Considerations Related to Post-Closure Monitoring Of Uranium In ...
Pathways to Long-Term Solutions for Post-Closure … Presentations/2017-11-09 - 4...Pathways to...
Transcript of Pathways to Long-Term Solutions for Post-Closure … Presentations/2017-11-09 - 4...Pathways to...
Pathways to Long-Term Solutions for Post-Closure Care
SWANA Evergreen Technical
Session November 9, 2017
Glen Wallace LG RG PhDAssociate Geologist
Pacific Groundwater Group
Goals and Elements
� Primary Goal: able to walk
away
� Interim Goal: long term plan
with regulatory approval
� Legacy facilities: WAC 173-304
� Modern facilities: WAC 173-351
� “What could go wrong?”
� Model Toxics Control Act
(MTCA)
� Case study: groundwater
contamination RI/FS path
Who’s Involved?
� Facility Owner/Operator
� Responsible for implementation
� Health Department
� Solid waste regulatory authority
� Department of Ecology
� Usual technical role for solid
waste issues
� MTCA regulatory authority if
contamination present
Allocation Tools, Attribution, Multiple Lines
173-304-407 Closure Criteria
� (7)post-closure includes
groundwater monitoring;
surface water monitoring; gas monitoring; and
maintenance of the facility,
facility structures, and
monitoring systems for their
intended use for a period of
twenty years.
� Note: 20 years is 2013 for
facilities closed under 173-304
� (8)(c) If the jurisdictional
health department finds that
post-closure monitoring has
established that the facility is
stabilized (i.e., little or no
settlement, gas production, or leachate generation), the
health department may
authorize the owner or
operator to discontinue post-
closure maintenance and
monitoring activities.
Allocation Tools, Attribution, Multiple Lines
173-351-500(2) Closure Criteria
� (iii) The jurisdictional health department and owner or operator will consider at least the following factors when determining when a landfill unit is functionally
stable or whether to decrease or increase the post-closure care period:
� (A) Leachate. Leachate production and quality must be such that maintenance
and operation of the leachate collection system can be ceased beyond the post-closure care period without posing a threat to human health or the
environment.
� (B) Landfill gas. Landfill gas production and composition must be such that
maintenance and operation of the gas collection system can be ceased beyond the post-closure care period while meeting the criteria in WAC 173-351-
200 (4)(a)(i) through (iii) and not pose a threat to human health or the
environment from methane or nonmethane compounds.
� (C) Settlement and cover integrity. The cover system must attain geotechnical
stability for slope and settlement. Vegetation and other erosion controls must
prevent exposing waste or otherwise threaten integrity of the cover system. The
cover system must stabilize such that no additional care is required beyond the post-closure care period to ensure its integrity from settlement or erosion.
� (D) Groundwater quality. Groundwater quality must remain in compliance with the protection standards established in WAC 173-351-440(8) at the relevant point
of compliance.
“What Could Go Wrong?”
� Landfill gas beyond
perimeter
� Groundwater
contamination
� Settlement and cover
performance
� When does MTCA
apply?
� When there is
contamination!
173-304 Path to Closure
Is this a 304 facility?
Do we have
monitoring data?
Stable?
LFG generation minimal?
Groundwater clean?
Prepare documentation
Regulatory Approval?
No
No
No
No
No
Close facility or alternate
regulatory approach.
Conduct post-closure
monitoring.
Repair and stabilize as needed.
May require engineered solution.
Control migration if needed.
Wait for methane curve...
MTCA applies: RI/FS/CAP/Action.
Consider AO vs VCP.
Regulatory negotiation, move
back up flow chartNo
Yes = Done!
Landfill Gas: The Long Tail
� Perimeter Monitoring
� Gas Control Systems
� What is “little or no” LFG generation?
Alshareedah (2016)
0
10
20
30
40
50
60
70
2003 2005 2008 2012 2015 2018
Me
tha
ne
Vo
lum
e %
GW-1 GW-10 GW-2 GW-3 GW-4
GW-5 GW-6 GW-7 GW-8 GW-9
Groundwater Issues
� Unlined landfills and anaerobic metals migration
� Volatile Organic Compounds (VOCs)
� Nitrate and inorganics
Groundwater Strategy
� Detection monitoring vs. MTCA requirements
� Understand: Nature and Extent, Fate and Transport
� Site vs. property boundaries
� Realistic options for addressing impacts
MTCA (WAC 173-340) Process
� Recognize a release has occurred
� Remedial Investigation (RI): How bad is it?
� Feasibility Study (FS): What can we do about it?
� Cleanup Action Plan (CAP): What we will do!
� Engineering & Implementation
� Reporting: What we did and did it work
Case Study: 173-304 Landfill
� City facility in former
gravel pit
� Capped and closed
under 173-304
� Some LFG
generation
� Historic VOC and
metals issues; metals
remain issue
Case Study: 173-304 Landfill
� Remedial Investigation:
Metals primary concern
� Feasibility Study: 3 options
evaluated, DCA ranking
� Long Term Plan: natural
attenuation, compliance
monitoring (groundwater +
LFG), institutional controls
� Cleanup Action Plan &
Implementation: coming
soon!
Reading Between The Lines
� Just because it has been 20 years does not mean
guaranteed closure.
� Form a team with all stakeholders:
Owner/Operator, Health, Ecology, any other PLPs.
� Make sure your team understands both solid waste
and MTCA if contamination issues are present.
� Form reasonable expectations for: timeline (years),
technical feasibility, and priorities.
� Prioritize use of resources: monitoring, action, etc.
� Look for insurance coverage for pre 1980 facilities.
� Good data makes for good decisions
173-304 Path to Closure
Is this a 304 facility?
Do we have
monitoring data?
Stable?
LFG generation minimal?
Groundwater clean?
Prepare documentation
Regulatory Approval?
No
No
No
No
No
Close facility or alternate
regulatory approach.
Conduct post-closure
monitoring.
Repair and stabilize as needed.
May require engineered solution.
Control migration if needed.
Wait for methane curve...
MTCA applies: RI/FS/CAP/Action.
Consider AO vs VCP.
Regulatory negotiation, move
back up flow chartNo
Yes = Done!
2377 Eastlake Avenue East,
Seattle, Washington 98102
(206) 329-0141
Remedial InvestigationGroundwater MonitoringGIS
Database
ManagementModeling
Statistic
sDetail Oriented
Research
Referencing Water Resources
Thank You