Friday, August 16, 2019

Dust buster: A plan to manage dust in and near Wallula

Things looked a lot different when the Lewis and Clark expedition camped at the confluence of the Snake and Columbia rivers in 1805 and traded with the Nez Perce. That spot is now Sacajawea Historical State Park, surrounded by the growing metropolis of the Tri-Cities – something that Lewis and Clark could hardly have imagined.

One thing the explorers might well recognize 200 years later, though, is the dust frequently kicked up as winds blow across the dry terrain. Indeed – and unfortunately – the dust in recent decades may be worse than in 1805 due to the impacts of modern life.

Near the Tri-Cities, hot, dry summers make soils more vulnerable. Heavy southwest winds pick up dust from the nearby Horse Heaven Hills and send it through Kennewick and into Wallula at times. Industrial growth, agriculture activity and increasing population have also contributed to billowing dust at times.

Lewis and Clark's route through eastern Washington

What's happening in Wallula?

Back in the late 1980s, frequent problems with wind and dust pushed the area around Wallula – a few miles downriver from Sacajawea Park — into violation of federal air quality standards.  In 1990, the U.S. EPA officially designated the area as being in “nonattainment” – meaning that the area didn't meet federal standards for particulate pollution. Boundaries were drawn and the Wallula nonattainment area was born.
A map showing the Wallula maintenance area

The Wallula nonattainment area (now maintenance area) lies in Washington's Central Basin, the lowest and driest section of eastern Washington. This area is generally rural and agricultural. It includes parts of Walla Walla, Lincoln and Benton counties, as well as a small portion of Sacajawea Park in Franklin County. Burbank is the biggest city.

Diagnosing the dust

In order to bring the area back into compliance, local governments, industry and agricultural interests worked together on methods to reduce dust and improve air quality. Thanks to these efforts, by 2002 the area was back in attainment. Although the regulatory focus was on the relatively small area around Wallula, these dust reductions have meant cleaner air across the Tri-Cities region. 

However, that doesn’t mean our work was done. 

Once the area was back into regulatory compliance, Ecology and our local partners created an initial maintenance plan in 2005. The plan included a range of measures to prevent, control and reduce dust in the region:  
  • Working with the agricultural community to encourage best practices for preventing windblown dust and soil erosion.
  • Ensuring that industrial air permits included dust control plans for each facility, and
  • Developing a publication on best practices to minimize dust at beef feedlots and a Natural Events Action Plan outlining other dust reduction strategies

What's wrong with a little dust? 

We may think of dust as a natural thing, but it’s a nasty air pollutant. 

In Wallula, Kennewick, and other eastern Washington areas, windblown dust consists of tiny particles called PM10 that can add up to a significant health problem. When inhaled, PM10 settles into people’s lungs and can irritate or damage sensitive tissue. 

Exposure to particulate matter is associated with emphysema, asthma, chronic bronchitis, cancer, heart disease and even death. These particles also may be carriers for other toxic materials. The particles can remain in the air for extended periods, potentially causing long-term health issues for vulnerable people.

Dust will never disappear from the Columbia Plateau, but we hope that these efforts return the area to something closer to what Capt. Meriwether Lewis and William Clark encountered back in 1805. 

Museum at Sacajawea Historical State Park

What's next?

Now, we’re putting the finishing touches on a second maintenance plan that will take us through the end of 2025. The new plan closely follows the first, with a few updates. Now, and through Sept. 29, we are looking for the public’s review and comment on the plan.

Find the draft plan on the Maintenance Plan page. 

Public input

We're holding a public comment period on the draft plan through Sept. 29. If requested, we will hold a public hearing at 6 p.m. Sept. 24 at the McNary Wildlife Refuge. You can comment or request a hearing online - http://aq.ecology.commentinput.com/?id=x2MVU.

More information

A related, but separate Dust Mitigation Plan addresses soil erosion from natural dust events from the nearby Horse Heaven Hills.

- Laurie Hulse-Moyer, Air Quality

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