seated 

landslides reactivating in response to human activity, seismic activity, stream erosion, or heavy 

precipitation. Assuming unchanged conditions, it is much less common for a deep-seated 

landslide to occur on a previously undisturbed and intact slope than reactivation of an existing 

landslide feature. Therefore, areas susceptible to deep-seated landslide movement were 

identified from existing geological maps and from topographic or photographic indications of 

historical or ancient landslide movement. 

Table B-2 (Attachment EIR RR6-1) from Pacific Connector’s response to the FERC staff’s June 

2, 2008 data request filed with the Commission on July 8, 2008, lists the identified deep-seated 

landslides, the data source, and the initial risk to the pipeline. Fifteen of the landslides were 

judged to pose a moderate to high potential risk to the proposed pipeline. In these instances, 

Pacific Connector either rerouted its proposed pipeline route to avoid the hazard or assessed the 

feature further through aerial reconnaissance and risk assessment. The subsequent aerial 

reconnaissance of the deep-seated landslides identified as moderate to high risk included 

assessments of geomorphic and vegetative conditions. These data were incorporated into a 

model of potential risk related to each deep-seated landslide. Pacific Connector then identified 

potential alternative routes around moderate- to high-risk landslides that appeared to be active or 

to have the potential to reactivate. Six landslides were identified as posing a moderate to high 

potential risk and were evaluated further in the field. Five of these six landslides are located in 

Coos County within the Coast Range physiographic province. 

Landslide Hazards Avoidance and Minimization of Adverse Effects

Risks associated with landslides include both the risk that installation of the pipeline may 

adversely affect slope stability, and the risk that post-construction land movements could damage 

the pipeline. Pacific Connector selected its proposed pipeline route to avoid existing landslides 
4.1-31 4.1 – Geological Resources

and areas susceptible to landsliding. Table B-2 (Attachment EIR RR6-1) from Pacific 

Connector’s response to the FERC staff’s June 2, 2008 data request filed with the Commission 

on July 8, 2008, and tables B-3a and B-3b of Appendix B from GeoEngineers’ (2007e) Geologic 

Hazards and Mineral Resources Report filed as Resource Report 6 with Pacific Connector’s 

September 2007 application to the FERC identify where Pacific Connector’s initial pipeline 

route was changed to avoid identified landslides and landslide hazard areas. Pacific Connector 

was able to modify its proposed route to avoid most moderate- and high-risk rapidly moving 

landslide hazards; however, two moderate-risk rapidly moving landslide sites could not be 

avoided (MPs 18.14 to 18.20 on private land, and MP 36.92 on BLM land). Additional 

investigation of the site at MP 36.92 resulted in a final risk determination of low (GeoEngineers 

2009). The remaining moderate-risk site is not considered hazardous enough to require 

additional mitigation or rerouting. 

Pacific Connector has prepared and would implement its ECRP to avoid and minimized impacts 

from pipeline construction, including to reduce the potential for construction to adversely affect 

slope stability. Because the proposed pipeline would cross extensive areas of rugged terrain, 

there is potential for previously unidentified landslides or new landslides to affect the pipeline 

after it is installed. Monitoring higher-risk areas along the pipeline can aid in detecting landslide 

occurrence and movement such that action can be taken to prevent damage to the pipeline. 

Monitoring can range from visual surface observations from the air or ground to the use of strain 

gauges and subsurface instrumentation, such as inclinometers, to detect and measure slope 

movements (typically, these instrumentation methods are used only on pipeline segments 

affected by active slope movement). 

The purpose of the monitoring would be to detect potential movement or pipe strain before it 

compromised the structural integrity of the pipeline. If movement was detected, immediate 

action would be taken to reduce the risk to the pipeline. Every landslide is unique, and there are 

no standard methods for reducing or eliminating landslide-related risks to buried pipelines. 

However, in concept, initial response actions generally include measures to reduce the stresses in 

the pipeline caused by slide movements. Secondary response actions are directed at improving 

the stability of the slide so that movements in the vicinity of pipeline are halted or the impacts to 

the pipeline are minimized. Tertiary response actions involve rerouting the pipeline to avoid 

landslide hazards by relocating the pipeline to a safer location. 

Exposure of the pipe by excavation is the initial response action typically taken to reduce stresses 

in the pipe. By exposing the pipe on both sides, the pipe is allowed to rebound to a position 

where it carries little residual stress. 

Improvements in surface drainage also are important initial response measures. Typical drainage 

improvement measures include: 1) placement of impermeable liners over the ground surface to 

limit infiltration of precipitation and erosion; 2) ditching to divert surface water around landslide 

areas; and 3) routing surface flows across slide areas within tightline drain pipes. 

Once the landslide area is initially stabilized, a decision of permanent action must be made. 

Permanent mitigation can include repairs and stabilization of the landslide area. Permanent 

repairs can include drainage improvements, loading and/or stabilization of the toe of the slope, 

decreasing the load at the head of the slope, or retaining structures at the base or within the slope. 

If the landslide is large and complex and stabilization is not a reasonable option, rerouting the 

pipeline around the slide may be the preferred mitigation. 
4.1-32 4.1 – Geological Resources 

Stream Migration and Scour Hazard Avoidance and Minimization of Adverse Effects 

The principal hazard resulting from channel migration and streambed scour is complete or partial 

exposure of the pipeline within the channel from streambed and bank erosion, or within the 

floodplain from channel migration or avulsion. Minimizing the effects of migration and scour 

hazards to the pipeline can be accomplished with the following approaches: 

• At each channel crossing, bury the pipe below the estimated depth of streambed scour. 

Where bedrock is encountered at shallower depths than the estimated scour depth, the 

elevation of competent bedrock represents the limit of scour. 

• Where feasible, place the pipe into bedrock. 

• Within floodplains adjacent to migrating channels, bury the pipe below the projected 

depth of the channel thalweg within the 25-year and 50-year channel migration zones. 

• Avoid stream crossings that are potentially hazardous to the integrity of the pipeline, and 

therefore to public safety, where possible. 

The pipeline crossing streams also could provide a new path for groundwater to flow into the 

pipeline trenches even after following backfilling. Water diversion would be prevented by 

implementing the ECRP, which requires installing trench breakers around the pipeline and in the 

trench on slopes. Pacific Connector also would install trench plugs after the pipeline was 

installed in the trench and prior to trench backfilling. Pacific Connector would use sandbags (or 

foam if approved by the authorized company representative) for trench plug construction. 

Topsoil would not be used to fill the bags. Where necessary, Pacific Connector would use 

bentonite trench plugs to prevent flow from wetlands or streams into the trench and to preserve 

the original wetland and/or waterbody hydrology. Trench breakers and trench plugs would be 

keyed into the trench sidewalls. 

Stream Channel Migration and Scour Hazards

Erosion and channel migration hazards to pipelines potentially exist on the banks and beds of 

stream channel crossings. Portions of the Coos Bay estuary, including the terminal delta areas of 

the Coos River and Catching Slough, also would be subject to scour from flood events, tidal 

currents, and tsunamis. Pacific Connector conducted analyses to assess the potential for channel 

migration and the depth of streambed scour in the streams and the estuary. The results of the 

migration and scour studies are summarized below and discussed in detail in the Pacific 

Connector Gas Pipeline Project Phase II Channel Migration and Scour Analysis report 

(GeoEngineers 2007b). Pacific Connector updated this information with an Addendum to 

Geologic Hazards Evaluation (GeoEngineers 2009) in a filing on January 21, 2009. 

Fluvial erosion may represent a hazard to the proposed pipeline where streams have the potential 

to expose the pipe as a result of significant lateral bank erosion (channel migration), avulsion, or 

widening and/or downcutting (scour) of the streambed. Lateral channel migration is the 

movement over time of an entire channel segment perpendicular to the direction of stream flow. 

Channel avulsion is the sudden abandonment of an active channel for a newly created, or 

previously abandoned, channel located on the floodplain. Channel widening is defined as the 

erosion and subsequent recession of one or both streambanks that widens the channel without 

changing the channel location. Streambed scour is erosion of the streambed resulting in the 

development of deep pools and/or the systematic lowering of the channel floor elevation. 

Streambed scour may also result from the passage of debris flows and debris torrents. Debris 
4.1-33 4.1 – Geological Resources

flows and torrents consist of large volumes of water, soil, rock fragments and boulders, wood 

and other organic materials moving rapidly downstream as a fluid through a defined channel. 

Debris flows and torrents often start as rapidly moving landslides that liquefy as the landslide 

mass progresses downslope. 

All streams that would be crossed by the proposed route were evaluated with respect to potential 

risk to the pipeline. The evaluation was conducted in two phases: a preliminary evaluation in 

which all stream crossings were ranked for potential risk, and detailed analyses of stream 

crossings posing potentially significant risk to the pipeline (GeoEngineers 2007b). Potential risk 

was evaluated based on the likelihood of migration, avulsion, and/or scour as determined through 

evaluations of aerial photographs and GIS data. A total of 321 were identified as Level 0, 37 

were identified as Level 1, and 13 were identified as Level 2. Level 0 crossings present very low 

risk from channel migration or streambed scour when standard pipeline construction methods are 

used. Level 1 stream crossings, though presenting a low to moderate erosion risk, would not 

pose a significant risk to the pipeline provided that standard pipeline construction techniques and 

BMPs were used. Level 2 stream crossings represent a high scour or migration risk and were 

analyzed in additional detail and on a case-by-case basis. 

In addition to the initial 13 Level 2 stream crossings, 7 additional crossings were evaluated in 

detail. These 20 sites were reviewed in a field reconnaissance and detailed analyses to assess 

potential migration, avulsion, or scour. One of the crossings, Spencer Creek, was avoided as a 

result of subsequent reroutes. Pacific Connector estimated the 25-, 50-, and 100-year Channel 

Migration Zones (CMZs) for each crossing. The width of the CMZ identifies the distance the 

channel could travel in 25, 50, or 100 years, respectively, in the absence of confining structures. 

These were estimated based on historical channel occupation tracts, the character of migration in 

each reach, the maximum rate of lateral and downstream migration for each reach, and the 

locations of ancient and historic abandoned channels. Based on evaluations of each crossing, the 

25-year CMZ best represents future migration potential for all crossings. The applicability of the 

50-year CMZ depends on site-specific conditions, and the 100-year CMZ is least representative 

of future channel migration potential and channel location for all crossings. Based on a detailed 

analysis of the 25-year and 50-year CMZs, Pacific Connector would design all waterbody 

crossings for the 50-year condition. This level of design would be protective of the pipeline, and 

therefore public safety, given the level of natural channel migration at each site. 

The scour analysis included surveying several channel cross sections upstream, downstream and 

at the crossing location; modeling channel hydrology and hydraulic conditions at each site; 

evaluating depth to bedrock beneath crossings; and calculating scour depths for multiple flow 

events based on the results of hydraulic modeling using HEC-RAS (Hydrologic Engineering 

Center-River Analysis System), geomorphic evaluation, and observed field conditions. 

Hydraulic output from HEC-RAS was used to evaluate stream scour for the 10-, 25-, and 50-year 

peak flow events. Return intervals were calculated from regional regression equations or peak 

discharge statistics from nearby USGS gaging stations (GeoEngineers 2007b). 

A summary of the scour results is presented below and in table 4.1.3.2-3: 

• Quantitative scour depth analysis was not completed for South Myrtle Creek because 

field observations indicated that the streambed was composed of bedrock. If bedrock was 

not observed at the pipeline crossing location, depth of scour into alluvial material was 

calculated for design flood events. 
4.1-34 4.1 – Geological Resources 

TABLE 4.1.3.2-3 

Summary of Scour Results using HEC-RAS 

Stream Name at Crossing Milepost 

Expected Scour Depth 

Based on Interpreted Depth 

(feet) to Bedrock 

Calculated Total Potential 

Scour Depth (feet) in Alluvium 

(10/25/50/100yr) Ownership 

Middle (Park) Creek 27.04 2 - 7.0 a/ 7.0/9.0/9.0/10.5 b/,c/ BLM 

South Fork Elk Creek 34.46 -- 4.0/5.0/5.0/6.0 Private 

Olalla Creek 58.77 -- 6.0/7.0/7.0/7.5 Private 

South Umpqua River Crossing No. 1 69.05 0.3 - 8.3 a/ 21.0/23.5/25.5/27.0 c/ Private 

North Myrtle Creek 79.12 -- 5.0/6.0/6.0/6.5 b/ Private 

South Umpqua River Crossing No. 2 94.73 0.7 - 8.7 a/ 11.0/13.5/16.0/18.0 c/ Private 

Rogue River 122.65 0.9 - 6.9 a/ 13.5/16.5/18.5/20.5 c/ State 

a/ Depth to bedrock interpreted from nearby boring logs and outcrops. Depth of scour is expected to be limited by bedrock. 

b/ Minimum scour depth calculated at October 2006 crossing location. Pipeline subsequently moved to current location. 

c/ Calculated depth of scour assumes absence of bedrock. 

• Shallow bedrock is known to exist near Middle Creek, South Umpqua River Crossing 

No. 1, South Umpqua River Crossing No. 2, and Rogue River. At these crossings, depth 

to bedrock was interpreted based on observed bedrock contacts, outcrops, and borings 

drilled near pipeline crossings. For each crossing, bedrock would likely be encountered 

at shallower depths than the calculated depth of scour into alluvial material. 

• Detailed scour analyses were completed at the crossings for Middle Creek, South Fork 

Elk Creek, Olalla Creek, South Umpqua Crossing No. 1, North Myrtle Creek, South 

Umpqua River Crossing No. 2, and Rogue River. 

Potential scour from debris flows could occur where the proposed pipeline crosses streams 

within rapidly moving landslide hazards. A site reconnaissance was performed at these crossings 

where they had the potential for scour based on the apparent gradient measured from 10-meter 

DEM and LiDAR. Table B-3b of Appendix B from GeoEngineers’ (2007e) Geologic Hazards 

and Mineral Resources Report filed as Resource Report 6 of Pacific Connector’s application 

presents the data collected during the site reconnaissance and conclusions regarding the potential 

risk of rapidly moving landslide scour. 

Field evaluations were performed at stream crossings within rapidly moving landslide hazard 

areas (mapped by DOGAMI in Hofmeister et al. 2002) where scour was possible based on 

stream gradients. Where no bedrock was observed within channel, and the stream gradient 

exceeded 15 percent, the channel was classified as high risk. Where the channel was composed 

of bedrock or the channel gradient was less than 15 percent, the channel was classified as low 

risk. Rapidly moving landslides typically occur on steep (greater than 50 percent) slopes 

(GeoEngineers 2007b). 

Based on these criteria, stream crossings at MPs 50 and 70 were identified as having a potential 

high risk from rapidly moving landslide scour. Based on additional site-specific evaluation of 

the site near MP 70, this channel was classified as low risk. Based on site reconnaissance of the 

site near MP 50, the pipeline was rerouted in this area to avoid this site. 

Potential scour depth from Coos Bay currents of approximately 3 feet was estimated at the 

proposed pipeline crossing of the Coos River. The scour estimate is based on modeling the 

sediment as silt, and do not factor any sediment load in the Coos River, which results in very 

conservative scour estimates. Modeling results indicate that no significant scouring would occur 
4.1-35 4.1 – Geological Resources

over the pipeline from vessel-induced pressure fields or propeller wash. Pacific Connector 

proposes to cross the Coos River by HDD, which would place the pipeline well below the 

potential scour depth. 

In January 2009, GeoEngineers further studied 114 stream crossings identified along pipeline 

route changes filed by Pacific Connector on December 4, 2008 using GIS data and stream layers 

from the Pacific Northwest Hydrography Framework Clearinghouse. For new crossings more 

than 250 feet away from the September 2007 route, GeoEngineers used orthorectified aerial 

photographs, LiDAR topography where available, USGS and DOGAMI geology maps, NRCS 

soil maps, and field notes from previous assessments to refine its evaluations. Four new crossing 

locations were found to have potential risk for scour: Coos Bay (MP 1.7), West Fork of Trail 

Creek (MP 118.9), Indian Creek (MP 128.6), and North Fork of Little Butte Creek (MP 145.7). 

The pipeline crossing of Coos Bay is discussed in more detail below with regards to the scour 

studies. The potential for channel migration at Indian Creek extends about 125 from valley wall 

to valley wall. GeoEngineers recommended that the pipeline be buried with at least 5 feet of 

cover across Indian Creek and the adjacent floodplain. To evaluate the potential for scour or 

stream migration at the crossings of West Fork of Trail Creek and North Fork of Little Butte 

Creek, GeoEngineers recommended additional analyses, including examination of historical 

photographs, field reconnaissance, topographic and bathymetric survey, and subsurface 

explorations (GeoEngineers 2009). We recommended that field reconnaissance be completed at 

the West Fork Trail Creek and North Fork Butte Creek pipeline crossing locations and the 

measures be identified to mitigate impacts at these crossings. GeoEngineers completed this 

additional evaluation of West Fork Trail Creek and North Fork Butte Creek and presented the 

results in their March 30, 2009 letter report, Stream Scour and Migration Field Reconnaissance. 

Based on field review of the proposed West Fork Trail Creek pipeline crossing, the potential for 

scour, channel migration, or channel avulsion is low. GeoEngineers recommended that Pacific 

Connector use standard watercourse crossing techniques and bury the pipeline at least 5 feet 

below the streambed at this crossing. Based on field review of the proposed North Fork Little 

Butte Creek pipeline crossing, the potential for scour or channel avulsion is low. Bank recession 

associated with channel widening is ongoing at the crossing site and could affect the proposed 

pipeline. GeoEngineers identified a channel migration zone from approximately 65 feet south of 

the left bank to 40 feet north of the right bank along the crossing centerline. The channel could 

scour or occupy any portion of this channel migration zone within the expected 50-year lifespan 

of the proposed pipeline. To mitigate this hazard, GeoEngineers recommended that Pacific 

Connector bury the pipeline at least 5 feet below the existing streambed and extend that burial 

depth through the entire channel migration zone. To ensure that appropriate mitigation measures 

are implemented, we recommend that:

• Prior to pipeline construction, Pacific Connector should file with the Secretary, for 

review and approval of the Director of OEP, measures that would be implemented 

to mitigate impacts associated with stream scour or migration at the pipeline 

crossings of Indian Creek, West Fork Trail Creek, and North Fork Butte Creek. 
4.1-36 4.1 – Geological Resources 

Coos Bay Erosion and Scour Hazards

Pacific Connector conducted analysis and numerical modeling to assess the potential locations 

where erosion and scour could occur along the proposed pipeline route within Coos Bay. The 

results are described in a separate report (Coast & Harbors 2007) and are summarized in this 

EIS. Processes that were identified as potentially affecting the sediment cover over the pipeline 

or stability of the bottom in which the pipeline would be buried are: 

• tidal currents (bottom scour); 

• tidal channels and bay shoreline morphology (channel and dredged material disposal 

island migration and scour); 

• waves generated by wind blowing over the surface of Coos Bay (bay bottom scour and 

shoreline erosion); 

• effects by vessel wakes, pressure fields, and propeller wash of vessels operating in Coos 

Bay (bay bottom scour and shoreline erosion); and 

• tsunami inundation and retreat. 

Based on very conservative estimates (Coast & Harbors 2007), the model output suggests that 

limited scour may occur along the pipeline trench within Coos Bay due to currents or extreme 

wind events. To account for unexpected possible short-term migration of sediment resulting 

from currents or wind-generated waves, a conservative estimate of up to 1 foot of potential scour 

should be assumed. 

Pacific Connector used flow simulation and modeling to evaluate the potential for scour in the 

Coos Bay estuary associated with hydrodynamic conditions generated from tsunami floodwaters. 

Tsunami wave input was developed to match the ocean tsunami amplitude reported in the 

Tsunami Hazard Map of the Coos Bay Triangle, Coos County, Oregon (Priest 1995b). The 

analysis showed that some temporary scour (approximately 1 to 2 hours) may occur in Coos Bay 

along the proposed pipeline during inundation of the tsunami. As a consequence of the scour, 

significant sedimentation would be likely in the same areas during the second phase of a tsunami 

event (next 2 to 3 hours). At the end of a tsunami event, the entire pipeline area likely would be 

covered with deposited coastal sediments and sediment of the lower part of the bay. The 

modeled depth of scour during the temporary scour event was 3 feet. 

The January 16, 2009 GeoEngineers study indicated that the pipeline would be susceptible to 

scour only within Coos Bay where it would cross Hayes Inlet (between MPs 1.7 and 4.1). 

Pacific Connector proposes to install the pipeline within Coos Bay with 5 feet of cover, which 

would protect the pipeline from scour resulting from regular tidal or current movements, or in the 

event of a tsunami. 

Mine Hazards 

Mine hazards potentially exist in areas underlain by or adjacent to underground mine workings 

and surface mines that have not been properly stabilized, closed, and made safe in accordance 

with applicable local, state, and federal laws. Pacific Connector identified surface and 

subsurface mines within 0.5 mile of the proposed construction right-of-way from USGS 

topographic maps, BLM and USFS databases, DOGAMI GIS data, published reports, published 

and unpublished maps, and county mineral overlay maps. 
4.1-37 4.1 – Geological Resources

The primary hazards involve the potential for: 

• subsidence in areas underlain by or adjacent to air shafts, tunnels, underground workings, 

and mine tailings; 

• rockfalls and slides caused by the failure of unstable benches, slopes, and tailing piles in 

nearby surface mines, including those benches and slopes occurring within water-filled 

pits; and 

• the presence of tailings or waste piles containing naturally occurring metals. 

According to Pacific Connector’s application (table B-5 of Appendix B from GeoEngineers’ 

[2007e] Geologic Hazards and Mineral Resources Report), 27 sections of the September 2007 

proposed pipeline route were within 500 feet of potential mine hazards based on the information 

provided in the databases. A re-evaluation of the route as modified by Pacific Connector’s 

December 2008 filing reduced the number of pipeline segments near potential mine hazards to 

23 (GeoEngineers 2009). Thirteen of these are sand, gravel, or aggregate-related mines (likely 

consisting of open excavations). Two are clay or shale mines, and one is a quarry (see table 

4.1.3.2-4). The primary potential hazards at these mines would be related to failure of steep 

slopes or high walls. 

TABLE 4.1.3.2-4 

Potential Mine Hazards Along the Proposed Pacific Connector Pipeline a/

Milepost 

Distance 

from 

Centerline Resource – Name Ownership Status 

Threat to the 

Pipeline 

9.83 400 feet Coal – Messiere Coals Private Abandoned No 

10.02 50 feet Coal – Messiere Coals Private Abandoned No 

16.24 450 feet Coal – Summer No. 6 Private Likely Abandoned No 

45.88 110 feet Aggregate Unknown Unknown Unlikely 

56.77 500 feet Aggregate Private Unknown Unlikely 

58.71 500 feet Sand and gravel Unknown Active Unlikely 

58.73 170 feet Sand and gravel – Looking Glass Creek Private Unknown Unlikely 

58.78 80 feet Aggregate Unknown Likely Abandoned No 

58.86 100 feet Gravel Private Unknown Unlikely 

69.00 150 feet Aggregate ODOT Active Unlikely 

75.30 b/ 100 feet Aggregate Unknown Inactive No 

79.87 33 feet Quarry Unknown Unknown Unlikely 

105.62 380 feet Gold – Red Hill Prospect Unknown Inactive No 

109.30 400 feet Mercury – Thompson Group Unknown Inactive Unlikely 

109.41 Intersects Mercury – Thompson Mine Unknown Inactive Unlikely 

111.67 350 feet Aggregate USFS Inactive Unlikely 

118.66 460 feet Shale Unknown Active Unlikely 

118.98 300 feet Clay/Shale – Gaines Property Private Unknown Unlikely 

122.70 200 feet Aggregate Unknown Inactive Unlikely 

142.08 250 feet Aggregate Unknown Unknown Unlikely 

142.62 440 feet Manganese Unknown Inactive No 

150.50 Intersects Aggregate – Heppsie Mountain Quarry BLM Active Potentially 

176.40 c/ Intersects Aggregate Unknown Unknown Unlikely 

a/ Source: Table B-5 Revised (GeoEngineers 2009). 

b/ This may be the same aggregate mine listed on table B-7 revised at MP 75.3 on BLM land of unknown status (GeoEngineers 

2009). 

c/ This may be the same aggregate mine listed on table B-7 revised at MP 176.3 on BLM land that is calculated to be 340 feet 

south of the pipeline (GeoEngineers 2009). 
4.1-38 4.1 – Geological Resources 

Active Quarries

The new proposed route between MPs 108.6 and 110.9 avoids the Peavine Quarry within the 

Umpqua National Forest. Between MPs 150.4 and 150.7 the pipeline would be near the active 

Heppsie Mountain Quarry on BLM land. The BLM is concerned that installation of the pipeline 

may affect the future use of the quarry, and requested that Pacific Connector blast 60,000 to 

80,000 cy of rock from the quarry for future users. Instead, Pacific Connector indicated that it 

would develop a blast plan to remove the volume and type of rock found at the quarry. Based on 

this blast plan, Pacific Connector would calculate and analyze the vibration and stress on the 

pipeline that would result from future blasting at the quarry. Pacific Connector would consult 

with the BLM, and include the blast plan and pipe stress and vibration analysis in the POD. This 

consultation should consider BLM’s recommendation that the blasting protocol that Pacific 

Connector that would apply to pipeline construction near other pipelines should, at a minimum, 

be applied to the proposed pipeline near the Heppsie Quarry. Depending on the analysis, and 

results of the consultations, Pacific Connector identified three options: 

• do nothing, if the vibration and stress levels posed no threat to the pipeline; 

• mitigate impacts and implement measures to protect the pipeline, if future quarry blasting 

would be a threat; or 

• blast and stockpile on site 60,000 to 80,000 cy of rock from the quarry for future users, if 

quarry blasting would affect the pipeline and no mitigation measures were identified to 

protect it. 

We recommend that: 

• Prior to pipeline construction, Pacific Connector should file with the Secretary the 

blast plan and vibration and stress analysis for the Heppsie Mountain Quarry, and 

the comments of the BLM on the plan and analyses. 

The BLM would require Pacific Connector to obtain a third-party review of Pacific Connector’s 

vibration and stress analysis for the Heppsie Mountain Quarry. The analysis would include the 

amount and premium of any additional insurance a certified blaster and/or quarry operator would 

be required to obtain to operate within the Heppsie Mountain Quarry because of the location of 

the proposed pipeline. 

Mercury Mines

Pacific Connector’s September 2007 pipeline route would have passed near the Nivinson and 

Red Cloud mercury mines. However, the route filed on December 4, 2008, which goes around 

the Peavine Quarry between MPs 108.6 and 110.9, would avoid these mines.27 The new 

proposed pipeline route would cross areas mapped as volcanic and volcanogenic rocks at the 

current crossings of the East Fork Cow Creek. These bedrock units have not been identified as a 

significant source of naturally occurring mercury. Naturally occurring mercury in this area 

typically is associated with metamorphic bedrock units such as amphibolite. There are no mines 

or mercury-bearing mine tailings along the new crossings of the East Fork of Cow Creek. The 

 

27 Table B-7 Revised (GeoEngineers 2009) listed the Nivinon Mercury Mine as being located 1,450 feet west of the pipeline near 

MP 109.3R and the Red Cloud Mercury Mine as 2,790 feet west of MP 109.7R. 
4.1-39 4.1 – Geological Resources

 new crossing locations are not expected to alter or adversely affect ecological health in the East 

Fork Cow Creek because appropriate erosion and sediment control measures would be 

implemented in accordance with the Project’s ECRP. Additionally, the East Fork Cow Creek 

would be crossed during the dry summer months, which would minimize the potential of any 

sedimentation into the creek. 

According to GeoEngineers’ (2009) Addendum to Geologic Hazards Evaluation, two mercury 

mines occur along the newly proposed pipeline route in this area. At about MP 109.3 the 

pipeline would be within 400 feet of an unnamed mercury mine, and at about MP 109.4 the 

pipeline would intersect with the Thompson mercury mine. According to a 1963 DOGAMI 

publication (Brooks 1963), both these mines are part of the Thompson Group. Thompson was 

said to have drilled 500 auger holes to a maximum depth of 8 feet at his claims, although none of 

the excavations extended below the soil horizon into bedrock. DOGAMI noted several bulldozer 

trenches, about 100 feet long, and several shallow shafts. In the opinion of Pacific Connector’s 

consultant, the Thompson Group is unlikely to pose a mine hazard risk to the proposed pipeline 

(GeoEngineers 2009). On January 2, 2009, Pacific Connector filed with the FERC a draft 

Contaminated Substances Discovery Plan. In the unlikely even that mercury contaminated soils 

are encountered in the vicinity of the Thompson Group mines, Pacific Connector should follow 

the procedures outlined in that Plan. 

4.1.3.3 Mineral Resources 

Mineral resources that occur in the pipeline area include the following metals: chromite, copper, 

gold, manganese, mercury, and silver. Other mineral resources include basalt, cinders, coal, 

conglomerate, limestone, natural gas (including coal bed methane), sand and gravel, sandstone, 

shale, silica, talc, and tuff/breccia. Most of the non-metal minerals are mined to produce 

aggregate. Mineral resources, surface and subsurface mines, and oil and gas fields located 

within 0.5 mile of the proposed Pacific Connector pipeline construction right-of-way were 

identified from USGS topographic maps, BLM and USFS mineral resource databases (including 

oil and gas leases, geothermal leases, and mining claims), ODOT aggregate resources GIS data, 

DOGAMI GIS data, published reports, published and unpublished maps, and county mineral 

overlay maps. Detailed maps showing mineral resources, mines, leases, mining claims, and 

related features are included in Appendix G of GeoEngineers’ (2009) Addendum to Geologic 

Hazards Evaluation, filed with the FERC by Pacific Connector on January 21, 2009. 

Portions of the proposed alignment cross six areas with county zoning that recognizes the 

potential for future mineral resource development. This zoning implies that mines and oil and 

gas wells could be sited at any location within these areas in the future as long as the zoning 

remains compatible with the proposed resource extraction operations. 

Table B-7 of Appendix B from GeoEngineers’ (2007e) Geologic Hazards and Mineral 

Resources Report, filed as Resource Report 6 of Pacific Connector’s September 2007 application 

to the FERC, identified the active, inactive, and planned mineral resources or mining sites 

(organized by MP) within 0.25 mile of the proposed pipeline. These data were updated in an 

Addendum to Geologic Hazard Evaluation (GeoEngineers 2009) filed with the FERC by Pacific 

Connector on January 21, 2009. The updated addendum indicated that no new mineral resources 

were located along pipeline route changes filed by Pacific Connector on December 4, 2008, 

although the MP locations were revised from the September 2007 route. A total of 23 mineral or 

mine locations were identified as within 500 feet of the proposed pipeline. However, these 
4.1-40 4.1 – Geological Resources 

numbers likely include duplications because the various databases appear to report slightly 

different locations for what are probably the same mines. 

Table B-8 of Appendix B from GeoEngineers’ (2007e) Geologic Hazards and Mineral 

Resources Report, as updated by GeoEngineers’ (2009) addendum identified areas where the 

proposed pipeline would cross: 1) areas where county land-use zoning allows mineral resource 

extraction, or 2) federal land that has been or is available for mineral resource or geothermal 

leases. Coos County recognizes two coal-basin resource areas and an oil and gas area between 

MPs 7 and 26. The ODSL also has four coalbed methane leases located on or near MPs 0 and 

11.7. Jackson County recognizes mineral resources near MPs 122 and 175. 

The proposed pipeline would intersect with two quarries on federal lands. The Green Butte 

Quarry was identified at MP 101.8 within the Umpqua National Forest. However, GeoEngineers 

indicated that this quarry was never opened and there are no plans for its future development. 

The Heppsie Mountain Quarry on BLM land at MP 150.4 is discussed above in section 4.1.3.2. 

The proposed pipeline could potentially interfere with future mining and reclamation activities 

on lands adjacent to the right-of-way. Future expansions of surface mines near the proposed 

right-of-way potentially could be limited or precluded in some cases because mineral resources 

could not be extracted from slopes immediately above or below the pipeline right-of-way or from 

beneath the pipeline. Similarly, the presence of the proposed pipeline could limit or preclude the 

stockpiling of mineral resources or development of a processing area on slopes above or below 

the pipeline. These considerations also could limit or preclude reclamation activities at mine 

sites near the proposed pipeline because of the potential to disturb the slopes above and below 

the pipeline and right-of-way. Any impact would be site-specific and would depend on 

topography, drainage, and subsurface conditions in that area. 

4.1.3.4 Rock Sources and Permanent Disposal Sites 

Pacific Connector has identified 43 potential rock source and permanent disposal sites that total 

151.09 acres along the proposed route. Rock source sites may contain useable mineral deposits 

that may be extracted and/or purchased for use during construction. Disposal sites were 

identified for final placement of unusable, non-merchantable materials. These sites are typically 

exhausted areas within active quarries or abandoned quarries and may include commercial sites. 

Other permanent storage sites, including some TEWAs, were identified for permanent storage of 

excavated material. The material disposed of in these areas would be properly graded, drained 

(if necessary), and revegetated. The sites identified are not proposed for expansion beyond their 

proposed permitted or authorized boundaries. Use of any site would be permitted as required by 

the appropriate jurisdiction or landowner, and Pacific Connector would comply with applicable 

permits/stipulations. The disposal of mineral material to Pacific Connector from rock sources 

proposed to be utilized on BLM lands would follow regulations in 43 CFR 3600. 

Table 7A-1 in Appendix 7 of Resource Report 7 filed with Pacific Connector’s application to the 

FERC lists the proposed rock source and disposal sites, their sizes, approximate mileposts in 

relation to the proposed pipeline, jurisdiction, existing land use, and the soil mapping unit and 

sensitive soil characteristics of the sites. Sensitive soil information was not provided for the 

existing quarry sites because soils at these sites have been significantly altered. Only the 

disposal sites (and not the TEWAs) identified in table 7A-1 in Resource Report 7 are being 

proposed for use as permanent disposal sites. 
4.1-41 4.1 – Geological Resources

Of the 43 identified potential rock source and permanent disposal sites, 24 sites are existing 

quarries/gravel pits or abandoned quarries/gravel pits. Although some of the existing/abandoned 

sites appear to have land use types other than quarries/gravel pits, Pacific Connector does not 

intend to expand these sites beyond the existing or previously disturbed footprints. If Pacific 

Connector acquired rock from these sources or permanently disposed of excavated material, all 

available topsoil would be salvaged. The salvaged topsoil would be used to restore the site as 

required by landowner stipulations. Rock resource areas managed and developed by Pacific 

Connector would need quarry Operation and Reclamation Plans, to the extent required by 

DOGAMI’s regulatory authority (OAR 632-030-0005 through 0070 and ORS 517.750 through 

990). Appropriate BMPs would be implemented, such as those in Norman et al. (1998). No 

impacts are anticipated from the rock sources and permanent disposal sites. 

4.1.3.5 Blasting During Trench Excavation 

Blasting could be required for pipeline trench excavation in areas where hard, non-rippable 

bedrock occurs. The bedrock units where blasting could be necessary would consist primarily of 

volcanic and metavolcanic rocks in the Klamath Mountains and volcanic rocks in the Cascade 

Range as well as along the ridges in the Basin and Range physiographic province. In addition, 

local areas of well-lithified sedimentary rock may need to be blasted in the Coast Range. 

Pacific Connector identified areas where blasting may be necessary by reviewing the NRCS soils 

maps and descriptions to identify soil units that typically contain bedrock within 5 feet of the 

ground surface. Soils data, geological maps, and topographic relief were used to rank the 

qualitative likelihood for blasting along the pipeline as follows: 

• No Potential – Areas containing deep soils and alluvial, fluvial, lacustrine, and estuarine 

sediments that could be readily excavated. General occurrence: the coastal and Klamath 

basin lowlands and the major valleys and floodplains in all of the physiographic 

provinces. 

• Low Potential – Areas containing soft sedimentary rock and tuff that can typically be 

excavated without ripping. General occurrence: Coast Range, and local areas of the 

Klamath Mountains, Cascade Range, and the Basin and Range physiographic provinces. 

• Moderate Potential – Areas containing fractured, faulted, or weathered metamorphic or 

volcanic rocks that generally can be excavated with ripping, but that could require local 

blasting. General occurrence: local areas in the Klamath Mountains, Cascade Range, 

and the Basin and Range physiographic provinces. 

• High Potential – Areas containing hard or fresh plutonic (for example, granitic) and 

volcanic rocks that could not be excavated without blasting. General occurrence: local 

areas of the Klamath Mountains physiographic province, portions of the Cascade Range 

physiographic province, and local areas in the Basin and Range physiographic province. 

Table 4.1.3.4-1 provides a summary of the blasting potential along the proposed pipeline. This 

table has been updated based on table B-6 Revised of GeoEngineers’ (2009) addendum, which 

updated the MPs based on the pipeline reroutes. No new areas of high blasting potential were 

identified relative to the pipeline reroutes. Blasting would not likely be required to construct the 

first 78 miles of the pipeline because the materials are expected to consist of soil, sediments, and 

rippable sedimentary rocks. Although the blasting potential is classified as high for about 100 

miles of the proposed route, this distance estimate includes local areas as much as 0.9 mile in 

length that contain valley fill, thick soils, and soft volcanic rocks (such as tuffs) that would not 
4.1-42 4.1 – Geological Resources 

TABLE 4.1.3.4-1. 

Summary of Blasting Potential Along the Proposed Pacific Connector Pipeline 

From MP To MP Blasting Potential Material Ownership 

0.0 60.0 None to Low Soil, sediments, sedimentary rocks and 

valley fill 

Private, State, BLM 

60.0 72.0 None to Moderate Sedimentary rocks with local valley fill Private, BLM 

72.0 78.1 Low to Moderate Sedimentary and metamorphic rocks Private, BLM 

78.1 88.2 High a/ Igneous rocks with sedimentary rocks 

and local valley fill 

Private, BLM 

88.2 88.8 None to Low Sedimentary rocks with local valley fill Private 

88.8 89.6 High Igneous rocks Private 

89.6 90.8 Moderate Sedimentary rocks Private, BLM 

90.8 93.5 Low Sedimentary rocks Private, BLM 

93.5 94.0 High Igneous rocks Private, BLM 

94.0 95.0 None to Low Sedimentary rocks with local valley fill Private, BLM 

95.0 95.7 High Igneous rocks Private, BLM 

95.7 96.9 Low Sedimentary rocks with local valley fill Private, BLM 

96.9 110.9 High Igneous rocks with sedimentary rocks 

and local valley fill 

Private, BLM, USFS 

110.9 112.4 Low Soft igneous rock USFS 

112.4 117.3 High Igneous and locally tuffaceous rock 

and local valley fill 

USFS, Private, BLM, State 

117.3 117.8 Low Soft igneous rock Private, BLM, State 

117.8 133.7 High a/ Igneous and locally tuffaceous rock 

and local valley fill 

Private, BLM, State 

133.7 134.2 Low Soft igneous rock Private, BLM, State 

134.2 137.1 High Igneous and locally tuffaceous rock BLM, Private 

137.1 138.6 Low Landslide deposit BLM, Private 

138.6 145.7 Moderate to High Igneous rock, tuffs, breccias, 

conglomerates, lahar deposits, local 

valley fill 

Private, BLM 

145.7 145.9 Low Terrace, valley fill Private, BLM 

145.9 159.9 Moderate to High Igneous rock, tuffs, breccias, 

conglomerates, lahar deposits, local 

valley fill 

Private, BLM, USFS 

159.9 160.3 Low Unconsolidated volcanic deposits USFS, Private 

160.3 160.6 High Igneous rock and locally tuffaceous 

rock with local valley fill 

USFS, Private 

160.6 160.8 Low Unconsolidated volcanic deposits USFS, Private 

160.8 172.0 High Igneous rock and locally tuffaceous 

rock with local valley fill 

USFS, Private 

172.0 175.4 None Thick soil USFS, Private 

175.4 181.0 High Lava flows Private, BLM, 

181.0 182.8 Low Unconsolidated volcanic deposits Private 

182.8 191.7 Moderate to High Igneous rocks with local soil and 

sediment 

Private, State 

191.7 219.2 None to Moderate Soft igneous rocks with local sediment 

and valley fill 

Private, State, BOR 

219.2 221.3 High Igneous rocks Private 

221.3 226.9 None to Moderate Soil, soft igneous rocks valley fill Private 

226.9 230.9 None Landslide deposit and valley fill Private 

a/ Blasting potential intermittently rated as None where pipeline crosses a valley floor or thick soil. 

need to be blasted. In addition, some of the proposed route classified as having a high or 

moderate potential for blasting may contain weathered rock that could instead be ripped by 

conventional excavation equipment. 
4.1-43 4.1 – Geological Resources

Pacific Connector would conduct all blasting in accordance with all federal, state, and local 

regulations and Pacific Connector Construction Specifications. Pacific Connector would include 

specifications in any blasting contract to control adverse impacts, including measures to 

minimize vibrations and flyrock, measures for safe blasting practices near active pipelines, and 

seasonal restrictions to protect wildlife, as needed (see sections 4.5 and 4.6 for more 

information). Pacific Connector would have blasting inspectors present to ensure that all 

specifications were met and to perform pre- and post-blast inspections of nearby structures and 

wells. BOR has requested to be informed prior to blasting on BOR property to allow them to 

consider the integrity of their aging infrastructure. When crossing BOR facilities, Pacific 

Connector has stated that trench excavation would comply with the most current OSHA 

standards or BOR health and safety standards, whichever are more stringent. 

Blasting for trench excavation could result in several types of impact, as described below. 

Water Wells and Springs 

In general, vibration effects to wells would be expected to be limited to the immediate proximity 

of the blasting. A common measurement unit for vibration is the peak particle velocity (PPV) of 

blasting-induced ground motion in inches per second. Siskind (1999) summarizes information 

on four blasting studies conducted to evaluate vibration effects on wells. One study showed, 

“There were no physical vibration effects on the wells even as close as 300 feet.” The maximum 

velocities for this testing ranged from 0.84 to 5.44 inches per second, with four of the five sites 

exceeding 2 inches per second. In another study, a well was tested for casing cement bond 

damage. The study indicated initial bond losses occurred at 4.7 inches per second. A third study 

indicated that wells outside the blast pattern were exposed to as much as 8.7 inches per second at 

a distance of 31 feet and no damage occurred; however, the construction details for these wells 

are not described in the Siskind (1999) report. Nearly all households in the Shady Cove area 

(MPs 122 and 123) obtain water from wells already impacted by the relatively high density of 

nearby development.

Pacific Connector developed a Groundwater Supply Monitoring and Mitigation Plan in order to 

identify monitoring and mitigation measures to prevent and/or minimize impacts to groundwater, 

including from blasting (see also section 4.3.1.4). The plan would include identification of 

groundwater supplies through records review, field surveys, and landowners; the determination 

of susceptibility of identified supplies, and pre- and post-construction monitoring at the 

landowners request and with the landowners permission. Should it be determined after 

construction that there has been an impact on groundwater supply (either yield or quality), 

Pacific Connector would work with the landowner to ensure a temporary supply of water, and if 

determined necessary, Pacific Connector would replace a permanent water supply. Mitigation 

measures would be coordinated with the individual landowner in order to meet the landowner’s 

specific needs. Mitigation measures for groundwater wells, springs, and seeps would be specific 

to each property and would be determined during landowner negotiations. 

Yields from perennial springs could decrease if blasting vibrations damaged the related aquifer. 

Pacific Connector would request authorization from landowners to test and document the 

baseline condition, yield, and water quality of any private wells or springs being used as 

permitted water supplies within 200 feet of the pipeline construction right-of-way. This testing 

would occur before the pipeline construction started in the nearby area, and the testing results 

would be shared with the property owner, if requested. Data collected during the dry season may 
4.1-44 4.1 – Geological Resources 

prove most useful in determining potential effects. Testing of non-permitted wells and springs 

may be necessary to determine whether these would be affected. Similar information would be 

gathered for any public water wells or water supply springs located within 400 feet of the 

pipeline construction right-of-way. 

Maximum PPV of 2 inches per second would be specified at the locations of private and public 

water supply wells. In specific cases, vibration could be reduced by drilling relief boreholes 

between the portion of the trench being blasted and any private or public water wells located 

within 200 feet of the pipeline construction right-of-way. The number and location of the relief 

boreholes would be determined on a site-specific basis. 

Any turbidity in wells or springs caused by the blasting vibrations would be expected to be 

temporary and would likely dissipate shortly after blasting or after the well was pumped several 

times. Water quality impacts to groundwater or springs from blasting agents, if any, would be 

expected to be temporary and localized because only small amounts of these agents generally 

would be needed for trench excavation. 

Wetlands 

Blasting could potentially redirect surface water and groundwater flows to and from wetlands. 

In addition, turbidity and blasting agent by-products could possibly temporarily degrade surface 

water and groundwater quality. 

Any turbidity resulting from blasting is expected to be temporary and to dissipate shortly after 

blasting. Water quality impacts to wetlands from blasting agents, if any, would be expected to 

be temporary and localized because only small amounts of blasting agents generally would be 

needed for trenching. 

Slopes 

Unstable rock and soil slopes could locally fail as a result of blasting vibrations. Pacific 

Connector would complete a reconnaissance of slopes in the vicinity of the blasting, including 

measuring slope inclinations and observing areas adjacent to planned blasting locations for 

potential indicators of unstable slopes. Identified slope areas that could be impacted by blasting 

would be monitored and evaluated for hazards to people and property during the blasting 

operations. 

Structures 

Blasting vibrations and flying debris could potentially damage aboveground structures. If 

structures were present in areas where blasting was necessary, Pacific Connector would request 

authorization from landowners to inspect structures located within 200 feet of the pipeline 

construction right-of-way before and after blasting. Blasting mats or padding also would be used 

when blasting near structures to limit potential damage from flying rocks. 

As an additional precaution, Pacific Connector would require the contractor conducting blasting 

to limit the size of charges in accordance with the scaled distance factor (SD) guidelines 

developed by the Office of Surface Mining Reclamation and Enforcement (OSMRE). The SD is 

equal to the distance from the blast to an aboveground structure divided by the square root of the 

charge (pound per delay). For distances less than 300 feet, OSMRE states that the SD shall 

exceed 50. 
4.1-45 4.1 – Geological Resources

Adjacent Pipelines and Buried Utilities 

Blasting vibrations could potentially damage adjacent underground pipelines and utilities. In 

general, blasting would not be allowed within 10 feet of an existing pipeline or buried utility. In 

cases where blasting near an existing utility was necessary, the pipeline or utility owner would be 

notified in advance of the blasting, and measures would be taken to minimize the potential for 

utility damage. 

In summary, potential effects associated with blasting include temporary and localized impacts 

to wells and springs and to water quality in wetlands. Blasting could potentially redirect surface 

water and groundwater flows to and from wetlands. We believe that use of Pacific Connector’s 

proposed monitoring and mitigation, Pacific Connector would avoid or reduce the likelihood of 

local failures of unstable rock and soil, and damage to structures or utilities from blasting 

vibrations. 

4.1.3.6 Paleontological Resources 

There are no state or federal laws or regulations that protect paleontological resources on private 

lands (Niewendorp, DOGAMI, personal communication, 2008). The Antiquities Act of 1906 

protects “objects of antiquity” on federal lands. 

4.1.4 Environmental Consequences on Federal Lands 

4.1.4.1 Potential for Seismic Activity, Liquefaction, and Landslides 

There is potential for surface rupture from faulting where the pipeline would cross traces of the 

Quaternary-age Sky Lakes fault zone near MP 174 within the Fremont-Winema National Forest. 

As mitigation for this pipeline crossing, during construction Pacific Connector would have the 

pipeline trench carefully examined by a qualified professional for evidence of stratigraphic 

offsets potentially related to ground rupture. If such features are observed, Pacific Connector 

would implement additional mitigation measures, with the specific mitigation developed at that 

time. However, the intent would be to follow published guidance to estimate the potential 

amount and direction of fault offsets as well as the magnitude of strain accumulation at the pipe 

crossing location (Takada et al. 2001; Honegger and Nyman 2004). Such measures could 

include burying the pipe in a wide trench that was backfilled with loose gravel or sand, which 

would allow for relatively unrestrained movement of the buried pipe within the zone of fault 

movement. 

Two areas crossed by the proposed pipeline within BLM Coos Bay and Roseburg District lands 

(Park Creek near MP 27 and Deep Creek near MP 48, respectively) are characterized as having 

low potential for liquefaction and lateral spreading. Low potential include sites with subsurface 

conditions of fine-grained soils that are not susceptible to liquefaction or soils that are not 

expected to be saturated. 

The potential exists locally along portions of the proposed pipeline route for seismically induced 

ground shaking to induce rockfalls, landslides, or soil slumps. Of those locations identified, 10 

locations totaling about 2.1 miles would be within BLM-administered lands, and two locations, 

totaling about 1.8 miles would be within USFS-administered lands (based on landslides with low 

final risk that cross BLM and NFS lands). GeoEngineers’ (2009) Addendum to Geologic 
4.1-46 4.1 – Geological Resources 

Hazards Evaluation includes another five landslides (based on new SLIDO data) with low final 

risk that the pipeline would cross along approximately 0.56 mile of BLM-administered lands. 

Pacific Connector selected its proposed pipeline route to avoid existing landslides and areas 

susceptible to landsliding. Pacific Connector was able to modify its proposed route to avoid 

most moderate- and high-risk rapidly moving landslide hazards; however, two moderate-risk 

rapidly moving landslide sites could not be avoided, including one site at MP 36.92 on BLM 

Coos District land. Additional investigation of this site resulted in a final risk determination of 

low (GeoEngineers 2009). The landslide risk at this site is not considered hazardous enough to 

require additional mitigation or rerouting. To minimize landslide risk, Pacific Connector would 

implement its ECRP during pipeline construction, which would reduce the potential for 

construction to adversely affect slope stability. 

Because the proposed pipeline would cross hundreds of miles of rugged terrain including within 

BLM and NFS lands, there is potential for previously unidentified landslides or new landslides to 

affect the pipeline after it is installed. As part of its pipeline operation, Pacific Connector would 

conduct regular monitoring of the pipeline right-of-way, which would aid in detecting landslide 

occurrence or slope movement. On federal lands, USFS and BLM representatives would 

conduct monitoring with Pacific Connector personnel. Mitigation could include the use of 

shutoff valves. If movement is detected, immediate action would be taken to reduce the risk to 

the pipeline. Actions would include initial response to reduce the stresses on the pipeline, and 

follow-up actions to stabilize the slide. If the slide is large and complex enough such that 

stabilization would not be feasible, the pipeline could be relocated around the slide area. 

Several agency requests were included in the April 5, 2007 document, Bureau of Land 

Management and USFS Conceptual Mitigation Measures for the Pacific Connector Gas Pipeline 

Project. Among these was a request for an emergency response plan in the event of a landslide. 

Such a plan would need to address the entire life of the Project. The development of a pipeline 

Emergency Response Plan can be included in the POD that would be developed by Pacific 

Connector, in consultation with the federal land management agencies, to support Pacific 

Connector’s application for a Right-of-Way Grant. 

Pacific Connector conducted analyses to assess the potential for channel migration and the depth 

of streambed scour in the waterbodies that would be crossed by the proposed pipeline. One 

waterbody identified with potential moderate risk for scour, Middle Creek MP 27.04, would be 

crossed within BLM lands. Pacific Connector would design this crossing to withstand estimated 

potential scour that could occur during 50-year maximum scour events. Based on the sitespecific analysis performed at this site (GeoEngineers 2007b), we believe this would adequately 

protect the pipeline at this crossing location. 

4.1.4.2 Mineral Resources on Federal Lands 

Oil and gas leases existed on BLM lands located between MPs 17 and 55, MPs 131 and 167, and 

around MP 205; however, all of these leases are reported to be closed. In addition, BLM is 

reported to have three areas of geothermal leases. These geothermal leases are located near MP 

193 and between MPs 216 and 221. Mining claims on federal lands are reported between MPs 

74 and 119 as well as near MPs 140 and 170; records indicate that most of these claims are 

closed. A placer claim reported on federal land near MP 0 is also indicated as being closed. 
4.1-47 4.1 – Geological Resources

Three quarries were identified on NFS lands near the pipeline at MPs 101.8, 111.7, and 160.7 

(GeoEngineers 2009). The pipeline would intersect the Green Butte Quarry at MP 101.8, but 

GeoEngineers indicated that this quarry has not yet been opened and there are no plans for its 

future development. At MP 111.7 the pipeline would be within 360 feet of an aggregate quarry 

that has not yet been developed. At MP 160.7 the pipeline would be about 630 feet away from 

an aggregate mine whose status is unknown. Because the quarries identified on NFS lands are 

not yet developed or are inactive, the proposed pipeline should not affect their operation. 

A number of gold and mercury mines or mining claims are located near the pipeline between 

MPs 105.6 and 111.7 within the Umpqua National Forest. GeoEngineers (2009) indicated that 

all of these mines are currently inactive. As discussed above in section 4.1.3.2, the pipeline 

would intersect with the Thompson Group mercury mine at about MP 109.4. Pacific Connector 

does not believe that this mine represents a hazard to its pipeline. 

On BLM land, between MPs 140.0 and 140.5, GeoEngineers (2009) identified two manganese 

mines. The Gove Prospect at MP 140.0 would be about 1,130 feet from the pipeline, while the 

Call of the Wild mine at MP 140.5 would be 1,140 feet away. Both of these mines appear to be 

inactive, and the proposed pipeline should have no effect on them. 

Three aggregate mines were identified on BLM land at MPs 75.3, 150.4, and 176.3. The 

aggregate mine at MP 75.3 is about 105 feet south of the pipeline, and its status is unknown. The 

aggregate mine at MP 176.3 is about 340 feet south of the pipeline and is also of unknown status. 

The Heppsie Mountain Quarry at MP 150.4 is discussed above in section 4.1.3.2. The BLM is 

concerned that the pipeline may affect the future use of the quarry. We are recommending that 

Pacific Connector file plans to mitigate potential impacts. 

4.1.4.3 Paleontological Resources on Federal Lands 

Paleontological resources on federal lands are regulated, as outlined in 36 CFR Ch. 11 261.9 (i). 

Pacific Connector consulted with federal land management agencies for information on potential 

paleontological resources crossed by or within the proposed right-of-way. 

Pacific Connector states that consultation with staff of the Real Estate and Mineral Resources 

Section of the Umpqua National Forest reported that there were no known paleontological 

resources on the portions of the proposed right-of-way located within the boundaries of the 

Umpqua, Rogue River-Siskiyou, and Fremont-Winema National Forests. According to 

Paleontology Associates, only the Umpqua and Rogue River-Siskiyou National Forests bear 

potentially favorable lithologic units for fossil content along the pipeline corridor. These units 

occur in: 

• Umpqua National Forest MP 106 to 109—Fisher formation-volcanic ash and lacustrine 

siltstone; 

• Umpqua National Forest MP 109.5 to 115.5—Little Butte and Colestin formationstuffaceous sediments; and 

• Rogue River-Siskiyou National Forest MP 120 to 121—Colestin formation-tuffaceous 

sediments; and 

• Rogue River-Siskiyou National Forest MP 155 to 158—No formal formation 

designation-tuffaceous sediments, lahars, waterlaid tuffs. 
4.1-48 4.1 – Geological Resources 

Based on this information, no measures appear necessary for the avoidance and minimization of 

adverse effects to paleontological resources on NFS lands. Pacific Connector does not plan to 

monitor for lithologic units on NFS lands. 

Pacific Connector conducted an analysis of existing paleontological data for the portions of the 

proposed right-of-way that would be located on BLM lands (GeoEngineers 2007c). The analysis 

was conducted in general accordance with BLM Manual H-8270-1 (General Procedural 

Guidance for Paleontological Resource Management, Release 8-69, dated July 13, 1998). The 

assessment indicates a limited potential for encountering paleontological resources on the BLM 

lands. 

Fossil-bearing rock formations along the portions of the proposed right-of-way on BLM lands 

range in age from the Jurassic period (almost 200 million years old) to the Pleistocene epoch 

(about 12,000 years before present). Between MPs 17 and 54, the proposed right-of-way on 

BLM lands would cross Eocene units of the southern Coast Range. The units span the entire 

epoch, with a wide variety of clastics ranging from coarse conglomerates to very fine-grained 

deep water silts and shales. Paleocene epoch intervals in the lower Roseburg formation could 

potentially contain plants, invertebrates, reptiles (turtles), and odontocete cetacea (primitive 

toothed whales). In addition, Pleistocene intervals in localized swamp boggy areas of the 

Roseburg formation could potentially yield bones of large Ice Age mammals. 

The portion of the BLM lands in the Klamath Mountain interval between MPs 54 and 97 has 

some of the oldest and most complex rocks in Oregon. Because most of the Klamath rocks are 

mapped as exotic accretionary terranes, even the most fragmentary fossils discovered would be 

significant. 

BLM lands would be crossed between MPs 110 and 123, MPs 128 and 137, and MPs 167 and 

172 in the Cascade Range. Two formations in this region, the Colestin and Little Butte, have a 

potential for producing plant fossils. Both were deposited in nonmarine, continental settings 

with volcanogenic ash, tuff, and silts mixed with extrusive volcanics of basalt, basaltic andesite, 

and related igneous rocks. Despite the wide range of ages and environments, the floral lists for 

either formation are limited at any given site. As a result, any new taxa recorded or salvaged in 

the course of the construction activities would add to the knowledge of the Cascade geological 

history. 

Between MPs 216 and 217, the proposed right-of-way crosses BLM lands in the Basin and 

Range province. Lake sediments of Cascade ash dating between 5 million to 11,000 years ago in 

this area bear a limited, but stratigraphically important fauna. 

Pacific Connector conducted a field survey for paleontological resources of the proposed rightof-way that would occur on BLM lands. The locations observed during the survey were selected 

using the results of the analysis of the existing data and a mile-by-mile evaluation of the 

geological formations along the proposed right-of-way. 

Based on the field survey, all but 1 mile of the proposed right-of-way on BLM lands was 

classified as very unlikely to produce vertebrate fossils or noteworthy occurrences of invertebrate 

or plant fossils (based on the surficial geology or the presence of igneous or metamorphic rocks, 

extremely young alluvium, colluvium or aeolian deposits, or deep soils). Pacific Connector 

proposes to conduct spot monitoring along approximately 25 miles of BLM lands during pipeline 
4.1-49 4.1 – Geological Resources

construction because the potential presence of fossils could not be eliminated completely. 

Pacific Connector divided the remaining 1 mile of proposed right-of-way on BLM Lakeview 

District lands into areas known to contain vertebrate fossils or noteworthy occurrences of 

invertebrate or plant fossils; and areas with exposures of geological units or settings that have a 

high potential to contain vertebrate fossils or noteworthy occurrences of invertebrate or plant 

fossils. Pacific Connector proposes to conduct continuous monitoring for the potential presence 

of paleontological resources during pipeline construction in these areas. The spot or continuous 

monitoring during construction would be conducted by a field paleontologist working under the 

supervision of the lead paleontologist. Additional details of monitoring for paleontological 

resources during construction, including the roles and responsibilities of monitors, would be 

developed in consultation with the BLM and included in the POD. 

Procedures for Recovering Significant Discoveries of Vertebrate or Invertebrate Fossil 

Remains on Federally Administered Lands 

Although the likelihood of discovering paleontologically significant fossils on federal lands is 

considered remote, it could potentially occur during the proposed surveys, brush clearing, or 

construction activities. The field inspector or field paleontologist identifying a fossil of potential 

interest would be responsible for notifying the lead paleontologist immediately of the discovery. 

The lead paleontologist would, in turn, evaluate the significance of the finding relative to the 

salvage parameters. If the fossil was considered salvageable material, it would be recovered 

under the direction of the lead paleontologist and Pacific Connector. Pacific Connector proposes 

to designate the University of Oregon Museum of Natural and Cultural History as the repository 

for any salvageable material recovered from the portion of the proposed right-of-way located on 

BLM lands.