Report interpretation

Understand water characteristics and report terms.

Use these explanations to read hardness, pH, minerals, and other water characteristics in a report. A listed characteristic is not automatically a regulated contaminant or a violation.

Browse report termsBrowse contaminants →

Reading framework

Keep standards, report evidence, and current notices separate

A reported value, a regulatory violation, and a current advisory mean different things. An annual report does not establish current conditions at your tap.

Two interpretation libraries, two different jobs

The contaminant library explains regulated contaminants, disinfectants, monitoring topics, and treatment measures. This library explains water properties, minerals, and secondary standards related to taste, appearance, and system operation. Keep these separate from primary health-based contaminant limits.

Regulated contaminants

Substances or indicators governed through applicable primary standards, action levels, or treatment techniques. See the contaminant library for explanations of these requirements.

Water characteristics

Properties such as alkalinity, hardness, and pH that describe water chemistry or behavior rather than naming one primary regulated contaminant.

Treatment or operational measures

Measurements used to understand treatment, corrosion, mineral scale, or system operation. An annual report's measurement does not show how the system is operating today.

Primary standards

Federal primary standards and treatment techniques are legally enforceable requirements established for health protection under EPA's Part 141 framework.

Secondary standards

Federal Part 143 values primarily address aesthetic or operational qualities and are not federal primary health-based MCLs. State application can differ, including New Mexico's incorporation of Part 143.

Annual report evidence

A Consumer Confidence Report summarizes a named report period. Its rows do not establish live conditions or a result at every tap.

Current official notices

Current advisories and instructions come from the water provider, state agency, or another appropriate official source, not from an annual row alone.

Report examples

Eight terms from Silver City's 2025 report

Each explanation includes an example from the report, its original label and unit, and a link to the source.

Water chemistry characteristics

Properties that describe buffering, acidity or basicity, and aggregate mineral behavior without naming one primary regulated contaminant.

Water chemistry characteristic

Alkalinity

Alkalinity describes water's capacity to neutralize acids and bases and resist rapid pH change. It is a water property, not a contaminant identity or the same thing as pH.

Water chemistry characteristic

Hardness

Hardness is an aggregate water characteristic driven mainly by dissolved calcium and magnesium. It can affect soap performance and mineral scale without being a primary contaminant standard.

Water chemistry characteristic

pH

pH measures how acidic or basic water is on a logarithmic scale. EPA lists a secondary range, not a federal primary health-based MCL.

Mineral and dissolved constituents

Individual dissolved constituents that can contribute to broader characteristics but do not equal hardness or total dissolved solids on their own.

Mineral or dissolved constituent

Calcium

Calcium is a dissolved mineral constituent that can contribute to hardness and total dissolved solids. Its individual report row is not the same as either aggregate measure.

Mineral or dissolved constituent

Magnesium

Magnesium is a dissolved mineral constituent that can contribute to hardness and total dissolved solids. Its individual row does not equal either aggregate characteristic.

Mineral or dissolved constituent

Sodium

Sodium is a dissolved constituent with separate federal special-monitoring and reporting requirements. The reviewed current primary table does not set an EPA primary MCL for sodium.

Aesthetic and operational characteristics

Terms with practical, secondary-standard, or aggregate context that remains separate from federal primary health-based MCL language.

Aesthetic or operational characteristic

Iron

Iron has federal secondary-standard context focused primarily on aesthetic and operational considerations. That secondary value is not a federal primary health-based MCL.

Aesthetic or operational characteristic

Total Dissolved Solids

Total dissolved solids, or TDS, is an aggregate measure of dissolved substances. It does not identify which substances are present or their individual concentrations.

Official source path

Sources behind these explanations

These explanations draw on EPA guidance, federal and New Mexico regulations, and Silver City's 2025 report. Each term links to the sources used for its explanation.

Evidence

Official sources for the directory

Use official federal, state, utility, or report sources before treating a page as final.

Silver City 2025 report

Read the summary's 21 report entries with their original table headings, units, dates, and source notes.

View Silver City 2025 report

Data methodology

Review source hierarchy, report limits, and how the site keeps annual evidence separate from current status.

View Data methodology