Planning applications are said to be “at a standstill” in Wales due to new targets for phosphate pollution in rivers.
In January, Natural Resources Wales (NRW) set new targets for phosphate pollution in Special Areas of Conservation (SACs) across the country.
Frustrated builders and developers say the targets have created a “complete impasse” on developments in some areas.
The Welsh government said some factors “must not be jeopardised”.
Across Ceredigion, there are 45 applications at a standstill because of the new rules, including 47 dwellings and 22 other applications.
Phosphates are naturally occurring minerals found in human and animal waste.
They aid growth of plants, but can lead to a dramatic growth in algae and deplete oxygen levels when they enter water courses in large quantities.
More than 60% of water bodies in affected areas failed the targets set my NRW, including large swathes of the Usk, Wye and Cleddau rivers, and the lower reaches of the Teifi and the Dee.