Health officials are warning residents on Roberts Lake to be careful with your water use.

The North Bay Parry Sound District Health Unit has discovered a blue-green algae bloom in the northern part of the lake in Seguin Township. While some homes and cottages may not be affected, the health unit says it’s hard to determine where exactly the toxins are in the lake. Because of this, property owners are advised against using lake water for cooking, washing or cleaning as the toxins cannot be filtered or boiled out.

Blue-green algae toxins can cause stomach sickness and skin rashes.

Blooms can be identified by the smell of freshly mowed grass or rotting garbage and turn the water around them a pea-soup colour. The health unit will continue to monitor the bloom and provide any updates on the water quality.