Cleaning up the Everett Smelter lowland area

We finalized the Cleanup Action Plan in November 2016 for the lowland area of the Everett smelter site, east of East Marine View Drive. We’ll be cleaning up 14 areas in the lowland area. Cleanup methods include soil removal or capping (covering the soil with a material that prevents people being exposed or rainwater soaking in). In some areas, we will require institutional controls — measures taken to limit or prohibit activities that might result in exposure to contamination. In other areas, we will allow natural processes to reduce the contamination, while monitoring surface water and groundwater quality to confirm that it's working.

Cleanup is phased

  • We finished cleanup in area A1 in 2018.

  • The 2016 groundwater study conducted in area B2 showed small cracks in the stormwater drainage system. Ecology is partnering with the City of Everett to install a lining inside the cracked pipes to prevent contaminated groundwater from entering the Snohomish River. This work is happening in 2022. 

  • The City of Everett will also put in fencing along E Marine View Dr. (area C2 and C3) at the top of the steep slope above the railroad tracks. They are installing this fencing to limit access to contaminated soil on the steep slope.

Cleanup Action Plan for the lowland area

We found that arsenic, lead, and mercury are the main contaminants in the lowland area. These contaminants exist in soil, shallow and deep groundwater, and in limited areas of the sediment below outfalls along the shoreline. The contamination must be addressed because it exceeds limits allowed by the state’s cleanup laws (the Model Toxics Control Act and the Sediment Cleanup Standards).

The Cleanup Action Plan addresses 14 contaminated areas in the lowland area. We plan to use several different cleanup technologies. More than one technology may be used at some of the locations. These technologies are described below and the locations for their use are shown on the map.

The cleanup site is divided into Uplands (residential) and Lowlands cleanup areas. The two areas are on different cleanup schedules.

Removal of contamination is planned for A1 and A2. Contaminated material will be excavated and transported offsite for disposal at an approved facility.

Capping of contamination is planned for areas B1–B3, C4, and C5. A natural or synthetic material is installed over contaminated soil to prevent rain water from entering the contaminated soil. This reduces the potential for human exposure.

  • New caps will be installed at B1 and B2
  • Existing caps will be maintained at B3, C5, and C6

Institutional Controls will be used at C1–C3, C6, and D1–D4. These include fences, permit requirements, restrictive covenants, and zoning regulations to minimize the potential for human exposure. These controls do not physically change the site or reduce contamination levels.

Monitored Natural Attenuation will be used at C1, C6, and D1–D4. The plan is to monitor the water quality of surface water and groundwater to confirm that natural processes are reducing the contamination.

All sites will be monitored after cleanup actions are completed to confirm that the cleanup remains effective. We prioritize removal of contamination sources and plan to phase in the work as funding allows.


During the smelter operation, the lowland area was an undeveloped flood plain/tide flats area. In 1914, after the the smelter facility closed, Weyerhaeuser acquired most of the land in the lowland area. Over the years, Weyerhaeuser constructed and operated a large wood products manufacturing complex.

When Weyerhaeuser decommissioned its timber industry operations within the lowlands area in the 1980s and 1990s, it provided a good deal of environmental data. Ecology oversaw cleanup of contamination from the timber operation on the three former Weyerhaeuser properties that are located within the Everett smelter lowland area, see "Related Links" below.

This contamination is not being addressed in our Everett smelter lowland area cleanup plans. The cleanup activities for the Everett smelter site will only address metals contamination (mainly arsenic and lead) from the smelter operation.

Using the Asarco settlement funds, Ecology investigated the nature and extent of the smelter contamination in the lowlands area and reported it in the Supplemental Remedial Investigation Report. Cleanup alternatives were then developed and evaluated in the Feasibility Study report. Both reports were finalized in February 2016. You can view these reports in our online document repository.