Canterbury Regional Council says a Springston corporate dairy farmer has been fined a record $90,000 for dirty dairying - the illegal discharge of effluent.
Pollution by White Gold Ltd was reported by members of the public in 2010 who saw effluent flowing into drains that feed into Lake Ellesmere.
The farm manager has already been fined $20,000 and sentenced to 260 hours of community service for his involvement.
The regional council says about a third of Canterbury's nearly 1000 dairy farms were found not to comply with effluent disposal regulations last year.
Council environment regulation director Kim Drummond says the fine shows farmers will be facing harsher penalties for non-compliance.
