He said the discharge of paint at the landfill was not a one-off.
"We believe the effects were likely to be minor but as it had been a practice that had been going on for some time; there is no evidence that was so."
The paint leakage first became public in October when Transfer Station neighbour Colin Gowans brought photographs into the Times-Age office.
He raised the issue with the Greater Wellington Regional Council saying the contaminates could leach into rivers and other waterways.
Mr Cross said the fine of $300 was not a discretionary amount but was set by regulation.
Masterton District Council assets and operations manager David Hopman said the council would not oppose paying the fine. He said the council had for years been drying small amounts of paint which people were encouraged to bring to the Transfer Station - rather than carelessly disposing of it elsewhere - by drying it on sawdust at a designated spot at the landfill. Once it had dried it was scooped up and transported to Bonny Glen.
But the council did not have a consent to dry paint on sawdust.
Mr Hopman said as a result of the infringement notice the district council was awaiting direction from Greater Wellington on what was acceptable.
"We may have to put the sawdust on a concrete pad."
He said it was not a matter of large quantities, as commercial paint waste was not accepted at the Transfer Station.
"We are only talking about a half tin, maybe once a day," Mr Hopman said.