The spraying last August in both urban and rural areas of the county was aimed at controlling the spread of West Nile Virus.

David Brown – manager of the Sacramento-Yolo Mosquito and Vector Control District – says they contracted out with an independent water sampling company to test water quality at various sites and the results show no significant mortality to fresh water plants and animals.

"More than half of the areas that they sampled had no detection, any of the areas where samples were detected, they broke down to either non-detectable or were sharply reduced within 12 hours."

All water quality monitoring was done by a company called Larry Walker Associates.

Meantime, so far this year, no birds, sentinel chickens, mosquito pools or humans have tested positive for West Nile Virus.