Water quality and risk assessments at Marsden Point oil refinery
Dr Mike Stewart led the water quality aspects of an application for renewal of resource consents to discharge contaminants from Marsden Point refinery to the marine receiving environment. Mike worked with experts in hydrodynamic modelling, marine ecology, and human health. The project included an assessment of effects of chemicals that are discharged as part of the refining process (including TPH, PAHs) and a risk assessment of industrial process chemicals used in the process. Mike was responsible for liaising with the client and other consultants to determine the appropriate water quality monitoring to be undertaken to fill gaps in knowledge from current data, which had been collected by Northland Regional Council (NRC) and Refining NZ. In addition, Mike was responsible for integrating the hydrodynamic modelling into his assessment, which was used in the marine ecology and human health risk assessments. The water quality assessment was complicated by Northland undergoing a plan change process during the course of the assessment, which resulted in some of the water quality standards changing.
The application for discharge of contaminants to the marine receiving environment was approved by NRC without a hearing taking place, which saved all parties time and money. This was primarily due to having regular team meetings between the client, consultants, Council and stakeholders (including mana whenua), where issues were discussed and solutions identified prior to lodgment of the application. Dr Stewart has been retained by Refining NZ (now Channel Infrastructure NZ) to undertake risk assessments for new chemicals being used on site.