Campaigners fighting plans for a £450m incinerator have lost a Court of Appeal bid to block the plant.
Recycling and waste firm Covanta wants to build the incinerator at Rookery Pit, Stewartby, near Bedford.
In November 2018, campaigners lost a High Court case against a permit for the plant being issued by the Environment Agency.
The challenge by Bedfordshire Against Covanta Incinerator against the ruling was rejected at the Appeal Court.
In a statement, the campaign group said there was "great sadness" over the court's decision and said it had "done everything possible under the Judicial Review process".
The group had claimed "toxic metals" would be discharged into people's drinking water.
However, both the Environment Agency and Covanta Energy denied there was any risk to the public.
A spokesman for Covanta said it was "pleased with the Court of Appeal's decision to uphold the Environment Agency's issuance of the environmental permit for the Rookery South project".
He added: "We look forward to advancing construction on the Energy Recovery Facility, which represents critical waste infrastructure that will help the UK achieve national landfill diversion and meet the energy needs of over 112,500 homes."
An Environment Agency spokeswoman said: "We are aware of the Court of Appeal's judgement and are satisfied our original decision has been upheld."