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Local Projects - Riverbend Landfill
For a summary of this project and current updates, please visit our new overview page.
DEQ is responsible for managing three permits for the facility:
Solid Waste Disposal Permit No. 345
Stormwater 1200-Z Discharge Permit No. 13016, File No. 106959
Significant Modification to Permit - 2012
Significant Modification - Review Report - 2012
Public Hearing Slides
These permits contain the limits, standards, monitoring, testing, recordkeeping, and reporting requirements based upon Oregon statutes, DEQ rules, or federal rules.
Following are links to key documents related to Riverbend Landfill.
Environmental Monitoring Plan
The facility's permits require the company to monitor environmental conditions at the site in accordance with the facility's Environmental Monitoring Plan.
The facility records the results of this monitoring in an annual environmental monitoring report. The most recent of these reports is found at this link:
DEQ Inspection Reports
Leachate is rainwater that percolates through the waste in a landfill. It is captured by the landfill's leachate collection system and conveyed to a storage pond prior to disposal. In 2011, 21.6 million gallons of leachate were generated at Riverbend Landfill. Approximately 11.9 million gallons were trucked to an offsite treatment facility. The remaining 9.7 million gallons were applied to a 43-acre poplar tree farm on the landfill property through a drip irrigation system. Soil and groundwater are monitored to evaluate environmental conditions at the poplar tree farm. These are documented in an annual report, the most recent of which can be found here:
Recent modifications to the monitoring plan for the poplar tree farm are summarized in the following report:
Floodplain and Flood Way Issues
There was a discrepancy regarding the location of the landfill relative to floodplain and flood way boundary, as shown on flood insurance maps issued by the Federal Emergency Management Agency, or FEMA. On May 31, 2012, Waste Management submitted a request to FEMA for a Letter of May Revision to address this discrepancy. Portions of this submittal are found here:
Letters to affected property owners
FEMA form 1
FEMA form 2
Figure 1 - Work Map
Flood Map 395
Flood Map 415
On December 26, 2012, FEMA issued the requested Letter of Map Revision, which indicates that the landfill is outside the floodplain and flood way boundaries. A copy of the Letter of Map Revision can be found here:
Letter of Map Revision issued by FEMA, December 26, 2012
Mechanically Stabilized Earthen Berm
Waste Management plans to build a mechanically stabilized earth berm along the west side of the landfill. The berm is an earthen wall reinforced with layers of plastic geogrid (Geogrid is a plastic sheet with openings used to reinforce soil structures). This berm would be a maximum of 40 feet high, with a steep outer face (1 horizontal to 3 vertical). It would allow an additional one million cubic yards of disposal capacity. The area of the landfill, currently 84 acres, would increase by 4 acres as a result of the new berm.
More information about the MSE berm is found in a March 2012 report, which is available at the following five links:
March 22, 2012 Phase 1 MSE berm design report - part 2 of 4
March 22, 2012 Phase 1 MSE berm design report - part 3 of 4
March 22, 2012 Phase 1 MSE berm design report - part 4 of 4
Applications for landfill expansions must be accompanied by a Land Use Compatibility Statement issued by the local authority which, in this case, is Yamhill County. A copy of the Land Use Compatibility Statement is here.
Review of geotechnical issues concerning the proposed MSE berm are documented in the following correspondence between the consultant for Waste Management (Geosyntec) and the consultant for DEQ (Hart Crowser). Also provided below are review documents from the consultant for opponents of the landfill (Kleinfelder).
Hart Crowser documents
DEQ has had several discussions with the Oregon Department of Geology and Mineral Industries regarding the seismic analysis for this site. Communication between the agencies includes a January 16, 2013 letter, in which DOGAMI recommended that DEQ consider the magnitude 9.0 Cascadia Subduction Zone earthquake in designs for the landfill. Following that letter, DEQ and DOGAMI met twice to discuss the seismic analysis. These discussions are summarized in a Feb. 22, 2013 letter from DEQ to DOGAMI.
A discussion of maintenance and monitoring of the mechanically stabilized earthen berm is also included in the attached document.
Construction drawings and specifications
Groundwater QualityThere is localized groundwater contamination, as indicated by the presence of volatile organic compounds in one groundwater monitoring well. Volatile organic compounds are of particular importance in evaluating a landfill's effects on groundwater for a couple of reasons. They move fairly quickly through groundwater and therefore provide an early indication of a problem. Unlike other contaminants, such as metals, most volatile organic compounds do not occur in nature, so if they are detected, they are likely from the landfill. We suspect the contaminants found in this well may have been carried by landfill gas moving under the ground. Concentrations have dropped over the years, primarily because the owner has installed an extensive landfill gas removal system.
Low concentrations of volatile organic compounds have also been detected in other wells but subsequent sampling has not found the compounds in these wells. The permit requires that if a volatile organic compound is detected and is not due to sample handling or lab contamination, the well must be resampled to confirm the presence of that contaminant. Confirmation sampling has never shown the presence of volatile organic compounds in any of the wells, other than the one mentioned above.
More information regarding this is found in the attached report:
Monthly reports will be posted to this website as they are received.
Stormwater Pollution Control Plans
The following links include the SWPCP and related revisions received by DEQ:
Pollution Control Plan OCTOBER 2012
Draft Letter DECEMBER 2012
Pollution Control Plan Checklist
Renewal Application APRIL 2012
Cover letter, revised plan APRIL 2011
Revised plan APRIL 2011
Updated site maps for plan JUNE 2010
Response to comments, permit renewal NOVEMBER 2008
Change in Best Management Practices MARCH 2007
Discharge Monitoring Reports
The following links are the DMRs from Riverbend Landfill:
2013-2014, Monitoring Waiver , Monitoring Waiver 2
Tier I Corrective Action
The previously issued 1200-Z General Stormwater permit (expired in 2012) required facility to submit an Action Plan to DEQ for benchmark exceedences. Copies of the Action Plans are available through DEQ Public Records Request
Future stormwater plans and discharge monitoring reports will be posted as they are received.
Impacts to the creek were evaluated in a March 13, 2014 report prepared by Waste Management’s consultant, CH2M HILL. The report concludes that “No mortality of aquatic flora or fauna was observed during either site visit [conducted on February 12 and 21, 2014]. Overall, the impact to aquatic biota was estimated to be minimal on the basis of the high flows of the unnamed creek and the South Yamhill River, and the comparison to aquatic water quality criteria and human health criteria.” A copy of CH2M HILL’s report is found here.
DEQ inspected the site on February 12, 2014. The inspection report, along with photographs, is found here. DEQ concurs with the findings of the consultant's report. However, in light of the release of leachate to the creek, DEQ is pursuing enforcement action against the landfill.
Another consultant for Waste Management, SCS Engineers, sampled soil in the area between the landfill and the creek through which the leachate traveled. Results of the SCS study were provided in a report found here.
A previous seep was found on January 28, 2014, approximately 400 feet west of the February 10 seep. This leachate migrated beyond the perimeter of the landfill, but did not travel far from the landfill perimeter. This release was from an old perimeter French drain that was clogged as the result of recent construction of a stormwater diversion swale. The drain had been installed during construction of the landfill cell to convey leachate to the leachate collection line that runs to the onsite leachate storage pond. To address this problem, the landfill contractor removed all drain rock from the French drain along that portion beneath the stormwater diversion berm. Between January 28 and 29, this rock was removed and the area was backfilled with compacted clay. Four vertical 12-inch sump pipes were installed and backfilled with drain rock. Soil from the impacted area north of the landfill was sampled on January 29. Soil impacted by the leachate release was then excavated, and a vacuum truck was used to remove standing stormwater that may have been contaminated by the release. Soil from this area was resampled on January 31. Results were provided in a technical memorandum dated March 14, 2014, prepared by SCS Engineers. These results indicate that residual contaminant concentrations are below safe levels.
Well and piezometer boring logs: 2010-2012
Piezometer boring logs: 1993-2000
Elevations of groundwater relative to bottom of waste
Potential for migration of the South Yamhill River
Closure and post-closure financing
Financial assurance documents are provide here:
Expansion of Landfill Gas Management System
Recent Cell Construction
Contact InformationBob Schwarz: 541-298-7255 ext. 230, toll free at 800-452-4011, or by email
DEQ Northwest Region