Impact Assessment of the Proposed Pebble Mine Project on Night Sky Brightness
Dark Sky Partners, LLC. 2019. Impact Assessment of the Proposed Pebble Mine Project on Night Sky Brightness. National Park Service
In the absence of a draft project lighting plan in the Pebble Project DEIS (https://www.arlis.org/docs/vol1/Pebble/Draft-EIS/index.html), NPS contracted Dark Sky Partners, LLC to conduct an impact assessment of the proposed development on night sky brightness at Keyes Point (near LACL) under two potential lighting design conditions, with and without snow cover. Using an approximation of project lighting parameters as described in the DEIS, the model predicts that in the direction of the proposed mine, maximum night sky luminance would increase over existing conditions by 886% when snow is on the ground, if the light fixtures are unshielded. Fully shielded light fixtures would increase the maximum sky luminance over existing conditions by 570% with snow on the ground, and 103% with no snow on the ground. When averaged over the entire night sky, brightness (average sky luminance) would increase 4% to 15% over existing conditions, depending on shielding and snow cover conditions.
- Type
- Published Report
- Authors
- Dark Sky Partners, LLC
- Date of Issue
- 2019-04
- Publisher
- National Park Service
- Units
- LACL
- Keywords
- all-sky brightness, light pollution, lighting, night sky, pebble mine