The Hawaii Department of Health said it recently detected low levels of 2,4-Dichlorophenoxyacetic acid during routine sampling at the Haleakala National Park drinking water system.

The water remains safe to drink, DOH said, and continues to be in full compliance with all federal and state standards. The water system serves approximately 1,200 people in Kula, Maui.

According to the U.S. Environmental Protection Agency, 2,4-D is a widely used herbicide that controls broadleaf weeds. Since the 1940s, it has been used on a variety of field, fruit and vegetable crops, including sugar cane, but is also used on turfs and lawns.

The EPA says 2,4-D and related compounds are currently undergoing a re-evaluation, which is done for all pesticides on a 15-year cycle.

DOH says the levels of 2,4-D in the system were well below the EPA and state maximum contaminant level of 70 parts per billion.

The EPA defines the maximum contaminant level as the highest level of a contaminant allowed in drinking water, with standards set to avoid human health risks based on a lifetime of consuming water containing that level.

The detections of 2,4-D ranged from 0.26 to 0.39 ppb, which is less than 0.6% of the maximum contaminant level. The drinking water is tested as mandated by federal and state drinking water regulations.