WikiWaste Data Sources & Limitations

WikiWaste uses a number of data bases with open source licenses and conditional licenses; these are listed in the reference section at the bottom of the page.

Each database has its own user obligations and restrictions which define the limitations associated with the data.

This page does not repeat any individual licence limitations, instead it summarises the key constraints within the data sets and highlights how WikiWaste has applied them.

WikiWaste acts in good faith with all licensing terms associated with third party data sources.

WikiWaste also consolidates and aggregates FOI and market-based information into its own data sets. These have their own limitations which are described wherever they are used.

Any use of data within WikiWaste must continue to comply with the terms of the original data sources. Users should also acknowledge WikIWaste as the source of any additional data or content and adhere to WikiWaste's Terms and Conditions.

• DEFRA publish and refresh their website regularly, but the macro data for the UK and England is only refreshed every two years. The latest available data is therefore 2020 for the UK and 2022 for England.
• Macro data does not capture sites handling waste under exemptions from permitting. Whilst each exemption is small, the cumulative impact is relatively large. This leads to an under reporting of some materials, especially recyclables, which fall under many of the available exemptions.
• Tonnage arisings often under report the total waste put on the market (POM). This is because there is still a substantial mixed waste tonnage that does not differentiate materials or estimate its make-up/composition.
• WiKiWaste does not currently publish seperate macro-level data for Scotland, Wales and Northern Ireland even where more up-to-date figures exist. This is because the reporting formats of the devolved nations are not fully aligned and cannot be reliably reconciled with DEFRA's UK-wide consolidation methodology.

• In calculating C&I waste DEFRA adjust the figures in an effort to reconcile the under-reporting from exempt sites.
• These adjustments are outlined within their C&I reports, however they are not easily replicated by any third party.
• For ease of presentation, WikiWaste only uses the tonnage arisings for the Service, Manufacturing and Water Treatment sectors in line with the DEFRA approach before adjustments.
• This results in tables, for example in Paper & Card, which slighlty under-report the C&I tonnage.

• Municipal Waste (MSW) is household and similar waste, but macro DEFRA data uses the 'Waste from Households' (WfH) figures instead which is subtly different i.e. does not include wider Local Authority collected tonnage such as from businesses, parks, beaches etc.
• Some data sets, especially in Sctotland and Wales, refer to recycling rates in relation to MSW, but this appears, in some cases, to only include those MSW tonnages that are collected by local authorities.
• A recent EfW capacity analysis by DEFRA for England looked at MSW tonnage, but did not tie back directlty to any tonnage reported under the macro data sets.
• To give an indication of the tonnage of MSW in the UK and England, WikiWaste uses the Household and Service sector tonnages reported.
• Although this is not a fully accurate analysis (e.g. some Service-sector waste may not be strictly Household in nature), back-calculating to the totals and comparing against DEFRA's capacity work shows this it provides a very close proxy.

• The tonnage published in WikiWaste for Construction Waste follows the STAT codes (Statisitc Codes) used by DEFRA in their macro data.
• This does not align with the tonnage reported by DEFRA for Construction and Demolition Waste primarily because: a) excavation wastes are excluded, and b) the DEFRA target applies to non-hazardous waste whereas the macro data set includes hazardous waste.

• The Waste Data Interrogator (WDI) data set is published by DEFRA in October each year for the previous calendar year (thus data for 2025 will be released in October 2026)
• In most cases the reporting year is shown next to the data outlined in WikiWaste
• WDI publishes tonnage going into and leaving permitted sites in England only, the equivalent data sets for Scotland, Wales and Northern Ireland are seperately reported in WikiWaste where available.
• In WikiWaste the focus and use of data is generally on waste entering into sites. In some cases the data for tonnage leaving sites is also used but tonnage within these datasets will not align - primarily for two main reasons: a) tonnage may be in treatment/storage across the reporting period and/or b) tonnage may leave a site having been processed and is no longer classified as waste (it's now a product) - for example recycled aggregate.
• Furthermore, WDI tonnage into and out of sites needs to be handled with care as it can lead to double counting (i.e. the output of one site becomes the input to another site).

• Operators of incinerators of a certain scale (excluding Cement Kilns) are required to produce an Annual Report at the close of each calendar year. Copies of these reports are obtained by WikiWaste under an FOI request annually following their submission into the regulatory authorities.
• These Annual Reports focus primarily on emissions and plant performance, but include tonnage managed; this is published by waste type rather than EWC-STAT code as per WDI.
• The Annual Reports have become increasingly detailed over the last five years including, for example, most sites now differentiate between the tonnage they receive and the tonnage they combust or transfer back out for processing elsewhere.
• In many cases the Annual Report tonnages and the WDI data do not completely align.
• Where WDI tonnage exceeds data published in the Annual Reports (for the same calendar year) this may be because: a) tonnage may have been received but not incinerated, i.e. the material is held in in the bunker pending incineration; b) material may have been received into the site but treated in some manner other than incineration; c) material may have been received but transferred off site for disposal/treatment at another site rather than incinerated on the site.

• Tonnage incinerated within Clinical Waste Incinerators and the incineration of clinical waste in Residual Waste EfW are a specific example where data has historically not been in alignment across the datasets (and to some degree does still not align).
• Previously at least five Clinical Waste Incinerators did not report tonnage in WDI, but did produce Annual Reports.
• In 2024 all Clinical Waste Incinerators reported data in WDI (except those micro sites regulated by local authorities). This means that macro DEFRA data will under report clinical waste arisings in 2020 and 2022.
• Annual Reports for Clinical Waste Incincerators were produced for sites even though they were not in WDI data. These reports have improved in consistency and quality in the last three years and shows more tonnage treated and sent out from several sites than is actually incinerated on site.
• Annual Reports for Residual Waste EfW, in some cases, have reported clincial waste as C&I waste (because they have received the tonnage from C&I customers). Interrogating WDI alongside the Annual Reports demonstrates that the Annual Report data can under-report in this case.
• To some degree the historical figures are also slightly distorted as higher-risk Healthcare Waste, generated during the COVID pandemic, was permitted to be incinerated via Residual Waste EfW sites under a Regulatory Position Statement[2]; this was subsequently withdrawn in July 2021.

• WasteDataFlow (WDF) is published for the financial year (April to March) around 12 months after the year end
• WDI and Annual Report data does not align due to differences in reporting calendar vs financial years, although the full 12 months of data provides a reasonable comparison
• The latest WDF dataset is 2024/25 (with data for 2025/26 available in Spring 2027).
• WDF has data inconsistencies, with some local authorities continuing to enter historical permit/site information for sites which in some cases, no longer exist.
• In many cases local authorities use sites exempt from permitting, especially for recyclables, which makes identification of the destination site and comparison with WDI derived data not possible.

A 'zero return' in the tables in WikiWaste (or a below expected return, when compared to the WDI data) indicates, especially for residual waste to incineration, that either:

• no local authority tonnage was recorded/no tonnage was sent to the site in the period (but has been listed as it may previously have received tonnage from a local authority) or
• a result of the plant being commissioned and actually having received no tonnage or
• a lower than expected tonnage maybe a result of a local authority splitting their tonnage over multiple sites, having less tonnage to send than might be anticipated or
• it may be a new plant in 'ramp up' towards full capacity after construction or
• may be a result of plant shut down and subsequent re-start in a year or
• the local authority may not have correctly entered the site's details on WasteDataFlow

• In some data tables local authorty tonnage is reported twice - this is a consequence of the way the data is structured when generating reports on the tonnage managed.

• Data is only presented for sites listed within published data sets, which exclude exempt sites - this is likley to impact inert capacity the most, where exemptions are used extensively, for example, on agricultural land, golf courses and noise bunds
• No data is currently available for sites in Northern Ireland
• The most recent data for Wales is calendar year 2018
• The data for England and Scotland assumes that a site with inputs for 2023 and 2024 and with remaining void is operational
• The data for England and Scotland assumes that a site with no inputs for 2023 and 2024 but remaining void is mothballed
• The data for England and Scotland assumes that a site with no inputs for 2023 and 2024 and no remaning void is closed
• The void presented in the graphs is for total void, whereas the void for the tables is based on operational sites only
• Remaining life is a simple calculation of the remaining operational void divided by the the input in 2024. It does not reflect mothballed sites that may come back into operation
• Tonnage may continue to drop, in which case site lives will extend beyond that indicated
• The void calculations do not reflect regional supply and demand - some void in some areas may run out sooner than in other areas