The news that trace residues of potentially dangerous farm chemicals have been detected in Melbourne's drinking water is not a cause for concern according to the nation's peak body for the crop protection sector.

Friends of the Earth raised the matter earlier this month, highlighting their Freedom of Information (FOI) request regarding the status of drinking water supplies for Melbourne.

They said the results confirmed the presence of 173 pesticides in the water since 2019, with 89.6 per cent of the detections from the Yarra River near Sugarloaf reservoir, which supplies water to Melbourne.

Chemicals found in the water included agricultural herbicides such as simazine, MCPA and metolachlor, with Friends of the Earth saying it was concerned about the impact on both the Yarra and Sugarloaf.

Matthew Cossey, chief executive at the crop protection sector's peak body CropLife Australia, said the findings represent the result of more sophisticated testing equipment.

He said there was nothing for the public to be concerned about, both in terms of Melbourne specifically and in other areas where water storages are in agricultural regions.

"Advancements in laboratory analysis can now detect compounds at the most minuscule levels, which are thousands of times below safety thresholds or their biological relevance," Mr Cossey said.

"It's disappointing to continually see the deliberate misrepresentation and mischaracterisation of monitoring data by activist groups in an attempt to mislead and scare the community."

Friends of the Earth confirmed the readings were low and that there was no dangerous PFAS material in the samples, but said it had been detected in the past and said it was concerned about the ability of the city's treatment plant to safely filter out residues.

"The Winneke Treatment Plant was never designed to properly filter out micropollutants such as pesticides, microplastics and PFAS," the group said.

Internationally, metolachlor, registered in Australia as a selective herbicide to control certain grasses and broadleaf weeds, has been banned in Europe due to concerns about water quality.

However, Mr Cossey said it was important to distinguish between the presence of a chemical and its toxicity.

"The mere presence of a chemical, be it organic or synthetic, or the number of detections tells us nothing about its toxicity - it's the concentration that counts."

"The examples cited, presented as worst-case scenarios, are thousands of times below safety guidelines, showing pesticides are being used safely, judiciously and in line with their label directions."

"These infrequent and transient detections demonstrate the result of both best-practice application of pesticides, and the robust monitoring systems in place to assure the absolute safety of drinking water."