Common potentially high-risk water pollution sites:
- Industrial premises
- Oil storage sites
- Timber treatment plants
- Chemical stores
- Pesticides, Herbicides and BASIS Stores
- Construction sites
- Vehicle wash operators
The following are some general pollution prevention practices for an industrial environment:
- Proper containment provision (bunding) of above ground oil storage containers and tanks to ensure compliance with best practice if under 200 litres (see Guidance for Pollution Prevention (GPPs) and Control of Pollution (Oil Storage) Regulations (Northern Ireland) 2010, if over 200 litres);
- Secure containment/bunding of all chemicals on site in line with best practice (see Guidance for Pollution Prevention (GPPs));
- Ensure that all drums and containers on site are in good condition and fit for purpose and protected from accidental impact;
- Separate site storm and foul drainage;
- Clear identification of site drainage points (blue for storm, red for foul);
- Ensure proper use of drains (see NIEA Proper use of Drains Leaflet for further information);
- Installation of appropriately classed interceptors/separators on site storm drains where necessary (see Guidance for Pollution Prevention 3 (GPP 3));
- Discharge of any vehicle wash effluent to foul sewer only (see Guidance for Pollution Prevention 3 (GPP 3) and 13 (GPP 13)) and:
- Minimise waste production by reusing or recycling.
To minimise the effects of pollution at industrial premises it is recommended that you have an Emergency Spill Contingency Plan in place to safely deal with potential pollution incidents
Contingency plans should consist of information such as;
- Emergency containment equipment such as absorbent mats/granules, drain protectors and absorbent booms.
- An up-to-date drainage plan of the site to ensure that any potential pollution discharge points are identified.
- A list of essential contacts who should be notified in the event of a major pollution event reaching the waterway. These contacts should include;
- The emergency services
- Any downstream abstractors
- The NIEA Water Pollution Hotline 0800 80 70 60
- Staff should be properly trained in the use of the emergency containment equipment and be aware of proper contingency plan procedures.
- It is important to test your contingency plan frequently.
Guidance documents giving advice on preventing pollution can be found at Guidance for Pollution Prevention (GPPs).
Oil is a toxic chemical which is harmful to plants and animals and a threat to natural habitats.
Oil depots can pose a particularly high environmental risk due to the very high volumes of oil stored and the toxic nature of oil if it were to enter the environment.
Oil spills can pollute streams, rivers and lakes, cause fish kills and if it soaks through the soil it can contaminate drinking water and groundwater supplies.
In the UK drinking water supplies come from rivers and groundwater. We must protect them both from pollution.
The best way to prevent oil entering watercourses is to contain it.
The current legislation that concerns the proper storage and control of oil in Northern Ireland is The Control of Pollution (Oil Storage) Regulations (Northern Ireland) 2010.
In Northern Ireland, ‘oil’ means any kind of oil and includes petrol, diesel, waste, vegetable and plant oils; but does not include uncut bitumen.
The Regulations apply to all premises that are not wholly or primarily a private dwelling, that is industrial, commercial, institutional, and public body sites storing oil in containers over 200 litres, including drums and Intermediate Bulk Containers (IBCs), and to domestic premises storing heating oil in a tank with a capacity of 3500 litres or more.
The regulations apply to:
- Above ground oil storage in containers over 200 litres.
- Private domestic oil tanks over 3,500 litres.
- Waste oil storage.
The regulations do not apply where:
- Oil is stored on farms for agricultural use, where the Silage, Slurry and Agricultural Fuel Oil (SSAFO) Regulations apply (see DAERA webpage for more information).
- Where oil is stored on premises regulated under the Control of Major Accident Hazards Regulations (Northern Ireland) 2015.
- Where the container is 2500 tonnes or more.
- Where oil stored in tanks which are wholly underground.
Guidance documents giving advice on preventing pollution from oil depots can be found at Guidance for Pollution Prevention (GPPs).
Timber is treated to preserve it against attack from the weather, pests (insects, fungi, and bacteria) and fire. The process normally involves pressure impregnation and/or immersion of timber with either water, or organic based preservative, creosote, or fire retardant.
Chemicals used in the timber treatment process are highly poisonous to the insects and fungi they are designed to control but are also poisonous to a large range of non-target species including aquatic invertebrates and humans.
For this reason, all precautions should be taken to protect public health and the environment from these substances when selecting a site for a new timber plant.
- Ensure that proper mitigation measures are in place to minimise the risk of any releases of timber preservative to the water (surface and groundwater) environment. The principle of total containment should be followed during site design and applied to processing plant, preservative storage area and the holding area for treated timber.
- Wood-preservative products should only enter the treatment site in sealed, properly labelled, and approved containers.
- Any waste produced or handled must be disposed of safely by following the relevant legal waste management requirements including the Duty of Care.
- Permanent tanks used for the storage of products on site should be properly labelled, secure, and provided with adequate secondary containment.
- Clean, uncontaminated rain or surface water should be diverted away from the plant area unless a purpose designed and built water harvesting system is operational.
- Wherever possible the use of processes and products that present lower risks to the environment and the workplace should be adopted.
- It is recommended that a pollution incident response plan for the site is drawn up as described in Guidance for Pollution Prevention 21 (GPP 21) and that all other relevant pollution mitigation recommendations are incorporated where applicable.
Guidance documents giving advice on preventing pollution from timber treatment plants can be found at Guidance for Pollution Prevention (GPPs). See also:
Code of Practice for safe design and operation of timber treatment installations
Businesses routinely store and move a variety of potentially polluting chemicals ranging in capacity from a few litres up to multiple tonnes.
Chemicals can be highly damaging if they escape to the environment.
Pollution can be caused by spills from:
- Incorrect storage and handling of containers;
- Accidental leaks;
- Overfilling or failure of storage structures;
- Run-off from fires and contaminated firewater and;
- Incorrect or damaged drainage systems.
These materials must be stored in a safe, appropriate manner and in accordance with:
- Appropriate legislation and best practice (for example The Yellow Code) for suppliers of Pesticides.
- All relevant Health & Safety requirements.
- Any other relevant guidelines such as those issued by the Northern Ireland Fire & Rescue Service.
Good management practices help to prevent pollution incidents. Stores should ensure that their staff and contractors use spill management practices they have in place.
It is important to understand the potential links between pollution hazard sources, pathways and receptors and how proper storage site planning and management procedures can mitigate the risks of a spill occurring or reaching the water environment from their premises.
To control the pollution risk from a chemical storage site it is important to be able to identify the materials stored at the site quickly, know what chemicals are being stored, and precisely what volumes are being stored on the site.
It is recommended that:
- Individual containers are clearly labelled with details of what they contain and any hazard they pose.
- Storage areas are clearly labelled with details of what can be stored in them.
- Clear warning signs including pictograms are installed at access points to dedicated stores.
- Store distinct materials separately so they do not mix. If a spill occurs it is easier to deal with a spill of just one material than a mixture.
- Only keep the minimum working quantity of materials on site.
- Use secondary containment for chemical containers which is fit for purpose and correctly sized.
- Protect storage from extremes in weather whenever possible, for example sunlight, frost, and flood waters.
- Keep storage areas away, or isolated, from onsite drainage, surface waters and groundwater and vehicle routes.
- Colour code drains on site.
- Have a spill contingency plan for the site.
Depending on the chemicals stored there may also be additional legal requirements (for example Health & Safety). It is the store owner’s responsibility to ensure that the premises is compliant with all relevant legislation.
Safe Pesticide/Herbicide storage is enforced by a number of regulations;
Include strict controls over the storage of pesticides.
The Control of Pesticides Regulations 1986 require all reasonable precautions being taken to protect people, creatures, plants and the environment from pesticides.
For further information and guidance regarding pesticides, please see Section 6 of the DAERA Code of Good Agricultural Practice for the Prevention of Pollution of Water, Air and Soil, 2008 and the Code of Practice for Using Plant Protection Products.
The BASIS (British Agrochemicals Standards Inspection Scheme) group is a system of self-regulation by the agrochemical industry for the safe storage and transport of agrochemicals. Working in partnership with the Northern Ireland Fire and Rescue Service (NIFRS), the Health and Safety Executive Northern Ireland (HSENI) and the NIEA.
Further information regarding Pesticides/Herbicides and BASIS can be found at the following links:
- BASIS website
- Guidance on the use of pesticides
- Pesticide storage - are you covered?
- The facts about pesticide storage
- Departmental responsibilities regarding pesticides
See the leaflet Care in Pesticide Use Near Waterways.
Guidance documents giving advice on preventing pollution from pesticides, herbicides, and BASIS stores can be found at Guidance for Pollution Prevention (GPPs).
Mineral extraction has the potential to impact on water quality, water quantity and/or the established flow regime.
Changes to the local water environment resulting from mineral working can affect nearby receptors such as wells/boreholes, springs, wetlands, and waterways.
In certain situations, changes to water levels, flow or quality can have implications for dependent ecology and/or land.
Mineral extraction often involves the removal of rock and sediment that in some cases will be a reservoir for groundwater.
Site runoff that has been contaminated with silt, suspended solids and/or oil during the mineral extraction process can destroy riverbed habitats, kill fish, and reduce the amount of oxygen available in a watercourse.
The prevention of pollution from these sites can be achieved by careful planning, installation, and maintenance of well-designed surface water treatment facilities for site discharges.
Extractive industry offers advice and information for companies involved in managing site drainage.
Guidance documents giving advice on preventing pollution from quarries can be found at Guidance for Pollution Prevention (GPPs).
Construction sites have the potential to impact on water quality of nearby rivers, waterways, and groundwater. Polluting discharges and/or contaminated run-off entering the surface water or groundwater environment as a result of the construction and/or the operation of the proposed activity on the site can impact water quality.
Common potential pollution risks from construction sites include;
- Damage to surface water quality
- Damage to ground water quality
- Effects on river hydromorphology
- Damage to fisheries habitats
Common potential sources of pollution from construction sites include;
- Suspended solids
- Concrete, cement, and grout
- Oil or fuel
Waterways are extremely sensitive environments which are protected by legislation within Northern Ireland. The Water Environment (Water Framework Directive) Regulations (Northern Ireland) 2017 is the primary driver for assessing our local waters and achieving good ecological status for our water environment.
Mitigation measures should be in place to prevent the generation of pollutants and the release or escape of any polluting discharges to any waterway throughout all stages of a construction project to minimise the impact on the receiving water environment.
If works are to be carried out in close proximity to a waterway, the Pollution Prevention Team encourage the designer/contractors to consult with them from early planning/design stages.
This will serve to:
- Ensure perceived pollution risks to the waterway during the construction and operational phase have been identified (SOURCE);
- Ensure potential pollution pathways have been identified (PATHWAY);
- Ensure environmental receptors are identified (RECEPTOR);
- Ensure appropriate mitigation measures have been identified and utilised;
- Ensure management and maintenance of mitigation measures and;
- Ensure that efforts are made and measures are in place to reduce the number of water pollution incidents and minimise the impact of human activities on the environment during both the construction and operational phase.
Consideration should be made of current best practice, see Guidance for Pollution Prevention (GPPs).
Such considerations should include:
- Maintenance of vegetative buffer zones alongside any waterway of a min of 10 metres including any un-named tributary or ditch that runs through the site during land stripping.
- Regular inspections of machinery working near any waterway should be made to prevent pollution by fuel/oil.
- Refuelling of equipment should be carried out in accordance with best practice (see Guidance for Pollution Prevention 6 (GPP 6)).
- No machinery should enter any waterway at any time. This may affect decisions relating to the project. Any work in a waterway should be conducted ‘in the dry’ behind coffer dams using over pumping etc. Permissions may be required from other authorities.
- Consult with NIEA to agree a method of works statement for any works in near or likely to impact a waterway. Contact the Pollution Prevention Team by emailing firstname.lastname@example.org at least 8 weeks prior to the works starting.
- Any runoff contaminated with cement washings should be directed via an impermeable pathway to purpose built impermeable containment. These washings should be only disposed of by a licensed waste carrier.
- Management of soil stockpiles in accordance with best practice
- Minimisation of exposed earth, over land flow and control of all surface water discharges from the site. Surface water management must prevent entry of suspended solids and contaminants to waterways. Cut off channels along with check dams directed to settlement systems that are designed and maintained in accordance with best practice (see the CIRIA website) can also serve to minimise the amount of surface runoff from the site and assist in the settlement of suspended solids.
- Water from construction sites should never be pumped directly to a watercourse or be allowed to enter storm drains unless consent to discharge has been obtained from the NIEA Industrial Discharges section. All pumping activities must be supervised.
- A waste management plan should be drawn up with the emphasis on reducing the volume of waste produced, reusing materials again or recycling them.
WMU does not permit the settlement of suspended solids within any waterway. Water containing suspended solids must be fully treated prior to it entering any waterway. This may require surface water flow to be channelled towards settlement systems.
- Silt settlement ponds should be constructed in a manner that adheres to industry best practice with respect to length: width ratios and depth.
- A washed stone dam in the middle of each pond helps settlement.
- There must be a management/ maintenance program for such settlement systems in place to ensure effective functioning.
Guidance documents giving advice on preventing pollution from construction sites can be found at Guidance for Pollution Prevention (GPPs).
Wash water from vehicle washes, especially those using detergents/vehicle wash formulations, has the potential to pollute waterways and groundwater as it is likely to contain a mixture of detergents, dirt/silt, organic matter, and oil residues.
The effluent produced by vehicle wash installations is moderately toxic to aquatic life and will pollute any receiving watercourse.
Where feasible, it is recommended that this effluent should be connected to foul sewer for treatment and disposal, subject to a consent to discharge being obtained from Northern Ireland Water at https://www.niwater.com/trade-effluent/.
If a consent to discharge cannot be obtained from Northern Ireland Water, DAERA has a preference for how such effluent is disposed of based on the potential to pollute.
The options in order of preference are:
- Re-cycling without discharge.
- Holding tank and disposal via a registered/licensed carrier to a consented treatment facility with the capacity to adequately treat the effluent prior to discharge.
- NIEA Consent to Discharge – this will only be considered EITHER where detergents will not be used OR where the effluent is going to a treatment system that has a separate nutrient supply (e.g. sewage) and has the ability to reduce the combined biochemical oxygen demand (BOD) to within consent limits.
For further information on NIEA Consent to Discharge please see the DAERA webpage ‘regulating water discharges’.
Action if a pollution incident/breach of legislation occurs
It is beneficial for a business to invest time and money into mitigation measures that reduce the risk of a water pollution incident occurring at their site.
If a spill is found to have entered a waterway it is very likely that an offence has been committed.
The Water (NI) Order 1999 states that:
“it is an offence under the Water (Northern Ireland) Order 1999 to discharge or deposit, whether knowingly or otherwise, any poisonous, noxious or polluting matter so that it enters a waterway or water in any underground strata. Conviction of such an offence may incur a fine of up to £20,000 and / or three months imprisonment.”
In addition to any fine or punishment a court may impose if a person is found guilty of causing pollution, you may;
- Have to pay for analysis and court costs.
- Be liable for the cost of clean-up operations, which can easily run into tens of thousands of pounds.
- Have to pay compensation to angling clubs if a fish kill occurs.
- Receive publicity accompanying the prosecution which can have a negative effect on a company's public image due to society's increasing environmental awareness.
It is recommended that customers and business owners ensure that their premises remain compliant with any relevant updates to environmental legislation as breaches or shortcomings in regard to environmental standards can cause pollution incidents to occur.
If you require any further advice, please do not hesitate to contact the Pollution Prevention Team at by emailing email@example.com; Or
TO REPORT WATER POLLUTION PLEASE CALL THE WATER POLLUTION HOTLINE: 0800 80 70 60