A long battle over a Hawai’i local government’s pollution to the ocean via groundwater ended late last week with a federal judge’s order making clear that the discharges are illegal if not authorized by regulators. The decree indicates that continued use around the nation of a widespread method for storing pollutants will depend on acquisition of a permit.
The Hawai’i dispute centers on Maui County’s practice of using injection wells as a method for disposing of wastewater produced by a population of about 40,000 people. About three- to five million gallons of partially treated sewage has been added to underground porous rock formations every day for more than 30 years. Pollutants in the wastewater encouraged algae growth in shallows seas off the island’s coast, which in turn damaged coral reefs.
Human health may have been compromised by Maui County’s wastewater storage practices. “In addition to pollutants like nitrogen and phosphorus, the wastewater contains bacteria and other pathogens,” according to a 2013 Earthjustice press release. “In September 2011, the Environmental Protection Agency required the County to disinfect all of the wastewater pumped into the injection wells at the Lahaina facility by the end of 2013. The County’s failure to adequately disinfect the water over the past several years has been linked to staph infections among swimmers and other users of Kahekili Beach Park.”
U.S. District Judge Susan Oki Mollway, in her July 15 order, compared Maui County’s release of partially treated wastewater into spongy openings in subsurface rock to those of a person “who proposed to stand at the shoreline and empty directly into the ocean each day thousands of large drums filled with pollutants.” The question presented by the Maui case, she explained, “is whether the [c]ounty is violating the Clean Water Act in having failed to obtain an NPDES permit while releasing pollutants, not by pouring them directly into the Pacific Ocean, but instead by introducing the pollutants into injection wells at the Lahaina Wastewater Reclamation Facility…half a mile from the ocean.” Molloway referred to the formal name of the water pollution permit required by federal law.
Mollway ruled that Maui County’s obligation to obtain a permit did not depend on whether every drop of wastewater stored in injection wells travels to the sea. Though monitoring equipment has traced only about 2% of the wastewater’s path to the Pacific, that discharge “is still an enormous amount of pollutant being put into the ocean,” Mollway wrote. “[E]ven if this court looks only at that less-than-2-percent, that is still tens of thousands of gallons of pollutant-containing wastewater entering the ocean every day. Millions of gallons enter the ocean every year at just the handful of monitored points.”
The Honolulu-based jurist applied the seven factors laid out by the Supreme Court in a 2020 ruling involving the same dispute. In an opinion by Justice Stephen Breyer, the high court explained that excluding from permit requirements all discharges that travel through groundwater would invite evasion of the Clean Water Act. “Consider a pipe that spews pollution directly into coastal waters,” Breyer wrote. There is an addition of a pollutant to navigable waters from a point source.” A permit would be needed in that circumstance.
The justices’ majority opinion directed federal judges to consider seven factors in deciding whether a Clean Water Act permit is required. They include “transit time,” “distance traveled,” “the nature of the material through which the pollutant travels,” “the extent to which the pollutant is diluted or chemically changed as it travels,” “the amount of pollutant entering the navigable waters relative to the amount of the pollutant that leaves the point source, “the manner by or area in which the pollutant enters the navigable waters,” and “the degree to which the pollution (at that point) has maintained its specific identity.” Breyer emphasized that while time and distance will usually be “the most important factors,” that will not be true in “every case.”
“Maui and the [U.S.] [g]overnment read the permitting requirement not to apply if there is any amount of groundwater between the end of the pipe and the edge of the navigable water,” Breyer continued. “If that is the correct interpretation of the statute, then why could not the pipe’s owner, seeking to avoid the permit requirement, simply move the pipe back, perhaps only a few yards, so that the pollution must travel through at least some groundwater before reaching the sea?”
Mollway explained that the Maui County case is not like either of two examples set forth by Breyer in his opinion for the Supreme Court. “The LWRF’s injection wells are neither located just a few feet from the ocean nor 50 miles from shore,” she wrote. “Instead, the wells are about half a mile from the ocean. Even if the wastewater is diverted off of a straight line to the sea, at least some of it appears to travel between half a mile and a mile and a half. Nor does the pollutant routinely take many years to reach the sea. Some of it reaches the sea in 84 days, and much of it within 400 days.”
She emphasized that the Supreme Court recognized that permits could be demanded by regulators even if the time it takes for pollutants to reach a protected water body is measured in months or even several years. “Because the Supreme Court knew it was dealing with movement through groundwater, it makes sense to assume that the Court expected the parties to be dealing with transport time measured in months. Notably, the Supreme Court set its extreme at ‘many years,’ not at ‘many months,’ and not even at one year or two years,” Mollway wrote.
Injection well technology, which allows for the storage of liquids in porous rock formations below the ground, is also used at oil and gas wells and by refineries, chemical manufacturers, and food producers. More than 680,000 injection wells have been drilled in the U.S.
“Communities across this country are fighting to protect their rivers, lakes, and oceans from pollution via groundwater, from Hawai‘i to New York, and from Alabama to Montana,” said David Henkin, senior attorney at Earthjustice. “As the first court to apply the Supreme Court’s test, the Hawai‘i federal court’s ruling is a victory for clean water, for justice, and for common sense.”
The aquifer into which Maui County’s wastewater is deposited was created by volcanic rock. In 2009 the U.S. Geological Survey determined that contaminated plumes from the Lahaina Wastewater Reclamation Facility travel southwesterly from the facility and pollute waters off Maui’s famous Ka’anapali Beach complex. A 2013 study by University of Hawai’i researchers verified that the coastal aquifer is geologically and hydrologically linked to the Pacific Ocean.
According to a June 2012 report by ProPublica, more than 30 trillion gallons of wastewater have been injected into U.S. aquifers. “Those wells — more holes punched in the ground — are changing the earth’s geology, adding man-made fractures that allow water and waste to flow more freely,” according to the report.