Two men have been fined $9,000 each, plus court costs, in the Armadale Magistrates Court for illegally dumping waste in State Forest in the Perth Hills suburb of Ashendon in January last year.
Tom Songsak Cox and Luke James Rodwell were convicted earlier this month and fined by Magistrate Dianne Scaddan.
Environment Minister Stephen Dawson said the convictions should act as a warning that illegal dumping is a crime and offenders face serious penalties.
The court heard the men were employed to dispose of the contents and fittings from a Northbridge restaurant which had closed down.
Internal security camera footage from the restaurant captured Cox, Rodwell and another two unidentified persons removing the shop's contents and fittings on January 19, 2018.
A few weeks later, on February 9, 2018, Water Corporation staff discovered discarded waste within a priority one drinking water source area in State Forest near Albany Highway.
The officers photographed the waste and contacted the Department of Water and Environmental Regulation.
An investigation by the department traced the waste back to the restaurant and notified the owner.
The owner confirmed that the waste was from his restaurant and that he had paid to have it removed and legally disposed of by Cox and Rodwell.
However, the pair opted to illegally dispose of the waste.
As stated by Environment Minister Stephen Dawson:
"If people think they can illegally dump rubbish and get away with it, they have another thing coming.
"These fines send a strong message that people who break the law will pay a price.
"Illegal dumping is not only costly for the community but is also detrimental to the health of our environment."