Five petrol stations in Tamworth are being investigated for potential contamination, but have been stuck on a backlog with hundreds of other sites.

The NSW Environment Protection Authority (EPA) couldn’t confirm when the sites – which are not limited to petrol stations – were first listed as “under assessment”, but The Leader understands many have been left of the backlog for years.

Without knowing the full extent of the possible contaminations, it’s impossible to say if neighbouring properties or nearby water sources have also been effected.

The issue is not isolated to Tamworth – Inverell has five sites being assessed, while another four are still undetermined in Armidale.

Narrabri has three sites under investigation, while Quirindi, Gunnedah, Glen Innes all have two each. Even the small communities of Uralla, Moonbi and Guyra all have a site stuck in the backlog.

An EPA spokesperson said the organisation planned to completed the assessment of the Tamworth Caltex and Mobil sites by early 2018.

“A similar timeframe is expected for the assessment for the BP site,” they said.

Tamworth council general manager Paul Bennett said council had worked closely with the EPA in previous investigations, such as the petrol leak at the Woolomin petrol station, where the contamination has been deemed significant enough to warrant regulation.

“We like to see investigations progress as quickly as the situation allows to ensure the safety of our residents,” Mr Bennett said.

When a site is determined as significantly contaminated – Tamworth Coles Express on Goonoo Goonoo Rd – it is added to the public record, with notification provided to the local council. They must then record this information on property planning certificates.

If there is an impact on neighbouring properties, it is the responsibility of councils to consider the inclusion of that information on the planning certificates.

There are thousands of toxic sites across NSW. The EPA insists it can manage them, but a Fairfax Media investigation has found the system is full of holes.

An independent review and report of the EPA, released in May, found the agency was taking 12 months to issue preliminary investigations orders into contaminated sites rather than the one month set down in its manuals. 

It also found the agency was slow to prioritise contaminated sites.

Around 1600 of sites have been reported to the NSW EPA and are listed on its website.

But the authority has struggled to assess or prioritise these sites. Around 44 per cent are still “under assessment” and around 100 sites notified to the EPA before mid-2013 remain to be allocated for assessment. The EPA said it expects to have sites notified before mid-2013 cleared by early next year.

EPA chairman Barry Buffier says the backlog occurred after reporting requirements changed in 2010, leading to landowners to report suspected contamination on masse.

“They went overboard and provided us with sites that had no information to suggest were contaminated,” he says.

When assessing a site, the authority does not necessarily conduct an on-site inspection but relies on information it receives, often from the polluter.

“Going out and looking at the site is not going to tell you whether it's contaminated or not by and large,” he says.

Mr Buffier says the agency was adequately resourced to get through the backlog.