March 11, 2011

Just the Facts – Pesticides Q&A

Q: What are pesticides?

Pesticides are any substances or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest. Pests can be insects, mice and other animals, unwanted plants (weeds), fungi, or microorganisms like bacteria and viruses. The term pesticide usually refers to insecticides, herbicides, and fungicides. A pesticide is also any substance or mixture of substances intended for use as a plant regulator, defoliant, or desiccant.

Q: Where does the contaminant come from?

From the watershed where pesticides are applied, both in urban and agricultural environments.

Q. Have pesticides been found in my drinking water?

The only regulated pesticide that has been found in your drinking water is Atrazine, which has an EPA-mandated maximum level of three (3) parts per billion (ppb). DMWW’s lab has never found pesticide levels in excess of three (3) ppb in your drinking water, even in periods of increased agricultural activity.

Q. How does Des Moines Water Works test for pesticides?

DMWW uses gas chromotography and gas chromatography-mass spectrometry to scan for pesticides in the water. We have been testing for pesticides since 1987.

Q: How does Des Moines Water Works treat for pesticides?

Powdered activated carbon, which is added during the treatment process, does absorb some pesticides, including atrazine, before settling out of the water. However, the best way to prevent pesticides from reaching the finished drinking water is through watershed protection and good land management practices which reduce the amount reaching the source water.

Q: What are the health effects?

Atrazine can cause cardiovascular problems and reproductive difficulties.

For more information, call Des Moines Water Works at (515) 283-8700 or visit

Want more Just the Facts? Visit:

Posted by: Laura Sarcone No Comments
Labels: , , , , Posted in Health, Water Quality

Leave a Reply