AN OPEN ‘anaerobic digestate’ lagoon the size of an Olympic swimming pool has been given a certificate of lawful development because it was put in more than four years ago – despite concerns it could leak into sensitive local waterways.

A retrospective planning application was made three years ago by farming firm FM Green for the unauthorised 2,500-square-metre capacity lagoon, put in six years ago at Great Treaddow Farm near Llangarron.

But while the application remained undetermined by Herefordshire Council planners, the farm made a separate application last summer for a lawful development certificate, saying that as the lagoon had been installed in May 2020, it was now immune from planning enforcement.

The 500-member Wye Salmon Association previously said it ‘objected strongly’ to the plan, given what it claimed was the threat it posed to the nearby Garren and Gamber brooks, tributaries of the River Wye.

These “should be viable spawning grounds for salmon but are not”, largely due, they said, to pollution from farms.

And liquid digestate “poses an extremely high environmental risk” to watercourses and even to ground water, they claimed.

Llangarron Parish Council also objected, saying there was no evidence to prove the efficacy of the lagoon, which is not covered or bunded and for this reason does not follow best practice.

This too raised concerns, with nearby resident Jennifer Clark saying she was appalled that the council’s failure to determine the earlier, retrospective application in good time “has now given the applicants the opportunity to apply for a lawful development certificate”.

Explaining the decision to grant this, planning officer Rebecca Jenman said: “Whilst recognising the concerns raised by the objector, these are not material to this type of application and there is no evidence to contradict the applicant’s claim.”

The original undecided planning application has now been withdrawn.