Core physical and chemical parameters
| Parameter | Common unit | What it describes | Treatment connection and limitation |
|---|---|---|---|
| pH | pH units | Hydrogen-ion activity; acidic/basic condition | Affects corrosion, scaling, oxidation and disinfection; pH alone does not define correction chemistry. |
| Alkalinity | mg/L as CaCO₃ | Acid-neutralizing or buffering capacity | Important for pH stability and dosing; not the same as pH or hardness. |
| Hardness | mg/L as CaCO₃ or grains/US gal | Primarily calcium and magnesium | Connects to softening and scale; does not indicate microorganisms or all dissolved solids. |
| Conductivity | µS/cm | Ability to conduct electricity from dissolved ions | Useful trend/salinity indicator; does not identify which ions are present. |
| Total dissolved solids | mg/L | Aggregate dissolved material by the stated method | Can connect to RO or source review; one total does not identify health risk or membrane design. |
| Turbidity | NTU | Light scattering from suspended or colloidal material | Can interfere with filtration/disinfection; it is not a direct pathogen count. |
| Color | Method-specific units | Apparent or true color under the stated method | May involve metals or organics; identify cause before selecting treatment. |
| Odor | Qualitative or threshold method | Perceived smell under stated conditions | Can guide testing but cannot diagnose a contaminant or safety. |
Common ions, nutrients and metals
| Parameter | Common unit | Planning meaning |
|---|---|---|
| Iron / manganese | mg/L | Oxidation state, pH and form affect removal; visible staining does not replace a test. |
| Chloride / sulfate | mg/L | Can affect taste, corrosion or source interpretation; applicable guidance varies. |
| Nitrate / nitrite / ammonia | mg/L with chemical basis stated | Forms and reporting bases differ; health-significant results require local-authority interpretation. |
| Chlorine residual | mg/L as stated chlorine species | Must be measured at a defined location/time; does not by itself prove CT or distribution safety. |
Biological and operational indicators
- Bacteria and indicator organisms
- Reported by method-specific presence/absence, counts or most-probable-number units. Indicators and pathogens are not interchangeable; positive or invalid results require the laboratory and health authority’s response.
- Dissolved oxygen
- Usually mg/L; influences corrosion, oxidation-reduction conditions and biological activity.
- Total organic carbon (TOC)
- Usually mg/L carbon; an aggregate organic indicator that does not identify individual compounds.
- ND and reporting limits
- Not detected means below the method/reporting threshold, not proven zero. Always read the qualifier and limit.
No universal table. Drinking-water standards and guidance vary by country, jurisdiction, source and use. Compare results only with the current requirement applicable to the specific project.
Reference boundary. Do not convert an indicative value into a universal design, health or legal requirement. Check the cited source, laboratory context, certified claim and applicable jurisdiction.
Sources
- U.S. Geological Survey — Water Science Glossary
- U.S. EPA — Protect Your Home’s Water
- U.S. CDC — Guidelines for Testing Well Water
- World Health Organization — Guidelines for Drinking-water Quality