Template revised April 12, 2018.

DATE: January 15, 2019

TO: Stephen P. Metruck, Executive Director

offers sound insulation for eligible single-family homes, apartments, condominiums, places of

worship, and schools located within the current Federal Aviation Administration (FAA)

approved Airport Noise Compatibility Program (Part 150) noise remedy boundary. Sound

insulation projects provide renovations at no cost to homeowners and include new windows,

exterior doors, storm doors and ventilation to meet the FAA standard of a 45 decibel (dB)

interior noise level. Approximately 80 percent of eligible costs are funded by FAA Airport

Improvement Program (AIP) grants. Owners are required to sign an avigation easement in

exchange for the improvements. The program began in 1985 and, to date, has insulated

approximately 9,400 homes, 8 Highline School District Schools, 5 condominium complexes (246

units), and 14 buildings on the Highline College campus. In addition to sound insulation, the

surrounding an airport, and to recommend measures to both correct existing incompatibilities

and to prevent future incompatibilities. For Part 150 Study purposes, noise incompatibilities are

defined as residences or public use noise-sensitive facilities and must be located within the 65

Day-Night Average Sound Level (DNL) noise contour and meet a stringent noise audit.

Seattle-Tacoma International Airport’s first Part 150 Noise Compatibility Study was completed

in 1985. A total of three study updates were completed in 1992, 2002, and 2014. The current

noise remedy boundary was an outcome of the 2014 study update.

COMMISSION AGENDA – Briefing Item No. 7c Page 2 of 3

Template revised September 22, 2016.

was completed on 41 single family homes in July 2018. Of those 41 single-family homes, 36

qualified for the program with an average interior DNL noise level of 45 dB or greater.

Construction is anticipated to begin in the first quarter of 2019.

Condominium Sound Insulation

The Airport Noise Office has identified three condominium complexes (approximately 240

units) located within the noise remedy boundary as potentially eligible for voluntary sound

insulation. The Port is currently procuring a consulting firm to administer the program by

providing project design and construction management. Once the consultant firm is selected

(anticipated in the first quarter 2019), a schedule detailing homeowner outreach, acoustic

testing, architectural design, cost estimation, construction, and closeout will be completed.

Places of Worship Sound Insulation

There are approximately seven places of worship located within the noise remedy boundary

that are potentially eligible for sound insulation. A pilot project consisting of one place of

worship to be determined by Port Noise staff would begin construction in 2023 at an estimated

cost of $1.1 million.

Voluntary Purchase of Avigation Easements on Parcels with Mobile Homes

Since mobile homes cannot be adequately sound insulated, it was recommended through the

Part 150 to offer avigation easements to owners. The avigation easement protects the airport

An ATZ is a defined area that extends 2,500 feet past the runway protection zone and was a

product of the third runway supplemental Environmental Impact Study and the Part 150 as an

eligible area for acquisition of residential parcels for noise compatibility purposes. The

COMMISSION AGENDA – Briefing Item No. 7c Page 3 of 3

Template revised September 22, 2016.

single-family homes and six apartment buildings have been identified as potentially eligible for

the program. Project is estimated to begin in 2022.

Highline School District Sound Insulation

The Highline School District has a 2002 Memorandum of Agreement (MOA) with the Port and

the FAA to sound insulate 15 noise-impacted schools at a total cost of $100 million. As of

December 2018, seven schools in the Highline School District remain to be sound insulated. In

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