Chemical manufacturing pollution prevention

Chemical manufacturing and water and sewer discharge


If you pollute water, or cause or risk causing environmental damage to water, you are committing an offence.

Your chemical manufacturing business can pollute waterways and sewers by discharging raw materials and effluent. You may produce contaminated wastewater from:

  • boiler operations
  • chemical reaction cooling processes
  • discharge from wet scrubbers
  • cleaning operations
  • effluent or other treatment plants
  • site drainage and stormwater run-off

These sources may contain:

  • heavy metals, eg cadmium and mercury
  • hydrocarbons, eg benzene
  • resins
  • solvents, eg dichloroethane

Get permission to discharge to water and sewers

You must get a discharge consent or groundwater authorisation from the Northern Ireland Environment Agency before you discharge anything other than uncontaminated water to surface waters or groundwater. You may also need consent if you need to construct a new outfall structure for your discharge.

You must comply with the conditions of your consent or authorisation or you may be prosecuted and fined.

You must have permission from NI Water before you discharge anything other than clean, uncontaminated water to their drainage system. If you discharge trade effluent to a public foul sewer, you must first have a trade effluent consent or agreement.

Prevent environmental damage

Water pollution can be classed as environmental damage in some circumstances.

You must prevent and clean up environmental damage that occurs from surface or groundwater pollution caused by your business activities. If anyone else reports environmental damage as a result of your activities, your enforcing authority will have to investigate.

Good practice to prevent water pollution

Store hazardous materials, fuel, oil and chemicals safely and in an area where you can contain spills. This may be a legal requirement when storing oil.

You should use an impermeable secondary containment system such as a:

  • bunded area
  • bunded pallet or spill pallet
  • sump pallet
  • bunded storage unit
  • bunded drum store
  • storage cabinet with an integral sump

Your bund and any bunded pallets should be able to contain at least 110 per cent of the volume of the largest tank or 25 per cent of the total volume you are likely to store, whichever is greater.

You should take steps to meet drainage system requirements to avoid pollution.

Follow the pollution prevention guidelines (PPGs) to avoid causing pollution. This is particularly important if your business is in an area that has vulnerable groundwater.

Prepare a pollution incident response procedure for dealing with spills. Make sure that your staff are familiar with the procedure and know how to implement your pollution incident plan.

  • NIEA Water Pollution Hotline
    0800 80 70 60