The three-piece band, comprising Logan Park High School pupils, formed in 2007 with the aim of becoming a covers band. After discovering they were terrible at covers, they found their own sound.
Drummer and vocalist Gabriel Griffin said the group came up with the name honestly - they felt the name reflected their music at that time.
The original line-up altered along the way as saxophonist and vocalist Rowena Rushton-Green arrived and "creative differences" forced a founding member out.
Now Rowena, Gabriel and guitarist and vocalist Sam Vennell are known for their "jazz-influenced noise-rock".
Having moved on from the music of their fledgling days, their unique sound led them to compete for a spot in the national Rockquest final in September.
The group has been busy recording a video for its submission. The first attempt, filmed at "venue of the year" Chicks Hotel, had sound issues, so the pressure was on to re-record and send it away by this weekend, Rowena said.
All three have been into music since they were children and Rowena and Sam plan to study music at university in the coming years.
However, they all know how hard it would be to make a living from their talent unless they began playing "mainstream" music, something they have vowed not to do.
Influenced by groups such as Die! Die! Die!, Thought Creature and Frank Zappa and Charlie Parker, Sewage play regular gigs - one or two per month - and made about $800 from busking in Albion Lane, Gabriel said.
Their aim for the future was "just have fun", Rowena said.
