2.15.360 Active, closed and abandoned landfills | Snohomish Health District Code

2.15.360 Active, closed and abandoned landfills.

A. Owner Responsibilities. The owner of a closed or abandoned landfill site is responsible for preventing negative impacts to human health and environment from the site. All landfill sites that are no longer operational shall be monitored by the owner and be subject to repair, maintenance, and remediation in order to prevent a threat to human health or the environment or a violation of federal, state, or local regulation. The Health Officer shall have the authority to require the owner to conduct:

1. Landfill cap and surface repairs and maintenance;

2. Explosive gases, such as methane, monitoring and control;

3. Surface and groundwater monitoring;

4. Leachate control and treatment; and

5. Any additional measures determined by the Health Officer to be necessary to protect human health and the environment.

B. The Health Officer has the right to inspect, monitor, direct and order remedial action on any closed or abandoned landfill site.

C. Construction Requirements. If an owner of a closed or abandoned landfill proposes or is required to conduct site work or construction on the landfill or the property that the landfill is on, then the owner of the landfill shall submit proposed construction and remediation plans to the Health Officer for review and comment. The remediation and/or construction plans must be approved by the Health Officer before site work begins. The plans shall be prepared by a licensed professional engineer and shall contain the following:

1. A description of the proposed activities;

2. A description of potential hazards from the activities and how the potential hazards will be controlled. Potential hazards may include but are not limited to subsidence, methane and other explosive gases or volatile compounds, leachate, hazards associated with subsurface utility installation, erosion, and water quality;

3. A proposed timeline for the activities;

4. Any other information that the Health Officer requests as part of the proposed activities; and

5. A signed and stamped document by the professional engineer attesting that the construction and remediation activities were completed in accordance with her/his recommendations for preventing negative impacts from the landfill to human health or the environment.

D. Site modifications made to abandoned or closed landfill sites outside of Health Officer approved plans may result in enforcement action against the landfill property owners and other responsible parties.

1. Owners of all operational, closed or abandoned landfills except inert waste landfills shall provide for adequate collecting, redirecting and venting of gases generated by solid waste. No explosive gas shall be allowed to migrate to or beyond the facility boundary above or below the ground in concentrations greater than the lower explosive limit for methane or in excess of 100 parts per million by volume of hydrocarbons (expressed as methane) in off-site structures, or in excess of 25 percent of the lower explosive limit for gases in facility structures (excluding gas control and recovery system components). It shall be the responsibility of the landfill owner to develop a sampling and testing program to monitor gas production and migration. Such program shall be approved by the Health Officer.

a. Any person constructing or developing any area within 1,000 feet of an active area of an active, closed or abandoned landfill shall provide documentation that demonstrates that levels of explosive gas within this 1,000-foot zone are below the lower explosive limits (LEL) under all conditions. A description of the investigation methodology, all analytical data, and conclusions shall be presented in a report submitted by a licensed professional engineer or professional geologist to the Health Officer and the local building department for review and approval.

b. Any person constructing or developing any area within 1,000 feet of an active area of an active, closed or abandoned landfill shall provide documentation that demonstrates that all enclosed structures are protected from potential explosive gas migration. The method for ensuring a structure’s protection from explosive gas shall be addressed in a report submitted by a licensed professional engineer to the Health Officer and the local building department for review and approval. Such a report shall contain a description of the mitigation measures to prevent the accumulation of explosive concentrations of gas within or under enclosed portions of a building or structure. At the time of the final inspection, the engineer shall furnish a signed statement attesting that the building or structure has been constructed in accordance with her/his recommendations for addressing the explosive gas migration.

c. The Health Officer may grant a variance to the requirements in subsection (E)(2)(b) of this section based on a review of the data submitted pursuant to subsection (E)(2)(a) of this section.

F. Solid Waste Handling Permit. Any owner of an active, closed or abandoned landfill found to be in violation of this section may be required to obtain a solid waste handling permit. Any owner required to obtain a solid waste handling permit shall renew the permit annually. A permit may be issued or denied for one or more activities without simultaneously issuing or denying a permit for all activities. [Res. 04-06. Prior code § 3.1(XXXVI)].