Hansville Landfill
Facility Site ID:
2605
Cleanup Site ID:
695
STATUS UPDATE
The landfill has been closed. An engineered landfill cap prevents rainfall from entering the landfill. This limits migration of landfill contaminants to ground water. Methane gas generated within the landfill is burned off. Long-term ground water monitoring is ongoing.
SITE BACKGROUND
The Hansville Landfill operated as a municipal landfill serving the northern portion of Kitsap County from about 1962 until June 1989. The landfill is divided into three separate areas: a 13-acre municipal solid waste landfill; a four-acre demolition landfill that accepted construction, demolition, and land clearing wastes; and a one-third acre septage lagoon that accepted septic tank pumping waste. The remaining landfill property consists of access roads, a soil borrow area, and wooded land. All three landfill units are capped with a final cover system. An active landfill gas extraction system extracts methane gas generated within the municipal solid waste and demolition landfill units. The methane is burned off.
Contaminated ground water flows from the landfill on to the Port Gamble S’Klallam Reservation. The contaminant concentrations decrease due to natural decay. The rate of attenuation is being monitored. The contamination is projected to decay to below applicable standards by 2034.
CONTAMINANTS OF CONCERN
Ground water: Arsenic, manganese, and vinyl chloride.
Surface water: Arsenic, manganese, and vinyl chloride.
The landfill has been closed. An engineered landfill cap prevents rainfall from entering the landfill. This limits migration of landfill contaminants to ground water. Methane gas generated within the landfill is burned off. Long-term ground water monitoring is ongoing.
SITE BACKGROUND
The Hansville Landfill operated as a municipal landfill serving the northern portion of Kitsap County from about 1962 until June 1989. The landfill is divided into three separate areas: a 13-acre municipal solid waste landfill; a four-acre demolition landfill that accepted construction, demolition, and land clearing wastes; and a one-third acre septage lagoon that accepted septic tank pumping waste. The remaining landfill property consists of access roads, a soil borrow area, and wooded land. All three landfill units are capped with a final cover system. An active landfill gas extraction system extracts methane gas generated within the municipal solid waste and demolition landfill units. The methane is burned off.
Contaminated ground water flows from the landfill on to the Port Gamble S’Klallam Reservation. The contaminant concentrations decrease due to natural decay. The rate of attenuation is being monitored. The contamination is projected to decay to below applicable standards by 2034.
CONTAMINANTS OF CONCERN
Ground water: Arsenic, manganese, and vinyl chloride.
Surface water: Arsenic, manganese, and vinyl chloride.
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 #:
201108220304
County Recording Date:
8/22/2011
Restrictions/Requirements
- Ongoing Maintenance of Remedy
- Prevent the Reuse or Relocation of Site Soil
- Prohibit Soil Disturbance
- Restrict All Ground Water Extraction/Well Installation
- Restrict Land Use
Restricted Media
- Groundwater
- Soil
Documents 55
Legal 7
| Document Title | Document Date | Document Type |
| Hansville Landfill Signed Restrictive Environmental Covenant | 8/17/2011 | Environmental Covenant; Alternative Mechanism |
| Hansville Landfill Signed Amended Consent Decree | 8/5/2011 | Consent Decree Amendment |
| Hansville Landfill Amended Consent Decree with Exhibits | 8/5/2011 | Consent Decree Amendment |
| Hansville Landfill Restrictive Covenant | 5/1/2011 | Environmental Covenant; Alternative Mechanism |
| Settlement Agreement Among Kitsap County, Waste Management of Washington, Inc., and the Port Gamble S'Klallam Tribe | 4/27/2007 | Court Settlement Agreement (liability allocation) |
| Hansville Landfill Consent Decree | 10/4/1995 | Consent Decree |
| Memorandum of Agreement between Ecology and the Port Gamble S'Klallam Tribe | 11/9/1993 | Interlocal/Interagency Agreement; Memorandum of Agreement or Understanding |
Outreach Information 4
| Document Title | Document Date | Document Type |
| Hansville Landfill Fact Sheet CD, DCAP, SEPA Documents Available for Public Comment | 5/1/2011 | Fact Sheet\Public Notices |
| Hansville Landfill Responsiveness Summary | 5/6/2009 | Responsiveness Summary |
| Hansville Landfill Fact Sheet Draft Feasibility Study (FS) Report | 2/1/2009 | Fact Sheet\Public Notices |
| Hansville Landfill Remedial Investigation Completed | 5/1/2007 | Fact Sheet\Public Notices |
Technical Reports 44
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
-
Northwest Regional Office15700 Dayton Ave NShoreline, 98133Please schedule an appointment to view print documents at this location.
-
Little Boston LibraryPort Gamble S'Klallam TribeKingston, 98346This location may only have print documents available during open comment periods.
-
Kitsap County Public Works Annex8600 SW Imperial WayBremerton, 98312This location may only have print documents available during open comment periods.
Contaminants 3
| Contaminant Type | Soil |
Groundwater |
Surface Water |
Air |
Sediment |
Bedrock |
|---|---|---|---|---|---|---|
| Metals - Metals Priority Pollutants | C | B | ||||
| Metals - Arsenic | C | RB | ||||
| Halogenated Organics - Other Halogenated Organics | C | RB | RB |
- 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.