The comments are in; we now await the response from the Department of Environmental Quality (DEQ) to the many suggestions for revising its proposed Closure Permit for Riverbend Landfill.
Most of the comments focus on particular language in the draft Permit, asking for restrictions that are more specific or for additional public participation. But one comment in particular focuses on important information that anyone living or working near Riverbend or downstream on the South Yamhill River -- or upstream, for that matter -- needs to know in order to plan for their own safety.
Richard McJunkin is a licensed and certified engineering geologist and hydrogeologist with more than 50 years experience evaluating landfills for compliance with seismic standards and regulations. For several years now, he has tried to share his expertise with DEQ, but no one in the agency has been listening. The latest evidence of this is the draft Permit's acceptance of a $15 million set-aside as sufficient to handle any "worst-case" scenario -- for example, a catastrophic failure of the dump in a 9.0 Cascadia subduction zone earthquake.
Per McJunkin's analysis, DEQ should be requiring Riverbend to set aside more than $750 million to pay for clean-up and compensate land and animal owners for damage resulting from a landfill collapse. His comment is worth reading in full. (Note: McJunkin also submitted comments regarding water contamination; we will feature those comments in a subsequent post.)
To: Permit Coordinator (deqwr.solidwastepermitcoordinator@deq.oregon.gov)
Oregon Department of Environmental Quality (DEQ)
I recommend that Oregon Department of Environmental Quality (DEQ) NOT ACCEPT “2021 Annual Financial Assurance Update and Recertification, Riverbend Landfill; Solid Waste Disposal Permit No. 345 Yamhill County,” or “Final Engineered Site Closure and Post-Closure Plan, Riverbend Landfill, McMinnville, Oregon” (CP).
My justification for this recommendation is that significant financial closing costs for Riverbend Landfill (RL) were not only omitted from planning but not even considered in the scenario for establishing Closing Costs.... [The] scenario for total financial closing costs for RL, in no uncertain terms, should have addressed a catastrophic seismic foundation failure from an earthquake. It appears that specific geologic sampling data from drilling data, that exposed wide-spread liquefiable sands to be everywhere present in the geologic foundation for RL, were ignored. If considered, these sampling data would have forced recognition of the landfill long-term vulnerability.
At least some of the liquefaction data collected by WMI [Waste Management, owner of RL] were in characterization efforts for constructing the Mechanically Stabilized Earthen (MSE) Berm; however and for whatever reason, liquefaction data were withheld from public access for approximately five years. During public WMI/DEQ meetings for the RL MSE Berm, the presence of liquefaction in the geologic foundation of RL was presented by the public as a big concern, especially as WMI sampling data indicated liquefiable sands were everywhere throughout the geologic foundation. DEQ, however, told the public that “No liquefiable sands were present beneath RL” even though sampling data from drilling operations at this same time period showed by laboratory analyses that liquefiable sands were wide-spread in the geologic foundation of RL. Samples, also verified as liquefiable by WMI laboratory analyses, appear to be present in 30 to 40 percent of subsurface sandsin the RL foundation.
Seismic/Liquefaction Considerations
At the time the landfill was permitted [1980], Oregon seismic issues were only beginning to be recognized as a potential threat to engineered structures. Today, news agencies routinely present forecasts of a pending Cascadia Fault Zone (CFZ) earthquake of Magnitude 9 on the Richter Scale. These earthquake forecasts are based on recent scientific research that indicates 19 earthquakes, caused by a complete break of the CFZ, have occurred in the last 10,000-years, five...in the last 2,000-years. Besides Magnitude 9 events, many magnitude 6, 7, and 8 earthquakes also occurred with epicenters within 100-miles of the Pacific coast.
The last full-break CFZ earthquake is well-dated and occurred in late January 1700, more than 100 years before the arrival of the Lewis and Clark expedition. Given that five major earthquakes have occurred in the last 2,000 years and that the last Magnitude 9 CFZ earthquake was 322-years in the past, the PNW is well into the window for a repeat full-break of the CFZ that will result in a Magnitude 9 devastating earthquake. How could RL propose and DEQ accept the total closing cost amount now set at a maximum cap of $15,425,086 given this pending earthquake threat? How could they, and who will pay for remediating a total failure of RL??
When the MSE Berm was being permitted, geologic data, confirmed by WMI laboratory analysis, showed that even though the landfill itself may be stable when exposed to a magnitude 9 earthquake, the geologic foundation for the landfill would fail by foundation liquefaction during an earthquake of even moderate magnitude. Totally overlooked (disregarded-?) in the RL Closure Plan was any mention of these liquefaction data and the single largest long-term threat to RL: Earthquakes
Seismic Wave Amplification: Overview
From the lack of comments in the CP, WMI and DEQ also appear to not fully recognize, or appreciate, that RL geologic site conditions favor amplifying seismic wave energy during earthquakes (Seismic Wave Amplification). This geologic situation is given to make shaking, even from small earthquakes, more intense. Seismic wave amplification will be generated at RL for one classic reason: loose geologic sedimentary river deposits overlie hard well-cemented bedrock. In this setting, seismic waves from deep underground earthquakes travel upward at thousands of feet per second in dense well-cemented rock and then propagate into soft near-surface sedimentary materials that have seismic velocities less than 1,000 feet per second. As these high-velocity waves are transmitted into near-surface much lower seismic velocity loose sands and gravels, conservation of total seismic wave energy must be maintained. To conserve total wave energy requires that seismic wave amplitude be increased significantly, a given, with some localized shaking severe. This setting translates into significantly higher ground shaking for RL that undoubtedly exceeds what was used in Peak Ground Acceleration (PGA) stability calculations by WMI and approved by DEQ.
In geologic settings for amplifying seismic wave energy similar to that of RL, two examples are well-known: 1) Olive View Hospital in San Fernando, California, which was destroyed in the 1971 San Fernando earthquake (magnitude=6.6) and 2) the Cypress Viaduct freeway structure for the Interstate 880 approach to the Bay Bridge from Oakland that failed by collapse during the 1989 Loma Prieta earthquake (magnitude 6.9) and also killed 42 people. In both of these cases, the structures were built on slow-velocity geologic materials overlying higher velocity bedrock with the low-velocity near-surface geologic materials amplifying seismic wave energy.
Even though both liquefaction and seismic wave amplification phenomena are associated with the RL site, WMI is committed to persist with the opinion that these threats are more conceptual than reality; therefore, not of significant threat to RL seismic stability. As WMI minimizes both concepts, they have had the full support of DEQ, which apparently also considers seismic wave amplification and liquefaction as incapable of generating any significant RL earthquake damage. Such a HUGE mistake!
Conclusions and Recommendations
The data are clear that RL is geologically subject to Seismic Wave Amplification. This phenomenon will increase ground shaking for any given earthquake and be a threat to RL surface structures. To address seismic data gaps that could be generated during any earthquake impacting RL, I propose that DEQ ask WMI to install a permanently affixed “strong-motion accelerograph” in an on-site location free from structurally influenced ground motion. This accellerograph would measure strong earthquake ground motion during seismic events and provide for collecting valuable engineering data to analyze precise ground motions, including PGAs, as well as enhanced motion velocities and displacements. Data from such an accelerograph would be beneficially invaluable for seismic engineering concerns, especially if RL sustained damage or underwent total failure during an earthquake. This installation may be of technical interest to US Geological Survey (USGS), which has an earthquake strong-motion monitoring program that installs and monitors accelerographs. In other words, USGS may install and service such an accelerograph free of charge.
In my more than 50-years of geologic experience, one thing has been deeply learned: moving earthen materials is expensive and time consuming. Further, the type of material being excavated and distance moved determines the final cost, and moving clean soil is much-much cheaper than moving contaminated soils. It is my estimate that a total seismic failure of RL would require all of the landfill materials to be ‘eventually’ excavated, loaded, hauled, and dumped, possibly temporarily for later movement to a final containment site.
In any catastrophic failure, RL waste and leachate would be comingled into huge quantities of soil, water, and pasty, leaking exposed landfill waste, all needing to be excavated and removed. Necessary excavation, containment, transportation, and disposal costs to an approved site could easily be in the range of $600 to $800 per cubic yard. With cost overruns and the fact that the waste needing to be remediated could be potentially hazardous, the final cost per cubic yardage could be $900 to $1,000 per yard.
At these rates (which address only remediating landfill waste), the minimum cost for a catastrophic failure is estimated, on the low end, to be between $500-million and $650-million dollars; a more realistic total of $750-million to $900-million is probably more correct. Where did WMI generate a dollar amount in the CP, that was approved by DEQ, of only $15,425,086, which is almost a humorous amount? Again, who is supposed to pay in the case of a total landfill failure? The citizens of Yamhill County who once voted to approve using the landfill?? The citizens of Oregon???
[The question is whether] the RL geologic foundation will perform without damage in future earthquakes. What should be especially considered are WMI soil samples, confirmed by laboratory analyses, showing loose liquefiable sands being wide-spread in the RL geologic foundation. An answer needs to be provided by DEQ.
Closing Statements
After personally reviewing and studying RL geologic and seismic data from drill logs and other measurements, and using my 50-years of professional drilling and characterization experience, it is clear to me that the geologic foundation of the RL is very fragile to seismic acceleration. In fact, it is much more fragile than WMI and DEQ have ever admitted. The high percentage of drill logs (30 - 40 percent) showing the presence of liquefiable sands proves RL is a seismic accident waiting to happen. Another condition is also set: Seismic failure of RL will provide for the single largest environmental disaster in the post-European settlement-history of Oregon.
RL permitting and closure efforts in no way support the DEQ ‘Mission Statement.’ RL failure debris will be a long-term issue with wide-spread watery contamination everywhere down-gradient from the landfill. The South Yamhill River, by its nature, will assist in spreading RL contamination toward McMinnville, Newberg, and beyond to Portland. Resources for addressing remediation of this disaster will not be available for months, and possibly years. And all the while, Yamhill County residents will be forced to live in conditions caused by failure of the landfill; stinking conditions that would possibly not have occurred if geologic and seismic data were fully recognized (understood) by DEQ and used to address RL technical reviews. Upon any failure of RL, especially from seismic sources, DEQ will encumber a huge long-term debt of responsibility to the citizens of Yamhill County and Oregon, who will be the ones truly experiencing post-disaster environmental effects. These individuals will be the ones who bear the very uncomfortable burden of living with a failed RL reality.
It is professionally disappointing to me that WMI very fully understands the threat from catastrophic geologic details underlying RL and that the details will provide for a total collapse during any future seismic event that lasts more than a few seconds. This fact is also understood by DEQ, which, it appears, fully supports the inadequate CP being submitted by WMI to the citizens of Oregon. Further, no explanation is provided by WMI or DEQ for apparently keeping confidential from public access, during a critical permitting period, the full scope of technical understanding for geologic and seismic liquefaction conditions underlying RL. Even though WMI and DEQ always knew the true seismic risk from geology underlying RL, it is minimized and disregarded. And the damaging data have been in the WMI and DEQ records for years.
RL Closure needs a Final Closure Plan that financially addresses a catastrophic event turning RL closure operations into the monumental remediation of a totally destroyed landfill. Closure should only be completed with a full commitment by WMI to adhere to future and long-term maintenance issues that also include a total landfill remediation from a PENDING extreme and scientifically forecasted Cascadia Fault Zone (CFZ) earthquake. The future occurrence of a magnitude 9 earthquake along the CFZ is a given. WMI has stated and shown by mathematical calculation that RL will be completely stable in a magnitude 9 earthquake. The landfill was sold to the Oregon public under the pretense of seismic stability; therefore, WMI should fully indemnify the landfill against seismic failure. Otherwise, the people of Oregon will suffer the long-term financial responsibility to remediate a failed landfill whose geologic foundation was positively known to be seismically unstable by WMI and DEQ, which has excused the geologic facts from Closure consideration. A more realistic ‘starting’ dollar amount of financial assurance for RL should be at least $750,000,000 to address a total landfill failure knowing that when such an event occurs, the final cost to remediate RL will be one billion dollars ($1,000,000,000) or more--and it is unavoidable.
