NOTICE OF CLEAN WATER BRANCH RECOMMENDATIONS FOR
WATER POLLUTION CONTROL PERMIT FOR
PEARL HARBOR NAVAL SHIPYARD AND
INTERMEDIATE MAINTENANCE FACILITY (PHNSY&IMF), CHLORINATION UNITS
NPDES PERMIT NO. HI1120801

The 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 Pearl Harbor Naval Shipyard and Intermediate Maintenance Facility (Facility, PHNSY&IMF) discharges from its chlorination units (CUs) to receiving State waters, subject to special conditions, to:

UNITED STATES OF AMERICA
DEPARTMENT OF THE NAVY

The proposed NPDES permit for the existing discharge would expire five (5) years from the date of issuance.
The Permittee owns and operates the facility located at 667 Safeguard Street, Suite 100, Joint Base Pearl Harbor-Hickam, Hawaii 96860, which provides repair and maintenance services for Navy vessels and other military vessels.
PHNSY&IMF operates a saltwater system that draws water from the Pearl Harbor estuary near the vicinity of Pier B-2. The collected seawater is pumped from a sump into the Navy’s saltwater distribution system which supplies the cooling water for the Permittee. No treatment or additives are applied to the seawater used for the cooling system.
The cooling water supplied to the Permittee must be chlorinated to prevent biological fouling (biofouling) in the cooling systems onboard vessels. Portable Dockside Chlorination Units (DCUs) and Topside Chlorination Units (TCUs) are used to produce chlorine from seawater in the intake system. Collectively, the permit and fact sheet refer to DCUs and TCUs as CUs. The CU is an electrolytic hypochlorite generator that uses electrical energy to create non-spontaneous, oxidation-reduction of the major constituents of the chloride and bromide rich seawater. Intake water from the PHNSY&IMF is sent through the CU and the resulting chlorinated seawater is injected into the operating suction sea chests of the authorized vessel’s cooling systems to prevent biofouling. Authorized vessels are vessels that are berthed at Piers B-1 to B 21, S-1 through S-21, Y-2, Y-3, F-12, F-13 and GD-1 to GD-5.
The receiving water, Pearl Harbor, is designated as “Class 2, Estuary.” Under Hawaii Administrative Rules Section 11-54-3(b)(2), the objective of class 2 waters is to protect their use for recreational purposes, the support and propagation of aquatic life, agricultural and industrial water supplies, shipping, and navigation. The uses to be protected in this class of waters are all uses compatible with the protection and propagation of fish, shellfish, and wildlife, and with recreation in and on these waters.
Persons wishing to comment upon or object to the CWB recommendations with respect to an 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 P.O. BOX 3378, Honolulu, Hawaii 96801-3378.
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-CWB office located at 2827 Waimano Home Road, Room 225, Pearl City, HI 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, CWB, 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 and all oral 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

(SA1488186 3/27/25)