Specific Conductivity

Specific conductivity (also called specific conductance or electrical conductivity) is a property, not a contaminant. EPA defines conductivity as "a measure of the ability of water to pass an electrical current", and explains that "dissolved salts and other inorganic chemicals conduct electrical current" — so the reading rises with the amount of dissolved mineral content. It is usually reported in micromhos or microsiemens per centimetre (µmhos/cm or µS/cm). EPA notes that "each water body tends to have a relatively constant range of conductivity that, once established, can be used as a baseline for comparison", which is how the number is meant to be read: against that source's own history, not against a safety threshold. EPA sets no drinking-water limit for conductivity. Because it tracks dissolved solids, it is often used as a quick proxy for total dissolved solids, which does carry an EPA secondary standard of 500 mg/L.

Source: EPA — National Aquatic Resource Surveys — Indicators (retrieved 2026-07-27)

Water filters certified under the following NSF standards are effective at removing Specific Conductivity: