As a part of a nationwide weather forecasting modernization project, in 1993 the Government began building a Next Generation Weather Radar (NEXRAD) on SulpherMountain in Ojai, California. Shortly thereafter, the Environmental Coalition (ECO) and others filed suit seeking a declaration that the U.S. Government had violated the National Environmental Policy Act (NEPA) and an injunction halting construction and operation of the system until the government complied with NEPA. When the district court granted summary judgment in favor of the government, ECO appealed. The Ninth Circuit affirmed the decision of the district court.

Prior to the beginning of the Ojai installation, the U.S. Government had issued several documents in an effort to comply with NEPA. At a national level, in 1984 the U.S. Government issued a programmatic environmental impact statement (PEIS), and it followed up with a draft and final supplemental environmental assessment (SEA) in 1993. Concluding that the project would have no significant adverse impacts on human health, it issued a finding of no significant impact (FONSI) in 1993. At the local level, in 1986 the government issued a preliminary site survey (PSS) for SulpherMountain, which included an initial environmental assessment (EA). In 1987 it produced an in-depth site survey (ISS) further assessing environmental impact. In 1989, the government issued a FONSI for the SulpherMountain project based on the 1984 PEIS, the 1986 PSS, and the 1987 ISS.

First, ECO argued that the government had violated NEPA by failing to give the local residents of Ojai adequate notice of the 1984 PEIS, the 1993 SEA, the 1989 FONSI for SulpherMountain, and the 1993 FONSI for the entire NEXRAD project. The Ninth Circuit held that the government had met the requirements for notice contained in 40 C.F.R. § 1506.6. Noting that the regulation had different requirements for matters of national concern and local concern, the Ninth Circuit held the Government had fulfilled the national notice requirement by publishing notice of the PEIS, the SEA, and the 1993 FONSI in the Federal Register, and had fulfilled the local notice requirement by filing notice of the 1989 FONSI with state and local clearinghouses. The court declined to impose additional requirements above those found in the governing regulation.

Next, ECO contended that the government had failed to consider the impact of the NEXRAD project on the local environment, and that the decision not to prepare a site-specific EIS was arbitrary and capricious. After reviewing proof that the government had considered the impact of the project on SulpherMountain's flora and fauna, its possible historic, cultural, and archaeological sites, and the possible negative visual impact on the area of the project, the Ninth Circuit found ECO's claims to be without merit. The court held that the government acted reasonably when it decided not to issue a site-specific EIS based on the conclusion that the installation would have no significant local environmental impact; therefore it was not an arbitrary or capricious decision.

Finally, ECO argued that the government acted arbitrarily and capriciously in issuing a FONSI instead of preparing a SEIS after new research concerning the negative biological effects of radio frequency radiation became known. The Ninth Circuit upheld the government's decision not to prepare a SEIS because it found that the government had conducted a reasoned evaluation of the relevant information in a SEA and had reached the conclusion, based on careful scientific analysis, that its initial conclusion remained valid. Thus, the government's decision was not arbitrary or capricious.