Methodology

How this site turns the Government of Canada's Federal Contaminated Sites Inventory (FCSI) export into the map, filters, and summary pages you see here.

Source data

The single source is the official FCSI open-data export published by the Treasury Board of Canada Secretariat — a bilingual XML file covering every site in the inventory. It is reproduced under the Open Government Licence – Canada. The current copy was published upstream on August 3, 2026.

Refresh cycle

An automated job checks the upstream export every Monday. If the published file has changed, the full export is downloaded and re-processed, and every page on this site — including the province and custodian summaries — is regenerated from scratch. The map header shows two dates: when the Government of Canada published the data, and when this site last verified the source. If nothing changed upstream, the published date stays put; that is the upstream data's real vintage, not a fault of the refresh.

Processing

• The XML is parsed into compact JSON artifacts; no records are added, dropped, or merged. The inventory currently holds 24,426 sites.
• Coordinates are taken as published. 23,502 sites carry usable coordinates and appear on the map; the remainder still appear in filters, lists, CSV exports, and summary counts.
• Expenditure figures are the sums of the annual assessment, remediation, care & maintenance, and monitoring amounts reported per site for fiscal years 1993-1994 through 2025-2026. Totals here are simple additions of what custodians reported — they are not adjusted for inflation.
• Site classifications, statuses, contaminants, media, and management strategies are shown exactly as coded in the inventory (see the glossary for what the codes mean).
• Summary pages aggregate these records by province/territory and by custodian department; every figure on those pages is recomputed at each refresh.

Known limitations

• The inventory reflects what custodian departments report; reporting practices vary between departments and over time.
• Some sites lack coordinates, and some coordinates are approximate. Do not use the map for property-boundary decisions.
• Expenditures are attributed to the fiscal year reported, and older records may be incomplete.
• This site performs no independent verification. For authoritative records, consult the official FCSI.

Open source

The full pipeline — source checking, parsing, and page generation — is public in the project repository, so every number on this site can be traced to the code that produced it.