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NOVEMBER 2009
Concerns over explosive situation bring agreement to
investigate landfill methane
Concern that elevated underground methane levels could
lead to an explosion has prompted St. Bernard and Ohio
Environmental Protection Agency (EPA) to reach an agreement
about how the city will investigate and correct problems
at its closed landfill.
The landfill stopped receiving waste in the 1970s and
closed in 1985.
Under state law, St. Bernard is required to monitor the
landfill’s boundaries for methane gas produced by waste
that moves underground between soil particles and along
utility pipes. Ohio EPA is concerned that methane is
moving underground from the landfill and may collect
in low areas or people’s homes at levels capable of igniting
or exploding.
Methane levels have fluctuated, but they have since returned
to unacceptably high levels. Based on these results,
the city needs to perform additional remedial measures
in order to minimize landfill gas production.
Landfill owners or operators must monitor methane gas
levels at their property boundaries and take action to
protect occupied structures, such as homes, that are
located within 1,000 feet of landfill waste placement.
In 2008, St. Bernard reported that 9 homes are within
200 feet of waste. Two hundred thirty-four occupied structures
are within 1,000 feet of waste.
Since 2000, the city has monitored methane gas levels,
reported gas level exceedances, and installed remedial
measures. Despite these measures, exceedances continue
to occur. In 2003, Ohio EPA ordered St. Bernard to abate
or minimize the formation or migration of explosive gas
from the landfill. The city was required to develop,
submit and implement a plan to remediate explosive gas
migration. The city also was required to revise its explosive
gas monitoring plan. While methane levels initially dropped,
they have returned to unacceptably high levels.
Ohio EPA and St. Bernard have agreed that the city will
do additional work to bring levels down.
The city has agreed to:
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Delineate exactly where waste explosive gas has
migrated; this will involve drilling monitoring
probes in people’s yards;
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If waste is found beyond the area in which it is
believed to be, additional work must be done while
performing the gas delineation;
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Propose remedial measures to abate or minimize explosive
gas levels;
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Convert its current gas extraction system into a
continuously operating, automated system;
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Revise its gas monitoring plan which may include
additional monitoring probe installation;
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Unless damaged or inaccessible, leave current and
future monitoring probes in place; and
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Install gas alarms in homes where property owners
authorize access.
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