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Just
the facts about TVA’s reportable events
and the self-auditing program that helps keep them in decline
By their
very nature, all reportable environmental events (REEs)—occurrences
that violate regulatory requirements and trigger notification to or
enforcement action by a regulatory agency—are important and taken
seriously. An REE may be a spill or other accidental release, a permit
exceedance, or a paperwork-related issue. In 1999 TVA experienced 48
REEs, of which seven had the greatest environmental impact.
 At
two TVA hydropower plants, accidental discharges of lubricating oil
from turbine units led to spills into the Tennessee River. A closed
valve at one facility caused pressure to rise until a seal ruptured
and began releasing oil. Some oil was seen downstream, but TVA workers
prevented the release of 1,200 gallons of oil by shutting down the turbine,
installing headgates and tailgates, and deploying a containment boom
below the dam to recover most of the oil. Improved maintenance procedures
have been implemented to ensure that valve settings are correct and
prevent overpressurization. At another plant, the failure of a compression
fitting caused an oil-line leak and some 800 gallons of lubrication
oil spilled onto the powerhouse floor. The break was quickly repaired
and less than a gallon of oil actually reached the river. The damaged
fitting and potentially faulty fittings on three other turbines were
replaced with a welded design that greatly reduces the likelihood of
failure.
Ash sluice-line breaks created problems at three of TVA’s fossil
plants. When lines carrying an ash-and-water mix ruptured, discharges
occurred at unpermitted points instead of in the plants’ appropriate
ash ponds. In each instance, the piping was repaired; then TVA instituted
preventive maintenance procedures and periodic inspections to help avoid
future ruptures. It also conducted employee training to help prevent
unpermitted discharges.
In TVA’s transmission operations, a failure to remove trees and
treetops felled during routine right-of-way maintenance caused blockage
in a nearby stream. The access road cut to the site was not seeded,
and erosion became an issue as well. TVA responded with appropriate
site-remediation measures and personnel training.
During an environmental audit at one of the agency’s hydro facilities,
workers noticed oil leaking from one of three plastic-wrapped transformers
in the powerhouse loading bay. The transformers had been removed from
service and were in temporary storage there, awaiting disposal at an
EPA-approved facility. A total of one gallon of polychlorinated biphenyl
(PCB) oil, which is used as insulation in older transformers, had leaked
from a broken seal. The oil was cleaned up according to EPA spill guidelines,
and all waste materials were properly disposed of.
TVA is actively working to decrease the number and severity of reportable
environmental events like these. By improving its processes and programs
and expanding its training, it has achieved a 59 percent reduction in
reportable events since 1995.
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Related
Page: Self-Auditing
Program
Causes of Reportable
Events in 1999
A
number of problems can lead to a reportable environmental event, but
often easily solved process and equipment flaws are the largest contributing
factors.
Click
chart for larger view and raw data.
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