Waste Water Management in Hawaii

Hawaii Is a Chain of Mountains

Truly, each island is a mountain formed by volcanic activity.  

Each mountain may have more than one peak.  But each island is actually a mountain.

Figure 1: Topographic Map of the Hawaiian Islands, source State of Hawaii Hillshades layer in ArcGIS Online

This creates a natural break point between groundwater supplies and influences on each island, with the peak diked and holding quickly infiltrated rainwater, that may overflow into the streams.  Farther down the slopes the groundwater is in aquifers with freshwater lenses of water floating on top of denser brackish and saline water influenced by ocean level and tidal cycles.

Topography in Hawaii lent itself naturally to the protection of the peaks, the land is too steep to farm or build on and often too steep to even access.  These areas became designated Conservation Areas by the State, and were in many cases already the sites of National Parks, Wildlife Refuges, and Forest Reserves.

Figure 2: State Land Use Districts and the Underground Injection Control Line (UIC) on Oahu

At the brackish groundwater boundary the State drew a line around each island, the Underground Injection Control line, above which underground injection wells are not allowed to protect the fresh groundwater that is our drinking water supply, and below which injection is allowed into the brackish undrinkable groundwater.  This line and permits to inject below it are regulated by the Safe Drinking Water Branch (SDWB) of the State of Hawaii Department of Health (HDOH) Environmental Management Division (EMD).  UIC permitted facilities can be found through EHA Connect.  This UIC regulation is the closest thing to groundwater quality regulation in the State of Hawaii, though the Lahaina Supreme Court ruling will change that, the State regulations have not yet caught up.

Historically municipal/domestic wastewater management in Hawaii was through  cesspools managed by Department of Health, Environmental Management Division, Wastewater Branch (WWB). In 2017 Hawaii passed Act 125 requiring the replacement of all cesspools by sanitary sewer connections or individual waste treatment systems by 2050.  Many areas of Hawaii are still on cesspools, which are not regulated under NPDES, but are regulated under Hawaii Administrative Rules Title 11 Chapter 62 (HAR 11-62).  There are GIS layers of on-site sewage disposal systems for the islands of Oahu, Hawaii, Kauai, Maui and Molokai produced in 2008 by Hawaii State Department of Health Source Water Protection Program along with a Human and Environmental Risk Ranking of Onsite Sewage Disposal Systems Report.

In 2020 the Hawaii Water Resources Research Center (WRRC) began the Work4Water Initiative with Wastewater Alternatives and Innovation (WAI).  Their main goal is to convert 400 cesspools, 100 per County, across the state by 2024 and in so doing develop technology options, training, and then workforce to be able to convert 3000 cesspools/year as required to meet the Act 125 deadline.  The HDOH Wastewater Branch is one of the partners.

The HDOH Wastewater Branch is also hosting the Cesspool Conversion Working Group, created by Act 132.  

Hawaii Department of Health (DOH) Clean Water Branch (CWB) only permits facilities with discharges to surface water.  Permit and facility information can be found in the Water Pollution Control (WPC) Viewer.  The NPDES permitted Wastewater Treatment Plants (WWTP) are

OAHU: Honouliuli, Sand Island, Kailua, Waianae, Schofield, NAVFAC, East Honolulu, Marine Corps Base Hawaii, and Wahiawa

KAUAI: Wailua

HAWAII: Hilo, Papaikou, Kulaimano

While most publicly available records for WWTP NPDES permits can be found on the WPC Viewer, please note that documents have not been uploaded since October 2018.  If you find a permit number for which you need records since October 2018, you would need to submit a Request to Access Government Records (as the Subject Line) via email to cleanwaterbranch@hawaii.doh.gov and include the permit number.  

There are other WWTP that discharge through injection wells to groundwater and while CWB does not have records for those, though this may change with the Lahaina Decision, SDWB System does.  They are permitted by the Waste Water Branch for operation and the Safe Drinking Water Branch Underground Injection Control Program for discharge.

HAWAII: Pahala, Naalehu, 

MAUI:

OAHU: Laie WRF, Paalaa Kai WWTP, Waimanalo WWTP, Kahuku WWTP

KAUAI: 

The Counties also have webpages on their waste water treatment:

City and County of Honolulu WWTP(s)

Hawaii Wastewater

Maui Wastewater Permits, Wastewater Reclamation, Wastewater Injection

Kauai Wastewater

Many WWTP (County and DOD) are converting to water reclamation, including Schofield Barracks, Marine Corps Base Hawaii, Laie, and Honouliuli on Oahu.  The majority of this reuse is irrigation of golf courses and agricultural land which does not require discharge permits.  Honouliuli is also producing highly filtered water for industrial purposes, but Hawaii is not yet producing potable reclaimed water, which falls between the two in cleanliness.  Drinking water is not reclaimed directly form the WWTP.  One could reasonably argue that everyone's drinking water is "naturally" reclaimed.  Water reclamation or recycling is regulated by the DOH Wastewater Branch: https://health.hawaii.gov/wastewater/home/reuse/ 

Both Industrial and Municipal Wastewater discharges to surface waters have Whole Effluent Testing (WET) requirements in their permits.  Section 101 of the Clean Water Act, 33USC26§1251(a)(3): "it is the national policy that the discharge of toxic pollutants in toxic amounts be prohibited."  There are over 50 million chemicals in production, and only 126 on the Priority Pollutants List with USEPA approved quantification methods at 40CFR136.  Therefore testing the toxicity of the effluent in general is a much more practical approach,].  It also captures any compounding impacts of multiple pollutants.

The Clean Water State Revolving Fund (CWSRF) for Hawaii is administered by the Waste Water Branch.