Permanent project revision
Revision 2026-10-11-baseline · effective 2026-10-11
Current revision. This is the snapshot used by the live entity page.
Created the first structured Evidence Passport with 18 claims and 10 source dossiers.
sha256:b5255ca07db786b0f4b918205d3d8952e6e61860c2494ff864ca49feabc738fd
add /evidencePassport — Added claim-level evidence mapping and source dossiers.add /revisionHistory — Established a permanent, hash-addressed baseline revision.The text below is copied verbatim from the published record. Each claim names the source dossiers that carry it; caveats stay attached to the claim they qualify.
clm-41016919edee5c49
quantitative
Johannesburg's Environment and Infrastructure Services Department has run ambient air-quality stations since 2004, when six were set up in Alexandra, Buccleuch, Delta Park, Jabavu, Newtown and Orange Farm
clm-1e74c31a231a69bb
quantitative
Diepsloot and Ivory Park followed in 2009 and a mobile station in Davidsonville in 2015
clm-2f43bb61ec4995c5
descriptive
Hourly averages go to SAAQIS, the national environment department's portal
clm-cf5e639503933dd1
quantitative
The City counted nine stations in 2019 and eight in 2025
clm-bf36d09f265bd1ee
quantitative
In March 2026 the Alexandra and Buccleuch stations detected a city-wide sulphur smell, Alexandra peaking at 36–37 ppb of hydrogen sulphide
clm-dd6b5c222cf32f88
quantitative
the City's 2019 plan found data availability "highly variable" and falling
clm-684fec7f267cad6c
descriptive
Davidsonville was offline for more than three years after vandalism
clm-95120259c76aac51
quantitative
Delta Park has been shut since 2015
clm-508b91dc6baf866c
descriptive
No reading triggers an automatic response, and no source states an effect of the network on pollution levels
clm-48ce508e6d50682b
quantitative
the City reported hydrogen sulphide peaking at 36–37 ppb and sulphur dioxide at around 52 ppb at Alexandra, advised residents to stay indoors and escalated the question of the source to the national and provincial departments
clm-ce82e0e6d0c22280
quantitative
the national department cited Buccleuch alongside Secunda, Springs, Irene and Midstream as stations whose peaks exceeded the WHO nuisance-odour threshold of 5.02 ppb, and attributed the plume to Mpumalanga
clm-8a9804d1654feb12
quantitative
a 2024 national report records seven City stations operational over the past five years, with four to five reporting above 75% data recovery
clm-36c1114df4d64afb
quantitative
Buccleuch and the Crown interchange were vandalised before 2019
clm-7d74cfb50d4fe40e
quantitative
Davidsonville stood dark for over three years, Delta Park has been shut since 2015 and awaits relocation
clm-6f73da736f77861e
quantitative
the City's plan dropped Ivory Park and Diepsloot from its 2004–2015 assessment for low data availability
clm-f44010b3745ce0a7
quantitative
Alexandra, was recorded as shut down since 2010 at the City's 2016 site visit
clm-3dcc4305bf6ff440
quantitative
it was the hydrogen sulphide monitoring the City added after the 2022 odour episode that let it speak
clm-ec144a4d634ebe7b
quantitative
the regulatory answer to sulphur — a tighter national emission limit — followed a 2022 investigation, not a city threshold
This layer records what is known about each source, what is still missing, and the exact snapshot this page is rendering. A missing date, archive or hash stays visible as missing.
Awaiting operator and domain-expert review; publication of this revision implies neither.
sha256:b5255ca07db786b0f4b918205d3d8952e6e61860c2494ff864ca49feabc738fd
src-65995158764a56c3The City's air quality management plan, dated October 2019. Section 3.1 states the network was first established in 2004 with six stations (Alexandra, Buccleuch, Delta Park, Jabavu, Newtown, Orange Farm), expanded in 2009 (Diepsloot, Ivory Park) and in 2015 (mobile station, Davidsonville), and now consists of nine stations; Table 4 records each station's status at the May–June 2016 site visits (Buccleuch not operational due to power problems, Alexandra shut down since 2010, Delta Park shut with all instruments removed, Newtown not operational, Orange Farm, Jabavu, Diepsloot, Ivory Park and Davidsonville operational); section 3.2 states that data availability per station per year was highly variable and decreased substantially over 2004–2015, and that Ivory Park and Diepsloot were excluded from the assessment for low data availability. Table 21 estimates approximately R2 862 500 per year over four years to expand all stations to all criteria pollutants.
src-e2c539577043145bCity newsroom item on the relaunch of the Orange Farm station. States that the city has nine monitoring stations across all regions, that since 2004 the City has spent over R5 million building and revamping them, that two stations (Crown interchange and Buccleuch) were vandalised in the past, and that the data is public on SAAQIS, hosted by the national environment department.
src-ec26fc90282ef77eCity media statement on the re-commissioning of the Davidsonville station. States the station had been offline for more than three years following vandalism and theft, that the City operates eight stations across all regions reporting to SAAQIS, that the Delta Park station is still derelict due to vandalism, that the City also uses low-cost sensors, and that the Air Quality Management Plan had recently been adopted.
src-ecd7941d583a2a02City newsroom item on Clean Air Week 2025. States that the City operates eight air quality monitoring stations that provide real-time data, accessible to the public through the SAAQIS website and app.
src-d0b82685eb541581City media statement on the sulphur-like odour of 9–10 March 2026. States that monitoring confirmed elevated hydrogen sulphide at the Buccleuch and Alexandra stations, that at the Alexandra station H2S peaked at approximately 36–37 ppb and sulphur dioxide at around 52 ppb, that the matter was escalated to the national and Gauteng environment departments, that residents were advised to remain indoors during strong odours, and that the City hosts no major heavy industrial operations.
src-ce8e6f010647c3bfNational department statement on the same episode. States that SAAQIS data showed hydrogen sulphide peaks at the Secunda, Springs, Irene, Midstream and Buccleuch stations above the WHO nuisance-odour threshold of 5.02 ppb, that south-easterly winds carried pollution from Mpumalanga into Gauteng, that since 2022 the City of Johannesburg has invested in two additional hydrogen sulphide monitoring stations in Alexandra and Buccleuch, and that after the 2022 investigation the department proposed tightening the hydrogen sulphide emission limit for coal gasification from 3500 to 600 mg per cubic metre.
src-ee29ba30e7c6a9b1Presentation by the National Air Quality Officer to the 18th Air Quality Governance Lekgotla, 2–4 September 2024. The Gauteng inputs slide states that 7 of the City of Johannesburg's stations have been operational over the past five years and that 4 to 5 stations report above 75% data recovery, and that the City secured technical support from C40, GIZ, the World Bank, the Clean Air Fund and Breathe Cities.
src-1ef419da7b1af9eeDepartment presentation to the 2025 Air Quality Governance Lekgotla. Its provincial summary lists the City of Johannesburg with six low-cost sensors that are operational but not reporting to SAAQIS, and a plan to deploy 200 sensors in Gauteng across the City of Johannesburg, Ekurhuleni, Tshwane, Sedibeng and the West Rand.
src-32920269a9103596Reports the Gauteng MEC's figures: of the province's 31 municipal-owned stations 12 are fully operational, three partially and 16 not at all; keeping one station running costs about R500,000 a year in maintenance; and Delta Park in Johannesburg has been shut since 2015 for security reasons and is awaiting relocation. The provincial counts are not Johannesburg's and are not used in the entry.
src-2f3fd550e33d468eReport on the Davidsonville relaunch. States the station is one of nine across the city, that seven are operational, that Delta Park is down because of vandalism, that the station also measures solar radiation, wind and humidity, and that its data goes to a local and a national station and is shared on SAAQIS. Byline 12 September 2022, 01:42 SAST; the URL slug carries the UTC date of 11 September.