Facility Site ID: 58794555 Cleanup Site ID: 2783

Site Background

The Lehigh Cement Company (Lehigh) owned and operated a cement-processing plant at this site from 1914 until the plant closed in 1989. Cement kiln dust (CKD), a by-product of cement production, was collected from the plant and disposed of in a landfill on the site.

In 1996, Lehigh closed the CKD landfill, which is now known as the closed CKD pile.

Contamination

Sullivan Creek
Sullivan Creek
Groundwater sampled at the site were strongly alkaline and contained arsenic, chromiumlead, and manganese that were greater than allowed by state standards set to protect human health and the environment.

Cleanup

Sullivan Creek
Sullivan Creek
In 1996, the Washington Department of Ecology (Ecology) approved Lehigh’s plan to close the CKD landfill. Lehigh constructed an impermeable cover over it and installed a stormwater management system. Because CKD remained in place at the site, Ecology issued an administrative order later in 1996, requiring Lehigh to submit and enact a plan for monitoring groundwater for two years around the closed CKD pile.

Lehigh submitted the monitoring plan in 1997 and collected groundwater samples monthly between December 1996 and December 1998. They also maintained and repaired the landfill cover and stormwater management system during this time.

Lehigh submitted the monitoring data to Ecology in 1999, which showed that contaminants had continued to seep from the closed CKD pile and reach groundwater under and down-gradient from the landfill on properties owned by three other parties. The contaminated groundwater was also reaching the surface in a series of springs that discharge to Sullivan Creek.

Because the groundwater contamination was not safely contained, Ecology signed an agreed order with Lehigh in 1999, requiring them to complete a remedial investigation and feasibility study. The purpose of the remedial investigation was to determine the extent and locations of contamination, and the feasibility study evaluated cleanup options.

Following these studies, Ecology and Lehigh signed a consent decree in 2006 requiring Lehigh to:
  • Install, operate, and maintain a groundwater treatment system between the CKD pile and Sullivan Creek.
  • Install, operate, and maintain a gravity drain on the edge of the Closed CKD Pile to direct groundwater away from it.
  • Continue groundwater monitoring.
  • Provide and maintain restrictive covenants, fences, and signs to keep people away from the contamination.
  • Operate and maintain the existing landfill cover and stormwater system.
In 2015, Ecology proposed to stabilize the bank of Sullivan Creek to prevent erosion near the groundwater treatment system. The enhancements included installing boulders and logs to redirect water flow along the left bank to protect Sullivan Creek from potential contamination and the treatment system from damage. The project was completed in August 2015.

We are continuing to monitor groundwater, its treatment system, the stability of the stream bank, and the cap over the CKD pile.

Mill Pond Dam Removal

In September 2017, Seattle City Light started removing the Mill Pond Dam, which is on Sullivan Creek upstream of the Lehigh Cement Co site. The project finished at the end of 2019. The dam was removed in phases, so that water and sediment that was trapped behind it didn't all wash down the creek bed at once and potentially damage the groundwater treatment system at Lehigh or any other downstream features. For more information on this project, please visit the Mill Pond Dam Removal and Habitat Restoration website.

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.

Environmental Covenant

County Recording #: 20080296396
County Recording Date: 2/19/2008

Restrictions/Requirements

  • Maintain/Protect Monitoring System
  • Ongoing Maintenance of Remedy
  • Prohibit Soil Disturbance
  • Restrict Access
  • Restrict All Ground Water Extraction/Well Installation
  • Restrictive Signage

Restricted Media

  • Groundwater
Legal 3
Document Title Document Date Document Type
Lehigh Cement Co. Environmental Covenant 2/19/2008 Environmental Covenant; Alternative Mechanism
Lehigh Cement Company Signed Consent Decree 2/28/2006 Consent Decree
Lehigh Cement Company AO Remedial Action 2/2/1999 Agreed Order
Outreach Information 4
State Environmental Policy Act 1
Document Title Document Date Document Type
Lehigh Cement Co SEPA 2015 5/14/2015 SEPA Documents
Technical Reports 2
Document Title Document Date Document Type
Lehigh Cement Company Engineering Design Report 6/30/2006 Engineering Design Report
Revised Feasibility Study 5/5/2005 Feasibility Study
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 Office
    N 4601 Monroe St
    Spokane, 99205-1265
    Please schedule an appointment to view print documents at this location.

Contaminants 2

Contaminant Type
Soil
Groundwater
Surface Water
Air
Sediment
Bedrock
Metals - Metals Priority Pollutants C C C
Reactive Wastes - Corrosive Wastes C C C
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.