Tasmania’s economic regulator still has some concerns about the quality of the state’s sewerage systems.

Tasmanian Economic Reg­ulator chairman Glenn Appleyard says the group’s new review covers TasWater’s first year of operation, July 2013 to July 2014.

“Despite the investment of a further $38 million in sewerage infrastructure during 2013-14, the performance of Tasmania’s wastewater assets continues to fail to meet environmental and public health standards,” Mr Appleyard told News Corp reporters.

“Sewerage performance, which has declined steadily since 2009, has not been helped by delays to major infra­structure upgrades and maintenance works.”

But the criticism was tempered by some kind remarks.

“Increased investment in water infrastructure has ­greatly reduced the percentage of the Tasmanian population that were receiving water that was not of drinking water quality,” Mr Appleyard said.

The regulator noted that performance and complaints reso­lution had improved.

The review found that customers usually experienced under 30 minutes of water service inter­ruptions, while TasWater was seen to respond quickly to sewerage service inter­ruptions as well.

TasWater acting chief executive Dean Page told The Mercury that report showed a “massive challenge” ahead for the company, as it seeks to improve the transport and treatment of sewage.

“We acknowledge the ­majority of our treatment plants do not perform to accept­able standards, and we have a significant capital ­investment ahead,” Mr Page said.

“Having made inroads into drinking water quality issues, sewerage will now be more of a focus as part of TasWater’s plan to spend $330 million on infrastructure development and upgrades over the next three years.”

He said there were planned projects to improve facilities in Kingborough, Rose­bery, Bridport, Burnie and Launceston.

TasWater has indicated that it will be a challenge to complete the upgrades while also paying dividends to its 29 shareholder councils.