Environment Waikato is to review a major dairy factory waste resource consent to ensure the waste will not pollute groundwater in the future.
Staff sought permission from this week’s Regulatory Committee to review a consent granted to D A Civil Ltd in March 2001 which allows 600 kg of nitrogen per hectare of dairy factory wastewater onto a property on Fencourt Road, near Hamilton. After three years of irrigation, monitoring now shows the application rate may not be sustainable, Resource Officer Barry Campbell told the Committee.
It was possible that significant adverse environmental effects might occur in the future. Submitters to the original consent hearing were concerned about intensive irrigation in terms of application load and odour, and consent conditions included a higher level of monitoring than normal to ensure the load was sustainable long-term, he said.
Mr Campbell said monitoring showed a significant shortfall between the nitrogen applied to the property, and what was removed as crops and livestock.
Staff felt the area could not support such rates and they should be reduced to a more sustainable level. To date, monitoring had not shown any significant increase in groundwater nitrate concentrations or stream contamination, but, given the shortfall in crop removal rates, it was likely the groundwater would start to show effects in the next few years.
Another year of monitoring was needed and discussion with Civil to assess whether different management systems on site would reduce environmental effects that would enable them to prevent adverse effects happening – however by then staff would have to wait another two years until 2008 to be able to review the consent, he said.
Council Chairman Jenni Vernon said she thought the Council should not have to wait and see if damage was happening, as it would then be too late. The consent was contentious when it was first approved and the company would be unlikely to get a consent now for such a high nitrogen irrigation rate.
The Committee recommended notifying the company that a review of the consent would happen.