Board OKs decomissioning plan for Caltech observatory

The Maunakea Management Board approved on Monday a decommissioning plan for a Maunakea summit observatory.

The Caltech Submillimeter Observatory is the first of five summit observatories scheduled for decommissioning in exchange for the planned construction of the Thirty Meter Telescope, and ceased operations in 2015.


Jim Hayes, president of Honolulu consultancy firm Planning Solutions, Inc., presented a preliminary environmental assessment and conservation district use application for the decommissioning process to the board Monday, which encompasses the total restoration of the site to pre-development conditions.

The decommissioning plan is unchanged from when they were presented to the board back in March. Then, as now, Hayes said the process is estimated to cost a little over $4 million and could be completed by the end of 2022.

“If we’re able to maintain our schedule, we’re hopeful that the Board of Land and Natural Resources will issue a conservation district use permit either in December of 2021 or January of 2022,” Hayes.

Hayes said the assessment found no significant impacts caused by the site restoration, and, in fact, may have beneficial long-term effects for the area. Hayes suggested that, over time, the decommissioning process will allow for the recolonization of local arthropods and plants in the environment.

Furthermore, Caltech will continue to monitor the site for three years after decommissioning in order to ensure that neither the structure itself nor the decommissioning process has left any long-term effects.

Hayes said Caltech could change its plans to a less-complete restoration of the site if and only if any unanticipated effects are discovered.

The board voted unanimously to approve the draft assessment and application Monday.


Although the board was also scheduled to discuss the decommissioning of Hoku Kea, the University of Hawaii’s teaching telescope, on Monday, that item was postponed to a future meeting.

Email Michael Brestovansky at

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