Mica Landfill Periodic Review: Public Comment Period 8/31 - 9/30/26

PUBLIC COMMENT
Draft Fourth Periodic Review - Mica Landfill
I support continued protection and remediation of the Mica Landfill site, but I urge the Washington
Department of Ecology to strengthen the Fourth Periodic Review so that long-term protectio...↓n of
groundwater, nearby drinking-water supplies, and the surrounding environment is an enforceable
obligation rather than an assumption based upon the present condition of the landfill.
This landfill received municipal wastes as well as industrial materials including pesticides, herbicides,
solvents, petroleum products, industrial sludges, electronics-industry chemicals, and other potentially
persistent contaminants. Contamination remains in groundwater. The passage of time does not eliminate
the responsibility to determine where those contaminants are moving and whether new contaminants of
concern are present.
I therefore urge Ecology to incorporate the following requirements into its final review and continuing
oversight of the site:
1. Continue groundwater monitoring for as long as contamination remains above applicable
cleanup standards. Monitoring should not be terminated merely because contaminant concentrations
are stable. Stability is not remediation, and groundwater conditions can change with precipitation,
groundwater levels, deterioration of containment systems, or other environmental conditions.
2. Require analytical methods capable of detecting vinyl chloride below the applicable state
cleanup level. A laboratory reporting limit above the health-based cleanup standard creates an
unacceptable monitoring blind spot. "Not detected" cannot be interpreted as safe when the analytical
method cannot reliably detect the contaminant at the concentration that defines safety.
3. Establish meaningful long-term PFAS monitoring. I support Ecology's proposed PFAS testing, but
limiting this investigation in advance to only three wells and one year risks creating an arbitrary
endpoint before the extent and behavior of any contamination are understood. Initial testing should
determine the appropriate future monitoring network and duration. If PFAS are detected, monitoring
should continue and expand as necessary to determine their source, concentration, direction of
movement, and potential threat to drinking-water supplies.
4. Use monitoring results to trigger additional investigation and remediation. The program should
contain explicit response criteria. Increasing contaminant concentrations, newly detected
contaminants, migration toward the landfill boundary or drinking-water wells, failure of containment
systems, or other evidence of increased risk should automatically require further investigation and,
where warranted, additional corrective action.
5. Maintain the landfill cap, leachate collection system, gas collection and treatment system,
monitoring wells, access controls, and environmental covenants for as long as residual
contamination requires them. Institutional controls must remain enforceable through changes in
ownership, land use, personnel, or governmental priorities.
6. Do not allow administrative closure to substitute for environmental cleanup. Any future
determination that monitoring, remediation, or institutional controls are no longer necessary should
require affirmative evidence demonstrating that remaining contamination no longer presents an
unacceptable risk to groundwater, surface water, drinking-water supplies, human health, or ecological
resources.
7. Preserve the precautionary burden of proof. Where uncertainty exists concerning contaminant
migration or long-term effectiveness of the remedy, the burden should not fall upon nearby residents
or future generations to demonstrate that contamination has reached them. The responsible parties
and regulatory agencies should demonstrate, with adequate monitoring data, that the remedy remains
protective.
This is particularly important for contaminants that can persist for decades and migrate through
groundwater. A landfill closed in 1991 can continue to influence groundwater long afterward. Long-term
stewardship must therefore be understood as an integral part of the cleanup remedy, not as a temporary
administrative program.
I support Ecology's continued oversight of the Mica Landfill and urge the Department to strengthen the
final Periodic Review accordingly: maintain monitoring and containment for as long as contamination
remains; eliminate analytical blind spots; expand PFAS investigation when the data warrant it; establish
clear triggers for additional remediation; and retain enforceable institutional controls until objective
evidence demonstrates that they are no longer necessary.
The appropriate standard should be straightforward: protection must continue for as long as the
contamination does.↓