The Crafar farming family has lost its appeal against convictions and sentences for dirty dairying practices on a Waikato dairy farm.

The High Court at Hamilton yesterday dismissed the appeals related to effluent prosecutions brought by the regional council, Environment Waikato (EW), following problems in 2007 and 2008 at a property owned by the Crafar company Hillside, southwest of Hamilton, EW said in a statement today.

Hillside directors Allan and Frank Crafar were fined $29,500 each on 10 charges, while Allan's wife Elizabeth, another director, was fined $1500 on four charges.

Justice Pamela Andrews said Allan, Frank and Elizabeth Crafar could not succeed on any of the grounds of their appeals against conviction and dismissed them.

She also found that they could not succeed in their appeal against the fines imposed.

The Crafars had argued that they should not have been personally found guilty by the District Court and the judge erred by holding them criminally liable for the actions of their sharemilker.

They also argued the fines were excessive.

However, Justice Andrews said the fines imposed on the Crafar brothers were at the lower end of the scale.

EW's investigations and complaints manager Patrick Lynch said the decision confirmed that the council had brought appropriate prosecutions in the Hillside case.

"We take any decision to prosecute very seriously and have robust processes to ensure we only take action where warranted."