Motorists on Interstate 664 and residents in North Suffolk may have noticed a foul odor this weekend, and it could continue for the next several days, officials say.

An electrical malfunction occurred Sunday in the fire suppression system at Hampton Roads Sanitation District’s Nansemond Treatment Plant near the interstate, according to a news release from HRSD. The malfunction resulted in a discharge of a mixture of fire suppression foam and methanol into a tank built to contain such spills.

Water was added to dilute the mixture to eliminate any potential fire hazard, according to the release. The Suffolk Fire Department visited the plant as a precaution.

The mixture has an alcohol-like smell that reached motorists traveling on I-664, according to the release.

HRSD is investigating the cause of the malfunction, according to the release. The cause has not yet been identified. The odor still could be detected off-site for the next few days while the mixture if transferred from the containment basin.