The Environmental Monitoring for Health Protection (EMHP) SARS-CoV-2 wastewater monitoring programme is being scaled back and paused at the end of March 2022. Wastewater based epidemiology is likely to be of significant importance in the future, both domestically and internationally, and we are exploring further opportunities for this technology.
These publications will therefore be discontinued. Transparency data covering the time period up to the end of March 2022 will be published in 2 final publications, this publication on 31 March 2022 and another on 12 May 2022, at which point regular publications will cease. Any future ad-hoc transparency publications will be announced in advance on this page and on the Statistics at UKHSA page.
Background on the EMHP wastewater monitoring programme
People infected with coronavirus (COVID-19) shed the virus during daily activities such as going to the toilet and blowing their nose. The virus enters the sewer system through sinks, drains and toilets. Fragments of SARS-CoV-2 (the virus that causes COVID-19) can be detected in samples of wastewater (untreated sewage).
The EMHP programme is led by the UK Health Security Agency (UKHSA) and run in partnership with the Department for Environment, Food and Rural Affairs (Defra), the Environment Agency (EA), the Centre for Environment, Fisheries and Aquaculture Science (Cefas), academia, and water companies. It provides coverage of approximately 74% of the population in England. The EMHP team coordinates with programmes in the devolved administrations to provide UK-wide wastewater monitoring.
The programme tests sewage for fragments of SARS-CoV-2 RNA. Untreated influent samples are taken from approximately 302 sewage treatment works (STWs) in England, 3 times a week (see figures 1 to 9). EMHP also samples from sewer network sites (manholes), untreated influent samples are taken from approximately 197 sewer network sites in England, 4 times a week.
Data from sewer network sites is not included in the concentration data in this publication as these sites generally fall within sewage treatment work (STW) catchments. Data from sewer network sites are included in the Omicron detection data in this publication. Further detail about EMHP wastewater coverage can be found in the latest population coverage publication Wastewater testing coverage data for 23 February 2022: EMHP programme.
The programme helps identify where the virus is circulating in England as well as detecting mutations of the virus, including those associated with known variants of concern (VOCs) and variants under investigation (VUIs). Findings are reported to national decision makers and local stakeholders on a regular basis, helping to inform national strategy and localised action. Wastewater analysis has the benefit of detecting the virus regardless of whether people have symptoms or whether they are tested. Wastewater monitoring complements other testing programmes and public health actions to help protect against the threat of new variants.
The data presented in this publication is generated by non-accredited research laboratories and should be considered experimental.
Formal validation of wastewater monitoring as a variant surveillance system is underway. EMHP advises caution when directly comparing data from STWs and concentration of SARS-CoV-2 RNA in wastewater with clinical testing data. Wastewater detections of a variant are reported as either confirmed or possible, based on the number of signature or unique SNPs, and co-occurrence on the same amplicon.
This describes the level of confidence EMHP has in the specificity of the detection; ‘confirmed’ status is assigned when there is a high degree of confidence the variant was present in the wastewater sample, ‘possible’ is assigned where there is some evidence that the variant was present.
These definitions are different to the clinical case definitions and the two should not be compared. Lack of a positive wastewater sequencing result is not necessarily confirmation that no variant cases reside within a given geography, due to factors such as rainfall dilution impacting RNA recovery.
Interpretation of all data in this publication should be made with careful consideration of the points in the Uncertainty, data quality, and revisions section.
EMHP sampling sites
EMHP samples at sewer network sites (manholes in the street which generally serve a local area) and STWs (which generally serve wider areas such as a city or town). Associated with every STW and sewer network site is a catchment, the geographical area from which wastewater flows into the sampling location. EMHP SARS-CoV-2 RNA concentrations data from sewer network sites is not included in this publication as these sites generally fall within STW catchments.
In addition, EMHP changes sampling strategy and locations of sewer network sites to meet epidemiological priorities (for example to support local public health responses). Further detail about EMHP wastewater coverage can be found in the publication Wastewater testing coverage data for 23 February 2022: EMHP programme.
Figures 1 to 9 show the location of STWs that EMHP samples at in each region.
Figure 1. Map showing the location of Sewage Treatment Works sampled in the East Midlands.
Location of STWs sampled in the East Midlands:
- Alfreton
- Anwick
- Boston
- Bourne
- Brackley
- Chesterfield
- Coalville
- Corby
- Daventry
- Derby
- Eastwood
- Gainsborough
- Grantham
- Hinckley
- Ilkeston
- Ingoldmells
- Leicester
- Lincoln
- Long Eaton
- Loughborough
- Louth
- Mablethorpe
- Market Harborough
- Mansfield
- Melton Mowbray
- Northampton
- Nottingham
- Oakham
- Retford
- Spalding
- Stamford
- Wellingborough
- Whaley Bridge
- Wigston
- Worksop
Figure 2. Map showing the location of Sewage Treatment Works sampled in the East of England.
Location of STWs sampled in the East of England:
- Basildon
- Basildon (Vange)
- Beccles
- Bedford
- Braintree
- Breckland
- Bury St Edmunds
- Cambridge
- Chalton
- Chelmsford
- Colchester
- Cromer
- Diss
- Downham Market
- Felixstowe
- Great Yarmouth
- Harlow
- Haverhill
- Hunstanton
- Huntingdon
- Ipswich
- Ipswich (Chantry)
- Jaywick
- Kings Lynn
- Letchworth
- Lowestoft
- Luton
- March
- Needham Market
- Newmarket
- Norwich
- Peterborough
- Radlett
- Reepham
- Rochford
- Royston
- Saffron Walden
- Shefford
- Soham
- St Albans
- Stalham
- Stowmarket
- Sudbury
- Southend-on-Sea
- Thetford
- Tilbury
- Wells-next-the-Sea
- Wickford
- Wisbech
- Witham
Figure 3. Map showing the location of Sewage Treatment Works sampled in London.
Location of STWs sampled in London:
- Beckton
- Beddington
- Crossness
- Deepham
- Hogsmill Valley
- Long Reach
- Mogden
- Riverside
Figure 4. Map showing the location of Sewage Treatment Works sampled in the North East.
Location of STWs sampled in the North East:
- Billingham
- Bishop Auckland
- Blyth
- Consett
- Cramlington
- Darlington
- Durham (Barkers Haugh)
- Durham (Belmont)
- Hartlepool
- Horden
- Houghton-le-Spring
- Marske Redcar
- Middlesbrough
- Newcastle
- Newton Aycliffe
- Seaham
- Sunderland
- Washington
Figure 5. Map showing the location of Sewage Treatment Works sampled in the North West.
Location of STWs sampled in the North West:
- Barnoldswick
- Barrow-in-Furness
- Birkenhead
- Blackburn
- Bolton
- Bromborough
- Burnley
- Bury
- Carlisle
- Clitheroe
- Congleton
- Crewe
- Ellesmere Port
- Fleetwood
- Huyton and Prescot
- Hyde
- Hyndburn
- Kendal
- Lancaster
- Leigh
- Liverpool (Sandon)
- Macclesfield
- Maghull
- Northwich
- Penrith
- Preston
- Rochdale
- Rossendale
- Skelmersdale
- St. Helens
- Stockport
- Walton-Le-Dale
- Warrington
- Wigan
- Wirral
- Workington
Figure 6. Map showing the location of Sewage Treatment Works sampled in the South East.
Location of STWs sampled in the South East:
- Andover
- Alton
- Ashford
- Aylesbury
- Banbury
- Basingstoke
- Bexhill
- Bicester
- Bordon
- Buckingham
- Burgess Hill
- Camberley
- Canterbury
- Chatham
- Chesham
- Chichester
- Crawley
- Didcot
- Dover and Folkestone
- Eastleigh
- Fareham and Gosport
- Guildford
- Hailsham
- Hythe
- Isle of Wight
- Lewes
- Littlehampton and Bognor
- Lymington and New Milton
- Maidstone and Aylesford
- Milton Keynes
- Newbury
- New Forest
- Oxford
- Portsmouth and Havant
- Ramsgate, Sandwich and Deal
- Reading
- Reigate
- Scaynes Hill
- Sittingbourne
- Slough
- Southampton
- Tonbridge
- Tunbridge Wells
- Witney
- Woking
- Worthing
- Wycombe
Figure 7. Map showing the location of Sewage Treatment Works sampled in the South West.
Location of STWs sampled in the South West:
- Barnstaple
- Bath
- Bideford
- Blandford Forum
- Bodmin Sc Well
- Bournemouth (Central)
- Bridport
- Bristol
- Camborne
- Chard
- Cheltenham
- Chippenham
- Cirencester
- Clevedon and Nailsea
- Ernesettle and Saltash
- Exmouth
- Falmouth
- Gloucester
- Helston
- Liskeard
- Lydney
- Menagwins
- Minehead
- Newquay
- Newton Abbot
- Par
- Plymouth (Camels Head)
- Plymouth
- Plympton
- Salisbury
- Shaftesbury
- Shepton Mallet
- Sidmouth
- St Ives and Penzance
- Stroud
- Swanage
- Swindon
- Taunton
- Tavistock
- Tiverton
- Torquay
- Trowbridge
- Wellington
- Weston-super-Mare
- Weymouth
- Yeovil
Figure 8. Map showing the location of Sewage Treatment Works sampled in the West Midlands.
Location of STWs sampled in the West Midlands:
- Barston
- Brancote
- Checkley
- Birmingham (Coleshill)
- Birmingham (Minworth)
- Burton on Trent
- Coventry
- Evesham
- Kidderminster
- Leek
- Ludlow
- Malvern
- Market Drayton
- Nuneaton
- Oswestry
- Rugby
- Spernal
- Stoke-on-Trent
- Stourbridge and Halesowen
- Telford
- Telford South
- Walsall
- Warwick
- Wolverhampton
- Worcester
Figure 9. Map showing the location of Sewage Treatment Works sampled in Yorkshire and the Humber.
Location of STWs sampled in Yorkshire and the Humber:
- Barnsley
- Barton-upon-Humber
- Beverley
- Bingley
- Bradford
- Bridlington
- Castleford
- Colburn
- Dewsbury
- Doncaster (Thorne)
- Doncaster (Sandall)
- Driffield
- Grimsby
- Halifax
- Harrogate North
- Harrogate South
- Hemsworth and South Elmsall
- Huddersfield
- Hull
- Keighley
- Leeds
- Maltby
- Malton
- Mexborough and Conisbrough
- Northallerton
- Pontefract
- Scarborough
- Scunthorpe
- Sheffield (Blackburn Meadows)
- Sheffield (Woodhouse Mill)
- Wakefield
- York
Concentration of SARS-CoV-2 RNA in wastewater samples
EMHP wastewater concentration data from 1 June 2021 to 7 March 2022 is available in the accompanying spreadsheet. The spreadsheet includes data from previous months’ publications, along with the latest data from February and March. The most recent 4 weeks of data are visualised in figures 10 and 11; England concentration maps. Note that STWs are omitted from figures 10 and 11 if no samples were taken during the week.
In the week beginning 8 February, 134 of 292 STWs (46%) had a decrease in average concentration levels compared to the previous week. In the week beginning 15 February, 211 of 299 STWs (71%) had lower average concentration than the preceding week. In the week beginning 22 February, 170 of 297 STWs (57%) had a decrease in average concentration relative to the previous week. In the week beginning 1 March, 120 out of 297 STWs (40%) showed a decrease in average concentrations compared to the previous week. Interpretation should be made with careful consideration of the points in the Uncertainty, data quality, and revisions section below.
Figure 10. England concentration map: map showing the location of Sewage Treatment Works sampled. Colour indicates the weekly-average SARS-CoV-2 RNA concentration (gene copies/litre) in the last 2 weeks. See regional maps for the names of each STWs.
Figure 11. England concentration map: map showing the location of Sewage Treatment Works sampled. Colour indicates the weekly-average SARS-CoV-2 RNA concentration (gene copies/litre) in the first 2 weeks. See regional maps for the names of each STWs.
Regional average concentration of SARS-CoV-2 RNA in wastewater
In the latest period (8 February to 7 March) concentration data showe
