The key environmental impacts from and documents/information that may be required for the construction and operation of anaerobic digestion facilities

Key environmental considerations

Nitrogen/ emissions/ deposition

  • possible direct toxic effects on vegetation
  • nutrient enrichment effects on crops, plants and water
  • increased acidification of soil
  • reduced biodiversity
  • habitat damage (including bogs, heathlands, woodlands and low nutrient grasslands)

Run-off contaminated with organic matter

  • increased biochemical oxygen demand of watercourses
  • nitrogen and phosphorus levels in excess of crop requirements in soil
  • nutrient leaching to watercourses and groundwater causing nutrient enrichment
  • potential for increased mineral and metal content of soils


  • potential nutrient enrichment of water
  • potential impacts on air quality
  • potential damage to vegetation


  • nuisance to residents and other users of the locality when at concentrations uncharacteristic of the area

The effects of emissions from an installation can be varied and depend to a large degree on the type and proximity of receptors to the installation.  Sensitive receptors include designated areas such as Areas of Special Scientific Interest, Special Areas of Conservation and Special Protection Areas, and Northern Ireland priority habitats.  Emissions can cause adverse impacts at some distance from the development site.

Documents/information required

The following lists the documents/information required to ensure that DAERA can provide a substantive response:

Agricultural Development Datasheet

Development details

Feedstock details:

  • type
  • source(s) including European Waste Code
  • arrangements for delivery, storage and transfer to digester

Site drainage details:

  • Full Drainage Plan (showing the provision of all dirty water/slurry tanks)


Air impact assessments e.g.

  • screening tools (ammonia, odour, dust emissions) e.g. SCAIL (Simple Calculation of Atmospheric Impact Limits)
  • detailed Air Dispersion Modelling (ammonia, odour, dust emissions) e.g. ADMS; AERMOD models


  • Nutrient Management Plan / Waste (digestate) Storage and Disposal Plan / evidence of export certificates etc.
  • Pollution Prevention Measures e.g. outline construction management plan.
  • Odour Management Plan (A requirement of the permitting process where a proposal will be subject to separate environmental permitting, such as a PPC permit)

Further Guidance

The following planning advice documents can be viewed on the DAERA website under Required Documentation

  • Ammonia Emmission Dispersion Modelling
  • Nutrient Management Plan
  • Contractual/Export Agreement
  • Outline Construction Environmental Management plan
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