Refinery & gas plant register · Refinery

Fawley Refinery: water, effluent and process profile

Fawley Refinery (Esso Refinery, Fawley) - integrated with ExxonMobil Chemical Fawley petrochemical plant. Operator: Esso Petroleum Company, Limited (ExxonMobil affiliate); petrochemical plant within the same EPR installation boundary operated by ExxonMobil Chemical Limited (permit ZP3839MG). Status: operating.

Compiled 25 September 2026 · confidence: medium · what that means here

Water & effluent

Intake source: sea (cooling, Southampton Water) + municipal (Southern Water Testwood works, River Test, for process water)
Cooling: once-through seawater
Raw water quality: Cooling: estuarine seawater from Southampton Water (analysis not public). Process/boiler make-up: Southern Water's Testwood works, which draws from the River Test and also supplies the Esso refinery at Fawley; there is a separate Testwood Industrial Water Supply Works. Treated on site by raw water treatment and RO for demineralised water.
Effluent treatment: API/CPI + DAF/IGF (oil separators, dual media filtration, DAF, clarifiers); no biological stage
Discharge to: Southampton Water via three outfalls (W1, W2, W3) onto intertidal mudflats close to high water within the Solent and Southampton Water SPA; the refinery also treats wastewater from the ExxonMobil Chemical plant
Discharge regime: EPR/BR6996IC (Environmental Permitting (England and Wales) Regulations 2016; IED; Refining BAT Conclusions 2014/738/EU; CWW BREF), consolidated variation V007 2018, V008 2019. W1 (SEPS 1 + sanitary): pH 6-9; HOI 2.5 mg/l annual average; oil 5 mg/l; TN 25 mg/l; NH4-N 5 mg/l; mono-phenols 1 mg/l; TOC 20 mg/l; COD 125 mg/l; TSS 25 mg/l; benzene 0.05 mg/l; Hg 0.3 ug/l; temperature 40 C; dry-weather flow 12,800 m3/h, 307,200 m3/d. W2 (SEPS 2, SEPS 3, Quay Cottage): HOI 2.5 mg/l; NH4-N 3 mg/l; phenols 0.5 mg/l; TOC 30 mg/l; COD 261 mg/l (derogation from BAT-AEL 30-125 mg/l); TSS 25 mg/l; temperature 40 C; dry-weather flow 9,500 m3/h, 228,000 m3/d. W3: phenols 0.5 mg/l; TOC 20 mg/l; COD by TOC x3; temperature 40 C; flow 350 m3/h, 8,400 m3/d. Metals (Cu, Zn, Ni, Pb, Cd, Hg) limits at ug/l level.
Sources: assets.publishing.service.gov.uk exxonmobil-fawley.co.uk waterprojectsonline.com assets.publishing.service.gov.uk

Known issues

COD at W2 above BAT-AEL: derogation to 261 mg/l; EA accepted that a BiOx plant costs more than its benefit; TOC review plan IC40 (2018)
Mercury at Outfall 1 needs detailed modelling and possible mitigation (IC45, due 30 Sep 2020)
AOX monitoring at Outfall 2 against the CWW BREF (IC46, due 31 Dec 2019)
Eel screening at seawater intakes and outfalls (IC37, Eels Regulations 2009)
Phenol at W1 reduced by reusing stripped sour water as desalter wash water (2010)
HD10 adds cooling water below 1% of total seawater flow and sends wastewater to the existing SWS (2019)
Outcome of IC40/IC45/IC46 and any later permit variations (after V008) not found in public sources

Site, ownership & capacity

Owners

Name	Share pct	Source
Exxon Mobil Corporation (via wholly owned Esso Petroleum Company, Limited)	100	en.wikipedia.org

Country

United Kingdom (England)

Region

Hampshire (New Forest District)

Town

Fawley, Southampton SO45 1TX (Marsh Lane); approx. 7.5 km south-east of Southampton

Lat

50.8331

Lon

-1.365

Coastal

Yes

Water body

Southampton Water (Solent estuary); site bounded east and north-east by mudflats, saltmarsh and Southampton Water

Not public

Site ground/platform elevation (m AOD) not public; would be answered by an Ordnance Survey level survey or the site flood risk assessment.

Notes

Lat/lon converted from Wikipedia 50deg49'59"N 1deg21'54"W. Installation area 613 ha, NGR SU 455043 (EA permit); operator states 3,250 acres.

Sources

en.wikipedia.org assets.publishing.service.gov.uk corporate.exxonmobil.com

Capacity

Crude bpd: 270,000
Crude bpd notes: Sources disagree: 270,000 b/d (Wikipedia; Reuters via Inspectioneering 2022; OGJ 2021; Bloomberg via Energy Voice 2024); OGJ 2024 gives 262,000 b/sd (246,900 b/cd); the 2011 Esso brochure and Solent Forum give up to 330,000 b/d (15 Mt/y). EA permit limits the two crude distillation units at PS1 3,600 kt/y and PS3 8,600 kt/y (12,200 kt/y combined). 270,000 b/d taken as the current nameplate figure.
Crude distillation permit limit kt per y: 12,200
Not public: Nelson complexity index not published; would be answered by the OGJ Worldwide Refining Survey unit capacities (paywalled) or an operator disclosure.
Sources: en.wikipedia.org ogj.com exxonmobil-fawley.co.uk solentforum.org assets.publishing.service.gov.uk

Process units

Unit	Capacity	Source	Not public	Year	Licensor
CDU	Pipestill PS1: 3,600 kt/y annual throughput (permit limit); combined with vacuum unit PV1 (LCP 150)	assets.publishing.service.gov.uk
CDU	Pipestill PS3: 8,600 kt/y annual throughput (permit limit); combined with vacuum unit PV3 (LCP 151)	assets.publishing.service.gov.uk
CDU	Wikipedia lists 3 atmospheric distillation units; a PS2 emission point appears in the permit air tables. Current status of the third unit not confirmed.	en.wikipedia.org	Status and capacity of PS2 not public in fetched sources.
VDU	PV1 and PV3 in current permit; Wikipedia: 3 vacuum distillation units, 1 shut in 2012	en.wikipedia.org		2012
FCC	FCCU (emission point A22); multistage cyclones on regenerator flue gas, DeSOx catalyst additive; dust derogation to 130 mg/Nm3 against BAT-AEL 10-50 mg/Nm3	assets.publishing.service.gov.uk
reformer	Two Powerformers (PH1 LCP 147, PH2 LCP 148, plus PH1-F4); also supply refinery hydrogen	assets.publishing.service.gov.uk			ExxonMobil (Powerforming is an Exxon process name)
HDS/HDT	Hydrotreatment units named in permit: SCAN, HD3, HD4, HD5, HD6, HD7, HD8, RESID (residfiner), ENSR (lubes hydrofiner, LCP 145). Wikipedia: 6 hydrofiners, 1 added 2013.	assets.publishing.service.gov.uk		2013
HDS/HDT	Residfiner: fourth reactor added and hot coker feed export enabled (variation V006, issued 18 Jul 2018)	assets.publishing.service.gov.uk		2018
HDS/HDT	HD10 high-pressure diesel hydrofiner (Block 36B), about 570 million US gal/y ULSD; inferred approx. 37,000 b/d (570e6 / 42 / 365, basis: inferred). Feed: three gas oil streams from distillation plus one from FCC; 12 MWth furnace (A32). Part of 'FAST' project, first diesel Q1 2025, full production 2025.	assets.publishing.service.gov.uk	Licensor not public.	2025
HDS/HDT	HD7 jet hydrofiner: new larger reactor replacing existing low-sulphur reactor (Block 7); throughput unchanged, lower product sulphur	assets.publishing.service.gov.uk	Commissioning year of HD7 reactor replacement not confirmed (permitted March 2019).
isomerisation	ISOM light naphtha isomeriser; WISR wax isomeriser (lubes)	assets.publishing.service.gov.uk
fractionation	LESR light ends unit; LPG odorising (C3/C4 stenching)	assets.publishing.service.gov.uk
SRU	Claus SRU trains SU3 and SU4, tail-gas unit, tail-gas incinerator, sulphur storage for export	assets.publishing.service.gov.uk
amine	Amine systems and amine recovery unit	assets.publishing.service.gov.uk
sour water stripper	Sour water stripper units; stripped water reused as desalter wash water (V002, 2010); spare capacity confirmed for HD10 load (2019)	assets.publishing.service.gov.uk		2010
hydrogen plant	New steam methane reformer, +55 MMscfd hydrogen; ZnO desulphurisation, PSA purification, 130 MWth furnace (A31), 50 m stack. Previously no hydrogen import: H2 came from the 2 Powerformers and a plant on the adjacent chemical plant.	ogj.com	Licensor not public.	2025
GTG	SP4 Unit 3 GTG/WHB 196 MWth (LCP 146); Unit 5 Cogen GTG/WHB 451 MWth (LCP 144), up to 230 t/h steam, net power exporter; plus 2 x 400 MWth boilers (SP4 Units 1 and 2, combined <500 MW by interlock)	assets.publishing.service.gov.uk
other	Lubricating oil complex; polymerisation plant; bitumen plant (shut 2009)	en.wikipedia.org		2009
alkylation		assets.publishing.service.gov.uk	No alkylation unit named in the permit or Wikipedia unit list; presence not confirmed.

Known equipment

Item	Detail	Source
desalter	Crude desalters with a wash water tank; sour water stripper effluent reused as desalter wash water to reduce phenol to outfall W1 (variation V002, 24 Aug 2010). Number, size, transformer rating not public.	assets.publishing.service.gov.uk
WWTP unit	Oil separators (SEPS 1, SEPS 2, SEPS 3 and Quay Cottage effluent treatment), dual media filtration, dissolved air flotation, clarifiers (sedimentation), general filtration, reverse osmosis plant, sludge tanker loading. Clean and dirty waters treated separately. No biological oxidation (BiOx) plant: EA accepted that a BiOx plant cost more than its benefit (BAT 12 derogation); gas stripper reconfiguration adopted instead to treat high-TOC streams.	assets.publishing.service.gov.uk
WWTP unit	Spent caustic collection and neutralisation (changed from batch to continuous, V002 2010); ballast water receipt and oil recovery treatment	assets.publishing.service.gov.uk
WWTP unit	Raw water treatment for steam raising; export of demineralised water to the refinery	assets.publishing.service.gov.uk
exchanger	Once-through seawater cooling: up to 1.8 million tonnes/day of seawater drawn from Southampton Water, mostly for cooling. Intakes and outfalls subject to eel screening review (IC37, Eels (England and Wales) Regulations 2009).	exxonmobil-fawley.co.uk
flare	Sour and sweet gas flares (emission points A24-A27), hydrocarbon gas recovery compressor, knock-out pots; flaring reduction study IC43 (due 31 Mar 2020)	assets.publishing.service.gov.uk
column	A large steel tower on an LPG duty partly collapsed on 8 Nov 2022 from corrosion known since 2010; about 2,400 kg LPG released over 33 hours	press.hse.gov.uk
separator	Marine terminal: about 1.5 km (1 mile) long, 9 berths (5 ocean-going 10.2-14.9 m depth, 4 coastal), VLCC up to 244,000 t, about 2,000 ship movements/year, 22 Mt/y; crude tanks about 21,000 m3 each	en.wikipedia.org

Feed

Crude slate

North Sea
West Africa
South America
Russia (as of 2011; likely stopped after the 2022-23 UK import bans, not confirmed for Fawley)
Over 20 crude grades a year (2011)

Gas composition

Mercury: Mercury is a parameter at outfall W1 (0.3 ug/l and 0.001 mg/l limits); further mercury assessment required (IC45)

Not public

Current crude slate, API, sulphur, TAN and salt content not public; would be answered by the operator's crude assay list or tanker-tracking data (Kpler/Vortexa). The permit monitors average FCCU feed sulphur yearly but does not publish it.

Sources

exxonmobil-fawley.co.uk

Chemistry & corrosion risks

chloride/overhead corrosion: crude desalting with stripped sour water as wash water; many different crudes (over 20 grades a year in 2011) changes the salt load (inferred from permit and brochure)
H2S/SSC: hydrotreating (HD3-HD10, residfiner), amine, SWS and 2 Claus SRU trains
amine degradation: amine systems and amine recovery unit on site
external/atmospheric corrosion in a marine environment: 2008 fatal corroded pipe; 2022 LPG tower partial collapse from corrosion known since 2010
mercury: outfall W1 mercury flagged for further assessment (IC45)
fouling: once-through estuarine seawater cooling (biofouling on intakes and exchangers, inferred); FCC catalyst fines
biocide/consent conflict: seawater cooling returns to a SPA/SAC/SSSI with metals limits at ug/l level; the biocide regime is not public (inferred risk)
emulsions: effluent includes ballast water and spent caustic neutralisation; COD/TOC loads are high (W2 COD derogation 261 mg/l)
naphthenic acid corrosion: not assessed; crude TAN not public

Site conditions

Climate: Temperate oceanic. Southampton (Mayflower Park) 1991-2020: July mean max 22.6 C, February mean min 3.0 C, annual precipitation 818.6 mm; record high 35.6 C (June), record low -16.6 C (January).
Ambient max c: 35.6
Not public (seismic): No site seismic data fetched; UK seismicity is generally low, but confirm the design basis from the site or BGS hazard maps before structural design.
Not public (ground): Ground investigation not public. The site is bounded by estuarine mudflats and saltmarsh (EA permit), so soft alluvial ground is likely near the shoreline (inferred). Historical contamination is confirmed: Biogenie Site Remediation operates a remediation, treatment and biopile facility (EPR/ZP3133RH) inside the refinery boundary.
Flood or coastal risk: Tidal. EA Southampton Water flood alerts (Feb and Apr 2024) list 'outbuildings at Fawley Refinery' as at risk; Ashlett Creek (Fawley) floods at high tide. The adjacent Fawley Waterside (former power station) site is 68% Flood Zone 1, 4% FZ2, 9% FZ3a and 19% FZ3b (JBA/NFNPA SFRA via WSP 2018). Refinery platform level not public.
Hazardous area regime: ATEX
Hazardous area notes: GB: DSEAR 2002 zoning, with equipment to UKEX (UKCA Ex) or ATEX. Site is a COMAH establishment (the 2015 LPG release was prosecuted under COMAH 2015). Upper tier status is inferred and not confirmed. Zone drawings not public.
Environmental designations: Solent and Southampton Water SPA/Ramsar, Solent Maritime SAC, Hythe to Calshot Marshes SSSI (saltmarsh bordering the site), River Itchen SAC, Portsmouth Harbour SPA
Sources: en.wikipedia.org floodassist.co.uk newforestnpa.gov.uk assets.publishing.service.gov.uk assets.publishing.service.gov.uk assets.publishing.service.gov.uk advertiserandtimes.co.uk

History

Year	Event	Detail	Source
1921	commissioning	First refinery built by Atlantic, Gulf and West Indies Oil Company (AGWI) on 270 ha	en.wikipedia.org
1925	ownership change	Taken over by Anglo-American Oil Company (Esso affiliate); British-Mexican Petroleum had acquired it in 1923	en.wikipedia.org
1935	incident	Major oil tank fire lasting several days	en.wikipedia.org
1939	outage	About 12,000 b/d before WWII; refining stopped during the war and the site was used for storage	en.wikipedia.org
1951	expansion	New Esso refinery opened by PM Clement Attlee on 14 Sep 1951, about 157,000 b/d; 1,200 ha added from 1949	en.wikipedia.org
1958	expansion	Chemical plant created	en.wikipedia.org
1969	incident	Major refinery fire	en.wikipedia.org
1973	expansion	Peak capacity about 400,000 b/d (19.5 Mt/y)	en.wikipedia.org
1992	upgrade	Refining and combustion authorised under IPC from 1992; EPR permit BR6996IC applied for 2006	assets.publishing.service.gov.uk
2007	incident	July 2007 steam plant fire; partial shutdown	en.wikipedia.org
2008	incident	Sailor killed by a corroded pipe failure; GBP 100,000 fine	en.wikipedia.org
2009	closure	Bitumen plant shut	en.wikipedia.org
2010	incident	June 2010: about 20 bbl vacuum gas oil spilled; GBP 10,000 fine	en.wikipedia.org
2010	upgrade	Permit V002 (24 Aug 2010): ENSR lubes hydrofiner recommissioned; spent caustic neutralisation made continuous; SWS effluent reused as desalter wash water to cut phenol at W1	assets.publishing.service.gov.uk
2011	incident	Fatal worker accident	en.wikipedia.org
2012	closure	One of three vacuum distillation units shut	en.wikipedia.org
2013	upgrade	One hydrofiner added; chemical plant steam cracker shut and dismantled; New Forest AQMA for SO2 revoked	en.wikipedia.org
2015	incident	15 Nov 2015: 15-21 t LPG released over about 5 h at a valve near the road tanker roadway after a relief valve procedure change; COMAH 2015 guilty plea, GBP 500,000 fine (14 Dec 2021)	advertiserandtimes.co.uk
2017	upgrade	Permit V005 (effective 1 Apr 2017): IED Large Combustion Plant ELVs; Cogen CHP consolidated into the permit	assets.publishing.service.gov.uk
2018	expansion	Permit V006 (18 Jul 2018): fourth residfiner reactor and hot coker feed export. V007: permit review against Refining BAT; derogations for COD (BAT 12), FCC dust (BAT 25), marine loading VOC (BAT 52)	assets.publishing.service.gov.uk
2019	upgrade	Permit V008 (4 Mar 2019): new SMR hydrogen plant, HD10 diesel hydrofiner and HD7 jet reactor replacement authorised	assets.publishing.service.gov.uk
2021	outage	Planned maintenance from 27 Feb 2021, about 3 weeks, on part of the process units	ogj.com
2022	upgrade	March 2022: PM/EPC consortium Kent, Taylor Woodrow (VINCI) and BGEN appointed for the HD10 and hydrogen plant project	ogj.com
2022	incident	8 Nov 2022: steel tower partly collapsed from long-standing corrosion; about 2,400 kg LPG released over 33 h; unit isolated, flaring. HSWA s3(1) guilty plea, GBP 1m fine plus GBP 12,277 costs, Southampton Magistrates, 12 Jun 2026	press.hse.gov.uk
2023	expansion	Nov 2023: main construction of the GBP 800m+ ($1bn) low-sulphur diesel project confirmed: +40% ULSD, about a quarter less UK diesel import; GBP 6m DfT funding for SAF feasibility study	corporate.exxonmobil.com
2025	expansion	HD10 and new hydrogen plant: bulk of new diesel supply in Q1 2025, full production 2025. The jet pipeline expansion to the West London terminal near Heathrow was already complete by Apr 2024.	energyvoice.com

Performance

Throughput recent: About 270,000 b/d quoted in 2024 (Bloomberg via Energy Voice); 22 Mt/y crude and products over the marine terminal
Notes: Refinery-level utilisation not published; DESNZ publishes UK totals only. Distribution: about 70% by pipeline (80% per 2011 brochure), 25% by sea, 5% rail/road; jet fuel piped to Heathrow and Gatwick. Refinery is a net power exporter (Cogen). About 2,500 staff and contractors.
Not public: Actual 2024-2026 crude runs and utilisation; would be answered by operator disclosure or paid data (Wood Mackenzie, Kpler).
Sources: energyvoice.com

Projects

Project	Status	Epc or licensor	Year	Source
FAST: HD10 high-pressure diesel hydrotreater (about 570 M gal/y) + 55 MMscfd SMR hydrogen plant, GBP 800m+	Started up; first diesel Q1 2025, full production 2025. Post-start-up performance not published.	Kent PLC, Taylor Woodrow (VINCI Construction UK), BGEN Ltd consortium (PM, engineering, procurement, module fabrication, logistics, completions, commissioning)	2025	ogj.com
HD10 reconfiguration option to conventional jet or HEFA SAF from vegetable oils	Option stated by plant head (2024)			energyvoice.com
Solent SAF plant: gasification of refuse-derived fuel to methanol, then ExxonMobil Methanol-to-Jet; 179,000 t/y SAF	Feasibility (GBP 6m DfT Advanced Fuels Fund, Nov 2023); target 2030 operation if approved	ExxonMobil MtJ (proprietary)	2030	corporate.exxonmobil.com
Solent Cluster CCS / hydrogen hub: capture at Fawley with offshore storage (English Channel Carbon Storage); region emits about 3.2 Mt/y CO2 from energy-intensive industry	Concept / consortium (founded 2022); no FID found			issuu.com

Sources & confidence

High for permit data (EA documents, but the latest consolidated permit fetched is V007 2018 plus V008 2019; later variations were not retrieved). Medium for capacity (sources conflict: 262k-330k b/d). Low for crude slate (2011 brochure only). Solent Cluster emissions figure is taken from a search summary of a University of Southampton magazine and was not fetched directly.

This profile is compiled from public documents only. Figures are quoted as published, and any inferred value is labelled as inferred. If you can correct or add to it, please contact us.