A nitrate advisory that went into effect three weeks ago for nearly half of Columbus, as well as surrounding communities, has been lifted.

The Columbus Department of Utilities says levels have fallen below the maximum contaminant level of 10.0 parts per million (ppm).

Monday’s announcement comes after the advisory went into effect June 8, when levels pushed to 10.7 ppm. 

A massive storm in the town of Prospect, about an hour north of Columbus, was to blame for the fertilizer runoff that carried the nitrates downstream. 

Amid the nitrate advisory, babies under six months and expecting mothers were advised not to drink water in the affected areas.  Columbus Department of Utilities says the water is now safe to consume for the two groups.

Utility officials did not provide a reason for the lower levels, however recent heavy rains may have helped dilute the water.