KAILUA-KONA — The hydrologist who studied potential impacts that a development in Kahaluu could have to groundwater said Monday that while the proposed timeshare project could slightly decrease the flow rate of groundwater and slightly increase its salinity, it also would lead to a decrease in the level of unwanted nutrients in the water that discharges at the shoreline.
KAILUA-KONA — The hydrologist who studied potential impacts that a development in Kahaluu could have to groundwater said Monday that while the proposed timeshare project could slightly decrease the flow rate of groundwater and slightly increase its salinity, it also would lead to a decrease in the level of unwanted nutrients in the water that discharges at the shoreline.
“The reality is that even with the addition of the fertilizer to the landscaped area, because the groundwater that’s being drawn to serve people also has nitrogen and phosphorus in it — you might not expect it — but the calculations show that the effect of the project will be … actually a decrease in the nitrogen and phosphorus in the groundwater moving beneath the site and ultimately discharging at the shoreline,” said hydrologist Tom Nance.
The testimony came during the third day of an evidentiary hearing for a contested case filed by Kahaluu resident Simmy McMichael in opposition to the proposed development of a 306-unit condominium in that area.
The Leeward Planning Commission granted McMichael’s petition for a contested case hearing in April 2016 during a hearing where many residents tried to discourage the commission from granting Towne Development of Hawaii Inc. the special management area permit needed for the project to move ahead.
The hearing’s first two days were in April and it continued Monday at the West Hawaii Civic Center, where McMichael questioned Nance, whose research is cited in the project’s environmental assessment. That assessment concluded that “groundwater and marine water quality will remain high and will not be materially affected by the project.”
McMichael, though, remained skeptical, questioning the data that led to that conclusion.
Nance’s testimony at the hearing came after more than two hours of public comments from residents who objected to the development, including employees of the developer.
Water, according to the final environmental assessment, will be supplied by five Kahaluu wells located almost directly up from the site of the development.
The report suggested water usage would amount to 136,000 gallons per day and wastewater generation would come to 85,000 gallons per day.
Those numbers are based on the development having 338 residential units, the initial number of multifamily/timeshare units and single-family units proposed in the draft environmental assessment. That number has since been reduced to 306 units.
One specific issue McMichael raised was the impact of something such as fertilizer on the groundwater that flows beneath the project and out to the ocean.
Nance said wastewater generated at the site is going to be sent away to be treated and reused for golf course irrigation. As a result, additional fertilizer use isn’t going to increase nutrient levels in the groundwater. He noted that the water being drawn out of the ground for use at the development already has some nutrients in it.
Nance said there would be a decrease in nitrogen and phosphorus levels in the water flowing beneath the project.
McMichael also raised the question of whether the new project could strain the region’s water infrastructure.
“We are asked to cut back (usage) 25 percent,” she said. “How does 306 units fit into this when we’re already asked (to cut back)?”
Nance said that issue isn’t one of resource limitations, it’s one of hardware.
With some high-level water wells out of service, pump rates increased at basal wells to meet demand. As a result, residents are asked to cut back their usage to keep salinity levels low.
“That 25 percent cut back is a short-term problem brought about by the unusual circumstance of three of the seven high-level wells being out of service,” he said. “The (Department of Water Supply) is working to get them back into service and it’s virtually certain that before this project comes online, those three wells will be back in service.”
Email Cameron Miculka at cmiculka@westhawaiitoday.com.