• Corrective action should reduce the problem, but unless other NPS pollution from agriculture, forestry and stormwater are also controlled, deteriorating ground water quality from increasing nitrate levels could continue.

• The leachate may contain a range of chemical contaminants, including high levels of phenols (which can give rise to significant taste and odour problems in drinking-water following chlorination), ammonia, nitrate and heavy metals.

• While the nitrate data do tend to confirm findings from previous assessments that water pollution from agriculture is widespread, urban sources are also significant drivers of water quality degradation in China.