Work is due to start next month on Herefordshire’s second constructed wetland, at a cost of £1 million.

It is intended to enable more building in the county by compensating for the likely water pollution this will generate. Developers pay the council for “phosphate credits” depending on the size of each development, which fund the wetlands.

The innovative approach has already won the county an environmental award for its first such wetland, at Luston north of Leominster.

A tender to appoint a contractor for the second, at the Tarrington waste water treatment works between Hereford and Ledbury, will close for bids on September 3.

The council’s tender notice gives the contract start date as September 26, taking until the end of October next year to complete.

The council granted itself planning permission for the scheme a year ago.

It explained at the time that the wetland would reduce phosphorus levels in waste water from the nearby treatment works before it drains into the adjacent Tarrington Beck.

This lies within the catchment of the river Lugg, in turn part of the wider protected river Wye catchment.

Consisting of an upper and lower lagoon, the wetland will also “deliver a range of ecosystem services, including enhancing biodiversity, carbon storage, amenity and wellbeing”, the council’s statement said.

A building “moratorium” since 2019 in much of Herefordshire caused by the nutrients issue is thought to have cost the county millions in lost investment – which the phosphate credit scheme is now addressing.