The presence of pesticides in river water, even in very small amounts, compromises the life cycle of aquatic organisms, such as algae and fish (tumors, interference with hormonal systems, respiration, growth, reproduction, etc.). Pesticides are harmful to the environment and a threat to the health of those who use these substances, notably those working in the agriculture (headaches, fertility loss, carcinogenic effect, etc.). But most importantly, the prolonged consumption of drinking water, fruits, and vegetables containing pesticides, even at very low doses, presents long-term risks to health. The question of pesticides brings up particular concerns in the area of drinking water production and wastewater treatment because these are among the principal pollutants that impact water resources.

Treatment of water contaminated by pesticides may, depending on the situation, call for the use of either powder or granular activated carbons. The choice of activated carbon will depend largely on the concentration of pesticides, the manner in which the activated carbon is used and the presence of other compounds to be eliminated.

Activated carbons can be used to eliminate accidental or seasonal pollution of water caused by agricultural and industrial effluents. They can be introduced to the drinking water or wastewater process upstream of the main water treatment process or even directly injected into surface waters

GACs are, for their part, well suited to the continual elimination of pesticides and other pollutants. They would then be used as a support activity for filtration in water treatment plants, either during or after the clarification stage.