Water quality standards for List I substances

Parameter

 Unit

 Water quality standard

Standstill Provision a

 Estuaryb

Marine

Mercury

g Hg/l

0.5 DAA

0.3 DAA

yesc

Cadmium

g Cd/l

5 DAA

2.5 DAA

yes

Hexachlorocyclohexaned

g HCH/l

0.02 TAA

0.02 TAA

yes

Carbon tetrachloride

g CCl4/l

12 TAA

12 TAA

no

Dichlorodiphenyltrichloroethane

 

 

 

 

(all 4 isomers, total DDT)

g DDT/l

0.025 TAA

0.025 TAA

yes

(para, para-DDT)

g ppDDT/l

0.01 TAA

0.01 TAA

yes

Pentachlorophenol

g PCP/l

2 TAA

2 TAA

yes

Total >drins=

g/l

0.03 TAA

0.03 TAA

yes

Aldrine

g/l

0.01 TAA

0.01 TAA

yes

Dieldrine

g/l

0.01 TAA

0.01 TAA

yes

Endrin

g/l

0.005 TAA

0.005 TAA

yes

Isodrine

g/l

0.005TAA

0.005 TAA

yes

Hexachlorobenzenef

g HCB/l

0.03 TAA

0.03 TAA

yes

Hexachlorobutadienef

g HCBD/l

0.1 TAA

0.1 TAA

yes

Chloroformf

g CHCl3/l

12 TAA

12 TAA

no

1,2-Dichloroethaneg (ethylenedichloride)

g EDC/l

10 TAA

10 TAA

no

Perchloroethyleneg (tetrachloroethylene)

g PER/l

10 TAA

10 TAA

no

Trichlorobenzeneg (all isomers)

g TCB/l

0.4 TAA

0.4 TAA

yes

Trichloroethyleneg

g TRI/l

10 TAA

10 TAA

no

Notes

Substances are listed in the order of publication of Directives.

D dissolved concentration, ie usually involving filtration through a 0.45-m membrane filter before analysis

T total concentration (ie without filtration)

AA standard defined as annual average

Most directives include, in addition to the standards for inland, estuary and marine waters, a provision that the total concentration of the substance in question in sediments and/or shellfish and/or fish must not increase significantly with time (the "standstill" provision).

In the UK the standards for estuaries are the same as for marine waters - The Surface Waters (Dangerous Substances) (Classification) Regulations 1989

In addition to a standstill provision applying to sediments or shellfish there is a further environmental quality standard of 0.3 mg Hg/kg wet flesh "in a representative sample of fish flesh chosen as an indicator".

All isomers, including lindane

The standard relating to the concentration of this substance came into effect on 1 January 1994.

The provisions of the directive on this substance came into force on 1 January 1990.

The provision of the directive on this substance came into effect on 1 January 1993.

References