Noise from Kona Airport Casts Pall over Proposed Development at O`oma

posted in: April 2010 | 0

By almost all accounts, the vision behind the residential and commercial development proposed for about 300 acres on the Kona Coast, in an area known as O`oma, is a model of progressive, state-of-the-art thinking when it comes to urban planning. Pedestrian friendly, with broad ocean setbacks and extensive parks, convenient mixed commercial and residential uses and a variety of housing choices to meet diverse economic needs and lifestyle options, the design has won an award for outstanding planning from the American Planning Association, Hawai`i Chapter, and embodies many of the smart-growth concepts championed by environmentalists.

At the meeting of the Land Use Commission last month in Waikoloa, praise for the design was not in short supply. Many of the dozens of members of the public who testified were liberal with their compliments. But time and again, witnesses concluded with the same thought: it’s a great project, but in the wrong place.

The site is about seven miles north of the village of Kailua-Kona, but only a mile south of the Keahole airport. And when the noise contours of approaching and departing planes are laid over the development area, the planned residential complexes in the project just barely squeeze under the level of noise deemed acceptable in Hawai`i for dwellings and schools.

‘Nonsensical Development’

Kathy McMillen, one of the public witnesses, made an eloquent case for the LUC’s denial of the redistricting petition, which covers 181 acres, or roughly two-thirds of the entire project area. Her objections were not typical of most open-space advocates, but focused instead on the inappropriateness of siting homes so close to the airport.

“I’m not anti-development,” she told the commissioners, “but I’m against nonsensical development.” The operation of the Kona airport was essential, she said, and it was sheer folly to allow residential development in such close proximity to the airport.

McMillen took issue with the acoustic study done by Y. Ebisu for the landowner, Midland Pacific Homes of Atascadero, California. “I take issue with the logic provided in the noise study,” she said. “The data may be factually correct, but the focus of the report centers on [Federal Aviation Administration] sound levels.” The study suggests that anything lower than a level of 60 DNL (a measure of the average noise levels over a day and night, or 24-hour period) is acceptable, she said. “It is not.”

[For a more detailed discussion of noise measurements and standards, see the sidebar in this issue.]

McMillan went on to note that in Hawai`i, because of the mild climate, houses tend to be more open and less sound-proof than houses built elsewhere in the United States. FAA standards were developed for the mainland, while in Hawai`i, the state Department of Transportation suggests that noise-sensitive uses – schools, houses, churches, and the like – be restricted to areas where the DNL is 55 or lower.

If the O`oma development is allowed to be built as proposed, McMillan said, “it is only a matter of time before taxpayers will be bailing out homeowners” there. Under FAA rules, the federal government has to purchase houses or pay for sound mitigation whenever airport activity increases to the point where noise levels are incompatible with residential use. The long-term projections for the Kona airport “were underestimated in a 1997 study” by the state, she noted. “The Conservation-zoned O`oma land is the last buffer we have for an airport that is only going to be more active in the future,” she warned.

McMillen distributed copies of a map, contained in the recent (2009) draft Kona airport master plan, depicting radar flight tracks at Keahole airport for a four-day period in January 2007. The tracks, showing arrivals, departures, and touch-and-go landings, formed a nearly solid pattern over much of the O`oma parcel. Projections for future noise contours show most of the petition area falling within the 55-60 DNL contour by 2013.

Bryan Yee, deputy attorney general representing the state Office of Planning, asked McMillen what kinds of mitigation measures she might recommend.

McMillen discounted the idea of sound insulation. “I’m not an expert in this, but do have some knowledge of it,” she said. “Once you have an opening, it blows the insulation. You open a window, and the insulation is gone.” The only way to avoid opening windows would be to have air-conditioning, she said – and she, for one, could simply not afford that.

“My concern here,” she said, “is that we taxpayers, with federal taxes, are buying land, people’s houses, because this kind of thing is happening, everywhere in the country.”

Yee asked if any other kind of mitigation measures might work.

“In the next development over,” she answered, referring to Kohanaiki, “they do have … noise easements.” Such easements, which give the state the right to use airspace, generally protect the state from having to purchase land or pay for sound attenuation where houses are later affected by increasing noise from airport operations.

But, she added, Kohanaiki is “kind of at the limits, if you look at the maps. In this parcel” – the O`oma one – “this doesn’t work.”

“Your objection is to residential use, not commercial?” Yee asked.

“Yes,” McMillen replied.

Noise Concerns

The following day, the developer’s attorney Jennifer Benck began presenting the case for the project with a series of expert witnesses. The last one to testify was Yoichi Ebisu, who prepared the noise analysis that was used in the environmental impact statement for O`oma Beachside Villages

“Yesterday we heard a lot of discussion about FAA regulations and 65 DNL contour lines versus 50 and 55 DNL lines,” Benck asked Ebisu. “Can you explain what these are?”

Ebisu responded that the federal Aviation Safety and Noise Abatement Act of 1979 required the FAA “to define how to best measure aircraft noise, define an acceptable threshold, and develop a program whereby airports develop noise exposure maps… In return, these maps get disclosed to the public and the airport receives limited immunity from litigation should anyone move into an unacceptable contour level.”

The FAA, he continued, “determined that as far as a federal regulatory level for aircraft noise is concerned, the 65 DNL line represents the threshold, the line of demarcation between what’s acceptable aircraft noise and unacceptable.”

Benck asked whether the O`oma project proposed any “incompatible development” within the 65 DNL area, as the state DOT projects it will exist in 2013.

“That’s a negative,” Ebisu replied. “There’s no incompatible development proposed” in that area. Hawai`i’s definition of what constitutes “incompatible” development is more stringent than that of the FAA, he went on to say, with the DOT having developed “planning criteria” – not standards, but criteria, he emphasized – that recommend no incompatible uses where noise levels exceed 60 DNL.

“The state 60 DNL level, does that take into account the fact that people in Hawai`i do keep their windows open?” Benck asked.

“Yes,” Ebisu answered. “That’s why it [the incompatible use level] was recommended to drop at least 5 units.” Below 60 DNL there are no incompatible uses, he explained. “Above 60, more sensitive uses, like residences, schools, et cetera, become incompatible.” The 55 DNL contour line, he said, is recommended for “disclosure purposes…. The reason for that is in coming up with the 60 DNL recommendation, we were aware … of the [Environmental Protection Agency] recommendation that the level of 55 DNL is a so-called safe level, the level below which there should be absolutely no adverse impacts from environmental noise. That 55 DNL level is out there in the scientific literature as being the safe level.”

“So why didn’t we pick 55 as the recommended level for local construction?” Ebisu asked himself.

“The reason,” he answered, “is that, like the federal government [the state] were also aware of the 55 contour, but made the determination that if we use 55 as a regulatory level, the cost of mitigation would be too high, it becomes impractical. So instead of picking 55 as the level for build or no-build, they decided to use 60.”

As far as the “twilight zone” – as Ebisu put it – between the 55 and 60 DNL contour lines, that’s where the need for disclosure kicks in. State law requires potential buyers be notified if properties for sale fall within this area, similar to tsunami zones, he said.

Benck raised the idea of possible mitigation measures. “When a home is constructed, what sort of interior noise should someone expect to consider in that band” of 60 DNL? she asked.

“For naturally ventilated homes, with no air-conditioning, most sound from outside will come in through open windows and doors, irrespective of how well you build walls and the roof,” he said. Still, there would be a reduction of about 10 points, or DNL units, he added. “If I’m on 60 contour line, when I go inside my house, the interior noise level should be 50 DNL,” he said. For a typical naturally ventilated house, “if I’m on the 55 contour, my interior level will be 45 DNL,” the level, he said, that the Environmental Protection Agency has found to pose no risk whatsoever of adverse impacts from noise.

Deputy attorney general Yee asked what it would take to reduce the noise inside houses in a 55 DNL contour down to 45 DNL.

“You need to air-condition,” Ebisu answered. “It requires total enclosure.”

Who Pays?

By the time commissioners were able to ask their questions of Ebisu, the time was approaching when the meeting would have to be adjourned if the LUC members and staff were to catch their flights.

Still, commissioner Lisa Judge was keen to follow up on the issues raised by McMillen in her testimony of the previous day. Judge asked Ebisu what would happen if the noise contour lines “move mauka” by 2020 – that is, if noise over the project area increases.

“An act was passed by Congress to address those types of situations,” Ebisu replied. “The act required disclosure of [current] noise plus a five-year period. Once those [noise contour] maps are disclosed, it puts the burden on airports to mitigate” if the noise increases to the point that once-allowed uses are in zones where they are no longer compatible.

If a developer builds something inside a noise contour zone that is incompatible, “then triggers for easements and noise mitigation and attenuation should occur,” Ebisu says. “But if he stays outside that contour, then he shouldn’t have to do anything.”

All bets are off, however, if the noise contours expand. “If,” Ebisu said, “20 years from now, things have changed, the [federal act] does not immunize the airport… If… the contours grow, where it now encompasses development, there is no immunization for that…. You’re not immunized for any increase that occurs over formerly compatible land that becomes incompatible.”

Judge: “What happens in 2040 if all houses are now in the 65 DNL contour. Is the airport responsible then to mitigate it?”

As long as the buildings were constructed without encroaching on the 65 DNL contour when they were built, Ebisu said, “then, yes.”

“So today, somebody buys a house, and it’s in the 60 DNL, and 20 years from now, it’s 65, it’s the federal government’s responsibility to fix that problem?” Judge asked.

“Right,” Ebisu replied.

The LUC will continue hearings on the O`oma petition over the next several months. For details on upcoming hearings, check the LUC website:

For Further Reading

Background on past proposals for the O`oma land may be found in an article that appeared in the March 2009 edition of Environment Hawai`i: “Residential Villages Are Proposed for Area near Kona Airport, NELHA.”

The final environmental impact statement for O`oma Beachside Village and appendices are available online at the website of the Office of Environmental Quality Control. Click on the line to the January 23, 2009, edition of the OEQC “Environmental Notice:” The Y. Ebisu analysis of noise impacts may be found in volume 2, appendices.

The noise study for the Keahole airport is available at:


Patricia Tummons


Volume 20, Number 10 — April 2010


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