The Waikato Regional Council says it's fed up with farmers and spray contractors breaking the rules around the use of agrichemicals.
Derek Hartley, the council's incident response team leader, says he has been getting complaints from the public that landowners aren't notifying their neighbours before they spray, as is required.
"Council's first concerns are that people spraying and people who are contracting spray applicators to come into their property are not notifying their neighbours. Which means that people living at the boundary of where the spray operations are going on don't have the opportunity to remove themself from harm's way or rearrange a family barbecue or protect their water supplies."
Mr Hartley said people's health is being put at risk.
"I certainly wouldn't want to be breathing in or drinking some of the agrichemicals that are being sprayed around. They're not designed for human consumption - they're designed to take care of funguses and pests."
All the council's investigations to date have shown some professional spray contractors are not that professional after all, he said.
"As we've made inquiries into some of those non-notifications, we've found out that some of the spray contractors are actually not appropriately qualified or certified in the first place and maybe shouldn't be spraying for hire or reward."
And the Rural Contractors association echoed the concerns of the council saying it too is concerned about unqualified people spraying agrichemicals in public places.
But the association believes it is toothless councils, too timid to enforce their own rules, that are largely to blame for the problem.
Chief executive of Rural Contractors Roger Parton agrees that people who are applying agrichemcials in a public place need to be trained and accredited but he said it is limp enforcement that has allowed the current problems to arise.
"We believe that if they (sprayers) have the appropriate accreditation and the local authorities enforced their bylaws this should not be a problem.
Mr Parton said Rural Contractors has two qualifications for sprayers.
A basic chemical applicator qualification for people learning the job and a registered chemical applicator - for professionals who have clocked up more than 200 hours spraying.