Indicators of Sustainable Development

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Indicator: Dangerous substances in water M2
Exceedences of Enviromental Quality Standards for selected List 1 Substances: 1995 to 2002
a) Heavy metals
Sites below discharge points National Network Reference sites
Cadmium
Indicator Chart
Mercury
Indicator Chart
b) Pesticides
HCH
Indicator Chart
DDT
Indicator Chart

Coverage: England and Wales

Source: Environment Agency

Cadmium
Change since
dots 1970
tick 1990
curvey 1997
Mercury
Change since
dots 1970
curvey 1990
curvey 1997
HCH, DDT
Change since
dots 1970
tick 1990
tick 1997 (No HCH in QoLC 1999)
Objective: Must not store up pollutant problems for the future
  • This indicator is assessed in terms of the number of EQS (Environmental Quality Standard) failures. Only a very small proportion of sites show failures of EQSs. In the charts, the number of failures is also shown above the bar for clarity.
  • Exceedences of HCH (including lindane) and DDT have reduced to the point where there are not normally any exceedences of EQSs.
  • Most failures for mercury below disharge points reflect the legacy of past industrial activity [1]. There have been no failures at National Network Reference sites.
  • The trend for cadmium failures is unclear. There have been fewer at National Reference Network sites, but there were three below discharge points in 2002.
Notes: [1] 2 sites below discharge points failing EQS have been added to the data for 1995-7 for consistency with the more recent data. They were not shown in the original edition of QoLC. These reflect the effect of mercury still in the sediment of the Trent & Mersey Canal from historic discharges.

Page last modified: 21 April 2004  |  Page published: 21 April 2004