Facts
Parties and subject matter of the proceedings: On 31 October 2018 Swisscom (Schweiz) AG submitted to the Arth Municipal Council the building application for the new construction of a mobile telecommunications installation on property KTN 646 in Goldau (Municipality of Arth SZ). The owner of the property is [C. AG] . During the public display period, among others, [A.] and [D.] filed objections.
Instance history: By decision of 15 April 2019 the Arth Municipal Council granted the building permit, notifying the cantonal overall decision of the Office for Spatial Development of 28 March 2019 as well as the railway-law consent of the SBB of 20 November 2018. The objections were dismissed insofar as they were admissible. The Government Council of the Canton of Schwyz dismissed the appeal by decision of 24 September 2019, as did the Administrative Court of the Canton of Schwyz, Chamber III, by decision of 27 May 2020 (III 2019 198).
Construction project: The installation is planned on the roof of the existing commercial building in the commercial zone and exceeds the ridge height of 15.13 m by 10 m. Three antennas transmit on the frequency bands 700-900 MHz, 1'400-2'600 MHz and 2'600 MHz. According to the finding of the lower court, these are conventional antennas, not adaptive 5G antennas.
Complaints of the appellant: The appellant argued that the NIRO (SR 814.710) contradicts constitutional and statutory law on the protection of people, animals and plants, that the limit values do not prevent harm, and that the ordinance requires revision. He relied on Art. 10 para. 2, Art. 11 para. 1, Art. 13 para. 2, Art. 74 and Art. 78 Cst. as well as Art. 11 para. 3 EPA.
Proceedings before the Federal Supreme Court: The appellant requested the annulment of the building permit, with costs and compensation to be borne by the respondents. Swisscom and the Government Council requested dismissal, the Administrative Court requested non-entry, and the ARE requested dismissal. The FOEN considered the contested decision to comply with environmental law. During the proceedings, the appellant [D.] died on 14 August 2020. The heirs ([A.] , [E.] , [F.] ) did not maintain the appeal, and [A.] continued it alone. New evidence on the harmfulness of mobile radiation was submitted for the first time before the Federal Supreme Court.
Considerations
Admissibility and entry into the case: The appeal in public law matters (Art. 82 lit. a, Art. 83, Art. 86 para. 1 lit. d and para. 2, Art. 90, Art. 100 para. 1 FSCA) is admissible against the final cantonal decision on the merits. The appellant, as a resident or owner within the objection perimeter, was entitled to appeal under Art. 89 para. 1 FSCA. After the death of the appellant [D.] , the heirs took her place; since they jointly did not maintain the appeal, the proceedings were written off with respect to the heirs' community due to withdrawal (Art. 71 FSCA in conjunction with Art. 6 para. 2-3 and Art. 17 para. 3 FCPA).
Scope of review and new facts: The Federal Supreme Court applies the law of its own motion but only examines the complaints raised (Art. 106 para. 1 FSCA; Art. 42 para. 1-2 FSCA). Constitutional rights are only examined where adequately raised (Art. 106 para. 2 FSCA). New facts and evidence are only admissible insofar as the lower decision gives rise to them (Art. 99 para. 1 FSCA). The studies and documents submitted for the first time were not considered, as no justification for their admissibility was provided.
Legal framework for radiation protection: Protection against non-ionising radiation is governed by the EPA and the NIRO. Emissions are limited at the source (Art. 11 para. 1 EPA), and the immission limit values must, under Art. 14 lit. a EPA, not endanger people, animals or plants. The NIRO provides immission limit values wherever people may stay (Art. 13 para. 1 NIRO), and installation limit values as precautionary emission limitation at locations with sensitive use (Art. 3 para. 3 and 6, Art. 4 para. 1 NIRO). The installation limit values serve precaution and contain a safety margin. The Federal Council has a certain discretion in setting them; the Federal Supreme Court has repeatedly held the limit values to be consistent with the Constitution and statute.
Compliance with limit values and protection of animals and plants: The Administrative Court had found that the installation complies with both the installation limit value and the immission limit value, that no additional emission limitations under Art. 11 para. 3 EPA or Art. 5 NIRO are required, and that there are no concrete indications of a threat to animals or plants. The appellant did not adequately demonstrate that the installation contradicts the NIRO. The NIRO is primarily directed at the protection of humans; for free-living wild animals and farm animals, whether immissions are…