Whanganui's new wastewater treatment plant is meeting resource consent conditions as commissioning of the $40 million facility continues.
Tighter conditions kick in on November 1 but council's infrastructure committee chairman Alan Taylor said these were already being met.
"The wastewater treatment plant is already exceeding expectations in terms of the cleanliness of the water at the end of the treatment process in this relatively early stage of the project," he said.
The consent from Horizons Regional Council specifies the concentration of key contaminants which can be discharged to the ocean and wastewater is sampled regularly.
Taylor said some odour could be expected from the plant throughout the commissioning process which ends in March.
"A slight smell was always expected as we work through commissioning at the plant, especially when parts of the structure are opened up for testing," he said.
"Of course, we are dealing with a plant which treats biological and chemical waste so at times there will be a smell."