State recommends renewal of stormwater runoff permit for TMT construction site

The state Department of Health recommended a permit for storm runoff from a future Thirty Meter Telescope construction site be approved.

On April 8, the DOH Clean Water Branch issued a recommendation that the department’s director renew the National Pollutant Discharge Elimination Permit for the TMT International Observatory Site on Maunakea, which was originally issued in 2014.

The permit requires any future TMT construction site conform to specific storm water runoff practices in order to prevent contamination of waters farther down the mountain. The permit identifies Kemole Gulch, Kuupahaa Gulch, Puupohakuoloa Gulch, Pohakuloa Gulch and the Wailuku River as the waters that will ultimately receive any storm water runoff from the site.

Darryl Lum, supervisor for the Clean Water Branch’s engineering section, said such permits must be renewed every five years, but the DOH was unable to renew the TMT permit when it first came up for renewal in 2019. Instead, Lum said, the DOH extended the permit indefinitely until earlier this year, when it re-submitted its recommendation to renew the permit.

Lum said the DOH recommended the permit be extended in 2019, but rescinded that recommendation in March in order to avoid making it seem as though the DOH director made a decision one way or another.

The permit only applies to stormwater runoff from a TMT construction site on Maunakea, not the TMT itself, Lum said. Nor does the renewal of the permit represent any major step forward for the TMT project, which has not made much progress in Hawaii since the months-long standoff with Native Hawaiian groups in 2019.

With the recommendation now filed, members of the public can submit comments on the recommendation until May 8 via email at cleanwaterbranch@doh.hawaii.gov.