In the islands, it’s our responsibility to safeguard the health of coral reef ecosystems from land-based sources of pollution. To that end, Maui County should opt for stepping up defense against an environmental threat rather than potentially side-stepping the matter in court.

Last year, the 9th U.S. Circuit Court of Appeals ruled that Lahaina Wastewater Reclamation Facility operations are violating the Clean Water Act (CWA). Maui County appealed to the U.S. Supreme Court, which is scheduled to hear the case in early November.

In advance of a Maui County Council committee session held Tuesday, petitions signed by more than 15,000 Sierra Club and Surfrider Foundation members were delivered to the Council, urging settlement of the case. Then scores of people testified before the Governance, Ethics, and Transparency Committee, with a majority echoing that call.

The committee, which has previously deadlocked in a vote on whether to recommend settlement, will deliberate again today. It should do right by the reef, which is critical to shoreline protections, local fisheries and the tourism industry.

The CWA bans the dumping of pollutants directly into surface waters, including oceans. At the heart of the legal case is whether this federal law should also apply to apparent indirect dumping — by way of the Lahaina facility’s injection wells.

The Lahaina facility injects a daily average of at least 3 million gallons of treated sewage into groundwater that flows toward the ocean. Its operations are permitted under the Safe Water Drinking Act, which protects underground sources of drinking water.

But due to ample evidence that the injected wastewater is seeping into the ocean, near a West Maui beach park — contributing to coral demise and algae blooms — the county should be held to some type of tougher standard for quality and quantity.

When the facility opened in the early 1980s, its wastewater was largely reused on agricultural fields, with injection wells serving as a disposal backup. According to the state Health Department, the phasing out of sugar has left the county injecting much greater quantities than initially envisioned.

In 2011, amid growing concerns about proliferation of reef-smothering algae blooms and other degradation, University of Hawaii scientists conducted a tracer-dye study that conclusively linked the Lahaina treatment-plant discharge with tainted near-shore waters. And U.S. Geological Survey research, released last year, concluded that discharge from injection wells — positioned about a half-mile offshore — had been undermining the area’s health.

The 9th Circuit concluded: “This case is about preventing the county from doing indirectly that which it cannot do directly.” The Supreme Court agreed to hear the case after circuit courts around the country were split over various rulings on the reach of the Clean Water Act.

For its part, Maui County maintains that it’s in compliance with the law and points to a West Maui fish study as proof that ocean water quality has even improved over the last decade. Supporters contend a ruling at the top judicial level is needed to eliminate confusion on the issue, as CWA compliance will be costly — easily upwards of $100 million for the Lahaina facility. Currently, none of the 600 injection wells statewide require CWA permitting.

It’s a given that if the Supreme Court sides with the county, backers of Trump-administration efforts to roll back Obama-era protections will cheer it as a win for correcting perceived federal overreach. But an outcome that condones the status quo would be a loss for Maui’s environmental health.

For the sake of restoring and preserving reefs, the county should prioritize mitigation and increasing wastewater reuse.