Opinion ID: 1359444
Heading Depth: 3
Heading Rank: 2

Heading: Impairment of the Natural Soundscape.

Text: Plaintiffs make several arguments in support of their claim that the Park Service acted arbitrarily and capriciously when it concluded that motorized uses of the Corridor do not impair the natural soundscape of the Park within the meaning of the Organic Act. The Court finds these arguments unpersuasive. First, Plaintiffs contend that the Park Service used the wrong baselinethat it compared motor-generated sounds to the noise of the Corridor with aircraft flying overhead, rather than comparing motorized noises to the natural quiet of the Park. This argument is incorrect. The Park Service compared periods of noise from river traffic (motorized and non-motorized) to periods when there was no noise. FEIS Vol. II at 348-87. The Park Service also evaluated the length of noise-free intervals when motorized traffic was in the Park. See, e.g., id. at 386. Plaintiffs next contend that the Park Service failed to consider the cumulative effects of noise from river traffic. This also is incorrect. After comparing river traffic noise to natural background sounds, and evaluating noise-free intervals, the Park Service considered the cumulative effect of such noise when added to other sounds in the Park such as aircraft overflights. The Park Service then reached the following conclusion: Although Modified Alternative H would contribute to the overall cumulative effects of noise on the park's natural soundscape, even if all noise from all river recreation was eliminated from the park (including river-related helicopter flights at Whitmore), the cumulative effects of aircraft noise would still be adverse, short-to long-term, and major. There would still be significant adverse effects on the natural soundscape due to frequent, periodic and noticeable noise from overflights, and substantial restoration of natural quiet would not be achieved as required by Public Law 100-91 and other mandates. Id. at 387 (emphasis omitted). Plaintiffs contend that this cumulative analysis should have caused the Park Service to eliminate sounds from motorized river traffic. But if a cumulative analysis were to result in the elimination of all sounds that can be eliminated by the Park Service-in this case, all sounds other than aircraft overflights, which are not within the jurisdiction of the Park Servicethen all human activity in the Park would be eliminated. And still the aircraft overflights would create substantial and adverse sound effects in the Park. Plaintiffs have articulated no principled basis upon which the Court can conclude that the Park Service should have eliminated motorized noises on the basis of such cumulative analysis, but not other human-caused noises such as hiking or non-motorized raft trips. The Court cannot conclude that the Park Service acted arbitrarily and capriciously when it concluded from a cumulative-effects analysis that motorized river traffic noise was not the source of serious sound problems in the Park and that elimination of such noise would not significantly improve the overall soundscape. Finally, Plaintiffs argue that the Park Service failed to consider earlier environmental impact statements and a number of studies conducted in the 1970s, some of which found that river use impacted the soundscape within the Park. The Park Service relied primarily on studies conducted by noise experts in 1993 and 2003. FEIS Vol. II at 352-53. These studies included field acoustic measurements, including sounds from motorized and non-motorized raft trips. The studies determined the distance at which motorized rafts could be heard and the length of time they were audible while traveling down-river, when measured from fixed points in the Park. Id. The studies also evaluated the effects of other sounds such as water flow, wind, wildlife, human voices, helicopters, and aircraft overflights. Id. The studies provide a reasonable basis for evaluating sound effects within the Park. Plaintiffs argue that the Park Service failed to consider 28 previous studies, but they identify no specific studies for the Court to consider. Nor do Plaintiffs cite any recent studies that call into question the findings of the 1993 and 2003 studies. Defendants also note that any studies conducted in the 1970s would have concerned louder two-stroke engines rather than the quieter and cleaner four-stroke engines now used in the Corridor. Finally, the 2003 study specifically considered and summarized the earlier studies relied on by Plaintiffs. Given all of these considerations, the Court cannot conclude that the Park Service acted arbitrarily and capriciously when it concluded that motorized uses do not impair the soundscape of the Park within the meaning of the Organic Act.