Eight prosecutions have been undertaken and 20 infringement notices issued after non-compliance with Otago dairy farm effluent discharge rules reached its ''second-worst'' level in recent years.
The Otago Regional Council's regulatory committee heard this week that non-compliance in the 2014-15 financial year was the second highest since the council introduced its effluent discharge enforcement policy in 2007-08.
And a report considered by the committee showed that ORC enforcement action over effluent rule breaches also peaked in 2014-15, with 18 infringement notices issued and 25 prosecutions undertaken.
Council environmental monitoring and operations director Scott MacLean said in the report that 451 dairy sheds were operating during the 2014-15 Otago summer milking season, and 416 (89.5%) were compliant.
But 48 dairy farms (10.5%) were found to have one or more breaches that could potentially result in ''adverse effects on the environment''.
Twenty out of the 48 non-compliant farms were in ''serious non-compliance''.
Approached for comment, regulatory committee chairman Cr Sam Neill said the many infringement notices reflected a ''disappointing'' situation.
A lot more work clearly needed to be done, but he remained optimistic that improvements could be achieved.
He agreed a mix of awareness-raising, monitoring and enforcement was needed.
And it was ''timely'' that the ORC was working increasingly closely with rural support and advocacy organisations such as Federated Farmers and Dairy NZ, to help raise awareness and to provide support for dairy farmers.
Installing fail-safe devices on irrigators was a practical way of preventing accidental effluent ponding, he said in an interview.
The 2014-15 dairy farm inspections report noted several forms of effluent rule non-compliance: stalled and failed travelling irrigators; discharges on saturated soils; overflowing ponds and sumps; ponding; and discharges to rivers.
The ''failure of infrastructure'' was not limited to old infrastructure, the report said.
Mr MacLean said that ''unfortunately'' the common element in most failures was ''human intervention, or lack of it''.
It was pleasing to see more owners taking a ''proactive staff management/training role on effluent disposal'' but this was still ''not the norm''.
''This issue needs to be at the forefront of all dairy owners' and sharemilkers' responsibilities,'' he said.
The eight prosecutions involved three alleged breaches in North Otago, one on the Taieri and four in the Clutha area.
Enforcement action had resulted in several infrastructural and other improvements being made, including installing a pump and growing native plants on a riparian strip.
The current monitoring and enforcement regime for dairy effluent had been ''successful in creating on-farm changes'', mainly in infrastructure and practices.
But having ''excellent infrastructure'' did not mean good management structures were in place to ''maintain and monitor the systems, and train staff on the importance of effluent management''.
It was timely that the council reviewed the approach it was taking on dairy effluent monitoring.
''Enforcement by itself can only go so far.
''A balanced approach between reinforcement of good practice/behaviour and compliance/enforcement was needed.''
Field days that focused primarily on good practice should be supplemented with information on compliance issues being observed by council staff, the report said.
At a glance
Compliance 2014-15
• 451 dairy sheds operating; 416 compliant
• 48 dairy farms had one or more breaches; 20 seriously non-compliant
• Effluent discharge: 20 infringements, 8 prosecutions
• Effluent rule breaches: 18 infringements, 25 prosecutions