A wastewater treatment plant is once again sending a bad smell across Lower Hutt

An error with routine maintenance at the Seaview plant, has caused the biological process to become unbalanced.

Wellington Water says the mistake's been corrected, but it has to remove wet sludge to manage any risk - which carries the smell.

It's been an ongoing issue for Seaview residents, after faults with the plant caused a stench to linger for months last year.