# Credits and sources

_Photograph licences and the primary sources behind every figure on this site._

Iowa Water Filtration Co. · Des Moines metro · Published 30 October 2026 · Reviewed 30 October 2026

Canonical: https://iowawaterfiltration.com/credits

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## Photographs

- Des Moines River (home page): "Des Moines River in Gotch Park, Humboldt County,
  Iowa" by Brandonrush, CC0 1.0, via Wikimedia Commons.
- Des Moines Water Works building: photograph by Tony Webster, CC BY-SA 2.0, via
  Wikimedia Commons. Resized and converted to WebP, not otherwise altered.
- Supply well under construction, 1870s: Robert N. Dennis collection of stereoscopic
  views, New York Public Library. Public domain, via Wikimedia Commons.
- Faucet and glass of water: CC0 1.0, via Wikimedia Commons.

## Data

- Figure 1: Central Iowa Water Works Stage III daily updates,
  https://www.ciww.gov/news-1/stage-iii-daily-updates. 43 dated readings per river,
  16 June to 30 July 2025.
- Founding members and ban coverage: Central Iowa Water Works, https://www.ciww.gov/about,
  and the Stage 3 water warning release, June 2026.
- Nitrate source attribution: Central Iowa Source Water Research Assessment,
  commissioned by Polk County, released July 2025.
- Hardness: City of Waukee water quality page, 7.5 to 8.5 grains per gallon.