Casper herbicide use in City of Wanneroo concerns Merriwa resident

Photo: Linda Robertson
Photo: Linda Robertson

A MERRIWA resident has raised concerns about a herbicide, Casper, used on parks in Merriwa, Ridgewood, Quinns Rocks, Marangaroo and Madeley.

Linda Robertson said she noticed a sign at Addison Park in Merriwa saying ‘Caution – Casper being applied – avoid contact with area when signs are displayed’ last month.

A sign advised people that Casper herbicide was applied at Addison Park in Merriwa last month. Picture: Linda Robertson.

After trying to contact the City to find out what ‘Casper’ was, she researched it herself and found the product had strict guidelines.

“The general instructions required that re-entry to the area within 14 days be restricted to those wearing cotton overalls buttoned to the neck and wrist and chemical resistant gloves to the elbow,” she said.

“This oval is used by every dog owner in the area and is the play area for Merriwa Primary School who started term 1 on February 4, meaning that children were unrestricted in their play as the school had no idea.”

What is Casper?

According to Nuturf, Casper contains dicamba and prosulfuron and controls weeds such as fleabane, cats ear, bindii, plantain, creeping oxalis, white clover and dandelion.

Ms Robertson said she was concerned it could have harmful effects on people and pets that came into contact with it, and could leach into water systems.

The City’s assets director Harminder Singh said Casper was used in rotation with other turf registered broadleaf herbicides to control broadleaf weeds in turf according to product labels.

“To date, the City has applied one application of Casper herbicide to Addison Park and Ridgewood Park in Merriwa, Belhaven Park in Quinns, Cabrini Park in Marangaroo and Kingsway Cricket in Madeley,” he said.

“Casper herbicide is used as part of an integrated pest management program for the control of broadleaf weeds in public open space.”

Mr Singh said the City notified people who had registered on its spraying notification list by telephone before any pesticides applications took place in their suburb.

Linda Robertson (Merriwa) at Stradbroke Gardens pond. Photo: Martin Kennealey

“City staff and contractors also place signage around public open space whilst pesticides are being applied to ensure the public are notified and informed of any restrictions on entering the site,” he said.

“The product label for Casper states that the safe re-entry for the general public is permitted once the product has dried on the leaf of the turf.”

The Australian Pesticides and Veterinary Medicines Authority (APVMA) assesses and approves agricultural and veterinary chemical products before they are sold and used in Australia.


It reviewed Casper in 2012 and found that there should be no adverse effects on human health if used according to the label instructions.

“Staff and contractors follow the safety precautions on the specific pesticide label instructions when applying chemicals throughout the City,” Mr Singh said.

“Contractors who apply pesticides in the City are required to hold a Department of Health pesticide technicians licence prior to undertaking any pesticide applications.”

Mr Singh said members of the public should take whatever precautions were listed on signs at parks during and after pesticide applications.

Algae blooms in Ridgewood pond

Ms Robertson said she thought it could be causing blue-green algae in the pond at Stradbroke Gardens, Ridgewood and was concerned it would be “deadly to aquatic life”.

Mr Singh said Casper was applied to the active playing surface at Ridgewood Park but not the adjacent passive park at Stradbroke Gardens which surrounds the lake.

“The City has no confirmed cases of blue-green algae in Ridgewood Lake,” he said.

The City of Wanneroo will drain the Ridgewood lake this year and remove sediment to improve water quality. Picture: Linda Robertson

“The primary purpose of the lake is water storage for the irrigation of Ridgewood Park.

“The lake also serves as a stormwater collection point for a number drainage systems in the adjacent streets.

“In general, algal blooms are normally attributed to high levels of nutrients in water.

“The City conducts weekly litter removal from the basin edge with all other rubbish in deeper parts of the basin removed on an ‘as required’ basis.”

The City of Wanneroo will drain the Ridgewood lake this year and remove sediment to improve water quality. Picture: Linda Robertson

Mr Singh said the lake water was tested in October 2015 and December 2017 and there was no need for more frequent water testing.

“Other programmed works in the next three months include the draining of the lake and removal of sediment to improve the quality of water,” he said.

“The replacement of the lake liner is programmed for the 2019-20 financial year.”

Mr Singh said the City was finalising a pesticide management policy, which would be presented to the council later this year with a report on submissions received during public consultation in late 2018.

He said residents concerned about pesticides used in the City could contact the parks and conservation manager via 9405 5000.