Internal documents reportedly show Hobart's largest wastewater treatment plant regularly breaches environmental standards for discharging chemicals.

Serious environmental problems with the Macquarie Point Sewage Treatment Plant are detailed in TasWater's business case for the plant's proposed relocation.

TasWater wants to move the plant to Selfs Point, further up the Derwent, and outfit it with more modern infrastructure.

But the business case shows regular environmental breaches for toxic discharge into the River Derwent. 

Documents obtained by the ABC under Right to Information allegedly show TasWater failed to meet a 2016 regulatory commitment it made to the Environment Protection Authority (EPA) to improve environmental compliance for the state's larger wastewater treatment plants.

More details are accessible here.