An unknown substance has reportedly possibly contaminated water for a portion of the Sacramento area.

The substance has been added to the drinking water supplied by the City of Sacramento, specific to the area south of Main Avenue, west of Norwood Avenue, east of Pell Drive and north of Interstate 80, according to City of Sacramento officials.

An estimated 600 to 1,000 people are in the warning zone, according to city officials.

The substance’s effect has reportedly turned the water the color purple, officials report.

City officials are warning those living in the affected area to not drink the tap water, which would include brushing teeth, washing dishes and/or making ice and any other food preparation. Officials emphasize those living in the area should only use bottled water.

Officials are also cautioning those living in that area to not try treating the water themselves by means of boiling, freezing, filtering, adding disinfectants or letting water stand.

A resident reported the discovery of the purple water late Tuesday, said Ellen Martin, a spokesperson for the City of Sacramento Department of Utilities.

Martin added the water system in the area has been flushed, and water is no longer purple, but city officials still do not want people to drink it yet. Residents who are still seeing the purple water coming from their taps are being asked to run the water to flush it out.

Bottled water will be available for residents to pick up at Robla Community Park, located at 625 Bell Avenue, Martin said. Bottled water will also be delivered to the two schools in the affected area, Glenwood Elementary School in the Robla Unified School District and Norwood Junior High School in the Twin Rivers Unified School District.

City officials expect to know around 4:30 p.m. whether or not there is any health risk.