Comprehensive Solid Waste Management Plan open house

Washington State law (RCW 70.95.080) requires that counties have a coordinated plan for handling regional waste. King County’s current Comprehensive Solid Waste Management Plan was adopted in November 2019 and outlined goals and strategies for the next 6 years, with consideration for the next 20 years.

The plan guides the many public and private elements that make up the regional solid waste system, including how waste is disposed. That plan is now under review for proposed updates to reflect the current needs of the King County waste system.

Because our county’s only disposal site, Cedar Hills Regional Landfill, is expected to reach capacity within 10–20 years, it is important that updates to the Comprehensive Plan also look at alternative waste disposal options for our region now.

Environmental Impact Statement review process

State law requires that as the County evaluates new methods for waste disposal it also evaluates the possible environmental impacts of each option. To meet that requirement, the County is developing a supplemental Environmental Impact Statement (EIS) for the 2019 Comprehensive Plan.

An EIS is the most rigorous and comprehensive type of environmental review required under Washington's State Environmental Policy Act (SEPA). It involves reviewing a large range of environmental components that could potentially be impacted by a project or plan. King County prepared an EIS in 2019 as part of adopting the current Comprehensive Solid Waste Management Plan. A preliminary update to that plan is also underway now. This supplemental EIS will further analyze the possible environmental impacts of the various disposal methods that are being proposed as part of that update.

View the current Comprehensive Solid Waste Management Plan

View the preliminary updates to the Solid Waste Management Plan

The draft of the supplemental EIS provides a detailed analysis of those proposed updates, including probable significant environmental impacts, reasonable alternatives, and potential mitigation measures. The draft supplemental EIS is also shared with the public, agencies, and tribal governments so that they can review and provide feedback. This feedback helps refine the proposal into a Final SEIS.

After the County issues the Final EIS, it can be used to decide whether to approve, approve with conditions, or deny the proposal. If approved, it will be used to guide decision making on the County's future disposal method.

Waste disposal options

As part of the supplemental EIS planning process, King County studied five potential long-term waste disposal methods to prepare for the eventual closure of the Cedar Hills Regional Landfill. As a result of those studies, three potentially viable approaches were identified: Waste Export by Rail, Waste-to-Energy utilizing mass burn technology, and a hybrid approach that combines Waste Export by Rail with a smaller Waste-to-Energy facility with mass burn technology.

Alternative 1: Waste Export by Rail (WEBR)

Under this alternative, municipal solid waste (everyday garbage generated by homes, businesses, schools, and institutions) would be exported by train to a landfill outside of King County. Prior to export, the waste would be sent to a King County transfer station to be prepared for shipment. Each shipping container, capable of holding 25 to 28 tons of waste, would be double stacked onto railroad cars for transport to an existing regional landfill in eastern Washington or Oregon.

Waste export by rail is a common way to transport municipal solid waste in the region. The City of Seattle and several neighboring jurisdictions, including Kitsap County, Thurston County, Skagit County, and Snohomish County, currently export their solid waste by rail.

Since this option would use existing infrastructure, it would provide cost-effective waste transport and disposal.

Alternative 2: Waste-to-Energy Facility with Mass Burn Technology (WTE-MB) + Ash Export

Under this alternative, municipal solid waste would be taken to a WTE-MB facility for incineration. WTE-MB facilities typically create energy that can be used directly for industrial processes, heating, or generating electricity. The facility would be expected to produce enough energy to power approximately 17,650 homes each year. King County could use the generated electricity to power the facility itself, sell it to out-of-state customers, or sell it to in-state wholesale customers.

About 5% of the processed material, or approximately 33,350 tons per year, would be recovered as metal for recycling. About 20% would remain as ash, which would require the use of rail to transport the remaining ash to the same landfills identified in Alternative 1. This option has the potential with offsets to offer the lowest carbon impacts; however, it is also the most expensive option because it would require siting, constructing, and permitting a new facility that uses the best available controls to maintain air quality.

Alternative 3: Hybrid

This alternative combines waste export by rail with a smaller WTE-MB facility. About half of the municipal solid waste would be processed at the facility, while the remaining waste would be transported by rail to the same landfills identified in Alternative 1.

About 5% of the materials processed through the WTE-MB would be recovered for metal recycling, and the ash remaining after incineration would be transported by rail to a disposal site. The facility would generate enough energy to power about 9,700 homes each year.

Because this alternative combines mass burn technology and rail export, its environmental effects, transportation needs, and facility-related impacts would fall between those of Alternatives 1 and 2.

Comparison summary of alternatives

Category	Alternative 1: WEBR	Alternative 2: WTE-MB	Alternative 3: Hybrid
What happens to the waste	Send King County's municipal solid waste to existing landfills in eastern Washington or Oregon.	Burn King County's municipal solid waste at a new facility and send the remaining ash to existing landfills in eastern Washington or Oregon.	Burn approximately half of King County's municipal solid waste at a smaller facility and send the rest, along with the ash, to landfills by train.
Estimated greenhouse gas emissions	Highest Equivalent to 13,000 cars driving on the road for one year.	Lowest Equivalent to 4,300 cars driving on the road for one year.	In between Equivalent to 8,200 cars driving on the road for one year.
New facilities	Requires a new waste-sorting facility but relies on existing rail and landfill infrastructure.	Requires a new waste-sorting facility and a full-size waste-to-energy facility on a 25-acre site.	Requires a new waste-sorting facility and a smaller waste-to-energy facility.
Materials sent by rail	Trains would carry about 667,000 tons of waste.	Trains would carry about 133,000 tons of ash.	Trains would carry about 300,000 tons of waste and 73,000 tons of ash.
Train traffic and crossings	Highest rail use Additional train traffic could delay drivers at rail crossings by up to about 2 minutes, 6 to 12 times a week.	Lowest rail use Railroads would transport less than one full train of ash per week.	Moderate rail use Additional train traffic could delay drivers at rail crossings by up to two minutes. Railroads would run one to two new trains per week or add rail cars to existing trains three to four times per week. Each new train could delay traffic at a crossing by about two minutes.
Energy and recycling	This alternative would create energy in the form of landfill gas but would not recover metal.	The new facility would produce enough energy to match the annual electricity use of about 17,650 homes and recover about 33,000 tons of metal.	The new facility would produce enough energy to match the annual electricity usage of about 9,700 homes and recover about 18,000 tons of metal.
Key environmental considerations	More waste transported by rail, increasing fuel use, rail activity, traffic near facilities, and delays at some railroad crossings.	Less waste transported by rail, but burning waste would produce air pollution, including a small amount of toxic pollutants. Localized earthwork, dust, runoff, vegetation disturbance, noise, traffic, and land use impacts may result from construction of a new WTE-MB facility.	Combines the effects of rail transport and waste burning, but at lower levels than the alternative that relies on either method.

How to share your feedback

Members of the public are invited to review and comment on the draft SEIS. The County will consider all comments on the draft plan that are received between October 6 and November 20, as well as comments received during earlier SEIS scoping periods, during their development of the Final SEIS.

General comments on the long-term disposal options will continue to be accepted after the formal comment period for the supplemental EIS has closed.

Mail: Comments sent by mail should be addressed to King County Solid Waste Division, Attn: Patty Liu, Project Manager, 201 S. Jackson Street, Suite 6400, Seattle, WA 98104-3855.
Comment Deadline: The deadline for submittal of comments is 11:59 p.m., November 20.

At a public meeting: Comments may be submitted during an in-person public meeting (see schedule below) in writing or via testimony with a court reporter. The County will also host an online public meeting for verbal and written comments.

Online: Send comments via email to SWDCompPlan@kingcounty.gov or via the online open house comment form below.

Public meetings

King County will host in-person and virtual meetings where you can provide verbal and written comments. Each comment will be recorded and transcribed as an official comment. Any questions during the Q&A portion of the meeting will not be considered official public comments.
Attend a meeting:

Thursday, Oct. 22, 6-7 pm
Kent Commons Community Center (Olympic Room)
Tuesday, October 27, 6-7 pm
White Center Library
Thursday, Oct. 29, 12-1 pm
Via Zoom: https://us06web.zoom.us/j/82109140166
Tuesday, Nov. 3, 6-7 pm
Third Place Commons
Tuesday, November 10, 6-7 pm
Highland Middle School