RENO — State environmental regulators plan to decide in January whether to cut off most bottled water deliveries to neighbors of an abandoned toxic mine in rural northern Nevada who have received it for 15 years.

Bottled water is currently available to more than 100 residents mostly on tribal lands neighboring the former Anaconda copper mine covering 5.5 square miles (14.2 square kilometers) near Yerington about 65 miles (104 kilometers) southeast of Reno.

If the decision is finalized, deliveries will be phased out over about six months, said Jeff Collins, chief of the Nevada Division of Environmental Protection’s Bureau of Corrective Actions. State officials emphasized in an email to The Associated Press on Tuesday that no final decision has been made.

Collins said at a public meeting in Yerington last week that there’s a “high likelihood” they’ll be discontinuing bottled water next year, the Reno Gazette Journal reported.

The state has been working for more than a decade to develop plans to clean up a 90-million-gallon (341-million-liter) toxic stew of uranium, arsenic and other chemicals abandoned at the site in 2000 — enough to cover 80 football fields 10 feet (3 meters) deep.

“NDEP anticipates making a decision in January,” wrote Samantha Thompson, spokeswoman for the division’s parent Department of Conservation and Natural Resources.

Now owned by BP, Atlantic Richfield paid $19.5 million to settle a class-action lawsuit in 2015 brought by about 700 nontribal neighbors of the mine. The neighbors accused past owners of conspiring to cover up the extent of groundwater contamination in a plume that has migrated off the mining site.

The state first alleged that Atlantic Richfield was discharging pollutants into the water in 1984. Atlantic Richfield in the early 2000s started offering free bottled water to residents with drinking water wells that tested for elevated uranium levels. Initial testing was conducted at about 360 wells on the mine site and near it.

Bottled water was provided to residents whose wells had 25 micrograms of uranium per liter or greater. The U.S. Environmental Protection Agency defines safe levels as 30 micrograms per liter.

Dietrick McGinnis, an environmental engineer working with the Yerington Paiute Tribe to address tribal concerns about the pollution, said he and the tribe believe the plume could be much larger than the one identified by the EPA.

The plume boundary line is based on 15 years of scientific data. A new groundwater risk assessment is scheduled to be completed next May, Thompson said.

“NDEP is continuously monitoring the plume and if the data indicates the plume is changing, then all appropriate actions will be taken, including resumption of bottled water if appropriate,” she said in the email to AP.