ETL 1110-1-162
30 Sep 01
project chemist.
b. Design Criteria. Detailed requirements for chemical analyses are described in ER 1110-1-263.
Guide Specification CEGS-01450 should be edited and included in the contract documents.
B-8. Operation and Maintenance Requirements.
a. General. The construction contractor is normally responsible for site operation and maintenance
on the project for 1 year after completion. The contractor should also monitor parameters such as
ground water, leachate generation, air quality, underground gas migration, and cover effectiveness.
Baseline conditions must be measured either prior to or immediately after construction, depending upon
the parameter. Consistent and accurate record-keeping during the post-closure period is essential.
b. Ground Water. Up- and down-gradient monitoring wells must be sampled after closure.
Federal or state regulatory authorities will specify the frequency of monitoring and contaminants tested
for. Samples are typically collected from ground water monitoring wells at a frequency of once every 1
to 3 months during the first year after construction; however, this frequency should be a function of the
database available for the site. During each round of sampling, the ground water elevation should also
be determined and changes in ground water flow conditions evaluated. Periodic maintenance of the
monitoring wells may be necessary to assure proper operation.
c. Leachate. Leachate should be monitored at discharge outlets for flow rate as well as chemical
composition. Leachate discharge should decrease with time once the cover is constructed.
d. Landfill Gas. The contractor should operate and maintain the landfill gas control system during
the 1-year post-closure period. Landfill gas concentrations should be monitored at compliance points
as determined by the EPA Regional Administrator or state regulatory authorities. Compliance points
may include gas-monitoring probes, boundary monitoring stations, wellheads for passive systems, or
flares for active systems. Monitoring at the compliance points is typically done once every 2 to 4 weeks
for the first year after construction.
e. Settlement. When settlement is anticipated to be a problem, settlement markers should be
installed on the final cover above the geomembrane. The contractor should place additional select fill
and topsoil in areas where settlement has occurred. It is recommended that settlement be monitored
visually each month and that settlement monuments be surveyed annually over time to determine long-
term trends.
f. Slope Stability. Slope stability is monitored by visual inspection. Movement markers can also be
placed on the steepest slopes of the cover and surveyed annually or more often if required.
g. Landfill cover. The contractor will be required to maintain the effectiveness of the final cover,
including maintaining the cap subdrainage system, establishing the vegetative cover, and repairing
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