S153 — Monitoring Surface Water Chemistry

U.S. Environmental Protection Agency (2022)

Open original source — www.epa.gov

official environmental dataset environmental_outcome_monitoring

Curated public use: Use for long-term chemistry monitoring within the network's site-selection boundary; not all North American waters.

Limitation: Source cards are evidence anchors, not proof that a linked claim is settled.

Source note: Provides the official long-term chemistry dataset and scope; monitored acid-sensitive sites are not representative of all North American waters.