My Tap Check
Menu

Our sources and method

Every figure on My Tap Check comes from a public source, named and dated. This page lists the data behind our area cards, map and school lookup, and how we write our guides.

The data we use

Drinking water test results (Ontario)

  • Publisher: Government of Ontario, Ministry of the Environment, Conservation and Parks
  • Dataset: Drinking Water Quality and Enforcement
  • What we use: lead test results from schools, private schools and child care centres, and from municipal drinking water systems
  • Years: fiscal years (April to March) 2022-23 to 2024-25
  • Refreshed: once a year, when the province publishes new results
  • Licence: Open Government Licence, Ontario
  • View the dataset

Census of Population, 2021

  • Publisher: Statistics Canada
  • What we use: the share of homes built in 1960 or before, by area
  • Year: 2021 (the census runs every five years)
  • Licence: Open Government Licence, Canada
  • View the dataset

Well records (Ontario)

  • Publisher: Government of Ontario
  • What we use: how many well records there are in each area. Records include water supply wells, test holes and wells that are no longer used, and wells drilled before 2003 may be placed approximately.
  • Years: 1899 to June 30, 2026
  • Refreshed: twice a year by the province; we update with it
  • Licence: Open Government Licence, Ontario
  • View the dataset

Postal area boundaries

  • Publisher: Statistics Canada
  • Dataset: 2021 Census Forward Sortation Area Boundary File
  • What we use: the boundaries of postal areas (the first three characters of a postal code). They are approximate, built from census responses, so they show your area, not your exact address.
  • Licence: Statistics Canada Open Licence
  • View the reference guide

Licensed laboratories (Ontario)

  • Publisher: Government of Ontario, Ministry of the Environment, Conservation and Parks
  • What we use: the list of labs licensed to test drinking water for lead, which we link to in our guides
  • Licence: Open Government Licence, Ontario
  • View the dataset

Area data (My Tap Check)

  • Publisher: My Tap Check (SociallyInfused Media)
  • What it is: the figures on our area cards and map, by postal area: the share of homes built in 1960 or before, how many well records there are, and drinking water test results. We build it from the datasets above. Residents’ shared results are included only as published area totals, never one home.
  • Licence: Creative Commons Attribution 4.0 (CC BY 4.0). You may reuse it, including commercially, as long as you credit us.
  • How to credit us: “Source: My Tap Check area data, mytapcheck.ca/sources/, CC BY 4.0.”
  • Each dataset above keeps its own licence.

Attributions

  • Contains information licensed under the Open Government Licence – Ontario.
  • Contains information licensed under the Open Government Licence – Canada.
  • Source: Statistics Canada, 2021 Census Forward Sortation Area Boundary File, 2021. Reproduced and distributed on an “as is” basis with the permission of Statistics Canada.
  • © This data includes information copied with permission from Canada Post Corporation (Canada Post).

How we write our guides

  • We use these sources, in this order: the City of Hamilton, Public Health Ontario, Health Canada and the Government of Ontario. For local programs and practical how-to, we also use other Ontario cities’ and public health units’ own pages.
  • Every figure names its source and the date we checked it.
  • We never use a company selling water products, or a blog, as a source.
  • When a result falls between Health Canada’s guideline (5 micrograms per litre) and Ontario’s standard (10), we show it against both.
  • We recheck each guide’s figures at least once a year.

Main references

The guides cite these most often:

Residents’ results

Results are anonymous and never shown for a single home. How we use your result

Corrections

If a page doesn’t match its source, tell us and we’ll fix it. Contact us

For school and child care results, questions about a result go to the facility or the Ontario Ministry of the Environment, Conservation and Parks, which publishes the data.