Eleven of Marlborough's 39 wineries breached their waste water resource consent conditions during last year's harvest, a council report says.
Only two were fully compliant, down from 14 the previous year.
The report, to be discussed at the Marlborough District Council's environment committee meeting on Thursday, does not name any wineries but says that 11, up from four the previous harvest, were non-compliant and needed remedial action to prevent ponding and potential soil damage and aquifer contamination from winery waste water.
"The compliance group considers that wineries still need to be more familiar with the permitted activities standards and resource consent conditions for discharging wastewater to land.
"Some wineries do not appear to have taken on board the recommendations and comments from the previous monitoring period."
The report says council staff had discussed expectations with winery staff, who, they said, had agreed to take corrective actions and demonstrated a willingness to improve their operations and records.
Council staff would continue to focus on education about the criteria required for consent conditions and plan rule standards this year, it said.
"The compliance group's expectation for the 2013-2014 report is that wineries are to provide the required information for consent conditions and plan rule standards. Where this information is not provided . . . enforcement action may be undertaken where wineries have failed to provide information for three consecutive years."
The council report said there were 39 wineries in the Wairau and Awatere rural zones, with 34 in the Wairau Plains, one north of Blenheim, and four in the Awatere area.
It said 37 wineries were assessed for compliance on annual reports, soil samples, and documents they submitted on wastewater volumes, discharge dates, and disposal area sizes.
The wineries had different requirements, the report said, but most had similar conditions dealing with wastewater volume, nitrogen loading to the land, wastewater and soil sampling, discharge rate, odour, buffer zones, annual reporting to identify adverse environmental effects, and record keeping.
Two wineries were fully compliant. Eight wineries (down from 21) were assessed as having minor breaches because one condition or rule was not met. Two wineries had breached several conditions or rules.
Although wineries provided records for the volumes of wastewater discharged, most did not keep clear and accurate daily records for the volumes and areas that wastewater was discharged to. As such, discharge rates were estimates, the report said.
The main problem found during inspections was ponding, caused by too much waste water discharge. Most ponding was minor and able to be corrected without long-term environmental effects.
Eleven wineries (four the previous vintage) were assessed as non-compliant because consented annual and daily discharge volumes and discharge rates were breached; only one of two soil samples was taken; or wastewater sample results were not provided. These breaches were not considered significant enough to warrant enforcement actions, the report said.
Liquid waste from winemaking is mainly water used for cleaning floors, equipment, fermentation tanks and barrels. It tends to be seasonal.
The Marlborough Express