Companies, researchers looking for new ways to protect Hawaii’s reefs

On a typically sunny Puako morning, Bluewater Pacific’s Matt Casey stops by a construction site to check the progress of the installation of a new type of septic system.

The home, mauka of Puako Beach Road, will be the first in Hawaii to use a Bluewater Pacific aerobic treatment unit. Casey described the system as “plug and play,” with no moving parts, save a fan to blow air into the plastic container. Wastewater flows into the tank from the house, then naturally present bacteria dissolve all the solids. The remaining water, which the state considers to be R2 level, could be used for underground lawn irrigation systems, although not at Puako, where it is too close to the water table, Casey said.

Casey and his Bluewater Pacific business partner, Josh Lawrence, see the technology as a way to reclaim a precious and finite resource, while protecting Hawaii’s reefs from sewage runoff.

“We’re trying to change the way people think about wastewater,” Lawrence said. “It’s not waste.”

Oahu-based Bluewater Pacific’s entrance into the market is timely. The state Department of Health recently proposed banning the installation of any new cesspools — pits into which a home’s sewage is dumped, and from which the waste can eventually filter through rocks and eventually reach the ocean — as well as require cesspools to be replaced when homes are sold. Lawrence said the company is planning to manufacture their tanks in state within the next three months.

The cost is higher, Lawrence said, although not significantly for many people.

“We’re talking a few thousand more,” he said, adding that for people who can reuse the water, water savings can eventually help offset that cost. “People want to do the right thing, especially for a place like Hawaii.”

Education is the key, he said, to bringing people around to the viewpoint that a little investment up front in technologies that don’t run off on the reefs, for example, are worthwhile.

It isn’t just private businesses taking initiative to address the impact that development and construction is having on reefs. Ecological economist Kirsten Oleson, an assistant professor in the University of Hawaii at Manoa’s Department of Natural Resources and Environmental Management, has been working on ways to help developers and land managers calculate the costs, benefits and ultimate results of various land uses and practices.

Her goal, she said, is to help land managers make the connection between certain practices and the resulting stressors on land, as well as understand the potential impact those stressors can have on people. The practice involves a “ridge to reef” view of the environment. Already, Oleson and her lab have been applying their methodology on Maui, and she is available to speak with land owners and managers from other islands.

Oleson uses a structured decision-making process that includes setting out objectives, identifying alternative actions and then evaluating those actions. She follows up after implementation with monitoring. Their focus has been on land-based sources of pollution, usually sediment. It’s difficult to predict just how much sediment a particular action might move, Oleson said, especially in Hawaii, where the usual models just don’t work.

The classic sediment model looks only at sheet erosion and doesn’t do well with pulse events, such as flash floods. Hawaii has more channel erosion, often fueled by quick rainstorms. The classic model doesn’t handle steep topography well, either, Oleson said.

That leaves her and her lab working out new ways of estimating how much sediment might be deposited onto a reef.

“We’re building simplified quantitative models, given the constraints of the data available, to give advice about what consequences would be on loads of sentiment,” Oleson said.

By focusing on the sediment, Oleson is able to calculate a relative change in the stress on a reef, for example. She’s also able to present information on how many acres of land or miles of road or reef that can be protected or rehabilitated by a particular action or change in action. Other values could be in the number of invasive species removed, feral ungulates killed or a figure expressed in money saved or spent.

In the trade off analysis, Oleson looks at the cost and benefit of the actions.

Through the analysis, land owners and managers should be able to see “there are certainly options that are better than others,” she said.

The benefits and costs aren’t always cut and dry, and sometimes may end with results that are mixed, because multiple goals may be at cross purposes.

In one example, the results might include “maybe a decrease in pigs and sediment, but maybe also a decrease in hunting and increase in reef health and certain fisheries,” she said.

Oleson’s lab just received a grant to continue studying sediment models and how sediment moves.

More information about her lab is available at olesonlab.org.

Email Erin Miller at emiller@westhawaiitoday. com.