"'Hush house' quiets PDX"

Sunday, September 7, 2003

'Hush house' quiets PDX
By SCOTT HEWITT
The Columbian, Vancouver (WA)


A draft report just issued by the Port of Portland calls Portland
International Airport's "hush house," a three-sided enclosure designed to
dampen the noise of airplanes revving their engines for testing purposes, a
success.

    The Ground Run-Up Enclosure (GRE), a $7.8 million structure on the south
side of the airport's south runway, has handled 99 percent of all the engine
run-ups at PDX since it went into service in June 2001.

    Before it went into use, a study of its potential effectiveness
predicted that while the GRE would significantly reduce run-up noise
reaching nearby residences, there still could be as many as 103 times per
year that the noise would exceed allowable noise levels set by the Oregon
Department of Environmental Quality. So the Port of Portland, which operates
PDX, applied for an exemption.

    The state approved the exemption on condition that the Port monitor
noise from the GRE at nearby residences to determine how many violations of
the standard actually took place, and issue a report two years after the GRE
went into operation.

    That report has just been issued in draft form, and from Vancouver's
perspective the good news is that the only place where run-ups result in
greater noise than Oregon DEQ allows is Bryant Street, south of the airport
and southeast of the GRE.

    "There may have been up to 50 times that the DEQ criteria were exceeded
at the Bryant impact site due to noise generated by a run-up in the GRE,"
the report concludes. "It is believed that the DEQ criteria were never
exceeded at any other residence around the airport" because of distance,
wind direction and airplane positioning inside the GRE.

    The DEQ noise standards are nighttime measurements six minutes or longer
of noise greater than 55 decibels, and 30 minutes or longer at greater than
50 decibels. PDX listened for violations of both standards.

    Wintler Park in Vancouver was an early GRE noise monitoring site,
according to PDX noise program manager Peggy McNees, but it was abandoned
after no noise impact was detected.

    "At Wintler we heard railroad noise and the river lapping the shore.
Based on that we didn't continue to do monitoring," she said. "Since the DEQ
gave an exception for up to 103 times when run-up noise at the airport could
exceed the DEQ criteria, and given the projected 50 times a year based on
the study results, it can be concluded that the GRE is very effective in
controlling run-up noise generated at the airport," the study says.

    In the two years since it opened, there were 4,003 run-ups in the GRE
and just 41 outside it. That's a much better average than planners had
expected; they had expected wind conditions, airport construction or other
factors to preclude use as much as 20 percent of the time.

    The enclosure is only the second the other is at Chicago's O'Hare that
accommodates wide-body commercial aircraft. Federal Aviation Administration
grants and airline funds paid for the Portland project, which was sparked
largely by citizen complaints and suggestions.

    The public is invited to view and comment on the draft report, which is
available online at www.flypdx.com (follow the noise management link).

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