Water

Completeness scorecard

Deterministic gap audit — no score is composite, no cell is LLM-judged. Each chip is re-derivable by re-running tools/evidence/build-ingredient-scorecard.mjs. review: residuals and missing data are worked autonomously via data/evidence/ingredient-scorecard-review-flags.csv and wiki/completeness-gaps.md.

FSA/Fera measured this ingredient or non-infant-specific food composite in Table 6 of the FS102048 survey. Exact concentration values remain in progress until Table 6 is parsed into structured ingredient rows with less-than and semi-quantitative flags preserved. fsa2016-infant-food-formula-metals-survey

Why this commodity accumulates heavy metals

Drinking water does not accumulate heavy metals through the biological mechanisms that apply to plant or animal food matrices. Instead, metals in potable water arise from two distinct source pathways. The first is source-water geochemistry: groundwater in aquifers underlain by arsenic-bearing minerals (sedimentary basins, volcanic tuffs, sulfide ore deposits) can carry naturally elevated iAs concentrations, with some regions of South Asia, South America, and the western United States documented as having groundwater As exceeding 10 ppb (epa-arsenic-drinking-water-mcl). Uranium in groundwater similarly reflects geological uranium mineralisation. The second pathway, and the dominant one for Pb specifically, is distribution-system infrastructure: lead service lines, lead solder used in older copper plumbing, and lead-bearing brass fittings can release Pb into tap water at points of use, particularly in building with pre-1986 plumbing when water is corrosive or sits stagnant. This is not a property of the water source but of the infrastructure through which treated water travels. The US Lead and Copper Rule targets this pathway through corrosion-control treatment requirements. Cadmium, mercury, and most organic metal species are not major concerns in treated municipal drinking water under normal operating conditions.

Heavy metal contamination profile

Per-analyte snapshot derived from the machine-readable contamination_profile in the frontmatter above. data gap indicates the literature has been reviewed for this commodity-analyte combination and no usable occurrence data was found (a finding, not a placeholder). The Key sources column shows the top 2-3 contributing sources by year and sample size, with numbered wikilink aliases.

Routing

This node is linked from flavored-waters.

Contamination Profile State

The machine-readable contamination profile is in_progress. Ingredient-level values belong here once parsed; finished-product values belong on the relevant product-category page.

Ranges by source, region, and variety

Drinking water arsenic concentrations vary by orders of magnitude depending on geological setting. In regions with naturally elevated groundwater As (parts of Bangladesh, West Bengal, Inner Mongolia, northern Chile, and southwestern United States including parts of Arizona and Nevada), well water can exceed 50 to several hundred ppb iAs (efsa-arsenic-contam-2009). Treated municipal tap water in most high-income countries is maintained well below the 10 ppb regulatory limit by treatment processes including coagulation, filtration, and adsorption on iron-based media. Lead in tap water shows high within-building variance driven by plumbing age and corrosion-control status; homes with lead service lines can exceed 15 ppb (the US EPA action level) at first-draw samples, while the same source water delivered through modern plastic or copper piping may register below 1 ppb. Bottled water is typically derived from protected springs or purified municipal water and is subject to FDA quality standards comparable to EPA tap-water standards.

Processing effects

Municipal water treatment is the operative processing step for drinking water. Conventional surface-water treatment (coagulation, flocculation, sedimentation, filtration, chlorination) effectively removes particulate metals and co-precipitates dissolved metals such as As with iron flocs. Advanced treatment technologies including reverse osmosis, activated alumina, and ion exchange reduce dissolved iAs below 2 to 5 ppb when applied. Coagulation-enhanced filtration using ferric salts is the primary technology for achieving the 10 ppb As MCL at scale. These treatments do not address Pb added downstream at the distribution system or building plumbing level; point-of-use filtration (NSF-certified pitcher or tap filters using activated alumina or reverse osmosis) is the most effective intervention for Pb at the household level.

Ingredient-derivative risk

Drinking water is used as an ingredient or reconstitution medium in a wide range of processed foods: soups, sauces, beverages, infant formula, baby food purees, and bakery products. When water with elevated Pb is used to reconstitute powdered infant formula, the Pb contributed by the water adds to the Pb already present in the formula powder, with the combined level determining infant exposure. This reconstitution pathway is a recognized concern in areas with lead service lines. The infant formula pages (infant-formula-non-soy-powder and related) address the reconstitution calculation. Bottled water and filtered tap water used in food manufacturing typically contribute negligible metal loads to finished products.

Mitigation options

Sourcing levers

For community water systems, source-water selection (surface water with low As versus groundwater from As-bearing aquifers) and blending across sources to dilute As concentrations are the primary upstream levers. Bottled-water processors selecting spring sources must characterise source-water As and other metals as part of source approval.

Agronomic levers

Not applicable to drinking water. Groundwater-fed agriculture in high-As regions constitutes a separate pathway (irrigation water As transferring to irrigated crops) addressed under specific ingredient pages.

Processing levers

Point-of-use activated alumina, anion exchange, or reverse osmosis filtration is the most effective household-level intervention for iAs in drinking water. At the treatment plant level, coagulation with ferric salts followed by filtration is the standard method for achieving As reduction below 10 ppb. For Pb specifically, corrosion-control treatment (phosphate dosing or pH and alkalinity adjustment) is the primary distribution-system intervention to reduce Pb release from lead service lines and solder.

Formulation levers

Food manufacturers using municipal tap water in high-As geological regions should characterise source-water As and consider point-of-entry or point-of-use treatment. For infant formula reconstitution, the recommendation to use low-As, low-Pb water (bottled water certified to meet NSF standard 53 for Pb) is the effective formulation lever at the consumer level.

Testing and QC levers

Food manufacturers using water as an ingredient should test incoming municipal water for Pb, As, and Cd on a periodic basis, with frequency calibrated to the regulatory status and geological context of the supply. First-draw sampling (after stagnation) provides the worst-case Pb estimate in building plumbing; running-water samples provide the distribution-system estimate. EPA Method 200.8 (ICP-MS) is the reference method for Pb and As in drinking water.

Packaging and storage levers

Lead service line replacement is the most impactful infrastructure-level intervention for Pb in tap water. Where replacement is not yet complete, phosphate-based corrosion inhibitors added at the water treatment plant reduce Pb release from existing lead service lines and solder. The US EPA Lead and Copper Rule Revisions (2021) mandate accelerated lead service line replacement on a regulated timeline.

Regulatory limits that apply

In the United States, the EPA Maximum Contaminant Level for arsenic in public drinking water is 10 µg/L (10 ppb) as iAs, established by the 2001 Arsenic Rule (epa-arsenic-drinking-water-mcl). For lead, the EPA action level is 15 µg/L (15 ppb); any public water system with more than 10 percent of samples exceeding this level must take remedial action under the Lead and Copper Rule. FDA applies equivalent standards to bottled water sold in interstate commerce. The EU Drinking Water Directive (2020/2184) sets a Pb limit of 5 µg/L (5 ppb) for tap water, a standard tighter than the US action level, and an As limit of 10 µg/L. The EU Cd limit in drinking water is 5 µg/L. codex-cadmium-mls covers maximum levels for Cd in natural mineral waters.

Sources

Auto-generated from source-page frontmatter. The “Used on this page for” column is populated by the orchestrator’s POPULATE-SOURCE-LEGEND action; pending entries appear as *[awaiting synthesis]*.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.