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Riverbend Landfill

DEQ issued a solid waste closure permit for the Riverbend Landfill on Aug. 31, 2022.  The permit expires June 30, 2032.  The permit requires the landfill to be fully closed within eight years of the permit issuance date. The permit also allows Riverbend to continue to accept waste until capacity is reached, provided the eight-year time limit is not exceeded.

The landfill has approximately 59 acres that need to be capped or closed over the next eight years.  Approximately 12,604,000 cubic yards of waste have been disposed at the landfill and it has a remaining capacity of approximately 400,000 cubic yards.

Once the landfill is closed it will enter a post-closure care period. During this period the landfill will be required to continue with gas collection and control, leachate collection and treatment, groundwater monitoring, stormwater management, inspections, maintenance, and repair. 

DEQ permitting and oversight of the closed landfill will continue as long as there is a need for active supervision of the site, maintenance of the site, or maintenance or operation of any system or facility on the site.

Status of landfill operations

Riverbend Landfill notified DEQ that, beginning July 1, 2021, their public disposal and recycling area will be closed for acceptance of waste and recyclables. The landfill will continue to accept petroleum contaminated soil and select loads of solid waste to fill in areas to aid in achieving proper slopes and grades in preparation for final cover or capping. The landfill has curtailed the type and amount of waste accepted but it has not closed.
This change is reflected in the latest version of the facility's Operations Plan.

The Operations Plan refers to the facility's Special Waste Management Plan.​

During a landfill's life, the landfill operator installs a watertight cover over portions of the landfill that have reached capacity. Approximately 28 acres of the 87 acres at Riverbend Landfill have already been capped.​

The closure and post-closure plan for Riverbend Landfill was last approved in February 2023​.

​Landfills are required to set aside funds sufficient for proper closure of the landfill and 30 years of post-closure maintenance and monitoring. Estimates of the necessary funding must be revised every year. 

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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 are:

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Permitting information

​DEQ is responsible for managing three permits for the facility:

These permits contain the limits, standards, monitoring, testing, recordkeeping, and reporting requirements based upon Oregon statutes, DEQ rules, or federal rules.

DEQ regulation of Riverbend Landfill leads to inspections, reports and other documents. Agency records relating to Riverbend are public records and many are found on this webpage. Additional records are available at public request through DEQ's Public Records Request Center.​

​The Title V operating permit requires annual reports by the facility certifying compliance or noncompliance with the various conditions in the permit. Annual reports containing this compliance certification as well as other operating data and annual emissions estimates.


Proposed closure permit: Public comment period

The operating permit for Riverbend Landfill has been administratively extended since 2009 because of uncertainty about the landfill's future operation and proposed expansion plans. Riverbend Landfill notified DEQ that, beginning July 1, 2021, their public disposal and recycling area would be closed for acceptance of waste and recyclables. In light of that development, and the County's denial of applications related to the 29-acre expansion, DEQ requested that the landfill submit an application for a closure permit. Riverbend Landfill submitted this application on Jan. 27, 2022.

Under the proposed closure permit, Riverbend Landfill will continue accepting waste until it has used all its capacity within the permitted 87-acre area. The landfill will also install an impermeable final cover on uncapped portions of the landfill once they are full. The draft permit requires that final closure be completed within eight years of the date of permit issuance. The closure permit does not prevent the landfill from continuing to accept waste in the approximately eight years prior to closure and does not prevent the applicant from applying for a permit modification an expansion in the future.

Public hearing

A virtual public hearing was held on June 22, 2022. 

On May 23, 2022, the Oregon Department of Environmental Quality issued a request for comments on the proposed solid waste closure permit for the Riverbend Landfill.  On June 22, 2022, DEQ held an informational meeting and public hearing. DEQ extended the public comment deadline from June 27 to 5 p.m. July 11, 2022 based on comments received at the hearing. DEQ received both written and verbal comments.

​Waste Management has permit coverage under the 1200-Z National Pollutant Discharge Elimination System general permit with DEQ for industrial stormwater discharges at Riverbend Landfill. This general permit authorizes the facility to discharge industrial stormwater to surface waters of the state. This general permit may be reviewed on DEQ's Industrial Stormwater Permits website, along with a variety of technical assistance documents.

The general permit requires the facility to create and maintain an accurate Stormwater Pollution Control Plan and site maps that describe how the facility manages industrial stormwater, what specific controls are in place to achieve the goals of the permit, where stormwater monitoring occurs, and where stormwater discharges from the facility, among many other details as outlined in Schedule A of the 1200-Z permit.

The general permit requires the facility to collect samples of industrial stormwater, analyze the stormwater samples for specific pollutants, and summarize the monitoring results on Discharge Monitoring Reports four times per year. Refer to Schedule B of the 1200-Z permit for the monitoring requirements and reporting frequency.

Other reports may be submitted throughout the year, such as corrective action reports and revisions to the Stormwater Pollution Control Plan. A summary of reporting requirements can be reviewed on page 31 of the current 1200-Z NPDES permit or on page 37 of the 1200-Z permit that will become effective July 1, 2021.​

Copies of the most recent Stormwater Pollution Control Plan, Discharge Monitoring Reports, or any other available documents associated with this facility may be requested from DEQ through the Public Record Request Center.

​​Boring Logs

Numerous studies of hydrogeologic conditions have been conducted by Waste Management's consultants.  These are based on boring logs that are recorded each time a well or piezometer is drilled. Monitoring wells are used to draw water samples for lab analysis, and to measure the elevation of the groundwater surface. 

Elevations of groundwater relative to bottom of waste

Waste Management's consultant prepared a report in November 2012 that assesses groundwater elevations relative to the elevation of the bottom of waste at the landfill. As shown in this report, the elevation of groundwater is higher than the bottom of waste in portions of the landfill. It is important to note that the waste lies above a liner that prevents the escape of contaminants. The liner system has become increasingly substantial as new sections of the landfill have been built, to provide a more effective barrier between waste and groundwater.

The report does not evaluate the three oldest cells (Modules 1 through 3), whose liner systems consist of low-permeable soil but do not include plastic geomembranes. This is because the consultant was unable to find base grade information for these older landfill cells.

​Water quality 1200-Z permit

Documents related to the 1200-Z permit for Riverbend Landfill include:

Groundwater ​Quality

There 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 not shown the presence of volatile organic compounds in any of the wells, other than the one mentioned above.

​Inspections 

DEQ officials inspect Riverbend Landfill in accordance with the facility's air, land and water quality permits.

Air quality inspection reports

The U.S. Environmental Protection Agency and the Title V operating permit program require that inspections of the facility occur at least every other year. Prior inspections of the facility have shown it to be in compliance with the Title V permit conditions. The inspection reports for 2010 and 2012 are found below:

Solid Waste inspection reports

Water quality inspection reports

The NPDES 1200-Z General Stormwater Permit compliance can also be evaluated through an on site compliance inspection.

Nuisance odor investigation​

The goal of DEQ’s Nuisance Odor Strategy is to resolve odor complaints with cooperative voluntary remedies instead of using enforcement actions to address the issue.  DEQ staff identified possible violations at Riverbend Landfill and referred those violations to EPA for further investigation and potential enforcement action.  In September 2021, EPA completed its investigation and enforcement action which resulted in a consent agreement between EPA and Riverbend Landfill and assessed a civil penalty of $104,482.  Since enforcement action has been taken, use of the Nuisance Odor Strategy is no longer appropriate and the nuisance odor study has been closed.​

Potential for migration of the South Yamhill River
Residents have expressed concern about the potential for the South Yamhill River to migrate over time, because it could therefore move closer to the landfill. This issue was evaluated in a September 2012 report by Waterways Consulting, Inc. The report concludes that the river has not migrated in this direction substantially in the past. Among the factors considered, the report points to the presence of 3,000-year-old Native American artifacts found in the land between the river and the landfill. 

Topographic Maps

Landfill contours are documented using aerial photography every year.

Contact

Dylan Darling
Office of Communications and Outreach
541-600-6119