Cr Richardson said he planned to refer two recent "potentially quite serious" incidents for investigation.

"One involved the application of herbicides in the vicinity of a bus stop where kids were waiting to go to school, and I want to get a full report on that first," he said.

"The other one concerned spraying near an area where the people concerned are organic-based in terms of their farm production.

"I need to get the absolute facts, and I'm talking to those people and asking for council to investigate before I go further.

"What I want to do is establish the truth, and I think that's what's important."

Cr Richardson said he was concerned about how pesticides were used, where else in Australia herbicides were used, and why.

"I also want to know whether [pesticides] are still used in places like Europe and North America, and if not why not," he said.

"I've had several people come in complaining, some of them quite vehemently . . . about the amount of brown vegetation that had appeared, obviously as a consequence of spraying herbicides.

"A number of those people were specifically concerned when they noticed the drainage ditches going brown.

"My understanding is that most of the spraying is contracted, and I want to know what the rules are related to contractors.

"In the next two or three months I'll be putting a bit of pressure on to find that out."