A cement company's plan to burn more tires draws opposition from South Seattle neighbors

Driving on Highway 99 or the West Seattle Bridge, you might recognize the gray domes and towers of the Ash Grove Cement Company along the Duwamish River.

What you might not know is that the facility, which is responsible for producing one of the most consumed materials in the world, burns whole tires in the process, some 1.2 million a year.

The practice has garnered significant opposition in the Duwamish Valley as Ash Grove has sought a permit that would remove the limit on how many tires the company can use to fire its kiln. Currently, tires can’t make up more than 30% of its fuel supply.

The Duwamish River Community Coalition, an environmental justice group, has sounded the alarm this year that burning more tires at Ash Grove would lead to worse public health outcomes for people living nearby and increase harmful greenhouse gas emissions.

The company disagrees and has said it “expects no increases in emissions” for any regulated pollutants with the change, according to the company’s application to the Puget Sound Clean Air Agency, which regulates polluters in the region.

The agency declined to comment on DRCC’s concerns, citing the pending review on Ash Grove’s permit and proposal. Since December, the agency has sought public comment on draft documents approving the change and modifying the company’s clean air permit. In that announcement, the agency wrote it had completed a review of the application and made a “preliminary determination that the proposal” meets regulations and should be approved.

In a statement, Ash Grove said it is “committed to being a good neighbor and has consistently invested in ensuring compliance with relevant permitting, environmental, health and safety, and other regulatory requirements at its Seattle Plant.”

But DRCC has called on the clean air agency to deny the permit and argued there was not sufficient testing done to prove emissions will not increase.

Groups that have joined to oppose the modified permit include Earthjustice, the King County International Airport Community Coalition, the Georgetown Community Council, Peace Lutheran Church, Orcas Business Park and the Georgetown Steamplant Community Development Authority, according to DRCC.

Cement and its emissions

Ash Grove’s Seattle plant is the state’s only kiln that produces powder cement from raw materials. According to documents filed to the Puget Sound Clean Air Agency, it relies on a mix of coal, natural gas, tires and other materials to power a kiln that produces the chemical reaction that creates what eventually becomes powder cement. The plant is capable of generating over 750,000 tons of cement each year.

Concrete, which is created when cement binds with water, sand and rock, is one of the world’s most consumed materials, making up highways, pipes, parking garages, stadiums and skyscrapers. In the past decade, Washington state used an average of 1.8 million metric tons of cement a year, according to the American Cement Association.

Cement production is also responsible for around 8% of humanmade carbon emissions worldwide. Emissions come from both the chemical reaction when cement is created that releases carbon dioxide and from firing the kilns.

In Seattle and Washington state, Ash Grove is a major greenhouse gas emitter, generating around 360,000 of metric tons of planet-warming gas in 2021, making it the largest polluter in South Seattle and South King County. While that amount pales in comparison to the state’s natural gas plants and refineries, Ash Grove’s emissions account for around 6% of the city of Seattle’s total greenhouse gas emissions in 2022 when including industrial sources.

The plant is also subject to regulation on its emissions of carbon monoxide, nitrogen dioxide, particulate matter, sulfur dioxide, mercury, dioxins and other compounds.

Those emissions contribute to poorer air quality in the Duwamish Valley that has led to worse health outcomes, said Mia Ayala-Marshall, DRCC’s clean air program manager.

The state’s Department of Ecology considers the area along the Duwamish River, including Sodo, South Park and parts of Beacon Hill, Tukwila and SeaTac, as one of the state’s 16 “overburdened communities highly impacted by air pollution” due to transportation and industrial emissions.

A 2013 study funded by the Environmental Protection Agency has also found that residents of South Park and Georgetown live eight years shorter on average compared with the average Seattle and King County resident and 13 years shorter compared with residents of the wealthier neighborhood Laurelhurst. The same study found that children in the Duwamish Valley have among the highest rates of hospitalization due to asthma than any other neighborhood in the city.

Why tires?

Old tires, which are cheap and plentiful, are commonly used in cement production across the country and are often portrayed as an alternative to other fossil fuels.

According to the EPA, “tire-derived fuel” has a higher heating value than coal and can be environmentally sound when used “in appropriate applications” and when proper pollution controls, testing and monitoring are in place.

A 2021 report on Washington’s cement emissions by the Clean Energy Transition Institute stated that the carbon intensity of Ash Grove’s Seattle Plant is “lower than the U.S. average” likely due to its use of natural gas and tires and that the plant has been “consistently recognized” for its energy efficiency.

According to the Puget Sound Clean Air Agency, Ash Grove’s 30% tire fuel limit was initially requested by the facility so it would be exempt from federal waste combustion regulations, which would have applied if the facility exceeded that limit. However, those regulations have since changed to no longer include tires, removing the need for a limit, according to the agency.

In Ash Grove’s application to remove the limit on “tire-derived fuel” in 2020, the company wrote that using tires as fuel is common at cement plants across U.S. and Canada and the company would like to “utilize more available tires in Washington and nearby states on an annual basis.”

The company also wrote that this change “does not result in any emission changes on hourly or annual averaging periods” and that its request will provide an “environmentally safe disposal option for the available used tires in WA.”

In a statement, Ash Grove said alternative fuels, which includes tires, have been used “safely in the cement industry around the world” and use of alternative fuel sources allow cement plants to benefit from using locally available materials that would otherwise end up in the landfill.

The company said removing the limit on tires will help it “align with industry best practice and ensure the plant will continue to provide high-quality cement for use in Washington and the Pacific Northwest.”

Where things stand for the opposition

Local residents are not so convinced.

The Duwamish River Community Coalition argues the change would threaten public health and called on the Puget Sound Clean Air Agency to deny Ash Grove’s modified permit. At least 250 community members have signed on to this campaign, according to Ayala-Marshall.

“This is one of the many issues that impact the Duwamish Valley, one more of those cumulative impacts that we have, so we obviously are taking it to heart to make sure that community is informed,” said DRCC executive director Paulina López.

In March, the group and Earthjustice filed a 500-page comment alleging that the draft permit for Ash Grove is based on outdated information and is “plainly illegal.”

The comment letter has also challenged Ash Grove’s assertion that emissions will not change and alleged there was insufficient review and monitoring done ahead of the preliminary approval.

The comment letter said Ash Grove is not a “trustworthy neighbor” and included copies of 58 permit violations issued to Ash Grove by the Puget Sound Clean Air Agency.

Members of DRCC are waiting for a response from the Puget Sound Clean Air Agency on its final permitting decision as well as the agency’s response to public comments. The agency has said the process is underway and declined to say when it will be finished.