Background and Explanation
The discharge of contaminants onto or into land is an essential part of many resource use activities throughout the Region. In the absence of rules in regional plans enabling these discharges, most would require resource consents. The definition of contaminant* in the RMA is sufficiently wide to include discharges of relatively benign products such as irrigation water, soil conditioners and fertilisers, as well as hazardous substances, wastes and other products that may have significant adverse effects. The activities covered in this Chapter are:
Integration with Water and Air Management
This Chapter focuses on discharges of contaminants onto or into land where the primary effects of the discharge are likely to be on the land and soil resource in terms of soil contamination, increased risk from natural hazards or infilling of sensitive environments. However, the discharge of contaminants onto or into land can affect other natural and physical resources such as air or water. There are many examples of discharges onto or into land that occur in the Region which may not cause soil contamination or adversely affect land but may have other adverse effects such as objectionable odour.
Discharges to air such as those from abrasive blasting which will primarily affect air quality but may result in discharges of contaminants to land in some circumstances are addressed more fully in Chapters 6.1 and 6.2.
Discharges onto or into land, such as on-site sewage, farm animal effluent discharges, stormwater, fertiliser use and the use of treated biosolids as fertiliser substitutes are unlikely to cause significant soil contamination. The primary effects of these discharges are mainly related to water quality which is discussed in Chapter 3.5. Discharges onto or into land around geothermal features are addressed in Module 7 Geothermal.
The methods developed in Chapters 3.5, 6.1, 6.2 and Module 7 Geothermal take into account the objective and policy directions developed in this Chapter.
Integration with Accelerated Erosion Management
This Chapter deals with the adverse effects of discharges onto or into land, soil and water. There is an overlap with Chapter 5.1, which addresses the adverse effects of soil disturbance activities such as moving or removing soil, land contouring, blading, cutting of batters, blasting, extraction and roading and tracking. Chapter 5.2 addresses soil disturbance and vegetation clearance where soil from the disturbance is disposed of as cleanfill or overburden. Some of these activities may result in the discharge or overburden into specific sites. In those circumstance there is a discharge into or onto land that requires a consent under s15 of the RMA, unless enabled by a rule in a plan. This Chapter addresses these discharges.
Meaning of Significant Risk
This Chapter uses the term “significant risk”, when referring to activities that may have the effect of contaminating soil. Significant risk in terms of chemical contamination of soils can be determined through reference to relevant guidelines. The process of developing New Zealand specific guidelines for managing risk from hazardous substances is underway through the development of regulations under the Hazardous Substances and New Organisms Act 1996 and the development of guidelines for managing contaminated sites1. Where New Zealand specific guidelines do not exist, relevant guidelines from overseas organisations such as the Australia/New Zealand Environment and Conservation Council (ANZECC) or the United States Environmental Protection Agency (USEPA) can be used. Decision-makers will need to determine which of these overseas guidelines is most appropriate for the activity being considered.