Environment Agency
class="gem-c-govspeak govuk-govspeak govuk-!-margin-bottom-0">
You must follow this guide if both of the following apply:
- you are applying for a permit that includes discharging hazardous chemicals and elements to surface water under the Environmental Permitting Regulations
- you need to carry out a bespoke risk assessment bespoke permits are environmental permits customised to your own activities and are usually required if your site produces emissions that exceed certain levels or multiple types of emissions
Read the risk assessment overview before reading this guide.
Hazardous chemicals and elements are listed in the following tables:
Hazardous chemicals and elements are also known as specific substances.
You must evaluate and assess any hazardous chemicals and elements you plan to release into surface water. You must then carry out screening tests on the pollutants to check if theyre a risk to the environment. This is called a specific substances assessment.
You must carry out screening tests when:
- you are applying for a new permit
- you need to change your permit to cover an increase in the amount of hazardous chemicals and elements you plan to discharge or if you plan to discharge a new hazardous pollutant
- you are applying to change (vary) your permit for another reason and there are potentially hazardous chemicals and elements in your discharge
Screening tests check the risk from hazardous chemicals and elements to the environment.
If your screening tests show there is a risk to the environment, the Environment Agency will tell you if more detailed tests need to be carried out. The detailed tests are known as modelling:
- the Environment Agency may need to carry out modelling if you are discharging to freshwater (you will need to carry out modelling if its required if you are discharging to a lake or canal)
- you may need to carry out modelling if you are discharging to an estuary or coastal waters
When you do not need to carry out screening tests
You do not usually need to carry out screening tests if you:
- discharge water taken from a river or groundwater to the same body of water you originally took it from
- have not added any additional hazardous chemicals and elements to the water
However, you do need to do screening tests if you:
- take the water from groundwater and discharge it to surface water
- use the water in a process which concentrates the existing pollutants before its discharged, for example water which is used for cooling and therefore partially evaporates
- keep the water before you discharge it and you make the quality of the river worse than when the water was taken
How to do your screening tests
There are 3 stages to screening.
Identify the pollutants released from your plant.
Gather data on your pollutants before screening them.
Carry out screening tests on the data.
Identify the pollutants released from your plant
You will need to produce a list of any hazardous chemicals and elements that are likely to be in the discharge from your site. Find potentially hazardous chemicals and elements in the following tables:
Pollutants are likely to be in the discharge if:
- theyre allowed to be added to the discharge (for example water company trade effluent consent or discharges from installations)
- youve added them to the discharge (for example iron or aluminium to remove phosphorus) read the guidance on dosed substances for the rules on this
- youve detected them using chemical analysis
To do chemical analysis you will need to take samples of the discharge and send them to a United Kingdom Accreditation Service (UKAS) accredited laboratory like the National Laboratory Service. Make sure the laboratory tests for all pollutants which you expect to find in the discharge and that they use an appropriate minimum reporting value (MRV) (usually 10% of the environmental quality standards (EQS)).
You must submit the chemical analysis data thats been analysed to an appropriate