But the owners of 1,926 dwellings have not participated or expressed interest, officials said, including some who haven’t responded to mailings and personal visits.
Of those, 115 are multi-family structures, which the Federal Aviation Administration discontinued covering about two years ago, said Mark Hardyment, director of environmental programs at Bob Hope Airport.
Officials, though, expect the multi-family buildings to be eligible again in the future, airport spokesman Victor Gill said.
Because the soundproof eligibility area shrank between the initial study in 1989 and a follow-up in 1998, it’s possible that it could get even smaller, knocking some homes out of the eligibility zone, airport officials said.
The first study identified 1,580 acres in the eligibility area. The second study shifted some homes located southwest of the airport out of the area, Hardyment said. Specific figures for that study were not immediately available.
The homes that haven’t yet been soundproofed are sprinkled throughout the eligibility area, Hardyment said, adding that there is a small concentration of eligible homes north of the airfield.
Gill said some homeowners may not want to participate because their homes have code violations, such as a garage converted into a bedroom without a permit. The airport has upped the amount it pays homeowners to address code violations from $5,000 to $7,500, Gill added.
Since the initial study, the airport has used its own equipment to monitor noise levels, which officials say have improved dramatically.
On Dec. 31, 1990, the noise-impact area encompassed 1,138 acres, of which 303 acres, or 26%, had unacceptable noise levels for homes, churches or schools, according to the airport’s sound-monitoring system.
Because of quieter aircraft, reduced operations and continued efforts to make residential soundproofing improvements, the impact area had shrunk to a little more than 757 acres as of June 2010. Of that, only 19 acres, or 2.5%, were identified as unacceptable under state noise standards.