Cascade Timber 3 POT
Site Description
The Cascade Timber 3 POT [Port of Tacoma] property sits along Maxwell Way between Port of Tacoma Road and Thorne Road in Tacoma. The property is currently used for lining up trucks entering the main Port of Tacoma terminal.
From 1978 to 1984, the Cascade Timber Company used the property as a log sort yard. In 1982, the company brought in about 500 tons of smelter slag from the American Smelting and Refining Company (ASARCO) to use for ballast to keep heavy equipment from sinking into the soft soil.
The slag was a byproduct of copper smelting at the ASARCO plant in Ruston and it contained high levels of arsenic and other metals.
A 1985 Ecology study found high levels of metals in stormwater leaving log sort yards, including Cascade Timber 3 POT. Stormwater from this site drained into Commencement Bay via Sitcum Waterway.
In 1994, Ecology and the Port of Tacoma entered into a legal agreement to clean up the site. The Port put a thick paved cap over the contaminated area. This cap keeps rainwater from getting into the soil and carrying contamination into Commencement Bay. The Port also put in groundwater monitoring wells.
This site has a restrictive covenant. It ensures that the cap is maintained and only allows industrial uses of the property.
Current Status
Ecology completed periodic reviews of the Cascade Timber 3 POT cleanup site in 2012, 2017, and 2025. Ecology conducts periodic reviews about every 5 years, because contamination remains at this site.
The 2025 periodic review found that arsenic levels in groundwater were above cleanup levels. However, this is consistent with past monitoring, and there does not appear to be an increasing or decreasing trend in concentrations. The 2025 periodic review also found that the cap covering contamination is working and doesn’t need repairs.
No further cleanup is required at this time. The property owner is responsible for ensuring the cap is maintained and conducting groundwater monitoring every 18 months. The next periodic review will be in about five years.
Site use restrictions called institutional controls are in effect
Institutional controls can be fences, signs, or restrictions on how the property is used. For instance, an institutional control may prohibit installing drinking water wells or disturbing a protective cap that isolates contamination. These restrictions keep the contamination contained and keep people from being exposed to the contamination. The controls are usually listed in environmental covenants recorded with the county.
Periodic reviews are required when institutional controls are required at a site. Ecology conducts reviews to make sure the controls remain effective and the cleanup still protects human health and the environment. We conduct periodic reviews about every five years.
Institutional Controls 1
Environmental Covenant
Restrictions/Requirements
- Ongoing Maintenance of Remedy
- Prohibit Soil Disturbance
- Restrict Access
- Restrict Land Use
Restricted Media
- Soil
Documents 26
Legal 6
| Document Title | Document Date | Document Type |
| Environmental Covenant | 8/2/1994 | Environmental Covenant; Alternative Mechanism |
| Cascade Timber 3 POT Consent Decree April 1994 | 4/11/1994 | Consent Decree |
| Cascade Timber #3B Consent Decree No. 94TC-S197 | 4/11/1994 | Consent Decree |
| Cascade Timber #3B Order No. DE 91TC-S198 First Amendment | 6/29/1993 | Agreed Order Amendment |
| Cascade Timber 3 Agreed Order DE91TC-S198 | 11/25/1991 | Agreed Order |
| Cascade Timber 3 Agreed Order DE91-S199 | 10/7/1991 | Agreed Order |
Outreach Information 4
| Document Title | Document Date | Document Type |
| 2025 Responsiveness Summary | 4/16/2025 | Responsiveness Summary |
| Public Participation Plan | 3/3/2025 | Public Participation Plan |
| Comments Invited: Cascade Timber 3 POT Periodic Review | 3/3/2025 | Fact Sheet\Public Notices |
| Cascade Timber 3 Responsiveness Summary | 2/22/2012 | Responsiveness Summary |
Technical Reports 16
Places to see print documents
-
Southwest Regional Office300 Desmond Dr SELacey, 98503-1274Please schedule an appointment to view print documents at this location.
Contaminants 1
| Contaminant Type | Soil |
Groundwater |
Surface Water |
Air |
Sediment |
Bedrock |
|---|---|---|---|---|---|---|
| Metals - Metals Priority Pollutants | R | R | R |
- S
- Suspected
- C
- Confirmed Above Cleanup Levels
- B
- Below Cleanup Levels
- RA
- Remediated-Above
- RB
- Remediated-Below
- R
- Remediated