In 1996, the Ministry of Transport (MoT) released a discussion paper on environmental externalities as part of the Land Transport Pricing Study (MoT 1996). MoT (1996) reported that the contribution of road run-off to the flux of contaminants to freshwater and marine environments was unclear.Road run-off was however, considered to account for 40-50% of urban metalcontamination to aquatic ecosystems. It was considered at that time that although effects on water quality and associated aquatic ecosystems was one of the key potential impact areas of road transport, research about the environmental effects of road transport on water quality was not well advanced and that this resulted in an inability to quantify the contribution that road transport made to any specific effects.
MoT (1996) identified effects on water quality and associated aquatic ecosystems as one of the key impact areas of road transport. Work by the Ministry for the Environment (MfE) has subsequently identified motor vehicle emission discharges via stormwater as a key effect issue in relation to freshwater, estuaries and coastal areas.
In 1998, MoT released the final report of the Vehicle Fleet Emissions Control Strategy (VFECS) (MoT 1998). The VFECS report examined the nature of exhaust emissions from the vehicle fleet and local air quality. Overall, the approach used in the VFECS was impact-based.
Internationally there have been a number of reports prepared that have reviewed the effects of road and highway run-off on aquatic ecosystems.This series of reports produced by Kingett Mitchell Limited, in association with Fuels and Energy Ltd, for the Ministry of Transport examines the effects of contaminants derived from road transport on aquatic ecosystems in a New Zealand context wherever possible. This series of reports aims to provide an overview as to what is known about the effects of the contaminants released by motor vehicles. As such, the assessment is dependent upon what is known about contaminants emitted by motor vehicles to aquatic ecosystems. It should be noted that the report does not deal with:
As outlined in this series of reports, the stormwater from roads in most locations does not just transport the contaminants generated by motor vehicles. Roads are typically surrounded by other activities that have a significant influence on the nature of runoff from various landuses. This series of reports provides information as part of the overall Ministry of Transport study on the effects of road transport on aquatic ecosystems.
The full series of reports prepared as part of this study by Kingett Mitchell Limited for the Ministry of Transport are listed on the right hand side of this page.