Lough Neagh Sand Traders and the Shaftesbury Estate have welcomed the fact that the court has recognised that they have acted lawfully and that they are following proper procedure.
"Indeed since this case we have carried out and submitted a further vast body of research and studies, which further indicates our desire to be compliant with the proper planning process," they said in a statement.
Friends of the Earth failed in a High Court bid to force a halt to sand dredging from Lough Neagh.
The environmental group was challenging a former Stormont Minister's decision to issue an enforcement notice rather than order an immediate stop to the extraction of up to 1.5m tonnes a year from the UK's largest fresh water body.
The move in 2015 by Mark H Durkan during his tenure as Environment Minister enabled dredging firms to lodge an appeal with the Planning Appeals Commission (PAC).
But a judge rejected claims that the decision amounted to Mr Durkan effectively giving consent by "turning a blind eye" to the practice.
Mr Justice Maguire held there was legal authority for the conclusion reached after consideration of the issue.
"This is not a case where the Minister/Department has been standing by and doing nothing," he said.
Sand traders have been carrying out extraction work on the Lough, a designated Special Protection Area due to its wintering population of birds, since the 1930s.
No planning permission for dredging has ever been sought or obtained.
However, firms have been able to continue activities pending the outcome of their appeal to the PAC on the enforcement notice.
Friends of the Earth mounted a judicial review challenge, claiming the failure to halt extraction brought planning laws in Northern Ireland into ridicule.
Counsel for the group likened the alleged breach to something from a primitive dictatorship.
The court heard Lough Neagh has internationally recognised environmental significance, and been classed as an area of special scientific interest.
It was contended that under Environmental Impact Assessment law the Minister acted unlawfully.
But lawyers representing the Department of Agriculture, Environment and Rural Affairs contended that the environmental group had "grossly overstated" the impact of dredging on Lough Neagh.
The court also heard sand dredging firms have spent £500,000 on studies to back their case that they are causing no environmental harm to Lough Neagh.
Steps have been taken to ensure they have authority for both retrospective and future extractions, the companies' legal representatives submitted.
Dismissing the judicial review challenge, Mr Justice Maguire held that the Minister's objective was to secure a situation where steps were taken to ensure the situation had to be confronted by the dredging firms.
Acknowledging that his determination will not settle the issue, the judge pointed out that the Minister has not ruled out the option of serving a stop notice in future.
He added: "This is a case where it is more likely than not that events will occur which will require continual appraisal."