Greater Wellington Regioanl Council Selected Land Use Register (locations where hazardous substances are)
An example query to extract locations of asbestos
http://mapping.gw.govt.nz/arcgis/rest/services/GW/Our_Environment_P/MapServer/39/query?where=%22ANZECCSUB%22+like+%27%25besto%25%27&text=&objectIds=&time=&geometry=&geometryType=esriGeometryEnvelope&inSR=&spatialRel=esriSpatialRelIntersects&relationParam=&outFields=*&returnGeometry=true&maxAllowableOffset=&geometryPrecision=&outSR=2193&returnIdsOnly=false&returnCountOnly=false&orderByFields=&groupByFieldsForStatistics=&outStatistics=&returnZ=false&returnM=false&gdbVersion=&returnDistinctValues=false&f=pjson