NOTICE OF CLEAN WATER BRANCH RECOMMENDATIONS FOR
WATER POLLUTION CONTROL PERMIT FOR
WAIANAE WASTEWATER TREATMENT PLANT
WAIANAE, ISLAND OF OAHU
NPDES PERMIT NO. HI 0020109
DOCKET NO. HI 0020109
October 4, 2022
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 discharge of secondary treated wastewater to the Pacific Ocean, subject to certain effluent limitations and special conditions, to:
CITY AND COUNTY OF HONOLULU (CCH)
DEPARTMENT OF ENVIRONMENTAL SERVICES
1000 Uluohia Street, Suite 308
Kapolei, Hawaii 96707
The proposed permit for the existing discharge will expire five (5) years from the date of issuance.
The Waianae Wastewater Treatment Plant (facility) is located on the southwestern coastal plain of the island of Oahu, between Maili and Pokai Bay. The facility serves the communities of Waianae, Nanakuli, Maili, and Makaha.
The facility was upgraded to provide secondary treatment beginning in January 1996, for a design flow of 5.2 million gallons per day. The treatment of the liquid stream consists of bar screening, aerated grit removal, preaeration, sedimentation using the primary clarifiers, biological removal using trickling filters, and sedimentation using the final clarifiers. Sludge from the final clarifiers is pumped back to the headworks and allowed to settle in the primary clarifiers where it is co-thickened with primary sludge. The sludge is then sent to the anaerobic digesters before it is dewatered through centrifuges. The sludge is then taken to a landfill or H-Power for final disposal.
Treated effluent is discharged into the Pacific Ocean through a deep ocean outfall, Outfall Serial No. 001. The outfall extends 6,184 feet from the shore and discharges at a depth of 107.5 feet at Latitude 21°25’26"N and Longitude 158°11’54"W.
The receiving water, the Pacific Ocean, is designated as a “Class A, Dry Open Coastal Waters” is classified by the DOH as Class A, Marine Waters. Under Hawaii Administrative Rules (HAR), Section 11-54-3(c)(2), the objective for Class A waters is to protect their use for recreational purposes and aesthetic enjoyment. 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 Clean Water Branch office located at 2827 Waimano Home Road, Room 225, Pearl City, Hawaii 96782. Copies may be bought. The public notice permit and rationale are also available on the internet at: https://health.hawaii.gov/cwb/clean-water-branch-home-page/public-notices-and-updates/. For more information or if you have special needs that will aid you in inspecting and/or commenting on the public notice permit and related information due to disability, please contact Mr. Darryl Lum, Supervisor of the Engineering Section, Clean Water Branch, at the above address or (808) 586-4309 (Voice) at least seven (7) calendar days before the comment deadline. For those who use a TTY/TDD, please call through Sprint Relay Hawaii, at 1-711 or 1-877-447-5991.
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.
ALEC WONG, P.E.
Clean Water Branch Chief
(SA1389005 10/4/22)
