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Local Projects - Riverbend Landfill
Groundwater sampling results taken in May 2016 at one of the monitoring wells at Riverbend Landfill showed an exceedance of four water quality parameters. Monitoring well number 12A exceeded limits for bicarbonate alkalinity, dissolved magnesium, dissolved sodium, and total dissolved solids. These are nontoxic substances that occur in nature. However, the concentrations found in this well may indicate a change in groundwater quality related to the landfill.
The landfill’s permit required the well to be resampled, which occurred in June 2016. These results confirmed exceedances for three of the four parameters: bicarbonate alkalinity, dissolved magnesium and dissolved sodium.
In response to these results, Waste Management prepared a work plan to assess the source of the change in groundwater quality. That work plan is provided here:
Waste Management has submitted an application for a 29-acre expansion of the landfill. DEQ is reviewing the application documents, which include:
The U.S. Army Corp of Engineers issued a public notice related to a proposed dredge and fill permit at the Riverbend Landfill. The public notice incorporates the public notice for DEQ’s 401 Certification for the project.
DEQ delays action on expansion request pending valid Land Use Compatibility Statement
DEQ is not currently acting on a permit modification request that would allow an expansion of Riverbend Landfill. The request is on hold until DEQ receives a valid Land Use Compatibility Statement, or LUCS.
The landfill’s owner, Waste Management, had submitted the compatibility statement with the modification request. However, the land use decisions supporting that compatibility statement were legally challenged, and the Land Use Board of Appeals recently remanded a portion of the decision that underlies the LUCS back to Yamhill County for further consideration.
DEQ will wait until Yamhill County issues a new decision or DEQ otherwise receives a valid LUCS supporting the modification to the permit before moving forward with permitting decisions on the expansion.
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.
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
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:
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:
Discharge Monitoring Reports
The following links are the DMRs from Riverbend Landfill:
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.
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:
Recent Cell Construction
Contact InformationBob Schwarz: 541-298-7255 ext. 230, toll free at 800-452-4011, or by email
700 NE Multnomah St., Suite #600