Guidance

Hazardous substances to groundwater: minimum reporting values

Updated 13 January 2017

The Environment Agency has indicative minimum reporting values (MRVs) for selected hazardous substances in clean water.

Use these values when you carry out a groundwater risk assessment involving hazardous substances.

If the MRV for a hazardous substance is not on this list, you can contact the Environment Agency. The Environment Agency will formulate the MRV for you.

The values are based on environmental permitting guidance for groundwater activities. You can read more about how to assess discernibility of hazardous substances.

In January 2017 UKTAG published a . The Environment Agency will consider the report, and incorporate it into current regulatory approaches and guidance if appropriate.

1. Minimum reporting values

Substance Minimum reporting value (micrograms per litre) Notes
1,1,1-trichloroethane 0.1 Ìý
1,1,2-trichloroethane 0.1 Ìý
1,2-dichloroethane 1 Ìý
2,4-D ester 0.1 methyl, ethyl, isopropyl, isobutyl and butyl each to 0.1 micrograms per litre
2,4-dichlorophenol 0.1 Ìý
2-chlorophenol 0.1 Ìý
4-chloro-3-methylphenol 0.1 Ìý
aldrin 0.003 Ìý
atrazine 0.03 Ìý
azinphos-ethyl 0.02 Ìý
azinphos-methyl 0.001 Ìý
benzene 1 Ìý
cadmium 0.1 Ìý
carbon tetrachloride 0.1 Ìý
chlorfenvinphos 0.001 Ìý
chloroform 0.1 Ìý
chloronitrotoluenes 1 2,6-CNT; 4,2-CNT; 4,3-CNT; 2,4-CNT; 2,5-CNT each to 1 microgram per litre
PCB (individual congeners) 0.001 Ìý
demeton 0.05 demeton-s-methyl only
diazinon 0.001 Ìý
dieldrin 0.003 Ìý
dimethoate 0.01 Ìý
endosulfan 0.005 endosulphan a and endosulphan b, each to 0.005 micrograms per litre
endrin 0.003 Ìý
fenitrothion 0.001 Ìý
fenthion 0.01 Ìý
hexachlorobenzene 0.001 Ìý
hexachlorobutadiene 0.005 Ìý
hexachlorocyclohexanes 0.001 alpha-HCH, gamma-HCH and delta-HCH each to 0.001 micrograms per litre, beta-HCH to 0.005 micrograms per litre
isodrin 0.003 Ìý
malathion 0.001 Ìý
mecoprop 0.04 Ìý
mercury 0.01 Ìý
mevinphos 0.005 Ìý
op DDT 0.002 o = ortho; p = para
pp DDT 0.002 Ìý
op DDE 0.002 Ìý
pp DDE 0.002 Ìý
op TDE 0.002 Ìý
pp TDE 0.002 Ìý
parathion 0.01 Ìý
parathion methyl 0.015 Ìý
pentachlorophenol 0.1 Ìý
permethrin 0.001 cis and trans-permethrin both to 0.001 micrograms per litre
simazine 0.03 Ìý
tetrachloroethylene 0.1 Ìý
toluene 4 Ìý
tributyltin compounds 0.001 Ìý
trichlorobenzene 0.01 135 tcb; 124 tcb; 123 tcb each to 0.01 micrograms per litre
trichloroethylene 0.1 Ìý
trifluralin 0.01 Ìý
triphenyltin compounds 0.001 Ìý
xylenes 3 o-xylene and m/p-xylene each to 3 micrograms per litre. May not be possible to separate m- and p-xylene.

2. List of hazardous substances

On 16 January 2017 the Environment Agency published an updated on the JAGDAG (Joint Agencies Groundwater Directive Advisory Group) website.

The Environment Agency will use the updated list of hazardous substances from 16 January 2017 for all new activities that may lead to the discharge of hazardous substances to groundwater.

If your activity has a permit issued before 16 January 2017, the Environment Agency will regulate the activity in line with your existing permit conditions.

The Environment Agency will review all permits in light of the updated list of hazardous substances. These permit reviews will be in line with the existing arrangements for each industry sector. If you want your permit reviewed sooner, you can discuss this with your local site inspector. The permit review may show you need to implement new or amended measures. These measures will be only be required where considered ‘necessary and reasonable’ in accordance with the environmental permitting guidance for groundwater activities.