KAILUA-KONA — Engineers from Brown and Caldwell convened an informational meeting with county officials and members of the public Monday night where they provided a presentation on the draft environmental impact statement for upgrades to the Kealakehe Wastewater Treatment Plant and fielded questions.
The first upgrade will be the transition to production of R1 recycled water, which is safe for use in public irrigation. The plant should be ready for the switch by the end of 2020, said Hawaii County Department of Environmental Management Director Bill Kucharski.
The second phase, which includes building out and connecting pipelines and other infrastructure to move water to large-consumption customers, should be ready sometime in 2022, said Craig Lekven, project manager with Brown and Caldwell.
“We’re developing the backbone of a recycled water system that can be expanded in the future as this area grows,” he continued.
Old Kona Airport Park and Kohanaiki Golf and Ocean Club will be initial users of the plant’s recycled water once infrastructure is complete.
In the meantime, Kucharski said the superior treated R1 water will be disposed of using the plant’s functional disposal system that currently handles R2 water. After that, DEM will become a supplier, offering its R1 water to suitable customers at around 75-80 percent cost of potable water.
Part of the plan is also to upgrade the disposal process to incorporate a filtration system and UV light disinfection, which Kucharski said is superior to the use of chlorine employed at present.
Along with that change will be the addition of a subsurface flow constructed wetland for de-nitrification and a soil aquifer treatment system to remove phosphorous from effluent that doesn’t end up recycled or stored for recycling purposes.
As to public complaints and concerns, they can be submitted online or by way of the postal service. Directions for submissions are available on the draft EIS, which can be accessed by visiting the state’s Office of Environmental Quality Control website at https://health.hawaii.gov/oeqc/.
All comments are due by April 9 and those who submit via traditional mail are asked to include a return address.
Kucharski said the three most common complaints he’s encountered from members of the public are that the work should have been done sooner, more similar work should be done elsewhere on the island and that the water produced should be pristine.
Lekven explained R1 water held up in a clear glass alongside potable water looks more or less the same but it’s still not safe for consumption, only irrigation.
Kelly Drysdale, a private citizen who attended the meeting, brought up the use of pumps at the plant in the wake of the pump failures at the Hawaii County Department of Water Supply and the resulting water shortage that spanned more than a year.
“We’re going to have extra pumps, so we will have redundant pumps,” Lekven said. “So when one goes out of service … we’ll have a spare.”
Drysdale also asked about the shelf life of sand to be used in the soil aquifer treatment basins as part of the disposal system. Lekven said it should last at least 30-40 years.
Riley Smith, another citizen in attendance, brought up the question of how the WWTP will manage any overgrown plant material it plans to utilize as part of its de-nitrification process.
Lekven said the vegetation, which will be comprised of native Hawaiian plants, is meant to die and decompose on site then be replaced by new plant life in a sustainable circle.
He noted vegetation could potentially get so thick that some would need to be cleared out. Were that the case, he said the green material could either be composted or sent to a landfill.