Conserving water statewide is crucial, especially as yearly average rainfall rates decline and drought, population growth and climate change continue to strain our islands’ limited freshwater supply.
Developer Kobayashi Group is set to deliver Hawai‘i’s first on-site residential greywater reuse system at Kuilei Place, working with Epic Cleantec — a California-based company specializing in on-site water reuse technology.
Epic Cleantec’s Cofounder and CEO Aaron Tartakovsky explains that greywater systems promote sustainability by reusing water for nonpotable purposes like landscape irrigation, flushing toilets and cooling water towers. He says these systems decrease the demand on municipal water systems by cutting potable water needs and reducing output to local sewer systems. They can provide a significant cost savings to both building residents and utility districts overall.
“As cities confront the combined challenges of increasing water scarcity, climate volatility and rising utility costs, recycling water at the building scale helps flatten peak demand, defer costly infrastructure upgrades and reduce the energy and emissions associated with water treatment and conveyance over long distances,” says Tartakovsky.
Laying the Groundwork
Kuilei Place’s 3.15-acre property will have 1,005 units spanning a 43-story tower and 12-story midrise. Construction for the building broke ground in April 2025, but the planning process to implement the greywater system of course began much earlier.
Alana Kobayashi Pakkala, CEO and partner at Kobayashi Group, says that over the past five years the developer has made a distinct effort to commit to more sustainable construction.
She was particularly “intrigued at the idea of trying to innovate surrounding water,” which led to initial research into greywater reuse and eventual implementation of Epic Cleantec’s OneWater system at Kuilei Place.
“While it’s very expensive on the upfront for us as a developer … it actually saves considerable money for the long-term residents and of course has a lighter footprint on our environment and our community resources,” says Kobayashi Pakkala.
Kuilei Place’s OneWater reuse system can recycle up to 30,000 gallons of greywater per day, potentially saving close to 11 million gallons of potable water per year. The annual utility savings is estimated to be approximately $161,000.
“We are really trying to make decisions that will manage long-term housing costs and maintenance fees … so this seemed like an ideal opportunity to kind of make a sustainable choice that … is financially sustainable for our future residents as well,” Kobayashi Pakkala says.
Trusted Technology
Although this greywater system will be the first of its kind in Hawai‘i, Epic Cleantec has similar projects in California that have proven successful.
“The core treatment technology remains consistent across projects,” says Tartakovsky. “What changes from project to project is how that technology is applied and configured.”
For Kuilei Place, he says “[t]reatment capacity, tank storage volumes, piping layouts and control strategies were customized to accommodate peak usage periods while integrating seamlessly with the building’s mechanical and plumbing infrastructure.”
According to Epic Cleantec’s website explanation, the system’s biological treatment consists of four steps:
- Prefiltration – “coarse screening and grit removal, followed by equalization and primary settling to manage solids loading and flow fluctuations”
- Biological treatment – “membrane bioreactor (MBR) to achieve BOD (biochemical oxygen demand), COD (chemical oxygen demand) and nutrient reduction”
- Membrane filtration – “ultrafiltration membranes provide removal of bacteria, protozoa and viruses”
- Disinfection – “redundant UV (ultraviolet) disinfection with chlorine injection dosing”
The system also has cloud-based monitoring and, in case of any water quality issues or other malfunctions, is designed to automatically shut down and dump any questionable water into the sewer, after which the water tank fills with potable water from the municipal water supply. An air gap between the water tank and the municipal backup supply ensures no cross-contamination.
Strategic Partnerships and Permitting Process
While the technology itself is not new, Kuilei Place’s OneWater reuse system will pioneer on-site residential greywater systems in Hawai‘i. As such, there was both an extensive vetting process for specific companies and technologies as well as a comprehensive permitting process locally.
Kobayashi Group partnered with Commercial Plumbing Inc., ensuring that there would be local contractors capable of the long-term maintenance of the greywater system.
Commercial Plumbing has since had staff undergo training and obtain accreditation for maintaining the OneWater system, ensuring that any potential malfunctions can be fixed promptly and effectively.
As far as permitting, “[Epic Cleantec’s] technology in particular was something that the Department of Health was really comfortable with,” says Kobayashi Pakkala.
Epic Cleantec also played a crucial role in the entire process as both an educator and partner throughout the permitting and approval stages, says Kobayashi Pakkala.
The approval process took multiple years, requiring extensive coordination with the Honolulu Board of Water Supply, the City’s Department of Environmental Services and the state Department of Health (DOH).
After receiving a variance from the DOH, separate approval was also needed from the Department of Planning and Permitting.
Paving the Way
With the greywater system at Kuilei Place, developer Kobayashi Group is not only creating a more sustainable building for the future residents and promoting municipal water system sustainability, they’re also carving the path for developers to pursue similar sustainability efforts.
The OneWater system is expected to go live in Q4 of 2027, and Kobayashi Group is planning to be transparent about cost and benefits and share complete testing information.
Kobayashi Pakkala says they wanted to use their project as a “launching point” for greywater systems in Hawai‘i. Although the overall approval and permitting process was lengthy and meticulous, they hope subsequent projects can be more streamlined.
“We’re really looking to share [information] broadly because … we do want to inspire other developers to do it. We do want to also inspire the Department of Health and the counties to help promote it versus just … approve it,” says Kobayashi Pakkala.
The company is continuing to advocate for government incentives, such as reducing county impact fees for sewer and water connections, to offset upfront costs and incentivize more developers to implement greywater systems in their future projects.
Kobayashi Group is optimistic that the success of Epic Cleantec’s OneWater system at Kuilei Place will encourage wider adoption across the state.
“It’s really about moving the ball forward sustainably,” says Kobayashi Pakkala.
“If we could really work together to create a program … we could really have developers implement this broadly in projects,” says Kobayashi Pakkala. “Fundamentally we can make a big impact … to our precious resource of water, and our aquifer[’s] long-term health.”
