Work to upgrade a waste water treatment plant as part of the River Wye clean-up is nearing completion.
Welsh Water says the £3.5 million upgrade of its plant in Weobley, Herefordshire, will be completed by early 2023.
It said the plant had already treated the wastewater it received to a “high standard”, but the main improvement was to remove phosphates.
Campaigners say the River Wye has excessive algae growth – often caused by high levels of phosphate in the water.
This growth makes it difficult for wildlife to thrive, they said, and they have raised concerns about the level of pollution, which is believed to be affected by agricultural practices and sewage.
In the summer, a statue of the Virgin Mary was taken on a river trip to raise awareness of the issue.
The legal requirement for phosphate before the water is discharged into streams and rivers is 1.5 mg.
Using iron to treat the water means that about 0.4 mg is discharged, the company said.
Data from Natural Resources Wales and Welsh Water for the River Wye shows that 72% of phosphate comes from land use and 23% from waste water.
The river flows through mid and south Wales, Herefordshire and Gloucestershire.
“Phosphates can cause algal blooms. So removing them from the treated wastewater will help lower levels in nearby Newbridge Brook – in turn benefiting the quality of the river and aquatic life,” said a spokesman for Welsh Water.
Jenny Grubb, river quality links manager, added that the CEO Peter Perry had committed to invest an additional £100 million over the summer to improve water quality in England and Wales.
“And £60 million of that will be for phosphate removal,” she said.
She told the BBC that the company was aware of the power of feeling about phosphates.
“It’s definitely interesting for our customers and we definitely took note of that and just felt that further investment couldn’t wait until our next investment cycle which was due to start in 2025.”
Welsh Water has installed similar technology at other treatment plants and will soon begin work at other Herefordshire sites, including Leominster and Rotherwas.
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