Applications that reduce the impact or risk of pollution (GN 020)

Legislation, best available techniques and good practice continually evolve. In order to realise the environmental benefits of this evolution, changes can be required to practice and infrastructure that can require planning permission or an environmental permit. The impacts of the changes may be subject to multiple legislative requirements and therefore need to be assessed to ensure compliance with relevant legislation frameworks. 

This page clarifies how we will deal with such developments and what information NRW will need to support or approve developments that are subject to multiple pieces of legislation.  

We will support, in principle, a project that results in a reduction in the impact or risk of pollution and is not likely to have an adverse impact on sensitive sites. 

However, this will be subject to the circumstances of a project and be subject to enough evidence being available to make an assessment. 


Examples of projects that could result in a reduction in the impact or risk of pollution.  

Building new organic manure systems or improving the containment of slurry within existing  systems. 

  • changing livestock types  
  • improving infrastructure to reduce the risk of pollution such as installing new drainage systems or organic manure management. 
  • legislative requirements for infrastructure such as Water Resources (Control of Pollution) (Silage and Slurry)(Wales) Regulations known as SSAFOregs or OIL storage regulation 

Reducing impacts or risk of pollution 

Evidence needs 

The reason for the improvement (e.g. legislation, COGAP, NRW advice) 

  • A range of alternative solutionsidentified and assessed for practicality and cost, in order to show the most appropriate technique is identified and that best practice is followed. 
  • An assessment of the current situation using appropriate tools and guidance to air, land and water. 
  • An assessment of the improved situation using appropriate tools and guidance to air, land and water. 
  • Farm infrastructure technical report detailing organic manure production, minimising measures and the range of techniques for storage and subsequent landspreading  that could be applied to minimise the emissions (to land, air and water) 
  • For sizing of slurry storage read Silage and slurry storage page. AHDB Slurry Wizard is recommended

Important Points to consider 

  • This position does not circumvent the requirements of the Habitats Directive.  
  • This position applies to emissions to air, land and water collectively. A reduction in one type of pollution cannot result in an increase in another type of pollution to the detriment of sensitive sites. 
  • The whole activity and the resultant potentially polluting materials stream need to be included in the assessment (including manure transfer, storage, timing and application methods plus nutrient requirement of crops to demonstrate agricultural benefit). 
  • The long-term effects need to be evaluated. If the application would result in pollution occurring for a longer time period than if the project was refused, then this needs to be considered.  
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