Explosive Gas Monitoring
(A)
• Not necessary to update approved EGMPs,
however, there are changes which benefit the
owner/operator.
– Existing EGMPs can be altered to comply with
parts (doesn’t have to comply with entire rule)
• New EGMPs under review do need to
comply with all new rule changes
(B)
• Plan approval criteria
– Designed and capable of being constructed and
operated in accordance with rule
– Director can make a decision if sufficient
information provided
– Director can request additional information
Notes: plan approval criteria
• Plan approval criteria similar to PTI.
(D)(5)(a)(i)(b) and (D)(5)(a)(ii)(a)
• Structure is on waste…
– Put alarm in building
(D)(5)(a)(i)(c) and (D)(5)(a)(ii)(b)
• Structure < 200 ft of waste…
– Put alarm in building
– And either probe or punch bar
(D)(5)(a)(i)(d) and (D)(5)(a)(ii)(c)
• Structure < 1000 feet of waste…
– No change (probe or punch bar between
building and waste)
– But, if unable, then put alarm in building
(D)(5)
• Alarms
– To be placed on consent of owner
• Punch bars
– Use only if… pathway being monitored does not
represent a potential hazard to the structure
Note: alarms and punch bars
• Rules provide for proof from applicant that
they made good faith effort to install alarm
in structure and were denied.
• Punch bars are shallow monitors. Cannot
determine if deeper migration. Appropriate
where uniform geology (no discrete
pathway to monitor).
(E)(1)
• Quarterly monitoring unless…
– Portion of landfill is unlined by FML – then
monthly
– Pre-1994 facility can automatically reduce to
semiannual after 5th year of post-closure care.
Post-1994 ISW and RSW need to request
reduction, MSW cannot reduce frequency.
Notes: monitoring frequency
• Current rules require monthly monitoring at
operating landfills, quarterly during first 5
years of post-closure and semiannually
thereafter. If landfill completely lined by
FML, can do quarterly. MSW landfill
regulated pursuant to Subtitle D is not
eligible for monitoring less than quarterly.
(E)(2)
• Set order for monitoring of probes
–
–
–
–
–
–
–
1st gas pressure in probe
2nd gas concentration (NO VENTING!)
3rd water level in probe
4th barometric pressure
5th air temperature
6th weather conditions
7th relative humidity
Notes: no venting
• DSIWM philosophy for how to make use of probes for
monitoring explosive gas migration risk to structures
has changed. Old approach was to monitor migration
occurring that day, so venting was appropriate. Probe
is now viewed as a model or analog for a structure.
Gas movement is variable, it’s there one day and gone
the next. But monitoring frequency is infrequent (e.g.
quarterly). So to see if any migration incidents
occurred during the intervening period, do not want
probe vented.
(E)(5)
• Contingency Plan
– Able to self implement return to detection
monitoring by establishing criteria to be met
– Plan to include…
• Phone numbers of authorities
• Increased monitoring frequency (at least weekly)
• Description of any additional monitors
Notes: contingency plan
• This is a rule change that owner/operators
may want to alter their plans to take
advantage of.
(E)(5)
– Contingency Plan to include…
• Criteria to determine contingency
monitoring no longer warranted
– A minimum of 4 sequential monitoring events
below the threshold limit
– Over a minimum period of 2 weeks
– A lower threshold may be used to avoid
bouncing right back into contingency monitoring
(E)(5)
– Contingency Plan to include…
• Steps to protect human health and environment
– Examples are adjusting or expanding active gas
extraction system, installing alarms in buildings,
installing vents or barriers
– May need to update financial assurance cost
estimates (e.g. install extraction system)
– If at any point it does not appear steps are effective,
director can order further action (I)
(E)(5)
– Contingency Plan to include…
• Reporting
– Initial report 7 days after exceedence of monitoring results
and steps to be taken to protect human health and
environment
– New: Every 30 days thereafter while doing contingency
monitoring, report the results, characterization of pathways,
possible causes of increased gas concentration, steps being
taken
– New: Leaving contingency monitoring, report summary of
monitoring results, characterization of pathway, possible
causes of increased gas concentration
(A) and (D)(5)(c) and (f)
• New Structures
– If no EGMP and structure built, have one year
to submit plan. Then have sixty days to
implement
– If EGMP approved and then structure is built,
have one year to install monitors (no longer
require Director’s approval for new monitor)