Mica Landfill
Facility Site ID:
633
Cleanup Site ID:
1020
Site History
The 161-acre site is a municipal solid waste landfill approximately 11 miles southeast of Spokane and 1.5 miles north of the Town of Mica.
Spokane County operated the landfill from 1972 until 1990, and Spokane County and the City of Spokane jointly operated it from 1990 through 1991. The landfill stopped receiving waste in late 1991.
The landfill received about 65,000 tons of waste per year in the form of residential and municipal solid waste, dewatered sewage treatment plant sludge, demolition debris, and industrial wastes. Demolition debris was generally mixed with municipal waste or used as base material for landfill roads. Industrial wastes included pesticides, fungicides, herbicides, fertilizers, electronics industry chemicals, petroleum products, degreaser solvents, dyes and paints, industrial sludges, baghouse dust wastes, and other miscellaneous chemicals. About 24,000 tons of black dross, which is a byproduct of the aluminum production industry, was disposed in a designated area of the landfill between 1974 and 1987.
The landfill was added to the Superfund: National Priorities List in 1985 after an evaluation by the U.S. Environmental Protection Agency, and Ecology became the lead cleanup agency for the site.
Spokane County operated the landfill from 1972 until 1990, and Spokane County and the City of Spokane jointly operated it from 1990 through 1991. The landfill stopped receiving waste in late 1991.
The landfill received about 65,000 tons of waste per year in the form of residential and municipal solid waste, dewatered sewage treatment plant sludge, demolition debris, and industrial wastes. Demolition debris was generally mixed with municipal waste or used as base material for landfill roads. Industrial wastes included pesticides, fungicides, herbicides, fertilizers, electronics industry chemicals, petroleum products, degreaser solvents, dyes and paints, industrial sludges, baghouse dust wastes, and other miscellaneous chemicals. About 24,000 tons of black dross, which is a byproduct of the aluminum production industry, was disposed in a designated area of the landfill between 1974 and 1987.
The landfill was added to the Superfund: National Priorities List in 1985 after an evaluation by the U.S. Environmental Protection Agency, and Ecology became the lead cleanup agency for the site.
Cleanup
Several cleanup actions protect human health and the environment, including:
- An engineered cap over the landfill
- A leachate collection system
- A gas collection and treatment system
- Property deed restrictions
Periodic Reviews
The cleanup at Mica Landfill continues to protect human health and the environment. Compliance monitoring ensures remaining soil and groundwater contamination does not migrate off-site. The deed restrictions ensure site uses will not expose remaining contamination.
You can learn more in the periodic review reports:
You can learn more in the periodic review reports:
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
County Recording #:
5644780
County Recording Date:
2/22/2008
Restrictions/Requirements
- Ongoing Maintenance of Remedy
- Prevent the Reuse or Relocation of Site Soil
- Prohibit Soil Disturbance
- Restrict Access
- Restrict All Ground Water Extraction/Well Installation
- Restrict Land Use
- Restrictive Signage
Restricted Media
- Groundwater
- Soil
Documents 31
Legal 5
| Document Title | Document Date | Document Type |
| Restrictive Covenant: Mica Landfill | 5/29/2007 | Environmental Covenant; Alternative Mechanism |
| CD Involving Environmental Claims: Mica Landfill | 6/6/2005 | Consent Decree |
| Consent Decree for Cleanup: Mica Landfill | 5/7/2003 | Consent Decree |
| First Amendment of CD: Mica Landfill | 4/17/1991 | Consent Decree Amendment |
| Consent Decree for RI/FS: Mica Landfill | 3/15/1988 | Consent Decree |
Outreach Information 3
| Document Title | Document Date | Document Type |
| CD to Settle Liability: Mica Landfill | 7/1/2005 | Fact Sheet\Public Notices |
| Draft CD to Implement CAP: Mica Landfill | 12/1/2002 | Fact Sheet\Public Notices |
| Draft Cleanup Action Plan and SEPA DNS: Mica Landfill | 11/1/2001 | Fact Sheet\Public Notices |
Technical Reports 23
There may be more documents related to this site. To obtain documents not available electronically, you will need to make a public records request.
Places to see print documents
-
Eastern Regional OfficeN 4601 Monroe StSpokane, 99205-1265Please schedule an appointment to view print documents at this location.
Contaminants 10
| Contaminant Type | Soil |
Groundwater |
Surface Water |
Air |
Sediment |
Bedrock |
|---|---|---|---|---|---|---|
| Other Contaminant - Base/Neutral/Acid Organics | C | |||||
| Halogenated Organics - Halogenated Organics | C | C | ||||
| Metals - Metals Priority Pollutants | C | C | B | |||
| Metals - Metals - Other | C | C | B | |||
| Non-Halogenated Organics - Petroleum Products-Unspecified | C | |||||
| Non-Halogenated Organics - Phenolic Compounds | C | C | ||||
| Non-Halogenated Organics - Non-Halogenated Solvents | C | C | ||||
| Non-Halogenated Organics - Polycyclic Aromatic Hydrocarbons | C | |||||
| Other Contaminant - Conventional Contaminants, Organic | C | |||||
| Other Contaminant - Conventional Contaminants, Inorganic | C | C | B |
- S
- Suspected
- C
- Confirmed Above Cleanup Levels
- B
- Below Cleanup Levels
- RA
- Remediated-Above
- RB
- Remediated-Below
- R
- Remediated
This contaminant list was based on our best information at the time it was entered. It may not reflect current conditions at the site.
Draft 5-Year Periodic Review Report
You are invited to review and comment on the fourth periodic review for the Mica Landfill site. We review conditions at sites where some contamination remains about every five years, to make sure the cleanup is still effective.
In May 2026, we visited the site and found the monitoring wells, landfill cap, leachate ponds, and flare system in good condition. We also reviewed all groundwater monitoring data and found contamination is generally remaining at consistent levels in the same locations. Groundwater monitoring will continue to track cleanup progress and ensure remaining contamination does not move off-site. The deed restrictions prevent exposure to remaining contamination.
Moving forward, we recommend:
Review the draft report
Submit comments via email, mail, or online by 11:59 p.m. Sept. 30 to:
Sandra Treccani, sandra.treccani@ecy.wa.gov
N. 4601 Monroe St., Spokane, WA 99205-1265
Online comment form
Next steps
We will review comments received during the comment period and make recommendations for suggested changes. The periodic review will become final if no significant changes are made. An additional public comment period will be held if significant changes are made. We will hold an online public meeting if 10 people request one.