Tomlinson Environmental is disputing the city auditor's finding it has failed to provide information on the Springhill landfill or that it contaminating nearby groundwater.

Michael Clement, the company's general manager, appeared on CBC's All in a Day to respond to the damning audit on Friday.

The city's auditor general Ken Hughes released a report Thursday saying the city had potentially missed out on revenues it is entitled to from the landfill. Tomlinson withheld important documents that would give the city an accurate account of the royalties it's owed, Hughes said.

"It just isn't possible to be sure that the revenues provided to the municipality were correct," he said.

Clement said that isn't the case.

"Any written requests for information that have been asked of us we have provided the city," he said.

He said the city gets annual reports on the landfill.

"That information is audited by an independent firm yearly and provided to the city."

The landfill was opened by the former Osgoode Township and has been operated by Tomlinson since it opened in 1996. As part of the agreement, which the City of Ottawa inherited with amalgamation, the city is supposed to get a share of revenues.

The city was also notified in December 2017 by the Ontario Ministry of the Environment and Climate Change that contaminated groundwater from the landfill was migrating to neighbouring properties and mixing with surface water outside of the dump.

Clement said they don't believe there is any contamination problem outside of the landfill.

"With an older landfill like the one at Springhill there is always contamination within the footprint of the landfill and our job is to mitigate that as much as possible," he said. "It is not affecting water off the property. We monitor neighbours' wells on a regular basis and there is no contamination in neighbours' wells."

Hughes said the city could be looking at more than $7 million in cleanup costs.

Clement said they have already reached out to the city to talk about these concerns, but wouldn't commit to paying for that cleanup.

"We have had discussions with senior staff to discuss that and we are ready to co-operate with the city in any way we need to," he said. "We want to get going on this and get this cleaned up."

City staff said they were eager for those meetings as well and the auditor said he intends to follow up on this file soon.