NEW BRUNSWICK, NJ – An intruder has taken to one of New Brunswick’s two sources of drinking water, threatening drinking water for residents here and beyond, according to City Hall.

The New Jersey Water Supply Authority, the public entity that oversees the Delaware & Raritan Canal, hopes to curb the growth of Hydrilla, an “invasive aquatic weed” whose presence could affect 1.5 million Central Jersey residents’ drinking water, according to the city.

“It grows very quickly—as much as an inch or more per day—and poses a threat to water flow and water quality in the canal,” city spokesperson Jennifer Bradshaw said online. “If left untreated, this weed has the potential to limit water flow in the canal by up to 85 percent, which would drastically reduce the amount of raw water available for our drinking water supply.”

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The New Brunswick Water Utility draws water from the D&R Canal and another source. It then treats the water and serves it to customers in the city, Milltown and Franklin Township.

State water supply workers have launched a 120-day battle against the invasive weed. They plan to add a “low dose of a slow-acting herbicide” named Sonar Genesis to the canal, to “mitigate” growth, according to the city.*

The chemical is “non-toxic to humans, animals and fish in the low concentrations in which it is being introduced,” Bradshaw wrote.

New Brunswick’s water treatment and distribution plant is expected to remove the herbicide through a carbon-feed system, she said. The process should keep water quality in line with state and federal standards, she noted.

But water authorities may place restrictions on irrigation systems for nurseries, greenhouses and hydroponic plants, according to the city. That’s because some plants “may be sensitive” to Sonar Genesis.

The water supply authority intends to pump the herbicide into the canal in Hunterdon County. It will flow down the 60-mile channel toward New Brunswick, battling Hydrilla as it goes.

“The herbicide will not be directly added to the canal within New Brunswick City limits,” Bradshaw wrote.

Last summer, aquatic plants caused the water supply authority “extreme difficulty” in running water through the canal and to customers, according to its website.

The D&R Canal provides as much 100 million gallons of water per day to Central Jersey residents, according to the state water authority.

Hydrilla—which is named after Hydra, the nine-headed serpent enshrined in Greek mythology—is native to areas in Asia, Africa, Australia and Europe, according to the state. It made its way to the U.S. in the 1950s through aquariums.

The plant produces “dense mats” capable of cutting down water flow and clogging culverts and pipes, according to the water supply authority.

It’s also been known to change water chemistry, from pH and dissolved oxygen levels to temperature, the state wrote.

*Correction: The original version of this story called the herbicide “Solar Genesis.” Its name is Sonar Genesis. TAPinto New Brunswick regrets the error.