What this document is
This document describes the atmospheric emissions from a modern energy from waste (EfW) plant.
The document explains what the emissions are, how they are controlled and their impact on human health.
What are the emissions from the site?
By far the largest products emitted from the stack of an energy from waste (EfW) plant are carbon dioxide and water vapour. These are released to the atmosphere under controlled conditions and do not cause any harm.
Other products arising from the production of energy include ash and particulates, the acid forming gases (including nitrogen oxides, sulfur oxides and hydrogen chloride), as well as dioxins. Each of these emissions is strictly regulated by the Environment Agency (EA), and the control methods are set out below.
How would the emissions from the site be controlled?
Emissions from the existing EfW plant are well within the targets as set out in the Industrial Emissions Directive (IED) (2010/75/EU). Energy Recovery Facilities (ERFs) operate under strict emission limits shown in IED and require a permit (issued by the Environment Agency) to operate.
Modern EfW plants must be designed and operated to minimise the production and release of pollutants. They must be built with sophisticated pollution monitoring and control systems. These capture virtually all of the potential harmful emissions from the plant.
The operating conditions and emissions from the process are monitored continuously all day, every day and are recorded and report to the EA.
Acid forming gases are removed through controlled chemical reactions in a pollution control system (flue gas treatment system).
Fly ash containing the majority of potentially harmful chemicals is trapped in air filters and safely removed from the gas before it can be released to the atmosphere.
Particulates are tiny pieces of dust and are also trapped in the air filters.
Dioxins are largely prevented from forming by the design of the plant which is intended to ensure complete combustion. Any that are formed are trapped almost entirely in the air filters.
What does the stack do?
It is necessary to have a stack to ensure that the very small amounts of pollutants that are released to the atmosphere are dispersed as quickly and effectively as possible. This ensures that the emissions are soon indistinguishable from the levels which otherwise exist in the atmosphere.
The minimum stack height is approved by the Environment Agency to ensure that effective
dispersion of pollutants and the minimum health impact is achieved.
Do I need to worry about the health impacts?
We know people are concerned about emissions and we hope that the following facts will reassure you.
In 2009 The Health Protection Agency, now Public Health England (PHE), which has statutory responsibility to advise Governments and Local Governments on the potential health impact of incinerators, reviewed studies examining the suggested association between municipal solid waste incinerator emissions and effects on human health. PHE concluded that “Modern, well regulated incinerators make only a small contribution to local concentrations of air pollutants. It is possible that such small additions could have an impact on health but such effects, if they exist, are likely to be very small and not detectable.”
Public Health England has indicated it will publish an updated position statement in 2015. PHE is not aware of any evidence that would require a change in its position statement.
Concerns about the health of people living near an EfW plant have also been addressed by the UK Committee on Carcinogenicity of Chemicals in Food, Consumer Products & the Environment. Calculations show that consuming a significant proportion of foodstuffs produced near incinerators provides an almost insignificant dioxin intake, well below the tolerable daily intake recommended by the Committee on Toxicity.
A recent study undertaken in the Netherlands and published by scientific journal Chemosphere in March 2015 showed that nearby ERF emissions did not affect the quality of crops and cow milk. The biomonitoring study, which took place between 2004 and 2013, demonstrated how concentrations of heavy metals, Polycyclic Aromatic Hydrocarbons (PAHs) and dioxins were generally similar to background levels and did not exceed standards for maximum allowable concentrations in foodstuffs (i.e. vegetables and cow milk).
Data from Energy Recovery Facilities around the UK are strictly monitored by the Environment Agency (EA). This information is available to the public and can be requested via their website.
Opponents of new facilities often cite examples of the measured emissions from before the year 2000 when the emissions standards were lower than now to show that energy from waste plants are harmful. This is misleading as all the plants that were operational at that time have either closed or undergone significant upgrades to operate to much higher environmental and health standards.
The emissions from ERFs have been reduced significantly over the course of the last 40 years. Substantial reductions have been made since the 1990s. ERFs’ emissions of the main pollutants under the current regulation (IED and Best Available Techniques Reference Document) have been reduced by a factor of around 10 compared to the mid-1990s and by a factor of around 100 compared to previous decades before any regulations were implemented. This applies to important pollutants such as particulate matter, HCl, dioxin and most Trace Heavy Metals. Other pollutants such as SO2 and NOx are also reduced significantly.
The Impact on Health of Emissions to Air from Municipal Waste Incinerators (2009)
Van Dijk, C., van Doorn, W. & van Alfen, B. (2015). Long term plant biomonitoring in the vicinity of waste incinerators in the Netherlands. Chemosphere 122: 45 – 51.