NOTICE OF CLEAN WATER BRANCH RECOMMENDATIONS FOR
WATER POLLUTION CONTROL PERMIT FOR
THE CITY AND COUNTY OF HONOLULU (CITY), MUNICIPAL SEPARATE STORM SEWER SYSTEM (MS4), ISLAND OF OAHU
NPDES PERMIT NO. HIS000002
DOCKET NO. HIS000002
PUBLIC COMMENT PERIOD
October 20, 2025 – November 19, 2025
The State of Hawaii, Department of Health (DOH), Clean Water Branch (CWB) tentatively recommends to the Director of Health (Director) to renew a National Pollutant Discharge Elimination System (NPDES) permit to regulate and impose water pollution control requirements on the discharge of municipal storm water runoff and certain non storm water discharges which are collected by the MS4, to receiving State waters, subject to special conditions, to:
CITY AND COUNTY OF HONOLULU
DEPARTMENT OF FACILITY MAINTENANCE
A permit for such discharge would expire five (5) years after the effective date of the permit. The permit covers discharges to all State waters in and around the Island of Oahu.
The City owns and operates the MS4 which is a system of conveyances, including storm drains, catch basins, curbs, and gutters, designed to collect and convey storm water runoff on the Island of Oahu. The volume of discharge is dependent upon rainfall-induced runoff and is highly variable. Storm water discharges from the City’s Industrial facilities are covered under a separate NPDES General Permit (i.e., Hawaii Administrative Rules Chapter 11-55 Appendix B).
The goal of this proposed draft NPDES permit is to reduce storm water runoff pollution from the MS4 to the Maximum Extent Practicable (MEP). It is intended to develop, achieve, and implement a timely, comprehensive, cost-effective storm water management program to reduce the discharge of pollutants to the MEP from the City’s MS4 to waters of the State.
Persons wishing to comment upon or object to the proposed NPDES permit or to request a public hearing, should submit their comments or requests in writing no later than 30 calendar days after the date of this notice, either through E-mail at cleanwaterbranch@doh.hawaii.gov or by mail at 2827 Waimano Home Road, Room 225, Pearl City, Hawaii 96782.
Copies of the public notice permit recommended by CWB and other information are available for public inspection, Monday through Friday (excluding holidays) from 7:45 a.m. until 4:15 p.m., at the DOH Clean Water Branch office located at 2827 Waimano Home Road, Room 225, Pearl City, Hawaii 96782. Copies may be bought. Electronic copies of the proposed public notice permit and other information are also available online at
https://health.hawaii.gov/cwb/clean-water-branch-home-page/public-notices-and-updates/.
For more information or if you have special needs due to disability that will aid you in inspecting and/or commenting on the public notice permit and related information, please contact Mr. Reef Migita, Supervisor of the Engineering Section, Clean Water Branch, at the above address or (808) 586-4309 (Voice) as soon as possible before the end of the comment period. For those who use a TTY/TDD, please call through Sprint Relay Hawaii, at 1 711 or 1-877-447-5991. If a request for assistance is made after the end of the comment period, the CWB will try to fulfill the request, but cannot guarantee that the request can be fulfilled prior to a final determination.
All written comments and requests received on time will be considered. If the Director determines that there is significant public interest, a public hearing may be held after at least 30 calendar days of public notice.
If CWB believes, after considering all timely written comments at any public hearing that may be held, that no substantive changes to the conditions of the public notice permit are necessary or warranted, then CWB may recommend to the Director that the NPDES permit be issued.
Please notify anyone you know who would be interested in this matter.
DARRYL LUM, P.E.
Clean Water Branch Chief
(SA1508138 10/20/25)