Observatory method and source limits

Origins and editions

The Observatory brings together public data selected and processed by Aguas SB. It uses EEA Waterbase-UWWTD: 2023 reporting, 2022 data; for the United Kingdom, 2019 reporting, 2018 data. It includes HydroWASTE v1.0 and, in the relevant US variant, EPA CWNS 2022. HydroWASTE's publication in 2022 does not date each national observation.

Sources: AEMA / EEA, Waterbase-UWWTD, convocatorias / reporting 2023 y / and 2019 · HydroWASTE v1.0 · Ehalt Macedo et al. (2022), Distribution and characteristics of wastewater treatment plants within the global river network · EPA, Clean Watersheds Needs Survey 2022 Report and Data

Coverage and selection

Coverage depends on inventory, country and edition; this is neither a complete global census nor a snapshot of current conditions. HydroWASTE selection excludes its European block, OSM-origin records and historical statuses other than Operational or Not Reported; these filters do not describe selection from the other inventories. Not Reported means status was not reported, not confirmed operation. Missing data do not mean zero or establish absence from the original source.

Sources: HydroWASTE v1.0 · Ehalt Macedo et al. (2022), Distribution and characteristics of wastewater treatment plants within the global river network · AEMA / EEA, Waterbase-UWWTD, convocatorias / reporting 2023 y / and 2019

Records and physical facilities

A key identifies a record within an inventory and country, not necessarily one unique physical facility across sources. Similar names or nearby positions are insufficient to merge records. Computational matches retain their uncertainty and do not establish administrative identity. Enrichment requires checking code and edition; a web address or translation does not validate identity either.

Sources: Ehalt Macedo et al. (2022), Distribution and characteristics of wastewater treatment plants within the global river network · AEMA / EEA, Waterbase-UWWTD, convocatorias / reporting 2023 y / and 2019 · EPA, Clean Watersheds Needs Survey 2022 Report and Data

Independent profiles and ownership

Each profile is an independent technical reading of public data. Aguas SB does not manage, operate or represent any of the facilities in the observatory. Ownership lies with the competent authority where documented. To contact a facility, please refer to the owning authority named in the public source.

Reported data, dates and corrections

Figures are those reported by each inventory for its data year; they are not inspections or current measurements of the plant. Later works, expansions or changes do not appear until the next official release. Where public sources document them, they are shown under “What public sources say”, with date and link. Anyone who operates, designs or knows a plant can propose a correction: it is reviewed before publication and their contact details are not published.

Sources: AEMA / EEA, Waterbase-UWWTD, convocatorias / reporting 2023 y / and 2019 · HydroWASTE v1.0 · EPA, Clean Watersheds Needs Survey 2022 Report and Data

Locations and estimates

Coordinates may be approximate or refer to another feature: municipal centres are used in Mexico and discharge locations in Canada. Indian records do not distinguish satellite locations from urban centres individually. Quality indicators describe provenance and limitations; they are not individual inspections. A map point does not establish a plant's perimeter.

Sources: HydroWASTE v1.0 · Ehalt Macedo et al. (2022), Distribution and characteristics of wastewater treatment plants within the global river network

Quantities that are not equivalent

Population served, flow in MGD and population equivalents (h-e) express different quantities. MGD is flow in million US gallons per day; h-e expresses an organic-load reference, not a headcount. Design capacity and reported load are not interchangeable either. Source units are retained, without converting people or MGD into h-e or treating unknown values as measured zeros.

Sources: Ehalt Macedo et al. (2022), Distribution and characteristics of wastewater treatment plants within the global river network · EPA, Clean Watersheds Needs Survey 2022 Report and Data · AEMA / EEA, Waterbase-UWWTD, convocatorias / reporting 2023 y / and 2019

Ranks, shares and proximity

The rank orders records with a reported size in the same inventory and country, in that inventory's unit; the profile states which one and its edition. Active status is not required: a record without a size is excluded and unknown activity is not presented as active. Equal figures share a rank and ties are stated. The share is the record's size over the sum of those same records: it is not actual national capacity nor a count of deduplicated physical plants. Distance to the nearest inventoried plant and records within 10 km are computed between reported coordinates, excluding doubtful positions; records at the same point (under 50 m) are flagged separately, without asserting they are the same facility. Proximity does not establish a hydraulic connection or a shared basin.

Sources: AEMA / EEA, Waterbase-UWWTD, convocatorias / reporting 2023 y / and 2019 · HydroWASTE v1.0 · EPA, Clean Watersheds Needs Survey 2022 Report and Data

Reported treatment levels

Each inventory uses its own categories and the profile keeps them, without inferring stages that are not reported. In the European inventory, P is primary, S secondary and T treatment more stringent than secondary; nitrogen or phosphorus removal and UV disinfection are shown only when expressly reported. HydroWASTE and the EPA use levels such as Primary, Secondary or Advanced, with no automatic equivalence to the European categories. When the source flags a level as estimated, the profile says so.

Sources: AEMA / EEA, Waterbase-UWWTD, convocatorias / reporting 2023 y / and 2019 · HydroWASTE v1.0 · EPA, Clean Watersheds Needs Survey 2022 Report and Data

Geographic neighbours

Neighbours describe geographic proximity within the same country and inventory, not hydraulic connections, shared sewers or a common catchment. Interpretation depends on location quality and reported status. An uncertain or coincident location may prevent a reliable relationship. Distance alone does not demonstrate water transfers or reuse opportunities.

Sources: HydroWASTE v1.0 · AEMA / EEA, Waterbase-UWWTD, convocatorias / reporting 2023 y / and 2019

Scope of the global league

The proposed league has two independent tables of 50: active European plants ordered by reported design capacity in h-e, and the rest of the world ordered by HydroWASTE population served. The latter excludes SOURCE 12 and QUAL_POP 2; QUAL_POP 1, 3 or 4, positive population and Operational or Not Reported status are required. Reported and estimated population are distinguished per row.

There is no combined world rank: these metrics are not homogeneous. EPA design flow remains in MGD and is not converted to population. Only resolved canonical identities may be linked; records without a resolved route are omitted and the next eligible record is selected.

The league compares reported size; it does not assess operation or compliance. League navigation remains disabled pending review.

Sources: HydroWASTE v1.0 · Ehalt Macedo et al. (2022), Distribution and characteristics of wastewater treatment plants within the global river network · EPA, Clean Watersheds Needs Survey 2022 Report and Data

Regulatory context

Regulatory references provide context, not findings about individual obligations, permits or compliance. Europe and the European inventory are not equivalent to the European Union. For Norway and Iceland, membership of the European Economic Area does not imply automatic application of Directive (EU) 2024/3019: incorporation and the national framework require checking. A record's size alone does not establish its legal scope.

Energy as a hypothesis

Energy scenarios are hypothetical exercises, not measurements of consumption, production or savings. If capacity replaces reported load, the result describes a capacity hypothesis, not actual load. Reference per-capita flows, concentrations and technologies do not establish conditions at that plant. Without traceable units and parameters, an estimate is not defensible; reported zero and unknown data must remain distinct.

Reuse potential as an estimate

The volume of treated water that could be reclaimed is estimated only when a reported load compatible with the calculation engine is available. It is a technical starting point: it does not establish available water, permits or suitability for a given use, which depend on the applicable rules and additional treatment. Where no estimate is possible, the profile omits this section.

Sources: AEMA / EEA, Waterbase-UWWTD, convocatorias / reporting 2023 y / and 2019

Presentation and limits

Repeated names are disambiguated by locality and, when needed, source identifier. Restricted operator names are replaced by neutral labels in the public presentation, while source records remain unchanged. Technical scenarios are estimates, not measurements. Regulatory references do not establish applicability to an individual plant.