Council, in deciding to go with the staff recommendation of a north short pipe, said the effluent would receive extra treatment including additional sand filtration, further phosphorous removal and UV disinfection.

Council also said it would investigate further reuse options, particularly with respect to the Pambula-Merimbula Golf Club.

Councillors were told the Environmental Protection Agency (EPA) had mandated the outfall and Cr Jo Dodds asked for clarification about council's obligation. Director of assets and operations Anthony McMahon said the council had been given direction by the EPA and the project had been registered as a matter of state significance. "It is something we have to do," Mr McMahon told council.

However, while the EPA said it was supportive of council's work, it had not mandated an outfall.

In 2008, the EPA placed a condition on the Merimbula Sewage Treatment Plant environment protection licence requiring council to comprehensively investigate both beneficial reuse and disposal options available for treated effluent generated at Merimbula.

A spokeswoman for the EPA told the News Weekly that at the completion of the investigation, the EPA required council to nominate a preferred option for the beneficial reuse and disposal of treated effluent.

On receipt of council's preferred option - an outfall - in 2013, the EPA placed a condition of the Merimbula STP licence requiring council to obtain the necessary approvals, construct and commission a deep water ocean outfall for the disposal of treated effluent.

The EPA said its concern was to ensure the Merimbula sewage treatment system provided an effective and safe outcome for the environment and the community.

"The EPA has required council to develop options that integrate treatment, beneficial re-use and suitable disposal at times when beneficial re-use is not possible," the spokeswoman said.

"The EPA is supportive of the scientific work the council has been undertaking and is pleased to see that this matter is progressing."