Chapter 15 - Discharge of Contaminants to Land Policy 1.4 To undertake targeted monitoring and research to determine the effect of non-point source discharges on surface water quality in water bodies which require enhancement or are highly valued. Policy 1.5 To require self-monitoring for agricultural and industrial activities which discharge waste to land to determine the environmental effects associated with the discharge on soil and water quality. Policy 1.6 To develop land based discharge guidelines for key disposal activities and key physical environments within the planning area which avoid, remedy or mitigate adverse effects associated with disposal. Policy 1.7 To set standards of treatment for on-site human effluent disposal that avoid adverse environmental effects for all properties not connected to the reticulated sewerage system. Policy 1.8 To require comprehensive monitoring of effects associated with the existing and closed landfills in the planning area and take such action as required to mitigate those effects. The objective and policies recognise that activities involving the discharge of solid and liquid contaminants to land have varied effects on the environment. Activities with less significant environmental effects can be subject to less restrictive controls. However, activities with more significant effects should be subject to more restrictive controls. The policies also recognise that in certain locations, such as over the unconfined aquifer, activities have the potential to create more significant effects. In these locations activities will be subject to more restrictive controls. This is particularly important over the unconfined Wairau Aquifer which supplies the majority of the catchments domestic, agricultural, commercial and industrial water. Riparian management is considered an effective way of minimising adverse effects on adjacent surface water bodies. A number of waterbodies in the planning area have been identified as having high value or requiring enhancement. Riparian management should be encouraged on land adjacent to these resources to reduce the effects of sedimentation, stock trampling, cropping, and fertiliser/chemical application which can adversely affect water quality. Monitoring is important to determine the actual effects associated with non-point source discharges of contaminants on surface water and groundwater. This is poorly understood currently and it is therefore possible that current management methods are less than effective. Monitoring information will be used to develop the most effective and equitable controls. The development of land based discharge guidelines is important because these can be integrated into rules and therefore provide certainty to users while also ensuring that adverse effects are avoided, remedied or mitigated. The guidelines should be sufficiently comprehensive to cover key discharge activities and key receiving environments. Guidelines can also be used to educate users. One of the activities which has a significant adverse effect on soil and water quality and amenity values is the on-site treatment of human effluent. The majority of houses in the Blenheim urban area are connected to a reticulated sewerage system. However, rural residential houses and the townships of Renwick, Grovetown, Riverlands, Ashford Grove subdivision, Tuamarina, Rarangi and Burleigh are all unsewered. In some cases the on-site effluent treatment systems, (usually septic tanks), function very poorly, particularly in wet periods when the groundwater table is high. In these locations there 15 - 3