Progress has been made in a $35 million project to upgrade one of South East Queensland’s most important water treatment plants.

A filtration upgrade at the Mt Crosby East Bank Water Treatment Plant in Ipswich, to replace 20 sand filters that help purify the region’s drinking water, is almost 50 per cent complete.

The Mt Crosby water treatment plants, divided into East Bank and West Bank, are critical to the operation of the SEQ Water Grid and provide more than half of Brisbane and Ipswich’s daily water supply.

The project is designed to improve the plant’s filter design and controls so that it can better maintain water supply during extreme rain events and flooding.

In total, 20 filters at the plant require refurbishment which will be completed in five stages. The first year of construction has been completed on time and nine refurbished filters have successfully returned into service.

Taking filters offline has resulted in reduced production at East Bank, so Seqwater has been using the SEQ Water Grid and other treatment plants across the region to help supplement drinking water supply during the project.

The upgrade work will help the plant be more able to treat water with high levels of turbidity or sediment which can result from extreme rainfall events across the Wivenhoe catchment washing soil and debris into the creeks and waterways.

This project marks the first time the sand filters have been replaced since they were progressively installed over 20 years from 1948. The new filters are expected to be in use until about 2070.