Water property guide
Water Characteristics in Tap Water
Water characteristics describe properties such as hardness, pH, or dissolved solids. They often affect taste, scaling, corrosion, or treatment choices rather than act as contaminants.
What this page can tell you
It explains the family and organizes PurityMap’s published compound records. It does not establish whether any member is present at your tap.
Find the report for your address →Registry counts, not prevalence These counts describe records published by PurityMap. They do not measure how often this family occurs in U.S. drinking water or whether it is present locally.
What are water characteristics?
These records help explain how water behaves in plumbing and treatment. They are grouped for navigation, not to imply a shared health effect.
Many characteristics have aesthetic, operational, or secondary guidance instead of a health-based federal maximum. The individual record states the relevant context. Water hardness (dissolved calcium and magnesium, usually reported in grains per gallon) is the most common of these.
What the national records show
Hardness sits outside the federal drinking-water datasets: it comes from a utility’s own annual report rather than EPA monitoring. PurityMap has a sourced hardness value for only 42 cities so far, which is why most city reports mark hardness as pending rather than guess at a number. Hardness is an aesthetic and operational property (it causes scale, spots, and reduced soap lather), not a regulated health limit, so the decision to soften water is about comfort and appliance life, not safety.
Published compound guidesOpen the named compound before comparing a result. References, health context, aliases, and measurement notes belong to the individual record.
Identifier not published
Hard water
Calcium and magnesium hardness
Hardness is dissolved calcium and magnesium picked up from rock and soil. It is an aesthetic and plumbing consideration, not a health-based contaminant.
Identifier not published
Microplastics
Microplastic particles (< 5 mm)
Microplastics are plastic fragments smaller than 5 millimetres (down to microscopic nanoplastics) that shed from packaging, textiles, tyres and the breakdown of larger plastic waste. They are an emerging contaminant: increasingly detected in tap and bottled water, but not yet federally regulated in drinking water.
Sources named in the compound recordsThese are source descriptions carried by one or more published compound guides. They are possible pathways, not evidence about a specific water system.
- Groundwater through limestone/mineral formations
- Plastic packaging and litter breakdown
- Synthetic textile fibres
- Tyre and road wear
- Plastic distribution and bottling
How to read a local result
- 1Identify the named analyte
A family name may contain compounds with different standards and health contexts.
- 2Keep the measurement attached
Read the value with its unit, qualifier, sampling period, reporting limit, and source.
- 3Compare only with the stated reference
PurityMap does not turn unlike compound results into a family score or safety verdict.
- 4Verify the relevant treatment claim
A technology name is only a starting point; the product certification must name the compound or reduction claim.
Treatment capabilities in the published recordsTreatment relevance is compound-specific and conditional. This list is not a product recommendation and does not mean every technology applies to every member of the family.
Named by at least one compound guide in this family. Confirm the exact certified reduction claim before choosing equipment.
Named by at least one compound guide in this family. Confirm the exact certified reduction claim before choosing equipment.
Named by at least one compound guide in this family. Confirm the exact certified reduction claim before choosing equipment.
Named by at least one compound guide in this family. Confirm the exact certified reduction claim before choosing equipment.
Named by at least one compound guide in this family. Confirm the exact certified reduction claim before choosing equipment.
Named by at least one compound guide in this family. Confirm the exact certified reduction claim before choosing equipment.
Sources and methodology
This page is assembled from PurityMap’s governed contaminant records. Family counts and capability lists are derived only from those published records; local occurrence stays on water-system evidence pages.
How PurityMap analyzes water data →