Guidance

Groundwater activity exclusions from environmental permits

Updated 5 August 2021

Some extremely low-risk discharges are not groundwater activities. These are called exclusions and you do not need an environmental permit or exemption for them.

If you’re not sure whether your activity qualifies as an exclusion contact the Environment Agency and ask for an assessment from the local Groundwater and Contaminated Land team.

You’ll need to provide:

• information about the discharge, including volume, type and frequency
• the location of the discharge – a map or the 12-digit grid reference
• reasons you think an exclusion applies

The Environment Agency will decide if your activity meets the exclusion conditions and tell you what to do if it does not.

1. Accidents and natural causes exclusion

This exclusion concerns discharges caused by an accident or exceptional natural cause that could not have been foreseen, avoided or lessened, for example:

• an event like a traffic accident on a public road or a train or plane crash
• unpredictable extreme weather events

If the discharge is caused by an ‘accident or exceptional natural cause’ then you will not have committed an offence under the Environmental Permitting Regulations (EPR).

It does not apply where standard pollution prevention and good practice would have prevented the input. For example, it’s unlikely to apply if the accident was caused by poorly maintained or designed equipment which can obviously have been foreseen.

2. Very minor discharges exclusion – also called ‘de minimis’

This exclusion relates to discharges that are so small in quantity and concentration, that they only pose an extremely low risk of polluting groundwater. There must also be no danger of any future deterioration in groundwater quality.

It may include the possible attenuation effects of the unsaturated zone, or dilution as the discharge enters the water table. It must be self-evident the pollutant is very minor, with no need for investigation.

It applies to both hazardous substances and non-hazardous pollutants. The discharge of hazardous substances must not be discernible or exceed the minimum reporting value (MRV).

The Environment Agency has determined some activities are ‘de minimis’ so are excluded from EPR. The cases where the de minimis exclusion applies are known as classes of case.

You will need to assess whether a ‘class of case’ exclusion applies. It will depend on:

• your site
• the substances likely to be present and the potential volumes
• the details of your proposed activity

If you think your activity qualifies for the de minimis exclusion and it’s not listed as a ‘class of case’ please contact the Environment Agency. Your local Groundwater and Contaminated Land team will decide if your activity qualifies for a site-specific de minimis exclusion.

2.1 De minimis exclusions

You do not have to contact the Environment Agency if your discharge meets any of these requirements exactly:

• rinses of pesticide spraying equipment and containers and sheep ‘pour-on’ containers – for example the third flush of such equipment
• non-hazardous pollutants arising from the emergency treatment of water for drinking supply – for example military water decontamination systems
• individual animal carcass burial made according to good practice guidelines
• small quantities of clean water distillate from boilers
• low-use waterless urinals of 10 litres a day or less – for example on golf courses

2.2 Discharges to boreholes

These types of discharges to boreholes are also de minimis:

• recirculation back into the same strata of water abstracted at natural background quality and unaltered
• selective groundwater tracer tests and remediation schemes – direct input into groundwater of the equivalent of 10 litres of any non-hazardous pollutant for the scientific purpose of groundwater testing or promoting remediation at a concentration not greater than 10 times the concentration at which it’s suitable for human consumption
• very small quantities of substances arising from essential use and maintenance of equipment – for example lubrication of screw threads when drilling boreholes
• mains water of drinkable quality not containing any discernible hazardous substances

2.3 Disinfectant discharge onto land

These types of disinfectant discharge onto land, typically deriving from farm use, are also de minimis:

• disinfectant footbaths for human use
• disinfectant footbaths for animal use of 10 litres or less – all substances
• disinfectant footbaths for animal use of greater than 10 litres – non-hazardous pollutants only and only via admixture with farm slurry or dirty water

2.4 Single human burials and ash discharge

These types of ash discharge and single human burial are also de minimis:

• single human burial and any associated personal artefacts, such as a holy book, as long as you prevent groundwater pollution
• scattering of ashes from individual human or animal cremations
• burial of ashes from individual human or animal cremations, as long as the burial is not directly into groundwater

Follow the guidance for the disposal of ashes.

2.5 Swimming pool water

You can also discharge onto land 5 cubic metres per day or less of swimming pool drain down water that’s of drinking water quality. It must have no discernible hazardous substances or concentrations of non-hazardous pollutants above drinking water standards.

You must leave swimming pool water to dechlorinate for at least 2 days before discharging it. It must not contain concentrations of chlorine above 0.2mg per litre.

2.6 Backwash waters from maintenance of abstraction equipment

You can discharge filter backwash waters that come from the maintenance of abstraction equipment, which have elevated levels of iron, manganese and other non-hazardous metals. The elevated levels of metals must originate from non–anthropogenic sources, derived from the process of abstraction of groundwater on site.

Discharge should be via a sub-surface infiltration system and must not be direct to groundwater. Discharge volumes should not exceed 1 cubic metre within any 24 hour period.

2.7 Discharge onto ground of groundwater that meets drinking water quality standards

You can discharge groundwater that meets drinking water quality standards onto ground when the:

• discharge activity is temporary and is for a maximum duration of 30 consecutive days
• quality of the groundwater is either naturally at drinking water quality standards, or is groundwater of mains quality that has been treated to drinking water quality standards
• location (ground) where the discharge is to occur is free from any obvious sources of contamination
• volume and rate of discharge will not cause pollution or any other adverse environmental impacts, including flooding, to the underlying groundwater or any adjacent surface waters (rivers, streams) or habitats

2.8 Discharge onto ground of public water supply auto analyser waters

You can discharge water onto ground from a public water supply auto analyser when:

• it meets UK drinking water quality standards and is suitable for public drinking water supply
• the discharge is for no more than 5m³ a day
• the location (ground), where the discharge is to occur, is free from any obvious sources of contamination
• the discharge is via a sub-surface infiltration system and not directly to groundwater
• the volume and rate of discharge will not cause pollution or any other adverse environmental impacts, including flooding, to the underlying groundwater or any adjacent surface waters (rivers, streams) or habitats

3. Risks to human health or the environment exclusion

This exclusion applies when the input of a pollutant into groundwater is incapable, for technical reasons, of being either:

• prevented (for hazardous substances) without increasing the risk of harm to human health or the environment
• limited (for non-hazardous pollutants) without increasing the risk of harm to human health or the environment

The following classes of case meet this exclusion:

• carcass burials of less than 2 tonnes in an emergency situation subject to the application of both position statement M1 and minimum groundwater protection requirements
• substances or pollutants in foams used for emergency firefighting, subject to good pollution prevention practice – this does not include training exercises or non-emergency use

This exclusion may apply to some sustainable drainage schemes where low concentrations of pollutants are involved.

This exclusion may also be relevant to one or more individual substances within a permitted effluent discharge. For example, it may not be possible to use reasonable measures to remove certain substances at a sewage works and the only alternative would be to make an unacceptable discharge to surface water. However, you must contact the Environment Agency and explain to the local Groundwater and Contaminated Land team the need for such a discharge at that location.

4. Disproportionate cost for land contamination exclusion

This exclusion only applies to land contamination. It relates to the input of a pollutant that, for technical reasons, cannot be prevented from entering ground or sub-soil without using disproportionately costly measures to either:

• remove the pollutant
• otherwise control percolation of the pollutant

The need for bespoke determination is rare because passive discharges from contaminated soils are not regarded as discharges for the purposes of EPR. For more information on passive discharges read section J of the groundwater protection position statements.

Passive discharges from land contamination continue to be controlled through a combination of:

• voluntary remediation
• the development planning system
• Part 2A of the Environmental Protection Act 1990
• anti-pollution works notices under section 161A of the Water Resources Act 1991

You should contact the Environment Agency and ask the Groundwater and Contaminated Land team if this exclusion applies.