---
title: Total Dissolved Solids (TDS)
description: "## Summary Total dissolved solids (TDS) is a measure of all dissolved materials in water, including minerals, salts, and metals. Elevated TDS is common in AMD-impacted streams. This page explains what TDS measures and how it relates to water quality.…"
url: "https://aml-connect.org/aml-knowledge-base/chemical-monitoring-tds/"
updated: "2026-03-13"
category: Watershed Tools and Methods / Water Monitoring / Chemical Monitoring
---

# Total Dissolved Solids (TDS)

## Summary

Total dissolved solids (TDS) is a measure of all dissolved materials in water, including minerals, salts, and metals. Elevated TDS is common in AMD-impacted streams. This page explains what TDS measures and how it relates to water quality.

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Total Dissolved Solids (TDS) refers to the ions and other particles dissolved in the water that you can't see. Be careful not to confuse this test with conductivity, which measures the electrical conductance of water. The two are closely related, but no the same. The major components of TDS are bicarbonate, calcium, sulfate, hydrogen, silica, chlorine, magnesium, sodium, potassium, nitrogen, and phosphorus. It is essential to maintain a constant level of these solids. For example, a sudden increase is salt from brine leakage of a mineral extraction pond can have a devastating effect on the aquatic life. Streams containing flow primarily from groundwater have a high TDS level as minerals leach into the water as it filters through the rocks. Storm water is usually low in TDS.

**Sources/Links (as provided in the source text):**

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## Related Pages

- [Developing a Monitoring Plan](/docs/developing-a-monitoring-plan) -- Structuring your monitoring program

## Source and Last Reviewed

Source: AMR Clearinghouse (amrclearinghouse.org). Migrated to AML-Connect. Last Reviewed: 2026-03-13.

**Tags:** monitoring, sampling, education