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 isn’t 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 technical report on groundwater hazardous substances. 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|
|2,4-D ester||0.1||methyl, ethyl, isopropyl, isobutyl and butyl each to 0.1 microgram per litre|
|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|
|endosulfan||0.005||endosulphan a and endosulphan b, each to 0.005 micrograms per litre|
|hexachlorocyclohexanes||0.001||alpha-HCH, gamma-HCH and delta-HCH each to 0.001 mictogram per litre. beta-HCH to 0.005 micrograms per litre|
|op DDT||0.002||o = ortho; p = para|
|permethrin||0.001||cis and trans-permethrin both to 0.001 micrograms per litre|
|trichlorobenzene||0.01||135 tcb; 124 tcb; 123 tcb each to 0.01 microgram per litre|
|xylenes||3||o-xylene and m/p-xylene each to 3 micgrograms 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 list of hazardous substances 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.